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 static void resume (gdb_signal sig);
97 /* Asynchronous signal handler registered as event loop source for
98 when we have pending events ready to be passed to the core. */
99 static struct async_event_handler *infrun_async_inferior_event_token;
101 /* Stores whether infrun_async was previously enabled or disabled.
102 Starts off as -1, indicating "never enabled/disabled". */
103 static int infrun_is_async = -1;
108 infrun_async (int enable)
110 if (infrun_is_async != enable)
112 infrun_is_async = enable;
115 fprintf_unfiltered (gdb_stdlog,
116 "infrun: infrun_async(%d)\n",
120 mark_async_event_handler (infrun_async_inferior_event_token);
122 clear_async_event_handler (infrun_async_inferior_event_token);
129 mark_infrun_async_event_handler (void)
131 mark_async_event_handler (infrun_async_inferior_event_token);
134 /* When set, stop the 'step' command if we enter a function which has
135 no line number information. The normal behavior is that we step
136 over such function. */
137 int step_stop_if_no_debug = 0;
139 show_step_stop_if_no_debug (struct ui_file *file, int from_tty,
140 struct cmd_list_element *c, const char *value)
142 fprintf_filtered (file, _("Mode of the step operation is %s.\n"), value);
145 /* proceed and normal_stop use this to notify the user when the
146 inferior stopped in a different thread than it had been running
149 static ptid_t previous_inferior_ptid;
151 /* If set (default for legacy reasons), when following a fork, GDB
152 will detach from one of the fork branches, child or parent.
153 Exactly which branch is detached depends on 'set follow-fork-mode'
156 static int detach_fork = 1;
158 int debug_displaced = 0;
160 show_debug_displaced (struct ui_file *file, int from_tty,
161 struct cmd_list_element *c, const char *value)
163 fprintf_filtered (file, _("Displace stepping debugging is %s.\n"), value);
166 unsigned int debug_infrun = 0;
168 show_debug_infrun (struct ui_file *file, int from_tty,
169 struct cmd_list_element *c, const char *value)
171 fprintf_filtered (file, _("Inferior debugging is %s.\n"), value);
175 /* Support for disabling address space randomization. */
177 int disable_randomization = 1;
180 show_disable_randomization (struct ui_file *file, int from_tty,
181 struct cmd_list_element *c, const char *value)
183 if (target_supports_disable_randomization ())
184 fprintf_filtered (file,
185 _("Disabling randomization of debuggee's "
186 "virtual address space is %s.\n"),
189 fputs_filtered (_("Disabling randomization of debuggee's "
190 "virtual address space is unsupported on\n"
191 "this platform.\n"), file);
195 set_disable_randomization (const char *args, int from_tty,
196 struct cmd_list_element *c)
198 if (!target_supports_disable_randomization ())
199 error (_("Disabling randomization of debuggee's "
200 "virtual address space is unsupported on\n"
204 /* User interface for non-stop mode. */
207 static int non_stop_1 = 0;
210 set_non_stop (const char *args, int from_tty,
211 struct cmd_list_element *c)
213 if (target_has_execution)
215 non_stop_1 = non_stop;
216 error (_("Cannot change this setting while the inferior is running."));
219 non_stop = non_stop_1;
223 show_non_stop (struct ui_file *file, int from_tty,
224 struct cmd_list_element *c, const char *value)
226 fprintf_filtered (file,
227 _("Controlling the inferior in non-stop mode is %s.\n"),
231 /* "Observer mode" is somewhat like a more extreme version of
232 non-stop, in which all GDB operations that might affect the
233 target's execution have been disabled. */
235 int observer_mode = 0;
236 static int observer_mode_1 = 0;
239 set_observer_mode (const char *args, int from_tty,
240 struct cmd_list_element *c)
242 if (target_has_execution)
244 observer_mode_1 = observer_mode;
245 error (_("Cannot change this setting while the inferior is running."));
248 observer_mode = observer_mode_1;
250 may_write_registers = !observer_mode;
251 may_write_memory = !observer_mode;
252 may_insert_breakpoints = !observer_mode;
253 may_insert_tracepoints = !observer_mode;
254 /* We can insert fast tracepoints in or out of observer mode,
255 but enable them if we're going into this mode. */
257 may_insert_fast_tracepoints = 1;
258 may_stop = !observer_mode;
259 update_target_permissions ();
261 /* Going *into* observer mode we must force non-stop, then
262 going out we leave it that way. */
265 pagination_enabled = 0;
266 non_stop = non_stop_1 = 1;
270 printf_filtered (_("Observer mode is now %s.\n"),
271 (observer_mode ? "on" : "off"));
275 show_observer_mode (struct ui_file *file, int from_tty,
276 struct cmd_list_element *c, const char *value)
278 fprintf_filtered (file, _("Observer mode is %s.\n"), value);
281 /* This updates the value of observer mode based on changes in
282 permissions. Note that we are deliberately ignoring the values of
283 may-write-registers and may-write-memory, since the user may have
284 reason to enable these during a session, for instance to turn on a
285 debugging-related global. */
288 update_observer_mode (void)
292 newval = (!may_insert_breakpoints
293 && !may_insert_tracepoints
294 && may_insert_fast_tracepoints
298 /* Let the user know if things change. */
299 if (newval != observer_mode)
300 printf_filtered (_("Observer mode is now %s.\n"),
301 (newval ? "on" : "off"));
303 observer_mode = observer_mode_1 = newval;
306 /* Tables of how to react to signals; the user sets them. */
308 static unsigned char *signal_stop;
309 static unsigned char *signal_print;
310 static unsigned char *signal_program;
312 /* Table of signals that are registered with "catch signal". A
313 non-zero entry indicates that the signal is caught by some "catch
314 signal" command. This has size GDB_SIGNAL_LAST, to accommodate all
316 static unsigned char *signal_catch;
318 /* Table of signals that the target may silently handle.
319 This is automatically determined from the flags above,
320 and simply cached here. */
321 static unsigned char *signal_pass;
323 #define SET_SIGS(nsigs,sigs,flags) \
325 int signum = (nsigs); \
326 while (signum-- > 0) \
327 if ((sigs)[signum]) \
328 (flags)[signum] = 1; \
331 #define UNSET_SIGS(nsigs,sigs,flags) \
333 int signum = (nsigs); \
334 while (signum-- > 0) \
335 if ((sigs)[signum]) \
336 (flags)[signum] = 0; \
339 /* Update the target's copy of SIGNAL_PROGRAM. The sole purpose of
340 this function is to avoid exporting `signal_program'. */
343 update_signals_program_target (void)
345 target_program_signals ((int) GDB_SIGNAL_LAST, signal_program);
348 /* Value to pass to target_resume() to cause all threads to resume. */
350 #define RESUME_ALL minus_one_ptid
352 /* Command list pointer for the "stop" placeholder. */
354 static struct cmd_list_element *stop_command;
356 /* Nonzero if we want to give control to the user when we're notified
357 of shared library events by the dynamic linker. */
358 int stop_on_solib_events;
360 /* Enable or disable optional shared library event breakpoints
361 as appropriate when the above flag is changed. */
364 set_stop_on_solib_events (const char *args,
365 int from_tty, struct cmd_list_element *c)
367 update_solib_breakpoints ();
371 show_stop_on_solib_events (struct ui_file *file, int from_tty,
372 struct cmd_list_element *c, const char *value)
374 fprintf_filtered (file, _("Stopping for shared library events is %s.\n"),
378 /* Nonzero after stop if current stack frame should be printed. */
380 static int stop_print_frame;
382 /* This is a cached copy of the pid/waitstatus of the last event
383 returned by target_wait()/deprecated_target_wait_hook(). This
384 information is returned by get_last_target_status(). */
385 static ptid_t target_last_wait_ptid;
386 static struct target_waitstatus target_last_waitstatus;
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_inf (current_inferior ());
464 if (print_inferior_events)
466 /* Ensure that we have a process ptid. */
467 ptid_t process_ptid = ptid_t (child_ptid.pid ());
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 (child_ptid.pid ());
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 (child_ptid.pid ());
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 = ptid_t (parent_ptid.pid ());
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 (wait_ptid != minus_one_ptid
693 && 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 thread_info *wait_thread
700 = find_thread_ptid (wait_ptid);
701 switch_to_thread (wait_thread);
706 tp = inferior_thread ();
708 /* If there were any forks/vforks that were caught and are now to be
709 followed, then do so now. */
710 switch (tp->pending_follow.kind)
712 case TARGET_WAITKIND_FORKED:
713 case TARGET_WAITKIND_VFORKED:
715 ptid_t parent, child;
717 /* If the user did a next/step, etc, over a fork call,
718 preserve the stepping state in the fork child. */
719 if (follow_child && should_resume)
721 step_resume_breakpoint = clone_momentary_breakpoint
722 (tp->control.step_resume_breakpoint);
723 step_range_start = tp->control.step_range_start;
724 step_range_end = tp->control.step_range_end;
725 step_frame_id = tp->control.step_frame_id;
726 exception_resume_breakpoint
727 = clone_momentary_breakpoint (tp->control.exception_resume_breakpoint);
728 thread_fsm = tp->thread_fsm;
730 /* For now, delete the parent's sr breakpoint, otherwise,
731 parent/child sr breakpoints are considered duplicates,
732 and the child version will not be installed. Remove
733 this when the breakpoints module becomes aware of
734 inferiors and address spaces. */
735 delete_step_resume_breakpoint (tp);
736 tp->control.step_range_start = 0;
737 tp->control.step_range_end = 0;
738 tp->control.step_frame_id = null_frame_id;
739 delete_exception_resume_breakpoint (tp);
740 tp->thread_fsm = NULL;
743 parent = inferior_ptid;
744 child = tp->pending_follow.value.related_pid;
746 /* Set up inferior(s) as specified by the caller, and tell the
747 target to do whatever is necessary to follow either parent
749 if (follow_fork_inferior (follow_child, detach_fork))
751 /* Target refused to follow, or there's some other reason
752 we shouldn't resume. */
757 /* This pending follow fork event is now handled, one way
758 or another. The previous selected thread may be gone
759 from the lists by now, but if it is still around, need
760 to clear the pending follow request. */
761 tp = find_thread_ptid (parent);
763 tp->pending_follow.kind = TARGET_WAITKIND_SPURIOUS;
765 /* This makes sure we don't try to apply the "Switched
766 over from WAIT_PID" logic above. */
767 nullify_last_target_wait_ptid ();
769 /* If we followed the child, switch to it... */
772 thread_info *child_thr = find_thread_ptid (child);
773 switch_to_thread (child_thr);
775 /* ... and preserve the stepping state, in case the
776 user was stepping over the fork call. */
779 tp = inferior_thread ();
780 tp->control.step_resume_breakpoint
781 = step_resume_breakpoint;
782 tp->control.step_range_start = step_range_start;
783 tp->control.step_range_end = step_range_end;
784 tp->control.step_frame_id = step_frame_id;
785 tp->control.exception_resume_breakpoint
786 = exception_resume_breakpoint;
787 tp->thread_fsm = thread_fsm;
791 /* If we get here, it was because we're trying to
792 resume from a fork catchpoint, but, the user
793 has switched threads away from the thread that
794 forked. In that case, the resume command
795 issued is most likely not applicable to the
796 child, so just warn, and refuse to resume. */
797 warning (_("Not resuming: switched threads "
798 "before following fork child."));
801 /* Reset breakpoints in the child as appropriate. */
802 follow_inferior_reset_breakpoints ();
807 case TARGET_WAITKIND_SPURIOUS:
808 /* Nothing to follow. */
811 internal_error (__FILE__, __LINE__,
812 "Unexpected pending_follow.kind %d\n",
813 tp->pending_follow.kind);
817 return should_resume;
821 follow_inferior_reset_breakpoints (void)
823 struct thread_info *tp = inferior_thread ();
825 /* Was there a step_resume breakpoint? (There was if the user
826 did a "next" at the fork() call.) If so, explicitly reset its
827 thread number. Cloned step_resume breakpoints are disabled on
828 creation, so enable it here now that it is associated with the
831 step_resumes are a form of bp that are made to be per-thread.
832 Since we created the step_resume bp when the parent process
833 was being debugged, and now are switching to the child process,
834 from the breakpoint package's viewpoint, that's a switch of
835 "threads". We must update the bp's notion of which thread
836 it is for, or it'll be ignored when it triggers. */
838 if (tp->control.step_resume_breakpoint)
840 breakpoint_re_set_thread (tp->control.step_resume_breakpoint);
841 tp->control.step_resume_breakpoint->loc->enabled = 1;
844 /* Treat exception_resume breakpoints like step_resume breakpoints. */
845 if (tp->control.exception_resume_breakpoint)
847 breakpoint_re_set_thread (tp->control.exception_resume_breakpoint);
848 tp->control.exception_resume_breakpoint->loc->enabled = 1;
851 /* Reinsert all breakpoints in the child. The user may have set
852 breakpoints after catching the fork, in which case those
853 were never set in the child, but only in the parent. This makes
854 sure the inserted breakpoints match the breakpoint list. */
856 breakpoint_re_set ();
857 insert_breakpoints ();
860 /* The child has exited or execed: resume threads of the parent the
861 user wanted to be executing. */
864 proceed_after_vfork_done (struct thread_info *thread,
867 int pid = * (int *) arg;
869 if (thread->ptid.pid () == pid
870 && thread->state == THREAD_RUNNING
871 && !thread->executing
872 && !thread->stop_requested
873 && thread->suspend.stop_signal == GDB_SIGNAL_0)
876 fprintf_unfiltered (gdb_stdlog,
877 "infrun: resuming vfork parent thread %s\n",
878 target_pid_to_str (thread->ptid));
880 switch_to_thread (thread);
881 clear_proceed_status (0);
882 proceed ((CORE_ADDR) -1, GDB_SIGNAL_DEFAULT);
888 /* Save/restore inferior_ptid, current program space and current
889 inferior. Only use this if the current context points at an exited
890 inferior (and therefore there's no current thread to save). */
891 class scoped_restore_exited_inferior
894 scoped_restore_exited_inferior ()
895 : m_saved_ptid (&inferior_ptid)
899 scoped_restore_tmpl<ptid_t> m_saved_ptid;
900 scoped_restore_current_program_space m_pspace;
901 scoped_restore_current_inferior m_inferior;
904 /* Called whenever we notice an exec or exit event, to handle
905 detaching or resuming a vfork parent. */
908 handle_vfork_child_exec_or_exit (int exec)
910 struct inferior *inf = current_inferior ();
912 if (inf->vfork_parent)
914 int resume_parent = -1;
916 /* This exec or exit marks the end of the shared memory region
917 between the parent and the child. If the user wanted to
918 detach from the parent, now is the time. */
920 if (inf->vfork_parent->pending_detach)
922 struct thread_info *tp;
923 struct program_space *pspace;
924 struct address_space *aspace;
926 /* follow-fork child, detach-on-fork on. */
928 inf->vfork_parent->pending_detach = 0;
930 gdb::optional<scoped_restore_exited_inferior>
931 maybe_restore_inferior;
932 gdb::optional<scoped_restore_current_pspace_and_thread>
933 maybe_restore_thread;
935 /* If we're handling a child exit, then inferior_ptid points
936 at the inferior's pid, not to a thread. */
938 maybe_restore_inferior.emplace ();
940 maybe_restore_thread.emplace ();
942 /* We're letting loose of the parent. */
943 tp = any_live_thread_of_inferior (inf->vfork_parent);
944 switch_to_thread (tp);
946 /* We're about to detach from the parent, which implicitly
947 removes breakpoints from its address space. There's a
948 catch here: we want to reuse the spaces for the child,
949 but, parent/child are still sharing the pspace at this
950 point, although the exec in reality makes the kernel give
951 the child a fresh set of new pages. The problem here is
952 that the breakpoints module being unaware of this, would
953 likely chose the child process to write to the parent
954 address space. Swapping the child temporarily away from
955 the spaces has the desired effect. Yes, this is "sort
958 pspace = inf->pspace;
959 aspace = inf->aspace;
963 if (print_inferior_events)
966 = target_pid_to_str (ptid_t (inf->vfork_parent->pid));
968 target_terminal::ours_for_output ();
972 fprintf_filtered (gdb_stdlog,
973 _("[Detaching vfork parent %s "
974 "after child exec]\n"), pidstr);
978 fprintf_filtered (gdb_stdlog,
979 _("[Detaching vfork parent %s "
980 "after child exit]\n"), pidstr);
984 target_detach (inf->vfork_parent, 0);
987 inf->pspace = pspace;
988 inf->aspace = aspace;
992 /* We're staying attached to the parent, so, really give the
993 child a new address space. */
994 inf->pspace = new program_space (maybe_new_address_space ());
995 inf->aspace = inf->pspace->aspace;
997 set_current_program_space (inf->pspace);
999 resume_parent = inf->vfork_parent->pid;
1001 /* Break the bonds. */
1002 inf->vfork_parent->vfork_child = NULL;
1006 struct program_space *pspace;
1008 /* If this is a vfork child exiting, then the pspace and
1009 aspaces were shared with the parent. Since we're
1010 reporting the process exit, we'll be mourning all that is
1011 found in the address space, and switching to null_ptid,
1012 preparing to start a new inferior. But, since we don't
1013 want to clobber the parent's address/program spaces, we
1014 go ahead and create a new one for this exiting
1017 /* Switch to null_ptid while running clone_program_space, so
1018 that clone_program_space doesn't want to read the
1019 selected frame of a dead process. */
1020 scoped_restore restore_ptid
1021 = make_scoped_restore (&inferior_ptid, null_ptid);
1023 /* This inferior is dead, so avoid giving the breakpoints
1024 module the option to write through to it (cloning a
1025 program space resets breakpoints). */
1028 pspace = new program_space (maybe_new_address_space ());
1029 set_current_program_space (pspace);
1031 inf->symfile_flags = SYMFILE_NO_READ;
1032 clone_program_space (pspace, inf->vfork_parent->pspace);
1033 inf->pspace = pspace;
1034 inf->aspace = pspace->aspace;
1036 resume_parent = inf->vfork_parent->pid;
1037 /* Break the bonds. */
1038 inf->vfork_parent->vfork_child = NULL;
1041 inf->vfork_parent = NULL;
1043 gdb_assert (current_program_space == inf->pspace);
1045 if (non_stop && resume_parent != -1)
1047 /* If the user wanted the parent to be running, let it go
1049 scoped_restore_current_thread restore_thread;
1052 fprintf_unfiltered (gdb_stdlog,
1053 "infrun: resuming vfork parent process %d\n",
1056 iterate_over_threads (proceed_after_vfork_done, &resume_parent);
1061 /* Enum strings for "set|show follow-exec-mode". */
1063 static const char follow_exec_mode_new[] = "new";
1064 static const char follow_exec_mode_same[] = "same";
1065 static const char *const follow_exec_mode_names[] =
1067 follow_exec_mode_new,
1068 follow_exec_mode_same,
1072 static const char *follow_exec_mode_string = follow_exec_mode_same;
1074 show_follow_exec_mode_string (struct ui_file *file, int from_tty,
1075 struct cmd_list_element *c, const char *value)
1077 fprintf_filtered (file, _("Follow exec mode is \"%s\".\n"), value);
1080 /* EXEC_FILE_TARGET is assumed to be non-NULL. */
1083 follow_exec (ptid_t ptid, char *exec_file_target)
1085 struct thread_info *th, *tmp;
1086 struct inferior *inf = current_inferior ();
1087 int pid = ptid.pid ();
1088 ptid_t process_ptid;
1090 /* This is an exec event that we actually wish to pay attention to.
1091 Refresh our symbol table to the newly exec'd program, remove any
1092 momentary bp's, etc.
1094 If there are breakpoints, they aren't really inserted now,
1095 since the exec() transformed our inferior into a fresh set
1098 We want to preserve symbolic breakpoints on the list, since
1099 we have hopes that they can be reset after the new a.out's
1100 symbol table is read.
1102 However, any "raw" breakpoints must be removed from the list
1103 (e.g., the solib bp's), since their address is probably invalid
1106 And, we DON'T want to call delete_breakpoints() here, since
1107 that may write the bp's "shadow contents" (the instruction
1108 value that was overwritten witha TRAP instruction). Since
1109 we now have a new a.out, those shadow contents aren't valid. */
1111 mark_breakpoints_out ();
1113 /* The target reports the exec event to the main thread, even if
1114 some other thread does the exec, and even if the main thread was
1115 stopped or already gone. We may still have non-leader threads of
1116 the process on our list. E.g., on targets that don't have thread
1117 exit events (like remote); or on native Linux in non-stop mode if
1118 there were only two threads in the inferior and the non-leader
1119 one is the one that execs (and nothing forces an update of the
1120 thread list up to here). When debugging remotely, it's best to
1121 avoid extra traffic, when possible, so avoid syncing the thread
1122 list with the target, and instead go ahead and delete all threads
1123 of the process but one that reported the event. Note this must
1124 be done before calling update_breakpoints_after_exec, as
1125 otherwise clearing the threads' resources would reference stale
1126 thread breakpoints -- it may have been one of these threads that
1127 stepped across the exec. We could just clear their stepping
1128 states, but as long as we're iterating, might as well delete
1129 them. Deleting them now rather than at the next user-visible
1130 stop provides a nicer sequence of events for user and MI
1132 ALL_THREADS_SAFE (th, tmp)
1133 if (th->ptid.pid () == pid && th->ptid != ptid)
1136 /* We also need to clear any left over stale state for the
1137 leader/event thread. E.g., if there was any step-resume
1138 breakpoint or similar, it's gone now. We cannot truly
1139 step-to-next statement through an exec(). */
1140 th = inferior_thread ();
1141 th->control.step_resume_breakpoint = NULL;
1142 th->control.exception_resume_breakpoint = NULL;
1143 th->control.single_step_breakpoints = NULL;
1144 th->control.step_range_start = 0;
1145 th->control.step_range_end = 0;
1147 /* The user may have had the main thread held stopped in the
1148 previous image (e.g., schedlock on, or non-stop). Release
1150 th->stop_requested = 0;
1152 update_breakpoints_after_exec ();
1154 /* What is this a.out's name? */
1155 process_ptid = ptid_t (pid);
1156 printf_unfiltered (_("%s is executing new program: %s\n"),
1157 target_pid_to_str (process_ptid),
1160 /* We've followed the inferior through an exec. Therefore, the
1161 inferior has essentially been killed & reborn. */
1163 gdb_flush (gdb_stdout);
1165 breakpoint_init_inferior (inf_execd);
1167 gdb::unique_xmalloc_ptr<char> exec_file_host
1168 = exec_file_find (exec_file_target, NULL);
1170 /* If we were unable to map the executable target pathname onto a host
1171 pathname, tell the user that. Otherwise GDB's subsequent behavior
1172 is confusing. Maybe it would even be better to stop at this point
1173 so that the user can specify a file manually before continuing. */
1174 if (exec_file_host == NULL)
1175 warning (_("Could not load symbols for executable %s.\n"
1176 "Do you need \"set sysroot\"?"),
1179 /* Reset the shared library package. This ensures that we get a
1180 shlib event when the child reaches "_start", at which point the
1181 dld will have had a chance to initialize the child. */
1182 /* Also, loading a symbol file below may trigger symbol lookups, and
1183 we don't want those to be satisfied by the libraries of the
1184 previous incarnation of this process. */
1185 no_shared_libraries (NULL, 0);
1187 if (follow_exec_mode_string == follow_exec_mode_new)
1189 /* The user wants to keep the old inferior and program spaces
1190 around. Create a new fresh one, and switch to it. */
1192 /* Do exit processing for the original inferior before setting the new
1193 inferior's pid. Having two inferiors with the same pid would confuse
1194 find_inferior_p(t)id. Transfer the terminal state and info from the
1195 old to the new inferior. */
1196 inf = add_inferior_with_spaces ();
1197 swap_terminal_info (inf, current_inferior ());
1198 exit_inferior_silent (current_inferior ());
1201 target_follow_exec (inf, exec_file_target);
1203 set_current_inferior (inf);
1204 set_current_program_space (inf->pspace);
1209 /* The old description may no longer be fit for the new image.
1210 E.g, a 64-bit process exec'ed a 32-bit process. Clear the
1211 old description; we'll read a new one below. No need to do
1212 this on "follow-exec-mode new", as the old inferior stays
1213 around (its description is later cleared/refetched on
1215 target_clear_description ();
1218 gdb_assert (current_program_space == inf->pspace);
1220 /* Attempt to open the exec file. SYMFILE_DEFER_BP_RESET is used
1221 because the proper displacement for a PIE (Position Independent
1222 Executable) main symbol file will only be computed by
1223 solib_create_inferior_hook below. breakpoint_re_set would fail
1224 to insert the breakpoints with the zero displacement. */
1225 try_open_exec_file (exec_file_host.get (), inf, SYMFILE_DEFER_BP_RESET);
1227 /* If the target can specify a description, read it. Must do this
1228 after flipping to the new executable (because the target supplied
1229 description must be compatible with the executable's
1230 architecture, and the old executable may e.g., be 32-bit, while
1231 the new one 64-bit), and before anything involving memory or
1233 target_find_description ();
1235 solib_create_inferior_hook (0);
1237 jit_inferior_created_hook ();
1239 breakpoint_re_set ();
1241 /* Reinsert all breakpoints. (Those which were symbolic have
1242 been reset to the proper address in the new a.out, thanks
1243 to symbol_file_command...). */
1244 insert_breakpoints ();
1246 /* The next resume of this inferior should bring it to the shlib
1247 startup breakpoints. (If the user had also set bp's on
1248 "main" from the old (parent) process, then they'll auto-
1249 matically get reset there in the new process.). */
1252 /* The queue of threads that need to do a step-over operation to get
1253 past e.g., a breakpoint. What technique is used to step over the
1254 breakpoint/watchpoint does not matter -- all threads end up in the
1255 same queue, to maintain rough temporal order of execution, in order
1256 to avoid starvation, otherwise, we could e.g., find ourselves
1257 constantly stepping the same couple threads past their breakpoints
1258 over and over, if the single-step finish fast enough. */
1259 struct thread_info *step_over_queue_head;
1261 /* Bit flags indicating what the thread needs to step over. */
1263 enum step_over_what_flag
1265 /* Step over a breakpoint. */
1266 STEP_OVER_BREAKPOINT = 1,
1268 /* Step past a non-continuable watchpoint, in order to let the
1269 instruction execute so we can evaluate the watchpoint
1271 STEP_OVER_WATCHPOINT = 2
1273 DEF_ENUM_FLAGS_TYPE (enum step_over_what_flag, step_over_what);
1275 /* Info about an instruction that is being stepped over. */
1277 struct step_over_info
1279 /* If we're stepping past a breakpoint, this is the address space
1280 and address of the instruction the breakpoint is set at. We'll
1281 skip inserting all breakpoints here. Valid iff ASPACE is
1283 const address_space *aspace;
1286 /* The instruction being stepped over triggers a nonsteppable
1287 watchpoint. If true, we'll skip inserting watchpoints. */
1288 int nonsteppable_watchpoint_p;
1290 /* The thread's global number. */
1294 /* The step-over info of the location that is being stepped over.
1296 Note that with async/breakpoint always-inserted mode, a user might
1297 set a new breakpoint/watchpoint/etc. exactly while a breakpoint is
1298 being stepped over. As setting a new breakpoint inserts all
1299 breakpoints, we need to make sure the breakpoint being stepped over
1300 isn't inserted then. We do that by only clearing the step-over
1301 info when the step-over is actually finished (or aborted).
1303 Presently GDB can only step over one breakpoint at any given time.
1304 Given threads that can't run code in the same address space as the
1305 breakpoint's can't really miss the breakpoint, GDB could be taught
1306 to step-over at most one breakpoint per address space (so this info
1307 could move to the address space object if/when GDB is extended).
1308 The set of breakpoints being stepped over will normally be much
1309 smaller than the set of all breakpoints, so a flag in the
1310 breakpoint location structure would be wasteful. A separate list
1311 also saves complexity and run-time, as otherwise we'd have to go
1312 through all breakpoint locations clearing their flag whenever we
1313 start a new sequence. Similar considerations weigh against storing
1314 this info in the thread object. Plus, not all step overs actually
1315 have breakpoint locations -- e.g., stepping past a single-step
1316 breakpoint, or stepping to complete a non-continuable
1318 static struct step_over_info step_over_info;
1320 /* Record the address of the breakpoint/instruction we're currently
1322 N.B. We record the aspace and address now, instead of say just the thread,
1323 because when we need the info later the thread may be running. */
1326 set_step_over_info (const address_space *aspace, CORE_ADDR address,
1327 int nonsteppable_watchpoint_p,
1330 step_over_info.aspace = aspace;
1331 step_over_info.address = address;
1332 step_over_info.nonsteppable_watchpoint_p = nonsteppable_watchpoint_p;
1333 step_over_info.thread = thread;
1336 /* Called when we're not longer stepping over a breakpoint / an
1337 instruction, so all breakpoints are free to be (re)inserted. */
1340 clear_step_over_info (void)
1343 fprintf_unfiltered (gdb_stdlog,
1344 "infrun: clear_step_over_info\n");
1345 step_over_info.aspace = NULL;
1346 step_over_info.address = 0;
1347 step_over_info.nonsteppable_watchpoint_p = 0;
1348 step_over_info.thread = -1;
1354 stepping_past_instruction_at (struct address_space *aspace,
1357 return (step_over_info.aspace != NULL
1358 && breakpoint_address_match (aspace, address,
1359 step_over_info.aspace,
1360 step_over_info.address));
1366 thread_is_stepping_over_breakpoint (int thread)
1368 return (step_over_info.thread != -1
1369 && thread == step_over_info.thread);
1375 stepping_past_nonsteppable_watchpoint (void)
1377 return step_over_info.nonsteppable_watchpoint_p;
1380 /* Returns true if step-over info is valid. */
1383 step_over_info_valid_p (void)
1385 return (step_over_info.aspace != NULL
1386 || stepping_past_nonsteppable_watchpoint ());
1390 /* Displaced stepping. */
1392 /* In non-stop debugging mode, we must take special care to manage
1393 breakpoints properly; in particular, the traditional strategy for
1394 stepping a thread past a breakpoint it has hit is unsuitable.
1395 'Displaced stepping' is a tactic for stepping one thread past a
1396 breakpoint it has hit while ensuring that other threads running
1397 concurrently will hit the breakpoint as they should.
1399 The traditional way to step a thread T off a breakpoint in a
1400 multi-threaded program in all-stop mode is as follows:
1402 a0) Initially, all threads are stopped, and breakpoints are not
1404 a1) We single-step T, leaving breakpoints uninserted.
1405 a2) We insert breakpoints, and resume all threads.
1407 In non-stop debugging, however, this strategy is unsuitable: we
1408 don't want to have to stop all threads in the system in order to
1409 continue or step T past a breakpoint. Instead, we use displaced
1412 n0) Initially, T is stopped, other threads are running, and
1413 breakpoints are inserted.
1414 n1) We copy the instruction "under" the breakpoint to a separate
1415 location, outside the main code stream, making any adjustments
1416 to the instruction, register, and memory state as directed by
1418 n2) We single-step T over the instruction at its new location.
1419 n3) We adjust the resulting register and memory state as directed
1420 by T's architecture. This includes resetting T's PC to point
1421 back into the main instruction stream.
1424 This approach depends on the following gdbarch methods:
1426 - gdbarch_max_insn_length and gdbarch_displaced_step_location
1427 indicate where to copy the instruction, and how much space must
1428 be reserved there. We use these in step n1.
1430 - gdbarch_displaced_step_copy_insn copies a instruction to a new
1431 address, and makes any necessary adjustments to the instruction,
1432 register contents, and memory. We use this in step n1.
1434 - gdbarch_displaced_step_fixup adjusts registers and memory after
1435 we have successfuly single-stepped the instruction, to yield the
1436 same effect the instruction would have had if we had executed it
1437 at its original address. We use this in step n3.
1439 The gdbarch_displaced_step_copy_insn and
1440 gdbarch_displaced_step_fixup functions must be written so that
1441 copying an instruction with gdbarch_displaced_step_copy_insn,
1442 single-stepping across the copied instruction, and then applying
1443 gdbarch_displaced_insn_fixup should have the same effects on the
1444 thread's memory and registers as stepping the instruction in place
1445 would have. Exactly which responsibilities fall to the copy and
1446 which fall to the fixup is up to the author of those functions.
1448 See the comments in gdbarch.sh for details.
1450 Note that displaced stepping and software single-step cannot
1451 currently be used in combination, although with some care I think
1452 they could be made to. Software single-step works by placing
1453 breakpoints on all possible subsequent instructions; if the
1454 displaced instruction is a PC-relative jump, those breakpoints
1455 could fall in very strange places --- on pages that aren't
1456 executable, or at addresses that are not proper instruction
1457 boundaries. (We do generally let other threads run while we wait
1458 to hit the software single-step breakpoint, and they might
1459 encounter such a corrupted instruction.) One way to work around
1460 this would be to have gdbarch_displaced_step_copy_insn fully
1461 simulate the effect of PC-relative instructions (and return NULL)
1462 on architectures that use software single-stepping.
