1 /* Target-struct-independent code to start (run) and stop an inferior
4 Copyright (C) 1986-2013 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/>. */
22 #include "gdb_string.h"
27 #include "exceptions.h"
28 #include "breakpoint.h"
32 #include "cli/cli-script.h"
34 #include "gdbthread.h"
46 #include "dictionary.h"
48 #include "gdb_assert.h"
49 #include "mi/mi-common.h"
50 #include "event-top.h"
52 #include "inline-frame.h"
54 #include "tracepoint.h"
55 #include "continuations.h"
60 #include "completer.h"
61 #include "target-descriptions.h"
63 /* Prototypes for local functions */
65 static void signals_info (char *, int);
67 static void handle_command (char *, int);
69 static void sig_print_info (enum gdb_signal);
71 static void sig_print_header (void);
73 static void resume_cleanups (void *);
75 static int hook_stop_stub (void *);
77 static int restore_selected_frame (void *);
79 static int follow_fork (void);
81 static void set_schedlock_func (char *args, int from_tty,
82 struct cmd_list_element *c);
84 static int currently_stepping (struct thread_info *tp);
86 static int currently_stepping_or_nexting_callback (struct thread_info *tp,
89 static void xdb_handle_command (char *args, int from_tty);
91 static int prepare_to_proceed (int);
93 static void print_exited_reason (int exitstatus);
95 static void print_signal_exited_reason (enum gdb_signal siggnal);
97 static void print_no_history_reason (void);
99 static void print_signal_received_reason (enum gdb_signal siggnal);
101 static void print_end_stepping_range_reason (void);
103 void _initialize_infrun (void);
105 void nullify_last_target_wait_ptid (void);
107 static void insert_hp_step_resume_breakpoint_at_frame (struct frame_info *);
109 static void insert_step_resume_breakpoint_at_caller (struct frame_info *);
111 static void insert_longjmp_resume_breakpoint (struct gdbarch *, CORE_ADDR);
113 /* When set, stop the 'step' command if we enter a function which has
114 no line number information. The normal behavior is that we step
115 over such function. */
116 int step_stop_if_no_debug = 0;
118 show_step_stop_if_no_debug (struct ui_file *file, int from_tty,
119 struct cmd_list_element *c, const char *value)
121 fprintf_filtered (file, _("Mode of the step operation is %s.\n"), value);
124 /* In asynchronous mode, but simulating synchronous execution. */
126 int sync_execution = 0;
128 /* wait_for_inferior and normal_stop use this to notify the user
129 when the inferior stopped in a different thread than it had been
132 static ptid_t previous_inferior_ptid;
134 /* Default behavior is to detach newly forked processes (legacy). */
137 int debug_displaced = 0;
139 show_debug_displaced (struct ui_file *file, int from_tty,
140 struct cmd_list_element *c, const char *value)
142 fprintf_filtered (file, _("Displace stepping debugging is %s.\n"), value);
145 unsigned int debug_infrun = 0;
147 show_debug_infrun (struct ui_file *file, int from_tty,
148 struct cmd_list_element *c, const char *value)
150 fprintf_filtered (file, _("Inferior debugging is %s.\n"), value);
154 /* Support for disabling address space randomization. */
156 int disable_randomization = 1;
159 show_disable_randomization (struct ui_file *file, int from_tty,
160 struct cmd_list_element *c, const char *value)
162 if (target_supports_disable_randomization ())
163 fprintf_filtered (file,
164 _("Disabling randomization of debuggee's "
165 "virtual address space is %s.\n"),
168 fputs_filtered (_("Disabling randomization of debuggee's "
169 "virtual address space is unsupported on\n"
170 "this platform.\n"), file);
174 set_disable_randomization (char *args, int from_tty,
175 struct cmd_list_element *c)
177 if (!target_supports_disable_randomization ())
178 error (_("Disabling randomization of debuggee's "
179 "virtual address space is unsupported on\n"
184 /* If the program uses ELF-style shared libraries, then calls to
185 functions in shared libraries go through stubs, which live in a
186 table called the PLT (Procedure Linkage Table). The first time the
187 function is called, the stub sends control to the dynamic linker,
188 which looks up the function's real address, patches the stub so
189 that future calls will go directly to the function, and then passes
190 control to the function.
192 If we are stepping at the source level, we don't want to see any of
193 this --- we just want to skip over the stub and the dynamic linker.
194 The simple approach is to single-step until control leaves the
197 However, on some systems (e.g., Red Hat's 5.2 distribution) the
198 dynamic linker calls functions in the shared C library, so you
199 can't tell from the PC alone whether the dynamic linker is still
200 running. In this case, we use a step-resume breakpoint to get us
201 past the dynamic linker, as if we were using "next" to step over a
204 in_solib_dynsym_resolve_code() says whether we're in the dynamic
205 linker code or not. Normally, this means we single-step. However,
206 if SKIP_SOLIB_RESOLVER then returns non-zero, then its value is an
207 address where we can place a step-resume breakpoint to get past the
208 linker's symbol resolution function.
210 in_solib_dynsym_resolve_code() can generally be implemented in a
211 pretty portable way, by comparing the PC against the address ranges
212 of the dynamic linker's sections.
