1 /* Target-struct-independent code to start (run) and stop an inferior
4 Copyright (C) 1986-2018 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"
41 #include "observable.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"
65 #include "thread-fsm.h"
66 #include "common/enum-flags.h"
67 #include "progspace-and-thread.h"
68 #include "common/gdb_optional.h"
69 #include "arch-utils.h"
71 /* Prototypes for local functions */
73 static void sig_print_info (enum gdb_signal);
75 static void sig_print_header (void);
77 static int follow_fork (void);
79 static int follow_fork_inferior (int follow_child, int detach_fork);
81 static void follow_inferior_reset_breakpoints (void);
83 static int currently_stepping (struct thread_info *tp);
85 void nullify_last_target_wait_ptid (void);
87 static void insert_hp_step_resume_breakpoint_at_frame (struct frame_info *);
89 static void insert_step_resume_breakpoint_at_caller (struct frame_info *);
91 static void insert_longjmp_resume_breakpoint (struct gdbarch *, CORE_ADDR);
93 static int maybe_software_singlestep (struct gdbarch *gdbarch, CORE_ADDR pc);
95 /* Asynchronous signal handler registered as event loop source for
96 when we have pending events ready to be passed to the core. */
97 static struct async_event_handler *infrun_async_inferior_event_token;
99 /* Stores whether infrun_async was previously enabled or disabled.
100 Starts off as -1, indicating "never enabled/disabled". */
101 static int infrun_is_async = -1;
106 infrun_async (int enable)
108 if (infrun_is_async != enable)
110 infrun_is_async = enable;
113 fprintf_unfiltered (gdb_stdlog,
114 "infrun: infrun_async(%d)\n",
118 mark_async_event_handler (infrun_async_inferior_event_token);
120 clear_async_event_handler (infrun_async_inferior_event_token);
127 mark_infrun_async_event_handler (void)
129 mark_async_event_handler (infrun_async_inferior_event_token);
132 /* When set, stop the 'step' command if we enter a function which has
133 no line number information. The normal behavior is that we step
134 over such function. */
135 int step_stop_if_no_debug = 0;
137 show_step_stop_if_no_debug (struct ui_file *file, int from_tty,
138 struct cmd_list_element *c, const char *value)
140 fprintf_filtered (file, _("Mode of the step operation is %s.\n"), value);
143 /* proceed and normal_stop use this to notify the user when the
144 inferior stopped in a different thread than it had been running
147 static ptid_t previous_inferior_ptid;
149 /* If set (default for legacy reasons), when following a fork, GDB
150 will detach from one of the fork branches, child or parent.
151 Exactly which branch is detached depends on 'set follow-fork-mode'
154 static int detach_fork = 1;
156 int debug_displaced = 0;
158 show_debug_displaced (struct ui_file *file, int from_tty,
159 struct cmd_list_element *c, const char *value)
161 fprintf_filtered (file, _("Displace stepping debugging is %s.\n"), value);
164 unsigned int debug_infrun = 0;
166 show_debug_infrun (struct ui_file *file, int from_tty,
167 struct cmd_list_element *c, const char *value)
169 fprintf_filtered (file, _("Inferior debugging is %s.\n"), value);
173 /* Support for disabling address space randomization. */
175 int disable_randomization = 1;
178 show_disable_randomization (struct ui_file *file, int from_tty,
179 struct cmd_list_element *c, const char *value)
181 if (target_supports_disable_randomization ())
182 fprintf_filtered (file,
183 _("Disabling randomization of debuggee's "
184 "virtual address space is %s.\n"),
187 fputs_filtered (_("Disabling randomization of debuggee's "
188 "virtual address space is unsupported on\n"
189 "this platform.\n"), file);
193 set_disable_randomization (const char *args, int from_tty,
194 struct cmd_list_element *c)
196 if (!target_supports_disable_randomization ())
197 error (_("Disabling randomization of debuggee's "
198 "virtual address space is unsupported on\n"
202 /* User interface for non-stop mode. */
205 static int non_stop_1 = 0;
208 set_non_stop (const char *args, int from_tty,
209 struct cmd_list_element *c)
211 if (target_has_execution)
213 non_stop_1 = non_stop;
214 error (_("Cannot change this setting while the inferior is running."));
217 non_stop = non_stop_1;
221 show_non_stop (struct ui_file *file, int from_tty,
222 struct cmd_list_element *c, const char *value)
224 fprintf_filtered (file,
225 _("Controlling the inferior in non-stop mode is %s.\n"),
229 /* "Observer mode" is somewhat like a more extreme version of
230 non-stop, in which all GDB operations that might affect the
231 target's execution have been disabled. */
233 int observer_mode = 0;
234 static int observer_mode_1 = 0;
237 set_observer_mode (const char *args, int from_tty,
238 struct cmd_list_element *c)
240 if (target_has_execution)
242 observer_mode_1 = observer_mode;
243 error (_("Cannot change this setting while the inferior is running."));
246 observer_mode = observer_mode_1;
248 may_write_registers = !observer_mode;
249 may_write_memory = !observer_mode;
250 may_insert_breakpoints = !observer_mode;
251 may_insert_tracepoints = !observer_mode;
252 /* We can insert fast tracepoints in or out of observer mode,
253 but enable them if we're going into this mode. */
255 may_insert_fast_tracepoints = 1;
256 may_stop = !observer_mode;
257 update_target_permissions ();
259 /* Going *into* observer mode we must force non-stop, then
260 going out we leave it that way. */
263 pagination_enabled = 0;
264 non_stop = non_stop_1 = 1;
268 printf_filtered (_("Observer mode is now %s.\n"),
269 (observer_mode ? "on" : "off"));
273 show_observer_mode (struct ui_file *file, int from_tty,
274 struct cmd_list_element *c, const char *value)
276 fprintf_filtered (file, _("Observer mode is %s.\n"), value);
279 /* This updates the value of observer mode based on changes in
280 permissions. Note that we are deliberately ignoring the values of
281 may-write-registers and may-write-memory, since the user may have
282 reason to enable these during a session, for instance to turn on a
283 debugging-related global. */
286 update_observer_mode (void)
290 newval = (!may_insert_breakpoints
291 && !may_insert_tracepoints
292 && may_insert_fast_tracepoints
296 /* Let the user know if things change. */
297 if (newval != observer_mode)
298 printf_filtered (_("Observer mode is now %s.\n"),
299 (newval ? "on" : "off"));
301 observer_mode = observer_mode_1 = newval;
304 /* Tables of how to react to signals; the user sets them. */
306 static unsigned char *signal_stop;
307 static unsigned char *signal_print;
308 static unsigned char *signal_program;
310 /* Table of signals that are registered with "catch signal". A
311 non-zero entry indicates that the signal is caught by some "catch
312 signal" command. This has size GDB_SIGNAL_LAST, to accommodate all
314 static unsigned char *signal_catch;
316 /* Table of signals that the target may silently handle.
317 This is automatically determined from the flags above,
318 and simply cached here. */
319 static unsigned char *signal_pass;
321 #define SET_SIGS(nsigs,sigs,flags) \
323 int signum = (nsigs); \
324 while (signum-- > 0) \
325 if ((sigs)[signum]) \
326 (flags)[signum] = 1; \
329 #define UNSET_SIGS(nsigs,sigs,flags) \
331 int signum = (nsigs); \
332 while (signum-- > 0) \
333 if ((sigs)[signum]) \
334 (flags)[signum] = 0; \
337 /* Update the target's copy of SIGNAL_PROGRAM. The sole purpose of
338 this function is to avoid exporting `signal_program'. */
341 update_signals_program_target (void)
343 target_program_signals ((int) GDB_SIGNAL_LAST, signal_program);
346 /* Value to pass to target_resume() to cause all threads to resume. */
348 #define RESUME_ALL minus_one_ptid
350 /* Command list pointer for the "stop" placeholder. */
352 static struct cmd_list_element *stop_command;
354 /* Nonzero if we want to give control to the user when we're notified
355 of shared library events by the dynamic linker. */
356 int stop_on_solib_events;
358 /* Enable or disable optional shared library event breakpoints
359 as appropriate when the above flag is changed. */
362 set_stop_on_solib_events (const char *args,
363 int from_tty, struct cmd_list_element *c)
365 update_solib_breakpoints ();
369 show_stop_on_solib_events (struct ui_file *file, int from_tty,
370 struct cmd_list_element *c, const char *value)
372 fprintf_filtered (file, _("Stopping for shared library events is %s.\n"),
376 /* Nonzero after stop if current stack frame should be printed. */
378 static int stop_print_frame;
380 /* This is a cached copy of the pid/waitstatus of the last event
381 returned by target_wait()/deprecated_target_wait_hook(). This
382 information is returned by get_last_target_status(). */
383 static ptid_t target_last_wait_ptid;
384 static struct target_waitstatus target_last_waitstatus;
386 static void context_switch (ptid_t ptid);
388 void init_thread_stepping_state (struct thread_info *tss);
390 static const char follow_fork_mode_child[] = "child";
391 static const char follow_fork_mode_parent[] = "parent";
393 static const char *const follow_fork_mode_kind_names[] = {
394 follow_fork_mode_child,
395 follow_fork_mode_parent,
399 static const char *follow_fork_mode_string = follow_fork_mode_parent;
401 show_follow_fork_mode_string (struct ui_file *file, int from_tty,
402 struct cmd_list_element *c, const char *value)
404 fprintf_filtered (file,
405 _("Debugger response to a program "
406 "call of fork or vfork is \"%s\".\n"),
411 /* Handle changes to the inferior list based on the type of fork,
412 which process is being followed, and whether the other process
413 should be detached. On entry inferior_ptid must be the ptid of
414 the fork parent. At return inferior_ptid is the ptid of the
415 followed inferior. */
418 follow_fork_inferior (int follow_child, int detach_fork)
421 ptid_t parent_ptid, child_ptid;
423 has_vforked = (inferior_thread ()->pending_follow.kind
424 == TARGET_WAITKIND_VFORKED);
425 parent_ptid = inferior_ptid;
426 child_ptid = inferior_thread ()->pending_follow.value.related_pid;
429 && !non_stop /* Non-stop always resumes both branches. */
430 && current_ui->prompt_state == PROMPT_BLOCKED
431 && !(follow_child || detach_fork || sched_multi))
433 /* The parent stays blocked inside the vfork syscall until the
434 child execs or exits. If we don't let the child run, then
435 the parent stays blocked. If we're telling the parent to run
436 in the foreground, the user will not be able to ctrl-c to get
437 back the terminal, effectively hanging the debug session. */
438 fprintf_filtered (gdb_stderr, _("\
439 Can not resume the parent process over vfork in the foreground while\n\
440 holding the child stopped. Try \"set detach-on-fork\" or \
441 \"set schedule-multiple\".\n"));
442 /* FIXME output string > 80 columns. */
448 /* Detach new forked process? */
451 /* Before detaching from the child, remove all breakpoints
452 from it. If we forked, then this has already been taken
453 care of by infrun.c. If we vforked however, any
454 breakpoint inserted in the parent is visible in the
455 child, even those added while stopped in a vfork
456 catchpoint. This will remove the breakpoints from the
457 parent also, but they'll be reinserted below. */
460 /* Keep breakpoints list in sync. */
461 remove_breakpoints_pid (ptid_get_pid (inferior_ptid));
464 if (print_inferior_events)
466 /* Ensure that we have a process ptid. */
467 ptid_t process_ptid = pid_to_ptid (ptid_get_pid (child_ptid));
469 target_terminal::ours_for_output ();
470 fprintf_filtered (gdb_stdlog,
471 _("[Detaching after %s from child %s]\n"),
472 has_vforked ? "vfork" : "fork",
473 target_pid_to_str (process_ptid));
478 struct inferior *parent_inf, *child_inf;
480 /* Add process to GDB's tables. */
481 child_inf = add_inferior (ptid_get_pid (child_ptid));
483 parent_inf = current_inferior ();
484 child_inf->attach_flag = parent_inf->attach_flag;
485 copy_terminal_info (child_inf, parent_inf);
486 child_inf->gdbarch = parent_inf->gdbarch;
487 copy_inferior_target_desc_info (child_inf, parent_inf);
489 scoped_restore_current_pspace_and_thread restore_pspace_thread;
491 inferior_ptid = child_ptid;
492 add_thread_silent (inferior_ptid);
493 set_current_inferior (child_inf);
494 child_inf->symfile_flags = SYMFILE_NO_READ;
496 /* If this is a vfork child, then the address-space is
497 shared with the parent. */
500 child_inf->pspace = parent_inf->pspace;
501 child_inf->aspace = parent_inf->aspace;
503 /* The parent will be frozen until the child is done
504 with the shared region. Keep track of the
506 child_inf->vfork_parent = parent_inf;
507 child_inf->pending_detach = 0;
508 parent_inf->vfork_child = child_inf;
509 parent_inf->pending_detach = 0;
513 child_inf->aspace = new_address_space ();
514 child_inf->pspace = new program_space (child_inf->aspace);
515 child_inf->removable = 1;
516 set_current_program_space (child_inf->pspace);
517 clone_program_space (child_inf->pspace, parent_inf->pspace);
519 /* Let the shared library layer (e.g., solib-svr4) learn
520 about this new process, relocate the cloned exec, pull
521 in shared libraries, and install the solib event
522 breakpoint. If a "cloned-VM" event was propagated
523 better throughout the core, this wouldn't be
525 solib_create_inferior_hook (0);
531 struct inferior *parent_inf;
533 parent_inf = current_inferior ();
535 /* If we detached from the child, then we have to be careful
536 to not insert breakpoints in the parent until the child
537 is done with the shared memory region. However, if we're
538 staying attached to the child, then we can and should
539 insert breakpoints, so that we can debug it. A
540 subsequent child exec or exit is enough to know when does
541 the child stops using the parent's address space. */
542 parent_inf->waiting_for_vfork_done = detach_fork;
543 parent_inf->pspace->breakpoints_not_allowed = detach_fork;
548 /* Follow the child. */
549 struct inferior *parent_inf, *child_inf;
550 struct program_space *parent_pspace;
552 if (print_inferior_events)
554 std::string parent_pid = target_pid_to_str (parent_ptid);
555 std::string child_pid = target_pid_to_str (child_ptid);
557 target_terminal::ours_for_output ();
558 fprintf_filtered (gdb_stdlog,
559 _("[Attaching after %s %s to child %s]\n"),
561 has_vforked ? "vfork" : "fork",
565 /* Add the new inferior first, so that the target_detach below
566 doesn't unpush the target. */
568 child_inf = add_inferior (ptid_get_pid (child_ptid));
570 parent_inf = current_inferior ();
571 child_inf->attach_flag = parent_inf->attach_flag;
572 copy_terminal_info (child_inf, parent_inf);
573 child_inf->gdbarch = parent_inf->gdbarch;
574 copy_inferior_target_desc_info (child_inf, parent_inf);
576 parent_pspace = parent_inf->pspace;
578 /* If we're vforking, we want to hold on to the parent until the
579 child exits or execs. At child exec or exit time we can
580 remove the old breakpoints from the parent and detach or
581 resume debugging it. Otherwise, detach the parent now; we'll
582 want to reuse it's program/address spaces, but we can't set
583 them to the child before removing breakpoints from the
584 parent, otherwise, the breakpoints module could decide to
585 remove breakpoints from the wrong process (since they'd be
586 assigned to the same address space). */
590 gdb_assert (child_inf->vfork_parent == NULL);
591 gdb_assert (parent_inf->vfork_child == NULL);
592 child_inf->vfork_parent = parent_inf;
593 child_inf->pending_detach = 0;
594 parent_inf->vfork_child = child_inf;
595 parent_inf->pending_detach = detach_fork;
596 parent_inf->waiting_for_vfork_done = 0;
598 else if (detach_fork)
600 if (print_inferior_events)
602 /* Ensure that we have a process ptid. */
603 ptid_t process_ptid = pid_to_ptid (ptid_get_pid (parent_ptid));
605 target_terminal::ours_for_output ();
606 fprintf_filtered (gdb_stdlog,
607 _("[Detaching after fork from "
609 target_pid_to_str (process_ptid));
612 target_detach (parent_inf, 0);
615 /* Note that the detach above makes PARENT_INF dangling. */
617 /* Add the child thread to the appropriate lists, and switch to
618 this new thread, before cloning the program space, and
619 informing the solib layer about this new process. */
621 inferior_ptid = child_ptid;
622 add_thread_silent (inferior_ptid);
623 set_current_inferior (child_inf);
625 /* If this is a vfork child, then the address-space is shared
626 with the parent. If we detached from the parent, then we can
627 reuse the parent's program/address spaces. */
628 if (has_vforked || detach_fork)
630 child_inf->pspace = parent_pspace;
631 child_inf->aspace = child_inf->pspace->aspace;
635 child_inf->aspace = new_address_space ();
636 child_inf->pspace = new program_space (child_inf->aspace);
637 child_inf->removable = 1;
638 child_inf->symfile_flags = SYMFILE_NO_READ;
639 set_current_program_space (child_inf->pspace);
640 clone_program_space (child_inf->pspace, parent_pspace);
642 /* Let the shared library layer (e.g., solib-svr4) learn
643 about this new process, relocate the cloned exec, pull in
644 shared libraries, and install the solib event breakpoint.
645 If a "cloned-VM" event was propagated better throughout
646 the core, this wouldn't be required. */
647 solib_create_inferior_hook (0);
651 return target_follow_fork (follow_child, detach_fork);
654 /* Tell the target to follow the fork we're stopped at. Returns true
655 if the inferior should be resumed; false, if the target for some
656 reason decided it's best not to resume. */
661 int follow_child = (follow_fork_mode_string == follow_fork_mode_child);
662 int should_resume = 1;
663 struct thread_info *tp;
665 /* Copy user stepping state to the new inferior thread. FIXME: the
666 followed fork child thread should have a copy of most of the
667 parent thread structure's run control related fields, not just these.
668 Initialized to avoid "may be used uninitialized" warnings from gcc. */
669 struct breakpoint *step_resume_breakpoint = NULL;
670 struct breakpoint *exception_resume_breakpoint = NULL;
671 CORE_ADDR step_range_start = 0;
672 CORE_ADDR step_range_end = 0;
673 struct frame_id step_frame_id = { 0 };
674 struct thread_fsm *thread_fsm = NULL;
679 struct target_waitstatus wait_status;
681 /* Get the last target status returned by target_wait(). */
682 get_last_target_status (&wait_ptid, &wait_status);
684 /* If not stopped at a fork event, then there's nothing else to
686 if (wait_status.kind != TARGET_WAITKIND_FORKED
687 && wait_status.kind != TARGET_WAITKIND_VFORKED)
690 /* Check if we switched over from WAIT_PTID, since the event was
692 if (!ptid_equal (wait_ptid, minus_one_ptid)
693 && !ptid_equal (inferior_ptid, wait_ptid))
695 /* We did. Switch back to WAIT_PTID thread, to tell the
696 target to follow it (in either direction). We'll
697 afterwards refuse to resume, and inform the user what
699 switch_to_thread (wait_ptid);
704 tp = inferior_thread ();
706 /* If there were any forks/vforks that were caught and are now to be
707 followed, then do so now. */
708 switch (tp->pending_follow.kind)
710 case TARGET_WAITKIND_FORKED:
711 case TARGET_WAITKIND_VFORKED:
713 ptid_t parent, child;
715 /* If the user did a next/step, etc, over a fork call,
716 preserve the stepping state in the fork child. */
717 if (follow_child && should_resume)
719 step_resume_breakpoint = clone_momentary_breakpoint
720 (tp->control.step_resume_breakpoint);
721 step_range_start = tp->control.step_range_start;
722 step_range_end = tp->control.step_range_end;
723 step_frame_id = tp->control.step_frame_id;
724 exception_resume_breakpoint
725 = clone_momentary_breakpoint (tp->control.exception_resume_breakpoint);
726 thread_fsm = tp->thread_fsm;
728 /* For now, delete the parent's sr breakpoint, otherwise,
729 parent/child sr breakpoints are considered duplicates,
730 and the child version will not be installed. Remove
731 this when the breakpoints module becomes aware of
732 inferiors and address spaces. */
733 delete_step_resume_breakpoint (tp);
734 tp->control.step_range_start = 0;
735 tp->control.step_range_end = 0;
736 tp->control.step_frame_id = null_frame_id;
737 delete_exception_resume_breakpoint (tp);
738 tp->thread_fsm = NULL;
741 parent = inferior_ptid;
742 child = tp->pending_follow.value.related_pid;
744 /* Set up inferior(s) as specified by the caller, and tell the
745 target to do whatever is necessary to follow either parent
747 if (follow_fork_inferior (follow_child, detach_fork))
749 /* Target refused to follow, or there's some other reason
750 we shouldn't resume. */
755 /* This pending follow fork event is now handled, one way
756 or another. The previous selected thread may be gone
757 from the lists by now, but if it is still around, need
758 to clear the pending follow request. */
759 tp = find_thread_ptid (parent);
761 tp->pending_follow.kind = TARGET_WAITKIND_SPURIOUS;
763 /* This makes sure we don't try to apply the "Switched
764 over from WAIT_PID" logic above. */
765 nullify_last_target_wait_ptid ();
767 /* If we followed the child, switch to it... */
770 switch_to_thread (child);
772 /* ... and preserve the stepping state, in case the
773 user was stepping over the fork call. */
776 tp = inferior_thread ();
777 tp->control.step_resume_breakpoint
778 = step_resume_breakpoint;
779 tp->control.step_range_start = step_range_start;
780 tp->control.step_range_end = step_range_end;
781 tp->control.step_frame_id = step_frame_id;
782 tp->control.exception_resume_breakpoint
783 = exception_resume_breakpoint;
784 tp->thread_fsm = thread_fsm;
788 /* If we get here, it was because we're trying to
789 resume from a fork catchpoint, but, the user
790 has switched threads away from the thread that
791 forked. In that case, the resume command
792 issued is most likely not applicable to the
793 child, so just warn, and refuse to resume. */
794 warning (_("Not resuming: switched threads "
795 "before following fork child."));
798 /* Reset breakpoints in the child as appropriate. */
799 follow_inferior_reset_breakpoints ();
802 switch_to_thread (parent);
806 case TARGET_WAITKIND_SPURIOUS:
807 /* Nothing to follow. */
810 internal_error (__FILE__, __LINE__,
811 "Unexpected pending_follow.kind %d\n",
812 tp->pending_follow.kind);
816 return should_resume;
820 follow_inferior_reset_breakpoints (void)
822 struct thread_info *tp = inferior_thread ();
824 /* Was there a step_resume breakpoint? (There was if the user
825 did a "next" at the fork() call.) If so, explicitly reset its
826 thread number. Cloned step_resume breakpoints are disabled on
827 creation, so enable it here now that it is associated with the
830 step_resumes are a form of bp that are made to be per-thread.
831 Since we created the step_resume bp when the parent process
832 was being debugged, and now are switching to the child process,
833 from the breakpoint package's viewpoint, that's a switch of
834 "threads". We must update the bp's notion of which thread
835 it is for, or it'll be ignored when it triggers. */
837 if (tp->control.step_resume_breakpoint)
839 breakpoint_re_set_thread (tp->control.step_resume_breakpoint);
840 tp->control.step_resume_breakpoint->loc->enabled = 1;
843 /* Treat exception_resume breakpoints like step_resume breakpoints. */
844 if (tp->control.exception_resume_breakpoint)
846 breakpoint_re_set_thread (tp->control.exception_resume_breakpoint);
847 tp->control.exception_resume_breakpoint->loc->enabled = 1;
850 /* Reinsert all breakpoints in the child. The user may have set
851 breakpoints after catching the fork, in which case those
852 were never set in the child, but only in the parent. This makes
853 sure the inserted breakpoints match the breakpoint list. */
855 breakpoint_re_set ();
856 insert_breakpoints ();
859 /* The child has exited or execed: resume threads of the parent the
860 user wanted to be executing. */
863 proceed_after_vfork_done (struct thread_info *thread,
866 int pid = * (int *) arg;
868 if (ptid_get_pid (thread->ptid) == pid
869 && is_running (thread->ptid)
870 && !is_executing (thread->ptid)
871 && !thread->stop_requested
872 && thread->suspend.stop_signal == GDB_SIGNAL_0)
875 fprintf_unfiltered (gdb_stdlog,
876 "infrun: resuming vfork parent thread %s\n",
877 target_pid_to_str (thread->ptid));
879 switch_to_thread (thread->ptid);
880 clear_proceed_status (0);
881 proceed ((CORE_ADDR) -1, GDB_SIGNAL_DEFAULT);
887 /* Save/restore inferior_ptid, current program space and current
888 inferior. Only use this if the current context points at an exited
889 inferior (and therefore there's no current thread to save). */
890 class scoped_restore_exited_inferior
893 scoped_restore_exited_inferior ()
894 : m_saved_ptid (&inferior_ptid)
898 scoped_restore_tmpl<ptid_t> m_saved_ptid;
899 scoped_restore_current_program_space m_pspace;
900 scoped_restore_current_inferior m_inferior;
903 /* Called whenever we notice an exec or exit event, to handle
904 detaching or resuming a vfork parent. */
907 handle_vfork_child_exec_or_exit (int exec)
909 struct inferior *inf = current_inferior ();
911 if (inf->vfork_parent)
913 int resume_parent = -1;
915 /* This exec or exit marks the end of the shared memory region
916 between the parent and the child. If the user wanted to
917 detach from the parent, now is the time. */
919 if (inf->vfork_parent->pending_detach)
921 struct thread_info *tp;
922 struct program_space *pspace;
923 struct address_space *aspace;
925 /* follow-fork child, detach-on-fork on. */
927 inf->vfork_parent->pending_detach = 0;
929 gdb::optional<scoped_restore_exited_inferior>
930 maybe_restore_inferior;
931 gdb::optional<scoped_restore_current_pspace_and_thread>
932 maybe_restore_thread;
934 /* If we're handling a child exit, then inferior_ptid points
935 at the inferior's pid, not to a thread. */
937 maybe_restore_inferior.emplace ();
939 maybe_restore_thread.emplace ();
941 /* We're letting loose of the parent. */
942 tp = any_live_thread_of_process (inf->vfork_parent->pid);
943 switch_to_thread (tp->ptid);
945 /* We're about to detach from the parent, which implicitly
946 removes breakpoints from its address space. There's a
947 catch here: we want to reuse the spaces for the child,
948 but, parent/child are still sharing the pspace at this
949 point, although the exec in reality makes the kernel give
950 the child a fresh set of new pages. The problem here is
951 that the breakpoints module being unaware of this, would
952 likely chose the child process to write to the parent
953 address space. Swapping the child temporarily away from
954 the spaces has the desired effect. Yes, this is "sort
957 pspace = inf->pspace;
958 aspace = inf->aspace;
962 if (print_inferior_events)
965 = target_pid_to_str (pid_to_ptid (inf->vfork_parent->pid));
967 target_terminal::ours_for_output ();
971 fprintf_filtered (gdb_stdlog,
972 _("[Detaching vfork parent %s "
973 "after child exec]\n"), pidstr);
977 fprintf_filtered (gdb_stdlog,
978 _("[Detaching vfork parent %s "
979 "after child exit]\n"), pidstr);
983 target_detach (inf->vfork_parent, 0);
986 inf->pspace = pspace;
987 inf->aspace = aspace;
991 /* We're staying attached to the parent, so, really give the
992 child a new address space. */
993 inf->pspace = new program_space (maybe_new_address_space ());
994 inf->aspace = inf->pspace->aspace;
996 set_current_program_space (inf->pspace);
998 resume_parent = inf->vfork_parent->pid;
1000 /* Break the bonds. */
1001 inf->vfork_parent->vfork_child = NULL;
1005 struct program_space *pspace;
1007 /* If this is a vfork child exiting, then the pspace and
1008 aspaces were shared with the parent. Since we're
1009 reporting the process exit, we'll be mourning all that is
1010 found in the address space, and switching to null_ptid,
1011 preparing to start a new inferior. But, since we don't
1012 want to clobber the parent's address/program spaces, we
1013 go ahead and create a new one for this exiting
1016 /* Switch to null_ptid while running clone_program_space, so
1017 that clone_program_space doesn't want to read the
1018 selected frame of a dead process. */
1019 scoped_restore restore_ptid
1020 = make_scoped_restore (&inferior_ptid, null_ptid);
1022 /* This inferior is dead, so avoid giving the breakpoints
1023 module the option to write through to it (cloning a
1024 program space resets breakpoints). */
1027 pspace = new program_space (maybe_new_address_space ());
1028 set_current_program_space (pspace);
1030 inf->symfile_flags = SYMFILE_NO_READ;
1031 clone_program_space (pspace, inf->vfork_parent->pspace);
1032 inf->pspace = pspace;
1033 inf->aspace = pspace->aspace;
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 scoped_restore_current_thread restore_thread;
1051 fprintf_unfiltered (gdb_stdlog,
1052 "infrun: resuming vfork parent process %d\n",
1055 iterate_over_threads (proceed_after_vfork_done, &resume_parent);
1060 /* Enum strings for "set|show follow-exec-mode". */
1062 static const char follow_exec_mode_new[] = "new";
1063 static const char follow_exec_mode_same[] = "same";
1064 static const char *const follow_exec_mode_names[] =
1066 follow_exec_mode_new,
1067 follow_exec_mode_same,
1071 static const char *follow_exec_mode_string = follow_exec_mode_same;
1073 show_follow_exec_mode_string (struct ui_file *file, int from_tty,
1074 struct cmd_list_element *c, const char *value)
1076 fprintf_filtered (file, _("Follow exec mode is \"%s\".\n"), value);
1079 /* EXEC_FILE_TARGET is assumed to be non-NULL. */
1082 follow_exec (ptid_t ptid, char *exec_file_target)
1084 struct thread_info *th, *tmp;
1085 struct inferior *inf = current_inferior ();
1086 int pid = ptid_get_pid (ptid);
1087 ptid_t process_ptid;
1089 /* This is an exec event that we actually wish to pay attention to.
1090 Refresh our symbol table to the newly exec'd program, remove any
1091 momentary bp's, etc.
1093 If there are breakpoints, they aren't really inserted now,
1094 since the exec() transformed our inferior into a fresh set
1097 We want to preserve symbolic breakpoints on the list, since
1098 we have hopes that they can be reset after the new a.out's
1099 symbol table is read.
1101 However, any "raw" breakpoints must be removed from the list
1102 (e.g., the solib bp's), since their address is probably invalid
1105 And, we DON'T want to call delete_breakpoints() here, since
1106 that may write the bp's "shadow contents" (the instruction
1107 value that was overwritten witha TRAP instruction). Since
1108 we now have a new a.out, those shadow contents aren't valid. */
1110 mark_breakpoints_out ();
1112 /* The target reports the exec event to the main thread, even if
1113 some other thread does the exec, and even if the main thread was
1114 stopped or already gone. We may still have non-leader threads of
1115 the process on our list. E.g., on targets that don't have thread
1116 exit events (like remote); or on native Linux in non-stop mode if
1117 there were only two threads in the inferior and the non-leader
1118 one is the one that execs (and nothing forces an update of the
1119 thread list up to here). When debugging remotely, it's best to
1120 avoid extra traffic, when possible, so avoid syncing the thread
1121 list with the target, and instead go ahead and delete all threads
1122 of the process but one that reported the event. Note this must
1123 be done before calling update_breakpoints_after_exec, as
1124 otherwise clearing the threads' resources would reference stale
1125 thread breakpoints -- it may have been one of these threads that
1126 stepped across the exec. We could just clear their stepping
1127 states, but as long as we're iterating, might as well delete
1128 them. Deleting them now rather than at the next user-visible
1129 stop provides a nicer sequence of events for user and MI
1131 ALL_THREADS_SAFE (th, tmp)
1132 if (ptid_get_pid (th->ptid) == pid && !ptid_equal (th->ptid, ptid))
1133 delete_thread (th->ptid);
1135 /* We also need to clear any left over stale state for the
1136 leader/event thread. E.g., if there was any step-resume
1137 breakpoint or similar, it's gone now. We cannot truly
1138 step-to-next statement through an exec(). */
1139 th = inferior_thread ();
1140 th->control.step_resume_breakpoint = NULL;
1141 th->control.exception_resume_breakpoint = NULL;
1142 th->control.single_step_breakpoints = NULL;
1143 th->control.step_range_start = 0;
1144 th->control.step_range_end = 0;
1146 /* The user may have had the main thread held stopped in the
1147 previous image (e.g., schedlock on, or non-stop). Release
1149 th->stop_requested = 0;
1151 update_breakpoints_after_exec ();
1153 /* What is this a.out's name? */
1154 process_ptid = pid_to_ptid (pid);
1155 printf_unfiltered (_("%s is executing new program: %s\n"),
1156 target_pid_to_str (process_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 gdb::unique_xmalloc_ptr<char> exec_file_host
1167 = exec_file_find (exec_file_target, NULL);
1169 /* If we were unable to map the executable target pathname onto a host
1170 pathname, tell the user that. Otherwise GDB's subsequent behavior
1171 is confusing. Maybe it would even be better to stop at this point
1172 so that the user can specify a file manually before continuing. */
1173 if (exec_file_host == NULL)
1174 warning (_("Could not load symbols for executable %s.\n"
1175 "Do you need \"set sysroot\"?"),
1178 /* Reset the shared library package. This ensures that we get a
1179 shlib event when the child reaches "_start", at which point the
1180 dld will have had a chance to initialize the child. */
1181 /* Also, loading a symbol file below may trigger symbol lookups, and
1182 we don't want those to be satisfied by the libraries of the
1183 previous incarnation of this process. */
1184 no_shared_libraries (NULL, 0);
1186 if (follow_exec_mode_string == follow_exec_mode_new)
1188 /* The user wants to keep the old inferior and program spaces
1189 around. Create a new fresh one, and switch to it. */
1191 /* Do exit processing for the original inferior before adding
1192 the new inferior so we don't have two active inferiors with
1193 the same ptid, which can confuse find_inferior_ptid. */
1194 exit_inferior_num_silent (current_inferior ()->num);
1196 inf = add_inferior_with_spaces ();
1198 target_follow_exec (inf, exec_file_target);
1200 set_current_inferior (inf);
1201 set_current_program_space (inf->pspace);
1205 /* The old description may no longer be fit for the new image.
1206 E.g, a 64-bit process exec'ed a 32-bit process. Clear the
1207 old description; we'll read a new one below. No need to do
1208 this on "follow-exec-mode new", as the old inferior stays
1209 around (its description is later cleared/refetched on
1211 target_clear_description ();
1214 gdb_assert (current_program_space == inf->pspace);
1216 /* Attempt to open the exec file. SYMFILE_DEFER_BP_RESET is used
1217 because the proper displacement for a PIE (Position Independent
1218 Executable) main symbol file will only be computed by
1219 solib_create_inferior_hook below. breakpoint_re_set would fail
1220 to insert the breakpoints with the zero displacement. */
1221 try_open_exec_file (exec_file_host.get (), inf, SYMFILE_DEFER_BP_RESET);
1223 /* If the target can specify a description, read it. Must do this
1224 after flipping to the new executable (because the target supplied
1225 description must be compatible with the executable's
1226 architecture, and the old executable may e.g., be 32-bit, while
1227 the new one 64-bit), and before anything involving memory or
1229 target_find_description ();
1231 /* The add_thread call ends up reading registers, so do it after updating the
1232 target description. */
1233 if (follow_exec_mode_string == follow_exec_mode_new)
1236 solib_create_inferior_hook (0);
1238 jit_inferior_created_hook ();
1240 breakpoint_re_set ();
1242 /* Reinsert all breakpoints. (Those which were symbolic have
1243 been reset to the proper address in the new a.out, thanks
1244 to symbol_file_command...). */
1245 insert_breakpoints ();
1247 /* The next resume of this inferior should bring it to the shlib
1248 startup breakpoints. (If the user had also set bp's on
1249 "main" from the old (parent) process, then they'll auto-
1250 matically get reset there in the new process.). */
1253 /* The queue of threads that need to do a step-over operation to get
1254 past e.g., a breakpoint. What technique is used to step over the
1255 breakpoint/watchpoint does not matter -- all threads end up in the
1256 same queue, to maintain rough temporal order of execution, in order
1257 to avoid starvation, otherwise, we could e.g., find ourselves
1258 constantly stepping the same couple threads past their breakpoints
1259 over and over, if the single-step finish fast enough. */
1260 struct thread_info *step_over_queue_head;
1262 /* Bit flags indicating what the thread needs to step over. */
1264 enum step_over_what_flag
1266 /* Step over a breakpoint. */
1267 STEP_OVER_BREAKPOINT = 1,
1269 /* Step past a non-continuable watchpoint, in order to let the
1270 instruction execute so we can evaluate the watchpoint
1272 STEP_OVER_WATCHPOINT = 2
1274 DEF_ENUM_FLAGS_TYPE (enum step_over_what_flag, step_over_what);
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 const 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;
1291 /* The thread's global number. */
1295 /* The step-over info of the location that is being stepped over.
