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_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 /* Return true if process PID has a thread doing a displaced step. */
1471 displaced_step_in_progress (int pid)
1473 struct displaced_step_inferior_state *displaced;
1475 displaced = get_displaced_stepping_state (pid);
1476 if (displaced != NULL && !ptid_equal (displaced->step_ptid, null_ptid))
1482 /* Add a new displaced stepping state for process PID to the displaced
1483 stepping state list, or return a pointer to an already existing
1484 entry, if it already exists. Never returns NULL. */
1486 static struct displaced_step_inferior_state *
1487 add_displaced_stepping_state (int pid)
1489 struct displaced_step_inferior_state *state;
1491 for (state = displaced_step_inferior_states;
1493 state = state->next)
1494 if (state->pid == pid)
1497 state = xcalloc (1, sizeof (*state));
1499 state->next = displaced_step_inferior_states;
1500 displaced_step_inferior_states = state;
1505 /* If inferior is in displaced stepping, and ADDR equals to starting address
1506 of copy area, return corresponding displaced_step_closure. Otherwise,
1509 struct displaced_step_closure*
1510 get_displaced_step_closure_by_addr (CORE_ADDR addr)
1512 struct displaced_step_inferior_state *displaced
1513 = get_displaced_stepping_state (ptid_get_pid (inferior_ptid));
1515 /* If checking the mode of displaced instruction in copy area. */
1516 if (displaced && !ptid_equal (displaced->step_ptid, null_ptid)
1517 && (displaced->step_copy == addr))
1518 return displaced->step_closure;
1523 /* Remove the displaced stepping state of process PID. */
1526 remove_displaced_stepping_state (int pid)
1528 struct displaced_step_inferior_state *it, **prev_next_p;
1530 gdb_assert (pid != 0);
1532 it = displaced_step_inferior_states;
1533 prev_next_p = &displaced_step_inferior_states;
1538 *prev_next_p = it->next;
1543 prev_next_p = &it->next;
1549 infrun_inferior_exit (struct inferior *inf)
1551 remove_displaced_stepping_state (inf->pid);
1554 /* If ON, and the architecture supports it, GDB will use displaced
1555 stepping to step over breakpoints. If OFF, or if the architecture
1556 doesn't support it, GDB will instead use the traditional
1557 hold-and-step approach. If AUTO (which is the default), GDB will
1558 decide which technique to use to step over breakpoints depending on
1559 which of all-stop or non-stop mode is active --- displaced stepping
1560 in non-stop mode; hold-and-step in all-stop mode. */
1562 static enum auto_boolean can_use_displaced_stepping = AUTO_BOOLEAN_AUTO;
1565 show_can_use_displaced_stepping (struct ui_file *file, int from_tty,
1566 struct cmd_list_element *c,
1569 if (can_use_displaced_stepping == AUTO_BOOLEAN_AUTO)
1570 fprintf_filtered (file,
1571 _("Debugger's willingness to use displaced stepping "
1572 "to step over breakpoints is %s (currently %s).\n"),
1573 value, non_stop ? "on" : "off");
1575 fprintf_filtered (file,
1576 _("Debugger's willingness to use displaced stepping "
1577 "to step over breakpoints is %s.\n"), value);
1580 /* Return non-zero if displaced stepping can/should be used to step
1581 over breakpoints. */
1584 use_displaced_stepping (struct gdbarch *gdbarch)
1586 return (((can_use_displaced_stepping == AUTO_BOOLEAN_AUTO && non_stop)
1587 || can_use_displaced_stepping == AUTO_BOOLEAN_TRUE)
1588 && gdbarch_displaced_step_copy_insn_p (gdbarch)
1589 && find_record_target () == NULL);
1592 /* Clean out any stray displaced stepping state. */
1594 displaced_step_clear (struct displaced_step_inferior_state *displaced)
1596 /* Indicate that there is no cleanup pending. */
1597 displaced->step_ptid = null_ptid;
1599 if (displaced->step_closure)
1601 gdbarch_displaced_step_free_closure (displaced->step_gdbarch,
1602 displaced->step_closure);
1603 displaced->step_closure = NULL;
1608 displaced_step_clear_cleanup (void *arg)
1610 struct displaced_step_inferior_state *state = arg;
1612 displaced_step_clear (state);
1615 /* Dump LEN bytes at BUF in hex to FILE, followed by a newline. */
1617 displaced_step_dump_bytes (struct ui_file *file,
1618 const gdb_byte *buf,
1623 for (i = 0; i < len; i++)
1624 fprintf_unfiltered (file, "%02x ", buf[i]);
1625 fputs_unfiltered ("\n", file);
1628 /* Prepare to single-step, using displaced stepping.
1630 Note that we cannot use displaced stepping when we have a signal to
1631 deliver. If we have a signal to deliver and an instruction to step
1632 over, then after the step, there will be no indication from the
1633 target whether the thread entered a signal handler or ignored the
1634 signal and stepped over the instruction successfully --- both cases
1635 result in a simple SIGTRAP. In the first case we mustn't do a
1636 fixup, and in the second case we must --- but we can't tell which.
1637 Comments in the code for 'random signals' in handle_inferior_event
1638 explain how we handle this case instead.
1640 Returns 1 if preparing was successful -- this thread is going to be
1641 stepped now; or 0 if displaced stepping this thread got queued. */
1643 displaced_step_prepare (ptid_t ptid)
1645 struct cleanup *old_cleanups, *ignore_cleanups;
1646 struct thread_info *tp = find_thread_ptid (ptid);
1647 struct regcache *regcache = get_thread_regcache (ptid);
1648 struct gdbarch *gdbarch = get_regcache_arch (regcache);
1649 CORE_ADDR original, copy;
1651 struct displaced_step_closure *closure;
1652 struct displaced_step_inferior_state *displaced;
1655 /* We should never reach this function if the architecture does not
1656 support displaced stepping. */
1657 gdb_assert (gdbarch_displaced_step_copy_insn_p (gdbarch));
1659 /* Disable range stepping while executing in the scratch pad. We
1660 want a single-step even if executing the displaced instruction in
1661 the scratch buffer lands within the stepping range (e.g., a
1663 tp->control.may_range_step = 0;
1665 /* We have to displaced step one thread at a time, as we only have
1666 access to a single scratch space per inferior. */
1668 displaced = add_displaced_stepping_state (ptid_get_pid (ptid));
1670 if (!ptid_equal (displaced->step_ptid, null_ptid))
1672 /* Already waiting for a displaced step to finish. Defer this
1673 request and place in queue. */
1674 struct displaced_step_request *req, *new_req;
1676 if (debug_displaced)
1677 fprintf_unfiltered (gdb_stdlog,
1678 "displaced: defering step of %s\n",
1679 target_pid_to_str (ptid));
1681 new_req = xmalloc (sizeof (*new_req));
1682 new_req->ptid = ptid;
1683 new_req->next = NULL;
1685 if (displaced->step_request_queue)
1687 for (req = displaced->step_request_queue;
1691 req->next = new_req;
1694 displaced->step_request_queue = new_req;
1700 if (debug_displaced)
1701 fprintf_unfiltered (gdb_stdlog,
1702 "displaced: stepping %s now\n",
1703 target_pid_to_str (ptid));
1706 displaced_step_clear (displaced);
1708 old_cleanups = save_inferior_ptid ();
1709 inferior_ptid = ptid;
1711 original = regcache_read_pc (regcache);
1713 copy = gdbarch_displaced_step_location (gdbarch);
1714 len = gdbarch_max_insn_length (gdbarch);
1716 /* Save the original contents of the copy area. */
1717 displaced->step_saved_copy = xmalloc (len);
1718 ignore_cleanups = make_cleanup (free_current_contents,
1719 &displaced->step_saved_copy);
1720 status = target_read_memory (copy, displaced->step_saved_copy, len);
1722 throw_error (MEMORY_ERROR,
1723 _("Error accessing memory address %s (%s) for "
1724 "displaced-stepping scratch space."),
1725 paddress (gdbarch, copy), safe_strerror (status));
1726 if (debug_displaced)
1728 fprintf_unfiltered (gdb_stdlog, "displaced: saved %s: ",
1729 paddress (gdbarch, copy));
1730 displaced_step_dump_bytes (gdb_stdlog,
1731 displaced->step_saved_copy,
1735 closure = gdbarch_displaced_step_copy_insn (gdbarch,
1736 original, copy, regcache);
1738 /* We don't support the fully-simulated case at present. */
1739 gdb_assert (closure);
1741 /* Save the information we need to fix things up if the step
1743 displaced->step_ptid = ptid;
1744 displaced->step_gdbarch = gdbarch;
1745 displaced->step_closure = closure;
1746 displaced->step_original = original;
1747 displaced->step_copy = copy;
1749 make_cleanup (displaced_step_clear_cleanup, displaced);
1751 /* Resume execution at the copy. */
1752 regcache_write_pc (regcache, copy);
1754 discard_cleanups (ignore_cleanups);
1756 do_cleanups (old_cleanups);
1758 if (debug_displaced)
1759 fprintf_unfiltered (gdb_stdlog, "displaced: displaced pc to %s\n",
1760 paddress (gdbarch, copy));
1766 write_memory_ptid (ptid_t ptid, CORE_ADDR memaddr,
1767 const gdb_byte *myaddr, int len)
1769 struct cleanup *ptid_cleanup = save_inferior_ptid ();
1771 inferior_ptid = ptid;
1772 write_memory (memaddr, myaddr, len);
1773 do_cleanups (ptid_cleanup);
1776 /* Restore the contents of the copy area for thread PTID. */
1779 displaced_step_restore (struct displaced_step_inferior_state *displaced,
1782 ULONGEST len = gdbarch_max_insn_length (displaced->step_gdbarch);
1784 write_memory_ptid (ptid, displaced->step_copy,
1785 displaced->step_saved_copy, len);
1786 if (debug_displaced)
1787 fprintf_unfiltered (gdb_stdlog, "displaced: restored %s %s\n",
1788 target_pid_to_str (ptid),
1789 paddress (displaced->step_gdbarch,
1790 displaced->step_copy));
1794 displaced_step_fixup (ptid_t event_ptid, enum gdb_signal signal)
1796 struct cleanup *old_cleanups;
1797 struct displaced_step_inferior_state *displaced
1798 = get_displaced_stepping_state (ptid_get_pid (event_ptid));
1800 /* Was any thread of this process doing a displaced step? */
1801 if (displaced == NULL)
1804 /* Was this event for the pid we displaced? */
1805 if (ptid_equal (displaced->step_ptid, null_ptid)
1806 || ! ptid_equal (displaced->step_ptid, event_ptid))
1809 old_cleanups = make_cleanup (displaced_step_clear_cleanup, displaced);
1811 displaced_step_restore (displaced, displaced->step_ptid);
1813 /* Fixup may need to read memory/registers. Switch to the thread
1814 that we're fixing up. Also, target_stopped_by_watchpoint checks
1815 the current thread. */
1816 switch_to_thread (event_ptid);
1818 /* Did the instruction complete successfully? */
1819 if (signal == GDB_SIGNAL_TRAP
1820 && !(target_stopped_by_watchpoint ()
1821 && (gdbarch_have_nonsteppable_watchpoint (displaced->step_gdbarch)
1822 || target_have_steppable_watchpoint)))
1824 /* Fix up the resulting state. */
1825 gdbarch_displaced_step_fixup (displaced->step_gdbarch,
1826 displaced->step_closure,
1827 displaced->step_original,
1828 displaced->step_copy,
1829 get_thread_regcache (displaced->step_ptid));
1833 /* Since the instruction didn't complete, all we can do is
1835 struct regcache *regcache = get_thread_regcache (event_ptid);
1836 CORE_ADDR pc = regcache_read_pc (regcache);
1838 pc = displaced->step_original + (pc - displaced->step_copy);
1839 regcache_write_pc (regcache, pc);
1842 do_cleanups (old_cleanups);
1844 displaced->step_ptid = null_ptid;
1846 /* Are there any pending displaced stepping requests? If so, run
1847 one now. Leave the state object around, since we're likely to
1848 need it again soon. */
1849 while (displaced->step_request_queue)
1851 struct displaced_step_request *head;
1853 struct regcache *regcache;
1854 struct gdbarch *gdbarch;
1855 CORE_ADDR actual_pc;
1856 struct address_space *aspace;
1858 head = displaced->step_request_queue;
1860 displaced->step_request_queue = head->next;
1863 context_switch (ptid);
1865 regcache = get_thread_regcache (ptid);
1866 actual_pc = regcache_read_pc (regcache);
1867 aspace = get_regcache_aspace (regcache);
1869 if (breakpoint_here_p (aspace, actual_pc))
1871 if (debug_displaced)
1872 fprintf_unfiltered (gdb_stdlog,
1873 "displaced: stepping queued %s now\n",
1874 target_pid_to_str (ptid));
1876 displaced_step_prepare (ptid);
1878 gdbarch = get_regcache_arch (regcache);
1880 if (debug_displaced)
1882 CORE_ADDR actual_pc = regcache_read_pc (regcache);
1885 fprintf_unfiltered (gdb_stdlog, "displaced: run %s: ",
1886 paddress (gdbarch, actual_pc));
1887 read_memory (actual_pc, buf, sizeof (buf));
1888 displaced_step_dump_bytes (gdb_stdlog, buf, sizeof (buf));
1891 if (gdbarch_displaced_step_hw_singlestep (gdbarch,
1892 displaced->step_closure))
1893 target_resume (ptid, 1, GDB_SIGNAL_0);
1895 target_resume (ptid, 0, GDB_SIGNAL_0);
1897 /* Done, we're stepping a thread. */
1903 struct thread_info *tp = inferior_thread ();
1905 /* The breakpoint we were sitting under has since been
1907 tp->control.trap_expected = 0;
1909 /* Go back to what we were trying to do. */
1910 step = currently_stepping (tp);
1912 if (debug_displaced)
1913 fprintf_unfiltered (gdb_stdlog,
1914 "displaced: breakpoint is gone: %s, step(%d)\n",
1915 target_pid_to_str (tp->ptid), step);
1917 target_resume (ptid, step, GDB_SIGNAL_0);
1918 tp->suspend.stop_signal = GDB_SIGNAL_0;
1920 /* This request was discarded. See if there's any other
1921 thread waiting for its turn. */
1926 /* Update global variables holding ptids to hold NEW_PTID if they were
1927 holding OLD_PTID. */
1929 infrun_thread_ptid_changed (ptid_t old_ptid, ptid_t new_ptid)
1931 struct displaced_step_request *it;
1932 struct displaced_step_inferior_state *displaced;
1934 if (ptid_equal (inferior_ptid, old_ptid))
1935 inferior_ptid = new_ptid;
1937 for (displaced = displaced_step_inferior_states;
1939 displaced = displaced->next)
1941 if (ptid_equal (displaced->step_ptid, old_ptid))
1942 displaced->step_ptid = new_ptid;
1944 for (it = displaced->step_request_queue; it; it = it->next)
1945 if (ptid_equal (it->ptid, old_ptid))
1946 it->ptid = new_ptid;
1953 /* Things to clean up if we QUIT out of resume (). */
1955 resume_cleanups (void *ignore)
1957 if (!ptid_equal (inferior_ptid, null_ptid))
1958 delete_single_step_breakpoints (inferior_thread ());
1963 static const char schedlock_off[] = "off";
1964 static const char schedlock_on[] = "on";
1965 static const char schedlock_step[] = "step";
1966 static const char *const scheduler_enums[] = {
1972 static const char *scheduler_mode = schedlock_off;
1974 show_scheduler_mode (struct ui_file *file, int from_tty,
1975 struct cmd_list_element *c, const char *value)
1977 fprintf_filtered (file,
1978 _("Mode for locking scheduler "
1979 "during execution is \"%s\".\n"),
1984 set_schedlock_func (char *args, int from_tty, struct cmd_list_element *c)
1986 if (!target_can_lock_scheduler)
1988 scheduler_mode = schedlock_off;
1989 error (_("Target '%s' cannot support this command."), target_shortname);
1993 /* True if execution commands resume all threads of all processes by
1994 default; otherwise, resume only threads of the current inferior
1996 int sched_multi = 0;
1998 /* Try to setup for software single stepping over the specified location.
1999 Return 1 if target_resume() should use hardware single step.
2001 GDBARCH the current gdbarch.
2002 PC the location to step over. */
2005 maybe_software_singlestep (struct gdbarch *gdbarch, CORE_ADDR pc)
2009 if (execution_direction == EXEC_FORWARD
2010 && gdbarch_software_single_step_p (gdbarch)
2011 && gdbarch_software_single_step (gdbarch, get_current_frame ()))
2021 user_visible_resume_ptid (int step)
2027 /* With non-stop mode on, threads are always handled
2029 resume_ptid = inferior_ptid;
2031 else if ((scheduler_mode == schedlock_on)
2032 || (scheduler_mode == schedlock_step && step))
2034 /* User-settable 'scheduler' mode requires solo thread
2036 resume_ptid = inferior_ptid;
2038 else if (!sched_multi && target_supports_multi_process ())
2040 /* Resume all threads of the current process (and none of other
2042 resume_ptid = pid_to_ptid (ptid_get_pid (inferior_ptid));
2046 /* Resume all threads of all processes. */
2047 resume_ptid = RESUME_ALL;
2053 /* Wrapper for target_resume, that handles infrun-specific
2057 do_target_resume (ptid_t resume_ptid, int step, enum gdb_signal sig)
2059 struct thread_info *tp = inferior_thread ();
2061 /* Install inferior's terminal modes. */
2062 target_terminal_inferior ();
2064 /* Avoid confusing the next resume, if the next stop/resume
2065 happens to apply to another thread. */
2066 tp->suspend.stop_signal = GDB_SIGNAL_0;
2068 /* Advise target which signals may be handled silently.
2070 If we have removed breakpoints because we are stepping over one
2071 in-line (in any thread), we need to receive all signals to avoid
2072 accidentally skipping a breakpoint during execution of a signal
2075 Likewise if we're displaced stepping, otherwise a trap for a
2076 breakpoint in a signal handler might be confused with the
2077 displaced step finishing. We don't make the displaced_step_fixup
2078 step distinguish the cases instead, because:
2080 - a backtrace while stopped in the signal handler would show the
2081 scratch pad as frame older than the signal handler, instead of
2082 the real mainline code.
2084 - when the thread is later resumed, the signal handler would
2085 return to the scratch pad area, which would no longer be
2087 if (step_over_info_valid_p ()
2088 || displaced_step_in_progress (ptid_get_pid (tp->ptid)))
2089 target_pass_signals (0, NULL);
2091 target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
2093 target_resume (resume_ptid, step, sig);
2096 /* Resume the inferior, but allow a QUIT. This is useful if the user
2097 wants to interrupt some lengthy single-stepping operation
2098 (for child processes, the SIGINT goes to the inferior, and so
2099 we get a SIGINT random_signal, but for remote debugging and perhaps
2100 other targets, that's not true).
2102 SIG is the signal to give the inferior (zero for none). */
2104 resume (enum gdb_signal sig)
2106 struct cleanup *old_cleanups = make_cleanup (resume_cleanups, 0);
2107 struct regcache *regcache = get_current_regcache ();
2108 struct gdbarch *gdbarch = get_regcache_arch (regcache);
2109 struct thread_info *tp = inferior_thread ();
2110 CORE_ADDR pc = regcache_read_pc (regcache);
2111 struct address_space *aspace = get_regcache_aspace (regcache);
2113 /* This represents the user's step vs continue request. When
2114 deciding whether "set scheduler-locking step" applies, it's the
2115 user's intention that counts. */
2116 const int user_step = tp->control.stepping_command;
2117 /* This represents what we'll actually request the target to do.
2118 This can decay from a step to a continue, if e.g., we need to
2119 implement single-stepping with breakpoints (software
2123 tp->stepped_breakpoint = 0;
2127 /* Depends on stepped_breakpoint. */
2128 step = currently_stepping (tp);
2130 if (current_inferior ()->waiting_for_vfork_done)
2132 /* Don't try to single-step a vfork parent that is waiting for
2133 the child to get out of the shared memory region (by exec'ing
2134 or exiting). This is particularly important on software
2135 single-step archs, as the child process would trip on the
2136 software single step breakpoint inserted for the parent
2137 process. Since the parent will not actually execute any
2138 instruction until the child is out of the shared region (such
2139 are vfork's semantics), it is safe to simply continue it.
2140 Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for
2141 the parent, and tell it to `keep_going', which automatically
2142 re-sets it stepping. */
2144 fprintf_unfiltered (gdb_stdlog,
2145 "infrun: resume : clear step\n");
2150 fprintf_unfiltered (gdb_stdlog,
2151 "infrun: resume (step=%d, signal=%s), "
2152 "trap_expected=%d, current thread [%s] at %s\n",
2153 step, gdb_signal_to_symbol_string (sig),
2154 tp->control.trap_expected,
2155 target_pid_to_str (inferior_ptid),
2156 paddress (gdbarch, pc));
2158 /* Normally, by the time we reach `resume', the breakpoints are either
2159 removed or inserted, as appropriate. The exception is if we're sitting
2160 at a permanent breakpoint; we need to step over it, but permanent
2161 breakpoints can't be removed. So we have to test for it here. */
2162 if (breakpoint_here_p (aspace, pc) == permanent_breakpoint_here)
2164 if (sig != GDB_SIGNAL_0)
2166 /* We have a signal to pass to the inferior. The resume
2167 may, or may not take us to the signal handler. If this
2168 is a step, we'll need to stop in the signal handler, if
2169 there's one, (if the target supports stepping into
2170 handlers), or in the next mainline instruction, if
2171 there's no handler. If this is a continue, we need to be
2172 sure to run the handler with all breakpoints inserted.
2173 In all cases, set a breakpoint at the current address
2174 (where the handler returns to), and once that breakpoint
2175 is hit, resume skipping the permanent breakpoint. If
2176 that breakpoint isn't hit, then we've stepped into the
2177 signal handler (or hit some other event). We'll delete
2178 the step-resume breakpoint then. */
2181 fprintf_unfiltered (gdb_stdlog,
2182 "infrun: resume: skipping permanent breakpoint, "
2183 "deliver signal first\n");
2185 clear_step_over_info ();
2186 tp->control.trap_expected = 0;
2188 if (tp->control.step_resume_breakpoint == NULL)
2190 /* Set a "high-priority" step-resume, as we don't want
2191 user breakpoints at PC to trigger (again) when this
2193 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2194 gdb_assert (tp->control.step_resume_breakpoint->loc->permanent);
2196 tp->step_after_step_resume_breakpoint = step;
2199 insert_breakpoints ();
2203 /* There's no signal to pass, we can go ahead and skip the
2204 permanent breakpoint manually. */
2206 fprintf_unfiltered (gdb_stdlog,
2207 "infrun: resume: skipping permanent breakpoint\n");
2208 gdbarch_skip_permanent_breakpoint (gdbarch, regcache);
2209 /* Update pc to reflect the new address from which we will
2210 execute instructions. */
2211 pc = regcache_read_pc (regcache);
2215 /* We've already advanced the PC, so the stepping part
2216 is done. Now we need to arrange for a trap to be
2217 reported to handle_inferior_event. Set a breakpoint
2218 at the current PC, and run to it. Don't update
2219 prev_pc, because if we end in
2220 switch_back_to_stepped_thread, we want the "expected
2221 thread advanced also" branch to be taken. IOW, we
2222 don't want this thread to step further from PC
2224 gdb_assert (!step_over_info_valid_p ());
2225 insert_single_step_breakpoint (gdbarch, aspace, pc);
2226 insert_breakpoints ();
2228 resume_ptid = user_visible_resume_ptid (user_step);
2229 do_target_resume (resume_ptid, 0, GDB_SIGNAL_0);
2230 discard_cleanups (old_cleanups);
2236 /* If we have a breakpoint to step over, make sure to do a single
2237 step only. Same if we have software watchpoints. */
2238 if (tp->control.trap_expected || bpstat_should_step ())
2239 tp->control.may_range_step = 0;
2241 /* If enabled, step over breakpoints by executing a copy of the
2242 instruction at a different address.
2244 We can't use displaced stepping when we have a signal to deliver;
2245 the comments for displaced_step_prepare explain why. The
2246 comments in the handle_inferior event for dealing with 'random
2247 signals' explain what we do instead.
2249 We can't use displaced stepping when we are waiting for vfork_done
2250 event, displaced stepping breaks the vfork child similarly as single
2251 step software breakpoint. */
2252 if (use_displaced_stepping (gdbarch)
2253 && tp->control.trap_expected
2254 && !step_over_info_valid_p ()
2255 && sig == GDB_SIGNAL_0
2256 && !current_inferior ()->waiting_for_vfork_done)
2258 struct displaced_step_inferior_state *displaced;
2260 if (!displaced_step_prepare (inferior_ptid))
2262 /* Got placed in displaced stepping queue. Will be resumed
2263 later when all the currently queued displaced stepping
2264 requests finish. The thread is not executing at this
2265 point, and the call to set_executing will be made later.
2266 But we need to call set_running here, since from the
2267 user/frontend's point of view, threads were set running.
2268 Unless we're calling an inferior function, as in that
2269 case we pretend the inferior doesn't run at all. */
2270 if (!tp->control.in_infcall)
2271 set_running (user_visible_resume_ptid (user_step), 1);
2272 discard_cleanups (old_cleanups);
2276 /* Update pc to reflect the new address from which we will execute
2277 instructions due to displaced stepping. */
2278 pc = regcache_read_pc (get_thread_regcache (inferior_ptid));
2280 displaced = get_displaced_stepping_state (ptid_get_pid (inferior_ptid));
2281 step = gdbarch_displaced_step_hw_singlestep (gdbarch,
2282 displaced->step_closure);
2285 /* Do we need to do it the hard way, w/temp breakpoints? */
2287 step = maybe_software_singlestep (gdbarch, pc);
2289 /* Currently, our software single-step implementation leads to different
2290 results than hardware single-stepping in one situation: when stepping
2291 into delivering a signal which has an associated signal handler,
2292 hardware single-step will stop at the first instruction of the handler,
2293 while software single-step will simply skip execution of the handler.
