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"
65 /* Prototypes for local functions */
67 static void signals_info (char *, int);
69 static void handle_command (char *, int);
71 static void sig_print_info (enum gdb_signal);
73 static void sig_print_header (void);
75 static void resume_cleanups (void *);
77 static int hook_stop_stub (void *);
79 static int restore_selected_frame (void *);
81 static int follow_fork (void);
83 static int follow_fork_inferior (int follow_child, int detach_fork);
85 static void follow_inferior_reset_breakpoints (void);
87 static void set_schedlock_func (char *args, int from_tty,
88 struct cmd_list_element *c);
90 static int currently_stepping (struct thread_info *tp);
92 void _initialize_infrun (void);
94 void nullify_last_target_wait_ptid (void);
96 static void insert_hp_step_resume_breakpoint_at_frame (struct frame_info *);
98 static void insert_step_resume_breakpoint_at_caller (struct frame_info *);
100 static void insert_longjmp_resume_breakpoint (struct gdbarch *, CORE_ADDR);
102 static int maybe_software_singlestep (struct gdbarch *gdbarch, CORE_ADDR pc);
104 /* When set, stop the 'step' command if we enter a function which has
105 no line number information. The normal behavior is that we step
106 over such function. */
107 int step_stop_if_no_debug = 0;
109 show_step_stop_if_no_debug (struct ui_file *file, int from_tty,
110 struct cmd_list_element *c, const char *value)
112 fprintf_filtered (file, _("Mode of the step operation is %s.\n"), value);
115 /* In asynchronous mode, but simulating synchronous execution. */
117 int sync_execution = 0;
119 /* proceed and normal_stop use this to notify the user when the
120 inferior stopped in a different thread than it had been running
123 static ptid_t previous_inferior_ptid;
125 /* If set (default for legacy reasons), when following a fork, GDB
126 will detach from one of the fork branches, child or parent.
127 Exactly which branch is detached depends on 'set follow-fork-mode'
130 static int detach_fork = 1;
132 int debug_displaced = 0;
134 show_debug_displaced (struct ui_file *file, int from_tty,
135 struct cmd_list_element *c, const char *value)
137 fprintf_filtered (file, _("Displace stepping debugging is %s.\n"), value);
140 unsigned int debug_infrun = 0;
142 show_debug_infrun (struct ui_file *file, int from_tty,
143 struct cmd_list_element *c, const char *value)
145 fprintf_filtered (file, _("Inferior debugging is %s.\n"), value);
149 /* Support for disabling address space randomization. */
151 int disable_randomization = 1;
154 show_disable_randomization (struct ui_file *file, int from_tty,
155 struct cmd_list_element *c, const char *value)
157 if (target_supports_disable_randomization ())
158 fprintf_filtered (file,
159 _("Disabling randomization of debuggee's "
160 "virtual address space is %s.\n"),
163 fputs_filtered (_("Disabling randomization of debuggee's "
164 "virtual address space is unsupported on\n"
165 "this platform.\n"), file);
169 set_disable_randomization (char *args, int from_tty,
170 struct cmd_list_element *c)
172 if (!target_supports_disable_randomization ())
173 error (_("Disabling randomization of debuggee's "
174 "virtual address space is unsupported on\n"
178 /* User interface for non-stop mode. */
181 static int non_stop_1 = 0;
184 set_non_stop (char *args, int from_tty,
185 struct cmd_list_element *c)
187 if (target_has_execution)
189 non_stop_1 = non_stop;
190 error (_("Cannot change this setting while the inferior is running."));
193 non_stop = non_stop_1;
197 show_non_stop (struct ui_file *file, int from_tty,
198 struct cmd_list_element *c, const char *value)
200 fprintf_filtered (file,
201 _("Controlling the inferior in non-stop mode is %s.\n"),
205 /* "Observer mode" is somewhat like a more extreme version of
206 non-stop, in which all GDB operations that might affect the
207 target's execution have been disabled. */
209 int observer_mode = 0;
210 static int observer_mode_1 = 0;
213 set_observer_mode (char *args, int from_tty,
214 struct cmd_list_element *c)
216 if (target_has_execution)
218 observer_mode_1 = observer_mode;
219 error (_("Cannot change this setting while the inferior is running."));
222 observer_mode = observer_mode_1;
224 may_write_registers = !observer_mode;
225 may_write_memory = !observer_mode;
226 may_insert_breakpoints = !observer_mode;
227 may_insert_tracepoints = !observer_mode;
228 /* We can insert fast tracepoints in or out of observer mode,
229 but enable them if we're going into this mode. */
231 may_insert_fast_tracepoints = 1;
232 may_stop = !observer_mode;
233 update_target_permissions ();
235 /* Going *into* observer mode we must force non-stop, then
236 going out we leave it that way. */
239 pagination_enabled = 0;
240 non_stop = non_stop_1 = 1;
244 printf_filtered (_("Observer mode is now %s.\n"),
245 (observer_mode ? "on" : "off"));
249 show_observer_mode (struct ui_file *file, int from_tty,
250 struct cmd_list_element *c, const char *value)
252 fprintf_filtered (file, _("Observer mode is %s.\n"), value);
255 /* This updates the value of observer mode based on changes in
256 permissions. Note that we are deliberately ignoring the values of
257 may-write-registers and may-write-memory, since the user may have
258 reason to enable these during a session, for instance to turn on a
259 debugging-related global. */
262 update_observer_mode (void)
266 newval = (!may_insert_breakpoints
267 && !may_insert_tracepoints
268 && may_insert_fast_tracepoints
272 /* Let the user know if things change. */
273 if (newval != observer_mode)
274 printf_filtered (_("Observer mode is now %s.\n"),
275 (newval ? "on" : "off"));
277 observer_mode = observer_mode_1 = newval;
280 /* Tables of how to react to signals; the user sets them. */
282 static unsigned char *signal_stop;
283 static unsigned char *signal_print;
284 static unsigned char *signal_program;
286 /* Table of signals that are registered with "catch signal". A
287 non-zero entry indicates that the signal is caught by some "catch
288 signal" command. This has size GDB_SIGNAL_LAST, to accommodate all
290 static unsigned char *signal_catch;
292 /* Table of signals that the target may silently handle.
293 This is automatically determined from the flags above,
294 and simply cached here. */
295 static unsigned char *signal_pass;
297 #define SET_SIGS(nsigs,sigs,flags) \
299 int signum = (nsigs); \
300 while (signum-- > 0) \
301 if ((sigs)[signum]) \
302 (flags)[signum] = 1; \
305 #define UNSET_SIGS(nsigs,sigs,flags) \
307 int signum = (nsigs); \
308 while (signum-- > 0) \
309 if ((sigs)[signum]) \
310 (flags)[signum] = 0; \
313 /* Update the target's copy of SIGNAL_PROGRAM. The sole purpose of
314 this function is to avoid exporting `signal_program'. */
317 update_signals_program_target (void)
319 target_program_signals ((int) GDB_SIGNAL_LAST, signal_program);
322 /* Value to pass to target_resume() to cause all threads to resume. */
324 #define RESUME_ALL minus_one_ptid
326 /* Command list pointer for the "stop" placeholder. */
328 static struct cmd_list_element *stop_command;
330 /* Nonzero if we want to give control to the user when we're notified
331 of shared library events by the dynamic linker. */
332 int stop_on_solib_events;
334 /* Enable or disable optional shared library event breakpoints
335 as appropriate when the above flag is changed. */
338 set_stop_on_solib_events (char *args, int from_tty, struct cmd_list_element *c)
340 update_solib_breakpoints ();
344 show_stop_on_solib_events (struct ui_file *file, int from_tty,
345 struct cmd_list_element *c, const char *value)
347 fprintf_filtered (file, _("Stopping for shared library events is %s.\n"),
351 /* Nonzero means expecting a trace trap
352 and should stop the inferior and return silently when it happens. */
356 /* Nonzero after stop if current stack frame should be printed. */
358 static int stop_print_frame;
360 /* This is a cached copy of the pid/waitstatus of the last event
361 returned by target_wait()/deprecated_target_wait_hook(). This
362 information is returned by get_last_target_status(). */
363 static ptid_t target_last_wait_ptid;
364 static struct target_waitstatus target_last_waitstatus;
366 static void context_switch (ptid_t ptid);
368 void init_thread_stepping_state (struct thread_info *tss);
370 static const char follow_fork_mode_child[] = "child";
371 static const char follow_fork_mode_parent[] = "parent";
373 static const char *const follow_fork_mode_kind_names[] = {
374 follow_fork_mode_child,
375 follow_fork_mode_parent,
379 static const char *follow_fork_mode_string = follow_fork_mode_parent;
381 show_follow_fork_mode_string (struct ui_file *file, int from_tty,
382 struct cmd_list_element *c, const char *value)
384 fprintf_filtered (file,
385 _("Debugger response to a program "
386 "call of fork or vfork is \"%s\".\n"),
391 /* Handle changes to the inferior list based on the type of fork,
392 which process is being followed, and whether the other process
393 should be detached. On entry inferior_ptid must be the ptid of
394 the fork parent. At return inferior_ptid is the ptid of the
395 followed inferior. */
398 follow_fork_inferior (int follow_child, int detach_fork)
401 ptid_t parent_ptid, child_ptid;
403 has_vforked = (inferior_thread ()->pending_follow.kind
404 == TARGET_WAITKIND_VFORKED);
405 parent_ptid = inferior_ptid;
406 child_ptid = inferior_thread ()->pending_follow.value.related_pid;
409 && !non_stop /* Non-stop always resumes both branches. */
410 && (!target_is_async_p () || sync_execution)
411 && !(follow_child || detach_fork || sched_multi))
413 /* The parent stays blocked inside the vfork syscall until the
414 child execs or exits. If we don't let the child run, then
415 the parent stays blocked. If we're telling the parent to run
416 in the foreground, the user will not be able to ctrl-c to get
417 back the terminal, effectively hanging the debug session. */
418 fprintf_filtered (gdb_stderr, _("\
419 Can not resume the parent process over vfork in the foreground while\n\
420 holding the child stopped. Try \"set detach-on-fork\" or \
421 \"set schedule-multiple\".\n"));
422 /* FIXME output string > 80 columns. */
428 /* Detach new forked process? */
431 struct cleanup *old_chain;
433 /* Before detaching from the child, remove all breakpoints
434 from it. If we forked, then this has already been taken
435 care of by infrun.c. If we vforked however, any
436 breakpoint inserted in the parent is visible in the
437 child, even those added while stopped in a vfork
438 catchpoint. This will remove the breakpoints from the
439 parent also, but they'll be reinserted below. */
442 /* Keep breakpoints list in sync. */
443 remove_breakpoints_pid (ptid_get_pid (inferior_ptid));
446 if (info_verbose || debug_infrun)
448 /* Ensure that we have a process ptid. */
449 ptid_t process_ptid = pid_to_ptid (ptid_get_pid (child_ptid));
451 target_terminal_ours_for_output ();
452 fprintf_filtered (gdb_stdlog,
453 _("Detaching after %s from child %s.\n"),
454 has_vforked ? "vfork" : "fork",
455 target_pid_to_str (process_ptid));
460 struct inferior *parent_inf, *child_inf;
461 struct cleanup *old_chain;
463 /* Add process to GDB's tables. */
464 child_inf = add_inferior (ptid_get_pid (child_ptid));
466 parent_inf = current_inferior ();
467 child_inf->attach_flag = parent_inf->attach_flag;
468 copy_terminal_info (child_inf, parent_inf);
469 child_inf->gdbarch = parent_inf->gdbarch;
470 copy_inferior_target_desc_info (child_inf, parent_inf);
472 old_chain = save_inferior_ptid ();
473 save_current_program_space ();
475 inferior_ptid = child_ptid;
476 add_thread (inferior_ptid);
477 child_inf->symfile_flags = SYMFILE_NO_READ;
479 /* If this is a vfork child, then the address-space is
480 shared with the parent. */
483 child_inf->pspace = parent_inf->pspace;
484 child_inf->aspace = parent_inf->aspace;
486 /* The parent will be frozen until the child is done
487 with the shared region. Keep track of the
489 child_inf->vfork_parent = parent_inf;
490 child_inf->pending_detach = 0;
491 parent_inf->vfork_child = child_inf;
492 parent_inf->pending_detach = 0;
496 child_inf->aspace = new_address_space ();
497 child_inf->pspace = add_program_space (child_inf->aspace);
498 child_inf->removable = 1;
499 set_current_program_space (child_inf->pspace);
500 clone_program_space (child_inf->pspace, parent_inf->pspace);
502 /* Let the shared library layer (e.g., solib-svr4) learn
503 about this new process, relocate the cloned exec, pull
504 in shared libraries, and install the solib event
505 breakpoint. If a "cloned-VM" event was propagated
506 better throughout the core, this wouldn't be
508 solib_create_inferior_hook (0);
511 do_cleanups (old_chain);
516 struct inferior *parent_inf;
518 parent_inf = current_inferior ();
520 /* If we detached from the child, then we have to be careful
521 to not insert breakpoints in the parent until the child
522 is done with the shared memory region. However, if we're
523 staying attached to the child, then we can and should
524 insert breakpoints, so that we can debug it. A
525 subsequent child exec or exit is enough to know when does
526 the child stops using the parent's address space. */
527 parent_inf->waiting_for_vfork_done = detach_fork;
528 parent_inf->pspace->breakpoints_not_allowed = detach_fork;
533 /* Follow the child. */
534 struct inferior *parent_inf, *child_inf;
535 struct program_space *parent_pspace;
537 if (info_verbose || debug_infrun)
539 target_terminal_ours_for_output ();
540 fprintf_filtered (gdb_stdlog,
541 _("Attaching after %s %s to child %s.\n"),
542 target_pid_to_str (parent_ptid),
543 has_vforked ? "vfork" : "fork",
544 target_pid_to_str (child_ptid));
547 /* Add the new inferior first, so that the target_detach below
548 doesn't unpush the target. */
550 child_inf = add_inferior (ptid_get_pid (child_ptid));
552 parent_inf = current_inferior ();
553 child_inf->attach_flag = parent_inf->attach_flag;
554 copy_terminal_info (child_inf, parent_inf);
555 child_inf->gdbarch = parent_inf->gdbarch;
556 copy_inferior_target_desc_info (child_inf, parent_inf);
558 parent_pspace = parent_inf->pspace;
560 /* If we're vforking, we want to hold on to the parent until the
561 child exits or execs. At child exec or exit time we can
562 remove the old breakpoints from the parent and detach or
563 resume debugging it. Otherwise, detach the parent now; we'll
564 want to reuse it's program/address spaces, but we can't set
565 them to the child before removing breakpoints from the
566 parent, otherwise, the breakpoints module could decide to
567 remove breakpoints from the wrong process (since they'd be
568 assigned to the same address space). */
572 gdb_assert (child_inf->vfork_parent == NULL);
573 gdb_assert (parent_inf->vfork_child == NULL);
574 child_inf->vfork_parent = parent_inf;
575 child_inf->pending_detach = 0;
576 parent_inf->vfork_child = child_inf;
577 parent_inf->pending_detach = detach_fork;
578 parent_inf->waiting_for_vfork_done = 0;
580 else if (detach_fork)
582 if (info_verbose || debug_infrun)
584 /* Ensure that we have a process ptid. */
585 ptid_t process_ptid = pid_to_ptid (ptid_get_pid (child_ptid));
587 target_terminal_ours_for_output ();
588 fprintf_filtered (gdb_stdlog,
589 _("Detaching after fork from "
591 target_pid_to_str (process_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 != NULL && *gdb_sysroot != '\0')
1138 char *name = exec_file_find (execd_pathname, NULL);
1140 execd_pathname = alloca (strlen (name) + 1);
1141 strcpy (execd_pathname, name);
1145 /* Reset the shared library package. This ensures that we get a
1146 shlib event when the child reaches "_start", at which point the
1147 dld will have had a chance to initialize the child. */
1148 /* Also, loading a symbol file below may trigger symbol lookups, and
1149 we don't want those to be satisfied by the libraries of the
1150 previous incarnation of this process. */
1151 no_shared_libraries (NULL, 0);
1153 if (follow_exec_mode_string == follow_exec_mode_new)
1155 struct program_space *pspace;
1157 /* The user wants to keep the old inferior and program spaces
1158 around. Create a new fresh one, and switch to it. */
1160 inf = add_inferior (current_inferior ()->pid);
1161 pspace = add_program_space (maybe_new_address_space ());
1162 inf->pspace = pspace;
1163 inf->aspace = pspace->aspace;
1165 exit_inferior_num_silent (current_inferior ()->num);
1167 set_current_inferior (inf);
1168 set_current_program_space (pspace);
1172 /* The old description may no longer be fit for the new image.
1173 E.g, a 64-bit process exec'ed a 32-bit process. Clear the
1174 old description; we'll read a new one below. No need to do
1175 this on "follow-exec-mode new", as the old inferior stays
1176 around (its description is later cleared/refetched on
1178 target_clear_description ();
1181 gdb_assert (current_program_space == inf->pspace);
1183 /* That a.out is now the one to use. */
1184 exec_file_attach (execd_pathname, 0);
1186 /* SYMFILE_DEFER_BP_RESET is used as the proper displacement for PIE
1187 (Position Independent Executable) main symbol file will get applied by
1188 solib_create_inferior_hook below. breakpoint_re_set would fail to insert
1189 the breakpoints with the zero displacement. */
1191 symbol_file_add (execd_pathname,
1193 | SYMFILE_MAINLINE | SYMFILE_DEFER_BP_RESET),
1196 if ((inf->symfile_flags & SYMFILE_NO_READ) == 0)
1197 set_initial_language ();
1199 /* If the target can specify a description, read it. Must do this
1200 after flipping to the new executable (because the target supplied
1201 description must be compatible with the executable's
1202 architecture, and the old executable may e.g., be 32-bit, while
1203 the new one 64-bit), and before anything involving memory or
1205 target_find_description ();
1207 solib_create_inferior_hook (0);
1209 jit_inferior_created_hook ();
1211 breakpoint_re_set ();
1213 /* Reinsert all breakpoints. (Those which were symbolic have
1214 been reset to the proper address in the new a.out, thanks
1215 to symbol_file_command...). */
1216 insert_breakpoints ();
1218 /* The next resume of this inferior should bring it to the shlib
1219 startup breakpoints. (If the user had also set bp's on
1220 "main" from the old (parent) process, then they'll auto-
1221 matically get reset there in the new process.). */
1224 /* Info about an instruction that is being stepped over. */
1226 struct step_over_info
1228 /* If we're stepping past a breakpoint, this is the address space
1229 and address of the instruction the breakpoint is set at. We'll
1230 skip inserting all breakpoints here. Valid iff ASPACE is
1232 struct address_space *aspace;
1235 /* The instruction being stepped over triggers a nonsteppable
1236 watchpoint. If true, we'll skip inserting watchpoints. */
1237 int nonsteppable_watchpoint_p;
1240 /* The step-over info of the location that is being stepped over.
1242 Note that with async/breakpoint always-inserted mode, a user might
1243 set a new breakpoint/watchpoint/etc. exactly while a breakpoint is
1244 being stepped over. As setting a new breakpoint inserts all
1245 breakpoints, we need to make sure the breakpoint being stepped over
1246 isn't inserted then. We do that by only clearing the step-over
1247 info when the step-over is actually finished (or aborted).
1249 Presently GDB can only step over one breakpoint at any given time.
1250 Given threads that can't run code in the same address space as the
1251 breakpoint's can't really miss the breakpoint, GDB could be taught
1252 to step-over at most one breakpoint per address space (so this info
1253 could move to the address space object if/when GDB is extended).
1254 The set of breakpoints being stepped over will normally be much
1255 smaller than the set of all breakpoints, so a flag in the
1256 breakpoint location structure would be wasteful. A separate list
1257 also saves complexity and run-time, as otherwise we'd have to go
1258 through all breakpoint locations clearing their flag whenever we
1259 start a new sequence. Similar considerations weigh against storing
1260 this info in the thread object. Plus, not all step overs actually
1261 have breakpoint locations -- e.g., stepping past a single-step
1262 breakpoint, or stepping to complete a non-continuable
1264 static struct step_over_info step_over_info;
1266 /* Record the address of the breakpoint/instruction we're currently
1270 set_step_over_info (struct address_space *aspace, CORE_ADDR address,
1271 int nonsteppable_watchpoint_p)
1273 step_over_info.aspace = aspace;
1274 step_over_info.address = address;
1275 step_over_info.nonsteppable_watchpoint_p = nonsteppable_watchpoint_p;
1278 /* Called when we're not longer stepping over a breakpoint / an
1279 instruction, so all breakpoints are free to be (re)inserted. */
1282 clear_step_over_info (void)
1284 step_over_info.aspace = NULL;
1285 step_over_info.address = 0;
1286 step_over_info.nonsteppable_watchpoint_p = 0;
1292 stepping_past_instruction_at (struct address_space *aspace,
1295 return (step_over_info.aspace != NULL
1296 && breakpoint_address_match (aspace, address,
1297 step_over_info.aspace,
1298 step_over_info.address));
1304 stepping_past_nonsteppable_watchpoint (void)
1306 return step_over_info.nonsteppable_watchpoint_p;
1309 /* Returns true if step-over info is valid. */
1312 step_over_info_valid_p (void)
1314 return (step_over_info.aspace != NULL
1315 || stepping_past_nonsteppable_watchpoint ());
1319 /* Displaced stepping. */
1321 /* In non-stop debugging mode, we must take special care to manage
1322 breakpoints properly; in particular, the traditional strategy for
1323 stepping a thread past a breakpoint it has hit is unsuitable.
1324 'Displaced stepping' is a tactic for stepping one thread past a
1325 breakpoint it has hit while ensuring that other threads running
1326 concurrently will hit the breakpoint as they should.
1328 The traditional way to step a thread T off a breakpoint in a
1329 multi-threaded program in all-stop mode is as follows:
1331 a0) Initially, all threads are stopped, and breakpoints are not
1333 a1) We single-step T, leaving breakpoints uninserted.
1334 a2) We insert breakpoints, and resume all threads.
1336 In non-stop debugging, however, this strategy is unsuitable: we
1337 don't want to have to stop all threads in the system in order to
1338 continue or step T past a breakpoint. Instead, we use displaced
1341 n0) Initially, T is stopped, other threads are running, and
1342 breakpoints are inserted.
1343 n1) We copy the instruction "under" the breakpoint to a separate
1344 location, outside the main code stream, making any adjustments
1345 to the instruction, register, and memory state as directed by
1347 n2) We single-step T over the instruction at its new location.
1348 n3) We adjust the resulting register and memory state as directed
1349 by T's architecture. This includes resetting T's PC to point
1350 back into the main instruction stream.
1353 This approach depends on the following gdbarch methods:
1355 - gdbarch_max_insn_length and gdbarch_displaced_step_location
1356 indicate where to copy the instruction, and how much space must
1357 be reserved there. We use these in step n1.
1359 - gdbarch_displaced_step_copy_insn copies a instruction to a new
1360 address, and makes any necessary adjustments to the instruction,
1361 register contents, and memory. We use this in step n1.
1363 - gdbarch_displaced_step_fixup adjusts registers and memory after
1364 we have successfuly single-stepped the instruction, to yield the
1365 same effect the instruction would have had if we had executed it
1366 at its original address. We use this in step n3.
1368 - gdbarch_displaced_step_free_closure provides cleanup.
1370 The gdbarch_displaced_step_copy_insn and
1371 gdbarch_displaced_step_fixup functions must be written so that
1372 copying an instruction with gdbarch_displaced_step_copy_insn,
1373 single-stepping across the copied instruction, and then applying
1374 gdbarch_displaced_insn_fixup should have the same effects on the
1375 thread's memory and registers as stepping the instruction in place
1376 would have. Exactly which responsibilities fall to the copy and
1377 which fall to the fixup is up to the author of those functions.
1379 See the comments in gdbarch.sh for details.
1381 Note that displaced stepping and software single-step cannot
1382 currently be used in combination, although with some care I think
1383 they could be made to. Software single-step works by placing
1384 breakpoints on all possible subsequent instructions; if the
1385 displaced instruction is a PC-relative jump, those breakpoints
1386 could fall in very strange places --- on pages that aren't
1387 executable, or at addresses that are not proper instruction
1388 boundaries. (We do generally let other threads run while we wait
1389 to hit the software single-step breakpoint, and they might
1390 encounter such a corrupted instruction.) One way to work around
1391 this would be to have gdbarch_displaced_step_copy_insn fully
1392 simulate the effect of PC-relative instructions (and return NULL)
1393 on architectures that use software single-stepping.