214 SKIP_SOLIB_RESOLVER is generally going to be system-specific, since
215 it depends on internal details of the dynamic linker. It's usually
216 not too hard to figure out where to put a breakpoint, but it
217 certainly isn't portable. SKIP_SOLIB_RESOLVER should do plenty of
218 sanity checking. If it can't figure things out, returning zero and
219 getting the (possibly confusing) stepping behavior is better than
220 signalling an error, which will obscure the change in the
223 /* This function returns TRUE if pc is the address of an instruction
224 that lies within the dynamic linker (such as the event hook, or the
227 This function must be used only when a dynamic linker event has
228 been caught, and the inferior is being stepped out of the hook, or
229 undefined results are guaranteed. */
231 #ifndef SOLIB_IN_DYNAMIC_LINKER
232 #define SOLIB_IN_DYNAMIC_LINKER(pid,pc) 0
235 /* "Observer mode" is somewhat like a more extreme version of
236 non-stop, in which all GDB operations that might affect the
237 target's execution have been disabled. */
239 static int non_stop_1 = 0;
241 int observer_mode = 0;
242 static int observer_mode_1 = 0;
245 set_observer_mode (char *args, int from_tty,
246 struct cmd_list_element *c)
248 extern int pagination_enabled;
250 if (target_has_execution)
252 observer_mode_1 = observer_mode;
253 error (_("Cannot change this setting while the inferior is running."));
256 observer_mode = observer_mode_1;
258 may_write_registers = !observer_mode;
259 may_write_memory = !observer_mode;
260 may_insert_breakpoints = !observer_mode;
261 may_insert_tracepoints = !observer_mode;
262 /* We can insert fast tracepoints in or out of observer mode,
263 but enable them if we're going into this mode. */
265 may_insert_fast_tracepoints = 1;
266 may_stop = !observer_mode;
267 update_target_permissions ();
269 /* Going *into* observer mode we must force non-stop, then
270 going out we leave it that way. */
273 target_async_permitted = 1;
274 pagination_enabled = 0;
275 non_stop = non_stop_1 = 1;
279 printf_filtered (_("Observer mode is now %s.\n"),
280 (observer_mode ? "on" : "off"));
284 show_observer_mode (struct ui_file *file, int from_tty,
285 struct cmd_list_element *c, const char *value)
287 fprintf_filtered (file, _("Observer mode is %s.\n"), value);
290 /* This updates the value of observer mode based on changes in
291 permissions. Note that we are deliberately ignoring the values of
292 may-write-registers and may-write-memory, since the user may have
293 reason to enable these during a session, for instance to turn on a
294 debugging-related global. */
297 update_observer_mode (void)
301 newval = (!may_insert_breakpoints
302 && !may_insert_tracepoints
303 && may_insert_fast_tracepoints
307 /* Let the user know if things change. */
308 if (newval != observer_mode)
309 printf_filtered (_("Observer mode is now %s.\n"),
310 (newval ? "on" : "off"));
312 observer_mode = observer_mode_1 = newval;
315 /* Tables of how to react to signals; the user sets them. */
317 static unsigned char *signal_stop;
318 static unsigned char *signal_print;
319 static unsigned char *signal_program;
321 /* Table of signals that are registered with "catch signal". A
322 non-zero entry indicates that the signal is caught by some "catch
323 signal" command. This has size GDB_SIGNAL_LAST, to accommodate all
325 static unsigned char *signal_catch;
327 /* Table of signals that the target may silently handle.
328 This is automatically determined from the flags above,
329 and simply cached here. */
330 static unsigned char *signal_pass;
332 #define SET_SIGS(nsigs,sigs,flags) \
334 int signum = (nsigs); \
335 while (signum-- > 0) \
336 if ((sigs)[signum]) \
337 (flags)[signum] = 1; \
340 #define UNSET_SIGS(nsigs,sigs,flags) \
342 int signum = (nsigs); \
343 while (signum-- > 0) \
344 if ((sigs)[signum]) \
345 (flags)[signum] = 0; \
348 /* Update the target's copy of SIGNAL_PROGRAM. The sole purpose of
349 this function is to avoid exporting `signal_program'. */
352 update_signals_program_target (void)
354 target_program_signals ((int) GDB_SIGNAL_LAST, signal_program);
357 /* Value to pass to target_resume() to cause all threads to resume. */
359 #define RESUME_ALL minus_one_ptid
361 /* Command list pointer for the "stop" placeholder. */
363 static struct cmd_list_element *stop_command;
365 /* Function inferior was in as of last step command. */
367 static struct symbol *step_start_function;
369 /* Nonzero if we want to give control to the user when we're notified
370 of shared library events by the dynamic linker. */
371 int stop_on_solib_events;
373 show_stop_on_solib_events (struct ui_file *file, int from_tty,
374 struct cmd_list_element *c, const char *value)
376 fprintf_filtered (file, _("Stopping for shared library events is %s.\n"),
380 /* Nonzero means expecting a trace trap
381 and should stop the inferior and return silently when it happens. */
385 /* Save register contents here when executing a "finish" command or are
386 about to pop a stack dummy frame, if-and-only-if proceed_to_finish is set.
387 Thus this contains the return value from the called function (assuming
388 values are returned in a register). */
390 struct regcache *stop_registers;
392 /* Nonzero after stop if current stack frame should be printed. */
394 static int stop_print_frame;
396 /* This is a cached copy of the pid/waitstatus of the last event
397 returned by target_wait()/deprecated_target_wait_hook(). This
398 information is returned by get_last_target_status(). */
399 static ptid_t target_last_wait_ptid;
400 static struct target_waitstatus target_last_waitstatus;
402 static void context_switch (ptid_t ptid);
404 void init_thread_stepping_state (struct thread_info *tss);
406 static void init_infwait_state (void);
408 static const char follow_fork_mode_child[] = "child";
409 static const char follow_fork_mode_parent[] = "parent";
411 static const char *const follow_fork_mode_kind_names[] = {
412 follow_fork_mode_child,
413 follow_fork_mode_parent,
417 static const char *follow_fork_mode_string = follow_fork_mode_parent;
419 show_follow_fork_mode_string (struct ui_file *file, int from_tty,
420 struct cmd_list_element *c, const char *value)
422 fprintf_filtered (file,
423 _("Debugger response to a program "
424 "call of fork or vfork is \"%s\".\n"),
429 /* Tell the target to follow the fork we're stopped at. Returns true
430 if the inferior should be resumed; false, if the target for some
431 reason decided it's best not to resume. */
436 int follow_child = (follow_fork_mode_string == follow_fork_mode_child);
437 int should_resume = 1;
438 struct thread_info *tp;
440 /* Copy user stepping state to the new inferior thread. FIXME: the
441 followed fork child thread should have a copy of most of the
442 parent thread structure's run control related fields, not just these.