1464 In non-stop mode, we can have independent and simultaneous step
1465 requests, so more than one thread may need to simultaneously step
1466 over a breakpoint. The current implementation assumes there is
1467 only one scratch space per process. In this case, we have to
1468 serialize access to the scratch space. If thread A wants to step
1469 over a breakpoint, but we are currently waiting for some other
1470 thread to complete a displaced step, we leave thread A stopped and
1471 place it in the displaced_step_request_queue. Whenever a displaced
1472 step finishes, we pick the next thread in the queue and start a new
1473 displaced step operation on it. See displaced_step_prepare and
1474 displaced_step_fixup for details. */
1476 /* Default destructor for displaced_step_closure. */
1478 displaced_step_closure::~displaced_step_closure () = default;
1480 /* Per-inferior displaced stepping state. */
1481 struct displaced_step_inferior_state
1483 /* The process this displaced step state refers to. */
1486 /* True if preparing a displaced step ever failed. If so, we won't
1487 try displaced stepping for this inferior again. */
1490 /* If this is not nullptr, this is the thread carrying out a
1491 displaced single-step in process PID. This thread's state will
1492 require fixing up once it has completed its step. */
1493 thread_info *step_thread;
1495 /* The architecture the thread had when we stepped it. */
1496 struct gdbarch *step_gdbarch;
1498 /* The closure provided gdbarch_displaced_step_copy_insn, to be used
1499 for post-step cleanup. */
1500 struct displaced_step_closure *step_closure;
1502 /* The address of the original instruction, and the copy we
1504 CORE_ADDR step_original, step_copy;
1506 /* Saved contents of copy area. */
1507 gdb_byte *step_saved_copy;
1510 /* The list of states of processes involved in displaced stepping
1512 static std::forward_list<displaced_step_inferior_state *>
1513 displaced_step_inferior_states;
1515 /* Get the displaced stepping state of process PID. */
1517 static displaced_step_inferior_state *
1518 get_displaced_stepping_state (inferior *inf)
1520 for (auto *state : displaced_step_inferior_states)
1522 if (state->inf == inf)
1529 /* Returns true if any inferior has a thread doing a displaced
1533 displaced_step_in_progress_any_inferior ()
1535 for (auto *state : displaced_step_inferior_states)
1537 if (state->step_thread != nullptr)
1544 /* Return true if thread represented by PTID is doing a displaced
1548 displaced_step_in_progress_thread (thread_info *thread)
1550 struct displaced_step_inferior_state *displaced;
1552 gdb_assert (thread != NULL);
1554 displaced = get_displaced_stepping_state (thread->inf);
1556 return (displaced != NULL && displaced->step_thread == thread);
1559 /* Return true if process PID has a thread doing a displaced step. */
1562 displaced_step_in_progress (inferior *inf)
1564 struct displaced_step_inferior_state *displaced;
1566 displaced = get_displaced_stepping_state (inf);
1567 if (displaced != NULL && displaced->step_thread != nullptr)
1573 /* Add a new displaced stepping state for process PID to the displaced
1574 stepping state list, or return a pointer to an already existing
1575 entry, if it already exists. Never returns NULL. */
1577 static displaced_step_inferior_state *
1578 add_displaced_stepping_state (inferior *inf)
1580 displaced_step_inferior_state *state
1581 = get_displaced_stepping_state (inf);
1583 if (state != nullptr)
1586 state = XCNEW (struct displaced_step_inferior_state);
1589 displaced_step_inferior_states.push_front (state);
1594 /* If inferior is in displaced stepping, and ADDR equals to starting address
1595 of copy area, return corresponding displaced_step_closure. Otherwise,
1598 struct displaced_step_closure*
1599 get_displaced_step_closure_by_addr (CORE_ADDR addr)
1601 struct displaced_step_inferior_state *displaced
1602 = get_displaced_stepping_state (current_inferior ());
1604 /* If checking the mode of displaced instruction in copy area. */
1605 if (displaced != NULL
1606 && displaced->step_thread != nullptr
1607 && displaced->step_copy == addr)
1608 return displaced->step_closure;
1613 /* Remove the displaced stepping state of process PID. */
1616 remove_displaced_stepping_state (inferior *inf)
1618 gdb_assert (inf != nullptr);
1620 displaced_step_inferior_states.remove_if
1621 ([inf] (displaced_step_inferior_state *state)
1623 if (state->inf == inf)
1634 infrun_inferior_exit (struct inferior *inf)
1636 remove_displaced_stepping_state (inf);
1639 /* If ON, and the architecture supports it, GDB will use displaced
1640 stepping to step over breakpoints. If OFF, or if the architecture
1641 doesn't support it, GDB will instead use the traditional
1642 hold-and-step approach. If AUTO (which is the default), GDB will
1643 decide which technique to use to step over breakpoints depending on
1644 which of all-stop or non-stop mode is active --- displaced stepping
1645 in non-stop mode; hold-and-step in all-stop mode. */
1647 static enum auto_boolean can_use_displaced_stepping = AUTO_BOOLEAN_AUTO;
1650 show_can_use_displaced_stepping (struct ui_file *file, int from_tty,
1651 struct cmd_list_element *c,
1654 if (can_use_displaced_stepping == AUTO_BOOLEAN_AUTO)
1655 fprintf_filtered (file,
1656 _("Debugger's willingness to use displaced stepping "
1657 "to step over breakpoints is %s (currently %s).\n"),
1658 value, target_is_non_stop_p () ? "on" : "off");
1660 fprintf_filtered (file,
1661 _("Debugger's willingness to use displaced stepping "
1662 "to step over breakpoints is %s.\n"), value);
1665 /* Return non-zero if displaced stepping can/should be used to step
1666 over breakpoints of thread TP. */
1669 use_displaced_stepping (struct thread_info *tp)
1671 struct regcache *regcache = get_thread_regcache (tp);
1672 struct gdbarch *gdbarch = regcache->arch ();
1673 struct displaced_step_inferior_state *displaced_state;
1675 displaced_state = get_displaced_stepping_state (tp->inf);
1677 return (((can_use_displaced_stepping == AUTO_BOOLEAN_AUTO
1678 && target_is_non_stop_p ())
1679 || can_use_displaced_stepping == AUTO_BOOLEAN_TRUE)
1680 && gdbarch_displaced_step_copy_insn_p (gdbarch)
1681 && find_record_target () == NULL
1682 && (displaced_state == NULL
1683 || !displaced_state->failed_before));
1686 /* Clean out any stray displaced stepping state. */
1688 displaced_step_clear (struct displaced_step_inferior_state *displaced)
1690 /* Indicate that there is no cleanup pending. */
1691 displaced->step_thread = nullptr;
1693 delete displaced->step_closure;
1694 displaced->step_closure = NULL;
1698 displaced_step_clear_cleanup (void *arg)
1700 struct displaced_step_inferior_state *state
1701 = (struct displaced_step_inferior_state *) arg;
1703 displaced_step_clear (state);
1706 /* Dump LEN bytes at BUF in hex to FILE, followed by a newline. */
1708 displaced_step_dump_bytes (struct ui_file *file,
1709 const gdb_byte *buf,
1714 for (i = 0; i < len; i++)
1715 fprintf_unfiltered (file, "%02x ", buf[i]);
1716 fputs_unfiltered ("\n", file);
1719 /* Prepare to single-step, using displaced stepping.
1721 Note that we cannot use displaced stepping when we have a signal to
1722 deliver. If we have a signal to deliver and an instruction to step
1723 over, then after the step, there will be no indication from the
1724 target whether the thread entered a signal handler or ignored the
1725 signal and stepped over the instruction successfully --- both cases
1726 result in a simple SIGTRAP. In the first case we mustn't do a
1727 fixup, and in the second case we must --- but we can't tell which.
1728 Comments in the code for 'random signals' in handle_inferior_event
1729 explain how we handle this case instead.
1731 Returns 1 if preparing was successful -- this thread is going to be
1732 stepped now; 0 if displaced stepping this thread got queued; or -1
1733 if this instruction can't be displaced stepped. */
1736 displaced_step_prepare_throw (thread_info *tp)
1738 struct cleanup *ignore_cleanups;
1739 regcache *regcache = get_thread_regcache (tp);
1740 struct gdbarch *gdbarch = regcache->arch ();
1741 const address_space *aspace = regcache->aspace ();
1742 CORE_ADDR original, copy;
1744 struct displaced_step_closure *closure;
1745 struct displaced_step_inferior_state *displaced;
1748 /* We should never reach this function if the architecture does not
1749 support displaced stepping. */
1750 gdb_assert (gdbarch_displaced_step_copy_insn_p (gdbarch));
1752 /* Nor if the thread isn't meant to step over a breakpoint. */
1753 gdb_assert (tp->control.trap_expected);
1755 /* Disable range stepping while executing in the scratch pad. We
1756 want a single-step even if executing the displaced instruction in
1757 the scratch buffer lands within the stepping range (e.g., a
1759 tp->control.may_range_step = 0;
1761 /* We have to displaced step one thread at a time, as we only have
1762 access to a single scratch space per inferior. */
1764 displaced = add_displaced_stepping_state (tp->inf);
1766 if (displaced->step_thread != nullptr)
1768 /* Already waiting for a displaced step to finish. Defer this
1769 request and place in queue. */
1771 if (debug_displaced)
1772 fprintf_unfiltered (gdb_stdlog,
1773 "displaced: deferring step of %s\n",
1774 target_pid_to_str (tp->ptid));
1776 thread_step_over_chain_enqueue (tp);
1781 if (debug_displaced)
1782 fprintf_unfiltered (gdb_stdlog,
1783 "displaced: stepping %s now\n",
1784 target_pid_to_str (tp->ptid));
1787 displaced_step_clear (displaced);
1789 scoped_restore_current_thread restore_thread;
1791 switch_to_thread (tp);
1793 original = regcache_read_pc (regcache);
1795 copy = gdbarch_displaced_step_location (gdbarch);
1796 len = gdbarch_max_insn_length (gdbarch);
1798 if (breakpoint_in_range_p (aspace, copy, len))
1800 /* There's a breakpoint set in the scratch pad location range
1801 (which is usually around the entry point). We'd either
1802 install it before resuming, which would overwrite/corrupt the
1803 scratch pad, or if it was already inserted, this displaced
1804 step would overwrite it. The latter is OK in the sense that
1805 we already assume that no thread is going to execute the code
1806 in the scratch pad range (after initial startup) anyway, but
1807 the former is unacceptable. Simply punt and fallback to
1808 stepping over this breakpoint in-line. */
1809 if (debug_displaced)
1811 fprintf_unfiltered (gdb_stdlog,
1812 "displaced: breakpoint set in scratch pad. "
1813 "Stepping over breakpoint in-line instead.\n");
1819 /* Save the original contents of the copy area. */
1820 displaced->step_saved_copy = (gdb_byte *) xmalloc (len);
1821 ignore_cleanups = make_cleanup (free_current_contents,
1822 &displaced->step_saved_copy);
1823 status = target_read_memory (copy, displaced->step_saved_copy, len);
1825 throw_error (MEMORY_ERROR,
1826 _("Error accessing memory address %s (%s) for "
1827 "displaced-stepping scratch space."),
1828 paddress (gdbarch, copy), safe_strerror (status));
1829 if (debug_displaced)
1831 fprintf_unfiltered (gdb_stdlog, "displaced: saved %s: ",
1832 paddress (gdbarch, copy));
1833 displaced_step_dump_bytes (gdb_stdlog,
1834 displaced->step_saved_copy,
1838 closure = gdbarch_displaced_step_copy_insn (gdbarch,
1839 original, copy, regcache);
1840 if (closure == NULL)
1842 /* The architecture doesn't know how or want to displaced step
1843 this instruction or instruction sequence. Fallback to
1844 stepping over the breakpoint in-line. */
1845 do_cleanups (ignore_cleanups);
1849 /* Save the information we need to fix things up if the step
1851 displaced->step_thread = tp;
1852 displaced->step_gdbarch = gdbarch;
1853 displaced->step_closure = closure;
1854 displaced->step_original = original;
1855 displaced->step_copy = copy;
1857 make_cleanup (displaced_step_clear_cleanup, displaced);
1859 /* Resume execution at the copy. */
1860 regcache_write_pc (regcache, copy);
1862 discard_cleanups (ignore_cleanups);
1864 if (debug_displaced)
1865 fprintf_unfiltered (gdb_stdlog, "displaced: displaced pc to %s\n",
1866 paddress (gdbarch, copy));
1871 /* Wrapper for displaced_step_prepare_throw that disabled further
1872 attempts at displaced stepping if we get a memory error. */
1875 displaced_step_prepare (thread_info *thread)
1881 prepared = displaced_step_prepare_throw (thread);
1883 CATCH (ex, RETURN_MASK_ERROR)
1885 struct displaced_step_inferior_state *displaced_state;
1887 if (ex.error != MEMORY_ERROR
1888 && ex.error != NOT_SUPPORTED_ERROR)
1889 throw_exception (ex);
1893 fprintf_unfiltered (gdb_stdlog,
1894 "infrun: disabling displaced stepping: %s\n",
1898 /* Be verbose if "set displaced-stepping" is "on", silent if
1900 if (can_use_displaced_stepping == AUTO_BOOLEAN_TRUE)
1902 warning (_("disabling displaced stepping: %s"),
1906 /* Disable further displaced stepping attempts. */
1908 = get_displaced_stepping_state (thread->inf);
1909 displaced_state->failed_before = 1;
1917 write_memory_ptid (ptid_t ptid, CORE_ADDR memaddr,
1918 const gdb_byte *myaddr, int len)
1920 scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid);
1922 inferior_ptid = ptid;
1923 write_memory (memaddr, myaddr, len);
1926 /* Restore the contents of the copy area for thread PTID. */
1929 displaced_step_restore (struct displaced_step_inferior_state *displaced,
1932 ULONGEST len = gdbarch_max_insn_length (displaced->step_gdbarch);
1934 write_memory_ptid (ptid, displaced->step_copy,
1935 displaced->step_saved_copy, len);
1936 if (debug_displaced)
1937 fprintf_unfiltered (gdb_stdlog, "displaced: restored %s %s\n",
1938 target_pid_to_str (ptid),
1939 paddress (displaced->step_gdbarch,
1940 displaced->step_copy));
1943 /* If we displaced stepped an instruction successfully, adjust
1944 registers and memory to yield the same effect the instruction would
1945 have had if we had executed it at its original address, and return
1946 1. If the instruction didn't complete, relocate the PC and return
1947 -1. If the thread wasn't displaced stepping, return 0. */
1950 displaced_step_fixup (thread_info *event_thread, enum gdb_signal signal)
1952 struct cleanup *old_cleanups;
1953 struct displaced_step_inferior_state *displaced
1954 = get_displaced_stepping_state (event_thread->inf);
1957 /* Was any thread of this process doing a displaced step? */
1958 if (displaced == NULL)
1961 /* Was this event for the thread we displaced? */
1962 if (displaced->step_thread != event_thread)
1965 old_cleanups = make_cleanup (displaced_step_clear_cleanup, displaced);
1967 displaced_step_restore (displaced, displaced->step_thread->ptid);
1969 /* Fixup may need to read memory/registers. Switch to the thread
1970 that we're fixing up. Also, target_stopped_by_watchpoint checks
1971 the current thread. */
1972 switch_to_thread (event_thread);
1974 /* Did the instruction complete successfully? */
1975 if (signal == GDB_SIGNAL_TRAP
1976 && !(target_stopped_by_watchpoint ()
1977 && (gdbarch_have_nonsteppable_watchpoint (displaced->step_gdbarch)
1978 || target_have_steppable_watchpoint)))
1980 /* Fix up the resulting state. */
1981 gdbarch_displaced_step_fixup (displaced->step_gdbarch,
1982 displaced->step_closure,
1983 displaced->step_original,
1984 displaced->step_copy,
1985 get_thread_regcache (displaced->step_thread));
1990 /* Since the instruction didn't complete, all we can do is
1992 struct regcache *regcache = get_thread_regcache (event_thread);
1993 CORE_ADDR pc = regcache_read_pc (regcache);
1995 pc = displaced->step_original + (pc - displaced->step_copy);
1996 regcache_write_pc (regcache, pc);
2000 do_cleanups (old_cleanups);
2002 displaced->step_thread = nullptr;
2007 /* Data to be passed around while handling an event. This data is
2008 discarded between events. */
2009 struct execution_control_state
2012 /* The thread that got the event, if this was a thread event; NULL
2014 struct thread_info *event_thread;
2016 struct target_waitstatus ws;
2017 int stop_func_filled_in;
2018 CORE_ADDR stop_func_start;
2019 CORE_ADDR stop_func_end;
2020 const char *stop_func_name;
2023 /* True if the event thread hit the single-step breakpoint of
2024 another thread. Thus the event doesn't cause a stop, the thread
2025 needs to be single-stepped past the single-step breakpoint before
2026 we can switch back to the original stepping thread. */
2027 int hit_singlestep_breakpoint;
2030 /* Clear ECS and set it to point at TP. */
2033 reset_ecs (struct execution_control_state *ecs, struct thread_info *tp)
2035 memset (ecs, 0, sizeof (*ecs));
2036 ecs->event_thread = tp;
2037 ecs->ptid = tp->ptid;
2040 static void keep_going_pass_signal (struct execution_control_state *ecs);
2041 static void prepare_to_wait (struct execution_control_state *ecs);
2042 static int keep_going_stepped_thread (struct thread_info *tp);
2043 static step_over_what thread_still_needs_step_over (struct thread_info *tp);
2045 /* Are there any pending step-over requests? If so, run all we can
2046 now and return true. Otherwise, return false. */
2049 start_step_over (void)
2051 struct thread_info *tp, *next;
2053 /* Don't start a new step-over if we already have an in-line
2054 step-over operation ongoing. */
2055 if (step_over_info_valid_p ())
2058 for (tp = step_over_queue_head; tp != NULL; tp = next)
2060 struct execution_control_state ecss;
2061 struct execution_control_state *ecs = &ecss;
2062 step_over_what step_what;
2063 int must_be_in_line;
2065 gdb_assert (!tp->stop_requested);
2067 next = thread_step_over_chain_next (tp);
2069 /* If this inferior already has a displaced step in process,
2070 don't start a new one. */
2071 if (displaced_step_in_progress (tp->inf))
2074 step_what = thread_still_needs_step_over (tp);
2075 must_be_in_line = ((step_what & STEP_OVER_WATCHPOINT)
2076 || ((step_what & STEP_OVER_BREAKPOINT)
2077 && !use_displaced_stepping (tp)));
2079 /* We currently stop all threads of all processes to step-over
2080 in-line. If we need to start a new in-line step-over, let
2081 any pending displaced steps finish first. */
2082 if (must_be_in_line && displaced_step_in_progress_any_inferior ())
2085 thread_step_over_chain_remove (tp);
2087 if (step_over_queue_head == NULL)
2090 fprintf_unfiltered (gdb_stdlog,
2091 "infrun: step-over queue now empty\n");
2094 if (tp->control.trap_expected
2098 internal_error (__FILE__, __LINE__,
2099 "[%s] has inconsistent state: "
2100 "trap_expected=%d, resumed=%d, executing=%d\n",
2101 target_pid_to_str (tp->ptid),
2102 tp->control.trap_expected,
2108 fprintf_unfiltered (gdb_stdlog,
2109 "infrun: resuming [%s] for step-over\n",
2110 target_pid_to_str (tp->ptid));
2112 /* keep_going_pass_signal skips the step-over if the breakpoint
2113 is no longer inserted. In all-stop, we want to keep looking
2114 for a thread that needs a step-over instead of resuming TP,
2115 because we wouldn't be able to resume anything else until the
2116 target stops again. In non-stop, the resume always resumes
2117 only TP, so it's OK to let the thread resume freely. */
2118 if (!target_is_non_stop_p () && !step_what)
2121 switch_to_thread (tp);
2122 reset_ecs (ecs, tp);
2123 keep_going_pass_signal (ecs);
2125 if (!ecs->wait_some_more)
2126 error (_("Command aborted."));
2128 gdb_assert (tp->resumed);
2130 /* If we started a new in-line step-over, we're done. */
2131 if (step_over_info_valid_p ())
2133 gdb_assert (tp->control.trap_expected);
2137 if (!target_is_non_stop_p ())
2139 /* On all-stop, shouldn't have resumed unless we needed a
2141 gdb_assert (tp->control.trap_expected
2142 || tp->step_after_step_resume_breakpoint);
2144 /* With remote targets (at least), in all-stop, we can't
2145 issue any further remote commands until the program stops
2150 /* Either the thread no longer needed a step-over, or a new
2151 displaced stepping sequence started. Even in the latter
2152 case, continue looking. Maybe we can also start another
2153 displaced step on a thread of other process. */
2159 /* Update global variables holding ptids to hold NEW_PTID if they were
2160 holding OLD_PTID. */
2162 infrun_thread_ptid_changed (ptid_t old_ptid, ptid_t new_ptid)
2164 if (inferior_ptid == old_ptid)
2165 inferior_ptid = new_ptid;
2170 static const char schedlock_off[] = "off";
2171 static const char schedlock_on[] = "on";
2172 static const char schedlock_step[] = "step";
2173 static const char schedlock_replay[] = "replay";
2174 static const char *const scheduler_enums[] = {
2181 static const char *scheduler_mode = schedlock_replay;
2183 show_scheduler_mode (struct ui_file *file, int from_tty,
2184 struct cmd_list_element *c, const char *value)
2186 fprintf_filtered (file,
2187 _("Mode for locking scheduler "
2188 "during execution is \"%s\".\n"),
2193 set_schedlock_func (const char *args, int from_tty, struct cmd_list_element *c)
2195 if (!target_can_lock_scheduler)
2197 scheduler_mode = schedlock_off;
2198 error (_("Target '%s' cannot support this command."), target_shortname);
2202 /* True if execution commands resume all threads of all processes by
2203 default; otherwise, resume only threads of the current inferior
2205 int sched_multi = 0;
2207 /* Try to setup for software single stepping over the specified location.
2208 Return 1 if target_resume() should use hardware single step.
2210 GDBARCH the current gdbarch.
2211 PC the location to step over. */
2214 maybe_software_singlestep (struct gdbarch *gdbarch, CORE_ADDR pc)
2218 if (execution_direction == EXEC_FORWARD
2219 && gdbarch_software_single_step_p (gdbarch))
2220 hw_step = !insert_single_step_breakpoints (gdbarch);
2228 user_visible_resume_ptid (int step)
2234 /* With non-stop mode on, threads are always handled
2236 resume_ptid = inferior_ptid;
2238 else if ((scheduler_mode == schedlock_on)
2239 || (scheduler_mode == schedlock_step && step))
2241 /* User-settable 'scheduler' mode requires solo thread
2243 resume_ptid = inferior_ptid;
2245 else if ((scheduler_mode == schedlock_replay)
2246 && target_record_will_replay (minus_one_ptid, execution_direction))
2248 /* User-settable 'scheduler' mode requires solo thread resume in replay
2250 resume_ptid = inferior_ptid;
2252 else if (!sched_multi && target_supports_multi_process ())
2254 /* Resume all threads of the current process (and none of other
2256 resume_ptid = ptid_t (inferior_ptid.pid ());
2260 /* Resume all threads of all processes. */
2261 resume_ptid = RESUME_ALL;
2267 /* Return a ptid representing the set of threads that we will resume,
2268 in the perspective of the target, assuming run control handling
2269 does not require leaving some threads stopped (e.g., stepping past
2270 breakpoint). USER_STEP indicates whether we're about to start the
2271 target for a stepping command. */
2274 internal_resume_ptid (int user_step)
2276 /* In non-stop, we always control threads individually. Note that
2277 the target may always work in non-stop mode even with "set
2278 non-stop off", in which case user_visible_resume_ptid could
2279 return a wildcard ptid. */
2280 if (target_is_non_stop_p ())
2281 return inferior_ptid;
2283 return user_visible_resume_ptid (user_step);
2286 /* Wrapper for target_resume, that handles infrun-specific
2290 do_target_resume (ptid_t resume_ptid, int step, enum gdb_signal sig)
2292 struct thread_info *tp = inferior_thread ();
2294 gdb_assert (!tp->stop_requested);
2296 /* Install inferior's terminal modes. */
2297 target_terminal::inferior ();
2299 /* Avoid confusing the next resume, if the next stop/resume
2300 happens to apply to another thread. */
2301 tp->suspend.stop_signal = GDB_SIGNAL_0;
2303 /* Advise target which signals may be handled silently.
2305 If we have removed breakpoints because we are stepping over one
2306 in-line (in any thread), we need to receive all signals to avoid
2307 accidentally skipping a breakpoint during execution of a signal
2310 Likewise if we're displaced stepping, otherwise a trap for a
2311 breakpoint in a signal handler might be confused with the
2312 displaced step finishing. We don't make the displaced_step_fixup
2313 step distinguish the cases instead, because:
2315 - a backtrace while stopped in the signal handler would show the
2316 scratch pad as frame older than the signal handler, instead of
2317 the real mainline code.
2319 - when the thread is later resumed, the signal handler would
2320 return to the scratch pad area, which would no longer be
2322 if (step_over_info_valid_p ()
2323 || displaced_step_in_progress (tp->inf))
2324 target_pass_signals (0, NULL);
2326 target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
2328 target_resume (resume_ptid, step, sig);
2330 target_commit_resume ();
2333 /* Resume the inferior. SIG is the signal to give the inferior
2334 (GDB_SIGNAL_0 for none). Note: don't call this directly; instead
2335 call 'resume', which handles exceptions. */
2338 resume_1 (enum gdb_signal sig)
2340 struct regcache *regcache = get_current_regcache ();
2341 struct gdbarch *gdbarch = regcache->arch ();
2342 struct thread_info *tp = inferior_thread ();
2343 CORE_ADDR pc = regcache_read_pc (regcache);
2344 const address_space *aspace = regcache->aspace ();
2346 /* This represents the user's step vs continue request. When
2347 deciding whether "set scheduler-locking step" applies, it's the
2348 user's intention that counts. */
2349 const int user_step = tp->control.stepping_command;
2350 /* This represents what we'll actually request the target to do.
2351 This can decay from a step to a continue, if e.g., we need to
2352 implement single-stepping with breakpoints (software
2356 gdb_assert (!tp->stop_requested);
2357 gdb_assert (!thread_is_in_step_over_chain (tp));
2359 if (tp->suspend.waitstatus_pending_p)
2364 = target_waitstatus_to_string (&tp->suspend.waitstatus);
2366 fprintf_unfiltered (gdb_stdlog,
2367 "infrun: resume: thread %s has pending wait "
2368 "status %s (currently_stepping=%d).\n",
2369 target_pid_to_str (tp->ptid), statstr.c_str (),
2370 currently_stepping (tp));
2375 /* FIXME: What should we do if we are supposed to resume this
2376 thread with a signal? Maybe we should maintain a queue of
2377 pending signals to deliver. */
2378 if (sig != GDB_SIGNAL_0)
2380 warning (_("Couldn't deliver signal %s to %s."),
2381 gdb_signal_to_name (sig), target_pid_to_str (tp->ptid));
2384 tp->suspend.stop_signal = GDB_SIGNAL_0;
2386 if (target_can_async_p ())
2389 /* Tell the event loop we have an event to process. */
2390 mark_async_event_handler (infrun_async_inferior_event_token);
2395 tp->stepped_breakpoint = 0;
2397 /* Depends on stepped_breakpoint. */
2398 step = currently_stepping (tp);
2400 if (current_inferior ()->waiting_for_vfork_done)
2402 /* Don't try to single-step a vfork parent that is waiting for
2403 the child to get out of the shared memory region (by exec'ing
2404 or exiting). This is particularly important on software
2405 single-step archs, as the child process would trip on the
2406 software single step breakpoint inserted for the parent
2407 process. Since the parent will not actually execute any
2408 instruction until the child is out of the shared region (such
2409 are vfork's semantics), it is safe to simply continue it.
2410 Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for
2411 the parent, and tell it to `keep_going', which automatically
2412 re-sets it stepping. */
2414 fprintf_unfiltered (gdb_stdlog,
2415 "infrun: resume : clear step\n");
2420 fprintf_unfiltered (gdb_stdlog,
2421 "infrun: resume (step=%d, signal=%s), "
2422 "trap_expected=%d, current thread [%s] at %s\n",
2423 step, gdb_signal_to_symbol_string (sig),
2424 tp->control.trap_expected,
2425 target_pid_to_str (inferior_ptid),
2426 paddress (gdbarch, pc));
2428 /* Normally, by the time we reach `resume', the breakpoints are either
2429 removed or inserted, as appropriate. The exception is if we're sitting
2430 at a permanent breakpoint; we need to step over it, but permanent
2431 breakpoints can't be removed. So we have to test for it here. */
2432 if (breakpoint_here_p (aspace, pc) == permanent_breakpoint_here)
2434 if (sig != GDB_SIGNAL_0)
2436 /* We have a signal to pass to the inferior. The resume
2437 may, or may not take us to the signal handler. If this
2438 is a step, we'll need to stop in the signal handler, if
2439 there's one, (if the target supports stepping into
2440 handlers), or in the next mainline instruction, if
2441 there's no handler. If this is a continue, we need to be
2442 sure to run the handler with all breakpoints inserted.
2443 In all cases, set a breakpoint at the current address
2444 (where the handler returns to), and once that breakpoint
2445 is hit, resume skipping the permanent breakpoint. If
2446 that breakpoint isn't hit, then we've stepped into the
2447 signal handler (or hit some other event). We'll delete
2448 the step-resume breakpoint then. */
2451 fprintf_unfiltered (gdb_stdlog,
2452 "infrun: resume: skipping permanent breakpoint, "
2453 "deliver signal first\n");
2455 clear_step_over_info ();
2456 tp->control.trap_expected = 0;
2458 if (tp->control.step_resume_breakpoint == NULL)
2460 /* Set a "high-priority" step-resume, as we don't want
2461 user breakpoints at PC to trigger (again) when this
2463 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2464 gdb_assert (tp->control.step_resume_breakpoint->loc->permanent);
2466 tp->step_after_step_resume_breakpoint = step;
2469 insert_breakpoints ();
2473 /* There's no signal to pass, we can go ahead and skip the
2474 permanent breakpoint manually. */
2476 fprintf_unfiltered (gdb_stdlog,
2477 "infrun: resume: skipping permanent breakpoint\n");
2478 gdbarch_skip_permanent_breakpoint (gdbarch, regcache);
2479 /* Update pc to reflect the new address from which we will
2480 execute instructions. */
2481 pc = regcache_read_pc (regcache);
2485 /* We've already advanced the PC, so the stepping part
2486 is done. Now we need to arrange for a trap to be
2487 reported to handle_inferior_event. Set a breakpoint
2488 at the current PC, and run to it. Don't update
2489 prev_pc, because if we end in
2490 switch_back_to_stepped_thread, we want the "expected
2491 thread advanced also" branch to be taken. IOW, we
2492 don't want this thread to step further from PC
2494 gdb_assert (!step_over_info_valid_p ());
2495 insert_single_step_breakpoint (gdbarch, aspace, pc);
2496 insert_breakpoints ();
2498 resume_ptid = internal_resume_ptid (user_step);
2499 do_target_resume (resume_ptid, 0, GDB_SIGNAL_0);
2506 /* If we have a breakpoint to step over, make sure to do a single
2507 step only. Same if we have software watchpoints. */
2508 if (tp->control.trap_expected || bpstat_should_step ())
2509 tp->control.may_range_step = 0;
2511 /* If enabled, step over breakpoints by executing a copy of the
2512 instruction at a different address.
2514 We can't use displaced stepping when we have a signal to deliver;
2515 the comments for displaced_step_prepare explain why. The
2516 comments in the handle_inferior event for dealing with 'random
2517 signals' explain what we do instead.
2519 We can't use displaced stepping when we are waiting for vfork_done
2520 event, displaced stepping breaks the vfork child similarly as single
2521 step software breakpoint. */
2522 if (tp->control.trap_expected
2523 && use_displaced_stepping (tp)
2524 && !step_over_info_valid_p ()
2525 && sig == GDB_SIGNAL_0
2526 && !current_inferior ()->waiting_for_vfork_done)
2528 int prepared = displaced_step_prepare (tp);
2533 fprintf_unfiltered (gdb_stdlog,
2534 "Got placed in step-over queue\n");
2536 tp->control.trap_expected = 0;
2539 else if (prepared < 0)
2541 /* Fallback to stepping over the breakpoint in-line. */
2543 if (target_is_non_stop_p ())
2544 stop_all_threads ();
2546 set_step_over_info (regcache->aspace (),
2547 regcache_read_pc (regcache), 0, tp->global_num);
2549 step = maybe_software_singlestep (gdbarch, pc);
2551 insert_breakpoints ();
2553 else if (prepared > 0)
2555 struct displaced_step_inferior_state *displaced;
2557 /* Update pc to reflect the new address from which we will
2558 execute instructions due to displaced stepping. */
2559 pc = regcache_read_pc (get_thread_regcache (tp));
2561 displaced = get_displaced_stepping_state (tp->inf);
2562 step = gdbarch_displaced_step_hw_singlestep (gdbarch,
2563 displaced->step_closure);
2567 /* Do we need to do it the hard way, w/temp breakpoints? */
2569 step = maybe_software_singlestep (gdbarch, pc);
2571 /* Currently, our software single-step implementation leads to different
2572 results than hardware single-stepping in one situation: when stepping
2573 into delivering a signal which has an associated signal handler,
2574 hardware single-step will stop at the first instruction of the handler,
2575 while software single-step will simply skip execution of the handler.
2577 For now, this difference in behavior is accepted since there is no
2578 easy way to actually implement single-stepping into a signal handler
2579 without kernel support.
2581 However, there is one scenario where this difference leads to follow-on
2582 problems: if we're stepping off a breakpoint by removing all breakpoints
2583 and then single-stepping. In this case, the software single-step
2584 behavior means that even if there is a *breakpoint* in the signal
2585 handler, GDB still would not stop.
2587 Fortunately, we can at least fix this particular issue. We detect
2588 here the case where we are about to deliver a signal while software
2589 single-stepping with breakpoints removed. In this situation, we
2590 revert the decisions to remove all breakpoints and insert single-
2591 step breakpoints, and instead we install a step-resume breakpoint
2592 at the current address, deliver the signal without stepping, and
2593 once we arrive back at the step-resume breakpoint, actually step
2594 over the breakpoint we originally wanted to step over. */
2595 if (thread_has_single_step_breakpoints_set (tp)
2596 && sig != GDB_SIGNAL_0
2597 && step_over_info_valid_p ())
2599 /* If we have nested signals or a pending signal is delivered
2600 immediately after a handler returns, might might already have
2601 a step-resume breakpoint set on the earlier handler. We cannot
2602 set another step-resume breakpoint; just continue on until the
2603 original breakpoint is hit. */
2604 if (tp->control.step_resume_breakpoint == NULL)
2606 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2607 tp->step_after_step_resume_breakpoint = 1;
2610 delete_single_step_breakpoints (tp);
2612 clear_step_over_info ();
2613 tp->control.trap_expected = 0;
2615 insert_breakpoints ();
2618 /* If STEP is set, it's a request to use hardware stepping
2619 facilities. But in that case, we should never
2620 use singlestep breakpoint. */
2621 gdb_assert (!(thread_has_single_step_breakpoints_set (tp) && step));
2623 /* Decide the set of threads to ask the target to resume. */
2624 if (tp->control.trap_expected)
2626 /* We're allowing a thread to run past a breakpoint it has
2627 hit, either by single-stepping the thread with the breakpoint
2628 removed, or by displaced stepping, with the breakpoint inserted.