1297 Note that with async/breakpoint always-inserted mode, a user might
1298 set a new breakpoint/watchpoint/etc. exactly while a breakpoint is
1299 being stepped over. As setting a new breakpoint inserts all
1300 breakpoints, we need to make sure the breakpoint being stepped over
1301 isn't inserted then. We do that by only clearing the step-over
1302 info when the step-over is actually finished (or aborted).
1304 Presently GDB can only step over one breakpoint at any given time.
1305 Given threads that can't run code in the same address space as the
1306 breakpoint's can't really miss the breakpoint, GDB could be taught
1307 to step-over at most one breakpoint per address space (so this info
1308 could move to the address space object if/when GDB is extended).
1309 The set of breakpoints being stepped over will normally be much
1310 smaller than the set of all breakpoints, so a flag in the
1311 breakpoint location structure would be wasteful. A separate list
1312 also saves complexity and run-time, as otherwise we'd have to go
1313 through all breakpoint locations clearing their flag whenever we
1314 start a new sequence. Similar considerations weigh against storing
1315 this info in the thread object. Plus, not all step overs actually
1316 have breakpoint locations -- e.g., stepping past a single-step
1317 breakpoint, or stepping to complete a non-continuable
1319 static struct step_over_info step_over_info;
1321 /* Record the address of the breakpoint/instruction we're currently
1323 N.B. We record the aspace and address now, instead of say just the thread,
1324 because when we need the info later the thread may be running. */
1327 set_step_over_info (const address_space *aspace, CORE_ADDR address,
1328 int nonsteppable_watchpoint_p,
1331 step_over_info.aspace = aspace;
1332 step_over_info.address = address;
1333 step_over_info.nonsteppable_watchpoint_p = nonsteppable_watchpoint_p;
1334 step_over_info.thread = thread;
1337 /* Called when we're not longer stepping over a breakpoint / an
1338 instruction, so all breakpoints are free to be (re)inserted. */
1341 clear_step_over_info (void)
1344 fprintf_unfiltered (gdb_stdlog,
1345 "infrun: clear_step_over_info\n");
1346 step_over_info.aspace = NULL;
1347 step_over_info.address = 0;
1348 step_over_info.nonsteppable_watchpoint_p = 0;
1349 step_over_info.thread = -1;
1355 stepping_past_instruction_at (struct address_space *aspace,
1358 return (step_over_info.aspace != NULL
1359 && breakpoint_address_match (aspace, address,
1360 step_over_info.aspace,
1361 step_over_info.address));
1367 thread_is_stepping_over_breakpoint (int thread)
1369 return (step_over_info.thread != -1
1370 && thread == step_over_info.thread);
1376 stepping_past_nonsteppable_watchpoint (void)
1378 return step_over_info.nonsteppable_watchpoint_p;
1381 /* Returns true if step-over info is valid. */
1384 step_over_info_valid_p (void)
1386 return (step_over_info.aspace != NULL
1387 || stepping_past_nonsteppable_watchpoint ());
1391 /* Displaced stepping. */
1393 /* In non-stop debugging mode, we must take special care to manage
1394 breakpoints properly; in particular, the traditional strategy for
1395 stepping a thread past a breakpoint it has hit is unsuitable.
1396 'Displaced stepping' is a tactic for stepping one thread past a
1397 breakpoint it has hit while ensuring that other threads running
1398 concurrently will hit the breakpoint as they should.
1400 The traditional way to step a thread T off a breakpoint in a
1401 multi-threaded program in all-stop mode is as follows:
1403 a0) Initially, all threads are stopped, and breakpoints are not
1405 a1) We single-step T, leaving breakpoints uninserted.
1406 a2) We insert breakpoints, and resume all threads.
1408 In non-stop debugging, however, this strategy is unsuitable: we
1409 don't want to have to stop all threads in the system in order to
1410 continue or step T past a breakpoint. Instead, we use displaced
1413 n0) Initially, T is stopped, other threads are running, and
1414 breakpoints are inserted.
1415 n1) We copy the instruction "under" the breakpoint to a separate
1416 location, outside the main code stream, making any adjustments
1417 to the instruction, register, and memory state as directed by
1419 n2) We single-step T over the instruction at its new location.
1420 n3) We adjust the resulting register and memory state as directed
1421 by T's architecture. This includes resetting T's PC to point
1422 back into the main instruction stream.
1425 This approach depends on the following gdbarch methods:
1427 - gdbarch_max_insn_length and gdbarch_displaced_step_location
1428 indicate where to copy the instruction, and how much space must
1429 be reserved there. We use these in step n1.
1431 - gdbarch_displaced_step_copy_insn copies a instruction to a new
1432 address, and makes any necessary adjustments to the instruction,
1433 register contents, and memory. We use this in step n1.
1435 - gdbarch_displaced_step_fixup adjusts registers and memory after
1436 we have successfuly single-stepped the instruction, to yield the
1437 same effect the instruction would have had if we had executed it
1438 at its original address. We use this in step n3.
1440 The gdbarch_displaced_step_copy_insn and
1441 gdbarch_displaced_step_fixup functions must be written so that
1442 copying an instruction with gdbarch_displaced_step_copy_insn,
1443 single-stepping across the copied instruction, and then applying
1444 gdbarch_displaced_insn_fixup should have the same effects on the
1445 thread's memory and registers as stepping the instruction in place
1446 would have. Exactly which responsibilities fall to the copy and
1447 which fall to the fixup is up to the author of those functions.
1449 See the comments in gdbarch.sh for details.
1451 Note that displaced stepping and software single-step cannot
1452 currently be used in combination, although with some care I think
1453 they could be made to. Software single-step works by placing
1454 breakpoints on all possible subsequent instructions; if the
1455 displaced instruction is a PC-relative jump, those breakpoints
1456 could fall in very strange places --- on pages that aren't
1457 executable, or at addresses that are not proper instruction
1458 boundaries. (We do generally let other threads run while we wait
1459 to hit the software single-step breakpoint, and they might
1460 encounter such a corrupted instruction.) One way to work around
1461 this would be to have gdbarch_displaced_step_copy_insn fully
1462 simulate the effect of PC-relative instructions (and return NULL)
1463 on architectures that use software single-stepping.
1465 In non-stop mode, we can have independent and simultaneous step
1466 requests, so more than one thread may need to simultaneously step
1467 over a breakpoint. The current implementation assumes there is
1468 only one scratch space per process. In this case, we have to
1469 serialize access to the scratch space. If thread A wants to step
1470 over a breakpoint, but we are currently waiting for some other
1471 thread to complete a displaced step, we leave thread A stopped and
1472 place it in the displaced_step_request_queue. Whenever a displaced
1473 step finishes, we pick the next thread in the queue and start a new
1474 displaced step operation on it. See displaced_step_prepare and
1475 displaced_step_fixup for details. */
1477 /* Default destructor for displaced_step_closure. */
1479 displaced_step_closure::~displaced_step_closure () = default;
1481 /* Per-inferior displaced stepping state. */
1482 struct displaced_step_inferior_state
1484 /* Pointer to next in linked list. */
1485 struct displaced_step_inferior_state *next;
1487 /* The process this displaced step state refers to. */
1490 /* True if preparing a displaced step ever failed. If so, we won't
1491 try displaced stepping for this inferior again. */
1494 /* If this is not null_ptid, this is the thread carrying out a
1495 displaced single-step in process PID. This thread's state will
1496 require fixing up once it has completed its step. */
1499 /* The architecture the thread had when we stepped it. */
1500 struct gdbarch *step_gdbarch;
1502 /* The closure provided gdbarch_displaced_step_copy_insn, to be used
1503 for post-step cleanup. */
1504 struct displaced_step_closure *step_closure;
1506 /* The address of the original instruction, and the copy we
1508 CORE_ADDR step_original, step_copy;
1510 /* Saved contents of copy area. */
1511 gdb_byte *step_saved_copy;
1514 /* The list of states of processes involved in displaced stepping
1516 static struct displaced_step_inferior_state *displaced_step_inferior_states;
1518 /* Get the displaced stepping state of process PID. */
1520 static struct displaced_step_inferior_state *
1521 get_displaced_stepping_state (int pid)
1523 struct displaced_step_inferior_state *state;
1525 for (state = displaced_step_inferior_states;
1527 state = state->next)
1528 if (state->pid == pid)
1534 /* Returns true if any inferior has a thread doing a displaced
1538 displaced_step_in_progress_any_inferior (void)
1540 struct displaced_step_inferior_state *state;
1542 for (state = displaced_step_inferior_states;
1544 state = state->next)
1545 if (!ptid_equal (state->step_ptid, null_ptid))
1551 /* Return true if thread represented by PTID is doing a displaced
1555 displaced_step_in_progress_thread (ptid_t ptid)
1557 struct displaced_step_inferior_state *displaced;
1559 gdb_assert (!ptid_equal (ptid, null_ptid));
1561 displaced = get_displaced_stepping_state (ptid_get_pid (ptid));
1563 return (displaced != NULL && ptid_equal (displaced->step_ptid, ptid));
1566 /* Return true if process PID has a thread doing a displaced step. */
1569 displaced_step_in_progress (int pid)
1571 struct displaced_step_inferior_state *displaced;
1573 displaced = get_displaced_stepping_state (pid);
1574 if (displaced != NULL && !ptid_equal (displaced->step_ptid, null_ptid))
1580 /* Add a new displaced stepping state for process PID to the displaced
1581 stepping state list, or return a pointer to an already existing
1582 entry, if it already exists. Never returns NULL. */
1584 static struct displaced_step_inferior_state *
1585 add_displaced_stepping_state (int pid)
1587 struct displaced_step_inferior_state *state;
1589 for (state = displaced_step_inferior_states;
1591 state = state->next)
1592 if (state->pid == pid)
1595 state = XCNEW (struct displaced_step_inferior_state);
1597 state->next = displaced_step_inferior_states;
1598 displaced_step_inferior_states = state;
1603 /* If inferior is in displaced stepping, and ADDR equals to starting address
1604 of copy area, return corresponding displaced_step_closure. Otherwise,
1607 struct displaced_step_closure*
1608 get_displaced_step_closure_by_addr (CORE_ADDR addr)
1610 struct displaced_step_inferior_state *displaced
1611 = get_displaced_stepping_state (ptid_get_pid (inferior_ptid));
1613 /* If checking the mode of displaced instruction in copy area. */
1614 if (displaced && !ptid_equal (displaced->step_ptid, null_ptid)
1615 && (displaced->step_copy == addr))
1616 return displaced->step_closure;
1621 /* Remove the displaced stepping state of process PID. */
1624 remove_displaced_stepping_state (int pid)
1626 struct displaced_step_inferior_state *it, **prev_next_p;
1628 gdb_assert (pid != 0);
1630 it = displaced_step_inferior_states;
1631 prev_next_p = &displaced_step_inferior_states;
1636 *prev_next_p = it->next;
1641 prev_next_p = &it->next;
1647 infrun_inferior_exit (struct inferior *inf)
1649 remove_displaced_stepping_state (inf->pid);
1652 /* If ON, and the architecture supports it, GDB will use displaced
1653 stepping to step over breakpoints. If OFF, or if the architecture
1654 doesn't support it, GDB will instead use the traditional
1655 hold-and-step approach. If AUTO (which is the default), GDB will
1656 decide which technique to use to step over breakpoints depending on
1657 which of all-stop or non-stop mode is active --- displaced stepping
1658 in non-stop mode; hold-and-step in all-stop mode. */
1660 static enum auto_boolean can_use_displaced_stepping = AUTO_BOOLEAN_AUTO;
1663 show_can_use_displaced_stepping (struct ui_file *file, int from_tty,
1664 struct cmd_list_element *c,
1667 if (can_use_displaced_stepping == AUTO_BOOLEAN_AUTO)
1668 fprintf_filtered (file,
1669 _("Debugger's willingness to use displaced stepping "
1670 "to step over breakpoints is %s (currently %s).\n"),
1671 value, target_is_non_stop_p () ? "on" : "off");
1673 fprintf_filtered (file,
1674 _("Debugger's willingness to use displaced stepping "
1675 "to step over breakpoints is %s.\n"), value);
1678 /* Return non-zero if displaced stepping can/should be used to step
1679 over breakpoints of thread TP. */
1682 use_displaced_stepping (struct thread_info *tp)
1684 struct regcache *regcache = get_thread_regcache (tp->ptid);
1685 struct gdbarch *gdbarch = regcache->arch ();
1686 struct displaced_step_inferior_state *displaced_state;
1688 displaced_state = get_displaced_stepping_state (ptid_get_pid (tp->ptid));
1690 return (((can_use_displaced_stepping == AUTO_BOOLEAN_AUTO
1691 && target_is_non_stop_p ())
1692 || can_use_displaced_stepping == AUTO_BOOLEAN_TRUE)
1693 && gdbarch_displaced_step_copy_insn_p (gdbarch)
1694 && find_record_target () == NULL
1695 && (displaced_state == NULL
1696 || !displaced_state->failed_before));
1699 /* Clean out any stray displaced stepping state. */
1701 displaced_step_clear (struct displaced_step_inferior_state *displaced)
1703 /* Indicate that there is no cleanup pending. */
1704 displaced->step_ptid = null_ptid;
1706 delete displaced->step_closure;
1707 displaced->step_closure = NULL;
1711 displaced_step_clear_cleanup (void *arg)
1713 struct displaced_step_inferior_state *state
1714 = (struct displaced_step_inferior_state *) arg;
1716 displaced_step_clear (state);
1719 /* Dump LEN bytes at BUF in hex to FILE, followed by a newline. */
1721 displaced_step_dump_bytes (struct ui_file *file,
1722 const gdb_byte *buf,
1727 for (i = 0; i < len; i++)
1728 fprintf_unfiltered (file, "%02x ", buf[i]);
1729 fputs_unfiltered ("\n", file);
1732 /* Prepare to single-step, using displaced stepping.
1734 Note that we cannot use displaced stepping when we have a signal to
1735 deliver. If we have a signal to deliver and an instruction to step
1736 over, then after the step, there will be no indication from the
1737 target whether the thread entered a signal handler or ignored the
1738 signal and stepped over the instruction successfully --- both cases
1739 result in a simple SIGTRAP. In the first case we mustn't do a
1740 fixup, and in the second case we must --- but we can't tell which.
1741 Comments in the code for 'random signals' in handle_inferior_event
1742 explain how we handle this case instead.
1744 Returns 1 if preparing was successful -- this thread is going to be
1745 stepped now; 0 if displaced stepping this thread got queued; or -1
1746 if this instruction can't be displaced stepped. */
1749 displaced_step_prepare_throw (ptid_t ptid)
1751 struct cleanup *ignore_cleanups;
1752 struct thread_info *tp = find_thread_ptid (ptid);
1753 struct regcache *regcache = get_thread_regcache (ptid);
1754 struct gdbarch *gdbarch = regcache->arch ();
1755 const address_space *aspace = regcache->aspace ();
1756 CORE_ADDR original, copy;
1758 struct displaced_step_closure *closure;
1759 struct displaced_step_inferior_state *displaced;
1762 /* We should never reach this function if the architecture does not
1763 support displaced stepping. */
1764 gdb_assert (gdbarch_displaced_step_copy_insn_p (gdbarch));
1766 /* Nor if the thread isn't meant to step over a breakpoint. */
1767 gdb_assert (tp->control.trap_expected);
1769 /* Disable range stepping while executing in the scratch pad. We
1770 want a single-step even if executing the displaced instruction in
1771 the scratch buffer lands within the stepping range (e.g., a
1773 tp->control.may_range_step = 0;
1775 /* We have to displaced step one thread at a time, as we only have
1776 access to a single scratch space per inferior. */
1778 displaced = add_displaced_stepping_state (ptid_get_pid (ptid));
1780 if (!ptid_equal (displaced->step_ptid, null_ptid))
1782 /* Already waiting for a displaced step to finish. Defer this
1783 request and place in queue. */
1785 if (debug_displaced)
1786 fprintf_unfiltered (gdb_stdlog,
1787 "displaced: deferring step of %s\n",
1788 target_pid_to_str (ptid));
1790 thread_step_over_chain_enqueue (tp);
1795 if (debug_displaced)
1796 fprintf_unfiltered (gdb_stdlog,
1797 "displaced: stepping %s now\n",
1798 target_pid_to_str (ptid));
1801 displaced_step_clear (displaced);
1803 scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid);
1804 inferior_ptid = ptid;
1806 original = regcache_read_pc (regcache);
1808 copy = gdbarch_displaced_step_location (gdbarch);
1809 len = gdbarch_max_insn_length (gdbarch);
1811 if (breakpoint_in_range_p (aspace, copy, len))
1813 /* There's a breakpoint set in the scratch pad location range
1814 (which is usually around the entry point). We'd either
1815 install it before resuming, which would overwrite/corrupt the
1816 scratch pad, or if it was already inserted, this displaced
1817 step would overwrite it. The latter is OK in the sense that
1818 we already assume that no thread is going to execute the code
1819 in the scratch pad range (after initial startup) anyway, but
1820 the former is unacceptable. Simply punt and fallback to
1821 stepping over this breakpoint in-line. */
1822 if (debug_displaced)
1824 fprintf_unfiltered (gdb_stdlog,
1825 "displaced: breakpoint set in scratch pad. "
1826 "Stepping over breakpoint in-line instead.\n");
1832 /* Save the original contents of the copy area. */
1833 displaced->step_saved_copy = (gdb_byte *) xmalloc (len);
1834 ignore_cleanups = make_cleanup (free_current_contents,
1835 &displaced->step_saved_copy);
1836 status = target_read_memory (copy, displaced->step_saved_copy, len);
1838 throw_error (MEMORY_ERROR,
1839 _("Error accessing memory address %s (%s) for "
1840 "displaced-stepping scratch space."),
1841 paddress (gdbarch, copy), safe_strerror (status));
1842 if (debug_displaced)
1844 fprintf_unfiltered (gdb_stdlog, "displaced: saved %s: ",
1845 paddress (gdbarch, copy));
1846 displaced_step_dump_bytes (gdb_stdlog,
1847 displaced->step_saved_copy,
1851 closure = gdbarch_displaced_step_copy_insn (gdbarch,
1852 original, copy, regcache);
1853 if (closure == NULL)
1855 /* The architecture doesn't know how or want to displaced step
1856 this instruction or instruction sequence. Fallback to
1857 stepping over the breakpoint in-line. */
1858 do_cleanups (ignore_cleanups);
1862 /* Save the information we need to fix things up if the step
1864 displaced->step_ptid = ptid;
1865 displaced->step_gdbarch = gdbarch;
1866 displaced->step_closure = closure;
1867 displaced->step_original = original;
1868 displaced->step_copy = copy;
1870 make_cleanup (displaced_step_clear_cleanup, displaced);
1872 /* Resume execution at the copy. */
1873 regcache_write_pc (regcache, copy);
1875 discard_cleanups (ignore_cleanups);
1877 if (debug_displaced)
1878 fprintf_unfiltered (gdb_stdlog, "displaced: displaced pc to %s\n",
1879 paddress (gdbarch, copy));
1884 /* Wrapper for displaced_step_prepare_throw that disabled further
1885 attempts at displaced stepping if we get a memory error. */
1888 displaced_step_prepare (ptid_t ptid)
1894 prepared = displaced_step_prepare_throw (ptid);
1896 CATCH (ex, RETURN_MASK_ERROR)
1898 struct displaced_step_inferior_state *displaced_state;
1900 if (ex.error != MEMORY_ERROR
1901 && ex.error != NOT_SUPPORTED_ERROR)
1902 throw_exception (ex);
1906 fprintf_unfiltered (gdb_stdlog,
1907 "infrun: disabling displaced stepping: %s\n",
1911 /* Be verbose if "set displaced-stepping" is "on", silent if
1913 if (can_use_displaced_stepping == AUTO_BOOLEAN_TRUE)
1915 warning (_("disabling displaced stepping: %s"),
1919 /* Disable further displaced stepping attempts. */
1921 = get_displaced_stepping_state (ptid_get_pid (ptid));
1922 displaced_state->failed_before = 1;
1930 write_memory_ptid (ptid_t ptid, CORE_ADDR memaddr,
1931 const gdb_byte *myaddr, int len)
1933 scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid);
1935 inferior_ptid = ptid;
1936 write_memory (memaddr, myaddr, len);
1939 /* Restore the contents of the copy area for thread PTID. */
1942 displaced_step_restore (struct displaced_step_inferior_state *displaced,
1945 ULONGEST len = gdbarch_max_insn_length (displaced->step_gdbarch);
1947 write_memory_ptid (ptid, displaced->step_copy,
1948 displaced->step_saved_copy, len);
1949 if (debug_displaced)
1950 fprintf_unfiltered (gdb_stdlog, "displaced: restored %s %s\n",
1951 target_pid_to_str (ptid),
1952 paddress (displaced->step_gdbarch,
1953 displaced->step_copy));
1956 /* If we displaced stepped an instruction successfully, adjust
1957 registers and memory to yield the same effect the instruction would
1958 have had if we had executed it at its original address, and return
1959 1. If the instruction didn't complete, relocate the PC and return
1960 -1. If the thread wasn't displaced stepping, return 0. */
1963 displaced_step_fixup (ptid_t event_ptid, enum gdb_signal signal)
1965 struct cleanup *old_cleanups;
1966 struct displaced_step_inferior_state *displaced
1967 = get_displaced_stepping_state (ptid_get_pid (event_ptid));
1970 /* Was any thread of this process doing a displaced step? */
1971 if (displaced == NULL)
1974 /* Was this event for the pid we displaced? */
1975 if (ptid_equal (displaced->step_ptid, null_ptid)
1976 || ! ptid_equal (displaced->step_ptid, event_ptid))
1979 old_cleanups = make_cleanup (displaced_step_clear_cleanup, displaced);
1981 displaced_step_restore (displaced, displaced->step_ptid);
1983 /* Fixup may need to read memory/registers. Switch to the thread
1984 that we're fixing up. Also, target_stopped_by_watchpoint checks
1985 the current thread. */
1986 switch_to_thread (event_ptid);
1988 /* Did the instruction complete successfully? */
1989 if (signal == GDB_SIGNAL_TRAP
1990 && !(target_stopped_by_watchpoint ()
1991 && (gdbarch_have_nonsteppable_watchpoint (displaced->step_gdbarch)
1992 || target_have_steppable_watchpoint)))
1994 /* Fix up the resulting state. */
1995 gdbarch_displaced_step_fixup (displaced->step_gdbarch,
1996 displaced->step_closure,
1997 displaced->step_original,
1998 displaced->step_copy,
1999 get_thread_regcache (displaced->step_ptid));
2004 /* Since the instruction didn't complete, all we can do is
2006 struct regcache *regcache = get_thread_regcache (event_ptid);
2007 CORE_ADDR pc = regcache_read_pc (regcache);
2009 pc = displaced->step_original + (pc - displaced->step_copy);
2010 regcache_write_pc (regcache, pc);
2014 do_cleanups (old_cleanups);
2016 displaced->step_ptid = null_ptid;
2021 /* Data to be passed around while handling an event. This data is
2022 discarded between events. */
2023 struct execution_control_state
2026 /* The thread that got the event, if this was a thread event; NULL
2028 struct thread_info *event_thread;
2030 struct target_waitstatus ws;
2031 int stop_func_filled_in;
2032 CORE_ADDR stop_func_start;
2033 CORE_ADDR stop_func_end;
2034 const char *stop_func_name;
2037 /* True if the event thread hit the single-step breakpoint of
2038 another thread. Thus the event doesn't cause a stop, the thread
2039 needs to be single-stepped past the single-step breakpoint before
2040 we can switch back to the original stepping thread. */
2041 int hit_singlestep_breakpoint;
2044 /* Clear ECS and set it to point at TP. */
2047 reset_ecs (struct execution_control_state *ecs, struct thread_info *tp)
2049 memset (ecs, 0, sizeof (*ecs));
2050 ecs->event_thread = tp;
2051 ecs->ptid = tp->ptid;
2054 static void keep_going_pass_signal (struct execution_control_state *ecs);
2055 static void prepare_to_wait (struct execution_control_state *ecs);
2056 static int keep_going_stepped_thread (struct thread_info *tp);
2057 static step_over_what thread_still_needs_step_over (struct thread_info *tp);
2059 /* Are there any pending step-over requests? If so, run all we can
2060 now and return true. Otherwise, return false. */
2063 start_step_over (void)
2065 struct thread_info *tp, *next;
2067 /* Don't start a new step-over if we already have an in-line
2068 step-over operation ongoing. */
2069 if (step_over_info_valid_p ())
2072 for (tp = step_over_queue_head; tp != NULL; tp = next)
2074 struct execution_control_state ecss;
2075 struct execution_control_state *ecs = &ecss;
2076 step_over_what step_what;
2077 int must_be_in_line;
2079 gdb_assert (!tp->stop_requested);
2081 next = thread_step_over_chain_next (tp);
2083 /* If this inferior already has a displaced step in process,
2084 don't start a new one. */
2085 if (displaced_step_in_progress (ptid_get_pid (tp->ptid)))
2088 step_what = thread_still_needs_step_over (tp);
2089 must_be_in_line = ((step_what & STEP_OVER_WATCHPOINT)
2090 || ((step_what & STEP_OVER_BREAKPOINT)
2091 && !use_displaced_stepping (tp)));
2093 /* We currently stop all threads of all processes to step-over
2094 in-line. If we need to start a new in-line step-over, let
2095 any pending displaced steps finish first. */
2096 if (must_be_in_line && displaced_step_in_progress_any_inferior ())
2099 thread_step_over_chain_remove (tp);
2101 if (step_over_queue_head == NULL)
2104 fprintf_unfiltered (gdb_stdlog,
2105 "infrun: step-over queue now empty\n");
2108 if (tp->control.trap_expected
2112 internal_error (__FILE__, __LINE__,
2113 "[%s] has inconsistent state: "
2114 "trap_expected=%d, resumed=%d, executing=%d\n",
2115 target_pid_to_str (tp->ptid),
2116 tp->control.trap_expected,
2122 fprintf_unfiltered (gdb_stdlog,
2123 "infrun: resuming [%s] for step-over\n",
2124 target_pid_to_str (tp->ptid));
2126 /* keep_going_pass_signal skips the step-over if the breakpoint
2127 is no longer inserted. In all-stop, we want to keep looking
2128 for a thread that needs a step-over instead of resuming TP,
2129 because we wouldn't be able to resume anything else until the
2130 target stops again. In non-stop, the resume always resumes
2131 only TP, so it's OK to let the thread resume freely. */
2132 if (!target_is_non_stop_p () && !step_what)
2135 switch_to_thread (tp->ptid);
2136 reset_ecs (ecs, tp);
2137 keep_going_pass_signal (ecs);
2139 if (!ecs->wait_some_more)
2140 error (_("Command aborted."));
2142 gdb_assert (tp->resumed);
2144 /* If we started a new in-line step-over, we're done. */
2145 if (step_over_info_valid_p ())
2147 gdb_assert (tp->control.trap_expected);
2151 if (!target_is_non_stop_p ())
2153 /* On all-stop, shouldn't have resumed unless we needed a
2155 gdb_assert (tp->control.trap_expected
2156 || tp->step_after_step_resume_breakpoint);
2158 /* With remote targets (at least), in all-stop, we can't
2159 issue any further remote commands until the program stops
2164 /* Either the thread no longer needed a step-over, or a new
2165 displaced stepping sequence started. Even in the latter
2166 case, continue looking. Maybe we can also start another
2167 displaced step on a thread of other process. */
2173 /* Update global variables holding ptids to hold NEW_PTID if they were
2174 holding OLD_PTID. */
2176 infrun_thread_ptid_changed (ptid_t old_ptid, ptid_t new_ptid)
2178 struct displaced_step_inferior_state *displaced;
2180 if (ptid_equal (inferior_ptid, old_ptid))
2181 inferior_ptid = new_ptid;
2183 for (displaced = displaced_step_inferior_states;
2185 displaced = displaced->next)
2187 if (ptid_equal (displaced->step_ptid, old_ptid))
2188 displaced->step_ptid = new_ptid;
2194 static const char schedlock_off[] = "off";
2195 static const char schedlock_on[] = "on";
2196 static const char schedlock_step[] = "step";
2197 static const char schedlock_replay[] = "replay";
2198 static const char *const scheduler_enums[] = {
2205 static const char *scheduler_mode = schedlock_replay;
2207 show_scheduler_mode (struct ui_file *file, int from_tty,
2208 struct cmd_list_element *c, const char *value)
2210 fprintf_filtered (file,
2211 _("Mode for locking scheduler "
2212 "during execution is \"%s\".\n"),
2217 set_schedlock_func (const char *args, int from_tty, struct cmd_list_element *c)
2219 if (!target_can_lock_scheduler)
2221 scheduler_mode = schedlock_off;
2222 error (_("Target '%s' cannot support this command."), target_shortname);
2226 /* True if execution commands resume all threads of all processes by
2227 default; otherwise, resume only threads of the current inferior
2229 int sched_multi = 0;
2231 /* Try to setup for software single stepping over the specified location.
2232 Return 1 if target_resume() should use hardware single step.
2234 GDBARCH the current gdbarch.
2235 PC the location to step over. */
2238 maybe_software_singlestep (struct gdbarch *gdbarch, CORE_ADDR pc)
2242 if (execution_direction == EXEC_FORWARD
2243 && gdbarch_software_single_step_p (gdbarch))
2244 hw_step = !insert_single_step_breakpoints (gdbarch);
2252 user_visible_resume_ptid (int step)
2258 /* With non-stop mode on, threads are always handled
2260 resume_ptid = inferior_ptid;
2262 else if ((scheduler_mode == schedlock_on)
2263 || (scheduler_mode == schedlock_step && step))
2265 /* User-settable 'scheduler' mode requires solo thread
2267 resume_ptid = inferior_ptid;
2269 else if ((scheduler_mode == schedlock_replay)
2270 && target_record_will_replay (minus_one_ptid, execution_direction))
2272 /* User-settable 'scheduler' mode requires solo thread resume in replay
2274 resume_ptid = inferior_ptid;
2276 else if (!sched_multi && target_supports_multi_process ())
2278 /* Resume all threads of the current process (and none of other
2280 resume_ptid = pid_to_ptid (ptid_get_pid (inferior_ptid));
2284 /* Resume all threads of all processes. */
2285 resume_ptid = RESUME_ALL;
2291 /* Return a ptid representing the set of threads that we will resume,
2292 in the perspective of the target, assuming run control handling
2293 does not require leaving some threads stopped (e.g., stepping past
2294 breakpoint). USER_STEP indicates whether we're about to start the
2295 target for a stepping command. */
2298 internal_resume_ptid (int user_step)
2300 /* In non-stop, we always control threads individually. Note that
2301 the target may always work in non-stop mode even with "set
2302 non-stop off", in which case user_visible_resume_ptid could
2303 return a wildcard ptid. */
2304 if (target_is_non_stop_p ())
2305 return inferior_ptid;
2307 return user_visible_resume_ptid (user_step);
2310 /* Wrapper for target_resume, that handles infrun-specific
2314 do_target_resume (ptid_t resume_ptid, int step, enum gdb_signal sig)
2316 struct thread_info *tp = inferior_thread ();
2318 gdb_assert (!tp->stop_requested);
2320 /* Install inferior's terminal modes. */
2321 target_terminal::inferior ();
2323 /* Avoid confusing the next resume, if the next stop/resume
2324 happens to apply to another thread. */
2325 tp->suspend.stop_signal = GDB_SIGNAL_0;
2327 /* Advise target which signals may be handled silently.
2329 If we have removed breakpoints because we are stepping over one
2330 in-line (in any thread), we need to receive all signals to avoid
2331 accidentally skipping a breakpoint during execution of a signal
2334 Likewise if we're displaced stepping, otherwise a trap for a
2335 breakpoint in a signal handler might be confused with the
2336 displaced step finishing. We don't make the displaced_step_fixup
2337 step distinguish the cases instead, because:
2339 - a backtrace while stopped in the signal handler would show the
2340 scratch pad as frame older than the signal handler, instead of
2341 the real mainline code.
2343 - when the thread is later resumed, the signal handler would
2344 return to the scratch pad area, which would no longer be
2346 if (step_over_info_valid_p ()
2347 || displaced_step_in_progress (ptid_get_pid (tp->ptid)))
2348 target_pass_signals (0, NULL);
2350 target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
2352 target_resume (resume_ptid, step, sig);
2354 target_commit_resume ();
2357 /* Resume the inferior. SIG is the signal to give the inferior
2358 (GDB_SIGNAL_0 for none). Note: don't call this directly; instead
2359 call 'resume', which handles exceptions. */
2362 resume_1 (enum gdb_signal sig)
2364 struct regcache *regcache = get_current_regcache ();
2365 struct gdbarch *gdbarch = regcache->arch ();
2366 struct thread_info *tp = inferior_thread ();
2367 CORE_ADDR pc = regcache_read_pc (regcache);
2368 const address_space *aspace = regcache->aspace ();
2370 /* This represents the user's step vs continue request. When
2371 deciding whether "set scheduler-locking step" applies, it's the
2372 user's intention that counts. */
2373 const int user_step = tp->control.stepping_command;
2374 /* This represents what we'll actually request the target to do.
2375 This can decay from a step to a continue, if e.g., we need to
2376 implement single-stepping with breakpoints (software
2380 gdb_assert (!tp->stop_requested);
2381 gdb_assert (!thread_is_in_step_over_chain (tp));
2383 if (tp->suspend.waitstatus_pending_p)
2388 = target_waitstatus_to_string (&tp->suspend.waitstatus);
2390 fprintf_unfiltered (gdb_stdlog,
2391 "infrun: resume: thread %s has pending wait "
2392 "status %s (currently_stepping=%d).\n",
2393 target_pid_to_str (tp->ptid), statstr.c_str (),
2394 currently_stepping (tp));
2399 /* FIXME: What should we do if we are supposed to resume this
2400 thread with a signal? Maybe we should maintain a queue of
2401 pending signals to deliver. */
2402 if (sig != GDB_SIGNAL_0)
2404 warning (_("Couldn't deliver signal %s to %s."),
2405 gdb_signal_to_name (sig), target_pid_to_str (tp->ptid));
2408 tp->suspend.stop_signal = GDB_SIGNAL_0;
2410 if (target_can_async_p ())
2415 tp->stepped_breakpoint = 0;
2417 /* Depends on stepped_breakpoint. */
2418 step = currently_stepping (tp);
2420 if (current_inferior ()->waiting_for_vfork_done)
2422 /* Don't try to single-step a vfork parent that is waiting for
2423 the child to get out of the shared memory region (by exec'ing
2424 or exiting). This is particularly important on software
2425 single-step archs, as the child process would trip on the
2426 software single step breakpoint inserted for the parent
2427 process. Since the parent will not actually execute any
2428 instruction until the child is out of the shared region (such
2429 are vfork's semantics), it is safe to simply continue it.