443 Initialized to avoid "may be used uninitialized" warnings from gcc. */
444 struct breakpoint *step_resume_breakpoint = NULL;
445 struct breakpoint *exception_resume_breakpoint = NULL;
446 CORE_ADDR step_range_start = 0;
447 CORE_ADDR step_range_end = 0;
448 struct frame_id step_frame_id = { 0 };
453 struct target_waitstatus wait_status;
455 /* Get the last target status returned by target_wait(). */
456 get_last_target_status (&wait_ptid, &wait_status);
458 /* If not stopped at a fork event, then there's nothing else to
460 if (wait_status.kind != TARGET_WAITKIND_FORKED
461 && wait_status.kind != TARGET_WAITKIND_VFORKED)
464 /* Check if we switched over from WAIT_PTID, since the event was
466 if (!ptid_equal (wait_ptid, minus_one_ptid)
467 && !ptid_equal (inferior_ptid, wait_ptid))
469 /* We did. Switch back to WAIT_PTID thread, to tell the
470 target to follow it (in either direction). We'll
471 afterwards refuse to resume, and inform the user what
473 switch_to_thread (wait_ptid);
478 tp = inferior_thread ();
480 /* If there were any forks/vforks that were caught and are now to be
481 followed, then do so now. */
482 switch (tp->pending_follow.kind)
484 case TARGET_WAITKIND_FORKED:
485 case TARGET_WAITKIND_VFORKED:
487 ptid_t parent, child;
489 /* If the user did a next/step, etc, over a fork call,
490 preserve the stepping state in the fork child. */
491 if (follow_child && should_resume)
493 step_resume_breakpoint = clone_momentary_breakpoint
494 (tp->control.step_resume_breakpoint);
495 step_range_start = tp->control.step_range_start;
496 step_range_end = tp->control.step_range_end;
497 step_frame_id = tp->control.step_frame_id;
498 exception_resume_breakpoint
499 = clone_momentary_breakpoint (tp->control.exception_resume_breakpoint);
501 /* For now, delete the parent's sr breakpoint, otherwise,
502 parent/child sr breakpoints are considered duplicates,
503 and the child version will not be installed. Remove
504 this when the breakpoints module becomes aware of
505 inferiors and address spaces. */
506 delete_step_resume_breakpoint (tp);
507 tp->control.step_range_start = 0;
508 tp->control.step_range_end = 0;
509 tp->control.step_frame_id = null_frame_id;
510 delete_exception_resume_breakpoint (tp);
513 parent = inferior_ptid;
514 child = tp->pending_follow.value.related_pid;
516 /* Tell the target to do whatever is necessary to follow
517 either parent or child. */
518 if (target_follow_fork (follow_child))
520 /* Target refused to follow, or there's some other reason
521 we shouldn't resume. */
526 /* This pending follow fork event is now handled, one way
527 or another. The previous selected thread may be gone
528 from the lists by now, but if it is still around, need
529 to clear the pending follow request. */
530 tp = find_thread_ptid (parent);
532 tp->pending_follow.kind = TARGET_WAITKIND_SPURIOUS;
534 /* This makes sure we don't try to apply the "Switched
535 over from WAIT_PID" logic above. */
536 nullify_last_target_wait_ptid ();
538 /* If we followed the child, switch to it... */
541 switch_to_thread (child);
543 /* ... and preserve the stepping state, in case the
544 user was stepping over the fork call. */
547 tp = inferior_thread ();
548 tp->control.step_resume_breakpoint
549 = step_resume_breakpoint;
550 tp->control.step_range_start = step_range_start;
551 tp->control.step_range_end = step_range_end;
552 tp->control.step_frame_id = step_frame_id;
553 tp->control.exception_resume_breakpoint
554 = exception_resume_breakpoint;
558 /* If we get here, it was because we're trying to
559 resume from a fork catchpoint, but, the user
560 has switched threads away from the thread that
561 forked. In that case, the resume command
562 issued is most likely not applicable to the
563 child, so just warn, and refuse to resume. */
564 warning (_("Not resuming: switched threads "
565 "before following fork child.\n"));
568 /* Reset breakpoints in the child as appropriate. */
569 follow_inferior_reset_breakpoints ();
572 switch_to_thread (parent);
576 case TARGET_WAITKIND_SPURIOUS:
577 /* Nothing to follow. */
580 internal_error (__FILE__, __LINE__,
581 "Unexpected pending_follow.kind %d\n",
582 tp->pending_follow.kind);
586 return should_resume;
590 follow_inferior_reset_breakpoints (void)
592 struct thread_info *tp = inferior_thread ();
594 /* Was there a step_resume breakpoint? (There was if the user
595 did a "next" at the fork() call.) If so, explicitly reset its
598 step_resumes are a form of bp that are made to be per-thread.
599 Since we created the step_resume bp when the parent process
600 was being debugged, and now are switching to the child process,
601 from the breakpoint package's viewpoint, that's a switch of
602 "threads". We must update the bp's notion of which thread
603 it is for, or it'll be ignored when it triggers. */
605 if (tp->control.step_resume_breakpoint)
606 breakpoint_re_set_thread (tp->control.step_resume_breakpoint);
608 if (tp->control.exception_resume_breakpoint)
609 breakpoint_re_set_thread (tp->control.exception_resume_breakpoint);
611 /* Reinsert all breakpoints in the child. The user may have set
612 breakpoints after catching the fork, in which case those
613 were never set in the child, but only in the parent. This makes
614 sure the inserted breakpoints match the breakpoint list. */
616 breakpoint_re_set ();
617 insert_breakpoints ();
620 /* The child has exited or execed: resume threads of the parent the
621 user wanted to be executing. */
624 proceed_after_vfork_done (struct thread_info *thread,
627 int pid = * (int *) arg;
629 if (ptid_get_pid (thread->ptid) == pid
630 && is_running (thread->ptid)
631 && !is_executing (thread->ptid)
632 && !thread->stop_requested