1395 In non-stop mode, we can have independent and simultaneous step
1396 requests, so more than one thread may need to simultaneously step
1397 over a breakpoint. The current implementation assumes there is
1398 only one scratch space per process. In this case, we have to
1399 serialize access to the scratch space. If thread A wants to step
1400 over a breakpoint, but we are currently waiting for some other
1401 thread to complete a displaced step, we leave thread A stopped and
1402 place it in the displaced_step_request_queue. Whenever a displaced
1403 step finishes, we pick the next thread in the queue and start a new
1404 displaced step operation on it. See displaced_step_prepare and
1405 displaced_step_fixup for details. */
1407 struct displaced_step_request
1410 struct displaced_step_request *next;
1413 /* Per-inferior displaced stepping state. */
1414 struct displaced_step_inferior_state
1416 /* Pointer to next in linked list. */
1417 struct displaced_step_inferior_state *next;
1419 /* The process this displaced step state refers to. */
1422 /* A queue of pending displaced stepping requests. One entry per
1423 thread that needs to do a displaced step. */
1424 struct displaced_step_request *step_request_queue;
1426 /* If this is not null_ptid, this is the thread carrying out a
1427 displaced single-step in process PID. This thread's state will
1428 require fixing up once it has completed its step. */
1431 /* The architecture the thread had when we stepped it. */
1432 struct gdbarch *step_gdbarch;
1434 /* The closure provided gdbarch_displaced_step_copy_insn, to be used
1435 for post-step cleanup. */
1436 struct displaced_step_closure *step_closure;
1438 /* The address of the original instruction, and the copy we
1440 CORE_ADDR step_original, step_copy;
1442 /* Saved contents of copy area. */
1443 gdb_byte *step_saved_copy;
1446 /* The list of states of processes involved in displaced stepping
1448 static struct displaced_step_inferior_state *displaced_step_inferior_states;
1450 /* Get the displaced stepping state of process PID. */
1452 static struct displaced_step_inferior_state *
1453 get_displaced_stepping_state (int pid)
1455 struct displaced_step_inferior_state *state;
1457 for (state = displaced_step_inferior_states;
1459 state = state->next)
1460 if (state->pid == pid)
1466 /* Return true if process PID has a thread doing a displaced step. */
1469 displaced_step_in_progress (int pid)
1471 struct displaced_step_inferior_state *displaced;
1473 displaced = get_displaced_stepping_state (pid);
1474 if (displaced != NULL && !ptid_equal (displaced->step_ptid, null_ptid))
1480 /* Add a new displaced stepping state for process PID to the displaced
1481 stepping state list, or return a pointer to an already existing
1482 entry, if it already exists. Never returns NULL. */
1484 static struct displaced_step_inferior_state *
1485 add_displaced_stepping_state (int pid)
1487 struct displaced_step_inferior_state *state;
1489 for (state = displaced_step_inferior_states;
1491 state = state->next)
1492 if (state->pid == pid)
1495 state = xcalloc (1, sizeof (*state));
1497 state->next = displaced_step_inferior_states;
1498 displaced_step_inferior_states = state;
1503 /* If inferior is in displaced stepping, and ADDR equals to starting address
1504 of copy area, return corresponding displaced_step_closure. Otherwise,
1507 struct displaced_step_closure*
1508 get_displaced_step_closure_by_addr (CORE_ADDR addr)
1510 struct displaced_step_inferior_state *displaced
1511 = get_displaced_stepping_state (ptid_get_pid (inferior_ptid));
1513 /* If checking the mode of displaced instruction in copy area. */
1514 if (displaced && !ptid_equal (displaced->step_ptid, null_ptid)
1515 && (displaced->step_copy == addr))
1516 return displaced->step_closure;
1521 /* Remove the displaced stepping state of process PID. */
1524 remove_displaced_stepping_state (int pid)
1526 struct displaced_step_inferior_state *it, **prev_next_p;
1528 gdb_assert (pid != 0);
1530 it = displaced_step_inferior_states;
1531 prev_next_p = &displaced_step_inferior_states;
1536 *prev_next_p = it->next;
1541 prev_next_p = &it->next;
1547 infrun_inferior_exit (struct inferior *inf)
1549 remove_displaced_stepping_state (inf->pid);
1552 /* If ON, and the architecture supports it, GDB will use displaced
1553 stepping to step over breakpoints. If OFF, or if the architecture
1554 doesn't support it, GDB will instead use the traditional
1555 hold-and-step approach. If AUTO (which is the default), GDB will
1556 decide which technique to use to step over breakpoints depending on
1557 which of all-stop or non-stop mode is active --- displaced stepping
1558 in non-stop mode; hold-and-step in all-stop mode. */
1560 static enum auto_boolean can_use_displaced_stepping = AUTO_BOOLEAN_AUTO;
1563 show_can_use_displaced_stepping (struct ui_file *file, int from_tty,
1564 struct cmd_list_element *c,
1567 if (can_use_displaced_stepping == AUTO_BOOLEAN_AUTO)
1568 fprintf_filtered (file,
1569 _("Debugger's willingness to use displaced stepping "
1570 "to step over breakpoints is %s (currently %s).\n"),
1571 value, non_stop ? "on" : "off");
1573 fprintf_filtered (file,
1574 _("Debugger's willingness to use displaced stepping "
1575 "to step over breakpoints is %s.\n"), value);
1578 /* Return non-zero if displaced stepping can/should be used to step
1579 over breakpoints. */
1582 use_displaced_stepping (struct gdbarch *gdbarch)
1584 return (((can_use_displaced_stepping == AUTO_BOOLEAN_AUTO && non_stop)
1585 || can_use_displaced_stepping == AUTO_BOOLEAN_TRUE)
1586 && gdbarch_displaced_step_copy_insn_p (gdbarch)
1587 && find_record_target () == NULL);
1590 /* Clean out any stray displaced stepping state. */
1592 displaced_step_clear (struct displaced_step_inferior_state *displaced)
1594 /* Indicate that there is no cleanup pending. */
1595 displaced->step_ptid = null_ptid;
1597 if (displaced->step_closure)
1599 gdbarch_displaced_step_free_closure (displaced->step_gdbarch,
1600 displaced->step_closure);
1601 displaced->step_closure = NULL;
1606 displaced_step_clear_cleanup (void *arg)
1608 struct displaced_step_inferior_state *state = arg;
1610 displaced_step_clear (state);
1613 /* Dump LEN bytes at BUF in hex to FILE, followed by a newline. */
1615 displaced_step_dump_bytes (struct ui_file *file,
1616 const gdb_byte *buf,
1621 for (i = 0; i < len; i++)
1622 fprintf_unfiltered (file, "%02x ", buf[i]);
1623 fputs_unfiltered ("\n", file);
1626 /* Prepare to single-step, using displaced stepping.
1628 Note that we cannot use displaced stepping when we have a signal to
1629 deliver. If we have a signal to deliver and an instruction to step
1630 over, then after the step, there will be no indication from the
1631 target whether the thread entered a signal handler or ignored the
1632 signal and stepped over the instruction successfully --- both cases
1633 result in a simple SIGTRAP. In the first case we mustn't do a
1634 fixup, and in the second case we must --- but we can't tell which.
1635 Comments in the code for 'random signals' in handle_inferior_event
1636 explain how we handle this case instead.
1638 Returns 1 if preparing was successful -- this thread is going to be
1639 stepped now; or 0 if displaced stepping this thread got queued. */
1641 displaced_step_prepare (ptid_t ptid)
1643 struct cleanup *old_cleanups, *ignore_cleanups;
1644 struct thread_info *tp = find_thread_ptid (ptid);
1645 struct regcache *regcache = get_thread_regcache (ptid);
1646 struct gdbarch *gdbarch = get_regcache_arch (regcache);
1647 CORE_ADDR original, copy;
1649 struct displaced_step_closure *closure;
1650 struct displaced_step_inferior_state *displaced;
1653 /* We should never reach this function if the architecture does not
1654 support displaced stepping. */
1655 gdb_assert (gdbarch_displaced_step_copy_insn_p (gdbarch));
1657 /* Disable range stepping while executing in the scratch pad. We
1658 want a single-step even if executing the displaced instruction in
1659 the scratch buffer lands within the stepping range (e.g., a
1661 tp->control.may_range_step = 0;
1663 /* We have to displaced step one thread at a time, as we only have
1664 access to a single scratch space per inferior. */
1666 displaced = add_displaced_stepping_state (ptid_get_pid (ptid));
1668 if (!ptid_equal (displaced->step_ptid, null_ptid))
1670 /* Already waiting for a displaced step to finish. Defer this
1671 request and place in queue. */
1672 struct displaced_step_request *req, *new_req;
1674 if (debug_displaced)
1675 fprintf_unfiltered (gdb_stdlog,
1676 "displaced: defering step of %s\n",
1677 target_pid_to_str (ptid));
1679 new_req = xmalloc (sizeof (*new_req));
1680 new_req->ptid = ptid;
1681 new_req->next = NULL;
1683 if (displaced->step_request_queue)
1685 for (req = displaced->step_request_queue;
1689 req->next = new_req;
1692 displaced->step_request_queue = new_req;
1698 if (debug_displaced)
1699 fprintf_unfiltered (gdb_stdlog,
1700 "displaced: stepping %s now\n",
1701 target_pid_to_str (ptid));
1704 displaced_step_clear (displaced);
1706 old_cleanups = save_inferior_ptid ();
1707 inferior_ptid = ptid;
1709 original = regcache_read_pc (regcache);
1711 copy = gdbarch_displaced_step_location (gdbarch);
1712 len = gdbarch_max_insn_length (gdbarch);
1714 /* Save the original contents of the copy area. */
1715 displaced->step_saved_copy = xmalloc (len);
1716 ignore_cleanups = make_cleanup (free_current_contents,
1717 &displaced->step_saved_copy);
1718 status = target_read_memory (copy, displaced->step_saved_copy, len);
1720 throw_error (MEMORY_ERROR,
1721 _("Error accessing memory address %s (%s) for "
1722 "displaced-stepping scratch space."),
1723 paddress (gdbarch, copy), safe_strerror (status));
1724 if (debug_displaced)
1726 fprintf_unfiltered (gdb_stdlog, "displaced: saved %s: ",
1727 paddress (gdbarch, copy));
1728 displaced_step_dump_bytes (gdb_stdlog,
1729 displaced->step_saved_copy,
1733 closure = gdbarch_displaced_step_copy_insn (gdbarch,
1734 original, copy, regcache);
1736 /* We don't support the fully-simulated case at present. */
1737 gdb_assert (closure);
1739 /* Save the information we need to fix things up if the step
1741 displaced->step_ptid = ptid;
1742 displaced->step_gdbarch = gdbarch;
1743 displaced->step_closure = closure;
1744 displaced->step_original = original;
1745 displaced->step_copy = copy;
1747 make_cleanup (displaced_step_clear_cleanup, displaced);
1749 /* Resume execution at the copy. */
1750 regcache_write_pc (regcache, copy);
1752 discard_cleanups (ignore_cleanups);
1754 do_cleanups (old_cleanups);
1756 if (debug_displaced)
1757 fprintf_unfiltered (gdb_stdlog, "displaced: displaced pc to %s\n",
1758 paddress (gdbarch, copy));
1764 write_memory_ptid (ptid_t ptid, CORE_ADDR memaddr,
1765 const gdb_byte *myaddr, int len)
1767 struct cleanup *ptid_cleanup = save_inferior_ptid ();
1769 inferior_ptid = ptid;
1770 write_memory (memaddr, myaddr, len);
1771 do_cleanups (ptid_cleanup);
1774 /* Restore the contents of the copy area for thread PTID. */
1777 displaced_step_restore (struct displaced_step_inferior_state *displaced,
1780 ULONGEST len = gdbarch_max_insn_length (displaced->step_gdbarch);
1782 write_memory_ptid (ptid, displaced->step_copy,
1783 displaced->step_saved_copy, len);
1784 if (debug_displaced)
1785 fprintf_unfiltered (gdb_stdlog, "displaced: restored %s %s\n",
1786 target_pid_to_str (ptid),
1787 paddress (displaced->step_gdbarch,
1788 displaced->step_copy));
1792 displaced_step_fixup (ptid_t event_ptid, enum gdb_signal signal)
1794 struct cleanup *old_cleanups;
1795 struct displaced_step_inferior_state *displaced
1796 = get_displaced_stepping_state (ptid_get_pid (event_ptid));
1798 /* Was any thread of this process doing a displaced step? */
1799 if (displaced == NULL)
1802 /* Was this event for the pid we displaced? */
1803 if (ptid_equal (displaced->step_ptid, null_ptid)
1804 || ! ptid_equal (displaced->step_ptid, event_ptid))
1807 old_cleanups = make_cleanup (displaced_step_clear_cleanup, displaced);
1809 displaced_step_restore (displaced, displaced->step_ptid);
1811 /* Fixup may need to read memory/registers. Switch to the thread
1812 that we're fixing up. Also, target_stopped_by_watchpoint checks
1813 the current thread. */
1814 switch_to_thread (event_ptid);
1816 /* Did the instruction complete successfully? */
1817 if (signal == GDB_SIGNAL_TRAP
1818 && !(target_stopped_by_watchpoint ()
1819 && (gdbarch_have_nonsteppable_watchpoint (displaced->step_gdbarch)
1820 || target_have_steppable_watchpoint)))
1822 /* Fix up the resulting state. */
1823 gdbarch_displaced_step_fixup (displaced->step_gdbarch,
1824 displaced->step_closure,
1825 displaced->step_original,
1826 displaced->step_copy,
1827 get_thread_regcache (displaced->step_ptid));
1831 /* Since the instruction didn't complete, all we can do is
1833 struct regcache *regcache = get_thread_regcache (event_ptid);
1834 CORE_ADDR pc = regcache_read_pc (regcache);
1836 pc = displaced->step_original + (pc - displaced->step_copy);
1837 regcache_write_pc (regcache, pc);
1840 do_cleanups (old_cleanups);
1842 displaced->step_ptid = null_ptid;
1844 /* Are there any pending displaced stepping requests? If so, run
1845 one now. Leave the state object around, since we're likely to
1846 need it again soon. */
1847 while (displaced->step_request_queue)
1849 struct displaced_step_request *head;
1851 struct regcache *regcache;
1852 struct gdbarch *gdbarch;
1853 CORE_ADDR actual_pc;
1854 struct address_space *aspace;
1856 head = displaced->step_request_queue;
1858 displaced->step_request_queue = head->next;
1861 context_switch (ptid);
1863 regcache = get_thread_regcache (ptid);
1864 actual_pc = regcache_read_pc (regcache);
1865 aspace = get_regcache_aspace (regcache);
1866 gdbarch = get_regcache_arch (regcache);
1868 if (breakpoint_here_p (aspace, actual_pc))
1870 if (debug_displaced)
1871 fprintf_unfiltered (gdb_stdlog,
1872 "displaced: stepping queued %s now\n",
1873 target_pid_to_str (ptid));
1875 displaced_step_prepare (ptid);
1877 if (debug_displaced)
1879 CORE_ADDR actual_pc = regcache_read_pc (regcache);
1882 fprintf_unfiltered (gdb_stdlog, "displaced: run %s: ",
1883 paddress (gdbarch, actual_pc));
1884 read_memory (actual_pc, buf, sizeof (buf));
1885 displaced_step_dump_bytes (gdb_stdlog, buf, sizeof (buf));
1888 if (gdbarch_displaced_step_hw_singlestep (gdbarch,
1889 displaced->step_closure))
1890 target_resume (ptid, 1, GDB_SIGNAL_0);
1892 target_resume (ptid, 0, GDB_SIGNAL_0);
1894 /* Done, we're stepping a thread. */
1900 struct thread_info *tp = inferior_thread ();
1902 /* The breakpoint we were sitting under has since been
1904 tp->control.trap_expected = 0;
1906 /* Go back to what we were trying to do. */
1907 step = currently_stepping (tp);
1910 step = maybe_software_singlestep (gdbarch, actual_pc);
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 ();
2509 /* Returns true if TP is still stopped at a breakpoint that needs
2510 stepping-over in order to make progress. If the breakpoint is gone
2511 meanwhile, we can skip the whole step-over dance. */
2514 thread_still_needs_step_over (struct thread_info *tp)
2516 if (tp->stepping_over_breakpoint)
2518 struct regcache *regcache = get_thread_regcache (tp->ptid);
2520 if (breakpoint_here_p (get_regcache_aspace (regcache),
2521 regcache_read_pc (regcache))
2522 == ordinary_breakpoint_here)
2525 tp->stepping_over_breakpoint = 0;
2531 /* Returns true if scheduler locking applies. STEP indicates whether
2532 we're about to do a step/next-like command to a thread. */
2535 schedlock_applies (struct thread_info *tp)
2537 return (scheduler_mode == schedlock_on
2538 || (scheduler_mode == schedlock_step
2539 && tp->control.stepping_command));
2542 /* Look a thread other than EXCEPT that has previously reported a
2543 breakpoint event, and thus needs a step-over in order to make
2544 progress. Returns NULL is none is found. */
2546 static struct thread_info *
2547 find_thread_needs_step_over (struct thread_info *except)
2549 struct thread_info *tp, *current;
2551 /* With non-stop mode on, threads are always handled individually. */
2552 gdb_assert (! non_stop);
2554 current = inferior_thread ();
2556 /* If scheduler locking applies, we can avoid iterating over all
2558 if (schedlock_applies (except))
2560 if (except != current
2561 && thread_still_needs_step_over (current))
2567 ALL_NON_EXITED_THREADS (tp)
2569 /* Ignore the EXCEPT thread. */
2572 /* Ignore threads of processes we're not resuming. */
2574 && ptid_get_pid (tp->ptid) != ptid_get_pid (inferior_ptid))
2577 if (thread_still_needs_step_over (tp))
2584 /* Basic routine for continuing the program in various fashions.
2586 ADDR is the address to resume at, or -1 for resume where stopped.
2587 SIGGNAL is the signal to give it, or 0 for none,
2588 or -1 for act according to how it stopped.
2589 STEP is nonzero if should trap after one instruction.
2590 -1 means return after that and print nothing.
2591 You should probably set various step_... variables
2592 before calling here, if you are stepping.
2594 You should call clear_proceed_status before calling proceed. */
2597 proceed (CORE_ADDR addr, enum gdb_signal siggnal)
2599 struct regcache *regcache;
2600 struct gdbarch *gdbarch;
2601 struct thread_info *tp;
2603 struct address_space *aspace;
2605 /* If we're stopped at a fork/vfork, follow the branch set by the
2606 "set follow-fork-mode" command; otherwise, we'll just proceed
2607 resuming the current thread. */
2608 if (!follow_fork ())
2610 /* The target for some reason decided not to resume. */
2612 if (target_can_async_p ())
2613 inferior_event_handler (INF_EXEC_COMPLETE, NULL);
2617 /* We'll update this if & when we switch to a new thread. */
2618 previous_inferior_ptid = inferior_ptid;
2620 regcache = get_current_regcache ();
2621 gdbarch = get_regcache_arch (regcache);
2622 aspace = get_regcache_aspace (regcache);
2623 pc = regcache_read_pc (regcache);
2624 tp = inferior_thread ();
2626 /* Fill in with reasonable starting values. */
2627 init_thread_stepping_state (tp);
2629 if (addr == (CORE_ADDR) -1)
2632 && breakpoint_here_p (aspace, pc) == ordinary_breakpoint_here
2633 && execution_direction != EXEC_REVERSE)
2634 /* There is a breakpoint at the address we will resume at,
2635 step one instruction before inserting breakpoints so that
2636 we do not stop right away (and report a second hit at this
2639 Note, we don't do this in reverse, because we won't
2640 actually be executing the breakpoint insn anyway.
2641 We'll be (un-)executing the previous instruction. */
2642 tp->stepping_over_breakpoint = 1;
2643 else if (gdbarch_single_step_through_delay_p (gdbarch)
2644 && gdbarch_single_step_through_delay (gdbarch,
2645 get_current_frame ()))
2646 /* We stepped onto an instruction that needs to be stepped
2647 again before re-inserting the breakpoint, do so. */
2648 tp->stepping_over_breakpoint = 1;
2652 regcache_write_pc (regcache, addr);
2655 if (siggnal != GDB_SIGNAL_DEFAULT)
2656 tp->suspend.stop_signal = siggnal;
2658 /* Record the interpreter that issued the execution command that
2659 caused this thread to resume. If the top level interpreter is
2660 MI/async, and the execution command was a CLI command
2661 (next/step/etc.), we'll want to print stop event output to the MI
2662 console channel (the stepped-to line, etc.), as if the user
2663 entered the execution command on a real GDB console. */
2664 inferior_thread ()->control.command_interp = command_interp ();
2667 fprintf_unfiltered (gdb_stdlog,
2668 "infrun: proceed (addr=%s, signal=%s)\n",
2669 paddress (gdbarch, addr),
2670 gdb_signal_to_symbol_string (siggnal));
2673 /* In non-stop, each thread is handled individually. The context
2674 must already be set to the right thread here. */
2678 struct thread_info *step_over;
2680 /* In a multi-threaded task we may select another thread and
2681 then continue or step.
2683 But if the old thread was stopped at a breakpoint, it will
2684 immediately cause another breakpoint stop without any
2685 execution (i.e. it will report a breakpoint hit incorrectly).
2686 So we must step over it first.
2688 Look for a thread other than the current (TP) that reported a
2689 breakpoint hit and hasn't been resumed yet since. */
2690 step_over = find_thread_needs_step_over (tp);
2691 if (step_over != NULL)
2694 fprintf_unfiltered (gdb_stdlog,
2695 "infrun: need to step-over [%s] first\n",
2696 target_pid_to_str (step_over->ptid));
2698 /* Store the prev_pc for the stepping thread too, needed by
2699 switch_back_to_stepped_thread. */
2700 tp->prev_pc = regcache_read_pc (get_current_regcache ());
2701 switch_to_thread (step_over->ptid);
2706 /* If we need to step over a breakpoint, and we're not using
2707 displaced stepping to do so, insert all breakpoints (watchpoints,
2708 etc.) but the one we're stepping over, step one instruction, and
2709 then re-insert the breakpoint when that step is finished. */
2710 if (tp->stepping_over_breakpoint && !use_displaced_stepping (gdbarch))
2712 struct regcache *regcache = get_current_regcache ();
2714 set_step_over_info (get_regcache_aspace (regcache),
2715 regcache_read_pc (regcache), 0);
2718 clear_step_over_info ();
2720 insert_breakpoints ();
2722 tp->control.trap_expected = tp->stepping_over_breakpoint;
2724 annotate_starting ();
2726 /* Make sure that output from GDB appears before output from the
2728 gdb_flush (gdb_stdout);
2730 /* Refresh prev_pc value just prior to resuming. This used to be
2731 done in stop_waiting, however, setting prev_pc there did not handle
2732 scenarios such as inferior function calls or returning from
2733 a function via the return command. In those cases, the prev_pc
2734 value was not set properly for subsequent commands. The prev_pc value
2735 is used to initialize the starting line number in the ecs. With an
2736 invalid value, the gdb next command ends up stopping at the position
2737 represented by the next line table entry past our start position.
2738 On platforms that generate one line table entry per line, this
2739 is not a problem. However, on the ia64, the compiler generates
2740 extraneous line table entries that do not increase the line number.
2741 When we issue the gdb next command on the ia64 after an inferior call
2742 or a return command, we often end up a few instructions forward, still
2743 within the original line we started.
2745 An attempt was made to refresh the prev_pc at the same time the
2746 execution_control_state is initialized (for instance, just before
2747 waiting for an inferior event). But this approach did not work
2748 because of platforms that use ptrace, where the pc register cannot
2749 be read unless the inferior is stopped. At that point, we are not
2750 guaranteed the inferior is stopped and so the regcache_read_pc() call
2751 can fail. Setting the prev_pc value here ensures the value is updated
2752 correctly when the inferior is stopped. */
2753 tp->prev_pc = regcache_read_pc (get_current_regcache ());
2755 /* Resume inferior. */
2756 resume (tp->suspend.stop_signal);
2758 /* Wait for it to stop (if not standalone)
2759 and in any case decode why it stopped, and act accordingly. */
2760 /* Do this only if we are not using the event loop, or if the target
2761 does not support asynchronous execution. */
2762 if (!target_can_async_p ())
2764 wait_for_inferior ();
2770 /* Start remote-debugging of a machine over a serial link. */
2773 start_remote (int from_tty)
2775 struct inferior *inferior;
2777 inferior = current_inferior ();
2778 inferior->control.stop_soon = STOP_QUIETLY_REMOTE;
2780 /* Always go on waiting for the target, regardless of the mode. */
2781 /* FIXME: cagney/1999-09-23: At present it isn't possible to
2782 indicate to wait_for_inferior that a target should timeout if
2783 nothing is returned (instead of just blocking). Because of this,
2784 targets expecting an immediate response need to, internally, set
2785 things up so that the target_wait() is forced to eventually
2787 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
2788 differentiate to its caller what the state of the target is after
2789 the initial open has been performed. Here we're assuming that
2790 the target has stopped. It should be possible to eventually have
2791 target_open() return to the caller an indication that the target
2792 is currently running and GDB state should be set to the same as
2793 for an async run. */
2794 wait_for_inferior ();
2796 /* Now that the inferior has stopped, do any bookkeeping like
2797 loading shared libraries. We want to do this before normal_stop,
2798 so that the displayed frame is up to date. */
2799 post_create_inferior (¤t_target, from_tty);
2804 /* Initialize static vars when a new inferior begins. */
2807 init_wait_for_inferior (void)
2809 /* These are meaningless until the first time through wait_for_inferior. */
2811 breakpoint_init_inferior (inf_starting);
2813 clear_proceed_status (0);
2815 target_last_wait_ptid = minus_one_ptid;
2817 previous_inferior_ptid = inferior_ptid;
2819 /* Discard any skipped inlined frames. */
2820 clear_inline_frame_state (minus_one_ptid);
2824 /* Data to be passed around while handling an event. This data is
2825 discarded between events. */
2826 struct execution_control_state
2829 /* The thread that got the event, if this was a thread event; NULL
2831 struct thread_info *event_thread;
2833 struct target_waitstatus ws;
2834 int stop_func_filled_in;
2835 CORE_ADDR stop_func_start;
2836 CORE_ADDR stop_func_end;
2837 const char *stop_func_name;
2840 /* True if the event thread hit the single-step breakpoint of
2841 another thread. Thus the event doesn't cause a stop, the thread
2842 needs to be single-stepped past the single-step breakpoint before
2843 we can switch back to the original stepping thread. */
2844 int hit_singlestep_breakpoint;
2847 static void handle_inferior_event (struct execution_control_state *ecs);
2849 static void handle_step_into_function (struct gdbarch *gdbarch,
2850 struct execution_control_state *ecs);
2851 static void handle_step_into_function_backward (struct gdbarch *gdbarch,
2852 struct execution_control_state *ecs);
2853 static void handle_signal_stop (struct execution_control_state *ecs);
2854 static void check_exception_resume (struct execution_control_state *,
2855 struct frame_info *);
2857 static void end_stepping_range (struct execution_control_state *ecs);
2858 static void stop_waiting (struct execution_control_state *ecs);
2859 static void prepare_to_wait (struct execution_control_state *ecs);
2860 static void keep_going (struct execution_control_state *ecs);
2861 static void process_event_stop_test (struct execution_control_state *ecs);
2862 static int switch_back_to_stepped_thread (struct execution_control_state *ecs);
2864 /* Callback for iterate over threads. If the thread is stopped, but
2865 the user/frontend doesn't know about that yet, go through
2866 normal_stop, as if the thread had just stopped now. ARG points at
2867 a ptid. If PTID is MINUS_ONE_PTID, applies to all threads. If
2868 ptid_is_pid(PTID) is true, applies to all threads of the process
2869 pointed at by PTID. Otherwise, apply only to the thread pointed by
2873 infrun_thread_stop_requested_callback (struct thread_info *info, void *arg)
2875 ptid_t ptid = * (ptid_t *) arg;
2877 if ((ptid_equal (info->ptid, ptid)
2878 || ptid_equal (minus_one_ptid, ptid)
2879 || (ptid_is_pid (ptid)
2880 && ptid_get_pid (ptid) == ptid_get_pid (info->ptid)))
2881 && is_running (info->ptid)
2882 && !is_executing (info->ptid))
2884 struct cleanup *old_chain;
2885 struct execution_control_state ecss;
2886 struct execution_control_state *ecs = &ecss;
2888 memset (ecs, 0, sizeof (*ecs));
2890 old_chain = make_cleanup_restore_current_thread ();
2892 overlay_cache_invalid = 1;
2893 /* Flush target cache before starting to handle each event.