2629 In the former case, we need to single-step only this thread,
2630 and keep others stopped, as they can miss this breakpoint if
2631 allowed to run. That's not really a problem for displaced
2632 stepping, but, we still keep other threads stopped, in case
2633 another thread is also stopped for a breakpoint waiting for
2634 its turn in the displaced stepping queue. */
2635 resume_ptid = inferior_ptid;
2638 resume_ptid = internal_resume_ptid (user_step);
2640 if (execution_direction != EXEC_REVERSE
2641 && step && breakpoint_inserted_here_p (aspace, pc))
2643 /* There are two cases where we currently need to step a
2644 breakpoint instruction when we have a signal to deliver:
2646 - See handle_signal_stop where we handle random signals that
2647 could take out us out of the stepping range. Normally, in
2648 that case we end up continuing (instead of stepping) over the
2649 signal handler with a breakpoint at PC, but there are cases
2650 where we should _always_ single-step, even if we have a
2651 step-resume breakpoint, like when a software watchpoint is
2652 set. Assuming single-stepping and delivering a signal at the
2653 same time would takes us to the signal handler, then we could
2654 have removed the breakpoint at PC to step over it. However,
2655 some hardware step targets (like e.g., Mac OS) can't step
2656 into signal handlers, and for those, we need to leave the
2657 breakpoint at PC inserted, as otherwise if the handler
2658 recurses and executes PC again, it'll miss the breakpoint.
2659 So we leave the breakpoint inserted anyway, but we need to
2660 record that we tried to step a breakpoint instruction, so
2661 that adjust_pc_after_break doesn't end up confused.
2663 - In non-stop if we insert a breakpoint (e.g., a step-resume)
2664 in one thread after another thread that was stepping had been
2665 momentarily paused for a step-over. When we re-resume the
2666 stepping thread, it may be resumed from that address with a
2667 breakpoint that hasn't trapped yet. Seen with
2668 gdb.threads/non-stop-fair-events.exp, on targets that don't
2669 do displaced stepping. */
2672 fprintf_unfiltered (gdb_stdlog,
2673 "infrun: resume: [%s] stepped breakpoint\n",
2674 target_pid_to_str (tp->ptid));
2676 tp->stepped_breakpoint = 1;
2678 /* Most targets can step a breakpoint instruction, thus
2679 executing it normally. But if this one cannot, just
2680 continue and we will hit it anyway. */
2681 if (gdbarch_cannot_step_breakpoint (gdbarch))
2686 && tp->control.trap_expected
2687 && use_displaced_stepping (tp)
2688 && !step_over_info_valid_p ())
2690 struct regcache *resume_regcache = get_thread_regcache (tp);
2691 struct gdbarch *resume_gdbarch = resume_regcache->arch ();
2692 CORE_ADDR actual_pc = regcache_read_pc (resume_regcache);
2695 fprintf_unfiltered (gdb_stdlog, "displaced: run %s: ",
2696 paddress (resume_gdbarch, actual_pc));
2697 read_memory (actual_pc, buf, sizeof (buf));
2698 displaced_step_dump_bytes (gdb_stdlog, buf, sizeof (buf));
2701 if (tp->control.may_range_step)
2703 /* If we're resuming a thread with the PC out of the step
2704 range, then we're doing some nested/finer run control
2705 operation, like stepping the thread out of the dynamic
2706 linker or the displaced stepping scratch pad. We
2707 shouldn't have allowed a range step then. */
2708 gdb_assert (pc_in_thread_step_range (pc, tp));
2711 do_target_resume (resume_ptid, step, sig);
2715 /* Resume the inferior. SIG is the signal to give the inferior
2716 (GDB_SIGNAL_0 for none). This is a wrapper around 'resume_1' that
2717 rolls back state on error. */
2720 resume (gdb_signal sig)
2726 CATCH (ex, RETURN_MASK_ALL)
2728 /* If resuming is being aborted for any reason, delete any
2729 single-step breakpoint resume_1 may have created, to avoid
2730 confusing the following resumption, and to avoid leaving
2731 single-step breakpoints perturbing other threads, in case
2732 we're running in non-stop mode. */
2733 if (inferior_ptid != null_ptid)
2734 delete_single_step_breakpoints (inferior_thread ());
2735 throw_exception (ex);
2745 /* Counter that tracks number of user visible stops. This can be used
2746 to tell whether a command has proceeded the inferior past the
2747 current location. This allows e.g., inferior function calls in
2748 breakpoint commands to not interrupt the command list. When the
2749 call finishes successfully, the inferior is standing at the same
2750 breakpoint as if nothing happened (and so we don't call
2752 static ULONGEST current_stop_id;
2759 return current_stop_id;
2762 /* Called when we report a user visible stop. */
2770 /* Clear out all variables saying what to do when inferior is continued.
2771 First do this, then set the ones you want, then call `proceed'. */
2774 clear_proceed_status_thread (struct thread_info *tp)
2777 fprintf_unfiltered (gdb_stdlog,
2778 "infrun: clear_proceed_status_thread (%s)\n",
2779 target_pid_to_str (tp->ptid));
2781 /* If we're starting a new sequence, then the previous finished
2782 single-step is no longer relevant. */
2783 if (tp->suspend.waitstatus_pending_p)
2785 if (tp->suspend.stop_reason == TARGET_STOPPED_BY_SINGLE_STEP)
2788 fprintf_unfiltered (gdb_stdlog,
2789 "infrun: clear_proceed_status: pending "
2790 "event of %s was a finished step. "
2792 target_pid_to_str (tp->ptid));
2794 tp->suspend.waitstatus_pending_p = 0;
2795 tp->suspend.stop_reason = TARGET_STOPPED_BY_NO_REASON;
2797 else if (debug_infrun)
2800 = target_waitstatus_to_string (&tp->suspend.waitstatus);
2802 fprintf_unfiltered (gdb_stdlog,
2803 "infrun: clear_proceed_status_thread: thread %s "
2804 "has pending wait status %s "
2805 "(currently_stepping=%d).\n",
2806 target_pid_to_str (tp->ptid), statstr.c_str (),
2807 currently_stepping (tp));
2811 /* If this signal should not be seen by program, give it zero.
2812 Used for debugging signals. */
2813 if (!signal_pass_state (tp->suspend.stop_signal))
2814 tp->suspend.stop_signal = GDB_SIGNAL_0;
2816 thread_fsm_delete (tp->thread_fsm);
2817 tp->thread_fsm = NULL;
2819 tp->control.trap_expected = 0;
2820 tp->control.step_range_start = 0;
2821 tp->control.step_range_end = 0;
2822 tp->control.may_range_step = 0;
2823 tp->control.step_frame_id = null_frame_id;
2824 tp->control.step_stack_frame_id = null_frame_id;
2825 tp->control.step_over_calls = STEP_OVER_UNDEBUGGABLE;
2826 tp->control.step_start_function = NULL;
2827 tp->stop_requested = 0;
2829 tp->control.stop_step = 0;
2831 tp->control.proceed_to_finish = 0;
2833 tp->control.stepping_command = 0;
2835 /* Discard any remaining commands or status from previous stop. */
2836 bpstat_clear (&tp->control.stop_bpstat);
2840 clear_proceed_status (int step)
2842 /* With scheduler-locking replay, stop replaying other threads if we're
2843 not replaying the user-visible resume ptid.
2845 This is a convenience feature to not require the user to explicitly
2846 stop replaying the other threads. We're assuming that the user's
2847 intent is to resume tracing the recorded process. */
2848 if (!non_stop && scheduler_mode == schedlock_replay
2849 && target_record_is_replaying (minus_one_ptid)
2850 && !target_record_will_replay (user_visible_resume_ptid (step),
2851 execution_direction))
2852 target_record_stop_replaying ();
2856 struct thread_info *tp;
2859 resume_ptid = user_visible_resume_ptid (step);
2861 /* In all-stop mode, delete the per-thread status of all threads
2862 we're about to resume, implicitly and explicitly. */
2863 ALL_NON_EXITED_THREADS (tp)
2865 if (!tp->ptid.matches (resume_ptid))
2867 clear_proceed_status_thread (tp);
2871 if (inferior_ptid != null_ptid)
2873 struct inferior *inferior;
2877 /* If in non-stop mode, only delete the per-thread status of
2878 the current thread. */
2879 clear_proceed_status_thread (inferior_thread ());
2882 inferior = current_inferior ();
2883 inferior->control.stop_soon = NO_STOP_QUIETLY;
2886 gdb::observers::about_to_proceed.notify ();
2889 /* Returns true if TP is still stopped at a breakpoint that needs
2890 stepping-over in order to make progress. If the breakpoint is gone
2891 meanwhile, we can skip the whole step-over dance. */
2894 thread_still_needs_step_over_bp (struct thread_info *tp)
2896 if (tp->stepping_over_breakpoint)
2898 struct regcache *regcache = get_thread_regcache (tp);
2900 if (breakpoint_here_p (regcache->aspace (),
2901 regcache_read_pc (regcache))
2902 == ordinary_breakpoint_here)
2905 tp->stepping_over_breakpoint = 0;
2911 /* Check whether thread TP still needs to start a step-over in order
2912 to make progress when resumed. Returns an bitwise or of enum
2913 step_over_what bits, indicating what needs to be stepped over. */
2915 static step_over_what
2916 thread_still_needs_step_over (struct thread_info *tp)
2918 step_over_what what = 0;
2920 if (thread_still_needs_step_over_bp (tp))
2921 what |= STEP_OVER_BREAKPOINT;
2923 if (tp->stepping_over_watchpoint
2924 && !target_have_steppable_watchpoint)
2925 what |= STEP_OVER_WATCHPOINT;
2930 /* Returns true if scheduler locking applies. STEP indicates whether
2931 we're about to do a step/next-like command to a thread. */
2934 schedlock_applies (struct thread_info *tp)
2936 return (scheduler_mode == schedlock_on
2937 || (scheduler_mode == schedlock_step
2938 && tp->control.stepping_command)
2939 || (scheduler_mode == schedlock_replay
2940 && target_record_will_replay (minus_one_ptid,
2941 execution_direction)));
2944 /* Basic routine for continuing the program in various fashions.
2946 ADDR is the address to resume at, or -1 for resume where stopped.
2947 SIGGNAL is the signal to give it, or GDB_SIGNAL_0 for none,
2948 or GDB_SIGNAL_DEFAULT for act according to how it stopped.
2950 You should call clear_proceed_status before calling proceed. */
2953 proceed (CORE_ADDR addr, enum gdb_signal siggnal)
2955 struct regcache *regcache;
2956 struct gdbarch *gdbarch;
2957 struct thread_info *tp;
2960 struct execution_control_state ecss;
2961 struct execution_control_state *ecs = &ecss;
2964 /* If we're stopped at a fork/vfork, follow the branch set by the
2965 "set follow-fork-mode" command; otherwise, we'll just proceed
2966 resuming the current thread. */
2967 if (!follow_fork ())
2969 /* The target for some reason decided not to resume. */
2971 if (target_can_async_p ())
2972 inferior_event_handler (INF_EXEC_COMPLETE, NULL);
2976 /* We'll update this if & when we switch to a new thread. */
2977 previous_inferior_ptid = inferior_ptid;
2979 regcache = get_current_regcache ();
2980 gdbarch = regcache->arch ();
2981 const address_space *aspace = regcache->aspace ();
2983 pc = regcache_read_pc (regcache);
2984 tp = inferior_thread ();
2986 /* Fill in with reasonable starting values. */
2987 init_thread_stepping_state (tp);
2989 gdb_assert (!thread_is_in_step_over_chain (tp));
2991 if (addr == (CORE_ADDR) -1)
2993 if (pc == tp->suspend.stop_pc
2994 && breakpoint_here_p (aspace, pc) == ordinary_breakpoint_here
2995 && execution_direction != EXEC_REVERSE)
2996 /* There is a breakpoint at the address we will resume at,
2997 step one instruction before inserting breakpoints so that
2998 we do not stop right away (and report a second hit at this
3001 Note, we don't do this in reverse, because we won't
3002 actually be executing the breakpoint insn anyway.
3003 We'll be (un-)executing the previous instruction. */
3004 tp->stepping_over_breakpoint = 1;
3005 else if (gdbarch_single_step_through_delay_p (gdbarch)
3006 && gdbarch_single_step_through_delay (gdbarch,
3007 get_current_frame ()))
3008 /* We stepped onto an instruction that needs to be stepped
3009 again before re-inserting the breakpoint, do so. */
3010 tp->stepping_over_breakpoint = 1;
3014 regcache_write_pc (regcache, addr);
3017 if (siggnal != GDB_SIGNAL_DEFAULT)
3018 tp->suspend.stop_signal = siggnal;
3020 resume_ptid = user_visible_resume_ptid (tp->control.stepping_command);
3022 /* If an exception is thrown from this point on, make sure to
3023 propagate GDB's knowledge of the executing state to the
3024 frontend/user running state. */
3025 scoped_finish_thread_state finish_state (resume_ptid);
3027 /* Even if RESUME_PTID is a wildcard, and we end up resuming fewer
3028 threads (e.g., we might need to set threads stepping over
3029 breakpoints first), from the user/frontend's point of view, all
3030 threads in RESUME_PTID are now running. Unless we're calling an
3031 inferior function, as in that case we pretend the inferior
3032 doesn't run at all. */
3033 if (!tp->control.in_infcall)
3034 set_running (resume_ptid, 1);
3037 fprintf_unfiltered (gdb_stdlog,
3038 "infrun: proceed (addr=%s, signal=%s)\n",
3039 paddress (gdbarch, addr),
3040 gdb_signal_to_symbol_string (siggnal));
3042 annotate_starting ();
3044 /* Make sure that output from GDB appears before output from the
3046 gdb_flush (gdb_stdout);
3048 /* Since we've marked the inferior running, give it the terminal. A
3049 QUIT/Ctrl-C from here on is forwarded to the target (which can
3050 still detect attempts to unblock a stuck connection with repeated
3051 Ctrl-C from within target_pass_ctrlc). */
3052 target_terminal::inferior ();
3054 /* In a multi-threaded task we may select another thread and
3055 then continue or step.
3057 But if a thread that we're resuming had stopped at a breakpoint,
3058 it will immediately cause another breakpoint stop without any
3059 execution (i.e. it will report a breakpoint hit incorrectly). So
3060 we must step over it first.
3062 Look for threads other than the current (TP) that reported a
3063 breakpoint hit and haven't been resumed yet since. */
3065 /* If scheduler locking applies, we can avoid iterating over all
3067 if (!non_stop && !schedlock_applies (tp))
3069 struct thread_info *current = tp;
3071 ALL_NON_EXITED_THREADS (tp)
3073 /* Ignore the current thread here. It's handled
3078 /* Ignore threads of processes we're not resuming. */
3079 if (!tp->ptid.matches (resume_ptid))
3082 if (!thread_still_needs_step_over (tp))
3085 gdb_assert (!thread_is_in_step_over_chain (tp));
3088 fprintf_unfiltered (gdb_stdlog,
3089 "infrun: need to step-over [%s] first\n",
3090 target_pid_to_str (tp->ptid));
3092 thread_step_over_chain_enqueue (tp);
3098 /* Enqueue the current thread last, so that we move all other
3099 threads over their breakpoints first. */
3100 if (tp->stepping_over_breakpoint)
3101 thread_step_over_chain_enqueue (tp);
3103 /* If the thread isn't started, we'll still need to set its prev_pc,
3104 so that switch_back_to_stepped_thread knows the thread hasn't
3105 advanced. Must do this before resuming any thread, as in
3106 all-stop/remote, once we resume we can't send any other packet
3107 until the target stops again. */
3108 tp->prev_pc = regcache_read_pc (regcache);
3111 scoped_restore save_defer_tc = make_scoped_defer_target_commit_resume ();
3113 started = start_step_over ();
3115 if (step_over_info_valid_p ())
3117 /* Either this thread started a new in-line step over, or some
3118 other thread was already doing one. In either case, don't
3119 resume anything else until the step-over is finished. */
3121 else if (started && !target_is_non_stop_p ())
3123 /* A new displaced stepping sequence was started. In all-stop,
3124 we can't talk to the target anymore until it next stops. */
3126 else if (!non_stop && target_is_non_stop_p ())
3128 /* In all-stop, but the target is always in non-stop mode.
3129 Start all other threads that are implicitly resumed too. */
3130 ALL_NON_EXITED_THREADS (tp)
3132 /* Ignore threads of processes we're not resuming. */
3133 if (!tp->ptid.matches (resume_ptid))
3139 fprintf_unfiltered (gdb_stdlog,
3140 "infrun: proceed: [%s] resumed\n",
3141 target_pid_to_str (tp->ptid));
3142 gdb_assert (tp->executing || tp->suspend.waitstatus_pending_p);
3146 if (thread_is_in_step_over_chain (tp))
3149 fprintf_unfiltered (gdb_stdlog,
3150 "infrun: proceed: [%s] needs step-over\n",
3151 target_pid_to_str (tp->ptid));
3156 fprintf_unfiltered (gdb_stdlog,
3157 "infrun: proceed: resuming %s\n",
3158 target_pid_to_str (tp->ptid));
3160 reset_ecs (ecs, tp);
3161 switch_to_thread (tp);
3162 keep_going_pass_signal (ecs);
3163 if (!ecs->wait_some_more)
3164 error (_("Command aborted."));
3167 else if (!tp->resumed && !thread_is_in_step_over_chain (tp))
3169 /* The thread wasn't started, and isn't queued, run it now. */
3170 reset_ecs (ecs, tp);
3171 switch_to_thread (tp);
3172 keep_going_pass_signal (ecs);
3173 if (!ecs->wait_some_more)
3174 error (_("Command aborted."));
3178 target_commit_resume ();
3180 finish_state.release ();
3182 /* Tell the event loop to wait for it to stop. If the target
3183 supports asynchronous execution, it'll do this from within
3185 if (!target_can_async_p ())
3186 mark_async_event_handler (infrun_async_inferior_event_token);
3190 /* Start remote-debugging of a machine over a serial link. */
3193 start_remote (int from_tty)
3195 struct inferior *inferior;
3197 inferior = current_inferior ();
3198 inferior->control.stop_soon = STOP_QUIETLY_REMOTE;
3200 /* Always go on waiting for the target, regardless of the mode. */
3201 /* FIXME: cagney/1999-09-23: At present it isn't possible to
3202 indicate to wait_for_inferior that a target should timeout if
3203 nothing is returned (instead of just blocking). Because of this,
3204 targets expecting an immediate response need to, internally, set
3205 things up so that the target_wait() is forced to eventually
3207 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
3208 differentiate to its caller what the state of the target is after
3209 the initial open has been performed. Here we're assuming that
3210 the target has stopped. It should be possible to eventually have
3211 target_open() return to the caller an indication that the target
3212 is currently running and GDB state should be set to the same as
3213 for an async run. */
3214 wait_for_inferior ();
3216 /* Now that the inferior has stopped, do any bookkeeping like
3217 loading shared libraries. We want to do this before normal_stop,
3218 so that the displayed frame is up to date. */
3219 post_create_inferior (current_top_target (), from_tty);
3224 /* Initialize static vars when a new inferior begins. */
3227 init_wait_for_inferior (void)
3229 /* These are meaningless until the first time through wait_for_inferior. */
3231 breakpoint_init_inferior (inf_starting);
3233 clear_proceed_status (0);
3235 target_last_wait_ptid = minus_one_ptid;
3237 previous_inferior_ptid = inferior_ptid;
3239 /* Discard any skipped inlined frames. */
3240 clear_inline_frame_state (minus_one_ptid);
3245 static void handle_inferior_event (struct execution_control_state *ecs);
3247 static void handle_step_into_function (struct gdbarch *gdbarch,
3248 struct execution_control_state *ecs);
3249 static void handle_step_into_function_backward (struct gdbarch *gdbarch,
3250 struct execution_control_state *ecs);
3251 static void handle_signal_stop (struct execution_control_state *ecs);
3252 static void check_exception_resume (struct execution_control_state *,
3253 struct frame_info *);
3255 static void end_stepping_range (struct execution_control_state *ecs);
3256 static void stop_waiting (struct execution_control_state *ecs);
3257 static void keep_going (struct execution_control_state *ecs);
3258 static void process_event_stop_test (struct execution_control_state *ecs);
3259 static int switch_back_to_stepped_thread (struct execution_control_state *ecs);
3261 /* This function is attached as a "thread_stop_requested" observer.
3262 Cleanup local state that assumed the PTID was to be resumed, and
3263 report the stop to the frontend. */
3266 infrun_thread_stop_requested (ptid_t ptid)
3268 struct thread_info *tp;
3270 /* PTID was requested to stop. If the thread was already stopped,
3271 but the user/frontend doesn't know about that yet (e.g., the
3272 thread had been temporarily paused for some step-over), set up
3273 for reporting the stop now. */
3274 ALL_NON_EXITED_THREADS (tp)
3275 if (tp->ptid.matches (ptid))
3277 if (tp->state != THREAD_RUNNING)
3282 /* Remove matching threads from the step-over queue, so
3283 start_step_over doesn't try to resume them
3285 if (thread_is_in_step_over_chain (tp))
3286 thread_step_over_chain_remove (tp);
3288 /* If the thread is stopped, but the user/frontend doesn't
3289 know about that yet, queue a pending event, as if the
3290 thread had just stopped now. Unless the thread already had
3292 if (!tp->suspend.waitstatus_pending_p)
3294 tp->suspend.waitstatus_pending_p = 1;
3295 tp->suspend.waitstatus.kind = TARGET_WAITKIND_STOPPED;
3296 tp->suspend.waitstatus.value.sig = GDB_SIGNAL_0;
3299 /* Clear the inline-frame state, since we're re-processing the
3301 clear_inline_frame_state (tp->ptid);
3303 /* If this thread was paused because some other thread was
3304 doing an inline-step over, let that finish first. Once
3305 that happens, we'll restart all threads and consume pending
3306 stop events then. */
3307 if (step_over_info_valid_p ())
3310 /* Otherwise we can process the (new) pending event now. Set
3311 it so this pending event is considered by
3318 infrun_thread_thread_exit (struct thread_info *tp, int silent)
3320 if (target_last_wait_ptid == tp->ptid)
3321 nullify_last_target_wait_ptid ();
3324 /* Delete the step resume, single-step and longjmp/exception resume
3325 breakpoints of TP. */
3328 delete_thread_infrun_breakpoints (struct thread_info *tp)
3330 delete_step_resume_breakpoint (tp);
3331 delete_exception_resume_breakpoint (tp);
3332 delete_single_step_breakpoints (tp);
3335 /* If the target still has execution, call FUNC for each thread that
3336 just stopped. In all-stop, that's all the non-exited threads; in
3337 non-stop, that's the current thread, only. */
3339 typedef void (*for_each_just_stopped_thread_callback_func)
3340 (struct thread_info *tp);
3343 for_each_just_stopped_thread (for_each_just_stopped_thread_callback_func func)
3345 if (!target_has_execution || inferior_ptid == null_ptid)
3348 if (target_is_non_stop_p ())
3350 /* If in non-stop mode, only the current thread stopped. */
3351 func (inferior_thread ());
3355 struct thread_info *tp;
3357 /* In all-stop mode, all threads have stopped. */
3358 ALL_NON_EXITED_THREADS (tp)
3365 /* Delete the step resume and longjmp/exception resume breakpoints of
3366 the threads that just stopped. */
3369 delete_just_stopped_threads_infrun_breakpoints (void)
3371 for_each_just_stopped_thread (delete_thread_infrun_breakpoints);
3374 /* Delete the single-step breakpoints of the threads that just
3378 delete_just_stopped_threads_single_step_breakpoints (void)
3380 for_each_just_stopped_thread (delete_single_step_breakpoints);
3383 /* A cleanup wrapper. */
3386 delete_just_stopped_threads_infrun_breakpoints_cleanup (void *arg)
3388 delete_just_stopped_threads_infrun_breakpoints ();
3394 print_target_wait_results (ptid_t waiton_ptid, ptid_t result_ptid,
3395 const struct target_waitstatus *ws)
3397 std::string status_string = target_waitstatus_to_string (ws);
3400 /* The text is split over several lines because it was getting too long.
3401 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
3402 output as a unit; we want only one timestamp printed if debug_timestamp
3405 stb.printf ("infrun: target_wait (%d.%ld.%ld",
3408 waiton_ptid.tid ());
3409 if (waiton_ptid.pid () != -1)
3410 stb.printf (" [%s]", target_pid_to_str (waiton_ptid));
3411 stb.printf (", status) =\n");
3412 stb.printf ("infrun: %d.%ld.%ld [%s],\n",
3416 target_pid_to_str (result_ptid));
3417 stb.printf ("infrun: %s\n", status_string.c_str ());
3419 /* This uses %s in part to handle %'s in the text, but also to avoid
3420 a gcc error: the format attribute requires a string literal. */
3421 fprintf_unfiltered (gdb_stdlog, "%s", stb.c_str ());
3424 /* Select a thread at random, out of those which are resumed and have
3427 static struct thread_info *
3428 random_pending_event_thread (ptid_t waiton_ptid)
3430 struct thread_info *event_tp;
3432 int random_selector;
3434 /* First see how many events we have. Count only resumed threads
3435 that have an event pending. */
3436 ALL_NON_EXITED_THREADS (event_tp)
3437 if (event_tp->ptid.matches (waiton_ptid)
3438 && event_tp->resumed
3439 && event_tp->suspend.waitstatus_pending_p)
3442 if (num_events == 0)
3445 /* Now randomly pick a thread out of those that have had events. */
3446 random_selector = (int)
3447 ((num_events * (double) rand ()) / (RAND_MAX + 1.0));
3449 if (debug_infrun && num_events > 1)
3450 fprintf_unfiltered (gdb_stdlog,
3451 "infrun: Found %d events, selecting #%d\n",
3452 num_events, random_selector);
3454 /* Select the Nth thread that has had an event. */
3455 ALL_NON_EXITED_THREADS (event_tp)
3456 if (event_tp->ptid.matches (waiton_ptid)
3457 && event_tp->resumed
3458 && event_tp->suspend.waitstatus_pending_p)
3459 if (random_selector-- == 0)
3465 /* Wrapper for target_wait that first checks whether threads have
3466 pending statuses to report before actually asking the target for
3470 do_target_wait (ptid_t ptid, struct target_waitstatus *status, int options)
3473 struct thread_info *tp;
3475 /* First check if there is a resumed thread with a wait status
3477 if (ptid == minus_one_ptid || ptid.is_pid ())
3479 tp = random_pending_event_thread (ptid);
3484 fprintf_unfiltered (gdb_stdlog,
3485 "infrun: Waiting for specific thread %s.\n",
3486 target_pid_to_str (ptid));
3488 /* We have a specific thread to check. */
3489 tp = find_thread_ptid (ptid);
3490 gdb_assert (tp != NULL);
3491 if (!tp->suspend.waitstatus_pending_p)
3496 && (tp->suspend.stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT
3497 || tp->suspend.stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT))
3499 struct regcache *regcache = get_thread_regcache (tp);
3500 struct gdbarch *gdbarch = regcache->arch ();
3504 pc = regcache_read_pc (regcache);
3506 if (pc != tp->suspend.stop_pc)
3509 fprintf_unfiltered (gdb_stdlog,
3510 "infrun: PC of %s changed. was=%s, now=%s\n",
3511 target_pid_to_str (tp->ptid),
3512 paddress (gdbarch, tp->suspend.stop_pc),
3513 paddress (gdbarch, pc));
3516 else if (!breakpoint_inserted_here_p (regcache->aspace (), pc))
3519 fprintf_unfiltered (gdb_stdlog,
3520 "infrun: previous breakpoint of %s, at %s gone\n",
3521 target_pid_to_str (tp->ptid),
3522 paddress (gdbarch, pc));
3530 fprintf_unfiltered (gdb_stdlog,
3531 "infrun: pending event of %s cancelled.\n",
3532 target_pid_to_str (tp->ptid));
3534 tp->suspend.waitstatus.kind = TARGET_WAITKIND_SPURIOUS;
3535 tp->suspend.stop_reason = TARGET_STOPPED_BY_NO_REASON;
3544 = target_waitstatus_to_string (&tp->suspend.waitstatus);
3546 fprintf_unfiltered (gdb_stdlog,
3547 "infrun: Using pending wait status %s for %s.\n",
3549 target_pid_to_str (tp->ptid));
3552 /* Now that we've selected our final event LWP, un-adjust its PC
3553 if it was a software breakpoint (and the target doesn't
3554 always adjust the PC itself). */
3555 if (tp->suspend.stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT
3556 && !target_supports_stopped_by_sw_breakpoint ())
3558 struct regcache *regcache;
3559 struct gdbarch *gdbarch;
3562 regcache = get_thread_regcache (tp);
3563 gdbarch = regcache->arch ();
3565 decr_pc = gdbarch_decr_pc_after_break (gdbarch);
3570 pc = regcache_read_pc (regcache);
3571 regcache_write_pc (regcache, pc + decr_pc);
3575 tp->suspend.stop_reason = TARGET_STOPPED_BY_NO_REASON;
3576 *status = tp->suspend.waitstatus;
3577 tp->suspend.waitstatus_pending_p = 0;
3579 /* Wake up the event loop again, until all pending events are
3581 if (target_is_async_p ())
3582 mark_async_event_handler (infrun_async_inferior_event_token);
3586 /* But if we don't find one, we'll have to wait. */
3588 if (deprecated_target_wait_hook)
3589 event_ptid = deprecated_target_wait_hook (ptid, status, options);
3591 event_ptid = target_wait (ptid, status, options);
3596 /* Prepare and stabilize the inferior for detaching it. E.g.,
3597 detaching while a thread is displaced stepping is a recipe for
3598 crashing it, as nothing would readjust the PC out of the scratch
3602 prepare_for_detach (void)
3604 struct inferior *inf = current_inferior ();
3605 ptid_t pid_ptid = ptid_t (inf->pid);
3607 displaced_step_inferior_state *displaced = get_displaced_stepping_state (inf);
3609 /* Is any thread of this process displaced stepping? If not,
3610 there's nothing else to do. */
3611 if (displaced == NULL || displaced->step_thread == nullptr)
3615 fprintf_unfiltered (gdb_stdlog,
3616 "displaced-stepping in-process while detaching");
3618 scoped_restore restore_detaching = make_scoped_restore (&inf->detaching, true);
3620 while (displaced->step_thread != nullptr)
3622 struct execution_control_state ecss;
3623 struct execution_control_state *ecs;
3626 memset (ecs, 0, sizeof (*ecs));
3628 overlay_cache_invalid = 1;
3629 /* Flush target cache before starting to handle each event.
3630 Target was running and cache could be stale. This is just a
3631 heuristic. Running threads may modify target memory, but we
3632 don't get any event. */
3633 target_dcache_invalidate ();
3635 ecs->ptid = do_target_wait (pid_ptid, &ecs->ws, 0);
3638 print_target_wait_results (pid_ptid, ecs->ptid, &ecs->ws);
3640 /* If an error happens while handling the event, propagate GDB's
3641 knowledge of the executing state to the frontend/user running
3643 scoped_finish_thread_state finish_state (minus_one_ptid);
3645 /* Now figure out what to do with the result of the result. */
3646 handle_inferior_event (ecs);
3648 /* No error, don't finish the state yet. */
3649 finish_state.release ();
3651 /* Breakpoints and watchpoints are not installed on the target
3652 at this point, and signals are passed directly to the
3653 inferior, so this must mean the process is gone. */
3654 if (!ecs->wait_some_more)
3656 restore_detaching.release ();
3657 error (_("Program exited while detaching"));
3661 restore_detaching.release ();
3664 /* Wait for control to return from inferior to debugger.
3666 If inferior gets a signal, we may decide to start it up again
3667 instead of returning. That is why there is a loop in this function.
3668 When this function actually returns it means the inferior
3669 should be left stopped and GDB should read more commands. */
3672 wait_for_inferior (void)
3674 struct cleanup *old_cleanups;
3678 (gdb_stdlog, "infrun: wait_for_inferior ()\n");
3681 = make_cleanup (delete_just_stopped_threads_infrun_breakpoints_cleanup,
3684 /* If an error happens while handling the event, propagate GDB's
3685 knowledge of the executing state to the frontend/user running
3687 scoped_finish_thread_state finish_state (minus_one_ptid);
3691 struct execution_control_state ecss;
3692 struct execution_control_state *ecs = &ecss;
3693 ptid_t waiton_ptid = minus_one_ptid;
3695 memset (ecs, 0, sizeof (*ecs));
3697 overlay_cache_invalid = 1;
3699 /* Flush target cache before starting to handle each event.