633 && thread->suspend.stop_signal == GDB_SIGNAL_0)
636 fprintf_unfiltered (gdb_stdlog,
637 "infrun: resuming vfork parent thread %s\n",
638 target_pid_to_str (thread->ptid));
640 switch_to_thread (thread->ptid);
641 clear_proceed_status ();
642 proceed ((CORE_ADDR) -1, GDB_SIGNAL_DEFAULT, 0);
648 /* Called whenever we notice an exec or exit event, to handle
649 detaching or resuming a vfork parent. */
652 handle_vfork_child_exec_or_exit (int exec)
654 struct inferior *inf = current_inferior ();
656 if (inf->vfork_parent)
658 int resume_parent = -1;
660 /* This exec or exit marks the end of the shared memory region
661 between the parent and the child. If the user wanted to
662 detach from the parent, now is the time. */
664 if (inf->vfork_parent->pending_detach)
666 struct thread_info *tp;
667 struct cleanup *old_chain;
668 struct program_space *pspace;
669 struct address_space *aspace;
671 /* follow-fork child, detach-on-fork on. */
673 inf->vfork_parent->pending_detach = 0;
677 /* If we're handling a child exit, then inferior_ptid
678 points at the inferior's pid, not to a thread. */
679 old_chain = save_inferior_ptid ();
680 save_current_program_space ();
681 save_current_inferior ();
684 old_chain = save_current_space_and_thread ();
686 /* We're letting loose of the parent. */
687 tp = any_live_thread_of_process (inf->vfork_parent->pid);
688 switch_to_thread (tp->ptid);
690 /* We're about to detach from the parent, which implicitly
691 removes breakpoints from its address space. There's a
692 catch here: we want to reuse the spaces for the child,
693 but, parent/child are still sharing the pspace at this
694 point, although the exec in reality makes the kernel give
695 the child a fresh set of new pages. The problem here is
696 that the breakpoints module being unaware of this, would
697 likely chose the child process to write to the parent
698 address space. Swapping the child temporarily away from
699 the spaces has the desired effect. Yes, this is "sort
702 pspace = inf->pspace;
703 aspace = inf->aspace;
707 if (debug_infrun || info_verbose)
709 target_terminal_ours ();
712 fprintf_filtered (gdb_stdlog,
713 "Detaching vfork parent process "
714 "%d after child exec.\n",
715 inf->vfork_parent->pid);
717 fprintf_filtered (gdb_stdlog,
718 "Detaching vfork parent process "
719 "%d after child exit.\n",
720 inf->vfork_parent->pid);
723 target_detach (NULL, 0);
726 inf->pspace = pspace;
727 inf->aspace = aspace;
729 do_cleanups (old_chain);
733 /* We're staying attached to the parent, so, really give the
734 child a new address space. */
735 inf->pspace = add_program_space (maybe_new_address_space ());
736 inf->aspace = inf->pspace->aspace;
738 set_current_program_space (inf->pspace);
740 resume_parent = inf->vfork_parent->pid;
742 /* Break the bonds. */
743 inf->vfork_parent->vfork_child = NULL;
747 struct cleanup *old_chain;
748 struct program_space *pspace;
750 /* If this is a vfork child exiting, then the pspace and
751 aspaces were shared with the parent. Since we're
752 reporting the process exit, we'll be mourning all that is
753 found in the address space, and switching to null_ptid,
754 preparing to start a new inferior. But, since we don't
755 want to clobber the parent's address/program spaces, we
756 go ahead and create a new one for this exiting
759 /* Switch to null_ptid, so that clone_program_space doesn't want
760 to read the selected frame of a dead process. */
761 old_chain = save_inferior_ptid ();
762 inferior_ptid = null_ptid;
764 /* This inferior is dead, so avoid giving the breakpoints
765 module the option to write through to it (cloning a
766 program space resets breakpoints). */
769 pspace = add_program_space (maybe_new_address_space ());
770 set_current_program_space (pspace);
772 inf->symfile_flags = SYMFILE_NO_READ;
773 clone_program_space (pspace, inf->vfork_parent->pspace);
774 inf->pspace = pspace;
775 inf->aspace = pspace->aspace;
777 /* Put back inferior_ptid. We'll continue mourning this
779 do_cleanups (old_chain);
781 resume_parent = inf->vfork_parent->pid;
782 /* Break the bonds. */
783 inf->vfork_parent->vfork_child = NULL;
786 inf->vfork_parent = NULL;
788 gdb_assert (current_program_space == inf->pspace);
790 if (non_stop && resume_parent != -1)
792 /* If the user wanted the parent to be running, let it go
794 struct cleanup *old_chain = make_cleanup_restore_current_thread ();
797 fprintf_unfiltered (gdb_stdlog,
798 "infrun: resuming vfork parent process %d\n",
801 iterate_over_threads (proceed_after_vfork_done, &resume_parent);
803 do_cleanups (old_chain);
808 /* Enum strings for "set|show displaced-stepping". */
810 static const char follow_exec_mode_new[] = "new";
811 static const char follow_exec_mode_same[] = "same";
812 static const char *const follow_exec_mode_names[] =
814 follow_exec_mode_new,
815 follow_exec_mode_same,
819 static const char *follow_exec_mode_string = follow_exec_mode_same;
821 show_follow_exec_mode_string (struct ui_file *file, int from_tty,
822 struct cmd_list_element *c, const char *value)
824 fprintf_filtered (file, _("Follow exec mode is \"%s\".\n"), value);
827 /* EXECD_PATHNAME is assumed to be non-NULL. */
830 follow_exec (ptid_t pid, char *execd_pathname)
832 struct thread_info *th = inferior_thread ();
833 struct inferior *inf = current_inferior ();
835 /* This is an exec event that we actually wish to pay attention to.
836 Refresh our symbol table to the newly exec'd program, remove any
839 If there are breakpoints, they aren't really inserted now,
840 since the exec() transformed our inferior into a fresh set
843 We want to preserve symbolic breakpoints on the list, since
844 we have hopes that they can be reset after the new a.out's
845 symbol table is read.