2894 Target was running and cache could be stale. This is just a
2895 heuristic. Running threads may modify target memory, but we
2896 don't get any event. */
2897 target_dcache_invalidate ();
2899 /* Go through handle_inferior_event/normal_stop, so we always
2900 have consistent output as if the stop event had been
2902 ecs->ptid = info->ptid;
2903 ecs->event_thread = find_thread_ptid (info->ptid);
2904 ecs->ws.kind = TARGET_WAITKIND_STOPPED;
2905 ecs->ws.value.sig = GDB_SIGNAL_0;
2907 handle_inferior_event (ecs);
2909 if (!ecs->wait_some_more)
2911 struct thread_info *tp;
2915 /* Finish off the continuations. */
2916 tp = inferior_thread ();
2917 do_all_intermediate_continuations_thread (tp, 1);
2918 do_all_continuations_thread (tp, 1);
2921 do_cleanups (old_chain);
2927 /* This function is attached as a "thread_stop_requested" observer.
2928 Cleanup local state that assumed the PTID was to be resumed, and
2929 report the stop to the frontend. */
2932 infrun_thread_stop_requested (ptid_t ptid)
2934 struct displaced_step_inferior_state *displaced;
2936 /* PTID was requested to stop. Remove it from the displaced
2937 stepping queue, so we don't try to resume it automatically. */
2939 for (displaced = displaced_step_inferior_states;
2941 displaced = displaced->next)
2943 struct displaced_step_request *it, **prev_next_p;
2945 it = displaced->step_request_queue;
2946 prev_next_p = &displaced->step_request_queue;
2949 if (ptid_match (it->ptid, ptid))
2951 *prev_next_p = it->next;
2957 prev_next_p = &it->next;
2964 iterate_over_threads (infrun_thread_stop_requested_callback, &ptid);
2968 infrun_thread_thread_exit (struct thread_info *tp, int silent)
2970 if (ptid_equal (target_last_wait_ptid, tp->ptid))
2971 nullify_last_target_wait_ptid ();
2974 /* Delete the step resume, single-step and longjmp/exception resume
2975 breakpoints of TP. */
2978 delete_thread_infrun_breakpoints (struct thread_info *tp)
2980 delete_step_resume_breakpoint (tp);
2981 delete_exception_resume_breakpoint (tp);
2982 delete_single_step_breakpoints (tp);
2985 /* If the target still has execution, call FUNC for each thread that
2986 just stopped. In all-stop, that's all the non-exited threads; in
2987 non-stop, that's the current thread, only. */
2989 typedef void (*for_each_just_stopped_thread_callback_func)
2990 (struct thread_info *tp);
2993 for_each_just_stopped_thread (for_each_just_stopped_thread_callback_func func)
2995 if (!target_has_execution || ptid_equal (inferior_ptid, null_ptid))
3000 /* If in non-stop mode, only the current thread stopped. */
3001 func (inferior_thread ());
3005 struct thread_info *tp;
3007 /* In all-stop mode, all threads have stopped. */
3008 ALL_NON_EXITED_THREADS (tp)
3015 /* Delete the step resume and longjmp/exception resume breakpoints of
3016 the threads that just stopped. */
3019 delete_just_stopped_threads_infrun_breakpoints (void)
3021 for_each_just_stopped_thread (delete_thread_infrun_breakpoints);
3024 /* Delete the single-step breakpoints of the threads that just
3028 delete_just_stopped_threads_single_step_breakpoints (void)
3030 for_each_just_stopped_thread (delete_single_step_breakpoints);
3033 /* A cleanup wrapper. */
3036 delete_just_stopped_threads_infrun_breakpoints_cleanup (void *arg)
3038 delete_just_stopped_threads_infrun_breakpoints ();
3041 /* Pretty print the results of target_wait, for debugging purposes. */
3044 print_target_wait_results (ptid_t waiton_ptid, ptid_t result_ptid,
3045 const struct target_waitstatus *ws)
3047 char *status_string = target_waitstatus_to_string (ws);
3048 struct ui_file *tmp_stream = mem_fileopen ();
3051 /* The text is split over several lines because it was getting too long.
3052 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
3053 output as a unit; we want only one timestamp printed if debug_timestamp
3056 fprintf_unfiltered (tmp_stream,
3057 "infrun: target_wait (%d.%ld.%ld",
3058 ptid_get_pid (waiton_ptid),
3059 ptid_get_lwp (waiton_ptid),
3060 ptid_get_tid (waiton_ptid));
3061 if (ptid_get_pid (waiton_ptid) != -1)
3062 fprintf_unfiltered (tmp_stream,
3063 " [%s]", target_pid_to_str (waiton_ptid));
3064 fprintf_unfiltered (tmp_stream, ", status) =\n");
3065 fprintf_unfiltered (tmp_stream,
3066 "infrun: %d.%ld.%ld [%s],\n",
3067 ptid_get_pid (result_ptid),
3068 ptid_get_lwp (result_ptid),
3069 ptid_get_tid (result_ptid),
3070 target_pid_to_str (result_ptid));
3071 fprintf_unfiltered (tmp_stream,
3075 text = ui_file_xstrdup (tmp_stream, NULL);
3077 /* This uses %s in part to handle %'s in the text, but also to avoid
3078 a gcc error: the format attribute requires a string literal. */
3079 fprintf_unfiltered (gdb_stdlog, "%s", text);
3081 xfree (status_string);
3083 ui_file_delete (tmp_stream);
3086 /* Prepare and stabilize the inferior for detaching it. E.g.,
3087 detaching while a thread is displaced stepping is a recipe for
3088 crashing it, as nothing would readjust the PC out of the scratch
3092 prepare_for_detach (void)
3094 struct inferior *inf = current_inferior ();
3095 ptid_t pid_ptid = pid_to_ptid (inf->pid);
3096 struct cleanup *old_chain_1;
3097 struct displaced_step_inferior_state *displaced;
3099 displaced = get_displaced_stepping_state (inf->pid);
3101 /* Is any thread of this process displaced stepping? If not,
3102 there's nothing else to do. */
3103 if (displaced == NULL || ptid_equal (displaced->step_ptid, null_ptid))
3107 fprintf_unfiltered (gdb_stdlog,
3108 "displaced-stepping in-process while detaching");
3110 old_chain_1 = make_cleanup_restore_integer (&inf->detaching);
3113 while (!ptid_equal (displaced->step_ptid, null_ptid))
3115 struct cleanup *old_chain_2;
3116 struct execution_control_state ecss;
3117 struct execution_control_state *ecs;
3120 memset (ecs, 0, sizeof (*ecs));
3122 overlay_cache_invalid = 1;
3123 /* Flush target cache before starting to handle each event.
3124 Target was running and cache could be stale. This is just a
3125 heuristic. Running threads may modify target memory, but we
3126 don't get any event. */
3127 target_dcache_invalidate ();
3129 if (deprecated_target_wait_hook)
3130 ecs->ptid = deprecated_target_wait_hook (pid_ptid, &ecs->ws, 0);
3132 ecs->ptid = target_wait (pid_ptid, &ecs->ws, 0);
3135 print_target_wait_results (pid_ptid, ecs->ptid, &ecs->ws);
3137 /* If an error happens while handling the event, propagate GDB's
3138 knowledge of the executing state to the frontend/user running
3140 old_chain_2 = make_cleanup (finish_thread_state_cleanup,
3143 /* Now figure out what to do with the result of the result. */
3144 handle_inferior_event (ecs);
3146 /* No error, don't finish the state yet. */
3147 discard_cleanups (old_chain_2);
3149 /* Breakpoints and watchpoints are not installed on the target
3150 at this point, and signals are passed directly to the
3151 inferior, so this must mean the process is gone. */
3152 if (!ecs->wait_some_more)
3154 discard_cleanups (old_chain_1);
3155 error (_("Program exited while detaching"));
3159 discard_cleanups (old_chain_1);
3162 /* Wait for control to return from inferior to debugger.
3164 If inferior gets a signal, we may decide to start it up again
3165 instead of returning. That is why there is a loop in this function.
3166 When this function actually returns it means the inferior
3167 should be left stopped and GDB should read more commands. */
3170 wait_for_inferior (void)
3172 struct cleanup *old_cleanups;
3173 struct cleanup *thread_state_chain;
3177 (gdb_stdlog, "infrun: wait_for_inferior ()\n");
3180 = make_cleanup (delete_just_stopped_threads_infrun_breakpoints_cleanup,
3183 /* If an error happens while handling the event, propagate GDB's
3184 knowledge of the executing state to the frontend/user running
3186 thread_state_chain = make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
3190 struct execution_control_state ecss;
3191 struct execution_control_state *ecs = &ecss;
3192 ptid_t waiton_ptid = minus_one_ptid;
3194 memset (ecs, 0, sizeof (*ecs));
3196 overlay_cache_invalid = 1;
3198 /* Flush target cache before starting to handle each event.
3199 Target was running and cache could be stale. This is just a
3200 heuristic. Running threads may modify target memory, but we
3201 don't get any event. */
3202 target_dcache_invalidate ();
3204 if (deprecated_target_wait_hook)
3205 ecs->ptid = deprecated_target_wait_hook (waiton_ptid, &ecs->ws, 0);
3207 ecs->ptid = target_wait (waiton_ptid, &ecs->ws, 0);
3210 print_target_wait_results (waiton_ptid, ecs->ptid, &ecs->ws);
3212 /* Now figure out what to do with the result of the result. */
3213 handle_inferior_event (ecs);
3215 if (!ecs->wait_some_more)
3219 /* No error, don't finish the state yet. */
3220 discard_cleanups (thread_state_chain);
3222 do_cleanups (old_cleanups);
3225 /* Cleanup that reinstalls the readline callback handler, if the
3226 target is running in the background. If while handling the target
3227 event something triggered a secondary prompt, like e.g., a
3228 pagination prompt, we'll have removed the callback handler (see
3229 gdb_readline_wrapper_line). Need to do this as we go back to the
3230 event loop, ready to process further input. Note this has no
3231 effect if the handler hasn't actually been removed, because calling
3232 rl_callback_handler_install resets the line buffer, thus losing
3236 reinstall_readline_callback_handler_cleanup (void *arg)
3238 if (!interpreter_async)
3240 /* We're not going back to the top level event loop yet. Don't
3241 install the readline callback, as it'd prep the terminal,
3242 readline-style (raw, noecho) (e.g., --batch). We'll install
3243 it the next time the prompt is displayed, when we're ready
3248 if (async_command_editing_p && !sync_execution)
3249 gdb_rl_callback_handler_reinstall ();
3252 /* Asynchronous version of wait_for_inferior. It is called by the
3253 event loop whenever a change of state is detected on the file
3254 descriptor corresponding to the target. It can be called more than
3255 once to complete a single execution command. In such cases we need
3256 to keep the state in a global variable ECSS. If it is the last time
3257 that this function is called for a single execution command, then
3258 report to the user that the inferior has stopped, and do the
3259 necessary cleanups. */
3262 fetch_inferior_event (void *client_data)
3264 struct execution_control_state ecss;
3265 struct execution_control_state *ecs = &ecss;
3266 struct cleanup *old_chain = make_cleanup (null_cleanup, NULL);
3267 struct cleanup *ts_old_chain;
3268 int was_sync = sync_execution;
3270 ptid_t waiton_ptid = minus_one_ptid;
3272 memset (ecs, 0, sizeof (*ecs));
3274 /* End up with readline processing input, if necessary. */
3275 make_cleanup (reinstall_readline_callback_handler_cleanup, NULL);
3277 /* We're handling a live event, so make sure we're doing live
3278 debugging. If we're looking at traceframes while the target is
3279 running, we're going to need to get back to that mode after
3280 handling the event. */
3283 make_cleanup_restore_current_traceframe ();
3284 set_current_traceframe (-1);
3288 /* In non-stop mode, the user/frontend should not notice a thread
3289 switch due to internal events. Make sure we reverse to the
3290 user selected thread and frame after handling the event and
3291 running any breakpoint commands. */
3292 make_cleanup_restore_current_thread ();
3294 overlay_cache_invalid = 1;
3295 /* Flush target cache before starting to handle each event. Target
3296 was running and cache could be stale. This is just a heuristic.
3297 Running threads may modify target memory, but we don't get any
3299 target_dcache_invalidate ();
3301 make_cleanup_restore_integer (&execution_direction);
3302 execution_direction = target_execution_direction ();
3304 if (deprecated_target_wait_hook)
3306 deprecated_target_wait_hook (waiton_ptid, &ecs->ws, TARGET_WNOHANG);
3308 ecs->ptid = target_wait (waiton_ptid, &ecs->ws, TARGET_WNOHANG);
3311 print_target_wait_results (waiton_ptid, ecs->ptid, &ecs->ws);
3313 /* If an error happens while handling the event, propagate GDB's
3314 knowledge of the executing state to the frontend/user running
3317 ts_old_chain = make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
3319 ts_old_chain = make_cleanup (finish_thread_state_cleanup, &ecs->ptid);
3321 /* Get executed before make_cleanup_restore_current_thread above to apply
3322 still for the thread which has thrown the exception. */
3323 make_bpstat_clear_actions_cleanup ();
3325 make_cleanup (delete_just_stopped_threads_infrun_breakpoints_cleanup, NULL);
3327 /* Now figure out what to do with the result of the result. */
3328 handle_inferior_event (ecs);
3330 if (!ecs->wait_some_more)
3332 struct inferior *inf = find_inferior_ptid (ecs->ptid);
3334 delete_just_stopped_threads_infrun_breakpoints ();
3336 /* We may not find an inferior if this was a process exit. */
3337 if (inf == NULL || inf->control.stop_soon == NO_STOP_QUIETLY)
3340 if (target_has_execution
3341 && ecs->ws.kind != TARGET_WAITKIND_NO_RESUMED
3342 && ecs->ws.kind != TARGET_WAITKIND_EXITED
3343 && ecs->ws.kind != TARGET_WAITKIND_SIGNALLED
3344 && ecs->event_thread->step_multi
3345 && ecs->event_thread->control.stop_step)
3346 inferior_event_handler (INF_EXEC_CONTINUE, NULL);
3349 inferior_event_handler (INF_EXEC_COMPLETE, NULL);
3354 /* No error, don't finish the thread states yet. */
3355 discard_cleanups (ts_old_chain);
3357 /* Revert thread and frame. */
3358 do_cleanups (old_chain);
3360 /* If the inferior was in sync execution mode, and now isn't,
3361 restore the prompt (a synchronous execution command has finished,
3362 and we're ready for input). */
3363 if (interpreter_async && was_sync && !sync_execution)
3364 observer_notify_sync_execution_done ();
3368 && exec_done_display_p
3369 && (ptid_equal (inferior_ptid, null_ptid)
3370 || !is_running (inferior_ptid)))
3371 printf_unfiltered (_("completed.\n"));
3374 /* Record the frame and location we're currently stepping through. */
3376 set_step_info (struct frame_info *frame, struct symtab_and_line sal)
3378 struct thread_info *tp = inferior_thread ();
3380 tp->control.step_frame_id = get_frame_id (frame);
3381 tp->control.step_stack_frame_id = get_stack_frame_id (frame);
3383 tp->current_symtab = sal.symtab;
3384 tp->current_line = sal.line;
3387 /* Clear context switchable stepping state. */
3390 init_thread_stepping_state (struct thread_info *tss)
3392 tss->stepped_breakpoint = 0;
3393 tss->stepping_over_breakpoint = 0;
3394 tss->stepping_over_watchpoint = 0;
3395 tss->step_after_step_resume_breakpoint = 0;
3398 /* Set the cached copy of the last ptid/waitstatus. */
3401 set_last_target_status (ptid_t ptid, struct target_waitstatus status)
3403 target_last_wait_ptid = ptid;
3404 target_last_waitstatus = status;
3407 /* Return the cached copy of the last pid/waitstatus returned by
3408 target_wait()/deprecated_target_wait_hook(). The data is actually
3409 cached by handle_inferior_event(), which gets called immediately
3410 after target_wait()/deprecated_target_wait_hook(). */
3413 get_last_target_status (ptid_t *ptidp, struct target_waitstatus *status)
3415 *ptidp = target_last_wait_ptid;
3416 *status = target_last_waitstatus;
3420 nullify_last_target_wait_ptid (void)
3422 target_last_wait_ptid = minus_one_ptid;
3425 /* Switch thread contexts. */
3428 context_switch (ptid_t ptid)
3430 if (debug_infrun && !ptid_equal (ptid, inferior_ptid))
3432 fprintf_unfiltered (gdb_stdlog, "infrun: Switching context from %s ",
3433 target_pid_to_str (inferior_ptid));
3434 fprintf_unfiltered (gdb_stdlog, "to %s\n",
3435 target_pid_to_str (ptid));
3438 switch_to_thread (ptid);
3442 adjust_pc_after_break (struct execution_control_state *ecs)
3444 struct regcache *regcache;
3445 struct gdbarch *gdbarch;
3446 struct address_space *aspace;
3447 CORE_ADDR breakpoint_pc, decr_pc;
3449 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
3450 we aren't, just return.
3452 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
3453 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
3454 implemented by software breakpoints should be handled through the normal
3457 NOTE drow/2004-01-31: On some targets, breakpoints may generate
3458 different signals (SIGILL or SIGEMT for instance), but it is less
3459 clear where the PC is pointing afterwards. It may not match
3460 gdbarch_decr_pc_after_break. I don't know any specific target that
3461 generates these signals at breakpoints (the code has been in GDB since at
3462 least 1992) so I can not guess how to handle them here.
3464 In earlier versions of GDB, a target with
3465 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
3466 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
3467 target with both of these set in GDB history, and it seems unlikely to be
3468 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
3470 if (ecs->ws.kind != TARGET_WAITKIND_STOPPED)
3473 if (ecs->ws.value.sig != GDB_SIGNAL_TRAP)
3476 /* In reverse execution, when a breakpoint is hit, the instruction
3477 under it has already been de-executed. The reported PC always
3478 points at the breakpoint address, so adjusting it further would
3479 be wrong. E.g., consider this case on a decr_pc_after_break == 1
3482 B1 0x08000000 : INSN1
3483 B2 0x08000001 : INSN2
3485 PC -> 0x08000003 : INSN4
3487 Say you're stopped at 0x08000003 as above. Reverse continuing
3488 from that point should hit B2 as below. Reading the PC when the
3489 SIGTRAP is reported should read 0x08000001 and INSN2 should have
3490 been de-executed already.
3492 B1 0x08000000 : INSN1
3493 B2 PC -> 0x08000001 : INSN2
3497 We can't apply the same logic as for forward execution, because
3498 we would wrongly adjust the PC to 0x08000000, since there's a
3499 breakpoint at PC - 1. We'd then report a hit on B1, although
3500 INSN1 hadn't been de-executed yet. Doing nothing is the correct
3502 if (execution_direction == EXEC_REVERSE)
3505 /* If the target can tell whether the thread hit a SW breakpoint,
3506 trust it. Targets that can tell also adjust the PC
3508 if (target_supports_stopped_by_sw_breakpoint ())
3511 /* Note that relying on whether a breakpoint is planted in memory to
3512 determine this can fail. E.g,. the breakpoint could have been
3513 removed since. Or the thread could have been told to step an
3514 instruction the size of a breakpoint instruction, and only
3515 _after_ was a breakpoint inserted at its address. */
3517 /* If this target does not decrement the PC after breakpoints, then
3518 we have nothing to do. */
3519 regcache = get_thread_regcache (ecs->ptid);
3520 gdbarch = get_regcache_arch (regcache);
3522 decr_pc = gdbarch_decr_pc_after_break (gdbarch);
3526 aspace = get_regcache_aspace (regcache);
3528 /* Find the location where (if we've hit a breakpoint) the
3529 breakpoint would be. */
3530 breakpoint_pc = regcache_read_pc (regcache) - decr_pc;
3532 /* If the target can't tell whether a software breakpoint triggered,
3533 fallback to figuring it out based on breakpoints we think were
3534 inserted in the target, and on whether the thread was stepped or
3537 /* Check whether there actually is a software breakpoint inserted at
3540 If in non-stop mode, a race condition is possible where we've
3541 removed a breakpoint, but stop events for that breakpoint were
3542 already queued and arrive later. To suppress those spurious
3543 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
3544 and retire them after a number of stop events are reported. Note
3545 this is an heuristic and can thus get confused. The real fix is
3546 to get the "stopped by SW BP and needs adjustment" info out of
3547 the target/kernel (and thus never reach here; see above). */
3548 if (software_breakpoint_inserted_here_p (aspace, breakpoint_pc)
3549 || (non_stop && moribund_breakpoint_here_p (aspace, breakpoint_pc)))
3551 struct cleanup *old_cleanups = make_cleanup (null_cleanup, NULL);
3553 if (record_full_is_used ())
3554 record_full_gdb_operation_disable_set ();
3556 /* When using hardware single-step, a SIGTRAP is reported for both
3557 a completed single-step and a software breakpoint. Need to
3558 differentiate between the two, as the latter needs adjusting
3559 but the former does not.
3561 The SIGTRAP can be due to a completed hardware single-step only if
3562 - we didn't insert software single-step breakpoints
3563 - this thread is currently being stepped
3565 If any of these events did not occur, we must have stopped due
3566 to hitting a software breakpoint, and have to back up to the
3569 As a special case, we could have hardware single-stepped a
3570 software breakpoint. In this case (prev_pc == breakpoint_pc),
3571 we also need to back up to the breakpoint address. */
3573 if (thread_has_single_step_breakpoints_set (ecs->event_thread)
3574 || !currently_stepping (ecs->event_thread)
3575 || (ecs->event_thread->stepped_breakpoint
3576 && ecs->event_thread->prev_pc == breakpoint_pc))
3577 regcache_write_pc (regcache, breakpoint_pc);
3579 do_cleanups (old_cleanups);
3584 stepped_in_from (struct frame_info *frame, struct frame_id step_frame_id)
3586 for (frame = get_prev_frame (frame);
3588 frame = get_prev_frame (frame))
3590 if (frame_id_eq (get_frame_id (frame), step_frame_id))
3592 if (get_frame_type (frame) != INLINE_FRAME)
3599 /* Auxiliary function that handles syscall entry/return events.
3600 It returns 1 if the inferior should keep going (and GDB
3601 should ignore the event), or 0 if the event deserves to be
3605 handle_syscall_event (struct execution_control_state *ecs)
3607 struct regcache *regcache;
3610 if (!ptid_equal (ecs->ptid, inferior_ptid))
3611 context_switch (ecs->ptid);
3613 regcache = get_thread_regcache (ecs->ptid);
3614 syscall_number = ecs->ws.value.syscall_number;
3615 stop_pc = regcache_read_pc (regcache);
3617 if (catch_syscall_enabled () > 0
3618 && catching_syscall_number (syscall_number) > 0)
3621 fprintf_unfiltered (gdb_stdlog, "infrun: syscall number = '%d'\n",
3624 ecs->event_thread->control.stop_bpstat
3625 = bpstat_stop_status (get_regcache_aspace (regcache),
3626 stop_pc, ecs->ptid, &ecs->ws);
3628 if (bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
3630 /* Catchpoint hit. */
3635 /* If no catchpoint triggered for this, then keep going. */
3640 /* Lazily fill in the execution_control_state's stop_func_* fields. */
3643 fill_in_stop_func (struct gdbarch *gdbarch,
3644 struct execution_control_state *ecs)
3646 if (!ecs->stop_func_filled_in)
3648 /* Don't care about return value; stop_func_start and stop_func_name
3649 will both be 0 if it doesn't work. */
3650 find_pc_partial_function (stop_pc, &ecs->stop_func_name,
3651 &ecs->stop_func_start, &ecs->stop_func_end);
3652 ecs->stop_func_start
3653 += gdbarch_deprecated_function_start_offset (gdbarch);
3655 if (gdbarch_skip_entrypoint_p (gdbarch))
3656 ecs->stop_func_start = gdbarch_skip_entrypoint (gdbarch,
3657 ecs->stop_func_start);
3659 ecs->stop_func_filled_in = 1;
3664 /* Return the STOP_SOON field of the inferior pointed at by PTID. */
3666 static enum stop_kind
3667 get_inferior_stop_soon (ptid_t ptid)
3669 struct inferior *inf = find_inferior_ptid (ptid);
3671 gdb_assert (inf != NULL);
3672 return inf->control.stop_soon;
3675 /* Given an execution control state that has been freshly filled in by
3676 an event from the inferior, figure out what it means and take
3679 The alternatives are:
3681 1) stop_waiting and return; to really stop and return to the
3684 2) keep_going and return; to wait for the next event (set
3685 ecs->event_thread->stepping_over_breakpoint to 1 to single step
3689 handle_inferior_event_1 (struct execution_control_state *ecs)
3691 enum stop_kind stop_soon;
3693 if (ecs->ws.kind == TARGET_WAITKIND_IGNORE)
3695 /* We had an event in the inferior, but we are not interested in
3696 handling it at this level. The lower layers have already
3697 done what needs to be done, if anything.