2295 For now, this difference in behavior is accepted since there is no
2296 easy way to actually implement single-stepping into a signal handler
2297 without kernel support.
2299 However, there is one scenario where this difference leads to follow-on
2300 problems: if we're stepping off a breakpoint by removing all breakpoints
2301 and then single-stepping. In this case, the software single-step
2302 behavior means that even if there is a *breakpoint* in the signal
2303 handler, GDB still would not stop.
2305 Fortunately, we can at least fix this particular issue. We detect
2306 here the case where we are about to deliver a signal while software
2307 single-stepping with breakpoints removed. In this situation, we
2308 revert the decisions to remove all breakpoints and insert single-
2309 step breakpoints, and instead we install a step-resume breakpoint
2310 at the current address, deliver the signal without stepping, and
2311 once we arrive back at the step-resume breakpoint, actually step
2312 over the breakpoint we originally wanted to step over. */
2313 if (thread_has_single_step_breakpoints_set (tp)
2314 && sig != GDB_SIGNAL_0
2315 && step_over_info_valid_p ())
2317 /* If we have nested signals or a pending signal is delivered
2318 immediately after a handler returns, might might already have
2319 a step-resume breakpoint set on the earlier handler. We cannot
2320 set another step-resume breakpoint; just continue on until the
2321 original breakpoint is hit. */
2322 if (tp->control.step_resume_breakpoint == NULL)
2324 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2325 tp->step_after_step_resume_breakpoint = 1;
2328 delete_single_step_breakpoints (tp);
2330 clear_step_over_info ();
2331 tp->control.trap_expected = 0;
2333 insert_breakpoints ();
2336 /* If STEP is set, it's a request to use hardware stepping
2337 facilities. But in that case, we should never
2338 use singlestep breakpoint. */
2339 gdb_assert (!(thread_has_single_step_breakpoints_set (tp) && step));
2341 /* Decide the set of threads to ask the target to resume. Start
2342 by assuming everything will be resumed, than narrow the set
2343 by applying increasingly restricting conditions. */
2344 resume_ptid = user_visible_resume_ptid (user_step);
2346 /* Even if RESUME_PTID is a wildcard, and we end up resuming less
2347 (e.g., we might need to step over a breakpoint), from the
2348 user/frontend's point of view, all threads in RESUME_PTID are now
2349 running. Unless we're calling an inferior function, as in that
2350 case pretend we inferior doesn't run at all. */
2351 if (!tp->control.in_infcall)
2352 set_running (resume_ptid, 1);
2354 /* Maybe resume a single thread after all. */
2355 if ((step || thread_has_single_step_breakpoints_set (tp))
2356 && tp->control.trap_expected)
2358 /* We're allowing a thread to run past a breakpoint it has
2359 hit, by single-stepping the thread with the breakpoint
2360 removed. In which case, we need to single-step only this
2361 thread, and keep others stopped, as they can miss this
2362 breakpoint if allowed to run. */
2363 resume_ptid = inferior_ptid;
2366 if (execution_direction != EXEC_REVERSE
2367 && step && breakpoint_inserted_here_p (aspace, pc))
2369 /* The only case we currently need to step a breakpoint
2370 instruction is when we have a signal to deliver. See
2371 handle_signal_stop where we handle random signals that could
2372 take out us out of the stepping range. Normally, in that
2373 case we end up continuing (instead of stepping) over the
2374 signal handler with a breakpoint at PC, but there are cases
2375 where we should _always_ single-step, even if we have a
2376 step-resume breakpoint, like when a software watchpoint is
2377 set. Assuming single-stepping and delivering a signal at the
2378 same time would takes us to the signal handler, then we could
2379 have removed the breakpoint at PC to step over it. However,
2380 some hardware step targets (like e.g., Mac OS) can't step
2381 into signal handlers, and for those, we need to leave the
2382 breakpoint at PC inserted, as otherwise if the handler
2383 recurses and executes PC again, it'll miss the breakpoint.
2384 So we leave the breakpoint inserted anyway, but we need to
2385 record that we tried to step a breakpoint instruction, so
2386 that adjust_pc_after_break doesn't end up confused. */
2387 gdb_assert (sig != GDB_SIGNAL_0);
2389 tp->stepped_breakpoint = 1;
2391 /* Most targets can step a breakpoint instruction, thus
2392 executing it normally. But if this one cannot, just
2393 continue and we will hit it anyway. */
2394 if (gdbarch_cannot_step_breakpoint (gdbarch))
2399 && use_displaced_stepping (gdbarch)
2400 && tp->control.trap_expected
2401 && !step_over_info_valid_p ())
2403 struct regcache *resume_regcache = get_thread_regcache (tp->ptid);
2404 struct gdbarch *resume_gdbarch = get_regcache_arch (resume_regcache);
2405 CORE_ADDR actual_pc = regcache_read_pc (resume_regcache);
2408 fprintf_unfiltered (gdb_stdlog, "displaced: run %s: ",
2409 paddress (resume_gdbarch, actual_pc));
2410 read_memory (actual_pc, buf, sizeof (buf));
2411 displaced_step_dump_bytes (gdb_stdlog, buf, sizeof (buf));
2414 if (tp->control.may_range_step)
2416 /* If we're resuming a thread with the PC out of the step
2417 range, then we're doing some nested/finer run control
2418 operation, like stepping the thread out of the dynamic
2419 linker or the displaced stepping scratch pad. We
2420 shouldn't have allowed a range step then. */
2421 gdb_assert (pc_in_thread_step_range (pc, tp));
2424 do_target_resume (resume_ptid, step, sig);
2425 discard_cleanups (old_cleanups);
2430 /* Clear out all variables saying what to do when inferior is continued.
2431 First do this, then set the ones you want, then call `proceed'. */
2434 clear_proceed_status_thread (struct thread_info *tp)
2437 fprintf_unfiltered (gdb_stdlog,
2438 "infrun: clear_proceed_status_thread (%s)\n",
2439 target_pid_to_str (tp->ptid));
2441 /* If this signal should not be seen by program, give it zero.
2442 Used for debugging signals. */
2443 if (!signal_pass_state (tp->suspend.stop_signal))
2444 tp->suspend.stop_signal = GDB_SIGNAL_0;
2446 tp->control.trap_expected = 0;
2447 tp->control.step_range_start = 0;
2448 tp->control.step_range_end = 0;
2449 tp->control.may_range_step = 0;
2450 tp->control.step_frame_id = null_frame_id;
2451 tp->control.step_stack_frame_id = null_frame_id;
2452 tp->control.step_over_calls = STEP_OVER_UNDEBUGGABLE;
2453 tp->control.step_start_function = NULL;
2454 tp->stop_requested = 0;
2456 tp->control.stop_step = 0;
2458 tp->control.proceed_to_finish = 0;
2460 tp->control.command_interp = NULL;
2461 tp->control.stepping_command = 0;
2463 /* Discard any remaining commands or status from previous stop. */
2464 bpstat_clear (&tp->control.stop_bpstat);
2468 clear_proceed_status (int step)
2472 struct thread_info *tp;
2475 resume_ptid = user_visible_resume_ptid (step);
2477 /* In all-stop mode, delete the per-thread status of all threads
2478 we're about to resume, implicitly and explicitly. */
2479 ALL_NON_EXITED_THREADS (tp)
2481 if (!ptid_match (tp->ptid, resume_ptid))
2483 clear_proceed_status_thread (tp);
2487 if (!ptid_equal (inferior_ptid, null_ptid))
2489 struct inferior *inferior;
2493 /* If in non-stop mode, only delete the per-thread status of
2494 the current thread. */
2495 clear_proceed_status_thread (inferior_thread ());
2498 inferior = current_inferior ();
2499 inferior->control.stop_soon = NO_STOP_QUIETLY;
2502 stop_after_trap = 0;
2504 clear_step_over_info ();
2506 observer_notify_about_to_proceed ();
2510 regcache_xfree (stop_registers);
2511 stop_registers = NULL;
2515 /* Returns true if TP is still stopped at a breakpoint that needs
2516 stepping-over in order to make progress. If the breakpoint is gone
2517 meanwhile, we can skip the whole step-over dance. */
2520 thread_still_needs_step_over (struct thread_info *tp)
2522 if (tp->stepping_over_breakpoint)
2524 struct regcache *regcache = get_thread_regcache (tp->ptid);
2526 if (breakpoint_here_p (get_regcache_aspace (regcache),
2527 regcache_read_pc (regcache))
2528 == ordinary_breakpoint_here)
2531 tp->stepping_over_breakpoint = 0;
2537 /* Returns true if scheduler locking applies. STEP indicates whether
2538 we're about to do a step/next-like command to a thread. */
2541 schedlock_applies (struct thread_info *tp)
2543 return (scheduler_mode == schedlock_on
2544 || (scheduler_mode == schedlock_step
2545 && tp->control.stepping_command));
2548 /* Look a thread other than EXCEPT that has previously reported a
2549 breakpoint event, and thus needs a step-over in order to make
2550 progress. Returns NULL is none is found. */
2552 static struct thread_info *
2553 find_thread_needs_step_over (struct thread_info *except)
2555 struct thread_info *tp, *current;
2557 /* With non-stop mode on, threads are always handled individually. */
2558 gdb_assert (! non_stop);
2560 current = inferior_thread ();
2562 /* If scheduler locking applies, we can avoid iterating over all
2564 if (schedlock_applies (except))
2566 if (except != current
2567 && thread_still_needs_step_over (current))
2573 ALL_NON_EXITED_THREADS (tp)
2575 /* Ignore the EXCEPT thread. */
2578 /* Ignore threads of processes we're not resuming. */
2580 && ptid_get_pid (tp->ptid) != ptid_get_pid (inferior_ptid))
2583 if (thread_still_needs_step_over (tp))
2590 /* Basic routine for continuing the program in various fashions.
2592 ADDR is the address to resume at, or -1 for resume where stopped.
2593 SIGGNAL is the signal to give it, or 0 for none,
2594 or -1 for act according to how it stopped.
2595 STEP is nonzero if should trap after one instruction.
2596 -1 means return after that and print nothing.
2597 You should probably set various step_... variables
2598 before calling here, if you are stepping.
2600 You should call clear_proceed_status before calling proceed. */
2603 proceed (CORE_ADDR addr, enum gdb_signal siggnal)
2605 struct regcache *regcache;
2606 struct gdbarch *gdbarch;
2607 struct thread_info *tp;
2609 struct address_space *aspace;
2611 /* If we're stopped at a fork/vfork, follow the branch set by the
2612 "set follow-fork-mode" command; otherwise, we'll just proceed
2613 resuming the current thread. */
2614 if (!follow_fork ())
2616 /* The target for some reason decided not to resume. */
2618 if (target_can_async_p ())
2619 inferior_event_handler (INF_EXEC_COMPLETE, NULL);
2623 /* We'll update this if & when we switch to a new thread. */
2624 previous_inferior_ptid = inferior_ptid;
2626 regcache = get_current_regcache ();
2627 gdbarch = get_regcache_arch (regcache);
2628 aspace = get_regcache_aspace (regcache);
2629 pc = regcache_read_pc (regcache);
2630 tp = inferior_thread ();
2632 /* Fill in with reasonable starting values. */
2633 init_thread_stepping_state (tp);
2635 if (addr == (CORE_ADDR) -1)
2638 && breakpoint_here_p (aspace, pc) == ordinary_breakpoint_here
2639 && execution_direction != EXEC_REVERSE)
2640 /* There is a breakpoint at the address we will resume at,
2641 step one instruction before inserting breakpoints so that
2642 we do not stop right away (and report a second hit at this
2645 Note, we don't do this in reverse, because we won't
2646 actually be executing the breakpoint insn anyway.
2647 We'll be (un-)executing the previous instruction. */
2648 tp->stepping_over_breakpoint = 1;
2649 else if (gdbarch_single_step_through_delay_p (gdbarch)
2650 && gdbarch_single_step_through_delay (gdbarch,
2651 get_current_frame ()))
2652 /* We stepped onto an instruction that needs to be stepped
2653 again before re-inserting the breakpoint, do so. */
2654 tp->stepping_over_breakpoint = 1;
2658 regcache_write_pc (regcache, addr);
2661 if (siggnal != GDB_SIGNAL_DEFAULT)
2662 tp->suspend.stop_signal = siggnal;
2664 /* Record the interpreter that issued the execution command that
2665 caused this thread to resume. If the top level interpreter is
2666 MI/async, and the execution command was a CLI command
2667 (next/step/etc.), we'll want to print stop event output to the MI
2668 console channel (the stepped-to line, etc.), as if the user
2669 entered the execution command on a real GDB console. */
2670 inferior_thread ()->control.command_interp = command_interp ();
2673 fprintf_unfiltered (gdb_stdlog,
2674 "infrun: proceed (addr=%s, signal=%s)\n",
2675 paddress (gdbarch, addr),
2676 gdb_signal_to_symbol_string (siggnal));
2679 /* In non-stop, each thread is handled individually. The context
2680 must already be set to the right thread here. */
2684 struct thread_info *step_over;
2686 /* In a multi-threaded task we may select another thread and
2687 then continue or step.
2689 But if the old thread was stopped at a breakpoint, it will
2690 immediately cause another breakpoint stop without any
2691 execution (i.e. it will report a breakpoint hit incorrectly).
2692 So we must step over it first.
2694 Look for a thread other than the current (TP) that reported a
2695 breakpoint hit and hasn't been resumed yet since. */
2696 step_over = find_thread_needs_step_over (tp);
2697 if (step_over != NULL)
2700 fprintf_unfiltered (gdb_stdlog,
2701 "infrun: need to step-over [%s] first\n",
2702 target_pid_to_str (step_over->ptid));
2704 /* Store the prev_pc for the stepping thread too, needed by
2705 switch_back_to_stepped_thread. */
2706 tp->prev_pc = regcache_read_pc (get_current_regcache ());
2707 switch_to_thread (step_over->ptid);
2712 /* If we need to step over a breakpoint, and we're not using
2713 displaced stepping to do so, insert all breakpoints (watchpoints,
2714 etc.) but the one we're stepping over, step one instruction, and
2715 then re-insert the breakpoint when that step is finished. */
2716 if (tp->stepping_over_breakpoint && !use_displaced_stepping (gdbarch))
2718 struct regcache *regcache = get_current_regcache ();
2720 set_step_over_info (get_regcache_aspace (regcache),
2721 regcache_read_pc (regcache), 0);
2724 clear_step_over_info ();
2726 insert_breakpoints ();
2728 tp->control.trap_expected = tp->stepping_over_breakpoint;
2730 annotate_starting ();
2732 /* Make sure that output from GDB appears before output from the
2734 gdb_flush (gdb_stdout);
2736 /* Refresh prev_pc value just prior to resuming. This used to be
2737 done in stop_waiting, however, setting prev_pc there did not handle
2738 scenarios such as inferior function calls or returning from
2739 a function via the return command. In those cases, the prev_pc
2740 value was not set properly for subsequent commands. The prev_pc value
2741 is used to initialize the starting line number in the ecs. With an
2742 invalid value, the gdb next command ends up stopping at the position
2743 represented by the next line table entry past our start position.
2744 On platforms that generate one line table entry per line, this
2745 is not a problem. However, on the ia64, the compiler generates
2746 extraneous line table entries that do not increase the line number.
2747 When we issue the gdb next command on the ia64 after an inferior call
2748 or a return command, we often end up a few instructions forward, still
2749 within the original line we started.
2751 An attempt was made to refresh the prev_pc at the same time the
2752 execution_control_state is initialized (for instance, just before
2753 waiting for an inferior event). But this approach did not work
2754 because of platforms that use ptrace, where the pc register cannot
2755 be read unless the inferior is stopped. At that point, we are not
2756 guaranteed the inferior is stopped and so the regcache_read_pc() call
2757 can fail. Setting the prev_pc value here ensures the value is updated
2758 correctly when the inferior is stopped. */
2759 tp->prev_pc = regcache_read_pc (get_current_regcache ());
2761 /* Resume inferior. */
2762 resume (tp->suspend.stop_signal);
2764 /* Wait for it to stop (if not standalone)
2765 and in any case decode why it stopped, and act accordingly. */
2766 /* Do this only if we are not using the event loop, or if the target
2767 does not support asynchronous execution. */
2768 if (!target_can_async_p ())
2770 wait_for_inferior ();
2776 /* Start remote-debugging of a machine over a serial link. */
2779 start_remote (int from_tty)
2781 struct inferior *inferior;
2783 inferior = current_inferior ();
2784 inferior->control.stop_soon = STOP_QUIETLY_REMOTE;
2786 /* Always go on waiting for the target, regardless of the mode. */
2787 /* FIXME: cagney/1999-09-23: At present it isn't possible to
2788 indicate to wait_for_inferior that a target should timeout if
2789 nothing is returned (instead of just blocking). Because of this,
2790 targets expecting an immediate response need to, internally, set
2791 things up so that the target_wait() is forced to eventually
2793 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
2794 differentiate to its caller what the state of the target is after
2795 the initial open has been performed. Here we're assuming that
2796 the target has stopped. It should be possible to eventually have
2797 target_open() return to the caller an indication that the target
2798 is currently running and GDB state should be set to the same as
2799 for an async run. */
2800 wait_for_inferior ();
2802 /* Now that the inferior has stopped, do any bookkeeping like
2803 loading shared libraries. We want to do this before normal_stop,
2804 so that the displayed frame is up to date. */
2805 post_create_inferior (¤t_target, from_tty);
2810 /* Initialize static vars when a new inferior begins. */
2813 init_wait_for_inferior (void)
2815 /* These are meaningless until the first time through wait_for_inferior. */
2817 breakpoint_init_inferior (inf_starting);
2819 clear_proceed_status (0);
2821 target_last_wait_ptid = minus_one_ptid;
2823 previous_inferior_ptid = inferior_ptid;
2825 /* Discard any skipped inlined frames. */
2826 clear_inline_frame_state (minus_one_ptid);
2830 /* Data to be passed around while handling an event. This data is
2831 discarded between events. */
2832 struct execution_control_state
2835 /* The thread that got the event, if this was a thread event; NULL
2837 struct thread_info *event_thread;
2839 struct target_waitstatus ws;
2840 int stop_func_filled_in;
2841 CORE_ADDR stop_func_start;
2842 CORE_ADDR stop_func_end;
2843 const char *stop_func_name;
2846 /* True if the event thread hit the single-step breakpoint of
2847 another thread. Thus the event doesn't cause a stop, the thread
2848 needs to be single-stepped past the single-step breakpoint before
2849 we can switch back to the original stepping thread. */
2850 int hit_singlestep_breakpoint;
2853 static void handle_inferior_event (struct execution_control_state *ecs);
2855 static void handle_step_into_function (struct gdbarch *gdbarch,
2856 struct execution_control_state *ecs);
2857 static void handle_step_into_function_backward (struct gdbarch *gdbarch,
2858 struct execution_control_state *ecs);
2859 static void handle_signal_stop (struct execution_control_state *ecs);
2860 static void check_exception_resume (struct execution_control_state *,
2861 struct frame_info *);
2863 static void end_stepping_range (struct execution_control_state *ecs);
2864 static void stop_waiting (struct execution_control_state *ecs);
2865 static void prepare_to_wait (struct execution_control_state *ecs);
2866 static void keep_going (struct execution_control_state *ecs);
2867 static void process_event_stop_test (struct execution_control_state *ecs);
2868 static int switch_back_to_stepped_thread (struct execution_control_state *ecs);
2870 /* Callback for iterate over threads. If the thread is stopped, but
2871 the user/frontend doesn't know about that yet, go through
2872 normal_stop, as if the thread had just stopped now. ARG points at
2873 a ptid. If PTID is MINUS_ONE_PTID, applies to all threads. If
2874 ptid_is_pid(PTID) is true, applies to all threads of the process
2875 pointed at by PTID. Otherwise, apply only to the thread pointed by
2879 infrun_thread_stop_requested_callback (struct thread_info *info, void *arg)
2881 ptid_t ptid = * (ptid_t *) arg;
2883 if ((ptid_equal (info->ptid, ptid)
2884 || ptid_equal (minus_one_ptid, ptid)
2885 || (ptid_is_pid (ptid)
2886 && ptid_get_pid (ptid) == ptid_get_pid (info->ptid)))
2887 && is_running (info->ptid)
2888 && !is_executing (info->ptid))
2890 struct cleanup *old_chain;
2891 struct execution_control_state ecss;
2892 struct execution_control_state *ecs = &ecss;
2894 memset (ecs, 0, sizeof (*ecs));
2896 old_chain = make_cleanup_restore_current_thread ();
2898 overlay_cache_invalid = 1;
2899 /* Flush target cache before starting to handle each event.
2900 Target was running and cache could be stale. This is just a
2901 heuristic. Running threads may modify target memory, but we
2902 don't get any event. */
2903 target_dcache_invalidate ();
2905 /* Go through handle_inferior_event/normal_stop, so we always
2906 have consistent output as if the stop event had been
2908 ecs->ptid = info->ptid;
2909 ecs->event_thread = find_thread_ptid (info->ptid);
2910 ecs->ws.kind = TARGET_WAITKIND_STOPPED;
2911 ecs->ws.value.sig = GDB_SIGNAL_0;
2913 handle_inferior_event (ecs);
2915 if (!ecs->wait_some_more)
2917 struct thread_info *tp;
2921 /* Finish off the continuations. */
2922 tp = inferior_thread ();
2923 do_all_intermediate_continuations_thread (tp, 1);
2924 do_all_continuations_thread (tp, 1);
2927 do_cleanups (old_chain);
2933 /* This function is attached as a "thread_stop_requested" observer.
2934 Cleanup local state that assumed the PTID was to be resumed, and
2935 report the stop to the frontend. */
2938 infrun_thread_stop_requested (ptid_t ptid)
2940 struct displaced_step_inferior_state *displaced;
2942 /* PTID was requested to stop. Remove it from the displaced
2943 stepping queue, so we don't try to resume it automatically. */
2945 for (displaced = displaced_step_inferior_states;
2947 displaced = displaced->next)
2949 struct displaced_step_request *it, **prev_next_p;
2951 it = displaced->step_request_queue;
2952 prev_next_p = &displaced->step_request_queue;
2955 if (ptid_match (it->ptid, ptid))
2957 *prev_next_p = it->next;
2963 prev_next_p = &it->next;
2970 iterate_over_threads (infrun_thread_stop_requested_callback, &ptid);
2974 infrun_thread_thread_exit (struct thread_info *tp, int silent)
2976 if (ptid_equal (target_last_wait_ptid, tp->ptid))
2977 nullify_last_target_wait_ptid ();
2980 /* Delete the step resume, single-step and longjmp/exception resume
2981 breakpoints of TP. */
2984 delete_thread_infrun_breakpoints (struct thread_info *tp)
2986 delete_step_resume_breakpoint (tp);
2987 delete_exception_resume_breakpoint (tp);
2988 delete_single_step_breakpoints (tp);
2991 /* If the target still has execution, call FUNC for each thread that
2992 just stopped. In all-stop, that's all the non-exited threads; in
2993 non-stop, that's the current thread, only. */
2995 typedef void (*for_each_just_stopped_thread_callback_func)
2996 (struct thread_info *tp);
2999 for_each_just_stopped_thread (for_each_just_stopped_thread_callback_func func)
3001 if (!target_has_execution || ptid_equal (inferior_ptid, null_ptid))
3006 /* If in non-stop mode, only the current thread stopped. */
3007 func (inferior_thread ());
3011 struct thread_info *tp;
3013 /* In all-stop mode, all threads have stopped. */
3014 ALL_NON_EXITED_THREADS (tp)
3021 /* Delete the step resume and longjmp/exception resume breakpoints of
3022 the threads that just stopped. */
3025 delete_just_stopped_threads_infrun_breakpoints (void)
3027 for_each_just_stopped_thread (delete_thread_infrun_breakpoints);
3030 /* Delete the single-step breakpoints of the threads that just
3034 delete_just_stopped_threads_single_step_breakpoints (void)
3036 for_each_just_stopped_thread (delete_single_step_breakpoints);
3039 /* A cleanup wrapper. */
3042 delete_just_stopped_threads_infrun_breakpoints_cleanup (void *arg)
3044 delete_just_stopped_threads_infrun_breakpoints ();
3047 /* Pretty print the results of target_wait, for debugging purposes. */
3050 print_target_wait_results (ptid_t waiton_ptid, ptid_t result_ptid,
3051 const struct target_waitstatus *ws)
3053 char *status_string = target_waitstatus_to_string (ws);
3054 struct ui_file *tmp_stream = mem_fileopen ();
3057 /* The text is split over several lines because it was getting too long.
3058 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
3059 output as a unit; we want only one timestamp printed if debug_timestamp
3062 fprintf_unfiltered (tmp_stream,
3063 "infrun: target_wait (%d.%ld.%ld",
3064 ptid_get_pid (waiton_ptid),
3065 ptid_get_lwp (waiton_ptid),
3066 ptid_get_tid (waiton_ptid));
3067 if (ptid_get_pid (waiton_ptid) != -1)
3068 fprintf_unfiltered (tmp_stream,
3069 " [%s]", target_pid_to_str (waiton_ptid));
3070 fprintf_unfiltered (tmp_stream, ", status) =\n");
3071 fprintf_unfiltered (tmp_stream,
3072 "infrun: %d.%ld.%ld [%s],\n",
3073 ptid_get_pid (result_ptid),
3074 ptid_get_lwp (result_ptid),
3075 ptid_get_tid (result_ptid),
3076 target_pid_to_str (result_ptid));
3077 fprintf_unfiltered (tmp_stream,
3081 text = ui_file_xstrdup (tmp_stream, NULL);
3083 /* This uses %s in part to handle %'s in the text, but also to avoid
3084 a gcc error: the format attribute requires a string literal. */
3085 fprintf_unfiltered (gdb_stdlog, "%s", text);
3087 xfree (status_string);
3089 ui_file_delete (tmp_stream);
3092 /* Prepare and stabilize the inferior for detaching it. E.g.,
3093 detaching while a thread is displaced stepping is a recipe for
3094 crashing it, as nothing would readjust the PC out of the scratch
3098 prepare_for_detach (void)
3100 struct inferior *inf = current_inferior ();
3101 ptid_t pid_ptid = pid_to_ptid (inf->pid);
3102 struct cleanup *old_chain_1;
3103 struct displaced_step_inferior_state *displaced;
3105 displaced = get_displaced_stepping_state (inf->pid);
3107 /* Is any thread of this process displaced stepping? If not,
3108 there's nothing else to do. */
3109 if (displaced == NULL || ptid_equal (displaced->step_ptid, null_ptid))
3113 fprintf_unfiltered (gdb_stdlog,
3114 "displaced-stepping in-process while detaching");
3116 old_chain_1 = make_cleanup_restore_integer (&inf->detaching);
3119 while (!ptid_equal (displaced->step_ptid, null_ptid))
3121 struct cleanup *old_chain_2;
3122 struct execution_control_state ecss;
3123 struct execution_control_state *ecs;
3126 memset (ecs, 0, sizeof (*ecs));
3128 overlay_cache_invalid = 1;
3129 /* Flush target cache before starting to handle each event.