2430 Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for
2431 the parent, and tell it to `keep_going', which automatically
2432 re-sets it stepping. */
2434 fprintf_unfiltered (gdb_stdlog,
2435 "infrun: resume : clear step\n");
2440 fprintf_unfiltered (gdb_stdlog,
2441 "infrun: resume (step=%d, signal=%s), "
2442 "trap_expected=%d, current thread [%s] at %s\n",
2443 step, gdb_signal_to_symbol_string (sig),
2444 tp->control.trap_expected,
2445 target_pid_to_str (inferior_ptid),
2446 paddress (gdbarch, pc));
2448 /* Normally, by the time we reach `resume', the breakpoints are either
2449 removed or inserted, as appropriate. The exception is if we're sitting
2450 at a permanent breakpoint; we need to step over it, but permanent
2451 breakpoints can't be removed. So we have to test for it here. */
2452 if (breakpoint_here_p (aspace, pc) == permanent_breakpoint_here)
2454 if (sig != GDB_SIGNAL_0)
2456 /* We have a signal to pass to the inferior. The resume
2457 may, or may not take us to the signal handler. If this
2458 is a step, we'll need to stop in the signal handler, if
2459 there's one, (if the target supports stepping into
2460 handlers), or in the next mainline instruction, if
2461 there's no handler. If this is a continue, we need to be
2462 sure to run the handler with all breakpoints inserted.
2463 In all cases, set a breakpoint at the current address
2464 (where the handler returns to), and once that breakpoint
2465 is hit, resume skipping the permanent breakpoint. If
2466 that breakpoint isn't hit, then we've stepped into the
2467 signal handler (or hit some other event). We'll delete
2468 the step-resume breakpoint then. */
2471 fprintf_unfiltered (gdb_stdlog,
2472 "infrun: resume: skipping permanent breakpoint, "
2473 "deliver signal first\n");
2475 clear_step_over_info ();
2476 tp->control.trap_expected = 0;
2478 if (tp->control.step_resume_breakpoint == NULL)
2480 /* Set a "high-priority" step-resume, as we don't want
2481 user breakpoints at PC to trigger (again) when this
2483 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2484 gdb_assert (tp->control.step_resume_breakpoint->loc->permanent);
2486 tp->step_after_step_resume_breakpoint = step;
2489 insert_breakpoints ();
2493 /* There's no signal to pass, we can go ahead and skip the
2494 permanent breakpoint manually. */
2496 fprintf_unfiltered (gdb_stdlog,
2497 "infrun: resume: skipping permanent breakpoint\n");
2498 gdbarch_skip_permanent_breakpoint (gdbarch, regcache);
2499 /* Update pc to reflect the new address from which we will
2500 execute instructions. */
2501 pc = regcache_read_pc (regcache);
2505 /* We've already advanced the PC, so the stepping part
2506 is done. Now we need to arrange for a trap to be
2507 reported to handle_inferior_event. Set a breakpoint
2508 at the current PC, and run to it. Don't update
2509 prev_pc, because if we end in
2510 switch_back_to_stepped_thread, we want the "expected
2511 thread advanced also" branch to be taken. IOW, we
2512 don't want this thread to step further from PC
2514 gdb_assert (!step_over_info_valid_p ());
2515 insert_single_step_breakpoint (gdbarch, aspace, pc);
2516 insert_breakpoints ();
2518 resume_ptid = internal_resume_ptid (user_step);
2519 do_target_resume (resume_ptid, 0, GDB_SIGNAL_0);
2526 /* If we have a breakpoint to step over, make sure to do a single
2527 step only. Same if we have software watchpoints. */
2528 if (tp->control.trap_expected || bpstat_should_step ())
2529 tp->control.may_range_step = 0;
2531 /* If enabled, step over breakpoints by executing a copy of the
2532 instruction at a different address.
2534 We can't use displaced stepping when we have a signal to deliver;
2535 the comments for displaced_step_prepare explain why. The
2536 comments in the handle_inferior event for dealing with 'random
2537 signals' explain what we do instead.
2539 We can't use displaced stepping when we are waiting for vfork_done
2540 event, displaced stepping breaks the vfork child similarly as single
2541 step software breakpoint. */
2542 if (tp->control.trap_expected
2543 && use_displaced_stepping (tp)
2544 && !step_over_info_valid_p ()
2545 && sig == GDB_SIGNAL_0
2546 && !current_inferior ()->waiting_for_vfork_done)
2548 int prepared = displaced_step_prepare (inferior_ptid);
2553 fprintf_unfiltered (gdb_stdlog,
2554 "Got placed in step-over queue\n");
2556 tp->control.trap_expected = 0;
2559 else if (prepared < 0)
2561 /* Fallback to stepping over the breakpoint in-line. */
2563 if (target_is_non_stop_p ())
2564 stop_all_threads ();
2566 set_step_over_info (regcache->aspace (),
2567 regcache_read_pc (regcache), 0, tp->global_num);
2569 step = maybe_software_singlestep (gdbarch, pc);
2571 insert_breakpoints ();
2573 else if (prepared > 0)
2575 struct displaced_step_inferior_state *displaced;
2577 /* Update pc to reflect the new address from which we will
2578 execute instructions due to displaced stepping. */
2579 pc = regcache_read_pc (get_thread_regcache (inferior_ptid));
2581 displaced = get_displaced_stepping_state (ptid_get_pid (inferior_ptid));
2582 step = gdbarch_displaced_step_hw_singlestep (gdbarch,
2583 displaced->step_closure);
2587 /* Do we need to do it the hard way, w/temp breakpoints? */
2589 step = maybe_software_singlestep (gdbarch, pc);
2591 /* Currently, our software single-step implementation leads to different
2592 results than hardware single-stepping in one situation: when stepping
2593 into delivering a signal which has an associated signal handler,
2594 hardware single-step will stop at the first instruction of the handler,
2595 while software single-step will simply skip execution of the handler.
2597 For now, this difference in behavior is accepted since there is no
2598 easy way to actually implement single-stepping into a signal handler
2599 without kernel support.
2601 However, there is one scenario where this difference leads to follow-on
2602 problems: if we're stepping off a breakpoint by removing all breakpoints
2603 and then single-stepping. In this case, the software single-step
2604 behavior means that even if there is a *breakpoint* in the signal
2605 handler, GDB still would not stop.
2607 Fortunately, we can at least fix this particular issue. We detect
2608 here the case where we are about to deliver a signal while software
2609 single-stepping with breakpoints removed. In this situation, we
2610 revert the decisions to remove all breakpoints and insert single-
2611 step breakpoints, and instead we install a step-resume breakpoint
2612 at the current address, deliver the signal without stepping, and
2613 once we arrive back at the step-resume breakpoint, actually step
2614 over the breakpoint we originally wanted to step over. */
2615 if (thread_has_single_step_breakpoints_set (tp)
2616 && sig != GDB_SIGNAL_0
2617 && step_over_info_valid_p ())
2619 /* If we have nested signals or a pending signal is delivered
2620 immediately after a handler returns, might might already have
2621 a step-resume breakpoint set on the earlier handler. We cannot
2622 set another step-resume breakpoint; just continue on until the
2623 original breakpoint is hit. */
2624 if (tp->control.step_resume_breakpoint == NULL)
2626 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2627 tp->step_after_step_resume_breakpoint = 1;
2630 delete_single_step_breakpoints (tp);
2632 clear_step_over_info ();
2633 tp->control.trap_expected = 0;
2635 insert_breakpoints ();
2638 /* If STEP is set, it's a request to use hardware stepping
2639 facilities. But in that case, we should never
2640 use singlestep breakpoint. */
2641 gdb_assert (!(thread_has_single_step_breakpoints_set (tp) && step));
2643 /* Decide the set of threads to ask the target to resume. */
2644 if (tp->control.trap_expected)
2646 /* We're allowing a thread to run past a breakpoint it has
2647 hit, either by single-stepping the thread with the breakpoint
2648 removed, or by displaced stepping, with the breakpoint inserted.
2649 In the former case, we need to single-step only this thread,
2650 and keep others stopped, as they can miss this breakpoint if
2651 allowed to run. That's not really a problem for displaced
2652 stepping, but, we still keep other threads stopped, in case
2653 another thread is also stopped for a breakpoint waiting for
2654 its turn in the displaced stepping queue. */
2655 resume_ptid = inferior_ptid;
2658 resume_ptid = internal_resume_ptid (user_step);
2660 if (execution_direction != EXEC_REVERSE
2661 && step && breakpoint_inserted_here_p (aspace, pc))
2663 /* There are two cases where we currently need to step a
2664 breakpoint instruction when we have a signal to deliver:
2666 - See handle_signal_stop where we handle random signals that
2667 could take out us out of the stepping range. Normally, in
2668 that case we end up continuing (instead of stepping) over the
2669 signal handler with a breakpoint at PC, but there are cases
2670 where we should _always_ single-step, even if we have a
2671 step-resume breakpoint, like when a software watchpoint is
2672 set. Assuming single-stepping and delivering a signal at the
2673 same time would takes us to the signal handler, then we could
2674 have removed the breakpoint at PC to step over it. However,
2675 some hardware step targets (like e.g., Mac OS) can't step
2676 into signal handlers, and for those, we need to leave the
2677 breakpoint at PC inserted, as otherwise if the handler
2678 recurses and executes PC again, it'll miss the breakpoint.
2679 So we leave the breakpoint inserted anyway, but we need to
2680 record that we tried to step a breakpoint instruction, so
2681 that adjust_pc_after_break doesn't end up confused.
2683 - In non-stop if we insert a breakpoint (e.g., a step-resume)
2684 in one thread after another thread that was stepping had been
2685 momentarily paused for a step-over. When we re-resume the
2686 stepping thread, it may be resumed from that address with a
2687 breakpoint that hasn't trapped yet. Seen with
2688 gdb.threads/non-stop-fair-events.exp, on targets that don't
2689 do displaced stepping. */
2692 fprintf_unfiltered (gdb_stdlog,
2693 "infrun: resume: [%s] stepped breakpoint\n",
2694 target_pid_to_str (tp->ptid));
2696 tp->stepped_breakpoint = 1;
2698 /* Most targets can step a breakpoint instruction, thus
2699 executing it normally. But if this one cannot, just
2700 continue and we will hit it anyway. */
2701 if (gdbarch_cannot_step_breakpoint (gdbarch))
2706 && tp->control.trap_expected
2707 && use_displaced_stepping (tp)
2708 && !step_over_info_valid_p ())
2710 struct regcache *resume_regcache = get_thread_regcache (tp->ptid);
2711 struct gdbarch *resume_gdbarch = resume_regcache->arch ();
2712 CORE_ADDR actual_pc = regcache_read_pc (resume_regcache);
2715 fprintf_unfiltered (gdb_stdlog, "displaced: run %s: ",
2716 paddress (resume_gdbarch, actual_pc));
2717 read_memory (actual_pc, buf, sizeof (buf));
2718 displaced_step_dump_bytes (gdb_stdlog, buf, sizeof (buf));
2721 if (tp->control.may_range_step)
2723 /* If we're resuming a thread with the PC out of the step
2724 range, then we're doing some nested/finer run control
2725 operation, like stepping the thread out of the dynamic
2726 linker or the displaced stepping scratch pad. We
2727 shouldn't have allowed a range step then. */
2728 gdb_assert (pc_in_thread_step_range (pc, tp));
2731 do_target_resume (resume_ptid, step, sig);
2735 /* Resume the inferior. SIG is the signal to give the inferior
2736 (GDB_SIGNAL_0 for none). This is a wrapper around 'resume_1' that
2737 rolls back state on error. */
2740 resume (gdb_signal sig)
2746 CATCH (ex, RETURN_MASK_ALL)
2748 /* If resuming is being aborted for any reason, delete any
2749 single-step breakpoint resume_1 may have created, to avoid
2750 confusing the following resumption, and to avoid leaving
2751 single-step breakpoints perturbing other threads, in case
2752 we're running in non-stop mode. */
2753 if (inferior_ptid != null_ptid)
2754 delete_single_step_breakpoints (inferior_thread ());
2755 throw_exception (ex);
2765 /* Counter that tracks number of user visible stops. This can be used
2766 to tell whether a command has proceeded the inferior past the
2767 current location. This allows e.g., inferior function calls in
2768 breakpoint commands to not interrupt the command list. When the
2769 call finishes successfully, the inferior is standing at the same
2770 breakpoint as if nothing happened (and so we don't call
2772 static ULONGEST current_stop_id;
2779 return current_stop_id;
2782 /* Called when we report a user visible stop. */
2790 /* Clear out all variables saying what to do when inferior is continued.
2791 First do this, then set the ones you want, then call `proceed'. */
2794 clear_proceed_status_thread (struct thread_info *tp)
2797 fprintf_unfiltered (gdb_stdlog,
2798 "infrun: clear_proceed_status_thread (%s)\n",
2799 target_pid_to_str (tp->ptid));
2801 /* If we're starting a new sequence, then the previous finished
2802 single-step is no longer relevant. */
2803 if (tp->suspend.waitstatus_pending_p)
2805 if (tp->suspend.stop_reason == TARGET_STOPPED_BY_SINGLE_STEP)
2808 fprintf_unfiltered (gdb_stdlog,
2809 "infrun: clear_proceed_status: pending "
2810 "event of %s was a finished step. "
2812 target_pid_to_str (tp->ptid));
2814 tp->suspend.waitstatus_pending_p = 0;
2815 tp->suspend.stop_reason = TARGET_STOPPED_BY_NO_REASON;
2817 else if (debug_infrun)
2820 = target_waitstatus_to_string (&tp->suspend.waitstatus);
2822 fprintf_unfiltered (gdb_stdlog,
2823 "infrun: clear_proceed_status_thread: thread %s "
2824 "has pending wait status %s "
2825 "(currently_stepping=%d).\n",
2826 target_pid_to_str (tp->ptid), statstr.c_str (),
2827 currently_stepping (tp));
2831 /* If this signal should not be seen by program, give it zero.
2832 Used for debugging signals. */
2833 if (!signal_pass_state (tp->suspend.stop_signal))
2834 tp->suspend.stop_signal = GDB_SIGNAL_0;
2836 thread_fsm_delete (tp->thread_fsm);
2837 tp->thread_fsm = NULL;
2839 tp->control.trap_expected = 0;
2840 tp->control.step_range_start = 0;
2841 tp->control.step_range_end = 0;
2842 tp->control.may_range_step = 0;
2843 tp->control.step_frame_id = null_frame_id;
2844 tp->control.step_stack_frame_id = null_frame_id;
2845 tp->control.step_over_calls = STEP_OVER_UNDEBUGGABLE;
2846 tp->control.step_start_function = NULL;
2847 tp->stop_requested = 0;
2849 tp->control.stop_step = 0;
2851 tp->control.proceed_to_finish = 0;
2853 tp->control.stepping_command = 0;
2855 /* Discard any remaining commands or status from previous stop. */
2856 bpstat_clear (&tp->control.stop_bpstat);
2860 clear_proceed_status (int step)
2862 /* With scheduler-locking replay, stop replaying other threads if we're
2863 not replaying the user-visible resume ptid.
2865 This is a convenience feature to not require the user to explicitly
2866 stop replaying the other threads. We're assuming that the user's
2867 intent is to resume tracing the recorded process. */
2868 if (!non_stop && scheduler_mode == schedlock_replay
2869 && target_record_is_replaying (minus_one_ptid)
2870 && !target_record_will_replay (user_visible_resume_ptid (step),
2871 execution_direction))
2872 target_record_stop_replaying ();
2876 struct thread_info *tp;
2879 resume_ptid = user_visible_resume_ptid (step);
2881 /* In all-stop mode, delete the per-thread status of all threads
2882 we're about to resume, implicitly and explicitly. */
2883 ALL_NON_EXITED_THREADS (tp)
2885 if (!ptid_match (tp->ptid, resume_ptid))
2887 clear_proceed_status_thread (tp);
2891 if (!ptid_equal (inferior_ptid, null_ptid))
2893 struct inferior *inferior;
2897 /* If in non-stop mode, only delete the per-thread status of
2898 the current thread. */
2899 clear_proceed_status_thread (inferior_thread ());
2902 inferior = current_inferior ();
2903 inferior->control.stop_soon = NO_STOP_QUIETLY;
2906 gdb::observers::about_to_proceed.notify ();
2909 /* Returns true if TP is still stopped at a breakpoint that needs
2910 stepping-over in order to make progress. If the breakpoint is gone
2911 meanwhile, we can skip the whole step-over dance. */
2914 thread_still_needs_step_over_bp (struct thread_info *tp)
2916 if (tp->stepping_over_breakpoint)
2918 struct regcache *regcache = get_thread_regcache (tp->ptid);
2920 if (breakpoint_here_p (regcache->aspace (),
2921 regcache_read_pc (regcache))
2922 == ordinary_breakpoint_here)
2925 tp->stepping_over_breakpoint = 0;
2931 /* Check whether thread TP still needs to start a step-over in order
2932 to make progress when resumed. Returns an bitwise or of enum
2933 step_over_what bits, indicating what needs to be stepped over. */
2935 static step_over_what
2936 thread_still_needs_step_over (struct thread_info *tp)
2938 step_over_what what = 0;
2940 if (thread_still_needs_step_over_bp (tp))
2941 what |= STEP_OVER_BREAKPOINT;
2943 if (tp->stepping_over_watchpoint
2944 && !target_have_steppable_watchpoint)
2945 what |= STEP_OVER_WATCHPOINT;
2950 /* Returns true if scheduler locking applies. STEP indicates whether
2951 we're about to do a step/next-like command to a thread. */
2954 schedlock_applies (struct thread_info *tp)
2956 return (scheduler_mode == schedlock_on
2957 || (scheduler_mode == schedlock_step
2958 && tp->control.stepping_command)
2959 || (scheduler_mode == schedlock_replay
2960 && target_record_will_replay (minus_one_ptid,
2961 execution_direction)));
2964 /* Basic routine for continuing the program in various fashions.
2966 ADDR is the address to resume at, or -1 for resume where stopped.
2967 SIGGNAL is the signal to give it, or 0 for none,
2968 or -1 for act according to how it stopped.
2969 STEP is nonzero if should trap after one instruction.
2970 -1 means return after that and print nothing.
2971 You should probably set various step_... variables
2972 before calling here, if you are stepping.
2974 You should call clear_proceed_status before calling proceed. */
2977 proceed (CORE_ADDR addr, enum gdb_signal siggnal)
2979 struct regcache *regcache;
2980 struct gdbarch *gdbarch;
2981 struct thread_info *tp;
2984 struct execution_control_state ecss;
2985 struct execution_control_state *ecs = &ecss;
2988 /* If we're stopped at a fork/vfork, follow the branch set by the
2989 "set follow-fork-mode" command; otherwise, we'll just proceed
2990 resuming the current thread. */
2991 if (!follow_fork ())
2993 /* The target for some reason decided not to resume. */
2995 if (target_can_async_p ())
2996 inferior_event_handler (INF_EXEC_COMPLETE, NULL);
3000 /* We'll update this if & when we switch to a new thread. */
3001 previous_inferior_ptid = inferior_ptid;
3003 regcache = get_current_regcache ();
3004 gdbarch = regcache->arch ();
3005 const address_space *aspace = regcache->aspace ();
3007 pc = regcache_read_pc (regcache);
3008 tp = inferior_thread ();
3010 /* Fill in with reasonable starting values. */
3011 init_thread_stepping_state (tp);
3013 gdb_assert (!thread_is_in_step_over_chain (tp));
3015 if (addr == (CORE_ADDR) -1)
3018 && breakpoint_here_p (aspace, pc) == ordinary_breakpoint_here
3019 && execution_direction != EXEC_REVERSE)
3020 /* There is a breakpoint at the address we will resume at,
3021 step one instruction before inserting breakpoints so that
3022 we do not stop right away (and report a second hit at this
3025 Note, we don't do this in reverse, because we won't
3026 actually be executing the breakpoint insn anyway.
3027 We'll be (un-)executing the previous instruction. */
3028 tp->stepping_over_breakpoint = 1;
3029 else if (gdbarch_single_step_through_delay_p (gdbarch)
3030 && gdbarch_single_step_through_delay (gdbarch,
3031 get_current_frame ()))
3032 /* We stepped onto an instruction that needs to be stepped
3033 again before re-inserting the breakpoint, do so. */
3034 tp->stepping_over_breakpoint = 1;
3038 regcache_write_pc (regcache, addr);
3041 if (siggnal != GDB_SIGNAL_DEFAULT)
3042 tp->suspend.stop_signal = siggnal;
3044 resume_ptid = user_visible_resume_ptid (tp->control.stepping_command);
3046 /* If an exception is thrown from this point on, make sure to
3047 propagate GDB's knowledge of the executing state to the
3048 frontend/user running state. */
3049 scoped_finish_thread_state finish_state (resume_ptid);
3051 /* Even if RESUME_PTID is a wildcard, and we end up resuming fewer
3052 threads (e.g., we might need to set threads stepping over
3053 breakpoints first), from the user/frontend's point of view, all
3054 threads in RESUME_PTID are now running. Unless we're calling an
3055 inferior function, as in that case we pretend the inferior
3056 doesn't run at all. */
3057 if (!tp->control.in_infcall)
3058 set_running (resume_ptid, 1);
3061 fprintf_unfiltered (gdb_stdlog,
3062 "infrun: proceed (addr=%s, signal=%s)\n",
3063 paddress (gdbarch, addr),
3064 gdb_signal_to_symbol_string (siggnal));
3066 annotate_starting ();
3068 /* Make sure that output from GDB appears before output from the
3070 gdb_flush (gdb_stdout);
3072 /* Since we've marked the inferior running, give it the terminal. A
3073 QUIT/Ctrl-C from here on is forwarded to the target (which can
3074 still detect attempts to unblock a stuck connection with repeated
3075 Ctrl-C from within target_pass_ctrlc). */
3076 target_terminal::inferior ();
3078 /* In a multi-threaded task we may select another thread and
3079 then continue or step.
3081 But if a thread that we're resuming had stopped at a breakpoint,
3082 it will immediately cause another breakpoint stop without any
3083 execution (i.e. it will report a breakpoint hit incorrectly). So
3084 we must step over it first.
3086 Look for threads other than the current (TP) that reported a
3087 breakpoint hit and haven't been resumed yet since. */
3089 /* If scheduler locking applies, we can avoid iterating over all
3091 if (!non_stop && !schedlock_applies (tp))
3093 struct thread_info *current = tp;
3095 ALL_NON_EXITED_THREADS (tp)
3097 /* Ignore the current thread here. It's handled
3102 /* Ignore threads of processes we're not resuming. */
3103 if (!ptid_match (tp->ptid, resume_ptid))
3106 if (!thread_still_needs_step_over (tp))
3109 gdb_assert (!thread_is_in_step_over_chain (tp));
3112 fprintf_unfiltered (gdb_stdlog,
3113 "infrun: need to step-over [%s] first\n",
3114 target_pid_to_str (tp->ptid));
3116 thread_step_over_chain_enqueue (tp);
3122 /* Enqueue the current thread last, so that we move all other
3123 threads over their breakpoints first. */
3124 if (tp->stepping_over_breakpoint)
3125 thread_step_over_chain_enqueue (tp);
3127 /* If the thread isn't started, we'll still need to set its prev_pc,
3128 so that switch_back_to_stepped_thread knows the thread hasn't
3129 advanced. Must do this before resuming any thread, as in
3130 all-stop/remote, once we resume we can't send any other packet
3131 until the target stops again. */
3132 tp->prev_pc = regcache_read_pc (regcache);
3135 scoped_restore save_defer_tc = make_scoped_defer_target_commit_resume ();
3137 started = start_step_over ();
3139 if (step_over_info_valid_p ())
3141 /* Either this thread started a new in-line step over, or some
3142 other thread was already doing one. In either case, don't
3143 resume anything else until the step-over is finished. */
3145 else if (started && !target_is_non_stop_p ())
3147 /* A new displaced stepping sequence was started. In all-stop,
3148 we can't talk to the target anymore until it next stops. */
3150 else if (!non_stop && target_is_non_stop_p ())
3152 /* In all-stop, but the target is always in non-stop mode.
3153 Start all other threads that are implicitly resumed too. */
3154 ALL_NON_EXITED_THREADS (tp)
3156 /* Ignore threads of processes we're not resuming. */
3157 if (!ptid_match (tp->ptid, resume_ptid))
3163 fprintf_unfiltered (gdb_stdlog,
3164 "infrun: proceed: [%s] resumed\n",
3165 target_pid_to_str (tp->ptid));
3166 gdb_assert (tp->executing || tp->suspend.waitstatus_pending_p);
3170 if (thread_is_in_step_over_chain (tp))
3173 fprintf_unfiltered (gdb_stdlog,
3174 "infrun: proceed: [%s] needs step-over\n",
3175 target_pid_to_str (tp->ptid));
3180 fprintf_unfiltered (gdb_stdlog,
3181 "infrun: proceed: resuming %s\n",
3182 target_pid_to_str (tp->ptid));
3184 reset_ecs (ecs, tp);
3185 switch_to_thread (tp->ptid);
3186 keep_going_pass_signal (ecs);
3187 if (!ecs->wait_some_more)
3188 error (_("Command aborted."));
3191 else if (!tp->resumed && !thread_is_in_step_over_chain (tp))
3193 /* The thread wasn't started, and isn't queued, run it now. */
3194 reset_ecs (ecs, tp);
3195 switch_to_thread (tp->ptid);
3196 keep_going_pass_signal (ecs);
3197 if (!ecs->wait_some_more)
3198 error (_("Command aborted."));
3202 target_commit_resume ();
3204 finish_state.release ();
3206 /* Tell the event loop to wait for it to stop. If the target
3207 supports asynchronous execution, it'll do this from within
3209 if (!target_can_async_p ())
3210 mark_async_event_handler (infrun_async_inferior_event_token);
3214 /* Start remote-debugging of a machine over a serial link. */
3217 start_remote (int from_tty)
3219 struct inferior *inferior;
3221 inferior = current_inferior ();
3222 inferior->control.stop_soon = STOP_QUIETLY_REMOTE;
3224 /* Always go on waiting for the target, regardless of the mode. */
3225 /* FIXME: cagney/1999-09-23: At present it isn't possible to
3226 indicate to wait_for_inferior that a target should timeout if
3227 nothing is returned (instead of just blocking). Because of this,
3228 targets expecting an immediate response need to, internally, set
3229 things up so that the target_wait() is forced to eventually
3231 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
3232 differentiate to its caller what the state of the target is after
3233 the initial open has been performed. Here we're assuming that
3234 the target has stopped. It should be possible to eventually have
3235 target_open() return to the caller an indication that the target
3236 is currently running and GDB state should be set to the same as
3237 for an async run. */
3238 wait_for_inferior ();
3240 /* Now that the inferior has stopped, do any bookkeeping like
3241 loading shared libraries. We want to do this before normal_stop,
3242 so that the displayed frame is up to date. */
3243 post_create_inferior (¤t_target, from_tty);
3248 /* Initialize static vars when a new inferior begins. */
3251 init_wait_for_inferior (void)
3253 /* These are meaningless until the first time through wait_for_inferior. */
3255 breakpoint_init_inferior (inf_starting);
3257 clear_proceed_status (0);
3259 target_last_wait_ptid = minus_one_ptid;
3261 previous_inferior_ptid = inferior_ptid;
3263 /* Discard any skipped inlined frames. */
3264 clear_inline_frame_state (minus_one_ptid);
3269 static void handle_inferior_event (struct execution_control_state *ecs);
3271 static void handle_step_into_function (struct gdbarch *gdbarch,
3272 struct execution_control_state *ecs);
3273 static void handle_step_into_function_backward (struct gdbarch *gdbarch,
3274 struct execution_control_state *ecs);
3275 static void handle_signal_stop (struct execution_control_state *ecs);
3276 static void check_exception_resume (struct execution_control_state *,
3277 struct frame_info *);
3279 static void end_stepping_range (struct execution_control_state *ecs);
3280 static void stop_waiting (struct execution_control_state *ecs);
3281 static void keep_going (struct execution_control_state *ecs);
3282 static void process_event_stop_test (struct execution_control_state *ecs);
3283 static int switch_back_to_stepped_thread (struct execution_control_state *ecs);
3285 /* This function is attached as a "thread_stop_requested" observer.
3286 Cleanup local state that assumed the PTID was to be resumed, and
3287 report the stop to the frontend. */
3290 infrun_thread_stop_requested (ptid_t ptid)
3292 struct thread_info *tp;
3294 /* PTID was requested to stop. If the thread was already stopped,
3295 but the user/frontend doesn't know about that yet (e.g., the
3296 thread had been temporarily paused for some step-over), set up
3297 for reporting the stop now. */
3298 ALL_NON_EXITED_THREADS (tp)
3299 if (ptid_match (tp->ptid, ptid))
3301 if (tp->state != THREAD_RUNNING)
3306 /* Remove matching threads from the step-over queue, so
3307 start_step_over doesn't try to resume them
3309 if (thread_is_in_step_over_chain (tp))
3310 thread_step_over_chain_remove (tp);
3312 /* If the thread is stopped, but the user/frontend doesn't
3313 know about that yet, queue a pending event, as if the
3314 thread had just stopped now. Unless the thread already had
3316 if (!tp->suspend.waitstatus_pending_p)
3318 tp->suspend.waitstatus_pending_p = 1;
3319 tp->suspend.waitstatus.kind = TARGET_WAITKIND_STOPPED;
3320 tp->suspend.waitstatus.value.sig = GDB_SIGNAL_0;
3323 /* Clear the inline-frame state, since we're re-processing the
3325 clear_inline_frame_state (tp->ptid);
3327 /* If this thread was paused because some other thread was
3328 doing an inline-step over, let that finish first. Once
3329 that happens, we'll restart all threads and consume pending
3330 stop events then. */
3331 if (step_over_info_valid_p ())
3334 /* Otherwise we can process the (new) pending event now. Set
3335 it so this pending event is considered by
3342 infrun_thread_thread_exit (struct thread_info *tp, int silent)
3344 if (ptid_equal (target_last_wait_ptid, tp->ptid))
3345 nullify_last_target_wait_ptid ();
3348 /* Delete the step resume, single-step and longjmp/exception resume
3349 breakpoints of TP. */
3352 delete_thread_infrun_breakpoints (struct thread_info *tp)
3354 delete_step_resume_breakpoint (tp);
3355 delete_exception_resume_breakpoint (tp);
3356 delete_single_step_breakpoints (tp);
3359 /* If the target still has execution, call FUNC for each thread that
3360 just stopped. In all-stop, that's all the non-exited threads; in
3361 non-stop, that's the current thread, only. */
3363 typedef void (*for_each_just_stopped_thread_callback_func)
3364 (struct thread_info *tp);
3367 for_each_just_stopped_thread (for_each_just_stopped_thread_callback_func func)
3369 if (!target_has_execution || ptid_equal (inferior_ptid, null_ptid))
3372 if (target_is_non_stop_p ())
3374 /* If in non-stop mode, only the current thread stopped. */
3375 func (inferior_thread ());
3379 struct thread_info *tp;
3381 /* In all-stop mode, all threads have stopped. */
3382 ALL_NON_EXITED_THREADS (tp)
3389 /* Delete the step resume and longjmp/exception resume breakpoints of
3390 the threads that just stopped. */
3393 delete_just_stopped_threads_infrun_breakpoints (void)
3395 for_each_just_stopped_thread (delete_thread_infrun_breakpoints);
3398 /* Delete the single-step breakpoints of the threads that just
3402 delete_just_stopped_threads_single_step_breakpoints (void)
3404 for_each_just_stopped_thread (delete_single_step_breakpoints);
3407 /* A cleanup wrapper. */
3410 delete_just_stopped_threads_infrun_breakpoints_cleanup (void *arg)
3412 delete_just_stopped_threads_infrun_breakpoints ();
3418 print_target_wait_results (ptid_t waiton_ptid, ptid_t result_ptid,
3419 const struct target_waitstatus *ws)
3421 std::string status_string = target_waitstatus_to_string (ws);
3424 /* The text is split over several lines because it was getting too long.
3425 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
3426 output as a unit; we want only one timestamp printed if debug_timestamp
3429 stb.printf ("infrun: target_wait (%d.%ld.%ld",
3430 ptid_get_pid (waiton_ptid),
3431 ptid_get_lwp (waiton_ptid),
3432 ptid_get_tid (waiton_ptid));
3433 if (ptid_get_pid (waiton_ptid) != -1)
3434 stb.printf (" [%s]", target_pid_to_str (waiton_ptid));
3435 stb.printf (", status) =\n");
3436 stb.printf ("infrun: %d.%ld.%ld [%s],\n",
3437 ptid_get_pid (result_ptid),
3438 ptid_get_lwp (result_ptid),
3439 ptid_get_tid (result_ptid),
3440 target_pid_to_str (result_ptid));
3441 stb.printf ("infrun: %s\n", status_string.c_str ());
3443 /* This uses %s in part to handle %'s in the text, but also to avoid
3444 a gcc error: the format attribute requires a string literal. */
3445 fprintf_unfiltered (gdb_stdlog, "%s", stb.c_str ());
3448 /* Select a thread at random, out of those which are resumed and have
3451 static struct thread_info *
3452 random_pending_event_thread (ptid_t waiton_ptid)
3454 struct thread_info *event_tp;
3456 int random_selector;
3458 /* First see how many events we have. Count only resumed threads
3459 that have an event pending. */
3460 ALL_NON_EXITED_THREADS (event_tp)
3461 if (ptid_match (event_tp->ptid, waiton_ptid)
3462 && event_tp->resumed
3463 && event_tp->suspend.waitstatus_pending_p)
3466 if (num_events == 0)
3469 /* Now randomly pick a thread out of those that have had events. */
3470 random_selector = (int)
3471 ((num_events * (double) rand ()) / (RAND_MAX + 1.0));
3473 if (debug_infrun && num_events > 1)
3474 fprintf_unfiltered (gdb_stdlog,
3475 "infrun: Found %d events, selecting #%d\n",
3476 num_events, random_selector);
3478 /* Select the Nth thread that has had an event. */
3479 ALL_NON_EXITED_THREADS (event_tp)
3480 if (ptid_match (event_tp->ptid, waiton_ptid)
3481 && event_tp->resumed
3482 && event_tp->suspend.waitstatus_pending_p)
3483 if (random_selector-- == 0)
3489 /* Wrapper for target_wait that first checks whether threads have
3490 pending statuses to report before actually asking the target for
3494 do_target_wait (ptid_t ptid, struct target_waitstatus *status, int options)
3497 struct thread_info *tp;
3499 /* First check if there is a resumed thread with a wait status
3501 if (ptid_equal (ptid, minus_one_ptid) || ptid_is_pid (ptid))
3503 tp = random_pending_event_thread (ptid);
3508 fprintf_unfiltered (gdb_stdlog,
3509 "infrun: Waiting for specific thread %s.\n",
3510 target_pid_to_str (ptid));
3512 /* We have a specific thread to check. */
3513 tp = find_thread_ptid (ptid);
3514 gdb_assert (tp != NULL);
3515 if (!tp->suspend.waitstatus_pending_p)
3520 && (tp->suspend.stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT
3521 || tp->suspend.stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT))
3523 struct regcache *regcache = get_thread_regcache (tp->ptid);
3524 struct gdbarch *gdbarch = regcache->arch ();
3528 pc = regcache_read_pc (regcache);
3530 if (pc != tp->suspend.stop_pc)
3533 fprintf_unfiltered (gdb_stdlog,
3534 "infrun: PC of %s changed. was=%s, now=%s\n",
3535 target_pid_to_str (tp->ptid),
3536 paddress (gdbarch, tp->prev_pc),
3537 paddress (gdbarch, pc));
3540 else if (!breakpoint_inserted_here_p (regcache->aspace (), pc))
3543 fprintf_unfiltered (gdb_stdlog,
3544 "infrun: previous breakpoint of %s, at %s gone\n",
3545 target_pid_to_str (tp->ptid),
3546 paddress (gdbarch, pc));
3554 fprintf_unfiltered (gdb_stdlog,
3555 "infrun: pending event of %s cancelled.\n",
3556 target_pid_to_str (tp->ptid));
3558 tp->suspend.waitstatus.kind = TARGET_WAITKIND_SPURIOUS;
3559 tp->suspend.stop_reason = TARGET_STOPPED_BY_NO_REASON;
3568 = target_waitstatus_to_string (&tp->suspend.waitstatus);
3570 fprintf_unfiltered (gdb_stdlog,
3571 "infrun: Using pending wait status %s for %s.\n",
3573 target_pid_to_str (tp->ptid));
3576 /* Now that we've selected our final event LWP, un-adjust its PC
3577 if it was a software breakpoint (and the target doesn't
3578 always adjust the PC itself). */
3579 if (tp->suspend.stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT
3580 && !target_supports_stopped_by_sw_breakpoint ())
3582 struct regcache *regcache;
3583 struct gdbarch *gdbarch;
3586 regcache = get_thread_regcache (tp->ptid);
3587 gdbarch = regcache->arch ();
3589 decr_pc = gdbarch_decr_pc_after_break (gdbarch);
3594 pc = regcache_read_pc (regcache);
3595 regcache_write_pc (regcache, pc + decr_pc);
3599 tp->suspend.stop_reason = TARGET_STOPPED_BY_NO_REASON;
3600 *status = tp->suspend.waitstatus;
3601 tp->suspend.waitstatus_pending_p = 0;
3603 /* Wake up the event loop again, until all pending events are
3605 if (target_is_async_p ())
3606 mark_async_event_handler (infrun_async_inferior_event_token);
3610 /* But if we don't find one, we'll have to wait. */
3612 if (deprecated_target_wait_hook)
3613 event_ptid = deprecated_target_wait_hook (ptid, status, options);
3615 event_ptid = target_wait (ptid, status, options);
3620 /* Prepare and stabilize the inferior for detaching it. E.g.,
3621 detaching while a thread is displaced stepping is a recipe for
3622 crashing it, as nothing would readjust the PC out of the scratch
3626 prepare_for_detach (void)
3628 struct inferior *inf = current_inferior ();
3629 ptid_t pid_ptid = pid_to_ptid (inf->pid);
3630 struct displaced_step_inferior_state *displaced;
3632 displaced = get_displaced_stepping_state (inf->pid);
3634 /* Is any thread of this process displaced stepping? If not,
3635 there's nothing else to do. */
3636 if (displaced == NULL || ptid_equal (displaced->step_ptid, null_ptid))
3640 fprintf_unfiltered (gdb_stdlog,
3641 "displaced-stepping in-process while detaching");
3643 scoped_restore restore_detaching = make_scoped_restore (&inf->detaching, true);
3645 while (!ptid_equal (displaced->step_ptid, null_ptid))
3647 struct execution_control_state ecss;
3648 struct execution_control_state *ecs;
3651 memset (ecs, 0, sizeof (*ecs));
3653 overlay_cache_invalid = 1;
3654 /* Flush target cache before starting to handle each event.