3700 Target was running and cache could be stale. This is just a
3701 heuristic. Running threads may modify target memory, but we
3702 don't get any event. */
3703 target_dcache_invalidate ();
3705 ecs->ptid = do_target_wait (waiton_ptid, &ecs->ws, 0);
3708 print_target_wait_results (waiton_ptid, ecs->ptid, &ecs->ws);
3710 /* Now figure out what to do with the result of the result. */
3711 handle_inferior_event (ecs);
3713 if (!ecs->wait_some_more)
3717 /* No error, don't finish the state yet. */
3718 finish_state.release ();
3720 do_cleanups (old_cleanups);
3723 /* Cleanup that reinstalls the readline callback handler, if the
3724 target is running in the background. If while handling the target
3725 event something triggered a secondary prompt, like e.g., a
3726 pagination prompt, we'll have removed the callback handler (see
3727 gdb_readline_wrapper_line). Need to do this as we go back to the
3728 event loop, ready to process further input. Note this has no
3729 effect if the handler hasn't actually been removed, because calling
3730 rl_callback_handler_install resets the line buffer, thus losing
3734 reinstall_readline_callback_handler_cleanup (void *arg)
3736 struct ui *ui = current_ui;
3740 /* We're not going back to the top level event loop yet. Don't
3741 install the readline callback, as it'd prep the terminal,
3742 readline-style (raw, noecho) (e.g., --batch). We'll install
3743 it the next time the prompt is displayed, when we're ready
3748 if (ui->command_editing && ui->prompt_state != PROMPT_BLOCKED)
3749 gdb_rl_callback_handler_reinstall ();
3752 /* Clean up the FSMs of threads that are now stopped. In non-stop,
3753 that's just the event thread. In all-stop, that's all threads. */
3756 clean_up_just_stopped_threads_fsms (struct execution_control_state *ecs)
3758 struct thread_info *thr = ecs->event_thread;
3760 if (thr != NULL && thr->thread_fsm != NULL)
3761 thread_fsm_clean_up (thr->thread_fsm, thr);
3765 ALL_NON_EXITED_THREADS (thr)
3767 if (thr->thread_fsm == NULL)
3769 if (thr == ecs->event_thread)
3772 switch_to_thread (thr);
3773 thread_fsm_clean_up (thr->thread_fsm, thr);
3776 if (ecs->event_thread != NULL)
3777 switch_to_thread (ecs->event_thread);
3781 /* Helper for all_uis_check_sync_execution_done that works on the
3785 check_curr_ui_sync_execution_done (void)
3787 struct ui *ui = current_ui;
3789 if (ui->prompt_state == PROMPT_NEEDED
3791 && !gdb_in_secondary_prompt_p (ui))
3793 target_terminal::ours ();
3794 gdb::observers::sync_execution_done.notify ();
3795 ui_register_input_event_handler (ui);
3802 all_uis_check_sync_execution_done (void)
3804 SWITCH_THRU_ALL_UIS ()
3806 check_curr_ui_sync_execution_done ();
3813 all_uis_on_sync_execution_starting (void)
3815 SWITCH_THRU_ALL_UIS ()
3817 if (current_ui->prompt_state == PROMPT_NEEDED)
3818 async_disable_stdin ();
3822 /* Asynchronous version of wait_for_inferior. It is called by the
3823 event loop whenever a change of state is detected on the file
3824 descriptor corresponding to the target. It can be called more than
3825 once to complete a single execution command. In such cases we need
3826 to keep the state in a global variable ECSS. If it is the last time
3827 that this function is called for a single execution command, then
3828 report to the user that the inferior has stopped, and do the
3829 necessary cleanups. */
3832 fetch_inferior_event (void *client_data)
3834 struct execution_control_state ecss;
3835 struct execution_control_state *ecs = &ecss;
3836 struct cleanup *old_chain = make_cleanup (null_cleanup, NULL);
3838 ptid_t waiton_ptid = minus_one_ptid;
3840 memset (ecs, 0, sizeof (*ecs));
3842 /* Events are always processed with the main UI as current UI. This
3843 way, warnings, debug output, etc. are always consistently sent to
3844 the main console. */
3845 scoped_restore save_ui = make_scoped_restore (¤t_ui, main_ui);
3847 /* End up with readline processing input, if necessary. */
3848 make_cleanup (reinstall_readline_callback_handler_cleanup, NULL);
3850 /* We're handling a live event, so make sure we're doing live
3851 debugging. If we're looking at traceframes while the target is
3852 running, we're going to need to get back to that mode after
3853 handling the event. */
3854 gdb::optional<scoped_restore_current_traceframe> maybe_restore_traceframe;
3857 maybe_restore_traceframe.emplace ();
3858 set_current_traceframe (-1);
3861 gdb::optional<scoped_restore_current_thread> maybe_restore_thread;
3864 /* In non-stop mode, the user/frontend should not notice a thread
3865 switch due to internal events. Make sure we reverse to the
3866 user selected thread and frame after handling the event and
3867 running any breakpoint commands. */
3868 maybe_restore_thread.emplace ();
3870 overlay_cache_invalid = 1;
3871 /* Flush target cache before starting to handle each event. Target
3872 was running and cache could be stale. This is just a heuristic.
3873 Running threads may modify target memory, but we don't get any
3875 target_dcache_invalidate ();
3877 scoped_restore save_exec_dir
3878 = make_scoped_restore (&execution_direction, target_execution_direction ());
3880 ecs->ptid = do_target_wait (waiton_ptid, &ecs->ws,
3881 target_can_async_p () ? TARGET_WNOHANG : 0);
3884 print_target_wait_results (waiton_ptid, ecs->ptid, &ecs->ws);
3886 /* If an error happens while handling the event, propagate GDB's
3887 knowledge of the executing state to the frontend/user running
3889 ptid_t finish_ptid = !target_is_non_stop_p () ? minus_one_ptid : ecs->ptid;
3890 scoped_finish_thread_state finish_state (finish_ptid);
3892 /* Get executed before make_cleanup_restore_current_thread above to apply
3893 still for the thread which has thrown the exception. */
3894 struct cleanup *ts_old_chain = make_bpstat_clear_actions_cleanup ();
3896 make_cleanup (delete_just_stopped_threads_infrun_breakpoints_cleanup, NULL);
3898 /* Now figure out what to do with the result of the result. */
3899 handle_inferior_event (ecs);
3901 if (!ecs->wait_some_more)
3903 struct inferior *inf = find_inferior_ptid (ecs->ptid);
3904 int should_stop = 1;
3905 struct thread_info *thr = ecs->event_thread;
3907 delete_just_stopped_threads_infrun_breakpoints ();
3911 struct thread_fsm *thread_fsm = thr->thread_fsm;
3913 if (thread_fsm != NULL)
3914 should_stop = thread_fsm_should_stop (thread_fsm, thr);
3923 int should_notify_stop = 1;
3926 clean_up_just_stopped_threads_fsms (ecs);
3928 if (thr != NULL && thr->thread_fsm != NULL)
3931 = thread_fsm_should_notify_stop (thr->thread_fsm);
3934 if (should_notify_stop)
3936 /* We may not find an inferior if this was a process exit. */
3937 if (inf == NULL || inf->control.stop_soon == NO_STOP_QUIETLY)
3938 proceeded = normal_stop ();
3943 inferior_event_handler (INF_EXEC_COMPLETE, NULL);
3949 discard_cleanups (ts_old_chain);
3951 /* No error, don't finish the thread states yet. */
3952 finish_state.release ();
3954 /* Revert thread and frame. */
3955 do_cleanups (old_chain);
3957 /* If a UI was in sync execution mode, and now isn't, restore its
3958 prompt (a synchronous execution command has finished, and we're
3959 ready for input). */
3960 all_uis_check_sync_execution_done ();
3963 && exec_done_display_p
3964 && (inferior_ptid == null_ptid
3965 || inferior_thread ()->state != THREAD_RUNNING))
3966 printf_unfiltered (_("completed.\n"));
3969 /* Record the frame and location we're currently stepping through. */
3971 set_step_info (struct frame_info *frame, struct symtab_and_line sal)
3973 struct thread_info *tp = inferior_thread ();
3975 tp->control.step_frame_id = get_frame_id (frame);
3976 tp->control.step_stack_frame_id = get_stack_frame_id (frame);
3978 tp->current_symtab = sal.symtab;
3979 tp->current_line = sal.line;
3982 /* Clear context switchable stepping state. */
3985 init_thread_stepping_state (struct thread_info *tss)
3987 tss->stepped_breakpoint = 0;
3988 tss->stepping_over_breakpoint = 0;
3989 tss->stepping_over_watchpoint = 0;
3990 tss->step_after_step_resume_breakpoint = 0;
3993 /* Set the cached copy of the last ptid/waitstatus. */
3996 set_last_target_status (ptid_t ptid, struct target_waitstatus status)
3998 target_last_wait_ptid = ptid;
3999 target_last_waitstatus = status;
4002 /* Return the cached copy of the last pid/waitstatus returned by
4003 target_wait()/deprecated_target_wait_hook(). The data is actually
4004 cached by handle_inferior_event(), which gets called immediately
4005 after target_wait()/deprecated_target_wait_hook(). */
4008 get_last_target_status (ptid_t *ptidp, struct target_waitstatus *status)
4010 *ptidp = target_last_wait_ptid;
4011 *status = target_last_waitstatus;
4015 nullify_last_target_wait_ptid (void)
4017 target_last_wait_ptid = minus_one_ptid;
4020 /* Switch thread contexts. */
4023 context_switch (execution_control_state *ecs)
4026 && ecs->ptid != inferior_ptid
4027 && ecs->event_thread != inferior_thread ())
4029 fprintf_unfiltered (gdb_stdlog, "infrun: Switching context from %s ",
4030 target_pid_to_str (inferior_ptid));
4031 fprintf_unfiltered (gdb_stdlog, "to %s\n",
4032 target_pid_to_str (ecs->ptid));
4035 switch_to_thread (ecs->event_thread);
4038 /* If the target can't tell whether we've hit breakpoints
4039 (target_supports_stopped_by_sw_breakpoint), and we got a SIGTRAP,
4040 check whether that could have been caused by a breakpoint. If so,
4041 adjust the PC, per gdbarch_decr_pc_after_break. */
4044 adjust_pc_after_break (struct thread_info *thread,
4045 struct target_waitstatus *ws)
4047 struct regcache *regcache;
4048 struct gdbarch *gdbarch;
4049 CORE_ADDR breakpoint_pc, decr_pc;
4051 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
4052 we aren't, just return.
4054 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
4055 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
4056 implemented by software breakpoints should be handled through the normal
4059 NOTE drow/2004-01-31: On some targets, breakpoints may generate
4060 different signals (SIGILL or SIGEMT for instance), but it is less
4061 clear where the PC is pointing afterwards. It may not match
4062 gdbarch_decr_pc_after_break. I don't know any specific target that
4063 generates these signals at breakpoints (the code has been in GDB since at
4064 least 1992) so I can not guess how to handle them here.
4066 In earlier versions of GDB, a target with
4067 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
4068 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
4069 target with both of these set in GDB history, and it seems unlikely to be
4070 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
4072 if (ws->kind != TARGET_WAITKIND_STOPPED)
4075 if (ws->value.sig != GDB_SIGNAL_TRAP)
4078 /* In reverse execution, when a breakpoint is hit, the instruction
4079 under it has already been de-executed. The reported PC always
4080 points at the breakpoint address, so adjusting it further would
4081 be wrong. E.g., consider this case on a decr_pc_after_break == 1
4084 B1 0x08000000 : INSN1
4085 B2 0x08000001 : INSN2
4087 PC -> 0x08000003 : INSN4
4089 Say you're stopped at 0x08000003 as above. Reverse continuing
4090 from that point should hit B2 as below. Reading the PC when the
4091 SIGTRAP is reported should read 0x08000001 and INSN2 should have
4092 been de-executed already.
4094 B1 0x08000000 : INSN1
4095 B2 PC -> 0x08000001 : INSN2
4099 We can't apply the same logic as for forward execution, because
4100 we would wrongly adjust the PC to 0x08000000, since there's a
4101 breakpoint at PC - 1. We'd then report a hit on B1, although
4102 INSN1 hadn't been de-executed yet. Doing nothing is the correct
4104 if (execution_direction == EXEC_REVERSE)
4107 /* If the target can tell whether the thread hit a SW breakpoint,
4108 trust it. Targets that can tell also adjust the PC
4110 if (target_supports_stopped_by_sw_breakpoint ())
4113 /* Note that relying on whether a breakpoint is planted in memory to
4114 determine this can fail. E.g,. the breakpoint could have been
4115 removed since. Or the thread could have been told to step an
4116 instruction the size of a breakpoint instruction, and only
4117 _after_ was a breakpoint inserted at its address. */
4119 /* If this target does not decrement the PC after breakpoints, then
4120 we have nothing to do. */
4121 regcache = get_thread_regcache (thread);
4122 gdbarch = regcache->arch ();
4124 decr_pc = gdbarch_decr_pc_after_break (gdbarch);
4128 const address_space *aspace = regcache->aspace ();
4130 /* Find the location where (if we've hit a breakpoint) the
4131 breakpoint would be. */
4132 breakpoint_pc = regcache_read_pc (regcache) - decr_pc;
4134 /* If the target can't tell whether a software breakpoint triggered,
4135 fallback to figuring it out based on breakpoints we think were
4136 inserted in the target, and on whether the thread was stepped or
4139 /* Check whether there actually is a software breakpoint inserted at
4142 If in non-stop mode, a race condition is possible where we've
4143 removed a breakpoint, but stop events for that breakpoint were
4144 already queued and arrive later. To suppress those spurious
4145 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
4146 and retire them after a number of stop events are reported. Note
4147 this is an heuristic and can thus get confused. The real fix is
4148 to get the "stopped by SW BP and needs adjustment" info out of
4149 the target/kernel (and thus never reach here; see above). */
4150 if (software_breakpoint_inserted_here_p (aspace, breakpoint_pc)
4151 || (target_is_non_stop_p ()
4152 && moribund_breakpoint_here_p (aspace, breakpoint_pc)))
4154 gdb::optional<scoped_restore_tmpl<int>> restore_operation_disable;
4156 if (record_full_is_used ())
4157 restore_operation_disable.emplace
4158 (record_full_gdb_operation_disable_set ());
4160 /* When using hardware single-step, a SIGTRAP is reported for both
4161 a completed single-step and a software breakpoint. Need to
4162 differentiate between the two, as the latter needs adjusting
4163 but the former does not.
4165 The SIGTRAP can be due to a completed hardware single-step only if
4166 - we didn't insert software single-step breakpoints
4167 - this thread is currently being stepped
4169 If any of these events did not occur, we must have stopped due
4170 to hitting a software breakpoint, and have to back up to the
4173 As a special case, we could have hardware single-stepped a
4174 software breakpoint. In this case (prev_pc == breakpoint_pc),
4175 we also need to back up to the breakpoint address. */
4177 if (thread_has_single_step_breakpoints_set (thread)
4178 || !currently_stepping (thread)
4179 || (thread->stepped_breakpoint
4180 && thread->prev_pc == breakpoint_pc))
4181 regcache_write_pc (regcache, breakpoint_pc);
4186 stepped_in_from (struct frame_info *frame, struct frame_id step_frame_id)
4188 for (frame = get_prev_frame (frame);
4190 frame = get_prev_frame (frame))
4192 if (frame_id_eq (get_frame_id (frame), step_frame_id))
4194 if (get_frame_type (frame) != INLINE_FRAME)
4201 /* If the event thread has the stop requested flag set, pretend it
4202 stopped for a GDB_SIGNAL_0 (i.e., as if it stopped due to
4206 handle_stop_requested (struct execution_control_state *ecs)
4208 if (ecs->event_thread->stop_requested)
4210 ecs->ws.kind = TARGET_WAITKIND_STOPPED;
4211 ecs->ws.value.sig = GDB_SIGNAL_0;
4212 handle_signal_stop (ecs);
4218 /* Auxiliary function that handles syscall entry/return events.
4219 It returns 1 if the inferior should keep going (and GDB
4220 should ignore the event), or 0 if the event deserves to be
4224 handle_syscall_event (struct execution_control_state *ecs)
4226 struct regcache *regcache;
4229 context_switch (ecs);
4231 regcache = get_thread_regcache (ecs->event_thread);
4232 syscall_number = ecs->ws.value.syscall_number;
4233 ecs->event_thread->suspend.stop_pc = regcache_read_pc (regcache);
4235 if (catch_syscall_enabled () > 0
4236 && catching_syscall_number (syscall_number) > 0)
4239 fprintf_unfiltered (gdb_stdlog, "infrun: syscall number = '%d'\n",
4242 ecs->event_thread->control.stop_bpstat
4243 = bpstat_stop_status (regcache->aspace (),
4244 ecs->event_thread->suspend.stop_pc,
4245 ecs->event_thread, &ecs->ws);
4247 if (handle_stop_requested (ecs))
4250 if (bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
4252 /* Catchpoint hit. */
4257 if (handle_stop_requested (ecs))
4260 /* If no catchpoint triggered for this, then keep going. */
4265 /* Lazily fill in the execution_control_state's stop_func_* fields. */
4268 fill_in_stop_func (struct gdbarch *gdbarch,
4269 struct execution_control_state *ecs)
4271 if (!ecs->stop_func_filled_in)
4273 /* Don't care about return value; stop_func_start and stop_func_name
4274 will both be 0 if it doesn't work. */
4275 find_function_entry_range_from_pc (ecs->event_thread->suspend.stop_pc,
4276 &ecs->stop_func_name,
4277 &ecs->stop_func_start,
4278 &ecs->stop_func_end);
4279 ecs->stop_func_start
4280 += gdbarch_deprecated_function_start_offset (gdbarch);
4282 if (gdbarch_skip_entrypoint_p (gdbarch))
4283 ecs->stop_func_start = gdbarch_skip_entrypoint (gdbarch,
4284 ecs->stop_func_start);
4286 ecs->stop_func_filled_in = 1;
4291 /* Return the STOP_SOON field of the inferior pointed at by ECS. */
4293 static enum stop_kind
4294 get_inferior_stop_soon (execution_control_state *ecs)
4296 struct inferior *inf = find_inferior_ptid (ecs->ptid);
4298 gdb_assert (inf != NULL);
4299 return inf->control.stop_soon;
4302 /* Wait for one event. Store the resulting waitstatus in WS, and
4303 return the event ptid. */
4306 wait_one (struct target_waitstatus *ws)
4309 ptid_t wait_ptid = minus_one_ptid;
4311 overlay_cache_invalid = 1;
4313 /* Flush target cache before starting to handle each event.
4314 Target was running and cache could be stale. This is just a
4315 heuristic. Running threads may modify target memory, but we
4316 don't get any event. */
4317 target_dcache_invalidate ();
4319 if (deprecated_target_wait_hook)
4320 event_ptid = deprecated_target_wait_hook (wait_ptid, ws, 0);
4322 event_ptid = target_wait (wait_ptid, ws, 0);
4325 print_target_wait_results (wait_ptid, event_ptid, ws);
4330 /* Generate a wrapper for target_stopped_by_REASON that works on PTID
4331 instead of the current thread. */
4332 #define THREAD_STOPPED_BY(REASON) \
4334 thread_stopped_by_ ## REASON (ptid_t ptid) \
4336 scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid); \
4337 inferior_ptid = ptid; \
4339 return target_stopped_by_ ## REASON (); \
4342 /* Generate thread_stopped_by_watchpoint. */
4343 THREAD_STOPPED_BY (watchpoint)
4344 /* Generate thread_stopped_by_sw_breakpoint. */
4345 THREAD_STOPPED_BY (sw_breakpoint)
4346 /* Generate thread_stopped_by_hw_breakpoint. */
4347 THREAD_STOPPED_BY (hw_breakpoint)
4349 /* Save the thread's event and stop reason to process it later. */
4352 save_waitstatus (struct thread_info *tp, struct target_waitstatus *ws)
4356 std::string statstr = target_waitstatus_to_string (ws);
4358 fprintf_unfiltered (gdb_stdlog,
4359 "infrun: saving status %s for %d.%ld.%ld\n",
4366 /* Record for later. */
4367 tp->suspend.waitstatus = *ws;
4368 tp->suspend.waitstatus_pending_p = 1;
4370 struct regcache *regcache = get_thread_regcache (tp);
4371 const address_space *aspace = regcache->aspace ();
4373 if (ws->kind == TARGET_WAITKIND_STOPPED
4374 && ws->value.sig == GDB_SIGNAL_TRAP)
4376 CORE_ADDR pc = regcache_read_pc (regcache);
4378 adjust_pc_after_break (tp, &tp->suspend.waitstatus);
4380 if (thread_stopped_by_watchpoint (tp->ptid))
4382 tp->suspend.stop_reason
4383 = TARGET_STOPPED_BY_WATCHPOINT;
4385 else if (target_supports_stopped_by_sw_breakpoint ()
4386 && thread_stopped_by_sw_breakpoint (tp->ptid))
4388 tp->suspend.stop_reason
4389 = TARGET_STOPPED_BY_SW_BREAKPOINT;
4391 else if (target_supports_stopped_by_hw_breakpoint ()
4392 && thread_stopped_by_hw_breakpoint (tp->ptid))
4394 tp->suspend.stop_reason
4395 = TARGET_STOPPED_BY_HW_BREAKPOINT;
4397 else if (!target_supports_stopped_by_hw_breakpoint ()
4398 && hardware_breakpoint_inserted_here_p (aspace,
4401 tp->suspend.stop_reason
4402 = TARGET_STOPPED_BY_HW_BREAKPOINT;
4404 else if (!target_supports_stopped_by_sw_breakpoint ()
4405 && software_breakpoint_inserted_here_p (aspace,
4408 tp->suspend.stop_reason
4409 = TARGET_STOPPED_BY_SW_BREAKPOINT;
4411 else if (!thread_has_single_step_breakpoints_set (tp)
4412 && currently_stepping (tp))
4414 tp->suspend.stop_reason
4415 = TARGET_STOPPED_BY_SINGLE_STEP;
4420 /* A cleanup that disables thread create/exit events. */
4423 disable_thread_events (void *arg)
4425 target_thread_events (0);
4431 stop_all_threads (void)
4433 /* We may need multiple passes to discover all threads. */
4436 struct cleanup *old_chain;
4438 gdb_assert (target_is_non_stop_p ());
4441 fprintf_unfiltered (gdb_stdlog, "infrun: stop_all_threads\n");
4443 scoped_restore_current_thread restore_thread;
4445 target_thread_events (1);
4446 old_chain = make_cleanup (disable_thread_events, NULL);
4448 /* Request threads to stop, and then wait for the stops. Because
4449 threads we already know about can spawn more threads while we're
4450 trying to stop them, and we only learn about new threads when we
4451 update the thread list, do this in a loop, and keep iterating
4452 until two passes find no threads that need to be stopped. */
4453 for (pass = 0; pass < 2; pass++, iterations++)
4456 fprintf_unfiltered (gdb_stdlog,
4457 "infrun: stop_all_threads, pass=%d, "
4458 "iterations=%d\n", pass, iterations);
4462 struct target_waitstatus ws;
4464 struct thread_info *t;
4466 update_thread_list ();
4468 /* Go through all threads looking for threads that we need
4469 to tell the target to stop. */
4470 ALL_NON_EXITED_THREADS (t)
4474 /* If already stopping, don't request a stop again.
4475 We just haven't seen the notification yet. */
4476 if (!t->stop_requested)
4479 fprintf_unfiltered (gdb_stdlog,
4480 "infrun: %s executing, "
4482 target_pid_to_str (t->ptid));
4483 target_stop (t->ptid);
4484 t->stop_requested = 1;
4489 fprintf_unfiltered (gdb_stdlog,
4490 "infrun: %s executing, "
4491 "already stopping\n",
4492 target_pid_to_str (t->ptid));
4495 if (t->stop_requested)
4501 fprintf_unfiltered (gdb_stdlog,
4502 "infrun: %s not executing\n",
4503 target_pid_to_str (t->ptid));
4505 /* The thread may be not executing, but still be
4506 resumed with a pending status to process. */
4514 /* If we find new threads on the second iteration, restart
4515 over. We want to see two iterations in a row with all
4520 event_ptid = wait_one (&ws);
4522 if (ws.kind == TARGET_WAITKIND_NO_RESUMED)
4524 /* All resumed threads exited. */
4526 else if (ws.kind == TARGET_WAITKIND_THREAD_EXITED
4527 || ws.kind == TARGET_WAITKIND_EXITED
4528 || ws.kind == TARGET_WAITKIND_SIGNALLED)
4532 ptid_t ptid = ptid_t (ws.value.integer);
4534 fprintf_unfiltered (gdb_stdlog,
4535 "infrun: %s exited while "
4536 "stopping threads\n",
4537 target_pid_to_str (ptid));
4544 t = find_thread_ptid (event_ptid);
4546 t = add_thread (event_ptid);
4548 t->stop_requested = 0;
4551 t->control.may_range_step = 0;
4553 /* This may be the first time we see the inferior report
4555 inf = find_inferior_ptid (event_ptid);
4556 if (inf->needs_setup)
4558 switch_to_thread_no_regs (t);
4562 if (ws.kind == TARGET_WAITKIND_STOPPED
4563 && ws.value.sig == GDB_SIGNAL_0)
4565 /* We caught the event that we intended to catch, so
4566 there's no event pending. */
4567 t->suspend.waitstatus.kind = TARGET_WAITKIND_IGNORE;
4568 t->suspend.waitstatus_pending_p = 0;
4570 if (displaced_step_fixup (t, GDB_SIGNAL_0) < 0)
4572 /* Add it back to the step-over queue. */
4575 fprintf_unfiltered (gdb_stdlog,
4576 "infrun: displaced-step of %s "
4577 "canceled: adding back to the "
4578 "step-over queue\n",
4579 target_pid_to_str (t->ptid));
4581 t->control.trap_expected = 0;
4582 thread_step_over_chain_enqueue (t);
4587 enum gdb_signal sig;
4588 struct regcache *regcache;
4592 std::string statstr = target_waitstatus_to_string (&ws);
4594 fprintf_unfiltered (gdb_stdlog,
4595 "infrun: target_wait %s, saving "
4596 "status for %d.%ld.%ld\n",
4603 /* Record for later. */
4604 save_waitstatus (t, &ws);
4606 sig = (ws.kind == TARGET_WAITKIND_STOPPED
4607 ? ws.value.sig : GDB_SIGNAL_0);
4609 if (displaced_step_fixup (t, sig) < 0)
4611 /* Add it back to the step-over queue. */
4612 t->control.trap_expected = 0;
4613 thread_step_over_chain_enqueue (t);
4616 regcache = get_thread_regcache (t);
4617 t->suspend.stop_pc = regcache_read_pc (regcache);
4621 fprintf_unfiltered (gdb_stdlog,
4622 "infrun: saved stop_pc=%s for %s "
4623 "(currently_stepping=%d)\n",
4624 paddress (target_gdbarch (),
4625 t->suspend.stop_pc),
4626 target_pid_to_str (t->ptid),
4627 currently_stepping (t));
4634 do_cleanups (old_chain);
4637 fprintf_unfiltered (gdb_stdlog, "infrun: stop_all_threads done\n");
4640 /* Handle a TARGET_WAITKIND_NO_RESUMED event. */
4643 handle_no_resumed (struct execution_control_state *ecs)
4645 struct inferior *inf;
4646 struct thread_info *thread;
4648 if (target_can_async_p ())
4655 if (ui->prompt_state == PROMPT_BLOCKED)
4663 /* There were no unwaited-for children left in the target, but,
4664 we're not synchronously waiting for events either. Just
4668 fprintf_unfiltered (gdb_stdlog,
4669 "infrun: TARGET_WAITKIND_NO_RESUMED "
4670 "(ignoring: bg)\n");
4671 prepare_to_wait (ecs);
4676 /* Otherwise, if we were running a synchronous execution command, we
4677 may need to cancel it and give the user back the terminal.
4679 In non-stop mode, the target can't tell whether we've already
4680 consumed previous stop events, so it can end up sending us a
4681 no-resumed event like so:
4683 #0 - thread 1 is left stopped
4685 #1 - thread 2 is resumed and hits breakpoint
4686 -> TARGET_WAITKIND_STOPPED
4688 #2 - thread 3 is resumed and exits
4689 this is the last resumed thread, so
4690 -> TARGET_WAITKIND_NO_RESUMED
4692 #3 - gdb processes stop for thread 2 and decides to re-resume
4695 #4 - gdb processes the TARGET_WAITKIND_NO_RESUMED event.
4696 thread 2 is now resumed, so the event should be ignored.
4698 IOW, if the stop for thread 2 doesn't end a foreground command,
4699 then we need to ignore the following TARGET_WAITKIND_NO_RESUMED
4700 event. But it could be that the event meant that thread 2 itself
4701 (or whatever other thread was the last resumed thread) exited.
4703 To address this we refresh the thread list and check whether we
4704 have resumed threads _now_. In the example above, this removes
4705 thread 3 from the thread list. If thread 2 was re-resumed, we
4706 ignore this event. If we find no thread resumed, then we cancel
4707 the synchronous command show "no unwaited-for " to the user. */
4708 update_thread_list ();
4710 ALL_NON_EXITED_THREADS (thread)
4712 if (thread->executing
4713 || thread->suspend.waitstatus_pending_p)
4715 /* There were no unwaited-for children left in the target at
4716 some point, but there are now. Just ignore. */
4718 fprintf_unfiltered (gdb_stdlog,
4719 "infrun: TARGET_WAITKIND_NO_RESUMED "
4720 "(ignoring: found resumed)\n");
4721 prepare_to_wait (ecs);
4726 /* Note however that we may find no resumed thread because the whole
4727 process exited meanwhile (thus updating the thread list results
4728 in an empty thread list). In this case we know we'll be getting
4729 a process exit event shortly. */
4735 thread = any_live_thread_of_inferior (inf);
4739 fprintf_unfiltered (gdb_stdlog,
4740 "infrun: TARGET_WAITKIND_NO_RESUMED "
4741 "(expect process exit)\n");
4742 prepare_to_wait (ecs);
4747 /* Go ahead and report the event. */
4751 /* Given an execution control state that has been freshly filled in by
4752 an event from the inferior, figure out what it means and take
4755 The alternatives are:
4757 1) stop_waiting and return; to really stop and return to the
4760 2) keep_going and return; to wait for the next event (set
4761 ecs->event_thread->stepping_over_breakpoint to 1 to single step
4765 handle_inferior_event_1 (struct execution_control_state *ecs)
4767 enum stop_kind stop_soon;
4769 if (ecs->ws.kind == TARGET_WAITKIND_IGNORE)
4771 /* We had an event in the inferior, but we are not interested in
4772 handling it at this level. The lower layers have already
4773 done what needs to be done, if anything.
4775 One of the possible circumstances for this is when the
4776 inferior produces output for the console. The inferior has
4777 not stopped, and we are ignoring the event. Another possible
4778 circumstance is any event which the lower level knows will be
4779 reported multiple times without an intervening resume. */
4781 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_IGNORE\n");
4782 prepare_to_wait (ecs);
4786 if (ecs->ws.kind == TARGET_WAITKIND_THREAD_EXITED)
4789 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_THREAD_EXITED\n");
4790 prepare_to_wait (ecs);
4794 if (ecs->ws.kind == TARGET_WAITKIND_NO_RESUMED
4795 && handle_no_resumed (ecs))
4798 /* Cache the last pid/waitstatus. */
4799 set_last_target_status (ecs->ptid, ecs->ws);
4801 /* Always clear state belonging to the previous time we stopped. */
4802 stop_stack_dummy = STOP_NONE;
4804 if (ecs->ws.kind == TARGET_WAITKIND_NO_RESUMED)
4806 /* No unwaited-for children left. IOW, all resumed children
4809 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_NO_RESUMED\n");
4811 stop_print_frame = 0;
4816 if (ecs->ws.kind != TARGET_WAITKIND_EXITED
4817 && ecs->ws.kind != TARGET_WAITKIND_SIGNALLED)
4819 ecs->event_thread = find_thread_ptid (ecs->ptid);
4820 /* If it's a new thread, add it to the thread database. */
4821 if (ecs->event_thread == NULL)
4822 ecs->event_thread = add_thread (ecs->ptid);
4824 /* Disable range stepping. If the next step request could use a
4825 range, this will be end up re-enabled then. */
4826 ecs->event_thread->control.may_range_step = 0;
4829 /* Dependent on valid ECS->EVENT_THREAD. */
4830 adjust_pc_after_break (ecs->event_thread, &ecs->ws);
4832 /* Dependent on the current PC value modified by adjust_pc_after_break. */
4833 reinit_frame_cache ();
4835 breakpoint_retire_moribund ();
4837 /* First, distinguish signals caused by the debugger from signals
4838 that have to do with the program's own actions. Note that
4839 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
4840 on the operating system version. Here we detect when a SIGILL or
4841 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
4842 something similar for SIGSEGV, since a SIGSEGV will be generated
4843 when we're trying to execute a breakpoint instruction on a
4844 non-executable stack. This happens for call dummy breakpoints
4845 for architectures like SPARC that place call dummies on the
4847 if (ecs->ws.kind == TARGET_WAITKIND_STOPPED
4848 && (ecs->ws.value.sig == GDB_SIGNAL_ILL
4849 || ecs->ws.value.sig == GDB_SIGNAL_SEGV
4850 || ecs->ws.value.sig == GDB_SIGNAL_EMT))
4852 struct regcache *regcache = get_thread_regcache (ecs->event_thread);
4854 if (breakpoint_inserted_here_p (regcache->aspace (),
4855 regcache_read_pc (regcache)))
4858 fprintf_unfiltered (gdb_stdlog,
4859 "infrun: Treating signal as SIGTRAP\n");
4860 ecs->ws.value.sig = GDB_SIGNAL_TRAP;
4864 /* Mark the non-executing threads accordingly. In all-stop, all
4865 threads of all processes are stopped when we get any event
4866 reported. In non-stop mode, only the event thread stops. */
4870 if (!target_is_non_stop_p ())
4871 mark_ptid = minus_one_ptid;
4872 else if (ecs->ws.kind == TARGET_WAITKIND_SIGNALLED
4873 || ecs->ws.kind == TARGET_WAITKIND_EXITED)
4875 /* If we're handling a process exit in non-stop mode, even
4876 though threads haven't been deleted yet, one would think
4877 that there is nothing to do, as threads of the dead process
4878 will be soon deleted, and threads of any other process were
4879 left running. However, on some targets, threads survive a
4880 process exit event. E.g., for the "checkpoint" command,
4881 when the current checkpoint/fork exits, linux-fork.c
4882 automatically switches to another fork from within
4883 target_mourn_inferior, by associating the same
4884 inferior/thread to another fork. We haven't mourned yet at
4885 this point, but we must mark any threads left in the
4886 process as not-executing so that finish_thread_state marks
4887 them stopped (in the user's perspective) if/when we present
4888 the stop to the user. */
4889 mark_ptid = ptid_t (ecs->ptid.pid ());
4892 mark_ptid = ecs->ptid;
4894 set_executing (mark_ptid, 0);
4896 /* Likewise the resumed flag. */
4897 set_resumed (mark_ptid, 0);
4900 switch (ecs->ws.kind)
4902 case TARGET_WAITKIND_LOADED:
4904 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_LOADED\n");
4905 context_switch (ecs);
4906 /* Ignore gracefully during startup of the inferior, as it might
4907 be the shell which has just loaded some objects, otherwise
4908 add the symbols for the newly loaded objects. Also ignore at
4909 the beginning of an attach or remote session; we will query
4910 the full list of libraries once the connection is
4913 stop_soon = get_inferior_stop_soon (ecs);
4914 if (stop_soon == NO_STOP_QUIETLY)
4916 struct regcache *regcache;
4918 regcache = get_thread_regcache (ecs->event_thread);
4920 handle_solib_event ();
4922 ecs->event_thread->control.stop_bpstat
4923 = bpstat_stop_status (regcache->aspace (),
4924 ecs->event_thread->suspend.stop_pc,
4925 ecs->event_thread, &ecs->ws);
4927 if (handle_stop_requested (ecs))
4930 if (bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
4932 /* A catchpoint triggered. */
4933 process_event_stop_test (ecs);
4937 /* If requested, stop when the dynamic linker notifies
4938 gdb of events. This allows the user to get control
4939 and place breakpoints in initializer routines for
4940 dynamically loaded objects (among other things). */
4941 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
4942 if (stop_on_solib_events)
4944 /* Make sure we print "Stopped due to solib-event" in
4946 stop_print_frame = 1;
4953 /* If we are skipping through a shell, or through shared library
4954 loading that we aren't interested in, resume the program. If
4955 we're running the program normally, also resume. */
4956 if (stop_soon == STOP_QUIETLY || stop_soon == NO_STOP_QUIETLY)
4958 /* Loading of shared libraries might have changed breakpoint
4959 addresses. Make sure new breakpoints are inserted. */
4960 if (stop_soon == NO_STOP_QUIETLY)
4961 insert_breakpoints ();
4962 resume (GDB_SIGNAL_0);
4963 prepare_to_wait (ecs);
4967 /* But stop if we're attaching or setting up a remote
4969 if (stop_soon == STOP_QUIETLY_NO_SIGSTOP
4970 || stop_soon == STOP_QUIETLY_REMOTE)
4973 fprintf_unfiltered (gdb_stdlog, "infrun: quietly stopped\n");
4978 internal_error (__FILE__, __LINE__,
4979 _("unhandled stop_soon: %d"), (int) stop_soon);
4981 case TARGET_WAITKIND_SPURIOUS:
4983 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_SPURIOUS\n");
4984 if (handle_stop_requested (ecs))
4986 context_switch (ecs);
4987 resume (GDB_SIGNAL_0);
4988 prepare_to_wait (ecs);
4991 case TARGET_WAITKIND_THREAD_CREATED:
4993 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_THREAD_CREATED\n");
4994 if (handle_stop_requested (ecs))
4996 context_switch (ecs);
4997 if (!switch_back_to_stepped_thread (ecs))
5001 case TARGET_WAITKIND_EXITED:
5002 case TARGET_WAITKIND_SIGNALLED:
5005 if (ecs->ws.kind == TARGET_WAITKIND_EXITED)
5006 fprintf_unfiltered (gdb_stdlog,
5007 "infrun: TARGET_WAITKIND_EXITED\n");
5009 fprintf_unfiltered (gdb_stdlog,
5010 "infrun: TARGET_WAITKIND_SIGNALLED\n");
5013 inferior_ptid = ecs->ptid;
5014 set_current_inferior (find_inferior_ptid (ecs->ptid));
5015 set_current_program_space (current_inferior ()->pspace);
5016 handle_vfork_child_exec_or_exit (0);
5017 target_terminal::ours (); /* Must do this before mourn anyway. */
5019 /* Clearing any previous state of convenience variables. */
5020 clear_exit_convenience_vars ();
5022 if (ecs->ws.kind == TARGET_WAITKIND_EXITED)
5024 /* Record the exit code in the convenience variable $_exitcode, so
5025 that the user can inspect this again later. */
5026 set_internalvar_integer (lookup_internalvar ("_exitcode"),
5027 (LONGEST) ecs->ws.value.integer);
5029 /* Also record this in the inferior itself. */
5030 current_inferior ()->has_exit_code = 1;
5031 current_inferior ()->exit_code = (LONGEST) ecs->ws.value.integer;
5033 /* Support the --return-child-result option. */
5034 return_child_result_value = ecs->ws.value.integer;
5036 gdb::observers::exited.notify (ecs->ws.value.integer);
5040 struct gdbarch *gdbarch = current_inferior ()->gdbarch;
5042 if (gdbarch_gdb_signal_to_target_p (gdbarch))
5044 /* Set the value of the internal variable $_exitsignal,
5045 which holds the signal uncaught by the inferior. */
5046 set_internalvar_integer (lookup_internalvar ("_exitsignal"),
5047 gdbarch_gdb_signal_to_target (gdbarch,
5048 ecs->ws.value.sig));
5052 /* We don't have access to the target's method used for
5053 converting between signal numbers (GDB's internal
5054 representation <-> target's representation).