3130 Target was running and cache could be stale. This is just a
3131 heuristic. Running threads may modify target memory, but we
3132 don't get any event. */
3133 target_dcache_invalidate ();
3135 if (deprecated_target_wait_hook)
3136 ecs->ptid = deprecated_target_wait_hook (pid_ptid, &ecs->ws, 0);
3138 ecs->ptid = target_wait (pid_ptid, &ecs->ws, 0);
3141 print_target_wait_results (pid_ptid, ecs->ptid, &ecs->ws);
3143 /* If an error happens while handling the event, propagate GDB's
3144 knowledge of the executing state to the frontend/user running
3146 old_chain_2 = make_cleanup (finish_thread_state_cleanup,
3149 /* Now figure out what to do with the result of the result. */
3150 handle_inferior_event (ecs);
3152 /* No error, don't finish the state yet. */
3153 discard_cleanups (old_chain_2);
3155 /* Breakpoints and watchpoints are not installed on the target
3156 at this point, and signals are passed directly to the
3157 inferior, so this must mean the process is gone. */
3158 if (!ecs->wait_some_more)
3160 discard_cleanups (old_chain_1);
3161 error (_("Program exited while detaching"));
3165 discard_cleanups (old_chain_1);
3168 /* Wait for control to return from inferior to debugger.
3170 If inferior gets a signal, we may decide to start it up again
3171 instead of returning. That is why there is a loop in this function.
3172 When this function actually returns it means the inferior
3173 should be left stopped and GDB should read more commands. */
3176 wait_for_inferior (void)
3178 struct cleanup *old_cleanups;
3179 struct cleanup *thread_state_chain;
3183 (gdb_stdlog, "infrun: wait_for_inferior ()\n");
3186 = make_cleanup (delete_just_stopped_threads_infrun_breakpoints_cleanup,
3189 /* If an error happens while handling the event, propagate GDB's
3190 knowledge of the executing state to the frontend/user running
3192 thread_state_chain = make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
3196 struct execution_control_state ecss;
3197 struct execution_control_state *ecs = &ecss;
3198 ptid_t waiton_ptid = minus_one_ptid;
3200 memset (ecs, 0, sizeof (*ecs));
3202 overlay_cache_invalid = 1;
3204 /* Flush target cache before starting to handle each event.
3205 Target was running and cache could be stale. This is just a
3206 heuristic. Running threads may modify target memory, but we
3207 don't get any event. */
3208 target_dcache_invalidate ();
3210 if (deprecated_target_wait_hook)
3211 ecs->ptid = deprecated_target_wait_hook (waiton_ptid, &ecs->ws, 0);
3213 ecs->ptid = target_wait (waiton_ptid, &ecs->ws, 0);
3216 print_target_wait_results (waiton_ptid, ecs->ptid, &ecs->ws);
3218 /* Now figure out what to do with the result of the result. */
3219 handle_inferior_event (ecs);
3221 if (!ecs->wait_some_more)
3225 /* No error, don't finish the state yet. */
3226 discard_cleanups (thread_state_chain);
3228 do_cleanups (old_cleanups);
3231 /* Cleanup that reinstalls the readline callback handler, if the
3232 target is running in the background. If while handling the target
3233 event something triggered a secondary prompt, like e.g., a
3234 pagination prompt, we'll have removed the callback handler (see
3235 gdb_readline_wrapper_line). Need to do this as we go back to the
3236 event loop, ready to process further input. Note this has no
3237 effect if the handler hasn't actually been removed, because calling
3238 rl_callback_handler_install resets the line buffer, thus losing
3242 reinstall_readline_callback_handler_cleanup (void *arg)
3244 if (!interpreter_async)
3246 /* We're not going back to the top level event loop yet. Don't
3247 install the readline callback, as it'd prep the terminal,
3248 readline-style (raw, noecho) (e.g., --batch). We'll install
3249 it the next time the prompt is displayed, when we're ready
3254 if (async_command_editing_p && !sync_execution)
3255 gdb_rl_callback_handler_reinstall ();
3258 /* Asynchronous version of wait_for_inferior. It is called by the
3259 event loop whenever a change of state is detected on the file
3260 descriptor corresponding to the target. It can be called more than
3261 once to complete a single execution command. In such cases we need
3262 to keep the state in a global variable ECSS. If it is the last time
3263 that this function is called for a single execution command, then
3264 report to the user that the inferior has stopped, and do the
3265 necessary cleanups. */
3268 fetch_inferior_event (void *client_data)
3270 struct execution_control_state ecss;
3271 struct execution_control_state *ecs = &ecss;
3272 struct cleanup *old_chain = make_cleanup (null_cleanup, NULL);
3273 struct cleanup *ts_old_chain;
3274 int was_sync = sync_execution;
3276 ptid_t waiton_ptid = minus_one_ptid;
3278 memset (ecs, 0, sizeof (*ecs));
3280 /* End up with readline processing input, if necessary. */
3281 make_cleanup (reinstall_readline_callback_handler_cleanup, NULL);
3283 /* We're handling a live event, so make sure we're doing live
3284 debugging. If we're looking at traceframes while the target is
3285 running, we're going to need to get back to that mode after
3286 handling the event. */
3289 make_cleanup_restore_current_traceframe ();
3290 set_current_traceframe (-1);
3294 /* In non-stop mode, the user/frontend should not notice a thread
3295 switch due to internal events. Make sure we reverse to the
3296 user selected thread and frame after handling the event and
3297 running any breakpoint commands. */
3298 make_cleanup_restore_current_thread ();
3300 overlay_cache_invalid = 1;
3301 /* Flush target cache before starting to handle each event. Target
3302 was running and cache could be stale. This is just a heuristic.
3303 Running threads may modify target memory, but we don't get any
3305 target_dcache_invalidate ();
3307 make_cleanup_restore_integer (&execution_direction);
3308 execution_direction = target_execution_direction ();
3310 if (deprecated_target_wait_hook)
3312 deprecated_target_wait_hook (waiton_ptid, &ecs->ws, TARGET_WNOHANG);
3314 ecs->ptid = target_wait (waiton_ptid, &ecs->ws, TARGET_WNOHANG);
3317 print_target_wait_results (waiton_ptid, ecs->ptid, &ecs->ws);
3319 /* If an error happens while handling the event, propagate GDB's
3320 knowledge of the executing state to the frontend/user running
3323 ts_old_chain = make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
3325 ts_old_chain = make_cleanup (finish_thread_state_cleanup, &ecs->ptid);
3327 /* Get executed before make_cleanup_restore_current_thread above to apply
3328 still for the thread which has thrown the exception. */
3329 make_bpstat_clear_actions_cleanup ();
3331 make_cleanup (delete_just_stopped_threads_infrun_breakpoints_cleanup, NULL);
3333 /* Now figure out what to do with the result of the result. */
3334 handle_inferior_event (ecs);
3336 if (!ecs->wait_some_more)
3338 struct inferior *inf = find_inferior_ptid (ecs->ptid);
3340 delete_just_stopped_threads_infrun_breakpoints ();
3342 /* We may not find an inferior if this was a process exit. */
3343 if (inf == NULL || inf->control.stop_soon == NO_STOP_QUIETLY)
3346 if (target_has_execution
3347 && ecs->ws.kind != TARGET_WAITKIND_NO_RESUMED
3348 && ecs->ws.kind != TARGET_WAITKIND_EXITED
3349 && ecs->ws.kind != TARGET_WAITKIND_SIGNALLED
3350 && ecs->event_thread->step_multi
3351 && ecs->event_thread->control.stop_step)
3352 inferior_event_handler (INF_EXEC_CONTINUE, NULL);
3355 inferior_event_handler (INF_EXEC_COMPLETE, NULL);
3360 /* No error, don't finish the thread states yet. */
3361 discard_cleanups (ts_old_chain);
3363 /* Revert thread and frame. */
3364 do_cleanups (old_chain);
3366 /* If the inferior was in sync execution mode, and now isn't,
3367 restore the prompt (a synchronous execution command has finished,
3368 and we're ready for input). */
3369 if (interpreter_async && was_sync && !sync_execution)
3370 observer_notify_sync_execution_done ();
3374 && exec_done_display_p
3375 && (ptid_equal (inferior_ptid, null_ptid)
3376 || !is_running (inferior_ptid)))
3377 printf_unfiltered (_("completed.\n"));
3380 /* Record the frame and location we're currently stepping through. */
3382 set_step_info (struct frame_info *frame, struct symtab_and_line sal)
3384 struct thread_info *tp = inferior_thread ();
3386 tp->control.step_frame_id = get_frame_id (frame);
3387 tp->control.step_stack_frame_id = get_stack_frame_id (frame);
3389 tp->current_symtab = sal.symtab;
3390 tp->current_line = sal.line;
3393 /* Clear context switchable stepping state. */
3396 init_thread_stepping_state (struct thread_info *tss)
3398 tss->stepped_breakpoint = 0;
3399 tss->stepping_over_breakpoint = 0;
3400 tss->stepping_over_watchpoint = 0;
3401 tss->step_after_step_resume_breakpoint = 0;
3404 /* Set the cached copy of the last ptid/waitstatus. */
3407 set_last_target_status (ptid_t ptid, struct target_waitstatus status)
3409 target_last_wait_ptid = ptid;
3410 target_last_waitstatus = status;
3413 /* Return the cached copy of the last pid/waitstatus returned by
3414 target_wait()/deprecated_target_wait_hook(). The data is actually
3415 cached by handle_inferior_event(), which gets called immediately
3416 after target_wait()/deprecated_target_wait_hook(). */
3419 get_last_target_status (ptid_t *ptidp, struct target_waitstatus *status)
3421 *ptidp = target_last_wait_ptid;
3422 *status = target_last_waitstatus;
3426 nullify_last_target_wait_ptid (void)
3428 target_last_wait_ptid = minus_one_ptid;
3431 /* Switch thread contexts. */
3434 context_switch (ptid_t ptid)
3436 if (debug_infrun && !ptid_equal (ptid, inferior_ptid))
3438 fprintf_unfiltered (gdb_stdlog, "infrun: Switching context from %s ",
3439 target_pid_to_str (inferior_ptid));
3440 fprintf_unfiltered (gdb_stdlog, "to %s\n",
3441 target_pid_to_str (ptid));
3444 switch_to_thread (ptid);
3448 adjust_pc_after_break (struct execution_control_state *ecs)
3450 struct regcache *regcache;
3451 struct gdbarch *gdbarch;
3452 struct address_space *aspace;
3453 CORE_ADDR breakpoint_pc, decr_pc;
3455 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
3456 we aren't, just return.
3458 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
3459 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
3460 implemented by software breakpoints should be handled through the normal
3463 NOTE drow/2004-01-31: On some targets, breakpoints may generate
3464 different signals (SIGILL or SIGEMT for instance), but it is less
3465 clear where the PC is pointing afterwards. It may not match
3466 gdbarch_decr_pc_after_break. I don't know any specific target that
3467 generates these signals at breakpoints (the code has been in GDB since at
3468 least 1992) so I can not guess how to handle them here.
3470 In earlier versions of GDB, a target with
3471 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
3472 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
3473 target with both of these set in GDB history, and it seems unlikely to be
3474 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
3476 if (ecs->ws.kind != TARGET_WAITKIND_STOPPED)
3479 if (ecs->ws.value.sig != GDB_SIGNAL_TRAP)
3482 /* In reverse execution, when a breakpoint is hit, the instruction
3483 under it has already been de-executed. The reported PC always
3484 points at the breakpoint address, so adjusting it further would
3485 be wrong. E.g., consider this case on a decr_pc_after_break == 1
3488 B1 0x08000000 : INSN1
3489 B2 0x08000001 : INSN2
3491 PC -> 0x08000003 : INSN4
3493 Say you're stopped at 0x08000003 as above. Reverse continuing
3494 from that point should hit B2 as below. Reading the PC when the
3495 SIGTRAP is reported should read 0x08000001 and INSN2 should have
3496 been de-executed already.
3498 B1 0x08000000 : INSN1
3499 B2 PC -> 0x08000001 : INSN2
3503 We can't apply the same logic as for forward execution, because
3504 we would wrongly adjust the PC to 0x08000000, since there's a
3505 breakpoint at PC - 1. We'd then report a hit on B1, although
3506 INSN1 hadn't been de-executed yet. Doing nothing is the correct
3508 if (execution_direction == EXEC_REVERSE)
3511 /* If the target can tell whether the thread hit a SW breakpoint,
3512 trust it. Targets that can tell also adjust the PC
3514 if (target_supports_stopped_by_sw_breakpoint ())
3517 /* Note that relying on whether a breakpoint is planted in memory to
3518 determine this can fail. E.g,. the breakpoint could have been
3519 removed since. Or the thread could have been told to step an
3520 instruction the size of a breakpoint instruction, and only
3521 _after_ was a breakpoint inserted at its address. */
3523 /* If this target does not decrement the PC after breakpoints, then
3524 we have nothing to do. */
3525 regcache = get_thread_regcache (ecs->ptid);
3526 gdbarch = get_regcache_arch (regcache);
3528 decr_pc = gdbarch_decr_pc_after_break (gdbarch);
3532 aspace = get_regcache_aspace (regcache);
3534 /* Find the location where (if we've hit a breakpoint) the
3535 breakpoint would be. */
3536 breakpoint_pc = regcache_read_pc (regcache) - decr_pc;
3538 /* If the target can't tell whether a software breakpoint triggered,
3539 fallback to figuring it out based on breakpoints we think were
3540 inserted in the target, and on whether the thread was stepped or
3543 /* Check whether there actually is a software breakpoint inserted at
3546 If in non-stop mode, a race condition is possible where we've
3547 removed a breakpoint, but stop events for that breakpoint were
3548 already queued and arrive later. To suppress those spurious
3549 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
3550 and retire them after a number of stop events are reported. Note
3551 this is an heuristic and can thus get confused. The real fix is
3552 to get the "stopped by SW BP and needs adjustment" info out of
3553 the target/kernel (and thus never reach here; see above). */
3554 if (software_breakpoint_inserted_here_p (aspace, breakpoint_pc)
3555 || (non_stop && moribund_breakpoint_here_p (aspace, breakpoint_pc)))
3557 struct cleanup *old_cleanups = make_cleanup (null_cleanup, NULL);
3559 if (record_full_is_used ())
3560 record_full_gdb_operation_disable_set ();
3562 /* When using hardware single-step, a SIGTRAP is reported for both
3563 a completed single-step and a software breakpoint. Need to
3564 differentiate between the two, as the latter needs adjusting
3565 but the former does not.
3567 The SIGTRAP can be due to a completed hardware single-step only if
3568 - we didn't insert software single-step breakpoints
3569 - this thread is currently being stepped
3571 If any of these events did not occur, we must have stopped due
3572 to hitting a software breakpoint, and have to back up to the
3575 As a special case, we could have hardware single-stepped a
3576 software breakpoint. In this case (prev_pc == breakpoint_pc),
3577 we also need to back up to the breakpoint address. */
3579 if (thread_has_single_step_breakpoints_set (ecs->event_thread)
3580 || !currently_stepping (ecs->event_thread)
3581 || (ecs->event_thread->stepped_breakpoint
3582 && ecs->event_thread->prev_pc == breakpoint_pc))
3583 regcache_write_pc (regcache, breakpoint_pc);
3585 do_cleanups (old_cleanups);
3590 stepped_in_from (struct frame_info *frame, struct frame_id step_frame_id)
3592 for (frame = get_prev_frame (frame);
3594 frame = get_prev_frame (frame))
3596 if (frame_id_eq (get_frame_id (frame), step_frame_id))
3598 if (get_frame_type (frame) != INLINE_FRAME)
3605 /* Auxiliary function that handles syscall entry/return events.
3606 It returns 1 if the inferior should keep going (and GDB
3607 should ignore the event), or 0 if the event deserves to be
3611 handle_syscall_event (struct execution_control_state *ecs)
3613 struct regcache *regcache;
3616 if (!ptid_equal (ecs->ptid, inferior_ptid))
3617 context_switch (ecs->ptid);
3619 regcache = get_thread_regcache (ecs->ptid);
3620 syscall_number = ecs->ws.value.syscall_number;
3621 stop_pc = regcache_read_pc (regcache);
3623 if (catch_syscall_enabled () > 0
3624 && catching_syscall_number (syscall_number) > 0)
3627 fprintf_unfiltered (gdb_stdlog, "infrun: syscall number = '%d'\n",
3630 ecs->event_thread->control.stop_bpstat
3631 = bpstat_stop_status (get_regcache_aspace (regcache),
3632 stop_pc, ecs->ptid, &ecs->ws);
3634 if (bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
3636 /* Catchpoint hit. */
3641 /* If no catchpoint triggered for this, then keep going. */
3646 /* Lazily fill in the execution_control_state's stop_func_* fields. */
3649 fill_in_stop_func (struct gdbarch *gdbarch,
3650 struct execution_control_state *ecs)
3652 if (!ecs->stop_func_filled_in)
3654 /* Don't care about return value; stop_func_start and stop_func_name
3655 will both be 0 if it doesn't work. */
3656 find_pc_partial_function (stop_pc, &ecs->stop_func_name,
3657 &ecs->stop_func_start, &ecs->stop_func_end);
3658 ecs->stop_func_start
3659 += gdbarch_deprecated_function_start_offset (gdbarch);
3661 if (gdbarch_skip_entrypoint_p (gdbarch))
3662 ecs->stop_func_start = gdbarch_skip_entrypoint (gdbarch,
3663 ecs->stop_func_start);
3665 ecs->stop_func_filled_in = 1;
3670 /* Return the STOP_SOON field of the inferior pointed at by PTID. */
3672 static enum stop_kind
3673 get_inferior_stop_soon (ptid_t ptid)
3675 struct inferior *inf = find_inferior_ptid (ptid);
3677 gdb_assert (inf != NULL);
3678 return inf->control.stop_soon;
3681 /* Given an execution control state that has been freshly filled in by
3682 an event from the inferior, figure out what it means and take
3685 The alternatives are:
3687 1) stop_waiting and return; to really stop and return to the
3690 2) keep_going and return; to wait for the next event (set
3691 ecs->event_thread->stepping_over_breakpoint to 1 to single step
3695 handle_inferior_event (struct execution_control_state *ecs)
3697 enum stop_kind stop_soon;
3699 if (ecs->ws.kind == TARGET_WAITKIND_IGNORE)
3701 /* We had an event in the inferior, but we are not interested in
3702 handling it at this level. The lower layers have already
3703 done what needs to be done, if anything.
3705 One of the possible circumstances for this is when the
3706 inferior produces output for the console. The inferior has
3707 not stopped, and we are ignoring the event. Another possible
3708 circumstance is any event which the lower level knows will be
3709 reported multiple times without an intervening resume. */
3711 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_IGNORE\n");
3712 prepare_to_wait (ecs);
3716 if (ecs->ws.kind == TARGET_WAITKIND_NO_RESUMED
3717 && target_can_async_p () && !sync_execution)
3719 /* There were no unwaited-for children left in the target, but,
3720 we're not synchronously waiting for events either. Just
3721 ignore. Otherwise, if we were running a synchronous
3722 execution command, we need to cancel it and give the user
3723 back the terminal. */
3725 fprintf_unfiltered (gdb_stdlog,
3726 "infrun: TARGET_WAITKIND_NO_RESUMED (ignoring)\n");
3727 prepare_to_wait (ecs);
3731 /* Cache the last pid/waitstatus. */
3732 set_last_target_status (ecs->ptid, ecs->ws);
3734 /* Always clear state belonging to the previous time we stopped. */
3735 stop_stack_dummy = STOP_NONE;
3737 if (ecs->ws.kind == TARGET_WAITKIND_NO_RESUMED)
3739 /* No unwaited-for children left. IOW, all resumed children
3742 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_NO_RESUMED\n");
3744 stop_print_frame = 0;
3749 if (ecs->ws.kind != TARGET_WAITKIND_EXITED
3750 && ecs->ws.kind != TARGET_WAITKIND_SIGNALLED)
3752 ecs->event_thread = find_thread_ptid (ecs->ptid);
3753 /* If it's a new thread, add it to the thread database. */
3754 if (ecs->event_thread == NULL)
3755 ecs->event_thread = add_thread (ecs->ptid);
3757 /* Disable range stepping. If the next step request could use a
3758 range, this will be end up re-enabled then. */
3759 ecs->event_thread->control.may_range_step = 0;
3762 /* Dependent on valid ECS->EVENT_THREAD. */
3763 adjust_pc_after_break (ecs);
3765 /* Dependent on the current PC value modified by adjust_pc_after_break. */
3766 reinit_frame_cache ();
3768 breakpoint_retire_moribund ();
3770 /* First, distinguish signals caused by the debugger from signals
3771 that have to do with the program's own actions. Note that
3772 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
3773 on the operating system version. Here we detect when a SIGILL or
3774 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
3775 something similar for SIGSEGV, since a SIGSEGV will be generated
3776 when we're trying to execute a breakpoint instruction on a
3777 non-executable stack. This happens for call dummy breakpoints
3778 for architectures like SPARC that place call dummies on the
3780 if (ecs->ws.kind == TARGET_WAITKIND_STOPPED
3781 && (ecs->ws.value.sig == GDB_SIGNAL_ILL
3782 || ecs->ws.value.sig == GDB_SIGNAL_SEGV
3783 || ecs->ws.value.sig == GDB_SIGNAL_EMT))
3785 struct regcache *regcache = get_thread_regcache (ecs->ptid);
3787 if (breakpoint_inserted_here_p (get_regcache_aspace (regcache),
3788 regcache_read_pc (regcache)))
3791 fprintf_unfiltered (gdb_stdlog,
3792 "infrun: Treating signal as SIGTRAP\n");
3793 ecs->ws.value.sig = GDB_SIGNAL_TRAP;
3797 /* Mark the non-executing threads accordingly. In all-stop, all
3798 threads of all processes are stopped when we get any event
3799 reported. In non-stop mode, only the event thread stops. If
3800 we're handling a process exit in non-stop mode, there's nothing
3801 to do, as threads of the dead process are gone, and threads of
3802 any other process were left running. */
3804 set_executing (minus_one_ptid, 0);
3805 else if (ecs->ws.kind != TARGET_WAITKIND_SIGNALLED
3806 && ecs->ws.kind != TARGET_WAITKIND_EXITED)
3807 set_executing (ecs->ptid, 0);
3809 switch (ecs->ws.kind)
3811 case TARGET_WAITKIND_LOADED:
3813 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_LOADED\n");
3814 if (!ptid_equal (ecs->ptid, inferior_ptid))
3815 context_switch (ecs->ptid);
3816 /* Ignore gracefully during startup of the inferior, as it might
3817 be the shell which has just loaded some objects, otherwise
3818 add the symbols for the newly loaded objects. Also ignore at
3819 the beginning of an attach or remote session; we will query
3820 the full list of libraries once the connection is
3823 stop_soon = get_inferior_stop_soon (ecs->ptid);
3824 if (stop_soon == NO_STOP_QUIETLY)
3826 struct regcache *regcache;
3828 regcache = get_thread_regcache (ecs->ptid);
3830 handle_solib_event ();
3832 ecs->event_thread->control.stop_bpstat
3833 = bpstat_stop_status (get_regcache_aspace (regcache),
3834 stop_pc, ecs->ptid, &ecs->ws);
3836 if (bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
3838 /* A catchpoint triggered. */
3839 process_event_stop_test (ecs);
3843 /* If requested, stop when the dynamic linker notifies
3844 gdb of events. This allows the user to get control
3845 and place breakpoints in initializer routines for
3846 dynamically loaded objects (among other things). */
3847 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
3848 if (stop_on_solib_events)
3850 /* Make sure we print "Stopped due to solib-event" in
3852 stop_print_frame = 1;
3859 /* If we are skipping through a shell, or through shared library
3860 loading that we aren't interested in, resume the program. If
3861 we're running the program normally, also resume. */
3862 if (stop_soon == STOP_QUIETLY || stop_soon == NO_STOP_QUIETLY)
3864 /* Loading of shared libraries might have changed breakpoint
3865 addresses. Make sure new breakpoints are inserted. */
3866 if (stop_soon == NO_STOP_QUIETLY)
3867 insert_breakpoints ();
3868 resume (GDB_SIGNAL_0);
3869 prepare_to_wait (ecs);
3873 /* But stop if we're attaching or setting up a remote
3875 if (stop_soon == STOP_QUIETLY_NO_SIGSTOP
3876 || stop_soon == STOP_QUIETLY_REMOTE)
3879 fprintf_unfiltered (gdb_stdlog, "infrun: quietly stopped\n");
3884 internal_error (__FILE__, __LINE__,
3885 _("unhandled stop_soon: %d"), (int) stop_soon);
3887 case TARGET_WAITKIND_SPURIOUS:
3889 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_SPURIOUS\n");
3890 if (!ptid_equal (ecs->ptid, inferior_ptid))
3891 context_switch (ecs->ptid);
3892 resume (GDB_SIGNAL_0);
3893 prepare_to_wait (ecs);
3896 case TARGET_WAITKIND_EXITED:
3897 case TARGET_WAITKIND_SIGNALLED:
3900 if (ecs->ws.kind == TARGET_WAITKIND_EXITED)
3901 fprintf_unfiltered (gdb_stdlog,
3902 "infrun: TARGET_WAITKIND_EXITED\n");
3904 fprintf_unfiltered (gdb_stdlog,
3905 "infrun: TARGET_WAITKIND_SIGNALLED\n");
3908 inferior_ptid = ecs->ptid;
3909 set_current_inferior (find_inferior_ptid (ecs->ptid));
3910 set_current_program_space (current_inferior ()->pspace);
3911 handle_vfork_child_exec_or_exit (0);
3912 target_terminal_ours (); /* Must do this before mourn anyway. */
3914 /* Clearing any previous state of convenience variables. */
3915 clear_exit_convenience_vars ();
3917 if (ecs->ws.kind == TARGET_WAITKIND_EXITED)
3919 /* Record the exit code in the convenience variable $_exitcode, so
3920 that the user can inspect this again later. */
3921 set_internalvar_integer (lookup_internalvar ("_exitcode"),
3922 (LONGEST) ecs->ws.value.integer);
3924 /* Also record this in the inferior itself. */
3925 current_inferior ()->has_exit_code = 1;
3926 current_inferior ()->exit_code = (LONGEST) ecs->ws.value.integer;
3928 /* Support the --return-child-result option. */
3929 return_child_result_value = ecs->ws.value.integer;
3931 observer_notify_exited (ecs->ws.value.integer);
3935 struct regcache *regcache = get_thread_regcache (ecs->ptid);
3936 struct gdbarch *gdbarch = get_regcache_arch (regcache);
3938 if (gdbarch_gdb_signal_to_target_p (gdbarch))
3940 /* Set the value of the internal variable $_exitsignal,
3941 which holds the signal uncaught by the inferior. */
3942 set_internalvar_integer (lookup_internalvar ("_exitsignal"),
3943 gdbarch_gdb_signal_to_target (gdbarch,
3944 ecs->ws.value.sig));
3948 /* We don't have access to the target's method used for
3949 converting between signal numbers (GDB's internal
3950 representation <-> target's representation).