3699 One of the possible circumstances for this is when the
3700 inferior produces output for the console. The inferior has
3701 not stopped, and we are ignoring the event. Another possible
3702 circumstance is any event which the lower level knows will be
3703 reported multiple times without an intervening resume. */
3705 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_IGNORE\n");
3706 prepare_to_wait (ecs);
3710 if (ecs->ws.kind == TARGET_WAITKIND_NO_RESUMED
3711 && target_can_async_p () && !sync_execution)
3713 /* There were no unwaited-for children left in the target, but,
3714 we're not synchronously waiting for events either. Just
3715 ignore. Otherwise, if we were running a synchronous
3716 execution command, we need to cancel it and give the user
3717 back the terminal. */
3719 fprintf_unfiltered (gdb_stdlog,
3720 "infrun: TARGET_WAITKIND_NO_RESUMED (ignoring)\n");
3721 prepare_to_wait (ecs);
3725 /* Cache the last pid/waitstatus. */
3726 set_last_target_status (ecs->ptid, ecs->ws);
3728 /* Always clear state belonging to the previous time we stopped. */
3729 stop_stack_dummy = STOP_NONE;
3731 if (ecs->ws.kind == TARGET_WAITKIND_NO_RESUMED)
3733 /* No unwaited-for children left. IOW, all resumed children
3736 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_NO_RESUMED\n");
3738 stop_print_frame = 0;
3743 if (ecs->ws.kind != TARGET_WAITKIND_EXITED
3744 && ecs->ws.kind != TARGET_WAITKIND_SIGNALLED)
3746 ecs->event_thread = find_thread_ptid (ecs->ptid);
3747 /* If it's a new thread, add it to the thread database. */
3748 if (ecs->event_thread == NULL)
3749 ecs->event_thread = add_thread (ecs->ptid);
3751 /* Disable range stepping. If the next step request could use a
3752 range, this will be end up re-enabled then. */
3753 ecs->event_thread->control.may_range_step = 0;
3756 /* Dependent on valid ECS->EVENT_THREAD. */
3757 adjust_pc_after_break (ecs);
3759 /* Dependent on the current PC value modified by adjust_pc_after_break. */
3760 reinit_frame_cache ();
3762 breakpoint_retire_moribund ();
3764 /* First, distinguish signals caused by the debugger from signals
3765 that have to do with the program's own actions. Note that
3766 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
3767 on the operating system version. Here we detect when a SIGILL or
3768 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
3769 something similar for SIGSEGV, since a SIGSEGV will be generated
3770 when we're trying to execute a breakpoint instruction on a
3771 non-executable stack. This happens for call dummy breakpoints
3772 for architectures like SPARC that place call dummies on the
3774 if (ecs->ws.kind == TARGET_WAITKIND_STOPPED
3775 && (ecs->ws.value.sig == GDB_SIGNAL_ILL
3776 || ecs->ws.value.sig == GDB_SIGNAL_SEGV
3777 || ecs->ws.value.sig == GDB_SIGNAL_EMT))
3779 struct regcache *regcache = get_thread_regcache (ecs->ptid);
3781 if (breakpoint_inserted_here_p (get_regcache_aspace (regcache),
3782 regcache_read_pc (regcache)))
3785 fprintf_unfiltered (gdb_stdlog,
3786 "infrun: Treating signal as SIGTRAP\n");
3787 ecs->ws.value.sig = GDB_SIGNAL_TRAP;
3791 /* Mark the non-executing threads accordingly. In all-stop, all
3792 threads of all processes are stopped when we get any event
3793 reported. In non-stop mode, only the event thread stops. If
3794 we're handling a process exit in non-stop mode, there's nothing
3795 to do, as threads of the dead process are gone, and threads of
3796 any other process were left running. */
3798 set_executing (minus_one_ptid, 0);
3799 else if (ecs->ws.kind != TARGET_WAITKIND_SIGNALLED
3800 && ecs->ws.kind != TARGET_WAITKIND_EXITED)
3801 set_executing (ecs->ptid, 0);
3803 switch (ecs->ws.kind)
3805 case TARGET_WAITKIND_LOADED:
3807 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_LOADED\n");
3808 if (!ptid_equal (ecs->ptid, inferior_ptid))
3809 context_switch (ecs->ptid);
3810 /* Ignore gracefully during startup of the inferior, as it might
3811 be the shell which has just loaded some objects, otherwise
3812 add the symbols for the newly loaded objects. Also ignore at
3813 the beginning of an attach or remote session; we will query
3814 the full list of libraries once the connection is
3817 stop_soon = get_inferior_stop_soon (ecs->ptid);
3818 if (stop_soon == NO_STOP_QUIETLY)
3820 struct regcache *regcache;
3822 regcache = get_thread_regcache (ecs->ptid);
3824 handle_solib_event ();
3826 ecs->event_thread->control.stop_bpstat
3827 = bpstat_stop_status (get_regcache_aspace (regcache),
3828 stop_pc, ecs->ptid, &ecs->ws);
3830 if (bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
3832 /* A catchpoint triggered. */
3833 process_event_stop_test (ecs);
3837 /* If requested, stop when the dynamic linker notifies
3838 gdb of events. This allows the user to get control
3839 and place breakpoints in initializer routines for
3840 dynamically loaded objects (among other things). */
3841 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
3842 if (stop_on_solib_events)
3844 /* Make sure we print "Stopped due to solib-event" in
3846 stop_print_frame = 1;
3853 /* If we are skipping through a shell, or through shared library
3854 loading that we aren't interested in, resume the program. If
3855 we're running the program normally, also resume. */
3856 if (stop_soon == STOP_QUIETLY || stop_soon == NO_STOP_QUIETLY)
3858 /* Loading of shared libraries might have changed breakpoint
3859 addresses. Make sure new breakpoints are inserted. */
3860 if (stop_soon == NO_STOP_QUIETLY)
3861 insert_breakpoints ();
3862 resume (GDB_SIGNAL_0);
3863 prepare_to_wait (ecs);
3867 /* But stop if we're attaching or setting up a remote
3869 if (stop_soon == STOP_QUIETLY_NO_SIGSTOP
3870 || stop_soon == STOP_QUIETLY_REMOTE)
3873 fprintf_unfiltered (gdb_stdlog, "infrun: quietly stopped\n");
3878 internal_error (__FILE__, __LINE__,
3879 _("unhandled stop_soon: %d"), (int) stop_soon);
3881 case TARGET_WAITKIND_SPURIOUS:
3883 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_SPURIOUS\n");
3884 if (!ptid_equal (ecs->ptid, inferior_ptid))
3885 context_switch (ecs->ptid);
3886 resume (GDB_SIGNAL_0);
3887 prepare_to_wait (ecs);
3890 case TARGET_WAITKIND_EXITED:
3891 case TARGET_WAITKIND_SIGNALLED:
3894 if (ecs->ws.kind == TARGET_WAITKIND_EXITED)
3895 fprintf_unfiltered (gdb_stdlog,
3896 "infrun: TARGET_WAITKIND_EXITED\n");
3898 fprintf_unfiltered (gdb_stdlog,
3899 "infrun: TARGET_WAITKIND_SIGNALLED\n");
3902 inferior_ptid = ecs->ptid;
3903 set_current_inferior (find_inferior_ptid (ecs->ptid));
3904 set_current_program_space (current_inferior ()->pspace);
3905 handle_vfork_child_exec_or_exit (0);
3906 target_terminal_ours (); /* Must do this before mourn anyway. */
3908 /* Clearing any previous state of convenience variables. */
3909 clear_exit_convenience_vars ();
3911 if (ecs->ws.kind == TARGET_WAITKIND_EXITED)
3913 /* Record the exit code in the convenience variable $_exitcode, so
3914 that the user can inspect this again later. */
3915 set_internalvar_integer (lookup_internalvar ("_exitcode"),
3916 (LONGEST) ecs->ws.value.integer);
3918 /* Also record this in the inferior itself. */
3919 current_inferior ()->has_exit_code = 1;
3920 current_inferior ()->exit_code = (LONGEST) ecs->ws.value.integer;
3922 /* Support the --return-child-result option. */
3923 return_child_result_value = ecs->ws.value.integer;
3925 observer_notify_exited (ecs->ws.value.integer);
3929 struct regcache *regcache = get_thread_regcache (ecs->ptid);
3930 struct gdbarch *gdbarch = get_regcache_arch (regcache);
3932 if (gdbarch_gdb_signal_to_target_p (gdbarch))
3934 /* Set the value of the internal variable $_exitsignal,
3935 which holds the signal uncaught by the inferior. */
3936 set_internalvar_integer (lookup_internalvar ("_exitsignal"),
3937 gdbarch_gdb_signal_to_target (gdbarch,
3938 ecs->ws.value.sig));
3942 /* We don't have access to the target's method used for
3943 converting between signal numbers (GDB's internal
3944 representation <-> target's representation).
3945 Therefore, we cannot do a good job at displaying this
3946 information to the user. It's better to just warn
3947 her about it (if infrun debugging is enabled), and
3950 fprintf_filtered (gdb_stdlog, _("\
3951 Cannot fill $_exitsignal with the correct signal number.\n"));
3954 observer_notify_signal_exited (ecs->ws.value.sig);
3957 gdb_flush (gdb_stdout);
3958 target_mourn_inferior ();
3959 stop_print_frame = 0;
3963 /* The following are the only cases in which we keep going;
3964 the above cases end in a continue or goto. */
3965 case TARGET_WAITKIND_FORKED:
3966 case TARGET_WAITKIND_VFORKED:
3969 if (ecs->ws.kind == TARGET_WAITKIND_FORKED)
3970 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_FORKED\n");
3972 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_VFORKED\n");
3975 /* Check whether the inferior is displaced stepping. */
3977 struct regcache *regcache = get_thread_regcache (ecs->ptid);
3978 struct gdbarch *gdbarch = get_regcache_arch (regcache);
3979 struct displaced_step_inferior_state *displaced
3980 = get_displaced_stepping_state (ptid_get_pid (ecs->ptid));
3982 /* If checking displaced stepping is supported, and thread
3983 ecs->ptid is displaced stepping. */
3984 if (displaced && ptid_equal (displaced->step_ptid, ecs->ptid))
3986 struct inferior *parent_inf
3987 = find_inferior_ptid (ecs->ptid);
3988 struct regcache *child_regcache;
3989 CORE_ADDR parent_pc;
3991 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
3992 indicating that the displaced stepping of syscall instruction
3993 has been done. Perform cleanup for parent process here. Note
3994 that this operation also cleans up the child process for vfork,
3995 because their pages are shared. */
3996 displaced_step_fixup (ecs->ptid, GDB_SIGNAL_TRAP);
3998 if (ecs->ws.kind == TARGET_WAITKIND_FORKED)
4000 /* Restore scratch pad for child process. */
4001 displaced_step_restore (displaced, ecs->ws.value.related_pid);
4004 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
4005 the child's PC is also within the scratchpad. Set the child's PC
4006 to the parent's PC value, which has already been fixed up.
4007 FIXME: we use the parent's aspace here, although we're touching
4008 the child, because the child hasn't been added to the inferior
4009 list yet at this point. */
4012 = get_thread_arch_aspace_regcache (ecs->ws.value.related_pid,
4014 parent_inf->aspace);
4015 /* Read PC value of parent process. */
4016 parent_pc = regcache_read_pc (regcache);
4018 if (debug_displaced)
4019 fprintf_unfiltered (gdb_stdlog,
4020 "displaced: write child pc from %s to %s\n",
4022 regcache_read_pc (child_regcache)),
4023 paddress (gdbarch, parent_pc));
4025 regcache_write_pc (child_regcache, parent_pc);
4029 if (!ptid_equal (ecs->ptid, inferior_ptid))
4030 context_switch (ecs->ptid);
4032 /* Immediately detach breakpoints from the child before there's
4033 any chance of letting the user delete breakpoints from the
4034 breakpoint lists. If we don't do this early, it's easy to
4035 leave left over traps in the child, vis: "break foo; catch
4036 fork; c; <fork>; del; c; <child calls foo>". We only follow
4037 the fork on the last `continue', and by that time the
4038 breakpoint at "foo" is long gone from the breakpoint table.
4039 If we vforked, then we don't need to unpatch here, since both
4040 parent and child are sharing the same memory pages; we'll
4041 need to unpatch at follow/detach time instead to be certain
4042 that new breakpoints added between catchpoint hit time and
4043 vfork follow are detached. */
4044 if (ecs->ws.kind != TARGET_WAITKIND_VFORKED)
4046 /* This won't actually modify the breakpoint list, but will
4047 physically remove the breakpoints from the child. */
4048 detach_breakpoints (ecs->ws.value.related_pid);
4051 delete_just_stopped_threads_single_step_breakpoints ();
4053 /* In case the event is caught by a catchpoint, remember that
4054 the event is to be followed at the next resume of the thread,
4055 and not immediately. */
4056 ecs->event_thread->pending_follow = ecs->ws;
4058 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
4060 ecs->event_thread->control.stop_bpstat
4061 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
4062 stop_pc, ecs->ptid, &ecs->ws);
4064 /* If no catchpoint triggered for this, then keep going. Note
4065 that we're interested in knowing the bpstat actually causes a
4066 stop, not just if it may explain the signal. Software
4067 watchpoints, for example, always appear in the bpstat. */
4068 if (!bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
4074 = (follow_fork_mode_string == follow_fork_mode_child);
4076 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
4078 should_resume = follow_fork ();
4081 child = ecs->ws.value.related_pid;
4083 /* In non-stop mode, also resume the other branch. */
4084 if (non_stop && !detach_fork)
4087 switch_to_thread (parent);
4089 switch_to_thread (child);
4091 ecs->event_thread = inferior_thread ();
4092 ecs->ptid = inferior_ptid;
4097 switch_to_thread (child);
4099 switch_to_thread (parent);
4101 ecs->event_thread = inferior_thread ();
4102 ecs->ptid = inferior_ptid;
4110 process_event_stop_test (ecs);
4113 case TARGET_WAITKIND_VFORK_DONE:
4114 /* Done with the shared memory region. Re-insert breakpoints in
4115 the parent, and keep going. */
4118 fprintf_unfiltered (gdb_stdlog,
4119 "infrun: TARGET_WAITKIND_VFORK_DONE\n");
4121 if (!ptid_equal (ecs->ptid, inferior_ptid))
4122 context_switch (ecs->ptid);
4124 current_inferior ()->waiting_for_vfork_done = 0;
4125 current_inferior ()->pspace->breakpoints_not_allowed = 0;
4126 /* This also takes care of reinserting breakpoints in the
4127 previously locked inferior. */
4131 case TARGET_WAITKIND_EXECD:
4133 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_EXECD\n");
4135 if (!ptid_equal (ecs->ptid, inferior_ptid))
4136 context_switch (ecs->ptid);
4138 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
4140 /* Do whatever is necessary to the parent branch of the vfork. */
4141 handle_vfork_child_exec_or_exit (1);
4143 /* This causes the eventpoints and symbol table to be reset.
4144 Must do this now, before trying to determine whether to
4146 follow_exec (inferior_ptid, ecs->ws.value.execd_pathname);
4148 ecs->event_thread->control.stop_bpstat
4149 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
4150 stop_pc, ecs->ptid, &ecs->ws);
4152 /* Note that this may be referenced from inside
4153 bpstat_stop_status above, through inferior_has_execd. */
4154 xfree (ecs->ws.value.execd_pathname);
4155 ecs->ws.value.execd_pathname = NULL;
4157 /* If no catchpoint triggered for this, then keep going. */
4158 if (!bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
4160 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
4164 process_event_stop_test (ecs);
4167 /* Be careful not to try to gather much state about a thread
4168 that's in a syscall. It's frequently a losing proposition. */
4169 case TARGET_WAITKIND_SYSCALL_ENTRY:
4171 fprintf_unfiltered (gdb_stdlog,
4172 "infrun: TARGET_WAITKIND_SYSCALL_ENTRY\n");
4173 /* Getting the current syscall number. */
4174 if (handle_syscall_event (ecs) == 0)
4175 process_event_stop_test (ecs);
4178 /* Before examining the threads further, step this thread to
4179 get it entirely out of the syscall. (We get notice of the
4180 event when the thread is just on the verge of exiting a
4181 syscall. Stepping one instruction seems to get it back
4183 case TARGET_WAITKIND_SYSCALL_RETURN:
4185 fprintf_unfiltered (gdb_stdlog,
4186 "infrun: TARGET_WAITKIND_SYSCALL_RETURN\n");
4187 if (handle_syscall_event (ecs) == 0)
4188 process_event_stop_test (ecs);
4191 case TARGET_WAITKIND_STOPPED:
4193 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_STOPPED\n");
4194 ecs->event_thread->suspend.stop_signal = ecs->ws.value.sig;
4195 handle_signal_stop (ecs);
4198 case TARGET_WAITKIND_NO_HISTORY:
4200 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_NO_HISTORY\n");
4201 /* Reverse execution: target ran out of history info. */
4203 delete_just_stopped_threads_single_step_breakpoints ();
4204 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
4205 observer_notify_no_history ();
4211 /* A wrapper around handle_inferior_event_1, which also makes sure
4212 that all temporary struct value objects that were created during
4213 the handling of the event get deleted at the end. */
4216 handle_inferior_event (struct execution_control_state *ecs)
4218 struct value *mark = value_mark ();
4220 handle_inferior_event_1 (ecs);
4221 /* Purge all temporary values created during the event handling,
4222 as it could be a long time before we return to the command level
4223 where such values would otherwise be purged. */
4224 value_free_to_mark (mark);
4227 /* Come here when the program has stopped with a signal. */
4230 handle_signal_stop (struct execution_control_state *ecs)
4232 struct frame_info *frame;
4233 struct gdbarch *gdbarch;
4234 int stopped_by_watchpoint;
4235 enum stop_kind stop_soon;
4238 gdb_assert (ecs->ws.kind == TARGET_WAITKIND_STOPPED);
4240 /* Do we need to clean up the state of a thread that has
4241 completed a displaced single-step? (Doing so usually affects
4242 the PC, so do it here, before we set stop_pc.) */
4243 displaced_step_fixup (ecs->ptid,
4244 ecs->event_thread->suspend.stop_signal);
4246 /* If we either finished a single-step or hit a breakpoint, but
4247 the user wanted this thread to be stopped, pretend we got a
4248 SIG0 (generic unsignaled stop). */
4249 if (ecs->event_thread->stop_requested
4250 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
4251 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
4253 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
4257 struct regcache *regcache = get_thread_regcache (ecs->ptid);
4258 struct gdbarch *gdbarch = get_regcache_arch (regcache);
4259 struct cleanup *old_chain = save_inferior_ptid ();
4261 inferior_ptid = ecs->ptid;
4263 fprintf_unfiltered (gdb_stdlog, "infrun: stop_pc = %s\n",
4264 paddress (gdbarch, stop_pc));
4265 if (target_stopped_by_watchpoint ())
4269 fprintf_unfiltered (gdb_stdlog, "infrun: stopped by watchpoint\n");
4271 if (target_stopped_data_address (¤t_target, &addr))
4272 fprintf_unfiltered (gdb_stdlog,
4273 "infrun: stopped data address = %s\n",
4274 paddress (gdbarch, addr));
4276 fprintf_unfiltered (gdb_stdlog,
4277 "infrun: (no data address available)\n");
4280 do_cleanups (old_chain);
4283 /* This is originated from start_remote(), start_inferior() and
4284 shared libraries hook functions. */
4285 stop_soon = get_inferior_stop_soon (ecs->ptid);
4286 if (stop_soon == STOP_QUIETLY || stop_soon == STOP_QUIETLY_REMOTE)
4288 if (!ptid_equal (ecs->ptid, inferior_ptid))
4289 context_switch (ecs->ptid);
4291 fprintf_unfiltered (gdb_stdlog, "infrun: quietly stopped\n");
4292 stop_print_frame = 1;
4297 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
4300 if (!ptid_equal (ecs->ptid, inferior_ptid))
4301 context_switch (ecs->ptid);
4303 fprintf_unfiltered (gdb_stdlog, "infrun: stopped\n");
4304 stop_print_frame = 0;
4309 /* This originates from attach_command(). We need to overwrite
4310 the stop_signal here, because some kernels don't ignore a
4311 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
4312 See more comments in inferior.h. On the other hand, if we
4313 get a non-SIGSTOP, report it to the user - assume the backend
4314 will handle the SIGSTOP if it should show up later.
4316 Also consider that the attach is complete when we see a
4317 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
4318 target extended-remote report it instead of a SIGSTOP
4319 (e.g. gdbserver). We already rely on SIGTRAP being our
4320 signal, so this is no exception.
4322 Also consider that the attach is complete when we see a
4323 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
4324 the target to stop all threads of the inferior, in case the
4325 low level attach operation doesn't stop them implicitly. If
4326 they weren't stopped implicitly, then the stub will report a
4327 GDB_SIGNAL_0, meaning: stopped for no particular reason
4328 other than GDB's request. */
4329 if (stop_soon == STOP_QUIETLY_NO_SIGSTOP
4330 && (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_STOP
4331 || ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
4332 || ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_0))
4334 stop_print_frame = 1;
4336 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
4340 /* See if something interesting happened to the non-current thread. If
4341 so, then switch to that thread. */
4342 if (!ptid_equal (ecs->ptid, inferior_ptid))
4345 fprintf_unfiltered (gdb_stdlog, "infrun: context switch\n");
4347 context_switch (ecs->ptid);
4349 if (deprecated_context_hook)
4350 deprecated_context_hook (pid_to_thread_id (ecs->ptid));
4353 /* At this point, get hold of the now-current thread's frame. */
4354 frame = get_current_frame ();
4355 gdbarch = get_frame_arch (frame);
4357 /* Pull the single step breakpoints out of the target. */
4358 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
4360 struct regcache *regcache;
4361 struct address_space *aspace;
4364 regcache = get_thread_regcache (ecs->ptid);
4365 aspace = get_regcache_aspace (regcache);
4366 pc = regcache_read_pc (regcache);
4368 /* However, before doing so, if this single-step breakpoint was
4369 actually for another thread, set this thread up for moving
4371 if (!thread_has_single_step_breakpoint_here (ecs->event_thread,
4374 if (single_step_breakpoint_inserted_here_p (aspace, pc))
4378 fprintf_unfiltered (gdb_stdlog,
4379 "infrun: [%s] hit another thread's "
4380 "single-step breakpoint\n",
4381 target_pid_to_str (ecs->ptid));
4383 ecs->hit_singlestep_breakpoint = 1;
4390 fprintf_unfiltered (gdb_stdlog,
4391 "infrun: [%s] hit its "
4392 "single-step breakpoint\n",
4393 target_pid_to_str (ecs->ptid));
4397 delete_just_stopped_threads_single_step_breakpoints ();
4399 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
4400 && ecs->event_thread->control.trap_expected
4401 && ecs->event_thread->stepping_over_watchpoint)
4402 stopped_by_watchpoint = 0;
4404 stopped_by_watchpoint = watchpoints_triggered (&ecs->ws);
4406 /* If necessary, step over this watchpoint. We'll be back to display
4408 if (stopped_by_watchpoint
4409 && (target_have_steppable_watchpoint
4410 || gdbarch_have_nonsteppable_watchpoint (gdbarch)))
4412 /* At this point, we are stopped at an instruction which has
4413 attempted to write to a piece of memory under control of
4414 a watchpoint. The instruction hasn't actually executed
4415 yet. If we were to evaluate the watchpoint expression
4416 now, we would get the old value, and therefore no change
4417 would seem to have occurred.
4419 In order to make watchpoints work `right', we really need
4420 to complete the memory write, and then evaluate the
4421 watchpoint expression. We do this by single-stepping the
4424 It may not be necessary to disable the watchpoint to step over
4425 it. For example, the PA can (with some kernel cooperation)
4426 single step over a watchpoint without disabling the watchpoint.
4428 It is far more common to need to disable a watchpoint to step
4429 the inferior over it. If we have non-steppable watchpoints,
4430 we must disable the current watchpoint; it's simplest to
4431 disable all watchpoints.
4433 Any breakpoint at PC must also be stepped over -- if there's
4434 one, it will have already triggered before the watchpoint
4435 triggered, and we either already reported it to the user, or
4436 it didn't cause a stop and we called keep_going. In either
4437 case, if there was a breakpoint at PC, we must be trying to
4439 ecs->event_thread->stepping_over_watchpoint = 1;
4444 ecs->event_thread->stepping_over_breakpoint = 0;
4445 ecs->event_thread->stepping_over_watchpoint = 0;
4446 bpstat_clear (&ecs->event_thread->control.stop_bpstat);
4447 ecs->event_thread->control.stop_step = 0;
4448 stop_print_frame = 1;
4449 stopped_by_random_signal = 0;
4451 /* Hide inlined functions starting here, unless we just performed stepi or
4452 nexti. After stepi and nexti, always show the innermost frame (not any
4453 inline function call sites). */
4454 if (ecs->event_thread->control.step_range_end != 1)
4456 struct address_space *aspace =
4457 get_regcache_aspace (get_thread_regcache (ecs->ptid));
4459 /* skip_inline_frames is expensive, so we avoid it if we can
4460 determine that the address is one where functions cannot have
4461 been inlined. This improves performance with inferiors that
4462 load a lot of shared libraries, because the solib event
4463 breakpoint is defined as the address of a function (i.e. not
4464 inline). Note that we have to check the previous PC as well
4465 as the current one to catch cases when we have just
4466 single-stepped off a breakpoint prior to reinstating it.
4467 Note that we're assuming that the code we single-step to is
4468 not inline, but that's not definitive: there's nothing
4469 preventing the event breakpoint function from containing
4470 inlined code, and the single-step ending up there. If the
4471 user had set a breakpoint on that inlined code, the missing
4472 skip_inline_frames call would break things. Fortunately
4473 that's an extremely unlikely scenario. */
4474 if (!pc_at_non_inline_function (aspace, stop_pc, &ecs->ws)
4475 && !(ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
4476 && ecs->event_thread->control.trap_expected
4477 && pc_at_non_inline_function (aspace,
4478 ecs->event_thread->prev_pc,
4481 skip_inline_frames (ecs->ptid);
4483 /* Re-fetch current thread's frame in case that invalidated
4485 frame = get_current_frame ();
4486 gdbarch = get_frame_arch (frame);
4490 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
4491 && ecs->event_thread->control.trap_expected
4492 && gdbarch_single_step_through_delay_p (gdbarch)
4493 && currently_stepping (ecs->event_thread))
4495 /* We're trying to step off a breakpoint. Turns out that we're
4496 also on an instruction that needs to be stepped multiple
4497 times before it's been fully executing. E.g., architectures
4498 with a delay slot. It needs to be stepped twice, once for
4499 the instruction and once for the delay slot. */
4500 int step_through_delay
4501 = gdbarch_single_step_through_delay (gdbarch, frame);
4503 if (debug_infrun && step_through_delay)
4504 fprintf_unfiltered (gdb_stdlog, "infrun: step through delay\n");
4505 if (ecs->event_thread->control.step_range_end == 0
4506 && step_through_delay)
4508 /* The user issued a continue when stopped at a breakpoint.
4509 Set up for another trap and get out of here. */
4510 ecs->event_thread->stepping_over_breakpoint = 1;
4514 else if (step_through_delay)
4516 /* The user issued a step when stopped at a breakpoint.
