1 /* Target-struct-independent code to start (run) and stop an inferior
4 Copyright (C) 1986-2015 Free Software Foundation, Inc.
6 This file is part of GDB.
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program. If not, see <http://www.gnu.org/licenses/>. */
27 #include "breakpoint.h"
31 #include "cli/cli-script.h"
33 #include "gdbthread.h"
45 #include "dictionary.h"
47 #include "mi/mi-common.h"
48 #include "event-top.h"
50 #include "record-full.h"
51 #include "inline-frame.h"
53 #include "tracepoint.h"
54 #include "continuations.h"
59 #include "completer.h"
60 #include "target-descriptions.h"
61 #include "target-dcache.h"
64 #include "event-loop.h"
66 /* Prototypes for local functions */
68 static void signals_info (char *, int);
70 static void handle_command (char *, int);
72 static void sig_print_info (enum gdb_signal);
74 static void sig_print_header (void);
76 static void resume_cleanups (void *);
78 static int hook_stop_stub (void *);
80 static int restore_selected_frame (void *);
82 static int follow_fork (void);
84 static int follow_fork_inferior (int follow_child, int detach_fork);
86 static void follow_inferior_reset_breakpoints (void);
88 static void set_schedlock_func (char *args, int from_tty,
89 struct cmd_list_element *c);
91 static int currently_stepping (struct thread_info *tp);
93 void _initialize_infrun (void);
95 void nullify_last_target_wait_ptid (void);
97 static void insert_hp_step_resume_breakpoint_at_frame (struct frame_info *);
99 static void insert_step_resume_breakpoint_at_caller (struct frame_info *);
101 static void insert_longjmp_resume_breakpoint (struct gdbarch *, CORE_ADDR);
103 static int maybe_software_singlestep (struct gdbarch *gdbarch, CORE_ADDR pc);
105 /* Asynchronous signal handler registered as event loop source for
106 when we have pending events ready to be passed to the core. */
107 static struct async_event_handler *infrun_async_inferior_event_token;
109 /* Stores whether infrun_async was previously enabled or disabled.
110 Starts off as -1, indicating "never enabled/disabled". */
111 static int infrun_is_async = -1;
116 infrun_async (int enable)
118 if (infrun_is_async != enable)
120 infrun_is_async = enable;
123 fprintf_unfiltered (gdb_stdlog,
124 "infrun: infrun_async(%d)\n",
128 mark_async_event_handler (infrun_async_inferior_event_token);
130 clear_async_event_handler (infrun_async_inferior_event_token);
134 /* When set, stop the 'step' command if we enter a function which has
135 no line number information. The normal behavior is that we step
136 over such function. */
137 int step_stop_if_no_debug = 0;
139 show_step_stop_if_no_debug (struct ui_file *file, int from_tty,
140 struct cmd_list_element *c, const char *value)
142 fprintf_filtered (file, _("Mode of the step operation is %s.\n"), value);
145 /* In asynchronous mode, but simulating synchronous execution. */
147 int sync_execution = 0;
149 /* proceed and normal_stop use this to notify the user when the
150 inferior stopped in a different thread than it had been running
153 static ptid_t previous_inferior_ptid;
155 /* If set (default for legacy reasons), when following a fork, GDB
156 will detach from one of the fork branches, child or parent.
157 Exactly which branch is detached depends on 'set follow-fork-mode'
160 static int detach_fork = 1;
162 int debug_displaced = 0;
164 show_debug_displaced (struct ui_file *file, int from_tty,
165 struct cmd_list_element *c, const char *value)
167 fprintf_filtered (file, _("Displace stepping debugging is %s.\n"), value);
170 unsigned int debug_infrun = 0;
172 show_debug_infrun (struct ui_file *file, int from_tty,
173 struct cmd_list_element *c, const char *value)
175 fprintf_filtered (file, _("Inferior debugging is %s.\n"), value);
179 /* Support for disabling address space randomization. */
181 int disable_randomization = 1;
184 show_disable_randomization (struct ui_file *file, int from_tty,
185 struct cmd_list_element *c, const char *value)
187 if (target_supports_disable_randomization ())
188 fprintf_filtered (file,
189 _("Disabling randomization of debuggee's "
190 "virtual address space is %s.\n"),
193 fputs_filtered (_("Disabling randomization of debuggee's "
194 "virtual address space is unsupported on\n"
195 "this platform.\n"), file);
199 set_disable_randomization (char *args, int from_tty,
200 struct cmd_list_element *c)
202 if (!target_supports_disable_randomization ())
203 error (_("Disabling randomization of debuggee's "
204 "virtual address space is unsupported on\n"
208 /* User interface for non-stop mode. */
211 static int non_stop_1 = 0;
214 set_non_stop (char *args, int from_tty,
215 struct cmd_list_element *c)
217 if (target_has_execution)
219 non_stop_1 = non_stop;
220 error (_("Cannot change this setting while the inferior is running."));
223 non_stop = non_stop_1;
227 show_non_stop (struct ui_file *file, int from_tty,
228 struct cmd_list_element *c, const char *value)
230 fprintf_filtered (file,
231 _("Controlling the inferior in non-stop mode is %s.\n"),
235 /* "Observer mode" is somewhat like a more extreme version of
236 non-stop, in which all GDB operations that might affect the
237 target's execution have been disabled. */
239 int observer_mode = 0;
240 static int observer_mode_1 = 0;
243 set_observer_mode (char *args, int from_tty,
244 struct cmd_list_element *c)
246 if (target_has_execution)
248 observer_mode_1 = observer_mode;
249 error (_("Cannot change this setting while the inferior is running."));
252 observer_mode = observer_mode_1;
254 may_write_registers = !observer_mode;
255 may_write_memory = !observer_mode;
256 may_insert_breakpoints = !observer_mode;
257 may_insert_tracepoints = !observer_mode;
258 /* We can insert fast tracepoints in or out of observer mode,
259 but enable them if we're going into this mode. */
261 may_insert_fast_tracepoints = 1;
262 may_stop = !observer_mode;
263 update_target_permissions ();
265 /* Going *into* observer mode we must force non-stop, then
266 going out we leave it that way. */
269 pagination_enabled = 0;
270 non_stop = non_stop_1 = 1;
274 printf_filtered (_("Observer mode is now %s.\n"),
275 (observer_mode ? "on" : "off"));
279 show_observer_mode (struct ui_file *file, int from_tty,
280 struct cmd_list_element *c, const char *value)
282 fprintf_filtered (file, _("Observer mode is %s.\n"), value);
285 /* This updates the value of observer mode based on changes in
286 permissions. Note that we are deliberately ignoring the values of
287 may-write-registers and may-write-memory, since the user may have
288 reason to enable these during a session, for instance to turn on a
289 debugging-related global. */
292 update_observer_mode (void)
296 newval = (!may_insert_breakpoints
297 && !may_insert_tracepoints
298 && may_insert_fast_tracepoints
302 /* Let the user know if things change. */
303 if (newval != observer_mode)
304 printf_filtered (_("Observer mode is now %s.\n"),
305 (newval ? "on" : "off"));
307 observer_mode = observer_mode_1 = newval;
310 /* Tables of how to react to signals; the user sets them. */
312 static unsigned char *signal_stop;
313 static unsigned char *signal_print;
314 static unsigned char *signal_program;
316 /* Table of signals that are registered with "catch signal". A
317 non-zero entry indicates that the signal is caught by some "catch
318 signal" command. This has size GDB_SIGNAL_LAST, to accommodate all
320 static unsigned char *signal_catch;
322 /* Table of signals that the target may silently handle.
323 This is automatically determined from the flags above,
324 and simply cached here. */
325 static unsigned char *signal_pass;
327 #define SET_SIGS(nsigs,sigs,flags) \
329 int signum = (nsigs); \
330 while (signum-- > 0) \
331 if ((sigs)[signum]) \
332 (flags)[signum] = 1; \
335 #define UNSET_SIGS(nsigs,sigs,flags) \
337 int signum = (nsigs); \
338 while (signum-- > 0) \
339 if ((sigs)[signum]) \
340 (flags)[signum] = 0; \
343 /* Update the target's copy of SIGNAL_PROGRAM. The sole purpose of
344 this function is to avoid exporting `signal_program'. */
347 update_signals_program_target (void)
349 target_program_signals ((int) GDB_SIGNAL_LAST, signal_program);
352 /* Value to pass to target_resume() to cause all threads to resume. */
354 #define RESUME_ALL minus_one_ptid
356 /* Command list pointer for the "stop" placeholder. */
358 static struct cmd_list_element *stop_command;
360 /* Nonzero if we want to give control to the user when we're notified
361 of shared library events by the dynamic linker. */
362 int stop_on_solib_events;
364 /* Enable or disable optional shared library event breakpoints
365 as appropriate when the above flag is changed. */
368 set_stop_on_solib_events (char *args, int from_tty, struct cmd_list_element *c)
370 update_solib_breakpoints ();
374 show_stop_on_solib_events (struct ui_file *file, int from_tty,
375 struct cmd_list_element *c, const char *value)
377 fprintf_filtered (file, _("Stopping for shared library events is %s.\n"),
381 /* Nonzero means expecting a trace trap
382 and should stop the inferior and return silently when it happens. */
386 /* Nonzero after stop if current stack frame should be printed. */
388 static int stop_print_frame;
390 /* This is a cached copy of the pid/waitstatus of the last event
391 returned by target_wait()/deprecated_target_wait_hook(). This
392 information is returned by get_last_target_status(). */
393 static ptid_t target_last_wait_ptid;
394 static struct target_waitstatus target_last_waitstatus;
396 static void context_switch (ptid_t ptid);
398 void init_thread_stepping_state (struct thread_info *tss);
400 static const char follow_fork_mode_child[] = "child";
401 static const char follow_fork_mode_parent[] = "parent";
403 static const char *const follow_fork_mode_kind_names[] = {
404 follow_fork_mode_child,
405 follow_fork_mode_parent,
409 static const char *follow_fork_mode_string = follow_fork_mode_parent;
411 show_follow_fork_mode_string (struct ui_file *file, int from_tty,
412 struct cmd_list_element *c, const char *value)
414 fprintf_filtered (file,
415 _("Debugger response to a program "
416 "call of fork or vfork is \"%s\".\n"),
421 /* Handle changes to the inferior list based on the type of fork,
422 which process is being followed, and whether the other process
423 should be detached. On entry inferior_ptid must be the ptid of
424 the fork parent. At return inferior_ptid is the ptid of the
425 followed inferior. */
428 follow_fork_inferior (int follow_child, int detach_fork)
431 ptid_t parent_ptid, child_ptid;
433 has_vforked = (inferior_thread ()->pending_follow.kind
434 == TARGET_WAITKIND_VFORKED);
435 parent_ptid = inferior_ptid;
436 child_ptid = inferior_thread ()->pending_follow.value.related_pid;
439 && !non_stop /* Non-stop always resumes both branches. */
440 && (!target_is_async_p () || sync_execution)
441 && !(follow_child || detach_fork || sched_multi))
443 /* The parent stays blocked inside the vfork syscall until the
444 child execs or exits. If we don't let the child run, then
445 the parent stays blocked. If we're telling the parent to run
446 in the foreground, the user will not be able to ctrl-c to get
447 back the terminal, effectively hanging the debug session. */
448 fprintf_filtered (gdb_stderr, _("\
449 Can not resume the parent process over vfork in the foreground while\n\
450 holding the child stopped. Try \"set detach-on-fork\" or \
451 \"set schedule-multiple\".\n"));
452 /* FIXME output string > 80 columns. */
458 /* Detach new forked process? */
461 struct cleanup *old_chain;
463 /* Before detaching from the child, remove all breakpoints
464 from it. If we forked, then this has already been taken
465 care of by infrun.c. If we vforked however, any
466 breakpoint inserted in the parent is visible in the
467 child, even those added while stopped in a vfork
468 catchpoint. This will remove the breakpoints from the
469 parent also, but they'll be reinserted below. */
472 /* Keep breakpoints list in sync. */
473 remove_breakpoints_pid (ptid_get_pid (inferior_ptid));
476 if (info_verbose || debug_infrun)
478 /* Ensure that we have a process ptid. */
479 ptid_t process_ptid = pid_to_ptid (ptid_get_pid (child_ptid));
481 target_terminal_ours_for_output ();
482 fprintf_filtered (gdb_stdlog,
483 _("Detaching after %s from child %s.\n"),
484 has_vforked ? "vfork" : "fork",
485 target_pid_to_str (process_ptid));
490 struct inferior *parent_inf, *child_inf;
491 struct cleanup *old_chain;
493 /* Add process to GDB's tables. */
494 child_inf = add_inferior (ptid_get_pid (child_ptid));
496 parent_inf = current_inferior ();
497 child_inf->attach_flag = parent_inf->attach_flag;
498 copy_terminal_info (child_inf, parent_inf);
499 child_inf->gdbarch = parent_inf->gdbarch;
500 copy_inferior_target_desc_info (child_inf, parent_inf);
502 old_chain = save_inferior_ptid ();
503 save_current_program_space ();
505 inferior_ptid = child_ptid;
506 add_thread (inferior_ptid);
507 child_inf->symfile_flags = SYMFILE_NO_READ;
509 /* If this is a vfork child, then the address-space is
510 shared with the parent. */
513 child_inf->pspace = parent_inf->pspace;
514 child_inf->aspace = parent_inf->aspace;
516 /* The parent will be frozen until the child is done
517 with the shared region. Keep track of the
519 child_inf->vfork_parent = parent_inf;
520 child_inf->pending_detach = 0;
521 parent_inf->vfork_child = child_inf;
522 parent_inf->pending_detach = 0;
526 child_inf->aspace = new_address_space ();
527 child_inf->pspace = add_program_space (child_inf->aspace);
528 child_inf->removable = 1;
529 set_current_program_space (child_inf->pspace);
530 clone_program_space (child_inf->pspace, parent_inf->pspace);
532 /* Let the shared library layer (e.g., solib-svr4) learn
533 about this new process, relocate the cloned exec, pull
534 in shared libraries, and install the solib event
535 breakpoint. If a "cloned-VM" event was propagated
536 better throughout the core, this wouldn't be
538 solib_create_inferior_hook (0);
541 do_cleanups (old_chain);
546 struct inferior *parent_inf;
548 parent_inf = current_inferior ();
550 /* If we detached from the child, then we have to be careful
551 to not insert breakpoints in the parent until the child
552 is done with the shared memory region. However, if we're
553 staying attached to the child, then we can and should
554 insert breakpoints, so that we can debug it. A
555 subsequent child exec or exit is enough to know when does
556 the child stops using the parent's address space. */
557 parent_inf->waiting_for_vfork_done = detach_fork;
558 parent_inf->pspace->breakpoints_not_allowed = detach_fork;
563 /* Follow the child. */
564 struct inferior *parent_inf, *child_inf;
565 struct program_space *parent_pspace;
567 if (info_verbose || debug_infrun)
569 target_terminal_ours_for_output ();
570 fprintf_filtered (gdb_stdlog,
571 _("Attaching after %s %s to child %s.\n"),
572 target_pid_to_str (parent_ptid),
573 has_vforked ? "vfork" : "fork",
574 target_pid_to_str (child_ptid));
577 /* Add the new inferior first, so that the target_detach below
578 doesn't unpush the target. */
580 child_inf = add_inferior (ptid_get_pid (child_ptid));
582 parent_inf = current_inferior ();
583 child_inf->attach_flag = parent_inf->attach_flag;
584 copy_terminal_info (child_inf, parent_inf);
585 child_inf->gdbarch = parent_inf->gdbarch;
586 copy_inferior_target_desc_info (child_inf, parent_inf);
588 parent_pspace = parent_inf->pspace;
590 /* If we're vforking, we want to hold on to the parent until the
591 child exits or execs. At child exec or exit time we can
592 remove the old breakpoints from the parent and detach or
593 resume debugging it. Otherwise, detach the parent now; we'll
594 want to reuse it's program/address spaces, but we can't set
595 them to the child before removing breakpoints from the
596 parent, otherwise, the breakpoints module could decide to
597 remove breakpoints from the wrong process (since they'd be
598 assigned to the same address space). */
602 gdb_assert (child_inf->vfork_parent == NULL);
603 gdb_assert (parent_inf->vfork_child == NULL);
604 child_inf->vfork_parent = parent_inf;
605 child_inf->pending_detach = 0;
606 parent_inf->vfork_child = child_inf;
607 parent_inf->pending_detach = detach_fork;
608 parent_inf->waiting_for_vfork_done = 0;
610 else if (detach_fork)
612 if (info_verbose || debug_infrun)
614 /* Ensure that we have a process ptid. */
615 ptid_t process_ptid = pid_to_ptid (ptid_get_pid (child_ptid));
617 target_terminal_ours_for_output ();
618 fprintf_filtered (gdb_stdlog,
619 _("Detaching after fork from "
621 target_pid_to_str (process_ptid));
624 target_detach (NULL, 0);
627 /* Note that the detach above makes PARENT_INF dangling. */
629 /* Add the child thread to the appropriate lists, and switch to
630 this new thread, before cloning the program space, and
631 informing the solib layer about this new process. */
633 inferior_ptid = child_ptid;
634 add_thread (inferior_ptid);
636 /* If this is a vfork child, then the address-space is shared
637 with the parent. If we detached from the parent, then we can
638 reuse the parent's program/address spaces. */
639 if (has_vforked || detach_fork)
641 child_inf->pspace = parent_pspace;
642 child_inf->aspace = child_inf->pspace->aspace;
646 child_inf->aspace = new_address_space ();
647 child_inf->pspace = add_program_space (child_inf->aspace);
648 child_inf->removable = 1;
649 child_inf->symfile_flags = SYMFILE_NO_READ;
650 set_current_program_space (child_inf->pspace);
651 clone_program_space (child_inf->pspace, parent_pspace);
653 /* Let the shared library layer (e.g., solib-svr4) learn
654 about this new process, relocate the cloned exec, pull in
655 shared libraries, and install the solib event breakpoint.
656 If a "cloned-VM" event was propagated better throughout
657 the core, this wouldn't be required. */
658 solib_create_inferior_hook (0);
662 return target_follow_fork (follow_child, detach_fork);
665 /* Tell the target to follow the fork we're stopped at. Returns true
666 if the inferior should be resumed; false, if the target for some
667 reason decided it's best not to resume. */
672 int follow_child = (follow_fork_mode_string == follow_fork_mode_child);
673 int should_resume = 1;
674 struct thread_info *tp;
676 /* Copy user stepping state to the new inferior thread. FIXME: the
677 followed fork child thread should have a copy of most of the
678 parent thread structure's run control related fields, not just these.
679 Initialized to avoid "may be used uninitialized" warnings from gcc. */
680 struct breakpoint *step_resume_breakpoint = NULL;
681 struct breakpoint *exception_resume_breakpoint = NULL;
682 CORE_ADDR step_range_start = 0;
683 CORE_ADDR step_range_end = 0;
684 struct frame_id step_frame_id = { 0 };
685 struct interp *command_interp = NULL;
690 struct target_waitstatus wait_status;
692 /* Get the last target status returned by target_wait(). */
693 get_last_target_status (&wait_ptid, &wait_status);
695 /* If not stopped at a fork event, then there's nothing else to
697 if (wait_status.kind != TARGET_WAITKIND_FORKED
698 && wait_status.kind != TARGET_WAITKIND_VFORKED)
701 /* Check if we switched over from WAIT_PTID, since the event was
703 if (!ptid_equal (wait_ptid, minus_one_ptid)
704 && !ptid_equal (inferior_ptid, wait_ptid))
706 /* We did. Switch back to WAIT_PTID thread, to tell the
707 target to follow it (in either direction). We'll
708 afterwards refuse to resume, and inform the user what
710 switch_to_thread (wait_ptid);
715 tp = inferior_thread ();
717 /* If there were any forks/vforks that were caught and are now to be
718 followed, then do so now. */
719 switch (tp->pending_follow.kind)
721 case TARGET_WAITKIND_FORKED:
722 case TARGET_WAITKIND_VFORKED:
724 ptid_t parent, child;
726 /* If the user did a next/step, etc, over a fork call,
727 preserve the stepping state in the fork child. */
728 if (follow_child && should_resume)
730 step_resume_breakpoint = clone_momentary_breakpoint
731 (tp->control.step_resume_breakpoint);
732 step_range_start = tp->control.step_range_start;
733 step_range_end = tp->control.step_range_end;
734 step_frame_id = tp->control.step_frame_id;
735 exception_resume_breakpoint
736 = clone_momentary_breakpoint (tp->control.exception_resume_breakpoint);
737 command_interp = tp->control.command_interp;
739 /* For now, delete the parent's sr breakpoint, otherwise,
740 parent/child sr breakpoints are considered duplicates,
741 and the child version will not be installed. Remove
742 this when the breakpoints module becomes aware of
743 inferiors and address spaces. */
744 delete_step_resume_breakpoint (tp);
745 tp->control.step_range_start = 0;
746 tp->control.step_range_end = 0;
747 tp->control.step_frame_id = null_frame_id;
748 delete_exception_resume_breakpoint (tp);
749 tp->control.command_interp = NULL;
752 parent = inferior_ptid;
753 child = tp->pending_follow.value.related_pid;
755 /* Set up inferior(s) as specified by the caller, and tell the
756 target to do whatever is necessary to follow either parent
758 if (follow_fork_inferior (follow_child, detach_fork))
760 /* Target refused to follow, or there's some other reason
761 we shouldn't resume. */
766 /* This pending follow fork event is now handled, one way
767 or another. The previous selected thread may be gone
768 from the lists by now, but if it is still around, need
769 to clear the pending follow request. */
770 tp = find_thread_ptid (parent);
772 tp->pending_follow.kind = TARGET_WAITKIND_SPURIOUS;
774 /* This makes sure we don't try to apply the "Switched
775 over from WAIT_PID" logic above. */
776 nullify_last_target_wait_ptid ();
778 /* If we followed the child, switch to it... */
781 switch_to_thread (child);
783 /* ... and preserve the stepping state, in case the
784 user was stepping over the fork call. */
787 tp = inferior_thread ();
788 tp->control.step_resume_breakpoint
789 = step_resume_breakpoint;
790 tp->control.step_range_start = step_range_start;
791 tp->control.step_range_end = step_range_end;
792 tp->control.step_frame_id = step_frame_id;
793 tp->control.exception_resume_breakpoint
794 = exception_resume_breakpoint;
795 tp->control.command_interp = command_interp;
799 /* If we get here, it was because we're trying to
800 resume from a fork catchpoint, but, the user
801 has switched threads away from the thread that
802 forked. In that case, the resume command
803 issued is most likely not applicable to the
804 child, so just warn, and refuse to resume. */
805 warning (_("Not resuming: switched threads "
806 "before following fork child."));
809 /* Reset breakpoints in the child as appropriate. */
810 follow_inferior_reset_breakpoints ();
813 switch_to_thread (parent);
817 case TARGET_WAITKIND_SPURIOUS:
818 /* Nothing to follow. */
821 internal_error (__FILE__, __LINE__,
822 "Unexpected pending_follow.kind %d\n",
823 tp->pending_follow.kind);
827 return should_resume;
831 follow_inferior_reset_breakpoints (void)
833 struct thread_info *tp = inferior_thread ();
835 /* Was there a step_resume breakpoint? (There was if the user
836 did a "next" at the fork() call.) If so, explicitly reset its
837 thread number. Cloned step_resume breakpoints are disabled on
838 creation, so enable it here now that it is associated with the
841 step_resumes are a form of bp that are made to be per-thread.
842 Since we created the step_resume bp when the parent process
843 was being debugged, and now are switching to the child process,
844 from the breakpoint package's viewpoint, that's a switch of
845 "threads". We must update the bp's notion of which thread
846 it is for, or it'll be ignored when it triggers. */
848 if (tp->control.step_resume_breakpoint)
850 breakpoint_re_set_thread (tp->control.step_resume_breakpoint);
851 tp->control.step_resume_breakpoint->loc->enabled = 1;
854 /* Treat exception_resume breakpoints like step_resume breakpoints. */
855 if (tp->control.exception_resume_breakpoint)
857 breakpoint_re_set_thread (tp->control.exception_resume_breakpoint);
858 tp->control.exception_resume_breakpoint->loc->enabled = 1;
861 /* Reinsert all breakpoints in the child. The user may have set
862 breakpoints after catching the fork, in which case those
863 were never set in the child, but only in the parent. This makes
864 sure the inserted breakpoints match the breakpoint list. */
866 breakpoint_re_set ();
867 insert_breakpoints ();
870 /* The child has exited or execed: resume threads of the parent the
871 user wanted to be executing. */
874 proceed_after_vfork_done (struct thread_info *thread,
877 int pid = * (int *) arg;
879 if (ptid_get_pid (thread->ptid) == pid
880 && is_running (thread->ptid)
881 && !is_executing (thread->ptid)
882 && !thread->stop_requested
883 && thread->suspend.stop_signal == GDB_SIGNAL_0)
886 fprintf_unfiltered (gdb_stdlog,
887 "infrun: resuming vfork parent thread %s\n",
888 target_pid_to_str (thread->ptid));
890 switch_to_thread (thread->ptid);
891 clear_proceed_status (0);
892 proceed ((CORE_ADDR) -1, GDB_SIGNAL_DEFAULT);
898 /* Called whenever we notice an exec or exit event, to handle
899 detaching or resuming a vfork parent. */
902 handle_vfork_child_exec_or_exit (int exec)
904 struct inferior *inf = current_inferior ();
906 if (inf->vfork_parent)
908 int resume_parent = -1;
910 /* This exec or exit marks the end of the shared memory region
911 between the parent and the child. If the user wanted to
912 detach from the parent, now is the time. */
914 if (inf->vfork_parent->pending_detach)
916 struct thread_info *tp;
917 struct cleanup *old_chain;
918 struct program_space *pspace;
919 struct address_space *aspace;
921 /* follow-fork child, detach-on-fork on. */
923 inf->vfork_parent->pending_detach = 0;
927 /* If we're handling a child exit, then inferior_ptid
928 points at the inferior's pid, not to a thread. */
929 old_chain = save_inferior_ptid ();
930 save_current_program_space ();
931 save_current_inferior ();
934 old_chain = save_current_space_and_thread ();
936 /* We're letting loose of the parent. */
937 tp = any_live_thread_of_process (inf->vfork_parent->pid);
938 switch_to_thread (tp->ptid);
940 /* We're about to detach from the parent, which implicitly
941 removes breakpoints from its address space. There's a
942 catch here: we want to reuse the spaces for the child,
943 but, parent/child are still sharing the pspace at this
944 point, although the exec in reality makes the kernel give
945 the child a fresh set of new pages. The problem here is
946 that the breakpoints module being unaware of this, would
947 likely chose the child process to write to the parent
948 address space. Swapping the child temporarily away from
949 the spaces has the desired effect. Yes, this is "sort
952 pspace = inf->pspace;
953 aspace = inf->aspace;
957 if (debug_infrun || info_verbose)
959 target_terminal_ours_for_output ();
963 fprintf_filtered (gdb_stdlog,
964 _("Detaching vfork parent process "
965 "%d after child exec.\n"),
966 inf->vfork_parent->pid);
970 fprintf_filtered (gdb_stdlog,
971 _("Detaching vfork parent process "
972 "%d after child exit.\n"),
973 inf->vfork_parent->pid);
977 target_detach (NULL, 0);
980 inf->pspace = pspace;
981 inf->aspace = aspace;
983 do_cleanups (old_chain);
987 /* We're staying attached to the parent, so, really give the
988 child a new address space. */
989 inf->pspace = add_program_space (maybe_new_address_space ());
990 inf->aspace = inf->pspace->aspace;
992 set_current_program_space (inf->pspace);
994 resume_parent = inf->vfork_parent->pid;
996 /* Break the bonds. */
997 inf->vfork_parent->vfork_child = NULL;
1001 struct cleanup *old_chain;
1002 struct program_space *pspace;
1004 /* If this is a vfork child exiting, then the pspace and
1005 aspaces were shared with the parent. Since we're
1006 reporting the process exit, we'll be mourning all that is
1007 found in the address space, and switching to null_ptid,
1008 preparing to start a new inferior. But, since we don't
1009 want to clobber the parent's address/program spaces, we
1010 go ahead and create a new one for this exiting
1013 /* Switch to null_ptid, so that clone_program_space doesn't want
1014 to read the selected frame of a dead process. */
1015 old_chain = save_inferior_ptid ();
1016 inferior_ptid = null_ptid;
1018 /* This inferior is dead, so avoid giving the breakpoints
1019 module the option to write through to it (cloning a
1020 program space resets breakpoints). */
1023 pspace = add_program_space (maybe_new_address_space ());
1024 set_current_program_space (pspace);
1026 inf->symfile_flags = SYMFILE_NO_READ;
1027 clone_program_space (pspace, inf->vfork_parent->pspace);
1028 inf->pspace = pspace;
1029 inf->aspace = pspace->aspace;
1031 /* Put back inferior_ptid. We'll continue mourning this
1033 do_cleanups (old_chain);
1035 resume_parent = inf->vfork_parent->pid;
1036 /* Break the bonds. */
1037 inf->vfork_parent->vfork_child = NULL;
1040 inf->vfork_parent = NULL;
1042 gdb_assert (current_program_space == inf->pspace);
1044 if (non_stop && resume_parent != -1)
1046 /* If the user wanted the parent to be running, let it go
1048 struct cleanup *old_chain = make_cleanup_restore_current_thread ();
1051 fprintf_unfiltered (gdb_stdlog,
1052 "infrun: resuming vfork parent process %d\n",
1055 iterate_over_threads (proceed_after_vfork_done, &resume_parent);
1057 do_cleanups (old_chain);
1062 /* Enum strings for "set|show follow-exec-mode". */
1064 static const char follow_exec_mode_new[] = "new";
1065 static const char follow_exec_mode_same[] = "same";
1066 static const char *const follow_exec_mode_names[] =
1068 follow_exec_mode_new,
1069 follow_exec_mode_same,
1073 static const char *follow_exec_mode_string = follow_exec_mode_same;
1075 show_follow_exec_mode_string (struct ui_file *file, int from_tty,
1076 struct cmd_list_element *c, const char *value)
1078 fprintf_filtered (file, _("Follow exec mode is \"%s\".\n"), value);
1081 /* EXECD_PATHNAME is assumed to be non-NULL. */
1084 follow_exec (ptid_t ptid, char *execd_pathname)
1086 struct thread_info *th, *tmp;
1087 struct inferior *inf = current_inferior ();
1088 int pid = ptid_get_pid (ptid);
1090 /* This is an exec event that we actually wish to pay attention to.
1091 Refresh our symbol table to the newly exec'd program, remove any
1092 momentary bp's, etc.
1094 If there are breakpoints, they aren't really inserted now,
1095 since the exec() transformed our inferior into a fresh set
1098 We want to preserve symbolic breakpoints on the list, since
1099 we have hopes that they can be reset after the new a.out's
1100 symbol table is read.
1102 However, any "raw" breakpoints must be removed from the list
1103 (e.g., the solib bp's), since their address is probably invalid
1106 And, we DON'T want to call delete_breakpoints() here, since
1107 that may write the bp's "shadow contents" (the instruction
1108 value that was overwritten witha TRAP instruction). Since
1109 we now have a new a.out, those shadow contents aren't valid. */
1111 mark_breakpoints_out ();
1113 /* The target reports the exec event to the main thread, even if
1114 some other thread does the exec, and even if the main thread was
1115 stopped or already gone. We may still have non-leader threads of
1116 the process on our list. E.g., on targets that don't have thread
1117 exit events (like remote); or on native Linux in non-stop mode if
1118 there were only two threads in the inferior and the non-leader
1119 one is the one that execs (and nothing forces an update of the
1120 thread list up to here). When debugging remotely, it's best to
1121 avoid extra traffic, when possible, so avoid syncing the thread
1122 list with the target, and instead go ahead and delete all threads
1123 of the process but one that reported the event. Note this must
1124 be done before calling update_breakpoints_after_exec, as
1125 otherwise clearing the threads' resources would reference stale
1126 thread breakpoints -- it may have been one of these threads that
1127 stepped across the exec. We could just clear their stepping
1128 states, but as long as we're iterating, might as well delete
1129 them. Deleting them now rather than at the next user-visible
1130 stop provides a nicer sequence of events for user and MI
1132 ALL_THREADS_SAFE (th, tmp)
1133 if (ptid_get_pid (th->ptid) == pid && !ptid_equal (th->ptid, ptid))
1134 delete_thread (th->ptid);
1136 /* We also need to clear any left over stale state for the
1137 leader/event thread. E.g., if there was any step-resume
1138 breakpoint or similar, it's gone now. We cannot truly
1139 step-to-next statement through an exec(). */
1140 th = inferior_thread ();
1141 th->control.step_resume_breakpoint = NULL;
1142 th->control.exception_resume_breakpoint = NULL;
1143 th->control.single_step_breakpoints = NULL;
1144 th->control.step_range_start = 0;
1145 th->control.step_range_end = 0;
1147 /* The user may have had the main thread held stopped in the
1148 previous image (e.g., schedlock on, or non-stop). Release
1150 th->stop_requested = 0;
1152 update_breakpoints_after_exec ();
1154 /* What is this a.out's name? */
1155 printf_unfiltered (_("%s is executing new program: %s\n"),
1156 target_pid_to_str (inferior_ptid),
1159 /* We've followed the inferior through an exec. Therefore, the
1160 inferior has essentially been killed & reborn. */
1162 gdb_flush (gdb_stdout);
1164 breakpoint_init_inferior (inf_execd);
1166 if (*gdb_sysroot != '\0')
1168 char *name = exec_file_find (execd_pathname, NULL);
1170 execd_pathname = alloca (strlen (name) + 1);
1171 strcpy (execd_pathname, name);
1175 /* Reset the shared library package. This ensures that we get a
1176 shlib event when the child reaches "_start", at which point the
1177 dld will have had a chance to initialize the child. */
1178 /* Also, loading a symbol file below may trigger symbol lookups, and
1179 we don't want those to be satisfied by the libraries of the
1180 previous incarnation of this process. */
1181 no_shared_libraries (NULL, 0);
1183 if (follow_exec_mode_string == follow_exec_mode_new)
1185 struct program_space *pspace;
1187 /* The user wants to keep the old inferior and program spaces
1188 around. Create a new fresh one, and switch to it. */
1190 inf = add_inferior (current_inferior ()->pid);
1191 pspace = add_program_space (maybe_new_address_space ());
1192 inf->pspace = pspace;
1193 inf->aspace = pspace->aspace;
1195 exit_inferior_num_silent (current_inferior ()->num);
1197 set_current_inferior (inf);
1198 set_current_program_space (pspace);
1202 /* The old description may no longer be fit for the new image.