3951 Therefore, we cannot do a good job at displaying this
3952 information to the user. It's better to just warn
3953 her about it (if infrun debugging is enabled), and
3956 fprintf_filtered (gdb_stdlog, _("\
3957 Cannot fill $_exitsignal with the correct signal number.\n"));
3960 observer_notify_signal_exited (ecs->ws.value.sig);
3963 gdb_flush (gdb_stdout);
3964 target_mourn_inferior ();
3965 stop_print_frame = 0;
3969 /* The following are the only cases in which we keep going;
3970 the above cases end in a continue or goto. */
3971 case TARGET_WAITKIND_FORKED:
3972 case TARGET_WAITKIND_VFORKED:
3975 if (ecs->ws.kind == TARGET_WAITKIND_FORKED)
3976 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_FORKED\n");
3978 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_VFORKED\n");
3981 /* Check whether the inferior is displaced stepping. */
3983 struct regcache *regcache = get_thread_regcache (ecs->ptid);
3984 struct gdbarch *gdbarch = get_regcache_arch (regcache);
3985 struct displaced_step_inferior_state *displaced
3986 = get_displaced_stepping_state (ptid_get_pid (ecs->ptid));
3988 /* If checking displaced stepping is supported, and thread
3989 ecs->ptid is displaced stepping. */
3990 if (displaced && ptid_equal (displaced->step_ptid, ecs->ptid))
3992 struct inferior *parent_inf
3993 = find_inferior_ptid (ecs->ptid);
3994 struct regcache *child_regcache;
3995 CORE_ADDR parent_pc;
3997 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
3998 indicating that the displaced stepping of syscall instruction
3999 has been done. Perform cleanup for parent process here. Note
4000 that this operation also cleans up the child process for vfork,
4001 because their pages are shared. */
4002 displaced_step_fixup (ecs->ptid, GDB_SIGNAL_TRAP);
4004 if (ecs->ws.kind == TARGET_WAITKIND_FORKED)
4006 /* Restore scratch pad for child process. */
4007 displaced_step_restore (displaced, ecs->ws.value.related_pid);
4010 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
4011 the child's PC is also within the scratchpad. Set the child's PC
4012 to the parent's PC value, which has already been fixed up.
4013 FIXME: we use the parent's aspace here, although we're touching
4014 the child, because the child hasn't been added to the inferior
4015 list yet at this point. */
4018 = get_thread_arch_aspace_regcache (ecs->ws.value.related_pid,
4020 parent_inf->aspace);
4021 /* Read PC value of parent process. */
4022 parent_pc = regcache_read_pc (regcache);
4024 if (debug_displaced)
4025 fprintf_unfiltered (gdb_stdlog,
4026 "displaced: write child pc from %s to %s\n",
4028 regcache_read_pc (child_regcache)),
4029 paddress (gdbarch, parent_pc));
4031 regcache_write_pc (child_regcache, parent_pc);
4035 if (!ptid_equal (ecs->ptid, inferior_ptid))
4036 context_switch (ecs->ptid);
4038 /* Immediately detach breakpoints from the child before there's
4039 any chance of letting the user delete breakpoints from the
4040 breakpoint lists. If we don't do this early, it's easy to
4041 leave left over traps in the child, vis: "break foo; catch
4042 fork; c; <fork>; del; c; <child calls foo>". We only follow
4043 the fork on the last `continue', and by that time the
4044 breakpoint at "foo" is long gone from the breakpoint table.
4045 If we vforked, then we don't need to unpatch here, since both
4046 parent and child are sharing the same memory pages; we'll
4047 need to unpatch at follow/detach time instead to be certain
4048 that new breakpoints added between catchpoint hit time and
4049 vfork follow are detached. */
4050 if (ecs->ws.kind != TARGET_WAITKIND_VFORKED)
4052 /* This won't actually modify the breakpoint list, but will
4053 physically remove the breakpoints from the child. */
4054 detach_breakpoints (ecs->ws.value.related_pid);
4057 delete_just_stopped_threads_single_step_breakpoints ();
4059 /* In case the event is caught by a catchpoint, remember that
4060 the event is to be followed at the next resume of the thread,
4061 and not immediately. */
4062 ecs->event_thread->pending_follow = ecs->ws;
4064 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
4066 ecs->event_thread->control.stop_bpstat
4067 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
4068 stop_pc, ecs->ptid, &ecs->ws);
4070 /* If no catchpoint triggered for this, then keep going. Note
4071 that we're interested in knowing the bpstat actually causes a
4072 stop, not just if it may explain the signal. Software
4073 watchpoints, for example, always appear in the bpstat. */
4074 if (!bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
4080 = (follow_fork_mode_string == follow_fork_mode_child);
4082 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
4084 should_resume = follow_fork ();
4087 child = ecs->ws.value.related_pid;
4089 /* In non-stop mode, also resume the other branch. */
4090 if (non_stop && !detach_fork)
4093 switch_to_thread (parent);
4095 switch_to_thread (child);
4097 ecs->event_thread = inferior_thread ();
4098 ecs->ptid = inferior_ptid;
4103 switch_to_thread (child);
4105 switch_to_thread (parent);
4107 ecs->event_thread = inferior_thread ();
4108 ecs->ptid = inferior_ptid;
4116 process_event_stop_test (ecs);
4119 case TARGET_WAITKIND_VFORK_DONE:
4120 /* Done with the shared memory region. Re-insert breakpoints in
4121 the parent, and keep going. */
4124 fprintf_unfiltered (gdb_stdlog,
4125 "infrun: TARGET_WAITKIND_VFORK_DONE\n");
4127 if (!ptid_equal (ecs->ptid, inferior_ptid))
4128 context_switch (ecs->ptid);
4130 current_inferior ()->waiting_for_vfork_done = 0;
4131 current_inferior ()->pspace->breakpoints_not_allowed = 0;
4132 /* This also takes care of reinserting breakpoints in the
4133 previously locked inferior. */
4137 case TARGET_WAITKIND_EXECD:
4139 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_EXECD\n");
4141 if (!ptid_equal (ecs->ptid, inferior_ptid))
4142 context_switch (ecs->ptid);
4144 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
4146 /* Do whatever is necessary to the parent branch of the vfork. */
4147 handle_vfork_child_exec_or_exit (1);
4149 /* This causes the eventpoints and symbol table to be reset.
4150 Must do this now, before trying to determine whether to
4152 follow_exec (inferior_ptid, ecs->ws.value.execd_pathname);
4154 ecs->event_thread->control.stop_bpstat
4155 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
4156 stop_pc, ecs->ptid, &ecs->ws);
4158 /* Note that this may be referenced from inside
4159 bpstat_stop_status above, through inferior_has_execd. */
4160 xfree (ecs->ws.value.execd_pathname);
4161 ecs->ws.value.execd_pathname = NULL;
4163 /* If no catchpoint triggered for this, then keep going. */
4164 if (!bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
4166 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
4170 process_event_stop_test (ecs);
4173 /* Be careful not to try to gather much state about a thread
4174 that's in a syscall. It's frequently a losing proposition. */
4175 case TARGET_WAITKIND_SYSCALL_ENTRY:
4177 fprintf_unfiltered (gdb_stdlog,
4178 "infrun: TARGET_WAITKIND_SYSCALL_ENTRY\n");
4179 /* Getting the current syscall number. */
4180 if (handle_syscall_event (ecs) == 0)
4181 process_event_stop_test (ecs);
4184 /* Before examining the threads further, step this thread to
4185 get it entirely out of the syscall. (We get notice of the
4186 event when the thread is just on the verge of exiting a
4187 syscall. Stepping one instruction seems to get it back
4189 case TARGET_WAITKIND_SYSCALL_RETURN:
4191 fprintf_unfiltered (gdb_stdlog,
4192 "infrun: TARGET_WAITKIND_SYSCALL_RETURN\n");
4193 if (handle_syscall_event (ecs) == 0)
4194 process_event_stop_test (ecs);
4197 case TARGET_WAITKIND_STOPPED:
4199 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_STOPPED\n");
4200 ecs->event_thread->suspend.stop_signal = ecs->ws.value.sig;
4201 handle_signal_stop (ecs);
4204 case TARGET_WAITKIND_NO_HISTORY:
4206 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_NO_HISTORY\n");
4207 /* Reverse execution: target ran out of history info. */
4209 delete_just_stopped_threads_single_step_breakpoints ();
4210 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
4211 observer_notify_no_history ();
4217 /* Come here when the program has stopped with a signal. */
4220 handle_signal_stop (struct execution_control_state *ecs)
4222 struct frame_info *frame;
4223 struct gdbarch *gdbarch;
4224 int stopped_by_watchpoint;
4225 enum stop_kind stop_soon;
4228 gdb_assert (ecs->ws.kind == TARGET_WAITKIND_STOPPED);
4230 /* Do we need to clean up the state of a thread that has
4231 completed a displaced single-step? (Doing so usually affects
4232 the PC, so do it here, before we set stop_pc.) */
4233 displaced_step_fixup (ecs->ptid,
4234 ecs->event_thread->suspend.stop_signal);
4236 /* If we either finished a single-step or hit a breakpoint, but
4237 the user wanted this thread to be stopped, pretend we got a
4238 SIG0 (generic unsignaled stop). */
4239 if (ecs->event_thread->stop_requested
4240 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
4241 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
4243 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
4247 struct regcache *regcache = get_thread_regcache (ecs->ptid);
4248 struct gdbarch *gdbarch = get_regcache_arch (regcache);
4249 struct cleanup *old_chain = save_inferior_ptid ();
4251 inferior_ptid = ecs->ptid;
4253 fprintf_unfiltered (gdb_stdlog, "infrun: stop_pc = %s\n",
4254 paddress (gdbarch, stop_pc));
4255 if (target_stopped_by_watchpoint ())
4259 fprintf_unfiltered (gdb_stdlog, "infrun: stopped by watchpoint\n");
4261 if (target_stopped_data_address (¤t_target, &addr))
4262 fprintf_unfiltered (gdb_stdlog,
4263 "infrun: stopped data address = %s\n",
4264 paddress (gdbarch, addr));
4266 fprintf_unfiltered (gdb_stdlog,
4267 "infrun: (no data address available)\n");
4270 do_cleanups (old_chain);
4273 /* This is originated from start_remote(), start_inferior() and
4274 shared libraries hook functions. */
4275 stop_soon = get_inferior_stop_soon (ecs->ptid);
4276 if (stop_soon == STOP_QUIETLY || stop_soon == STOP_QUIETLY_REMOTE)
4278 if (!ptid_equal (ecs->ptid, inferior_ptid))
4279 context_switch (ecs->ptid);
4281 fprintf_unfiltered (gdb_stdlog, "infrun: quietly stopped\n");
4282 stop_print_frame = 1;
4287 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
4290 if (!ptid_equal (ecs->ptid, inferior_ptid))
4291 context_switch (ecs->ptid);
4293 fprintf_unfiltered (gdb_stdlog, "infrun: stopped\n");
4294 stop_print_frame = 0;
4299 /* This originates from attach_command(). We need to overwrite
4300 the stop_signal here, because some kernels don't ignore a
4301 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
4302 See more comments in inferior.h. On the other hand, if we
4303 get a non-SIGSTOP, report it to the user - assume the backend
4304 will handle the SIGSTOP if it should show up later.
4306 Also consider that the attach is complete when we see a
4307 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
4308 target extended-remote report it instead of a SIGSTOP
4309 (e.g. gdbserver). We already rely on SIGTRAP being our
4310 signal, so this is no exception.
4312 Also consider that the attach is complete when we see a
4313 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
4314 the target to stop all threads of the inferior, in case the
4315 low level attach operation doesn't stop them implicitly. If
4316 they weren't stopped implicitly, then the stub will report a
4317 GDB_SIGNAL_0, meaning: stopped for no particular reason
4318 other than GDB's request. */
4319 if (stop_soon == STOP_QUIETLY_NO_SIGSTOP
4320 && (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_STOP
4321 || ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
4322 || ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_0))
4324 stop_print_frame = 1;
4326 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
4330 /* See if something interesting happened to the non-current thread. If
4331 so, then switch to that thread. */
4332 if (!ptid_equal (ecs->ptid, inferior_ptid))
4335 fprintf_unfiltered (gdb_stdlog, "infrun: context switch\n");
4337 context_switch (ecs->ptid);
4339 if (deprecated_context_hook)
4340 deprecated_context_hook (pid_to_thread_id (ecs->ptid));
4343 /* At this point, get hold of the now-current thread's frame. */
4344 frame = get_current_frame ();
4345 gdbarch = get_frame_arch (frame);
4347 /* Pull the single step breakpoints out of the target. */
4348 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
4350 struct regcache *regcache;
4351 struct address_space *aspace;
4354 regcache = get_thread_regcache (ecs->ptid);
4355 aspace = get_regcache_aspace (regcache);
4356 pc = regcache_read_pc (regcache);
4358 /* However, before doing so, if this single-step breakpoint was
4359 actually for another thread, set this thread up for moving
4361 if (!thread_has_single_step_breakpoint_here (ecs->event_thread,
4364 if (single_step_breakpoint_inserted_here_p (aspace, pc))
4368 fprintf_unfiltered (gdb_stdlog,
4369 "infrun: [%s] hit another thread's "
4370 "single-step breakpoint\n",
4371 target_pid_to_str (ecs->ptid));
4373 ecs->hit_singlestep_breakpoint = 1;
4380 fprintf_unfiltered (gdb_stdlog,
4381 "infrun: [%s] hit its "
4382 "single-step breakpoint\n",
4383 target_pid_to_str (ecs->ptid));
4387 delete_just_stopped_threads_single_step_breakpoints ();
4389 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
4390 && ecs->event_thread->control.trap_expected
4391 && ecs->event_thread->stepping_over_watchpoint)
4392 stopped_by_watchpoint = 0;
4394 stopped_by_watchpoint = watchpoints_triggered (&ecs->ws);
4396 /* If necessary, step over this watchpoint. We'll be back to display
4398 if (stopped_by_watchpoint
4399 && (target_have_steppable_watchpoint
4400 || gdbarch_have_nonsteppable_watchpoint (gdbarch)))
4402 /* At this point, we are stopped at an instruction which has
4403 attempted to write to a piece of memory under control of
4404 a watchpoint. The instruction hasn't actually executed
4405 yet. If we were to evaluate the watchpoint expression
4406 now, we would get the old value, and therefore no change
4407 would seem to have occurred.
4409 In order to make watchpoints work `right', we really need
4410 to complete the memory write, and then evaluate the
4411 watchpoint expression. We do this by single-stepping the
4414 It may not be necessary to disable the watchpoint to step over
4415 it. For example, the PA can (with some kernel cooperation)
4416 single step over a watchpoint without disabling the watchpoint.
4418 It is far more common to need to disable a watchpoint to step
4419 the inferior over it. If we have non-steppable watchpoints,
4420 we must disable the current watchpoint; it's simplest to
4421 disable all watchpoints.
4423 Any breakpoint at PC must also be stepped over -- if there's
4424 one, it will have already triggered before the watchpoint
4425 triggered, and we either already reported it to the user, or
4426 it didn't cause a stop and we called keep_going. In either
4427 case, if there was a breakpoint at PC, we must be trying to
4429 ecs->event_thread->stepping_over_watchpoint = 1;
4434 ecs->event_thread->stepping_over_breakpoint = 0;
4435 ecs->event_thread->stepping_over_watchpoint = 0;
4436 bpstat_clear (&ecs->event_thread->control.stop_bpstat);
4437 ecs->event_thread->control.stop_step = 0;
4438 stop_print_frame = 1;
4439 stopped_by_random_signal = 0;
4441 /* Hide inlined functions starting here, unless we just performed stepi or
4442 nexti. After stepi and nexti, always show the innermost frame (not any
4443 inline function call sites). */
4444 if (ecs->event_thread->control.step_range_end != 1)
4446 struct address_space *aspace =
4447 get_regcache_aspace (get_thread_regcache (ecs->ptid));
4449 /* skip_inline_frames is expensive, so we avoid it if we can
4450 determine that the address is one where functions cannot have
4451 been inlined. This improves performance with inferiors that
4452 load a lot of shared libraries, because the solib event
4453 breakpoint is defined as the address of a function (i.e. not
4454 inline). Note that we have to check the previous PC as well
4455 as the current one to catch cases when we have just
4456 single-stepped off a breakpoint prior to reinstating it.
4457 Note that we're assuming that the code we single-step to is
4458 not inline, but that's not definitive: there's nothing
4459 preventing the event breakpoint function from containing
4460 inlined code, and the single-step ending up there. If the
4461 user had set a breakpoint on that inlined code, the missing
4462 skip_inline_frames call would break things. Fortunately
4463 that's an extremely unlikely scenario. */
4464 if (!pc_at_non_inline_function (aspace, stop_pc, &ecs->ws)
4465 && !(ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
4466 && ecs->event_thread->control.trap_expected
4467 && pc_at_non_inline_function (aspace,
4468 ecs->event_thread->prev_pc,
4471 skip_inline_frames (ecs->ptid);
4473 /* Re-fetch current thread's frame in case that invalidated
4475 frame = get_current_frame ();
4476 gdbarch = get_frame_arch (frame);
4480 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
4481 && ecs->event_thread->control.trap_expected
4482 && gdbarch_single_step_through_delay_p (gdbarch)
4483 && currently_stepping (ecs->event_thread))
4485 /* We're trying to step off a breakpoint. Turns out that we're
4486 also on an instruction that needs to be stepped multiple
4487 times before it's been fully executing. E.g., architectures
4488 with a delay slot. It needs to be stepped twice, once for
4489 the instruction and once for the delay slot. */
4490 int step_through_delay
4491 = gdbarch_single_step_through_delay (gdbarch, frame);
4493 if (debug_infrun && step_through_delay)
4494 fprintf_unfiltered (gdb_stdlog, "infrun: step through delay\n");
4495 if (ecs->event_thread->control.step_range_end == 0
4496 && step_through_delay)
4498 /* The user issued a continue when stopped at a breakpoint.
4499 Set up for another trap and get out of here. */
4500 ecs->event_thread->stepping_over_breakpoint = 1;
4504 else if (step_through_delay)
4506 /* The user issued a step when stopped at a breakpoint.
4507 Maybe we should stop, maybe we should not - the delay
4508 slot *might* correspond to a line of source. In any
4509 case, don't decide that here, just set
4510 ecs->stepping_over_breakpoint, making sure we
4511 single-step again before breakpoints are re-inserted. */
4512 ecs->event_thread->stepping_over_breakpoint = 1;
4516 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
4517 handles this event. */
4518 ecs->event_thread->control.stop_bpstat
4519 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
4520 stop_pc, ecs->ptid, &ecs->ws);
4522 /* Following in case break condition called a
4524 stop_print_frame = 1;
4526 /* This is where we handle "moribund" watchpoints. Unlike
4527 software breakpoints traps, hardware watchpoint traps are
4528 always distinguishable from random traps. If no high-level
4529 watchpoint is associated with the reported stop data address
4530 anymore, then the bpstat does not explain the signal ---
4531 simply make sure to ignore it if `stopped_by_watchpoint' is
4535 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
4536 && !bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
4538 && stopped_by_watchpoint)
4539 fprintf_unfiltered (gdb_stdlog,
4540 "infrun: no user watchpoint explains "
4541 "watchpoint SIGTRAP, ignoring\n");
4543 /* NOTE: cagney/2003-03-29: These checks for a random signal
4544 at one stage in the past included checks for an inferior
4545 function call's call dummy's return breakpoint. The original
4546 comment, that went with the test, read:
4548 ``End of a stack dummy. Some systems (e.g. Sony news) give
4549 another signal besides SIGTRAP, so check here as well as
4552 If someone ever tries to get call dummys on a
4553 non-executable stack to work (where the target would stop
4554 with something like a SIGSEGV), then those tests might need
4555 to be re-instated. Given, however, that the tests were only
4556 enabled when momentary breakpoints were not being used, I
4557 suspect that it won't be the case.
4559 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
4560 be necessary for call dummies on a non-executable stack on
4563 /* See if the breakpoints module can explain the signal. */
4565 = !bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
4566 ecs->event_thread->suspend.stop_signal);
4568 /* Maybe this was a trap for a software breakpoint that has since
4570 if (random_signal && target_stopped_by_sw_breakpoint ())
4572 if (program_breakpoint_here_p (gdbarch, stop_pc))
4574 struct regcache *regcache;
4577 /* Re-adjust PC to what the program would see if GDB was not
4579 regcache = get_thread_regcache (ecs->event_thread->ptid);
4580 decr_pc = gdbarch_decr_pc_after_break (gdbarch);
4583 struct cleanup *old_cleanups = make_cleanup (null_cleanup, NULL);
4585 if (record_full_is_used ())
4586 record_full_gdb_operation_disable_set ();
4588 regcache_write_pc (regcache, stop_pc + decr_pc);
4590 do_cleanups (old_cleanups);
4595 /* A delayed software breakpoint event. Ignore the trap. */
4597 fprintf_unfiltered (gdb_stdlog,
4598 "infrun: delayed software breakpoint "
4599 "trap, ignoring\n");
4604 /* Maybe this was a trap for a hardware breakpoint/watchpoint that
4605 has since been removed. */
4606 if (random_signal && target_stopped_by_hw_breakpoint ())
4608 /* A delayed hardware breakpoint event. Ignore the trap. */
4610 fprintf_unfiltered (gdb_stdlog,
4611 "infrun: delayed hardware breakpoint/watchpoint "
4612 "trap, ignoring\n");
4616 /* If not, perhaps stepping/nexting can. */
4618 random_signal = !(ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
4619 && currently_stepping (ecs->event_thread));
4621 /* Perhaps the thread hit a single-step breakpoint of _another_
4622 thread. Single-step breakpoints are transparent to the
4623 breakpoints module. */
4625 random_signal = !ecs->hit_singlestep_breakpoint;
4627 /* No? Perhaps we got a moribund watchpoint. */
4629 random_signal = !stopped_by_watchpoint;
4631 /* For the program's own signals, act according to
4632 the signal handling tables. */
4636 /* Signal not for debugging purposes. */
4637 struct inferior *inf = find_inferior_ptid (ecs->ptid);
4638 enum gdb_signal stop_signal = ecs->event_thread->suspend.stop_signal;
4641 fprintf_unfiltered (gdb_stdlog, "infrun: random signal (%s)\n",
4642 gdb_signal_to_symbol_string (stop_signal));
4644 stopped_by_random_signal = 1;
4646 /* Always stop on signals if we're either just gaining control
4647 of the program, or the user explicitly requested this thread
4648 to remain stopped. */
4649 if (stop_soon != NO_STOP_QUIETLY
4650 || ecs->event_thread->stop_requested
4652 && signal_stop_state (ecs->event_thread->suspend.stop_signal)))
4658 /* Notify observers the signal has "handle print" set. Note we
4659 returned early above if stopping; normal_stop handles the
4660 printing in that case. */
4661 if (signal_print[ecs->event_thread->suspend.stop_signal])
4663 /* The signal table tells us to print about this signal. */
4664 target_terminal_ours_for_output ();
4665 observer_notify_signal_received (ecs->event_thread->suspend.stop_signal);
4666 target_terminal_inferior ();
4669 /* Clear the signal if it should not be passed. */
4670 if (signal_program[ecs->event_thread->suspend.stop_signal] == 0)
4671 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
4673 if (ecs->event_thread->prev_pc == stop_pc
4674 && ecs->event_thread->control.trap_expected
4675 && ecs->event_thread->control.step_resume_breakpoint == NULL)
4677 /* We were just starting a new sequence, attempting to
4678 single-step off of a breakpoint and expecting a SIGTRAP.