4517 Maybe we should stop, maybe we should not - the delay
4518 slot *might* correspond to a line of source. In any
4519 case, don't decide that here, just set
4520 ecs->stepping_over_breakpoint, making sure we
4521 single-step again before breakpoints are re-inserted. */
4522 ecs->event_thread->stepping_over_breakpoint = 1;
4526 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
4527 handles this event. */
4528 ecs->event_thread->control.stop_bpstat
4529 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
4530 stop_pc, ecs->ptid, &ecs->ws);
4532 /* Following in case break condition called a
4534 stop_print_frame = 1;
4536 /* This is where we handle "moribund" watchpoints. Unlike
4537 software breakpoints traps, hardware watchpoint traps are
4538 always distinguishable from random traps. If no high-level
4539 watchpoint is associated with the reported stop data address
4540 anymore, then the bpstat does not explain the signal ---
4541 simply make sure to ignore it if `stopped_by_watchpoint' is
4545 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
4546 && !bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
4548 && stopped_by_watchpoint)
4549 fprintf_unfiltered (gdb_stdlog,
4550 "infrun: no user watchpoint explains "
4551 "watchpoint SIGTRAP, ignoring\n");
4553 /* NOTE: cagney/2003-03-29: These checks for a random signal
4554 at one stage in the past included checks for an inferior
4555 function call's call dummy's return breakpoint. The original
4556 comment, that went with the test, read:
4558 ``End of a stack dummy. Some systems (e.g. Sony news) give
4559 another signal besides SIGTRAP, so check here as well as
4562 If someone ever tries to get call dummys on a
4563 non-executable stack to work (where the target would stop
4564 with something like a SIGSEGV), then those tests might need
4565 to be re-instated. Given, however, that the tests were only
4566 enabled when momentary breakpoints were not being used, I
4567 suspect that it won't be the case.
4569 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
4570 be necessary for call dummies on a non-executable stack on
4573 /* See if the breakpoints module can explain the signal. */
4575 = !bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
4576 ecs->event_thread->suspend.stop_signal);
4578 /* Maybe this was a trap for a software breakpoint that has since
4580 if (random_signal && target_stopped_by_sw_breakpoint ())
4582 if (program_breakpoint_here_p (gdbarch, stop_pc))
4584 struct regcache *regcache;
4587 /* Re-adjust PC to what the program would see if GDB was not
4589 regcache = get_thread_regcache (ecs->event_thread->ptid);
4590 decr_pc = gdbarch_decr_pc_after_break (gdbarch);
4593 struct cleanup *old_cleanups = make_cleanup (null_cleanup, NULL);
4595 if (record_full_is_used ())
4596 record_full_gdb_operation_disable_set ();
4598 regcache_write_pc (regcache, stop_pc + decr_pc);
4600 do_cleanups (old_cleanups);
4605 /* A delayed software breakpoint event. Ignore the trap. */
4607 fprintf_unfiltered (gdb_stdlog,
4608 "infrun: delayed software breakpoint "
4609 "trap, ignoring\n");
4614 /* Maybe this was a trap for a hardware breakpoint/watchpoint that
4615 has since been removed. */
4616 if (random_signal && target_stopped_by_hw_breakpoint ())
4618 /* A delayed hardware breakpoint event. Ignore the trap. */
4620 fprintf_unfiltered (gdb_stdlog,
4621 "infrun: delayed hardware breakpoint/watchpoint "
4622 "trap, ignoring\n");
4626 /* If not, perhaps stepping/nexting can. */
4628 random_signal = !(ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
4629 && currently_stepping (ecs->event_thread));
4631 /* Perhaps the thread hit a single-step breakpoint of _another_
4632 thread. Single-step breakpoints are transparent to the
4633 breakpoints module. */
4635 random_signal = !ecs->hit_singlestep_breakpoint;
4637 /* No? Perhaps we got a moribund watchpoint. */
4639 random_signal = !stopped_by_watchpoint;
4641 /* For the program's own signals, act according to
4642 the signal handling tables. */
4646 /* Signal not for debugging purposes. */
4647 struct inferior *inf = find_inferior_ptid (ecs->ptid);
4648 enum gdb_signal stop_signal = ecs->event_thread->suspend.stop_signal;
4651 fprintf_unfiltered (gdb_stdlog, "infrun: random signal (%s)\n",
4652 gdb_signal_to_symbol_string (stop_signal));
4654 stopped_by_random_signal = 1;
4656 /* Always stop on signals if we're either just gaining control
4657 of the program, or the user explicitly requested this thread
4658 to remain stopped. */
4659 if (stop_soon != NO_STOP_QUIETLY
4660 || ecs->event_thread->stop_requested
4662 && signal_stop_state (ecs->event_thread->suspend.stop_signal)))
4668 /* Notify observers the signal has "handle print" set. Note we
4669 returned early above if stopping; normal_stop handles the
4670 printing in that case. */
4671 if (signal_print[ecs->event_thread->suspend.stop_signal])
4673 /* The signal table tells us to print about this signal. */
4674 target_terminal_ours_for_output ();
4675 observer_notify_signal_received (ecs->event_thread->suspend.stop_signal);
4676 target_terminal_inferior ();
4679 /* Clear the signal if it should not be passed. */
4680 if (signal_program[ecs->event_thread->suspend.stop_signal] == 0)
4681 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
4683 if (ecs->event_thread->prev_pc == stop_pc
4684 && ecs->event_thread->control.trap_expected
4685 && ecs->event_thread->control.step_resume_breakpoint == NULL)
4687 /* We were just starting a new sequence, attempting to
4688 single-step off of a breakpoint and expecting a SIGTRAP.
4689 Instead this signal arrives. This signal will take us out
4690 of the stepping range so GDB needs to remember to, when
4691 the signal handler returns, resume stepping off that
4693 /* To simplify things, "continue" is forced to use the same
4694 code paths as single-step - set a breakpoint at the
4695 signal return address and then, once hit, step off that
4698 fprintf_unfiltered (gdb_stdlog,
4699 "infrun: signal arrived while stepping over "
4702 insert_hp_step_resume_breakpoint_at_frame (frame);
4703 ecs->event_thread->step_after_step_resume_breakpoint = 1;
4704 /* Reset trap_expected to ensure breakpoints are re-inserted. */
4705 ecs->event_thread->control.trap_expected = 0;
4707 /* If we were nexting/stepping some other thread, switch to
4708 it, so that we don't continue it, losing control. */
4709 if (!switch_back_to_stepped_thread (ecs))
4714 if (ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_0
4715 && (pc_in_thread_step_range (stop_pc, ecs->event_thread)
4716 || ecs->event_thread->control.step_range_end == 1)
4717 && frame_id_eq (get_stack_frame_id (frame),
4718 ecs->event_thread->control.step_stack_frame_id)
4719 && ecs->event_thread->control.step_resume_breakpoint == NULL)
4721 /* The inferior is about to take a signal that will take it
4722 out of the single step range. Set a breakpoint at the
4723 current PC (which is presumably where the signal handler
4724 will eventually return) and then allow the inferior to
4727 Note that this is only needed for a signal delivered
4728 while in the single-step range. Nested signals aren't a
4729 problem as they eventually all return. */
4731 fprintf_unfiltered (gdb_stdlog,
4732 "infrun: signal may take us out of "
4733 "single-step range\n");
4735 insert_hp_step_resume_breakpoint_at_frame (frame);
4736 ecs->event_thread->step_after_step_resume_breakpoint = 1;
4737 /* Reset trap_expected to ensure breakpoints are re-inserted. */
4738 ecs->event_thread->control.trap_expected = 0;
4743 /* Note: step_resume_breakpoint may be non-NULL. This occures
4744 when either there's a nested signal, or when there's a
4745 pending signal enabled just as the signal handler returns
4746 (leaving the inferior at the step-resume-breakpoint without
4747 actually executing it). Either way continue until the
4748 breakpoint is really hit. */
4750 if (!switch_back_to_stepped_thread (ecs))
4753 fprintf_unfiltered (gdb_stdlog,
4754 "infrun: random signal, keep going\n");
4761 process_event_stop_test (ecs);
4764 /* Come here when we've got some debug event / signal we can explain
4765 (IOW, not a random signal), and test whether it should cause a
4766 stop, or whether we should resume the inferior (transparently).
4767 E.g., could be a breakpoint whose condition evaluates false; we
4768 could be still stepping within the line; etc. */
4771 process_event_stop_test (struct execution_control_state *ecs)
4773 struct symtab_and_line stop_pc_sal;
4774 struct frame_info *frame;
4775 struct gdbarch *gdbarch;
4776 CORE_ADDR jmp_buf_pc;
4777 struct bpstat_what what;
4779 /* Handle cases caused by hitting a breakpoint. */
4781 frame = get_current_frame ();
4782 gdbarch = get_frame_arch (frame);
4784 what = bpstat_what (ecs->event_thread->control.stop_bpstat);
4786 if (what.call_dummy)
4788 stop_stack_dummy = what.call_dummy;
4791 /* If we hit an internal event that triggers symbol changes, the
4792 current frame will be invalidated within bpstat_what (e.g., if we
4793 hit an internal solib event). Re-fetch it. */
4794 frame = get_current_frame ();
4795 gdbarch = get_frame_arch (frame);
4797 switch (what.main_action)
4799 case BPSTAT_WHAT_SET_LONGJMP_RESUME:
4800 /* If we hit the breakpoint at longjmp while stepping, we
4801 install a momentary breakpoint at the target of the
4805 fprintf_unfiltered (gdb_stdlog,
4806 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME\n");
4808 ecs->event_thread->stepping_over_breakpoint = 1;
4810 if (what.is_longjmp)
4812 struct value *arg_value;
4814 /* If we set the longjmp breakpoint via a SystemTap probe,
4815 then use it to extract the arguments. The destination PC
4816 is the third argument to the probe. */
4817 arg_value = probe_safe_evaluate_at_pc (frame, 2);
4820 jmp_buf_pc = value_as_address (arg_value);
4821 jmp_buf_pc = gdbarch_addr_bits_remove (gdbarch, jmp_buf_pc);
4823 else if (!gdbarch_get_longjmp_target_p (gdbarch)
4824 || !gdbarch_get_longjmp_target (gdbarch,
4825 frame, &jmp_buf_pc))
4828 fprintf_unfiltered (gdb_stdlog,
4829 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME "
4830 "(!gdbarch_get_longjmp_target)\n");
4835 /* Insert a breakpoint at resume address. */
4836 insert_longjmp_resume_breakpoint (gdbarch, jmp_buf_pc);
4839 check_exception_resume (ecs, frame);
4843 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME:
4845 struct frame_info *init_frame;
4847 /* There are several cases to consider.
4849 1. The initiating frame no longer exists. In this case we
4850 must stop, because the exception or longjmp has gone too
4853 2. The initiating frame exists, and is the same as the
4854 current frame. We stop, because the exception or longjmp
4857 3. The initiating frame exists and is different from the
4858 current frame. This means the exception or longjmp has
4859 been caught beneath the initiating frame, so keep going.
4861 4. longjmp breakpoint has been placed just to protect
4862 against stale dummy frames and user is not interested in
4863 stopping around longjmps. */
4866 fprintf_unfiltered (gdb_stdlog,
4867 "infrun: BPSTAT_WHAT_CLEAR_LONGJMP_RESUME\n");
4869 gdb_assert (ecs->event_thread->control.exception_resume_breakpoint
4871 delete_exception_resume_breakpoint (ecs->event_thread);
4873 if (what.is_longjmp)
4875 check_longjmp_breakpoint_for_call_dummy (ecs->event_thread);
4877 if (!frame_id_p (ecs->event_thread->initiating_frame))
4885 init_frame = frame_find_by_id (ecs->event_thread->initiating_frame);
4889 struct frame_id current_id
4890 = get_frame_id (get_current_frame ());
4891 if (frame_id_eq (current_id,
4892 ecs->event_thread->initiating_frame))
4894 /* Case 2. Fall through. */
4904 /* For Cases 1 and 2, remove the step-resume breakpoint, if it
4906 delete_step_resume_breakpoint (ecs->event_thread);
4908 end_stepping_range (ecs);
4912 case BPSTAT_WHAT_SINGLE:
4914 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_SINGLE\n");
4915 ecs->event_thread->stepping_over_breakpoint = 1;
4916 /* Still need to check other stuff, at least the case where we
4917 are stepping and step out of the right range. */
4920 case BPSTAT_WHAT_STEP_RESUME:
4922 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STEP_RESUME\n");
4924 delete_step_resume_breakpoint (ecs->event_thread);
4925 if (ecs->event_thread->control.proceed_to_finish
4926 && execution_direction == EXEC_REVERSE)
4928 struct thread_info *tp = ecs->event_thread;
4930 /* We are finishing a function in reverse, and just hit the
4931 step-resume breakpoint at the start address of the
4932 function, and we're almost there -- just need to back up
4933 by one more single-step, which should take us back to the
4935 tp->control.step_range_start = tp->control.step_range_end = 1;
4939 fill_in_stop_func (gdbarch, ecs);
4940 if (stop_pc == ecs->stop_func_start
4941 && execution_direction == EXEC_REVERSE)
4943 /* We are stepping over a function call in reverse, and just
4944 hit the step-resume breakpoint at the start address of
4945 the function. Go back to single-stepping, which should
4946 take us back to the function call. */
4947 ecs->event_thread->stepping_over_breakpoint = 1;
4953 case BPSTAT_WHAT_STOP_NOISY:
4955 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_NOISY\n");
4956 stop_print_frame = 1;
4958 /* Assume the thread stopped for a breapoint. We'll still check
4959 whether a/the breakpoint is there when the thread is next
4961 ecs->event_thread->stepping_over_breakpoint = 1;
4966 case BPSTAT_WHAT_STOP_SILENT:
4968 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_SILENT\n");
4969 stop_print_frame = 0;
4971 /* Assume the thread stopped for a breapoint. We'll still check
4972 whether a/the breakpoint is there when the thread is next
4974 ecs->event_thread->stepping_over_breakpoint = 1;
4978 case BPSTAT_WHAT_HP_STEP_RESUME:
4980 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_HP_STEP_RESUME\n");
4982 delete_step_resume_breakpoint (ecs->event_thread);
4983 if (ecs->event_thread->step_after_step_resume_breakpoint)
4985 /* Back when the step-resume breakpoint was inserted, we
4986 were trying to single-step off a breakpoint. Go back to
4988 ecs->event_thread->step_after_step_resume_breakpoint = 0;
4989 ecs->event_thread->stepping_over_breakpoint = 1;
4995 case BPSTAT_WHAT_KEEP_CHECKING:
4999 /* If we stepped a permanent breakpoint and we had a high priority
5000 step-resume breakpoint for the address we stepped, but we didn't
5001 hit it, then we must have stepped into the signal handler. The
5002 step-resume was only necessary to catch the case of _not_
5003 stepping into the handler, so delete it, and fall through to
5004 checking whether the step finished. */
5005 if (ecs->event_thread->stepped_breakpoint)
5007 struct breakpoint *sr_bp
5008 = ecs->event_thread->control.step_resume_breakpoint;
5011 && sr_bp->loc->permanent
5012 && sr_bp->type == bp_hp_step_resume
5013 && sr_bp->loc->address == ecs->event_thread->prev_pc)
5016 fprintf_unfiltered (gdb_stdlog,
5017 "infrun: stepped permanent breakpoint, stopped in "
5019 delete_step_resume_breakpoint (ecs->event_thread);
5020 ecs->event_thread->step_after_step_resume_breakpoint = 0;
5024 /* We come here if we hit a breakpoint but should not stop for it.
5025 Possibly we also were stepping and should stop for that. So fall
5026 through and test for stepping. But, if not stepping, do not
5029 /* In all-stop mode, if we're currently stepping but have stopped in
5030 some other thread, we need to switch back to the stepped thread. */
5031 if (switch_back_to_stepped_thread (ecs))
5034 if (ecs->event_thread->control.step_resume_breakpoint)
5037 fprintf_unfiltered (gdb_stdlog,
5038 "infrun: step-resume breakpoint is inserted\n");
5040 /* Having a step-resume breakpoint overrides anything
5041 else having to do with stepping commands until
5042 that breakpoint is reached. */
5047 if (ecs->event_thread->control.step_range_end == 0)
5050 fprintf_unfiltered (gdb_stdlog, "infrun: no stepping, continue\n");
5051 /* Likewise if we aren't even stepping. */
5056 /* Re-fetch current thread's frame in case the code above caused
5057 the frame cache to be re-initialized, making our FRAME variable
5058 a dangling pointer. */
5059 frame = get_current_frame ();
5060 gdbarch = get_frame_arch (frame);
5061 fill_in_stop_func (gdbarch, ecs);
5063 /* If stepping through a line, keep going if still within it.
5065 Note that step_range_end is the address of the first instruction
5066 beyond the step range, and NOT the address of the last instruction
5069 Note also that during reverse execution, we may be stepping
5070 through a function epilogue and therefore must detect when
5071 the current-frame changes in the middle of a line. */
5073 if (pc_in_thread_step_range (stop_pc, ecs->event_thread)
5074 && (execution_direction != EXEC_REVERSE
5075 || frame_id_eq (get_frame_id (frame),
5076 ecs->event_thread->control.step_frame_id)))
5080 (gdb_stdlog, "infrun: stepping inside range [%s-%s]\n",
5081 paddress (gdbarch, ecs->event_thread->control.step_range_start),
5082 paddress (gdbarch, ecs->event_thread->control.step_range_end));
5084 /* Tentatively re-enable range stepping; `resume' disables it if
5085 necessary (e.g., if we're stepping over a breakpoint or we
5086 have software watchpoints). */
5087 ecs->event_thread->control.may_range_step = 1;
5089 /* When stepping backward, stop at beginning of line range
5090 (unless it's the function entry point, in which case
5091 keep going back to the call point). */
5092 if (stop_pc == ecs->event_thread->control.step_range_start
5093 && stop_pc != ecs->stop_func_start
5094 && execution_direction == EXEC_REVERSE)
5095 end_stepping_range (ecs);
5102 /* We stepped out of the stepping range. */
5104 /* If we are stepping at the source level and entered the runtime
5105 loader dynamic symbol resolution code...
5107 EXEC_FORWARD: we keep on single stepping until we exit the run
5108 time loader code and reach the callee's address.
5110 EXEC_REVERSE: we've already executed the callee (backward), and
5111 the runtime loader code is handled just like any other
5112 undebuggable function call. Now we need only keep stepping
5113 backward through the trampoline code, and that's handled further
5114 down, so there is nothing for us to do here. */
5116 if (execution_direction != EXEC_REVERSE
5117 && ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
5118 && in_solib_dynsym_resolve_code (stop_pc))
5120 CORE_ADDR pc_after_resolver =
5121 gdbarch_skip_solib_resolver (gdbarch, stop_pc);
5124 fprintf_unfiltered (gdb_stdlog,
5125 "infrun: stepped into dynsym resolve code\n");
5127 if (pc_after_resolver)
5129 /* Set up a step-resume breakpoint at the address
5130 indicated by SKIP_SOLIB_RESOLVER. */
5131 struct symtab_and_line sr_sal;
5134 sr_sal.pc = pc_after_resolver;
5135 sr_sal.pspace = get_frame_program_space (frame);
5137 insert_step_resume_breakpoint_at_sal (gdbarch,
5138 sr_sal, null_frame_id);
5145 if (ecs->event_thread->control.step_range_end != 1
5146 && (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
5147 || ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
5148 && get_frame_type (frame) == SIGTRAMP_FRAME)
5151 fprintf_unfiltered (gdb_stdlog,
5152 "infrun: stepped into signal trampoline\n");
5153 /* The inferior, while doing a "step" or "next", has ended up in
5154 a signal trampoline (either by a signal being delivered or by
5155 the signal handler returning). Just single-step until the
5156 inferior leaves the trampoline (either by calling the handler
5162 /* If we're in the return path from a shared library trampoline,
5163 we want to proceed through the trampoline when stepping. */
5164 /* macro/2012-04-25: This needs to come before the subroutine
5165 call check below as on some targets return trampolines look
5166 like subroutine calls (MIPS16 return thunks). */
5167 if (gdbarch_in_solib_return_trampoline (gdbarch,
5168 stop_pc, ecs->stop_func_name)
5169 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE)
5171 /* Determine where this trampoline returns. */
5172 CORE_ADDR real_stop_pc;
5174 real_stop_pc = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc);
5177 fprintf_unfiltered (gdb_stdlog,
5178 "infrun: stepped into solib return tramp\n");
5180 /* Only proceed through if we know where it's going. */
5183 /* And put the step-breakpoint there and go until there. */
5184 struct symtab_and_line sr_sal;
5186 init_sal (&sr_sal); /* initialize to zeroes */
5187 sr_sal.pc = real_stop_pc;
5188 sr_sal.section = find_pc_overlay (sr_sal.pc);
5189 sr_sal.pspace = get_frame_program_space (frame);
5191 /* Do not specify what the fp should be when we stop since
5192 on some machines the prologue is where the new fp value
5194 insert_step_resume_breakpoint_at_sal (gdbarch,
5195 sr_sal, null_frame_id);
5197 /* Restart without fiddling with the step ranges or
5204 /* Check for subroutine calls. The check for the current frame
5205 equalling the step ID is not necessary - the check of the
5206 previous frame's ID is sufficient - but it is a common case and
5207 cheaper than checking the previous frame's ID.
5209 NOTE: frame_id_eq will never report two invalid frame IDs as
5210 being equal, so to get into this block, both the current and
5211 previous frame must have valid frame IDs. */
5212 /* The outer_frame_id check is a heuristic to detect stepping
5213 through startup code. If we step over an instruction which
5214 sets the stack pointer from an invalid value to a valid value,
5215 we may detect that as a subroutine call from the mythical
5216 "outermost" function. This could be fixed by marking
5217 outermost frames as !stack_p,code_p,special_p. Then the
5218 initial outermost frame, before sp was valid, would
5219 have code_addr == &_start. See the comment in frame_id_eq
5221 if (!frame_id_eq (get_stack_frame_id (frame),
5222 ecs->event_thread->control.step_stack_frame_id)
5223 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
5224 ecs->event_thread->control.step_stack_frame_id)
5225 && (!frame_id_eq (ecs->event_thread->control.step_stack_frame_id,
5227 || (ecs->event_thread->control.step_start_function
5228 != find_pc_function (stop_pc)))))
5230 CORE_ADDR real_stop_pc;
5233 fprintf_unfiltered (gdb_stdlog, "infrun: stepped into subroutine\n");
5235 if (ecs->event_thread->control.step_over_calls == STEP_OVER_NONE)
5237 /* I presume that step_over_calls is only 0 when we're
5238 supposed to be stepping at the assembly language level
5239 ("stepi"). Just stop. */
5240 /* And this works the same backward as frontward. MVS */
5241 end_stepping_range (ecs);
5245 /* Reverse stepping through solib trampolines. */
5247 if (execution_direction == EXEC_REVERSE
5248 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE
5249 && (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc)
5250 || (ecs->stop_func_start == 0
5251 && in_solib_dynsym_resolve_code (stop_pc))))
5253 /* Any solib trampoline code can be handled in reverse
5254 by simply continuing to single-step. We have already
5255 executed the solib function (backwards), and a few
5256 steps will take us back through the trampoline to the
5262 if (ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
5264 /* We're doing a "next".
5266 Normal (forward) execution: set a breakpoint at the
5267 callee's return address (the address at which the caller
5270 Reverse (backward) execution. set the step-resume
5271 breakpoint at the start of the function that we just
5272 stepped into (backwards), and continue to there. When we
5273 get there, we'll need to single-step back to the caller. */
5275 if (execution_direction == EXEC_REVERSE)
5277 /* If we're already at the start of the function, we've either
5278 just stepped backward into a single instruction function,
5279 or stepped back out of a signal handler to the first instruction
5280 of the function. Just keep going, which will single-step back
5282 if (ecs->stop_func_start != stop_pc && ecs->stop_func_start != 0)
5284 struct symtab_and_line sr_sal;
5286 /* Normal function call return (static or dynamic). */
5288 sr_sal.pc = ecs->stop_func_start;
5289 sr_sal.pspace = get_frame_program_space (frame);
5290 insert_step_resume_breakpoint_at_sal (gdbarch,
5291 sr_sal, null_frame_id);
5295 insert_step_resume_breakpoint_at_caller (frame);
5301 /* If we are in a function call trampoline (a stub between the
5302 calling routine and the real function), locate the real
5303 function. That's what tells us (a) whether we want to step
5304 into it at all, and (b) what prologue we want to run to the
5305 end of, if we do step into it. */
5306 real_stop_pc = skip_language_trampoline (frame, stop_pc);
5307 if (real_stop_pc == 0)
5308 real_stop_pc = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc);
5309 if (real_stop_pc != 0)
5310 ecs->stop_func_start = real_stop_pc;
5312 if (real_stop_pc != 0 && in_solib_dynsym_resolve_code (real_stop_pc))
5314 struct symtab_and_line sr_sal;
5317 sr_sal.pc = ecs->stop_func_start;
5318 sr_sal.pspace = get_frame_program_space (frame);
5320 insert_step_resume_breakpoint_at_sal (gdbarch,
5321 sr_sal, null_frame_id);
5326 /* If we have line number information for the function we are
5327 thinking of stepping into and the function isn't on the skip
5330 If there are several symtabs at that PC (e.g. with include
5331 files), just want to know whether *any* of them have line
5332 numbers. find_pc_line handles this. */
5334 struct symtab_and_line tmp_sal;
5336 tmp_sal = find_pc_line (ecs->stop_func_start, 0);
5337 if (tmp_sal.line != 0
5338 && !function_name_is_marked_for_skip (ecs->stop_func_name,
5341 if (execution_direction == EXEC_REVERSE)
5342 handle_step_into_function_backward (gdbarch, ecs);
5344 handle_step_into_function (gdbarch, ecs);
5349 /* If we have no line number and the step-stop-if-no-debug is
5350 set, we stop the step so that the user has a chance to switch
5351 in assembly mode. */
5352 if (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
5353 && step_stop_if_no_debug)
5355 end_stepping_range (ecs);
5359 if (execution_direction == EXEC_REVERSE)
5361 /* If we're already at the start of the function, we've either just
5362 stepped backward into a single instruction function without line
5363 number info, or stepped back out of a signal handler to the first
5364 instruction of the function without line number info. Just keep
5365 going, which will single-step back to the caller. */
5366 if (ecs->stop_func_start != stop_pc)
5368 /* Set a breakpoint at callee's start address.