1203 E.g, a 64-bit process exec'ed a 32-bit process. Clear the
1204 old description; we'll read a new one below. No need to do
1205 this on "follow-exec-mode new", as the old inferior stays
1206 around (its description is later cleared/refetched on
1208 target_clear_description ();
1211 gdb_assert (current_program_space == inf->pspace);
1213 /* That a.out is now the one to use. */
1214 exec_file_attach (execd_pathname, 0);
1216 /* SYMFILE_DEFER_BP_RESET is used as the proper displacement for PIE
1217 (Position Independent Executable) main symbol file will get applied by
1218 solib_create_inferior_hook below. breakpoint_re_set would fail to insert
1219 the breakpoints with the zero displacement. */
1221 symbol_file_add (execd_pathname,
1223 | SYMFILE_MAINLINE | SYMFILE_DEFER_BP_RESET),
1226 if ((inf->symfile_flags & SYMFILE_NO_READ) == 0)
1227 set_initial_language ();
1229 /* If the target can specify a description, read it. Must do this
1230 after flipping to the new executable (because the target supplied
1231 description must be compatible with the executable's
1232 architecture, and the old executable may e.g., be 32-bit, while
1233 the new one 64-bit), and before anything involving memory or
1235 target_find_description ();
1237 solib_create_inferior_hook (0);
1239 jit_inferior_created_hook ();
1241 breakpoint_re_set ();
1243 /* Reinsert all breakpoints. (Those which were symbolic have
1244 been reset to the proper address in the new a.out, thanks
1245 to symbol_file_command...). */
1246 insert_breakpoints ();
1248 /* The next resume of this inferior should bring it to the shlib
1249 startup breakpoints. (If the user had also set bp's on
1250 "main" from the old (parent) process, then they'll auto-
1251 matically get reset there in the new process.). */
1254 /* The queue of threads that need to do a step-over operation to get
1255 past e.g., a breakpoint. What technique is used to step over the
1256 breakpoint/watchpoint does not matter -- all threads end up in the
1257 same queue, to maintain rough temporal order of execution, in order
1258 to avoid starvation, otherwise, we could e.g., find ourselves
1259 constantly stepping the same couple threads past their breakpoints
1260 over and over, if the single-step finish fast enough. */
1261 struct thread_info *step_over_queue_head;
1263 /* Bit flags indicating what the thread needs to step over. */
1267 /* Step over a breakpoint. */
1268 STEP_OVER_BREAKPOINT = 1,
1270 /* Step past a non-continuable watchpoint, in order to let the
1271 instruction execute so we can evaluate the watchpoint
1273 STEP_OVER_WATCHPOINT = 2
1276 /* Info about an instruction that is being stepped over. */
1278 struct step_over_info
1280 /* If we're stepping past a breakpoint, this is the address space
1281 and address of the instruction the breakpoint is set at. We'll
1282 skip inserting all breakpoints here. Valid iff ASPACE is
1284 struct address_space *aspace;
1287 /* The instruction being stepped over triggers a nonsteppable
1288 watchpoint. If true, we'll skip inserting watchpoints. */
1289 int nonsteppable_watchpoint_p;
1292 /* The step-over info of the location that is being stepped over.
1294 Note that with async/breakpoint always-inserted mode, a user might
1295 set a new breakpoint/watchpoint/etc. exactly while a breakpoint is
1296 being stepped over. As setting a new breakpoint inserts all
1297 breakpoints, we need to make sure the breakpoint being stepped over
1298 isn't inserted then. We do that by only clearing the step-over
1299 info when the step-over is actually finished (or aborted).
1301 Presently GDB can only step over one breakpoint at any given time.
1302 Given threads that can't run code in the same address space as the
1303 breakpoint's can't really miss the breakpoint, GDB could be taught
1304 to step-over at most one breakpoint per address space (so this info
1305 could move to the address space object if/when GDB is extended).
1306 The set of breakpoints being stepped over will normally be much
1307 smaller than the set of all breakpoints, so a flag in the
1308 breakpoint location structure would be wasteful. A separate list
1309 also saves complexity and run-time, as otherwise we'd have to go
1310 through all breakpoint locations clearing their flag whenever we
1311 start a new sequence. Similar considerations weigh against storing
1312 this info in the thread object. Plus, not all step overs actually
1313 have breakpoint locations -- e.g., stepping past a single-step
1314 breakpoint, or stepping to complete a non-continuable
1316 static struct step_over_info step_over_info;
1318 /* Record the address of the breakpoint/instruction we're currently
1322 set_step_over_info (struct address_space *aspace, CORE_ADDR address,
1323 int nonsteppable_watchpoint_p)
1325 step_over_info.aspace = aspace;
1326 step_over_info.address = address;
1327 step_over_info.nonsteppable_watchpoint_p = nonsteppable_watchpoint_p;
1330 /* Called when we're not longer stepping over a breakpoint / an
1331 instruction, so all breakpoints are free to be (re)inserted. */
1334 clear_step_over_info (void)
1337 fprintf_unfiltered (gdb_stdlog,
1338 "infrun: clear_step_over_info\n");
1339 step_over_info.aspace = NULL;
1340 step_over_info.address = 0;
1341 step_over_info.nonsteppable_watchpoint_p = 0;
1347 stepping_past_instruction_at (struct address_space *aspace,
1350 return (step_over_info.aspace != NULL
1351 && breakpoint_address_match (aspace, address,
1352 step_over_info.aspace,
1353 step_over_info.address));
1359 stepping_past_nonsteppable_watchpoint (void)
1361 return step_over_info.nonsteppable_watchpoint_p;
1364 /* Returns true if step-over info is valid. */
1367 step_over_info_valid_p (void)
1369 return (step_over_info.aspace != NULL
1370 || stepping_past_nonsteppable_watchpoint ());
1374 /* Displaced stepping. */
1376 /* In non-stop debugging mode, we must take special care to manage
1377 breakpoints properly; in particular, the traditional strategy for
1378 stepping a thread past a breakpoint it has hit is unsuitable.
1379 'Displaced stepping' is a tactic for stepping one thread past a
1380 breakpoint it has hit while ensuring that other threads running
1381 concurrently will hit the breakpoint as they should.
1383 The traditional way to step a thread T off a breakpoint in a
1384 multi-threaded program in all-stop mode is as follows:
1386 a0) Initially, all threads are stopped, and breakpoints are not
1388 a1) We single-step T, leaving breakpoints uninserted.
1389 a2) We insert breakpoints, and resume all threads.
1391 In non-stop debugging, however, this strategy is unsuitable: we
1392 don't want to have to stop all threads in the system in order to
1393 continue or step T past a breakpoint. Instead, we use displaced
1396 n0) Initially, T is stopped, other threads are running, and
1397 breakpoints are inserted.
1398 n1) We copy the instruction "under" the breakpoint to a separate
1399 location, outside the main code stream, making any adjustments
1400 to the instruction, register, and memory state as directed by
1402 n2) We single-step T over the instruction at its new location.
1403 n3) We adjust the resulting register and memory state as directed
1404 by T's architecture. This includes resetting T's PC to point
1405 back into the main instruction stream.
1408 This approach depends on the following gdbarch methods:
1410 - gdbarch_max_insn_length and gdbarch_displaced_step_location
1411 indicate where to copy the instruction, and how much space must
1412 be reserved there. We use these in step n1.
1414 - gdbarch_displaced_step_copy_insn copies a instruction to a new
1415 address, and makes any necessary adjustments to the instruction,
1416 register contents, and memory. We use this in step n1.
1418 - gdbarch_displaced_step_fixup adjusts registers and memory after
1419 we have successfuly single-stepped the instruction, to yield the
1420 same effect the instruction would have had if we had executed it
1421 at its original address. We use this in step n3.
1423 - gdbarch_displaced_step_free_closure provides cleanup.
1425 The gdbarch_displaced_step_copy_insn and
1426 gdbarch_displaced_step_fixup functions must be written so that
1427 copying an instruction with gdbarch_displaced_step_copy_insn,
1428 single-stepping across the copied instruction, and then applying
1429 gdbarch_displaced_insn_fixup should have the same effects on the
1430 thread's memory and registers as stepping the instruction in place
1431 would have. Exactly which responsibilities fall to the copy and
1432 which fall to the fixup is up to the author of those functions.
1434 See the comments in gdbarch.sh for details.
1436 Note that displaced stepping and software single-step cannot
1437 currently be used in combination, although with some care I think
1438 they could be made to. Software single-step works by placing
1439 breakpoints on all possible subsequent instructions; if the
1440 displaced instruction is a PC-relative jump, those breakpoints
1441 could fall in very strange places --- on pages that aren't
1442 executable, or at addresses that are not proper instruction
1443 boundaries. (We do generally let other threads run while we wait
1444 to hit the software single-step breakpoint, and they might
1445 encounter such a corrupted instruction.) One way to work around
1446 this would be to have gdbarch_displaced_step_copy_insn fully
1447 simulate the effect of PC-relative instructions (and return NULL)
1448 on architectures that use software single-stepping.
1450 In non-stop mode, we can have independent and simultaneous step
1451 requests, so more than one thread may need to simultaneously step
1452 over a breakpoint. The current implementation assumes there is
1453 only one scratch space per process. In this case, we have to
1454 serialize access to the scratch space. If thread A wants to step
1455 over a breakpoint, but we are currently waiting for some other
1456 thread to complete a displaced step, we leave thread A stopped and
1457 place it in the displaced_step_request_queue. Whenever a displaced
1458 step finishes, we pick the next thread in the queue and start a new
1459 displaced step operation on it. See displaced_step_prepare and
1460 displaced_step_fixup for details. */
1462 /* Per-inferior displaced stepping state. */
1463 struct displaced_step_inferior_state
1465 /* Pointer to next in linked list. */
1466 struct displaced_step_inferior_state *next;
1468 /* The process this displaced step state refers to. */
1471 /* True if preparing a displaced step ever failed. If so, we won't
1472 try displaced stepping for this inferior again. */
1475 /* If this is not null_ptid, this is the thread carrying out a
1476 displaced single-step in process PID. This thread's state will
1477 require fixing up once it has completed its step. */
1480 /* The architecture the thread had when we stepped it. */
1481 struct gdbarch *step_gdbarch;
1483 /* The closure provided gdbarch_displaced_step_copy_insn, to be used
1484 for post-step cleanup. */
1485 struct displaced_step_closure *step_closure;
1487 /* The address of the original instruction, and the copy we
1489 CORE_ADDR step_original, step_copy;
1491 /* Saved contents of copy area. */
1492 gdb_byte *step_saved_copy;
1495 /* The list of states of processes involved in displaced stepping
1497 static struct displaced_step_inferior_state *displaced_step_inferior_states;
1499 /* Get the displaced stepping state of process PID. */
1501 static struct displaced_step_inferior_state *
1502 get_displaced_stepping_state (int pid)
1504 struct displaced_step_inferior_state *state;
1506 for (state = displaced_step_inferior_states;
1508 state = state->next)
1509 if (state->pid == pid)
1515 /* Returns true if any inferior has a thread doing a displaced
1519 displaced_step_in_progress_any_inferior (void)
1521 struct displaced_step_inferior_state *state;
1523 for (state = displaced_step_inferior_states;
1525 state = state->next)
1526 if (!ptid_equal (state->step_ptid, null_ptid))
1532 /* Return true if process PID has a thread doing a displaced step. */
1535 displaced_step_in_progress (int pid)
1537 struct displaced_step_inferior_state *displaced;
1539 displaced = get_displaced_stepping_state (pid);
1540 if (displaced != NULL && !ptid_equal (displaced->step_ptid, null_ptid))
1546 /* Add a new displaced stepping state for process PID to the displaced
1547 stepping state list, or return a pointer to an already existing
1548 entry, if it already exists. Never returns NULL. */
1550 static struct displaced_step_inferior_state *
1551 add_displaced_stepping_state (int pid)
1553 struct displaced_step_inferior_state *state;
1555 for (state = displaced_step_inferior_states;
1557 state = state->next)
1558 if (state->pid == pid)
1561 state = xcalloc (1, sizeof (*state));
1563 state->next = displaced_step_inferior_states;
1564 displaced_step_inferior_states = state;
1569 /* If inferior is in displaced stepping, and ADDR equals to starting address
1570 of copy area, return corresponding displaced_step_closure. Otherwise,
1573 struct displaced_step_closure*
1574 get_displaced_step_closure_by_addr (CORE_ADDR addr)
1576 struct displaced_step_inferior_state *displaced
1577 = get_displaced_stepping_state (ptid_get_pid (inferior_ptid));
1579 /* If checking the mode of displaced instruction in copy area. */
1580 if (displaced && !ptid_equal (displaced->step_ptid, null_ptid)
1581 && (displaced->step_copy == addr))
1582 return displaced->step_closure;
1587 /* Remove the displaced stepping state of process PID. */
1590 remove_displaced_stepping_state (int pid)
1592 struct displaced_step_inferior_state *it, **prev_next_p;
1594 gdb_assert (pid != 0);
1596 it = displaced_step_inferior_states;
1597 prev_next_p = &displaced_step_inferior_states;
1602 *prev_next_p = it->next;
1607 prev_next_p = &it->next;
1613 infrun_inferior_exit (struct inferior *inf)
1615 remove_displaced_stepping_state (inf->pid);
1618 /* If ON, and the architecture supports it, GDB will use displaced
1619 stepping to step over breakpoints. If OFF, or if the architecture
1620 doesn't support it, GDB will instead use the traditional
1621 hold-and-step approach. If AUTO (which is the default), GDB will
1622 decide which technique to use to step over breakpoints depending on
1623 which of all-stop or non-stop mode is active --- displaced stepping
1624 in non-stop mode; hold-and-step in all-stop mode. */
1626 static enum auto_boolean can_use_displaced_stepping = AUTO_BOOLEAN_AUTO;
1629 show_can_use_displaced_stepping (struct ui_file *file, int from_tty,
1630 struct cmd_list_element *c,
1633 if (can_use_displaced_stepping == AUTO_BOOLEAN_AUTO)
1634 fprintf_filtered (file,
1635 _("Debugger's willingness to use displaced stepping "
1636 "to step over breakpoints is %s (currently %s).\n"),
1637 value, target_is_non_stop_p () ? "on" : "off");
1639 fprintf_filtered (file,
1640 _("Debugger's willingness to use displaced stepping "
1641 "to step over breakpoints is %s.\n"), value);
1644 /* Return non-zero if displaced stepping can/should be used to step
1645 over breakpoints of thread TP. */
1648 use_displaced_stepping (struct thread_info *tp)
1650 struct regcache *regcache = get_thread_regcache (tp->ptid);
1651 struct gdbarch *gdbarch = get_regcache_arch (regcache);
1652 struct displaced_step_inferior_state *displaced_state;
1654 displaced_state = get_displaced_stepping_state (ptid_get_pid (tp->ptid));
1656 return (((can_use_displaced_stepping == AUTO_BOOLEAN_AUTO
1657 && target_is_non_stop_p ())
1658 || can_use_displaced_stepping == AUTO_BOOLEAN_TRUE)
1659 && gdbarch_displaced_step_copy_insn_p (gdbarch)
1660 && find_record_target () == NULL
1661 && (displaced_state == NULL
1662 || !displaced_state->failed_before));
1665 /* Clean out any stray displaced stepping state. */
1667 displaced_step_clear (struct displaced_step_inferior_state *displaced)
1669 /* Indicate that there is no cleanup pending. */
1670 displaced->step_ptid = null_ptid;
1672 if (displaced->step_closure)
1674 gdbarch_displaced_step_free_closure (displaced->step_gdbarch,
1675 displaced->step_closure);
1676 displaced->step_closure = NULL;
1681 displaced_step_clear_cleanup (void *arg)
1683 struct displaced_step_inferior_state *state = arg;
1685 displaced_step_clear (state);
1688 /* Dump LEN bytes at BUF in hex to FILE, followed by a newline. */
1690 displaced_step_dump_bytes (struct ui_file *file,
1691 const gdb_byte *buf,
1696 for (i = 0; i < len; i++)
1697 fprintf_unfiltered (file, "%02x ", buf[i]);
1698 fputs_unfiltered ("\n", file);
1701 /* Prepare to single-step, using displaced stepping.
1703 Note that we cannot use displaced stepping when we have a signal to
1704 deliver. If we have a signal to deliver and an instruction to step
1705 over, then after the step, there will be no indication from the
1706 target whether the thread entered a signal handler or ignored the
1707 signal and stepped over the instruction successfully --- both cases
1708 result in a simple SIGTRAP. In the first case we mustn't do a
1709 fixup, and in the second case we must --- but we can't tell which.
1710 Comments in the code for 'random signals' in handle_inferior_event
1711 explain how we handle this case instead.
1713 Returns 1 if preparing was successful -- this thread is going to be
1714 stepped now; 0 if displaced stepping this thread got queued; or -1
1715 if this instruction can't be displaced stepped. */
1718 displaced_step_prepare_throw (ptid_t ptid)
1720 struct cleanup *old_cleanups, *ignore_cleanups;
1721 struct thread_info *tp = find_thread_ptid (ptid);
1722 struct regcache *regcache = get_thread_regcache (ptid);
1723 struct gdbarch *gdbarch = get_regcache_arch (regcache);
1724 CORE_ADDR original, copy;
1726 struct displaced_step_closure *closure;
1727 struct displaced_step_inferior_state *displaced;
1730 /* We should never reach this function if the architecture does not
1731 support displaced stepping. */
1732 gdb_assert (gdbarch_displaced_step_copy_insn_p (gdbarch));
1734 /* Nor if the thread isn't meant to step over a breakpoint. */
1735 gdb_assert (tp->control.trap_expected);
1737 /* Disable range stepping while executing in the scratch pad. We
1738 want a single-step even if executing the displaced instruction in
1739 the scratch buffer lands within the stepping range (e.g., a
1741 tp->control.may_range_step = 0;
1743 /* We have to displaced step one thread at a time, as we only have
1744 access to a single scratch space per inferior. */
1746 displaced = add_displaced_stepping_state (ptid_get_pid (ptid));
1748 if (!ptid_equal (displaced->step_ptid, null_ptid))
1750 /* Already waiting for a displaced step to finish. Defer this
1751 request and place in queue. */
1753 if (debug_displaced)
1754 fprintf_unfiltered (gdb_stdlog,
1755 "displaced: deferring step of %s\n",
1756 target_pid_to_str (ptid));
1758 thread_step_over_chain_enqueue (tp);
1763 if (debug_displaced)
1764 fprintf_unfiltered (gdb_stdlog,
1765 "displaced: stepping %s now\n",
1766 target_pid_to_str (ptid));
1769 displaced_step_clear (displaced);
1771 old_cleanups = save_inferior_ptid ();
1772 inferior_ptid = ptid;
1774 original = regcache_read_pc (regcache);
1776 copy = gdbarch_displaced_step_location (gdbarch);
1777 len = gdbarch_max_insn_length (gdbarch);
1779 /* Save the original contents of the copy area. */
1780 displaced->step_saved_copy = xmalloc (len);
1781 ignore_cleanups = make_cleanup (free_current_contents,
1782 &displaced->step_saved_copy);
1783 status = target_read_memory (copy, displaced->step_saved_copy, len);
1785 throw_error (MEMORY_ERROR,
1786 _("Error accessing memory address %s (%s) for "
1787 "displaced-stepping scratch space."),
1788 paddress (gdbarch, copy), safe_strerror (status));
1789 if (debug_displaced)
1791 fprintf_unfiltered (gdb_stdlog, "displaced: saved %s: ",
1792 paddress (gdbarch, copy));
1793 displaced_step_dump_bytes (gdb_stdlog,
1794 displaced->step_saved_copy,
1798 closure = gdbarch_displaced_step_copy_insn (gdbarch,
1799 original, copy, regcache);
1800 if (closure == NULL)
1802 /* The architecture doesn't know how or want to displaced step
1803 this instruction or instruction sequence. Fallback to
1804 stepping over the breakpoint in-line. */
1805 do_cleanups (old_cleanups);
1809 /* Save the information we need to fix things up if the step
1811 displaced->step_ptid = ptid;
1812 displaced->step_gdbarch = gdbarch;
1813 displaced->step_closure = closure;
1814 displaced->step_original = original;
1815 displaced->step_copy = copy;
1817 make_cleanup (displaced_step_clear_cleanup, displaced);
1819 /* Resume execution at the copy. */
1820 regcache_write_pc (regcache, copy);
1822 discard_cleanups (ignore_cleanups);
1824 do_cleanups (old_cleanups);
1826 if (debug_displaced)
1827 fprintf_unfiltered (gdb_stdlog, "displaced: displaced pc to %s\n",
1828 paddress (gdbarch, copy));
1833 /* Wrapper for displaced_step_prepare_throw that disabled further
1834 attempts at displaced stepping if we get a memory error. */
1837 displaced_step_prepare (ptid_t ptid)
1843 prepared = displaced_step_prepare_throw (ptid);
1845 CATCH (ex, RETURN_MASK_ERROR)
1847 struct displaced_step_inferior_state *displaced_state;
1849 if (ex.error != MEMORY_ERROR)
1850 throw_exception (ex);
1854 fprintf_unfiltered (gdb_stdlog,
1855 "infrun: disabling displaced stepping: %s\n",
1859 /* Be verbose if "set displaced-stepping" is "on", silent if
1861 if (can_use_displaced_stepping == AUTO_BOOLEAN_TRUE)
1863 warning (_("disabling displaced stepping: %s"),
1867 /* Disable further displaced stepping attempts. */
1869 = get_displaced_stepping_state (ptid_get_pid (ptid));
1870 displaced_state->failed_before = 1;
1878 write_memory_ptid (ptid_t ptid, CORE_ADDR memaddr,
1879 const gdb_byte *myaddr, int len)
1881 struct cleanup *ptid_cleanup = save_inferior_ptid ();
1883 inferior_ptid = ptid;
1884 write_memory (memaddr, myaddr, len);
1885 do_cleanups (ptid_cleanup);
1888 /* Restore the contents of the copy area for thread PTID. */
1891 displaced_step_restore (struct displaced_step_inferior_state *displaced,
1894 ULONGEST len = gdbarch_max_insn_length (displaced->step_gdbarch);
1896 write_memory_ptid (ptid, displaced->step_copy,
1897 displaced->step_saved_copy, len);
1898 if (debug_displaced)
1899 fprintf_unfiltered (gdb_stdlog, "displaced: restored %s %s\n",
1900 target_pid_to_str (ptid),
1901 paddress (displaced->step_gdbarch,
1902 displaced->step_copy));
1905 /* If we displaced stepped an instruction successfully, adjust
1906 registers and memory to yield the same effect the instruction would
1907 have had if we had executed it at its original address, and return
1908 1. If the instruction didn't complete, relocate the PC and return
1909 -1. If the thread wasn't displaced stepping, return 0. */
1912 displaced_step_fixup (ptid_t event_ptid, enum gdb_signal signal)
1914 struct cleanup *old_cleanups;
1915 struct displaced_step_inferior_state *displaced
1916 = get_displaced_stepping_state (ptid_get_pid (event_ptid));
1919 /* Was any thread of this process doing a displaced step? */
1920 if (displaced == NULL)
1923 /* Was this event for the pid we displaced? */
1924 if (ptid_equal (displaced->step_ptid, null_ptid)
1925 || ! ptid_equal (displaced->step_ptid, event_ptid))
1928 old_cleanups = make_cleanup (displaced_step_clear_cleanup, displaced);
1930 displaced_step_restore (displaced, displaced->step_ptid);
1932 /* Fixup may need to read memory/registers. Switch to the thread
1933 that we're fixing up. Also, target_stopped_by_watchpoint checks
1934 the current thread. */
1935 switch_to_thread (event_ptid);
1937 /* Did the instruction complete successfully? */
1938 if (signal == GDB_SIGNAL_TRAP
1939 && !(target_stopped_by_watchpoint ()
1940 && (gdbarch_have_nonsteppable_watchpoint (displaced->step_gdbarch)
1941 || target_have_steppable_watchpoint)))
1943 /* Fix up the resulting state. */
1944 gdbarch_displaced_step_fixup (displaced->step_gdbarch,
1945 displaced->step_closure,
1946 displaced->step_original,
1947 displaced->step_copy,
1948 get_thread_regcache (displaced->step_ptid));
1953 /* Since the instruction didn't complete, all we can do is
1955 struct regcache *regcache = get_thread_regcache (event_ptid);
1956 CORE_ADDR pc = regcache_read_pc (regcache);
1958 pc = displaced->step_original + (pc - displaced->step_copy);
1959 regcache_write_pc (regcache, pc);
1963 do_cleanups (old_cleanups);
1965 displaced->step_ptid = null_ptid;
1970 /* Data to be passed around while handling an event. This data is
1971 discarded between events. */
1972 struct execution_control_state
1975 /* The thread that got the event, if this was a thread event; NULL
1977 struct thread_info *event_thread;
1979 struct target_waitstatus ws;
1980 int stop_func_filled_in;
1981 CORE_ADDR stop_func_start;
1982 CORE_ADDR stop_func_end;
1983 const char *stop_func_name;
1986 /* True if the event thread hit the single-step breakpoint of
1987 another thread. Thus the event doesn't cause a stop, the thread
1988 needs to be single-stepped past the single-step breakpoint before
1989 we can switch back to the original stepping thread. */
1990 int hit_singlestep_breakpoint;
1993 /* Clear ECS and set it to point at TP. */
1996 reset_ecs (struct execution_control_state *ecs, struct thread_info *tp)
1998 memset (ecs, 0, sizeof (*ecs));
1999 ecs->event_thread = tp;
2000 ecs->ptid = tp->ptid;
2003 static void keep_going_pass_signal (struct execution_control_state *ecs);
2004 static void prepare_to_wait (struct execution_control_state *ecs);
2005 static int keep_going_stepped_thread (struct thread_info *tp);
2006 static int thread_still_needs_step_over (struct thread_info *tp);
2007 static void stop_all_threads (void);
2009 /* Are there any pending step-over requests? If so, run all we can
2010 now and return true. Otherwise, return false. */
2013 start_step_over (void)
2015 struct thread_info *tp, *next;
2017 /* Don't start a new step-over if we already have an in-line
2018 step-over operation ongoing. */
2019 if (step_over_info_valid_p ())
2022 for (tp = step_over_queue_head; tp != NULL; tp = next)
2024 struct execution_control_state ecss;
2025 struct execution_control_state *ecs = &ecss;
2026 enum step_over_what step_what;
2027 int must_be_in_line;
2029 next = thread_step_over_chain_next (tp);
2031 /* If this inferior already has a displaced step in process,
2032 don't start a new one. */
2033 if (displaced_step_in_progress (ptid_get_pid (tp->ptid)))
2036 step_what = thread_still_needs_step_over (tp);
2037 must_be_in_line = ((step_what & STEP_OVER_WATCHPOINT)
2038 || ((step_what & STEP_OVER_BREAKPOINT)
2039 && !use_displaced_stepping (tp)));
2041 /* We currently stop all threads of all processes to step-over
2042 in-line. If we need to start a new in-line step-over, let
2043 any pending displaced steps finish first. */
2044 if (must_be_in_line && displaced_step_in_progress_any_inferior ())
2047 thread_step_over_chain_remove (tp);
2049 if (step_over_queue_head == NULL)
2052 fprintf_unfiltered (gdb_stdlog,
2053 "infrun: step-over queue now empty\n");
2056 if (tp->control.trap_expected
2060 internal_error (__FILE__, __LINE__,
2061 "[%s] has inconsistent state: "
2062 "trap_expected=%d, resumed=%d, executing=%d\n",
2063 target_pid_to_str (tp->ptid),
2064 tp->control.trap_expected,
2070 fprintf_unfiltered (gdb_stdlog,
2071 "infrun: resuming [%s] for step-over\n",
2072 target_pid_to_str (tp->ptid));
2074 /* keep_going_pass_signal skips the step-over if the breakpoint
2075 is no longer inserted. In all-stop, we want to keep looking
2076 for a thread that needs a step-over instead of resuming TP,
2077 because we wouldn't be able to resume anything else until the
2078 target stops again. In non-stop, the resume always resumes
2079 only TP, so it's OK to let the thread resume freely. */
2080 if (!target_is_non_stop_p () && !step_what)
2083 switch_to_thread (tp->ptid);
2084 reset_ecs (ecs, tp);
2085 keep_going_pass_signal (ecs);
2087 if (!ecs->wait_some_more)
2088 error (_("Command aborted."));
2090 gdb_assert (tp->resumed);
2092 /* If we started a new in-line step-over, we're done. */
2093 if (step_over_info_valid_p ())
2095 gdb_assert (tp->control.trap_expected);
2099 if (!target_is_non_stop_p ())
2101 /* On all-stop, shouldn't have resumed unless we needed a
2103 gdb_assert (tp->control.trap_expected
2104 || tp->step_after_step_resume_breakpoint);
2106 /* With remote targets (at least), in all-stop, we can't
2107 issue any further remote commands until the program stops
2112 /* Either the thread no longer needed a step-over, or a new
2113 displaced stepping sequence started. Even in the latter
2114 case, continue looking. Maybe we can also start another
2115 displaced step on a thread of other process. */
2121 /* Update global variables holding ptids to hold NEW_PTID if they were
2122 holding OLD_PTID. */
2124 infrun_thread_ptid_changed (ptid_t old_ptid, ptid_t new_ptid)
2126 struct displaced_step_request *it;
2127 struct displaced_step_inferior_state *displaced;
2129 if (ptid_equal (inferior_ptid, old_ptid))
2130 inferior_ptid = new_ptid;
2132 for (displaced = displaced_step_inferior_states;
2134 displaced = displaced->next)
2136 if (ptid_equal (displaced->step_ptid, old_ptid))
2137 displaced->step_ptid = new_ptid;
2144 /* Things to clean up if we QUIT out of resume (). */
2146 resume_cleanups (void *ignore)
2148 if (!ptid_equal (inferior_ptid, null_ptid))
2149 delete_single_step_breakpoints (inferior_thread ());
2154 static const char schedlock_off[] = "off";
2155 static const char schedlock_on[] = "on";
2156 static const char schedlock_step[] = "step";
2157 static const char *const scheduler_enums[] = {
2163 static const char *scheduler_mode = schedlock_off;
2165 show_scheduler_mode (struct ui_file *file, int from_tty,
2166 struct cmd_list_element *c, const char *value)
2168 fprintf_filtered (file,
2169 _("Mode for locking scheduler "
2170 "during execution is \"%s\".\n"),
2175 set_schedlock_func (char *args, int from_tty, struct cmd_list_element *c)
2177 if (!target_can_lock_scheduler)
2179 scheduler_mode = schedlock_off;
2180 error (_("Target '%s' cannot support this command."), target_shortname);
2184 /* True if execution commands resume all threads of all processes by
2185 default; otherwise, resume only threads of the current inferior
2187 int sched_multi = 0;
2189 /* Try to setup for software single stepping over the specified location.
2190 Return 1 if target_resume() should use hardware single step.
2192 GDBARCH the current gdbarch.
2193 PC the location to step over. */
2196 maybe_software_singlestep (struct gdbarch *gdbarch, CORE_ADDR pc)
2200 if (execution_direction == EXEC_FORWARD
2201 && gdbarch_software_single_step_p (gdbarch)
2202 && gdbarch_software_single_step (gdbarch, get_current_frame ()))
2212 user_visible_resume_ptid (int step)
2218 /* With non-stop mode on, threads are always handled
2220 resume_ptid = inferior_ptid;
2222 else if ((scheduler_mode == schedlock_on)
2223 || (scheduler_mode == schedlock_step && step))
2225 /* User-settable 'scheduler' mode requires solo thread
2227 resume_ptid = inferior_ptid;
2229 else if (!sched_multi && target_supports_multi_process ())
2231 /* Resume all threads of the current process (and none of other
2233 resume_ptid = pid_to_ptid (ptid_get_pid (inferior_ptid));
2237 /* Resume all threads of all processes. */
2238 resume_ptid = RESUME_ALL;
2244 /* Return a ptid representing the set of threads that we will resume,
2245 in the perspective of the target, assuming run control handling
2246 does not require leaving some threads stopped (e.g., stepping past
2247 breakpoint). USER_STEP indicates whether we're about to start the
2248 target for a stepping command. */
2251 internal_resume_ptid (int user_step)
2253 /* In non-stop, we always control threads individually. Note that
2254 the target may always work in non-stop mode even with "set
2255 non-stop off", in which case user_visible_resume_ptid could
2256 return a wildcard ptid. */
2257 if (target_is_non_stop_p ())
2258 return inferior_ptid;
2260 return user_visible_resume_ptid (user_step);
2263 /* Wrapper for target_resume, that handles infrun-specific
2267 do_target_resume (ptid_t resume_ptid, int step, enum gdb_signal sig)
2269 struct thread_info *tp = inferior_thread ();
2271 /* Install inferior's terminal modes. */
2272 target_terminal_inferior ();
2274 /* Avoid confusing the next resume, if the next stop/resume
2275 happens to apply to another thread. */
2276 tp->suspend.stop_signal = GDB_SIGNAL_0;
2278 /* Advise target which signals may be handled silently.
2280 If we have removed breakpoints because we are stepping over one
2281 in-line (in any thread), we need to receive all signals to avoid
2282 accidentally skipping a breakpoint during execution of a signal
2285 Likewise if we're displaced stepping, otherwise a trap for a
2286 breakpoint in a signal handler might be confused with the
2287 displaced step finishing. We don't make the displaced_step_fixup
2288 step distinguish the cases instead, because:
2290 - a backtrace while stopped in the signal handler would show the
2291 scratch pad as frame older than the signal handler, instead of
2292 the real mainline code.
2294 - when the thread is later resumed, the signal handler would
2295 return to the scratch pad area, which would no longer be
2297 if (step_over_info_valid_p ()
2298 || displaced_step_in_progress (ptid_get_pid (tp->ptid)))
2299 target_pass_signals (0, NULL);
2301 target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
2303 target_resume (resume_ptid, step, sig);
2306 /* Resume the inferior, but allow a QUIT. This is useful if the user
2307 wants to interrupt some lengthy single-stepping operation
2308 (for child processes, the SIGINT goes to the inferior, and so
2309 we get a SIGINT random_signal, but for remote debugging and perhaps
2310 other targets, that's not true).
2312 SIG is the signal to give the inferior (zero for none). */
2314 resume (enum gdb_signal sig)
2316 struct cleanup *old_cleanups = make_cleanup (resume_cleanups, 0);
2317 struct regcache *regcache = get_current_regcache ();
2318 struct gdbarch *gdbarch = get_regcache_arch (regcache);
2319 struct thread_info *tp = inferior_thread ();
2320 CORE_ADDR pc = regcache_read_pc (regcache);
2321 struct address_space *aspace = get_regcache_aspace (regcache);
2323 /* This represents the user's step vs continue request. When
2324 deciding whether "set scheduler-locking step" applies, it's the
2325 user's intention that counts. */
2326 const int user_step = tp->control.stepping_command;
2327 /* This represents what we'll actually request the target to do.
2328 This can decay from a step to a continue, if e.g., we need to
2329 implement single-stepping with breakpoints (software
2333 gdb_assert (!thread_is_in_step_over_chain (tp));
2337 if (tp->suspend.waitstatus_pending_p)
2343 statstr = target_waitstatus_to_string (&tp->suspend.waitstatus);
2344 fprintf_unfiltered (gdb_stdlog,
2345 "infrun: resume: thread %s has pending wait status %s "
2346 "(currently_stepping=%d).\n",
2347 target_pid_to_str (tp->ptid), statstr,
2348 currently_stepping (tp));
2354 /* FIXME: What should we do if we are supposed to resume this
2355 thread with a signal? Maybe we should maintain a queue of
2356 pending signals to deliver. */
2357 if (sig != GDB_SIGNAL_0)
2359 warning (_("Couldn't deliver signal %s to %s."),
2360 gdb_signal_to_name (sig), target_pid_to_str (tp->ptid));
2363 tp->suspend.stop_signal = GDB_SIGNAL_0;
2364 discard_cleanups (old_cleanups);
2366 if (target_can_async_p ())
2371 tp->stepped_breakpoint = 0;
2373 /* Depends on stepped_breakpoint. */
2374 step = currently_stepping (tp);
2376 if (current_inferior ()->waiting_for_vfork_done)
2378 /* Don't try to single-step a vfork parent that is waiting for
2379 the child to get out of the shared memory region (by exec'ing
2380 or exiting). This is particularly important on software
2381 single-step archs, as the child process would trip on the
2382 software single step breakpoint inserted for the parent
2383 process. Since the parent will not actually execute any
2384 instruction until the child is out of the shared region (such
2385 are vfork's semantics), it is safe to simply continue it.