4679 Instead this signal arrives. This signal will take us out
4680 of the stepping range so GDB needs to remember to, when
4681 the signal handler returns, resume stepping off that
4683 /* To simplify things, "continue" is forced to use the same
4684 code paths as single-step - set a breakpoint at the
4685 signal return address and then, once hit, step off that
4688 fprintf_unfiltered (gdb_stdlog,
4689 "infrun: signal arrived while stepping over "
4692 insert_hp_step_resume_breakpoint_at_frame (frame);
4693 ecs->event_thread->step_after_step_resume_breakpoint = 1;
4694 /* Reset trap_expected to ensure breakpoints are re-inserted. */
4695 ecs->event_thread->control.trap_expected = 0;
4697 /* If we were nexting/stepping some other thread, switch to
4698 it, so that we don't continue it, losing control. */
4699 if (!switch_back_to_stepped_thread (ecs))
4704 if (ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_0
4705 && (pc_in_thread_step_range (stop_pc, ecs->event_thread)
4706 || ecs->event_thread->control.step_range_end == 1)
4707 && frame_id_eq (get_stack_frame_id (frame),
4708 ecs->event_thread->control.step_stack_frame_id)
4709 && ecs->event_thread->control.step_resume_breakpoint == NULL)
4711 /* The inferior is about to take a signal that will take it
4712 out of the single step range. Set a breakpoint at the
4713 current PC (which is presumably where the signal handler
4714 will eventually return) and then allow the inferior to
4717 Note that this is only needed for a signal delivered
4718 while in the single-step range. Nested signals aren't a
4719 problem as they eventually all return. */
4721 fprintf_unfiltered (gdb_stdlog,
4722 "infrun: signal may take us out of "
4723 "single-step range\n");
4725 insert_hp_step_resume_breakpoint_at_frame (frame);
4726 ecs->event_thread->step_after_step_resume_breakpoint = 1;
4727 /* Reset trap_expected to ensure breakpoints are re-inserted. */
4728 ecs->event_thread->control.trap_expected = 0;
4733 /* Note: step_resume_breakpoint may be non-NULL. This occures
4734 when either there's a nested signal, or when there's a
4735 pending signal enabled just as the signal handler returns
4736 (leaving the inferior at the step-resume-breakpoint without
4737 actually executing it). Either way continue until the
4738 breakpoint is really hit. */
4740 if (!switch_back_to_stepped_thread (ecs))
4743 fprintf_unfiltered (gdb_stdlog,
4744 "infrun: random signal, keep going\n");
4751 process_event_stop_test (ecs);
4754 /* Come here when we've got some debug event / signal we can explain
4755 (IOW, not a random signal), and test whether it should cause a
4756 stop, or whether we should resume the inferior (transparently).
4757 E.g., could be a breakpoint whose condition evaluates false; we
4758 could be still stepping within the line; etc. */
4761 process_event_stop_test (struct execution_control_state *ecs)
4763 struct symtab_and_line stop_pc_sal;
4764 struct frame_info *frame;
4765 struct gdbarch *gdbarch;
4766 CORE_ADDR jmp_buf_pc;
4767 struct bpstat_what what;
4769 /* Handle cases caused by hitting a breakpoint. */
4771 frame = get_current_frame ();
4772 gdbarch = get_frame_arch (frame);
4774 what = bpstat_what (ecs->event_thread->control.stop_bpstat);
4776 if (what.call_dummy)
4778 stop_stack_dummy = what.call_dummy;
4781 /* If we hit an internal event that triggers symbol changes, the
4782 current frame will be invalidated within bpstat_what (e.g., if we
4783 hit an internal solib event). Re-fetch it. */
4784 frame = get_current_frame ();
4785 gdbarch = get_frame_arch (frame);
4787 switch (what.main_action)
4789 case BPSTAT_WHAT_SET_LONGJMP_RESUME:
4790 /* If we hit the breakpoint at longjmp while stepping, we
4791 install a momentary breakpoint at the target of the
4795 fprintf_unfiltered (gdb_stdlog,
4796 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME\n");
4798 ecs->event_thread->stepping_over_breakpoint = 1;
4800 if (what.is_longjmp)
4802 struct value *arg_value;
4804 /* If we set the longjmp breakpoint via a SystemTap probe,
4805 then use it to extract the arguments. The destination PC
4806 is the third argument to the probe. */
4807 arg_value = probe_safe_evaluate_at_pc (frame, 2);
4810 jmp_buf_pc = value_as_address (arg_value);
4811 jmp_buf_pc = gdbarch_addr_bits_remove (gdbarch, jmp_buf_pc);
4813 else if (!gdbarch_get_longjmp_target_p (gdbarch)
4814 || !gdbarch_get_longjmp_target (gdbarch,
4815 frame, &jmp_buf_pc))
4818 fprintf_unfiltered (gdb_stdlog,
4819 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME "
4820 "(!gdbarch_get_longjmp_target)\n");
4825 /* Insert a breakpoint at resume address. */
4826 insert_longjmp_resume_breakpoint (gdbarch, jmp_buf_pc);
4829 check_exception_resume (ecs, frame);
4833 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME:
4835 struct frame_info *init_frame;
4837 /* There are several cases to consider.
4839 1. The initiating frame no longer exists. In this case we
4840 must stop, because the exception or longjmp has gone too
4843 2. The initiating frame exists, and is the same as the
4844 current frame. We stop, because the exception or longjmp
4847 3. The initiating frame exists and is different from the
4848 current frame. This means the exception or longjmp has
4849 been caught beneath the initiating frame, so keep going.
4851 4. longjmp breakpoint has been placed just to protect
4852 against stale dummy frames and user is not interested in
4853 stopping around longjmps. */
4856 fprintf_unfiltered (gdb_stdlog,
4857 "infrun: BPSTAT_WHAT_CLEAR_LONGJMP_RESUME\n");
4859 gdb_assert (ecs->event_thread->control.exception_resume_breakpoint
4861 delete_exception_resume_breakpoint (ecs->event_thread);
4863 if (what.is_longjmp)
4865 check_longjmp_breakpoint_for_call_dummy (ecs->event_thread);
4867 if (!frame_id_p (ecs->event_thread->initiating_frame))
4875 init_frame = frame_find_by_id (ecs->event_thread->initiating_frame);
4879 struct frame_id current_id
4880 = get_frame_id (get_current_frame ());
4881 if (frame_id_eq (current_id,
4882 ecs->event_thread->initiating_frame))
4884 /* Case 2. Fall through. */
4894 /* For Cases 1 and 2, remove the step-resume breakpoint, if it
4896 delete_step_resume_breakpoint (ecs->event_thread);
4898 end_stepping_range (ecs);
4902 case BPSTAT_WHAT_SINGLE:
4904 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_SINGLE\n");
4905 ecs->event_thread->stepping_over_breakpoint = 1;
4906 /* Still need to check other stuff, at least the case where we
4907 are stepping and step out of the right range. */
4910 case BPSTAT_WHAT_STEP_RESUME:
4912 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STEP_RESUME\n");
4914 delete_step_resume_breakpoint (ecs->event_thread);
4915 if (ecs->event_thread->control.proceed_to_finish
4916 && execution_direction == EXEC_REVERSE)
4918 struct thread_info *tp = ecs->event_thread;
4920 /* We are finishing a function in reverse, and just hit the
4921 step-resume breakpoint at the start address of the
4922 function, and we're almost there -- just need to back up
4923 by one more single-step, which should take us back to the
4925 tp->control.step_range_start = tp->control.step_range_end = 1;
4929 fill_in_stop_func (gdbarch, ecs);
4930 if (stop_pc == ecs->stop_func_start
4931 && execution_direction == EXEC_REVERSE)
4933 /* We are stepping over a function call in reverse, and just
4934 hit the step-resume breakpoint at the start address of
4935 the function. Go back to single-stepping, which should
4936 take us back to the function call. */
4937 ecs->event_thread->stepping_over_breakpoint = 1;
4943 case BPSTAT_WHAT_STOP_NOISY:
4945 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_NOISY\n");
4946 stop_print_frame = 1;
4948 /* Assume the thread stopped for a breapoint. We'll still check
4949 whether a/the breakpoint is there when the thread is next
4951 ecs->event_thread->stepping_over_breakpoint = 1;
4956 case BPSTAT_WHAT_STOP_SILENT:
4958 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_SILENT\n");
4959 stop_print_frame = 0;
4961 /* Assume the thread stopped for a breapoint. We'll still check
4962 whether a/the breakpoint is there when the thread is next
4964 ecs->event_thread->stepping_over_breakpoint = 1;
4968 case BPSTAT_WHAT_HP_STEP_RESUME:
4970 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_HP_STEP_RESUME\n");
4972 delete_step_resume_breakpoint (ecs->event_thread);
4973 if (ecs->event_thread->step_after_step_resume_breakpoint)
4975 /* Back when the step-resume breakpoint was inserted, we
4976 were trying to single-step off a breakpoint. Go back to
4978 ecs->event_thread->step_after_step_resume_breakpoint = 0;
4979 ecs->event_thread->stepping_over_breakpoint = 1;
4985 case BPSTAT_WHAT_KEEP_CHECKING:
4989 /* If we stepped a permanent breakpoint and we had a high priority
4990 step-resume breakpoint for the address we stepped, but we didn't
4991 hit it, then we must have stepped into the signal handler. The
4992 step-resume was only necessary to catch the case of _not_
4993 stepping into the handler, so delete it, and fall through to
4994 checking whether the step finished. */
4995 if (ecs->event_thread->stepped_breakpoint)
4997 struct breakpoint *sr_bp
4998 = ecs->event_thread->control.step_resume_breakpoint;
5001 && sr_bp->loc->permanent
5002 && sr_bp->type == bp_hp_step_resume
5003 && sr_bp->loc->address == ecs->event_thread->prev_pc)
5006 fprintf_unfiltered (gdb_stdlog,
5007 "infrun: stepped permanent breakpoint, stopped in "
5009 delete_step_resume_breakpoint (ecs->event_thread);
5010 ecs->event_thread->step_after_step_resume_breakpoint = 0;
5014 /* We come here if we hit a breakpoint but should not stop for it.
5015 Possibly we also were stepping and should stop for that. So fall
5016 through and test for stepping. But, if not stepping, do not
5019 /* In all-stop mode, if we're currently stepping but have stopped in
5020 some other thread, we need to switch back to the stepped thread. */
5021 if (switch_back_to_stepped_thread (ecs))
5024 if (ecs->event_thread->control.step_resume_breakpoint)
5027 fprintf_unfiltered (gdb_stdlog,
5028 "infrun: step-resume breakpoint is inserted\n");
5030 /* Having a step-resume breakpoint overrides anything
5031 else having to do with stepping commands until
5032 that breakpoint is reached. */
5037 if (ecs->event_thread->control.step_range_end == 0)
5040 fprintf_unfiltered (gdb_stdlog, "infrun: no stepping, continue\n");
5041 /* Likewise if we aren't even stepping. */
5046 /* Re-fetch current thread's frame in case the code above caused
5047 the frame cache to be re-initialized, making our FRAME variable
5048 a dangling pointer. */
5049 frame = get_current_frame ();
5050 gdbarch = get_frame_arch (frame);
5051 fill_in_stop_func (gdbarch, ecs);
5053 /* If stepping through a line, keep going if still within it.
5055 Note that step_range_end is the address of the first instruction
5056 beyond the step range, and NOT the address of the last instruction
5059 Note also that during reverse execution, we may be stepping
5060 through a function epilogue and therefore must detect when
5061 the current-frame changes in the middle of a line. */
5063 if (pc_in_thread_step_range (stop_pc, ecs->event_thread)
5064 && (execution_direction != EXEC_REVERSE
5065 || frame_id_eq (get_frame_id (frame),
5066 ecs->event_thread->control.step_frame_id)))
5070 (gdb_stdlog, "infrun: stepping inside range [%s-%s]\n",
5071 paddress (gdbarch, ecs->event_thread->control.step_range_start),
5072 paddress (gdbarch, ecs->event_thread->control.step_range_end));
5074 /* Tentatively re-enable range stepping; `resume' disables it if
5075 necessary (e.g., if we're stepping over a breakpoint or we
5076 have software watchpoints). */
5077 ecs->event_thread->control.may_range_step = 1;
5079 /* When stepping backward, stop at beginning of line range
5080 (unless it's the function entry point, in which case
5081 keep going back to the call point). */
5082 if (stop_pc == ecs->event_thread->control.step_range_start
5083 && stop_pc != ecs->stop_func_start
5084 && execution_direction == EXEC_REVERSE)
5085 end_stepping_range (ecs);
5092 /* We stepped out of the stepping range. */
5094 /* If we are stepping at the source level and entered the runtime
5095 loader dynamic symbol resolution code...
5097 EXEC_FORWARD: we keep on single stepping until we exit the run
5098 time loader code and reach the callee's address.
5100 EXEC_REVERSE: we've already executed the callee (backward), and
5101 the runtime loader code is handled just like any other
5102 undebuggable function call. Now we need only keep stepping
5103 backward through the trampoline code, and that's handled further
5104 down, so there is nothing for us to do here. */
5106 if (execution_direction != EXEC_REVERSE
5107 && ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
5108 && in_solib_dynsym_resolve_code (stop_pc))
5110 CORE_ADDR pc_after_resolver =
5111 gdbarch_skip_solib_resolver (gdbarch, stop_pc);
5114 fprintf_unfiltered (gdb_stdlog,
5115 "infrun: stepped into dynsym resolve code\n");
5117 if (pc_after_resolver)
5119 /* Set up a step-resume breakpoint at the address
5120 indicated by SKIP_SOLIB_RESOLVER. */
5121 struct symtab_and_line sr_sal;
5124 sr_sal.pc = pc_after_resolver;
5125 sr_sal.pspace = get_frame_program_space (frame);
5127 insert_step_resume_breakpoint_at_sal (gdbarch,
5128 sr_sal, null_frame_id);
5135 if (ecs->event_thread->control.step_range_end != 1
5136 && (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
5137 || ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
5138 && get_frame_type (frame) == SIGTRAMP_FRAME)
5141 fprintf_unfiltered (gdb_stdlog,
5142 "infrun: stepped into signal trampoline\n");
5143 /* The inferior, while doing a "step" or "next", has ended up in
5144 a signal trampoline (either by a signal being delivered or by
5145 the signal handler returning). Just single-step until the
5146 inferior leaves the trampoline (either by calling the handler
5152 /* If we're in the return path from a shared library trampoline,
5153 we want to proceed through the trampoline when stepping. */
5154 /* macro/2012-04-25: This needs to come before the subroutine
5155 call check below as on some targets return trampolines look
5156 like subroutine calls (MIPS16 return thunks). */
5157 if (gdbarch_in_solib_return_trampoline (gdbarch,
5158 stop_pc, ecs->stop_func_name)
5159 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE)
5161 /* Determine where this trampoline returns. */
5162 CORE_ADDR real_stop_pc;
5164 real_stop_pc = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc);
5167 fprintf_unfiltered (gdb_stdlog,
5168 "infrun: stepped into solib return tramp\n");
5170 /* Only proceed through if we know where it's going. */
5173 /* And put the step-breakpoint there and go until there. */
5174 struct symtab_and_line sr_sal;
5176 init_sal (&sr_sal); /* initialize to zeroes */
5177 sr_sal.pc = real_stop_pc;
5178 sr_sal.section = find_pc_overlay (sr_sal.pc);
5179 sr_sal.pspace = get_frame_program_space (frame);
5181 /* Do not specify what the fp should be when we stop since
5182 on some machines the prologue is where the new fp value
5184 insert_step_resume_breakpoint_at_sal (gdbarch,
5185 sr_sal, null_frame_id);
5187 /* Restart without fiddling with the step ranges or
5194 /* Check for subroutine calls. The check for the current frame
5195 equalling the step ID is not necessary - the check of the
5196 previous frame's ID is sufficient - but it is a common case and
5197 cheaper than checking the previous frame's ID.
5199 NOTE: frame_id_eq will never report two invalid frame IDs as
5200 being equal, so to get into this block, both the current and
5201 previous frame must have valid frame IDs. */
5202 /* The outer_frame_id check is a heuristic to detect stepping
5203 through startup code. If we step over an instruction which
5204 sets the stack pointer from an invalid value to a valid value,
5205 we may detect that as a subroutine call from the mythical
5206 "outermost" function. This could be fixed by marking
5207 outermost frames as !stack_p,code_p,special_p. Then the
5208 initial outermost frame, before sp was valid, would
5209 have code_addr == &_start. See the comment in frame_id_eq
5211 if (!frame_id_eq (get_stack_frame_id (frame),
5212 ecs->event_thread->control.step_stack_frame_id)
5213 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
5214 ecs->event_thread->control.step_stack_frame_id)
5215 && (!frame_id_eq (ecs->event_thread->control.step_stack_frame_id,
5217 || (ecs->event_thread->control.step_start_function
5218 != find_pc_function (stop_pc)))))
5220 CORE_ADDR real_stop_pc;
5223 fprintf_unfiltered (gdb_stdlog, "infrun: stepped into subroutine\n");
5225 if (ecs->event_thread->control.step_over_calls == STEP_OVER_NONE)
5227 /* I presume that step_over_calls is only 0 when we're
5228 supposed to be stepping at the assembly language level
5229 ("stepi"). Just stop. */
5230 /* And this works the same backward as frontward. MVS */
5231 end_stepping_range (ecs);
5235 /* Reverse stepping through solib trampolines. */
5237 if (execution_direction == EXEC_REVERSE
5238 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE
5239 && (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc)
5240 || (ecs->stop_func_start == 0
5241 && in_solib_dynsym_resolve_code (stop_pc))))
5243 /* Any solib trampoline code can be handled in reverse
5244 by simply continuing to single-step. We have already
5245 executed the solib function (backwards), and a few
5246 steps will take us back through the trampoline to the
5252 if (ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
5254 /* We're doing a "next".
5256 Normal (forward) execution: set a breakpoint at the
5257 callee's return address (the address at which the caller
5260 Reverse (backward) execution. set the step-resume
5261 breakpoint at the start of the function that we just
5262 stepped into (backwards), and continue to there. When we
5263 get there, we'll need to single-step back to the caller. */
5265 if (execution_direction == EXEC_REVERSE)
5267 /* If we're already at the start of the function, we've either
5268 just stepped backward into a single instruction function,
5269 or stepped back out of a signal handler to the first instruction
5270 of the function. Just keep going, which will single-step back
5272 if (ecs->stop_func_start != stop_pc && ecs->stop_func_start != 0)
5274 struct symtab_and_line sr_sal;
5276 /* Normal function call return (static or dynamic). */
5278 sr_sal.pc = ecs->stop_func_start;
5279 sr_sal.pspace = get_frame_program_space (frame);
5280 insert_step_resume_breakpoint_at_sal (gdbarch,
5281 sr_sal, null_frame_id);
5285 insert_step_resume_breakpoint_at_caller (frame);
5291 /* If we are in a function call trampoline (a stub between the
5292 calling routine and the real function), locate the real
5293 function. That's what tells us (a) whether we want to step
5294 into it at all, and (b) what prologue we want to run to the
5295 end of, if we do step into it. */
5296 real_stop_pc = skip_language_trampoline (frame, stop_pc);
5297 if (real_stop_pc == 0)
5298 real_stop_pc = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc);
5299 if (real_stop_pc != 0)
5300 ecs->stop_func_start = real_stop_pc;
5302 if (real_stop_pc != 0 && in_solib_dynsym_resolve_code (real_stop_pc))
5304 struct symtab_and_line sr_sal;
5307 sr_sal.pc = ecs->stop_func_start;
5308 sr_sal.pspace = get_frame_program_space (frame);
5310 insert_step_resume_breakpoint_at_sal (gdbarch,
5311 sr_sal, null_frame_id);
5316 /* If we have line number information for the function we are
5317 thinking of stepping into and the function isn't on the skip
5320 If there are several symtabs at that PC (e.g. with include
5321 files), just want to know whether *any* of them have line
5322 numbers. find_pc_line handles this. */
5324 struct symtab_and_line tmp_sal;
5326 tmp_sal = find_pc_line (ecs->stop_func_start, 0);
5327 if (tmp_sal.line != 0
5328 && !function_name_is_marked_for_skip (ecs->stop_func_name,
5331 if (execution_direction == EXEC_REVERSE)
5332 handle_step_into_function_backward (gdbarch, ecs);
5334 handle_step_into_function (gdbarch, ecs);
5339 /* If we have no line number and the step-stop-if-no-debug is
5340 set, we stop the step so that the user has a chance to switch
5341 in assembly mode. */
5342 if (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
5343 && step_stop_if_no_debug)
5345 end_stepping_range (ecs);
5349 if (execution_direction == EXEC_REVERSE)
5351 /* If we're already at the start of the function, we've either just
5352 stepped backward into a single instruction function without line
5353 number info, or stepped back out of a signal handler to the first
5354 instruction of the function without line number info. Just keep
5355 going, which will single-step back to the caller. */
5356 if (ecs->stop_func_start != stop_pc)
5358 /* Set a breakpoint at callee's start address.
5359 From there we can step once and be back in the caller. */
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);
5370 /* Set a breakpoint at callee's return address (the address
5371 at which the caller will resume). */
5372 insert_step_resume_breakpoint_at_caller (frame);
5378 /* Reverse stepping through solib trampolines. */
5380 if (execution_direction == EXEC_REVERSE
5381 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE)
5383 if (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc)
5384 || (ecs->stop_func_start == 0
5385 && in_solib_dynsym_resolve_code (stop_pc)))
5387 /* Any solib trampoline code can be handled in reverse
5388 by simply continuing to single-step. We have already
5389 executed the solib function (backwards), and a few
5390 steps will take us back through the trampoline to the
5395 else if (in_solib_dynsym_resolve_code (stop_pc))
5397 /* Stepped backward into the solib dynsym resolver.
5398 Set a breakpoint at its start and continue, then
5399 one more step will take us out. */
5400 struct symtab_and_line sr_sal;
5403 sr_sal.pc = ecs->stop_func_start;
5404 sr_sal.pspace = get_frame_program_space (frame);
5405 insert_step_resume_breakpoint_at_sal (gdbarch,
5406 sr_sal, null_frame_id);
5412 stop_pc_sal = find_pc_line (stop_pc, 0);
5414 /* NOTE: tausq/2004-05-24: This if block used to be done before all
5415 the trampoline processing logic, however, there are some trampolines
5416 that have no names, so we should do trampoline handling first. */
5417 if (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
5418 && ecs->stop_func_name == NULL
5419 && stop_pc_sal.line == 0)
5422 fprintf_unfiltered (gdb_stdlog,
5423 "infrun: stepped into undebuggable function\n");
5425 /* The inferior just stepped into, or returned to, an
5426 undebuggable function (where there is no debugging information
5427 and no line number corresponding to the address where the
5428 inferior stopped). Since we want to skip this kind of code,
5429 we keep going until the inferior returns from this
5430 function - unless the user has asked us not to (via
5431 set step-mode) or we no longer know how to get back
5432 to the call site. */
5433 if (step_stop_if_no_debug
5434 || !frame_id_p (frame_unwind_caller_id (frame)))
5436 /* If we have no line number and the step-stop-if-no-debug
5437 is set, we stop the step so that the user has a chance to
5438 switch in assembly mode. */
5439 end_stepping_range (ecs);
5444 /* Set a breakpoint at callee's return address (the address
5445 at which the caller will resume). */
5446 insert_step_resume_breakpoint_at_caller (frame);
5452 if (ecs->event_thread->control.step_range_end == 1)
5454 /* It is stepi or nexti. We always want to stop stepping after
5457 fprintf_unfiltered (gdb_stdlog, "infrun: stepi/nexti\n");
5458 end_stepping_range (ecs);
5462 if (stop_pc_sal.line == 0)
5464 /* We have no line number information. That means to stop
5465 stepping (does this always happen right after one instruction,
5466 when we do "s" in a function with no line numbers,
5467 or can this happen as a result of a return or longjmp?). */
5469 fprintf_unfiltered (gdb_stdlog, "infrun: no line number info\n");
5470 end_stepping_range (ecs);
5474 /* Look for "calls" to inlined functions, part one. If the inline
5475 frame machinery detected some skipped call sites, we have entered
5476 a new inline function. */
5478 if (frame_id_eq (get_frame_id (get_current_frame ()),
5479 ecs->event_thread->control.step_frame_id)
5480 && inline_skipped_frames (ecs->ptid))
5482 struct symtab_and_line call_sal;
5485 fprintf_unfiltered (gdb_stdlog,
5486 "infrun: stepped into inlined function\n");
5488 find_frame_sal (get_current_frame (), &call_sal);
5490 if (ecs->event_thread->control.step_over_calls != STEP_OVER_ALL)
5492 /* For "step", we're going to stop. But if the call site
5493 for this inlined function is on the same source line as
5494 we were previously stepping, go down into the function
5495 first. Otherwise stop at the call site. */
5497 if (call_sal.line == ecs->event_thread->current_line
5498 && call_sal.symtab == ecs->event_thread->current_symtab)
5499 step_into_inline_frame (ecs->ptid);
5501 end_stepping_range (ecs);
5506 /* For "next", we should stop at the call site if it is on a
5507 different source line. Otherwise continue through the
5508 inlined function. */
5509 if (call_sal.line == ecs->event_thread->current_line
5510 && call_sal.symtab == ecs->event_thread->current_symtab)
5513 end_stepping_range (ecs);
5518 /* Look for "calls" to inlined functions, part two. If we are still
5519 in the same real function we were stepping through, but we have
5520 to go further up to find the exact frame ID, we are stepping
5521 through a more inlined call beyond its call site. */
5523 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
5524 && !frame_id_eq (get_frame_id (get_current_frame ()),
5525 ecs->event_thread->control.step_frame_id)
5526 && stepped_in_from (get_current_frame (),
5527 ecs->event_thread->control.step_frame_id))
5530 fprintf_unfiltered (gdb_stdlog,
5531 "infrun: stepping through inlined function\n");
5533 if (ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
5536 end_stepping_range (ecs);
5540 if ((stop_pc == stop_pc_sal.pc)
5541 && (ecs->event_thread->current_line != stop_pc_sal.line
5542 || ecs->event_thread->current_symtab != stop_pc_sal.symtab))
5544 /* We are at the start of a different line. So stop. Note that
5545 we don't stop if we step into the middle of a different line.