5055 Therefore, we cannot do a good job at displaying this
5056 information to the user. It's better to just warn
5057 her about it (if infrun debugging is enabled), and
5060 fprintf_filtered (gdb_stdlog, _("\
5061 Cannot fill $_exitsignal with the correct signal number.\n"));
5064 gdb::observers::signal_exited.notify (ecs->ws.value.sig);
5067 gdb_flush (gdb_stdout);
5068 target_mourn_inferior (inferior_ptid);
5069 stop_print_frame = 0;
5073 /* The following are the only cases in which we keep going;
5074 the above cases end in a continue or goto. */
5075 case TARGET_WAITKIND_FORKED:
5076 case TARGET_WAITKIND_VFORKED:
5079 if (ecs->ws.kind == TARGET_WAITKIND_FORKED)
5080 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_FORKED\n");
5082 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_VFORKED\n");
5085 /* Check whether the inferior is displaced stepping. */
5087 struct regcache *regcache = get_thread_regcache (ecs->event_thread);
5088 struct gdbarch *gdbarch = regcache->arch ();
5090 /* If checking displaced stepping is supported, and thread
5091 ecs->ptid is displaced stepping. */
5092 if (displaced_step_in_progress_thread (ecs->event_thread))
5094 struct inferior *parent_inf
5095 = find_inferior_ptid (ecs->ptid);
5096 struct regcache *child_regcache;
5097 CORE_ADDR parent_pc;
5099 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
5100 indicating that the displaced stepping of syscall instruction
5101 has been done. Perform cleanup for parent process here. Note
5102 that this operation also cleans up the child process for vfork,
5103 because their pages are shared. */
5104 displaced_step_fixup (ecs->event_thread, GDB_SIGNAL_TRAP);
5105 /* Start a new step-over in another thread if there's one
5109 if (ecs->ws.kind == TARGET_WAITKIND_FORKED)
5111 struct displaced_step_inferior_state *displaced
5112 = get_displaced_stepping_state (parent_inf);
5114 /* Restore scratch pad for child process. */
5115 displaced_step_restore (displaced, ecs->ws.value.related_pid);
5118 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
5119 the child's PC is also within the scratchpad. Set the child's PC
5120 to the parent's PC value, which has already been fixed up.
5121 FIXME: we use the parent's aspace here, although we're touching
5122 the child, because the child hasn't been added to the inferior
5123 list yet at this point. */
5126 = get_thread_arch_aspace_regcache (ecs->ws.value.related_pid,
5128 parent_inf->aspace);
5129 /* Read PC value of parent process. */
5130 parent_pc = regcache_read_pc (regcache);
5132 if (debug_displaced)
5133 fprintf_unfiltered (gdb_stdlog,
5134 "displaced: write child pc from %s to %s\n",
5136 regcache_read_pc (child_regcache)),
5137 paddress (gdbarch, parent_pc));
5139 regcache_write_pc (child_regcache, parent_pc);
5143 context_switch (ecs);
5145 /* Immediately detach breakpoints from the child before there's
5146 any chance of letting the user delete breakpoints from the
5147 breakpoint lists. If we don't do this early, it's easy to
5148 leave left over traps in the child, vis: "break foo; catch
5149 fork; c; <fork>; del; c; <child calls foo>". We only follow
5150 the fork on the last `continue', and by that time the
5151 breakpoint at "foo" is long gone from the breakpoint table.
5152 If we vforked, then we don't need to unpatch here, since both
5153 parent and child are sharing the same memory pages; we'll
5154 need to unpatch at follow/detach time instead to be certain
5155 that new breakpoints added between catchpoint hit time and
5156 vfork follow are detached. */
5157 if (ecs->ws.kind != TARGET_WAITKIND_VFORKED)
5159 /* This won't actually modify the breakpoint list, but will
5160 physically remove the breakpoints from the child. */
5161 detach_breakpoints (ecs->ws.value.related_pid);
5164 delete_just_stopped_threads_single_step_breakpoints ();
5166 /* In case the event is caught by a catchpoint, remember that
5167 the event is to be followed at the next resume of the thread,
5168 and not immediately. */
5169 ecs->event_thread->pending_follow = ecs->ws;
5171 ecs->event_thread->suspend.stop_pc
5172 = regcache_read_pc (get_thread_regcache (ecs->event_thread));
5174 ecs->event_thread->control.stop_bpstat
5175 = bpstat_stop_status (get_current_regcache ()->aspace (),
5176 ecs->event_thread->suspend.stop_pc,
5177 ecs->event_thread, &ecs->ws);
5179 if (handle_stop_requested (ecs))
5182 /* If no catchpoint triggered for this, then keep going. Note
5183 that we're interested in knowing the bpstat actually causes a
5184 stop, not just if it may explain the signal. Software
5185 watchpoints, for example, always appear in the bpstat. */
5186 if (!bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
5190 = (follow_fork_mode_string == follow_fork_mode_child);
5192 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5194 should_resume = follow_fork ();
5196 thread_info *parent = ecs->event_thread;
5197 thread_info *child = find_thread_ptid (ecs->ws.value.related_pid);
5199 /* At this point, the parent is marked running, and the
5200 child is marked stopped. */
5202 /* If not resuming the parent, mark it stopped. */
5203 if (follow_child && !detach_fork && !non_stop && !sched_multi)
5204 parent->set_running (false);
5206 /* If resuming the child, mark it running. */
5207 if (follow_child || (!detach_fork && (non_stop || sched_multi)))
5208 child->set_running (true);
5210 /* In non-stop mode, also resume the other branch. */
5211 if (!detach_fork && (non_stop
5212 || (sched_multi && target_is_non_stop_p ())))
5215 switch_to_thread (parent);
5217 switch_to_thread (child);
5219 ecs->event_thread = inferior_thread ();
5220 ecs->ptid = inferior_ptid;
5225 switch_to_thread (child);
5227 switch_to_thread (parent);
5229 ecs->event_thread = inferior_thread ();
5230 ecs->ptid = inferior_ptid;
5238 process_event_stop_test (ecs);
5241 case TARGET_WAITKIND_VFORK_DONE:
5242 /* Done with the shared memory region. Re-insert breakpoints in
5243 the parent, and keep going. */
5246 fprintf_unfiltered (gdb_stdlog,
5247 "infrun: TARGET_WAITKIND_VFORK_DONE\n");
5249 context_switch (ecs);
5251 current_inferior ()->waiting_for_vfork_done = 0;
5252 current_inferior ()->pspace->breakpoints_not_allowed = 0;
5254 if (handle_stop_requested (ecs))
5257 /* This also takes care of reinserting breakpoints in the
5258 previously locked inferior. */
5262 case TARGET_WAITKIND_EXECD:
5264 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_EXECD\n");
5266 /* Note we can't read registers yet (the stop_pc), because we
5267 don't yet know the inferior's post-exec architecture.
5268 'stop_pc' is explicitly read below instead. */
5269 switch_to_thread_no_regs (ecs->event_thread);
5271 /* Do whatever is necessary to the parent branch of the vfork. */
5272 handle_vfork_child_exec_or_exit (1);
5274 /* This causes the eventpoints and symbol table to be reset.
5275 Must do this now, before trying to determine whether to
5277 follow_exec (inferior_ptid, ecs->ws.value.execd_pathname);
5279 /* In follow_exec we may have deleted the original thread and
5280 created a new one. Make sure that the event thread is the
5281 execd thread for that case (this is a nop otherwise). */
5282 ecs->event_thread = inferior_thread ();
5284 ecs->event_thread->suspend.stop_pc
5285 = regcache_read_pc (get_thread_regcache (ecs->event_thread));
5287 ecs->event_thread->control.stop_bpstat
5288 = bpstat_stop_status (get_current_regcache ()->aspace (),
5289 ecs->event_thread->suspend.stop_pc,
5290 ecs->event_thread, &ecs->ws);
5292 /* Note that this may be referenced from inside
5293 bpstat_stop_status above, through inferior_has_execd. */
5294 xfree (ecs->ws.value.execd_pathname);
5295 ecs->ws.value.execd_pathname = NULL;
5297 if (handle_stop_requested (ecs))
5300 /* If no catchpoint triggered for this, then keep going. */
5301 if (!bpstat_causes_stop (ecs->event_thread->control.stop_bpstat))
5303 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5307 process_event_stop_test (ecs);
5310 /* Be careful not to try to gather much state about a thread
5311 that's in a syscall. It's frequently a losing proposition. */
5312 case TARGET_WAITKIND_SYSCALL_ENTRY:
5314 fprintf_unfiltered (gdb_stdlog,
5315 "infrun: TARGET_WAITKIND_SYSCALL_ENTRY\n");
5316 /* Getting the current syscall number. */
5317 if (handle_syscall_event (ecs) == 0)
5318 process_event_stop_test (ecs);
5321 /* Before examining the threads further, step this thread to
5322 get it entirely out of the syscall. (We get notice of the
5323 event when the thread is just on the verge of exiting a
5324 syscall. Stepping one instruction seems to get it back
5326 case TARGET_WAITKIND_SYSCALL_RETURN:
5328 fprintf_unfiltered (gdb_stdlog,
5329 "infrun: TARGET_WAITKIND_SYSCALL_RETURN\n");
5330 if (handle_syscall_event (ecs) == 0)
5331 process_event_stop_test (ecs);
5334 case TARGET_WAITKIND_STOPPED:
5336 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_STOPPED\n");
5337 handle_signal_stop (ecs);
5340 case TARGET_WAITKIND_NO_HISTORY:
5342 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_NO_HISTORY\n");
5343 /* Reverse execution: target ran out of history info. */
5345 /* Switch to the stopped thread. */
5346 context_switch (ecs);
5348 fprintf_unfiltered (gdb_stdlog, "infrun: stopped\n");
5350 delete_just_stopped_threads_single_step_breakpoints ();
5351 ecs->event_thread->suspend.stop_pc
5352 = regcache_read_pc (get_thread_regcache (inferior_thread ()));
5354 if (handle_stop_requested (ecs))
5357 gdb::observers::no_history.notify ();
5363 /* A wrapper around handle_inferior_event_1, which also makes sure
5364 that all temporary struct value objects that were created during
5365 the handling of the event get deleted at the end. */
5368 handle_inferior_event (struct execution_control_state *ecs)
5370 struct value *mark = value_mark ();
5372 handle_inferior_event_1 (ecs);
5373 /* Purge all temporary values created during the event handling,
5374 as it could be a long time before we return to the command level
5375 where such values would otherwise be purged. */
5376 value_free_to_mark (mark);
5379 /* Restart threads back to what they were trying to do back when we
5380 paused them for an in-line step-over. The EVENT_THREAD thread is
5384 restart_threads (struct thread_info *event_thread)
5386 struct thread_info *tp;
5388 /* In case the instruction just stepped spawned a new thread. */
5389 update_thread_list ();
5391 ALL_NON_EXITED_THREADS (tp)
5393 if (tp == event_thread)
5396 fprintf_unfiltered (gdb_stdlog,
5397 "infrun: restart threads: "
5398 "[%s] is event thread\n",
5399 target_pid_to_str (tp->ptid));
5403 if (!(tp->state == THREAD_RUNNING || tp->control.in_infcall))
5406 fprintf_unfiltered (gdb_stdlog,
5407 "infrun: restart threads: "
5408 "[%s] not meant to be running\n",
5409 target_pid_to_str (tp->ptid));
5416 fprintf_unfiltered (gdb_stdlog,
5417 "infrun: restart threads: [%s] resumed\n",
5418 target_pid_to_str (tp->ptid));
5419 gdb_assert (tp->executing || tp->suspend.waitstatus_pending_p);
5423 if (thread_is_in_step_over_chain (tp))
5426 fprintf_unfiltered (gdb_stdlog,
5427 "infrun: restart threads: "
5428 "[%s] needs step-over\n",
5429 target_pid_to_str (tp->ptid));
5430 gdb_assert (!tp->resumed);
5435 if (tp->suspend.waitstatus_pending_p)
5438 fprintf_unfiltered (gdb_stdlog,
5439 "infrun: restart threads: "
5440 "[%s] has pending status\n",
5441 target_pid_to_str (tp->ptid));
5446 gdb_assert (!tp->stop_requested);
5448 /* If some thread needs to start a step-over at this point, it
5449 should still be in the step-over queue, and thus skipped
5451 if (thread_still_needs_step_over (tp))
5453 internal_error (__FILE__, __LINE__,
5454 "thread [%s] needs a step-over, but not in "
5455 "step-over queue\n",
5456 target_pid_to_str (tp->ptid));
5459 if (currently_stepping (tp))
5462 fprintf_unfiltered (gdb_stdlog,
5463 "infrun: restart threads: [%s] was stepping\n",
5464 target_pid_to_str (tp->ptid));
5465 keep_going_stepped_thread (tp);
5469 struct execution_control_state ecss;
5470 struct execution_control_state *ecs = &ecss;
5473 fprintf_unfiltered (gdb_stdlog,
5474 "infrun: restart threads: [%s] continuing\n",
5475 target_pid_to_str (tp->ptid));
5476 reset_ecs (ecs, tp);
5477 switch_to_thread (tp);
5478 keep_going_pass_signal (ecs);
5483 /* Callback for iterate_over_threads. Find a resumed thread that has
5484 a pending waitstatus. */
5487 resumed_thread_with_pending_status (struct thread_info *tp,
5491 && tp->suspend.waitstatus_pending_p);
5494 /* Called when we get an event that may finish an in-line or
5495 out-of-line (displaced stepping) step-over started previously.
5496 Return true if the event is processed and we should go back to the
5497 event loop; false if the caller should continue processing the
5501 finish_step_over (struct execution_control_state *ecs)
5503 int had_step_over_info;
5505 displaced_step_fixup (ecs->event_thread,
5506 ecs->event_thread->suspend.stop_signal);
5508 had_step_over_info = step_over_info_valid_p ();
5510 if (had_step_over_info)
5512 /* If we're stepping over a breakpoint with all threads locked,
5513 then only the thread that was stepped should be reporting
5515 gdb_assert (ecs->event_thread->control.trap_expected);
5517 clear_step_over_info ();
5520 if (!target_is_non_stop_p ())
5523 /* Start a new step-over in another thread if there's one that
5527 /* If we were stepping over a breakpoint before, and haven't started
5528 a new in-line step-over sequence, then restart all other threads
5529 (except the event thread). We can't do this in all-stop, as then
5530 e.g., we wouldn't be able to issue any other remote packet until
5531 these other threads stop. */
5532 if (had_step_over_info && !step_over_info_valid_p ())
5534 struct thread_info *pending;
5536 /* If we only have threads with pending statuses, the restart
5537 below won't restart any thread and so nothing re-inserts the
5538 breakpoint we just stepped over. But we need it inserted
5539 when we later process the pending events, otherwise if
5540 another thread has a pending event for this breakpoint too,
5541 we'd discard its event (because the breakpoint that
5542 originally caused the event was no longer inserted). */
5543 context_switch (ecs);
5544 insert_breakpoints ();
5546 restart_threads (ecs->event_thread);
5548 /* If we have events pending, go through handle_inferior_event
5549 again, picking up a pending event at random. This avoids
5550 thread starvation. */
5552 /* But not if we just stepped over a watchpoint in order to let
5553 the instruction execute so we can evaluate its expression.
5554 The set of watchpoints that triggered is recorded in the
5555 breakpoint objects themselves (see bp->watchpoint_triggered).
5556 If we processed another event first, that other event could
5557 clobber this info. */
5558 if (ecs->event_thread->stepping_over_watchpoint)
5561 pending = iterate_over_threads (resumed_thread_with_pending_status,
5563 if (pending != NULL)
5565 struct thread_info *tp = ecs->event_thread;
5566 struct regcache *regcache;
5570 fprintf_unfiltered (gdb_stdlog,
5571 "infrun: found resumed threads with "
5572 "pending events, saving status\n");
5575 gdb_assert (pending != tp);
5577 /* Record the event thread's event for later. */
5578 save_waitstatus (tp, &ecs->ws);
5579 /* This was cleared early, by handle_inferior_event. Set it
5580 so this pending event is considered by
5584 gdb_assert (!tp->executing);
5586 regcache = get_thread_regcache (tp);
5587 tp->suspend.stop_pc = regcache_read_pc (regcache);
5591 fprintf_unfiltered (gdb_stdlog,
5592 "infrun: saved stop_pc=%s for %s "
5593 "(currently_stepping=%d)\n",
5594 paddress (target_gdbarch (),
5595 tp->suspend.stop_pc),
5596 target_pid_to_str (tp->ptid),
5597 currently_stepping (tp));
5600 /* This in-line step-over finished; clear this so we won't
5601 start a new one. This is what handle_signal_stop would
5602 do, if we returned false. */
5603 tp->stepping_over_breakpoint = 0;
5605 /* Wake up the event loop again. */
5606 mark_async_event_handler (infrun_async_inferior_event_token);
5608 prepare_to_wait (ecs);
5616 /* Come here when the program has stopped with a signal. */
5619 handle_signal_stop (struct execution_control_state *ecs)
5621 struct frame_info *frame;
5622 struct gdbarch *gdbarch;
5623 int stopped_by_watchpoint;
5624 enum stop_kind stop_soon;
5627 gdb_assert (ecs->ws.kind == TARGET_WAITKIND_STOPPED);
5629 ecs->event_thread->suspend.stop_signal = ecs->ws.value.sig;
5631 /* Do we need to clean up the state of a thread that has
5632 completed a displaced single-step? (Doing so usually affects
5633 the PC, so do it here, before we set stop_pc.) */
5634 if (finish_step_over (ecs))
5637 /* If we either finished a single-step or hit a breakpoint, but
5638 the user wanted this thread to be stopped, pretend we got a
5639 SIG0 (generic unsignaled stop). */
5640 if (ecs->event_thread->stop_requested
5641 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
5642 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5644 ecs->event_thread->suspend.stop_pc
5645 = regcache_read_pc (get_thread_regcache (ecs->event_thread));
5649 struct regcache *regcache = get_thread_regcache (ecs->event_thread);
5650 struct gdbarch *reg_gdbarch = regcache->arch ();
5651 scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid);
5653 inferior_ptid = ecs->ptid;
5655 fprintf_unfiltered (gdb_stdlog, "infrun: stop_pc = %s\n",
5656 paddress (reg_gdbarch,
5657 ecs->event_thread->suspend.stop_pc));
5658 if (target_stopped_by_watchpoint ())
5662 fprintf_unfiltered (gdb_stdlog, "infrun: stopped by watchpoint\n");
5664 if (target_stopped_data_address (current_top_target (), &addr))
5665 fprintf_unfiltered (gdb_stdlog,
5666 "infrun: stopped data address = %s\n",
5667 paddress (reg_gdbarch, addr));
5669 fprintf_unfiltered (gdb_stdlog,
5670 "infrun: (no data address available)\n");
5674 /* This is originated from start_remote(), start_inferior() and
5675 shared libraries hook functions. */
5676 stop_soon = get_inferior_stop_soon (ecs);
5677 if (stop_soon == STOP_QUIETLY || stop_soon == STOP_QUIETLY_REMOTE)
5679 context_switch (ecs);
5681 fprintf_unfiltered (gdb_stdlog, "infrun: quietly stopped\n");
5682 stop_print_frame = 1;
5687 /* This originates from attach_command(). We need to overwrite
5688 the stop_signal here, because some kernels don't ignore a
5689 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
5690 See more comments in inferior.h. On the other hand, if we
5691 get a non-SIGSTOP, report it to the user - assume the backend
5692 will handle the SIGSTOP if it should show up later.
5694 Also consider that the attach is complete when we see a
5695 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
5696 target extended-remote report it instead of a SIGSTOP
5697 (e.g. gdbserver). We already rely on SIGTRAP being our
5698 signal, so this is no exception.
5700 Also consider that the attach is complete when we see a
5701 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
5702 the target to stop all threads of the inferior, in case the
5703 low level attach operation doesn't stop them implicitly. If
5704 they weren't stopped implicitly, then the stub will report a
5705 GDB_SIGNAL_0, meaning: stopped for no particular reason
5706 other than GDB's request. */
5707 if (stop_soon == STOP_QUIETLY_NO_SIGSTOP
5708 && (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_STOP
5709 || ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5710 || ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_0))
5712 stop_print_frame = 1;
5714 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5718 /* See if something interesting happened to the non-current thread. If
5719 so, then switch to that thread. */
5720 if (ecs->ptid != inferior_ptid)
5723 fprintf_unfiltered (gdb_stdlog, "infrun: context switch\n");
5725 context_switch (ecs);
5727 if (deprecated_context_hook)
5728 deprecated_context_hook (ecs->event_thread->global_num);
5731 /* At this point, get hold of the now-current thread's frame. */
5732 frame = get_current_frame ();
5733 gdbarch = get_frame_arch (frame);
5735 /* Pull the single step breakpoints out of the target. */
5736 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
5738 struct regcache *regcache;
5741 regcache = get_thread_regcache (ecs->event_thread);
5742 const address_space *aspace = regcache->aspace ();
5744 pc = regcache_read_pc (regcache);
5746 /* However, before doing so, if this single-step breakpoint was
5747 actually for another thread, set this thread up for moving
5749 if (!thread_has_single_step_breakpoint_here (ecs->event_thread,
5752 if (single_step_breakpoint_inserted_here_p (aspace, pc))
5756 fprintf_unfiltered (gdb_stdlog,
5757 "infrun: [%s] hit another thread's "
5758 "single-step breakpoint\n",
5759 target_pid_to_str (ecs->ptid));
5761 ecs->hit_singlestep_breakpoint = 1;
5768 fprintf_unfiltered (gdb_stdlog,
5769 "infrun: [%s] hit its "
5770 "single-step breakpoint\n",
5771 target_pid_to_str (ecs->ptid));
5775 delete_just_stopped_threads_single_step_breakpoints ();
5777 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5778 && ecs->event_thread->control.trap_expected
5779 && ecs->event_thread->stepping_over_watchpoint)
5780 stopped_by_watchpoint = 0;
5782 stopped_by_watchpoint = watchpoints_triggered (&ecs->ws);
5784 /* If necessary, step over this watchpoint. We'll be back to display
5786 if (stopped_by_watchpoint
5787 && (target_have_steppable_watchpoint
5788 || gdbarch_have_nonsteppable_watchpoint (gdbarch)))
5790 /* At this point, we are stopped at an instruction which has
5791 attempted to write to a piece of memory under control of
5792 a watchpoint. The instruction hasn't actually executed
5793 yet. If we were to evaluate the watchpoint expression
5794 now, we would get the old value, and therefore no change
5795 would seem to have occurred.
5797 In order to make watchpoints work `right', we really need
5798 to complete the memory write, and then evaluate the
5799 watchpoint expression. We do this by single-stepping the
5802 It may not be necessary to disable the watchpoint to step over
5803 it. For example, the PA can (with some kernel cooperation)
5804 single step over a watchpoint without disabling the watchpoint.
5806 It is far more common to need to disable a watchpoint to step
5807 the inferior over it. If we have non-steppable watchpoints,
5808 we must disable the current watchpoint; it's simplest to
5809 disable all watchpoints.
5811 Any breakpoint at PC must also be stepped over -- if there's
5812 one, it will have already triggered before the watchpoint
5813 triggered, and we either already reported it to the user, or
5814 it didn't cause a stop and we called keep_going. In either
5815 case, if there was a breakpoint at PC, we must be trying to
5817 ecs->event_thread->stepping_over_watchpoint = 1;
5822 ecs->event_thread->stepping_over_breakpoint = 0;
5823 ecs->event_thread->stepping_over_watchpoint = 0;
5824 bpstat_clear (&ecs->event_thread->control.stop_bpstat);
5825 ecs->event_thread->control.stop_step = 0;
5826 stop_print_frame = 1;
5827 stopped_by_random_signal = 0;
5828 bpstat stop_chain = NULL;
5830 /* Hide inlined functions starting here, unless we just performed stepi or
5831 nexti. After stepi and nexti, always show the innermost frame (not any
5832 inline function call sites). */
5833 if (ecs->event_thread->control.step_range_end != 1)
5835 const address_space *aspace
5836 = get_thread_regcache (ecs->event_thread)->aspace ();
5838 /* skip_inline_frames is expensive, so we avoid it if we can
5839 determine that the address is one where functions cannot have
5840 been inlined. This improves performance with inferiors that
5841 load a lot of shared libraries, because the solib event
5842 breakpoint is defined as the address of a function (i.e. not
5843 inline). Note that we have to check the previous PC as well
5844 as the current one to catch cases when we have just
5845 single-stepped off a breakpoint prior to reinstating it.
5846 Note that we're assuming that the code we single-step to is
5847 not inline, but that's not definitive: there's nothing
5848 preventing the event breakpoint function from containing
5849 inlined code, and the single-step ending up there. If the
5850 user had set a breakpoint on that inlined code, the missing
5851 skip_inline_frames call would break things. Fortunately
5852 that's an extremely unlikely scenario. */
5853 if (!pc_at_non_inline_function (aspace,
5854 ecs->event_thread->suspend.stop_pc,
5856 && !(ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5857 && ecs->event_thread->control.trap_expected
5858 && pc_at_non_inline_function (aspace,
5859 ecs->event_thread->prev_pc,
5862 stop_chain = build_bpstat_chain (aspace,
5863 ecs->event_thread->suspend.stop_pc,
5865 skip_inline_frames (ecs->event_thread, stop_chain);
5867 /* Re-fetch current thread's frame in case that invalidated
5869 frame = get_current_frame ();
5870 gdbarch = get_frame_arch (frame);
5874 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5875 && ecs->event_thread->control.trap_expected
5876 && gdbarch_single_step_through_delay_p (gdbarch)
5877 && currently_stepping (ecs->event_thread))
5879 /* We're trying to step off a breakpoint. Turns out that we're
5880 also on an instruction that needs to be stepped multiple
5881 times before it's been fully executing. E.g., architectures
5882 with a delay slot. It needs to be stepped twice, once for
5883 the instruction and once for the delay slot. */
5884 int step_through_delay
5885 = gdbarch_single_step_through_delay (gdbarch, frame);
5887 if (debug_infrun && step_through_delay)
5888 fprintf_unfiltered (gdb_stdlog, "infrun: step through delay\n");
5889 if (ecs->event_thread->control.step_range_end == 0
5890 && step_through_delay)
5892 /* The user issued a continue when stopped at a breakpoint.
5893 Set up for another trap and get out of here. */
5894 ecs->event_thread->stepping_over_breakpoint = 1;
5898 else if (step_through_delay)
5900 /* The user issued a step when stopped at a breakpoint.
5901 Maybe we should stop, maybe we should not - the delay
5902 slot *might* correspond to a line of source. In any
5903 case, don't decide that here, just set
5904 ecs->stepping_over_breakpoint, making sure we
5905 single-step again before breakpoints are re-inserted. */
5906 ecs->event_thread->stepping_over_breakpoint = 1;
5910 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
5911 handles this event. */
5912 ecs->event_thread->control.stop_bpstat
5913 = bpstat_stop_status (get_current_regcache ()->aspace (),
5914 ecs->event_thread->suspend.stop_pc,
5915 ecs->event_thread, &ecs->ws, stop_chain);
5917 /* Following in case break condition called a
5919 stop_print_frame = 1;
5921 /* This is where we handle "moribund" watchpoints. Unlike
5922 software breakpoints traps, hardware watchpoint traps are
5923 always distinguishable from random traps. If no high-level
5924 watchpoint is associated with the reported stop data address
5925 anymore, then the bpstat does not explain the signal ---
5926 simply make sure to ignore it if `stopped_by_watchpoint' is
5930 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5931 && !bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
5933 && stopped_by_watchpoint)
5934 fprintf_unfiltered (gdb_stdlog,
5935 "infrun: no user watchpoint explains "
5936 "watchpoint SIGTRAP, ignoring\n");
5938 /* NOTE: cagney/2003-03-29: These checks for a random signal
5939 at one stage in the past included checks for an inferior
5940 function call's call dummy's return breakpoint. The original
5941 comment, that went with the test, read:
5943 ``End of a stack dummy. Some systems (e.g. Sony news) give
5944 another signal besides SIGTRAP, so check here as well as
5947 If someone ever tries to get call dummys on a
5948 non-executable stack to work (where the target would stop
5949 with something like a SIGSEGV), then those tests might need
5950 to be re-instated. Given, however, that the tests were only
5951 enabled when momentary breakpoints were not being used, I
5952 suspect that it won't be the case.
5954 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
5955 be necessary for call dummies on a non-executable stack on
5958 /* See if the breakpoints module can explain the signal. */
5960 = !bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
5961 ecs->event_thread->suspend.stop_signal);
5963 /* Maybe this was a trap for a software breakpoint that has since
5965 if (random_signal && target_stopped_by_sw_breakpoint ())
5967 if (program_breakpoint_here_p (gdbarch,
5968 ecs->event_thread->suspend.stop_pc))
5970 struct regcache *regcache;
5973 /* Re-adjust PC to what the program would see if GDB was not
5975 regcache = get_thread_regcache (ecs->event_thread);
5976 decr_pc = gdbarch_decr_pc_after_break (gdbarch);
5979 gdb::optional<scoped_restore_tmpl<int>>
5980 restore_operation_disable;
5982 if (record_full_is_used ())
5983 restore_operation_disable.emplace
5984 (record_full_gdb_operation_disable_set ());
5986 regcache_write_pc (regcache,
5987 ecs->event_thread->suspend.stop_pc + decr_pc);
5992 /* A delayed software breakpoint event. Ignore the trap. */
5994 fprintf_unfiltered (gdb_stdlog,
5995 "infrun: delayed software breakpoint "
5996 "trap, ignoring\n");
6001 /* Maybe this was a trap for a hardware breakpoint/watchpoint that
6002 has since been removed. */
6003 if (random_signal && target_stopped_by_hw_breakpoint ())
6005 /* A delayed hardware breakpoint event. Ignore the trap. */
6007 fprintf_unfiltered (gdb_stdlog,
6008 "infrun: delayed hardware breakpoint/watchpoint "
6009 "trap, ignoring\n");
6013 /* If not, perhaps stepping/nexting can. */
6015 random_signal = !(ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
6016 && currently_stepping (ecs->event_thread));
6018 /* Perhaps the thread hit a single-step breakpoint of _another_
6019 thread. Single-step breakpoints are transparent to the
6020 breakpoints module. */
6022 random_signal = !ecs->hit_singlestep_breakpoint;
6024 /* No? Perhaps we got a moribund watchpoint. */
6026 random_signal = !stopped_by_watchpoint;
6028 /* Always stop if the user explicitly requested this thread to
6030 if (ecs->event_thread->stop_requested)
6034 fprintf_unfiltered (gdb_stdlog, "infrun: user-requested stop\n");
6037 /* For the program's own signals, act according to
6038 the signal handling tables. */
6042 /* Signal not for debugging purposes. */
6043 struct inferior *inf = find_inferior_ptid (ecs->ptid);
6044 enum gdb_signal stop_signal = ecs->event_thread->suspend.stop_signal;
6047 fprintf_unfiltered (gdb_stdlog, "infrun: random signal (%s)\n",
6048 gdb_signal_to_symbol_string (stop_signal));
6050 stopped_by_random_signal = 1;
6052 /* Always stop on signals if we're either just gaining control
6053 of the program, or the user explicitly requested this thread
6054 to remain stopped. */
6055 if (stop_soon != NO_STOP_QUIETLY
6056 || ecs->event_thread->stop_requested
6058 && signal_stop_state (ecs->event_thread->suspend.stop_signal)))
6064 /* Notify observers the signal has "handle print" set. Note we
6065 returned early above if stopping; normal_stop handles the
6066 printing in that case. */
6067 if (signal_print[ecs->event_thread->suspend.stop_signal])
6069 /* The signal table tells us to print about this signal. */
6070 target_terminal::ours_for_output ();
6071 gdb::observers::signal_received.notify (ecs->event_thread->suspend.stop_signal);
6072 target_terminal::inferior ();
6075 /* Clear the signal if it should not be passed. */
6076 if (signal_program[ecs->event_thread->suspend.stop_signal] == 0)
6077 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
6079 if (ecs->event_thread->prev_pc == ecs->event_thread->suspend.stop_pc
6080 && ecs->event_thread->control.trap_expected
6081 && ecs->event_thread->control.step_resume_breakpoint == NULL)
6083 /* We were just starting a new sequence, attempting to
6084 single-step off of a breakpoint and expecting a SIGTRAP.