2386 Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for
2387 the parent, and tell it to `keep_going', which automatically
2388 re-sets it stepping. */
2390 fprintf_unfiltered (gdb_stdlog,
2391 "infrun: resume : clear step\n");
2396 fprintf_unfiltered (gdb_stdlog,
2397 "infrun: resume (step=%d, signal=%s), "
2398 "trap_expected=%d, current thread [%s] at %s\n",
2399 step, gdb_signal_to_symbol_string (sig),
2400 tp->control.trap_expected,
2401 target_pid_to_str (inferior_ptid),
2402 paddress (gdbarch, pc));
2404 /* Normally, by the time we reach `resume', the breakpoints are either
2405 removed or inserted, as appropriate. The exception is if we're sitting
2406 at a permanent breakpoint; we need to step over it, but permanent
2407 breakpoints can't be removed. So we have to test for it here. */
2408 if (breakpoint_here_p (aspace, pc) == permanent_breakpoint_here)
2410 if (sig != GDB_SIGNAL_0)
2412 /* We have a signal to pass to the inferior. The resume
2413 may, or may not take us to the signal handler. If this
2414 is a step, we'll need to stop in the signal handler, if
2415 there's one, (if the target supports stepping into
2416 handlers), or in the next mainline instruction, if
2417 there's no handler. If this is a continue, we need to be
2418 sure to run the handler with all breakpoints inserted.
2419 In all cases, set a breakpoint at the current address
2420 (where the handler returns to), and once that breakpoint
2421 is hit, resume skipping the permanent breakpoint. If
2422 that breakpoint isn't hit, then we've stepped into the
2423 signal handler (or hit some other event). We'll delete
2424 the step-resume breakpoint then. */
2427 fprintf_unfiltered (gdb_stdlog,
2428 "infrun: resume: skipping permanent breakpoint, "
2429 "deliver signal first\n");
2431 clear_step_over_info ();
2432 tp->control.trap_expected = 0;
2434 if (tp->control.step_resume_breakpoint == NULL)
2436 /* Set a "high-priority" step-resume, as we don't want
2437 user breakpoints at PC to trigger (again) when this
2439 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2440 gdb_assert (tp->control.step_resume_breakpoint->loc->permanent);
2442 tp->step_after_step_resume_breakpoint = step;
2445 insert_breakpoints ();
2449 /* There's no signal to pass, we can go ahead and skip the
2450 permanent breakpoint manually. */
2452 fprintf_unfiltered (gdb_stdlog,
2453 "infrun: resume: skipping permanent breakpoint\n");
2454 gdbarch_skip_permanent_breakpoint (gdbarch, regcache);
2455 /* Update pc to reflect the new address from which we will
2456 execute instructions. */
2457 pc = regcache_read_pc (regcache);
2461 /* We've already advanced the PC, so the stepping part
2462 is done. Now we need to arrange for a trap to be
2463 reported to handle_inferior_event. Set a breakpoint
2464 at the current PC, and run to it. Don't update
2465 prev_pc, because if we end in
2466 switch_back_to_stepped_thread, we want the "expected
2467 thread advanced also" branch to be taken. IOW, we
2468 don't want this thread to step further from PC
2470 gdb_assert (!step_over_info_valid_p ());
2471 insert_single_step_breakpoint (gdbarch, aspace, pc);
2472 insert_breakpoints ();
2474 resume_ptid = internal_resume_ptid (user_step);
2475 do_target_resume (resume_ptid, 0, GDB_SIGNAL_0);
2476 discard_cleanups (old_cleanups);
2483 /* If we have a breakpoint to step over, make sure to do a single
2484 step only. Same if we have software watchpoints. */
2485 if (tp->control.trap_expected || bpstat_should_step ())
2486 tp->control.may_range_step = 0;
2488 /* If enabled, step over breakpoints by executing a copy of the
2489 instruction at a different address.
2491 We can't use displaced stepping when we have a signal to deliver;
2492 the comments for displaced_step_prepare explain why. The
2493 comments in the handle_inferior event for dealing with 'random
2494 signals' explain what we do instead.
2496 We can't use displaced stepping when we are waiting for vfork_done
2497 event, displaced stepping breaks the vfork child similarly as single
2498 step software breakpoint. */
2499 if (tp->control.trap_expected
2500 && use_displaced_stepping (tp)
2501 && !step_over_info_valid_p ()
2502 && sig == GDB_SIGNAL_0
2503 && !current_inferior ()->waiting_for_vfork_done)
2505 int prepared = displaced_step_prepare (inferior_ptid);
2510 fprintf_unfiltered (gdb_stdlog,
2511 "Got placed in step-over queue\n");
2513 tp->control.trap_expected = 0;
2514 discard_cleanups (old_cleanups);
2517 else if (prepared < 0)
2519 /* Fallback to stepping over the breakpoint in-line. */
2521 if (target_is_non_stop_p ())
2522 stop_all_threads ();
2524 set_step_over_info (get_regcache_aspace (regcache),
2525 regcache_read_pc (regcache), 0);
2527 step = maybe_software_singlestep (gdbarch, pc);
2529 insert_breakpoints ();
2531 else if (prepared > 0)
2533 struct displaced_step_inferior_state *displaced;
2535 /* Update pc to reflect the new address from which we will
2536 execute instructions due to displaced stepping. */
2537 pc = regcache_read_pc (get_thread_regcache (inferior_ptid));
2539 displaced = get_displaced_stepping_state (ptid_get_pid (inferior_ptid));
2540 step = gdbarch_displaced_step_hw_singlestep (gdbarch,
2541 displaced->step_closure);
2545 /* Do we need to do it the hard way, w/temp breakpoints? */
2547 step = maybe_software_singlestep (gdbarch, pc);
2549 /* Currently, our software single-step implementation leads to different
2550 results than hardware single-stepping in one situation: when stepping
2551 into delivering a signal which has an associated signal handler,
2552 hardware single-step will stop at the first instruction of the handler,
2553 while software single-step will simply skip execution of the handler.
2555 For now, this difference in behavior is accepted since there is no
2556 easy way to actually implement single-stepping into a signal handler
2557 without kernel support.
2559 However, there is one scenario where this difference leads to follow-on
2560 problems: if we're stepping off a breakpoint by removing all breakpoints
2561 and then single-stepping. In this case, the software single-step
2562 behavior means that even if there is a *breakpoint* in the signal
2563 handler, GDB still would not stop.
2565 Fortunately, we can at least fix this particular issue. We detect
2566 here the case where we are about to deliver a signal while software
2567 single-stepping with breakpoints removed. In this situation, we
2568 revert the decisions to remove all breakpoints and insert single-
2569 step breakpoints, and instead we install a step-resume breakpoint
2570 at the current address, deliver the signal without stepping, and
2571 once we arrive back at the step-resume breakpoint, actually step
2572 over the breakpoint we originally wanted to step over. */
2573 if (thread_has_single_step_breakpoints_set (tp)
2574 && sig != GDB_SIGNAL_0
2575 && step_over_info_valid_p ())
2577 /* If we have nested signals or a pending signal is delivered
2578 immediately after a handler returns, might might already have
2579 a step-resume breakpoint set on the earlier handler. We cannot
2580 set another step-resume breakpoint; just continue on until the
2581 original breakpoint is hit. */
2582 if (tp->control.step_resume_breakpoint == NULL)
2584 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2585 tp->step_after_step_resume_breakpoint = 1;
2588 delete_single_step_breakpoints (tp);
2590 clear_step_over_info ();
2591 tp->control.trap_expected = 0;
2593 insert_breakpoints ();
2596 /* If STEP is set, it's a request to use hardware stepping
2597 facilities. But in that case, we should never
2598 use singlestep breakpoint. */
2599 gdb_assert (!(thread_has_single_step_breakpoints_set (tp) && step));
2601 /* Decide the set of threads to ask the target to resume. */
2602 if ((step || thread_has_single_step_breakpoints_set (tp))
2603 && tp->control.trap_expected)
2605 /* We're allowing a thread to run past a breakpoint it has
2606 hit, by single-stepping the thread with the breakpoint
2607 removed. In which case, we need to single-step only this
2608 thread, and keep others stopped, as they can miss this
2609 breakpoint if allowed to run. */
2610 resume_ptid = inferior_ptid;
2613 resume_ptid = internal_resume_ptid (user_step);
2615 if (execution_direction != EXEC_REVERSE
2616 && step && breakpoint_inserted_here_p (aspace, pc))
2618 /* There are two cases where we currently need to step a
2619 breakpoint instruction when we have a signal to deliver:
2621 - See handle_signal_stop where we handle random signals that
2622 could take out us out of the stepping range. Normally, in
2623 that case we end up continuing (instead of stepping) over the
2624 signal handler with a breakpoint at PC, but there are cases
2625 where we should _always_ single-step, even if we have a
2626 step-resume breakpoint, like when a software watchpoint is
2627 set. Assuming single-stepping and delivering a signal at the
2628 same time would takes us to the signal handler, then we could
2629 have removed the breakpoint at PC to step over it. However,
2630 some hardware step targets (like e.g., Mac OS) can't step
2631 into signal handlers, and for those, we need to leave the
2632 breakpoint at PC inserted, as otherwise if the handler
2633 recurses and executes PC again, it'll miss the breakpoint.
2634 So we leave the breakpoint inserted anyway, but we need to
2635 record that we tried to step a breakpoint instruction, so
2636 that adjust_pc_after_break doesn't end up confused.
2638 - In non-stop if we insert a breakpoint (e.g., a step-resume)
2639 in one thread after another thread that was stepping had been
2640 momentarily paused for a step-over. When we re-resume the
2641 stepping thread, it may be resumed from that address with a
2642 breakpoint that hasn't trapped yet. Seen with
2643 gdb.threads/non-stop-fair-events.exp, on targets that don't
2644 do displaced stepping. */
2647 fprintf_unfiltered (gdb_stdlog,
2648 "infrun: resume: [%s] stepped breakpoint\n",
2649 target_pid_to_str (tp->ptid));
2651 tp->stepped_breakpoint = 1;
2653 /* Most targets can step a breakpoint instruction, thus
2654 executing it normally. But if this one cannot, just
2655 continue and we will hit it anyway. */
2656 if (gdbarch_cannot_step_breakpoint (gdbarch))
2661 && tp->control.trap_expected
2662 && use_displaced_stepping (tp)
2663 && !step_over_info_valid_p ())
2665 struct regcache *resume_regcache = get_thread_regcache (tp->ptid);
2666 struct gdbarch *resume_gdbarch = get_regcache_arch (resume_regcache);
2667 CORE_ADDR actual_pc = regcache_read_pc (resume_regcache);
2670 fprintf_unfiltered (gdb_stdlog, "displaced: run %s: ",
2671 paddress (resume_gdbarch, actual_pc));
2672 read_memory (actual_pc, buf, sizeof (buf));
2673 displaced_step_dump_bytes (gdb_stdlog, buf, sizeof (buf));
2676 if (tp->control.may_range_step)
2678 /* If we're resuming a thread with the PC out of the step
2679 range, then we're doing some nested/finer run control
2680 operation, like stepping the thread out of the dynamic
2681 linker or the displaced stepping scratch pad. We
2682 shouldn't have allowed a range step then. */
2683 gdb_assert (pc_in_thread_step_range (pc, tp));
2686 do_target_resume (resume_ptid, step, sig);
2688 discard_cleanups (old_cleanups);
2693 /* Clear out all variables saying what to do when inferior is continued.
2694 First do this, then set the ones you want, then call `proceed'. */
2697 clear_proceed_status_thread (struct thread_info *tp)
2700 fprintf_unfiltered (gdb_stdlog,
2701 "infrun: clear_proceed_status_thread (%s)\n",
2702 target_pid_to_str (tp->ptid));
2704 /* If we're starting a new sequence, then the previous finished
2705 single-step is no longer relevant. */
2706 if (tp->suspend.waitstatus_pending_p)
2708 if (tp->suspend.stop_reason == TARGET_STOPPED_BY_SINGLE_STEP)
2711 fprintf_unfiltered (gdb_stdlog,
2712 "infrun: clear_proceed_status: pending "
2713 "event of %s was a finished step. "
2715 target_pid_to_str (tp->ptid));
2717 tp->suspend.waitstatus_pending_p = 0;
2718 tp->suspend.stop_reason = TARGET_STOPPED_BY_NO_REASON;
2720 else if (debug_infrun)
2724 statstr = target_waitstatus_to_string (&tp->suspend.waitstatus);
2725 fprintf_unfiltered (gdb_stdlog,
2726 "infrun: clear_proceed_status_thread: thread %s "
2727 "has pending wait status %s "
2728 "(currently_stepping=%d).\n",
2729 target_pid_to_str (tp->ptid), statstr,
2730 currently_stepping (tp));
2735 /* If this signal should not be seen by program, give it zero.
2736 Used for debugging signals. */
2737 if (!signal_pass_state (tp->suspend.stop_signal))
2738 tp->suspend.stop_signal = GDB_SIGNAL_0;
2740 tp->control.trap_expected = 0;
2741 tp->control.step_range_start = 0;
2742 tp->control.step_range_end = 0;
2743 tp->control.may_range_step = 0;
2744 tp->control.step_frame_id = null_frame_id;
2745 tp->control.step_stack_frame_id = null_frame_id;
2746 tp->control.step_over_calls = STEP_OVER_UNDEBUGGABLE;
2747 tp->control.step_start_function = NULL;
2748 tp->stop_requested = 0;
2750 tp->control.stop_step = 0;
2752 tp->control.proceed_to_finish = 0;
2754 tp->control.command_interp = NULL;
2755 tp->control.stepping_command = 0;
2757 /* Discard any remaining commands or status from previous stop. */
2758 bpstat_clear (&tp->control.stop_bpstat);
2762 clear_proceed_status (int step)
2766 struct thread_info *tp;
2769 resume_ptid = user_visible_resume_ptid (step);
2771 /* In all-stop mode, delete the per-thread status of all threads
2772 we're about to resume, implicitly and explicitly. */
2773 ALL_NON_EXITED_THREADS (tp)
2775 if (!ptid_match (tp->ptid, resume_ptid))
2777 clear_proceed_status_thread (tp);
2781 if (!ptid_equal (inferior_ptid, null_ptid))
2783 struct inferior *inferior;
2787 /* If in non-stop mode, only delete the per-thread status of
2788 the current thread. */
2789 clear_proceed_status_thread (inferior_thread ());
2792 inferior = current_inferior ();
2793 inferior->control.stop_soon = NO_STOP_QUIETLY;
2796 stop_after_trap = 0;
2798 observer_notify_about_to_proceed ();
2801 /* Returns true if TP is still stopped at a breakpoint that needs
2802 stepping-over in order to make progress. If the breakpoint is gone
2803 meanwhile, we can skip the whole step-over dance. */
2806 thread_still_needs_step_over_bp (struct thread_info *tp)
2808 if (tp->stepping_over_breakpoint)
2810 struct regcache *regcache = get_thread_regcache (tp->ptid);
2812 if (breakpoint_here_p (get_regcache_aspace (regcache),
2813 regcache_read_pc (regcache))
2814 == ordinary_breakpoint_here)
2817 tp->stepping_over_breakpoint = 0;
2823 /* Check whether thread TP still needs to start a step-over in order
2824 to make progress when resumed. Returns an bitwise or of enum
2825 step_over_what bits, indicating what needs to be stepped over. */
2828 thread_still_needs_step_over (struct thread_info *tp)
2830 struct inferior *inf = find_inferior_ptid (tp->ptid);
2833 if (thread_still_needs_step_over_bp (tp))
2834 what |= STEP_OVER_BREAKPOINT;
2836 if (tp->stepping_over_watchpoint
2837 && !target_have_steppable_watchpoint)
2838 what |= STEP_OVER_WATCHPOINT;
2843 /* Returns true if scheduler locking applies. STEP indicates whether
2844 we're about to do a step/next-like command to a thread. */
2847 schedlock_applies (struct thread_info *tp)
2849 return (scheduler_mode == schedlock_on
2850 || (scheduler_mode == schedlock_step
2851 && tp->control.stepping_command));
2854 /* Basic routine for continuing the program in various fashions.
2856 ADDR is the address to resume at, or -1 for resume where stopped.
2857 SIGGNAL is the signal to give it, or 0 for none,
2858 or -1 for act according to how it stopped.
2859 STEP is nonzero if should trap after one instruction.
2860 -1 means return after that and print nothing.
2861 You should probably set various step_... variables
2862 before calling here, if you are stepping.
2864 You should call clear_proceed_status before calling proceed. */
2867 proceed (CORE_ADDR addr, enum gdb_signal siggnal)
2869 struct regcache *regcache;
2870 struct gdbarch *gdbarch;
2871 struct thread_info *tp;
2873 struct address_space *aspace;
2875 struct execution_control_state ecss;
2876 struct execution_control_state *ecs = &ecss;
2877 struct cleanup *old_chain;
2880 /* If we're stopped at a fork/vfork, follow the branch set by the
2881 "set follow-fork-mode" command; otherwise, we'll just proceed
2882 resuming the current thread. */
2883 if (!follow_fork ())
2885 /* The target for some reason decided not to resume. */
2887 if (target_can_async_p ())
2888 inferior_event_handler (INF_EXEC_COMPLETE, NULL);
2892 /* We'll update this if & when we switch to a new thread. */
2893 previous_inferior_ptid = inferior_ptid;
2895 regcache = get_current_regcache ();
2896 gdbarch = get_regcache_arch (regcache);
2897 aspace = get_regcache_aspace (regcache);
2898 pc = regcache_read_pc (regcache);
2899 tp = inferior_thread ();
2901 /* Fill in with reasonable starting values. */
2902 init_thread_stepping_state (tp);
2904 gdb_assert (!thread_is_in_step_over_chain (tp));
2906 if (addr == (CORE_ADDR) -1)
2909 && breakpoint_here_p (aspace, pc) == ordinary_breakpoint_here
2910 && execution_direction != EXEC_REVERSE)
2911 /* There is a breakpoint at the address we will resume at,
2912 step one instruction before inserting breakpoints so that
2913 we do not stop right away (and report a second hit at this
2916 Note, we don't do this in reverse, because we won't
2917 actually be executing the breakpoint insn anyway.
2918 We'll be (un-)executing the previous instruction. */
2919 tp->stepping_over_breakpoint = 1;
2920 else if (gdbarch_single_step_through_delay_p (gdbarch)
2921 && gdbarch_single_step_through_delay (gdbarch,
2922 get_current_frame ()))
2923 /* We stepped onto an instruction that needs to be stepped
2924 again before re-inserting the breakpoint, do so. */
2925 tp->stepping_over_breakpoint = 1;
2929 regcache_write_pc (regcache, addr);
2932 if (siggnal != GDB_SIGNAL_DEFAULT)
2933 tp->suspend.stop_signal = siggnal;
2935 /* Record the interpreter that issued the execution command that
2936 caused this thread to resume. If the top level interpreter is
2937 MI/async, and the execution command was a CLI command
2938 (next/step/etc.), we'll want to print stop event output to the MI
2939 console channel (the stepped-to line, etc.), as if the user
2940 entered the execution command on a real GDB console. */
2941 tp->control.command_interp = command_interp ();
2943 resume_ptid = user_visible_resume_ptid (tp->control.stepping_command);
2945 /* If an exception is thrown from this point on, make sure to
2946 propagate GDB's knowledge of the executing state to the
2947 frontend/user running state. */
2948 old_chain = make_cleanup (finish_thread_state_cleanup, &resume_ptid);
2950 /* Even if RESUME_PTID is a wildcard, and we end up resuming fewer
2951 threads (e.g., we might need to set threads stepping over
2952 breakpoints first), from the user/frontend's point of view, all
2953 threads in RESUME_PTID are now running. Unless we're calling an
2954 inferior function, as in that case we pretend the inferior
2955 doesn't run at all. */
2956 if (!tp->control.in_infcall)
2957 set_running (resume_ptid, 1);
2960 fprintf_unfiltered (gdb_stdlog,
2961 "infrun: proceed (addr=%s, signal=%s)\n",
2962 paddress (gdbarch, addr),
2963 gdb_signal_to_symbol_string (siggnal));
2965 annotate_starting ();
2967 /* Make sure that output from GDB appears before output from the
2969 gdb_flush (gdb_stdout);
2971 /* In a multi-threaded task we may select another thread and
2972 then continue or step.
2974 But if a thread that we're resuming had stopped at a breakpoint,
2975 it will immediately cause another breakpoint stop without any
2976 execution (i.e. it will report a breakpoint hit incorrectly). So
2977 we must step over it first.
2979 Look for threads other than the current (TP) that reported a
2980 breakpoint hit and haven't been resumed yet since. */
2982 /* If scheduler locking applies, we can avoid iterating over all
2984 if (!non_stop && !schedlock_applies (tp))
2986 struct thread_info *current = tp;
2988 ALL_NON_EXITED_THREADS (tp)
2990 /* Ignore the current thread here. It's handled
2995 /* Ignore threads of processes we're not resuming. */
2996 if (!ptid_match (tp->ptid, resume_ptid))
2999 if (!thread_still_needs_step_over (tp))
3002 gdb_assert (!thread_is_in_step_over_chain (tp));
3005 fprintf_unfiltered (gdb_stdlog,
3006 "infrun: need to step-over [%s] first\n",
3007 target_pid_to_str (tp->ptid));
3009 thread_step_over_chain_enqueue (tp);
3015 /* Enqueue the current thread last, so that we move all other
3016 threads over their breakpoints first. */
3017 if (tp->stepping_over_breakpoint)
3018 thread_step_over_chain_enqueue (tp);
3020 /* If the thread isn't started, we'll still need to set its prev_pc,
3021 so that switch_back_to_stepped_thread knows the thread hasn't
3022 advanced. Must do this before resuming any thread, as in
3023 all-stop/remote, once we resume we can't send any other packet
3024 until the target stops again. */
3025 tp->prev_pc = regcache_read_pc (regcache);
3027 started = start_step_over ();
3029 if (step_over_info_valid_p ())
3031 /* Either this thread started a new in-line step over, or some
3032 other thread was already doing one. In either case, don't
3033 resume anything else until the step-over is finished. */
3035 else if (started && !target_is_non_stop_p ())
3037 /* A new displaced stepping sequence was started. In all-stop,
3038 we can't talk to the target anymore until it next stops. */
3040 else if (!non_stop && target_is_non_stop_p ())
3042 /* In all-stop, but the target is always in non-stop mode.
3043 Start all other threads that are implicitly resumed too. */
3044 ALL_NON_EXITED_THREADS (tp)
3046 /* Ignore threads of processes we're not resuming. */
3047 if (!ptid_match (tp->ptid, resume_ptid))
3053 fprintf_unfiltered (gdb_stdlog,
3054 "infrun: proceed: [%s] resumed\n",
3055 target_pid_to_str (tp->ptid));
3056 gdb_assert (tp->executing || tp->suspend.waitstatus_pending_p);
3060 if (thread_is_in_step_over_chain (tp))
3063 fprintf_unfiltered (gdb_stdlog,
3064 "infrun: proceed: [%s] needs step-over\n",
3065 target_pid_to_str (tp->ptid));
3070 fprintf_unfiltered (gdb_stdlog,
3071 "infrun: proceed: resuming %s\n",
3072 target_pid_to_str (tp->ptid));
3074 reset_ecs (ecs, tp);
3075 switch_to_thread (tp->ptid);
3076 keep_going_pass_signal (ecs);
3077 if (!ecs->wait_some_more)
3078 error (_("Command aborted."));
3081 else if (!tp->resumed && !thread_is_in_step_over_chain (tp))
3083 /* The thread wasn't started, and isn't queued, run it now. */
3084 reset_ecs (ecs, tp);
3085 switch_to_thread (tp->ptid);
3086 keep_going_pass_signal (ecs);
3087 if (!ecs->wait_some_more)
3088 error (_("Command aborted."));
3091 discard_cleanups (old_chain);
3093 /* Wait for it to stop (if not standalone)
3094 and in any case decode why it stopped, and act accordingly. */
3095 /* Do this only if we are not using the event loop, or if the target
3096 does not support asynchronous execution. */
3097 if (!target_can_async_p ())
3099 wait_for_inferior ();
3105 /* Start remote-debugging of a machine over a serial link. */
3108 start_remote (int from_tty)
3110 struct inferior *inferior;
3112 inferior = current_inferior ();
3113 inferior->control.stop_soon = STOP_QUIETLY_REMOTE;
3115 /* Always go on waiting for the target, regardless of the mode. */
3116 /* FIXME: cagney/1999-09-23: At present it isn't possible to
3117 indicate to wait_for_inferior that a target should timeout if
3118 nothing is returned (instead of just blocking). Because of this,
3119 targets expecting an immediate response need to, internally, set
3120 things up so that the target_wait() is forced to eventually
3122 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
3123 differentiate to its caller what the state of the target is after
3124 the initial open has been performed. Here we're assuming that
3125 the target has stopped. It should be possible to eventually have
3126 target_open() return to the caller an indication that the target
3127 is currently running and GDB state should be set to the same as
3128 for an async run. */
3129 wait_for_inferior ();
3131 /* Now that the inferior has stopped, do any bookkeeping like
3132 loading shared libraries. We want to do this before normal_stop,
3133 so that the displayed frame is up to date. */
3134 post_create_inferior (¤t_target, from_tty);
3139 /* Initialize static vars when a new inferior begins. */
3142 init_wait_for_inferior (void)
3144 /* These are meaningless until the first time through wait_for_inferior. */
3146 breakpoint_init_inferior (inf_starting);
3148 clear_proceed_status (0);
3150 target_last_wait_ptid = minus_one_ptid;
3152 previous_inferior_ptid = inferior_ptid;
3154 /* Discard any skipped inlined frames. */
3155 clear_inline_frame_state (minus_one_ptid);
3160 static void handle_inferior_event (struct execution_control_state *ecs);
3162 static void handle_step_into_function (struct gdbarch *gdbarch,
3163 struct execution_control_state *ecs);
3164 static void handle_step_into_function_backward (struct gdbarch *gdbarch,
3165 struct execution_control_state *ecs);
3166 static void handle_signal_stop (struct execution_control_state *ecs);
3167 static void check_exception_resume (struct execution_control_state *,
3168 struct frame_info *);
3170 static void end_stepping_range (struct execution_control_state *ecs);
3171 static void stop_waiting (struct execution_control_state *ecs);
3172 static void keep_going (struct execution_control_state *ecs);
3173 static void process_event_stop_test (struct execution_control_state *ecs);
3174 static int switch_back_to_stepped_thread (struct execution_control_state *ecs);
3176 /* Callback for iterate over threads. If the thread is stopped, but
3177 the user/frontend doesn't know about that yet, go through
3178 normal_stop, as if the thread had just stopped now. ARG points at
3179 a ptid. If PTID is MINUS_ONE_PTID, applies to all threads. If
3180 ptid_is_pid(PTID) is true, applies to all threads of the process
3181 pointed at by PTID. Otherwise, apply only to the thread pointed by
3185 infrun_thread_stop_requested_callback (struct thread_info *info, void *arg)
3187 ptid_t ptid = * (ptid_t *) arg;
3189 if ((ptid_equal (info->ptid, ptid)
3190 || ptid_equal (minus_one_ptid, ptid)
3191 || (ptid_is_pid (ptid)
3192 && ptid_get_pid (ptid) == ptid_get_pid (info->ptid)))
3193 && is_running (info->ptid)
3194 && !is_executing (info->ptid))
3196 struct cleanup *old_chain;
3197 struct execution_control_state ecss;
3198 struct execution_control_state *ecs = &ecss;
3200 memset (ecs, 0, sizeof (*ecs));
3202 old_chain = make_cleanup_restore_current_thread ();
3204 overlay_cache_invalid = 1;
3205 /* Flush target cache before starting to handle each event.
3206 Target was running and cache could be stale. This is just a
3207 heuristic. Running threads may modify target memory, but we
3208 don't get any event. */
3209 target_dcache_invalidate ();
3211 /* Go through handle_inferior_event/normal_stop, so we always
3212 have consistent output as if the stop event had been
3214 ecs->ptid = info->ptid;
3215 ecs->event_thread = find_thread_ptid (info->ptid);
3216 ecs->ws.kind = TARGET_WAITKIND_STOPPED;
3217 ecs->ws.value.sig = GDB_SIGNAL_0;
3219 handle_inferior_event (ecs);
3221 if (!ecs->wait_some_more)
3223 struct thread_info *tp;
3227 /* Finish off the continuations. */
3228 tp = inferior_thread ();
3229 do_all_intermediate_continuations_thread (tp, 1);
3230 do_all_continuations_thread (tp, 1);
3233 do_cleanups (old_chain);
3239 /* This function is attached as a "thread_stop_requested" observer.
3240 Cleanup local state that assumed the PTID was to be resumed, and
3241 report the stop to the frontend. */
3244 infrun_thread_stop_requested (ptid_t ptid)
3246 struct thread_info *tp;
3248 /* PTID was requested to stop. Remove matching threads from the
3249 step-over queue, so we don't try to resume them
3251 ALL_NON_EXITED_THREADS (tp)
3252 if (ptid_match (tp->ptid, ptid))
3254 if (thread_is_in_step_over_chain (tp))
3255 thread_step_over_chain_remove (tp);
3258 iterate_over_threads (infrun_thread_stop_requested_callback, &ptid);
3262 infrun_thread_thread_exit (struct thread_info *tp, int silent)
3264 if (ptid_equal (target_last_wait_ptid, tp->ptid))
3265 nullify_last_target_wait_ptid ();
3268 /* Delete the step resume, single-step and longjmp/exception resume
3269 breakpoints of TP. */
3272 delete_thread_infrun_breakpoints (struct thread_info *tp)
3274 delete_step_resume_breakpoint (tp);
3275 delete_exception_resume_breakpoint (tp);
3276 delete_single_step_breakpoints (tp);
3279 /* If the target still has execution, call FUNC for each thread that
3280 just stopped. In all-stop, that's all the non-exited threads; in
3281 non-stop, that's the current thread, only. */
3283 typedef void (*for_each_just_stopped_thread_callback_func)
3284 (struct thread_info *tp);
3287 for_each_just_stopped_thread (for_each_just_stopped_thread_callback_func func)
3289 if (!target_has_execution || ptid_equal (inferior_ptid, null_ptid))
3292 if (target_is_non_stop_p ())
3294 /* If in non-stop mode, only the current thread stopped. */
3295 func (inferior_thread ());
3299 struct thread_info *tp;
3301 /* In all-stop mode, all threads have stopped. */
3302 ALL_NON_EXITED_THREADS (tp)
3309 /* Delete the step resume and longjmp/exception resume breakpoints of
3310 the threads that just stopped. */
3313 delete_just_stopped_threads_infrun_breakpoints (void)
3315 for_each_just_stopped_thread (delete_thread_infrun_breakpoints);
3318 /* Delete the single-step breakpoints of the threads that just
3322 delete_just_stopped_threads_single_step_breakpoints (void)
3324 for_each_just_stopped_thread (delete_single_step_breakpoints);
3327 /* A cleanup wrapper. */
3330 delete_just_stopped_threads_infrun_breakpoints_cleanup (void *arg)
3332 delete_just_stopped_threads_infrun_breakpoints ();
3338 print_target_wait_results (ptid_t waiton_ptid, ptid_t result_ptid,
3339 const struct target_waitstatus *ws)
3341 char *status_string = target_waitstatus_to_string (ws);
3342 struct ui_file *tmp_stream = mem_fileopen ();
3345 /* The text is split over several lines because it was getting too long.