847 However, any "raw" breakpoints must be removed from the list
848 (e.g., the solib bp's), since their address is probably invalid
851 And, we DON'T want to call delete_breakpoints() here, since
852 that may write the bp's "shadow contents" (the instruction
853 value that was overwritten witha TRAP instruction). Since
854 we now have a new a.out, those shadow contents aren't valid. */
856 mark_breakpoints_out ();
858 update_breakpoints_after_exec ();
860 /* If there was one, it's gone now. We cannot truly step-to-next
861 statement through an exec(). */
862 th->control.step_resume_breakpoint = NULL;
863 th->control.exception_resume_breakpoint = NULL;
864 th->control.step_range_start = 0;
865 th->control.step_range_end = 0;
867 /* The target reports the exec event to the main thread, even if
868 some other thread does the exec, and even if the main thread was
869 already stopped --- if debugging in non-stop mode, it's possible
870 the user had the main thread held stopped in the previous image
871 --- release it now. This is the same behavior as step-over-exec
872 with scheduler-locking on in all-stop mode. */
873 th->stop_requested = 0;
875 /* What is this a.out's name? */
876 printf_unfiltered (_("%s is executing new program: %s\n"),
877 target_pid_to_str (inferior_ptid),
880 /* We've followed the inferior through an exec. Therefore, the
881 inferior has essentially been killed & reborn. */
883 gdb_flush (gdb_stdout);
885 breakpoint_init_inferior (inf_execd);
887 if (gdb_sysroot && *gdb_sysroot)
889 char *name = alloca (strlen (gdb_sysroot)
890 + strlen (execd_pathname)
893 strcpy (name, gdb_sysroot);
894 strcat (name, execd_pathname);
895 execd_pathname = name;
898 /* Reset the shared library package. This ensures that we get a
899 shlib event when the child reaches "_start", at which point the
900 dld will have had a chance to initialize the child. */
901 /* Also, loading a symbol file below may trigger symbol lookups, and
902 we don't want those to be satisfied by the libraries of the
903 previous incarnation of this process. */
904 no_shared_libraries (NULL, 0);
906 if (follow_exec_mode_string == follow_exec_mode_new)
908 struct program_space *pspace;
910 /* The user wants to keep the old inferior and program spaces
911 around. Create a new fresh one, and switch to it. */
913 inf = add_inferior (current_inferior ()->pid);
914 pspace = add_program_space (maybe_new_address_space ());
915 inf->pspace = pspace;
916 inf->aspace = pspace->aspace;
918 exit_inferior_num_silent (current_inferior ()->num);
920 set_current_inferior (inf);
921 set_current_program_space (pspace);
925 /* The old description may no longer be fit for the new image.
926 E.g, a 64-bit process exec'ed a 32-bit process. Clear the
927 old description; we'll read a new one below. No need to do
928 this on "follow-exec-mode new", as the old inferior stays
929 around (its description is later cleared/refetched on
931 target_clear_description ();
934 gdb_assert (current_program_space == inf->pspace);
936 /* That a.out is now the one to use. */
937 exec_file_attach (execd_pathname, 0);
939 /* SYMFILE_DEFER_BP_RESET is used as the proper displacement for PIE
940 (Position Independent Executable) main symbol file will get applied by
941 solib_create_inferior_hook below. breakpoint_re_set would fail to insert
942 the breakpoints with the zero displacement. */
944 symbol_file_add (execd_pathname,
946 | SYMFILE_MAINLINE | SYMFILE_DEFER_BP_RESET),
949 if ((inf->symfile_flags & SYMFILE_NO_READ) == 0)
950 set_initial_language ();
952 /* If the target can specify a description, read it. Must do this
953 after flipping to the new executable (because the target supplied
954 description must be compatible with the executable's
955 architecture, and the old executable may e.g., be 32-bit, while
956 the new one 64-bit), and before anything involving memory or
958 target_find_description ();
960 #ifdef SOLIB_CREATE_INFERIOR_HOOK
961 SOLIB_CREATE_INFERIOR_HOOK (PIDGET (inferior_ptid));
963 solib_create_inferior_hook (0);
966 jit_inferior_created_hook ();
968 breakpoint_re_set ();
970 /* Reinsert all breakpoints. (Those which were symbolic have
971 been reset to the proper address in the new a.out, thanks
972 to symbol_file_command...). */
973 insert_breakpoints ();
975 /* The next resume of this inferior should bring it to the shlib
976 startup breakpoints. (If the user had also set bp's on
977 "main" from the old (parent) process, then they'll auto-
978 matically get reset there in the new process.). */
981 /* Non-zero if we just simulating a single-step. This is needed
982 because we cannot remove the breakpoints in the inferior process
983 until after the `wait' in `wait_for_inferior'. */
984 static int singlestep_breakpoints_inserted_p = 0;
986 /* The thread we inserted single-step breakpoints for. */
987 static ptid_t singlestep_ptid;
989 /* PC when we started this single-step. */
990 static CORE_ADDR singlestep_pc;
992 /* If another thread hit the singlestep breakpoint, we save the original
993 thread here so that we can resume single-stepping it later. */
994 static ptid_t saved_singlestep_ptid;
995 static int stepping_past_singlestep_breakpoint;
997 /* If not equal to null_ptid, this means that after stepping over breakpoint
998 is finished, we need to switch to deferred_step_ptid, and step it.
1000 The use case is when one thread has hit a breakpoint, and then the user
1001 has switched to another thread and issued 'step'. We need to step over
1002 breakpoint in the thread which hit the breakpoint, but then continue
1003 stepping the thread user has selected. */
1004 static ptid_t deferred_step_ptid;
1006 /* Displaced stepping. */
1008 /* In non-stop debugging mode, we must take special care to manage
1009 breakpoints properly; in particular, the traditional strategy for
1010 stepping a thread past a breakpoint it has hit is unsuitable.
1011 'Displaced stepping' is a tactic for stepping one thread past a
1012 breakpoint it has hit while ensuring that other threads running
1013 concurrently will hit the breakpoint as they should.
1015 The traditional way to step a thread T off a breakpoint in a
1016 multi-threaded program in all-stop mode is as follows:
1018 a0) Initially, all threads are stopped, and breakpoints are not
1020 a1) We single-step T, leaving breakpoints uninserted.
1021 a2) We insert breakpoints, and resume all threads.
1023 In non-stop debugging, however, this strategy is unsuitable: we
1024 don't want to have to stop all threads in the system in order to
1025 continue or step T past a breakpoint. Instead, we use displaced
1028 n0) Initially, T is stopped, other threads are running, and
1029 breakpoints are inserted.
1030 n1) We copy the instruction "under" the breakpoint to a separate
1031 location, outside the main code stream, making any adjustments
1032 to the instruction, register, and memory state as directed by
1034 n2) We single-step T over the instruction at its new location.
1035 n3) We adjust the resulting register and memory state as directed
1036 by T's architecture. This includes resetting T's PC to point
1037 back into the main instruction stream.
1040 This approach depends on the following gdbarch methods:
1042 - gdbarch_max_insn_length and gdbarch_displaced_step_location
1043 indicate where to copy the instruction, and how much space must
1044 be reserved there. We use these in step n1.
1046 - gdbarch_displaced_step_copy_insn copies a instruction to a new
1047 address, and makes any necessary adjustments to the instruction,
1048 register contents, and memory. We use this in step n1.