3655 Target was running and cache could be stale. This is just a
3656 heuristic. Running threads may modify target memory, but we
3657 don't get any event. */
3658 target_dcache_invalidate ();
3660 ecs->ptid = do_target_wait (pid_ptid, &ecs->ws, 0);
3663 print_target_wait_results (pid_ptid, ecs->ptid, &ecs->ws);
3665 /* If an error happens while handling the event, propagate GDB's
3666 knowledge of the executing state to the frontend/user running
3668 scoped_finish_thread_state finish_state (minus_one_ptid);
3670 /* Now figure out what to do with the result of the result. */
3671 handle_inferior_event (ecs);
3673 /* No error, don't finish the state yet. */
3674 finish_state.release ();
3676 /* Breakpoints and watchpoints are not installed on the target
3677 at this point, and signals are passed directly to the
3678 inferior, so this must mean the process is gone. */
3679 if (!ecs->wait_some_more)
3681 restore_detaching.release ();
3682 error (_("Program exited while detaching"));
3686 restore_detaching.release ();
3689 /* Wait for control to return from inferior to debugger.
3691 If inferior gets a signal, we may decide to start it up again
3692 instead of returning. That is why there is a loop in this function.
3693 When this function actually returns it means the inferior
3694 should be left stopped and GDB should read more commands. */
3697 wait_for_inferior (void)
3699 struct cleanup *old_cleanups;
3703 (gdb_stdlog, "infrun: wait_for_inferior ()\n");
3706 = make_cleanup (delete_just_stopped_threads_infrun_breakpoints_cleanup,
3709 /* If an error happens while handling the event, propagate GDB's
3710 knowledge of the executing state to the frontend/user running
3712 scoped_finish_thread_state finish_state (minus_one_ptid);
3716 struct execution_control_state ecss;
3717 struct execution_control_state *ecs = &ecss;
3718 ptid_t waiton_ptid = minus_one_ptid;
3720 memset (ecs, 0, sizeof (*ecs));
3722 overlay_cache_invalid = 1;
3724 /* Flush target cache before starting to handle each event.
3725 Target was running and cache could be stale. This is just a
3726 heuristic. Running threads may modify target memory, but we
3727 don't get any event. */
3728 target_dcache_invalidate ();
3730 ecs->ptid = do_target_wait (waiton_ptid, &ecs->ws, 0);
3733 print_target_wait_results (waiton_ptid, ecs->ptid, &ecs->ws);
3735 /* Now figure out what to do with the result of the result. */
3736 handle_inferior_event (ecs);
3738 if (!ecs->wait_some_more)
3742 /* No error, don't finish the state yet. */
3743 finish_state.release ();
3745 do_cleanups (old_cleanups);
3748 /* Cleanup that reinstalls the readline callback handler, if the
3749 target is running in the background. If while handling the target
3750 event something triggered a secondary prompt, like e.g., a
3751 pagination prompt, we'll have removed the callback handler (see
3752 gdb_readline_wrapper_line). Need to do this as we go back to the
3753 event loop, ready to process further input. Note this has no
3754 effect if the handler hasn't actually been removed, because calling
3755 rl_callback_handler_install resets the line buffer, thus losing
3759 reinstall_readline_callback_handler_cleanup (void *arg)
3761 struct ui *ui = current_ui;
3765 /* We're not going back to the top level event loop yet. Don't
3766 install the readline callback, as it'd prep the terminal,
3767 readline-style (raw, noecho) (e.g., --batch). We'll install
3768 it the next time the prompt is displayed, when we're ready
3773 if (ui->command_editing && ui->prompt_state != PROMPT_BLOCKED)
3774 gdb_rl_callback_handler_reinstall ();
3777 /* Clean up the FSMs of threads that are now stopped. In non-stop,
3778 that's just the event thread. In all-stop, that's all threads. */
3781 clean_up_just_stopped_threads_fsms (struct execution_control_state *ecs)
3783 struct thread_info *thr = ecs->event_thread;
3785 if (thr != NULL && thr->thread_fsm != NULL)
3786 thread_fsm_clean_up (thr->thread_fsm, thr);
3790 ALL_NON_EXITED_THREADS (thr)
3792 if (thr->thread_fsm == NULL)
3794 if (thr == ecs->event_thread)
3797 switch_to_thread (thr->ptid);
3798 thread_fsm_clean_up (thr->thread_fsm, thr);
3801 if (ecs->event_thread != NULL)
3802 switch_to_thread (ecs->event_thread->ptid);
3806 /* Helper for all_uis_check_sync_execution_done that works on the
3810 check_curr_ui_sync_execution_done (void)
3812 struct ui *ui = current_ui;
3814 if (ui->prompt_state == PROMPT_NEEDED
3816 && !gdb_in_secondary_prompt_p (ui))
3818 target_terminal::ours ();
3819 gdb::observers::sync_execution_done.notify ();
3820 ui_register_input_event_handler (ui);
3827 all_uis_check_sync_execution_done (void)
3829 SWITCH_THRU_ALL_UIS ()
3831 check_curr_ui_sync_execution_done ();
3838 all_uis_on_sync_execution_starting (void)
3840 SWITCH_THRU_ALL_UIS ()
3842 if (current_ui->prompt_state == PROMPT_NEEDED)
3843 async_disable_stdin ();
3847 /* Asynchronous version of wait_for_inferior. It is called by the
3848 event loop whenever a change of state is detected on the file
3849 descriptor corresponding to the target. It can be called more than
3850 once to complete a single execution command. In such cases we need
3851 to keep the state in a global variable ECSS. If it is the last time
3852 that this function is called for a single execution command, then
3853 report to the user that the inferior has stopped, and do the
3854 necessary cleanups. */
3857 fetch_inferior_event (void *client_data)
3859 struct execution_control_state ecss;
3860 struct execution_control_state *ecs = &ecss;
3861 struct cleanup *old_chain = make_cleanup (null_cleanup, NULL);
3863 ptid_t waiton_ptid = minus_one_ptid;
3865 memset (ecs, 0, sizeof (*ecs));
3867 /* Events are always processed with the main UI as current UI. This
3868 way, warnings, debug output, etc. are always consistently sent to
3869 the main console. */
3870 scoped_restore save_ui = make_scoped_restore (¤t_ui, main_ui);
3872 /* End up with readline processing input, if necessary. */
3873 make_cleanup (reinstall_readline_callback_handler_cleanup, NULL);
3875 /* We're handling a live event, so make sure we're doing live
3876 debugging. If we're looking at traceframes while the target is
3877 running, we're going to need to get back to that mode after
3878 handling the event. */
3879 gdb::optional<scoped_restore_current_traceframe> maybe_restore_traceframe;
3882 maybe_restore_traceframe.emplace ();
3883 set_current_traceframe (-1);
3886 gdb::optional<scoped_restore_current_thread> maybe_restore_thread;
3889 /* In non-stop mode, the user/frontend should not notice a thread
3890 switch due to internal events. Make sure we reverse to the
3891 user selected thread and frame after handling the event and
3892 running any breakpoint commands. */
3893 maybe_restore_thread.emplace ();
3895 overlay_cache_invalid = 1;
3896 /* Flush target cache before starting to handle each event. Target
3897 was running and cache could be stale. This is just a heuristic.
3898 Running threads may modify target memory, but we don't get any
3900 target_dcache_invalidate ();
3902 scoped_restore save_exec_dir
3903 = make_scoped_restore (&execution_direction, target_execution_direction ());
3905 ecs->ptid = do_target_wait (waiton_ptid, &ecs->ws,
3906 target_can_async_p () ? TARGET_WNOHANG : 0);
3909 print_target_wait_results (waiton_ptid, ecs->ptid, &ecs->ws);
3911 /* If an error happens while handling the event, propagate GDB's
3912 knowledge of the executing state to the frontend/user running
3914 ptid_t finish_ptid = !target_is_non_stop_p () ? minus_one_ptid : ecs->ptid;
3915 scoped_finish_thread_state finish_state (finish_ptid);
3917 /* Get executed before make_cleanup_restore_current_thread above to apply
3918 still for the thread which has thrown the exception. */
3919 struct cleanup *ts_old_chain = make_bpstat_clear_actions_cleanup ();
3921 make_cleanup (delete_just_stopped_threads_infrun_breakpoints_cleanup, NULL);
3923 /* Now figure out what to do with the result of the result. */
3924 handle_inferior_event (ecs);
3926 if (!ecs->wait_some_more)
3928 struct inferior *inf = find_inferior_ptid (ecs->ptid);
3929 int should_stop = 1;
3930 struct thread_info *thr = ecs->event_thread;
3931 int should_notify_stop = 1;
3933 delete_just_stopped_threads_infrun_breakpoints ();
3937 struct thread_fsm *thread_fsm = thr->thread_fsm;
3939 if (thread_fsm != NULL)
3940 should_stop = thread_fsm_should_stop (thread_fsm, thr);
3949 clean_up_just_stopped_threads_fsms (ecs);
3951 if (thr != NULL && thr->thread_fsm != NULL)
3954 = thread_fsm_should_notify_stop (thr->thread_fsm);
3957 if (should_notify_stop)
3961 /* We may not find an inferior if this was a process exit. */
3962 if (inf == NULL || inf->control.stop_soon == NO_STOP_QUIETLY)
3963 proceeded = normal_stop ();
3967 inferior_event_handler (INF_EXEC_COMPLETE, NULL);
3974 discard_cleanups (ts_old_chain);
3976 /* No error, don't finish the thread states yet. */
3977 finish_state.release ();
3979 /* Revert thread and frame. */
3980 do_cleanups (old_chain);
3982 /* If a UI was in sync execution mode, and now isn't, restore its
3983 prompt (a synchronous execution command has finished, and we're
3984 ready for input). */
3985 all_uis_check_sync_execution_done ();
3988 && exec_done_display_p
3989 && (ptid_equal (inferior_ptid, null_ptid)
3990 || !is_running (inferior_ptid)))
3991 printf_unfiltered (_("completed.\n"));
3994 /* Record the frame and location we're currently stepping through. */
3996 set_step_info (struct frame_info *frame, struct symtab_and_line sal)
3998 struct thread_info *tp = inferior_thread ();
4000 tp->control.step_frame_id = get_frame_id (frame);
4001 tp->control.step_stack_frame_id = get_stack_frame_id (frame);
4003 tp->current_symtab = sal.symtab;
4004 tp->current_line = sal.line;
4007 /* Clear context switchable stepping state. */
4010 init_thread_stepping_state (struct thread_info *tss)
4012 tss->stepped_breakpoint = 0;
4013 tss->stepping_over_breakpoint = 0;
4014 tss->stepping_over_watchpoint = 0;
4015 tss->step_after_step_resume_breakpoint = 0;
4018 /* Set the cached copy of the last ptid/waitstatus. */
4021 set_last_target_status (ptid_t ptid, struct target_waitstatus status)
4023 target_last_wait_ptid = ptid;
4024 target_last_waitstatus = status;
4027 /* Return the cached copy of the last pid/waitstatus returned by
4028 target_wait()/deprecated_target_wait_hook(). The data is actually
4029 cached by handle_inferior_event(), which gets called immediately
4030 after target_wait()/deprecated_target_wait_hook(). */
4033 get_last_target_status (ptid_t *ptidp, struct target_waitstatus *status)
4035 *ptidp = target_last_wait_ptid;
4036 *status = target_last_waitstatus;
4040 nullify_last_target_wait_ptid (void)
4042 target_last_wait_ptid = minus_one_ptid;
4045 /* Switch thread contexts. */
4048 context_switch (ptid_t ptid)
4050 if (debug_infrun && !ptid_equal (ptid, inferior_ptid))
4052 fprintf_unfiltered (gdb_stdlog, "infrun: Switching context from %s ",
4053 target_pid_to_str (inferior_ptid));
4054 fprintf_unfiltered (gdb_stdlog, "to %s\n",
4055 target_pid_to_str (ptid));
4058 switch_to_thread (ptid);
4061 /* If the target can't tell whether we've hit breakpoints
4062 (target_supports_stopped_by_sw_breakpoint), and we got a SIGTRAP,
4063 check whether that could have been caused by a breakpoint. If so,
4064 adjust the PC, per gdbarch_decr_pc_after_break. */
4067 adjust_pc_after_break (struct thread_info *thread,
4068 struct target_waitstatus *ws)
4070 struct regcache *regcache;
4071 struct gdbarch *gdbarch;
4072 CORE_ADDR breakpoint_pc, decr_pc;
4074 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
4075 we aren't, just return.
4077 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
4078 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
4079 implemented by software breakpoints should be handled through the normal
4082 NOTE drow/2004-01-31: On some targets, breakpoints may generate
4083 different signals (SIGILL or SIGEMT for instance), but it is less
4084 clear where the PC is pointing afterwards. It may not match
4085 gdbarch_decr_pc_after_break. I don't know any specific target that
4086 generates these signals at breakpoints (the code has been in GDB since at
4087 least 1992) so I can not guess how to handle them here.
4089 In earlier versions of GDB, a target with
4090 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
4091 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
4092 target with both of these set in GDB history, and it seems unlikely to be
4093 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
4095 if (ws->kind != TARGET_WAITKIND_STOPPED)
4098 if (ws->value.sig != GDB_SIGNAL_TRAP)
4101 /* In reverse execution, when a breakpoint is hit, the instruction
4102 under it has already been de-executed. The reported PC always
4103 points at the breakpoint address, so adjusting it further would
4104 be wrong. E.g., consider this case on a decr_pc_after_break == 1
4107 B1 0x08000000 : INSN1
4108 B2 0x08000001 : INSN2
4110 PC -> 0x08000003 : INSN4
4112 Say you're stopped at 0x08000003 as above. Reverse continuing
4113 from that point should hit B2 as below. Reading the PC when the
4114 SIGTRAP is reported should read 0x08000001 and INSN2 should have
4115 been de-executed already.
4117 B1 0x08000000 : INSN1
4118 B2 PC -> 0x08000001 : INSN2
4122 We can't apply the same logic as for forward execution, because
4123 we would wrongly adjust the PC to 0x08000000, since there's a
4124 breakpoint at PC - 1. We'd then report a hit on B1, although
4125 INSN1 hadn't been de-executed yet. Doing nothing is the correct
4127 if (execution_direction == EXEC_REVERSE)
4130 /* If the target can tell whether the thread hit a SW breakpoint,
4131 trust it. Targets that can tell also adjust the PC
4133 if (target_supports_stopped_by_sw_breakpoint ())
4136 /* Note that relying on whether a breakpoint is planted in memory to
4137 determine this can fail. E.g,. the breakpoint could have been
4138 removed since. Or the thread could have been told to step an
4139 instruction the size of a breakpoint instruction, and only
4140 _after_ was a breakpoint inserted at its address. */
4142 /* If this target does not decrement the PC after breakpoints, then
4143 we have nothing to do. */
4144 regcache = get_thread_regcache (thread->ptid);
4145 gdbarch = regcache->arch ();
4147 decr_pc = gdbarch_decr_pc_after_break (gdbarch);
4151 const address_space *aspace = regcache->aspace ();
4153 /* Find the location where (if we've hit a breakpoint) the
4154 breakpoint would be. */
4155 breakpoint_pc = regcache_read_pc (regcache) - decr_pc;
4157 /* If the target can't tell whether a software breakpoint triggered,
4158 fallback to figuring it out based on breakpoints we think were
4159 inserted in the target, and on whether the thread was stepped or
4162 /* Check whether there actually is a software breakpoint inserted at
4165 If in non-stop mode, a race condition is possible where we've
4166 removed a breakpoint, but stop events for that breakpoint were
4167 already queued and arrive later. To suppress those spurious
4168 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
4169 and retire them after a number of stop events are reported. Note
4170 this is an heuristic and can thus get confused. The real fix is
4171 to get the "stopped by SW BP and needs adjustment" info out of
4172 the target/kernel (and thus never reach here; see above). */
4173 if (software_breakpoint_inserted_here_p (aspace, breakpoint_pc)
4174 || (target_is_non_stop_p ()
4175 && moribund_breakpoint_here_p (aspace, breakpoint_pc)))
4177 gdb::optional<scoped_restore_tmpl<int>> restore_operation_disable;
4179 if (record_full_is_used ())
4180 restore_operation_disable.emplace
4181 (record_full_gdb_operation_disable_set ());
4183 /* When using hardware single-step, a SIGTRAP is reported for both
4184 a completed single-step and a software breakpoint. Need to
4185 differentiate between the two, as the latter needs adjusting
4186 but the former does not.
4188 The SIGTRAP can be due to a completed hardware single-step only if
4189 - we didn't insert software single-step breakpoints
4190 - this thread is currently being stepped
4192 If any of these events did not occur, we must have stopped due
4193 to hitting a software breakpoint, and have to back up to the
4196 As a special case, we could have hardware single-stepped a
4197 software breakpoint. In this case (prev_pc == breakpoint_pc),
4198 we also need to back up to the breakpoint address. */
4200 if (thread_has_single_step_breakpoints_set (thread)
4201 || !currently_stepping (thread)
4202 || (thread->stepped_breakpoint
4203 && thread->prev_pc == breakpoint_pc))
4204 regcache_write_pc (regcache, breakpoint_pc);
4209 stepped_in_from (struct frame_info *frame, struct frame_id step_frame_id)
4211 for (frame = get_prev_frame (frame);
4213 frame = get_prev_frame (frame))
4215 if (frame_id_eq (get_frame_id (frame), step_frame_id))
4217 if (get_frame_type (frame) != INLINE_FRAME)
4224 /* If the event thread has the stop requested flag set, pretend it
4225 stopped for a GDB_SIGNAL_0 (i.e., as if it stopped due to
4229 handle_stop_requested (struct execution_control_state *ecs)
4231 if (ecs->event_thread->stop_requested)
4233 ecs->ws.kind = TARGET_WAITKIND_STOPPED;
4234 ecs->ws.value.sig = GDB_SIGNAL_0;
4235 handle_signal_stop (ecs);
4241 /* Auxiliary function that handles syscall entry/return events.
4242 It returns 1 if the inferior should keep going (and GDB
4243 should ignore the event), or 0 if the event deserves to be
4247 handle_syscall_event (struct execution_control_state *ecs)
4249 struct regcache *regcache;
4252 if (!ptid_equal (ecs->ptid, inferior_ptid))
4253 context_switch (ecs->ptid);
4255 regcache = get_thread_regcache (ecs->ptid);
4256 syscall_number = ecs->ws.value.syscall_number;
4257 stop_pc = regcache_read_pc (regcache);
4259 if (catch_syscall_enabled () > 0
4260 && catching_syscall_number (syscall_number) > 0)
4263 fprintf_unfiltered (gdb_stdlog, "infrun: syscall number = '%d'\n",
4266 ecs->event_thread->control.stop_bpstat
4267 = bpstat_stop_status (regcache->aspace (),
4268 stop_pc, ecs->ptid, &ecs->ws);
4270 if (handle_stop_requested (ecs))
4273 if (bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
4275 /* Catchpoint hit. */
4280 if (handle_stop_requested (ecs))
4283 /* If no catchpoint triggered for this, then keep going. */
4288 /* Lazily fill in the execution_control_state's stop_func_* fields. */
4291 fill_in_stop_func (struct gdbarch *gdbarch,
4292 struct execution_control_state *ecs)
4294 if (!ecs->stop_func_filled_in)
4296 /* Don't care about return value; stop_func_start and stop_func_name
4297 will both be 0 if it doesn't work. */
4298 find_pc_partial_function (stop_pc, &ecs->stop_func_name,
4299 &ecs->stop_func_start, &ecs->stop_func_end);
4300 ecs->stop_func_start
4301 += gdbarch_deprecated_function_start_offset (gdbarch);
4303 if (gdbarch_skip_entrypoint_p (gdbarch))
4304 ecs->stop_func_start = gdbarch_skip_entrypoint (gdbarch,
4305 ecs->stop_func_start);
4307 ecs->stop_func_filled_in = 1;
4312 /* Return the STOP_SOON field of the inferior pointed at by PTID. */
4314 static enum stop_kind
4315 get_inferior_stop_soon (ptid_t ptid)
4317 struct inferior *inf = find_inferior_ptid (ptid);
4319 gdb_assert (inf != NULL);
4320 return inf->control.stop_soon;
4323 /* Wait for one event. Store the resulting waitstatus in WS, and
4324 return the event ptid. */
4327 wait_one (struct target_waitstatus *ws)
4330 ptid_t wait_ptid = minus_one_ptid;
4332 overlay_cache_invalid = 1;
4334 /* Flush target cache before starting to handle each event.
4335 Target was running and cache could be stale. This is just a
4336 heuristic. Running threads may modify target memory, but we
4337 don't get any event. */
4338 target_dcache_invalidate ();
4340 if (deprecated_target_wait_hook)
4341 event_ptid = deprecated_target_wait_hook (wait_ptid, ws, 0);
4343 event_ptid = target_wait (wait_ptid, ws, 0);
4346 print_target_wait_results (wait_ptid, event_ptid, ws);
4351 /* Generate a wrapper for target_stopped_by_REASON that works on PTID
4352 instead of the current thread. */
4353 #define THREAD_STOPPED_BY(REASON) \
4355 thread_stopped_by_ ## REASON (ptid_t ptid) \
4357 scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid); \
4358 inferior_ptid = ptid; \
4360 return target_stopped_by_ ## REASON (); \
4363 /* Generate thread_stopped_by_watchpoint. */
4364 THREAD_STOPPED_BY (watchpoint)
4365 /* Generate thread_stopped_by_sw_breakpoint. */
4366 THREAD_STOPPED_BY (sw_breakpoint)
4367 /* Generate thread_stopped_by_hw_breakpoint. */
4368 THREAD_STOPPED_BY (hw_breakpoint)
4370 /* Cleanups that switches to the PTID pointed at by PTID_P. */
4373 switch_to_thread_cleanup (void *ptid_p)
4375 ptid_t ptid = *(ptid_t *) ptid_p;
4377 switch_to_thread (ptid);
4380 /* Save the thread's event and stop reason to process it later. */
4383 save_waitstatus (struct thread_info *tp, struct target_waitstatus *ws)
4385 struct regcache *regcache;
4389 std::string statstr = target_waitstatus_to_string (ws);
4391 fprintf_unfiltered (gdb_stdlog,
4392 "infrun: saving status %s for %d.%ld.%ld\n",
4394 ptid_get_pid (tp->ptid),
4395 ptid_get_lwp (tp->ptid),
4396 ptid_get_tid (tp->ptid));
4399 /* Record for later. */
4400 tp->suspend.waitstatus = *ws;
4401 tp->suspend.waitstatus_pending_p = 1;
4403 regcache = get_thread_regcache (tp->ptid);
4404 const address_space *aspace = regcache->aspace ();
4406 if (ws->kind == TARGET_WAITKIND_STOPPED
4407 && ws->value.sig == GDB_SIGNAL_TRAP)
4409 CORE_ADDR pc = regcache_read_pc (regcache);
4411 adjust_pc_after_break (tp, &tp->suspend.waitstatus);
4413 if (thread_stopped_by_watchpoint (tp->ptid))
4415 tp->suspend.stop_reason
4416 = TARGET_STOPPED_BY_WATCHPOINT;
4418 else if (target_supports_stopped_by_sw_breakpoint ()
4419 && thread_stopped_by_sw_breakpoint (tp->ptid))
4421 tp->suspend.stop_reason
4422 = TARGET_STOPPED_BY_SW_BREAKPOINT;
4424 else if (target_supports_stopped_by_hw_breakpoint ()
4425 && thread_stopped_by_hw_breakpoint (tp->ptid))
4427 tp->suspend.stop_reason
4428 = TARGET_STOPPED_BY_HW_BREAKPOINT;
4430 else if (!target_supports_stopped_by_hw_breakpoint ()
4431 && hardware_breakpoint_inserted_here_p (aspace,
4434 tp->suspend.stop_reason
4435 = TARGET_STOPPED_BY_HW_BREAKPOINT;
4437 else if (!target_supports_stopped_by_sw_breakpoint ()
4438 && software_breakpoint_inserted_here_p (aspace,
4441 tp->suspend.stop_reason
4442 = TARGET_STOPPED_BY_SW_BREAKPOINT;
4444 else if (!thread_has_single_step_breakpoints_set (tp)
4445 && currently_stepping (tp))
4447 tp->suspend.stop_reason
4448 = TARGET_STOPPED_BY_SINGLE_STEP;
4453 /* A cleanup that disables thread create/exit events. */
4456 disable_thread_events (void *arg)
4458 target_thread_events (0);
4464 stop_all_threads (void)
4466 /* We may need multiple passes to discover all threads. */
4470 struct cleanup *old_chain;
4472 gdb_assert (target_is_non_stop_p ());
4475 fprintf_unfiltered (gdb_stdlog, "infrun: stop_all_threads\n");
4477 entry_ptid = inferior_ptid;
4478 old_chain = make_cleanup (switch_to_thread_cleanup, &entry_ptid);
4480 target_thread_events (1);
4481 make_cleanup (disable_thread_events, NULL);
4483 /* Request threads to stop, and then wait for the stops. Because
4484 threads we already know about can spawn more threads while we're
4485 trying to stop them, and we only learn about new threads when we
4486 update the thread list, do this in a loop, and keep iterating
4487 until two passes find no threads that need to be stopped. */
4488 for (pass = 0; pass < 2; pass++, iterations++)
4491 fprintf_unfiltered (gdb_stdlog,
4492 "infrun: stop_all_threads, pass=%d, "
4493 "iterations=%d\n", pass, iterations);
4497 struct target_waitstatus ws;
4499 struct thread_info *t;
4501 update_thread_list ();
4503 /* Go through all threads looking for threads that we need
4504 to tell the target to stop. */
4505 ALL_NON_EXITED_THREADS (t)
4509 /* If already stopping, don't request a stop again.
4510 We just haven't seen the notification yet. */
4511 if (!t->stop_requested)
4514 fprintf_unfiltered (gdb_stdlog,
4515 "infrun: %s executing, "
4517 target_pid_to_str (t->ptid));
4518 target_stop (t->ptid);
4519 t->stop_requested = 1;
4524 fprintf_unfiltered (gdb_stdlog,
4525 "infrun: %s executing, "
4526 "already stopping\n",
4527 target_pid_to_str (t->ptid));
4530 if (t->stop_requested)
4536 fprintf_unfiltered (gdb_stdlog,
4537 "infrun: %s not executing\n",
4538 target_pid_to_str (t->ptid));
4540 /* The thread may be not executing, but still be
4541 resumed with a pending status to process. */
4549 /* If we find new threads on the second iteration, restart
4550 over. We want to see two iterations in a row with all
4555 event_ptid = wait_one (&ws);
4556 if (ws.kind == TARGET_WAITKIND_NO_RESUMED)
4558 /* All resumed threads exited. */
4560 else if (ws.kind == TARGET_WAITKIND_THREAD_EXITED
4561 || ws.kind == TARGET_WAITKIND_EXITED
4562 || ws.kind == TARGET_WAITKIND_SIGNALLED)
4566 ptid_t ptid = pid_to_ptid (ws.value.integer);
4568 fprintf_unfiltered (gdb_stdlog,
4569 "infrun: %s exited while "
4570 "stopping threads\n",
4571 target_pid_to_str (ptid));
4576 struct inferior *inf;
4578 t = find_thread_ptid (event_ptid);
4580 t = add_thread (event_ptid);
4582 t->stop_requested = 0;
4585 t->control.may_range_step = 0;
4587 /* This may be the first time we see the inferior report
4589 inf = find_inferior_ptid (event_ptid);
4590 if (inf->needs_setup)
4592 switch_to_thread_no_regs (t);
4596 if (ws.kind == TARGET_WAITKIND_STOPPED
4597 && ws.value.sig == GDB_SIGNAL_0)
4599 /* We caught the event that we intended to catch, so
4600 there's no event pending. */
4601 t->suspend.waitstatus.kind = TARGET_WAITKIND_IGNORE;
4602 t->suspend.waitstatus_pending_p = 0;
4604 if (displaced_step_fixup (t->ptid, GDB_SIGNAL_0) < 0)
4606 /* Add it back to the step-over queue. */
4609 fprintf_unfiltered (gdb_stdlog,
4610 "infrun: displaced-step of %s "
4611 "canceled: adding back to the "
4612 "step-over queue\n",
4613 target_pid_to_str (t->ptid));
4615 t->control.trap_expected = 0;
4616 thread_step_over_chain_enqueue (t);
4621 enum gdb_signal sig;
4622 struct regcache *regcache;
4626 std::string statstr = target_waitstatus_to_string (&ws);
4628 fprintf_unfiltered (gdb_stdlog,
4629 "infrun: target_wait %s, saving "
4630 "status for %d.%ld.%ld\n",
4632 ptid_get_pid (t->ptid),
4633 ptid_get_lwp (t->ptid),
4634 ptid_get_tid (t->ptid));
4637 /* Record for later. */
4638 save_waitstatus (t, &ws);
4640 sig = (ws.kind == TARGET_WAITKIND_STOPPED
4641 ? ws.value.sig : GDB_SIGNAL_0);
4643 if (displaced_step_fixup (t->ptid, sig) < 0)
4645 /* Add it back to the step-over queue. */
4646 t->control.trap_expected = 0;
4647 thread_step_over_chain_enqueue (t);
4650 regcache = get_thread_regcache (t->ptid);
4651 t->suspend.stop_pc = regcache_read_pc (regcache);
4655 fprintf_unfiltered (gdb_stdlog,
4656 "infrun: saved stop_pc=%s for %s "
4657 "(currently_stepping=%d)\n",
4658 paddress (target_gdbarch (),
4659 t->suspend.stop_pc),
4660 target_pid_to_str (t->ptid),
4661 currently_stepping (t));
4668 do_cleanups (old_chain);
4671 fprintf_unfiltered (gdb_stdlog, "infrun: stop_all_threads done\n");
4674 /* Handle a TARGET_WAITKIND_NO_RESUMED event. */
4677 handle_no_resumed (struct execution_control_state *ecs)
4679 struct inferior *inf;
4680 struct thread_info *thread;
4682 if (target_can_async_p ())
4689 if (ui->prompt_state == PROMPT_BLOCKED)
4697 /* There were no unwaited-for children left in the target, but,
4698 we're not synchronously waiting for events either. Just
4702 fprintf_unfiltered (gdb_stdlog,
4703 "infrun: TARGET_WAITKIND_NO_RESUMED "
4704 "(ignoring: bg)\n");
4705 prepare_to_wait (ecs);
4710 /* Otherwise, if we were running a synchronous execution command, we
4711 may need to cancel it and give the user back the terminal.
4713 In non-stop mode, the target can't tell whether we've already
4714 consumed previous stop events, so it can end up sending us a
4715 no-resumed event like so:
4717 #0 - thread 1 is left stopped
4719 #1 - thread 2 is resumed and hits breakpoint
4720 -> TARGET_WAITKIND_STOPPED
4722 #2 - thread 3 is resumed and exits
4723 this is the last resumed thread, so
4724 -> TARGET_WAITKIND_NO_RESUMED
4726 #3 - gdb processes stop for thread 2 and decides to re-resume
4729 #4 - gdb processes the TARGET_WAITKIND_NO_RESUMED event.
4730 thread 2 is now resumed, so the event should be ignored.
4732 IOW, if the stop for thread 2 doesn't end a foreground command,
4733 then we need to ignore the following TARGET_WAITKIND_NO_RESUMED
4734 event. But it could be that the event meant that thread 2 itself
4735 (or whatever other thread was the last resumed thread) exited.
4737 To address this we refresh the thread list and check whether we
4738 have resumed threads _now_. In the example above, this removes
4739 thread 3 from the thread list. If thread 2 was re-resumed, we
4740 ignore this event. If we find no thread resumed, then we cancel
4741 the synchronous command show "no unwaited-for " to the user. */
4742 update_thread_list ();
4744 ALL_NON_EXITED_THREADS (thread)
4746 if (thread->executing
4747 || thread->suspend.waitstatus_pending_p)
4749 /* There were no unwaited-for children left in the target at
4750 some point, but there are now. Just ignore. */
4752 fprintf_unfiltered (gdb_stdlog,
4753 "infrun: TARGET_WAITKIND_NO_RESUMED "
4754 "(ignoring: found resumed)\n");
4755 prepare_to_wait (ecs);
4760 /* Note however that we may find no resumed thread because the whole
4761 process exited meanwhile (thus updating the thread list results
4762 in an empty thread list). In this case we know we'll be getting
4763 a process exit event shortly. */
4769 thread = any_live_thread_of_process (inf->pid);
4773 fprintf_unfiltered (gdb_stdlog,
4774 "infrun: TARGET_WAITKIND_NO_RESUMED "
4775 "(expect process exit)\n");
4776 prepare_to_wait (ecs);
4781 /* Go ahead and report the event. */
4785 /* Given an execution control state that has been freshly filled in by
4786 an event from the inferior, figure out what it means and take
4789 The alternatives are:
4791 1) stop_waiting and return; to really stop and return to the
4794 2) keep_going and return; to wait for the next event (set
4795 ecs->event_thread->stepping_over_breakpoint to 1 to single step
4799 handle_inferior_event_1 (struct execution_control_state *ecs)
4801 enum stop_kind stop_soon;
4803 if (ecs->ws.kind == TARGET_WAITKIND_IGNORE)
4805 /* We had an event in the inferior, but we are not interested in
4806 handling it at this level. The lower layers have already
4807 done what needs to be done, if anything.