3346 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
3347 output as a unit; we want only one timestamp printed if debug_timestamp
3350 fprintf_unfiltered (tmp_stream,
3351 "infrun: target_wait (%d.%ld.%ld",
3352 ptid_get_pid (waiton_ptid),
3353 ptid_get_lwp (waiton_ptid),
3354 ptid_get_tid (waiton_ptid));
3355 if (ptid_get_pid (waiton_ptid) != -1)
3356 fprintf_unfiltered (tmp_stream,
3357 " [%s]", target_pid_to_str (waiton_ptid));
3358 fprintf_unfiltered (tmp_stream, ", status) =\n");
3359 fprintf_unfiltered (tmp_stream,
3360 "infrun: %d.%ld.%ld [%s],\n",
3361 ptid_get_pid (result_ptid),
3362 ptid_get_lwp (result_ptid),
3363 ptid_get_tid (result_ptid),
3364 target_pid_to_str (result_ptid));
3365 fprintf_unfiltered (tmp_stream,
3369 text = ui_file_xstrdup (tmp_stream, NULL);
3371 /* This uses %s in part to handle %'s in the text, but also to avoid
3372 a gcc error: the format attribute requires a string literal. */
3373 fprintf_unfiltered (gdb_stdlog, "%s", text);
3375 xfree (status_string);
3377 ui_file_delete (tmp_stream);
3380 /* Select a thread at random, out of those which are resumed and have
3383 static struct thread_info *
3384 random_pending_event_thread (ptid_t waiton_ptid)
3386 struct thread_info *event_tp;
3388 int random_selector;
3390 /* First see how many events we have. Count only resumed threads
3391 that have an event pending. */
3392 ALL_NON_EXITED_THREADS (event_tp)
3393 if (ptid_match (event_tp->ptid, waiton_ptid)
3394 && event_tp->resumed
3395 && event_tp->suspend.waitstatus_pending_p)
3398 if (num_events == 0)
3401 /* Now randomly pick a thread out of those that have had events. */
3402 random_selector = (int)
3403 ((num_events * (double) rand ()) / (RAND_MAX + 1.0));
3405 if (debug_infrun && num_events > 1)
3406 fprintf_unfiltered (gdb_stdlog,
3407 "infrun: Found %d events, selecting #%d\n",
3408 num_events, random_selector);
3410 /* Select the Nth thread that has had an event. */
3411 ALL_NON_EXITED_THREADS (event_tp)
3412 if (ptid_match (event_tp->ptid, waiton_ptid)
3413 && event_tp->resumed
3414 && event_tp->suspend.waitstatus_pending_p)
3415 if (random_selector-- == 0)
3421 /* Wrapper for target_wait that first checks whether threads have
3422 pending statuses to report before actually asking the target for
3426 do_target_wait (ptid_t ptid, struct target_waitstatus *status, int options)
3429 struct thread_info *tp;
3431 /* First check if there is a resumed thread with a wait status
3433 if (ptid_equal (ptid, minus_one_ptid) || ptid_is_pid (ptid))
3435 tp = random_pending_event_thread (ptid);
3440 fprintf_unfiltered (gdb_stdlog,
3441 "infrun: Waiting for specific thread %s.\n",
3442 target_pid_to_str (ptid));
3444 /* We have a specific thread to check. */
3445 tp = find_thread_ptid (ptid);
3446 gdb_assert (tp != NULL);
3447 if (!tp->suspend.waitstatus_pending_p)
3452 && (tp->suspend.stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT
3453 || tp->suspend.stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT))
3455 struct regcache *regcache = get_thread_regcache (tp->ptid);
3456 struct gdbarch *gdbarch = get_regcache_arch (regcache);
3460 pc = regcache_read_pc (regcache);
3462 if (pc != tp->suspend.stop_pc)
3465 fprintf_unfiltered (gdb_stdlog,
3466 "infrun: PC of %s changed. was=%s, now=%s\n",
3467 target_pid_to_str (tp->ptid),
3468 paddress (gdbarch, tp->prev_pc),
3469 paddress (gdbarch, pc));
3472 else if (!breakpoint_inserted_here_p (get_regcache_aspace (regcache), pc))
3475 fprintf_unfiltered (gdb_stdlog,
3476 "infrun: previous breakpoint of %s, at %s gone\n",
3477 target_pid_to_str (tp->ptid),
3478 paddress (gdbarch, pc));
3486 fprintf_unfiltered (gdb_stdlog,
3487 "infrun: pending event of %s cancelled.\n",
3488 target_pid_to_str (tp->ptid));
3490 tp->suspend.waitstatus.kind = TARGET_WAITKIND_SPURIOUS;
3491 tp->suspend.stop_reason = TARGET_STOPPED_BY_NO_REASON;
3501 statstr = target_waitstatus_to_string (&tp->suspend.waitstatus);
3502 fprintf_unfiltered (gdb_stdlog,
3503 "infrun: Using pending wait status %s for %s.\n",
3505 target_pid_to_str (tp->ptid));
3509 /* Now that we've selected our final event LWP, un-adjust its PC
3510 if it was a software breakpoint (and the target doesn't
3511 always adjust the PC itself). */
3512 if (tp->suspend.stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT
3513 && !target_supports_stopped_by_sw_breakpoint ())
3515 struct regcache *regcache;
3516 struct gdbarch *gdbarch;
3519 regcache = get_thread_regcache (tp->ptid);
3520 gdbarch = get_regcache_arch (regcache);
3522 decr_pc = gdbarch_decr_pc_after_break (gdbarch);
3527 pc = regcache_read_pc (regcache);
3528 regcache_write_pc (regcache, pc + decr_pc);
3532 tp->suspend.stop_reason = TARGET_STOPPED_BY_NO_REASON;
3533 *status = tp->suspend.waitstatus;
3534 tp->suspend.waitstatus_pending_p = 0;
3536 /* Wake up the event loop again, until all pending events are
3538 if (target_is_async_p ())
3539 mark_async_event_handler (infrun_async_inferior_event_token);
3543 /* But if we don't find one, we'll have to wait. */
3545 if (deprecated_target_wait_hook)
3546 event_ptid = deprecated_target_wait_hook (ptid, status, options);
3548 event_ptid = target_wait (ptid, status, options);
3553 /* Prepare and stabilize the inferior for detaching it. E.g.,
3554 detaching while a thread is displaced stepping is a recipe for
3555 crashing it, as nothing would readjust the PC out of the scratch
3559 prepare_for_detach (void)
3561 struct inferior *inf = current_inferior ();
3562 ptid_t pid_ptid = pid_to_ptid (inf->pid);
3563 struct cleanup *old_chain_1;
3564 struct displaced_step_inferior_state *displaced;
3566 displaced = get_displaced_stepping_state (inf->pid);
3568 /* Is any thread of this process displaced stepping? If not,
3569 there's nothing else to do. */
3570 if (displaced == NULL || ptid_equal (displaced->step_ptid, null_ptid))
3574 fprintf_unfiltered (gdb_stdlog,
3575 "displaced-stepping in-process while detaching");
3577 old_chain_1 = make_cleanup_restore_integer (&inf->detaching);
3580 while (!ptid_equal (displaced->step_ptid, null_ptid))
3582 struct cleanup *old_chain_2;
3583 struct execution_control_state ecss;
3584 struct execution_control_state *ecs;
3587 memset (ecs, 0, sizeof (*ecs));
3589 overlay_cache_invalid = 1;
3590 /* Flush target cache before starting to handle each event.
3591 Target was running and cache could be stale. This is just a
3592 heuristic. Running threads may modify target memory, but we
3593 don't get any event. */
3594 target_dcache_invalidate ();
3596 ecs->ptid = do_target_wait (pid_ptid, &ecs->ws, 0);
3599 print_target_wait_results (pid_ptid, ecs->ptid, &ecs->ws);
3601 /* If an error happens while handling the event, propagate GDB's
3602 knowledge of the executing state to the frontend/user running
3604 old_chain_2 = make_cleanup (finish_thread_state_cleanup,
3607 /* Now figure out what to do with the result of the result. */
3608 handle_inferior_event (ecs);
3610 /* No error, don't finish the state yet. */
3611 discard_cleanups (old_chain_2);
3613 /* Breakpoints and watchpoints are not installed on the target
3614 at this point, and signals are passed directly to the
3615 inferior, so this must mean the process is gone. */
3616 if (!ecs->wait_some_more)
3618 discard_cleanups (old_chain_1);
3619 error (_("Program exited while detaching"));
3623 discard_cleanups (old_chain_1);
3626 /* Wait for control to return from inferior to debugger.
3628 If inferior gets a signal, we may decide to start it up again
3629 instead of returning. That is why there is a loop in this function.
3630 When this function actually returns it means the inferior
3631 should be left stopped and GDB should read more commands. */
3634 wait_for_inferior (void)
3636 struct cleanup *old_cleanups;
3637 struct cleanup *thread_state_chain;
3641 (gdb_stdlog, "infrun: wait_for_inferior ()\n");
3644 = make_cleanup (delete_just_stopped_threads_infrun_breakpoints_cleanup,
3647 /* If an error happens while handling the event, propagate GDB's
3648 knowledge of the executing state to the frontend/user running
3650 thread_state_chain = make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
3654 struct execution_control_state ecss;
3655 struct execution_control_state *ecs = &ecss;
3656 ptid_t waiton_ptid = minus_one_ptid;
3658 memset (ecs, 0, sizeof (*ecs));
3660 overlay_cache_invalid = 1;
3662 /* Flush target cache before starting to handle each event.
3663 Target was running and cache could be stale. This is just a
3664 heuristic. Running threads may modify target memory, but we
3665 don't get any event. */
3666 target_dcache_invalidate ();
3668 ecs->ptid = do_target_wait (waiton_ptid, &ecs->ws, 0);
3671 print_target_wait_results (waiton_ptid, ecs->ptid, &ecs->ws);
3673 /* Now figure out what to do with the result of the result. */
3674 handle_inferior_event (ecs);
3676 if (!ecs->wait_some_more)
3680 /* No error, don't finish the state yet. */
3681 discard_cleanups (thread_state_chain);
3683 do_cleanups (old_cleanups);
3686 /* Cleanup that reinstalls the readline callback handler, if the
3687 target is running in the background. If while handling the target
3688 event something triggered a secondary prompt, like e.g., a
3689 pagination prompt, we'll have removed the callback handler (see
3690 gdb_readline_wrapper_line). Need to do this as we go back to the
3691 event loop, ready to process further input. Note this has no
3692 effect if the handler hasn't actually been removed, because calling
3693 rl_callback_handler_install resets the line buffer, thus losing
3697 reinstall_readline_callback_handler_cleanup (void *arg)
3699 if (!interpreter_async)
3701 /* We're not going back to the top level event loop yet. Don't
3702 install the readline callback, as it'd prep the terminal,
3703 readline-style (raw, noecho) (e.g., --batch). We'll install
3704 it the next time the prompt is displayed, when we're ready
3709 if (async_command_editing_p && !sync_execution)
3710 gdb_rl_callback_handler_reinstall ();
3713 /* Asynchronous version of wait_for_inferior. It is called by the
3714 event loop whenever a change of state is detected on the file
3715 descriptor corresponding to the target. It can be called more than
3716 once to complete a single execution command. In such cases we need
3717 to keep the state in a global variable ECSS. If it is the last time
3718 that this function is called for a single execution command, then
3719 report to the user that the inferior has stopped, and do the
3720 necessary cleanups. */
3723 fetch_inferior_event (void *client_data)
3725 struct execution_control_state ecss;
3726 struct execution_control_state *ecs = &ecss;
3727 struct cleanup *old_chain = make_cleanup (null_cleanup, NULL);
3728 struct cleanup *ts_old_chain;
3729 int was_sync = sync_execution;
3731 ptid_t waiton_ptid = minus_one_ptid;
3733 memset (ecs, 0, sizeof (*ecs));
3735 /* End up with readline processing input, if necessary. */
3736 make_cleanup (reinstall_readline_callback_handler_cleanup, NULL);
3738 /* We're handling a live event, so make sure we're doing live
3739 debugging. If we're looking at traceframes while the target is
3740 running, we're going to need to get back to that mode after
3741 handling the event. */
3744 make_cleanup_restore_current_traceframe ();
3745 set_current_traceframe (-1);
3749 /* In non-stop mode, the user/frontend should not notice a thread
3750 switch due to internal events. Make sure we reverse to the
3751 user selected thread and frame after handling the event and
3752 running any breakpoint commands. */
3753 make_cleanup_restore_current_thread ();
3755 overlay_cache_invalid = 1;
3756 /* Flush target cache before starting to handle each event. Target
3757 was running and cache could be stale. This is just a heuristic.
3758 Running threads may modify target memory, but we don't get any
3760 target_dcache_invalidate ();
3762 make_cleanup_restore_integer (&execution_direction);
3763 execution_direction = target_execution_direction ();
3765 ecs->ptid = do_target_wait (waiton_ptid, &ecs->ws, TARGET_WNOHANG);
3768 print_target_wait_results (waiton_ptid, ecs->ptid, &ecs->ws);
3770 /* If an error happens while handling the event, propagate GDB's
3771 knowledge of the executing state to the frontend/user running
3773 if (!target_is_non_stop_p ())
3774 ts_old_chain = make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
3776 ts_old_chain = make_cleanup (finish_thread_state_cleanup, &ecs->ptid);
3778 /* Get executed before make_cleanup_restore_current_thread above to apply
3779 still for the thread which has thrown the exception. */
3780 make_bpstat_clear_actions_cleanup ();
3782 make_cleanup (delete_just_stopped_threads_infrun_breakpoints_cleanup, NULL);
3784 /* Now figure out what to do with the result of the result. */
3785 handle_inferior_event (ecs);
3787 if (!ecs->wait_some_more)
3789 struct inferior *inf = find_inferior_ptid (ecs->ptid);
3791 delete_just_stopped_threads_infrun_breakpoints ();
3793 /* We may not find an inferior if this was a process exit. */
3794 if (inf == NULL || inf->control.stop_soon == NO_STOP_QUIETLY)
3797 if (target_has_execution
3798 && ecs->ws.kind != TARGET_WAITKIND_NO_RESUMED
3799 && ecs->ws.kind != TARGET_WAITKIND_EXITED
3800 && ecs->ws.kind != TARGET_WAITKIND_SIGNALLED
3801 && ecs->event_thread->step_multi
3802 && ecs->event_thread->control.stop_step)
3803 inferior_event_handler (INF_EXEC_CONTINUE, NULL);
3806 inferior_event_handler (INF_EXEC_COMPLETE, NULL);
3811 /* No error, don't finish the thread states yet. */
3812 discard_cleanups (ts_old_chain);
3814 /* Revert thread and frame. */
3815 do_cleanups (old_chain);
3817 /* If the inferior was in sync execution mode, and now isn't,
3818 restore the prompt (a synchronous execution command has finished,
3819 and we're ready for input). */
3820 if (interpreter_async && was_sync && !sync_execution)
3821 observer_notify_sync_execution_done ();
3825 && exec_done_display_p
3826 && (ptid_equal (inferior_ptid, null_ptid)
3827 || !is_running (inferior_ptid)))
3828 printf_unfiltered (_("completed.\n"));
3831 /* Record the frame and location we're currently stepping through. */
3833 set_step_info (struct frame_info *frame, struct symtab_and_line sal)
3835 struct thread_info *tp = inferior_thread ();
3837 tp->control.step_frame_id = get_frame_id (frame);
3838 tp->control.step_stack_frame_id = get_stack_frame_id (frame);
3840 tp->current_symtab = sal.symtab;
3841 tp->current_line = sal.line;
3844 /* Clear context switchable stepping state. */
3847 init_thread_stepping_state (struct thread_info *tss)
3849 tss->stepped_breakpoint = 0;
3850 tss->stepping_over_breakpoint = 0;
3851 tss->stepping_over_watchpoint = 0;
3852 tss->step_after_step_resume_breakpoint = 0;
3855 /* Set the cached copy of the last ptid/waitstatus. */
3858 set_last_target_status (ptid_t ptid, struct target_waitstatus status)
3860 target_last_wait_ptid = ptid;
3861 target_last_waitstatus = status;
3864 /* Return the cached copy of the last pid/waitstatus returned by
3865 target_wait()/deprecated_target_wait_hook(). The data is actually
3866 cached by handle_inferior_event(), which gets called immediately
3867 after target_wait()/deprecated_target_wait_hook(). */
3870 get_last_target_status (ptid_t *ptidp, struct target_waitstatus *status)
3872 *ptidp = target_last_wait_ptid;
3873 *status = target_last_waitstatus;
3877 nullify_last_target_wait_ptid (void)
3879 target_last_wait_ptid = minus_one_ptid;
3882 /* Switch thread contexts. */
3885 context_switch (ptid_t ptid)
3887 if (debug_infrun && !ptid_equal (ptid, inferior_ptid))
3889 fprintf_unfiltered (gdb_stdlog, "infrun: Switching context from %s ",
3890 target_pid_to_str (inferior_ptid));
3891 fprintf_unfiltered (gdb_stdlog, "to %s\n",
3892 target_pid_to_str (ptid));
3895 switch_to_thread (ptid);
3898 /* If the target can't tell whether we've hit breakpoints
3899 (target_supports_stopped_by_sw_breakpoint), and we got a SIGTRAP,
3900 check whether that could have been caused by a breakpoint. If so,
3901 adjust the PC, per gdbarch_decr_pc_after_break. */
3904 adjust_pc_after_break (struct thread_info *thread,
3905 struct target_waitstatus *ws)
3907 struct regcache *regcache;
3908 struct gdbarch *gdbarch;
3909 struct address_space *aspace;
3910 CORE_ADDR breakpoint_pc, decr_pc;
3912 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
3913 we aren't, just return.
3915 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
3916 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
3917 implemented by software breakpoints should be handled through the normal
3920 NOTE drow/2004-01-31: On some targets, breakpoints may generate
3921 different signals (SIGILL or SIGEMT for instance), but it is less
3922 clear where the PC is pointing afterwards. It may not match
3923 gdbarch_decr_pc_after_break. I don't know any specific target that
3924 generates these signals at breakpoints (the code has been in GDB since at
3925 least 1992) so I can not guess how to handle them here.
3927 In earlier versions of GDB, a target with
3928 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
3929 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
3930 target with both of these set in GDB history, and it seems unlikely to be
3931 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
3933 if (ws->kind != TARGET_WAITKIND_STOPPED)
3936 if (ws->value.sig != GDB_SIGNAL_TRAP)
3939 /* In reverse execution, when a breakpoint is hit, the instruction
3940 under it has already been de-executed. The reported PC always
3941 points at the breakpoint address, so adjusting it further would
3942 be wrong. E.g., consider this case on a decr_pc_after_break == 1
3945 B1 0x08000000 : INSN1
3946 B2 0x08000001 : INSN2
3948 PC -> 0x08000003 : INSN4
3950 Say you're stopped at 0x08000003 as above. Reverse continuing
3951 from that point should hit B2 as below. Reading the PC when the
3952 SIGTRAP is reported should read 0x08000001 and INSN2 should have
3953 been de-executed already.
3955 B1 0x08000000 : INSN1
3956 B2 PC -> 0x08000001 : INSN2
3960 We can't apply the same logic as for forward execution, because
3961 we would wrongly adjust the PC to 0x08000000, since there's a
3962 breakpoint at PC - 1. We'd then report a hit on B1, although
3963 INSN1 hadn't been de-executed yet. Doing nothing is the correct
3965 if (execution_direction == EXEC_REVERSE)
3968 /* If the target can tell whether the thread hit a SW breakpoint,
3969 trust it. Targets that can tell also adjust the PC
3971 if (target_supports_stopped_by_sw_breakpoint ())
3974 /* Note that relying on whether a breakpoint is planted in memory to
3975 determine this can fail. E.g,. the breakpoint could have been
3976 removed since. Or the thread could have been told to step an
3977 instruction the size of a breakpoint instruction, and only
3978 _after_ was a breakpoint inserted at its address. */
3980 /* If this target does not decrement the PC after breakpoints, then
3981 we have nothing to do. */
3982 regcache = get_thread_regcache (thread->ptid);
3983 gdbarch = get_regcache_arch (regcache);
3985 decr_pc = gdbarch_decr_pc_after_break (gdbarch);
3989 aspace = get_regcache_aspace (regcache);
3991 /* Find the location where (if we've hit a breakpoint) the
3992 breakpoint would be. */
3993 breakpoint_pc = regcache_read_pc (regcache) - decr_pc;
3995 /* If the target can't tell whether a software breakpoint triggered,
3996 fallback to figuring it out based on breakpoints we think were
3997 inserted in the target, and on whether the thread was stepped or
4000 /* Check whether there actually is a software breakpoint inserted at
4003 If in non-stop mode, a race condition is possible where we've
4004 removed a breakpoint, but stop events for that breakpoint were
4005 already queued and arrive later. To suppress those spurious
4006 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
4007 and retire them after a number of stop events are reported. Note
4008 this is an heuristic and can thus get confused. The real fix is
4009 to get the "stopped by SW BP and needs adjustment" info out of
4010 the target/kernel (and thus never reach here; see above). */
4011 if (software_breakpoint_inserted_here_p (aspace, breakpoint_pc)
4012 || (target_is_non_stop_p ()
4013 && moribund_breakpoint_here_p (aspace, breakpoint_pc)))
4015 struct cleanup *old_cleanups = make_cleanup (null_cleanup, NULL);
4017 if (record_full_is_used ())
4018 record_full_gdb_operation_disable_set ();
4020 /* When using hardware single-step, a SIGTRAP is reported for both
4021 a completed single-step and a software breakpoint. Need to
4022 differentiate between the two, as the latter needs adjusting
4023 but the former does not.
4025 The SIGTRAP can be due to a completed hardware single-step only if
4026 - we didn't insert software single-step breakpoints
4027 - this thread is currently being stepped
4029 If any of these events did not occur, we must have stopped due
4030 to hitting a software breakpoint, and have to back up to the
4033 As a special case, we could have hardware single-stepped a
4034 software breakpoint. In this case (prev_pc == breakpoint_pc),
4035 we also need to back up to the breakpoint address. */
4037 if (thread_has_single_step_breakpoints_set (thread)
4038 || !currently_stepping (thread)
4039 || (thread->stepped_breakpoint
4040 && thread->prev_pc == breakpoint_pc))
4041 regcache_write_pc (regcache, breakpoint_pc);
4043 do_cleanups (old_cleanups);
4048 stepped_in_from (struct frame_info *frame, struct frame_id step_frame_id)
4050 for (frame = get_prev_frame (frame);
4052 frame = get_prev_frame (frame))
4054 if (frame_id_eq (get_frame_id (frame), step_frame_id))
4056 if (get_frame_type (frame) != INLINE_FRAME)
4063 /* Auxiliary function that handles syscall entry/return events.
4064 It returns 1 if the inferior should keep going (and GDB
4065 should ignore the event), or 0 if the event deserves to be
4069 handle_syscall_event (struct execution_control_state *ecs)
4071 struct regcache *regcache;
4074 if (!ptid_equal (ecs->ptid, inferior_ptid))
4075 context_switch (ecs->ptid);
4077 regcache = get_thread_regcache (ecs->ptid);
4078 syscall_number = ecs->ws.value.syscall_number;
4079 stop_pc = regcache_read_pc (regcache);
4081 if (catch_syscall_enabled () > 0
4082 && catching_syscall_number (syscall_number) > 0)
4085 fprintf_unfiltered (gdb_stdlog, "infrun: syscall number = '%d'\n",
4088 ecs->event_thread->control.stop_bpstat
4089 = bpstat_stop_status (get_regcache_aspace (regcache),
4090 stop_pc, ecs->ptid, &ecs->ws);
4092 if (bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
4094 /* Catchpoint hit. */
4099 /* If no catchpoint triggered for this, then keep going. */
4104 /* Lazily fill in the execution_control_state's stop_func_* fields. */
4107 fill_in_stop_func (struct gdbarch *gdbarch,
4108 struct execution_control_state *ecs)
4110 if (!ecs->stop_func_filled_in)
4112 /* Don't care about return value; stop_func_start and stop_func_name
4113 will both be 0 if it doesn't work. */
4114 find_pc_partial_function (stop_pc, &ecs->stop_func_name,
4115 &ecs->stop_func_start, &ecs->stop_func_end);
4116 ecs->stop_func_start
4117 += gdbarch_deprecated_function_start_offset (gdbarch);
4119 if (gdbarch_skip_entrypoint_p (gdbarch))
4120 ecs->stop_func_start = gdbarch_skip_entrypoint (gdbarch,
4121 ecs->stop_func_start);
4123 ecs->stop_func_filled_in = 1;
4128 /* Return the STOP_SOON field of the inferior pointed at by PTID. */
4130 static enum stop_kind
4131 get_inferior_stop_soon (ptid_t ptid)
4133 struct inferior *inf = find_inferior_ptid (ptid);
4135 gdb_assert (inf != NULL);
4136 return inf->control.stop_soon;
4139 /* Wait for one event. Store the resulting waitstatus in WS, and
4140 return the event ptid. */
4143 wait_one (struct target_waitstatus *ws)
4146 ptid_t wait_ptid = minus_one_ptid;
4148 overlay_cache_invalid = 1;
4150 /* Flush target cache before starting to handle each event.
4151 Target was running and cache could be stale. This is just a
4152 heuristic. Running threads may modify target memory, but we
4153 don't get any event. */
4154 target_dcache_invalidate ();
4156 if (deprecated_target_wait_hook)
4157 event_ptid = deprecated_target_wait_hook (wait_ptid, ws, 0);
4159 event_ptid = target_wait (wait_ptid, ws, 0);
4162 print_target_wait_results (wait_ptid, event_ptid, ws);
4167 /* Generate a wrapper for target_stopped_by_REASON that works on PTID
4168 instead of the current thread. */
4169 #define THREAD_STOPPED_BY(REASON) \
4171 thread_stopped_by_ ## REASON (ptid_t ptid) \
4173 struct cleanup *old_chain; \
4176 old_chain = save_inferior_ptid (); \
4177 inferior_ptid = ptid; \
4179 res = target_stopped_by_ ## REASON (); \
4181 do_cleanups (old_chain); \
4186 /* Generate thread_stopped_by_watchpoint. */
4187 THREAD_STOPPED_BY (watchpoint)
4188 /* Generate thread_stopped_by_sw_breakpoint. */
4189 THREAD_STOPPED_BY (sw_breakpoint)
4190 /* Generate thread_stopped_by_hw_breakpoint. */
4191 THREAD_STOPPED_BY (hw_breakpoint)
4193 /* Cleanups that switches to the PTID pointed at by PTID_P. */
4196 switch_to_thread_cleanup (void *ptid_p)
4198 ptid_t ptid = *(ptid_t *) ptid_p;
4200 switch_to_thread (ptid);
4203 /* Save the thread's event and stop reason to process it later. */
4206 save_waitstatus (struct thread_info *tp, struct target_waitstatus *ws)
4208 struct regcache *regcache;
4209 struct address_space *aspace;
4215 statstr = target_waitstatus_to_string (ws);
4216 fprintf_unfiltered (gdb_stdlog,
4217 "infrun: saving status %s for %d.%ld.%ld\n",
4219 ptid_get_pid (tp->ptid),
4220 ptid_get_lwp (tp->ptid),
4221 ptid_get_tid (tp->ptid));
4225 /* Record for later. */
4226 tp->suspend.waitstatus = *ws;
4227 tp->suspend.waitstatus_pending_p = 1;
4229 regcache = get_thread_regcache (tp->ptid);
4230 aspace = get_regcache_aspace (regcache);
4232 if (ws->kind == TARGET_WAITKIND_STOPPED
4233 && ws->value.sig == GDB_SIGNAL_TRAP)
4235 CORE_ADDR pc = regcache_read_pc (regcache);
4237 adjust_pc_after_break (tp, &tp->suspend.waitstatus);
4239 if (thread_stopped_by_watchpoint (tp->ptid))
4241 tp->suspend.stop_reason
4242 = TARGET_STOPPED_BY_WATCHPOINT;
4244 else if (target_supports_stopped_by_sw_breakpoint ()
4245 && thread_stopped_by_sw_breakpoint (tp->ptid))
4247 tp->suspend.stop_reason
4248 = TARGET_STOPPED_BY_SW_BREAKPOINT;
4250 else if (target_supports_stopped_by_hw_breakpoint ()
4251 && thread_stopped_by_hw_breakpoint (tp->ptid))
4253 tp->suspend.stop_reason
4254 = TARGET_STOPPED_BY_HW_BREAKPOINT;
4256 else if (!target_supports_stopped_by_hw_breakpoint ()
4257 && hardware_breakpoint_inserted_here_p (aspace,
4260 tp->suspend.stop_reason
4261 = TARGET_STOPPED_BY_HW_BREAKPOINT;
4263 else if (!target_supports_stopped_by_sw_breakpoint ()
4264 && software_breakpoint_inserted_here_p (aspace,
4267 tp->suspend.stop_reason
4268 = TARGET_STOPPED_BY_SW_BREAKPOINT;
4270 else if (!thread_has_single_step_breakpoints_set (tp)
4271 && currently_stepping (tp))
4273 tp->suspend.stop_reason
4274 = TARGET_STOPPED_BY_SINGLE_STEP;
4279 /* Stop all threads. */
4282 stop_all_threads (void)
4284 /* We may need multiple passes to discover all threads. */
4288 struct cleanup *old_chain;
4290 gdb_assert (target_is_non_stop_p ());
4293 fprintf_unfiltered (gdb_stdlog, "infrun: stop_all_threads\n");
4295 entry_ptid = inferior_ptid;
4296 old_chain = make_cleanup (switch_to_thread_cleanup, &entry_ptid);
4298 /* Request threads to stop, and then wait for the stops. Because
4299 threads we already know about can spawn more threads while we're
4300 trying to stop them, and we only learn about new threads when we
4301 update the thread list, do this in a loop, and keep iterating
4302 until two passes find no threads that need to be stopped. */
4303 for (pass = 0; pass < 2; pass++, iterations++)
4306 fprintf_unfiltered (gdb_stdlog,
4307 "infrun: stop_all_threads, pass=%d, "
4308 "iterations=%d\n", pass, iterations);
4312 struct target_waitstatus ws;
4314 struct thread_info *t;
4316 update_thread_list ();
4318 /* Go through all threads looking for threads that we need
4319 to tell the target to stop. */
4320 ALL_NON_EXITED_THREADS (t)
4324 /* If already stopping, don't request a stop again.
4325 We just haven't seen the notification yet. */
4326 if (!t->stop_requested)
4329 fprintf_unfiltered (gdb_stdlog,
4330 "infrun: %s executing, "
4332 target_pid_to_str (t->ptid));
4333 target_stop (t->ptid);
4334 t->stop_requested = 1;
4339 fprintf_unfiltered (gdb_stdlog,
4340 "infrun: %s executing, "
4341 "already stopping\n",
4342 target_pid_to_str (t->ptid));
4345 if (t->stop_requested)
4351 fprintf_unfiltered (gdb_stdlog,
4352 "infrun: %s not executing\n",
4353 target_pid_to_str (t->ptid));
4355 /* The thread may be not executing, but still be
4356 resumed with a pending status to process. */
4364 /* If we find new threads on the second iteration, restart
4365 over. We want to see two iterations in a row with all
4370 event_ptid = wait_one (&ws);
4371 if (ws.kind == TARGET_WAITKIND_NO_RESUMED)
4373 /* All resumed threads exited. */
4375 else if (ws.kind == TARGET_WAITKIND_EXITED
4376 || ws.kind == TARGET_WAITKIND_SIGNALLED)
4380 ptid_t ptid = pid_to_ptid (ws.value.integer);
4382 fprintf_unfiltered (gdb_stdlog,
4383 "infrun: %s exited while "
4384 "stopping threads\n",
4385 target_pid_to_str (ptid));
4390 t = find_thread_ptid (event_ptid);
4392 t = add_thread (event_ptid);
4394 t->stop_requested = 0;
4397 t->control.may_range_step = 0;
4399 if (ws.kind == TARGET_WAITKIND_STOPPED
4400 && ws.value.sig == GDB_SIGNAL_0)
4402 /* We caught the event that we intended to catch, so
4403 there's no event pending. */
4404 t->suspend.waitstatus.kind = TARGET_WAITKIND_IGNORE;
4405 t->suspend.waitstatus_pending_p = 0;
4407 if (displaced_step_fixup (t->ptid, GDB_SIGNAL_0) < 0)
4409 /* Add it back to the step-over queue. */
4412 fprintf_unfiltered (gdb_stdlog,
4413 "infrun: displaced-step of %s "
4414 "canceled: adding back to the "
4415 "step-over queue\n",
4416 target_pid_to_str (t->ptid));
4418 t->control.trap_expected = 0;
4419 thread_step_over_chain_enqueue (t);
4424 enum gdb_signal sig;
4425 struct regcache *regcache;
4426 struct address_space *aspace;
4432 statstr = target_waitstatus_to_string (&ws);
4433 fprintf_unfiltered (gdb_stdlog,
4434 "infrun: target_wait %s, saving "
4435 "status for %d.%ld.%ld\n",
4437 ptid_get_pid (t->ptid),
4438 ptid_get_lwp (t->ptid),
4439 ptid_get_tid (t->ptid));
4443 /* Record for later. */
4444 save_waitstatus (t, &ws);
4446 sig = (ws.kind == TARGET_WAITKIND_STOPPED
4447 ? ws.value.sig : GDB_SIGNAL_0);
4449 if (displaced_step_fixup (t->ptid, sig) < 0)
4451 /* Add it back to the step-over queue. */
4452 t->control.trap_expected = 0;
4453 thread_step_over_chain_enqueue (t);
4456 regcache = get_thread_regcache (t->ptid);
4457 t->suspend.stop_pc = regcache_read_pc (regcache);
4461 fprintf_unfiltered (gdb_stdlog,
4462 "infrun: saved stop_pc=%s for %s "
4463 "(currently_stepping=%d)\n",
4464 paddress (target_gdbarch (),
4465 t->suspend.stop_pc),
4466 target_pid_to_str (t->ptid),
4467 currently_stepping (t));
4474 do_cleanups (old_chain);
4477 fprintf_unfiltered (gdb_stdlog, "infrun: stop_all_threads done\n");
4480 /* Given an execution control state that has been freshly filled in by
4481 an event from the inferior, figure out what it means and take
4484 The alternatives are:
4486 1) stop_waiting and return; to really stop and return to the
4489 2) keep_going and return; to wait for the next event (set
4490 ecs->event_thread->stepping_over_breakpoint to 1 to single step
4494 handle_inferior_event_1 (struct execution_control_state *ecs)
4496 enum stop_kind stop_soon;
4498 if (ecs->ws.kind == TARGET_WAITKIND_IGNORE)
4500 /* We had an event in the inferior, but we are not interested in
4501 handling it at this level. The lower layers have already
4502 done what needs to be done, if anything.