1050 - gdbarch_displaced_step_fixup adjusts registers and memory after
1051 we have successfuly single-stepped the instruction, to yield the
1052 same effect the instruction would have had if we had executed it
1053 at its original address. We use this in step n3.
1055 - gdbarch_displaced_step_free_closure provides cleanup.
1057 The gdbarch_displaced_step_copy_insn and
1058 gdbarch_displaced_step_fixup functions must be written so that
1059 copying an instruction with gdbarch_displaced_step_copy_insn,
1060 single-stepping across the copied instruction, and then applying
1061 gdbarch_displaced_insn_fixup should have the same effects on the
1062 thread's memory and registers as stepping the instruction in place
1063 would have. Exactly which responsibilities fall to the copy and
1064 which fall to the fixup is up to the author of those functions.
1066 See the comments in gdbarch.sh for details.
1068 Note that displaced stepping and software single-step cannot
1069 currently be used in combination, although with some care I think
1070 they could be made to. Software single-step works by placing
1071 breakpoints on all possible subsequent instructions; if the
1072 displaced instruction is a PC-relative jump, those breakpoints
1073 could fall in very strange places --- on pages that aren't
1074 executable, or at addresses that are not proper instruction
1075 boundaries. (We do generally let other threads run while we wait
1076 to hit the software single-step breakpoint, and they might
1077 encounter such a corrupted instruction.) One way to work around
1078 this would be to have gdbarch_displaced_step_copy_insn fully
1079 simulate the effect of PC-relative instructions (and return NULL)
1080 on architectures that use software single-stepping.
1082 In non-stop mode, we can have independent and simultaneous step
1083 requests, so more than one thread may need to simultaneously step
1084 over a breakpoint. The current implementation assumes there is
1085 only one scratch space per process. In this case, we have to
1086 serialize access to the scratch space. If thread A wants to step
1087 over a breakpoint, but we are currently waiting for some other
1088 thread to complete a displaced step, we leave thread A stopped and
1089 place it in the displaced_step_request_queue. Whenever a displaced
1090 step finishes, we pick the next thread in the queue and start a new
1091 displaced step operation on it. See displaced_step_prepare and
1092 displaced_step_fixup for details. */
1094 struct displaced_step_request
1097 struct displaced_step_request *next;
1100 /* Per-inferior displaced stepping state. */
1101 struct displaced_step_inferior_state
1103 /* Pointer to next in linked list. */
1104 struct displaced_step_inferior_state *next;
1106 /* The process this displaced step state refers to. */
1109 /* A queue of pending displaced stepping requests. One entry per
1110 thread that needs to do a displaced step. */
1111 struct displaced_step_request *step_request_queue;
1113 /* If this is not null_ptid, this is the thread carrying out a
1114 displaced single-step in process PID. This thread's state will
1115 require fixing up once it has completed its step. */
1118 /* The architecture the thread had when we stepped it. */
1119 struct gdbarch *step_gdbarch;
1121 /* The closure provided gdbarch_displaced_step_copy_insn, to be used
1122 for post-step cleanup. */
1123 struct displaced_step_closure *step_closure;
1125 /* The address of the original instruction, and the copy we
1127 CORE_ADDR step_original, step_copy;
1129 /* Saved contents of copy area. */
1130 gdb_byte *step_saved_copy;
1133 /* The list of states of processes involved in displaced stepping
1135 static struct displaced_step_inferior_state *displaced_step_inferior_states;
1137 /* Get the displaced stepping state of process PID. */
1139 static struct displaced_step_inferior_state *
1140 get_displaced_stepping_state (int pid)
1142 struct displaced_step_inferior_state *state;
1144 for (state = displaced_step_inferior_states;
1146 state = state->next)
1147 if (state->pid == pid)
1153 /* Add a new displaced stepping state for process PID to the displaced
1154 stepping state list, or return a pointer to an already existing
1155 entry, if it already exists. Never returns NULL. */
1157 static struct displaced_step_inferior_state *
1158 add_displaced_stepping_state (int pid)
1160 struct displaced_step_inferior_state *state;
1162 for (state = displaced_step_inferior_states;
1164 state = state->next)
1165 if (state->pid == pid)
1168 state = xcalloc (1, sizeof (*state));
1170 state->next = displaced_step_inferior_states;
1171 displaced_step_inferior_states = state;
1176 /* If inferior is in displaced stepping, and ADDR equals to starting address
1177 of copy area, return corresponding displaced_step_closure. Otherwise,
1180 struct displaced_step_closure*
1181 get_displaced_step_closure_by_addr (CORE_ADDR addr)
1183 struct displaced_step_inferior_state *displaced
1184 = get_displaced_stepping_state (ptid_get_pid (inferior_ptid));
1186 /* If checking the mode of displaced instruction in copy area. */
1187 if (displaced && !ptid_equal (displaced->step_ptid, null_ptid)
1188 && (displaced->step_copy == addr))
1189 return displaced->step_closure;
1194 /* Remove the displaced stepping state of process PID. */
1197 remove_displaced_stepping_state (int pid)
1199 struct displaced_step_inferior_state *it, **prev_next_p;
1201 gdb_assert (pid != 0);
1203 it = displaced_step_inferior_states;
1204 prev_next_p = &displaced_step_inferior_states;
1209 *prev_next_p = it->next;
1214 prev_next_p = &it->next;
1220 infrun_inferior_exit (struct inferior *inf)
1222 remove_displaced_stepping_state (inf->pid);
1225 /* If ON, and the architecture supports it, GDB will use displaced
1226 stepping to step over breakpoints. If OFF, or if the architecture
1227 doesn't support it, GDB will instead use the traditional
1228 hold-and-step approach. If AUTO (which is the default), GDB will
1229 decide which technique to use to step over breakpoints depending on
1230 which of all-stop or non-stop mode is active --- displaced stepping
1231 in non-stop mode; hold-and-step in all-stop mode. */
1233 static enum auto_boolean can_use_displaced_stepping = AUTO_BOOLEAN_AUTO;
1236 show_can_use_displaced_stepping (struct ui_file *file, int from_tty,
1237 struct cmd_list_element *c,
1240 if (can_use_displaced_stepping == AUTO_BOOLEAN_AUTO)
1241 fprintf_filtered (file,
1242 _("Debugger's willingness to use displaced stepping "
1243 "to step over breakpoints is %s (currently %s).\n"),
1244 value, non_stop ? "on" : "off");
1246 fprintf_filtered (file,
1247 _("Debugger's willingness to use displaced stepping "
1248 "to step over breakpoints is %s.\n"), value);
1251 /* Return non-zero if displaced stepping can/should be used to step
1252 over breakpoints. */
1255 use_displaced_stepping (struct gdbarch *gdbarch)
1257 return (((can_use_displaced_stepping == AUTO_BOOLEAN_AUTO && non_stop)
1258 || can_use_displaced_stepping == AUTO_BOOLEAN_TRUE)
1259 && gdbarch_displaced_step_copy_insn_p (gdbarch)
1260 && !RECORD_IS_USED);
1263 /* Clean out any stray displaced stepping state. */
1265 displaced_step_clear (struct displaced_step_inferior_state *displaced)
1267 /* Indicate that there is no cleanup pending. */
1268 displaced->step_ptid = null_ptid;
1270 if (displaced->step_closure)
1272 gdbarch_displaced_step_free_closure (displaced->step_gdbarch,
1273 displaced->step_closure);
1274 displaced->step_closure = NULL;
1279 displaced_step_clear_cleanup (void *arg)
1281 struct displaced_step_inferior_state *state = arg;
1283 displaced_step_clear (state);
1286 /* Dump LEN bytes at BUF in hex to FILE, followed by a newline. */
1288 displaced_step_dump_bytes (struct ui_file *file,
1289 const gdb_byte *buf,
1294 for (i = 0; i < len; i++)
1295 fprintf_unfiltered (file, "%02x ", buf[i]);
1296 fputs_unfiltered ("\n", file);
1299 /* Prepare to single-step, using displaced stepping.