4809 One of the possible circumstances for this is when the
4810 inferior produces output for the console. The inferior has
4811 not stopped, and we are ignoring the event. Another possible
4812 circumstance is any event which the lower level knows will be
4813 reported multiple times without an intervening resume. */
4815 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_IGNORE\n");
4816 prepare_to_wait (ecs);
4820 if (ecs->ws.kind == TARGET_WAITKIND_THREAD_EXITED)
4823 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_THREAD_EXITED\n");
4824 prepare_to_wait (ecs);
4828 if (ecs->ws.kind == TARGET_WAITKIND_NO_RESUMED
4829 && handle_no_resumed (ecs))
4832 /* Cache the last pid/waitstatus. */
4833 set_last_target_status (ecs->ptid, ecs->ws);
4835 /* Always clear state belonging to the previous time we stopped. */
4836 stop_stack_dummy = STOP_NONE;
4838 if (ecs->ws.kind == TARGET_WAITKIND_NO_RESUMED)
4840 /* No unwaited-for children left. IOW, all resumed children
4843 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_NO_RESUMED\n");
4845 stop_print_frame = 0;
4850 if (ecs->ws.kind != TARGET_WAITKIND_EXITED
4851 && ecs->ws.kind != TARGET_WAITKIND_SIGNALLED)
4853 ecs->event_thread = find_thread_ptid (ecs->ptid);
4854 /* If it's a new thread, add it to the thread database. */
4855 if (ecs->event_thread == NULL)
4856 ecs->event_thread = add_thread (ecs->ptid);
4858 /* Disable range stepping. If the next step request could use a
4859 range, this will be end up re-enabled then. */
4860 ecs->event_thread->control.may_range_step = 0;
4863 /* Dependent on valid ECS->EVENT_THREAD. */
4864 adjust_pc_after_break (ecs->event_thread, &ecs->ws);
4866 /* Dependent on the current PC value modified by adjust_pc_after_break. */
4867 reinit_frame_cache ();
4869 breakpoint_retire_moribund ();
4871 /* First, distinguish signals caused by the debugger from signals
4872 that have to do with the program's own actions. Note that
4873 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
4874 on the operating system version. Here we detect when a SIGILL or
4875 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
4876 something similar for SIGSEGV, since a SIGSEGV will be generated
4877 when we're trying to execute a breakpoint instruction on a
4878 non-executable stack. This happens for call dummy breakpoints
4879 for architectures like SPARC that place call dummies on the
4881 if (ecs->ws.kind == TARGET_WAITKIND_STOPPED
4882 && (ecs->ws.value.sig == GDB_SIGNAL_ILL
4883 || ecs->ws.value.sig == GDB_SIGNAL_SEGV
4884 || ecs->ws.value.sig == GDB_SIGNAL_EMT))
4886 struct regcache *regcache = get_thread_regcache (ecs->ptid);
4888 if (breakpoint_inserted_here_p (regcache->aspace (),
4889 regcache_read_pc (regcache)))
4892 fprintf_unfiltered (gdb_stdlog,
4893 "infrun: Treating signal as SIGTRAP\n");
4894 ecs->ws.value.sig = GDB_SIGNAL_TRAP;
4898 /* Mark the non-executing threads accordingly. In all-stop, all
4899 threads of all processes are stopped when we get any event
4900 reported. In non-stop mode, only the event thread stops. */
4904 if (!target_is_non_stop_p ())
4905 mark_ptid = minus_one_ptid;
4906 else if (ecs->ws.kind == TARGET_WAITKIND_SIGNALLED
4907 || ecs->ws.kind == TARGET_WAITKIND_EXITED)
4909 /* If we're handling a process exit in non-stop mode, even
4910 though threads haven't been deleted yet, one would think
4911 that there is nothing to do, as threads of the dead process
4912 will be soon deleted, and threads of any other process were
4913 left running. However, on some targets, threads survive a
4914 process exit event. E.g., for the "checkpoint" command,
4915 when the current checkpoint/fork exits, linux-fork.c
4916 automatically switches to another fork from within
4917 target_mourn_inferior, by associating the same
4918 inferior/thread to another fork. We haven't mourned yet at
4919 this point, but we must mark any threads left in the
4920 process as not-executing so that finish_thread_state marks
4921 them stopped (in the user's perspective) if/when we present
4922 the stop to the user. */
4923 mark_ptid = pid_to_ptid (ptid_get_pid (ecs->ptid));
4926 mark_ptid = ecs->ptid;
4928 set_executing (mark_ptid, 0);
4930 /* Likewise the resumed flag. */
4931 set_resumed (mark_ptid, 0);
4934 switch (ecs->ws.kind)
4936 case TARGET_WAITKIND_LOADED:
4938 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_LOADED\n");
4939 if (!ptid_equal (ecs->ptid, inferior_ptid))
4940 context_switch (ecs->ptid);
4941 /* Ignore gracefully during startup of the inferior, as it might
4942 be the shell which has just loaded some objects, otherwise
4943 add the symbols for the newly loaded objects. Also ignore at
4944 the beginning of an attach or remote session; we will query
4945 the full list of libraries once the connection is
4948 stop_soon = get_inferior_stop_soon (ecs->ptid);
4949 if (stop_soon == NO_STOP_QUIETLY)
4951 struct regcache *regcache;
4953 regcache = get_thread_regcache (ecs->ptid);
4955 handle_solib_event ();
4957 ecs->event_thread->control.stop_bpstat
4958 = bpstat_stop_status (regcache->aspace (),
4959 stop_pc, ecs->ptid, &ecs->ws);
4961 if (handle_stop_requested (ecs))
4964 if (bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
4966 /* A catchpoint triggered. */
4967 process_event_stop_test (ecs);
4971 /* If requested, stop when the dynamic linker notifies
4972 gdb of events. This allows the user to get control
4973 and place breakpoints in initializer routines for
4974 dynamically loaded objects (among other things). */
4975 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
4976 if (stop_on_solib_events)
4978 /* Make sure we print "Stopped due to solib-event" in
4980 stop_print_frame = 1;
4987 /* If we are skipping through a shell, or through shared library
4988 loading that we aren't interested in, resume the program. If
4989 we're running the program normally, also resume. */
4990 if (stop_soon == STOP_QUIETLY || stop_soon == NO_STOP_QUIETLY)
4992 /* Loading of shared libraries might have changed breakpoint
4993 addresses. Make sure new breakpoints are inserted. */
4994 if (stop_soon == NO_STOP_QUIETLY)
4995 insert_breakpoints ();
4996 resume (GDB_SIGNAL_0);
4997 prepare_to_wait (ecs);
5001 /* But stop if we're attaching or setting up a remote
5003 if (stop_soon == STOP_QUIETLY_NO_SIGSTOP
5004 || stop_soon == STOP_QUIETLY_REMOTE)
5007 fprintf_unfiltered (gdb_stdlog, "infrun: quietly stopped\n");
5012 internal_error (__FILE__, __LINE__,
5013 _("unhandled stop_soon: %d"), (int) stop_soon);
5015 case TARGET_WAITKIND_SPURIOUS:
5017 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_SPURIOUS\n");
5018 if (handle_stop_requested (ecs))
5020 if (!ptid_equal (ecs->ptid, inferior_ptid))
5021 context_switch (ecs->ptid);
5022 resume (GDB_SIGNAL_0);
5023 prepare_to_wait (ecs);
5026 case TARGET_WAITKIND_THREAD_CREATED:
5028 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_THREAD_CREATED\n");
5029 if (handle_stop_requested (ecs))
5031 if (!ptid_equal (ecs->ptid, inferior_ptid))
5032 context_switch (ecs->ptid);
5033 if (!switch_back_to_stepped_thread (ecs))
5037 case TARGET_WAITKIND_EXITED:
5038 case TARGET_WAITKIND_SIGNALLED:
5041 if (ecs->ws.kind == TARGET_WAITKIND_EXITED)
5042 fprintf_unfiltered (gdb_stdlog,
5043 "infrun: TARGET_WAITKIND_EXITED\n");
5045 fprintf_unfiltered (gdb_stdlog,
5046 "infrun: TARGET_WAITKIND_SIGNALLED\n");
5049 inferior_ptid = ecs->ptid;
5050 set_current_inferior (find_inferior_ptid (ecs->ptid));
5051 set_current_program_space (current_inferior ()->pspace);
5052 handle_vfork_child_exec_or_exit (0);
5053 target_terminal::ours (); /* Must do this before mourn anyway. */
5055 /* Clearing any previous state of convenience variables. */
5056 clear_exit_convenience_vars ();
5058 if (ecs->ws.kind == TARGET_WAITKIND_EXITED)
5060 /* Record the exit code in the convenience variable $_exitcode, so
5061 that the user can inspect this again later. */
5062 set_internalvar_integer (lookup_internalvar ("_exitcode"),
5063 (LONGEST) ecs->ws.value.integer);
5065 /* Also record this in the inferior itself. */
5066 current_inferior ()->has_exit_code = 1;
5067 current_inferior ()->exit_code = (LONGEST) ecs->ws.value.integer;
5069 /* Support the --return-child-result option. */
5070 return_child_result_value = ecs->ws.value.integer;
5072 gdb::observers::exited.notify (ecs->ws.value.integer);
5076 struct regcache *regcache = get_thread_regcache (ecs->ptid);
5077 struct gdbarch *gdbarch = regcache->arch ();
5079 if (gdbarch_gdb_signal_to_target_p (gdbarch))
5081 /* Set the value of the internal variable $_exitsignal,
5082 which holds the signal uncaught by the inferior. */
5083 set_internalvar_integer (lookup_internalvar ("_exitsignal"),
5084 gdbarch_gdb_signal_to_target (gdbarch,
5085 ecs->ws.value.sig));
5089 /* We don't have access to the target's method used for
5090 converting between signal numbers (GDB's internal
5091 representation <-> target's representation).
5092 Therefore, we cannot do a good job at displaying this
5093 information to the user. It's better to just warn
5094 her about it (if infrun debugging is enabled), and
5097 fprintf_filtered (gdb_stdlog, _("\
5098 Cannot fill $_exitsignal with the correct signal number.\n"));
5101 gdb::observers::signal_exited.notify (ecs->ws.value.sig);
5104 gdb_flush (gdb_stdout);
5105 target_mourn_inferior (inferior_ptid);
5106 stop_print_frame = 0;
5110 /* The following are the only cases in which we keep going;
5111 the above cases end in a continue or goto. */
5112 case TARGET_WAITKIND_FORKED:
5113 case TARGET_WAITKIND_VFORKED:
5116 if (ecs->ws.kind == TARGET_WAITKIND_FORKED)
5117 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_FORKED\n");
5119 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_VFORKED\n");
5122 /* Check whether the inferior is displaced stepping. */
5124 struct regcache *regcache = get_thread_regcache (ecs->ptid);
5125 struct gdbarch *gdbarch = regcache->arch ();
5127 /* If checking displaced stepping is supported, and thread
5128 ecs->ptid is displaced stepping. */
5129 if (displaced_step_in_progress_thread (ecs->ptid))
5131 struct inferior *parent_inf
5132 = find_inferior_ptid (ecs->ptid);
5133 struct regcache *child_regcache;
5134 CORE_ADDR parent_pc;
5136 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
5137 indicating that the displaced stepping of syscall instruction
5138 has been done. Perform cleanup for parent process here. Note
5139 that this operation also cleans up the child process for vfork,
5140 because their pages are shared. */
5141 displaced_step_fixup (ecs->ptid, GDB_SIGNAL_TRAP);
5142 /* Start a new step-over in another thread if there's one
5146 if (ecs->ws.kind == TARGET_WAITKIND_FORKED)
5148 struct displaced_step_inferior_state *displaced
5149 = get_displaced_stepping_state (ptid_get_pid (ecs->ptid));
5151 /* Restore scratch pad for child process. */
5152 displaced_step_restore (displaced, ecs->ws.value.related_pid);
5155 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
5156 the child's PC is also within the scratchpad. Set the child's PC
5157 to the parent's PC value, which has already been fixed up.
5158 FIXME: we use the parent's aspace here, although we're touching
5159 the child, because the child hasn't been added to the inferior
5160 list yet at this point. */
5163 = get_thread_arch_aspace_regcache (ecs->ws.value.related_pid,
5165 parent_inf->aspace);
5166 /* Read PC value of parent process. */
5167 parent_pc = regcache_read_pc (regcache);
5169 if (debug_displaced)
5170 fprintf_unfiltered (gdb_stdlog,
5171 "displaced: write child pc from %s to %s\n",
5173 regcache_read_pc (child_regcache)),
5174 paddress (gdbarch, parent_pc));
5176 regcache_write_pc (child_regcache, parent_pc);
5180 if (!ptid_equal (ecs->ptid, inferior_ptid))
5181 context_switch (ecs->ptid);
5183 /* Immediately detach breakpoints from the child before there's
5184 any chance of letting the user delete breakpoints from the
5185 breakpoint lists. If we don't do this early, it's easy to
5186 leave left over traps in the child, vis: "break foo; catch
5187 fork; c; <fork>; del; c; <child calls foo>". We only follow
5188 the fork on the last `continue', and by that time the
5189 breakpoint at "foo" is long gone from the breakpoint table.
5190 If we vforked, then we don't need to unpatch here, since both
5191 parent and child are sharing the same memory pages; we'll
5192 need to unpatch at follow/detach time instead to be certain
5193 that new breakpoints added between catchpoint hit time and
5194 vfork follow are detached. */
5195 if (ecs->ws.kind != TARGET_WAITKIND_VFORKED)
5197 /* This won't actually modify the breakpoint list, but will
5198 physically remove the breakpoints from the child. */
5199 detach_breakpoints (ecs->ws.value.related_pid);
5202 delete_just_stopped_threads_single_step_breakpoints ();
5204 /* In case the event is caught by a catchpoint, remember that
5205 the event is to be followed at the next resume of the thread,
5206 and not immediately. */
5207 ecs->event_thread->pending_follow = ecs->ws;
5209 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
5211 ecs->event_thread->control.stop_bpstat
5212 = bpstat_stop_status (get_current_regcache ()->aspace (),
5213 stop_pc, ecs->ptid, &ecs->ws);
5215 if (handle_stop_requested (ecs))
5218 /* If no catchpoint triggered for this, then keep going. Note
5219 that we're interested in knowing the bpstat actually causes a
5220 stop, not just if it may explain the signal. Software
5221 watchpoints, for example, always appear in the bpstat. */
5222 if (!bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
5228 = (follow_fork_mode_string == follow_fork_mode_child);
5230 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5232 should_resume = follow_fork ();
5235 child = ecs->ws.value.related_pid;
5237 /* At this point, the parent is marked running, and the
5238 child is marked stopped. */
5240 /* If not resuming the parent, mark it stopped. */
5241 if (follow_child && !detach_fork && !non_stop && !sched_multi)
5242 set_running (parent, 0);
5244 /* If resuming the child, mark it running. */
5245 if (follow_child || (!detach_fork && (non_stop || sched_multi)))
5246 set_running (child, 1);
5248 /* In non-stop mode, also resume the other branch. */
5249 if (!detach_fork && (non_stop
5250 || (sched_multi && target_is_non_stop_p ())))
5253 switch_to_thread (parent);
5255 switch_to_thread (child);
5257 ecs->event_thread = inferior_thread ();
5258 ecs->ptid = inferior_ptid;
5263 switch_to_thread (child);
5265 switch_to_thread (parent);
5267 ecs->event_thread = inferior_thread ();
5268 ecs->ptid = inferior_ptid;
5276 process_event_stop_test (ecs);
5279 case TARGET_WAITKIND_VFORK_DONE:
5280 /* Done with the shared memory region. Re-insert breakpoints in
5281 the parent, and keep going. */
5284 fprintf_unfiltered (gdb_stdlog,
5285 "infrun: TARGET_WAITKIND_VFORK_DONE\n");
5287 if (!ptid_equal (ecs->ptid, inferior_ptid))
5288 context_switch (ecs->ptid);
5290 current_inferior ()->waiting_for_vfork_done = 0;
5291 current_inferior ()->pspace->breakpoints_not_allowed = 0;
5293 if (handle_stop_requested (ecs))
5296 /* This also takes care of reinserting breakpoints in the
5297 previously locked inferior. */
5301 case TARGET_WAITKIND_EXECD:
5303 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_EXECD\n");
5305 /* Note we can't read registers yet (the stop_pc), because we
5306 don't yet know the inferior's post-exec architecture.
5307 'stop_pc' is explicitly read below instead. */
5308 if (!ptid_equal (ecs->ptid, inferior_ptid))
5309 switch_to_thread_no_regs (ecs->event_thread);
5311 /* Do whatever is necessary to the parent branch of the vfork. */
5312 handle_vfork_child_exec_or_exit (1);
5314 /* This causes the eventpoints and symbol table to be reset.
5315 Must do this now, before trying to determine whether to
5317 follow_exec (inferior_ptid, ecs->ws.value.execd_pathname);
5319 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
5321 /* In follow_exec we may have deleted the original thread and
5322 created a new one. Make sure that the event thread is the
5323 execd thread for that case (this is a nop otherwise). */
5324 ecs->event_thread = inferior_thread ();
5326 ecs->event_thread->control.stop_bpstat
5327 = bpstat_stop_status (get_current_regcache ()->aspace (),
5328 stop_pc, ecs->ptid, &ecs->ws);
5330 /* Note that this may be referenced from inside
5331 bpstat_stop_status above, through inferior_has_execd. */
5332 xfree (ecs->ws.value.execd_pathname);
5333 ecs->ws.value.execd_pathname = NULL;
5335 if (handle_stop_requested (ecs))
5338 /* If no catchpoint triggered for this, then keep going. */
5339 if (!bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
5341 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5345 process_event_stop_test (ecs);
5348 /* Be careful not to try to gather much state about a thread
5349 that's in a syscall. It's frequently a losing proposition. */
5350 case TARGET_WAITKIND_SYSCALL_ENTRY:
5352 fprintf_unfiltered (gdb_stdlog,
5353 "infrun: TARGET_WAITKIND_SYSCALL_ENTRY\n");
5354 /* Getting the current syscall number. */
5355 if (handle_syscall_event (ecs) == 0)
5356 process_event_stop_test (ecs);
5359 /* Before examining the threads further, step this thread to
5360 get it entirely out of the syscall. (We get notice of the
5361 event when the thread is just on the verge of exiting a
5362 syscall. Stepping one instruction seems to get it back
5364 case TARGET_WAITKIND_SYSCALL_RETURN:
5366 fprintf_unfiltered (gdb_stdlog,
5367 "infrun: TARGET_WAITKIND_SYSCALL_RETURN\n");
5368 if (handle_syscall_event (ecs) == 0)
5369 process_event_stop_test (ecs);
5372 case TARGET_WAITKIND_STOPPED:
5374 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_STOPPED\n");
5375 handle_signal_stop (ecs);
5378 case TARGET_WAITKIND_NO_HISTORY:
5380 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_NO_HISTORY\n");
5381 /* Reverse execution: target ran out of history info. */
5383 /* Switch to the stopped thread. */
5384 if (!ptid_equal (ecs->ptid, inferior_ptid))
5385 context_switch (ecs->ptid);
5387 fprintf_unfiltered (gdb_stdlog, "infrun: stopped\n");
5389 delete_just_stopped_threads_single_step_breakpoints ();
5390 stop_pc = regcache_read_pc (get_thread_regcache (inferior_ptid));
5392 if (handle_stop_requested (ecs))
5395 gdb::observers::no_history.notify ();
5401 /* A wrapper around handle_inferior_event_1, which also makes sure
5402 that all temporary struct value objects that were created during
5403 the handling of the event get deleted at the end. */
5406 handle_inferior_event (struct execution_control_state *ecs)
5408 struct value *mark = value_mark ();
5410 handle_inferior_event_1 (ecs);
5411 /* Purge all temporary values created during the event handling,
5412 as it could be a long time before we return to the command level
5413 where such values would otherwise be purged. */
5414 value_free_to_mark (mark);
5417 /* Restart threads back to what they were trying to do back when we
5418 paused them for an in-line step-over. The EVENT_THREAD thread is
5422 restart_threads (struct thread_info *event_thread)
5424 struct thread_info *tp;
5426 /* In case the instruction just stepped spawned a new thread. */
5427 update_thread_list ();
5429 ALL_NON_EXITED_THREADS (tp)
5431 if (tp == event_thread)
5434 fprintf_unfiltered (gdb_stdlog,
5435 "infrun: restart threads: "
5436 "[%s] is event thread\n",
5437 target_pid_to_str (tp->ptid));
5441 if (!(tp->state == THREAD_RUNNING || tp->control.in_infcall))
5444 fprintf_unfiltered (gdb_stdlog,
5445 "infrun: restart threads: "
5446 "[%s] not meant to be running\n",
5447 target_pid_to_str (tp->ptid));
5454 fprintf_unfiltered (gdb_stdlog,
5455 "infrun: restart threads: [%s] resumed\n",
5456 target_pid_to_str (tp->ptid));
5457 gdb_assert (tp->executing || tp->suspend.waitstatus_pending_p);
5461 if (thread_is_in_step_over_chain (tp))
5464 fprintf_unfiltered (gdb_stdlog,
5465 "infrun: restart threads: "
5466 "[%s] needs step-over\n",
5467 target_pid_to_str (tp->ptid));
5468 gdb_assert (!tp->resumed);
5473 if (tp->suspend.waitstatus_pending_p)
5476 fprintf_unfiltered (gdb_stdlog,
5477 "infrun: restart threads: "
5478 "[%s] has pending status\n",
5479 target_pid_to_str (tp->ptid));
5484 gdb_assert (!tp->stop_requested);
5486 /* If some thread needs to start a step-over at this point, it
5487 should still be in the step-over queue, and thus skipped
5489 if (thread_still_needs_step_over (tp))
5491 internal_error (__FILE__, __LINE__,
5492 "thread [%s] needs a step-over, but not in "
5493 "step-over queue\n",
5494 target_pid_to_str (tp->ptid));
5497 if (currently_stepping (tp))
5500 fprintf_unfiltered (gdb_stdlog,
5501 "infrun: restart threads: [%s] was stepping\n",
5502 target_pid_to_str (tp->ptid));
5503 keep_going_stepped_thread (tp);
5507 struct execution_control_state ecss;
5508 struct execution_control_state *ecs = &ecss;
5511 fprintf_unfiltered (gdb_stdlog,
5512 "infrun: restart threads: [%s] continuing\n",
5513 target_pid_to_str (tp->ptid));
5514 reset_ecs (ecs, tp);
5515 switch_to_thread (tp->ptid);
5516 keep_going_pass_signal (ecs);
5521 /* Callback for iterate_over_threads. Find a resumed thread that has
5522 a pending waitstatus. */
5525 resumed_thread_with_pending_status (struct thread_info *tp,
5529 && tp->suspend.waitstatus_pending_p);
5532 /* Called when we get an event that may finish an in-line or
5533 out-of-line (displaced stepping) step-over started previously.
5534 Return true if the event is processed and we should go back to the
5535 event loop; false if the caller should continue processing the
5539 finish_step_over (struct execution_control_state *ecs)
5541 int had_step_over_info;
5543 displaced_step_fixup (ecs->ptid,
5544 ecs->event_thread->suspend.stop_signal);
5546 had_step_over_info = step_over_info_valid_p ();
5548 if (had_step_over_info)
5550 /* If we're stepping over a breakpoint with all threads locked,
5551 then only the thread that was stepped should be reporting
5553 gdb_assert (ecs->event_thread->control.trap_expected);
5555 clear_step_over_info ();
5558 if (!target_is_non_stop_p ())
5561 /* Start a new step-over in another thread if there's one that
5565 /* If we were stepping over a breakpoint before, and haven't started
5566 a new in-line step-over sequence, then restart all other threads
5567 (except the event thread). We can't do this in all-stop, as then
5568 e.g., we wouldn't be able to issue any other remote packet until
5569 these other threads stop. */
5570 if (had_step_over_info && !step_over_info_valid_p ())
5572 struct thread_info *pending;
5574 /* If we only have threads with pending statuses, the restart
5575 below won't restart any thread and so nothing re-inserts the
5576 breakpoint we just stepped over. But we need it inserted
5577 when we later process the pending events, otherwise if
5578 another thread has a pending event for this breakpoint too,
5579 we'd discard its event (because the breakpoint that
5580 originally caused the event was no longer inserted). */
5581 context_switch (ecs->ptid);
5582 insert_breakpoints ();
5584 restart_threads (ecs->event_thread);
5586 /* If we have events pending, go through handle_inferior_event
5587 again, picking up a pending event at random. This avoids
5588 thread starvation. */
5590 /* But not if we just stepped over a watchpoint in order to let
5591 the instruction execute so we can evaluate its expression.
5592 The set of watchpoints that triggered is recorded in the
5593 breakpoint objects themselves (see bp->watchpoint_triggered).
5594 If we processed another event first, that other event could
5595 clobber this info. */
5596 if (ecs->event_thread->stepping_over_watchpoint)
5599 pending = iterate_over_threads (resumed_thread_with_pending_status,
5601 if (pending != NULL)
5603 struct thread_info *tp = ecs->event_thread;
5604 struct regcache *regcache;
5608 fprintf_unfiltered (gdb_stdlog,
5609 "infrun: found resumed threads with "
5610 "pending events, saving status\n");
5613 gdb_assert (pending != tp);
5615 /* Record the event thread's event for later. */
5616 save_waitstatus (tp, &ecs->ws);
5617 /* This was cleared early, by handle_inferior_event. Set it
5618 so this pending event is considered by
5622 gdb_assert (!tp->executing);
5624 regcache = get_thread_regcache (tp->ptid);
5625 tp->suspend.stop_pc = regcache_read_pc (regcache);
5629 fprintf_unfiltered (gdb_stdlog,
5630 "infrun: saved stop_pc=%s for %s "
5631 "(currently_stepping=%d)\n",
5632 paddress (target_gdbarch (),
5633 tp->suspend.stop_pc),
5634 target_pid_to_str (tp->ptid),
5635 currently_stepping (tp));
5638 /* This in-line step-over finished; clear this so we won't
5639 start a new one. This is what handle_signal_stop would
5640 do, if we returned false. */
5641 tp->stepping_over_breakpoint = 0;
5643 /* Wake up the event loop again. */
5644 mark_async_event_handler (infrun_async_inferior_event_token);
5646 prepare_to_wait (ecs);
5654 /* Come here when the program has stopped with a signal. */
5657 handle_signal_stop (struct execution_control_state *ecs)
5659 struct frame_info *frame;
5660 struct gdbarch *gdbarch;
5661 int stopped_by_watchpoint;
5662 enum stop_kind stop_soon;
5665 gdb_assert (ecs->ws.kind == TARGET_WAITKIND_STOPPED);
5667 ecs->event_thread->suspend.stop_signal = ecs->ws.value.sig;
5669 /* Do we need to clean up the state of a thread that has
5670 completed a displaced single-step? (Doing so usually affects
5671 the PC, so do it here, before we set stop_pc.) */
5672 if (finish_step_over (ecs))
5675 /* If we either finished a single-step or hit a breakpoint, but
5676 the user wanted this thread to be stopped, pretend we got a
5677 SIG0 (generic unsignaled stop). */
5678 if (ecs->event_thread->stop_requested
5679 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
5680 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5682 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
5686 struct regcache *regcache = get_thread_regcache (ecs->ptid);
5687 struct gdbarch *gdbarch = regcache->arch ();
5688 scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid);
5690 inferior_ptid = ecs->ptid;
5692 fprintf_unfiltered (gdb_stdlog, "infrun: stop_pc = %s\n",
5693 paddress (gdbarch, stop_pc));
5694 if (target_stopped_by_watchpoint ())
5698 fprintf_unfiltered (gdb_stdlog, "infrun: stopped by watchpoint\n");
5700 if (target_stopped_data_address (¤t_target, &addr))
5701 fprintf_unfiltered (gdb_stdlog,
5702 "infrun: stopped data address = %s\n",
5703 paddress (gdbarch, addr));
5705 fprintf_unfiltered (gdb_stdlog,
5706 "infrun: (no data address available)\n");
5710 /* This is originated from start_remote(), start_inferior() and
5711 shared libraries hook functions. */
5712 stop_soon = get_inferior_stop_soon (ecs->ptid);
5713 if (stop_soon == STOP_QUIETLY || stop_soon == STOP_QUIETLY_REMOTE)
5715 if (!ptid_equal (ecs->ptid, inferior_ptid))
5716 context_switch (ecs->ptid);
5718 fprintf_unfiltered (gdb_stdlog, "infrun: quietly stopped\n");
5719 stop_print_frame = 1;
5724 /* This originates from attach_command(). We need to overwrite
5725 the stop_signal here, because some kernels don't ignore a
5726 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
5727 See more comments in inferior.h. On the other hand, if we
5728 get a non-SIGSTOP, report it to the user - assume the backend
5729 will handle the SIGSTOP if it should show up later.
5731 Also consider that the attach is complete when we see a
5732 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
5733 target extended-remote report it instead of a SIGSTOP
5734 (e.g. gdbserver). We already rely on SIGTRAP being our
5735 signal, so this is no exception.
5737 Also consider that the attach is complete when we see a
5738 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
5739 the target to stop all threads of the inferior, in case the
5740 low level attach operation doesn't stop them implicitly. If
5741 they weren't stopped implicitly, then the stub will report a
5742 GDB_SIGNAL_0, meaning: stopped for no particular reason
5743 other than GDB's request. */
5744 if (stop_soon == STOP_QUIETLY_NO_SIGSTOP
5745 && (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_STOP
5746 || ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5747 || ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_0))
5749 stop_print_frame = 1;
5751 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5755 /* See if something interesting happened to the non-current thread. If
5756 so, then switch to that thread. */
5757 if (!ptid_equal (ecs->ptid, inferior_ptid))
5760 fprintf_unfiltered (gdb_stdlog, "infrun: context switch\n");
5762 context_switch (ecs->ptid);
5764 if (deprecated_context_hook)
5765 deprecated_context_hook (ptid_to_global_thread_id (ecs->ptid));
5768 /* At this point, get hold of the now-current thread's frame. */
5769 frame = get_current_frame ();
5770 gdbarch = get_frame_arch (frame);
5772 /* Pull the single step breakpoints out of the target. */
5773 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
5775 struct regcache *regcache;
5778 regcache = get_thread_regcache (ecs->ptid);
5779 const address_space *aspace = regcache->aspace ();
5781 pc = regcache_read_pc (regcache);
5783 /* However, before doing so, if this single-step breakpoint was
5784 actually for another thread, set this thread up for moving
5786 if (!thread_has_single_step_breakpoint_here (ecs->event_thread,
5789 if (single_step_breakpoint_inserted_here_p (aspace, pc))
5793 fprintf_unfiltered (gdb_stdlog,
5794 "infrun: [%s] hit another thread's "
5795 "single-step breakpoint\n",
5796 target_pid_to_str (ecs->ptid));
5798 ecs->hit_singlestep_breakpoint = 1;
5805 fprintf_unfiltered (gdb_stdlog,
5806 "infrun: [%s] hit its "
5807 "single-step breakpoint\n",
5808 target_pid_to_str (ecs->ptid));
5812 delete_just_stopped_threads_single_step_breakpoints ();
5814 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5815 && ecs->event_thread->control.trap_expected
5816 && ecs->event_thread->stepping_over_watchpoint)
5817 stopped_by_watchpoint = 0;
5819 stopped_by_watchpoint = watchpoints_triggered (&ecs->ws);
5821 /* If necessary, step over this watchpoint. We'll be back to display
5823 if (stopped_by_watchpoint
5824 && (target_have_steppable_watchpoint
5825 || gdbarch_have_nonsteppable_watchpoint (gdbarch)))
5827 /* At this point, we are stopped at an instruction which has
5828 attempted to write to a piece of memory under control of
5829 a watchpoint. The instruction hasn't actually executed
5830 yet. If we were to evaluate the watchpoint expression
5831 now, we would get the old value, and therefore no change
5832 would seem to have occurred.
5834 In order to make watchpoints work `right', we really need
5835 to complete the memory write, and then evaluate the
5836 watchpoint expression. We do this by single-stepping the
5839 It may not be necessary to disable the watchpoint to step over
5840 it. For example, the PA can (with some kernel cooperation)
5841 single step over a watchpoint without disabling the watchpoint.
5843 It is far more common to need to disable a watchpoint to step
5844 the inferior over it. If we have non-steppable watchpoints,
5845 we must disable the current watchpoint; it's simplest to
5846 disable all watchpoints.
5848 Any breakpoint at PC must also be stepped over -- if there's
5849 one, it will have already triggered before the watchpoint
5850 triggered, and we either already reported it to the user, or
5851 it didn't cause a stop and we called keep_going. In either
5852 case, if there was a breakpoint at PC, we must be trying to
5854 ecs->event_thread->stepping_over_watchpoint = 1;
5859 ecs->event_thread->stepping_over_breakpoint = 0;
5860 ecs->event_thread->stepping_over_watchpoint = 0;
5861 bpstat_clear (&ecs->event_thread->control.stop_bpstat);
5862 ecs->event_thread->control.stop_step = 0;
5863 stop_print_frame = 1;
5864 stopped_by_random_signal = 0;
5866 /* Hide inlined functions starting here, unless we just performed stepi or
5867 nexti. After stepi and nexti, always show the innermost frame (not any
5868 inline function call sites). */
5869 if (ecs->event_thread->control.step_range_end != 1)
5871 const address_space *aspace =
5872 get_thread_regcache (ecs->ptid)->aspace ();
5874 /* skip_inline_frames is expensive, so we avoid it if we can
5875 determine that the address is one where functions cannot have
5876 been inlined. This improves performance with inferiors that
5877 load a lot of shared libraries, because the solib event
5878 breakpoint is defined as the address of a function (i.e. not
5879 inline). Note that we have to check the previous PC as well
5880 as the current one to catch cases when we have just
5881 single-stepped off a breakpoint prior to reinstating it.
5882 Note that we're assuming that the code we single-step to is
5883 not inline, but that's not definitive: there's nothing
5884 preventing the event breakpoint function from containing
5885 inlined code, and the single-step ending up there. If the
5886 user had set a breakpoint on that inlined code, the missing
5887 skip_inline_frames call would break things. Fortunately
5888 that's an extremely unlikely scenario. */
5889 if (!pc_at_non_inline_function (aspace, stop_pc, &ecs->ws)
5890 && !(ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5891 && ecs->event_thread->control.trap_expected
5892 && pc_at_non_inline_function (aspace,
5893 ecs->event_thread->prev_pc,
5896 skip_inline_frames (ecs->ptid);
5898 /* Re-fetch current thread's frame in case that invalidated
5900 frame = get_current_frame ();
5901 gdbarch = get_frame_arch (frame);
5905 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5906 && ecs->event_thread->control.trap_expected
5907 && gdbarch_single_step_through_delay_p (gdbarch)
5908 && currently_stepping (ecs->event_thread))
5910 /* We're trying to step off a breakpoint. Turns out that we're
5911 also on an instruction that needs to be stepped multiple
5912 times before it's been fully executing. E.g., architectures
5913 with a delay slot. It needs to be stepped twice, once for
5914 the instruction and once for the delay slot. */
5915 int step_through_delay
5916 = gdbarch_single_step_through_delay (gdbarch, frame);
5918 if (debug_infrun && step_through_delay)
5919 fprintf_unfiltered (gdb_stdlog, "infrun: step through delay\n");
5920 if (ecs->event_thread->control.step_range_end == 0
5921 && step_through_delay)
5923 /* The user issued a continue when stopped at a breakpoint.
5924 Set up for another trap and get out of here. */
5925 ecs->event_thread->stepping_over_breakpoint = 1;
5929 else if (step_through_delay)
5931 /* The user issued a step when stopped at a breakpoint.