4504 One of the possible circumstances for this is when the
4505 inferior produces output for the console. The inferior has
4506 not stopped, and we are ignoring the event. Another possible
4507 circumstance is any event which the lower level knows will be
4508 reported multiple times without an intervening resume. */
4510 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_IGNORE\n");
4511 prepare_to_wait (ecs);
4515 if (ecs->ws.kind == TARGET_WAITKIND_NO_RESUMED
4516 && target_can_async_p () && !sync_execution)
4518 /* There were no unwaited-for children left in the target, but,
4519 we're not synchronously waiting for events either. Just
4520 ignore. Otherwise, if we were running a synchronous
4521 execution command, we need to cancel it and give the user
4522 back the terminal. */
4524 fprintf_unfiltered (gdb_stdlog,
4525 "infrun: TARGET_WAITKIND_NO_RESUMED (ignoring)\n");
4526 prepare_to_wait (ecs);
4530 /* Cache the last pid/waitstatus. */
4531 set_last_target_status (ecs->ptid, ecs->ws);
4533 /* Always clear state belonging to the previous time we stopped. */
4534 stop_stack_dummy = STOP_NONE;
4536 if (ecs->ws.kind == TARGET_WAITKIND_NO_RESUMED)
4538 /* No unwaited-for children left. IOW, all resumed children
4541 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_NO_RESUMED\n");
4543 stop_print_frame = 0;
4548 if (ecs->ws.kind != TARGET_WAITKIND_EXITED
4549 && ecs->ws.kind != TARGET_WAITKIND_SIGNALLED)
4551 ecs->event_thread = find_thread_ptid (ecs->ptid);
4552 /* If it's a new thread, add it to the thread database. */
4553 if (ecs->event_thread == NULL)
4554 ecs->event_thread = add_thread (ecs->ptid);
4556 /* Disable range stepping. If the next step request could use a
4557 range, this will be end up re-enabled then. */
4558 ecs->event_thread->control.may_range_step = 0;
4561 /* Dependent on valid ECS->EVENT_THREAD. */
4562 adjust_pc_after_break (ecs->event_thread, &ecs->ws);
4564 /* Dependent on the current PC value modified by adjust_pc_after_break. */
4565 reinit_frame_cache ();
4567 breakpoint_retire_moribund ();
4569 /* First, distinguish signals caused by the debugger from signals
4570 that have to do with the program's own actions. Note that
4571 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
4572 on the operating system version. Here we detect when a SIGILL or
4573 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
4574 something similar for SIGSEGV, since a SIGSEGV will be generated
4575 when we're trying to execute a breakpoint instruction on a
4576 non-executable stack. This happens for call dummy breakpoints
4577 for architectures like SPARC that place call dummies on the
4579 if (ecs->ws.kind == TARGET_WAITKIND_STOPPED
4580 && (ecs->ws.value.sig == GDB_SIGNAL_ILL
4581 || ecs->ws.value.sig == GDB_SIGNAL_SEGV
4582 || ecs->ws.value.sig == GDB_SIGNAL_EMT))
4584 struct regcache *regcache = get_thread_regcache (ecs->ptid);
4586 if (breakpoint_inserted_here_p (get_regcache_aspace (regcache),
4587 regcache_read_pc (regcache)))
4590 fprintf_unfiltered (gdb_stdlog,
4591 "infrun: Treating signal as SIGTRAP\n");
4592 ecs->ws.value.sig = GDB_SIGNAL_TRAP;
4596 /* Mark the non-executing threads accordingly. In all-stop, all
4597 threads of all processes are stopped when we get any event
4598 reported. In non-stop mode, only the event thread stops. */
4602 if (!target_is_non_stop_p ())
4603 mark_ptid = minus_one_ptid;
4604 else if (ecs->ws.kind == TARGET_WAITKIND_SIGNALLED
4605 || ecs->ws.kind == TARGET_WAITKIND_EXITED)
4607 /* If we're handling a process exit in non-stop mode, even
4608 though threads haven't been deleted yet, one would think
4609 that there is nothing to do, as threads of the dead process
4610 will be soon deleted, and threads of any other process were
4611 left running. However, on some targets, threads survive a
4612 process exit event. E.g., for the "checkpoint" command,
4613 when the current checkpoint/fork exits, linux-fork.c
4614 automatically switches to another fork from within
4615 target_mourn_inferior, by associating the same
4616 inferior/thread to another fork. We haven't mourned yet at
4617 this point, but we must mark any threads left in the
4618 process as not-executing so that finish_thread_state marks
4619 them stopped (in the user's perspective) if/when we present
4620 the stop to the user. */
4621 mark_ptid = pid_to_ptid (ptid_get_pid (ecs->ptid));
4624 mark_ptid = ecs->ptid;
4626 set_executing (mark_ptid, 0);
4628 /* Likewise the resumed flag. */
4629 set_resumed (mark_ptid, 0);
4632 switch (ecs->ws.kind)
4634 case TARGET_WAITKIND_LOADED:
4636 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_LOADED\n");
4637 if (!ptid_equal (ecs->ptid, inferior_ptid))
4638 context_switch (ecs->ptid);
4639 /* Ignore gracefully during startup of the inferior, as it might
4640 be the shell which has just loaded some objects, otherwise
4641 add the symbols for the newly loaded objects. Also ignore at
4642 the beginning of an attach or remote session; we will query
4643 the full list of libraries once the connection is
4646 stop_soon = get_inferior_stop_soon (ecs->ptid);
4647 if (stop_soon == NO_STOP_QUIETLY)
4649 struct regcache *regcache;
4651 regcache = get_thread_regcache (ecs->ptid);
4653 handle_solib_event ();
4655 ecs->event_thread->control.stop_bpstat
4656 = bpstat_stop_status (get_regcache_aspace (regcache),
4657 stop_pc, ecs->ptid, &ecs->ws);
4659 if (bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
4661 /* A catchpoint triggered. */
4662 process_event_stop_test (ecs);
4666 /* If requested, stop when the dynamic linker notifies
4667 gdb of events. This allows the user to get control
4668 and place breakpoints in initializer routines for
4669 dynamically loaded objects (among other things). */
4670 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
4671 if (stop_on_solib_events)
4673 /* Make sure we print "Stopped due to solib-event" in
4675 stop_print_frame = 1;
4682 /* If we are skipping through a shell, or through shared library
4683 loading that we aren't interested in, resume the program. If
4684 we're running the program normally, also resume. */
4685 if (stop_soon == STOP_QUIETLY || stop_soon == NO_STOP_QUIETLY)
4687 /* Loading of shared libraries might have changed breakpoint
4688 addresses. Make sure new breakpoints are inserted. */
4689 if (stop_soon == NO_STOP_QUIETLY)
4690 insert_breakpoints ();
4691 resume (GDB_SIGNAL_0);
4692 prepare_to_wait (ecs);
4696 /* But stop if we're attaching or setting up a remote
4698 if (stop_soon == STOP_QUIETLY_NO_SIGSTOP
4699 || stop_soon == STOP_QUIETLY_REMOTE)
4702 fprintf_unfiltered (gdb_stdlog, "infrun: quietly stopped\n");
4707 internal_error (__FILE__, __LINE__,
4708 _("unhandled stop_soon: %d"), (int) stop_soon);
4710 case TARGET_WAITKIND_SPURIOUS:
4712 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_SPURIOUS\n");
4713 if (!ptid_equal (ecs->ptid, inferior_ptid))
4714 context_switch (ecs->ptid);
4715 resume (GDB_SIGNAL_0);
4716 prepare_to_wait (ecs);
4719 case TARGET_WAITKIND_EXITED:
4720 case TARGET_WAITKIND_SIGNALLED:
4723 if (ecs->ws.kind == TARGET_WAITKIND_EXITED)
4724 fprintf_unfiltered (gdb_stdlog,
4725 "infrun: TARGET_WAITKIND_EXITED\n");
4727 fprintf_unfiltered (gdb_stdlog,
4728 "infrun: TARGET_WAITKIND_SIGNALLED\n");
4731 inferior_ptid = ecs->ptid;
4732 set_current_inferior (find_inferior_ptid (ecs->ptid));
4733 set_current_program_space (current_inferior ()->pspace);
4734 handle_vfork_child_exec_or_exit (0);
4735 target_terminal_ours (); /* Must do this before mourn anyway. */
4737 /* Clearing any previous state of convenience variables. */
4738 clear_exit_convenience_vars ();
4740 if (ecs->ws.kind == TARGET_WAITKIND_EXITED)
4742 /* Record the exit code in the convenience variable $_exitcode, so
4743 that the user can inspect this again later. */
4744 set_internalvar_integer (lookup_internalvar ("_exitcode"),
4745 (LONGEST) ecs->ws.value.integer);
4747 /* Also record this in the inferior itself. */
4748 current_inferior ()->has_exit_code = 1;
4749 current_inferior ()->exit_code = (LONGEST) ecs->ws.value.integer;
4751 /* Support the --return-child-result option. */
4752 return_child_result_value = ecs->ws.value.integer;
4754 observer_notify_exited (ecs->ws.value.integer);
4758 struct regcache *regcache = get_thread_regcache (ecs->ptid);
4759 struct gdbarch *gdbarch = get_regcache_arch (regcache);
4761 if (gdbarch_gdb_signal_to_target_p (gdbarch))
4763 /* Set the value of the internal variable $_exitsignal,
4764 which holds the signal uncaught by the inferior. */
4765 set_internalvar_integer (lookup_internalvar ("_exitsignal"),
4766 gdbarch_gdb_signal_to_target (gdbarch,
4767 ecs->ws.value.sig));
4771 /* We don't have access to the target's method used for
4772 converting between signal numbers (GDB's internal
4773 representation <-> target's representation).
4774 Therefore, we cannot do a good job at displaying this
4775 information to the user. It's better to just warn
4776 her about it (if infrun debugging is enabled), and
4779 fprintf_filtered (gdb_stdlog, _("\
4780 Cannot fill $_exitsignal with the correct signal number.\n"));
4783 observer_notify_signal_exited (ecs->ws.value.sig);
4786 gdb_flush (gdb_stdout);
4787 target_mourn_inferior ();
4788 stop_print_frame = 0;
4792 /* The following are the only cases in which we keep going;
4793 the above cases end in a continue or goto. */
4794 case TARGET_WAITKIND_FORKED:
4795 case TARGET_WAITKIND_VFORKED:
4798 if (ecs->ws.kind == TARGET_WAITKIND_FORKED)
4799 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_FORKED\n");
4801 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_VFORKED\n");
4804 /* Check whether the inferior is displaced stepping. */
4806 struct regcache *regcache = get_thread_regcache (ecs->ptid);
4807 struct gdbarch *gdbarch = get_regcache_arch (regcache);
4808 struct displaced_step_inferior_state *displaced
4809 = get_displaced_stepping_state (ptid_get_pid (ecs->ptid));
4811 /* If checking displaced stepping is supported, and thread
4812 ecs->ptid is displaced stepping. */
4813 if (displaced && ptid_equal (displaced->step_ptid, ecs->ptid))
4815 struct inferior *parent_inf
4816 = find_inferior_ptid (ecs->ptid);
4817 struct regcache *child_regcache;
4818 CORE_ADDR parent_pc;
4820 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
4821 indicating that the displaced stepping of syscall instruction
4822 has been done. Perform cleanup for parent process here. Note
4823 that this operation also cleans up the child process for vfork,
4824 because their pages are shared. */
4825 displaced_step_fixup (ecs->ptid, GDB_SIGNAL_TRAP);
4826 /* Start a new step-over in another thread if there's one
4830 if (ecs->ws.kind == TARGET_WAITKIND_FORKED)
4832 /* Restore scratch pad for child process. */
4833 displaced_step_restore (displaced, ecs->ws.value.related_pid);
4836 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
4837 the child's PC is also within the scratchpad. Set the child's PC
4838 to the parent's PC value, which has already been fixed up.
4839 FIXME: we use the parent's aspace here, although we're touching
4840 the child, because the child hasn't been added to the inferior
4841 list yet at this point. */
4844 = get_thread_arch_aspace_regcache (ecs->ws.value.related_pid,
4846 parent_inf->aspace);
4847 /* Read PC value of parent process. */
4848 parent_pc = regcache_read_pc (regcache);
4850 if (debug_displaced)
4851 fprintf_unfiltered (gdb_stdlog,
4852 "displaced: write child pc from %s to %s\n",
4854 regcache_read_pc (child_regcache)),
4855 paddress (gdbarch, parent_pc));
4857 regcache_write_pc (child_regcache, parent_pc);
4861 if (!ptid_equal (ecs->ptid, inferior_ptid))
4862 context_switch (ecs->ptid);
4864 /* Immediately detach breakpoints from the child before there's
4865 any chance of letting the user delete breakpoints from the
4866 breakpoint lists. If we don't do this early, it's easy to
4867 leave left over traps in the child, vis: "break foo; catch
4868 fork; c; <fork>; del; c; <child calls foo>". We only follow
4869 the fork on the last `continue', and by that time the
4870 breakpoint at "foo" is long gone from the breakpoint table.
4871 If we vforked, then we don't need to unpatch here, since both
4872 parent and child are sharing the same memory pages; we'll
4873 need to unpatch at follow/detach time instead to be certain
4874 that new breakpoints added between catchpoint hit time and
4875 vfork follow are detached. */
4876 if (ecs->ws.kind != TARGET_WAITKIND_VFORKED)
4878 /* This won't actually modify the breakpoint list, but will
4879 physically remove the breakpoints from the child. */
4880 detach_breakpoints (ecs->ws.value.related_pid);
4883 delete_just_stopped_threads_single_step_breakpoints ();
4885 /* In case the event is caught by a catchpoint, remember that
4886 the event is to be followed at the next resume of the thread,
4887 and not immediately. */
4888 ecs->event_thread->pending_follow = ecs->ws;
4890 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
4892 ecs->event_thread->control.stop_bpstat
4893 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
4894 stop_pc, ecs->ptid, &ecs->ws);
4896 /* If no catchpoint triggered for this, then keep going. Note
4897 that we're interested in knowing the bpstat actually causes a
4898 stop, not just if it may explain the signal. Software
4899 watchpoints, for example, always appear in the bpstat. */
4900 if (!bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
4906 = (follow_fork_mode_string == follow_fork_mode_child);
4908 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
4910 should_resume = follow_fork ();
4913 child = ecs->ws.value.related_pid;
4915 /* In non-stop mode, also resume the other branch. */
4916 if (!detach_fork && (non_stop
4917 || (sched_multi && target_is_non_stop_p ())))
4920 switch_to_thread (parent);
4922 switch_to_thread (child);
4924 ecs->event_thread = inferior_thread ();
4925 ecs->ptid = inferior_ptid;
4930 switch_to_thread (child);
4932 switch_to_thread (parent);
4934 ecs->event_thread = inferior_thread ();
4935 ecs->ptid = inferior_ptid;
4943 process_event_stop_test (ecs);
4946 case TARGET_WAITKIND_VFORK_DONE:
4947 /* Done with the shared memory region. Re-insert breakpoints in
4948 the parent, and keep going. */
4951 fprintf_unfiltered (gdb_stdlog,
4952 "infrun: TARGET_WAITKIND_VFORK_DONE\n");
4954 if (!ptid_equal (ecs->ptid, inferior_ptid))
4955 context_switch (ecs->ptid);
4957 current_inferior ()->waiting_for_vfork_done = 0;
4958 current_inferior ()->pspace->breakpoints_not_allowed = 0;
4959 /* This also takes care of reinserting breakpoints in the
4960 previously locked inferior. */
4964 case TARGET_WAITKIND_EXECD:
4966 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_EXECD\n");
4968 if (!ptid_equal (ecs->ptid, inferior_ptid))
4969 context_switch (ecs->ptid);
4971 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
4973 /* Do whatever is necessary to the parent branch of the vfork. */
4974 handle_vfork_child_exec_or_exit (1);
4976 /* This causes the eventpoints and symbol table to be reset.
4977 Must do this now, before trying to determine whether to
4979 follow_exec (inferior_ptid, ecs->ws.value.execd_pathname);
4981 ecs->event_thread->control.stop_bpstat
4982 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
4983 stop_pc, ecs->ptid, &ecs->ws);
4985 /* Note that this may be referenced from inside
4986 bpstat_stop_status above, through inferior_has_execd. */
4987 xfree (ecs->ws.value.execd_pathname);
4988 ecs->ws.value.execd_pathname = NULL;
4990 /* If no catchpoint triggered for this, then keep going. */
4991 if (!bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
4993 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
4997 process_event_stop_test (ecs);
5000 /* Be careful not to try to gather much state about a thread
5001 that's in a syscall. It's frequently a losing proposition. */
5002 case TARGET_WAITKIND_SYSCALL_ENTRY:
5004 fprintf_unfiltered (gdb_stdlog,
5005 "infrun: TARGET_WAITKIND_SYSCALL_ENTRY\n");
5006 /* Getting the current syscall number. */
5007 if (handle_syscall_event (ecs) == 0)
5008 process_event_stop_test (ecs);
5011 /* Before examining the threads further, step this thread to
5012 get it entirely out of the syscall. (We get notice of the
5013 event when the thread is just on the verge of exiting a
5014 syscall. Stepping one instruction seems to get it back
5016 case TARGET_WAITKIND_SYSCALL_RETURN:
5018 fprintf_unfiltered (gdb_stdlog,
5019 "infrun: TARGET_WAITKIND_SYSCALL_RETURN\n");
5020 if (handle_syscall_event (ecs) == 0)
5021 process_event_stop_test (ecs);
5024 case TARGET_WAITKIND_STOPPED:
5026 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_STOPPED\n");
5027 ecs->event_thread->suspend.stop_signal = ecs->ws.value.sig;
5028 handle_signal_stop (ecs);
5031 case TARGET_WAITKIND_NO_HISTORY:
5033 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_NO_HISTORY\n");
5034 /* Reverse execution: target ran out of history info. */
5036 delete_just_stopped_threads_single_step_breakpoints ();
5037 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
5038 observer_notify_no_history ();
5044 /* A wrapper around handle_inferior_event_1, which also makes sure
5045 that all temporary struct value objects that were created during
5046 the handling of the event get deleted at the end. */
5049 handle_inferior_event (struct execution_control_state *ecs)
5051 struct value *mark = value_mark ();
5053 handle_inferior_event_1 (ecs);
5054 /* Purge all temporary values created during the event handling,
5055 as it could be a long time before we return to the command level
5056 where such values would otherwise be purged. */
5057 value_free_to_mark (mark);
5060 /* Restart threads back to what they were trying to do back when we
5061 paused them for an in-line step-over. The EVENT_THREAD thread is
5065 restart_threads (struct thread_info *event_thread)
5067 struct thread_info *tp;
5068 struct thread_info *step_over = NULL;
5070 /* In case the instruction just stepped spawned a new thread. */
5071 update_thread_list ();
5073 ALL_NON_EXITED_THREADS (tp)
5075 if (tp == event_thread)
5078 fprintf_unfiltered (gdb_stdlog,
5079 "infrun: restart threads: "
5080 "[%s] is event thread\n",
5081 target_pid_to_str (tp->ptid));
5085 if (!(tp->state == THREAD_RUNNING || tp->control.in_infcall))
5088 fprintf_unfiltered (gdb_stdlog,
5089 "infrun: restart threads: "
5090 "[%s] not meant to be running\n",
5091 target_pid_to_str (tp->ptid));
5098 fprintf_unfiltered (gdb_stdlog,
5099 "infrun: restart threads: [%s] resumed\n",
5100 target_pid_to_str (tp->ptid));
5101 gdb_assert (tp->executing || tp->suspend.waitstatus_pending_p);
5105 if (thread_is_in_step_over_chain (tp))
5108 fprintf_unfiltered (gdb_stdlog,
5109 "infrun: restart threads: "
5110 "[%s] needs step-over\n",
5111 target_pid_to_str (tp->ptid));
5112 gdb_assert (!tp->resumed);
5117 if (tp->suspend.waitstatus_pending_p)
5120 fprintf_unfiltered (gdb_stdlog,
5121 "infrun: restart threads: "
5122 "[%s] has pending status\n",
5123 target_pid_to_str (tp->ptid));
5128 /* If some thread needs to start a step-over at this point, it
5129 should still be in the step-over queue, and thus skipped
5131 if (thread_still_needs_step_over (tp))
5133 internal_error (__FILE__, __LINE__,
5134 "thread [%s] needs a step-over, but not in "
5135 "step-over queue\n",
5136 target_pid_to_str (tp->ptid));
5139 if (currently_stepping (tp))
5142 fprintf_unfiltered (gdb_stdlog,
5143 "infrun: restart threads: [%s] was stepping\n",
5144 target_pid_to_str (tp->ptid));
5145 keep_going_stepped_thread (tp);
5149 struct execution_control_state ecss;
5150 struct execution_control_state *ecs = &ecss;
5153 fprintf_unfiltered (gdb_stdlog,
5154 "infrun: restart threads: [%s] continuing\n",
5155 target_pid_to_str (tp->ptid));
5156 reset_ecs (ecs, tp);
5157 switch_to_thread (tp->ptid);
5158 keep_going_pass_signal (ecs);
5163 /* Callback for iterate_over_threads. Find a resumed thread that has
5164 a pending waitstatus. */
5167 resumed_thread_with_pending_status (struct thread_info *tp,
5171 && tp->suspend.waitstatus_pending_p);
5174 /* Called when we get an event that may finish an in-line or
5175 out-of-line (displaced stepping) step-over started previously.
5176 Return true if the event is processed and we should go back to the
5177 event loop; false if the caller should continue processing the
5181 finish_step_over (struct execution_control_state *ecs)
5183 int had_step_over_info;
5185 displaced_step_fixup (ecs->ptid,
5186 ecs->event_thread->suspend.stop_signal);
5188 had_step_over_info = step_over_info_valid_p ();
5190 if (had_step_over_info)
5192 /* If we're stepping over a breakpoint with all threads locked,
5193 then only the thread that was stepped should be reporting
5195 gdb_assert (ecs->event_thread->control.trap_expected);
5197 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
5198 clear_step_over_info ();
5201 if (!target_is_non_stop_p ())
5204 /* Start a new step-over in another thread if there's one that
5208 /* If we were stepping over a breakpoint before, and haven't started
5209 a new in-line step-over sequence, then restart all other threads
5210 (except the event thread). We can't do this in all-stop, as then
5211 e.g., we wouldn't be able to issue any other remote packet until
5212 these other threads stop. */
5213 if (had_step_over_info && !step_over_info_valid_p ())
5215 struct thread_info *pending;
5217 /* If we only have threads with pending statuses, the restart
5218 below won't restart any thread and so nothing re-inserts the
5219 breakpoint we just stepped over. But we need it inserted
5220 when we later process the pending events, otherwise if
5221 another thread has a pending event for this breakpoint too,
5222 we'd discard its event (because the breakpoint that
5223 originally caused the event was no longer inserted). */
5224 context_switch (ecs->ptid);
5225 insert_breakpoints ();
5227 restart_threads (ecs->event_thread);
5229 /* If we have events pending, go through handle_inferior_event
5230 again, picking up a pending event at random. This avoids
5231 thread starvation. */
5233 /* But not if we just stepped over a watchpoint in order to let
5234 the instruction execute so we can evaluate its expression.
5235 The set of watchpoints that triggered is recorded in the
5236 breakpoint objects themselves (see bp->watchpoint_triggered).
5237 If we processed another event first, that other event could
5238 clobber this info. */
5239 if (ecs->event_thread->stepping_over_watchpoint)
5242 pending = iterate_over_threads (resumed_thread_with_pending_status,
5244 if (pending != NULL)
5246 struct thread_info *tp = ecs->event_thread;
5247 struct regcache *regcache;
5251 fprintf_unfiltered (gdb_stdlog,
5252 "infrun: found resumed threads with "
5253 "pending events, saving status\n");
5256 gdb_assert (pending != tp);
5258 /* Record the event thread's event for later. */
5259 save_waitstatus (tp, &ecs->ws);
5260 /* This was cleared early, by handle_inferior_event. Set it
5261 so this pending event is considered by
5265 gdb_assert (!tp->executing);
5267 regcache = get_thread_regcache (tp->ptid);
5268 tp->suspend.stop_pc = regcache_read_pc (regcache);
5272 fprintf_unfiltered (gdb_stdlog,
5273 "infrun: saved stop_pc=%s for %s "
5274 "(currently_stepping=%d)\n",
5275 paddress (target_gdbarch (),
5276 tp->suspend.stop_pc),
5277 target_pid_to_str (tp->ptid),
5278 currently_stepping (tp));
5281 /* This in-line step-over finished; clear this so we won't
5282 start a new one. This is what handle_signal_stop would
5283 do, if we returned false. */
5284 tp->stepping_over_breakpoint = 0;
5286 /* Wake up the event loop again. */
5287 mark_async_event_handler (infrun_async_inferior_event_token);
5289 prepare_to_wait (ecs);
5297 /* Come here when the program has stopped with a signal. */
5300 handle_signal_stop (struct execution_control_state *ecs)
5302 struct frame_info *frame;
5303 struct gdbarch *gdbarch;
5304 int stopped_by_watchpoint;
5305 enum stop_kind stop_soon;
5308 gdb_assert (ecs->ws.kind == TARGET_WAITKIND_STOPPED);
5310 /* Do we need to clean up the state of a thread that has
5311 completed a displaced single-step? (Doing so usually affects
5312 the PC, so do it here, before we set stop_pc.) */
5313 if (finish_step_over (ecs))
5316 /* If we either finished a single-step or hit a breakpoint, but
5317 the user wanted this thread to be stopped, pretend we got a
5318 SIG0 (generic unsignaled stop). */
5319 if (ecs->event_thread->stop_requested
5320 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
5321 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5323 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
5327 struct regcache *regcache = get_thread_regcache (ecs->ptid);
5328 struct gdbarch *gdbarch = get_regcache_arch (regcache);
5329 struct cleanup *old_chain = save_inferior_ptid ();
5331 inferior_ptid = ecs->ptid;
5333 fprintf_unfiltered (gdb_stdlog, "infrun: stop_pc = %s\n",
5334 paddress (gdbarch, stop_pc));
5335 if (target_stopped_by_watchpoint ())
5339 fprintf_unfiltered (gdb_stdlog, "infrun: stopped by watchpoint\n");
5341 if (target_stopped_data_address (¤t_target, &addr))
5342 fprintf_unfiltered (gdb_stdlog,
5343 "infrun: stopped data address = %s\n",
5344 paddress (gdbarch, addr));
5346 fprintf_unfiltered (gdb_stdlog,
5347 "infrun: (no data address available)\n");
5350 do_cleanups (old_chain);
5353 /* This is originated from start_remote(), start_inferior() and
5354 shared libraries hook functions. */
5355 stop_soon = get_inferior_stop_soon (ecs->ptid);
5356 if (stop_soon == STOP_QUIETLY || stop_soon == STOP_QUIETLY_REMOTE)
5358 if (!ptid_equal (ecs->ptid, inferior_ptid))
5359 context_switch (ecs->ptid);
5361 fprintf_unfiltered (gdb_stdlog, "infrun: quietly stopped\n");
5362 stop_print_frame = 1;
5367 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5370 if (!ptid_equal (ecs->ptid, inferior_ptid))
5371 context_switch (ecs->ptid);
5373 fprintf_unfiltered (gdb_stdlog, "infrun: stopped\n");
5374 stop_print_frame = 0;
5379 /* This originates from attach_command(). We need to overwrite
5380 the stop_signal here, because some kernels don't ignore a
5381 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
5382 See more comments in inferior.h. On the other hand, if we
5383 get a non-SIGSTOP, report it to the user - assume the backend
5384 will handle the SIGSTOP if it should show up later.
5386 Also consider that the attach is complete when we see a
5387 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
5388 target extended-remote report it instead of a SIGSTOP
5389 (e.g. gdbserver). We already rely on SIGTRAP being our
5390 signal, so this is no exception.
5392 Also consider that the attach is complete when we see a
5393 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
5394 the target to stop all threads of the inferior, in case the
5395 low level attach operation doesn't stop them implicitly. If
5396 they weren't stopped implicitly, then the stub will report a
5397 GDB_SIGNAL_0, meaning: stopped for no particular reason
5398 other than GDB's request. */
5399 if (stop_soon == STOP_QUIETLY_NO_SIGSTOP
5400 && (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_STOP
5401 || ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5402 || ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_0))
5404 stop_print_frame = 1;
5406 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5410 /* See if something interesting happened to the non-current thread. If
5411 so, then switch to that thread. */
5412 if (!ptid_equal (ecs->ptid, inferior_ptid))
5415 fprintf_unfiltered (gdb_stdlog, "infrun: context switch\n");
5417 context_switch (ecs->ptid);
5419 if (deprecated_context_hook)
5420 deprecated_context_hook (pid_to_thread_id (ecs->ptid));
5423 /* At this point, get hold of the now-current thread's frame. */
5424 frame = get_current_frame ();
5425 gdbarch = get_frame_arch (frame);
5427 /* Pull the single step breakpoints out of the target. */
5428 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
5430 struct regcache *regcache;
5431 struct address_space *aspace;
5434 regcache = get_thread_regcache (ecs->ptid);
5435 aspace = get_regcache_aspace (regcache);
5436 pc = regcache_read_pc (regcache);
5438 /* However, before doing so, if this single-step breakpoint was
5439 actually for another thread, set this thread up for moving
5441 if (!thread_has_single_step_breakpoint_here (ecs->event_thread,
5444 if (single_step_breakpoint_inserted_here_p (aspace, pc))
5448 fprintf_unfiltered (gdb_stdlog,
5449 "infrun: [%s] hit another thread's "
5450 "single-step breakpoint\n",
5451 target_pid_to_str (ecs->ptid));
5453 ecs->hit_singlestep_breakpoint = 1;
5460 fprintf_unfiltered (gdb_stdlog,
5461 "infrun: [%s] hit its "
5462 "single-step breakpoint\n",
5463 target_pid_to_str (ecs->ptid));
5467 delete_just_stopped_threads_single_step_breakpoints ();
5469 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5470 && ecs->event_thread->control.trap_expected
5471 && ecs->event_thread->stepping_over_watchpoint)
5472 stopped_by_watchpoint = 0;
5474 stopped_by_watchpoint = watchpoints_triggered (&ecs->ws);
5476 /* If necessary, step over this watchpoint. We'll be back to display
5478 if (stopped_by_watchpoint
5479 && (target_have_steppable_watchpoint
5480 || gdbarch_have_nonsteppable_watchpoint (gdbarch)))
5482 /* At this point, we are stopped at an instruction which has
5483 attempted to write to a piece of memory under control of
5484 a watchpoint. The instruction hasn't actually executed
5485 yet. If we were to evaluate the watchpoint expression
5486 now, we would get the old value, and therefore no change
5487 would seem to have occurred.
5489 In order to make watchpoints work `right', we really need
5490 to complete the memory write, and then evaluate the
5491 watchpoint expression. We do this by single-stepping the
5494 It may not be necessary to disable the watchpoint to step over
5495 it. For example, the PA can (with some kernel cooperation)
5496 single step over a watchpoint without disabling the watchpoint.
5498 It is far more common to need to disable a watchpoint to step
5499 the inferior over it. If we have non-steppable watchpoints,
5500 we must disable the current watchpoint; it's simplest to
5501 disable all watchpoints.
5503 Any breakpoint at PC must also be stepped over -- if there's
5504 one, it will have already triggered before the watchpoint
5505 triggered, and we either already reported it to the user, or
5506 it didn't cause a stop and we called keep_going. In either
5507 case, if there was a breakpoint at PC, we must be trying to
5509 ecs->event_thread->stepping_over_watchpoint = 1;
5514 ecs->event_thread->stepping_over_breakpoint = 0;
5515 ecs->event_thread->stepping_over_watchpoint = 0;
5516 bpstat_clear (&ecs->event_thread->control.stop_bpstat);
5517 ecs->event_thread->control.stop_step = 0;
5518 stop_print_frame = 1;
5519 stopped_by_random_signal = 0;
5521 /* Hide inlined functions starting here, unless we just performed stepi or
5522 nexti. After stepi and nexti, always show the innermost frame (not any
5523 inline function call sites). */
5524 if (ecs->event_thread->control.step_range_end != 1)
5526 struct address_space *aspace =
5527 get_regcache_aspace (get_thread_regcache (ecs->ptid));
5529 /* skip_inline_frames is expensive, so we avoid it if we can
5530 determine that the address is one where functions cannot have
5531 been inlined. This improves performance with inferiors that
5532 load a lot of shared libraries, because the solib event
5533 breakpoint is defined as the address of a function (i.e. not
5534 inline). Note that we have to check the previous PC as well
5535 as the current one to catch cases when we have just
5536 single-stepped off a breakpoint prior to reinstating it.
5537 Note that we're assuming that the code we single-step to is
5538 not inline, but that's not definitive: there's nothing
5539 preventing the event breakpoint function from containing
5540 inlined code, and the single-step ending up there. If the
5541 user had set a breakpoint on that inlined code, the missing
5542 skip_inline_frames call would break things. Fortunately
5543 that's an extremely unlikely scenario. */
5544 if (!pc_at_non_inline_function (aspace, stop_pc, &ecs->ws)
5545 && !(ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5546 && ecs->event_thread->control.trap_expected
5547 && pc_at_non_inline_function (aspace,
5548 ecs->event_thread->prev_pc,
5551 skip_inline_frames (ecs->ptid);
5553 /* Re-fetch current thread's frame in case that invalidated
5555 frame = get_current_frame ();
5556 gdbarch = get_frame_arch (frame);
5560 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5561 && ecs->event_thread->control.trap_expected
5562 && gdbarch_single_step_through_delay_p (gdbarch)
5563 && currently_stepping (ecs->event_thread))
5565 /* We're trying to step off a breakpoint. Turns out that we're
5566 also on an instruction that needs to be stepped multiple
5567 times before it's been fully executing. E.g., architectures
5568 with a delay slot. It needs to be stepped twice, once for
5569 the instruction and once for the delay slot. */
5570 int step_through_delay
5571 = gdbarch_single_step_through_delay (gdbarch, frame);
5573 if (debug_infrun && step_through_delay)
5574 fprintf_unfiltered (gdb_stdlog, "infrun: step through delay\n");
5575 if (ecs->event_thread->control.step_range_end == 0
5576 && step_through_delay)
5578 /* The user issued a continue when stopped at a breakpoint.
5579 Set up for another trap and get out of here. */
5580 ecs->event_thread->stepping_over_breakpoint = 1;
5584 else if (step_through_delay)
5586 /* The user issued a step when stopped at a breakpoint.
5587 Maybe we should stop, maybe we should not - the delay
5588 slot *might* correspond to a line of source. In any
5589 case, don't decide that here, just set
5590 ecs->stepping_over_breakpoint, making sure we
5591 single-step again before breakpoints are re-inserted. */
5592 ecs->event_thread->stepping_over_breakpoint = 1;
5596 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
5597 handles this event. */
5598 ecs->event_thread->control.stop_bpstat
5599 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
5600 stop_pc, ecs->ptid, &ecs->ws);
5602 /* Following in case break condition called a
5604 stop_print_frame = 1;
5606 /* This is where we handle "moribund" watchpoints. Unlike
5607 software breakpoints traps, hardware watchpoint traps are
5608 always distinguishable from random traps. If no high-level
5609 watchpoint is associated with the reported stop data address
5610 anymore, then the bpstat does not explain the signal ---
5611 simply make sure to ignore it if `stopped_by_watchpoint' is
5615 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5616 && !bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
5618 && stopped_by_watchpoint)
5619 fprintf_unfiltered (gdb_stdlog,
5620 "infrun: no user watchpoint explains "
5621 "watchpoint SIGTRAP, ignoring\n");
5623 /* NOTE: cagney/2003-03-29: These checks for a random signal
5624 at one stage in the past included checks for an inferior
5625 function call's call dummy's return breakpoint. The original
5626 comment, that went with the test, read:
5628 ``End of a stack dummy. Some systems (e.g. Sony news) give
5629 another signal besides SIGTRAP, so check here as well as
5632 If someone ever tries to get call dummys on a
5633 non-executable stack to work (where the target would stop
5634 with something like a SIGSEGV), then those tests might need
5635 to be re-instated. Given, however, that the tests were only
5636 enabled when momentary breakpoints were not being used, I
5637 suspect that it won't be the case.
5639 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
5640 be necessary for call dummies on a non-executable stack on
5643 /* See if the breakpoints module can explain the signal. */
5645 = !bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
5646 ecs->event_thread->suspend.stop_signal);
5648 /* Maybe this was a trap for a software breakpoint that has since
5650 if (random_signal && target_stopped_by_sw_breakpoint ())
5652 if (program_breakpoint_here_p (gdbarch, stop_pc))
5654 struct regcache *regcache;
5657 /* Re-adjust PC to what the program would see if GDB was not
5659 regcache = get_thread_regcache (ecs->event_thread->ptid);
5660 decr_pc = gdbarch_decr_pc_after_break (gdbarch);
5663 struct cleanup *old_cleanups = make_cleanup (null_cleanup, NULL);
5665 if (record_full_is_used ())
5666 record_full_gdb_operation_disable_set ();
5668 regcache_write_pc (regcache, stop_pc + decr_pc);
5670 do_cleanups (old_cleanups);
5675 /* A delayed software breakpoint event. Ignore the trap. */
5677 fprintf_unfiltered (gdb_stdlog,
5678 "infrun: delayed software breakpoint "
5679 "trap, ignoring\n");
5684 /* Maybe this was a trap for a hardware breakpoint/watchpoint that
5685 has since been removed. */
5686 if (random_signal && target_stopped_by_hw_breakpoint ())
5688 /* A delayed hardware breakpoint event. Ignore the trap. */
5690 fprintf_unfiltered (gdb_stdlog,
5691 "infrun: delayed hardware breakpoint/watchpoint "
5692 "trap, ignoring\n");
5696 /* If not, perhaps stepping/nexting can. */
5698 random_signal = !(ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5699 && currently_stepping (ecs->event_thread));
5701 /* Perhaps the thread hit a single-step breakpoint of _another_
5702 thread. Single-step breakpoints are transparent to the
5703 breakpoints module. */
5705 random_signal = !ecs->hit_singlestep_breakpoint;
5707 /* No? Perhaps we got a moribund watchpoint. */
5709 random_signal = !stopped_by_watchpoint;
5711 /* For the program's own signals, act according to
5712 the signal handling tables. */
5716 /* Signal not for debugging purposes. */
5717 struct inferior *inf = find_inferior_ptid (ecs->ptid);
5718 enum gdb_signal stop_signal = ecs->event_thread->suspend.stop_signal;
5721 fprintf_unfiltered (gdb_stdlog, "infrun: random signal (%s)\n",
5722 gdb_signal_to_symbol_string (stop_signal));
5724 stopped_by_random_signal = 1;
5726 /* Always stop on signals if we're either just gaining control
5727 of the program, or the user explicitly requested this thread
5728 to remain stopped. */
5729 if (stop_soon != NO_STOP_QUIETLY
5730 || ecs->event_thread->stop_requested
5732 && signal_stop_state (ecs->event_thread->suspend.stop_signal)))
5738 /* Notify observers the signal has "handle print" set. Note we
5739 returned early above if stopping; normal_stop handles the
5740 printing in that case. */
5741 if (signal_print[ecs->event_thread->suspend.stop_signal])
5743 /* The signal table tells us to print about this signal. */
5744 target_terminal_ours_for_output ();
5745 observer_notify_signal_received (ecs->event_thread->suspend.stop_signal);
5746 target_terminal_inferior ();
5749 /* Clear the signal if it should not be passed. */
5750 if (signal_program[ecs->event_thread->suspend.stop_signal] == 0)
5751 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5753 if (ecs->event_thread->prev_pc == stop_pc
5754 && ecs->event_thread->control.trap_expected
5755 && ecs->event_thread->control.step_resume_breakpoint == NULL)
5759 /* We were just starting a new sequence, attempting to
5760 single-step off of a breakpoint and expecting a SIGTRAP.