1301 Note that we cannot use displaced stepping when we have a signal to
1302 deliver. If we have a signal to deliver and an instruction to step
1303 over, then after the step, there will be no indication from the
1304 target whether the thread entered a signal handler or ignored the
1305 signal and stepped over the instruction successfully --- both cases
1306 result in a simple SIGTRAP. In the first case we mustn't do a
1307 fixup, and in the second case we must --- but we can't tell which.
1308 Comments in the code for 'random signals' in handle_inferior_event
1309 explain how we handle this case instead.
1311 Returns 1 if preparing was successful -- this thread is going to be
1312 stepped now; or 0 if displaced stepping this thread got queued. */
1314 displaced_step_prepare (ptid_t ptid)
1316 struct cleanup *old_cleanups, *ignore_cleanups;
1317 struct regcache *regcache = get_thread_regcache (ptid);
1318 struct gdbarch *gdbarch = get_regcache_arch (regcache);
1319 CORE_ADDR original, copy;
1321 struct displaced_step_closure *closure;
1322 struct displaced_step_inferior_state *displaced;
1325 /* We should never reach this function if the architecture does not
1326 support displaced stepping. */
1327 gdb_assert (gdbarch_displaced_step_copy_insn_p (gdbarch));
1329 /* We have to displaced step one thread at a time, as we only have
1330 access to a single scratch space per inferior. */
1332 displaced = add_displaced_stepping_state (ptid_get_pid (ptid));
1334 if (!ptid_equal (displaced->step_ptid, null_ptid))
1336 /* Already waiting for a displaced step to finish. Defer this
1337 request and place in queue. */
1338 struct displaced_step_request *req, *new_req;
1340 if (debug_displaced)
1341 fprintf_unfiltered (gdb_stdlog,
1342 "displaced: defering step of %s\n",
1343 target_pid_to_str (ptid));
1345 new_req = xmalloc (sizeof (*new_req));
1346 new_req->ptid = ptid;
1347 new_req->next = NULL;
1349 if (displaced->step_request_queue)
1351 for (req = displaced->step_request_queue;
1355 req->next = new_req;
1358 displaced->step_request_queue = new_req;
1364 if (debug_displaced)
1365 fprintf_unfiltered (gdb_stdlog,
1366 "displaced: stepping %s now\n",
1367 target_pid_to_str (ptid));
1370 displaced_step_clear (displaced);
1372 old_cleanups = save_inferior_ptid ();
1373 inferior_ptid = ptid;
1375 original = regcache_read_pc (regcache);
1377 copy = gdbarch_displaced_step_location (gdbarch);
1378 len = gdbarch_max_insn_length (gdbarch);
1380 /* Save the original contents of the copy area. */
1381 displaced->step_saved_copy = xmalloc (len);
1382 ignore_cleanups = make_cleanup (free_current_contents,
1383 &displaced->step_saved_copy);
1384 status = target_read_memory (copy, displaced->step_saved_copy, len);
1386 throw_error (MEMORY_ERROR,
1387 _("Error accessing memory address %s (%s) for "
1388 "displaced-stepping scratch space."),
1389 paddress (gdbarch, copy), safe_strerror (status));
1390 if (debug_displaced)
1392 fprintf_unfiltered (gdb_stdlog, "displaced: saved %s: ",
1393 paddress (gdbarch, copy));
1394 displaced_step_dump_bytes (gdb_stdlog,
1395 displaced->step_saved_copy,
1399 closure = gdbarch_displaced_step_copy_insn (gdbarch,
1400 original, copy, regcache);
1402 /* We don't support the fully-simulated case at present. */
1403 gdb_assert (closure);
1405 /* Save the information we need to fix things up if the step
1407 displaced->step_ptid = ptid;
1408 displaced->step_gdbarch = gdbarch;
1409 displaced->step_closure = closure;
1410 displaced->step_original = original;
1411 displaced->step_copy = copy;
1413 make_cleanup (displaced_step_clear_cleanup, displaced);
1415 /* Resume execution at the copy. */
1416 regcache_write_pc (regcache, copy);
1418 discard_cleanups (ignore_cleanups);
1420 do_cleanups (old_cleanups);
1422 if (debug_displaced)
1423 fprintf_unfiltered (gdb_stdlog, "displaced: displaced pc to %s\n",
1424 paddress (gdbarch, copy));
1430 write_memory_ptid (ptid_t ptid, CORE_ADDR memaddr,
1431 const gdb_byte *myaddr, int len)
1433 struct cleanup *ptid_cleanup = save_inferior_ptid ();
1435 inferior_ptid = ptid;
1436 write_memory (memaddr, myaddr, len);
1437 do_cleanups (ptid_cleanup);
1440 /* Restore the contents of the copy area for thread PTID. */
1443 displaced_step_restore (struct displaced_step_inferior_state *displaced,
1446 ULONGEST len = gdbarch_max_insn_length (displaced->step_gdbarch);
1448 write_memory_ptid (ptid, displaced->step_copy,
1449 displaced->step_saved_copy, len);
1450 if (debug_displaced)
1451 fprintf_unfiltered (gdb_stdlog, "displaced: restored %s %s\n",
1452 target_pid_to_str (ptid),
1453 paddress (displaced->step_gdbarch,
1454 displaced->step_copy));