5369 From there we can step once and be back in the caller. */
5370 struct symtab_and_line sr_sal;
5373 sr_sal.pc = ecs->stop_func_start;
5374 sr_sal.pspace = get_frame_program_space (frame);
5375 insert_step_resume_breakpoint_at_sal (gdbarch,
5376 sr_sal, null_frame_id);
5380 /* Set a breakpoint at callee's return address (the address
5381 at which the caller will resume). */
5382 insert_step_resume_breakpoint_at_caller (frame);
5388 /* Reverse stepping through solib trampolines. */
5390 if (execution_direction == EXEC_REVERSE
5391 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE)
5393 if (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc)
5394 || (ecs->stop_func_start == 0
5395 && in_solib_dynsym_resolve_code (stop_pc)))
5397 /* Any solib trampoline code can be handled in reverse
5398 by simply continuing to single-step. We have already
5399 executed the solib function (backwards), and a few
5400 steps will take us back through the trampoline to the
5405 else if (in_solib_dynsym_resolve_code (stop_pc))
5407 /* Stepped backward into the solib dynsym resolver.
5408 Set a breakpoint at its start and continue, then
5409 one more step will take us out. */
5410 struct symtab_and_line sr_sal;
5413 sr_sal.pc = ecs->stop_func_start;
5414 sr_sal.pspace = get_frame_program_space (frame);
5415 insert_step_resume_breakpoint_at_sal (gdbarch,
5416 sr_sal, null_frame_id);
5422 stop_pc_sal = find_pc_line (stop_pc, 0);
5424 /* NOTE: tausq/2004-05-24: This if block used to be done before all
5425 the trampoline processing logic, however, there are some trampolines
5426 that have no names, so we should do trampoline handling first. */
5427 if (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
5428 && ecs->stop_func_name == NULL
5429 && stop_pc_sal.line == 0)
5432 fprintf_unfiltered (gdb_stdlog,
5433 "infrun: stepped into undebuggable function\n");
5435 /* The inferior just stepped into, or returned to, an
5436 undebuggable function (where there is no debugging information
5437 and no line number corresponding to the address where the
5438 inferior stopped). Since we want to skip this kind of code,
5439 we keep going until the inferior returns from this
5440 function - unless the user has asked us not to (via
5441 set step-mode) or we no longer know how to get back
5442 to the call site. */
5443 if (step_stop_if_no_debug
5444 || !frame_id_p (frame_unwind_caller_id (frame)))
5446 /* If we have no line number and the step-stop-if-no-debug
5447 is set, we stop the step so that the user has a chance to
5448 switch in assembly mode. */
5449 end_stepping_range (ecs);
5454 /* Set a breakpoint at callee's return address (the address
5455 at which the caller will resume). */
5456 insert_step_resume_breakpoint_at_caller (frame);
5462 if (ecs->event_thread->control.step_range_end == 1)
5464 /* It is stepi or nexti. We always want to stop stepping after
5467 fprintf_unfiltered (gdb_stdlog, "infrun: stepi/nexti\n");
5468 end_stepping_range (ecs);
5472 if (stop_pc_sal.line == 0)
5474 /* We have no line number information. That means to stop
5475 stepping (does this always happen right after one instruction,
5476 when we do "s" in a function with no line numbers,
5477 or can this happen as a result of a return or longjmp?). */
5479 fprintf_unfiltered (gdb_stdlog, "infrun: no line number info\n");
5480 end_stepping_range (ecs);
5484 /* Look for "calls" to inlined functions, part one. If the inline
5485 frame machinery detected some skipped call sites, we have entered
5486 a new inline function. */
5488 if (frame_id_eq (get_frame_id (get_current_frame ()),
5489 ecs->event_thread->control.step_frame_id)
5490 && inline_skipped_frames (ecs->ptid))
5492 struct symtab_and_line call_sal;
5495 fprintf_unfiltered (gdb_stdlog,
5496 "infrun: stepped into inlined function\n");
5498 find_frame_sal (get_current_frame (), &call_sal);
5500 if (ecs->event_thread->control.step_over_calls != STEP_OVER_ALL)
5502 /* For "step", we're going to stop. But if the call site
5503 for this inlined function is on the same source line as
5504 we were previously stepping, go down into the function
5505 first. Otherwise stop at the call site. */
5507 if (call_sal.line == ecs->event_thread->current_line
5508 && call_sal.symtab == ecs->event_thread->current_symtab)
5509 step_into_inline_frame (ecs->ptid);
5511 end_stepping_range (ecs);
5516 /* For "next", we should stop at the call site if it is on a
5517 different source line. Otherwise continue through the
5518 inlined function. */
5519 if (call_sal.line == ecs->event_thread->current_line
5520 && call_sal.symtab == ecs->event_thread->current_symtab)
5523 end_stepping_range (ecs);
5528 /* Look for "calls" to inlined functions, part two. If we are still
5529 in the same real function we were stepping through, but we have
5530 to go further up to find the exact frame ID, we are stepping
5531 through a more inlined call beyond its call site. */
5533 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
5534 && !frame_id_eq (get_frame_id (get_current_frame ()),
5535 ecs->event_thread->control.step_frame_id)
5536 && stepped_in_from (get_current_frame (),
5537 ecs->event_thread->control.step_frame_id))
5540 fprintf_unfiltered (gdb_stdlog,
5541 "infrun: stepping through inlined function\n");
5543 if (ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
5546 end_stepping_range (ecs);
5550 if ((stop_pc == stop_pc_sal.pc)
5551 && (ecs->event_thread->current_line != stop_pc_sal.line
5552 || ecs->event_thread->current_symtab != stop_pc_sal.symtab))
5554 /* We are at the start of a different line. So stop. Note that
5555 we don't stop if we step into the middle of a different line.
5556 That is said to make things like for (;;) statements work
5559 fprintf_unfiltered (gdb_stdlog,
5560 "infrun: stepped to a different line\n");
5561 end_stepping_range (ecs);
5565 /* We aren't done stepping.
5567 Optimize by setting the stepping range to the line.
5568 (We might not be in the original line, but if we entered a
5569 new line in mid-statement, we continue stepping. This makes
5570 things like for(;;) statements work better.) */
5572 ecs->event_thread->control.step_range_start = stop_pc_sal.pc;
5573 ecs->event_thread->control.step_range_end = stop_pc_sal.end;
5574 ecs->event_thread->control.may_range_step = 1;
5575 set_step_info (frame, stop_pc_sal);
5578 fprintf_unfiltered (gdb_stdlog, "infrun: keep going\n");
5582 /* In all-stop mode, if we're currently stepping but have stopped in
5583 some other thread, we may need to switch back to the stepped
5584 thread. Returns true we set the inferior running, false if we left
5585 it stopped (and the event needs further processing). */
5588 switch_back_to_stepped_thread (struct execution_control_state *ecs)
5592 struct thread_info *tp;
5593 struct thread_info *stepping_thread;
5594 struct thread_info *step_over;
5596 /* If any thread is blocked on some internal breakpoint, and we
5597 simply need to step over that breakpoint to get it going
5598 again, do that first. */
5600 /* However, if we see an event for the stepping thread, then we
5601 know all other threads have been moved past their breakpoints
5602 already. Let the caller check whether the step is finished,
5603 etc., before deciding to move it past a breakpoint. */
5604 if (ecs->event_thread->control.step_range_end != 0)
5607 /* Check if the current thread is blocked on an incomplete
5608 step-over, interrupted by a random signal. */
5609 if (ecs->event_thread->control.trap_expected
5610 && ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_TRAP)
5614 fprintf_unfiltered (gdb_stdlog,
5615 "infrun: need to finish step-over of [%s]\n",
5616 target_pid_to_str (ecs->event_thread->ptid));
5622 /* Check if the current thread is blocked by a single-step
5623 breakpoint of another thread. */
5624 if (ecs->hit_singlestep_breakpoint)
5628 fprintf_unfiltered (gdb_stdlog,
5629 "infrun: need to step [%s] over single-step "
5631 target_pid_to_str (ecs->ptid));
5637 /* Otherwise, we no longer expect a trap in the current thread.
5638 Clear the trap_expected flag before switching back -- this is
5639 what keep_going does as well, if we call it. */
5640 ecs->event_thread->control.trap_expected = 0;
5642 /* Likewise, clear the signal if it should not be passed. */
5643 if (!signal_program[ecs->event_thread->suspend.stop_signal])
5644 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5646 /* If scheduler locking applies even if not stepping, there's no
5647 need to walk over threads. Above we've checked whether the
5648 current thread is stepping. If some other thread not the
5649 event thread is stepping, then it must be that scheduler
5650 locking is not in effect. */
5651 if (schedlock_applies (ecs->event_thread))
5654 /* Look for the stepping/nexting thread, and check if any other
5655 thread other than the stepping thread needs to start a
5656 step-over. Do all step-overs before actually proceeding with
5658 stepping_thread = NULL;
5660 ALL_NON_EXITED_THREADS (tp)
5662 /* Ignore threads of processes we're not resuming. */
5664 && ptid_get_pid (tp->ptid) != ptid_get_pid (inferior_ptid))
5667 /* When stepping over a breakpoint, we lock all threads
5668 except the one that needs to move past the breakpoint.
5669 If a non-event thread has this set, the "incomplete
5670 step-over" check above should have caught it earlier. */
5671 gdb_assert (!tp->control.trap_expected);
5673 /* Did we find the stepping thread? */
5674 if (tp->control.step_range_end)
5676 /* Yep. There should only one though. */
5677 gdb_assert (stepping_thread == NULL);
5679 /* The event thread is handled at the top, before we
5681 gdb_assert (tp != ecs->event_thread);
5683 /* If some thread other than the event thread is
5684 stepping, then scheduler locking can't be in effect,
5685 otherwise we wouldn't have resumed the current event
5686 thread in the first place. */
5687 gdb_assert (!schedlock_applies (tp));
5689 stepping_thread = tp;
5691 else if (thread_still_needs_step_over (tp))
5695 /* At the top we've returned early if the event thread
5696 is stepping. If some other thread not the event
5697 thread is stepping, then scheduler locking can't be
5698 in effect, and we can resume this thread. No need to
5699 keep looking for the stepping thread then. */
5704 if (step_over != NULL)
5709 fprintf_unfiltered (gdb_stdlog,
5710 "infrun: need to step-over [%s]\n",
5711 target_pid_to_str (tp->ptid));
5714 /* Only the stepping thread should have this set. */
5715 gdb_assert (tp->control.step_range_end == 0);
5717 ecs->ptid = tp->ptid;
5718 ecs->event_thread = tp;
5719 switch_to_thread (ecs->ptid);
5724 if (stepping_thread != NULL)
5726 struct frame_info *frame;
5727 struct gdbarch *gdbarch;
5729 tp = stepping_thread;
5731 /* If the stepping thread exited, then don't try to switch
5732 back and resume it, which could fail in several different
5733 ways depending on the target. Instead, just keep going.
5735 We can find a stepping dead thread in the thread list in
5738 - The target supports thread exit events, and when the
5739 target tries to delete the thread from the thread list,
5740 inferior_ptid pointed at the exiting thread. In such
5741 case, calling delete_thread does not really remove the
5742 thread from the list; instead, the thread is left listed,
5743 with 'exited' state.
5745 - The target's debug interface does not support thread
5746 exit events, and so we have no idea whatsoever if the
5747 previously stepping thread is still alive. For that
5748 reason, we need to synchronously query the target
5750 if (is_exited (tp->ptid)
5751 || !target_thread_alive (tp->ptid))
5754 fprintf_unfiltered (gdb_stdlog,
5755 "infrun: not switching back to "
5756 "stepped thread, it has vanished\n");
5758 delete_thread (tp->ptid);
5764 fprintf_unfiltered (gdb_stdlog,
5765 "infrun: switching back to stepped thread\n");
5767 ecs->event_thread = tp;
5768 ecs->ptid = tp->ptid;
5769 context_switch (ecs->ptid);
5771 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
5772 frame = get_current_frame ();
5773 gdbarch = get_frame_arch (frame);
5775 /* If the PC of the thread we were trying to single-step has
5776 changed, then that thread has trapped or been signaled,
5777 but the event has not been reported to GDB yet. Re-poll
5778 the target looking for this particular thread's event
5779 (i.e. temporarily enable schedlock) by:
5781 - setting a break at the current PC
5782 - resuming that particular thread, only (by setting
5785 This prevents us continuously moving the single-step
5786 breakpoint forward, one instruction at a time,
5789 if (stop_pc != tp->prev_pc)
5794 fprintf_unfiltered (gdb_stdlog,
5795 "infrun: expected thread advanced also\n");
5797 /* Clear the info of the previous step-over, as it's no
5798 longer valid. It's what keep_going would do too, if
5799 we called it. Must do this before trying to insert
5800 the sss breakpoint, otherwise if we were previously
5801 trying to step over this exact address in another
5802 thread, the breakpoint ends up not installed. */
5803 clear_step_over_info ();
5805 insert_single_step_breakpoint (get_frame_arch (frame),
5806 get_frame_address_space (frame),
5809 resume_ptid = user_visible_resume_ptid (tp->control.stepping_command);
5810 do_target_resume (resume_ptid,
5811 currently_stepping (tp), GDB_SIGNAL_0);
5812 prepare_to_wait (ecs);
5817 fprintf_unfiltered (gdb_stdlog,
5818 "infrun: expected thread still "
5819 "hasn't advanced\n");
5829 /* Is thread TP in the middle of single-stepping? */
5832 currently_stepping (struct thread_info *tp)
5834 return ((tp->control.step_range_end
5835 && tp->control.step_resume_breakpoint == NULL)
5836 || tp->control.trap_expected
5837 || tp->stepped_breakpoint
5838 || bpstat_should_step ());
5841 /* Inferior has stepped into a subroutine call with source code that
5842 we should not step over. Do step to the first line of code in
5846 handle_step_into_function (struct gdbarch *gdbarch,
5847 struct execution_control_state *ecs)
5849 struct compunit_symtab *cust;
5850 struct symtab_and_line stop_func_sal, sr_sal;
5852 fill_in_stop_func (gdbarch, ecs);
5854 cust = find_pc_compunit_symtab (stop_pc);
5855 if (cust != NULL && compunit_language (cust) != language_asm)
5856 ecs->stop_func_start = gdbarch_skip_prologue (gdbarch,
5857 ecs->stop_func_start);
5859 stop_func_sal = find_pc_line (ecs->stop_func_start, 0);
5860 /* Use the step_resume_break to step until the end of the prologue,
5861 even if that involves jumps (as it seems to on the vax under
5863 /* If the prologue ends in the middle of a source line, continue to
5864 the end of that source line (if it is still within the function).
5865 Otherwise, just go to end of prologue. */
5866 if (stop_func_sal.end
5867 && stop_func_sal.pc != ecs->stop_func_start
5868 && stop_func_sal.end < ecs->stop_func_end)
5869 ecs->stop_func_start = stop_func_sal.end;
5871 /* Architectures which require breakpoint adjustment might not be able
5872 to place a breakpoint at the computed address. If so, the test
5873 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
5874 ecs->stop_func_start to an address at which a breakpoint may be
5875 legitimately placed.
5877 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
5878 made, GDB will enter an infinite loop when stepping through
5879 optimized code consisting of VLIW instructions which contain
5880 subinstructions corresponding to different source lines. On
5881 FR-V, it's not permitted to place a breakpoint on any but the
5882 first subinstruction of a VLIW instruction. When a breakpoint is
5883 set, GDB will adjust the breakpoint address to the beginning of
5884 the VLIW instruction. Thus, we need to make the corresponding
5885 adjustment here when computing the stop address. */
5887 if (gdbarch_adjust_breakpoint_address_p (gdbarch))
5889 ecs->stop_func_start
5890 = gdbarch_adjust_breakpoint_address (gdbarch,
5891 ecs->stop_func_start);
5894 if (ecs->stop_func_start == stop_pc)
5896 /* We are already there: stop now. */
5897 end_stepping_range (ecs);
5902 /* Put the step-breakpoint there and go until there. */
5903 init_sal (&sr_sal); /* initialize to zeroes */
5904 sr_sal.pc = ecs->stop_func_start;
5905 sr_sal.section = find_pc_overlay (ecs->stop_func_start);
5906 sr_sal.pspace = get_frame_program_space (get_current_frame ());
5908 /* Do not specify what the fp should be when we stop since on
5909 some machines the prologue is where the new fp value is
5911 insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal, null_frame_id);
5913 /* And make sure stepping stops right away then. */
5914 ecs->event_thread->control.step_range_end
5915 = ecs->event_thread->control.step_range_start;
5920 /* Inferior has stepped backward into a subroutine call with source
5921 code that we should not step over. Do step to the beginning of the
5922 last line of code in it. */
5925 handle_step_into_function_backward (struct gdbarch *gdbarch,
5926 struct execution_control_state *ecs)
5928 struct compunit_symtab *cust;
5929 struct symtab_and_line stop_func_sal;
5931 fill_in_stop_func (gdbarch, ecs);
5933 cust = find_pc_compunit_symtab (stop_pc);
5934 if (cust != NULL && compunit_language (cust) != language_asm)
5935 ecs->stop_func_start = gdbarch_skip_prologue (gdbarch,
5936 ecs->stop_func_start);
5938 stop_func_sal = find_pc_line (stop_pc, 0);
5940 /* OK, we're just going to keep stepping here. */
5941 if (stop_func_sal.pc == stop_pc)
5943 /* We're there already. Just stop stepping now. */
5944 end_stepping_range (ecs);
5948 /* Else just reset the step range and keep going.
5949 No step-resume breakpoint, they don't work for
5950 epilogues, which can have multiple entry paths. */
5951 ecs->event_thread->control.step_range_start = stop_func_sal.pc;
5952 ecs->event_thread->control.step_range_end = stop_func_sal.end;
5958 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
5959 This is used to both functions and to skip over code. */
5962 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch *gdbarch,
5963 struct symtab_and_line sr_sal,
5964 struct frame_id sr_id,
5965 enum bptype sr_type)
5967 /* There should never be more than one step-resume or longjmp-resume
5968 breakpoint per thread, so we should never be setting a new
5969 step_resume_breakpoint when one is already active. */
5970 gdb_assert (inferior_thread ()->control.step_resume_breakpoint == NULL);
5971 gdb_assert (sr_type == bp_step_resume || sr_type == bp_hp_step_resume);
5974 fprintf_unfiltered (gdb_stdlog,
5975 "infrun: inserting step-resume breakpoint at %s\n",
5976 paddress (gdbarch, sr_sal.pc));
5978 inferior_thread ()->control.step_resume_breakpoint
5979 = set_momentary_breakpoint (gdbarch, sr_sal, sr_id, sr_type);
5983 insert_step_resume_breakpoint_at_sal (struct gdbarch *gdbarch,
5984 struct symtab_and_line sr_sal,
5985 struct frame_id sr_id)
5987 insert_step_resume_breakpoint_at_sal_1 (gdbarch,
5992 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
5993 This is used to skip a potential signal handler.
5995 This is called with the interrupted function's frame. The signal
5996 handler, when it returns, will resume the interrupted function at
6000 insert_hp_step_resume_breakpoint_at_frame (struct frame_info *return_frame)
6002 struct symtab_and_line sr_sal;
6003 struct gdbarch *gdbarch;
6005 gdb_assert (return_frame != NULL);
6006 init_sal (&sr_sal); /* initialize to zeros */
6008 gdbarch = get_frame_arch (return_frame);
6009 sr_sal.pc = gdbarch_addr_bits_remove (gdbarch, get_frame_pc (return_frame));
6010 sr_sal.section = find_pc_overlay (sr_sal.pc);
6011 sr_sal.pspace = get_frame_program_space (return_frame);
6013 insert_step_resume_breakpoint_at_sal_1 (gdbarch, sr_sal,
6014 get_stack_frame_id (return_frame),
6018 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
6019 is used to skip a function after stepping into it (for "next" or if
6020 the called function has no debugging information).
6022 The current function has almost always been reached by single
6023 stepping a call or return instruction. NEXT_FRAME belongs to the
6024 current function, and the breakpoint will be set at the caller's
6027 This is a separate function rather than reusing
6028 insert_hp_step_resume_breakpoint_at_frame in order to avoid
6029 get_prev_frame, which may stop prematurely (see the implementation
6030 of frame_unwind_caller_id for an example). */
6033 insert_step_resume_breakpoint_at_caller (struct frame_info *next_frame)
6035 struct symtab_and_line sr_sal;
6036 struct gdbarch *gdbarch;
6038 /* We shouldn't have gotten here if we don't know where the call site
6040 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame)));
6042 init_sal (&sr_sal); /* initialize to zeros */
6044 gdbarch = frame_unwind_caller_arch (next_frame);
6045 sr_sal.pc = gdbarch_addr_bits_remove (gdbarch,
6046 frame_unwind_caller_pc (next_frame));
6047 sr_sal.section = find_pc_overlay (sr_sal.pc);
6048 sr_sal.pspace = frame_unwind_program_space (next_frame);
6050 insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal,
6051 frame_unwind_caller_id (next_frame));
6054 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
6055 new breakpoint at the target of a jmp_buf. The handling of
6056 longjmp-resume uses the same mechanisms used for handling
6057 "step-resume" breakpoints. */
6060 insert_longjmp_resume_breakpoint (struct gdbarch *gdbarch, CORE_ADDR pc)
6062 /* There should never be more than one longjmp-resume breakpoint per
6063 thread, so we should never be setting a new
6064 longjmp_resume_breakpoint when one is already active. */
6065 gdb_assert (inferior_thread ()->control.exception_resume_breakpoint == NULL);
6068 fprintf_unfiltered (gdb_stdlog,
6069 "infrun: inserting longjmp-resume breakpoint at %s\n",
6070 paddress (gdbarch, pc));
6072 inferior_thread ()->control.exception_resume_breakpoint =
6073 set_momentary_breakpoint_at_pc (gdbarch, pc, bp_longjmp_resume);
6076 /* Insert an exception resume breakpoint. TP is the thread throwing
6077 the exception. The block B is the block of the unwinder debug hook
6078 function. FRAME is the frame corresponding to the call to this
6079 function. SYM is the symbol of the function argument holding the
6080 target PC of the exception. */
6083 insert_exception_resume_breakpoint (struct thread_info *tp,
6084 const struct block *b,
6085 struct frame_info *frame,
6090 struct symbol *vsym;
6091 struct value *value;
6093 struct breakpoint *bp;
6095 vsym = lookup_symbol (SYMBOL_LINKAGE_NAME (sym), b, VAR_DOMAIN, NULL);
6096 value = read_var_value (vsym, frame);
6097 /* If the value was optimized out, revert to the old behavior. */
6098 if (! value_optimized_out (value))
6100 handler = value_as_address (value);
6103 fprintf_unfiltered (gdb_stdlog,
6104 "infrun: exception resume at %lx\n",
6105 (unsigned long) handler);
6107 bp = set_momentary_breakpoint_at_pc (get_frame_arch (frame),
6108 handler, bp_exception_resume);
6110 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
6113 bp->thread = tp->num;
6114 inferior_thread ()->control.exception_resume_breakpoint = bp;
6117 CATCH (e, RETURN_MASK_ERROR)
6119 /* We want to ignore errors here. */
6124 /* A helper for check_exception_resume that sets an
6125 exception-breakpoint based on a SystemTap probe. */
6128 insert_exception_resume_from_probe (struct thread_info *tp,
6129 const struct bound_probe *probe,
6130 struct frame_info *frame)
6132 struct value *arg_value;
6134 struct breakpoint *bp;
6136 arg_value = probe_safe_evaluate_at_pc (frame, 1);
6140 handler = value_as_address (arg_value);
6143 fprintf_unfiltered (gdb_stdlog,
6144 "infrun: exception resume at %s\n",
6145 paddress (get_objfile_arch (probe->objfile),
6148 bp = set_momentary_breakpoint_at_pc (get_frame_arch (frame),
6149 handler, bp_exception_resume);
6150 bp->thread = tp->num;
6151 inferior_thread ()->control.exception_resume_breakpoint = bp;
6154 /* This is called when an exception has been intercepted. Check to
6155 see whether the exception's destination is of interest, and if so,
6156 set an exception resume breakpoint there. */
6159 check_exception_resume (struct execution_control_state *ecs,
6160 struct frame_info *frame)
6162 struct bound_probe probe;
6163 struct symbol *func;
6165 /* First see if this exception unwinding breakpoint was set via a
6166 SystemTap probe point. If so, the probe has two arguments: the
6167 CFA and the HANDLER. We ignore the CFA, extract the handler, and
6168 set a breakpoint there. */
6169 probe = find_probe_by_pc (get_frame_pc (frame));
6172 insert_exception_resume_from_probe (ecs->event_thread, &probe, frame);
6176 func = get_frame_function (frame);
6182 const struct block *b;
6183 struct block_iterator iter;
6187 /* The exception breakpoint is a thread-specific breakpoint on
6188 the unwinder's debug hook, declared as:
6190 void _Unwind_DebugHook (void *cfa, void *handler);
6192 The CFA argument indicates the frame to which control is
6193 about to be transferred. HANDLER is the destination PC.