6085 Instead this signal arrives. This signal will take us out
6086 of the stepping range so GDB needs to remember to, when
6087 the signal handler returns, resume stepping off that
6089 /* To simplify things, "continue" is forced to use the same
6090 code paths as single-step - set a breakpoint at the
6091 signal return address and then, once hit, step off that
6094 fprintf_unfiltered (gdb_stdlog,
6095 "infrun: signal arrived while stepping over "
6098 insert_hp_step_resume_breakpoint_at_frame (frame);
6099 ecs->event_thread->step_after_step_resume_breakpoint = 1;
6100 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6101 ecs->event_thread->control.trap_expected = 0;
6103 /* If we were nexting/stepping some other thread, switch to
6104 it, so that we don't continue it, losing control. */
6105 if (!switch_back_to_stepped_thread (ecs))
6110 if (ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_0
6111 && (pc_in_thread_step_range (ecs->event_thread->suspend.stop_pc,
6113 || ecs->event_thread->control.step_range_end == 1)
6114 && frame_id_eq (get_stack_frame_id (frame),
6115 ecs->event_thread->control.step_stack_frame_id)
6116 && ecs->event_thread->control.step_resume_breakpoint == NULL)
6118 /* The inferior is about to take a signal that will take it
6119 out of the single step range. Set a breakpoint at the
6120 current PC (which is presumably where the signal handler
6121 will eventually return) and then allow the inferior to
6124 Note that this is only needed for a signal delivered
6125 while in the single-step range. Nested signals aren't a
6126 problem as they eventually all return. */
6128 fprintf_unfiltered (gdb_stdlog,
6129 "infrun: signal may take us out of "
6130 "single-step range\n");
6132 clear_step_over_info ();
6133 insert_hp_step_resume_breakpoint_at_frame (frame);
6134 ecs->event_thread->step_after_step_resume_breakpoint = 1;
6135 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6136 ecs->event_thread->control.trap_expected = 0;
6141 /* Note: step_resume_breakpoint may be non-NULL. This occures
6142 when either there's a nested signal, or when there's a
6143 pending signal enabled just as the signal handler returns
6144 (leaving the inferior at the step-resume-breakpoint without
6145 actually executing it). Either way continue until the
6146 breakpoint is really hit. */
6148 if (!switch_back_to_stepped_thread (ecs))
6151 fprintf_unfiltered (gdb_stdlog,
6152 "infrun: random signal, keep going\n");
6159 process_event_stop_test (ecs);
6162 /* Come here when we've got some debug event / signal we can explain
6163 (IOW, not a random signal), and test whether it should cause a
6164 stop, or whether we should resume the inferior (transparently).
6165 E.g., could be a breakpoint whose condition evaluates false; we
6166 could be still stepping within the line; etc. */
6169 process_event_stop_test (struct execution_control_state *ecs)
6171 struct symtab_and_line stop_pc_sal;
6172 struct frame_info *frame;
6173 struct gdbarch *gdbarch;
6174 CORE_ADDR jmp_buf_pc;
6175 struct bpstat_what what;
6177 /* Handle cases caused by hitting a breakpoint. */
6179 frame = get_current_frame ();
6180 gdbarch = get_frame_arch (frame);
6182 what = bpstat_what (ecs->event_thread->control.stop_bpstat);
6184 if (what.call_dummy)
6186 stop_stack_dummy = what.call_dummy;
6189 /* A few breakpoint types have callbacks associated (e.g.,
6190 bp_jit_event). Run them now. */
6191 bpstat_run_callbacks (ecs->event_thread->control.stop_bpstat);
6193 /* If we hit an internal event that triggers symbol changes, the
6194 current frame will be invalidated within bpstat_what (e.g., if we
6195 hit an internal solib event). Re-fetch it. */
6196 frame = get_current_frame ();
6197 gdbarch = get_frame_arch (frame);
6199 switch (what.main_action)
6201 case BPSTAT_WHAT_SET_LONGJMP_RESUME:
6202 /* If we hit the breakpoint at longjmp while stepping, we
6203 install a momentary breakpoint at the target of the
6207 fprintf_unfiltered (gdb_stdlog,
6208 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME\n");
6210 ecs->event_thread->stepping_over_breakpoint = 1;
6212 if (what.is_longjmp)
6214 struct value *arg_value;
6216 /* If we set the longjmp breakpoint via a SystemTap probe,
6217 then use it to extract the arguments. The destination PC
6218 is the third argument to the probe. */
6219 arg_value = probe_safe_evaluate_at_pc (frame, 2);
6222 jmp_buf_pc = value_as_address (arg_value);
6223 jmp_buf_pc = gdbarch_addr_bits_remove (gdbarch, jmp_buf_pc);
6225 else if (!gdbarch_get_longjmp_target_p (gdbarch)
6226 || !gdbarch_get_longjmp_target (gdbarch,
6227 frame, &jmp_buf_pc))
6230 fprintf_unfiltered (gdb_stdlog,
6231 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME "
6232 "(!gdbarch_get_longjmp_target)\n");
6237 /* Insert a breakpoint at resume address. */
6238 insert_longjmp_resume_breakpoint (gdbarch, jmp_buf_pc);
6241 check_exception_resume (ecs, frame);
6245 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME:
6247 struct frame_info *init_frame;
6249 /* There are several cases to consider.
6251 1. The initiating frame no longer exists. In this case we
6252 must stop, because the exception or longjmp has gone too
6255 2. The initiating frame exists, and is the same as the
6256 current frame. We stop, because the exception or longjmp
6259 3. The initiating frame exists and is different from the
6260 current frame. This means the exception or longjmp has
6261 been caught beneath the initiating frame, so keep going.
6263 4. longjmp breakpoint has been placed just to protect
6264 against stale dummy frames and user is not interested in
6265 stopping around longjmps. */
6268 fprintf_unfiltered (gdb_stdlog,
6269 "infrun: BPSTAT_WHAT_CLEAR_LONGJMP_RESUME\n");
6271 gdb_assert (ecs->event_thread->control.exception_resume_breakpoint
6273 delete_exception_resume_breakpoint (ecs->event_thread);
6275 if (what.is_longjmp)
6277 check_longjmp_breakpoint_for_call_dummy (ecs->event_thread);
6279 if (!frame_id_p (ecs->event_thread->initiating_frame))
6287 init_frame = frame_find_by_id (ecs->event_thread->initiating_frame);
6291 struct frame_id current_id
6292 = get_frame_id (get_current_frame ());
6293 if (frame_id_eq (current_id,
6294 ecs->event_thread->initiating_frame))
6296 /* Case 2. Fall through. */
6306 /* For Cases 1 and 2, remove the step-resume breakpoint, if it
6308 delete_step_resume_breakpoint (ecs->event_thread);
6310 end_stepping_range (ecs);
6314 case BPSTAT_WHAT_SINGLE:
6316 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_SINGLE\n");
6317 ecs->event_thread->stepping_over_breakpoint = 1;
6318 /* Still need to check other stuff, at least the case where we
6319 are stepping and step out of the right range. */
6322 case BPSTAT_WHAT_STEP_RESUME:
6324 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STEP_RESUME\n");
6326 delete_step_resume_breakpoint (ecs->event_thread);
6327 if (ecs->event_thread->control.proceed_to_finish
6328 && execution_direction == EXEC_REVERSE)
6330 struct thread_info *tp = ecs->event_thread;
6332 /* We are finishing a function in reverse, and just hit the
6333 step-resume breakpoint at the start address of the
6334 function, and we're almost there -- just need to back up
6335 by one more single-step, which should take us back to the
6337 tp->control.step_range_start = tp->control.step_range_end = 1;
6341 fill_in_stop_func (gdbarch, ecs);
6342 if (ecs->event_thread->suspend.stop_pc == ecs->stop_func_start
6343 && execution_direction == EXEC_REVERSE)
6345 /* We are stepping over a function call in reverse, and just
6346 hit the step-resume breakpoint at the start address of
6347 the function. Go back to single-stepping, which should
6348 take us back to the function call. */
6349 ecs->event_thread->stepping_over_breakpoint = 1;
6355 case BPSTAT_WHAT_STOP_NOISY:
6357 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_NOISY\n");
6358 stop_print_frame = 1;
6360 /* Assume the thread stopped for a breapoint. We'll still check
6361 whether a/the breakpoint is there when the thread is next
6363 ecs->event_thread->stepping_over_breakpoint = 1;
6368 case BPSTAT_WHAT_STOP_SILENT:
6370 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_SILENT\n");
6371 stop_print_frame = 0;
6373 /* Assume the thread stopped for a breapoint. We'll still check
6374 whether a/the breakpoint is there when the thread is next
6376 ecs->event_thread->stepping_over_breakpoint = 1;
6380 case BPSTAT_WHAT_HP_STEP_RESUME:
6382 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_HP_STEP_RESUME\n");
6384 delete_step_resume_breakpoint (ecs->event_thread);
6385 if (ecs->event_thread->step_after_step_resume_breakpoint)
6387 /* Back when the step-resume breakpoint was inserted, we
6388 were trying to single-step off a breakpoint. Go back to
6390 ecs->event_thread->step_after_step_resume_breakpoint = 0;
6391 ecs->event_thread->stepping_over_breakpoint = 1;
6397 case BPSTAT_WHAT_KEEP_CHECKING:
6401 /* If we stepped a permanent breakpoint and we had a high priority
6402 step-resume breakpoint for the address we stepped, but we didn't
6403 hit it, then we must have stepped into the signal handler. The
6404 step-resume was only necessary to catch the case of _not_
6405 stepping into the handler, so delete it, and fall through to
6406 checking whether the step finished. */
6407 if (ecs->event_thread->stepped_breakpoint)
6409 struct breakpoint *sr_bp
6410 = ecs->event_thread->control.step_resume_breakpoint;
6413 && sr_bp->loc->permanent
6414 && sr_bp->type == bp_hp_step_resume
6415 && sr_bp->loc->address == ecs->event_thread->prev_pc)
6418 fprintf_unfiltered (gdb_stdlog,
6419 "infrun: stepped permanent breakpoint, stopped in "
6421 delete_step_resume_breakpoint (ecs->event_thread);
6422 ecs->event_thread->step_after_step_resume_breakpoint = 0;
6426 /* We come here if we hit a breakpoint but should not stop for it.
6427 Possibly we also were stepping and should stop for that. So fall
6428 through and test for stepping. But, if not stepping, do not
6431 /* In all-stop mode, if we're currently stepping but have stopped in
6432 some other thread, we need to switch back to the stepped thread. */
6433 if (switch_back_to_stepped_thread (ecs))
6436 if (ecs->event_thread->control.step_resume_breakpoint)
6439 fprintf_unfiltered (gdb_stdlog,
6440 "infrun: step-resume breakpoint is inserted\n");
6442 /* Having a step-resume breakpoint overrides anything
6443 else having to do with stepping commands until
6444 that breakpoint is reached. */
6449 if (ecs->event_thread->control.step_range_end == 0)
6452 fprintf_unfiltered (gdb_stdlog, "infrun: no stepping, continue\n");
6453 /* Likewise if we aren't even stepping. */
6458 /* Re-fetch current thread's frame in case the code above caused
6459 the frame cache to be re-initialized, making our FRAME variable
6460 a dangling pointer. */
6461 frame = get_current_frame ();
6462 gdbarch = get_frame_arch (frame);
6463 fill_in_stop_func (gdbarch, ecs);
6465 /* If stepping through a line, keep going if still within it.
6467 Note that step_range_end is the address of the first instruction
6468 beyond the step range, and NOT the address of the last instruction
6471 Note also that during reverse execution, we may be stepping
6472 through a function epilogue and therefore must detect when
6473 the current-frame changes in the middle of a line. */
6475 if (pc_in_thread_step_range (ecs->event_thread->suspend.stop_pc,
6477 && (execution_direction != EXEC_REVERSE
6478 || frame_id_eq (get_frame_id (frame),
6479 ecs->event_thread->control.step_frame_id)))
6483 (gdb_stdlog, "infrun: stepping inside range [%s-%s]\n",
6484 paddress (gdbarch, ecs->event_thread->control.step_range_start),
6485 paddress (gdbarch, ecs->event_thread->control.step_range_end));
6487 /* Tentatively re-enable range stepping; `resume' disables it if
6488 necessary (e.g., if we're stepping over a breakpoint or we
6489 have software watchpoints). */
6490 ecs->event_thread->control.may_range_step = 1;
6492 /* When stepping backward, stop at beginning of line range
6493 (unless it's the function entry point, in which case
6494 keep going back to the call point). */
6495 CORE_ADDR stop_pc = ecs->event_thread->suspend.stop_pc;
6496 if (stop_pc == ecs->event_thread->control.step_range_start
6497 && stop_pc != ecs->stop_func_start
6498 && execution_direction == EXEC_REVERSE)
6499 end_stepping_range (ecs);
6506 /* We stepped out of the stepping range. */
6508 /* If we are stepping at the source level and entered the runtime
6509 loader dynamic symbol resolution code...
6511 EXEC_FORWARD: we keep on single stepping until we exit the run
6512 time loader code and reach the callee's address.
6514 EXEC_REVERSE: we've already executed the callee (backward), and
6515 the runtime loader code is handled just like any other
6516 undebuggable function call. Now we need only keep stepping
6517 backward through the trampoline code, and that's handled further
6518 down, so there is nothing for us to do here. */
6520 if (execution_direction != EXEC_REVERSE
6521 && ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6522 && in_solib_dynsym_resolve_code (ecs->event_thread->suspend.stop_pc))
6524 CORE_ADDR pc_after_resolver =
6525 gdbarch_skip_solib_resolver (gdbarch,
6526 ecs->event_thread->suspend.stop_pc);
6529 fprintf_unfiltered (gdb_stdlog,
6530 "infrun: stepped into dynsym resolve code\n");
6532 if (pc_after_resolver)
6534 /* Set up a step-resume breakpoint at the address
6535 indicated by SKIP_SOLIB_RESOLVER. */
6536 symtab_and_line sr_sal;
6537 sr_sal.pc = pc_after_resolver;
6538 sr_sal.pspace = get_frame_program_space (frame);
6540 insert_step_resume_breakpoint_at_sal (gdbarch,
6541 sr_sal, null_frame_id);
6548 /* Step through an indirect branch thunk. */
6549 if (ecs->event_thread->control.step_over_calls != STEP_OVER_NONE
6550 && gdbarch_in_indirect_branch_thunk (gdbarch,
6551 ecs->event_thread->suspend.stop_pc))
6554 fprintf_unfiltered (gdb_stdlog,
6555 "infrun: stepped into indirect branch thunk\n");
6560 if (ecs->event_thread->control.step_range_end != 1
6561 && (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6562 || ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
6563 && get_frame_type (frame) == SIGTRAMP_FRAME)
6566 fprintf_unfiltered (gdb_stdlog,
6567 "infrun: stepped into signal trampoline\n");
6568 /* The inferior, while doing a "step" or "next", has ended up in
6569 a signal trampoline (either by a signal being delivered or by
6570 the signal handler returning). Just single-step until the
6571 inferior leaves the trampoline (either by calling the handler
6577 /* If we're in the return path from a shared library trampoline,
6578 we want to proceed through the trampoline when stepping. */
6579 /* macro/2012-04-25: This needs to come before the subroutine
6580 call check below as on some targets return trampolines look
6581 like subroutine calls (MIPS16 return thunks). */
6582 if (gdbarch_in_solib_return_trampoline (gdbarch,
6583 ecs->event_thread->suspend.stop_pc,
6584 ecs->stop_func_name)
6585 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE)
6587 /* Determine where this trampoline returns. */
6588 CORE_ADDR stop_pc = ecs->event_thread->suspend.stop_pc;
6589 CORE_ADDR real_stop_pc
6590 = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc);
6593 fprintf_unfiltered (gdb_stdlog,
6594 "infrun: stepped into solib return tramp\n");
6596 /* Only proceed through if we know where it's going. */
6599 /* And put the step-breakpoint there and go until there. */
6600 symtab_and_line sr_sal;
6601 sr_sal.pc = real_stop_pc;
6602 sr_sal.section = find_pc_overlay (sr_sal.pc);
6603 sr_sal.pspace = get_frame_program_space (frame);
6605 /* Do not specify what the fp should be when we stop since
6606 on some machines the prologue is where the new fp value
6608 insert_step_resume_breakpoint_at_sal (gdbarch,
6609 sr_sal, null_frame_id);
6611 /* Restart without fiddling with the step ranges or
6618 /* Check for subroutine calls. The check for the current frame
6619 equalling the step ID is not necessary - the check of the
6620 previous frame's ID is sufficient - but it is a common case and
6621 cheaper than checking the previous frame's ID.
6623 NOTE: frame_id_eq will never report two invalid frame IDs as
6624 being equal, so to get into this block, both the current and
6625 previous frame must have valid frame IDs. */
6626 /* The outer_frame_id check is a heuristic to detect stepping
6627 through startup code. If we step over an instruction which
6628 sets the stack pointer from an invalid value to a valid value,
6629 we may detect that as a subroutine call from the mythical
6630 "outermost" function. This could be fixed by marking
6631 outermost frames as !stack_p,code_p,special_p. Then the
6632 initial outermost frame, before sp was valid, would
6633 have code_addr == &_start. See the comment in frame_id_eq
6635 if (!frame_id_eq (get_stack_frame_id (frame),
6636 ecs->event_thread->control.step_stack_frame_id)
6637 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
6638 ecs->event_thread->control.step_stack_frame_id)
6639 && (!frame_id_eq (ecs->event_thread->control.step_stack_frame_id,
6641 || (ecs->event_thread->control.step_start_function
6642 != find_pc_function (ecs->event_thread->suspend.stop_pc)))))
6644 CORE_ADDR stop_pc = ecs->event_thread->suspend.stop_pc;
6645 CORE_ADDR real_stop_pc;
6648 fprintf_unfiltered (gdb_stdlog, "infrun: stepped into subroutine\n");
6650 if (ecs->event_thread->control.step_over_calls == STEP_OVER_NONE)
6652 /* I presume that step_over_calls is only 0 when we're
6653 supposed to be stepping at the assembly language level
6654 ("stepi"). Just stop. */
6655 /* And this works the same backward as frontward. MVS */
6656 end_stepping_range (ecs);
6660 /* Reverse stepping through solib trampolines. */
6662 if (execution_direction == EXEC_REVERSE
6663 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE
6664 && (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc)
6665 || (ecs->stop_func_start == 0
6666 && in_solib_dynsym_resolve_code (stop_pc))))
6668 /* Any solib trampoline code can be handled in reverse
6669 by simply continuing to single-step. We have already
6670 executed the solib function (backwards), and a few
6671 steps will take us back through the trampoline to the
6677 if (ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
6679 /* We're doing a "next".
6681 Normal (forward) execution: set a breakpoint at the
6682 callee's return address (the address at which the caller
6685 Reverse (backward) execution. set the step-resume
6686 breakpoint at the start of the function that we just
6687 stepped into (backwards), and continue to there. When we
6688 get there, we'll need to single-step back to the caller. */
6690 if (execution_direction == EXEC_REVERSE)
6692 /* If we're already at the start of the function, we've either
6693 just stepped backward into a single instruction function,
6694 or stepped back out of a signal handler to the first instruction
6695 of the function. Just keep going, which will single-step back
6697 if (ecs->stop_func_start != stop_pc && ecs->stop_func_start != 0)
6699 /* Normal function call return (static or dynamic). */
6700 symtab_and_line sr_sal;
6701 sr_sal.pc = ecs->stop_func_start;
6702 sr_sal.pspace = get_frame_program_space (frame);
6703 insert_step_resume_breakpoint_at_sal (gdbarch,
6704 sr_sal, null_frame_id);
6708 insert_step_resume_breakpoint_at_caller (frame);
6714 /* If we are in a function call trampoline (a stub between the
6715 calling routine and the real function), locate the real
6716 function. That's what tells us (a) whether we want to step
6717 into it at all, and (b) what prologue we want to run to the
6718 end of, if we do step into it. */
6719 real_stop_pc = skip_language_trampoline (frame, stop_pc);
6720 if (real_stop_pc == 0)
6721 real_stop_pc = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc);
6722 if (real_stop_pc != 0)
6723 ecs->stop_func_start = real_stop_pc;
6725 if (real_stop_pc != 0 && in_solib_dynsym_resolve_code (real_stop_pc))
6727 symtab_and_line sr_sal;
6728 sr_sal.pc = ecs->stop_func_start;
6729 sr_sal.pspace = get_frame_program_space (frame);
6731 insert_step_resume_breakpoint_at_sal (gdbarch,
6732 sr_sal, null_frame_id);
6737 /* If we have line number information for the function we are
6738 thinking of stepping into and the function isn't on the skip
6741 If there are several symtabs at that PC (e.g. with include
6742 files), just want to know whether *any* of them have line
6743 numbers. find_pc_line handles this. */
6745 struct symtab_and_line tmp_sal;
6747 tmp_sal = find_pc_line (ecs->stop_func_start, 0);
6748 if (tmp_sal.line != 0
6749 && !function_name_is_marked_for_skip (ecs->stop_func_name,
6752 if (execution_direction == EXEC_REVERSE)
6753 handle_step_into_function_backward (gdbarch, ecs);
6755 handle_step_into_function (gdbarch, ecs);
6760 /* If we have no line number and the step-stop-if-no-debug is
6761 set, we stop the step so that the user has a chance to switch
6762 in assembly mode. */
6763 if (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6764 && step_stop_if_no_debug)
6766 end_stepping_range (ecs);
6770 if (execution_direction == EXEC_REVERSE)
6772 /* If we're already at the start of the function, we've either just
6773 stepped backward into a single instruction function without line
6774 number info, or stepped back out of a signal handler to the first
6775 instruction of the function without line number info. Just keep
6776 going, which will single-step back to the caller. */
6777 if (ecs->stop_func_start != stop_pc)
6779 /* Set a breakpoint at callee's start address.
6780 From there we can step once and be back in the caller. */
6781 symtab_and_line sr_sal;
6782 sr_sal.pc = ecs->stop_func_start;
6783 sr_sal.pspace = get_frame_program_space (frame);
6784 insert_step_resume_breakpoint_at_sal (gdbarch,
6785 sr_sal, null_frame_id);
6789 /* Set a breakpoint at callee's return address (the address
6790 at which the caller will resume). */
6791 insert_step_resume_breakpoint_at_caller (frame);
6797 /* Reverse stepping through solib trampolines. */
6799 if (execution_direction == EXEC_REVERSE
6800 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE)
6802 CORE_ADDR stop_pc = ecs->event_thread->suspend.stop_pc;
6804 if (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc)
6805 || (ecs->stop_func_start == 0
6806 && in_solib_dynsym_resolve_code (stop_pc)))
6808 /* Any solib trampoline code can be handled in reverse
6809 by simply continuing to single-step. We have already
6810 executed the solib function (backwards), and a few
6811 steps will take us back through the trampoline to the
6816 else if (in_solib_dynsym_resolve_code (stop_pc))
6818 /* Stepped backward into the solib dynsym resolver.
6819 Set a breakpoint at its start and continue, then
6820 one more step will take us out. */
6821 symtab_and_line sr_sal;
6822 sr_sal.pc = ecs->stop_func_start;
6823 sr_sal.pspace = get_frame_program_space (frame);
6824 insert_step_resume_breakpoint_at_sal (gdbarch,
6825 sr_sal, null_frame_id);
6831 stop_pc_sal = find_pc_line (ecs->event_thread->suspend.stop_pc, 0);
6833 /* NOTE: tausq/2004-05-24: This if block used to be done before all
6834 the trampoline processing logic, however, there are some trampolines
6835 that have no names, so we should do trampoline handling first. */
6836 if (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
6837 && ecs->stop_func_name == NULL
6838 && stop_pc_sal.line == 0)
6841 fprintf_unfiltered (gdb_stdlog,
6842 "infrun: stepped into undebuggable function\n");
6844 /* The inferior just stepped into, or returned to, an
6845 undebuggable function (where there is no debugging information
6846 and no line number corresponding to the address where the
6847 inferior stopped). Since we want to skip this kind of code,
6848 we keep going until the inferior returns from this
6849 function - unless the user has asked us not to (via
6850 set step-mode) or we no longer know how to get back
6851 to the call site. */
6852 if (step_stop_if_no_debug
6853 || !frame_id_p (frame_unwind_caller_id (frame)))
6855 /* If we have no line number and the step-stop-if-no-debug
6856 is set, we stop the step so that the user has a chance to
6857 switch in assembly mode. */
6858 end_stepping_range (ecs);
6863 /* Set a breakpoint at callee's return address (the address
6864 at which the caller will resume). */
6865 insert_step_resume_breakpoint_at_caller (frame);
6871 if (ecs->event_thread->control.step_range_end == 1)
6873 /* It is stepi or nexti. We always want to stop stepping after
6876 fprintf_unfiltered (gdb_stdlog, "infrun: stepi/nexti\n");
6877 end_stepping_range (ecs);
6881 if (stop_pc_sal.line == 0)
6883 /* We have no line number information. That means to stop
6884 stepping (does this always happen right after one instruction,
6885 when we do "s" in a function with no line numbers,
6886 or can this happen as a result of a return or longjmp?). */
6888 fprintf_unfiltered (gdb_stdlog, "infrun: no line number info\n");
6889 end_stepping_range (ecs);
6893 /* Look for "calls" to inlined functions, part one. If the inline
6894 frame machinery detected some skipped call sites, we have entered
6895 a new inline function. */
6897 if (frame_id_eq (get_frame_id (get_current_frame ()),
6898 ecs->event_thread->control.step_frame_id)
6899 && inline_skipped_frames (ecs->event_thread))
6902 fprintf_unfiltered (gdb_stdlog,
6903 "infrun: stepped into inlined function\n");
6905 symtab_and_line call_sal = find_frame_sal (get_current_frame ());
6907 if (ecs->event_thread->control.step_over_calls != STEP_OVER_ALL)
6909 /* For "step", we're going to stop. But if the call site
6910 for this inlined function is on the same source line as
6911 we were previously stepping, go down into the function
6912 first. Otherwise stop at the call site. */
6914 if (call_sal.line == ecs->event_thread->current_line
6915 && call_sal.symtab == ecs->event_thread->current_symtab)
6916 step_into_inline_frame (ecs->event_thread);
6918 end_stepping_range (ecs);
6923 /* For "next", we should stop at the call site if it is on a
6924 different source line. Otherwise continue through the
6925 inlined function. */
6926 if (call_sal.line == ecs->event_thread->current_line
6927 && call_sal.symtab == ecs->event_thread->current_symtab)
6930 end_stepping_range (ecs);
6935 /* Look for "calls" to inlined functions, part two. If we are still
6936 in the same real function we were stepping through, but we have
6937 to go further up to find the exact frame ID, we are stepping
6938 through a more inlined call beyond its call site. */
6940 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
6941 && !frame_id_eq (get_frame_id (get_current_frame ()),
6942 ecs->event_thread->control.step_frame_id)
6943 && stepped_in_from (get_current_frame (),
6944 ecs->event_thread->control.step_frame_id))
6947 fprintf_unfiltered (gdb_stdlog,
6948 "infrun: stepping through inlined function\n");
6950 if (ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
6953 end_stepping_range (ecs);
6957 if ((ecs->event_thread->suspend.stop_pc == stop_pc_sal.pc)
6958 && (ecs->event_thread->current_line != stop_pc_sal.line
6959 || ecs->event_thread->current_symtab != stop_pc_sal.symtab))
6961 /* We are at the start of a different line. So stop. Note that
6962 we don't stop if we step into the middle of a different line.
6963 That is said to make things like for (;;) statements work
6966 fprintf_unfiltered (gdb_stdlog,
6967 "infrun: stepped to a different line\n");
6968 end_stepping_range (ecs);
6972 /* We aren't done stepping.
6974 Optimize by setting the stepping range to the line.
6975 (We might not be in the original line, but if we entered a
6976 new line in mid-statement, we continue stepping. This makes
6977 things like for(;;) statements work better.) */
6979 ecs->event_thread->control.step_range_start = stop_pc_sal.pc;
6980 ecs->event_thread->control.step_range_end = stop_pc_sal.end;
6981 ecs->event_thread->control.may_range_step = 1;
6982 set_step_info (frame, stop_pc_sal);
6985 fprintf_unfiltered (gdb_stdlog, "infrun: keep going\n");
6989 /* In all-stop mode, if we're currently stepping but have stopped in
6990 some other thread, we may need to switch back to the stepped
6991 thread. Returns true we set the inferior running, false if we left
6992 it stopped (and the event needs further processing). */
6995 switch_back_to_stepped_thread (struct execution_control_state *ecs)
6997 if (!target_is_non_stop_p ())
6999 struct thread_info *tp;
7000 struct thread_info *stepping_thread;
7002 /* If any thread is blocked on some internal breakpoint, and we
7003 simply need to step over that breakpoint to get it going
7004 again, do that first. */
7006 /* However, if we see an event for the stepping thread, then we
7007 know all other threads have been moved past their breakpoints
7008 already. Let the caller check whether the step is finished,
7009 etc., before deciding to move it past a breakpoint. */
7010 if (ecs->event_thread->control.step_range_end != 0)
7013 /* Check if the current thread is blocked on an incomplete
7014 step-over, interrupted by a random signal. */
7015 if (ecs->event_thread->control.trap_expected
7016 && ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_TRAP)
7020 fprintf_unfiltered (gdb_stdlog,
7021 "infrun: need to finish step-over of [%s]\n",
7022 target_pid_to_str (ecs->event_thread->ptid));
7028 /* Check if the current thread is blocked by a single-step
7029 breakpoint of another thread. */
7030 if (ecs->hit_singlestep_breakpoint)
7034 fprintf_unfiltered (gdb_stdlog,
7035 "infrun: need to step [%s] over single-step "
7037 target_pid_to_str (ecs->ptid));
7043 /* If this thread needs yet another step-over (e.g., stepping
7044 through a delay slot), do it first before moving on to
7046 if (thread_still_needs_step_over (ecs->event_thread))
7050 fprintf_unfiltered (gdb_stdlog,
7051 "infrun: thread [%s] still needs step-over\n",
7052 target_pid_to_str (ecs->event_thread->ptid));
7058 /* If scheduler locking applies even if not stepping, there's no
7059 need to walk over threads. Above we've checked whether the
7060 current thread is stepping. If some other thread not the
7061 event thread is stepping, then it must be that scheduler
7062 locking is not in effect. */
7063 if (schedlock_applies (ecs->event_thread))
7066 /* Otherwise, we no longer expect a trap in the current thread.
7067 Clear the trap_expected flag before switching back -- this is
7068 what keep_going does as well, if we call it. */
7069 ecs->event_thread->control.trap_expected = 0;
7071 /* Likewise, clear the signal if it should not be passed. */
7072 if (!signal_program[ecs->event_thread->suspend.stop_signal])
7073 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
7075 /* Do all pending step-overs before actually proceeding with
7077 if (start_step_over ())
7079 prepare_to_wait (ecs);
7083 /* Look for the stepping/nexting thread. */
7084 stepping_thread = NULL;
7086 ALL_NON_EXITED_THREADS (tp)
7088 /* Ignore threads of processes the caller is not
7091 && tp->ptid.pid () != ecs->ptid.pid ())
7094 /* When stepping over a breakpoint, we lock all threads
7095 except the one that needs to move past the breakpoint.
7096 If a non-event thread has this set, the "incomplete
7097 step-over" check above should have caught it earlier. */
7098 if (tp->control.trap_expected)
7100 internal_error (__FILE__, __LINE__,
7101 "[%s] has inconsistent state: "
7102 "trap_expected=%d\n",
7103 target_pid_to_str (tp->ptid),
7104 tp->control.trap_expected);
7107 /* Did we find the stepping thread? */
7108 if (tp->control.step_range_end)
7110 /* Yep. There should only one though. */
7111 gdb_assert (stepping_thread == NULL);
7113 /* The event thread is handled at the top, before we
7115 gdb_assert (tp != ecs->event_thread);
7117 /* If some thread other than the event thread is
7118 stepping, then scheduler locking can't be in effect,
7119 otherwise we wouldn't have resumed the current event
7120 thread in the first place. */
7121 gdb_assert (!schedlock_applies (tp));
7123 stepping_thread = tp;
7127 if (stepping_thread != NULL)
7130 fprintf_unfiltered (gdb_stdlog,
7131 "infrun: switching back to stepped thread\n");
7133 if (keep_going_stepped_thread (stepping_thread))
7135 prepare_to_wait (ecs);
7144 /* Set a previously stepped thread back to stepping. Returns true on
7145 success, false if the resume is not possible (e.g., the thread
7149 keep_going_stepped_thread (struct thread_info *tp)
7151 struct frame_info *frame;
7152 struct execution_control_state ecss;
7153 struct execution_control_state *ecs = &ecss;
7155 /* If the stepping thread exited, then don't try to switch back and
7156 resume it, which could fail in several different ways depending
7157 on the target. Instead, just keep going.