5546 That is said to make things like for (;;) statements work
5549 fprintf_unfiltered (gdb_stdlog,
5550 "infrun: stepped to a different line\n");
5551 end_stepping_range (ecs);
5555 /* We aren't done stepping.
5557 Optimize by setting the stepping range to the line.
5558 (We might not be in the original line, but if we entered a
5559 new line in mid-statement, we continue stepping. This makes
5560 things like for(;;) statements work better.) */
5562 ecs->event_thread->control.step_range_start = stop_pc_sal.pc;
5563 ecs->event_thread->control.step_range_end = stop_pc_sal.end;
5564 ecs->event_thread->control.may_range_step = 1;
5565 set_step_info (frame, stop_pc_sal);
5568 fprintf_unfiltered (gdb_stdlog, "infrun: keep going\n");
5572 /* In all-stop mode, if we're currently stepping but have stopped in
5573 some other thread, we may need to switch back to the stepped
5574 thread. Returns true we set the inferior running, false if we left
5575 it stopped (and the event needs further processing). */
5578 switch_back_to_stepped_thread (struct execution_control_state *ecs)
5582 struct thread_info *tp;
5583 struct thread_info *stepping_thread;
5584 struct thread_info *step_over;
5586 /* If any thread is blocked on some internal breakpoint, and we
5587 simply need to step over that breakpoint to get it going
5588 again, do that first. */
5590 /* However, if we see an event for the stepping thread, then we
5591 know all other threads have been moved past their breakpoints
5592 already. Let the caller check whether the step is finished,
5593 etc., before deciding to move it past a breakpoint. */
5594 if (ecs->event_thread->control.step_range_end != 0)
5597 /* Check if the current thread is blocked on an incomplete
5598 step-over, interrupted by a random signal. */
5599 if (ecs->event_thread->control.trap_expected
5600 && ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_TRAP)
5604 fprintf_unfiltered (gdb_stdlog,
5605 "infrun: need to finish step-over of [%s]\n",
5606 target_pid_to_str (ecs->event_thread->ptid));
5612 /* Check if the current thread is blocked by a single-step
5613 breakpoint of another thread. */
5614 if (ecs->hit_singlestep_breakpoint)
5618 fprintf_unfiltered (gdb_stdlog,
5619 "infrun: need to step [%s] over single-step "
5621 target_pid_to_str (ecs->ptid));
5627 /* Otherwise, we no longer expect a trap in the current thread.
5628 Clear the trap_expected flag before switching back -- this is
5629 what keep_going does as well, if we call it. */
5630 ecs->event_thread->control.trap_expected = 0;
5632 /* Likewise, clear the signal if it should not be passed. */
5633 if (!signal_program[ecs->event_thread->suspend.stop_signal])
5634 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5636 /* If scheduler locking applies even if not stepping, there's no
5637 need to walk over threads. Above we've checked whether the
5638 current thread is stepping. If some other thread not the
5639 event thread is stepping, then it must be that scheduler
5640 locking is not in effect. */
5641 if (schedlock_applies (ecs->event_thread))
5644 /* Look for the stepping/nexting thread, and check if any other
5645 thread other than the stepping thread needs to start a
5646 step-over. Do all step-overs before actually proceeding with
5648 stepping_thread = NULL;
5650 ALL_NON_EXITED_THREADS (tp)
5652 /* Ignore threads of processes we're not resuming. */
5654 && ptid_get_pid (tp->ptid) != ptid_get_pid (inferior_ptid))
5657 /* When stepping over a breakpoint, we lock all threads
5658 except the one that needs to move past the breakpoint.
5659 If a non-event thread has this set, the "incomplete
5660 step-over" check above should have caught it earlier. */
5661 gdb_assert (!tp->control.trap_expected);
5663 /* Did we find the stepping thread? */
5664 if (tp->control.step_range_end)
5666 /* Yep. There should only one though. */
5667 gdb_assert (stepping_thread == NULL);
5669 /* The event thread is handled at the top, before we
5671 gdb_assert (tp != ecs->event_thread);
5673 /* If some thread other than the event thread is
5674 stepping, then scheduler locking can't be in effect,
5675 otherwise we wouldn't have resumed the current event
5676 thread in the first place. */
5677 gdb_assert (!schedlock_applies (tp));
5679 stepping_thread = tp;
5681 else if (thread_still_needs_step_over (tp))
5685 /* At the top we've returned early if the event thread
5686 is stepping. If some other thread not the event
5687 thread is stepping, then scheduler locking can't be
5688 in effect, and we can resume this thread. No need to
5689 keep looking for the stepping thread then. */
5694 if (step_over != NULL)
5699 fprintf_unfiltered (gdb_stdlog,
5700 "infrun: need to step-over [%s]\n",
5701 target_pid_to_str (tp->ptid));
5704 /* Only the stepping thread should have this set. */
5705 gdb_assert (tp->control.step_range_end == 0);
5707 ecs->ptid = tp->ptid;
5708 ecs->event_thread = tp;
5709 switch_to_thread (ecs->ptid);
5714 if (stepping_thread != NULL)
5716 struct frame_info *frame;
5717 struct gdbarch *gdbarch;
5719 tp = stepping_thread;
5721 /* If the stepping thread exited, then don't try to switch
5722 back and resume it, which could fail in several different
5723 ways depending on the target. Instead, just keep going.
5725 We can find a stepping dead thread in the thread list in
5728 - The target supports thread exit events, and when the
5729 target tries to delete the thread from the thread list,
5730 inferior_ptid pointed at the exiting thread. In such
5731 case, calling delete_thread does not really remove the
5732 thread from the list; instead, the thread is left listed,
5733 with 'exited' state.
5735 - The target's debug interface does not support thread
5736 exit events, and so we have no idea whatsoever if the
5737 previously stepping thread is still alive. For that
5738 reason, we need to synchronously query the target
5740 if (is_exited (tp->ptid)
5741 || !target_thread_alive (tp->ptid))
5744 fprintf_unfiltered (gdb_stdlog,
5745 "infrun: not switching back to "
5746 "stepped thread, it has vanished\n");
5748 delete_thread (tp->ptid);
5754 fprintf_unfiltered (gdb_stdlog,
5755 "infrun: switching back to stepped thread\n");
5757 ecs->event_thread = tp;
5758 ecs->ptid = tp->ptid;
5759 context_switch (ecs->ptid);
5761 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
5762 frame = get_current_frame ();
5763 gdbarch = get_frame_arch (frame);
5765 /* If the PC of the thread we were trying to single-step has
5766 changed, then that thread has trapped or been signaled,
5767 but the event has not been reported to GDB yet. Re-poll
5768 the target looking for this particular thread's event
5769 (i.e. temporarily enable schedlock) by:
5771 - setting a break at the current PC
5772 - resuming that particular thread, only (by setting
5775 This prevents us continuously moving the single-step
5776 breakpoint forward, one instruction at a time,
5779 if (stop_pc != tp->prev_pc)
5784 fprintf_unfiltered (gdb_stdlog,
5785 "infrun: expected thread advanced also\n");
5787 /* Clear the info of the previous step-over, as it's no
5788 longer valid. It's what keep_going would do too, if
5789 we called it. Must do this before trying to insert
5790 the sss breakpoint, otherwise if we were previously
5791 trying to step over this exact address in another
5792 thread, the breakpoint ends up not installed. */
5793 clear_step_over_info ();
5795 insert_single_step_breakpoint (get_frame_arch (frame),
5796 get_frame_address_space (frame),
5799 resume_ptid = user_visible_resume_ptid (tp->control.stepping_command);
5800 do_target_resume (resume_ptid,
5801 currently_stepping (tp), GDB_SIGNAL_0);
5802 prepare_to_wait (ecs);
5807 fprintf_unfiltered (gdb_stdlog,
5808 "infrun: expected thread still "
5809 "hasn't advanced\n");
5819 /* Is thread TP in the middle of single-stepping? */
5822 currently_stepping (struct thread_info *tp)
5824 return ((tp->control.step_range_end
5825 && tp->control.step_resume_breakpoint == NULL)
5826 || tp->control.trap_expected
5827 || tp->stepped_breakpoint
5828 || bpstat_should_step ());
5831 /* Inferior has stepped into a subroutine call with source code that
5832 we should not step over. Do step to the first line of code in
5836 handle_step_into_function (struct gdbarch *gdbarch,
5837 struct execution_control_state *ecs)
5839 struct compunit_symtab *cust;
5840 struct symtab_and_line stop_func_sal, sr_sal;
5842 fill_in_stop_func (gdbarch, ecs);
5844 cust = find_pc_compunit_symtab (stop_pc);
5845 if (cust != NULL && compunit_language (cust) != language_asm)
5846 ecs->stop_func_start = gdbarch_skip_prologue (gdbarch,
5847 ecs->stop_func_start);
5849 stop_func_sal = find_pc_line (ecs->stop_func_start, 0);
5850 /* Use the step_resume_break to step until the end of the prologue,
5851 even if that involves jumps (as it seems to on the vax under
5853 /* If the prologue ends in the middle of a source line, continue to
5854 the end of that source line (if it is still within the function).
5855 Otherwise, just go to end of prologue. */
5856 if (stop_func_sal.end
5857 && stop_func_sal.pc != ecs->stop_func_start
5858 && stop_func_sal.end < ecs->stop_func_end)
5859 ecs->stop_func_start = stop_func_sal.end;
5861 /* Architectures which require breakpoint adjustment might not be able
5862 to place a breakpoint at the computed address. If so, the test
5863 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
5864 ecs->stop_func_start to an address at which a breakpoint may be
5865 legitimately placed.
5867 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
5868 made, GDB will enter an infinite loop when stepping through
5869 optimized code consisting of VLIW instructions which contain
5870 subinstructions corresponding to different source lines. On
5871 FR-V, it's not permitted to place a breakpoint on any but the
5872 first subinstruction of a VLIW instruction. When a breakpoint is
5873 set, GDB will adjust the breakpoint address to the beginning of
5874 the VLIW instruction. Thus, we need to make the corresponding
5875 adjustment here when computing the stop address. */
5877 if (gdbarch_adjust_breakpoint_address_p (gdbarch))
5879 ecs->stop_func_start
5880 = gdbarch_adjust_breakpoint_address (gdbarch,
5881 ecs->stop_func_start);
5884 if (ecs->stop_func_start == stop_pc)
5886 /* We are already there: stop now. */
5887 end_stepping_range (ecs);
5892 /* Put the step-breakpoint there and go until there. */
5893 init_sal (&sr_sal); /* initialize to zeroes */
5894 sr_sal.pc = ecs->stop_func_start;
5895 sr_sal.section = find_pc_overlay (ecs->stop_func_start);
5896 sr_sal.pspace = get_frame_program_space (get_current_frame ());
5898 /* Do not specify what the fp should be when we stop since on
5899 some machines the prologue is where the new fp value is
5901 insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal, null_frame_id);
5903 /* And make sure stepping stops right away then. */
5904 ecs->event_thread->control.step_range_end
5905 = ecs->event_thread->control.step_range_start;
5910 /* Inferior has stepped backward into a subroutine call with source
5911 code that we should not step over. Do step to the beginning of the
5912 last line of code in it. */
5915 handle_step_into_function_backward (struct gdbarch *gdbarch,
5916 struct execution_control_state *ecs)
5918 struct compunit_symtab *cust;
5919 struct symtab_and_line stop_func_sal;
5921 fill_in_stop_func (gdbarch, ecs);
5923 cust = find_pc_compunit_symtab (stop_pc);
5924 if (cust != NULL && compunit_language (cust) != language_asm)
5925 ecs->stop_func_start = gdbarch_skip_prologue (gdbarch,
5926 ecs->stop_func_start);
5928 stop_func_sal = find_pc_line (stop_pc, 0);
5930 /* OK, we're just going to keep stepping here. */
5931 if (stop_func_sal.pc == stop_pc)
5933 /* We're there already. Just stop stepping now. */
5934 end_stepping_range (ecs);
5938 /* Else just reset the step range and keep going.
5939 No step-resume breakpoint, they don't work for
5940 epilogues, which can have multiple entry paths. */
5941 ecs->event_thread->control.step_range_start = stop_func_sal.pc;
5942 ecs->event_thread->control.step_range_end = stop_func_sal.end;
5948 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
5949 This is used to both functions and to skip over code. */
5952 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch *gdbarch,
5953 struct symtab_and_line sr_sal,
5954 struct frame_id sr_id,
5955 enum bptype sr_type)
5957 /* There should never be more than one step-resume or longjmp-resume
5958 breakpoint per thread, so we should never be setting a new
5959 step_resume_breakpoint when one is already active. */
5960 gdb_assert (inferior_thread ()->control.step_resume_breakpoint == NULL);
5961 gdb_assert (sr_type == bp_step_resume || sr_type == bp_hp_step_resume);
5964 fprintf_unfiltered (gdb_stdlog,
5965 "infrun: inserting step-resume breakpoint at %s\n",
5966 paddress (gdbarch, sr_sal.pc));
5968 inferior_thread ()->control.step_resume_breakpoint
5969 = set_momentary_breakpoint (gdbarch, sr_sal, sr_id, sr_type);
5973 insert_step_resume_breakpoint_at_sal (struct gdbarch *gdbarch,
5974 struct symtab_and_line sr_sal,
5975 struct frame_id sr_id)
5977 insert_step_resume_breakpoint_at_sal_1 (gdbarch,
5982 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
5983 This is used to skip a potential signal handler.
5985 This is called with the interrupted function's frame. The signal
5986 handler, when it returns, will resume the interrupted function at
5990 insert_hp_step_resume_breakpoint_at_frame (struct frame_info *return_frame)
5992 struct symtab_and_line sr_sal;
5993 struct gdbarch *gdbarch;
5995 gdb_assert (return_frame != NULL);
5996 init_sal (&sr_sal); /* initialize to zeros */
5998 gdbarch = get_frame_arch (return_frame);
5999 sr_sal.pc = gdbarch_addr_bits_remove (gdbarch, get_frame_pc (return_frame));
6000 sr_sal.section = find_pc_overlay (sr_sal.pc);
6001 sr_sal.pspace = get_frame_program_space (return_frame);
6003 insert_step_resume_breakpoint_at_sal_1 (gdbarch, sr_sal,
6004 get_stack_frame_id (return_frame),
6008 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
6009 is used to skip a function after stepping into it (for "next" or if
6010 the called function has no debugging information).
6012 The current function has almost always been reached by single
6013 stepping a call or return instruction. NEXT_FRAME belongs to the
6014 current function, and the breakpoint will be set at the caller's
6017 This is a separate function rather than reusing
6018 insert_hp_step_resume_breakpoint_at_frame in order to avoid
6019 get_prev_frame, which may stop prematurely (see the implementation
6020 of frame_unwind_caller_id for an example). */
6023 insert_step_resume_breakpoint_at_caller (struct frame_info *next_frame)
6025 struct symtab_and_line sr_sal;
6026 struct gdbarch *gdbarch;
6028 /* We shouldn't have gotten here if we don't know where the call site
6030 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame)));
6032 init_sal (&sr_sal); /* initialize to zeros */
6034 gdbarch = frame_unwind_caller_arch (next_frame);
6035 sr_sal.pc = gdbarch_addr_bits_remove (gdbarch,
6036 frame_unwind_caller_pc (next_frame));
6037 sr_sal.section = find_pc_overlay (sr_sal.pc);
6038 sr_sal.pspace = frame_unwind_program_space (next_frame);
6040 insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal,
6041 frame_unwind_caller_id (next_frame));
6044 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
6045 new breakpoint at the target of a jmp_buf. The handling of
6046 longjmp-resume uses the same mechanisms used for handling
6047 "step-resume" breakpoints. */
6050 insert_longjmp_resume_breakpoint (struct gdbarch *gdbarch, CORE_ADDR pc)
6052 /* There should never be more than one longjmp-resume breakpoint per
6053 thread, so we should never be setting a new
6054 longjmp_resume_breakpoint when one is already active. */
6055 gdb_assert (inferior_thread ()->control.exception_resume_breakpoint == NULL);
6058 fprintf_unfiltered (gdb_stdlog,
6059 "infrun: inserting longjmp-resume breakpoint at %s\n",
6060 paddress (gdbarch, pc));
6062 inferior_thread ()->control.exception_resume_breakpoint =
6063 set_momentary_breakpoint_at_pc (gdbarch, pc, bp_longjmp_resume);
6066 /* Insert an exception resume breakpoint. TP is the thread throwing
6067 the exception. The block B is the block of the unwinder debug hook
6068 function. FRAME is the frame corresponding to the call to this
6069 function. SYM is the symbol of the function argument holding the
6070 target PC of the exception. */
6073 insert_exception_resume_breakpoint (struct thread_info *tp,
6074 const struct block *b,
6075 struct frame_info *frame,
6080 struct symbol *vsym;
6081 struct value *value;
6083 struct breakpoint *bp;
6085 vsym = lookup_symbol (SYMBOL_LINKAGE_NAME (sym), b, VAR_DOMAIN, NULL);
6086 value = read_var_value (vsym, frame);
6087 /* If the value was optimized out, revert to the old behavior. */
6088 if (! value_optimized_out (value))
6090 handler = value_as_address (value);
6093 fprintf_unfiltered (gdb_stdlog,
6094 "infrun: exception resume at %lx\n",
6095 (unsigned long) handler);
6097 bp = set_momentary_breakpoint_at_pc (get_frame_arch (frame),
6098 handler, bp_exception_resume);
6100 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
6103 bp->thread = tp->num;
6104 inferior_thread ()->control.exception_resume_breakpoint = bp;
6107 CATCH (e, RETURN_MASK_ERROR)
6109 /* We want to ignore errors here. */
6114 /* A helper for check_exception_resume that sets an
6115 exception-breakpoint based on a SystemTap probe. */
6118 insert_exception_resume_from_probe (struct thread_info *tp,
6119 const struct bound_probe *probe,
6120 struct frame_info *frame)
6122 struct value *arg_value;
6124 struct breakpoint *bp;
6126 arg_value = probe_safe_evaluate_at_pc (frame, 1);
6130 handler = value_as_address (arg_value);
6133 fprintf_unfiltered (gdb_stdlog,
6134 "infrun: exception resume at %s\n",
6135 paddress (get_objfile_arch (probe->objfile),
6138 bp = set_momentary_breakpoint_at_pc (get_frame_arch (frame),
6139 handler, bp_exception_resume);
6140 bp->thread = tp->num;
6141 inferior_thread ()->control.exception_resume_breakpoint = bp;
6144 /* This is called when an exception has been intercepted. Check to
6145 see whether the exception's destination is of interest, and if so,
6146 set an exception resume breakpoint there. */
6149 check_exception_resume (struct execution_control_state *ecs,
6150 struct frame_info *frame)
6152 struct bound_probe probe;
6153 struct symbol *func;
6155 /* First see if this exception unwinding breakpoint was set via a
6156 SystemTap probe point. If so, the probe has two arguments: the
6157 CFA and the HANDLER. We ignore the CFA, extract the handler, and
6158 set a breakpoint there. */
6159 probe = find_probe_by_pc (get_frame_pc (frame));
6162 insert_exception_resume_from_probe (ecs->event_thread, &probe, frame);
6166 func = get_frame_function (frame);
6172 const struct block *b;
6173 struct block_iterator iter;
6177 /* The exception breakpoint is a thread-specific breakpoint on
6178 the unwinder's debug hook, declared as:
6180 void _Unwind_DebugHook (void *cfa, void *handler);
6182 The CFA argument indicates the frame to which control is
6183 about to be transferred. HANDLER is the destination PC.
6185 We ignore the CFA and set a temporary breakpoint at HANDLER.
6186 This is not extremely efficient but it avoids issues in gdb
6187 with computing the DWARF CFA, and it also works even in weird
6188 cases such as throwing an exception from inside a signal
6191 b = SYMBOL_BLOCK_VALUE (func);
6192 ALL_BLOCK_SYMBOLS (b, iter, sym)
6194 if (!SYMBOL_IS_ARGUMENT (sym))
6201 insert_exception_resume_breakpoint (ecs->event_thread,
6207 CATCH (e, RETURN_MASK_ERROR)
6214 stop_waiting (struct execution_control_state *ecs)
6217 fprintf_unfiltered (gdb_stdlog, "infrun: stop_waiting\n");
6219 clear_step_over_info ();
6221 /* Let callers know we don't want to wait for the inferior anymore. */
6222 ecs->wait_some_more = 0;
6225 /* Called when we should continue running the inferior, because the
6226 current event doesn't cause a user visible stop. This does the
6227 resuming part; waiting for the next event is done elsewhere. */
6230 keep_going (struct execution_control_state *ecs)
6232 /* Make sure normal_stop is called if we get a QUIT handled before
6234 struct cleanup *old_cleanups = make_cleanup (resume_cleanups, 0);
6236 /* Save the pc before execution, to compare with pc after stop. */
6237 ecs->event_thread->prev_pc
6238 = regcache_read_pc (get_thread_regcache (ecs->ptid));
6240 if (ecs->event_thread->control.trap_expected
6241 && ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_TRAP)
6243 /* We haven't yet gotten our trap, and either: intercepted a
6244 non-signal event (e.g., a fork); or took a signal which we
6245 are supposed to pass through to the inferior. Simply
6247 discard_cleanups (old_cleanups);
6248 resume (ecs->event_thread->suspend.stop_signal);
6252 struct regcache *regcache = get_current_regcache ();
6256 /* Either the trap was not expected, but we are continuing
6257 anyway (if we got a signal, the user asked it be passed to
6260 We got our expected trap, but decided we should resume from
6263 We're going to run this baby now!
6265 Note that insert_breakpoints won't try to re-insert
6266 already inserted breakpoints. Therefore, we don't
6267 care if breakpoints were already inserted, or not. */
6269 /* If we need to step over a breakpoint, and we're not using
6270 displaced stepping to do so, insert all breakpoints
6271 (watchpoints, etc.) but the one we're stepping over, step one
6272 instruction, and then re-insert the breakpoint when that step
6275 remove_bp = (ecs->hit_singlestep_breakpoint
6276 || thread_still_needs_step_over (ecs->event_thread));
6277 remove_wps = (ecs->event_thread->stepping_over_watchpoint
6278 && !target_have_steppable_watchpoint);
6280 /* We can't use displaced stepping if we need to step past a
6281 watchpoint. The instruction copied to the scratch pad would
6282 still trigger the watchpoint. */
6285 || !use_displaced_stepping (get_regcache_arch (regcache))))
6287 set_step_over_info (get_regcache_aspace (regcache),
6288 regcache_read_pc (regcache), remove_wps);
6290 else if (remove_wps)
6291 set_step_over_info (NULL, 0, remove_wps);
6293 clear_step_over_info ();
6295 /* Stop stepping if inserting breakpoints fails. */
6298 insert_breakpoints ();
6300 CATCH (e, RETURN_MASK_ERROR)
6302 exception_print (gdb_stderr, e);
6304 discard_cleanups (old_cleanups);
6309 ecs->event_thread->control.trap_expected = (remove_bp || remove_wps);
6311 /* Do not deliver GDB_SIGNAL_TRAP (except when the user
6312 explicitly specifies that such a signal should be delivered
6313 to the target program). Typically, that would occur when a
6314 user is debugging a target monitor on a simulator: the target
6315 monitor sets a breakpoint; the simulator encounters this
6316 breakpoint and halts the simulation handing control to GDB;
6317 GDB, noting that the stop address doesn't map to any known
6318 breakpoint, returns control back to the simulator; the
6319 simulator then delivers the hardware equivalent of a
6320 GDB_SIGNAL_TRAP to the program being debugged. */
6321 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
6322 && !signal_program[ecs->event_thread->suspend.stop_signal])
6323 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
6325 discard_cleanups (old_cleanups);
6326 resume (ecs->event_thread->suspend.stop_signal);
6329 prepare_to_wait (ecs);
6332 /* This function normally comes after a resume, before
6333 handle_inferior_event exits. It takes care of any last bits of
6334 housekeeping, and sets the all-important wait_some_more flag. */
6337 prepare_to_wait (struct execution_control_state *ecs)
6340 fprintf_unfiltered (gdb_stdlog, "infrun: prepare_to_wait\n");
6342 /* This is the old end of the while loop. Let everybody know we
6343 want to wait for the inferior some more and get called again
6345 ecs->wait_some_more = 1;
6348 /* We are done with the step range of a step/next/si/ni command.
6349 Called once for each n of a "step n" operation. */
6352 end_stepping_range (struct execution_control_state *ecs)
6354 ecs->event_thread->control.stop_step = 1;
6358 /* Several print_*_reason functions to print why the inferior has stopped.
6359 We always print something when the inferior exits, or receives a signal.
6360 The rest of the cases are dealt with later on in normal_stop and
6361 print_it_typical. Ideally there should be a call to one of these
6362 print_*_reason functions functions from handle_inferior_event each time
6363 stop_waiting is called.