5932 Maybe we should stop, maybe we should not - the delay
5933 slot *might* correspond to a line of source. In any
5934 case, don't decide that here, just set
5935 ecs->stepping_over_breakpoint, making sure we
5936 single-step again before breakpoints are re-inserted. */
5937 ecs->event_thread->stepping_over_breakpoint = 1;
5941 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
5942 handles this event. */
5943 ecs->event_thread->control.stop_bpstat
5944 = bpstat_stop_status (get_current_regcache ()->aspace (),
5945 stop_pc, ecs->ptid, &ecs->ws);
5947 /* Following in case break condition called a
5949 stop_print_frame = 1;
5951 /* This is where we handle "moribund" watchpoints. Unlike
5952 software breakpoints traps, hardware watchpoint traps are
5953 always distinguishable from random traps. If no high-level
5954 watchpoint is associated with the reported stop data address
5955 anymore, then the bpstat does not explain the signal ---
5956 simply make sure to ignore it if `stopped_by_watchpoint' is
5960 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5961 && !bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
5963 && stopped_by_watchpoint)
5964 fprintf_unfiltered (gdb_stdlog,
5965 "infrun: no user watchpoint explains "
5966 "watchpoint SIGTRAP, ignoring\n");
5968 /* NOTE: cagney/2003-03-29: These checks for a random signal
5969 at one stage in the past included checks for an inferior
5970 function call's call dummy's return breakpoint. The original
5971 comment, that went with the test, read:
5973 ``End of a stack dummy. Some systems (e.g. Sony news) give
5974 another signal besides SIGTRAP, so check here as well as
5977 If someone ever tries to get call dummys on a
5978 non-executable stack to work (where the target would stop
5979 with something like a SIGSEGV), then those tests might need
5980 to be re-instated. Given, however, that the tests were only
5981 enabled when momentary breakpoints were not being used, I
5982 suspect that it won't be the case.
5984 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
5985 be necessary for call dummies on a non-executable stack on
5988 /* See if the breakpoints module can explain the signal. */
5990 = !bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
5991 ecs->event_thread->suspend.stop_signal);
5993 /* Maybe this was a trap for a software breakpoint that has since
5995 if (random_signal && target_stopped_by_sw_breakpoint ())
5997 if (program_breakpoint_here_p (gdbarch, stop_pc))
5999 struct regcache *regcache;
6002 /* Re-adjust PC to what the program would see if GDB was not
6004 regcache = get_thread_regcache (ecs->event_thread->ptid);
6005 decr_pc = gdbarch_decr_pc_after_break (gdbarch);
6008 gdb::optional<scoped_restore_tmpl<int>>
6009 restore_operation_disable;
6011 if (record_full_is_used ())
6012 restore_operation_disable.emplace
6013 (record_full_gdb_operation_disable_set ());
6015 regcache_write_pc (regcache, stop_pc + decr_pc);
6020 /* A delayed software breakpoint event. Ignore the trap. */
6022 fprintf_unfiltered (gdb_stdlog,
6023 "infrun: delayed software breakpoint "
6024 "trap, ignoring\n");
6029 /* Maybe this was a trap for a hardware breakpoint/watchpoint that
6030 has since been removed. */
6031 if (random_signal && target_stopped_by_hw_breakpoint ())
6033 /* A delayed hardware breakpoint event. Ignore the trap. */
6035 fprintf_unfiltered (gdb_stdlog,
6036 "infrun: delayed hardware breakpoint/watchpoint "
6037 "trap, ignoring\n");
6041 /* If not, perhaps stepping/nexting can. */
6043 random_signal = !(ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
6044 && currently_stepping (ecs->event_thread));
6046 /* Perhaps the thread hit a single-step breakpoint of _another_
6047 thread. Single-step breakpoints are transparent to the
6048 breakpoints module. */
6050 random_signal = !ecs->hit_singlestep_breakpoint;
6052 /* No? Perhaps we got a moribund watchpoint. */
6054 random_signal = !stopped_by_watchpoint;
6056 /* Always stop if the user explicitly requested this thread to
6058 if (ecs->event_thread->stop_requested)
6062 fprintf_unfiltered (gdb_stdlog, "infrun: user-requested stop\n");
6065 /* For the program's own signals, act according to
6066 the signal handling tables. */
6070 /* Signal not for debugging purposes. */
6071 struct inferior *inf = find_inferior_ptid (ecs->ptid);
6072 enum gdb_signal stop_signal = ecs->event_thread->suspend.stop_signal;
6075 fprintf_unfiltered (gdb_stdlog, "infrun: random signal (%s)\n",
6076 gdb_signal_to_symbol_string (stop_signal));
6078 stopped_by_random_signal = 1;
6080 /* Always stop on signals if we're either just gaining control
6081 of the program, or the user explicitly requested this thread
6082 to remain stopped. */
6083 if (stop_soon != NO_STOP_QUIETLY
6084 || ecs->event_thread->stop_requested
6086 && signal_stop_state (ecs->event_thread->suspend.stop_signal)))
6092 /* Notify observers the signal has "handle print" set. Note we
6093 returned early above if stopping; normal_stop handles the
6094 printing in that case. */
6095 if (signal_print[ecs->event_thread->suspend.stop_signal])
6097 /* The signal table tells us to print about this signal. */
6098 target_terminal::ours_for_output ();
6099 gdb::observers::signal_received.notify (ecs->event_thread->suspend.stop_signal);
6100 target_terminal::inferior ();
6103 /* Clear the signal if it should not be passed. */
6104 if (signal_program[ecs->event_thread->suspend.stop_signal] == 0)
6105 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
6107 if (ecs->event_thread->prev_pc == stop_pc
6108 && ecs->event_thread->control.trap_expected
6109 && ecs->event_thread->control.step_resume_breakpoint == NULL)
6111 /* We were just starting a new sequence, attempting to
6112 single-step off of a breakpoint and expecting a SIGTRAP.
6113 Instead this signal arrives. This signal will take us out
6114 of the stepping range so GDB needs to remember to, when
6115 the signal handler returns, resume stepping off that
6117 /* To simplify things, "continue" is forced to use the same
6118 code paths as single-step - set a breakpoint at the
6119 signal return address and then, once hit, step off that
6122 fprintf_unfiltered (gdb_stdlog,
6123 "infrun: signal arrived while stepping over "
6126 insert_hp_step_resume_breakpoint_at_frame (frame);
6127 ecs->event_thread->step_after_step_resume_breakpoint = 1;
6128 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6129 ecs->event_thread->control.trap_expected = 0;
6131 /* If we were nexting/stepping some other thread, switch to
6132 it, so that we don't continue it, losing control. */
6133 if (!switch_back_to_stepped_thread (ecs))
6138 if (ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_0
6139 && (pc_in_thread_step_range (stop_pc, ecs->event_thread)
6140 || ecs->event_thread->control.step_range_end == 1)
6141 && frame_id_eq (get_stack_frame_id (frame),
6142 ecs->event_thread->control.step_stack_frame_id)
6143 && ecs->event_thread->control.step_resume_breakpoint == NULL)
6145 /* The inferior is about to take a signal that will take it
6146 out of the single step range. Set a breakpoint at the
6147 current PC (which is presumably where the signal handler
6148 will eventually return) and then allow the inferior to
6151 Note that this is only needed for a signal delivered
6152 while in the single-step range. Nested signals aren't a
6153 problem as they eventually all return. */
6155 fprintf_unfiltered (gdb_stdlog,
6156 "infrun: signal may take us out of "
6157 "single-step range\n");
6159 clear_step_over_info ();
6160 insert_hp_step_resume_breakpoint_at_frame (frame);
6161 ecs->event_thread->step_after_step_resume_breakpoint = 1;
6162 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6163 ecs->event_thread->control.trap_expected = 0;
6168 /* Note: step_resume_breakpoint may be non-NULL. This occures
6169 when either there's a nested signal, or when there's a
6170 pending signal enabled just as the signal handler returns
6171 (leaving the inferior at the step-resume-breakpoint without
6172 actually executing it). Either way continue until the
6173 breakpoint is really hit. */
6175 if (!switch_back_to_stepped_thread (ecs))
6178 fprintf_unfiltered (gdb_stdlog,
6179 "infrun: random signal, keep going\n");
6186 process_event_stop_test (ecs);
6189 /* Come here when we've got some debug event / signal we can explain
6190 (IOW, not a random signal), and test whether it should cause a
6191 stop, or whether we should resume the inferior (transparently).
6192 E.g., could be a breakpoint whose condition evaluates false; we
6193 could be still stepping within the line; etc. */
6196 process_event_stop_test (struct execution_control_state *ecs)
6198 struct symtab_and_line stop_pc_sal;
6199 struct frame_info *frame;
6200 struct gdbarch *gdbarch;
6201 CORE_ADDR jmp_buf_pc;
6202 struct bpstat_what what;
6204 /* Handle cases caused by hitting a breakpoint. */
6206 frame = get_current_frame ();
6207 gdbarch = get_frame_arch (frame);
6209 what = bpstat_what (ecs->event_thread->control.stop_bpstat);
6211 if (what.call_dummy)
6213 stop_stack_dummy = what.call_dummy;
6216 /* A few breakpoint types have callbacks associated (e.g.,
6217 bp_jit_event). Run them now. */
6218 bpstat_run_callbacks (ecs->event_thread->control.stop_bpstat);
6220 /* If we hit an internal event that triggers symbol changes, the
6221 current frame will be invalidated within bpstat_what (e.g., if we
6222 hit an internal solib event). Re-fetch it. */
6223 frame = get_current_frame ();
6224 gdbarch = get_frame_arch (frame);
6226 switch (what.main_action)
6228 case BPSTAT_WHAT_SET_LONGJMP_RESUME:
6229 /* If we hit the breakpoint at longjmp while stepping, we
6230 install a momentary breakpoint at the target of the
6234 fprintf_unfiltered (gdb_stdlog,
6235 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME\n");
6237 ecs->event_thread->stepping_over_breakpoint = 1;
6239 if (what.is_longjmp)
6241 struct value *arg_value;
6243 /* If we set the longjmp breakpoint via a SystemTap probe,
6244 then use it to extract the arguments. The destination PC
6245 is the third argument to the probe. */
6246 arg_value = probe_safe_evaluate_at_pc (frame, 2);
6249 jmp_buf_pc = value_as_address (arg_value);
6250 jmp_buf_pc = gdbarch_addr_bits_remove (gdbarch, jmp_buf_pc);
6252 else if (!gdbarch_get_longjmp_target_p (gdbarch)
6253 || !gdbarch_get_longjmp_target (gdbarch,
6254 frame, &jmp_buf_pc))
6257 fprintf_unfiltered (gdb_stdlog,
6258 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME "
6259 "(!gdbarch_get_longjmp_target)\n");
6264 /* Insert a breakpoint at resume address. */
6265 insert_longjmp_resume_breakpoint (gdbarch, jmp_buf_pc);
6268 check_exception_resume (ecs, frame);
6272 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME:
6274 struct frame_info *init_frame;
6276 /* There are several cases to consider.
6278 1. The initiating frame no longer exists. In this case we
6279 must stop, because the exception or longjmp has gone too
6282 2. The initiating frame exists, and is the same as the
6283 current frame. We stop, because the exception or longjmp
6286 3. The initiating frame exists and is different from the
6287 current frame. This means the exception or longjmp has
6288 been caught beneath the initiating frame, so keep going.
6290 4. longjmp breakpoint has been placed just to protect
6291 against stale dummy frames and user is not interested in
6292 stopping around longjmps. */
6295 fprintf_unfiltered (gdb_stdlog,
6296 "infrun: BPSTAT_WHAT_CLEAR_LONGJMP_RESUME\n");
6298 gdb_assert (ecs->event_thread->control.exception_resume_breakpoint
6300 delete_exception_resume_breakpoint (ecs->event_thread);
6302 if (what.is_longjmp)
6304 check_longjmp_breakpoint_for_call_dummy (ecs->event_thread);
6306 if (!frame_id_p (ecs->event_thread->initiating_frame))
6314 init_frame = frame_find_by_id (ecs->event_thread->initiating_frame);
6318 struct frame_id current_id
6319 = get_frame_id (get_current_frame ());
6320 if (frame_id_eq (current_id,
6321 ecs->event_thread->initiating_frame))
6323 /* Case 2. Fall through. */
6333 /* For Cases 1 and 2, remove the step-resume breakpoint, if it
6335 delete_step_resume_breakpoint (ecs->event_thread);
6337 end_stepping_range (ecs);
6341 case BPSTAT_WHAT_SINGLE:
6343 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_SINGLE\n");
6344 ecs->event_thread->stepping_over_breakpoint = 1;
6345 /* Still need to check other stuff, at least the case where we
6346 are stepping and step out of the right range. */
6349 case BPSTAT_WHAT_STEP_RESUME:
6351 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STEP_RESUME\n");
6353 delete_step_resume_breakpoint (ecs->event_thread);
6354 if (ecs->event_thread->control.proceed_to_finish
6355 && execution_direction == EXEC_REVERSE)
6357 struct thread_info *tp = ecs->event_thread;
6359 /* We are finishing a function in reverse, and just hit the
6360 step-resume breakpoint at the start address of the
6361 function, and we're almost there -- just need to back up
6362 by one more single-step, which should take us back to the
6364 tp->control.step_range_start = tp->control.step_range_end = 1;
6368 fill_in_stop_func (gdbarch, ecs);
6369 if (stop_pc == ecs->stop_func_start
6370 && execution_direction == EXEC_REVERSE)
6372 /* We are stepping over a function call in reverse, and just
6373 hit the step-resume breakpoint at the start address of
6374 the function. Go back to single-stepping, which should
6375 take us back to the function call. */
6376 ecs->event_thread->stepping_over_breakpoint = 1;
6382 case BPSTAT_WHAT_STOP_NOISY:
6384 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_NOISY\n");
6385 stop_print_frame = 1;
6387 /* Assume the thread stopped for a breapoint. We'll still check
6388 whether a/the breakpoint is there when the thread is next
6390 ecs->event_thread->stepping_over_breakpoint = 1;
6395 case BPSTAT_WHAT_STOP_SILENT:
6397 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_SILENT\n");
6398 stop_print_frame = 0;
6400 /* Assume the thread stopped for a breapoint. We'll still check
6401 whether a/the breakpoint is there when the thread is next
6403 ecs->event_thread->stepping_over_breakpoint = 1;
6407 case BPSTAT_WHAT_HP_STEP_RESUME:
6409 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_HP_STEP_RESUME\n");
6411 delete_step_resume_breakpoint (ecs->event_thread);
6412 if (ecs->event_thread->step_after_step_resume_breakpoint)
6414 /* Back when the step-resume breakpoint was inserted, we
6415 were trying to single-step off a breakpoint. Go back to
6417 ecs->event_thread->step_after_step_resume_breakpoint = 0;
6418 ecs->event_thread->stepping_over_breakpoint = 1;
6424 case BPSTAT_WHAT_KEEP_CHECKING:
6428 /* If we stepped a permanent breakpoint and we had a high priority
6429 step-resume breakpoint for the address we stepped, but we didn't
6430 hit it, then we must have stepped into the signal handler. The
6431 step-resume was only necessary to catch the case of _not_
6432 stepping into the handler, so delete it, and fall through to
6433 checking whether the step finished. */
6434 if (ecs->event_thread->stepped_breakpoint)
6436 struct breakpoint *sr_bp
6437 = ecs->event_thread->control.step_resume_breakpoint;
6440 && sr_bp->loc->permanent
6441 && sr_bp->type == bp_hp_step_resume
6442 && sr_bp->loc->address == ecs->event_thread->prev_pc)
6445 fprintf_unfiltered (gdb_stdlog,
6446 "infrun: stepped permanent breakpoint, stopped in "
6448 delete_step_resume_breakpoint (ecs->event_thread);
6449 ecs->event_thread->step_after_step_resume_breakpoint = 0;
6453 /* We come here if we hit a breakpoint but should not stop for it.
6454 Possibly we also were stepping and should stop for that. So fall
6455 through and test for stepping. But, if not stepping, do not
6458 /* In all-stop mode, if we're currently stepping but have stopped in
6459 some other thread, we need to switch back to the stepped thread. */
6460 if (switch_back_to_stepped_thread (ecs))
6463 if (ecs->event_thread->control.step_resume_breakpoint)
6466 fprintf_unfiltered (gdb_stdlog,
6467 "infrun: step-resume breakpoint is inserted\n");
6469 /* Having a step-resume breakpoint overrides anything
6470 else having to do with stepping commands until
6471 that breakpoint is reached. */
6476 if (ecs->event_thread->control.step_range_end == 0)
6479 fprintf_unfiltered (gdb_stdlog, "infrun: no stepping, continue\n");
6480 /* Likewise if we aren't even stepping. */
6485 /* Re-fetch current thread's frame in case the code above caused
6486 the frame cache to be re-initialized, making our FRAME variable
6487 a dangling pointer. */
6488 frame = get_current_frame ();
6489 gdbarch = get_frame_arch (frame);
6490 fill_in_stop_func (gdbarch, ecs);
6492 /* If stepping through a line, keep going if still within it.
6494 Note that step_range_end is the address of the first instruction
6495 beyond the step range, and NOT the address of the last instruction
6498 Note also that during reverse execution, we may be stepping
6499 through a function epilogue and therefore must detect when
6500 the current-frame changes in the middle of a line. */
6502 if (pc_in_thread_step_range (stop_pc, ecs->event_thread)
6503 && (execution_direction != EXEC_REVERSE
6504 || frame_id_eq (get_frame_id (frame),
6505 ecs->event_thread->control.step_frame_id)))
6509 (gdb_stdlog, "infrun: stepping inside range [%s-%s]\n",
6510 paddress (gdbarch, ecs->event_thread->control.step_range_start),
6511 paddress (gdbarch, ecs->event_thread->control.step_range_end));
6513 /* Tentatively re-enable range stepping; `resume' disables it if
6514 necessary (e.g., if we're stepping over a breakpoint or we
6515 have software watchpoints). */
6516 ecs->event_thread->control.may_range_step = 1;
6518 /* When stepping backward, stop at beginning of line range
6519 (unless it's the function entry point, in which case
6520 keep going back to the call point). */
6521 if (stop_pc == ecs->event_thread->control.step_range_start
6522 && stop_pc != ecs->stop_func_start
6523 && execution_direction == EXEC_REVERSE)
6524 end_stepping_range (ecs);
6531 /* We stepped out of the stepping range. */
6533 /* If we are stepping at the source level and entered the runtime
6534 loader dynamic symbol resolution code...
6536 EXEC_FORWARD: we keep on single stepping until we exit the run
6537 time loader code and reach the callee's address.
6539 EXEC_REVERSE: we've already executed the callee (backward), and
6540 the runtime loader code is handled just like any other
6541 undebuggable function call. Now we need only keep stepping
6542 backward through the trampoline code, and that's handled further
6543 down, so there is nothing for us to do here. */
6545 if (execution_direction != EXEC_REVERSE
6546 && ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6547 && in_solib_dynsym_resolve_code (stop_pc))
6549 CORE_ADDR pc_after_resolver =
6550 gdbarch_skip_solib_resolver (gdbarch, stop_pc);
6553 fprintf_unfiltered (gdb_stdlog,
6554 "infrun: stepped into dynsym resolve code\n");
6556 if (pc_after_resolver)
6558 /* Set up a step-resume breakpoint at the address
6559 indicated by SKIP_SOLIB_RESOLVER. */
6560 symtab_and_line sr_sal;
6561 sr_sal.pc = pc_after_resolver;
6562 sr_sal.pspace = get_frame_program_space (frame);
6564 insert_step_resume_breakpoint_at_sal (gdbarch,
6565 sr_sal, null_frame_id);
6572 /* Step through an indirect branch thunk. */
6573 if (ecs->event_thread->control.step_over_calls != STEP_OVER_NONE
6574 && gdbarch_in_indirect_branch_thunk (gdbarch, stop_pc))
6577 fprintf_unfiltered (gdb_stdlog,
6578 "infrun: stepped into indirect branch thunk\n");
6583 if (ecs->event_thread->control.step_range_end != 1
6584 && (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6585 || ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
6586 && get_frame_type (frame) == SIGTRAMP_FRAME)
6589 fprintf_unfiltered (gdb_stdlog,
6590 "infrun: stepped into signal trampoline\n");
6591 /* The inferior, while doing a "step" or "next", has ended up in
6592 a signal trampoline (either by a signal being delivered or by
6593 the signal handler returning). Just single-step until the
6594 inferior leaves the trampoline (either by calling the handler
6600 /* If we're in the return path from a shared library trampoline,
6601 we want to proceed through the trampoline when stepping. */
6602 /* macro/2012-04-25: This needs to come before the subroutine
6603 call check below as on some targets return trampolines look
6604 like subroutine calls (MIPS16 return thunks). */
6605 if (gdbarch_in_solib_return_trampoline (gdbarch,
6606 stop_pc, ecs->stop_func_name)
6607 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE)
6609 /* Determine where this trampoline returns. */
6610 CORE_ADDR real_stop_pc;
6612 real_stop_pc = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc);
6615 fprintf_unfiltered (gdb_stdlog,
6616 "infrun: stepped into solib return tramp\n");
6618 /* Only proceed through if we know where it's going. */
6621 /* And put the step-breakpoint there and go until there. */
6622 symtab_and_line sr_sal;
6623 sr_sal.pc = real_stop_pc;
6624 sr_sal.section = find_pc_overlay (sr_sal.pc);
6625 sr_sal.pspace = get_frame_program_space (frame);
6627 /* Do not specify what the fp should be when we stop since
6628 on some machines the prologue is where the new fp value
6630 insert_step_resume_breakpoint_at_sal (gdbarch,
6631 sr_sal, null_frame_id);
6633 /* Restart without fiddling with the step ranges or
6640 /* Check for subroutine calls. The check for the current frame
6641 equalling the step ID is not necessary - the check of the
6642 previous frame's ID is sufficient - but it is a common case and
6643 cheaper than checking the previous frame's ID.
6645 NOTE: frame_id_eq will never report two invalid frame IDs as
6646 being equal, so to get into this block, both the current and
6647 previous frame must have valid frame IDs. */
6648 /* The outer_frame_id check is a heuristic to detect stepping
6649 through startup code. If we step over an instruction which
6650 sets the stack pointer from an invalid value to a valid value,
6651 we may detect that as a subroutine call from the mythical
6652 "outermost" function. This could be fixed by marking
6653 outermost frames as !stack_p,code_p,special_p. Then the
6654 initial outermost frame, before sp was valid, would
6655 have code_addr == &_start. See the comment in frame_id_eq
6657 if (!frame_id_eq (get_stack_frame_id (frame),
6658 ecs->event_thread->control.step_stack_frame_id)
6659 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
6660 ecs->event_thread->control.step_stack_frame_id)
6661 && (!frame_id_eq (ecs->event_thread->control.step_stack_frame_id,
6663 || (ecs->event_thread->control.step_start_function
6664 != find_pc_function (stop_pc)))))
6666 CORE_ADDR real_stop_pc;
6669 fprintf_unfiltered (gdb_stdlog, "infrun: stepped into subroutine\n");
6671 if (ecs->event_thread->control.step_over_calls == STEP_OVER_NONE)
6673 /* I presume that step_over_calls is only 0 when we're
6674 supposed to be stepping at the assembly language level
6675 ("stepi"). Just stop. */
6676 /* And this works the same backward as frontward. MVS */
6677 end_stepping_range (ecs);
6681 /* Reverse stepping through solib trampolines. */
6683 if (execution_direction == EXEC_REVERSE
6684 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE
6685 && (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc)
6686 || (ecs->stop_func_start == 0
6687 && in_solib_dynsym_resolve_code (stop_pc))))
6689 /* Any solib trampoline code can be handled in reverse
6690 by simply continuing to single-step. We have already
6691 executed the solib function (backwards), and a few
6692 steps will take us back through the trampoline to the
6698 if (ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
6700 /* We're doing a "next".
6702 Normal (forward) execution: set a breakpoint at the
6703 callee's return address (the address at which the caller
6706 Reverse (backward) execution. set the step-resume
6707 breakpoint at the start of the function that we just
6708 stepped into (backwards), and continue to there. When we
6709 get there, we'll need to single-step back to the caller. */
6711 if (execution_direction == EXEC_REVERSE)
6713 /* If we're already at the start of the function, we've either
6714 just stepped backward into a single instruction function,
6715 or stepped back out of a signal handler to the first instruction
6716 of the function. Just keep going, which will single-step back
6718 if (ecs->stop_func_start != stop_pc && ecs->stop_func_start != 0)
6720 /* Normal function call return (static or dynamic). */
6721 symtab_and_line sr_sal;
6722 sr_sal.pc = ecs->stop_func_start;
6723 sr_sal.pspace = get_frame_program_space (frame);
6724 insert_step_resume_breakpoint_at_sal (gdbarch,
6725 sr_sal, null_frame_id);
6729 insert_step_resume_breakpoint_at_caller (frame);
6735 /* If we are in a function call trampoline (a stub between the
6736 calling routine and the real function), locate the real
6737 function. That's what tells us (a) whether we want to step
6738 into it at all, and (b) what prologue we want to run to the
6739 end of, if we do step into it. */
6740 real_stop_pc = skip_language_trampoline (frame, stop_pc);
6741 if (real_stop_pc == 0)
6742 real_stop_pc = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc);
6743 if (real_stop_pc != 0)
6744 ecs->stop_func_start = real_stop_pc;
6746 if (real_stop_pc != 0 && in_solib_dynsym_resolve_code (real_stop_pc))
6748 symtab_and_line sr_sal;
6749 sr_sal.pc = ecs->stop_func_start;
6750 sr_sal.pspace = get_frame_program_space (frame);
6752 insert_step_resume_breakpoint_at_sal (gdbarch,
6753 sr_sal, null_frame_id);
6758 /* If we have line number information for the function we are
6759 thinking of stepping into and the function isn't on the skip
6762 If there are several symtabs at that PC (e.g. with include
6763 files), just want to know whether *any* of them have line
6764 numbers. find_pc_line handles this. */
6766 struct symtab_and_line tmp_sal;
6768 tmp_sal = find_pc_line (ecs->stop_func_start, 0);
6769 if (tmp_sal.line != 0
6770 && !function_name_is_marked_for_skip (ecs->stop_func_name,
6773 if (execution_direction == EXEC_REVERSE)
6774 handle_step_into_function_backward (gdbarch, ecs);
6776 handle_step_into_function (gdbarch, ecs);
6781 /* If we have no line number and the step-stop-if-no-debug is
6782 set, we stop the step so that the user has a chance to switch
6783 in assembly mode. */
6784 if (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6785 && step_stop_if_no_debug)
6787 end_stepping_range (ecs);
6791 if (execution_direction == EXEC_REVERSE)
6793 /* If we're already at the start of the function, we've either just
6794 stepped backward into a single instruction function without line
6795 number info, or stepped back out of a signal handler to the first
6796 instruction of the function without line number info. Just keep
6797 going, which will single-step back to the caller. */
6798 if (ecs->stop_func_start != stop_pc)
6800 /* Set a breakpoint at callee's start address.
6801 From there we can step once and be back in the caller. */
6802 symtab_and_line sr_sal;
6803 sr_sal.pc = ecs->stop_func_start;
6804 sr_sal.pspace = get_frame_program_space (frame);
6805 insert_step_resume_breakpoint_at_sal (gdbarch,
6806 sr_sal, null_frame_id);
6810 /* Set a breakpoint at callee's return address (the address
6811 at which the caller will resume). */
6812 insert_step_resume_breakpoint_at_caller (frame);
6818 /* Reverse stepping through solib trampolines. */
6820 if (execution_direction == EXEC_REVERSE
6821 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE)
6823 if (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc)
6824 || (ecs->stop_func_start == 0
6825 && in_solib_dynsym_resolve_code (stop_pc)))
6827 /* Any solib trampoline code can be handled in reverse
6828 by simply continuing to single-step. We have already
6829 executed the solib function (backwards), and a few
6830 steps will take us back through the trampoline to the
6835 else if (in_solib_dynsym_resolve_code (stop_pc))
6837 /* Stepped backward into the solib dynsym resolver.
6838 Set a breakpoint at its start and continue, then
6839 one more step will take us out. */
6840 symtab_and_line sr_sal;
6841 sr_sal.pc = ecs->stop_func_start;
6842 sr_sal.pspace = get_frame_program_space (frame);
6843 insert_step_resume_breakpoint_at_sal (gdbarch,
6844 sr_sal, null_frame_id);
6850 stop_pc_sal = find_pc_line (stop_pc, 0);
6852 /* NOTE: tausq/2004-05-24: This if block used to be done before all
6853 the trampoline processing logic, however, there are some trampolines
6854 that have no names, so we should do trampoline handling first. */
6855 if (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6856 && ecs->stop_func_name == NULL
6857 && stop_pc_sal.line == 0)
6860 fprintf_unfiltered (gdb_stdlog,
6861 "infrun: stepped into undebuggable function\n");
6863 /* The inferior just stepped into, or returned to, an
6864 undebuggable function (where there is no debugging information
6865 and no line number corresponding to the address where the
6866 inferior stopped). Since we want to skip this kind of code,
6867 we keep going until the inferior returns from this
6868 function - unless the user has asked us not to (via
6869 set step-mode) or we no longer know how to get back
6870 to the call site. */
6871 if (step_stop_if_no_debug
6872 || !frame_id_p (frame_unwind_caller_id (frame)))
6874 /* If we have no line number and the step-stop-if-no-debug
6875 is set, we stop the step so that the user has a chance to
6876 switch in assembly mode. */
6877 end_stepping_range (ecs);
6882 /* Set a breakpoint at callee's return address (the address
6883 at which the caller will resume). */
6884 insert_step_resume_breakpoint_at_caller (frame);
6890 if (ecs->event_thread->control.step_range_end == 1)
6892 /* It is stepi or nexti. We always want to stop stepping after
6895 fprintf_unfiltered (gdb_stdlog, "infrun: stepi/nexti\n");
6896 end_stepping_range (ecs);
6900 if (stop_pc_sal.line == 0)
6902 /* We have no line number information. That means to stop
6903 stepping (does this always happen right after one instruction,
6904 when we do "s" in a function with no line numbers,
6905 or can this happen as a result of a return or longjmp?). */
6907 fprintf_unfiltered (gdb_stdlog, "infrun: no line number info\n");
6908 end_stepping_range (ecs);
6912 /* Look for "calls" to inlined functions, part one. If the inline
6913 frame machinery detected some skipped call sites, we have entered
6914 a new inline function. */
6916 if (frame_id_eq (get_frame_id (get_current_frame ()),
6917 ecs->event_thread->control.step_frame_id)
6918 && inline_skipped_frames (ecs->ptid))
6921 fprintf_unfiltered (gdb_stdlog,
6922 "infrun: stepped into inlined function\n");
6924 symtab_and_line call_sal = find_frame_sal (get_current_frame ());
6926 if (ecs->event_thread->control.step_over_calls != STEP_OVER_ALL)
6928 /* For "step", we're going to stop. But if the call site
6929 for this inlined function is on the same source line as
6930 we were previously stepping, go down into the function
6931 first. Otherwise stop at the call site. */
6933 if (call_sal.line == ecs->event_thread->current_line
6934 && call_sal.symtab == ecs->event_thread->current_symtab)
6935 step_into_inline_frame (ecs->ptid);
6937 end_stepping_range (ecs);
6942 /* For "next", we should stop at the call site if it is on a
6943 different source line. Otherwise continue through the
6944 inlined function. */
6945 if (call_sal.line == ecs->event_thread->current_line
6946 && call_sal.symtab == ecs->event_thread->current_symtab)
6949 end_stepping_range (ecs);
6954 /* Look for "calls" to inlined functions, part two. If we are still
6955 in the same real function we were stepping through, but we have
6956 to go further up to find the exact frame ID, we are stepping
6957 through a more inlined call beyond its call site. */
6959 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
6960 && !frame_id_eq (get_frame_id (get_current_frame ()),
6961 ecs->event_thread->control.step_frame_id)
6962 && stepped_in_from (get_current_frame (),
6963 ecs->event_thread->control.step_frame_id))
6966 fprintf_unfiltered (gdb_stdlog,
6967 "infrun: stepping through inlined function\n");
6969 if (ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
6972 end_stepping_range (ecs);
6976 if ((stop_pc == stop_pc_sal.pc)
6977 && (ecs->event_thread->current_line != stop_pc_sal.line
6978 || ecs->event_thread->current_symtab != stop_pc_sal.symtab))
6980 /* We are at the start of a different line. So stop. Note that
6981 we don't stop if we step into the middle of a different line.
6982 That is said to make things like for (;;) statements work
6985 fprintf_unfiltered (gdb_stdlog,
6986 "infrun: stepped to a different line\n");
6987 end_stepping_range (ecs);
6991 /* We aren't done stepping.
6993 Optimize by setting the stepping range to the line.
6994 (We might not be in the original line, but if we entered a
6995 new line in mid-statement, we continue stepping. This makes
6996 things like for(;;) statements work better.) */
6998 ecs->event_thread->control.step_range_start = stop_pc_sal.pc;
6999 ecs->event_thread->control.step_range_end = stop_pc_sal.end;
7000 ecs->event_thread->control.may_range_step = 1;
7001 set_step_info (frame, stop_pc_sal);
7004 fprintf_unfiltered (gdb_stdlog, "infrun: keep going\n");
7008 /* In all-stop mode, if we're currently stepping but have stopped in
7009 some other thread, we may need to switch back to the stepped
7010 thread. Returns true we set the inferior running, false if we left
7011 it stopped (and the event needs further processing). */
7014 switch_back_to_stepped_thread (struct execution_control_state *ecs)
7016 if (!target_is_non_stop_p ())
7018 struct thread_info *tp;
7019 struct thread_info *stepping_thread;
7021 /* If any thread is blocked on some internal breakpoint, and we
7022 simply need to step over that breakpoint to get it going
7023 again, do that first. */
7025 /* However, if we see an event for the stepping thread, then we
7026 know all other threads have been moved past their breakpoints
7027 already. Let the caller check whether the step is finished,
7028 etc., before deciding to move it past a breakpoint. */
7029 if (ecs->event_thread->control.step_range_end != 0)
7032 /* Check if the current thread is blocked on an incomplete
7033 step-over, interrupted by a random signal. */
7034 if (ecs->event_thread->control.trap_expected
7035 && ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_TRAP)
7039 fprintf_unfiltered (gdb_stdlog,
7040 "infrun: need to finish step-over of [%s]\n",
7041 target_pid_to_str (ecs->event_thread->ptid));
7047 /* Check if the current thread is blocked by a single-step
7048 breakpoint of another thread. */
7049 if (ecs->hit_singlestep_breakpoint)
7053 fprintf_unfiltered (gdb_stdlog,
7054 "infrun: need to step [%s] over single-step "
7056 target_pid_to_str (ecs->ptid));
7062 /* If this thread needs yet another step-over (e.g., stepping
7063 through a delay slot), do it first before moving on to
7065 if (thread_still_needs_step_over (ecs->event_thread))
7069 fprintf_unfiltered (gdb_stdlog,
7070 "infrun: thread [%s] still needs step-over\n",
7071 target_pid_to_str (ecs->event_thread->ptid));
7077 /* If scheduler locking applies even if not stepping, there's no
7078 need to walk over threads. Above we've checked whether the
7079 current thread is stepping. If some other thread not the
7080 event thread is stepping, then it must be that scheduler
7081 locking is not in effect. */
7082 if (schedlock_applies (ecs->event_thread))
7085 /* Otherwise, we no longer expect a trap in the current thread.