5761 Instead this signal arrives. This signal will take us out
5762 of the stepping range so GDB needs to remember to, when
5763 the signal handler returns, resume stepping off that
5765 /* To simplify things, "continue" is forced to use the same
5766 code paths as single-step - set a breakpoint at the
5767 signal return address and then, once hit, step off that
5770 fprintf_unfiltered (gdb_stdlog,
5771 "infrun: signal arrived while stepping over "
5774 was_in_line = step_over_info_valid_p ();
5775 clear_step_over_info ();
5776 insert_hp_step_resume_breakpoint_at_frame (frame);
5777 ecs->event_thread->step_after_step_resume_breakpoint = 1;
5778 /* Reset trap_expected to ensure breakpoints are re-inserted. */
5779 ecs->event_thread->control.trap_expected = 0;
5781 if (target_is_non_stop_p ())
5783 /* Either "set non-stop" is "on", or the target is
5784 always in non-stop mode. In this case, we have a bit
5785 more work to do. Resume the current thread, and if
5786 we had paused all threads, restart them while the
5787 signal handler runs. */
5792 restart_threads (ecs->event_thread);
5794 else if (debug_infrun)
5796 fprintf_unfiltered (gdb_stdlog,
5797 "infrun: no need to restart threads\n");
5802 /* If we were nexting/stepping some other thread, switch to
5803 it, so that we don't continue it, losing control. */
5804 if (!switch_back_to_stepped_thread (ecs))
5809 if (ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_0
5810 && (pc_in_thread_step_range (stop_pc, ecs->event_thread)
5811 || ecs->event_thread->control.step_range_end == 1)
5812 && frame_id_eq (get_stack_frame_id (frame),
5813 ecs->event_thread->control.step_stack_frame_id)
5814 && ecs->event_thread->control.step_resume_breakpoint == NULL)
5816 /* The inferior is about to take a signal that will take it
5817 out of the single step range. Set a breakpoint at the
5818 current PC (which is presumably where the signal handler
5819 will eventually return) and then allow the inferior to
5822 Note that this is only needed for a signal delivered
5823 while in the single-step range. Nested signals aren't a
5824 problem as they eventually all return. */
5826 fprintf_unfiltered (gdb_stdlog,
5827 "infrun: signal may take us out of "
5828 "single-step range\n");
5830 clear_step_over_info ();
5831 insert_hp_step_resume_breakpoint_at_frame (frame);
5832 ecs->event_thread->step_after_step_resume_breakpoint = 1;
5833 /* Reset trap_expected to ensure breakpoints are re-inserted. */
5834 ecs->event_thread->control.trap_expected = 0;
5839 /* Note: step_resume_breakpoint may be non-NULL. This occures
5840 when either there's a nested signal, or when there's a
5841 pending signal enabled just as the signal handler returns
5842 (leaving the inferior at the step-resume-breakpoint without
5843 actually executing it). Either way continue until the
5844 breakpoint is really hit. */
5846 if (!switch_back_to_stepped_thread (ecs))
5849 fprintf_unfiltered (gdb_stdlog,
5850 "infrun: random signal, keep going\n");
5857 process_event_stop_test (ecs);
5860 /* Come here when we've got some debug event / signal we can explain
5861 (IOW, not a random signal), and test whether it should cause a
5862 stop, or whether we should resume the inferior (transparently).
5863 E.g., could be a breakpoint whose condition evaluates false; we
5864 could be still stepping within the line; etc. */
5867 process_event_stop_test (struct execution_control_state *ecs)
5869 struct symtab_and_line stop_pc_sal;
5870 struct frame_info *frame;
5871 struct gdbarch *gdbarch;
5872 CORE_ADDR jmp_buf_pc;
5873 struct bpstat_what what;
5875 /* Handle cases caused by hitting a breakpoint. */
5877 frame = get_current_frame ();
5878 gdbarch = get_frame_arch (frame);
5880 what = bpstat_what (ecs->event_thread->control.stop_bpstat);
5882 if (what.call_dummy)
5884 stop_stack_dummy = what.call_dummy;
5887 /* If we hit an internal event that triggers symbol changes, the
5888 current frame will be invalidated within bpstat_what (e.g., if we
5889 hit an internal solib event). Re-fetch it. */
5890 frame = get_current_frame ();
5891 gdbarch = get_frame_arch (frame);
5893 switch (what.main_action)
5895 case BPSTAT_WHAT_SET_LONGJMP_RESUME:
5896 /* If we hit the breakpoint at longjmp while stepping, we
5897 install a momentary breakpoint at the target of the
5901 fprintf_unfiltered (gdb_stdlog,
5902 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME\n");
5904 ecs->event_thread->stepping_over_breakpoint = 1;
5906 if (what.is_longjmp)
5908 struct value *arg_value;
5910 /* If we set the longjmp breakpoint via a SystemTap probe,
5911 then use it to extract the arguments. The destination PC
5912 is the third argument to the probe. */
5913 arg_value = probe_safe_evaluate_at_pc (frame, 2);
5916 jmp_buf_pc = value_as_address (arg_value);
5917 jmp_buf_pc = gdbarch_addr_bits_remove (gdbarch, jmp_buf_pc);
5919 else if (!gdbarch_get_longjmp_target_p (gdbarch)
5920 || !gdbarch_get_longjmp_target (gdbarch,
5921 frame, &jmp_buf_pc))
5924 fprintf_unfiltered (gdb_stdlog,
5925 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME "
5926 "(!gdbarch_get_longjmp_target)\n");
5931 /* Insert a breakpoint at resume address. */
5932 insert_longjmp_resume_breakpoint (gdbarch, jmp_buf_pc);
5935 check_exception_resume (ecs, frame);
5939 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME:
5941 struct frame_info *init_frame;
5943 /* There are several cases to consider.
5945 1. The initiating frame no longer exists. In this case we
5946 must stop, because the exception or longjmp has gone too
5949 2. The initiating frame exists, and is the same as the
5950 current frame. We stop, because the exception or longjmp
5953 3. The initiating frame exists and is different from the
5954 current frame. This means the exception or longjmp has
5955 been caught beneath the initiating frame, so keep going.
5957 4. longjmp breakpoint has been placed just to protect
5958 against stale dummy frames and user is not interested in
5959 stopping around longjmps. */
5962 fprintf_unfiltered (gdb_stdlog,
5963 "infrun: BPSTAT_WHAT_CLEAR_LONGJMP_RESUME\n");
5965 gdb_assert (ecs->event_thread->control.exception_resume_breakpoint
5967 delete_exception_resume_breakpoint (ecs->event_thread);
5969 if (what.is_longjmp)
5971 check_longjmp_breakpoint_for_call_dummy (ecs->event_thread);
5973 if (!frame_id_p (ecs->event_thread->initiating_frame))
5981 init_frame = frame_find_by_id (ecs->event_thread->initiating_frame);
5985 struct frame_id current_id
5986 = get_frame_id (get_current_frame ());
5987 if (frame_id_eq (current_id,
5988 ecs->event_thread->initiating_frame))
5990 /* Case 2. Fall through. */
6000 /* For Cases 1 and 2, remove the step-resume breakpoint, if it
6002 delete_step_resume_breakpoint (ecs->event_thread);
6004 end_stepping_range (ecs);
6008 case BPSTAT_WHAT_SINGLE:
6010 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_SINGLE\n");
6011 ecs->event_thread->stepping_over_breakpoint = 1;
6012 /* Still need to check other stuff, at least the case where we
6013 are stepping and step out of the right range. */
6016 case BPSTAT_WHAT_STEP_RESUME:
6018 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STEP_RESUME\n");
6020 delete_step_resume_breakpoint (ecs->event_thread);
6021 if (ecs->event_thread->control.proceed_to_finish
6022 && execution_direction == EXEC_REVERSE)
6024 struct thread_info *tp = ecs->event_thread;
6026 /* We are finishing a function in reverse, and just hit the
6027 step-resume breakpoint at the start address of the
6028 function, and we're almost there -- just need to back up
6029 by one more single-step, which should take us back to the
6031 tp->control.step_range_start = tp->control.step_range_end = 1;
6035 fill_in_stop_func (gdbarch, ecs);
6036 if (stop_pc == ecs->stop_func_start
6037 && execution_direction == EXEC_REVERSE)
6039 /* We are stepping over a function call in reverse, and just
6040 hit the step-resume breakpoint at the start address of
6041 the function. Go back to single-stepping, which should
6042 take us back to the function call. */
6043 ecs->event_thread->stepping_over_breakpoint = 1;
6049 case BPSTAT_WHAT_STOP_NOISY:
6051 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_NOISY\n");
6052 stop_print_frame = 1;
6054 /* Assume the thread stopped for a breapoint. We'll still check
6055 whether a/the breakpoint is there when the thread is next
6057 ecs->event_thread->stepping_over_breakpoint = 1;
6062 case BPSTAT_WHAT_STOP_SILENT:
6064 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_SILENT\n");
6065 stop_print_frame = 0;
6067 /* Assume the thread stopped for a breapoint. We'll still check
6068 whether a/the breakpoint is there when the thread is next
6070 ecs->event_thread->stepping_over_breakpoint = 1;
6074 case BPSTAT_WHAT_HP_STEP_RESUME:
6076 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_HP_STEP_RESUME\n");
6078 delete_step_resume_breakpoint (ecs->event_thread);
6079 if (ecs->event_thread->step_after_step_resume_breakpoint)
6081 /* Back when the step-resume breakpoint was inserted, we
6082 were trying to single-step off a breakpoint. Go back to
6084 ecs->event_thread->step_after_step_resume_breakpoint = 0;
6085 ecs->event_thread->stepping_over_breakpoint = 1;
6091 case BPSTAT_WHAT_KEEP_CHECKING:
6095 /* If we stepped a permanent breakpoint and we had a high priority
6096 step-resume breakpoint for the address we stepped, but we didn't
6097 hit it, then we must have stepped into the signal handler. The
6098 step-resume was only necessary to catch the case of _not_
6099 stepping into the handler, so delete it, and fall through to
6100 checking whether the step finished. */
6101 if (ecs->event_thread->stepped_breakpoint)
6103 struct breakpoint *sr_bp
6104 = ecs->event_thread->control.step_resume_breakpoint;
6107 && sr_bp->loc->permanent
6108 && sr_bp->type == bp_hp_step_resume
6109 && sr_bp->loc->address == ecs->event_thread->prev_pc)
6112 fprintf_unfiltered (gdb_stdlog,
6113 "infrun: stepped permanent breakpoint, stopped in "
6115 delete_step_resume_breakpoint (ecs->event_thread);
6116 ecs->event_thread->step_after_step_resume_breakpoint = 0;
6120 /* We come here if we hit a breakpoint but should not stop for it.
6121 Possibly we also were stepping and should stop for that. So fall
6122 through and test for stepping. But, if not stepping, do not
6125 /* In all-stop mode, if we're currently stepping but have stopped in
6126 some other thread, we need to switch back to the stepped thread. */
6127 if (switch_back_to_stepped_thread (ecs))
6130 if (ecs->event_thread->control.step_resume_breakpoint)
6133 fprintf_unfiltered (gdb_stdlog,
6134 "infrun: step-resume breakpoint is inserted\n");
6136 /* Having a step-resume breakpoint overrides anything
6137 else having to do with stepping commands until
6138 that breakpoint is reached. */
6143 if (ecs->event_thread->control.step_range_end == 0)
6146 fprintf_unfiltered (gdb_stdlog, "infrun: no stepping, continue\n");
6147 /* Likewise if we aren't even stepping. */
6152 /* Re-fetch current thread's frame in case the code above caused
6153 the frame cache to be re-initialized, making our FRAME variable
6154 a dangling pointer. */
6155 frame = get_current_frame ();
6156 gdbarch = get_frame_arch (frame);
6157 fill_in_stop_func (gdbarch, ecs);
6159 /* If stepping through a line, keep going if still within it.
6161 Note that step_range_end is the address of the first instruction
6162 beyond the step range, and NOT the address of the last instruction
6165 Note also that during reverse execution, we may be stepping
6166 through a function epilogue and therefore must detect when
6167 the current-frame changes in the middle of a line. */
6169 if (pc_in_thread_step_range (stop_pc, ecs->event_thread)
6170 && (execution_direction != EXEC_REVERSE
6171 || frame_id_eq (get_frame_id (frame),
6172 ecs->event_thread->control.step_frame_id)))
6176 (gdb_stdlog, "infrun: stepping inside range [%s-%s]\n",
6177 paddress (gdbarch, ecs->event_thread->control.step_range_start),
6178 paddress (gdbarch, ecs->event_thread->control.step_range_end));
6180 /* Tentatively re-enable range stepping; `resume' disables it if
6181 necessary (e.g., if we're stepping over a breakpoint or we
6182 have software watchpoints). */
6183 ecs->event_thread->control.may_range_step = 1;
6185 /* When stepping backward, stop at beginning of line range
6186 (unless it's the function entry point, in which case
6187 keep going back to the call point). */
6188 if (stop_pc == ecs->event_thread->control.step_range_start
6189 && stop_pc != ecs->stop_func_start
6190 && execution_direction == EXEC_REVERSE)
6191 end_stepping_range (ecs);
6198 /* We stepped out of the stepping range. */
6200 /* If we are stepping at the source level and entered the runtime
6201 loader dynamic symbol resolution code...
6203 EXEC_FORWARD: we keep on single stepping until we exit the run
6204 time loader code and reach the callee's address.
6206 EXEC_REVERSE: we've already executed the callee (backward), and
6207 the runtime loader code is handled just like any other
6208 undebuggable function call. Now we need only keep stepping
6209 backward through the trampoline code, and that's handled further
6210 down, so there is nothing for us to do here. */
6212 if (execution_direction != EXEC_REVERSE
6213 && ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6214 && in_solib_dynsym_resolve_code (stop_pc))
6216 CORE_ADDR pc_after_resolver =
6217 gdbarch_skip_solib_resolver (gdbarch, stop_pc);
6220 fprintf_unfiltered (gdb_stdlog,
6221 "infrun: stepped into dynsym resolve code\n");
6223 if (pc_after_resolver)
6225 /* Set up a step-resume breakpoint at the address
6226 indicated by SKIP_SOLIB_RESOLVER. */
6227 struct symtab_and_line sr_sal;
6230 sr_sal.pc = pc_after_resolver;
6231 sr_sal.pspace = get_frame_program_space (frame);
6233 insert_step_resume_breakpoint_at_sal (gdbarch,
6234 sr_sal, null_frame_id);
6241 if (ecs->event_thread->control.step_range_end != 1
6242 && (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6243 || ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
6244 && get_frame_type (frame) == SIGTRAMP_FRAME)
6247 fprintf_unfiltered (gdb_stdlog,
6248 "infrun: stepped into signal trampoline\n");
6249 /* The inferior, while doing a "step" or "next", has ended up in
6250 a signal trampoline (either by a signal being delivered or by
6251 the signal handler returning). Just single-step until the
6252 inferior leaves the trampoline (either by calling the handler
6258 /* If we're in the return path from a shared library trampoline,
6259 we want to proceed through the trampoline when stepping. */
6260 /* macro/2012-04-25: This needs to come before the subroutine
6261 call check below as on some targets return trampolines look
6262 like subroutine calls (MIPS16 return thunks). */
6263 if (gdbarch_in_solib_return_trampoline (gdbarch,
6264 stop_pc, ecs->stop_func_name)
6265 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE)
6267 /* Determine where this trampoline returns. */
6268 CORE_ADDR real_stop_pc;
6270 real_stop_pc = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc);
6273 fprintf_unfiltered (gdb_stdlog,
6274 "infrun: stepped into solib return tramp\n");
6276 /* Only proceed through if we know where it's going. */
6279 /* And put the step-breakpoint there and go until there. */
6280 struct symtab_and_line sr_sal;
6282 init_sal (&sr_sal); /* initialize to zeroes */
6283 sr_sal.pc = real_stop_pc;
6284 sr_sal.section = find_pc_overlay (sr_sal.pc);
6285 sr_sal.pspace = get_frame_program_space (frame);
6287 /* Do not specify what the fp should be when we stop since
6288 on some machines the prologue is where the new fp value
6290 insert_step_resume_breakpoint_at_sal (gdbarch,
6291 sr_sal, null_frame_id);
6293 /* Restart without fiddling with the step ranges or
6300 /* Check for subroutine calls. The check for the current frame
6301 equalling the step ID is not necessary - the check of the
6302 previous frame's ID is sufficient - but it is a common case and
6303 cheaper than checking the previous frame's ID.
6305 NOTE: frame_id_eq will never report two invalid frame IDs as
6306 being equal, so to get into this block, both the current and
6307 previous frame must have valid frame IDs. */
6308 /* The outer_frame_id check is a heuristic to detect stepping
6309 through startup code. If we step over an instruction which
6310 sets the stack pointer from an invalid value to a valid value,
6311 we may detect that as a subroutine call from the mythical
6312 "outermost" function. This could be fixed by marking
6313 outermost frames as !stack_p,code_p,special_p. Then the
6314 initial outermost frame, before sp was valid, would
6315 have code_addr == &_start. See the comment in frame_id_eq
6317 if (!frame_id_eq (get_stack_frame_id (frame),
6318 ecs->event_thread->control.step_stack_frame_id)
6319 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
6320 ecs->event_thread->control.step_stack_frame_id)
6321 && (!frame_id_eq (ecs->event_thread->control.step_stack_frame_id,
6323 || (ecs->event_thread->control.step_start_function
6324 != find_pc_function (stop_pc)))))
6326 CORE_ADDR real_stop_pc;
6329 fprintf_unfiltered (gdb_stdlog, "infrun: stepped into subroutine\n");
6331 if (ecs->event_thread->control.step_over_calls == STEP_OVER_NONE)
6333 /* I presume that step_over_calls is only 0 when we're
6334 supposed to be stepping at the assembly language level
6335 ("stepi"). Just stop. */
6336 /* And this works the same backward as frontward. MVS */
6337 end_stepping_range (ecs);
6341 /* Reverse stepping through solib trampolines. */
6343 if (execution_direction == EXEC_REVERSE
6344 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE
6345 && (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc)
6346 || (ecs->stop_func_start == 0
6347 && in_solib_dynsym_resolve_code (stop_pc))))
6349 /* Any solib trampoline code can be handled in reverse
6350 by simply continuing to single-step. We have already
6351 executed the solib function (backwards), and a few
6352 steps will take us back through the trampoline to the
6358 if (ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
6360 /* We're doing a "next".
6362 Normal (forward) execution: set a breakpoint at the
6363 callee's return address (the address at which the caller
6366 Reverse (backward) execution. set the step-resume
6367 breakpoint at the start of the function that we just
6368 stepped into (backwards), and continue to there. When we
6369 get there, we'll need to single-step back to the caller. */
6371 if (execution_direction == EXEC_REVERSE)
6373 /* If we're already at the start of the function, we've either
6374 just stepped backward into a single instruction function,
6375 or stepped back out of a signal handler to the first instruction
6376 of the function. Just keep going, which will single-step back
6378 if (ecs->stop_func_start != stop_pc && ecs->stop_func_start != 0)
6380 struct symtab_and_line sr_sal;
6382 /* Normal function call return (static or dynamic). */
6384 sr_sal.pc = ecs->stop_func_start;
6385 sr_sal.pspace = get_frame_program_space (frame);
6386 insert_step_resume_breakpoint_at_sal (gdbarch,
6387 sr_sal, null_frame_id);
6391 insert_step_resume_breakpoint_at_caller (frame);
6397 /* If we are in a function call trampoline (a stub between the
6398 calling routine and the real function), locate the real
6399 function. That's what tells us (a) whether we want to step
6400 into it at all, and (b) what prologue we want to run to the
6401 end of, if we do step into it. */
6402 real_stop_pc = skip_language_trampoline (frame, stop_pc);
6403 if (real_stop_pc == 0)
6404 real_stop_pc = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc);
6405 if (real_stop_pc != 0)
6406 ecs->stop_func_start = real_stop_pc;
6408 if (real_stop_pc != 0 && in_solib_dynsym_resolve_code (real_stop_pc))
6410 struct symtab_and_line sr_sal;
6413 sr_sal.pc = ecs->stop_func_start;
6414 sr_sal.pspace = get_frame_program_space (frame);
6416 insert_step_resume_breakpoint_at_sal (gdbarch,
6417 sr_sal, null_frame_id);
6422 /* If we have line number information for the function we are
6423 thinking of stepping into and the function isn't on the skip
6426 If there are several symtabs at that PC (e.g. with include
6427 files), just want to know whether *any* of them have line
6428 numbers. find_pc_line handles this. */
6430 struct symtab_and_line tmp_sal;
6432 tmp_sal = find_pc_line (ecs->stop_func_start, 0);
6433 if (tmp_sal.line != 0
6434 && !function_name_is_marked_for_skip (ecs->stop_func_name,
6437 if (execution_direction == EXEC_REVERSE)
6438 handle_step_into_function_backward (gdbarch, ecs);
6440 handle_step_into_function (gdbarch, ecs);
6445 /* If we have no line number and the step-stop-if-no-debug is
6446 set, we stop the step so that the user has a chance to switch
6447 in assembly mode. */
6448 if (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6449 && step_stop_if_no_debug)
6451 end_stepping_range (ecs);
6455 if (execution_direction == EXEC_REVERSE)
6457 /* If we're already at the start of the function, we've either just
6458 stepped backward into a single instruction function without line
6459 number info, or stepped back out of a signal handler to the first
6460 instruction of the function without line number info. Just keep
6461 going, which will single-step back to the caller. */
6462 if (ecs->stop_func_start != stop_pc)
6464 /* Set a breakpoint at callee's start address.
6465 From there we can step once and be back in the caller. */
6466 struct symtab_and_line sr_sal;
6469 sr_sal.pc = ecs->stop_func_start;
6470 sr_sal.pspace = get_frame_program_space (frame);
6471 insert_step_resume_breakpoint_at_sal (gdbarch,
6472 sr_sal, null_frame_id);
6476 /* Set a breakpoint at callee's return address (the address
6477 at which the caller will resume). */
6478 insert_step_resume_breakpoint_at_caller (frame);
6484 /* Reverse stepping through solib trampolines. */
6486 if (execution_direction == EXEC_REVERSE
6487 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE)
6489 if (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc)
6490 || (ecs->stop_func_start == 0
6491 && in_solib_dynsym_resolve_code (stop_pc)))
6493 /* Any solib trampoline code can be handled in reverse
6494 by simply continuing to single-step. We have already
6495 executed the solib function (backwards), and a few
6496 steps will take us back through the trampoline to the
6501 else if (in_solib_dynsym_resolve_code (stop_pc))
6503 /* Stepped backward into the solib dynsym resolver.
6504 Set a breakpoint at its start and continue, then
6505 one more step will take us out. */
6506 struct symtab_and_line sr_sal;
6509 sr_sal.pc = ecs->stop_func_start;
6510 sr_sal.pspace = get_frame_program_space (frame);
6511 insert_step_resume_breakpoint_at_sal (gdbarch,
6512 sr_sal, null_frame_id);
6518 stop_pc_sal = find_pc_line (stop_pc, 0);
6520 /* NOTE: tausq/2004-05-24: This if block used to be done before all
6521 the trampoline processing logic, however, there are some trampolines
6522 that have no names, so we should do trampoline handling first. */
6523 if (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6524 && ecs->stop_func_name == NULL
6525 && stop_pc_sal.line == 0)
6528 fprintf_unfiltered (gdb_stdlog,
6529 "infrun: stepped into undebuggable function\n");
6531 /* The inferior just stepped into, or returned to, an
6532 undebuggable function (where there is no debugging information
6533 and no line number corresponding to the address where the
6534 inferior stopped). Since we want to skip this kind of code,
6535 we keep going until the inferior returns from this
6536 function - unless the user has asked us not to (via
6537 set step-mode) or we no longer know how to get back
6538 to the call site. */
6539 if (step_stop_if_no_debug
6540 || !frame_id_p (frame_unwind_caller_id (frame)))
6542 /* If we have no line number and the step-stop-if-no-debug
6543 is set, we stop the step so that the user has a chance to
6544 switch in assembly mode. */
6545 end_stepping_range (ecs);
6550 /* Set a breakpoint at callee's return address (the address
6551 at which the caller will resume). */
6552 insert_step_resume_breakpoint_at_caller (frame);
6558 if (ecs->event_thread->control.step_range_end == 1)
6560 /* It is stepi or nexti. We always want to stop stepping after
6563 fprintf_unfiltered (gdb_stdlog, "infrun: stepi/nexti\n");
6564 end_stepping_range (ecs);
6568 if (stop_pc_sal.line == 0)
6570 /* We have no line number information. That means to stop
6571 stepping (does this always happen right after one instruction,
6572 when we do "s" in a function with no line numbers,
6573 or can this happen as a result of a return or longjmp?). */
6575 fprintf_unfiltered (gdb_stdlog, "infrun: no line number info\n");
6576 end_stepping_range (ecs);
6580 /* Look for "calls" to inlined functions, part one. If the inline
6581 frame machinery detected some skipped call sites, we have entered
6582 a new inline function. */
6584 if (frame_id_eq (get_frame_id (get_current_frame ()),
6585 ecs->event_thread->control.step_frame_id)
6586 && inline_skipped_frames (ecs->ptid))
6588 struct symtab_and_line call_sal;
6591 fprintf_unfiltered (gdb_stdlog,
6592 "infrun: stepped into inlined function\n");
6594 find_frame_sal (get_current_frame (), &call_sal);
6596 if (ecs->event_thread->control.step_over_calls != STEP_OVER_ALL)
6598 /* For "step", we're going to stop. But if the call site
6599 for this inlined function is on the same source line as
6600 we were previously stepping, go down into the function
6601 first. Otherwise stop at the call site. */
6603 if (call_sal.line == ecs->event_thread->current_line
6604 && call_sal.symtab == ecs->event_thread->current_symtab)
6605 step_into_inline_frame (ecs->ptid);
6607 end_stepping_range (ecs);
6612 /* For "next", we should stop at the call site if it is on a
6613 different source line. Otherwise continue through the
6614 inlined function. */
6615 if (call_sal.line == ecs->event_thread->current_line
6616 && call_sal.symtab == ecs->event_thread->current_symtab)
6619 end_stepping_range (ecs);
6624 /* Look for "calls" to inlined functions, part two. If we are still
6625 in the same real function we were stepping through, but we have
6626 to go further up to find the exact frame ID, we are stepping
6627 through a more inlined call beyond its call site. */
6629 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
6630 && !frame_id_eq (get_frame_id (get_current_frame ()),
6631 ecs->event_thread->control.step_frame_id)
6632 && stepped_in_from (get_current_frame (),
6633 ecs->event_thread->control.step_frame_id))
6636 fprintf_unfiltered (gdb_stdlog,
6637 "infrun: stepping through inlined function\n");
6639 if (ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
6642 end_stepping_range (ecs);
6646 if ((stop_pc == stop_pc_sal.pc)
6647 && (ecs->event_thread->current_line != stop_pc_sal.line
6648 || ecs->event_thread->current_symtab != stop_pc_sal.symtab))
6650 /* We are at the start of a different line. So stop. Note that
6651 we don't stop if we step into the middle of a different line.
6652 That is said to make things like for (;;) statements work
6655 fprintf_unfiltered (gdb_stdlog,
6656 "infrun: stepped to a different line\n");
6657 end_stepping_range (ecs);
6661 /* We aren't done stepping.
6663 Optimize by setting the stepping range to the line.
6664 (We might not be in the original line, but if we entered a
6665 new line in mid-statement, we continue stepping. This makes
6666 things like for(;;) statements work better.) */
6668 ecs->event_thread->control.step_range_start = stop_pc_sal.pc;
6669 ecs->event_thread->control.step_range_end = stop_pc_sal.end;
6670 ecs->event_thread->control.may_range_step = 1;
6671 set_step_info (frame, stop_pc_sal);
6674 fprintf_unfiltered (gdb_stdlog, "infrun: keep going\n");
6678 /* In all-stop mode, if we're currently stepping but have stopped in
6679 some other thread, we may need to switch back to the stepped
6680 thread. Returns true we set the inferior running, false if we left
6681 it stopped (and the event needs further processing). */
6684 switch_back_to_stepped_thread (struct execution_control_state *ecs)
6686 if (!target_is_non_stop_p ())
6688 struct thread_info *tp;
6689 struct thread_info *stepping_thread;
6691 /* If any thread is blocked on some internal breakpoint, and we
6692 simply need to step over that breakpoint to get it going
6693 again, do that first. */
6695 /* However, if we see an event for the stepping thread, then we
6696 know all other threads have been moved past their breakpoints
6697 already. Let the caller check whether the step is finished,
6698 etc., before deciding to move it past a breakpoint. */
6699 if (ecs->event_thread->control.step_range_end != 0)
6702 /* Check if the current thread is blocked on an incomplete
6703 step-over, interrupted by a random signal. */
6704 if (ecs->event_thread->control.trap_expected
6705 && ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_TRAP)
6709 fprintf_unfiltered (gdb_stdlog,
6710 "infrun: need to finish step-over of [%s]\n",
6711 target_pid_to_str (ecs->event_thread->ptid));
6717 /* Check if the current thread is blocked by a single-step
6718 breakpoint of another thread. */
6719 if (ecs->hit_singlestep_breakpoint)
6723 fprintf_unfiltered (gdb_stdlog,
6724 "infrun: need to step [%s] over single-step "
6726 target_pid_to_str (ecs->ptid));
6732 /* If this thread needs yet another step-over (e.g., stepping
6733 through a delay slot), do it first before moving on to
6735 if (thread_still_needs_step_over (ecs->event_thread))
6739 fprintf_unfiltered (gdb_stdlog,
6740 "infrun: thread [%s] still needs step-over\n",
6741 target_pid_to_str (ecs->event_thread->ptid));
6747 /* If scheduler locking applies even if not stepping, there's no
6748 need to walk over threads. Above we've checked whether the
6749 current thread is stepping. If some other thread not the
6750 event thread is stepping, then it must be that scheduler
6751 locking is not in effect. */
6752 if (schedlock_applies (ecs->event_thread))
6755 /* Otherwise, we no longer expect a trap in the current thread.
6756 Clear the trap_expected flag before switching back -- this is
6757 what keep_going does as well, if we call it. */
6758 ecs->event_thread->control.trap_expected = 0;
6760 /* Likewise, clear the signal if it should not be passed. */
6761 if (!signal_program[ecs->event_thread->suspend.stop_signal])
6762 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
6764 /* Do all pending step-overs before actually proceeding with
6766 if (start_step_over ())
6768 prepare_to_wait (ecs);
6772 /* Look for the stepping/nexting thread. */
6773 stepping_thread = NULL;
6775 ALL_NON_EXITED_THREADS (tp)
6777 /* Ignore threads of processes the caller is not
6780 && ptid_get_pid (tp->ptid) != ptid_get_pid (ecs->ptid))
6783 /* When stepping over a breakpoint, we lock all threads
6784 except the one that needs to move past the breakpoint.
6785 If a non-event thread has this set, the "incomplete
6786 step-over" check above should have caught it earlier. */
6787 if (tp->control.trap_expected)
6789 internal_error (__FILE__, __LINE__,
6790 "[%s] has inconsistent state: "
6791 "trap_expected=%d\n",
6792 target_pid_to_str (tp->ptid),
6793 tp->control.trap_expected);
6796 /* Did we find the stepping thread? */
6797 if (tp->control.step_range_end)
6799 /* Yep. There should only one though. */
6800 gdb_assert (stepping_thread == NULL);
6802 /* The event thread is handled at the top, before we
6804 gdb_assert (tp != ecs->event_thread);
6806 /* If some thread other than the event thread is
6807 stepping, then scheduler locking can't be in effect,
6808 otherwise we wouldn't have resumed the current event
6809 thread in the first place. */
6810 gdb_assert (!schedlock_applies (tp));
6812 stepping_thread = tp;
6816 if (stepping_thread != NULL)
6819 fprintf_unfiltered (gdb_stdlog,
6820 "infrun: switching back to stepped thread\n");
6822 if (keep_going_stepped_thread (stepping_thread))
6824 prepare_to_wait (ecs);
6833 /* Set a previously stepped thread back to stepping. Returns true on
6834 success, false if the resume is not possible (e.g., the thread
6838 keep_going_stepped_thread (struct thread_info *tp)
6840 struct frame_info *frame;
6841 struct gdbarch *gdbarch;
6842 struct execution_control_state ecss;
6843 struct execution_control_state *ecs = &ecss;
6845 /* If the stepping thread exited, then don't try to switch back and
6846 resume it, which could fail in several different ways depending
6847 on the target. Instead, just keep going.
6849 We can find a stepping dead thread in the thread list in two
6852 - The target supports thread exit events, and when the target
6853 tries to delete the thread from the thread list, inferior_ptid
6854 pointed at the exiting thread. In such case, calling
6855 delete_thread does not really remove the thread from the list;
6856 instead, the thread is left listed, with 'exited' state.