6365 Note that we don't call these directly, instead we delegate that to
6366 the interpreters, through observers. Interpreters then call these
6367 with whatever uiout is right. */
6370 print_end_stepping_range_reason (struct ui_out *uiout)
6372 /* For CLI-like interpreters, print nothing. */
6374 if (ui_out_is_mi_like_p (uiout))
6376 ui_out_field_string (uiout, "reason",
6377 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE));
6382 print_signal_exited_reason (struct ui_out *uiout, enum gdb_signal siggnal)
6384 annotate_signalled ();
6385 if (ui_out_is_mi_like_p (uiout))
6387 (uiout, "reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED));
6388 ui_out_text (uiout, "\nProgram terminated with signal ");
6389 annotate_signal_name ();
6390 ui_out_field_string (uiout, "signal-name",
6391 gdb_signal_to_name (siggnal));
6392 annotate_signal_name_end ();
6393 ui_out_text (uiout, ", ");
6394 annotate_signal_string ();
6395 ui_out_field_string (uiout, "signal-meaning",
6396 gdb_signal_to_string (siggnal));
6397 annotate_signal_string_end ();
6398 ui_out_text (uiout, ".\n");
6399 ui_out_text (uiout, "The program no longer exists.\n");
6403 print_exited_reason (struct ui_out *uiout, int exitstatus)
6405 struct inferior *inf = current_inferior ();
6406 const char *pidstr = target_pid_to_str (pid_to_ptid (inf->pid));
6408 annotate_exited (exitstatus);
6411 if (ui_out_is_mi_like_p (uiout))
6412 ui_out_field_string (uiout, "reason",
6413 async_reason_lookup (EXEC_ASYNC_EXITED));
6414 ui_out_text (uiout, "[Inferior ");
6415 ui_out_text (uiout, plongest (inf->num));
6416 ui_out_text (uiout, " (");
6417 ui_out_text (uiout, pidstr);
6418 ui_out_text (uiout, ") exited with code ");
6419 ui_out_field_fmt (uiout, "exit-code", "0%o", (unsigned int) exitstatus);
6420 ui_out_text (uiout, "]\n");
6424 if (ui_out_is_mi_like_p (uiout))
6426 (uiout, "reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY));
6427 ui_out_text (uiout, "[Inferior ");
6428 ui_out_text (uiout, plongest (inf->num));
6429 ui_out_text (uiout, " (");
6430 ui_out_text (uiout, pidstr);
6431 ui_out_text (uiout, ") exited normally]\n");
6436 print_signal_received_reason (struct ui_out *uiout, enum gdb_signal siggnal)
6440 if (siggnal == GDB_SIGNAL_0 && !ui_out_is_mi_like_p (uiout))
6442 struct thread_info *t = inferior_thread ();
6444 ui_out_text (uiout, "\n[");
6445 ui_out_field_string (uiout, "thread-name",
6446 target_pid_to_str (t->ptid));
6447 ui_out_field_fmt (uiout, "thread-id", "] #%d", t->num);
6448 ui_out_text (uiout, " stopped");
6452 ui_out_text (uiout, "\nProgram received signal ");
6453 annotate_signal_name ();
6454 if (ui_out_is_mi_like_p (uiout))
6456 (uiout, "reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED));
6457 ui_out_field_string (uiout, "signal-name",
6458 gdb_signal_to_name (siggnal));
6459 annotate_signal_name_end ();
6460 ui_out_text (uiout, ", ");
6461 annotate_signal_string ();
6462 ui_out_field_string (uiout, "signal-meaning",
6463 gdb_signal_to_string (siggnal));
6464 annotate_signal_string_end ();
6466 ui_out_text (uiout, ".\n");
6470 print_no_history_reason (struct ui_out *uiout)
6472 ui_out_text (uiout, "\nNo more reverse-execution history.\n");
6475 /* Print current location without a level number, if we have changed
6476 functions or hit a breakpoint. Print source line if we have one.
6477 bpstat_print contains the logic deciding in detail what to print,
6478 based on the event(s) that just occurred. */
6481 print_stop_event (struct target_waitstatus *ws)
6485 int do_frame_printing = 1;
6486 struct thread_info *tp = inferior_thread ();
6488 bpstat_ret = bpstat_print (tp->control.stop_bpstat, ws->kind);
6492 /* FIXME: cagney/2002-12-01: Given that a frame ID does (or
6493 should) carry around the function and does (or should) use
6494 that when doing a frame comparison. */
6495 if (tp->control.stop_step
6496 && frame_id_eq (tp->control.step_frame_id,
6497 get_frame_id (get_current_frame ()))
6498 && tp->control.step_start_function == find_pc_function (stop_pc))
6500 /* Finished step, just print source line. */
6501 source_flag = SRC_LINE;
6505 /* Print location and source line. */
6506 source_flag = SRC_AND_LOC;
6509 case PRINT_SRC_AND_LOC:
6510 /* Print location and source line. */
6511 source_flag = SRC_AND_LOC;
6513 case PRINT_SRC_ONLY:
6514 source_flag = SRC_LINE;
6517 /* Something bogus. */
6518 source_flag = SRC_LINE;
6519 do_frame_printing = 0;
6522 internal_error (__FILE__, __LINE__, _("Unknown value."));
6525 /* The behavior of this routine with respect to the source
6527 SRC_LINE: Print only source line
6528 LOCATION: Print only location
6529 SRC_AND_LOC: Print location and source line. */
6530 if (do_frame_printing)
6531 print_stack_frame (get_selected_frame (NULL), 0, source_flag, 1);
6533 /* Display the auto-display expressions. */
6537 /* Here to return control to GDB when the inferior stops for real.
6538 Print appropriate messages, remove breakpoints, give terminal our modes.
6540 STOP_PRINT_FRAME nonzero means print the executing frame
6541 (pc, function, args, file, line number and line text).
6542 BREAKPOINTS_FAILED nonzero means stop was due to error
6543 attempting to insert breakpoints. */
6548 struct target_waitstatus last;
6550 struct cleanup *old_chain = make_cleanup (null_cleanup, NULL);
6552 get_last_target_status (&last_ptid, &last);
6554 /* If an exception is thrown from this point on, make sure to
6555 propagate GDB's knowledge of the executing state to the
6556 frontend/user running state. A QUIT is an easy exception to see
6557 here, so do this before any filtered output. */
6559 make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
6560 else if (last.kind != TARGET_WAITKIND_SIGNALLED
6561 && last.kind != TARGET_WAITKIND_EXITED
6562 && last.kind != TARGET_WAITKIND_NO_RESUMED)
6563 make_cleanup (finish_thread_state_cleanup, &inferior_ptid);
6565 /* As we're presenting a stop, and potentially removing breakpoints,
6566 update the thread list so we can tell whether there are threads
6567 running on the target. With target remote, for example, we can
6568 only learn about new threads when we explicitly update the thread
6569 list. Do this before notifying the interpreters about signal
6570 stops, end of stepping ranges, etc., so that the "new thread"
6571 output is emitted before e.g., "Program received signal FOO",
6572 instead of after. */
6573 update_thread_list ();
6575 if (last.kind == TARGET_WAITKIND_STOPPED && stopped_by_random_signal)
6576 observer_notify_signal_received (inferior_thread ()->suspend.stop_signal);
6578 /* As with the notification of thread events, we want to delay
6579 notifying the user that we've switched thread context until
6580 the inferior actually stops.
6582 There's no point in saying anything if the inferior has exited.
6583 Note that SIGNALLED here means "exited with a signal", not
6584 "received a signal".
6586 Also skip saying anything in non-stop mode. In that mode, as we
6587 don't want GDB to switch threads behind the user's back, to avoid
6588 races where the user is typing a command to apply to thread x,
6589 but GDB switches to thread y before the user finishes entering
6590 the command, fetch_inferior_event installs a cleanup to restore
6591 the current thread back to the thread the user had selected right
6592 after this event is handled, so we're not really switching, only
6593 informing of a stop. */
6595 && !ptid_equal (previous_inferior_ptid, inferior_ptid)
6596 && target_has_execution
6597 && last.kind != TARGET_WAITKIND_SIGNALLED
6598 && last.kind != TARGET_WAITKIND_EXITED
6599 && last.kind != TARGET_WAITKIND_NO_RESUMED)
6601 target_terminal_ours_for_output ();
6602 printf_filtered (_("[Switching to %s]\n"),
6603 target_pid_to_str (inferior_ptid));
6604 annotate_thread_changed ();
6605 previous_inferior_ptid = inferior_ptid;
6608 if (last.kind == TARGET_WAITKIND_NO_RESUMED)
6610 gdb_assert (sync_execution || !target_can_async_p ());
6612 target_terminal_ours_for_output ();
6613 printf_filtered (_("No unwaited-for children left.\n"));
6616 /* Note: this depends on the update_thread_list call above. */
6617 if (!breakpoints_should_be_inserted_now () && target_has_execution)
6619 if (remove_breakpoints ())
6621 target_terminal_ours_for_output ();
6622 printf_filtered (_("Cannot remove breakpoints because "
6623 "program is no longer writable.\nFurther "
6624 "execution is probably impossible.\n"));
6628 /* If an auto-display called a function and that got a signal,
6629 delete that auto-display to avoid an infinite recursion. */
6631 if (stopped_by_random_signal)
6632 disable_current_display ();
6634 /* Notify observers if we finished a "step"-like command, etc. */
6635 if (target_has_execution
6636 && last.kind != TARGET_WAITKIND_SIGNALLED
6637 && last.kind != TARGET_WAITKIND_EXITED
6638 && inferior_thread ()->control.stop_step)
6640 /* But not if in the middle of doing a "step n" operation for
6642 if (inferior_thread ()->step_multi)
6645 observer_notify_end_stepping_range ();
6648 target_terminal_ours ();
6649 async_enable_stdin ();
6651 /* Set the current source location. This will also happen if we
6652 display the frame below, but the current SAL will be incorrect
6653 during a user hook-stop function. */
6654 if (has_stack_frames () && !stop_stack_dummy)
6655 set_current_sal_from_frame (get_current_frame ());
6657 /* Let the user/frontend see the threads as stopped, but do nothing
6658 if the thread was running an infcall. We may be e.g., evaluating
6659 a breakpoint condition. In that case, the thread had state
6660 THREAD_RUNNING before the infcall, and shall remain set to
6661 running, all without informing the user/frontend about state
6662 transition changes. If this is actually a call command, then the
6663 thread was originally already stopped, so there's no state to
6665 if (target_has_execution && inferior_thread ()->control.in_infcall)
6666 discard_cleanups (old_chain);
6668 do_cleanups (old_chain);
6670 /* Look up the hook_stop and run it (CLI internally handles problem
6671 of stop_command's pre-hook not existing). */
6673 catch_errors (hook_stop_stub, stop_command,
6674 "Error while running hook_stop:\n", RETURN_MASK_ALL);
6676 if (!has_stack_frames ())
6679 if (last.kind == TARGET_WAITKIND_SIGNALLED
6680 || last.kind == TARGET_WAITKIND_EXITED)
6683 /* Select innermost stack frame - i.e., current frame is frame 0,
6684 and current location is based on that.
6685 Don't do this on return from a stack dummy routine,
6686 or if the program has exited. */
6688 if (!stop_stack_dummy)
6690 select_frame (get_current_frame ());
6692 /* If --batch-silent is enabled then there's no need to print the current
6693 source location, and to try risks causing an error message about
6694 missing source files. */
6695 if (stop_print_frame && !batch_silent)
6696 print_stop_event (&last);
6699 /* Save the function value return registers, if we care.
6700 We might be about to restore their previous contents. */
6701 if (inferior_thread ()->control.proceed_to_finish
6702 && execution_direction != EXEC_REVERSE)
6704 /* This should not be necessary. */
6706 regcache_xfree (stop_registers);
6708 /* NB: The copy goes through to the target picking up the value of
6709 all the registers. */
6710 stop_registers = regcache_dup (get_current_regcache ());
6713 if (stop_stack_dummy == STOP_STACK_DUMMY)
6715 /* Pop the empty frame that contains the stack dummy.
6716 This also restores inferior state prior to the call
6717 (struct infcall_suspend_state). */
6718 struct frame_info *frame = get_current_frame ();
6720 gdb_assert (get_frame_type (frame) == DUMMY_FRAME);
6722 /* frame_pop() calls reinit_frame_cache as the last thing it
6723 does which means there's currently no selected frame. We
6724 don't need to re-establish a selected frame if the dummy call
6725 returns normally, that will be done by
6726 restore_infcall_control_state. However, we do have to handle
6727 the case where the dummy call is returning after being
6728 stopped (e.g. the dummy call previously hit a breakpoint).
6729 We can't know which case we have so just always re-establish
6730 a selected frame here. */
6731 select_frame (get_current_frame ());
6735 annotate_stopped ();
6737 /* Suppress the stop observer if we're in the middle of:
6739 - a step n (n > 1), as there still more steps to be done.
6741 - a "finish" command, as the observer will be called in
6742 finish_command_continuation, so it can include the inferior
6743 function's return value.
6745 - calling an inferior function, as we pretend we inferior didn't
6746 run at all. The return value of the call is handled by the
6747 expression evaluator, through call_function_by_hand. */
6749 if (!target_has_execution
6750 || last.kind == TARGET_WAITKIND_SIGNALLED
6751 || last.kind == TARGET_WAITKIND_EXITED
6752 || last.kind == TARGET_WAITKIND_NO_RESUMED
6753 || (!(inferior_thread ()->step_multi
6754 && inferior_thread ()->control.stop_step)
6755 && !(inferior_thread ()->control.stop_bpstat
6756 && inferior_thread ()->control.proceed_to_finish)
6757 && !inferior_thread ()->control.in_infcall))
6759 if (!ptid_equal (inferior_ptid, null_ptid))
6760 observer_notify_normal_stop (inferior_thread ()->control.stop_bpstat,
6763 observer_notify_normal_stop (NULL, stop_print_frame);
6766 if (target_has_execution)
6768 if (last.kind != TARGET_WAITKIND_SIGNALLED
6769 && last.kind != TARGET_WAITKIND_EXITED)
6770 /* Delete the breakpoint we stopped at, if it wants to be deleted.
6771 Delete any breakpoint that is to be deleted at the next stop. */
6772 breakpoint_auto_delete (inferior_thread ()->control.stop_bpstat);
6775 /* Try to get rid of automatically added inferiors that are no
6776 longer needed. Keeping those around slows down things linearly.
6777 Note that this never removes the current inferior. */
6782 hook_stop_stub (void *cmd)
6784 execute_cmd_pre_hook ((struct cmd_list_element *) cmd);
6789 signal_stop_state (int signo)
6791 return signal_stop[signo];
6795 signal_print_state (int signo)
6797 return signal_print[signo];
6801 signal_pass_state (int signo)
6803 return signal_program[signo];
6807 signal_cache_update (int signo)
6811 for (signo = 0; signo < (int) GDB_SIGNAL_LAST; signo++)
6812 signal_cache_update (signo);
6817 signal_pass[signo] = (signal_stop[signo] == 0
6818 && signal_print[signo] == 0
6819 && signal_program[signo] == 1
6820 && signal_catch[signo] == 0);
6824 signal_stop_update (int signo, int state)
6826 int ret = signal_stop[signo];
6828 signal_stop[signo] = state;
6829 signal_cache_update (signo);
6834 signal_print_update (int signo, int state)
6836 int ret = signal_print[signo];
6838 signal_print[signo] = state;
6839 signal_cache_update (signo);
6844 signal_pass_update (int signo, int state)
6846 int ret = signal_program[signo];
6848 signal_program[signo] = state;
6849 signal_cache_update (signo);
6853 /* Update the global 'signal_catch' from INFO and notify the
6857 signal_catch_update (const unsigned int *info)
6861 for (i = 0; i < GDB_SIGNAL_LAST; ++i)
6862 signal_catch[i] = info[i] > 0;
6863 signal_cache_update (-1);
6864 target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
6868 sig_print_header (void)
6870 printf_filtered (_("Signal Stop\tPrint\tPass "
6871 "to program\tDescription\n"));
6875 sig_print_info (enum gdb_signal oursig)
6877 const char *name = gdb_signal_to_name (oursig);
6878 int name_padding = 13 - strlen (name);
6880 if (name_padding <= 0)
6883 printf_filtered ("%s", name);
6884 printf_filtered ("%*.*s ", name_padding, name_padding, " ");
6885 printf_filtered ("%s\t", signal_stop[oursig] ? "Yes" : "No");
6886 printf_filtered ("%s\t", signal_print[oursig] ? "Yes" : "No");
6887 printf_filtered ("%s\t\t", signal_program[oursig] ? "Yes" : "No");
6888 printf_filtered ("%s\n", gdb_signal_to_string (oursig));
6891 /* Specify how various signals in the inferior should be handled. */
6894 handle_command (char *args, int from_tty)
6897 int digits, wordlen;
6898 int sigfirst, signum, siglast;
6899 enum gdb_signal oursig;
6902 unsigned char *sigs;
6903 struct cleanup *old_chain;
6907 error_no_arg (_("signal to handle"));
6910 /* Allocate and zero an array of flags for which signals to handle. */
6912 nsigs = (int) GDB_SIGNAL_LAST;
6913 sigs = (unsigned char *) alloca (nsigs);
6914 memset (sigs, 0, nsigs);
6916 /* Break the command line up into args. */
6918 argv = gdb_buildargv (args);
6919 old_chain = make_cleanup_freeargv (argv);
6921 /* Walk through the args, looking for signal oursigs, signal names, and
6922 actions. Signal numbers and signal names may be interspersed with
6923 actions, with the actions being performed for all signals cumulatively
6924 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
6926 while (*argv != NULL)
6928 wordlen = strlen (*argv);
6929 for (digits = 0; isdigit ((*argv)[digits]); digits++)
6933 sigfirst = siglast = -1;
6935 if (wordlen >= 1 && !strncmp (*argv, "all", wordlen))
6937 /* Apply action to all signals except those used by the
6938 debugger. Silently skip those. */
6941 siglast = nsigs - 1;
6943 else if (wordlen >= 1 && !strncmp (*argv, "stop", wordlen))
6945 SET_SIGS (nsigs, sigs, signal_stop);
6946 SET_SIGS (nsigs, sigs, signal_print);
6948 else if (wordlen >= 1 && !strncmp (*argv, "ignore", wordlen))
6950 UNSET_SIGS (nsigs, sigs, signal_program);
6952 else if (wordlen >= 2 && !strncmp (*argv, "print", wordlen))
6954 SET_SIGS (nsigs, sigs, signal_print);
6956 else if (wordlen >= 2 && !strncmp (*argv, "pass", wordlen))
6958 SET_SIGS (nsigs, sigs, signal_program);
6960 else if (wordlen >= 3 && !strncmp (*argv, "nostop", wordlen))
6962 UNSET_SIGS (nsigs, sigs, signal_stop);
6964 else if (wordlen >= 3 && !strncmp (*argv, "noignore", wordlen))
6966 SET_SIGS (nsigs, sigs, signal_program);
6968 else if (wordlen >= 4 && !strncmp (*argv, "noprint", wordlen))
6970 UNSET_SIGS (nsigs, sigs, signal_print);
6971 UNSET_SIGS (nsigs, sigs, signal_stop);
6973 else if (wordlen >= 4 && !strncmp (*argv, "nopass", wordlen))
6975 UNSET_SIGS (nsigs, sigs, signal_program);
6977 else if (digits > 0)
6979 /* It is numeric. The numeric signal refers to our own
6980 internal signal numbering from target.h, not to host/target
6981 signal number. This is a feature; users really should be
6982 using symbolic names anyway, and the common ones like
6983 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
6985 sigfirst = siglast = (int)
6986 gdb_signal_from_command (atoi (*argv));
6987 if ((*argv)[digits] == '-')
6990 gdb_signal_from_command (atoi ((*argv) + digits + 1));
6992 if (sigfirst > siglast)
6994 /* Bet he didn't figure we'd think of this case... */
7002 oursig = gdb_signal_from_name (*argv);
7003 if (oursig != GDB_SIGNAL_UNKNOWN)
7005 sigfirst = siglast = (int) oursig;
7009 /* Not a number and not a recognized flag word => complain. */
7010 error (_("Unrecognized or ambiguous flag word: \"%s\"."), *argv);
7014 /* If any signal numbers or symbol names were found, set flags for
7015 which signals to apply actions to. */
7017 for (signum = sigfirst; signum >= 0 && signum <= siglast; signum++)
7019 switch ((enum gdb_signal) signum)
7021 case GDB_SIGNAL_TRAP:
7022 case GDB_SIGNAL_INT:
7023 if (!allsigs && !sigs[signum])
7025 if (query (_("%s is used by the debugger.\n\
7026 Are you sure you want to change it? "),
7027 gdb_signal_to_name ((enum gdb_signal) signum)))
7033 printf_unfiltered (_("Not confirmed, unchanged.\n"));
7034 gdb_flush (gdb_stdout);
7039 case GDB_SIGNAL_DEFAULT:
7040 case GDB_SIGNAL_UNKNOWN:
7041 /* Make sure that "all" doesn't print these. */
7052 for (signum = 0; signum < nsigs; signum++)
7055 signal_cache_update (-1);
7056 target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
7057 target_program_signals ((int) GDB_SIGNAL_LAST, signal_program);
7061 /* Show the results. */
7062 sig_print_header ();
7063 for (; signum < nsigs; signum++)
7065 sig_print_info (signum);
7071 do_cleanups (old_chain);
7074 /* Complete the "handle" command. */
7076 static VEC (char_ptr) *
7077 handle_completer (struct cmd_list_element *ignore,
7078 const char *text, const char *word)
7080 VEC (char_ptr) *vec_signals, *vec_keywords, *return_val;
7081 static const char * const keywords[] =
7095 vec_signals = signal_completer (ignore, text, word);
7096 vec_keywords = complete_on_enum (keywords, word, word);
7098 return_val = VEC_merge (char_ptr, vec_signals, vec_keywords);
7099 VEC_free (char_ptr, vec_signals);
7100 VEC_free (char_ptr, vec_keywords);
7105 xdb_handle_command (char *args, int from_tty)
7108 struct cleanup *old_chain;
7111 error_no_arg (_("xdb command"));
7113 /* Break the command line up into args. */
7115 argv = gdb_buildargv (args);
7116 old_chain = make_cleanup_freeargv (argv);
7117 if (argv[1] != (char *) NULL)
7122 bufLen = strlen (argv[0]) + 20;
7123 argBuf = (char *) xmalloc (bufLen);
7127 enum gdb_signal oursig;
7129 oursig = gdb_signal_from_name (argv[0]);
7130 memset (argBuf, 0, bufLen);
7131 if (strcmp (argv[1], "Q") == 0)
7132 sprintf (argBuf, "%s %s", argv[0], "noprint");
7135 if (strcmp (argv[1], "s") == 0)
7137 if (!signal_stop[oursig])
7138 sprintf (argBuf, "%s %s", argv[0], "stop");
7140 sprintf (argBuf, "%s %s", argv[0], "nostop");
7142 else if (strcmp (argv[1], "i") == 0)
7144 if (!signal_program[oursig])
7145 sprintf (argBuf, "%s %s", argv[0], "pass");
7147 sprintf (argBuf, "%s %s", argv[0], "nopass");
7149 else if (strcmp (argv[1], "r") == 0)
7151 if (!signal_print[oursig])
7152 sprintf (argBuf, "%s %s", argv[0], "print");
7154 sprintf (argBuf, "%s %s", argv[0], "noprint");
7160 handle_command (argBuf, from_tty);
7162 printf_filtered (_("Invalid signal handling flag.\n"));
7167 do_cleanups (old_chain);
7171 gdb_signal_from_command (int num)
7173 if (num >= 1 && num <= 15)
7174 return (enum gdb_signal) num;
7175 error (_("Only signals 1-15 are valid as numeric signals.\n\
7176 Use \"info signals\" for a list of symbolic signals."));
7179 /* Print current contents of the tables set by the handle command.
7180 It is possible we should just be printing signals actually used
7181 by the current target (but for things to work right when switching
7182 targets, all signals should be in the signal tables). */
7185 signals_info (char *signum_exp, int from_tty)
7187 enum gdb_signal oursig;
7189 sig_print_header ();
7193 /* First see if this is a symbol name. */
7194 oursig = gdb_signal_from_name (signum_exp);
7195 if (oursig == GDB_SIGNAL_UNKNOWN)
7197 /* No, try numeric. */
7199 gdb_signal_from_command (parse_and_eval_long (signum_exp));
7201 sig_print_info (oursig);
7205 printf_filtered ("\n");
7206 /* These ugly casts brought to you by the native VAX compiler. */
7207 for (oursig = GDB_SIGNAL_FIRST;
7208 (int) oursig < (int) GDB_SIGNAL_LAST;
7209 oursig = (enum gdb_signal) ((int) oursig + 1))
7213 if (oursig != GDB_SIGNAL_UNKNOWN
7214 && oursig != GDB_SIGNAL_DEFAULT && oursig != GDB_SIGNAL_0)
7215 sig_print_info (oursig);
7218 printf_filtered (_("\nUse the \"handle\" command "
7219 "to change these tables.\n"));
7222 /* Check if it makes sense to read $_siginfo from the current thread
7223 at this point. If not, throw an error. */
7226 validate_siginfo_access (void)
7228 /* No current inferior, no siginfo. */
7229 if (ptid_equal (inferior_ptid, null_ptid))
7230 error (_("No thread selected."));
7232 /* Don't try to read from a dead thread. */
7233 if (is_exited (inferior_ptid))
7234 error (_("The current thread has terminated"));
7236 /* ... or from a spinning thread. */
7237 if (is_running (inferior_ptid))
7238 error (_("Selected thread is running."));
7241 /* The $_siginfo convenience variable is a bit special. We don't know
7242 for sure the type of the value until we actually have a chance to
7243 fetch the data. The type can change depending on gdbarch, so it is
7244 also dependent on which thread you have selected.