7159 We can find a stepping dead thread in the thread list in two
7162 - The target supports thread exit events, and when the target
7163 tries to delete the thread from the thread list, inferior_ptid
7164 pointed at the exiting thread. In such case, calling
7165 delete_thread does not really remove the thread from the list;
7166 instead, the thread is left listed, with 'exited' state.
7168 - The target's debug interface does not support thread exit
7169 events, and so we have no idea whatsoever if the previously
7170 stepping thread is still alive. For that reason, we need to
7171 synchronously query the target now. */
7173 if (tp->state == THREAD_EXITED || !target_thread_alive (tp->ptid))
7176 fprintf_unfiltered (gdb_stdlog,
7177 "infrun: not resuming previously "
7178 "stepped thread, it has vanished\n");
7185 fprintf_unfiltered (gdb_stdlog,
7186 "infrun: resuming previously stepped thread\n");
7188 reset_ecs (ecs, tp);
7189 switch_to_thread (tp);
7191 tp->suspend.stop_pc = regcache_read_pc (get_thread_regcache (tp));
7192 frame = get_current_frame ();
7194 /* If the PC of the thread we were trying to single-step has
7195 changed, then that thread has trapped or been signaled, but the
7196 event has not been reported to GDB yet. Re-poll the target
7197 looking for this particular thread's event (i.e. temporarily
7198 enable schedlock) by:
7200 - setting a break at the current PC
7201 - resuming that particular thread, only (by setting trap
7204 This prevents us continuously moving the single-step breakpoint
7205 forward, one instruction at a time, overstepping. */
7207 if (tp->suspend.stop_pc != tp->prev_pc)
7212 fprintf_unfiltered (gdb_stdlog,
7213 "infrun: expected thread advanced also (%s -> %s)\n",
7214 paddress (target_gdbarch (), tp->prev_pc),
7215 paddress (target_gdbarch (), tp->suspend.stop_pc));
7217 /* Clear the info of the previous step-over, as it's no longer
7218 valid (if the thread was trying to step over a breakpoint, it
7219 has already succeeded). It's what keep_going would do too,
7220 if we called it. Do this before trying to insert the sss
7221 breakpoint, otherwise if we were previously trying to step
7222 over this exact address in another thread, the breakpoint is
7224 clear_step_over_info ();
7225 tp->control.trap_expected = 0;
7227 insert_single_step_breakpoint (get_frame_arch (frame),
7228 get_frame_address_space (frame),
7229 tp->suspend.stop_pc);
7232 resume_ptid = internal_resume_ptid (tp->control.stepping_command);
7233 do_target_resume (resume_ptid, 0, GDB_SIGNAL_0);
7238 fprintf_unfiltered (gdb_stdlog,
7239 "infrun: expected thread still hasn't advanced\n");
7241 keep_going_pass_signal (ecs);
7246 /* Is thread TP in the middle of (software or hardware)
7247 single-stepping? (Note the result of this function must never be
7248 passed directly as target_resume's STEP parameter.) */
7251 currently_stepping (struct thread_info *tp)
7253 return ((tp->control.step_range_end
7254 && tp->control.step_resume_breakpoint == NULL)
7255 || tp->control.trap_expected
7256 || tp->stepped_breakpoint
7257 || bpstat_should_step ());
7260 /* Inferior has stepped into a subroutine call with source code that
7261 we should not step over. Do step to the first line of code in
7265 handle_step_into_function (struct gdbarch *gdbarch,
7266 struct execution_control_state *ecs)
7268 fill_in_stop_func (gdbarch, ecs);
7270 compunit_symtab *cust
7271 = find_pc_compunit_symtab (ecs->event_thread->suspend.stop_pc);
7272 if (cust != NULL && compunit_language (cust) != language_asm)
7273 ecs->stop_func_start
7274 = gdbarch_skip_prologue_noexcept (gdbarch, ecs->stop_func_start);
7276 symtab_and_line stop_func_sal = find_pc_line (ecs->stop_func_start, 0);
7277 /* Use the step_resume_break to step until the end of the prologue,
7278 even if that involves jumps (as it seems to on the vax under
7280 /* If the prologue ends in the middle of a source line, continue to
7281 the end of that source line (if it is still within the function).
7282 Otherwise, just go to end of prologue. */
7283 if (stop_func_sal.end
7284 && stop_func_sal.pc != ecs->stop_func_start
7285 && stop_func_sal.end < ecs->stop_func_end)
7286 ecs->stop_func_start = stop_func_sal.end;
7288 /* Architectures which require breakpoint adjustment might not be able
7289 to place a breakpoint at the computed address. If so, the test
7290 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
7291 ecs->stop_func_start to an address at which a breakpoint may be
7292 legitimately placed.
7294 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
7295 made, GDB will enter an infinite loop when stepping through
7296 optimized code consisting of VLIW instructions which contain
7297 subinstructions corresponding to different source lines. On
7298 FR-V, it's not permitted to place a breakpoint on any but the
7299 first subinstruction of a VLIW instruction. When a breakpoint is
7300 set, GDB will adjust the breakpoint address to the beginning of
7301 the VLIW instruction. Thus, we need to make the corresponding
7302 adjustment here when computing the stop address. */
7304 if (gdbarch_adjust_breakpoint_address_p (gdbarch))
7306 ecs->stop_func_start
7307 = gdbarch_adjust_breakpoint_address (gdbarch,
7308 ecs->stop_func_start);
7311 if (ecs->stop_func_start == ecs->event_thread->suspend.stop_pc)
7313 /* We are already there: stop now. */
7314 end_stepping_range (ecs);
7319 /* Put the step-breakpoint there and go until there. */
7320 symtab_and_line sr_sal;
7321 sr_sal.pc = ecs->stop_func_start;
7322 sr_sal.section = find_pc_overlay (ecs->stop_func_start);
7323 sr_sal.pspace = get_frame_program_space (get_current_frame ());
7325 /* Do not specify what the fp should be when we stop since on
7326 some machines the prologue is where the new fp value is
7328 insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal, null_frame_id);
7330 /* And make sure stepping stops right away then. */
7331 ecs->event_thread->control.step_range_end
7332 = ecs->event_thread->control.step_range_start;
7337 /* Inferior has stepped backward into a subroutine call with source
7338 code that we should not step over. Do step to the beginning of the
7339 last line of code in it. */
7342 handle_step_into_function_backward (struct gdbarch *gdbarch,
7343 struct execution_control_state *ecs)
7345 struct compunit_symtab *cust;
7346 struct symtab_and_line stop_func_sal;
7348 fill_in_stop_func (gdbarch, ecs);
7350 cust = find_pc_compunit_symtab (ecs->event_thread->suspend.stop_pc);
7351 if (cust != NULL && compunit_language (cust) != language_asm)
7352 ecs->stop_func_start
7353 = gdbarch_skip_prologue_noexcept (gdbarch, ecs->stop_func_start);
7355 stop_func_sal = find_pc_line (ecs->event_thread->suspend.stop_pc, 0);
7357 /* OK, we're just going to keep stepping here. */
7358 if (stop_func_sal.pc == ecs->event_thread->suspend.stop_pc)
7360 /* We're there already. Just stop stepping now. */
7361 end_stepping_range (ecs);
7365 /* Else just reset the step range and keep going.
7366 No step-resume breakpoint, they don't work for
7367 epilogues, which can have multiple entry paths. */
7368 ecs->event_thread->control.step_range_start = stop_func_sal.pc;
7369 ecs->event_thread->control.step_range_end = stop_func_sal.end;
7375 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
7376 This is used to both functions and to skip over code. */
7379 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch *gdbarch,
7380 struct symtab_and_line sr_sal,
7381 struct frame_id sr_id,
7382 enum bptype sr_type)
7384 /* There should never be more than one step-resume or longjmp-resume
7385 breakpoint per thread, so we should never be setting a new
7386 step_resume_breakpoint when one is already active. */
7387 gdb_assert (inferior_thread ()->control.step_resume_breakpoint == NULL);
7388 gdb_assert (sr_type == bp_step_resume || sr_type == bp_hp_step_resume);
7391 fprintf_unfiltered (gdb_stdlog,
7392 "infrun: inserting step-resume breakpoint at %s\n",
7393 paddress (gdbarch, sr_sal.pc));
7395 inferior_thread ()->control.step_resume_breakpoint
7396 = set_momentary_breakpoint (gdbarch, sr_sal, sr_id, sr_type).release ();
7400 insert_step_resume_breakpoint_at_sal (struct gdbarch *gdbarch,
7401 struct symtab_and_line sr_sal,
7402 struct frame_id sr_id)
7404 insert_step_resume_breakpoint_at_sal_1 (gdbarch,
7409 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
7410 This is used to skip a potential signal handler.
7412 This is called with the interrupted function's frame. The signal
7413 handler, when it returns, will resume the interrupted function at
7417 insert_hp_step_resume_breakpoint_at_frame (struct frame_info *return_frame)
7419 gdb_assert (return_frame != NULL);
7421 struct gdbarch *gdbarch = get_frame_arch (return_frame);
7423 symtab_and_line sr_sal;
7424 sr_sal.pc = gdbarch_addr_bits_remove (gdbarch, get_frame_pc (return_frame));
7425 sr_sal.section = find_pc_overlay (sr_sal.pc);
7426 sr_sal.pspace = get_frame_program_space (return_frame);
7428 insert_step_resume_breakpoint_at_sal_1 (gdbarch, sr_sal,
7429 get_stack_frame_id (return_frame),
7433 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
7434 is used to skip a function after stepping into it (for "next" or if
7435 the called function has no debugging information).
7437 The current function has almost always been reached by single
7438 stepping a call or return instruction. NEXT_FRAME belongs to the
7439 current function, and the breakpoint will be set at the caller's
7442 This is a separate function rather than reusing
7443 insert_hp_step_resume_breakpoint_at_frame in order to avoid
7444 get_prev_frame, which may stop prematurely (see the implementation
7445 of frame_unwind_caller_id for an example). */
7448 insert_step_resume_breakpoint_at_caller (struct frame_info *next_frame)
7450 /* We shouldn't have gotten here if we don't know where the call site
7452 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame)));
7454 struct gdbarch *gdbarch = frame_unwind_caller_arch (next_frame);
7456 symtab_and_line sr_sal;
7457 sr_sal.pc = gdbarch_addr_bits_remove (gdbarch,
7458 frame_unwind_caller_pc (next_frame));
7459 sr_sal.section = find_pc_overlay (sr_sal.pc);
7460 sr_sal.pspace = frame_unwind_program_space (next_frame);
7462 insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal,
7463 frame_unwind_caller_id (next_frame));
7466 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
7467 new breakpoint at the target of a jmp_buf. The handling of
7468 longjmp-resume uses the same mechanisms used for handling
7469 "step-resume" breakpoints. */
7472 insert_longjmp_resume_breakpoint (struct gdbarch *gdbarch, CORE_ADDR pc)
7474 /* There should never be more than one longjmp-resume breakpoint per
7475 thread, so we should never be setting a new
7476 longjmp_resume_breakpoint when one is already active. */
7477 gdb_assert (inferior_thread ()->control.exception_resume_breakpoint == NULL);
7480 fprintf_unfiltered (gdb_stdlog,
7481 "infrun: inserting longjmp-resume breakpoint at %s\n",
7482 paddress (gdbarch, pc));
7484 inferior_thread ()->control.exception_resume_breakpoint =
7485 set_momentary_breakpoint_at_pc (gdbarch, pc, bp_longjmp_resume).release ();
7488 /* Insert an exception resume breakpoint. TP is the thread throwing
7489 the exception. The block B is the block of the unwinder debug hook
7490 function. FRAME is the frame corresponding to the call to this
7491 function. SYM is the symbol of the function argument holding the
7492 target PC of the exception. */
7495 insert_exception_resume_breakpoint (struct thread_info *tp,
7496 const struct block *b,
7497 struct frame_info *frame,
7502 struct block_symbol vsym;
7503 struct value *value;
7505 struct breakpoint *bp;
7507 vsym = lookup_symbol_search_name (SYMBOL_SEARCH_NAME (sym),
7509 value = read_var_value (vsym.symbol, vsym.block, frame);
7510 /* If the value was optimized out, revert to the old behavior. */
7511 if (! value_optimized_out (value))
7513 handler = value_as_address (value);
7516 fprintf_unfiltered (gdb_stdlog,
7517 "infrun: exception resume at %lx\n",
7518 (unsigned long) handler);
7520 bp = set_momentary_breakpoint_at_pc (get_frame_arch (frame),
7522 bp_exception_resume).release ();
7524 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
7527 bp->thread = tp->global_num;
7528 inferior_thread ()->control.exception_resume_breakpoint = bp;
7531 CATCH (e, RETURN_MASK_ERROR)
7533 /* We want to ignore errors here. */
7538 /* A helper for check_exception_resume that sets an
7539 exception-breakpoint based on a SystemTap probe. */
7542 insert_exception_resume_from_probe (struct thread_info *tp,
7543 const struct bound_probe *probe,
7544 struct frame_info *frame)
7546 struct value *arg_value;
7548 struct breakpoint *bp;
7550 arg_value = probe_safe_evaluate_at_pc (frame, 1);
7554 handler = value_as_address (arg_value);
7557 fprintf_unfiltered (gdb_stdlog,
7558 "infrun: exception resume at %s\n",
7559 paddress (get_objfile_arch (probe->objfile),
7562 bp = set_momentary_breakpoint_at_pc (get_frame_arch (frame),
7563 handler, bp_exception_resume).release ();
7564 bp->thread = tp->global_num;
7565 inferior_thread ()->control.exception_resume_breakpoint = bp;
7568 /* This is called when an exception has been intercepted. Check to
7569 see whether the exception's destination is of interest, and if so,
7570 set an exception resume breakpoint there. */
7573 check_exception_resume (struct execution_control_state *ecs,
7574 struct frame_info *frame)
7576 struct bound_probe probe;
7577 struct symbol *func;
7579 /* First see if this exception unwinding breakpoint was set via a
7580 SystemTap probe point. If so, the probe has two arguments: the
7581 CFA and the HANDLER. We ignore the CFA, extract the handler, and
7582 set a breakpoint there. */
7583 probe = find_probe_by_pc (get_frame_pc (frame));
7586 insert_exception_resume_from_probe (ecs->event_thread, &probe, frame);
7590 func = get_frame_function (frame);
7596 const struct block *b;
7597 struct block_iterator iter;
7601 /* The exception breakpoint is a thread-specific breakpoint on
7602 the unwinder's debug hook, declared as:
7604 void _Unwind_DebugHook (void *cfa, void *handler);
7606 The CFA argument indicates the frame to which control is
7607 about to be transferred. HANDLER is the destination PC.
7609 We ignore the CFA and set a temporary breakpoint at HANDLER.
7610 This is not extremely efficient but it avoids issues in gdb
7611 with computing the DWARF CFA, and it also works even in weird
7612 cases such as throwing an exception from inside a signal
7615 b = SYMBOL_BLOCK_VALUE (func);
7616 ALL_BLOCK_SYMBOLS (b, iter, sym)
7618 if (!SYMBOL_IS_ARGUMENT (sym))
7625 insert_exception_resume_breakpoint (ecs->event_thread,
7631 CATCH (e, RETURN_MASK_ERROR)
7638 stop_waiting (struct execution_control_state *ecs)
7641 fprintf_unfiltered (gdb_stdlog, "infrun: stop_waiting\n");
7643 /* Let callers know we don't want to wait for the inferior anymore. */
7644 ecs->wait_some_more = 0;
7646 /* If all-stop, but the target is always in non-stop mode, stop all
7647 threads now that we're presenting the stop to the user. */
7648 if (!non_stop && target_is_non_stop_p ())
7649 stop_all_threads ();
7652 /* Like keep_going, but passes the signal to the inferior, even if the
7653 signal is set to nopass. */
7656 keep_going_pass_signal (struct execution_control_state *ecs)
7658 gdb_assert (ecs->event_thread->ptid == inferior_ptid);
7659 gdb_assert (!ecs->event_thread->resumed);
7661 /* Save the pc before execution, to compare with pc after stop. */
7662 ecs->event_thread->prev_pc
7663 = regcache_read_pc (get_thread_regcache (ecs->event_thread));
7665 if (ecs->event_thread->control.trap_expected)
7667 struct thread_info *tp = ecs->event_thread;
7670 fprintf_unfiltered (gdb_stdlog,
7671 "infrun: %s has trap_expected set, "
7672 "resuming to collect trap\n",
7673 target_pid_to_str (tp->ptid));
7675 /* We haven't yet gotten our trap, and either: intercepted a
7676 non-signal event (e.g., a fork); or took a signal which we
7677 are supposed to pass through to the inferior. Simply
7679 resume (ecs->event_thread->suspend.stop_signal);
7681 else if (step_over_info_valid_p ())
7683 /* Another thread is stepping over a breakpoint in-line. If
7684 this thread needs a step-over too, queue the request. In
7685 either case, this resume must be deferred for later. */
7686 struct thread_info *tp = ecs->event_thread;
7688 if (ecs->hit_singlestep_breakpoint
7689 || thread_still_needs_step_over (tp))
7692 fprintf_unfiltered (gdb_stdlog,
7693 "infrun: step-over already in progress: "
7694 "step-over for %s deferred\n",
7695 target_pid_to_str (tp->ptid));
7696 thread_step_over_chain_enqueue (tp);
7701 fprintf_unfiltered (gdb_stdlog,
7702 "infrun: step-over in progress: "
7703 "resume of %s deferred\n",
7704 target_pid_to_str (tp->ptid));
7709 struct regcache *regcache = get_current_regcache ();
7712 step_over_what step_what;
7714 /* Either the trap was not expected, but we are continuing
7715 anyway (if we got a signal, the user asked it be passed to
7718 We got our expected trap, but decided we should resume from
7721 We're going to run this baby now!
7723 Note that insert_breakpoints won't try to re-insert
7724 already inserted breakpoints. Therefore, we don't
7725 care if breakpoints were already inserted, or not. */
7727 /* If we need to step over a breakpoint, and we're not using
7728 displaced stepping to do so, insert all breakpoints
7729 (watchpoints, etc.) but the one we're stepping over, step one
7730 instruction, and then re-insert the breakpoint when that step
7733 step_what = thread_still_needs_step_over (ecs->event_thread);
7735 remove_bp = (ecs->hit_singlestep_breakpoint
7736 || (step_what & STEP_OVER_BREAKPOINT));
7737 remove_wps = (step_what & STEP_OVER_WATCHPOINT);
7739 /* We can't use displaced stepping if we need to step past a
7740 watchpoint. The instruction copied to the scratch pad would
7741 still trigger the watchpoint. */
7743 && (remove_wps || !use_displaced_stepping (ecs->event_thread)))
7745 set_step_over_info (regcache->aspace (),
7746 regcache_read_pc (regcache), remove_wps,
7747 ecs->event_thread->global_num);
7749 else if (remove_wps)
7750 set_step_over_info (NULL, 0, remove_wps, -1);
7752 /* If we now need to do an in-line step-over, we need to stop
7753 all other threads. Note this must be done before
7754 insert_breakpoints below, because that removes the breakpoint
7755 we're about to step over, otherwise other threads could miss
7757 if (step_over_info_valid_p () && target_is_non_stop_p ())
7758 stop_all_threads ();
7760 /* Stop stepping if inserting breakpoints fails. */
7763 insert_breakpoints ();
7765 CATCH (e, RETURN_MASK_ERROR)
7767 exception_print (gdb_stderr, e);
7769 clear_step_over_info ();
7774 ecs->event_thread->control.trap_expected = (remove_bp || remove_wps);
7776 resume (ecs->event_thread->suspend.stop_signal);
7779 prepare_to_wait (ecs);
7782 /* Called when we should continue running the inferior, because the
7783 current event doesn't cause a user visible stop. This does the
7784 resuming part; waiting for the next event is done elsewhere. */
7787 keep_going (struct execution_control_state *ecs)
7789 if (ecs->event_thread->control.trap_expected
7790 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
7791 ecs->event_thread->control.trap_expected = 0;
7793 if (!signal_program[ecs->event_thread->suspend.stop_signal])
7794 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
7795 keep_going_pass_signal (ecs);
7798 /* This function normally comes after a resume, before
7799 handle_inferior_event exits. It takes care of any last bits of
7800 housekeeping, and sets the all-important wait_some_more flag. */
7803 prepare_to_wait (struct execution_control_state *ecs)
7806 fprintf_unfiltered (gdb_stdlog, "infrun: prepare_to_wait\n");
7808 ecs->wait_some_more = 1;
7810 if (!target_is_async_p ())
7811 mark_infrun_async_event_handler ();
7814 /* We are done with the step range of a step/next/si/ni command.
7815 Called once for each n of a "step n" operation. */
7818 end_stepping_range (struct execution_control_state *ecs)
7820 ecs->event_thread->control.stop_step = 1;
7824 /* Several print_*_reason functions to print why the inferior has stopped.
7825 We always print something when the inferior exits, or receives a signal.
7826 The rest of the cases are dealt with later on in normal_stop and
7827 print_it_typical. Ideally there should be a call to one of these
7828 print_*_reason functions functions from handle_inferior_event each time
7829 stop_waiting is called.
7831 Note that we don't call these directly, instead we delegate that to
7832 the interpreters, through observers. Interpreters then call these
7833 with whatever uiout is right. */
7836 print_end_stepping_range_reason (struct ui_out *uiout)
7838 /* For CLI-like interpreters, print nothing. */
7840 if (uiout->is_mi_like_p ())
7842 uiout->field_string ("reason",
7843 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE));
7848 print_signal_exited_reason (struct ui_out *uiout, enum gdb_signal siggnal)
7850 annotate_signalled ();
7851 if (uiout->is_mi_like_p ())
7853 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED));
7854 uiout->text ("\nProgram terminated with signal ");
7855 annotate_signal_name ();
7856 uiout->field_string ("signal-name",
7857 gdb_signal_to_name (siggnal));
7858 annotate_signal_name_end ();
7860 annotate_signal_string ();
7861 uiout->field_string ("signal-meaning",
7862 gdb_signal_to_string (siggnal));
7863 annotate_signal_string_end ();
7864 uiout->text (".\n");
7865 uiout->text ("The program no longer exists.\n");
7869 print_exited_reason (struct ui_out *uiout, int exitstatus)
7871 struct inferior *inf = current_inferior ();
7872 const char *pidstr = target_pid_to_str (ptid_t (inf->pid));
7874 annotate_exited (exitstatus);
7877 if (uiout->is_mi_like_p ())
7878 uiout->field_string ("reason", async_reason_lookup (EXEC_ASYNC_EXITED));
7879 uiout->text ("[Inferior ");
7880 uiout->text (plongest (inf->num));
7882 uiout->text (pidstr);
7883 uiout->text (") exited with code ");
7884 uiout->field_fmt ("exit-code", "0%o", (unsigned int) exitstatus);
7885 uiout->text ("]\n");
7889 if (uiout->is_mi_like_p ())
7891 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY));
7892 uiout->text ("[Inferior ");
7893 uiout->text (plongest (inf->num));
7895 uiout->text (pidstr);
7896 uiout->text (") exited normally]\n");
7900 /* Some targets/architectures can do extra processing/display of
7901 segmentation faults. E.g., Intel MPX boundary faults.
7902 Call the architecture dependent function to handle the fault. */
7905 handle_segmentation_fault (struct ui_out *uiout)
7907 struct regcache *regcache = get_current_regcache ();
7908 struct gdbarch *gdbarch = regcache->arch ();
7910 if (gdbarch_handle_segmentation_fault_p (gdbarch))
7911 gdbarch_handle_segmentation_fault (gdbarch, uiout);
7915 print_signal_received_reason (struct ui_out *uiout, enum gdb_signal siggnal)
7917 struct thread_info *thr = inferior_thread ();
7921 if (uiout->is_mi_like_p ())
7923 else if (show_thread_that_caused_stop ())
7927 uiout->text ("\nThread ");
7928 uiout->field_fmt ("thread-id", "%s", print_thread_id (thr));
7930 name = thr->name != NULL ? thr->name : target_thread_name (thr);
7933 uiout->text (" \"");
7934 uiout->field_fmt ("name", "%s", name);
7939 uiout->text ("\nProgram");
7941 if (siggnal == GDB_SIGNAL_0 && !uiout->is_mi_like_p ())
7942 uiout->text (" stopped");
7945 uiout->text (" received signal ");
7946 annotate_signal_name ();
7947 if (uiout->is_mi_like_p ())
7949 ("reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED));
7950 uiout->field_string ("signal-name", gdb_signal_to_name (siggnal));
7951 annotate_signal_name_end ();
7953 annotate_signal_string ();
7954 uiout->field_string ("signal-meaning", gdb_signal_to_string (siggnal));
7956 if (siggnal == GDB_SIGNAL_SEGV)
7957 handle_segmentation_fault (uiout);
7959 annotate_signal_string_end ();
7961 uiout->text (".\n");
7965 print_no_history_reason (struct ui_out *uiout)
7967 uiout->text ("\nNo more reverse-execution history.\n");
7970 /* Print current location without a level number, if we have changed
7971 functions or hit a breakpoint. Print source line if we have one.
7972 bpstat_print contains the logic deciding in detail what to print,
7973 based on the event(s) that just occurred. */
7976 print_stop_location (struct target_waitstatus *ws)
7979 enum print_what source_flag;
7980 int do_frame_printing = 1;
7981 struct thread_info *tp = inferior_thread ();
7983 bpstat_ret = bpstat_print (tp->control.stop_bpstat, ws->kind);
7987 /* FIXME: cagney/2002-12-01: Given that a frame ID does (or
7988 should) carry around the function and does (or should) use
7989 that when doing a frame comparison. */
7990 if (tp->control.stop_step
7991 && frame_id_eq (tp->control.step_frame_id,
7992 get_frame_id (get_current_frame ()))
7993 && (tp->control.step_start_function
7994 == find_pc_function (tp->suspend.stop_pc)))
7996 /* Finished step, just print source line. */
7997 source_flag = SRC_LINE;
8001 /* Print location and source line. */
8002 source_flag = SRC_AND_LOC;
8005 case PRINT_SRC_AND_LOC:
8006 /* Print location and source line. */
8007 source_flag = SRC_AND_LOC;
8009 case PRINT_SRC_ONLY:
8010 source_flag = SRC_LINE;
8013 /* Something bogus. */
8014 source_flag = SRC_LINE;
8015 do_frame_printing = 0;
8018 internal_error (__FILE__, __LINE__, _("Unknown value."));
8021 /* The behavior of this routine with respect to the source
8023 SRC_LINE: Print only source line
8024 LOCATION: Print only location
8025 SRC_AND_LOC: Print location and source line. */
8026 if (do_frame_printing)
8027 print_stack_frame (get_selected_frame (NULL), 0, source_flag, 1);
8033 print_stop_event (struct ui_out *uiout)
8035 struct target_waitstatus last;
8037 struct thread_info *tp;
8039 get_last_target_status (&last_ptid, &last);
8042 scoped_restore save_uiout = make_scoped_restore (¤t_uiout, uiout);
8044 print_stop_location (&last);
8046 /* Display the auto-display expressions. */
8050 tp = inferior_thread ();
8051 if (tp->thread_fsm != NULL
8052 && thread_fsm_finished_p (tp->thread_fsm))
8054 struct return_value_info *rv;
8056 rv = thread_fsm_return_value (tp->thread_fsm);
8058 print_return_value (uiout, rv);
8065 maybe_remove_breakpoints (void)
8067 if (!breakpoints_should_be_inserted_now () && target_has_execution)
8069 if (remove_breakpoints ())
8071 target_terminal::ours_for_output ();
8072 printf_filtered (_("Cannot remove breakpoints because "
8073 "program is no longer writable.\nFurther "
8074 "execution is probably impossible.\n"));
8079 /* The execution context that just caused a normal stop. */
8086 DISABLE_COPY_AND_ASSIGN (stop_context);
8088 bool changed () const;
8093 /* The event PTID. */
8097 /* If stopp for a thread event, this is the thread that caused the
8099 struct thread_info *thread;
8101 /* The inferior that caused the stop. */
8105 /* Initializes a new stop context. If stopped for a thread event, this
8106 takes a strong reference to the thread. */
8108 stop_context::stop_context ()
8110 stop_id = get_stop_id ();
8111 ptid = inferior_ptid;
8112 inf_num = current_inferior ()->num;
8114 if (inferior_ptid != null_ptid)
8116 /* Take a strong reference so that the thread can't be deleted
8118 thread = inferior_thread ();
8125 /* Release a stop context previously created with save_stop_context.
8126 Releases the strong reference to the thread as well. */
8128 stop_context::~stop_context ()
8134 /* Return true if the current context no longer matches the saved stop
8138 stop_context::changed () const
8140 if (ptid != inferior_ptid)
8142 if (inf_num != current_inferior ()->num)
8144 if (thread != NULL && thread->state != THREAD_STOPPED)
8146 if (get_stop_id () != stop_id)
8156 struct target_waitstatus last;
8159 get_last_target_status (&last_ptid, &last);
8163 /* If an exception is thrown from this point on, make sure to
8164 propagate GDB's knowledge of the executing state to the
8165 frontend/user running state. A QUIT is an easy exception to see
8166 here, so do this before any filtered output. */
8168 gdb::optional<scoped_finish_thread_state> maybe_finish_thread_state;
8171 maybe_finish_thread_state.emplace (minus_one_ptid);
8172 else if (last.kind == TARGET_WAITKIND_SIGNALLED
8173 || last.kind == TARGET_WAITKIND_EXITED)
8175 /* On some targets, we may still have live threads in the
8176 inferior when we get a process exit event. E.g., for
8177 "checkpoint", when the current checkpoint/fork exits,
8178 linux-fork.c automatically switches to another fork from
8179 within target_mourn_inferior. */
8180 if (inferior_ptid != null_ptid)
8181 maybe_finish_thread_state.emplace (ptid_t (inferior_ptid.pid ()));
8183 else if (last.kind != TARGET_WAITKIND_NO_RESUMED)
8184 maybe_finish_thread_state.emplace (inferior_ptid);
8186 /* As we're presenting a stop, and potentially removing breakpoints,
8187 update the thread list so we can tell whether there are threads
8188 running on the target. With target remote, for example, we can
8189 only learn about new threads when we explicitly update the thread
8190 list. Do this before notifying the interpreters about signal
8191 stops, end of stepping ranges, etc., so that the "new thread"
8192 output is emitted before e.g., "Program received signal FOO",
8193 instead of after. */
8194 update_thread_list ();
8196 if (last.kind == TARGET_WAITKIND_STOPPED && stopped_by_random_signal)
8197 gdb::observers::signal_received.notify (inferior_thread ()->suspend.stop_signal);
8199 /* As with the notification of thread events, we want to delay
8200 notifying the user that we've switched thread context until
8201 the inferior actually stops.
8203 There's no point in saying anything if the inferior has exited.
8204 Note that SIGNALLED here means "exited with a signal", not
8205 "received a signal".
8207 Also skip saying anything in non-stop mode. In that mode, as we
8208 don't want GDB to switch threads behind the user's back, to avoid
8209 races where the user is typing a command to apply to thread x,
8210 but GDB switches to thread y before the user finishes entering
8211 the command, fetch_inferior_event installs a cleanup to restore
8212 the current thread back to the thread the user had selected right
8213 after this event is handled, so we're not really switching, only
8214 informing of a stop. */
8216 && previous_inferior_ptid != inferior_ptid
8217 && target_has_execution
8218 && last.kind != TARGET_WAITKIND_SIGNALLED
8219 && last.kind != TARGET_WAITKIND_EXITED
8220 && last.kind != TARGET_WAITKIND_NO_RESUMED)
8222 SWITCH_THRU_ALL_UIS ()
8224 target_terminal::ours_for_output ();
8225 printf_filtered (_("[Switching to %s]\n"),
8226 target_pid_to_str (inferior_ptid));
8227 annotate_thread_changed ();
8229 previous_inferior_ptid = inferior_ptid;
8232 if (last.kind == TARGET_WAITKIND_NO_RESUMED)
8234 SWITCH_THRU_ALL_UIS ()
8235 if (current_ui->prompt_state == PROMPT_BLOCKED)
8237 target_terminal::ours_for_output ();
8238 printf_filtered (_("No unwaited-for children left.\n"));
8242 /* Note: this depends on the update_thread_list call above. */
8243 maybe_remove_breakpoints ();
8245 /* If an auto-display called a function and that got a signal,
8246 delete that auto-display to avoid an infinite recursion. */
8248 if (stopped_by_random_signal)
8249 disable_current_display ();
8251 SWITCH_THRU_ALL_UIS ()
8253 async_enable_stdin ();
8256 /* Let the user/frontend see the threads as stopped. */
8257 maybe_finish_thread_state.reset ();
8259 /* Select innermost stack frame - i.e., current frame is frame 0,
8260 and current location is based on that. Handle the case where the
8261 dummy call is returning after being stopped. E.g. the dummy call
8262 previously hit a breakpoint. (If the dummy call returns
8263 normally, we won't reach here.) Do this before the stop hook is
8264 run, so that it doesn't get to see the temporary dummy frame,
8265 which is not where we'll present the stop. */
8266 if (has_stack_frames ())
8268 if (stop_stack_dummy == STOP_STACK_DUMMY)
8270 /* Pop the empty frame that contains the stack dummy. This
8271 also restores inferior state prior to the call (struct
8272 infcall_suspend_state). */
8273 struct frame_info *frame = get_current_frame ();
8275 gdb_assert (get_frame_type (frame) == DUMMY_FRAME);
8277 /* frame_pop calls reinit_frame_cache as the last thing it
8278 does which means there's now no selected frame. */
8281 select_frame (get_current_frame ());
8283 /* Set the current source location. */
8284 set_current_sal_from_frame (get_current_frame ());
8287 /* Look up the hook_stop and run it (CLI internally handles problem
8288 of stop_command's pre-hook not existing). */
8289 if (stop_command != NULL)
8291 stop_context saved_context;
8295 execute_cmd_pre_hook (stop_command);
8297 CATCH (ex, RETURN_MASK_ALL)
8299 exception_fprintf (gdb_stderr, ex,
8300 "Error while running hook_stop:\n");
8304 /* If the stop hook resumes the target, then there's no point in
8305 trying to notify about the previous stop; its context is
8306 gone. Likewise if the command switches thread or inferior --
8307 the observers would print a stop for the wrong
8309 if (saved_context.changed ())
8313 /* Notify observers about the stop. This is where the interpreters
8314 print the stop event. */
8315 if (inferior_ptid != null_ptid)
8316 gdb::observers::normal_stop.notify (inferior_thread ()->control.stop_bpstat,
8319 gdb::observers::normal_stop.notify (NULL, stop_print_frame);
8321 annotate_stopped ();
8323 if (target_has_execution)
8325 if (last.kind != TARGET_WAITKIND_SIGNALLED
8326 && last.kind != TARGET_WAITKIND_EXITED)
8327 /* Delete the breakpoint we stopped at, if it wants to be deleted.