6195 We ignore the CFA and set a temporary breakpoint at HANDLER.
6196 This is not extremely efficient but it avoids issues in gdb
6197 with computing the DWARF CFA, and it also works even in weird
6198 cases such as throwing an exception from inside a signal
6201 b = SYMBOL_BLOCK_VALUE (func);
6202 ALL_BLOCK_SYMBOLS (b, iter, sym)
6204 if (!SYMBOL_IS_ARGUMENT (sym))
6211 insert_exception_resume_breakpoint (ecs->event_thread,
6217 CATCH (e, RETURN_MASK_ERROR)
6224 stop_waiting (struct execution_control_state *ecs)
6227 fprintf_unfiltered (gdb_stdlog, "infrun: stop_waiting\n");
6229 clear_step_over_info ();
6231 /* Let callers know we don't want to wait for the inferior anymore. */
6232 ecs->wait_some_more = 0;
6235 /* Called when we should continue running the inferior, because the
6236 current event doesn't cause a user visible stop. This does the
6237 resuming part; waiting for the next event is done elsewhere. */
6240 keep_going (struct execution_control_state *ecs)
6242 /* Make sure normal_stop is called if we get a QUIT handled before
6244 struct cleanup *old_cleanups = make_cleanup (resume_cleanups, 0);
6246 /* Save the pc before execution, to compare with pc after stop. */
6247 ecs->event_thread->prev_pc
6248 = regcache_read_pc (get_thread_regcache (ecs->ptid));
6250 if (ecs->event_thread->control.trap_expected
6251 && ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_TRAP)
6253 /* We haven't yet gotten our trap, and either: intercepted a
6254 non-signal event (e.g., a fork); or took a signal which we
6255 are supposed to pass through to the inferior. Simply
6257 discard_cleanups (old_cleanups);
6258 resume (ecs->event_thread->suspend.stop_signal);
6262 struct regcache *regcache = get_current_regcache ();
6266 /* Either the trap was not expected, but we are continuing
6267 anyway (if we got a signal, the user asked it be passed to
6270 We got our expected trap, but decided we should resume from
6273 We're going to run this baby now!
6275 Note that insert_breakpoints won't try to re-insert
6276 already inserted breakpoints. Therefore, we don't
6277 care if breakpoints were already inserted, or not. */
6279 /* If we need to step over a breakpoint, and we're not using
6280 displaced stepping to do so, insert all breakpoints
6281 (watchpoints, etc.) but the one we're stepping over, step one
6282 instruction, and then re-insert the breakpoint when that step
6285 remove_bp = (ecs->hit_singlestep_breakpoint
6286 || thread_still_needs_step_over (ecs->event_thread));
6287 remove_wps = (ecs->event_thread->stepping_over_watchpoint
6288 && !target_have_steppable_watchpoint);
6290 /* We can't use displaced stepping if we need to step past a
6291 watchpoint. The instruction copied to the scratch pad would
6292 still trigger the watchpoint. */
6295 || !use_displaced_stepping (get_regcache_arch (regcache))))
6297 set_step_over_info (get_regcache_aspace (regcache),
6298 regcache_read_pc (regcache), remove_wps);
6300 else if (remove_wps)
6301 set_step_over_info (NULL, 0, remove_wps);
6303 clear_step_over_info ();
6305 /* Stop stepping if inserting breakpoints fails. */
6308 insert_breakpoints ();
6310 CATCH (e, RETURN_MASK_ERROR)
6312 exception_print (gdb_stderr, e);
6314 discard_cleanups (old_cleanups);
6319 ecs->event_thread->control.trap_expected = (remove_bp || remove_wps);
6321 /* Do not deliver GDB_SIGNAL_TRAP (except when the user
6322 explicitly specifies that such a signal should be delivered
6323 to the target program). Typically, that would occur when a
6324 user is debugging a target monitor on a simulator: the target
6325 monitor sets a breakpoint; the simulator encounters this
6326 breakpoint and halts the simulation handing control to GDB;
6327 GDB, noting that the stop address doesn't map to any known
6328 breakpoint, returns control back to the simulator; the
6329 simulator then delivers the hardware equivalent of a
6330 GDB_SIGNAL_TRAP to the program being debugged. */
6331 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
6332 && !signal_program[ecs->event_thread->suspend.stop_signal])
6333 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
6335 discard_cleanups (old_cleanups);
6336 resume (ecs->event_thread->suspend.stop_signal);
6339 prepare_to_wait (ecs);
6342 /* This function normally comes after a resume, before
6343 handle_inferior_event exits. It takes care of any last bits of
6344 housekeeping, and sets the all-important wait_some_more flag. */
6347 prepare_to_wait (struct execution_control_state *ecs)
6350 fprintf_unfiltered (gdb_stdlog, "infrun: prepare_to_wait\n");
6352 /* This is the old end of the while loop. Let everybody know we
6353 want to wait for the inferior some more and get called again
6355 ecs->wait_some_more = 1;
6358 /* We are done with the step range of a step/next/si/ni command.
6359 Called once for each n of a "step n" operation. */
6362 end_stepping_range (struct execution_control_state *ecs)
6364 ecs->event_thread->control.stop_step = 1;
6368 /* Several print_*_reason functions to print why the inferior has stopped.
6369 We always print something when the inferior exits, or receives a signal.
6370 The rest of the cases are dealt with later on in normal_stop and
6371 print_it_typical. Ideally there should be a call to one of these
6372 print_*_reason functions functions from handle_inferior_event each time
6373 stop_waiting is called.
6375 Note that we don't call these directly, instead we delegate that to
6376 the interpreters, through observers. Interpreters then call these
6377 with whatever uiout is right. */
6380 print_end_stepping_range_reason (struct ui_out *uiout)
6382 /* For CLI-like interpreters, print nothing. */
6384 if (ui_out_is_mi_like_p (uiout))
6386 ui_out_field_string (uiout, "reason",
6387 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE));
6392 print_signal_exited_reason (struct ui_out *uiout, enum gdb_signal siggnal)
6394 annotate_signalled ();
6395 if (ui_out_is_mi_like_p (uiout))
6397 (uiout, "reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED));
6398 ui_out_text (uiout, "\nProgram terminated with signal ");
6399 annotate_signal_name ();
6400 ui_out_field_string (uiout, "signal-name",
6401 gdb_signal_to_name (siggnal));
6402 annotate_signal_name_end ();
6403 ui_out_text (uiout, ", ");
6404 annotate_signal_string ();
6405 ui_out_field_string (uiout, "signal-meaning",
6406 gdb_signal_to_string (siggnal));
6407 annotate_signal_string_end ();
6408 ui_out_text (uiout, ".\n");
6409 ui_out_text (uiout, "The program no longer exists.\n");
6413 print_exited_reason (struct ui_out *uiout, int exitstatus)
6415 struct inferior *inf = current_inferior ();
6416 const char *pidstr = target_pid_to_str (pid_to_ptid (inf->pid));
6418 annotate_exited (exitstatus);
6421 if (ui_out_is_mi_like_p (uiout))
6422 ui_out_field_string (uiout, "reason",
6423 async_reason_lookup (EXEC_ASYNC_EXITED));
6424 ui_out_text (uiout, "[Inferior ");
6425 ui_out_text (uiout, plongest (inf->num));
6426 ui_out_text (uiout, " (");
6427 ui_out_text (uiout, pidstr);
6428 ui_out_text (uiout, ") exited with code ");
6429 ui_out_field_fmt (uiout, "exit-code", "0%o", (unsigned int) exitstatus);
6430 ui_out_text (uiout, "]\n");
6434 if (ui_out_is_mi_like_p (uiout))
6436 (uiout, "reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY));
6437 ui_out_text (uiout, "[Inferior ");
6438 ui_out_text (uiout, plongest (inf->num));
6439 ui_out_text (uiout, " (");
6440 ui_out_text (uiout, pidstr);
6441 ui_out_text (uiout, ") exited normally]\n");
6446 print_signal_received_reason (struct ui_out *uiout, enum gdb_signal siggnal)
6450 if (siggnal == GDB_SIGNAL_0 && !ui_out_is_mi_like_p (uiout))
6452 struct thread_info *t = inferior_thread ();
6454 ui_out_text (uiout, "\n[");
6455 ui_out_field_string (uiout, "thread-name",
6456 target_pid_to_str (t->ptid));
6457 ui_out_field_fmt (uiout, "thread-id", "] #%d", t->num);
6458 ui_out_text (uiout, " stopped");
6462 ui_out_text (uiout, "\nProgram received signal ");
6463 annotate_signal_name ();
6464 if (ui_out_is_mi_like_p (uiout))
6466 (uiout, "reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED));
6467 ui_out_field_string (uiout, "signal-name",
6468 gdb_signal_to_name (siggnal));
6469 annotate_signal_name_end ();
6470 ui_out_text (uiout, ", ");
6471 annotate_signal_string ();
6472 ui_out_field_string (uiout, "signal-meaning",
6473 gdb_signal_to_string (siggnal));
6474 annotate_signal_string_end ();
6476 ui_out_text (uiout, ".\n");
6480 print_no_history_reason (struct ui_out *uiout)
6482 ui_out_text (uiout, "\nNo more reverse-execution history.\n");
6485 /* Print current location without a level number, if we have changed
6486 functions or hit a breakpoint. Print source line if we have one.
6487 bpstat_print contains the logic deciding in detail what to print,
6488 based on the event(s) that just occurred. */
6491 print_stop_event (struct target_waitstatus *ws)
6495 int do_frame_printing = 1;
6496 struct thread_info *tp = inferior_thread ();
6498 bpstat_ret = bpstat_print (tp->control.stop_bpstat, ws->kind);
6502 /* FIXME: cagney/2002-12-01: Given that a frame ID does (or
6503 should) carry around the function and does (or should) use
6504 that when doing a frame comparison. */
6505 if (tp->control.stop_step
6506 && frame_id_eq (tp->control.step_frame_id,
6507 get_frame_id (get_current_frame ()))
6508 && tp->control.step_start_function == find_pc_function (stop_pc))
6510 /* Finished step, just print source line. */
6511 source_flag = SRC_LINE;
6515 /* Print location and source line. */
6516 source_flag = SRC_AND_LOC;
6519 case PRINT_SRC_AND_LOC:
6520 /* Print location and source line. */
6521 source_flag = SRC_AND_LOC;
6523 case PRINT_SRC_ONLY:
6524 source_flag = SRC_LINE;
6527 /* Something bogus. */
6528 source_flag = SRC_LINE;
6529 do_frame_printing = 0;
6532 internal_error (__FILE__, __LINE__, _("Unknown value."));
6535 /* The behavior of this routine with respect to the source
6537 SRC_LINE: Print only source line
6538 LOCATION: Print only location
6539 SRC_AND_LOC: Print location and source line. */
6540 if (do_frame_printing)
6541 print_stack_frame (get_selected_frame (NULL), 0, source_flag, 1);
6543 /* Display the auto-display expressions. */
6547 /* Here to return control to GDB when the inferior stops for real.
6548 Print appropriate messages, remove breakpoints, give terminal our modes.
6550 STOP_PRINT_FRAME nonzero means print the executing frame
6551 (pc, function, args, file, line number and line text).
6552 BREAKPOINTS_FAILED nonzero means stop was due to error
6553 attempting to insert breakpoints. */
6558 struct target_waitstatus last;
6560 struct cleanup *old_chain = make_cleanup (null_cleanup, NULL);
6562 get_last_target_status (&last_ptid, &last);
6564 /* If an exception is thrown from this point on, make sure to
6565 propagate GDB's knowledge of the executing state to the
6566 frontend/user running state. A QUIT is an easy exception to see
6567 here, so do this before any filtered output. */
6569 make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
6570 else if (last.kind != TARGET_WAITKIND_SIGNALLED
6571 && last.kind != TARGET_WAITKIND_EXITED
6572 && last.kind != TARGET_WAITKIND_NO_RESUMED)
6573 make_cleanup (finish_thread_state_cleanup, &inferior_ptid);
6575 /* As we're presenting a stop, and potentially removing breakpoints,
6576 update the thread list so we can tell whether there are threads
6577 running on the target. With target remote, for example, we can
6578 only learn about new threads when we explicitly update the thread
6579 list. Do this before notifying the interpreters about signal
6580 stops, end of stepping ranges, etc., so that the "new thread"
6581 output is emitted before e.g., "Program received signal FOO",
6582 instead of after. */
6583 update_thread_list ();
6585 if (last.kind == TARGET_WAITKIND_STOPPED && stopped_by_random_signal)
6586 observer_notify_signal_received (inferior_thread ()->suspend.stop_signal);
6588 /* As with the notification of thread events, we want to delay
6589 notifying the user that we've switched thread context until
6590 the inferior actually stops.
6592 There's no point in saying anything if the inferior has exited.
6593 Note that SIGNALLED here means "exited with a signal", not
6594 "received a signal".
6596 Also skip saying anything in non-stop mode. In that mode, as we
6597 don't want GDB to switch threads behind the user's back, to avoid
6598 races where the user is typing a command to apply to thread x,
6599 but GDB switches to thread y before the user finishes entering
6600 the command, fetch_inferior_event installs a cleanup to restore
6601 the current thread back to the thread the user had selected right
6602 after this event is handled, so we're not really switching, only
6603 informing of a stop. */
6605 && !ptid_equal (previous_inferior_ptid, inferior_ptid)
6606 && target_has_execution
6607 && last.kind != TARGET_WAITKIND_SIGNALLED
6608 && last.kind != TARGET_WAITKIND_EXITED
6609 && last.kind != TARGET_WAITKIND_NO_RESUMED)
6611 target_terminal_ours_for_output ();
6612 printf_filtered (_("[Switching to %s]\n"),
6613 target_pid_to_str (inferior_ptid));
6614 annotate_thread_changed ();
6615 previous_inferior_ptid = inferior_ptid;
6618 if (last.kind == TARGET_WAITKIND_NO_RESUMED)
6620 gdb_assert (sync_execution || !target_can_async_p ());
6622 target_terminal_ours_for_output ();
6623 printf_filtered (_("No unwaited-for children left.\n"));
6626 /* Note: this depends on the update_thread_list call above. */
6627 if (!breakpoints_should_be_inserted_now () && target_has_execution)
6629 if (remove_breakpoints ())
6631 target_terminal_ours_for_output ();
6632 printf_filtered (_("Cannot remove breakpoints because "
6633 "program is no longer writable.\nFurther "
6634 "execution is probably impossible.\n"));
6638 /* If an auto-display called a function and that got a signal,
6639 delete that auto-display to avoid an infinite recursion. */
6641 if (stopped_by_random_signal)
6642 disable_current_display ();
6644 /* Notify observers if we finished a "step"-like command, etc. */
6645 if (target_has_execution
6646 && last.kind != TARGET_WAITKIND_SIGNALLED
6647 && last.kind != TARGET_WAITKIND_EXITED
6648 && inferior_thread ()->control.stop_step)
6650 /* But not if in the middle of doing a "step n" operation for
6652 if (inferior_thread ()->step_multi)
6655 observer_notify_end_stepping_range ();
6658 target_terminal_ours ();
6659 async_enable_stdin ();
6661 /* Set the current source location. This will also happen if we
6662 display the frame below, but the current SAL will be incorrect
6663 during a user hook-stop function. */
6664 if (has_stack_frames () && !stop_stack_dummy)
6665 set_current_sal_from_frame (get_current_frame ());
6667 /* Let the user/frontend see the threads as stopped, but do nothing
6668 if the thread was running an infcall. We may be e.g., evaluating
6669 a breakpoint condition. In that case, the thread had state
6670 THREAD_RUNNING before the infcall, and shall remain set to
6671 running, all without informing the user/frontend about state
6672 transition changes. If this is actually a call command, then the
6673 thread was originally already stopped, so there's no state to
6675 if (target_has_execution && inferior_thread ()->control.in_infcall)
6676 discard_cleanups (old_chain);
6678 do_cleanups (old_chain);
6680 /* Look up the hook_stop and run it (CLI internally handles problem
6681 of stop_command's pre-hook not existing). */
6683 catch_errors (hook_stop_stub, stop_command,
6684 "Error while running hook_stop:\n", RETURN_MASK_ALL);
6686 if (!has_stack_frames ())
6689 if (last.kind == TARGET_WAITKIND_SIGNALLED
6690 || last.kind == TARGET_WAITKIND_EXITED)
6693 /* Select innermost stack frame - i.e., current frame is frame 0,
6694 and current location is based on that.
6695 Don't do this on return from a stack dummy routine,
6696 or if the program has exited. */
6698 if (!stop_stack_dummy)
6700 select_frame (get_current_frame ());
6702 /* If --batch-silent is enabled then there's no need to print the current
6703 source location, and to try risks causing an error message about
6704 missing source files. */
6705 if (stop_print_frame && !batch_silent)
6706 print_stop_event (&last);
6709 if (stop_stack_dummy == STOP_STACK_DUMMY)
6711 /* Pop the empty frame that contains the stack dummy.
6712 This also restores inferior state prior to the call
6713 (struct infcall_suspend_state). */
6714 struct frame_info *frame = get_current_frame ();
6716 gdb_assert (get_frame_type (frame) == DUMMY_FRAME);
6718 /* frame_pop() calls reinit_frame_cache as the last thing it
6719 does which means there's currently no selected frame. We
6720 don't need to re-establish a selected frame if the dummy call
6721 returns normally, that will be done by
6722 restore_infcall_control_state. However, we do have to handle
6723 the case where the dummy call is returning after being
6724 stopped (e.g. the dummy call previously hit a breakpoint).
6725 We can't know which case we have so just always re-establish
6726 a selected frame here. */
6727 select_frame (get_current_frame ());
6731 annotate_stopped ();
6733 /* Suppress the stop observer if we're in the middle of:
6735 - a step n (n > 1), as there still more steps to be done.
6737 - a "finish" command, as the observer will be called in
6738 finish_command_continuation, so it can include the inferior
6739 function's return value.
6741 - calling an inferior function, as we pretend we inferior didn't
6742 run at all. The return value of the call is handled by the
6743 expression evaluator, through call_function_by_hand. */
6745 if (!target_has_execution
6746 || last.kind == TARGET_WAITKIND_SIGNALLED
6747 || last.kind == TARGET_WAITKIND_EXITED
6748 || last.kind == TARGET_WAITKIND_NO_RESUMED
6749 || (!(inferior_thread ()->step_multi
6750 && inferior_thread ()->control.stop_step)
6751 && !(inferior_thread ()->control.stop_bpstat
6752 && inferior_thread ()->control.proceed_to_finish)
6753 && !inferior_thread ()->control.in_infcall))
6755 if (!ptid_equal (inferior_ptid, null_ptid))
6756 observer_notify_normal_stop (inferior_thread ()->control.stop_bpstat,
6759 observer_notify_normal_stop (NULL, stop_print_frame);
6762 if (target_has_execution)
6764 if (last.kind != TARGET_WAITKIND_SIGNALLED
6765 && last.kind != TARGET_WAITKIND_EXITED)
6766 /* Delete the breakpoint we stopped at, if it wants to be deleted.
6767 Delete any breakpoint that is to be deleted at the next stop. */
6768 breakpoint_auto_delete (inferior_thread ()->control.stop_bpstat);
6771 /* Try to get rid of automatically added inferiors that are no
6772 longer needed. Keeping those around slows down things linearly.
6773 Note that this never removes the current inferior. */
6778 hook_stop_stub (void *cmd)
6780 execute_cmd_pre_hook ((struct cmd_list_element *) cmd);
6785 signal_stop_state (int signo)
6787 return signal_stop[signo];
6791 signal_print_state (int signo)
6793 return signal_print[signo];
6797 signal_pass_state (int signo)
6799 return signal_program[signo];
6803 signal_cache_update (int signo)
6807 for (signo = 0; signo < (int) GDB_SIGNAL_LAST; signo++)
6808 signal_cache_update (signo);
6813 signal_pass[signo] = (signal_stop[signo] == 0
6814 && signal_print[signo] == 0
6815 && signal_program[signo] == 1
6816 && signal_catch[signo] == 0);
6820 signal_stop_update (int signo, int state)
6822 int ret = signal_stop[signo];
6824 signal_stop[signo] = state;
6825 signal_cache_update (signo);
6830 signal_print_update (int signo, int state)
6832 int ret = signal_print[signo];
6834 signal_print[signo] = state;
6835 signal_cache_update (signo);
6840 signal_pass_update (int signo, int state)
6842 int ret = signal_program[signo];
6844 signal_program[signo] = state;
6845 signal_cache_update (signo);
6849 /* Update the global 'signal_catch' from INFO and notify the
6853 signal_catch_update (const unsigned int *info)
6857 for (i = 0; i < GDB_SIGNAL_LAST; ++i)
6858 signal_catch[i] = info[i] > 0;
6859 signal_cache_update (-1);
6860 target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
6864 sig_print_header (void)
6866 printf_filtered (_("Signal Stop\tPrint\tPass "
6867 "to program\tDescription\n"));
6871 sig_print_info (enum gdb_signal oursig)
6873 const char *name = gdb_signal_to_name (oursig);
6874 int name_padding = 13 - strlen (name);
6876 if (name_padding <= 0)
6879 printf_filtered ("%s", name);
6880 printf_filtered ("%*.*s ", name_padding, name_padding, " ");
6881 printf_filtered ("%s\t", signal_stop[oursig] ? "Yes" : "No");
6882 printf_filtered ("%s\t", signal_print[oursig] ? "Yes" : "No");
6883 printf_filtered ("%s\t\t", signal_program[oursig] ? "Yes" : "No");
6884 printf_filtered ("%s\n", gdb_signal_to_string (oursig));
6887 /* Specify how various signals in the inferior should be handled. */
6890 handle_command (char *args, int from_tty)
6893 int digits, wordlen;
6894 int sigfirst, signum, siglast;
6895 enum gdb_signal oursig;
6898 unsigned char *sigs;
6899 struct cleanup *old_chain;
6903 error_no_arg (_("signal to handle"));
6906 /* Allocate and zero an array of flags for which signals to handle. */
6908 nsigs = (int) GDB_SIGNAL_LAST;
6909 sigs = (unsigned char *) alloca (nsigs);
6910 memset (sigs, 0, nsigs);
6912 /* Break the command line up into args. */
6914 argv = gdb_buildargv (args);
6915 old_chain = make_cleanup_freeargv (argv);
6917 /* Walk through the args, looking for signal oursigs, signal names, and
6918 actions. Signal numbers and signal names may be interspersed with
6919 actions, with the actions being performed for all signals cumulatively
6920 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
6922 while (*argv != NULL)
6924 wordlen = strlen (*argv);
6925 for (digits = 0; isdigit ((*argv)[digits]); digits++)
6929 sigfirst = siglast = -1;
6931 if (wordlen >= 1 && !strncmp (*argv, "all", wordlen))
6933 /* Apply action to all signals except those used by the
6934 debugger. Silently skip those. */
6937 siglast = nsigs - 1;
6939 else if (wordlen >= 1 && !strncmp (*argv, "stop", wordlen))
6941 SET_SIGS (nsigs, sigs, signal_stop);
6942 SET_SIGS (nsigs, sigs, signal_print);
6944 else if (wordlen >= 1 && !strncmp (*argv, "ignore", wordlen))
6946 UNSET_SIGS (nsigs, sigs, signal_program);
6948 else if (wordlen >= 2 && !strncmp (*argv, "print", wordlen))
6950 SET_SIGS (nsigs, sigs, signal_print);
6952 else if (wordlen >= 2 && !strncmp (*argv, "pass", wordlen))
6954 SET_SIGS (nsigs, sigs, signal_program);
6956 else if (wordlen >= 3 && !strncmp (*argv, "nostop", wordlen))
6958 UNSET_SIGS (nsigs, sigs, signal_stop);
6960 else if (wordlen >= 3 && !strncmp (*argv, "noignore", wordlen))
6962 SET_SIGS (nsigs, sigs, signal_program);
6964 else if (wordlen >= 4 && !strncmp (*argv, "noprint", wordlen))
6966 UNSET_SIGS (nsigs, sigs, signal_print);
6967 UNSET_SIGS (nsigs, sigs, signal_stop);
6969 else if (wordlen >= 4 && !strncmp (*argv, "nopass", wordlen))
6971 UNSET_SIGS (nsigs, sigs, signal_program);
6973 else if (digits > 0)
6975 /* It is numeric. The numeric signal refers to our own
6976 internal signal numbering from target.h, not to host/target
6977 signal number. This is a feature; users really should be
6978 using symbolic names anyway, and the common ones like
6979 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
6981 sigfirst = siglast = (int)
6982 gdb_signal_from_command (atoi (*argv));
6983 if ((*argv)[digits] == '-')
6986 gdb_signal_from_command (atoi ((*argv) + digits + 1));
6988 if (sigfirst > siglast)
6990 /* Bet he didn't figure we'd think of this case... */
6998 oursig = gdb_signal_from_name (*argv);
6999 if (oursig != GDB_SIGNAL_UNKNOWN)
7001 sigfirst = siglast = (int) oursig;
7005 /* Not a number and not a recognized flag word => complain. */
7006 error (_("Unrecognized or ambiguous flag word: \"%s\"."), *argv);
7010 /* If any signal numbers or symbol names were found, set flags for
7011 which signals to apply actions to. */
7013 for (signum = sigfirst; signum >= 0 && signum <= siglast; signum++)
7015 switch ((enum gdb_signal) signum)
7017 case GDB_SIGNAL_TRAP:
7018 case GDB_SIGNAL_INT:
7019 if (!allsigs && !sigs[signum])
7021 if (query (_("%s is used by the debugger.\n\
7022 Are you sure you want to change it? "),
7023 gdb_signal_to_name ((enum gdb_signal) signum)))
7029 printf_unfiltered (_("Not confirmed, unchanged.\n"));
7030 gdb_flush (gdb_stdout);
7035 case GDB_SIGNAL_DEFAULT:
7036 case GDB_SIGNAL_UNKNOWN:
7037 /* Make sure that "all" doesn't print these. */
7048 for (signum = 0; signum < nsigs; signum++)
7051 signal_cache_update (-1);
7052 target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
7053 target_program_signals ((int) GDB_SIGNAL_LAST, signal_program);
7057 /* Show the results. */
7058 sig_print_header ();
7059 for (; signum < nsigs; signum++)
7061 sig_print_info (signum);
7067 do_cleanups (old_chain);
7070 /* Complete the "handle" command. */
7072 static VEC (char_ptr) *
7073 handle_completer (struct cmd_list_element *ignore,
7074 const char *text, const char *word)
7076 VEC (char_ptr) *vec_signals, *vec_keywords, *return_val;
7077 static const char * const keywords[] =
7091 vec_signals = signal_completer (ignore, text, word);
7092 vec_keywords = complete_on_enum (keywords, word, word);
7094 return_val = VEC_merge (char_ptr, vec_signals, vec_keywords);
7095 VEC_free (char_ptr, vec_signals);
7096 VEC_free (char_ptr, vec_keywords);
7101 gdb_signal_from_command (int num)
7103 if (num >= 1 && num <= 15)
7104 return (enum gdb_signal) num;
7105 error (_("Only signals 1-15 are valid as numeric signals.\n\
7106 Use \"info signals\" for a list of symbolic signals."));
7109 /* Print current contents of the tables set by the handle command.