7246 1. making $_siginfo be an internalvar that creates a new value on
7249 2. making the value of $_siginfo be an lval_computed value. */
7251 /* This function implements the lval_computed support for reading a
7255 siginfo_value_read (struct value *v)
7257 LONGEST transferred;
7259 validate_siginfo_access ();
7262 target_read (¤t_target, TARGET_OBJECT_SIGNAL_INFO,
7264 value_contents_all_raw (v),
7266 TYPE_LENGTH (value_type (v)));
7268 if (transferred != TYPE_LENGTH (value_type (v)))
7269 error (_("Unable to read siginfo"));
7272 /* This function implements the lval_computed support for writing a
7276 siginfo_value_write (struct value *v, struct value *fromval)
7278 LONGEST transferred;
7280 validate_siginfo_access ();
7282 transferred = target_write (¤t_target,
7283 TARGET_OBJECT_SIGNAL_INFO,
7285 value_contents_all_raw (fromval),
7287 TYPE_LENGTH (value_type (fromval)));
7289 if (transferred != TYPE_LENGTH (value_type (fromval)))
7290 error (_("Unable to write siginfo"));
7293 static const struct lval_funcs siginfo_value_funcs =
7299 /* Return a new value with the correct type for the siginfo object of
7300 the current thread using architecture GDBARCH. Return a void value
7301 if there's no object available. */
7303 static struct value *
7304 siginfo_make_value (struct gdbarch *gdbarch, struct internalvar *var,
7307 if (target_has_stack
7308 && !ptid_equal (inferior_ptid, null_ptid)
7309 && gdbarch_get_siginfo_type_p (gdbarch))
7311 struct type *type = gdbarch_get_siginfo_type (gdbarch);
7313 return allocate_computed_value (type, &siginfo_value_funcs, NULL);
7316 return allocate_value (builtin_type (gdbarch)->builtin_void);
7320 /* infcall_suspend_state contains state about the program itself like its
7321 registers and any signal it received when it last stopped.
7322 This state must be restored regardless of how the inferior function call
7323 ends (either successfully, or after it hits a breakpoint or signal)
7324 if the program is to properly continue where it left off. */
7326 struct infcall_suspend_state
7328 struct thread_suspend_state thread_suspend;
7329 #if 0 /* Currently unused and empty structures are not valid C. */
7330 struct inferior_suspend_state inferior_suspend;
7335 struct regcache *registers;
7337 /* Format of SIGINFO_DATA or NULL if it is not present. */
7338 struct gdbarch *siginfo_gdbarch;
7340 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
7341 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
7342 content would be invalid. */
7343 gdb_byte *siginfo_data;
7346 struct infcall_suspend_state *
7347 save_infcall_suspend_state (void)
7349 struct infcall_suspend_state *inf_state;
7350 struct thread_info *tp = inferior_thread ();
7352 struct inferior *inf = current_inferior ();
7354 struct regcache *regcache = get_current_regcache ();
7355 struct gdbarch *gdbarch = get_regcache_arch (regcache);
7356 gdb_byte *siginfo_data = NULL;
7358 if (gdbarch_get_siginfo_type_p (gdbarch))
7360 struct type *type = gdbarch_get_siginfo_type (gdbarch);
7361 size_t len = TYPE_LENGTH (type);
7362 struct cleanup *back_to;
7364 siginfo_data = xmalloc (len);
7365 back_to = make_cleanup (xfree, siginfo_data);
7367 if (target_read (¤t_target, TARGET_OBJECT_SIGNAL_INFO, NULL,
7368 siginfo_data, 0, len) == len)
7369 discard_cleanups (back_to);
7372 /* Errors ignored. */
7373 do_cleanups (back_to);
7374 siginfo_data = NULL;
7378 inf_state = XCNEW (struct infcall_suspend_state);
7382 inf_state->siginfo_gdbarch = gdbarch;
7383 inf_state->siginfo_data = siginfo_data;
7386 inf_state->thread_suspend = tp->suspend;
7387 #if 0 /* Currently unused and empty structures are not valid C. */
7388 inf_state->inferior_suspend = inf->suspend;
7391 /* run_inferior_call will not use the signal due to its `proceed' call with
7392 GDB_SIGNAL_0 anyway. */
7393 tp->suspend.stop_signal = GDB_SIGNAL_0;
7395 inf_state->stop_pc = stop_pc;
7397 inf_state->registers = regcache_dup (regcache);
7402 /* Restore inferior session state to INF_STATE. */
7405 restore_infcall_suspend_state (struct infcall_suspend_state *inf_state)
7407 struct thread_info *tp = inferior_thread ();
7409 struct inferior *inf = current_inferior ();
7411 struct regcache *regcache = get_current_regcache ();
7412 struct gdbarch *gdbarch = get_regcache_arch (regcache);
7414 tp->suspend = inf_state->thread_suspend;
7415 #if 0 /* Currently unused and empty structures are not valid C. */
7416 inf->suspend = inf_state->inferior_suspend;
7419 stop_pc = inf_state->stop_pc;
7421 if (inf_state->siginfo_gdbarch == gdbarch)
7423 struct type *type = gdbarch_get_siginfo_type (gdbarch);
7425 /* Errors ignored. */
7426 target_write (¤t_target, TARGET_OBJECT_SIGNAL_INFO, NULL,
7427 inf_state->siginfo_data, 0, TYPE_LENGTH (type));
7430 /* The inferior can be gone if the user types "print exit(0)"
7431 (and perhaps other times). */
7432 if (target_has_execution)
7433 /* NB: The register write goes through to the target. */
7434 regcache_cpy (regcache, inf_state->registers);
7436 discard_infcall_suspend_state (inf_state);
7440 do_restore_infcall_suspend_state_cleanup (void *state)
7442 restore_infcall_suspend_state (state);
7446 make_cleanup_restore_infcall_suspend_state
7447 (struct infcall_suspend_state *inf_state)
7449 return make_cleanup (do_restore_infcall_suspend_state_cleanup, inf_state);
7453 discard_infcall_suspend_state (struct infcall_suspend_state *inf_state)
7455 regcache_xfree (inf_state->registers);
7456 xfree (inf_state->siginfo_data);
7461 get_infcall_suspend_state_regcache (struct infcall_suspend_state *inf_state)
7463 return inf_state->registers;
7466 /* infcall_control_state contains state regarding gdb's control of the
7467 inferior itself like stepping control. It also contains session state like
7468 the user's currently selected frame. */
7470 struct infcall_control_state
7472 struct thread_control_state thread_control;
7473 struct inferior_control_state inferior_control;
7476 enum stop_stack_kind stop_stack_dummy;
7477 int stopped_by_random_signal;
7478 int stop_after_trap;
7480 /* ID if the selected frame when the inferior function call was made. */
7481 struct frame_id selected_frame_id;
7484 /* Save all of the information associated with the inferior<==>gdb
7487 struct infcall_control_state *
7488 save_infcall_control_state (void)
7490 struct infcall_control_state *inf_status = xmalloc (sizeof (*inf_status));
7491 struct thread_info *tp = inferior_thread ();
7492 struct inferior *inf = current_inferior ();
7494 inf_status->thread_control = tp->control;
7495 inf_status->inferior_control = inf->control;
7497 tp->control.step_resume_breakpoint = NULL;
7498 tp->control.exception_resume_breakpoint = NULL;
7500 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
7501 chain. If caller's caller is walking the chain, they'll be happier if we
7502 hand them back the original chain when restore_infcall_control_state is
7504 tp->control.stop_bpstat = bpstat_copy (tp->control.stop_bpstat);
7507 inf_status->stop_stack_dummy = stop_stack_dummy;
7508 inf_status->stopped_by_random_signal = stopped_by_random_signal;
7509 inf_status->stop_after_trap = stop_after_trap;
7511 inf_status->selected_frame_id = get_frame_id (get_selected_frame (NULL));
7517 restore_selected_frame (void *args)
7519 struct frame_id *fid = (struct frame_id *) args;
7520 struct frame_info *frame;
7522 frame = frame_find_by_id (*fid);
7524 /* If inf_status->selected_frame_id is NULL, there was no previously
7528 warning (_("Unable to restore previously selected frame."));
7532 select_frame (frame);
7537 /* Restore inferior session state to INF_STATUS. */
7540 restore_infcall_control_state (struct infcall_control_state *inf_status)
7542 struct thread_info *tp = inferior_thread ();
7543 struct inferior *inf = current_inferior ();
7545 if (tp->control.step_resume_breakpoint)
7546 tp->control.step_resume_breakpoint->disposition = disp_del_at_next_stop;
7548 if (tp->control.exception_resume_breakpoint)
7549 tp->control.exception_resume_breakpoint->disposition
7550 = disp_del_at_next_stop;
7552 /* Handle the bpstat_copy of the chain. */
7553 bpstat_clear (&tp->control.stop_bpstat);
7555 tp->control = inf_status->thread_control;
7556 inf->control = inf_status->inferior_control;
7559 stop_stack_dummy = inf_status->stop_stack_dummy;
7560 stopped_by_random_signal = inf_status->stopped_by_random_signal;
7561 stop_after_trap = inf_status->stop_after_trap;
7563 if (target_has_stack)
7565 /* The point of catch_errors is that if the stack is clobbered,
7566 walking the stack might encounter a garbage pointer and
7567 error() trying to dereference it. */
7569 (restore_selected_frame, &inf_status->selected_frame_id,
7570 "Unable to restore previously selected frame:\n",
7571 RETURN_MASK_ERROR) == 0)
7572 /* Error in restoring the selected frame. Select the innermost
7574 select_frame (get_current_frame ());
7581 do_restore_infcall_control_state_cleanup (void *sts)
7583 restore_infcall_control_state (sts);
7587 make_cleanup_restore_infcall_control_state
7588 (struct infcall_control_state *inf_status)
7590 return make_cleanup (do_restore_infcall_control_state_cleanup, inf_status);
7594 discard_infcall_control_state (struct infcall_control_state *inf_status)
7596 if (inf_status->thread_control.step_resume_breakpoint)
7597 inf_status->thread_control.step_resume_breakpoint->disposition
7598 = disp_del_at_next_stop;
7600 if (inf_status->thread_control.exception_resume_breakpoint)
7601 inf_status->thread_control.exception_resume_breakpoint->disposition
7602 = disp_del_at_next_stop;
7604 /* See save_infcall_control_state for info on stop_bpstat. */
7605 bpstat_clear (&inf_status->thread_control.stop_bpstat);
7610 /* restore_inferior_ptid() will be used by the cleanup machinery
7611 to restore the inferior_ptid value saved in a call to
7612 save_inferior_ptid(). */
7615 restore_inferior_ptid (void *arg)
7617 ptid_t *saved_ptid_ptr = arg;
7619 inferior_ptid = *saved_ptid_ptr;
7623 /* Save the value of inferior_ptid so that it may be restored by a
7624 later call to do_cleanups(). Returns the struct cleanup pointer
7625 needed for later doing the cleanup. */
7628 save_inferior_ptid (void)
7630 ptid_t *saved_ptid_ptr;
7632 saved_ptid_ptr = xmalloc (sizeof (ptid_t));
7633 *saved_ptid_ptr = inferior_ptid;
7634 return make_cleanup (restore_inferior_ptid, saved_ptid_ptr);
7640 clear_exit_convenience_vars (void)
7642 clear_internalvar (lookup_internalvar ("_exitsignal"));
7643 clear_internalvar (lookup_internalvar ("_exitcode"));
7647 /* User interface for reverse debugging:
7648 Set exec-direction / show exec-direction commands
7649 (returns error unless target implements to_set_exec_direction method). */
7651 int execution_direction = EXEC_FORWARD;
7652 static const char exec_forward[] = "forward";
7653 static const char exec_reverse[] = "reverse";
7654 static const char *exec_direction = exec_forward;
7655 static const char *const exec_direction_names[] = {
7662 set_exec_direction_func (char *args, int from_tty,
7663 struct cmd_list_element *cmd)
7665 if (target_can_execute_reverse)
7667 if (!strcmp (exec_direction, exec_forward))
7668 execution_direction = EXEC_FORWARD;
7669 else if (!strcmp (exec_direction, exec_reverse))
7670 execution_direction = EXEC_REVERSE;
7674 exec_direction = exec_forward;
7675 error (_("Target does not support this operation."));
7680 show_exec_direction_func (struct ui_file *out, int from_tty,
7681 struct cmd_list_element *cmd, const char *value)
7683 switch (execution_direction) {
7685 fprintf_filtered (out, _("Forward.\n"));
7688 fprintf_filtered (out, _("Reverse.\n"));
7691 internal_error (__FILE__, __LINE__,
7692 _("bogus execution_direction value: %d"),
7693 (int) execution_direction);
7698 show_schedule_multiple (struct ui_file *file, int from_tty,
7699 struct cmd_list_element *c, const char *value)
7701 fprintf_filtered (file, _("Resuming the execution of threads "
7702 "of all processes is %s.\n"), value);
7705 /* Implementation of `siginfo' variable. */
7707 static const struct internalvar_funcs siginfo_funcs =
7715 _initialize_infrun (void)
7719 struct cmd_list_element *c;
7721 add_info ("signals", signals_info, _("\
7722 What debugger does when program gets various signals.\n\
7723 Specify a signal as argument to print info on that signal only."));
7724 add_info_alias ("handle", "signals", 0);
7726 c = add_com ("handle", class_run, handle_command, _("\
7727 Specify how to handle signals.\n\
7728 Usage: handle SIGNAL [ACTIONS]\n\
7729 Args are signals and actions to apply to those signals.\n\
7730 If no actions are specified, the current settings for the specified signals\n\
7731 will be displayed instead.\n\
7733 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
7734 from 1-15 are allowed for compatibility with old versions of GDB.\n\
7735 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
7736 The special arg \"all\" is recognized to mean all signals except those\n\
7737 used by the debugger, typically SIGTRAP and SIGINT.\n\
7739 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
7740 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
7741 Stop means reenter debugger if this signal happens (implies print).\n\
7742 Print means print a message if this signal happens.\n\
7743 Pass means let program see this signal; otherwise program doesn't know.\n\
7744 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
7745 Pass and Stop may be combined.\n\
7747 Multiple signals may be specified. Signal numbers and signal names\n\
7748 may be interspersed with actions, with the actions being performed for\n\
7749 all signals cumulatively specified."));
7750 set_cmd_completer (c, handle_completer);
7754 add_com ("lz", class_info, signals_info, _("\
7755 What debugger does when program gets various signals.\n\
7756 Specify a signal as argument to print info on that signal only."));
7757 add_com ("z", class_run, xdb_handle_command, _("\
7758 Specify how to handle a signal.\n\
7759 Args are signals and actions to apply to those signals.\n\
7760 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
7761 from 1-15 are allowed for compatibility with old versions of GDB.\n\
7762 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
7763 The special arg \"all\" is recognized to mean all signals except those\n\
7764 used by the debugger, typically SIGTRAP and SIGINT.\n\
7765 Recognized actions include \"s\" (toggles between stop and nostop),\n\
7766 \"r\" (toggles between print and noprint), \"i\" (toggles between pass and \
7767 nopass), \"Q\" (noprint)\n\
7768 Stop means reenter debugger if this signal happens (implies print).\n\
7769 Print means print a message if this signal happens.\n\
7770 Pass means let program see this signal; otherwise program doesn't know.\n\
7771 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
7772 Pass and Stop may be combined."));
7776 stop_command = add_cmd ("stop", class_obscure,
7777 not_just_help_class_command, _("\
7778 There is no `stop' command, but you can set a hook on `stop'.\n\
7779 This allows you to set a list of commands to be run each time execution\n\
7780 of the program stops."), &cmdlist);
7782 add_setshow_zuinteger_cmd ("infrun", class_maintenance, &debug_infrun, _("\
7783 Set inferior debugging."), _("\
7784 Show inferior debugging."), _("\
7785 When non-zero, inferior specific debugging is enabled."),
7788 &setdebuglist, &showdebuglist);
7790 add_setshow_boolean_cmd ("displaced", class_maintenance,
7791 &debug_displaced, _("\
7792 Set displaced stepping debugging."), _("\
7793 Show displaced stepping debugging."), _("\
7794 When non-zero, displaced stepping specific debugging is enabled."),
7796 show_debug_displaced,
7797 &setdebuglist, &showdebuglist);
7799 add_setshow_boolean_cmd ("non-stop", no_class,
7801 Set whether gdb controls the inferior in non-stop mode."), _("\
7802 Show whether gdb controls the inferior in non-stop mode."), _("\
7803 When debugging a multi-threaded program and this setting is\n\
7804 off (the default, also called all-stop mode), when one thread stops\n\
7805 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
7806 all other threads in the program while you interact with the thread of\n\
7807 interest. When you continue or step a thread, you can allow the other\n\
7808 threads to run, or have them remain stopped, but while you inspect any\n\
7809 thread's state, all threads stop.\n\
7811 In non-stop mode, when one thread stops, other threads can continue\n\
7812 to run freely. You'll be able to step each thread independently,\n\
7813 leave it stopped or free to run as needed."),
7819 numsigs = (int) GDB_SIGNAL_LAST;
7820 signal_stop = (unsigned char *) xmalloc (sizeof (signal_stop[0]) * numsigs);
7821 signal_print = (unsigned char *)
7822 xmalloc (sizeof (signal_print[0]) * numsigs);
7823 signal_program = (unsigned char *)
7824 xmalloc (sizeof (signal_program[0]) * numsigs);
7825 signal_catch = (unsigned char *)
7826 xmalloc (sizeof (signal_catch[0]) * numsigs);
7827 signal_pass = (unsigned char *)
7828 xmalloc (sizeof (signal_pass[0]) * numsigs);
7829 for (i = 0; i < numsigs; i++)
7832 signal_print[i] = 1;
7833 signal_program[i] = 1;
7834 signal_catch[i] = 0;
7837 /* Signals caused by debugger's own actions
7838 should not be given to the program afterwards. */
7839 signal_program[GDB_SIGNAL_TRAP] = 0;
7840 signal_program[GDB_SIGNAL_INT] = 0;
7842 /* Signals that are not errors should not normally enter the debugger. */
7843 signal_stop[GDB_SIGNAL_ALRM] = 0;
7844 signal_print[GDB_SIGNAL_ALRM] = 0;
7845 signal_stop[GDB_SIGNAL_VTALRM] = 0;
7846 signal_print[GDB_SIGNAL_VTALRM] = 0;
7847 signal_stop[GDB_SIGNAL_PROF] = 0;
7848 signal_print[GDB_SIGNAL_PROF] = 0;
7849 signal_stop[GDB_SIGNAL_CHLD] = 0;
7850 signal_print[GDB_SIGNAL_CHLD] = 0;
7851 signal_stop[GDB_SIGNAL_IO] = 0;
7852 signal_print[GDB_SIGNAL_IO] = 0;
7853 signal_stop[GDB_SIGNAL_POLL] = 0;
7854 signal_print[GDB_SIGNAL_POLL] = 0;
7855 signal_stop[GDB_SIGNAL_URG] = 0;
7856 signal_print[GDB_SIGNAL_URG] = 0;
7857 signal_stop[GDB_SIGNAL_WINCH] = 0;
7858 signal_print[GDB_SIGNAL_WINCH] = 0;
7859 signal_stop[GDB_SIGNAL_PRIO] = 0;
7860 signal_print[GDB_SIGNAL_PRIO] = 0;
7862 /* These signals are used internally by user-level thread
7863 implementations. (See signal(5) on Solaris.) Like the above
7864 signals, a healthy program receives and handles them as part of
7865 its normal operation. */
7866 signal_stop[GDB_SIGNAL_LWP] = 0;
7867 signal_print[GDB_SIGNAL_LWP] = 0;
7868 signal_stop[GDB_SIGNAL_WAITING] = 0;
7869 signal_print[GDB_SIGNAL_WAITING] = 0;
7870 signal_stop[GDB_SIGNAL_CANCEL] = 0;
7871 signal_print[GDB_SIGNAL_CANCEL] = 0;
7873 /* Update cached state. */
7874 signal_cache_update (-1);
7876 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support,
7877 &stop_on_solib_events, _("\
7878 Set stopping for shared library events."), _("\
7879 Show stopping for shared library events."), _("\
7880 If nonzero, gdb will give control to the user when the dynamic linker\n\
7881 notifies gdb of shared library events. The most common event of interest\n\
7882 to the user would be loading/unloading of a new library."),
7883 set_stop_on_solib_events,
7884 show_stop_on_solib_events,
7885 &setlist, &showlist);
7887 add_setshow_enum_cmd ("follow-fork-mode", class_run,
7888 follow_fork_mode_kind_names,
7889 &follow_fork_mode_string, _("\
7890 Set debugger response to a program call of fork or vfork."), _("\
7891 Show debugger response to a program call of fork or vfork."), _("\
7892 A fork or vfork creates a new process. follow-fork-mode can be:\n\
7893 parent - the original process is debugged after a fork\n\
7894 child - the new process is debugged after a fork\n\
7895 The unfollowed process will continue to run.\n\
7896 By default, the debugger will follow the parent process."),
7898 show_follow_fork_mode_string,
7899 &setlist, &showlist);
7901 add_setshow_enum_cmd ("follow-exec-mode", class_run,
7902 follow_exec_mode_names,
7903 &follow_exec_mode_string, _("\
7904 Set debugger response to a program call of exec."), _("\
7905 Show debugger response to a program call of exec."), _("\
7906 An exec call replaces the program image of a process.\n\
7908 follow-exec-mode can be:\n\
7910 new - the debugger creates a new inferior and rebinds the process\n\
7911 to this new inferior. The program the process was running before\n\
7912 the exec call can be restarted afterwards by restarting the original\n\
7915 same - the debugger keeps the process bound to the same inferior.\n\
7916 The new executable image replaces the previous executable loaded in\n\
7917 the inferior. Restarting the inferior after the exec call restarts\n\
7918 the executable the process was running after the exec call.\n\
7920 By default, the debugger will use the same inferior."),
7922 show_follow_exec_mode_string,
7923 &setlist, &showlist);
7925 add_setshow_enum_cmd ("scheduler-locking", class_run,
7926 scheduler_enums, &scheduler_mode, _("\
7927 Set mode for locking scheduler during execution."), _("\
7928 Show mode for locking scheduler during execution."), _("\
7929 off == no locking (threads may preempt at any time)\n\
7930 on == full locking (no thread except the current thread may run)\n\
7931 step == scheduler locked during stepping commands (step, next, stepi, nexti).\n\
7932 In this mode, other threads may run during other commands."),
7933 set_schedlock_func, /* traps on target vector */
7934 show_scheduler_mode,
7935 &setlist, &showlist);
7937 add_setshow_boolean_cmd ("schedule-multiple", class_run, &sched_multi, _("\
7938 Set mode for resuming threads of all processes."), _("\
7939 Show mode for resuming threads of all processes."), _("\
7940 When on, execution commands (such as 'continue' or 'next') resume all\n\
7941 threads of all processes. When off (which is the default), execution\n\
7942 commands only resume the threads of the current process. The set of\n\
7943 threads that are resumed is further refined by the scheduler-locking\n\
7944 mode (see help set scheduler-locking)."),
7946 show_schedule_multiple,
7947 &setlist, &showlist);
7949 add_setshow_boolean_cmd ("step-mode", class_run, &step_stop_if_no_debug, _("\
7950 Set mode of the step operation."), _("\
7951 Show mode of the step operation."), _("\
7952 When set, doing a step over a function without debug line information\n\
7953 will stop at the first instruction of that function. Otherwise, the\n\
7954 function is skipped and the step command stops at a different source line."),
7956 show_step_stop_if_no_debug,
7957 &setlist, &showlist);
7959 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run,
7960 &can_use_displaced_stepping, _("\
7961 Set debugger's willingness to use displaced stepping."), _("\
7962 Show debugger's willingness to use displaced stepping."), _("\
7963 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
7964 supported by the target architecture. If off, gdb will not use displaced\n\
7965 stepping to step over breakpoints, even if such is supported by the target\n\
7966 architecture. If auto (which is the default), gdb will use displaced stepping\n\
7967 if the target architecture supports it and non-stop mode is active, but will not\n\
7968 use it in all-stop mode (see help set non-stop)."),
7970 show_can_use_displaced_stepping,
7971 &setlist, &showlist);
7973 add_setshow_enum_cmd ("exec-direction", class_run, exec_direction_names,
7974 &exec_direction, _("Set direction of execution.\n\
7975 Options are 'forward' or 'reverse'."),
7976 _("Show direction of execution (forward/reverse)."),
7977 _("Tells gdb whether to execute forward or backward."),
7978 set_exec_direction_func, show_exec_direction_func,
7979 &setlist, &showlist);
7981 /* Set/show detach-on-fork: user-settable mode. */
7983 add_setshow_boolean_cmd ("detach-on-fork", class_run, &detach_fork, _("\
7984 Set whether gdb will detach the child of a fork."), _("\
7985 Show whether gdb will detach the child of a fork."), _("\
7986 Tells gdb whether to detach the child of a fork."),
7987 NULL, NULL, &setlist, &showlist);
7989 /* Set/show disable address space randomization mode. */
7991 add_setshow_boolean_cmd ("disable-randomization", class_support,
7992 &disable_randomization, _("\
7993 Set disabling of debuggee's virtual address space randomization."), _("\
7994 Show disabling of debuggee's virtual address space randomization."), _("\
7995 When this mode is on (which is the default), randomization of the virtual\n\
7996 address space is disabled. Standalone programs run with the randomization\n\
7997 enabled by default on some platforms."),
7998 &set_disable_randomization,
7999 &show_disable_randomization,
8000 &setlist, &showlist);
8002 /* ptid initializations */
8003 inferior_ptid = null_ptid;
8004 target_last_wait_ptid = minus_one_ptid;
8006 observer_attach_thread_ptid_changed (infrun_thread_ptid_changed);
8007 observer_attach_thread_stop_requested (infrun_thread_stop_requested);
8008 observer_attach_thread_exit (infrun_thread_thread_exit);
8009 observer_attach_inferior_exit (infrun_inferior_exit);
8011 /* Explicitly create without lookup, since that tries to create a
8012 value with a void typed value, and when we get here, gdbarch
8013 isn't initialized yet. At this point, we're quite sure there
8014 isn't another convenience variable of the same name. */
8015 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs, NULL);
8017 add_setshow_boolean_cmd ("observer", no_class,
8018 &observer_mode_1, _("\
8019 Set whether gdb controls the inferior in observer mode."), _("\
8020 Show whether gdb controls the inferior in observer mode."), _("\
8021 In observer mode, GDB can get data from the inferior, but not\n\
8022 affect its execution. Registers and memory may not be changed,\n\
8023 breakpoints may not be set, and the program cannot be interrupted\n\