6858 - The target's debug interface does not support thread exit
6859 events, and so we have no idea whatsoever if the previously
6860 stepping thread is still alive. For that reason, we need to
6861 synchronously query the target now. */
6863 if (is_exited (tp->ptid)
6864 || !target_thread_alive (tp->ptid))
6867 fprintf_unfiltered (gdb_stdlog,
6868 "infrun: not resuming previously "
6869 "stepped thread, it has vanished\n");
6871 delete_thread (tp->ptid);
6876 fprintf_unfiltered (gdb_stdlog,
6877 "infrun: resuming previously stepped thread\n");
6879 reset_ecs (ecs, tp);
6880 switch_to_thread (tp->ptid);
6882 stop_pc = regcache_read_pc (get_thread_regcache (tp->ptid));
6883 frame = get_current_frame ();
6884 gdbarch = get_frame_arch (frame);
6886 /* If the PC of the thread we were trying to single-step has
6887 changed, then that thread has trapped or been signaled, but the
6888 event has not been reported to GDB yet. Re-poll the target
6889 looking for this particular thread's event (i.e. temporarily
6890 enable schedlock) by:
6892 - setting a break at the current PC
6893 - resuming that particular thread, only (by setting trap
6896 This prevents us continuously moving the single-step breakpoint
6897 forward, one instruction at a time, overstepping. */
6899 if (stop_pc != tp->prev_pc)
6904 fprintf_unfiltered (gdb_stdlog,
6905 "infrun: expected thread advanced also (%s -> %s)\n",
6906 paddress (target_gdbarch (), tp->prev_pc),
6907 paddress (target_gdbarch (), stop_pc));
6909 /* Clear the info of the previous step-over, as it's no longer
6910 valid (if the thread was trying to step over a breakpoint, it
6911 has already succeeded). It's what keep_going would do too,
6912 if we called it. Do this before trying to insert the sss
6913 breakpoint, otherwise if we were previously trying to step
6914 over this exact address in another thread, the breakpoint is
6916 clear_step_over_info ();
6917 tp->control.trap_expected = 0;
6919 insert_single_step_breakpoint (get_frame_arch (frame),
6920 get_frame_address_space (frame),
6924 resume_ptid = internal_resume_ptid (tp->control.stepping_command);
6925 do_target_resume (resume_ptid, 0, GDB_SIGNAL_0);
6930 fprintf_unfiltered (gdb_stdlog,
6931 "infrun: expected thread still hasn't advanced\n");
6933 keep_going_pass_signal (ecs);
6938 /* Is thread TP in the middle of (software or hardware)
6939 single-stepping? (Note the result of this function must never be
6940 passed directly as target_resume's STEP parameter.) */
6943 currently_stepping (struct thread_info *tp)
6945 return ((tp->control.step_range_end
6946 && tp->control.step_resume_breakpoint == NULL)
6947 || tp->control.trap_expected
6948 || tp->stepped_breakpoint
6949 || bpstat_should_step ());
6952 /* Inferior has stepped into a subroutine call with source code that
6953 we should not step over. Do step to the first line of code in
6957 handle_step_into_function (struct gdbarch *gdbarch,
6958 struct execution_control_state *ecs)
6960 struct compunit_symtab *cust;
6961 struct symtab_and_line stop_func_sal, sr_sal;
6963 fill_in_stop_func (gdbarch, ecs);
6965 cust = find_pc_compunit_symtab (stop_pc);
6966 if (cust != NULL && compunit_language (cust) != language_asm)
6967 ecs->stop_func_start = gdbarch_skip_prologue (gdbarch,
6968 ecs->stop_func_start);
6970 stop_func_sal = find_pc_line (ecs->stop_func_start, 0);
6971 /* Use the step_resume_break to step until the end of the prologue,
6972 even if that involves jumps (as it seems to on the vax under
6974 /* If the prologue ends in the middle of a source line, continue to
6975 the end of that source line (if it is still within the function).
6976 Otherwise, just go to end of prologue. */
6977 if (stop_func_sal.end
6978 && stop_func_sal.pc != ecs->stop_func_start
6979 && stop_func_sal.end < ecs->stop_func_end)
6980 ecs->stop_func_start = stop_func_sal.end;
6982 /* Architectures which require breakpoint adjustment might not be able
6983 to place a breakpoint at the computed address. If so, the test
6984 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
6985 ecs->stop_func_start to an address at which a breakpoint may be
6986 legitimately placed.
6988 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
6989 made, GDB will enter an infinite loop when stepping through
6990 optimized code consisting of VLIW instructions which contain
6991 subinstructions corresponding to different source lines. On
6992 FR-V, it's not permitted to place a breakpoint on any but the
6993 first subinstruction of a VLIW instruction. When a breakpoint is
6994 set, GDB will adjust the breakpoint address to the beginning of
6995 the VLIW instruction. Thus, we need to make the corresponding
6996 adjustment here when computing the stop address. */
6998 if (gdbarch_adjust_breakpoint_address_p (gdbarch))
7000 ecs->stop_func_start
7001 = gdbarch_adjust_breakpoint_address (gdbarch,
7002 ecs->stop_func_start);
7005 if (ecs->stop_func_start == stop_pc)
7007 /* We are already there: stop now. */
7008 end_stepping_range (ecs);
7013 /* Put the step-breakpoint there and go until there. */
7014 init_sal (&sr_sal); /* initialize to zeroes */
7015 sr_sal.pc = ecs->stop_func_start;
7016 sr_sal.section = find_pc_overlay (ecs->stop_func_start);
7017 sr_sal.pspace = get_frame_program_space (get_current_frame ());
7019 /* Do not specify what the fp should be when we stop since on
7020 some machines the prologue is where the new fp value is
7022 insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal, null_frame_id);
7024 /* And make sure stepping stops right away then. */
7025 ecs->event_thread->control.step_range_end
7026 = ecs->event_thread->control.step_range_start;
7031 /* Inferior has stepped backward into a subroutine call with source
7032 code that we should not step over. Do step to the beginning of the
7033 last line of code in it. */
7036 handle_step_into_function_backward (struct gdbarch *gdbarch,
7037 struct execution_control_state *ecs)
7039 struct compunit_symtab *cust;
7040 struct symtab_and_line stop_func_sal;
7042 fill_in_stop_func (gdbarch, ecs);
7044 cust = find_pc_compunit_symtab (stop_pc);
7045 if (cust != NULL && compunit_language (cust) != language_asm)
7046 ecs->stop_func_start = gdbarch_skip_prologue (gdbarch,
7047 ecs->stop_func_start);
7049 stop_func_sal = find_pc_line (stop_pc, 0);
7051 /* OK, we're just going to keep stepping here. */
7052 if (stop_func_sal.pc == stop_pc)
7054 /* We're there already. Just stop stepping now. */
7055 end_stepping_range (ecs);
7059 /* Else just reset the step range and keep going.
7060 No step-resume breakpoint, they don't work for
7061 epilogues, which can have multiple entry paths. */
7062 ecs->event_thread->control.step_range_start = stop_func_sal.pc;
7063 ecs->event_thread->control.step_range_end = stop_func_sal.end;
7069 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
7070 This is used to both functions and to skip over code. */
7073 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch *gdbarch,
7074 struct symtab_and_line sr_sal,
7075 struct frame_id sr_id,
7076 enum bptype sr_type)
7078 /* There should never be more than one step-resume or longjmp-resume
7079 breakpoint per thread, so we should never be setting a new
7080 step_resume_breakpoint when one is already active. */
7081 gdb_assert (inferior_thread ()->control.step_resume_breakpoint == NULL);
7082 gdb_assert (sr_type == bp_step_resume || sr_type == bp_hp_step_resume);
7085 fprintf_unfiltered (gdb_stdlog,
7086 "infrun: inserting step-resume breakpoint at %s\n",
7087 paddress (gdbarch, sr_sal.pc));
7089 inferior_thread ()->control.step_resume_breakpoint
7090 = set_momentary_breakpoint (gdbarch, sr_sal, sr_id, sr_type);
7094 insert_step_resume_breakpoint_at_sal (struct gdbarch *gdbarch,
7095 struct symtab_and_line sr_sal,
7096 struct frame_id sr_id)
7098 insert_step_resume_breakpoint_at_sal_1 (gdbarch,
7103 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
7104 This is used to skip a potential signal handler.
7106 This is called with the interrupted function's frame. The signal
7107 handler, when it returns, will resume the interrupted function at
7111 insert_hp_step_resume_breakpoint_at_frame (struct frame_info *return_frame)
7113 struct symtab_and_line sr_sal;
7114 struct gdbarch *gdbarch;
7116 gdb_assert (return_frame != NULL);
7117 init_sal (&sr_sal); /* initialize to zeros */
7119 gdbarch = get_frame_arch (return_frame);
7120 sr_sal.pc = gdbarch_addr_bits_remove (gdbarch, get_frame_pc (return_frame));
7121 sr_sal.section = find_pc_overlay (sr_sal.pc);
7122 sr_sal.pspace = get_frame_program_space (return_frame);
7124 insert_step_resume_breakpoint_at_sal_1 (gdbarch, sr_sal,
7125 get_stack_frame_id (return_frame),
7129 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
7130 is used to skip a function after stepping into it (for "next" or if
7131 the called function has no debugging information).
7133 The current function has almost always been reached by single
7134 stepping a call or return instruction. NEXT_FRAME belongs to the
7135 current function, and the breakpoint will be set at the caller's
7138 This is a separate function rather than reusing
7139 insert_hp_step_resume_breakpoint_at_frame in order to avoid
7140 get_prev_frame, which may stop prematurely (see the implementation
7141 of frame_unwind_caller_id for an example). */
7144 insert_step_resume_breakpoint_at_caller (struct frame_info *next_frame)
7146 struct symtab_and_line sr_sal;
7147 struct gdbarch *gdbarch;
7149 /* We shouldn't have gotten here if we don't know where the call site
7151 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame)));
7153 init_sal (&sr_sal); /* initialize to zeros */
7155 gdbarch = frame_unwind_caller_arch (next_frame);
7156 sr_sal.pc = gdbarch_addr_bits_remove (gdbarch,
7157 frame_unwind_caller_pc (next_frame));
7158 sr_sal.section = find_pc_overlay (sr_sal.pc);
7159 sr_sal.pspace = frame_unwind_program_space (next_frame);
7161 insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal,
7162 frame_unwind_caller_id (next_frame));
7165 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
7166 new breakpoint at the target of a jmp_buf. The handling of
7167 longjmp-resume uses the same mechanisms used for handling
7168 "step-resume" breakpoints. */
7171 insert_longjmp_resume_breakpoint (struct gdbarch *gdbarch, CORE_ADDR pc)
7173 /* There should never be more than one longjmp-resume breakpoint per
7174 thread, so we should never be setting a new
7175 longjmp_resume_breakpoint when one is already active. */
7176 gdb_assert (inferior_thread ()->control.exception_resume_breakpoint == NULL);
7179 fprintf_unfiltered (gdb_stdlog,
7180 "infrun: inserting longjmp-resume breakpoint at %s\n",
7181 paddress (gdbarch, pc));
7183 inferior_thread ()->control.exception_resume_breakpoint =
7184 set_momentary_breakpoint_at_pc (gdbarch, pc, bp_longjmp_resume);
7187 /* Insert an exception resume breakpoint. TP is the thread throwing
7188 the exception. The block B is the block of the unwinder debug hook
7189 function. FRAME is the frame corresponding to the call to this
7190 function. SYM is the symbol of the function argument holding the
7191 target PC of the exception. */
7194 insert_exception_resume_breakpoint (struct thread_info *tp,
7195 const struct block *b,
7196 struct frame_info *frame,
7201 struct symbol *vsym;
7202 struct value *value;
7204 struct breakpoint *bp;
7206 vsym = lookup_symbol (SYMBOL_LINKAGE_NAME (sym), b, VAR_DOMAIN,
7208 value = read_var_value (vsym, frame);
7209 /* If the value was optimized out, revert to the old behavior. */
7210 if (! value_optimized_out (value))
7212 handler = value_as_address (value);
7215 fprintf_unfiltered (gdb_stdlog,
7216 "infrun: exception resume at %lx\n",
7217 (unsigned long) handler);
7219 bp = set_momentary_breakpoint_at_pc (get_frame_arch (frame),
7220 handler, bp_exception_resume);
7222 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
7225 bp->thread = tp->num;
7226 inferior_thread ()->control.exception_resume_breakpoint = bp;
7229 CATCH (e, RETURN_MASK_ERROR)
7231 /* We want to ignore errors here. */
7236 /* A helper for check_exception_resume that sets an
7237 exception-breakpoint based on a SystemTap probe. */
7240 insert_exception_resume_from_probe (struct thread_info *tp,
7241 const struct bound_probe *probe,
7242 struct frame_info *frame)
7244 struct value *arg_value;
7246 struct breakpoint *bp;
7248 arg_value = probe_safe_evaluate_at_pc (frame, 1);
7252 handler = value_as_address (arg_value);
7255 fprintf_unfiltered (gdb_stdlog,
7256 "infrun: exception resume at %s\n",
7257 paddress (get_objfile_arch (probe->objfile),
7260 bp = set_momentary_breakpoint_at_pc (get_frame_arch (frame),
7261 handler, bp_exception_resume);
7262 bp->thread = tp->num;
7263 inferior_thread ()->control.exception_resume_breakpoint = bp;
7266 /* This is called when an exception has been intercepted. Check to
7267 see whether the exception's destination is of interest, and if so,
7268 set an exception resume breakpoint there. */
7271 check_exception_resume (struct execution_control_state *ecs,
7272 struct frame_info *frame)
7274 struct bound_probe probe;
7275 struct symbol *func;
7277 /* First see if this exception unwinding breakpoint was set via a
7278 SystemTap probe point. If so, the probe has two arguments: the
7279 CFA and the HANDLER. We ignore the CFA, extract the handler, and
7280 set a breakpoint there. */
7281 probe = find_probe_by_pc (get_frame_pc (frame));
7284 insert_exception_resume_from_probe (ecs->event_thread, &probe, frame);
7288 func = get_frame_function (frame);
7294 const struct block *b;
7295 struct block_iterator iter;
7299 /* The exception breakpoint is a thread-specific breakpoint on
7300 the unwinder's debug hook, declared as:
7302 void _Unwind_DebugHook (void *cfa, void *handler);
7304 The CFA argument indicates the frame to which control is
7305 about to be transferred. HANDLER is the destination PC.
7307 We ignore the CFA and set a temporary breakpoint at HANDLER.
7308 This is not extremely efficient but it avoids issues in gdb
7309 with computing the DWARF CFA, and it also works even in weird
7310 cases such as throwing an exception from inside a signal
7313 b = SYMBOL_BLOCK_VALUE (func);
7314 ALL_BLOCK_SYMBOLS (b, iter, sym)
7316 if (!SYMBOL_IS_ARGUMENT (sym))
7323 insert_exception_resume_breakpoint (ecs->event_thread,
7329 CATCH (e, RETURN_MASK_ERROR)
7336 stop_waiting (struct execution_control_state *ecs)
7339 fprintf_unfiltered (gdb_stdlog, "infrun: stop_waiting\n");
7341 clear_step_over_info ();
7343 /* Let callers know we don't want to wait for the inferior anymore. */
7344 ecs->wait_some_more = 0;
7346 /* If all-stop, but the target is always in non-stop mode, stop all
7347 threads now that we're presenting the stop to the user. */
7348 if (!non_stop && target_is_non_stop_p ())
7349 stop_all_threads ();
7352 /* Like keep_going, but passes the signal to the inferior, even if the
7353 signal is set to nopass. */
7356 keep_going_pass_signal (struct execution_control_state *ecs)
7358 /* Make sure normal_stop is called if we get a QUIT handled before
7360 struct cleanup *old_cleanups = make_cleanup (resume_cleanups, 0);
7362 gdb_assert (ptid_equal (ecs->event_thread->ptid, inferior_ptid));
7363 gdb_assert (!ecs->event_thread->resumed);
7365 /* Save the pc before execution, to compare with pc after stop. */
7366 ecs->event_thread->prev_pc
7367 = regcache_read_pc (get_thread_regcache (ecs->ptid));
7369 if (ecs->event_thread->control.trap_expected)
7371 struct thread_info *tp = ecs->event_thread;
7374 fprintf_unfiltered (gdb_stdlog,
7375 "infrun: %s has trap_expected set, "
7376 "resuming to collect trap\n",
7377 target_pid_to_str (tp->ptid));
7379 /* We haven't yet gotten our trap, and either: intercepted a
7380 non-signal event (e.g., a fork); or took a signal which we
7381 are supposed to pass through to the inferior. Simply
7383 discard_cleanups (old_cleanups);
7384 resume (ecs->event_thread->suspend.stop_signal);
7386 else if (step_over_info_valid_p ())
7388 /* Another thread is stepping over a breakpoint in-line. If
7389 this thread needs a step-over too, queue the request. In
7390 either case, this resume must be deferred for later. */
7391 struct thread_info *tp = ecs->event_thread;
7393 if (ecs->hit_singlestep_breakpoint
7394 || thread_still_needs_step_over (tp))
7397 fprintf_unfiltered (gdb_stdlog,
7398 "infrun: step-over already in progress: "
7399 "step-over for %s deferred\n",
7400 target_pid_to_str (tp->ptid));
7401 thread_step_over_chain_enqueue (tp);
7406 fprintf_unfiltered (gdb_stdlog,
7407 "infrun: step-over in progress: "
7408 "resume of %s deferred\n",
7409 target_pid_to_str (tp->ptid));
7412 discard_cleanups (old_cleanups);
7416 struct regcache *regcache = get_current_regcache ();
7419 enum step_over_what step_what;
7421 /* Either the trap was not expected, but we are continuing
7422 anyway (if we got a signal, the user asked it be passed to
7425 We got our expected trap, but decided we should resume from
7428 We're going to run this baby now!
7430 Note that insert_breakpoints won't try to re-insert
7431 already inserted breakpoints. Therefore, we don't
7432 care if breakpoints were already inserted, or not. */
7434 /* If we need to step over a breakpoint, and we're not using
7435 displaced stepping to do so, insert all breakpoints
7436 (watchpoints, etc.) but the one we're stepping over, step one
7437 instruction, and then re-insert the breakpoint when that step
7440 step_what = thread_still_needs_step_over (ecs->event_thread);
7442 remove_bp = (ecs->hit_singlestep_breakpoint
7443 || (step_what & STEP_OVER_BREAKPOINT));
7444 remove_wps = (step_what & STEP_OVER_WATCHPOINT);
7446 /* We can't use displaced stepping if we need to step past a
7447 watchpoint. The instruction copied to the scratch pad would
7448 still trigger the watchpoint. */
7450 && (remove_wps || !use_displaced_stepping (ecs->event_thread)))
7452 set_step_over_info (get_regcache_aspace (regcache),
7453 regcache_read_pc (regcache), remove_wps);
7455 else if (remove_wps)
7456 set_step_over_info (NULL, 0, remove_wps);
7458 /* If we now need to do an in-line step-over, we need to stop
7459 all other threads. Note this must be done before
7460 insert_breakpoints below, because that removes the breakpoint
7461 we're about to step over, otherwise other threads could miss
7463 if (step_over_info_valid_p () && target_is_non_stop_p ())
7464 stop_all_threads ();
7466 /* Stop stepping if inserting breakpoints fails. */
7469 insert_breakpoints ();
7471 CATCH (e, RETURN_MASK_ERROR)
7473 exception_print (gdb_stderr, e);
7475 discard_cleanups (old_cleanups);
7480 ecs->event_thread->control.trap_expected = (remove_bp || remove_wps);
7482 discard_cleanups (old_cleanups);
7483 resume (ecs->event_thread->suspend.stop_signal);
7486 prepare_to_wait (ecs);
7489 /* Called when we should continue running the inferior, because the
7490 current event doesn't cause a user visible stop. This does the
7491 resuming part; waiting for the next event is done elsewhere. */
7494 keep_going (struct execution_control_state *ecs)
7496 if (ecs->event_thread->control.trap_expected
7497 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
7498 ecs->event_thread->control.trap_expected = 0;
7500 if (!signal_program[ecs->event_thread->suspend.stop_signal])
7501 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
7502 keep_going_pass_signal (ecs);
7505 /* This function normally comes after a resume, before
7506 handle_inferior_event exits. It takes care of any last bits of
7507 housekeeping, and sets the all-important wait_some_more flag. */
7510 prepare_to_wait (struct execution_control_state *ecs)
7513 fprintf_unfiltered (gdb_stdlog, "infrun: prepare_to_wait\n");
7515 /* This is the old end of the while loop. Let everybody know we
7516 want to wait for the inferior some more and get called again
7518 ecs->wait_some_more = 1;
7521 /* We are done with the step range of a step/next/si/ni command.
7522 Called once for each n of a "step n" operation. */
7525 end_stepping_range (struct execution_control_state *ecs)
7527 ecs->event_thread->control.stop_step = 1;
7531 /* Several print_*_reason functions to print why the inferior has stopped.
7532 We always print something when the inferior exits, or receives a signal.
7533 The rest of the cases are dealt with later on in normal_stop and
7534 print_it_typical. Ideally there should be a call to one of these
7535 print_*_reason functions functions from handle_inferior_event each time
7536 stop_waiting is called.
7538 Note that we don't call these directly, instead we delegate that to
7539 the interpreters, through observers. Interpreters then call these
7540 with whatever uiout is right. */
7543 print_end_stepping_range_reason (struct ui_out *uiout)
7545 /* For CLI-like interpreters, print nothing. */
7547 if (ui_out_is_mi_like_p (uiout))
7549 ui_out_field_string (uiout, "reason",
7550 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE));
7555 print_signal_exited_reason (struct ui_out *uiout, enum gdb_signal siggnal)
7557 annotate_signalled ();
7558 if (ui_out_is_mi_like_p (uiout))
7560 (uiout, "reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED));
7561 ui_out_text (uiout, "\nProgram terminated with signal ");
7562 annotate_signal_name ();
7563 ui_out_field_string (uiout, "signal-name",
7564 gdb_signal_to_name (siggnal));
7565 annotate_signal_name_end ();
7566 ui_out_text (uiout, ", ");
7567 annotate_signal_string ();
7568 ui_out_field_string (uiout, "signal-meaning",
7569 gdb_signal_to_string (siggnal));
7570 annotate_signal_string_end ();
7571 ui_out_text (uiout, ".\n");
7572 ui_out_text (uiout, "The program no longer exists.\n");
7576 print_exited_reason (struct ui_out *uiout, int exitstatus)
7578 struct inferior *inf = current_inferior ();
7579 const char *pidstr = target_pid_to_str (pid_to_ptid (inf->pid));
7581 annotate_exited (exitstatus);
7584 if (ui_out_is_mi_like_p (uiout))
7585 ui_out_field_string (uiout, "reason",
7586 async_reason_lookup (EXEC_ASYNC_EXITED));
7587 ui_out_text (uiout, "[Inferior ");
7588 ui_out_text (uiout, plongest (inf->num));
7589 ui_out_text (uiout, " (");
7590 ui_out_text (uiout, pidstr);
7591 ui_out_text (uiout, ") exited with code ");
7592 ui_out_field_fmt (uiout, "exit-code", "0%o", (unsigned int) exitstatus);
7593 ui_out_text (uiout, "]\n");
7597 if (ui_out_is_mi_like_p (uiout))
7599 (uiout, "reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY));
7600 ui_out_text (uiout, "[Inferior ");
7601 ui_out_text (uiout, plongest (inf->num));
7602 ui_out_text (uiout, " (");
7603 ui_out_text (uiout, pidstr);
7604 ui_out_text (uiout, ") exited normally]\n");
7609 print_signal_received_reason (struct ui_out *uiout, enum gdb_signal siggnal)
7613 if (siggnal == GDB_SIGNAL_0 && !ui_out_is_mi_like_p (uiout))
7615 struct thread_info *t = inferior_thread ();
7617 ui_out_text (uiout, "\n[");
7618 ui_out_field_string (uiout, "thread-name",
7619 target_pid_to_str (t->ptid));
7620 ui_out_field_fmt (uiout, "thread-id", "] #%d", t->num);
7621 ui_out_text (uiout, " stopped");
7625 ui_out_text (uiout, "\nProgram received signal ");
7626 annotate_signal_name ();
7627 if (ui_out_is_mi_like_p (uiout))
7629 (uiout, "reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED));
7630 ui_out_field_string (uiout, "signal-name",
7631 gdb_signal_to_name (siggnal));
7632 annotate_signal_name_end ();
7633 ui_out_text (uiout, ", ");
7634 annotate_signal_string ();
7635 ui_out_field_string (uiout, "signal-meaning",
7636 gdb_signal_to_string (siggnal));
7637 annotate_signal_string_end ();
7639 ui_out_text (uiout, ".\n");
7643 print_no_history_reason (struct ui_out *uiout)
7645 ui_out_text (uiout, "\nNo more reverse-execution history.\n");
7648 /* Print current location without a level number, if we have changed
7649 functions or hit a breakpoint. Print source line if we have one.
7650 bpstat_print contains the logic deciding in detail what to print,
7651 based on the event(s) that just occurred. */
7654 print_stop_event (struct target_waitstatus *ws)
7657 enum print_what source_flag;
7658 int do_frame_printing = 1;
7659 struct thread_info *tp = inferior_thread ();
7661 bpstat_ret = bpstat_print (tp->control.stop_bpstat, ws->kind);
7665 /* FIXME: cagney/2002-12-01: Given that a frame ID does (or
7666 should) carry around the function and does (or should) use
7667 that when doing a frame comparison. */
7668 if (tp->control.stop_step
7669 && frame_id_eq (tp->control.step_frame_id,
7670 get_frame_id (get_current_frame ()))
7671 && tp->control.step_start_function == find_pc_function (stop_pc))
7673 /* Finished step, just print source line. */
7674 source_flag = SRC_LINE;
7678 /* Print location and source line. */
7679 source_flag = SRC_AND_LOC;
7682 case PRINT_SRC_AND_LOC:
7683 /* Print location and source line. */
7684 source_flag = SRC_AND_LOC;
7686 case PRINT_SRC_ONLY:
7687 source_flag = SRC_LINE;
7690 /* Something bogus. */
7691 source_flag = SRC_LINE;
7692 do_frame_printing = 0;
7695 internal_error (__FILE__, __LINE__, _("Unknown value."));
7698 /* The behavior of this routine with respect to the source
7700 SRC_LINE: Print only source line
7701 LOCATION: Print only location
7702 SRC_AND_LOC: Print location and source line. */
7703 if (do_frame_printing)
7704 print_stack_frame (get_selected_frame (NULL), 0, source_flag, 1);
7706 /* Display the auto-display expressions. */
7710 /* Here to return control to GDB when the inferior stops for real.
7711 Print appropriate messages, remove breakpoints, give terminal our modes.
7713 STOP_PRINT_FRAME nonzero means print the executing frame
7714 (pc, function, args, file, line number and line text).
7715 BREAKPOINTS_FAILED nonzero means stop was due to error
7716 attempting to insert breakpoints. */
7721 struct target_waitstatus last;
7723 struct cleanup *old_chain = make_cleanup (null_cleanup, NULL);
7726 get_last_target_status (&last_ptid, &last);
7728 /* If an exception is thrown from this point on, make sure to
7729 propagate GDB's knowledge of the executing state to the
7730 frontend/user running state. A QUIT is an easy exception to see
7731 here, so do this before any filtered output. */
7733 make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
7734 else if (last.kind == TARGET_WAITKIND_SIGNALLED
7735 || last.kind == TARGET_WAITKIND_EXITED)
7737 /* On some targets, we may still have live threads in the
7738 inferior when we get a process exit event. E.g., for
7739 "checkpoint", when the current checkpoint/fork exits,
7740 linux-fork.c automatically switches to another fork from
7741 within target_mourn_inferior. */
7742 if (!ptid_equal (inferior_ptid, null_ptid))
7744 pid_ptid = pid_to_ptid (ptid_get_pid (inferior_ptid));
7745 make_cleanup (finish_thread_state_cleanup, &pid_ptid);
7748 else if (last.kind != TARGET_WAITKIND_NO_RESUMED)
7749 make_cleanup (finish_thread_state_cleanup, &inferior_ptid);
7751 /* As we're presenting a stop, and potentially removing breakpoints,
7752 update the thread list so we can tell whether there are threads
7753 running on the target. With target remote, for example, we can
7754 only learn about new threads when we explicitly update the thread
7755 list. Do this before notifying the interpreters about signal
7756 stops, end of stepping ranges, etc., so that the "new thread"
7757 output is emitted before e.g., "Program received signal FOO",
7758 instead of after. */
7759 update_thread_list ();
7761 if (last.kind == TARGET_WAITKIND_STOPPED && stopped_by_random_signal)
7762 observer_notify_signal_received (inferior_thread ()->suspend.stop_signal);
7764 /* As with the notification of thread events, we want to delay
7765 notifying the user that we've switched thread context until
7766 the inferior actually stops.
7768 There's no point in saying anything if the inferior has exited.
7769 Note that SIGNALLED here means "exited with a signal", not
7770 "received a signal".
7772 Also skip saying anything in non-stop mode. In that mode, as we
7773 don't want GDB to switch threads behind the user's back, to avoid
7774 races where the user is typing a command to apply to thread x,
7775 but GDB switches to thread y before the user finishes entering
7776 the command, fetch_inferior_event installs a cleanup to restore
7777 the current thread back to the thread the user had selected right
7778 after this event is handled, so we're not really switching, only
7779 informing of a stop. */
7781 && !ptid_equal (previous_inferior_ptid, inferior_ptid)
7782 && target_has_execution
7783 && last.kind != TARGET_WAITKIND_SIGNALLED
7784 && last.kind != TARGET_WAITKIND_EXITED
7785 && last.kind != TARGET_WAITKIND_NO_RESUMED)
7787 target_terminal_ours_for_output ();
7788 printf_filtered (_("[Switching to %s]\n"),
7789 target_pid_to_str (inferior_ptid));
7790 annotate_thread_changed ();
7791 previous_inferior_ptid = inferior_ptid;
7794 if (last.kind == TARGET_WAITKIND_NO_RESUMED)
7796 gdb_assert (sync_execution || !target_can_async_p ());
7798 target_terminal_ours_for_output ();
7799 printf_filtered (_("No unwaited-for children left.\n"));
7802 /* Note: this depends on the update_thread_list call above. */
7803 if (!breakpoints_should_be_inserted_now () && target_has_execution)
7805 if (remove_breakpoints ())
7807 target_terminal_ours_for_output ();
7808 printf_filtered (_("Cannot remove breakpoints because "
7809 "program is no longer writable.\nFurther "
7810 "execution is probably impossible.\n"));
7814 /* If an auto-display called a function and that got a signal,
7815 delete that auto-display to avoid an infinite recursion. */
7817 if (stopped_by_random_signal)
7818 disable_current_display ();
7820 /* Notify observers if we finished a "step"-like command, etc. */
7821 if (target_has_execution
7822 && last.kind != TARGET_WAITKIND_SIGNALLED
7823 && last.kind != TARGET_WAITKIND_EXITED
7824 && inferior_thread ()->control.stop_step)
7826 /* But not if in the middle of doing a "step n" operation for
7828 if (inferior_thread ()->step_multi)
7831 observer_notify_end_stepping_range ();
7834 target_terminal_ours ();
7835 async_enable_stdin ();
7837 /* Set the current source location. This will also happen if we
7838 display the frame below, but the current SAL will be incorrect
7839 during a user hook-stop function. */
7840 if (has_stack_frames () && !stop_stack_dummy)
7841 set_current_sal_from_frame (get_current_frame ());
7843 /* Let the user/frontend see the threads as stopped, but defer to
7844 call_function_by_hand if the thread finished an infcall
7845 successfully. We may be e.g., evaluating a breakpoint condition.
7846 In that case, the thread had state THREAD_RUNNING before the
7847 infcall, and shall remain marked running, all without informing
7848 the user/frontend about state transition changes. */
7849 if (target_has_execution
7850 && inferior_thread ()->control.in_infcall
7851 && stop_stack_dummy == STOP_STACK_DUMMY)
7852 discard_cleanups (old_chain);
7854 do_cleanups (old_chain);
7856 /* Look up the hook_stop and run it (CLI internally handles problem
7857 of stop_command's pre-hook not existing). */
7859 catch_errors (hook_stop_stub, stop_command,
7860 "Error while running hook_stop:\n", RETURN_MASK_ALL);
7862 if (!has_stack_frames ())
7865 if (last.kind == TARGET_WAITKIND_SIGNALLED
7866 || last.kind == TARGET_WAITKIND_EXITED)
7869 /* Select innermost stack frame - i.e., current frame is frame 0,
7870 and current location is based on that.
7871 Don't do this on return from a stack dummy routine,
7872 or if the program has exited. */
7874 if (!stop_stack_dummy)
7876 select_frame (get_current_frame ());
7878 /* If --batch-silent is enabled then there's no need to print the current
7879 source location, and to try risks causing an error message about
7880 missing source files. */
7881 if (stop_print_frame && !batch_silent)
7882 print_stop_event (&last);
7885 if (stop_stack_dummy == STOP_STACK_DUMMY)
7887 /* Pop the empty frame that contains the stack dummy.
7888 This also restores inferior state prior to the call
7889 (struct infcall_suspend_state). */
7890 struct frame_info *frame = get_current_frame ();
7892 gdb_assert (get_frame_type (frame) == DUMMY_FRAME);
7894 /* frame_pop() calls reinit_frame_cache as the last thing it
7895 does which means there's currently no selected frame. We
7896 don't need to re-establish a selected frame if the dummy call
7897 returns normally, that will be done by
7898 restore_infcall_control_state. However, we do have to handle
7899 the case where the dummy call is returning after being
7900 stopped (e.g. the dummy call previously hit a breakpoint).
7901 We can't know which case we have so just always re-establish
7902 a selected frame here. */
7903 select_frame (get_current_frame ());
7907 annotate_stopped ();
7909 /* Suppress the stop observer if we're in the middle of:
7911 - a step n (n > 1), as there still more steps to be done.
7913 - a "finish" command, as the observer will be called in
7914 finish_command_continuation, so it can include the inferior
7915 function's return value.
7917 - calling an inferior function, as we pretend we inferior didn't
7918 run at all. The return value of the call is handled by the
7919 expression evaluator, through call_function_by_hand. */
7921 if (!target_has_execution
7922 || last.kind == TARGET_WAITKIND_SIGNALLED
7923 || last.kind == TARGET_WAITKIND_EXITED
7924 || last.kind == TARGET_WAITKIND_NO_RESUMED
7925 || (!(inferior_thread ()->step_multi
7926 && inferior_thread ()->control.stop_step)
7927 && !(inferior_thread ()->control.stop_bpstat
7928 && inferior_thread ()->control.proceed_to_finish)
7929 && !inferior_thread ()->control.in_infcall))
7931 if (!ptid_equal (inferior_ptid, null_ptid))
7932 observer_notify_normal_stop (inferior_thread ()->control.stop_bpstat,
7935 observer_notify_normal_stop (NULL, stop_print_frame);
7938 if (target_has_execution)
7940 if (last.kind != TARGET_WAITKIND_SIGNALLED
7941 && last.kind != TARGET_WAITKIND_EXITED)
7942 /* Delete the breakpoint we stopped at, if it wants to be deleted.
7943 Delete any breakpoint that is to be deleted at the next stop. */
7944 breakpoint_auto_delete (inferior_thread ()->control.stop_bpstat);
7947 /* Try to get rid of automatically added inferiors that are no
7948 longer needed. Keeping those around slows down things linearly.