8328 Delete any breakpoint that is to be deleted at the next stop. */
8329 breakpoint_auto_delete (inferior_thread ()->control.stop_bpstat);
8332 /* Try to get rid of automatically added inferiors that are no
8333 longer needed. Keeping those around slows down things linearly.
8334 Note that this never removes the current inferior. */
8341 signal_stop_state (int signo)
8343 return signal_stop[signo];
8347 signal_print_state (int signo)
8349 return signal_print[signo];
8353 signal_pass_state (int signo)
8355 return signal_program[signo];
8359 signal_cache_update (int signo)
8363 for (signo = 0; signo < (int) GDB_SIGNAL_LAST; signo++)
8364 signal_cache_update (signo);
8369 signal_pass[signo] = (signal_stop[signo] == 0
8370 && signal_print[signo] == 0
8371 && signal_program[signo] == 1
8372 && signal_catch[signo] == 0);
8376 signal_stop_update (int signo, int state)
8378 int ret = signal_stop[signo];
8380 signal_stop[signo] = state;
8381 signal_cache_update (signo);
8386 signal_print_update (int signo, int state)
8388 int ret = signal_print[signo];
8390 signal_print[signo] = state;
8391 signal_cache_update (signo);
8396 signal_pass_update (int signo, int state)
8398 int ret = signal_program[signo];
8400 signal_program[signo] = state;
8401 signal_cache_update (signo);
8405 /* Update the global 'signal_catch' from INFO and notify the
8409 signal_catch_update (const unsigned int *info)
8413 for (i = 0; i < GDB_SIGNAL_LAST; ++i)
8414 signal_catch[i] = info[i] > 0;
8415 signal_cache_update (-1);
8416 target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
8420 sig_print_header (void)
8422 printf_filtered (_("Signal Stop\tPrint\tPass "
8423 "to program\tDescription\n"));
8427 sig_print_info (enum gdb_signal oursig)
8429 const char *name = gdb_signal_to_name (oursig);
8430 int name_padding = 13 - strlen (name);
8432 if (name_padding <= 0)
8435 printf_filtered ("%s", name);
8436 printf_filtered ("%*.*s ", name_padding, name_padding, " ");
8437 printf_filtered ("%s\t", signal_stop[oursig] ? "Yes" : "No");
8438 printf_filtered ("%s\t", signal_print[oursig] ? "Yes" : "No");
8439 printf_filtered ("%s\t\t", signal_program[oursig] ? "Yes" : "No");
8440 printf_filtered ("%s\n", gdb_signal_to_string (oursig));
8443 /* Specify how various signals in the inferior should be handled. */
8446 handle_command (const char *args, int from_tty)
8448 int digits, wordlen;
8449 int sigfirst, siglast;
8450 enum gdb_signal oursig;
8453 unsigned char *sigs;
8457 error_no_arg (_("signal to handle"));
8460 /* Allocate and zero an array of flags for which signals to handle. */
8462 nsigs = (int) GDB_SIGNAL_LAST;
8463 sigs = (unsigned char *) alloca (nsigs);
8464 memset (sigs, 0, nsigs);
8466 /* Break the command line up into args. */
8468 gdb_argv built_argv (args);
8470 /* Walk through the args, looking for signal oursigs, signal names, and
8471 actions. Signal numbers and signal names may be interspersed with
8472 actions, with the actions being performed for all signals cumulatively
8473 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
8475 for (char *arg : built_argv)
8477 wordlen = strlen (arg);
8478 for (digits = 0; isdigit (arg[digits]); digits++)
8482 sigfirst = siglast = -1;
8484 if (wordlen >= 1 && !strncmp (arg, "all", wordlen))
8486 /* Apply action to all signals except those used by the
8487 debugger. Silently skip those. */
8490 siglast = nsigs - 1;
8492 else if (wordlen >= 1 && !strncmp (arg, "stop", wordlen))
8494 SET_SIGS (nsigs, sigs, signal_stop);
8495 SET_SIGS (nsigs, sigs, signal_print);
8497 else if (wordlen >= 1 && !strncmp (arg, "ignore", wordlen))
8499 UNSET_SIGS (nsigs, sigs, signal_program);
8501 else if (wordlen >= 2 && !strncmp (arg, "print", wordlen))
8503 SET_SIGS (nsigs, sigs, signal_print);
8505 else if (wordlen >= 2 && !strncmp (arg, "pass", wordlen))
8507 SET_SIGS (nsigs, sigs, signal_program);
8509 else if (wordlen >= 3 && !strncmp (arg, "nostop", wordlen))
8511 UNSET_SIGS (nsigs, sigs, signal_stop);
8513 else if (wordlen >= 3 && !strncmp (arg, "noignore", wordlen))
8515 SET_SIGS (nsigs, sigs, signal_program);
8517 else if (wordlen >= 4 && !strncmp (arg, "noprint", wordlen))
8519 UNSET_SIGS (nsigs, sigs, signal_print);
8520 UNSET_SIGS (nsigs, sigs, signal_stop);
8522 else if (wordlen >= 4 && !strncmp (arg, "nopass", wordlen))
8524 UNSET_SIGS (nsigs, sigs, signal_program);
8526 else if (digits > 0)
8528 /* It is numeric. The numeric signal refers to our own
8529 internal signal numbering from target.h, not to host/target
8530 signal number. This is a feature; users really should be
8531 using symbolic names anyway, and the common ones like
8532 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
8534 sigfirst = siglast = (int)
8535 gdb_signal_from_command (atoi (arg));
8536 if (arg[digits] == '-')
8539 gdb_signal_from_command (atoi (arg + digits + 1));
8541 if (sigfirst > siglast)
8543 /* Bet he didn't figure we'd think of this case... */
8544 std::swap (sigfirst, siglast);
8549 oursig = gdb_signal_from_name (arg);
8550 if (oursig != GDB_SIGNAL_UNKNOWN)
8552 sigfirst = siglast = (int) oursig;
8556 /* Not a number and not a recognized flag word => complain. */
8557 error (_("Unrecognized or ambiguous flag word: \"%s\"."), arg);
8561 /* If any signal numbers or symbol names were found, set flags for
8562 which signals to apply actions to. */
8564 for (int signum = sigfirst; signum >= 0 && signum <= siglast; signum++)
8566 switch ((enum gdb_signal) signum)
8568 case GDB_SIGNAL_TRAP:
8569 case GDB_SIGNAL_INT:
8570 if (!allsigs && !sigs[signum])
8572 if (query (_("%s is used by the debugger.\n\
8573 Are you sure you want to change it? "),
8574 gdb_signal_to_name ((enum gdb_signal) signum)))
8580 printf_unfiltered (_("Not confirmed, unchanged.\n"));
8581 gdb_flush (gdb_stdout);
8586 case GDB_SIGNAL_DEFAULT:
8587 case GDB_SIGNAL_UNKNOWN:
8588 /* Make sure that "all" doesn't print these. */
8597 for (int signum = 0; signum < nsigs; signum++)
8600 signal_cache_update (-1);
8601 target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
8602 target_program_signals ((int) GDB_SIGNAL_LAST, signal_program);
8606 /* Show the results. */
8607 sig_print_header ();
8608 for (; signum < nsigs; signum++)
8610 sig_print_info ((enum gdb_signal) signum);
8617 /* Complete the "handle" command. */
8620 handle_completer (struct cmd_list_element *ignore,
8621 completion_tracker &tracker,
8622 const char *text, const char *word)
8624 static const char * const keywords[] =
8638 signal_completer (ignore, tracker, text, word);
8639 complete_on_enum (tracker, keywords, word, word);
8643 gdb_signal_from_command (int num)
8645 if (num >= 1 && num <= 15)
8646 return (enum gdb_signal) num;
8647 error (_("Only signals 1-15 are valid as numeric signals.\n\
8648 Use \"info signals\" for a list of symbolic signals."));
8651 /* Print current contents of the tables set by the handle command.
8652 It is possible we should just be printing signals actually used
8653 by the current target (but for things to work right when switching
8654 targets, all signals should be in the signal tables). */
8657 info_signals_command (const char *signum_exp, int from_tty)
8659 enum gdb_signal oursig;
8661 sig_print_header ();
8665 /* First see if this is a symbol name. */
8666 oursig = gdb_signal_from_name (signum_exp);
8667 if (oursig == GDB_SIGNAL_UNKNOWN)
8669 /* No, try numeric. */
8671 gdb_signal_from_command (parse_and_eval_long (signum_exp));
8673 sig_print_info (oursig);
8677 printf_filtered ("\n");
8678 /* These ugly casts brought to you by the native VAX compiler. */
8679 for (oursig = GDB_SIGNAL_FIRST;
8680 (int) oursig < (int) GDB_SIGNAL_LAST;
8681 oursig = (enum gdb_signal) ((int) oursig + 1))
8685 if (oursig != GDB_SIGNAL_UNKNOWN
8686 && oursig != GDB_SIGNAL_DEFAULT && oursig != GDB_SIGNAL_0)
8687 sig_print_info (oursig);
8690 printf_filtered (_("\nUse the \"handle\" command "
8691 "to change these tables.\n"));
8694 /* The $_siginfo convenience variable is a bit special. We don't know
8695 for sure the type of the value until we actually have a chance to
8696 fetch the data. The type can change depending on gdbarch, so it is
8697 also dependent on which thread you have selected.
8699 1. making $_siginfo be an internalvar that creates a new value on
8702 2. making the value of $_siginfo be an lval_computed value. */
8704 /* This function implements the lval_computed support for reading a
8708 siginfo_value_read (struct value *v)
8710 LONGEST transferred;
8712 /* If we can access registers, so can we access $_siginfo. Likewise
8714 validate_registers_access ();
8717 target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO,
8719 value_contents_all_raw (v),
8721 TYPE_LENGTH (value_type (v)));
8723 if (transferred != TYPE_LENGTH (value_type (v)))
8724 error (_("Unable to read siginfo"));
8727 /* This function implements the lval_computed support for writing a
8731 siginfo_value_write (struct value *v, struct value *fromval)
8733 LONGEST transferred;
8735 /* If we can access registers, so can we access $_siginfo. Likewise
8737 validate_registers_access ();
8739 transferred = target_write (current_top_target (),
8740 TARGET_OBJECT_SIGNAL_INFO,
8742 value_contents_all_raw (fromval),
8744 TYPE_LENGTH (value_type (fromval)));
8746 if (transferred != TYPE_LENGTH (value_type (fromval)))
8747 error (_("Unable to write siginfo"));
8750 static const struct lval_funcs siginfo_value_funcs =
8756 /* Return a new value with the correct type for the siginfo object of
8757 the current thread using architecture GDBARCH. Return a void value
8758 if there's no object available. */
8760 static struct value *
8761 siginfo_make_value (struct gdbarch *gdbarch, struct internalvar *var,
8764 if (target_has_stack
8765 && inferior_ptid != null_ptid
8766 && gdbarch_get_siginfo_type_p (gdbarch))
8768 struct type *type = gdbarch_get_siginfo_type (gdbarch);
8770 return allocate_computed_value (type, &siginfo_value_funcs, NULL);
8773 return allocate_value (builtin_type (gdbarch)->builtin_void);
8777 /* infcall_suspend_state contains state about the program itself like its
8778 registers and any signal it received when it last stopped.
8779 This state must be restored regardless of how the inferior function call
8780 ends (either successfully, or after it hits a breakpoint or signal)
8781 if the program is to properly continue where it left off. */
8783 struct infcall_suspend_state
8785 struct thread_suspend_state thread_suspend;
8788 std::unique_ptr<readonly_detached_regcache> registers;
8790 /* Format of SIGINFO_DATA or NULL if it is not present. */
8791 struct gdbarch *siginfo_gdbarch = nullptr;
8793 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
8794 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
8795 content would be invalid. */
8796 gdb::unique_xmalloc_ptr<gdb_byte> siginfo_data;
8799 infcall_suspend_state_up
8800 save_infcall_suspend_state ()
8802 struct thread_info *tp = inferior_thread ();
8803 struct regcache *regcache = get_current_regcache ();
8804 struct gdbarch *gdbarch = regcache->arch ();
8805 gdb::unique_xmalloc_ptr<gdb_byte> siginfo_data;
8807 if (gdbarch_get_siginfo_type_p (gdbarch))
8809 struct type *type = gdbarch_get_siginfo_type (gdbarch);
8810 size_t len = TYPE_LENGTH (type);
8812 siginfo_data.reset ((gdb_byte *) xmalloc (len));
8814 if (target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO, NULL,
8815 siginfo_data.get (), 0, len) != len)
8817 /* Errors ignored. */
8818 siginfo_data.reset (nullptr);
8822 infcall_suspend_state_up inf_state (new struct infcall_suspend_state);
8826 inf_state->siginfo_gdbarch = gdbarch;
8827 inf_state->siginfo_data = std::move (siginfo_data);
8830 inf_state->thread_suspend = tp->suspend;
8832 /* run_inferior_call will not use the signal due to its `proceed' call with
8833 GDB_SIGNAL_0 anyway. */
8834 tp->suspend.stop_signal = GDB_SIGNAL_0;
8836 inf_state->registers.reset (new readonly_detached_regcache (*regcache));
8841 /* Restore inferior session state to INF_STATE. */
8844 restore_infcall_suspend_state (struct infcall_suspend_state *inf_state)
8846 struct thread_info *tp = inferior_thread ();
8847 struct regcache *regcache = get_current_regcache ();
8848 struct gdbarch *gdbarch = regcache->arch ();
8850 tp->suspend = inf_state->thread_suspend;
8852 if (inf_state->siginfo_gdbarch == gdbarch)
8854 struct type *type = gdbarch_get_siginfo_type (gdbarch);
8856 /* Errors ignored. */
8857 target_write (current_top_target (), TARGET_OBJECT_SIGNAL_INFO, NULL,
8858 inf_state->siginfo_data.get (), 0, TYPE_LENGTH (type));
8861 /* The inferior can be gone if the user types "print exit(0)"
8862 (and perhaps other times). */
8863 if (target_has_execution)
8864 /* NB: The register write goes through to the target. */
8865 regcache->restore (inf_state->registers.get ());
8867 discard_infcall_suspend_state (inf_state);
8871 discard_infcall_suspend_state (struct infcall_suspend_state *inf_state)
8876 readonly_detached_regcache *
8877 get_infcall_suspend_state_regcache (struct infcall_suspend_state *inf_state)
8879 return inf_state->registers.get ();
8882 /* infcall_control_state contains state regarding gdb's control of the
8883 inferior itself like stepping control. It also contains session state like
8884 the user's currently selected frame. */
8886 struct infcall_control_state
8888 struct thread_control_state thread_control;
8889 struct inferior_control_state inferior_control;
8892 enum stop_stack_kind stop_stack_dummy = STOP_NONE;
8893 int stopped_by_random_signal = 0;
8895 /* ID if the selected frame when the inferior function call was made. */
8896 struct frame_id selected_frame_id {};
8899 /* Save all of the information associated with the inferior<==>gdb
8902 infcall_control_state_up
8903 save_infcall_control_state ()
8905 infcall_control_state_up inf_status (new struct infcall_control_state);
8906 struct thread_info *tp = inferior_thread ();
8907 struct inferior *inf = current_inferior ();
8909 inf_status->thread_control = tp->control;
8910 inf_status->inferior_control = inf->control;
8912 tp->control.step_resume_breakpoint = NULL;
8913 tp->control.exception_resume_breakpoint = NULL;
8915 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
8916 chain. If caller's caller is walking the chain, they'll be happier if we
8917 hand them back the original chain when restore_infcall_control_state is
8919 tp->control.stop_bpstat = bpstat_copy (tp->control.stop_bpstat);
8922 inf_status->stop_stack_dummy = stop_stack_dummy;
8923 inf_status->stopped_by_random_signal = stopped_by_random_signal;
8925 inf_status->selected_frame_id = get_frame_id (get_selected_frame (NULL));
8931 restore_selected_frame (const frame_id &fid)
8933 frame_info *frame = frame_find_by_id (fid);
8935 /* If inf_status->selected_frame_id is NULL, there was no previously
8939 warning (_("Unable to restore previously selected frame."));
8943 select_frame (frame);
8946 /* Restore inferior session state to INF_STATUS. */
8949 restore_infcall_control_state (struct infcall_control_state *inf_status)
8951 struct thread_info *tp = inferior_thread ();
8952 struct inferior *inf = current_inferior ();
8954 if (tp->control.step_resume_breakpoint)
8955 tp->control.step_resume_breakpoint->disposition = disp_del_at_next_stop;
8957 if (tp->control.exception_resume_breakpoint)
8958 tp->control.exception_resume_breakpoint->disposition
8959 = disp_del_at_next_stop;
8961 /* Handle the bpstat_copy of the chain. */
8962 bpstat_clear (&tp->control.stop_bpstat);
8964 tp->control = inf_status->thread_control;
8965 inf->control = inf_status->inferior_control;
8968 stop_stack_dummy = inf_status->stop_stack_dummy;
8969 stopped_by_random_signal = inf_status->stopped_by_random_signal;
8971 if (target_has_stack)
8973 /* The point of the try/catch is that if the stack is clobbered,
8974 walking the stack might encounter a garbage pointer and
8975 error() trying to dereference it. */
8978 restore_selected_frame (inf_status->selected_frame_id);
8980 CATCH (ex, RETURN_MASK_ERROR)
8982 exception_fprintf (gdb_stderr, ex,
8983 "Unable to restore previously selected frame:\n");
8984 /* Error in restoring the selected frame. Select the
8986 select_frame (get_current_frame ());
8995 discard_infcall_control_state (struct infcall_control_state *inf_status)
8997 if (inf_status->thread_control.step_resume_breakpoint)
8998 inf_status->thread_control.step_resume_breakpoint->disposition
8999 = disp_del_at_next_stop;
9001 if (inf_status->thread_control.exception_resume_breakpoint)
9002 inf_status->thread_control.exception_resume_breakpoint->disposition
9003 = disp_del_at_next_stop;
9005 /* See save_infcall_control_state for info on stop_bpstat. */
9006 bpstat_clear (&inf_status->thread_control.stop_bpstat);
9014 clear_exit_convenience_vars (void)
9016 clear_internalvar (lookup_internalvar ("_exitsignal"));
9017 clear_internalvar (lookup_internalvar ("_exitcode"));
9021 /* User interface for reverse debugging:
9022 Set exec-direction / show exec-direction commands
9023 (returns error unless target implements to_set_exec_direction method). */
9025 enum exec_direction_kind execution_direction = EXEC_FORWARD;
9026 static const char exec_forward[] = "forward";
9027 static const char exec_reverse[] = "reverse";
9028 static const char *exec_direction = exec_forward;
9029 static const char *const exec_direction_names[] = {
9036 set_exec_direction_func (const char *args, int from_tty,
9037 struct cmd_list_element *cmd)
9039 if (target_can_execute_reverse)
9041 if (!strcmp (exec_direction, exec_forward))
9042 execution_direction = EXEC_FORWARD;
9043 else if (!strcmp (exec_direction, exec_reverse))
9044 execution_direction = EXEC_REVERSE;
9048 exec_direction = exec_forward;
9049 error (_("Target does not support this operation."));
9054 show_exec_direction_func (struct ui_file *out, int from_tty,
9055 struct cmd_list_element *cmd, const char *value)
9057 switch (execution_direction) {
9059 fprintf_filtered (out, _("Forward.\n"));
9062 fprintf_filtered (out, _("Reverse.\n"));
9065 internal_error (__FILE__, __LINE__,
9066 _("bogus execution_direction value: %d"),
9067 (int) execution_direction);
9072 show_schedule_multiple (struct ui_file *file, int from_tty,
9073 struct cmd_list_element *c, const char *value)
9075 fprintf_filtered (file, _("Resuming the execution of threads "
9076 "of all processes is %s.\n"), value);
9079 /* Implementation of `siginfo' variable. */
9081 static const struct internalvar_funcs siginfo_funcs =
9088 /* Callback for infrun's target events source. This is marked when a
9089 thread has a pending status to process. */
9092 infrun_async_inferior_event_handler (gdb_client_data data)
9094 inferior_event_handler (INF_REG_EVENT, NULL);
9098 _initialize_infrun (void)
9102 struct cmd_list_element *c;
9104 /* Register extra event sources in the event loop. */
9105 infrun_async_inferior_event_token
9106 = create_async_event_handler (infrun_async_inferior_event_handler, NULL);
9108 add_info ("signals", info_signals_command, _("\
9109 What debugger does when program gets various signals.\n\
9110 Specify a signal as argument to print info on that signal only."));
9111 add_info_alias ("handle", "signals", 0);
9113 c = add_com ("handle", class_run, handle_command, _("\
9114 Specify how to handle signals.\n\
9115 Usage: handle SIGNAL [ACTIONS]\n\
9116 Args are signals and actions to apply to those signals.\n\
9117 If no actions are specified, the current settings for the specified signals\n\
9118 will be displayed instead.\n\
9120 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
9121 from 1-15 are allowed for compatibility with old versions of GDB.\n\
9122 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
9123 The special arg \"all\" is recognized to mean all signals except those\n\
9124 used by the debugger, typically SIGTRAP and SIGINT.\n\
9126 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
9127 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
9128 Stop means reenter debugger if this signal happens (implies print).\n\
9129 Print means print a message if this signal happens.\n\
9130 Pass means let program see this signal; otherwise program doesn't know.\n\
9131 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
9132 Pass and Stop may be combined.\n\
9134 Multiple signals may be specified. Signal numbers and signal names\n\
9135 may be interspersed with actions, with the actions being performed for\n\
9136 all signals cumulatively specified."));
9137 set_cmd_completer (c, handle_completer);
9140 stop_command = add_cmd ("stop", class_obscure,
9141 not_just_help_class_command, _("\
9142 There is no `stop' command, but you can set a hook on `stop'.\n\
9143 This allows you to set a list of commands to be run each time execution\n\
9144 of the program stops."), &cmdlist);
9146 add_setshow_zuinteger_cmd ("infrun", class_maintenance, &debug_infrun, _("\
9147 Set inferior debugging."), _("\
9148 Show inferior debugging."), _("\
9149 When non-zero, inferior specific debugging is enabled."),
9152 &setdebuglist, &showdebuglist);
9154 add_setshow_boolean_cmd ("displaced", class_maintenance,
9155 &debug_displaced, _("\
9156 Set displaced stepping debugging."), _("\
9157 Show displaced stepping debugging."), _("\
9158 When non-zero, displaced stepping specific debugging is enabled."),
9160 show_debug_displaced,
9161 &setdebuglist, &showdebuglist);
9163 add_setshow_boolean_cmd ("non-stop", no_class,
9165 Set whether gdb controls the inferior in non-stop mode."), _("\
9166 Show whether gdb controls the inferior in non-stop mode."), _("\
9167 When debugging a multi-threaded program and this setting is\n\
9168 off (the default, also called all-stop mode), when one thread stops\n\
9169 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
9170 all other threads in the program while you interact with the thread of\n\
9171 interest. When you continue or step a thread, you can allow the other\n\
9172 threads to run, or have them remain stopped, but while you inspect any\n\
9173 thread's state, all threads stop.\n\
9175 In non-stop mode, when one thread stops, other threads can continue\n\
9176 to run freely. You'll be able to step each thread independently,\n\
9177 leave it stopped or free to run as needed."),
9183 numsigs = (int) GDB_SIGNAL_LAST;
9184 signal_stop = XNEWVEC (unsigned char, numsigs);
9185 signal_print = XNEWVEC (unsigned char, numsigs);
9186 signal_program = XNEWVEC (unsigned char, numsigs);
9187 signal_catch = XNEWVEC (unsigned char, numsigs);
9188 signal_pass = XNEWVEC (unsigned char, numsigs);
9189 for (i = 0; i < numsigs; i++)
9192 signal_print[i] = 1;
9193 signal_program[i] = 1;
9194 signal_catch[i] = 0;
9197 /* Signals caused by debugger's own actions should not be given to
9198 the program afterwards.
9200 Do not deliver GDB_SIGNAL_TRAP by default, except when the user
9201 explicitly specifies that it should be delivered to the target
9202 program. Typically, that would occur when a user is debugging a
9203 target monitor on a simulator: the target monitor sets a
9204 breakpoint; the simulator encounters this breakpoint and halts
9205 the simulation handing control to GDB; GDB, noting that the stop
9206 address doesn't map to any known breakpoint, returns control back
9207 to the simulator; the simulator then delivers the hardware
9208 equivalent of a GDB_SIGNAL_TRAP to the program being
9210 signal_program[GDB_SIGNAL_TRAP] = 0;
9211 signal_program[GDB_SIGNAL_INT] = 0;
9213 /* Signals that are not errors should not normally enter the debugger. */
9214 signal_stop[GDB_SIGNAL_ALRM] = 0;
9215 signal_print[GDB_SIGNAL_ALRM] = 0;
9216 signal_stop[GDB_SIGNAL_VTALRM] = 0;
9217 signal_print[GDB_SIGNAL_VTALRM] = 0;
9218 signal_stop[GDB_SIGNAL_PROF] = 0;
9219 signal_print[GDB_SIGNAL_PROF] = 0;
9220 signal_stop[GDB_SIGNAL_CHLD] = 0;
9221 signal_print[GDB_SIGNAL_CHLD] = 0;
9222 signal_stop[GDB_SIGNAL_IO] = 0;
9223 signal_print[GDB_SIGNAL_IO] = 0;
9224 signal_stop[GDB_SIGNAL_POLL] = 0;
9225 signal_print[GDB_SIGNAL_POLL] = 0;
9226 signal_stop[GDB_SIGNAL_URG] = 0;
9227 signal_print[GDB_SIGNAL_URG] = 0;
9228 signal_stop[GDB_SIGNAL_WINCH] = 0;
9229 signal_print[GDB_SIGNAL_WINCH] = 0;
9230 signal_stop[GDB_SIGNAL_PRIO] = 0;
9231 signal_print[GDB_SIGNAL_PRIO] = 0;
9233 /* These signals are used internally by user-level thread
9234 implementations. (See signal(5) on Solaris.) Like the above
9235 signals, a healthy program receives and handles them as part of
9236 its normal operation. */
9237 signal_stop[GDB_SIGNAL_LWP] = 0;
9238 signal_print[GDB_SIGNAL_LWP] = 0;
9239 signal_stop[GDB_SIGNAL_WAITING] = 0;
9240 signal_print[GDB_SIGNAL_WAITING] = 0;
9241 signal_stop[GDB_SIGNAL_CANCEL] = 0;
9242 signal_print[GDB_SIGNAL_CANCEL] = 0;
9243 signal_stop[GDB_SIGNAL_LIBRT] = 0;
9244 signal_print[GDB_SIGNAL_LIBRT] = 0;
9246 /* Update cached state. */
9247 signal_cache_update (-1);
9249 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support,
9250 &stop_on_solib_events, _("\
9251 Set stopping for shared library events."), _("\
9252 Show stopping for shared library events."), _("\
9253 If nonzero, gdb will give control to the user when the dynamic linker\n\
9254 notifies gdb of shared library events. The most common event of interest\n\
9255 to the user would be loading/unloading of a new library."),
9256 set_stop_on_solib_events,
9257 show_stop_on_solib_events,
9258 &setlist, &showlist);
9260 add_setshow_enum_cmd ("follow-fork-mode", class_run,
9261 follow_fork_mode_kind_names,
9262 &follow_fork_mode_string, _("\
9263 Set debugger response to a program call of fork or vfork."), _("\
9264 Show debugger response to a program call of fork or vfork."), _("\
9265 A fork or vfork creates a new process. follow-fork-mode can be:\n\
9266 parent - the original process is debugged after a fork\n\
9267 child - the new process is debugged after a fork\n\
9268 The unfollowed process will continue to run.\n\
9269 By default, the debugger will follow the parent process."),
9271 show_follow_fork_mode_string,
9272 &setlist, &showlist);
9274 add_setshow_enum_cmd ("follow-exec-mode", class_run,
9275 follow_exec_mode_names,
9276 &follow_exec_mode_string, _("\
9277 Set debugger response to a program call of exec."), _("\
9278 Show debugger response to a program call of exec."), _("\
9279 An exec call replaces the program image of a process.\n\
9281 follow-exec-mode can be:\n\
9283 new - the debugger creates a new inferior and rebinds the process\n\
9284 to this new inferior. The program the process was running before\n\
9285 the exec call can be restarted afterwards by restarting the original\n\
9288 same - the debugger keeps the process bound to the same inferior.\n\
9289 The new executable image replaces the previous executable loaded in\n\
9290 the inferior. Restarting the inferior after the exec call restarts\n\
9291 the executable the process was running after the exec call.\n\
9293 By default, the debugger will use the same inferior."),
9295 show_follow_exec_mode_string,
9296 &setlist, &showlist);
9298 add_setshow_enum_cmd ("scheduler-locking", class_run,
9299 scheduler_enums, &scheduler_mode, _("\
9300 Set mode for locking scheduler during execution."), _("\
9301 Show mode for locking scheduler during execution."), _("\
9302 off == no locking (threads may preempt at any time)\n\
9303 on == full locking (no thread except the current thread may run)\n\
9304 This applies to both normal execution and replay mode.\n\
9305 step == scheduler locked during stepping commands (step, next, stepi, nexti).\n\
9306 In this mode, other threads may run during other commands.\n\
9307 This applies to both normal execution and replay mode.\n\
9308 replay == scheduler locked in replay mode and unlocked during normal execution."),
9309 set_schedlock_func, /* traps on target vector */
9310 show_scheduler_mode,
9311 &setlist, &showlist);
9313 add_setshow_boolean_cmd ("schedule-multiple", class_run, &sched_multi, _("\
9314 Set mode for resuming threads of all processes."), _("\
9315 Show mode for resuming threads of all processes."), _("\
9316 When on, execution commands (such as 'continue' or 'next') resume all\n\
9317 threads of all processes. When off (which is the default), execution\n\
9318 commands only resume the threads of the current process. The set of\n\
9319 threads that are resumed is further refined by the scheduler-locking\n\
9320 mode (see help set scheduler-locking)."),
9322 show_schedule_multiple,
9323 &setlist, &showlist);
9325 add_setshow_boolean_cmd ("step-mode", class_run, &step_stop_if_no_debug, _("\
9326 Set mode of the step operation."), _("\
9327 Show mode of the step operation."), _("\
9328 When set, doing a step over a function without debug line information\n\
9329 will stop at the first instruction of that function. Otherwise, the\n\
9330 function is skipped and the step command stops at a different source line."),
9332 show_step_stop_if_no_debug,
9333 &setlist, &showlist);
9335 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run,
9336 &can_use_displaced_stepping, _("\
9337 Set debugger's willingness to use displaced stepping."), _("\
9338 Show debugger's willingness to use displaced stepping."), _("\
9339 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
9340 supported by the target architecture. If off, gdb will not use displaced\n\
9341 stepping to step over breakpoints, even if such is supported by the target\n\
9342 architecture. If auto (which is the default), gdb will use displaced stepping\n\
9343 if the target architecture supports it and non-stop mode is active, but will not\n\
9344 use it in all-stop mode (see help set non-stop)."),
9346 show_can_use_displaced_stepping,
9347 &setlist, &showlist);
9349 add_setshow_enum_cmd ("exec-direction", class_run, exec_direction_names,
9350 &exec_direction, _("Set direction of execution.\n\
9351 Options are 'forward' or 'reverse'."),
9352 _("Show direction of execution (forward/reverse)."),
9353 _("Tells gdb whether to execute forward or backward."),
9354 set_exec_direction_func, show_exec_direction_func,
9355 &setlist, &showlist);
9357 /* Set/show detach-on-fork: user-settable mode. */
9359 add_setshow_boolean_cmd ("detach-on-fork", class_run, &detach_fork, _("\
9360 Set whether gdb will detach the child of a fork."), _("\
9361 Show whether gdb will detach the child of a fork."), _("\
9362 Tells gdb whether to detach the child of a fork."),
9363 NULL, NULL, &setlist, &showlist);
9365 /* Set/show disable address space randomization mode. */
9367 add_setshow_boolean_cmd ("disable-randomization", class_support,
9368 &disable_randomization, _("\
9369 Set disabling of debuggee's virtual address space randomization."), _("\
9370 Show disabling of debuggee's virtual address space randomization."), _("\
9371 When this mode is on (which is the default), randomization of the virtual\n\
9372 address space is disabled. Standalone programs run with the randomization\n\
9373 enabled by default on some platforms."),
9374 &set_disable_randomization,
9375 &show_disable_randomization,
9376 &setlist, &showlist);
9378 /* ptid initializations */
9379 inferior_ptid = null_ptid;
9380 target_last_wait_ptid = minus_one_ptid;
9382 gdb::observers::thread_ptid_changed.attach (infrun_thread_ptid_changed);
9383 gdb::observers::thread_stop_requested.attach (infrun_thread_stop_requested);
9384 gdb::observers::thread_exit.attach (infrun_thread_thread_exit);
9385 gdb::observers::inferior_exit.attach (infrun_inferior_exit);
9387 /* Explicitly create without lookup, since that tries to create a
9388 value with a void typed value, and when we get here, gdbarch
9389 isn't initialized yet. At this point, we're quite sure there
9390 isn't another convenience variable of the same name. */
9391 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs, NULL);
9393 add_setshow_boolean_cmd ("observer", no_class,
9394 &observer_mode_1, _("\
9395 Set whether gdb controls the inferior in observer mode."), _("\
9396 Show whether gdb controls the inferior in observer mode."), _("\
9397 In observer mode, GDB can get data from the inferior, but not\n\
9398 affect its execution. Registers and memory may not be changed,\n\
9399 breakpoints may not be set, and the program cannot be interrupted\n\