7110 It is possible we should just be printing signals actually used
7111 by the current target (but for things to work right when switching
7112 targets, all signals should be in the signal tables). */
7115 signals_info (char *signum_exp, int from_tty)
7117 enum gdb_signal oursig;
7119 sig_print_header ();
7123 /* First see if this is a symbol name. */
7124 oursig = gdb_signal_from_name (signum_exp);
7125 if (oursig == GDB_SIGNAL_UNKNOWN)
7127 /* No, try numeric. */
7129 gdb_signal_from_command (parse_and_eval_long (signum_exp));
7131 sig_print_info (oursig);
7135 printf_filtered ("\n");
7136 /* These ugly casts brought to you by the native VAX compiler. */
7137 for (oursig = GDB_SIGNAL_FIRST;
7138 (int) oursig < (int) GDB_SIGNAL_LAST;
7139 oursig = (enum gdb_signal) ((int) oursig + 1))
7143 if (oursig != GDB_SIGNAL_UNKNOWN
7144 && oursig != GDB_SIGNAL_DEFAULT && oursig != GDB_SIGNAL_0)
7145 sig_print_info (oursig);
7148 printf_filtered (_("\nUse the \"handle\" command "
7149 "to change these tables.\n"));
7152 /* Check if it makes sense to read $_siginfo from the current thread
7153 at this point. If not, throw an error. */
7156 validate_siginfo_access (void)
7158 /* No current inferior, no siginfo. */
7159 if (ptid_equal (inferior_ptid, null_ptid))
7160 error (_("No thread selected."));
7162 /* Don't try to read from a dead thread. */
7163 if (is_exited (inferior_ptid))
7164 error (_("The current thread has terminated"));
7166 /* ... or from a spinning thread. */
7167 if (is_running (inferior_ptid))
7168 error (_("Selected thread is running."));
7171 /* The $_siginfo convenience variable is a bit special. We don't know
7172 for sure the type of the value until we actually have a chance to
7173 fetch the data. The type can change depending on gdbarch, so it is
7174 also dependent on which thread you have selected.
7176 1. making $_siginfo be an internalvar that creates a new value on
7179 2. making the value of $_siginfo be an lval_computed value. */
7181 /* This function implements the lval_computed support for reading a
7185 siginfo_value_read (struct value *v)
7187 LONGEST transferred;
7189 validate_siginfo_access ();
7192 target_read (¤t_target, TARGET_OBJECT_SIGNAL_INFO,
7194 value_contents_all_raw (v),
7196 TYPE_LENGTH (value_type (v)));
7198 if (transferred != TYPE_LENGTH (value_type (v)))
7199 error (_("Unable to read siginfo"));
7202 /* This function implements the lval_computed support for writing a
7206 siginfo_value_write (struct value *v, struct value *fromval)
7208 LONGEST transferred;
7210 validate_siginfo_access ();
7212 transferred = target_write (¤t_target,
7213 TARGET_OBJECT_SIGNAL_INFO,
7215 value_contents_all_raw (fromval),
7217 TYPE_LENGTH (value_type (fromval)));
7219 if (transferred != TYPE_LENGTH (value_type (fromval)))
7220 error (_("Unable to write siginfo"));
7223 static const struct lval_funcs siginfo_value_funcs =
7229 /* Return a new value with the correct type for the siginfo object of
7230 the current thread using architecture GDBARCH. Return a void value
7231 if there's no object available. */
7233 static struct value *
7234 siginfo_make_value (struct gdbarch *gdbarch, struct internalvar *var,
7237 if (target_has_stack
7238 && !ptid_equal (inferior_ptid, null_ptid)
7239 && gdbarch_get_siginfo_type_p (gdbarch))
7241 struct type *type = gdbarch_get_siginfo_type (gdbarch);
7243 return allocate_computed_value (type, &siginfo_value_funcs, NULL);
7246 return allocate_value (builtin_type (gdbarch)->builtin_void);
7250 /* infcall_suspend_state contains state about the program itself like its
7251 registers and any signal it received when it last stopped.
7252 This state must be restored regardless of how the inferior function call
7253 ends (either successfully, or after it hits a breakpoint or signal)
7254 if the program is to properly continue where it left off. */
7256 struct infcall_suspend_state
7258 struct thread_suspend_state thread_suspend;
7262 struct regcache *registers;
7264 /* Format of SIGINFO_DATA or NULL if it is not present. */
7265 struct gdbarch *siginfo_gdbarch;
7267 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
7268 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
7269 content would be invalid. */
7270 gdb_byte *siginfo_data;
7273 struct infcall_suspend_state *
7274 save_infcall_suspend_state (void)
7276 struct infcall_suspend_state *inf_state;
7277 struct thread_info *tp = inferior_thread ();
7278 struct regcache *regcache = get_current_regcache ();
7279 struct gdbarch *gdbarch = get_regcache_arch (regcache);
7280 gdb_byte *siginfo_data = NULL;
7282 if (gdbarch_get_siginfo_type_p (gdbarch))
7284 struct type *type = gdbarch_get_siginfo_type (gdbarch);
7285 size_t len = TYPE_LENGTH (type);
7286 struct cleanup *back_to;
7288 siginfo_data = xmalloc (len);
7289 back_to = make_cleanup (xfree, siginfo_data);
7291 if (target_read (¤t_target, TARGET_OBJECT_SIGNAL_INFO, NULL,
7292 siginfo_data, 0, len) == len)
7293 discard_cleanups (back_to);
7296 /* Errors ignored. */
7297 do_cleanups (back_to);
7298 siginfo_data = NULL;
7302 inf_state = XCNEW (struct infcall_suspend_state);
7306 inf_state->siginfo_gdbarch = gdbarch;
7307 inf_state->siginfo_data = siginfo_data;
7310 inf_state->thread_suspend = tp->suspend;
7312 /* run_inferior_call will not use the signal due to its `proceed' call with
7313 GDB_SIGNAL_0 anyway. */
7314 tp->suspend.stop_signal = GDB_SIGNAL_0;
7316 inf_state->stop_pc = stop_pc;
7318 inf_state->registers = regcache_dup (regcache);
7323 /* Restore inferior session state to INF_STATE. */
7326 restore_infcall_suspend_state (struct infcall_suspend_state *inf_state)
7328 struct thread_info *tp = inferior_thread ();
7329 struct regcache *regcache = get_current_regcache ();
7330 struct gdbarch *gdbarch = get_regcache_arch (regcache);
7332 tp->suspend = inf_state->thread_suspend;
7334 stop_pc = inf_state->stop_pc;
7336 if (inf_state->siginfo_gdbarch == gdbarch)
7338 struct type *type = gdbarch_get_siginfo_type (gdbarch);
7340 /* Errors ignored. */
7341 target_write (¤t_target, TARGET_OBJECT_SIGNAL_INFO, NULL,
7342 inf_state->siginfo_data, 0, TYPE_LENGTH (type));
7345 /* The inferior can be gone if the user types "print exit(0)"
7346 (and perhaps other times). */
7347 if (target_has_execution)
7348 /* NB: The register write goes through to the target. */
7349 regcache_cpy (regcache, inf_state->registers);
7351 discard_infcall_suspend_state (inf_state);
7355 do_restore_infcall_suspend_state_cleanup (void *state)
7357 restore_infcall_suspend_state (state);
7361 make_cleanup_restore_infcall_suspend_state
7362 (struct infcall_suspend_state *inf_state)
7364 return make_cleanup (do_restore_infcall_suspend_state_cleanup, inf_state);
7368 discard_infcall_suspend_state (struct infcall_suspend_state *inf_state)
7370 regcache_xfree (inf_state->registers);
7371 xfree (inf_state->siginfo_data);
7376 get_infcall_suspend_state_regcache (struct infcall_suspend_state *inf_state)
7378 return inf_state->registers;
7381 /* infcall_control_state contains state regarding gdb's control of the
7382 inferior itself like stepping control. It also contains session state like
7383 the user's currently selected frame. */
7385 struct infcall_control_state
7387 struct thread_control_state thread_control;
7388 struct inferior_control_state inferior_control;
7391 enum stop_stack_kind stop_stack_dummy;
7392 int stopped_by_random_signal;
7393 int stop_after_trap;
7395 /* ID if the selected frame when the inferior function call was made. */
7396 struct frame_id selected_frame_id;
7399 /* Save all of the information associated with the inferior<==>gdb
7402 struct infcall_control_state *
7403 save_infcall_control_state (void)
7405 struct infcall_control_state *inf_status = xmalloc (sizeof (*inf_status));
7406 struct thread_info *tp = inferior_thread ();
7407 struct inferior *inf = current_inferior ();
7409 inf_status->thread_control = tp->control;
7410 inf_status->inferior_control = inf->control;
7412 tp->control.step_resume_breakpoint = NULL;
7413 tp->control.exception_resume_breakpoint = NULL;
7415 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
7416 chain. If caller's caller is walking the chain, they'll be happier if we
7417 hand them back the original chain when restore_infcall_control_state is
7419 tp->control.stop_bpstat = bpstat_copy (tp->control.stop_bpstat);
7422 inf_status->stop_stack_dummy = stop_stack_dummy;
7423 inf_status->stopped_by_random_signal = stopped_by_random_signal;
7424 inf_status->stop_after_trap = stop_after_trap;
7426 inf_status->selected_frame_id = get_frame_id (get_selected_frame (NULL));
7432 restore_selected_frame (void *args)
7434 struct frame_id *fid = (struct frame_id *) args;
7435 struct frame_info *frame;
7437 frame = frame_find_by_id (*fid);
7439 /* If inf_status->selected_frame_id is NULL, there was no previously
7443 warning (_("Unable to restore previously selected frame."));
7447 select_frame (frame);
7452 /* Restore inferior session state to INF_STATUS. */
7455 restore_infcall_control_state (struct infcall_control_state *inf_status)
7457 struct thread_info *tp = inferior_thread ();
7458 struct inferior *inf = current_inferior ();
7460 if (tp->control.step_resume_breakpoint)
7461 tp->control.step_resume_breakpoint->disposition = disp_del_at_next_stop;
7463 if (tp->control.exception_resume_breakpoint)
7464 tp->control.exception_resume_breakpoint->disposition
7465 = disp_del_at_next_stop;
7467 /* Handle the bpstat_copy of the chain. */
7468 bpstat_clear (&tp->control.stop_bpstat);
7470 tp->control = inf_status->thread_control;
7471 inf->control = inf_status->inferior_control;
7474 stop_stack_dummy = inf_status->stop_stack_dummy;
7475 stopped_by_random_signal = inf_status->stopped_by_random_signal;
7476 stop_after_trap = inf_status->stop_after_trap;
7478 if (target_has_stack)
7480 /* The point of catch_errors is that if the stack is clobbered,
7481 walking the stack might encounter a garbage pointer and
7482 error() trying to dereference it. */
7484 (restore_selected_frame, &inf_status->selected_frame_id,
7485 "Unable to restore previously selected frame:\n",
7486 RETURN_MASK_ERROR) == 0)
7487 /* Error in restoring the selected frame. Select the innermost
7489 select_frame (get_current_frame ());
7496 do_restore_infcall_control_state_cleanup (void *sts)
7498 restore_infcall_control_state (sts);
7502 make_cleanup_restore_infcall_control_state
7503 (struct infcall_control_state *inf_status)
7505 return make_cleanup (do_restore_infcall_control_state_cleanup, inf_status);
7509 discard_infcall_control_state (struct infcall_control_state *inf_status)
7511 if (inf_status->thread_control.step_resume_breakpoint)
7512 inf_status->thread_control.step_resume_breakpoint->disposition
7513 = disp_del_at_next_stop;
7515 if (inf_status->thread_control.exception_resume_breakpoint)
7516 inf_status->thread_control.exception_resume_breakpoint->disposition
7517 = disp_del_at_next_stop;
7519 /* See save_infcall_control_state for info on stop_bpstat. */
7520 bpstat_clear (&inf_status->thread_control.stop_bpstat);
7525 /* restore_inferior_ptid() will be used by the cleanup machinery
7526 to restore the inferior_ptid value saved in a call to
7527 save_inferior_ptid(). */
7530 restore_inferior_ptid (void *arg)
7532 ptid_t *saved_ptid_ptr = arg;
7534 inferior_ptid = *saved_ptid_ptr;
7538 /* Save the value of inferior_ptid so that it may be restored by a
7539 later call to do_cleanups(). Returns the struct cleanup pointer
7540 needed for later doing the cleanup. */
7543 save_inferior_ptid (void)
7545 ptid_t *saved_ptid_ptr;
7547 saved_ptid_ptr = xmalloc (sizeof (ptid_t));
7548 *saved_ptid_ptr = inferior_ptid;
7549 return make_cleanup (restore_inferior_ptid, saved_ptid_ptr);
7555 clear_exit_convenience_vars (void)
7557 clear_internalvar (lookup_internalvar ("_exitsignal"));
7558 clear_internalvar (lookup_internalvar ("_exitcode"));
7562 /* User interface for reverse debugging:
7563 Set exec-direction / show exec-direction commands
7564 (returns error unless target implements to_set_exec_direction method). */
7566 int execution_direction = EXEC_FORWARD;
7567 static const char exec_forward[] = "forward";
7568 static const char exec_reverse[] = "reverse";
7569 static const char *exec_direction = exec_forward;
7570 static const char *const exec_direction_names[] = {
7577 set_exec_direction_func (char *args, int from_tty,
7578 struct cmd_list_element *cmd)
7580 if (target_can_execute_reverse)
7582 if (!strcmp (exec_direction, exec_forward))
7583 execution_direction = EXEC_FORWARD;
7584 else if (!strcmp (exec_direction, exec_reverse))
7585 execution_direction = EXEC_REVERSE;
7589 exec_direction = exec_forward;
7590 error (_("Target does not support this operation."));
7595 show_exec_direction_func (struct ui_file *out, int from_tty,
7596 struct cmd_list_element *cmd, const char *value)
7598 switch (execution_direction) {
7600 fprintf_filtered (out, _("Forward.\n"));
7603 fprintf_filtered (out, _("Reverse.\n"));
7606 internal_error (__FILE__, __LINE__,
7607 _("bogus execution_direction value: %d"),
7608 (int) execution_direction);
7613 show_schedule_multiple (struct ui_file *file, int from_tty,
7614 struct cmd_list_element *c, const char *value)
7616 fprintf_filtered (file, _("Resuming the execution of threads "
7617 "of all processes is %s.\n"), value);
7620 /* Implementation of `siginfo' variable. */
7622 static const struct internalvar_funcs siginfo_funcs =
7630 _initialize_infrun (void)
7634 struct cmd_list_element *c;
7636 add_info ("signals", signals_info, _("\
7637 What debugger does when program gets various signals.\n\
7638 Specify a signal as argument to print info on that signal only."));
7639 add_info_alias ("handle", "signals", 0);
7641 c = add_com ("handle", class_run, handle_command, _("\
7642 Specify how to handle signals.\n\
7643 Usage: handle SIGNAL [ACTIONS]\n\
7644 Args are signals and actions to apply to those signals.\n\
7645 If no actions are specified, the current settings for the specified signals\n\
7646 will be displayed instead.\n\
7648 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
7649 from 1-15 are allowed for compatibility with old versions of GDB.\n\
7650 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
7651 The special arg \"all\" is recognized to mean all signals except those\n\
7652 used by the debugger, typically SIGTRAP and SIGINT.\n\
7654 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
7655 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
7656 Stop means reenter debugger if this signal happens (implies print).\n\
7657 Print means print a message if this signal happens.\n\
7658 Pass means let program see this signal; otherwise program doesn't know.\n\
7659 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
7660 Pass and Stop may be combined.\n\
7662 Multiple signals may be specified. Signal numbers and signal names\n\
7663 may be interspersed with actions, with the actions being performed for\n\
7664 all signals cumulatively specified."));
7665 set_cmd_completer (c, handle_completer);
7668 stop_command = add_cmd ("stop", class_obscure,
7669 not_just_help_class_command, _("\
7670 There is no `stop' command, but you can set a hook on `stop'.\n\
7671 This allows you to set a list of commands to be run each time execution\n\
7672 of the program stops."), &cmdlist);
7674 add_setshow_zuinteger_cmd ("infrun", class_maintenance, &debug_infrun, _("\
7675 Set inferior debugging."), _("\
7676 Show inferior debugging."), _("\
7677 When non-zero, inferior specific debugging is enabled."),
7680 &setdebuglist, &showdebuglist);
7682 add_setshow_boolean_cmd ("displaced", class_maintenance,
7683 &debug_displaced, _("\
7684 Set displaced stepping debugging."), _("\
7685 Show displaced stepping debugging."), _("\
7686 When non-zero, displaced stepping specific debugging is enabled."),
7688 show_debug_displaced,
7689 &setdebuglist, &showdebuglist);
7691 add_setshow_boolean_cmd ("non-stop", no_class,
7693 Set whether gdb controls the inferior in non-stop mode."), _("\
7694 Show whether gdb controls the inferior in non-stop mode."), _("\
7695 When debugging a multi-threaded program and this setting is\n\
7696 off (the default, also called all-stop mode), when one thread stops\n\
7697 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
7698 all other threads in the program while you interact with the thread of\n\
7699 interest. When you continue or step a thread, you can allow the other\n\
7700 threads to run, or have them remain stopped, but while you inspect any\n\
7701 thread's state, all threads stop.\n\
7703 In non-stop mode, when one thread stops, other threads can continue\n\
7704 to run freely. You'll be able to step each thread independently,\n\
7705 leave it stopped or free to run as needed."),
7711 numsigs = (int) GDB_SIGNAL_LAST;
7712 signal_stop = (unsigned char *) xmalloc (sizeof (signal_stop[0]) * numsigs);
7713 signal_print = (unsigned char *)
7714 xmalloc (sizeof (signal_print[0]) * numsigs);
7715 signal_program = (unsigned char *)
7716 xmalloc (sizeof (signal_program[0]) * numsigs);
7717 signal_catch = (unsigned char *)
7718 xmalloc (sizeof (signal_catch[0]) * numsigs);
7719 signal_pass = (unsigned char *)
7720 xmalloc (sizeof (signal_pass[0]) * numsigs);
7721 for (i = 0; i < numsigs; i++)
7724 signal_print[i] = 1;
7725 signal_program[i] = 1;
7726 signal_catch[i] = 0;
7729 /* Signals caused by debugger's own actions
7730 should not be given to the program afterwards. */
7731 signal_program[GDB_SIGNAL_TRAP] = 0;
7732 signal_program[GDB_SIGNAL_INT] = 0;
7734 /* Signals that are not errors should not normally enter the debugger. */
7735 signal_stop[GDB_SIGNAL_ALRM] = 0;
7736 signal_print[GDB_SIGNAL_ALRM] = 0;
7737 signal_stop[GDB_SIGNAL_VTALRM] = 0;
7738 signal_print[GDB_SIGNAL_VTALRM] = 0;
7739 signal_stop[GDB_SIGNAL_PROF] = 0;
7740 signal_print[GDB_SIGNAL_PROF] = 0;
7741 signal_stop[GDB_SIGNAL_CHLD] = 0;
7742 signal_print[GDB_SIGNAL_CHLD] = 0;
7743 signal_stop[GDB_SIGNAL_IO] = 0;
7744 signal_print[GDB_SIGNAL_IO] = 0;
7745 signal_stop[GDB_SIGNAL_POLL] = 0;
7746 signal_print[GDB_SIGNAL_POLL] = 0;
7747 signal_stop[GDB_SIGNAL_URG] = 0;
7748 signal_print[GDB_SIGNAL_URG] = 0;
7749 signal_stop[GDB_SIGNAL_WINCH] = 0;
7750 signal_print[GDB_SIGNAL_WINCH] = 0;
7751 signal_stop[GDB_SIGNAL_PRIO] = 0;
7752 signal_print[GDB_SIGNAL_PRIO] = 0;
7754 /* These signals are used internally by user-level thread
7755 implementations. (See signal(5) on Solaris.) Like the above
7756 signals, a healthy program receives and handles them as part of
7757 its normal operation. */
7758 signal_stop[GDB_SIGNAL_LWP] = 0;
7759 signal_print[GDB_SIGNAL_LWP] = 0;
7760 signal_stop[GDB_SIGNAL_WAITING] = 0;
7761 signal_print[GDB_SIGNAL_WAITING] = 0;
7762 signal_stop[GDB_SIGNAL_CANCEL] = 0;
7763 signal_print[GDB_SIGNAL_CANCEL] = 0;
7765 /* Update cached state. */
7766 signal_cache_update (-1);
7768 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support,
7769 &stop_on_solib_events, _("\
7770 Set stopping for shared library events."), _("\
7771 Show stopping for shared library events."), _("\
7772 If nonzero, gdb will give control to the user when the dynamic linker\n\
7773 notifies gdb of shared library events. The most common event of interest\n\
7774 to the user would be loading/unloading of a new library."),
7775 set_stop_on_solib_events,
7776 show_stop_on_solib_events,
7777 &setlist, &showlist);
7779 add_setshow_enum_cmd ("follow-fork-mode", class_run,
7780 follow_fork_mode_kind_names,
7781 &follow_fork_mode_string, _("\
7782 Set debugger response to a program call of fork or vfork."), _("\
7783 Show debugger response to a program call of fork or vfork."), _("\
7784 A fork or vfork creates a new process. follow-fork-mode can be:\n\
7785 parent - the original process is debugged after a fork\n\
7786 child - the new process is debugged after a fork\n\
7787 The unfollowed process will continue to run.\n\
7788 By default, the debugger will follow the parent process."),
7790 show_follow_fork_mode_string,
7791 &setlist, &showlist);
7793 add_setshow_enum_cmd ("follow-exec-mode", class_run,
7794 follow_exec_mode_names,
7795 &follow_exec_mode_string, _("\
7796 Set debugger response to a program call of exec."), _("\
7797 Show debugger response to a program call of exec."), _("\
7798 An exec call replaces the program image of a process.\n\
7800 follow-exec-mode can be:\n\
7802 new - the debugger creates a new inferior and rebinds the process\n\
7803 to this new inferior. The program the process was running before\n\
7804 the exec call can be restarted afterwards by restarting the original\n\
7807 same - the debugger keeps the process bound to the same inferior.\n\
7808 The new executable image replaces the previous executable loaded in\n\
7809 the inferior. Restarting the inferior after the exec call restarts\n\
7810 the executable the process was running after the exec call.\n\
7812 By default, the debugger will use the same inferior."),
7814 show_follow_exec_mode_string,
7815 &setlist, &showlist);
7817 add_setshow_enum_cmd ("scheduler-locking", class_run,
7818 scheduler_enums, &scheduler_mode, _("\
7819 Set mode for locking scheduler during execution."), _("\
7820 Show mode for locking scheduler during execution."), _("\
7821 off == no locking (threads may preempt at any time)\n\
7822 on == full locking (no thread except the current thread may run)\n\
7823 step == scheduler locked during stepping commands (step, next, stepi, nexti).\n\
7824 In this mode, other threads may run during other commands."),
7825 set_schedlock_func, /* traps on target vector */
7826 show_scheduler_mode,
7827 &setlist, &showlist);
7829 add_setshow_boolean_cmd ("schedule-multiple", class_run, &sched_multi, _("\
7830 Set mode for resuming threads of all processes."), _("\
7831 Show mode for resuming threads of all processes."), _("\
7832 When on, execution commands (such as 'continue' or 'next') resume all\n\
7833 threads of all processes. When off (which is the default), execution\n\
7834 commands only resume the threads of the current process. The set of\n\
7835 threads that are resumed is further refined by the scheduler-locking\n\
7836 mode (see help set scheduler-locking)."),
7838 show_schedule_multiple,
7839 &setlist, &showlist);
7841 add_setshow_boolean_cmd ("step-mode", class_run, &step_stop_if_no_debug, _("\
7842 Set mode of the step operation."), _("\
7843 Show mode of the step operation."), _("\
7844 When set, doing a step over a function without debug line information\n\
7845 will stop at the first instruction of that function. Otherwise, the\n\
7846 function is skipped and the step command stops at a different source line."),
7848 show_step_stop_if_no_debug,
7849 &setlist, &showlist);
7851 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run,
7852 &can_use_displaced_stepping, _("\
7853 Set debugger's willingness to use displaced stepping."), _("\
7854 Show debugger's willingness to use displaced stepping."), _("\
7855 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
7856 supported by the target architecture. If off, gdb will not use displaced\n\
7857 stepping to step over breakpoints, even if such is supported by the target\n\
7858 architecture. If auto (which is the default), gdb will use displaced stepping\n\
7859 if the target architecture supports it and non-stop mode is active, but will not\n\
7860 use it in all-stop mode (see help set non-stop)."),
7862 show_can_use_displaced_stepping,
7863 &setlist, &showlist);
7865 add_setshow_enum_cmd ("exec-direction", class_run, exec_direction_names,
7866 &exec_direction, _("Set direction of execution.\n\
7867 Options are 'forward' or 'reverse'."),
7868 _("Show direction of execution (forward/reverse)."),
7869 _("Tells gdb whether to execute forward or backward."),
7870 set_exec_direction_func, show_exec_direction_func,
7871 &setlist, &showlist);
7873 /* Set/show detach-on-fork: user-settable mode. */
7875 add_setshow_boolean_cmd ("detach-on-fork", class_run, &detach_fork, _("\
7876 Set whether gdb will detach the child of a fork."), _("\
7877 Show whether gdb will detach the child of a fork."), _("\
7878 Tells gdb whether to detach the child of a fork."),
7879 NULL, NULL, &setlist, &showlist);
7881 /* Set/show disable address space randomization mode. */
7883 add_setshow_boolean_cmd ("disable-randomization", class_support,
7884 &disable_randomization, _("\
7885 Set disabling of debuggee's virtual address space randomization."), _("\
7886 Show disabling of debuggee's virtual address space randomization."), _("\
7887 When this mode is on (which is the default), randomization of the virtual\n\
7888 address space is disabled. Standalone programs run with the randomization\n\
7889 enabled by default on some platforms."),
7890 &set_disable_randomization,
7891 &show_disable_randomization,
7892 &setlist, &showlist);
7894 /* ptid initializations */
7895 inferior_ptid = null_ptid;
7896 target_last_wait_ptid = minus_one_ptid;
7898 observer_attach_thread_ptid_changed (infrun_thread_ptid_changed);
7899 observer_attach_thread_stop_requested (infrun_thread_stop_requested);
7900 observer_attach_thread_exit (infrun_thread_thread_exit);
7901 observer_attach_inferior_exit (infrun_inferior_exit);
7903 /* Explicitly create without lookup, since that tries to create a
7904 value with a void typed value, and when we get here, gdbarch
7905 isn't initialized yet. At this point, we're quite sure there
7906 isn't another convenience variable of the same name. */
7907 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs, NULL);
7909 add_setshow_boolean_cmd ("observer", no_class,
7910 &observer_mode_1, _("\
7911 Set whether gdb controls the inferior in observer mode."), _("\
7912 Show whether gdb controls the inferior in observer mode."), _("\
7913 In observer mode, GDB can get data from the inferior, but not\n\
7914 affect its execution. Registers and memory may not be changed,\n\
7915 breakpoints may not be set, and the program cannot be interrupted\n\