7949 Note that this never removes the current inferior. */
7954 hook_stop_stub (void *cmd)
7956 execute_cmd_pre_hook ((struct cmd_list_element *) cmd);
7961 signal_stop_state (int signo)
7963 return signal_stop[signo];
7967 signal_print_state (int signo)
7969 return signal_print[signo];
7973 signal_pass_state (int signo)
7975 return signal_program[signo];
7979 signal_cache_update (int signo)
7983 for (signo = 0; signo < (int) GDB_SIGNAL_LAST; signo++)
7984 signal_cache_update (signo);
7989 signal_pass[signo] = (signal_stop[signo] == 0
7990 && signal_print[signo] == 0
7991 && signal_program[signo] == 1
7992 && signal_catch[signo] == 0);
7996 signal_stop_update (int signo, int state)
7998 int ret = signal_stop[signo];
8000 signal_stop[signo] = state;
8001 signal_cache_update (signo);
8006 signal_print_update (int signo, int state)
8008 int ret = signal_print[signo];
8010 signal_print[signo] = state;
8011 signal_cache_update (signo);
8016 signal_pass_update (int signo, int state)
8018 int ret = signal_program[signo];
8020 signal_program[signo] = state;
8021 signal_cache_update (signo);
8025 /* Update the global 'signal_catch' from INFO and notify the
8029 signal_catch_update (const unsigned int *info)
8033 for (i = 0; i < GDB_SIGNAL_LAST; ++i)
8034 signal_catch[i] = info[i] > 0;
8035 signal_cache_update (-1);
8036 target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
8040 sig_print_header (void)
8042 printf_filtered (_("Signal Stop\tPrint\tPass "
8043 "to program\tDescription\n"));
8047 sig_print_info (enum gdb_signal oursig)
8049 const char *name = gdb_signal_to_name (oursig);
8050 int name_padding = 13 - strlen (name);
8052 if (name_padding <= 0)
8055 printf_filtered ("%s", name);
8056 printf_filtered ("%*.*s ", name_padding, name_padding, " ");
8057 printf_filtered ("%s\t", signal_stop[oursig] ? "Yes" : "No");
8058 printf_filtered ("%s\t", signal_print[oursig] ? "Yes" : "No");
8059 printf_filtered ("%s\t\t", signal_program[oursig] ? "Yes" : "No");
8060 printf_filtered ("%s\n", gdb_signal_to_string (oursig));
8063 /* Specify how various signals in the inferior should be handled. */
8066 handle_command (char *args, int from_tty)
8069 int digits, wordlen;
8070 int sigfirst, signum, siglast;
8071 enum gdb_signal oursig;
8074 unsigned char *sigs;
8075 struct cleanup *old_chain;
8079 error_no_arg (_("signal to handle"));
8082 /* Allocate and zero an array of flags for which signals to handle. */
8084 nsigs = (int) GDB_SIGNAL_LAST;
8085 sigs = (unsigned char *) alloca (nsigs);
8086 memset (sigs, 0, nsigs);
8088 /* Break the command line up into args. */
8090 argv = gdb_buildargv (args);
8091 old_chain = make_cleanup_freeargv (argv);
8093 /* Walk through the args, looking for signal oursigs, signal names, and
8094 actions. Signal numbers and signal names may be interspersed with
8095 actions, with the actions being performed for all signals cumulatively
8096 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
8098 while (*argv != NULL)
8100 wordlen = strlen (*argv);
8101 for (digits = 0; isdigit ((*argv)[digits]); digits++)
8105 sigfirst = siglast = -1;
8107 if (wordlen >= 1 && !strncmp (*argv, "all", wordlen))
8109 /* Apply action to all signals except those used by the
8110 debugger. Silently skip those. */
8113 siglast = nsigs - 1;
8115 else if (wordlen >= 1 && !strncmp (*argv, "stop", wordlen))
8117 SET_SIGS (nsigs, sigs, signal_stop);
8118 SET_SIGS (nsigs, sigs, signal_print);
8120 else if (wordlen >= 1 && !strncmp (*argv, "ignore", wordlen))
8122 UNSET_SIGS (nsigs, sigs, signal_program);
8124 else if (wordlen >= 2 && !strncmp (*argv, "print", wordlen))
8126 SET_SIGS (nsigs, sigs, signal_print);
8128 else if (wordlen >= 2 && !strncmp (*argv, "pass", wordlen))
8130 SET_SIGS (nsigs, sigs, signal_program);
8132 else if (wordlen >= 3 && !strncmp (*argv, "nostop", wordlen))
8134 UNSET_SIGS (nsigs, sigs, signal_stop);
8136 else if (wordlen >= 3 && !strncmp (*argv, "noignore", wordlen))
8138 SET_SIGS (nsigs, sigs, signal_program);
8140 else if (wordlen >= 4 && !strncmp (*argv, "noprint", wordlen))
8142 UNSET_SIGS (nsigs, sigs, signal_print);
8143 UNSET_SIGS (nsigs, sigs, signal_stop);
8145 else if (wordlen >= 4 && !strncmp (*argv, "nopass", wordlen))
8147 UNSET_SIGS (nsigs, sigs, signal_program);
8149 else if (digits > 0)
8151 /* It is numeric. The numeric signal refers to our own
8152 internal signal numbering from target.h, not to host/target
8153 signal number. This is a feature; users really should be
8154 using symbolic names anyway, and the common ones like
8155 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
8157 sigfirst = siglast = (int)
8158 gdb_signal_from_command (atoi (*argv));
8159 if ((*argv)[digits] == '-')
8162 gdb_signal_from_command (atoi ((*argv) + digits + 1));
8164 if (sigfirst > siglast)
8166 /* Bet he didn't figure we'd think of this case... */
8174 oursig = gdb_signal_from_name (*argv);
8175 if (oursig != GDB_SIGNAL_UNKNOWN)
8177 sigfirst = siglast = (int) oursig;
8181 /* Not a number and not a recognized flag word => complain. */
8182 error (_("Unrecognized or ambiguous flag word: \"%s\"."), *argv);
8186 /* If any signal numbers or symbol names were found, set flags for
8187 which signals to apply actions to. */
8189 for (signum = sigfirst; signum >= 0 && signum <= siglast; signum++)
8191 switch ((enum gdb_signal) signum)
8193 case GDB_SIGNAL_TRAP:
8194 case GDB_SIGNAL_INT:
8195 if (!allsigs && !sigs[signum])
8197 if (query (_("%s is used by the debugger.\n\
8198 Are you sure you want to change it? "),
8199 gdb_signal_to_name ((enum gdb_signal) signum)))
8205 printf_unfiltered (_("Not confirmed, unchanged.\n"));
8206 gdb_flush (gdb_stdout);
8211 case GDB_SIGNAL_DEFAULT:
8212 case GDB_SIGNAL_UNKNOWN:
8213 /* Make sure that "all" doesn't print these. */
8224 for (signum = 0; signum < nsigs; signum++)
8227 signal_cache_update (-1);
8228 target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
8229 target_program_signals ((int) GDB_SIGNAL_LAST, signal_program);
8233 /* Show the results. */
8234 sig_print_header ();
8235 for (; signum < nsigs; signum++)
8237 sig_print_info ((enum gdb_signal) signum);
8243 do_cleanups (old_chain);
8246 /* Complete the "handle" command. */
8248 static VEC (char_ptr) *
8249 handle_completer (struct cmd_list_element *ignore,
8250 const char *text, const char *word)
8252 VEC (char_ptr) *vec_signals, *vec_keywords, *return_val;
8253 static const char * const keywords[] =
8267 vec_signals = signal_completer (ignore, text, word);
8268 vec_keywords = complete_on_enum (keywords, word, word);
8270 return_val = VEC_merge (char_ptr, vec_signals, vec_keywords);
8271 VEC_free (char_ptr, vec_signals);
8272 VEC_free (char_ptr, vec_keywords);
8277 gdb_signal_from_command (int num)
8279 if (num >= 1 && num <= 15)
8280 return (enum gdb_signal) num;
8281 error (_("Only signals 1-15 are valid as numeric signals.\n\
8282 Use \"info signals\" for a list of symbolic signals."));
8285 /* Print current contents of the tables set by the handle command.
8286 It is possible we should just be printing signals actually used
8287 by the current target (but for things to work right when switching
8288 targets, all signals should be in the signal tables). */
8291 signals_info (char *signum_exp, int from_tty)
8293 enum gdb_signal oursig;
8295 sig_print_header ();
8299 /* First see if this is a symbol name. */
8300 oursig = gdb_signal_from_name (signum_exp);
8301 if (oursig == GDB_SIGNAL_UNKNOWN)
8303 /* No, try numeric. */
8305 gdb_signal_from_command (parse_and_eval_long (signum_exp));
8307 sig_print_info (oursig);
8311 printf_filtered ("\n");
8312 /* These ugly casts brought to you by the native VAX compiler. */
8313 for (oursig = GDB_SIGNAL_FIRST;
8314 (int) oursig < (int) GDB_SIGNAL_LAST;
8315 oursig = (enum gdb_signal) ((int) oursig + 1))
8319 if (oursig != GDB_SIGNAL_UNKNOWN
8320 && oursig != GDB_SIGNAL_DEFAULT && oursig != GDB_SIGNAL_0)
8321 sig_print_info (oursig);
8324 printf_filtered (_("\nUse the \"handle\" command "
8325 "to change these tables.\n"));
8328 /* Check if it makes sense to read $_siginfo from the current thread
8329 at this point. If not, throw an error. */
8332 validate_siginfo_access (void)
8334 /* No current inferior, no siginfo. */
8335 if (ptid_equal (inferior_ptid, null_ptid))
8336 error (_("No thread selected."));
8338 /* Don't try to read from a dead thread. */
8339 if (is_exited (inferior_ptid))
8340 error (_("The current thread has terminated"));
8342 /* ... or from a spinning thread. */
8343 if (is_running (inferior_ptid))
8344 error (_("Selected thread is running."));
8347 /* The $_siginfo convenience variable is a bit special. We don't know
8348 for sure the type of the value until we actually have a chance to
8349 fetch the data. The type can change depending on gdbarch, so it is
8350 also dependent on which thread you have selected.
8352 1. making $_siginfo be an internalvar that creates a new value on
8355 2. making the value of $_siginfo be an lval_computed value. */
8357 /* This function implements the lval_computed support for reading a
8361 siginfo_value_read (struct value *v)
8363 LONGEST transferred;
8365 validate_siginfo_access ();
8368 target_read (¤t_target, TARGET_OBJECT_SIGNAL_INFO,
8370 value_contents_all_raw (v),
8372 TYPE_LENGTH (value_type (v)));
8374 if (transferred != TYPE_LENGTH (value_type (v)))
8375 error (_("Unable to read siginfo"));
8378 /* This function implements the lval_computed support for writing a
8382 siginfo_value_write (struct value *v, struct value *fromval)
8384 LONGEST transferred;
8386 validate_siginfo_access ();
8388 transferred = target_write (¤t_target,
8389 TARGET_OBJECT_SIGNAL_INFO,
8391 value_contents_all_raw (fromval),
8393 TYPE_LENGTH (value_type (fromval)));
8395 if (transferred != TYPE_LENGTH (value_type (fromval)))
8396 error (_("Unable to write siginfo"));
8399 static const struct lval_funcs siginfo_value_funcs =
8405 /* Return a new value with the correct type for the siginfo object of
8406 the current thread using architecture GDBARCH. Return a void value
8407 if there's no object available. */
8409 static struct value *
8410 siginfo_make_value (struct gdbarch *gdbarch, struct internalvar *var,
8413 if (target_has_stack
8414 && !ptid_equal (inferior_ptid, null_ptid)
8415 && gdbarch_get_siginfo_type_p (gdbarch))
8417 struct type *type = gdbarch_get_siginfo_type (gdbarch);
8419 return allocate_computed_value (type, &siginfo_value_funcs, NULL);
8422 return allocate_value (builtin_type (gdbarch)->builtin_void);
8426 /* infcall_suspend_state contains state about the program itself like its
8427 registers and any signal it received when it last stopped.
8428 This state must be restored regardless of how the inferior function call
8429 ends (either successfully, or after it hits a breakpoint or signal)
8430 if the program is to properly continue where it left off. */
8432 struct infcall_suspend_state
8434 struct thread_suspend_state thread_suspend;
8438 struct regcache *registers;
8440 /* Format of SIGINFO_DATA or NULL if it is not present. */
8441 struct gdbarch *siginfo_gdbarch;
8443 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
8444 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
8445 content would be invalid. */
8446 gdb_byte *siginfo_data;
8449 struct infcall_suspend_state *
8450 save_infcall_suspend_state (void)
8452 struct infcall_suspend_state *inf_state;
8453 struct thread_info *tp = inferior_thread ();
8454 struct regcache *regcache = get_current_regcache ();
8455 struct gdbarch *gdbarch = get_regcache_arch (regcache);
8456 gdb_byte *siginfo_data = NULL;
8458 if (gdbarch_get_siginfo_type_p (gdbarch))
8460 struct type *type = gdbarch_get_siginfo_type (gdbarch);
8461 size_t len = TYPE_LENGTH (type);
8462 struct cleanup *back_to;
8464 siginfo_data = xmalloc (len);
8465 back_to = make_cleanup (xfree, siginfo_data);
8467 if (target_read (¤t_target, TARGET_OBJECT_SIGNAL_INFO, NULL,
8468 siginfo_data, 0, len) == len)
8469 discard_cleanups (back_to);
8472 /* Errors ignored. */
8473 do_cleanups (back_to);
8474 siginfo_data = NULL;
8478 inf_state = XCNEW (struct infcall_suspend_state);
8482 inf_state->siginfo_gdbarch = gdbarch;
8483 inf_state->siginfo_data = siginfo_data;
8486 inf_state->thread_suspend = tp->suspend;
8488 /* run_inferior_call will not use the signal due to its `proceed' call with
8489 GDB_SIGNAL_0 anyway. */
8490 tp->suspend.stop_signal = GDB_SIGNAL_0;
8492 inf_state->stop_pc = stop_pc;
8494 inf_state->registers = regcache_dup (regcache);
8499 /* Restore inferior session state to INF_STATE. */
8502 restore_infcall_suspend_state (struct infcall_suspend_state *inf_state)
8504 struct thread_info *tp = inferior_thread ();
8505 struct regcache *regcache = get_current_regcache ();
8506 struct gdbarch *gdbarch = get_regcache_arch (regcache);
8508 tp->suspend = inf_state->thread_suspend;
8510 stop_pc = inf_state->stop_pc;
8512 if (inf_state->siginfo_gdbarch == gdbarch)
8514 struct type *type = gdbarch_get_siginfo_type (gdbarch);
8516 /* Errors ignored. */
8517 target_write (¤t_target, TARGET_OBJECT_SIGNAL_INFO, NULL,
8518 inf_state->siginfo_data, 0, TYPE_LENGTH (type));
8521 /* The inferior can be gone if the user types "print exit(0)"
8522 (and perhaps other times). */
8523 if (target_has_execution)
8524 /* NB: The register write goes through to the target. */
8525 regcache_cpy (regcache, inf_state->registers);
8527 discard_infcall_suspend_state (inf_state);
8531 do_restore_infcall_suspend_state_cleanup (void *state)
8533 restore_infcall_suspend_state (state);
8537 make_cleanup_restore_infcall_suspend_state
8538 (struct infcall_suspend_state *inf_state)
8540 return make_cleanup (do_restore_infcall_suspend_state_cleanup, inf_state);
8544 discard_infcall_suspend_state (struct infcall_suspend_state *inf_state)
8546 regcache_xfree (inf_state->registers);
8547 xfree (inf_state->siginfo_data);
8552 get_infcall_suspend_state_regcache (struct infcall_suspend_state *inf_state)
8554 return inf_state->registers;
8557 /* infcall_control_state contains state regarding gdb's control of the
8558 inferior itself like stepping control. It also contains session state like
8559 the user's currently selected frame. */
8561 struct infcall_control_state
8563 struct thread_control_state thread_control;
8564 struct inferior_control_state inferior_control;
8567 enum stop_stack_kind stop_stack_dummy;
8568 int stopped_by_random_signal;
8569 int stop_after_trap;
8571 /* ID if the selected frame when the inferior function call was made. */
8572 struct frame_id selected_frame_id;
8575 /* Save all of the information associated with the inferior<==>gdb
8578 struct infcall_control_state *
8579 save_infcall_control_state (void)
8581 struct infcall_control_state *inf_status = xmalloc (sizeof (*inf_status));
8582 struct thread_info *tp = inferior_thread ();
8583 struct inferior *inf = current_inferior ();
8585 inf_status->thread_control = tp->control;
8586 inf_status->inferior_control = inf->control;
8588 tp->control.step_resume_breakpoint = NULL;
8589 tp->control.exception_resume_breakpoint = NULL;
8591 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
8592 chain. If caller's caller is walking the chain, they'll be happier if we
8593 hand them back the original chain when restore_infcall_control_state is
8595 tp->control.stop_bpstat = bpstat_copy (tp->control.stop_bpstat);
8598 inf_status->stop_stack_dummy = stop_stack_dummy;
8599 inf_status->stopped_by_random_signal = stopped_by_random_signal;
8600 inf_status->stop_after_trap = stop_after_trap;
8602 inf_status->selected_frame_id = get_frame_id (get_selected_frame (NULL));
8608 restore_selected_frame (void *args)
8610 struct frame_id *fid = (struct frame_id *) args;
8611 struct frame_info *frame;
8613 frame = frame_find_by_id (*fid);
8615 /* If inf_status->selected_frame_id is NULL, there was no previously
8619 warning (_("Unable to restore previously selected frame."));
8623 select_frame (frame);
8628 /* Restore inferior session state to INF_STATUS. */
8631 restore_infcall_control_state (struct infcall_control_state *inf_status)
8633 struct thread_info *tp = inferior_thread ();
8634 struct inferior *inf = current_inferior ();
8636 if (tp->control.step_resume_breakpoint)
8637 tp->control.step_resume_breakpoint->disposition = disp_del_at_next_stop;
8639 if (tp->control.exception_resume_breakpoint)
8640 tp->control.exception_resume_breakpoint->disposition
8641 = disp_del_at_next_stop;
8643 /* Handle the bpstat_copy of the chain. */
8644 bpstat_clear (&tp->control.stop_bpstat);
8646 tp->control = inf_status->thread_control;
8647 inf->control = inf_status->inferior_control;
8650 stop_stack_dummy = inf_status->stop_stack_dummy;
8651 stopped_by_random_signal = inf_status->stopped_by_random_signal;
8652 stop_after_trap = inf_status->stop_after_trap;
8654 if (target_has_stack)
8656 /* The point of catch_errors is that if the stack is clobbered,
8657 walking the stack might encounter a garbage pointer and
8658 error() trying to dereference it. */
8660 (restore_selected_frame, &inf_status->selected_frame_id,
8661 "Unable to restore previously selected frame:\n",
8662 RETURN_MASK_ERROR) == 0)
8663 /* Error in restoring the selected frame. Select the innermost
8665 select_frame (get_current_frame ());
8672 do_restore_infcall_control_state_cleanup (void *sts)
8674 restore_infcall_control_state (sts);
8678 make_cleanup_restore_infcall_control_state
8679 (struct infcall_control_state *inf_status)
8681 return make_cleanup (do_restore_infcall_control_state_cleanup, inf_status);
8685 discard_infcall_control_state (struct infcall_control_state *inf_status)
8687 if (inf_status->thread_control.step_resume_breakpoint)
8688 inf_status->thread_control.step_resume_breakpoint->disposition
8689 = disp_del_at_next_stop;
8691 if (inf_status->thread_control.exception_resume_breakpoint)
8692 inf_status->thread_control.exception_resume_breakpoint->disposition
8693 = disp_del_at_next_stop;
8695 /* See save_infcall_control_state for info on stop_bpstat. */
8696 bpstat_clear (&inf_status->thread_control.stop_bpstat);
8701 /* restore_inferior_ptid() will be used by the cleanup machinery
8702 to restore the inferior_ptid value saved in a call to
8703 save_inferior_ptid(). */
8706 restore_inferior_ptid (void *arg)
8708 ptid_t *saved_ptid_ptr = arg;
8710 inferior_ptid = *saved_ptid_ptr;
8714 /* Save the value of inferior_ptid so that it may be restored by a
8715 later call to do_cleanups(). Returns the struct cleanup pointer
8716 needed for later doing the cleanup. */
8719 save_inferior_ptid (void)
8721 ptid_t *saved_ptid_ptr;
8723 saved_ptid_ptr = xmalloc (sizeof (ptid_t));
8724 *saved_ptid_ptr = inferior_ptid;
8725 return make_cleanup (restore_inferior_ptid, saved_ptid_ptr);
8731 clear_exit_convenience_vars (void)
8733 clear_internalvar (lookup_internalvar ("_exitsignal"));
8734 clear_internalvar (lookup_internalvar ("_exitcode"));
8738 /* User interface for reverse debugging:
8739 Set exec-direction / show exec-direction commands
8740 (returns error unless target implements to_set_exec_direction method). */
8742 int execution_direction = EXEC_FORWARD;
8743 static const char exec_forward[] = "forward";
8744 static const char exec_reverse[] = "reverse";
8745 static const char *exec_direction = exec_forward;
8746 static const char *const exec_direction_names[] = {
8753 set_exec_direction_func (char *args, int from_tty,
8754 struct cmd_list_element *cmd)
8756 if (target_can_execute_reverse)
8758 if (!strcmp (exec_direction, exec_forward))
8759 execution_direction = EXEC_FORWARD;
8760 else if (!strcmp (exec_direction, exec_reverse))
8761 execution_direction = EXEC_REVERSE;
8765 exec_direction = exec_forward;
8766 error (_("Target does not support this operation."));
8771 show_exec_direction_func (struct ui_file *out, int from_tty,
8772 struct cmd_list_element *cmd, const char *value)
8774 switch (execution_direction) {
8776 fprintf_filtered (out, _("Forward.\n"));
8779 fprintf_filtered (out, _("Reverse.\n"));
8782 internal_error (__FILE__, __LINE__,
8783 _("bogus execution_direction value: %d"),
8784 (int) execution_direction);
8789 show_schedule_multiple (struct ui_file *file, int from_tty,
8790 struct cmd_list_element *c, const char *value)
8792 fprintf_filtered (file, _("Resuming the execution of threads "
8793 "of all processes is %s.\n"), value);
8796 /* Implementation of `siginfo' variable. */
8798 static const struct internalvar_funcs siginfo_funcs =
8805 /* Callback for infrun's target events source. This is marked when a
8806 thread has a pending status to process. */
8809 infrun_async_inferior_event_handler (gdb_client_data data)
8811 /* If the target is closed while this event source is marked, we
8812 will reach here without execution, or a target to call
8813 target_wait on, which is an error. Instead of tracking whether
8814 the target has been popped already, or whether we do have threads
8815 with pending statutes, simply ignore the event. */
8816 if (!target_is_async_p ())
8819 inferior_event_handler (INF_REG_EVENT, NULL);
8823 _initialize_infrun (void)
8827 struct cmd_list_element *c;
8829 /* Register extra event sources in the event loop. */
8830 infrun_async_inferior_event_token
8831 = create_async_event_handler (infrun_async_inferior_event_handler, NULL);
8833 add_info ("signals", signals_info, _("\
8834 What debugger does when program gets various signals.\n\
8835 Specify a signal as argument to print info on that signal only."));
8836 add_info_alias ("handle", "signals", 0);
8838 c = add_com ("handle", class_run, handle_command, _("\
8839 Specify how to handle signals.\n\
8840 Usage: handle SIGNAL [ACTIONS]\n\
8841 Args are signals and actions to apply to those signals.\n\
8842 If no actions are specified, the current settings for the specified signals\n\
8843 will be displayed instead.\n\
8845 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
8846 from 1-15 are allowed for compatibility with old versions of GDB.\n\
8847 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
8848 The special arg \"all\" is recognized to mean all signals except those\n\
8849 used by the debugger, typically SIGTRAP and SIGINT.\n\
8851 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
8852 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
8853 Stop means reenter debugger if this signal happens (implies print).\n\
8854 Print means print a message if this signal happens.\n\
8855 Pass means let program see this signal; otherwise program doesn't know.\n\
8856 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
8857 Pass and Stop may be combined.\n\
8859 Multiple signals may be specified. Signal numbers and signal names\n\
8860 may be interspersed with actions, with the actions being performed for\n\
8861 all signals cumulatively specified."));
8862 set_cmd_completer (c, handle_completer);
8865 stop_command = add_cmd ("stop", class_obscure,
8866 not_just_help_class_command, _("\
8867 There is no `stop' command, but you can set a hook on `stop'.\n\
8868 This allows you to set a list of commands to be run each time execution\n\
8869 of the program stops."), &cmdlist);
8871 add_setshow_zuinteger_cmd ("infrun", class_maintenance, &debug_infrun, _("\
8872 Set inferior debugging."), _("\
8873 Show inferior debugging."), _("\
8874 When non-zero, inferior specific debugging is enabled."),
8877 &setdebuglist, &showdebuglist);
8879 add_setshow_boolean_cmd ("displaced", class_maintenance,
8880 &debug_displaced, _("\
8881 Set displaced stepping debugging."), _("\
8882 Show displaced stepping debugging."), _("\
8883 When non-zero, displaced stepping specific debugging is enabled."),
8885 show_debug_displaced,
8886 &setdebuglist, &showdebuglist);
8888 add_setshow_boolean_cmd ("non-stop", no_class,
8890 Set whether gdb controls the inferior in non-stop mode."), _("\
8891 Show whether gdb controls the inferior in non-stop mode."), _("\
8892 When debugging a multi-threaded program and this setting is\n\
8893 off (the default, also called all-stop mode), when one thread stops\n\
8894 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
8895 all other threads in the program while you interact with the thread of\n\
8896 interest. When you continue or step a thread, you can allow the other\n\
8897 threads to run, or have them remain stopped, but while you inspect any\n\
8898 thread's state, all threads stop.\n\
8900 In non-stop mode, when one thread stops, other threads can continue\n\
8901 to run freely. You'll be able to step each thread independently,\n\
8902 leave it stopped or free to run as needed."),
8908 numsigs = (int) GDB_SIGNAL_LAST;
8909 signal_stop = (unsigned char *) xmalloc (sizeof (signal_stop[0]) * numsigs);
8910 signal_print = (unsigned char *)
8911 xmalloc (sizeof (signal_print[0]) * numsigs);
8912 signal_program = (unsigned char *)
8913 xmalloc (sizeof (signal_program[0]) * numsigs);
8914 signal_catch = (unsigned char *)
8915 xmalloc (sizeof (signal_catch[0]) * numsigs);
8916 signal_pass = (unsigned char *)
8917 xmalloc (sizeof (signal_pass[0]) * numsigs);
8918 for (i = 0; i < numsigs; i++)
8921 signal_print[i] = 1;
8922 signal_program[i] = 1;
8923 signal_catch[i] = 0;
8926 /* Signals caused by debugger's own actions should not be given to
8927 the program afterwards.
8929 Do not deliver GDB_SIGNAL_TRAP by default, except when the user
8930 explicitly specifies that it should be delivered to the target
8931 program. Typically, that would occur when a user is debugging a
8932 target monitor on a simulator: the target monitor sets a
8933 breakpoint; the simulator encounters this breakpoint and halts
8934 the simulation handing control to GDB; GDB, noting that the stop
8935 address doesn't map to any known breakpoint, returns control back
8936 to the simulator; the simulator then delivers the hardware
8937 equivalent of a GDB_SIGNAL_TRAP to the program being
8939 signal_program[GDB_SIGNAL_TRAP] = 0;
8940 signal_program[GDB_SIGNAL_INT] = 0;
8942 /* Signals that are not errors should not normally enter the debugger. */
8943 signal_stop[GDB_SIGNAL_ALRM] = 0;
8944 signal_print[GDB_SIGNAL_ALRM] = 0;
8945 signal_stop[GDB_SIGNAL_VTALRM] = 0;
8946 signal_print[GDB_SIGNAL_VTALRM] = 0;
8947 signal_stop[GDB_SIGNAL_PROF] = 0;
8948 signal_print[GDB_SIGNAL_PROF] = 0;
8949 signal_stop[GDB_SIGNAL_CHLD] = 0;
8950 signal_print[GDB_SIGNAL_CHLD] = 0;
8951 signal_stop[GDB_SIGNAL_IO] = 0;
8952 signal_print[GDB_SIGNAL_IO] = 0;
8953 signal_stop[GDB_SIGNAL_POLL] = 0;
8954 signal_print[GDB_SIGNAL_POLL] = 0;
8955 signal_stop[GDB_SIGNAL_URG] = 0;
8956 signal_print[GDB_SIGNAL_URG] = 0;
8957 signal_stop[GDB_SIGNAL_WINCH] = 0;
8958 signal_print[GDB_SIGNAL_WINCH] = 0;
8959 signal_stop[GDB_SIGNAL_PRIO] = 0;
8960 signal_print[GDB_SIGNAL_PRIO] = 0;
8962 /* These signals are used internally by user-level thread
8963 implementations. (See signal(5) on Solaris.) Like the above
8964 signals, a healthy program receives and handles them as part of
8965 its normal operation. */
8966 signal_stop[GDB_SIGNAL_LWP] = 0;
8967 signal_print[GDB_SIGNAL_LWP] = 0;
8968 signal_stop[GDB_SIGNAL_WAITING] = 0;
8969 signal_print[GDB_SIGNAL_WAITING] = 0;
8970 signal_stop[GDB_SIGNAL_CANCEL] = 0;
8971 signal_print[GDB_SIGNAL_CANCEL] = 0;
8973 /* Update cached state. */
8974 signal_cache_update (-1);
8976 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support,
8977 &stop_on_solib_events, _("\
8978 Set stopping for shared library events."), _("\
8979 Show stopping for shared library events."), _("\
8980 If nonzero, gdb will give control to the user when the dynamic linker\n\
8981 notifies gdb of shared library events. The most common event of interest\n\
8982 to the user would be loading/unloading of a new library."),
8983 set_stop_on_solib_events,
8984 show_stop_on_solib_events,
8985 &setlist, &showlist);
8987 add_setshow_enum_cmd ("follow-fork-mode", class_run,
8988 follow_fork_mode_kind_names,
8989 &follow_fork_mode_string, _("\
8990 Set debugger response to a program call of fork or vfork."), _("\
8991 Show debugger response to a program call of fork or vfork."), _("\
8992 A fork or vfork creates a new process. follow-fork-mode can be:\n\
8993 parent - the original process is debugged after a fork\n\
8994 child - the new process is debugged after a fork\n\
8995 The unfollowed process will continue to run.\n\
8996 By default, the debugger will follow the parent process."),
8998 show_follow_fork_mode_string,
8999 &setlist, &showlist);
9001 add_setshow_enum_cmd ("follow-exec-mode", class_run,
9002 follow_exec_mode_names,
9003 &follow_exec_mode_string, _("\
9004 Set debugger response to a program call of exec."), _("\
9005 Show debugger response to a program call of exec."), _("\
9006 An exec call replaces the program image of a process.\n\
9008 follow-exec-mode can be:\n\
9010 new - the debugger creates a new inferior and rebinds the process\n\
9011 to this new inferior. The program the process was running before\n\
9012 the exec call can be restarted afterwards by restarting the original\n\
9015 same - the debugger keeps the process bound to the same inferior.\n\
9016 The new executable image replaces the previous executable loaded in\n\
9017 the inferior. Restarting the inferior after the exec call restarts\n\
9018 the executable the process was running after the exec call.\n\
9020 By default, the debugger will use the same inferior."),
9022 show_follow_exec_mode_string,
9023 &setlist, &showlist);
9025 add_setshow_enum_cmd ("scheduler-locking", class_run,
9026 scheduler_enums, &scheduler_mode, _("\
9027 Set mode for locking scheduler during execution."), _("\
9028 Show mode for locking scheduler during execution."), _("\
9029 off == no locking (threads may preempt at any time)\n\
9030 on == full locking (no thread except the current thread may run)\n\
9031 step == scheduler locked during stepping commands (step, next, stepi, nexti).\n\
9032 In this mode, other threads may run during other commands."),
9033 set_schedlock_func, /* traps on target vector */
9034 show_scheduler_mode,
9035 &setlist, &showlist);
9037 add_setshow_boolean_cmd ("schedule-multiple", class_run, &sched_multi, _("\
9038 Set mode for resuming threads of all processes."), _("\
9039 Show mode for resuming threads of all processes."), _("\
9040 When on, execution commands (such as 'continue' or 'next') resume all\n\
9041 threads of all processes. When off (which is the default), execution\n\
9042 commands only resume the threads of the current process. The set of\n\
9043 threads that are resumed is further refined by the scheduler-locking\n\
9044 mode (see help set scheduler-locking)."),
9046 show_schedule_multiple,
9047 &setlist, &showlist);
9049 add_setshow_boolean_cmd ("step-mode", class_run, &step_stop_if_no_debug, _("\
9050 Set mode of the step operation."), _("\
9051 Show mode of the step operation."), _("\
9052 When set, doing a step over a function without debug line information\n\
9053 will stop at the first instruction of that function. Otherwise, the\n\
9054 function is skipped and the step command stops at a different source line."),
9056 show_step_stop_if_no_debug,
9057 &setlist, &showlist);
9059 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run,
9060 &can_use_displaced_stepping, _("\
9061 Set debugger's willingness to use displaced stepping."), _("\
9062 Show debugger's willingness to use displaced stepping."), _("\
9063 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
9064 supported by the target architecture. If off, gdb will not use displaced\n\
9065 stepping to step over breakpoints, even if such is supported by the target\n\
9066 architecture. If auto (which is the default), gdb will use displaced stepping\n\
9067 if the target architecture supports it and non-stop mode is active, but will not\n\
9068 use it in all-stop mode (see help set non-stop)."),
9070 show_can_use_displaced_stepping,
9071 &setlist, &showlist);
9073 add_setshow_enum_cmd ("exec-direction", class_run, exec_direction_names,
9074 &exec_direction, _("Set direction of execution.\n\
9075 Options are 'forward' or 'reverse'."),
9076 _("Show direction of execution (forward/reverse)."),
9077 _("Tells gdb whether to execute forward or backward."),
9078 set_exec_direction_func, show_exec_direction_func,
9079 &setlist, &showlist);
9081 /* Set/show detach-on-fork: user-settable mode. */
9083 add_setshow_boolean_cmd ("detach-on-fork", class_run, &detach_fork, _("\
9084 Set whether gdb will detach the child of a fork."), _("\
9085 Show whether gdb will detach the child of a fork."), _("\
9086 Tells gdb whether to detach the child of a fork."),
9087 NULL, NULL, &setlist, &showlist);
9089 /* Set/show disable address space randomization mode. */
9091 add_setshow_boolean_cmd ("disable-randomization", class_support,
9092 &disable_randomization, _("\
9093 Set disabling of debuggee's virtual address space randomization."), _("\
9094 Show disabling of debuggee's virtual address space randomization."), _("\
9095 When this mode is on (which is the default), randomization of the virtual\n\
9096 address space is disabled. Standalone programs run with the randomization\n\
9097 enabled by default on some platforms."),
9098 &set_disable_randomization,
9099 &show_disable_randomization,
9100 &setlist, &showlist);
9102 /* ptid initializations */
9103 inferior_ptid = null_ptid;
9104 target_last_wait_ptid = minus_one_ptid;
9106 observer_attach_thread_ptid_changed (infrun_thread_ptid_changed);
9107 observer_attach_thread_stop_requested (infrun_thread_stop_requested);
9108 observer_attach_thread_exit (infrun_thread_thread_exit);
9109 observer_attach_inferior_exit (infrun_inferior_exit);
9111 /* Explicitly create without lookup, since that tries to create a
9112 value with a void typed value, and when we get here, gdbarch
9113 isn't initialized yet. At this point, we're quite sure there
9114 isn't another convenience variable of the same name. */
9115 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs, NULL);
9117 add_setshow_boolean_cmd ("observer", no_class,
9118 &observer_mode_1, _("\
9119 Set whether gdb controls the inferior in observer mode."), _("\
9120 Show whether gdb controls the inferior in observer mode."), _("\
9121 In observer mode, GDB can get data from the inferior, but not\n\
9122 affect its execution. Registers and memory may not be changed,\n\
9123 breakpoints may not be set, and the program cannot be interrupted\n\