7086 Clear the trap_expected flag before switching back -- this is
7087 what keep_going does as well, if we call it. */
7088 ecs->event_thread->control.trap_expected = 0;
7090 /* Likewise, clear the signal if it should not be passed. */
7091 if (!signal_program[ecs->event_thread->suspend.stop_signal])
7092 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
7094 /* Do all pending step-overs before actually proceeding with
7096 if (start_step_over ())
7098 prepare_to_wait (ecs);
7102 /* Look for the stepping/nexting thread. */
7103 stepping_thread = NULL;
7105 ALL_NON_EXITED_THREADS (tp)
7107 /* Ignore threads of processes the caller is not
7110 && ptid_get_pid (tp->ptid) != ptid_get_pid (ecs->ptid))
7113 /* When stepping over a breakpoint, we lock all threads
7114 except the one that needs to move past the breakpoint.
7115 If a non-event thread has this set, the "incomplete
7116 step-over" check above should have caught it earlier. */
7117 if (tp->control.trap_expected)
7119 internal_error (__FILE__, __LINE__,
7120 "[%s] has inconsistent state: "
7121 "trap_expected=%d\n",
7122 target_pid_to_str (tp->ptid),
7123 tp->control.trap_expected);
7126 /* Did we find the stepping thread? */
7127 if (tp->control.step_range_end)
7129 /* Yep. There should only one though. */
7130 gdb_assert (stepping_thread == NULL);
7132 /* The event thread is handled at the top, before we
7134 gdb_assert (tp != ecs->event_thread);
7136 /* If some thread other than the event thread is
7137 stepping, then scheduler locking can't be in effect,
7138 otherwise we wouldn't have resumed the current event
7139 thread in the first place. */
7140 gdb_assert (!schedlock_applies (tp));
7142 stepping_thread = tp;
7146 if (stepping_thread != NULL)
7149 fprintf_unfiltered (gdb_stdlog,
7150 "infrun: switching back to stepped thread\n");
7152 if (keep_going_stepped_thread (stepping_thread))
7154 prepare_to_wait (ecs);
7163 /* Set a previously stepped thread back to stepping. Returns true on
7164 success, false if the resume is not possible (e.g., the thread
7168 keep_going_stepped_thread (struct thread_info *tp)
7170 struct frame_info *frame;
7171 struct execution_control_state ecss;
7172 struct execution_control_state *ecs = &ecss;
7174 /* If the stepping thread exited, then don't try to switch back and
7175 resume it, which could fail in several different ways depending
7176 on the target. Instead, just keep going.
7178 We can find a stepping dead thread in the thread list in two
7181 - The target supports thread exit events, and when the target
7182 tries to delete the thread from the thread list, inferior_ptid
7183 pointed at the exiting thread. In such case, calling
7184 delete_thread does not really remove the thread from the list;
7185 instead, the thread is left listed, with 'exited' state.
7187 - The target's debug interface does not support thread exit
7188 events, and so we have no idea whatsoever if the previously
7189 stepping thread is still alive. For that reason, we need to
7190 synchronously query the target now. */
7192 if (is_exited (tp->ptid)
7193 || !target_thread_alive (tp->ptid))
7196 fprintf_unfiltered (gdb_stdlog,
7197 "infrun: not resuming previously "
7198 "stepped thread, it has vanished\n");
7200 delete_thread (tp->ptid);
7205 fprintf_unfiltered (gdb_stdlog,
7206 "infrun: resuming previously stepped thread\n");
7208 reset_ecs (ecs, tp);
7209 switch_to_thread (tp->ptid);
7211 stop_pc = regcache_read_pc (get_thread_regcache (tp->ptid));
7212 frame = get_current_frame ();
7214 /* If the PC of the thread we were trying to single-step has
7215 changed, then that thread has trapped or been signaled, but the
7216 event has not been reported to GDB yet. Re-poll the target
7217 looking for this particular thread's event (i.e. temporarily
7218 enable schedlock) by:
7220 - setting a break at the current PC
7221 - resuming that particular thread, only (by setting trap
7224 This prevents us continuously moving the single-step breakpoint
7225 forward, one instruction at a time, overstepping. */
7227 if (stop_pc != tp->prev_pc)
7232 fprintf_unfiltered (gdb_stdlog,
7233 "infrun: expected thread advanced also (%s -> %s)\n",
7234 paddress (target_gdbarch (), tp->prev_pc),
7235 paddress (target_gdbarch (), stop_pc));
7237 /* Clear the info of the previous step-over, as it's no longer
7238 valid (if the thread was trying to step over a breakpoint, it
7239 has already succeeded). It's what keep_going would do too,
7240 if we called it. Do this before trying to insert the sss
7241 breakpoint, otherwise if we were previously trying to step
7242 over this exact address in another thread, the breakpoint is
7244 clear_step_over_info ();
7245 tp->control.trap_expected = 0;
7247 insert_single_step_breakpoint (get_frame_arch (frame),
7248 get_frame_address_space (frame),
7252 resume_ptid = internal_resume_ptid (tp->control.stepping_command);
7253 do_target_resume (resume_ptid, 0, GDB_SIGNAL_0);
7258 fprintf_unfiltered (gdb_stdlog,
7259 "infrun: expected thread still hasn't advanced\n");
7261 keep_going_pass_signal (ecs);
7266 /* Is thread TP in the middle of (software or hardware)
7267 single-stepping? (Note the result of this function must never be
7268 passed directly as target_resume's STEP parameter.) */
7271 currently_stepping (struct thread_info *tp)
7273 return ((tp->control.step_range_end
7274 && tp->control.step_resume_breakpoint == NULL)
7275 || tp->control.trap_expected
7276 || tp->stepped_breakpoint
7277 || bpstat_should_step ());
7280 /* Inferior has stepped into a subroutine call with source code that
7281 we should not step over. Do step to the first line of code in
7285 handle_step_into_function (struct gdbarch *gdbarch,
7286 struct execution_control_state *ecs)
7288 fill_in_stop_func (gdbarch, ecs);
7290 compunit_symtab *cust = find_pc_compunit_symtab (stop_pc);
7291 if (cust != NULL && compunit_language (cust) != language_asm)
7292 ecs->stop_func_start
7293 = gdbarch_skip_prologue_noexcept (gdbarch, ecs->stop_func_start);
7295 symtab_and_line stop_func_sal = find_pc_line (ecs->stop_func_start, 0);
7296 /* Use the step_resume_break to step until the end of the prologue,
7297 even if that involves jumps (as it seems to on the vax under
7299 /* If the prologue ends in the middle of a source line, continue to
7300 the end of that source line (if it is still within the function).
7301 Otherwise, just go to end of prologue. */
7302 if (stop_func_sal.end
7303 && stop_func_sal.pc != ecs->stop_func_start
7304 && stop_func_sal.end < ecs->stop_func_end)
7305 ecs->stop_func_start = stop_func_sal.end;
7307 /* Architectures which require breakpoint adjustment might not be able
7308 to place a breakpoint at the computed address. If so, the test
7309 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
7310 ecs->stop_func_start to an address at which a breakpoint may be
7311 legitimately placed.
7313 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
7314 made, GDB will enter an infinite loop when stepping through
7315 optimized code consisting of VLIW instructions which contain
7316 subinstructions corresponding to different source lines. On
7317 FR-V, it's not permitted to place a breakpoint on any but the
7318 first subinstruction of a VLIW instruction. When a breakpoint is
7319 set, GDB will adjust the breakpoint address to the beginning of
7320 the VLIW instruction. Thus, we need to make the corresponding
7321 adjustment here when computing the stop address. */
7323 if (gdbarch_adjust_breakpoint_address_p (gdbarch))
7325 ecs->stop_func_start
7326 = gdbarch_adjust_breakpoint_address (gdbarch,
7327 ecs->stop_func_start);
7330 if (ecs->stop_func_start == stop_pc)
7332 /* We are already there: stop now. */
7333 end_stepping_range (ecs);
7338 /* Put the step-breakpoint there and go until there. */
7339 symtab_and_line sr_sal;
7340 sr_sal.pc = ecs->stop_func_start;
7341 sr_sal.section = find_pc_overlay (ecs->stop_func_start);
7342 sr_sal.pspace = get_frame_program_space (get_current_frame ());
7344 /* Do not specify what the fp should be when we stop since on
7345 some machines the prologue is where the new fp value is
7347 insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal, null_frame_id);
7349 /* And make sure stepping stops right away then. */
7350 ecs->event_thread->control.step_range_end
7351 = ecs->event_thread->control.step_range_start;
7356 /* Inferior has stepped backward into a subroutine call with source
7357 code that we should not step over. Do step to the beginning of the
7358 last line of code in it. */
7361 handle_step_into_function_backward (struct gdbarch *gdbarch,
7362 struct execution_control_state *ecs)
7364 struct compunit_symtab *cust;
7365 struct symtab_and_line stop_func_sal;
7367 fill_in_stop_func (gdbarch, ecs);
7369 cust = find_pc_compunit_symtab (stop_pc);
7370 if (cust != NULL && compunit_language (cust) != language_asm)
7371 ecs->stop_func_start
7372 = gdbarch_skip_prologue_noexcept (gdbarch, ecs->stop_func_start);
7374 stop_func_sal = find_pc_line (stop_pc, 0);
7376 /* OK, we're just going to keep stepping here. */
7377 if (stop_func_sal.pc == stop_pc)
7379 /* We're there already. Just stop stepping now. */
7380 end_stepping_range (ecs);
7384 /* Else just reset the step range and keep going.
7385 No step-resume breakpoint, they don't work for
7386 epilogues, which can have multiple entry paths. */
7387 ecs->event_thread->control.step_range_start = stop_func_sal.pc;
7388 ecs->event_thread->control.step_range_end = stop_func_sal.end;
7394 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
7395 This is used to both functions and to skip over code. */
7398 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch *gdbarch,
7399 struct symtab_and_line sr_sal,
7400 struct frame_id sr_id,
7401 enum bptype sr_type)
7403 /* There should never be more than one step-resume or longjmp-resume
7404 breakpoint per thread, so we should never be setting a new
7405 step_resume_breakpoint when one is already active. */
7406 gdb_assert (inferior_thread ()->control.step_resume_breakpoint == NULL);
7407 gdb_assert (sr_type == bp_step_resume || sr_type == bp_hp_step_resume);
7410 fprintf_unfiltered (gdb_stdlog,
7411 "infrun: inserting step-resume breakpoint at %s\n",
7412 paddress (gdbarch, sr_sal.pc));
7414 inferior_thread ()->control.step_resume_breakpoint
7415 = set_momentary_breakpoint (gdbarch, sr_sal, sr_id, sr_type).release ();
7419 insert_step_resume_breakpoint_at_sal (struct gdbarch *gdbarch,
7420 struct symtab_and_line sr_sal,
7421 struct frame_id sr_id)
7423 insert_step_resume_breakpoint_at_sal_1 (gdbarch,
7428 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
7429 This is used to skip a potential signal handler.
7431 This is called with the interrupted function's frame. The signal
7432 handler, when it returns, will resume the interrupted function at
7436 insert_hp_step_resume_breakpoint_at_frame (struct frame_info *return_frame)
7438 gdb_assert (return_frame != NULL);
7440 struct gdbarch *gdbarch = get_frame_arch (return_frame);
7442 symtab_and_line sr_sal;
7443 sr_sal.pc = gdbarch_addr_bits_remove (gdbarch, get_frame_pc (return_frame));
7444 sr_sal.section = find_pc_overlay (sr_sal.pc);
7445 sr_sal.pspace = get_frame_program_space (return_frame);
7447 insert_step_resume_breakpoint_at_sal_1 (gdbarch, sr_sal,
7448 get_stack_frame_id (return_frame),
7452 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
7453 is used to skip a function after stepping into it (for "next" or if
7454 the called function has no debugging information).
7456 The current function has almost always been reached by single
7457 stepping a call or return instruction. NEXT_FRAME belongs to the
7458 current function, and the breakpoint will be set at the caller's
7461 This is a separate function rather than reusing
7462 insert_hp_step_resume_breakpoint_at_frame in order to avoid
7463 get_prev_frame, which may stop prematurely (see the implementation
7464 of frame_unwind_caller_id for an example). */
7467 insert_step_resume_breakpoint_at_caller (struct frame_info *next_frame)
7469 /* We shouldn't have gotten here if we don't know where the call site
7471 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame)));
7473 struct gdbarch *gdbarch = frame_unwind_caller_arch (next_frame);
7475 symtab_and_line sr_sal;
7476 sr_sal.pc = gdbarch_addr_bits_remove (gdbarch,
7477 frame_unwind_caller_pc (next_frame));
7478 sr_sal.section = find_pc_overlay (sr_sal.pc);
7479 sr_sal.pspace = frame_unwind_program_space (next_frame);
7481 insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal,
7482 frame_unwind_caller_id (next_frame));
7485 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
7486 new breakpoint at the target of a jmp_buf. The handling of
7487 longjmp-resume uses the same mechanisms used for handling
7488 "step-resume" breakpoints. */
7491 insert_longjmp_resume_breakpoint (struct gdbarch *gdbarch, CORE_ADDR pc)
7493 /* There should never be more than one longjmp-resume breakpoint per
7494 thread, so we should never be setting a new
7495 longjmp_resume_breakpoint when one is already active. */
7496 gdb_assert (inferior_thread ()->control.exception_resume_breakpoint == NULL);
7499 fprintf_unfiltered (gdb_stdlog,
7500 "infrun: inserting longjmp-resume breakpoint at %s\n",
7501 paddress (gdbarch, pc));
7503 inferior_thread ()->control.exception_resume_breakpoint =
7504 set_momentary_breakpoint_at_pc (gdbarch, pc, bp_longjmp_resume).release ();
7507 /* Insert an exception resume breakpoint. TP is the thread throwing
7508 the exception. The block B is the block of the unwinder debug hook
7509 function. FRAME is the frame corresponding to the call to this
7510 function. SYM is the symbol of the function argument holding the
7511 target PC of the exception. */
7514 insert_exception_resume_breakpoint (struct thread_info *tp,
7515 const struct block *b,
7516 struct frame_info *frame,
7521 struct block_symbol vsym;
7522 struct value *value;
7524 struct breakpoint *bp;
7526 vsym = lookup_symbol_search_name (SYMBOL_SEARCH_NAME (sym),
7528 value = read_var_value (vsym.symbol, vsym.block, frame);
7529 /* If the value was optimized out, revert to the old behavior. */
7530 if (! value_optimized_out (value))
7532 handler = value_as_address (value);
7535 fprintf_unfiltered (gdb_stdlog,
7536 "infrun: exception resume at %lx\n",
7537 (unsigned long) handler);
7539 bp = set_momentary_breakpoint_at_pc (get_frame_arch (frame),
7541 bp_exception_resume).release ();
7543 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
7546 bp->thread = tp->global_num;
7547 inferior_thread ()->control.exception_resume_breakpoint = bp;
7550 CATCH (e, RETURN_MASK_ERROR)
7552 /* We want to ignore errors here. */
7557 /* A helper for check_exception_resume that sets an
7558 exception-breakpoint based on a SystemTap probe. */
7561 insert_exception_resume_from_probe (struct thread_info *tp,
7562 const struct bound_probe *probe,
7563 struct frame_info *frame)
7565 struct value *arg_value;
7567 struct breakpoint *bp;
7569 arg_value = probe_safe_evaluate_at_pc (frame, 1);
7573 handler = value_as_address (arg_value);
7576 fprintf_unfiltered (gdb_stdlog,
7577 "infrun: exception resume at %s\n",
7578 paddress (get_objfile_arch (probe->objfile),
7581 bp = set_momentary_breakpoint_at_pc (get_frame_arch (frame),
7582 handler, bp_exception_resume).release ();
7583 bp->thread = tp->global_num;
7584 inferior_thread ()->control.exception_resume_breakpoint = bp;
7587 /* This is called when an exception has been intercepted. Check to
7588 see whether the exception's destination is of interest, and if so,
7589 set an exception resume breakpoint there. */
7592 check_exception_resume (struct execution_control_state *ecs,
7593 struct frame_info *frame)
7595 struct bound_probe probe;
7596 struct symbol *func;
7598 /* First see if this exception unwinding breakpoint was set via a
7599 SystemTap probe point. If so, the probe has two arguments: the
7600 CFA and the HANDLER. We ignore the CFA, extract the handler, and
7601 set a breakpoint there. */
7602 probe = find_probe_by_pc (get_frame_pc (frame));
7605 insert_exception_resume_from_probe (ecs->event_thread, &probe, frame);
7609 func = get_frame_function (frame);
7615 const struct block *b;
7616 struct block_iterator iter;
7620 /* The exception breakpoint is a thread-specific breakpoint on
7621 the unwinder's debug hook, declared as:
7623 void _Unwind_DebugHook (void *cfa, void *handler);
7625 The CFA argument indicates the frame to which control is
7626 about to be transferred. HANDLER is the destination PC.
7628 We ignore the CFA and set a temporary breakpoint at HANDLER.
7629 This is not extremely efficient but it avoids issues in gdb
7630 with computing the DWARF CFA, and it also works even in weird
7631 cases such as throwing an exception from inside a signal
7634 b = SYMBOL_BLOCK_VALUE (func);
7635 ALL_BLOCK_SYMBOLS (b, iter, sym)
7637 if (!SYMBOL_IS_ARGUMENT (sym))
7644 insert_exception_resume_breakpoint (ecs->event_thread,
7650 CATCH (e, RETURN_MASK_ERROR)
7657 stop_waiting (struct execution_control_state *ecs)
7660 fprintf_unfiltered (gdb_stdlog, "infrun: stop_waiting\n");
7662 /* Let callers know we don't want to wait for the inferior anymore. */
7663 ecs->wait_some_more = 0;
7665 /* If all-stop, but the target is always in non-stop mode, stop all
7666 threads now that we're presenting the stop to the user. */
7667 if (!non_stop && target_is_non_stop_p ())
7668 stop_all_threads ();
7671 /* Like keep_going, but passes the signal to the inferior, even if the
7672 signal is set to nopass. */
7675 keep_going_pass_signal (struct execution_control_state *ecs)
7677 gdb_assert (ptid_equal (ecs->event_thread->ptid, inferior_ptid));
7678 gdb_assert (!ecs->event_thread->resumed);
7680 /* Save the pc before execution, to compare with pc after stop. */
7681 ecs->event_thread->prev_pc
7682 = regcache_read_pc (get_thread_regcache (ecs->ptid));
7684 if (ecs->event_thread->control.trap_expected)
7686 struct thread_info *tp = ecs->event_thread;
7689 fprintf_unfiltered (gdb_stdlog,
7690 "infrun: %s has trap_expected set, "
7691 "resuming to collect trap\n",
7692 target_pid_to_str (tp->ptid));
7694 /* We haven't yet gotten our trap, and either: intercepted a
7695 non-signal event (e.g., a fork); or took a signal which we
7696 are supposed to pass through to the inferior. Simply
7698 resume (ecs->event_thread->suspend.stop_signal);
7700 else if (step_over_info_valid_p ())
7702 /* Another thread is stepping over a breakpoint in-line. If
7703 this thread needs a step-over too, queue the request. In
7704 either case, this resume must be deferred for later. */
7705 struct thread_info *tp = ecs->event_thread;
7707 if (ecs->hit_singlestep_breakpoint
7708 || thread_still_needs_step_over (tp))
7711 fprintf_unfiltered (gdb_stdlog,
7712 "infrun: step-over already in progress: "
7713 "step-over for %s deferred\n",
7714 target_pid_to_str (tp->ptid));
7715 thread_step_over_chain_enqueue (tp);
7720 fprintf_unfiltered (gdb_stdlog,
7721 "infrun: step-over in progress: "
7722 "resume of %s deferred\n",
7723 target_pid_to_str (tp->ptid));
7728 struct regcache *regcache = get_current_regcache ();
7731 step_over_what step_what;
7733 /* Either the trap was not expected, but we are continuing
7734 anyway (if we got a signal, the user asked it be passed to
7737 We got our expected trap, but decided we should resume from
7740 We're going to run this baby now!
7742 Note that insert_breakpoints won't try to re-insert
7743 already inserted breakpoints. Therefore, we don't
7744 care if breakpoints were already inserted, or not. */
7746 /* If we need to step over a breakpoint, and we're not using
7747 displaced stepping to do so, insert all breakpoints
7748 (watchpoints, etc.) but the one we're stepping over, step one
7749 instruction, and then re-insert the breakpoint when that step
7752 step_what = thread_still_needs_step_over (ecs->event_thread);
7754 remove_bp = (ecs->hit_singlestep_breakpoint
7755 || (step_what & STEP_OVER_BREAKPOINT));
7756 remove_wps = (step_what & STEP_OVER_WATCHPOINT);
7758 /* We can't use displaced stepping if we need to step past a
7759 watchpoint. The instruction copied to the scratch pad would
7760 still trigger the watchpoint. */
7762 && (remove_wps || !use_displaced_stepping (ecs->event_thread)))
7764 set_step_over_info (regcache->aspace (),
7765 regcache_read_pc (regcache), remove_wps,
7766 ecs->event_thread->global_num);
7768 else if (remove_wps)
7769 set_step_over_info (NULL, 0, remove_wps, -1);
7771 /* If we now need to do an in-line step-over, we need to stop
7772 all other threads. Note this must be done before
7773 insert_breakpoints below, because that removes the breakpoint
7774 we're about to step over, otherwise other threads could miss
7776 if (step_over_info_valid_p () && target_is_non_stop_p ())
7777 stop_all_threads ();
7779 /* Stop stepping if inserting breakpoints fails. */
7782 insert_breakpoints ();
7784 CATCH (e, RETURN_MASK_ERROR)
7786 exception_print (gdb_stderr, e);
7788 clear_step_over_info ();
7793 ecs->event_thread->control.trap_expected = (remove_bp || remove_wps);
7795 resume (ecs->event_thread->suspend.stop_signal);
7798 prepare_to_wait (ecs);
7801 /* Called when we should continue running the inferior, because the
7802 current event doesn't cause a user visible stop. This does the
7803 resuming part; waiting for the next event is done elsewhere. */
7806 keep_going (struct execution_control_state *ecs)
7808 if (ecs->event_thread->control.trap_expected
7809 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
7810 ecs->event_thread->control.trap_expected = 0;
7812 if (!signal_program[ecs->event_thread->suspend.stop_signal])
7813 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
7814 keep_going_pass_signal (ecs);
7817 /* This function normally comes after a resume, before
7818 handle_inferior_event exits. It takes care of any last bits of
7819 housekeeping, and sets the all-important wait_some_more flag. */
7822 prepare_to_wait (struct execution_control_state *ecs)
7825 fprintf_unfiltered (gdb_stdlog, "infrun: prepare_to_wait\n");
7827 ecs->wait_some_more = 1;
7829 if (!target_is_async_p ())
7830 mark_infrun_async_event_handler ();
7833 /* We are done with the step range of a step/next/si/ni command.
7834 Called once for each n of a "step n" operation. */
7837 end_stepping_range (struct execution_control_state *ecs)
7839 ecs->event_thread->control.stop_step = 1;
7843 /* Several print_*_reason functions to print why the inferior has stopped.
7844 We always print something when the inferior exits, or receives a signal.
7845 The rest of the cases are dealt with later on in normal_stop and
7846 print_it_typical. Ideally there should be a call to one of these
7847 print_*_reason functions functions from handle_inferior_event each time
7848 stop_waiting is called.
7850 Note that we don't call these directly, instead we delegate that to
7851 the interpreters, through observers. Interpreters then call these
7852 with whatever uiout is right. */
7855 print_end_stepping_range_reason (struct ui_out *uiout)
7857 /* For CLI-like interpreters, print nothing. */
7859 if (uiout->is_mi_like_p ())
7861 uiout->field_string ("reason",
7862 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE));
7867 print_signal_exited_reason (struct ui_out *uiout, enum gdb_signal siggnal)
7869 annotate_signalled ();
7870 if (uiout->is_mi_like_p ())
7872 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED));
7873 uiout->text ("\nProgram terminated with signal ");
7874 annotate_signal_name ();
7875 uiout->field_string ("signal-name",
7876 gdb_signal_to_name (siggnal));
7877 annotate_signal_name_end ();
7879 annotate_signal_string ();
7880 uiout->field_string ("signal-meaning",
7881 gdb_signal_to_string (siggnal));
7882 annotate_signal_string_end ();
7883 uiout->text (".\n");
7884 uiout->text ("The program no longer exists.\n");
7888 print_exited_reason (struct ui_out *uiout, int exitstatus)
7890 struct inferior *inf = current_inferior ();
7891 const char *pidstr = target_pid_to_str (pid_to_ptid (inf->pid));
7893 annotate_exited (exitstatus);
7896 if (uiout->is_mi_like_p ())
7897 uiout->field_string ("reason", async_reason_lookup (EXEC_ASYNC_EXITED));
7898 uiout->text ("[Inferior ");
7899 uiout->text (plongest (inf->num));
7901 uiout->text (pidstr);
7902 uiout->text (") exited with code ");
7903 uiout->field_fmt ("exit-code", "0%o", (unsigned int) exitstatus);
7904 uiout->text ("]\n");
7908 if (uiout->is_mi_like_p ())
7910 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY));
7911 uiout->text ("[Inferior ");
7912 uiout->text (plongest (inf->num));
7914 uiout->text (pidstr);
7915 uiout->text (") exited normally]\n");
7919 /* Some targets/architectures can do extra processing/display of
7920 segmentation faults. E.g., Intel MPX boundary faults.
7921 Call the architecture dependent function to handle the fault. */
7924 handle_segmentation_fault (struct ui_out *uiout)
7926 struct regcache *regcache = get_current_regcache ();
7927 struct gdbarch *gdbarch = regcache->arch ();
7929 if (gdbarch_handle_segmentation_fault_p (gdbarch))
7930 gdbarch_handle_segmentation_fault (gdbarch, uiout);
7934 print_signal_received_reason (struct ui_out *uiout, enum gdb_signal siggnal)
7936 struct thread_info *thr = inferior_thread ();
7940 if (uiout->is_mi_like_p ())
7942 else if (show_thread_that_caused_stop ())
7946 uiout->text ("\nThread ");
7947 uiout->field_fmt ("thread-id", "%s", print_thread_id (thr));
7949 name = thr->name != NULL ? thr->name : target_thread_name (thr);
7952 uiout->text (" \"");
7953 uiout->field_fmt ("name", "%s", name);
7958 uiout->text ("\nProgram");
7960 if (siggnal == GDB_SIGNAL_0 && !uiout->is_mi_like_p ())
7961 uiout->text (" stopped");
7964 uiout->text (" received signal ");
7965 annotate_signal_name ();
7966 if (uiout->is_mi_like_p ())
7968 ("reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED));
7969 uiout->field_string ("signal-name", gdb_signal_to_name (siggnal));
7970 annotate_signal_name_end ();
7972 annotate_signal_string ();
7973 uiout->field_string ("signal-meaning", gdb_signal_to_string (siggnal));
7975 if (siggnal == GDB_SIGNAL_SEGV)
7976 handle_segmentation_fault (uiout);
7978 annotate_signal_string_end ();
7980 uiout->text (".\n");
7984 print_no_history_reason (struct ui_out *uiout)
7986 uiout->text ("\nNo more reverse-execution history.\n");
7989 /* Print current location without a level number, if we have changed
7990 functions or hit a breakpoint. Print source line if we have one.
7991 bpstat_print contains the logic deciding in detail what to print,
7992 based on the event(s) that just occurred. */
7995 print_stop_location (struct target_waitstatus *ws)
7998 enum print_what source_flag;
7999 int do_frame_printing = 1;
8000 struct thread_info *tp = inferior_thread ();
8002 bpstat_ret = bpstat_print (tp->control.stop_bpstat, ws->kind);
8006 /* FIXME: cagney/2002-12-01: Given that a frame ID does (or
8007 should) carry around the function and does (or should) use
8008 that when doing a frame comparison. */
8009 if (tp->control.stop_step
8010 && frame_id_eq (tp->control.step_frame_id,
8011 get_frame_id (get_current_frame ()))
8012 && tp->control.step_start_function == find_pc_function (stop_pc))
8014 /* Finished step, just print source line. */
8015 source_flag = SRC_LINE;
8019 /* Print location and source line. */
8020 source_flag = SRC_AND_LOC;
8023 case PRINT_SRC_AND_LOC:
8024 /* Print location and source line. */
8025 source_flag = SRC_AND_LOC;
8027 case PRINT_SRC_ONLY:
8028 source_flag = SRC_LINE;
8031 /* Something bogus. */
8032 source_flag = SRC_LINE;
8033 do_frame_printing = 0;
8036 internal_error (__FILE__, __LINE__, _("Unknown value."));
8039 /* The behavior of this routine with respect to the source
8041 SRC_LINE: Print only source line
8042 LOCATION: Print only location
8043 SRC_AND_LOC: Print location and source line. */
8044 if (do_frame_printing)
8045 print_stack_frame (get_selected_frame (NULL), 0, source_flag, 1);
8051 print_stop_event (struct ui_out *uiout)
8053 struct target_waitstatus last;
8055 struct thread_info *tp;
8057 get_last_target_status (&last_ptid, &last);
8060 scoped_restore save_uiout = make_scoped_restore (¤t_uiout, uiout);
8062 print_stop_location (&last);
8064 /* Display the auto-display expressions. */
8068 tp = inferior_thread ();
8069 if (tp->thread_fsm != NULL
8070 && thread_fsm_finished_p (tp->thread_fsm))
8072 struct return_value_info *rv;
8074 rv = thread_fsm_return_value (tp->thread_fsm);
8076 print_return_value (uiout, rv);
8083 maybe_remove_breakpoints (void)
8085 if (!breakpoints_should_be_inserted_now () && target_has_execution)
8087 if (remove_breakpoints ())
8089 target_terminal::ours_for_output ();
8090 printf_filtered (_("Cannot remove breakpoints because "
8091 "program is no longer writable.\nFurther "
8092 "execution is probably impossible.\n"));
8097 /* The execution context that just caused a normal stop. */
8104 /* The event PTID. */
8108 /* If stopp for a thread event, this is the thread that caused the
8110 struct thread_info *thread;
8112 /* The inferior that caused the stop. */
8116 /* Returns a new stop context. If stopped for a thread event, this
8117 takes a strong reference to the thread. */
8119 static struct stop_context *
8120 save_stop_context (void)
8122 struct stop_context *sc = XNEW (struct stop_context);
8124 sc->stop_id = get_stop_id ();
8125 sc->ptid = inferior_ptid;
8126 sc->inf_num = current_inferior ()->num;
8128 if (!ptid_equal (inferior_ptid, null_ptid))
8130 /* Take a strong reference so that the thread can't be deleted
8132 sc->thread = inferior_thread ();
8133 sc->thread->incref ();
8141 /* Release a stop context previously created with save_stop_context.
8142 Releases the strong reference to the thread as well. */
8145 release_stop_context_cleanup (void *arg)
8147 struct stop_context *sc = (struct stop_context *) arg;
8149 if (sc->thread != NULL)
8150 sc->thread->decref ();
8154 /* Return true if the current context no longer matches the saved stop
8158 stop_context_changed (struct stop_context *prev)
8160 if (!ptid_equal (prev->ptid, inferior_ptid))
8162 if (prev->inf_num != current_inferior ()->num)
8164 if (prev->thread != NULL && prev->thread->state != THREAD_STOPPED)
8166 if (get_stop_id () != prev->stop_id)
8176 struct target_waitstatus last;
8179 get_last_target_status (&last_ptid, &last);
8183 /* If an exception is thrown from this point on, make sure to
8184 propagate GDB's knowledge of the executing state to the
8185 frontend/user running state. A QUIT is an easy exception to see
8186 here, so do this before any filtered output. */
8188 gdb::optional<scoped_finish_thread_state> maybe_finish_thread_state;
8191 maybe_finish_thread_state.emplace (minus_one_ptid);
8192 else if (last.kind == TARGET_WAITKIND_SIGNALLED
8193 || last.kind == TARGET_WAITKIND_EXITED)
8195 /* On some targets, we may still have live threads in the
8196 inferior when we get a process exit event. E.g., for
8197 "checkpoint", when the current checkpoint/fork exits,
8198 linux-fork.c automatically switches to another fork from
8199 within target_mourn_inferior. */
8200 if (inferior_ptid != null_ptid)
8201 maybe_finish_thread_state.emplace (ptid_t (inferior_ptid.pid ()));
8203 else if (last.kind != TARGET_WAITKIND_NO_RESUMED)
8204 maybe_finish_thread_state.emplace (inferior_ptid);
8206 /* As we're presenting a stop, and potentially removing breakpoints,
8207 update the thread list so we can tell whether there are threads
8208 running on the target. With target remote, for example, we can
8209 only learn about new threads when we explicitly update the thread
8210 list. Do this before notifying the interpreters about signal
8211 stops, end of stepping ranges, etc., so that the "new thread"
8212 output is emitted before e.g., "Program received signal FOO",
8213 instead of after. */
8214 update_thread_list ();
8216 if (last.kind == TARGET_WAITKIND_STOPPED && stopped_by_random_signal)
8217 gdb::observers::signal_received.notify (inferior_thread ()->suspend.stop_signal);
8219 /* As with the notification of thread events, we want to delay
8220 notifying the user that we've switched thread context until
8221 the inferior actually stops.
8223 There's no point in saying anything if the inferior has exited.
8224 Note that SIGNALLED here means "exited with a signal", not
8225 "received a signal".
8227 Also skip saying anything in non-stop mode. In that mode, as we
8228 don't want GDB to switch threads behind the user's back, to avoid
8229 races where the user is typing a command to apply to thread x,
8230 but GDB switches to thread y before the user finishes entering
8231 the command, fetch_inferior_event installs a cleanup to restore
8232 the current thread back to the thread the user had selected right
8233 after this event is handled, so we're not really switching, only
8234 informing of a stop. */
8236 && previous_inferior_ptid != inferior_ptid
8237 && target_has_execution
8238 && last.kind != TARGET_WAITKIND_SIGNALLED
8239 && last.kind != TARGET_WAITKIND_EXITED
8240 && last.kind != TARGET_WAITKIND_NO_RESUMED)
8242 SWITCH_THRU_ALL_UIS ()
8244 target_terminal::ours_for_output ();
8245 printf_filtered (_("[Switching to %s]\n"),
8246 target_pid_to_str (inferior_ptid));
8247 annotate_thread_changed ();
8249 previous_inferior_ptid = inferior_ptid;
8252 if (last.kind == TARGET_WAITKIND_NO_RESUMED)
8254 SWITCH_THRU_ALL_UIS ()
8255 if (current_ui->prompt_state == PROMPT_BLOCKED)
8257 target_terminal::ours_for_output ();
8258 printf_filtered (_("No unwaited-for children left.\n"));
8262 /* Note: this depends on the update_thread_list call above. */
8263 maybe_remove_breakpoints ();
8265 /* If an auto-display called a function and that got a signal,
8266 delete that auto-display to avoid an infinite recursion. */
8268 if (stopped_by_random_signal)
8269 disable_current_display ();
8271 SWITCH_THRU_ALL_UIS ()
8273 async_enable_stdin ();
8276 /* Let the user/frontend see the threads as stopped. */
8277 maybe_finish_thread_state.reset ();
8279 /* Select innermost stack frame - i.e., current frame is frame 0,
8280 and current location is based on that. Handle the case where the
8281 dummy call is returning after being stopped. E.g. the dummy call
8282 previously hit a breakpoint. (If the dummy call returns
8283 normally, we won't reach here.) Do this before the stop hook is
8284 run, so that it doesn't get to see the temporary dummy frame,
8285 which is not where we'll present the stop. */
8286 if (has_stack_frames ())
8288 if (stop_stack_dummy == STOP_STACK_DUMMY)
8290 /* Pop the empty frame that contains the stack dummy. This
8291 also restores inferior state prior to the call (struct
8292 infcall_suspend_state). */
8293 struct frame_info *frame = get_current_frame ();
8295 gdb_assert (get_frame_type (frame) == DUMMY_FRAME);
8297 /* frame_pop calls reinit_frame_cache as the last thing it
8298 does which means there's now no selected frame. */
8301 select_frame (get_current_frame ());
8303 /* Set the current source location. */
8304 set_current_sal_from_frame (get_current_frame ());
8307 /* Look up the hook_stop and run it (CLI internally handles problem
8308 of stop_command's pre-hook not existing). */
8309 if (stop_command != NULL)
8311 struct stop_context *saved_context = save_stop_context ();
8312 struct cleanup *old_chain
8313 = make_cleanup (release_stop_context_cleanup, saved_context);
8317 execute_cmd_pre_hook (stop_command);
8319 CATCH (ex, RETURN_MASK_ALL)
8321 exception_fprintf (gdb_stderr, ex,
8322 "Error while running hook_stop:\n");
8326 /* If the stop hook resumes the target, then there's no point in
8327 trying to notify about the previous stop; its context is
8328 gone. Likewise if the command switches thread or inferior --
8329 the observers would print a stop for the wrong
8331 if (stop_context_changed (saved_context))
8333 do_cleanups (old_chain);
8336 do_cleanups (old_chain);
8339 /* Notify observers about the stop. This is where the interpreters
8340 print the stop event. */
8341 if (!ptid_equal (inferior_ptid, null_ptid))
8342 gdb::observers::normal_stop.notify (inferior_thread ()->control.stop_bpstat,
8345 gdb::observers::normal_stop.notify (NULL, stop_print_frame);
8347 annotate_stopped ();
8349 if (target_has_execution)
8351 if (last.kind != TARGET_WAITKIND_SIGNALLED
8352 && last.kind != TARGET_WAITKIND_EXITED)
8353 /* Delete the breakpoint we stopped at, if it wants to be deleted.
8354 Delete any breakpoint that is to be deleted at the next stop. */
8355 breakpoint_auto_delete (inferior_thread ()->control.stop_bpstat);
8358 /* Try to get rid of automatically added inferiors that are no
8359 longer needed. Keeping those around slows down things linearly.
8360 Note that this never removes the current inferior. */
8367 signal_stop_state (int signo)
8369 return signal_stop[signo];
8373 signal_print_state (int signo)
8375 return signal_print[signo];
8379 signal_pass_state (int signo)
8381 return signal_program[signo];
8385 signal_cache_update (int signo)
8389 for (signo = 0; signo < (int) GDB_SIGNAL_LAST; signo++)
8390 signal_cache_update (signo);
8395 signal_pass[signo] = (signal_stop[signo] == 0
8396 && signal_print[signo] == 0
8397 && signal_program[signo] == 1
8398 && signal_catch[signo] == 0);
8402 signal_stop_update (int signo, int state)
8404 int ret = signal_stop[signo];
8406 signal_stop[signo] = state;
8407 signal_cache_update (signo);
8412 signal_print_update (int signo, int state)
8414 int ret = signal_print[signo];
8416 signal_print[signo] = state;
8417 signal_cache_update (signo);
8422 signal_pass_update (int signo, int state)
8424 int ret = signal_program[signo];
8426 signal_program[signo] = state;
8427 signal_cache_update (signo);
8431 /* Update the global 'signal_catch' from INFO and notify the
8435 signal_catch_update (const unsigned int *info)
8439 for (i = 0; i < GDB_SIGNAL_LAST; ++i)
8440 signal_catch[i] = info[i] > 0;
8441 signal_cache_update (-1);
8442 target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
8446 sig_print_header (void)
8448 printf_filtered (_("Signal Stop\tPrint\tPass "
8449 "to program\tDescription\n"));
8453 sig_print_info (enum gdb_signal oursig)
8455 const char *name = gdb_signal_to_name (oursig);
8456 int name_padding = 13 - strlen (name);
8458 if (name_padding <= 0)
8461 printf_filtered ("%s", name);
8462 printf_filtered ("%*.*s ", name_padding, name_padding, " ");
8463 printf_filtered ("%s\t", signal_stop[oursig] ? "Yes" : "No");
8464 printf_filtered ("%s\t", signal_print[oursig] ? "Yes" : "No");
8465 printf_filtered ("%s\t\t", signal_program[oursig] ? "Yes" : "No");
8466 printf_filtered ("%s\n", gdb_signal_to_string (oursig));
8469 /* Specify how various signals in the inferior should be handled. */
8472 handle_command (const char *args, int from_tty)
8474 int digits, wordlen;
8475 int sigfirst, signum, siglast;
8476 enum gdb_signal oursig;
8479 unsigned char *sigs;
8483 error_no_arg (_("signal to handle"));
8486 /* Allocate and zero an array of flags for which signals to handle. */
8488 nsigs = (int) GDB_SIGNAL_LAST;
8489 sigs = (unsigned char *) alloca (nsigs);
8490 memset (sigs, 0, nsigs);
8492 /* Break the command line up into args. */
8494 gdb_argv built_argv (args);
8496 /* Walk through the args, looking for signal oursigs, signal names, and
8497 actions. Signal numbers and signal names may be interspersed with
8498 actions, with the actions being performed for all signals cumulatively
8499 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
8501 for (char *arg : built_argv)
8503 wordlen = strlen (arg);
8504 for (digits = 0; isdigit (arg[digits]); digits++)
8508 sigfirst = siglast = -1;
8510 if (wordlen >= 1 && !strncmp (arg, "all", wordlen))
8512 /* Apply action to all signals except those used by the
8513 debugger. Silently skip those. */
8516 siglast = nsigs - 1;
8518 else if (wordlen >= 1 && !strncmp (arg, "stop", wordlen))
8520 SET_SIGS (nsigs, sigs, signal_stop);
8521 SET_SIGS (nsigs, sigs, signal_print);
8523 else if (wordlen >= 1 && !strncmp (arg, "ignore", wordlen))
8525 UNSET_SIGS (nsigs, sigs, signal_program);
8527 else if (wordlen >= 2 && !strncmp (arg, "print", wordlen))
8529 SET_SIGS (nsigs, sigs, signal_print);
8531 else if (wordlen >= 2 && !strncmp (arg, "pass", wordlen))
8533 SET_SIGS (nsigs, sigs, signal_program);
8535 else if (wordlen >= 3 && !strncmp (arg, "nostop", wordlen))
8537 UNSET_SIGS (nsigs, sigs, signal_stop);
8539 else if (wordlen >= 3 && !strncmp (arg, "noignore", wordlen))
8541 SET_SIGS (nsigs, sigs, signal_program);
8543 else if (wordlen >= 4 && !strncmp (arg, "noprint", wordlen))
8545 UNSET_SIGS (nsigs, sigs, signal_print);
8546 UNSET_SIGS (nsigs, sigs, signal_stop);
8548 else if (wordlen >= 4 && !strncmp (arg, "nopass", wordlen))
8550 UNSET_SIGS (nsigs, sigs, signal_program);
8552 else if (digits > 0)
8554 /* It is numeric. The numeric signal refers to our own
8555 internal signal numbering from target.h, not to host/target
8556 signal number. This is a feature; users really should be
8557 using symbolic names anyway, and the common ones like
8558 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
8560 sigfirst = siglast = (int)
8561 gdb_signal_from_command (atoi (arg));
8562 if (arg[digits] == '-')
8565 gdb_signal_from_command (atoi (arg + digits + 1));
8567 if (sigfirst > siglast)
8569 /* Bet he didn't figure we'd think of this case... */
8577 oursig = gdb_signal_from_name (arg);
8578 if (oursig != GDB_SIGNAL_UNKNOWN)
8580 sigfirst = siglast = (int) oursig;
8584 /* Not a number and not a recognized flag word => complain. */
8585 error (_("Unrecognized or ambiguous flag word: \"%s\"."), arg);
8589 /* If any signal numbers or symbol names were found, set flags for
8590 which signals to apply actions to. */
8592 for (signum = sigfirst; signum >= 0 && signum <= siglast; signum++)
8594 switch ((enum gdb_signal) signum)
8596 case GDB_SIGNAL_TRAP:
8597 case GDB_SIGNAL_INT:
8598 if (!allsigs && !sigs[signum])
8600 if (query (_("%s is used by the debugger.\n\
8601 Are you sure you want to change it? "),
8602 gdb_signal_to_name ((enum gdb_signal) signum)))
8608 printf_unfiltered (_("Not confirmed, unchanged.\n"));
8609 gdb_flush (gdb_stdout);
8614 case GDB_SIGNAL_DEFAULT:
8615 case GDB_SIGNAL_UNKNOWN:
8616 /* Make sure that "all" doesn't print these. */
8625 for (signum = 0; signum < nsigs; signum++)
8628 signal_cache_update (-1);
8629 target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
8630 target_program_signals ((int) GDB_SIGNAL_LAST, signal_program);
8634 /* Show the results. */
8635 sig_print_header ();
8636 for (; signum < nsigs; signum++)
8638 sig_print_info ((enum gdb_signal) signum);
8645 /* Complete the "handle" command. */
8648 handle_completer (struct cmd_list_element *ignore,
8649 completion_tracker &tracker,
8650 const char *text, const char *word)
8652 static const char * const keywords[] =
8666 signal_completer (ignore, tracker, text, word);
8667 complete_on_enum (tracker, keywords, word, word);
8671 gdb_signal_from_command (int num)
8673 if (num >= 1 && num <= 15)
8674 return (enum gdb_signal) num;
8675 error (_("Only signals 1-15 are valid as numeric signals.\n\
8676 Use \"info signals\" for a list of symbolic signals."));
8679 /* Print current contents of the tables set by the handle command.
8680 It is possible we should just be printing signals actually used
8681 by the current target (but for things to work right when switching
8682 targets, all signals should be in the signal tables). */
8685 info_signals_command (const char *signum_exp, int from_tty)
8687 enum gdb_signal oursig;
8689 sig_print_header ();
8693 /* First see if this is a symbol name. */
8694 oursig = gdb_signal_from_name (signum_exp);
8695 if (oursig == GDB_SIGNAL_UNKNOWN)
8697 /* No, try numeric. */
8699 gdb_signal_from_command (parse_and_eval_long (signum_exp));
8701 sig_print_info (oursig);
8705 printf_filtered ("\n");
8706 /* These ugly casts brought to you by the native VAX compiler. */
8707 for (oursig = GDB_SIGNAL_FIRST;
8708 (int) oursig < (int) GDB_SIGNAL_LAST;
8709 oursig = (enum gdb_signal) ((int) oursig + 1))
8713 if (oursig != GDB_SIGNAL_UNKNOWN
8714 && oursig != GDB_SIGNAL_DEFAULT && oursig != GDB_SIGNAL_0)
8715 sig_print_info (oursig);
8718 printf_filtered (_("\nUse the \"handle\" command "
8719 "to change these tables.\n"));
8722 /* The $_siginfo convenience variable is a bit special. We don't know
8723 for sure the type of the value until we actually have a chance to
8724 fetch the data. The type can change depending on gdbarch, so it is
8725 also dependent on which thread you have selected.
8727 1. making $_siginfo be an internalvar that creates a new value on
8730 2. making the value of $_siginfo be an lval_computed value. */
8732 /* This function implements the lval_computed support for reading a
8736 siginfo_value_read (struct value *v)
8738 LONGEST transferred;
8740 /* If we can access registers, so can we access $_siginfo. Likewise
8742 validate_registers_access ();
8745 target_read (¤t_target, TARGET_OBJECT_SIGNAL_INFO,
8747 value_contents_all_raw (v),
8749 TYPE_LENGTH (value_type (v)));
8751 if (transferred != TYPE_LENGTH (value_type (v)))
8752 error (_("Unable to read siginfo"));
8755 /* This function implements the lval_computed support for writing a
8759 siginfo_value_write (struct value *v, struct value *fromval)
8761 LONGEST transferred;
8763 /* If we can access registers, so can we access $_siginfo. Likewise
8765 validate_registers_access ();
8767 transferred = target_write (¤t_target,
8768 TARGET_OBJECT_SIGNAL_INFO,
8770 value_contents_all_raw (fromval),
8772 TYPE_LENGTH (value_type (fromval)));
8774 if (transferred != TYPE_LENGTH (value_type (fromval)))
8775 error (_("Unable to write siginfo"));
8778 static const struct lval_funcs siginfo_value_funcs =
8784 /* Return a new value with the correct type for the siginfo object of
8785 the current thread using architecture GDBARCH. Return a void value
8786 if there's no object available. */
8788 static struct value *
8789 siginfo_make_value (struct gdbarch *gdbarch, struct internalvar *var,
8792 if (target_has_stack
8793 && !ptid_equal (inferior_ptid, null_ptid)
8794 && gdbarch_get_siginfo_type_p (gdbarch))
8796 struct type *type = gdbarch_get_siginfo_type (gdbarch);
8798 return allocate_computed_value (type, &siginfo_value_funcs, NULL);
8801 return allocate_value (builtin_type (gdbarch)->builtin_void);
8805 /* infcall_suspend_state contains state about the program itself like its
8806 registers and any signal it received when it last stopped.
8807 This state must be restored regardless of how the inferior function call
8808 ends (either successfully, or after it hits a breakpoint or signal)
8809 if the program is to properly continue where it left off. */
8811 struct infcall_suspend_state
8813 struct thread_suspend_state thread_suspend;
8817 readonly_detached_regcache *registers;
8819 /* Format of SIGINFO_DATA or NULL if it is not present. */
8820 struct gdbarch *siginfo_gdbarch;
8822 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
8823 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
8824 content would be invalid. */
8825 gdb_byte *siginfo_data;
8828 struct infcall_suspend_state *
8829 save_infcall_suspend_state (void)
8831 struct infcall_suspend_state *inf_state;
8832 struct thread_info *tp = inferior_thread ();
8833 struct regcache *regcache = get_current_regcache ();
8834 struct gdbarch *gdbarch = regcache->arch ();
8835 gdb_byte *siginfo_data = NULL;
8837 if (gdbarch_get_siginfo_type_p (gdbarch))
8839 struct type *type = gdbarch_get_siginfo_type (gdbarch);
8840 size_t len = TYPE_LENGTH (type);
8841 struct cleanup *back_to;
8843 siginfo_data = (gdb_byte *) xmalloc (len);
8844 back_to = make_cleanup (xfree, siginfo_data);
8846 if (target_read (¤t_target, TARGET_OBJECT_SIGNAL_INFO, NULL,
8847 siginfo_data, 0, len) == len)
8848 discard_cleanups (back_to);
8851 /* Errors ignored. */
8852 do_cleanups (back_to);
8853 siginfo_data = NULL;
8857 inf_state = XCNEW (struct infcall_suspend_state);
8861 inf_state->siginfo_gdbarch = gdbarch;
8862 inf_state->siginfo_data = siginfo_data;
8865 inf_state->thread_suspend = tp->suspend;
8867 /* run_inferior_call will not use the signal due to its `proceed' call with
8868 GDB_SIGNAL_0 anyway. */
8869 tp->suspend.stop_signal = GDB_SIGNAL_0;
8871 inf_state->stop_pc = stop_pc;
8873 inf_state->registers = new readonly_detached_regcache (*regcache);
8878 /* Restore inferior session state to INF_STATE. */
8881 restore_infcall_suspend_state (struct infcall_suspend_state *inf_state)
8883 struct thread_info *tp = inferior_thread ();
8884 struct regcache *regcache = get_current_regcache ();
8885 struct gdbarch *gdbarch = regcache->arch ();
8887 tp->suspend = inf_state->thread_suspend;
8889 stop_pc = inf_state->stop_pc;
8891 if (inf_state->siginfo_gdbarch == gdbarch)
8893 struct type *type = gdbarch_get_siginfo_type (gdbarch);
8895 /* Errors ignored. */
8896 target_write (¤t_target, TARGET_OBJECT_SIGNAL_INFO, NULL,
8897 inf_state->siginfo_data, 0, TYPE_LENGTH (type));
8900 /* The inferior can be gone if the user types "print exit(0)"
8901 (and perhaps other times). */
8902 if (target_has_execution)
8903 /* NB: The register write goes through to the target. */
8904 regcache->restore (inf_state->registers);
8906 discard_infcall_suspend_state (inf_state);
8910 do_restore_infcall_suspend_state_cleanup (void *state)
8912 restore_infcall_suspend_state ((struct infcall_suspend_state *) state);
8916 make_cleanup_restore_infcall_suspend_state
8917 (struct infcall_suspend_state *inf_state)
8919 return make_cleanup (do_restore_infcall_suspend_state_cleanup, inf_state);
8923 discard_infcall_suspend_state (struct infcall_suspend_state *inf_state)
8925 delete inf_state->registers;
8926 xfree (inf_state->siginfo_data);
8930 readonly_detached_regcache *
8931 get_infcall_suspend_state_regcache (struct infcall_suspend_state *inf_state)
8933 return inf_state->registers;
8936 /* infcall_control_state contains state regarding gdb's control of the
8937 inferior itself like stepping control. It also contains session state like
8938 the user's currently selected frame. */
8940 struct infcall_control_state
8942 struct thread_control_state thread_control;
8943 struct inferior_control_state inferior_control;
8946 enum stop_stack_kind stop_stack_dummy;
8947 int stopped_by_random_signal;
8949 /* ID if the selected frame when the inferior function call was made. */
8950 struct frame_id selected_frame_id;
8953 /* Save all of the information associated with the inferior<==>gdb
8956 struct infcall_control_state *
8957 save_infcall_control_state (void)
8959 struct infcall_control_state *inf_status =
8960 XNEW (struct infcall_control_state);
8961 struct thread_info *tp = inferior_thread ();
8962 struct inferior *inf = current_inferior ();
8964 inf_status->thread_control = tp->control;
8965 inf_status->inferior_control = inf->control;
8967 tp->control.step_resume_breakpoint = NULL;
8968 tp->control.exception_resume_breakpoint = NULL;
8970 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
8971 chain. If caller's caller is walking the chain, they'll be happier if we
8972 hand them back the original chain when restore_infcall_control_state is
8974 tp->control.stop_bpstat = bpstat_copy (tp->control.stop_bpstat);
8977 inf_status->stop_stack_dummy = stop_stack_dummy;
8978 inf_status->stopped_by_random_signal = stopped_by_random_signal;
8980 inf_status->selected_frame_id = get_frame_id (get_selected_frame (NULL));
8986 restore_selected_frame (const frame_id &fid)
8988 frame_info *frame = frame_find_by_id (fid);
8990 /* If inf_status->selected_frame_id is NULL, there was no previously
8994 warning (_("Unable to restore previously selected frame."));
8998 select_frame (frame);
9001 /* Restore inferior session state to INF_STATUS. */
9004 restore_infcall_control_state (struct infcall_control_state *inf_status)
9006 struct thread_info *tp = inferior_thread ();
9007 struct inferior *inf = current_inferior ();
9009 if (tp->control.step_resume_breakpoint)
9010 tp->control.step_resume_breakpoint->disposition = disp_del_at_next_stop;
9012 if (tp->control.exception_resume_breakpoint)
9013 tp->control.exception_resume_breakpoint->disposition
9014 = disp_del_at_next_stop;
9016 /* Handle the bpstat_copy of the chain. */
9017 bpstat_clear (&tp->control.stop_bpstat);
9019 tp->control = inf_status->thread_control;
9020 inf->control = inf_status->inferior_control;
9023 stop_stack_dummy = inf_status->stop_stack_dummy;
9024 stopped_by_random_signal = inf_status->stopped_by_random_signal;
9026 if (target_has_stack)
9028 /* The point of the try/catch is that if the stack is clobbered,
9029 walking the stack might encounter a garbage pointer and
9030 error() trying to dereference it. */
9033 restore_selected_frame (inf_status->selected_frame_id);
9035 CATCH (ex, RETURN_MASK_ERROR)
9037 exception_fprintf (gdb_stderr, ex,
9038 "Unable to restore previously selected frame:\n");
9039 /* Error in restoring the selected frame. Select the
9041 select_frame (get_current_frame ());
9050 do_restore_infcall_control_state_cleanup (void *sts)
9052 restore_infcall_control_state ((struct infcall_control_state *) sts);
9056 make_cleanup_restore_infcall_control_state
9057 (struct infcall_control_state *inf_status)
9059 return make_cleanup (do_restore_infcall_control_state_cleanup, inf_status);
9063 discard_infcall_control_state (struct infcall_control_state *inf_status)
9065 if (inf_status->thread_control.step_resume_breakpoint)
9066 inf_status->thread_control.step_resume_breakpoint->disposition
9067 = disp_del_at_next_stop;
9069 if (inf_status->thread_control.exception_resume_breakpoint)
9070 inf_status->thread_control.exception_resume_breakpoint->disposition
9071 = disp_del_at_next_stop;
9073 /* See save_infcall_control_state for info on stop_bpstat. */
9074 bpstat_clear (&inf_status->thread_control.stop_bpstat);
9082 clear_exit_convenience_vars (void)
9084 clear_internalvar (lookup_internalvar ("_exitsignal"));
9085 clear_internalvar (lookup_internalvar ("_exitcode"));
9089 /* User interface for reverse debugging:
9090 Set exec-direction / show exec-direction commands
9091 (returns error unless target implements to_set_exec_direction method). */
9093 enum exec_direction_kind execution_direction = EXEC_FORWARD;
9094 static const char exec_forward[] = "forward";
9095 static const char exec_reverse[] = "reverse";
9096 static const char *exec_direction = exec_forward;
9097 static const char *const exec_direction_names[] = {
9104 set_exec_direction_func (const char *args, int from_tty,
9105 struct cmd_list_element *cmd)
9107 if (target_can_execute_reverse)
9109 if (!strcmp (exec_direction, exec_forward))
9110 execution_direction = EXEC_FORWARD;
9111 else if (!strcmp (exec_direction, exec_reverse))
9112 execution_direction = EXEC_REVERSE;
9116 exec_direction = exec_forward;
9117 error (_("Target does not support this operation."));
9122 show_exec_direction_func (struct ui_file *out, int from_tty,
9123 struct cmd_list_element *cmd, const char *value)
9125 switch (execution_direction) {
9127 fprintf_filtered (out, _("Forward.\n"));
9130 fprintf_filtered (out, _("Reverse.\n"));
9133 internal_error (__FILE__, __LINE__,
9134 _("bogus execution_direction value: %d"),
9135 (int) execution_direction);
9140 show_schedule_multiple (struct ui_file *file, int from_tty,
9141 struct cmd_list_element *c, const char *value)
9143 fprintf_filtered (file, _("Resuming the execution of threads "
9144 "of all processes is %s.\n"), value);
9147 /* Implementation of `siginfo' variable. */
9149 static const struct internalvar_funcs siginfo_funcs =
9156 /* Callback for infrun's target events source. This is marked when a
9157 thread has a pending status to process. */
9160 infrun_async_inferior_event_handler (gdb_client_data data)
9162 inferior_event_handler (INF_REG_EVENT, NULL);
9166 _initialize_infrun (void)
9170 struct cmd_list_element *c;
9172 /* Register extra event sources in the event loop. */
9173 infrun_async_inferior_event_token
9174 = create_async_event_handler (infrun_async_inferior_event_handler, NULL);
9176 add_info ("signals", info_signals_command, _("\
9177 What debugger does when program gets various signals.\n\
9178 Specify a signal as argument to print info on that signal only."));
9179 add_info_alias ("handle", "signals", 0);
9181 c = add_com ("handle", class_run, handle_command, _("\
9182 Specify how to handle signals.\n\
9183 Usage: handle SIGNAL [ACTIONS]\n\
9184 Args are signals and actions to apply to those signals.\n\
9185 If no actions are specified, the current settings for the specified signals\n\
9186 will be displayed instead.\n\
9188 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
9189 from 1-15 are allowed for compatibility with old versions of GDB.\n\
9190 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
9191 The special arg \"all\" is recognized to mean all signals except those\n\
9192 used by the debugger, typically SIGTRAP and SIGINT.\n\
9194 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
9195 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
9196 Stop means reenter debugger if this signal happens (implies print).\n\
9197 Print means print a message if this signal happens.\n\
9198 Pass means let program see this signal; otherwise program doesn't know.\n\
9199 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
9200 Pass and Stop may be combined.\n\
9202 Multiple signals may be specified. Signal numbers and signal names\n\
9203 may be interspersed with actions, with the actions being performed for\n\
9204 all signals cumulatively specified."));
9205 set_cmd_completer (c, handle_completer);
9208 stop_command = add_cmd ("stop", class_obscure,
9209 not_just_help_class_command, _("\
9210 There is no `stop' command, but you can set a hook on `stop'.\n\
9211 This allows you to set a list of commands to be run each time execution\n\
9212 of the program stops."), &cmdlist);
9214 add_setshow_zuinteger_cmd ("infrun", class_maintenance, &debug_infrun, _("\
9215 Set inferior debugging."), _("\
9216 Show inferior debugging."), _("\
9217 When non-zero, inferior specific debugging is enabled."),
9220 &setdebuglist, &showdebuglist);
9222 add_setshow_boolean_cmd ("displaced", class_maintenance,
9223 &debug_displaced, _("\
9224 Set displaced stepping debugging."), _("\
9225 Show displaced stepping debugging."), _("\
9226 When non-zero, displaced stepping specific debugging is enabled."),
9228 show_debug_displaced,
9229 &setdebuglist, &showdebuglist);
9231 add_setshow_boolean_cmd ("non-stop", no_class,
9233 Set whether gdb controls the inferior in non-stop mode."), _("\
9234 Show whether gdb controls the inferior in non-stop mode."), _("\
9235 When debugging a multi-threaded program and this setting is\n\
9236 off (the default, also called all-stop mode), when one thread stops\n\
9237 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
9238 all other threads in the program while you interact with the thread of\n\
9239 interest. When you continue or step a thread, you can allow the other\n\
9240 threads to run, or have them remain stopped, but while you inspect any\n\
9241 thread's state, all threads stop.\n\
9243 In non-stop mode, when one thread stops, other threads can continue\n\
9244 to run freely. You'll be able to step each thread independently,\n\
9245 leave it stopped or free to run as needed."),
9251 numsigs = (int) GDB_SIGNAL_LAST;
9252 signal_stop = XNEWVEC (unsigned char, numsigs);
9253 signal_print = XNEWVEC (unsigned char, numsigs);
9254 signal_program = XNEWVEC (unsigned char, numsigs);
9255 signal_catch = XNEWVEC (unsigned char, numsigs);
9256 signal_pass = XNEWVEC (unsigned char, numsigs);
9257 for (i = 0; i < numsigs; i++)
9260 signal_print[i] = 1;
9261 signal_program[i] = 1;
9262 signal_catch[i] = 0;
9265 /* Signals caused by debugger's own actions should not be given to
9266 the program afterwards.
9268 Do not deliver GDB_SIGNAL_TRAP by default, except when the user
9269 explicitly specifies that it should be delivered to the target
9270 program. Typically, that would occur when a user is debugging a
9271 target monitor on a simulator: the target monitor sets a
9272 breakpoint; the simulator encounters this breakpoint and halts
9273 the simulation handing control to GDB; GDB, noting that the stop
9274 address doesn't map to any known breakpoint, returns control back
9275 to the simulator; the simulator then delivers the hardware
9276 equivalent of a GDB_SIGNAL_TRAP to the program being
9278 signal_program[GDB_SIGNAL_TRAP] = 0;
9279 signal_program[GDB_SIGNAL_INT] = 0;
9281 /* Signals that are not errors should not normally enter the debugger. */
9282 signal_stop[GDB_SIGNAL_ALRM] = 0;
9283 signal_print[GDB_SIGNAL_ALRM] = 0;
9284 signal_stop[GDB_SIGNAL_VTALRM] = 0;
9285 signal_print[GDB_SIGNAL_VTALRM] = 0;
9286 signal_stop[GDB_SIGNAL_PROF] = 0;
9287 signal_print[GDB_SIGNAL_PROF] = 0;
9288 signal_stop[GDB_SIGNAL_CHLD] = 0;
9289 signal_print[GDB_SIGNAL_CHLD] = 0;
9290 signal_stop[GDB_SIGNAL_IO] = 0;
9291 signal_print[GDB_SIGNAL_IO] = 0;
9292 signal_stop[GDB_SIGNAL_POLL] = 0;
9293 signal_print[GDB_SIGNAL_POLL] = 0;
9294 signal_stop[GDB_SIGNAL_URG] = 0;
9295 signal_print[GDB_SIGNAL_URG] = 0;
9296 signal_stop[GDB_SIGNAL_WINCH] = 0;
9297 signal_print[GDB_SIGNAL_WINCH] = 0;
9298 signal_stop[GDB_SIGNAL_PRIO] = 0;
9299 signal_print[GDB_SIGNAL_PRIO] = 0;
9301 /* These signals are used internally by user-level thread
9302 implementations. (See signal(5) on Solaris.) Like the above
9303 signals, a healthy program receives and handles them as part of
9304 its normal operation. */
9305 signal_stop[GDB_SIGNAL_LWP] = 0;
9306 signal_print[GDB_SIGNAL_LWP] = 0;
9307 signal_stop[GDB_SIGNAL_WAITING] = 0;
9308 signal_print[GDB_SIGNAL_WAITING] = 0;
9309 signal_stop[GDB_SIGNAL_CANCEL] = 0;
9310 signal_print[GDB_SIGNAL_CANCEL] = 0;
9311 signal_stop[GDB_SIGNAL_LIBRT] = 0;
9312 signal_print[GDB_SIGNAL_LIBRT] = 0;
9314 /* Update cached state. */
9315 signal_cache_update (-1);
9317 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support,
9318 &stop_on_solib_events, _("\
9319 Set stopping for shared library events."), _("\
9320 Show stopping for shared library events."), _("\
9321 If nonzero, gdb will give control to the user when the dynamic linker\n\
9322 notifies gdb of shared library events. The most common event of interest\n\
9323 to the user would be loading/unloading of a new library."),
9324 set_stop_on_solib_events,
9325 show_stop_on_solib_events,
9326 &setlist, &showlist);
9328 add_setshow_enum_cmd ("follow-fork-mode", class_run,
9329 follow_fork_mode_kind_names,
9330 &follow_fork_mode_string, _("\
9331 Set debugger response to a program call of fork or vfork."), _("\
9332 Show debugger response to a program call of fork or vfork."), _("\
9333 A fork or vfork creates a new process. follow-fork-mode can be:\n\
9334 parent - the original process is debugged after a fork\n\
9335 child - the new process is debugged after a fork\n\
9336 The unfollowed process will continue to run.\n\
9337 By default, the debugger will follow the parent process."),
9339 show_follow_fork_mode_string,
9340 &setlist, &showlist);
9342 add_setshow_enum_cmd ("follow-exec-mode", class_run,
9343 follow_exec_mode_names,
9344 &follow_exec_mode_string, _("\
9345 Set debugger response to a program call of exec."), _("\
9346 Show debugger response to a program call of exec."), _("\
9347 An exec call replaces the program image of a process.\n\
9349 follow-exec-mode can be:\n\
9351 new - the debugger creates a new inferior and rebinds the process\n\
9352 to this new inferior. The program the process was running before\n\
9353 the exec call can be restarted afterwards by restarting the original\n\
9356 same - the debugger keeps the process bound to the same inferior.\n\
9357 The new executable image replaces the previous executable loaded in\n\
9358 the inferior. Restarting the inferior after the exec call restarts\n\
9359 the executable the process was running after the exec call.\n\
9361 By default, the debugger will use the same inferior."),
9363 show_follow_exec_mode_string,
9364 &setlist, &showlist);
9366 add_setshow_enum_cmd ("scheduler-locking", class_run,
9367 scheduler_enums, &scheduler_mode, _("\
9368 Set mode for locking scheduler during execution."), _("\
9369 Show mode for locking scheduler during execution."), _("\
9370 off == no locking (threads may preempt at any time)\n\
9371 on == full locking (no thread except the current thread may run)\n\
9372 This applies to both normal execution and replay mode.\n\
9373 step == scheduler locked during stepping commands (step, next, stepi, nexti).\n\
9374 In this mode, other threads may run during other commands.\n\
9375 This applies to both normal execution and replay mode.\n\
9376 replay == scheduler locked in replay mode and unlocked during normal execution."),
9377 set_schedlock_func, /* traps on target vector */
9378 show_scheduler_mode,
9379 &setlist, &showlist);
9381 add_setshow_boolean_cmd ("schedule-multiple", class_run, &sched_multi, _("\
9382 Set mode for resuming threads of all processes."), _("\
9383 Show mode for resuming threads of all processes."), _("\
9384 When on, execution commands (such as 'continue' or 'next') resume all\n\
9385 threads of all processes. When off (which is the default), execution\n\
9386 commands only resume the threads of the current process. The set of\n\
9387 threads that are resumed is further refined by the scheduler-locking\n\
9388 mode (see help set scheduler-locking)."),
9390 show_schedule_multiple,
9391 &setlist, &showlist);
9393 add_setshow_boolean_cmd ("step-mode", class_run, &step_stop_if_no_debug, _("\
9394 Set mode of the step operation."), _("\
9395 Show mode of the step operation."), _("\
9396 When set, doing a step over a function without debug line information\n\
9397 will stop at the first instruction of that function. Otherwise, the\n\
9398 function is skipped and the step command stops at a different source line."),
9400 show_step_stop_if_no_debug,
9401 &setlist, &showlist);
9403 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run,
9404 &can_use_displaced_stepping, _("\
9405 Set debugger's willingness to use displaced stepping."), _("\
9406 Show debugger's willingness to use displaced stepping."), _("\
9407 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
9408 supported by the target architecture. If off, gdb will not use displaced\n\
9409 stepping to step over breakpoints, even if such is supported by the target\n\
9410 architecture. If auto (which is the default), gdb will use displaced stepping\n\
9411 if the target architecture supports it and non-stop mode is active, but will not\n\
9412 use it in all-stop mode (see help set non-stop)."),
9414 show_can_use_displaced_stepping,
9415 &setlist, &showlist);
9417 add_setshow_enum_cmd ("exec-direction", class_run, exec_direction_names,
9418 &exec_direction, _("Set direction of execution.\n\
9419 Options are 'forward' or 'reverse'."),
9420 _("Show direction of execution (forward/reverse)."),
9421 _("Tells gdb whether to execute forward or backward."),
9422 set_exec_direction_func, show_exec_direction_func,
9423 &setlist, &showlist);
9425 /* Set/show detach-on-fork: user-settable mode. */
9427 add_setshow_boolean_cmd ("detach-on-fork", class_run, &detach_fork, _("\
9428 Set whether gdb will detach the child of a fork."), _("\
9429 Show whether gdb will detach the child of a fork."), _("\
9430 Tells gdb whether to detach the child of a fork."),
9431 NULL, NULL, &setlist, &showlist);
9433 /* Set/show disable address space randomization mode. */
9435 add_setshow_boolean_cmd ("disable-randomization", class_support,
9436 &disable_randomization, _("\
9437 Set disabling of debuggee's virtual address space randomization."), _("\
9438 Show disabling of debuggee's virtual address space randomization."), _("\
9439 When this mode is on (which is the default), randomization of the virtual\n\
9440 address space is disabled. Standalone programs run with the randomization\n\
9441 enabled by default on some platforms."),
9442 &set_disable_randomization,
9443 &show_disable_randomization,
9444 &setlist, &showlist);
9446 /* ptid initializations */
9447 inferior_ptid = null_ptid;
9448 target_last_wait_ptid = minus_one_ptid;
9450 gdb::observers::thread_ptid_changed.attach (infrun_thread_ptid_changed);
9451 gdb::observers::thread_stop_requested.attach (infrun_thread_stop_requested);
9452 gdb::observers::thread_exit.attach (infrun_thread_thread_exit);
9453 gdb::observers::inferior_exit.attach (infrun_inferior_exit);
9455 /* Explicitly create without lookup, since that tries to create a
9456 value with a void typed value, and when we get here, gdbarch
9457 isn't initialized yet. At this point, we're quite sure there
9458 isn't another convenience variable of the same name. */
9459 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs, NULL);
9461 add_setshow_boolean_cmd ("observer", no_class,
9462 &observer_mode_1, _("\
9463 Set whether gdb controls the inferior in observer mode."), _("\
9464 Show whether gdb controls the inferior in observer mode."), _("\
9465 In observer mode, GDB can get data from the inferior, but not\n\
9466 affect its execution. Registers and memory may not be changed,\n\
9467 breakpoints may not be set, and the program cannot be interrupted\n\