1458 displaced_step_fixup (ptid_t event_ptid, enum gdb_signal signal)
1460 struct cleanup *old_cleanups;
1461 struct displaced_step_inferior_state *displaced
1462 = get_displaced_stepping_state (ptid_get_pid (event_ptid));
1464 /* Was any thread of this process doing a displaced step? */
1465 if (displaced == NULL)
1468 /* Was this event for the pid we displaced? */
1469 if (ptid_equal (displaced->step_ptid, null_ptid)
1470 || ! ptid_equal (displaced->step_ptid, event_ptid))
1473 old_cleanups = make_cleanup (displaced_step_clear_cleanup, displaced);
1475 displaced_step_restore (displaced, displaced->step_ptid);
1477 /* Did the instruction complete successfully? */
1478 if (signal == GDB_SIGNAL_TRAP)
1480 /* Fix up the resulting state. */
1481 gdbarch_displaced_step_fixup (displaced->step_gdbarch,
1482 displaced->step_closure,
1483 displaced->step_original,
1484 displaced->step_copy,
1485 get_thread_regcache (displaced->step_ptid));
1489 /* Since the instruction didn't complete, all we can do is
1491 struct regcache *regcache = get_thread_regcache (event_ptid);
1492 CORE_ADDR pc = regcache_read_pc (regcache);
1494 pc = displaced->step_original + (pc - displaced->step_copy);
1495 regcache_write_pc (regcache, pc);
1498 do_cleanups (old_cleanups);
1500 displaced->step_ptid = null_ptid;
1502 /* Are there any pending displaced stepping requests? If so, run
1503 one now. Leave the state object around, since we're likely to
1504 need it again soon. */
1505 while (displaced->step_request_queue)
1507 struct displaced_step_request *head;
1509 struct regcache *regcache;
1510 struct gdbarch *gdbarch;
1511 CORE_ADDR actual_pc;
1512 struct address_space *aspace;
1514 head = displaced->step_request_queue;
1516 displaced->step_request_queue = head->next;
1519 context_switch (ptid);
1521 regcache = get_thread_regcache (ptid);
1522 actual_pc = regcache_read_pc (regcache);
1523 aspace = get_regcache_aspace (regcache);
1525 if (breakpoint_here_p (aspace, actual_pc))
1527 if (debug_displaced)
1528 fprintf_unfiltered (gdb_stdlog,
1529 "displaced: stepping queued %s now\n",
1530 target_pid_to_str (ptid));
1532 displaced_step_prepare (ptid);
1534 gdbarch = get_regcache_arch (regcache);
1536 if (debug_displaced)
1538 CORE_ADDR actual_pc = regcache_read_pc (regcache);
1541 fprintf_unfiltered (gdb_stdlog, "displaced: run %s: ",
1542 paddress (gdbarch, actual_pc));
1543 read_memory (actual_pc, buf, sizeof (buf));
1544 displaced_step_dump_bytes (gdb_stdlog, buf, sizeof (buf));
1547 if (gdbarch_displaced_step_hw_singlestep (gdbarch,
1548 displaced->step_closure))
1549 target_resume (ptid, 1, GDB_SIGNAL_0);
1551 target_resume (ptid, 0, GDB_SIGNAL_0);
1553 /* Done, we're stepping a thread. */
1559 struct thread_info *tp = inferior_thread ();
1561 /* The breakpoint we were sitting under has since been
1563 tp->control.trap_expected = 0;
1565 /* Go back to what we were trying to do. */
1566 step = currently_stepping (tp);
1568 if (debug_displaced)
1569 fprintf_unfiltered (gdb_stdlog,
1570 "displaced: breakpoint is gone: %s, step(%d)\n",
1571 target_pid_to_str (tp->ptid), step);
1573 target_resume (ptid, step, GDB_SIGNAL_0);
1574 tp->suspend.stop_signal = GDB_SIGNAL_0;
1576 /* This request was discarded. See if there's any other
1577 thread waiting for its turn. */
1582 /* Update global variables holding ptids to hold NEW_PTID if they were
1583 holding OLD_PTID. */
1585 infrun_thread_ptid_changed (ptid_t old_ptid, ptid_t new_ptid)
1587 struct displaced_step_request *it;
1588 struct displaced_step_inferior_state *displaced;
1590 if (ptid_equal (inferior_ptid, old_ptid))
1591 inferior_ptid = new_ptid;
1593 if (ptid_equal (singlestep_ptid, old_ptid))
1594 singlestep_ptid = new_ptid;
1596 if (ptid_equal (deferred_step_ptid, old_ptid))
1597 deferred_step_ptid = new_ptid;
1599 for (displaced = displaced_step_inferior_states;
1601 displaced = displaced->next)
1603 if (ptid_equal (displaced->step_ptid, old_ptid))
1604 displaced->step_ptid = new_ptid;
1606 for (it = displaced->step_request_queue; it; it = it->next)
1607 if (ptid_equal (it->ptid, old_ptid))
1608 it->ptid = new_ptid;
1615 /* Things to clean up if we QUIT out of resume (). */
1617 resume_cleanups (void *ignore)
1622 static const char schedlock_off[] = "off";
1623 static const char schedlock_on[] = "on";
1624 static const char schedlock_step[] = "step";
1625 static const char *const scheduler_enums[] = {
1631 static const char *scheduler_mode = schedlock_off;
1633 show_scheduler_mode (struct ui_file *file, int from_tty,
1634 struct cmd_list_element *c, const char *value)
1636 fprintf_filtered (file,
1637 _("Mode for locking scheduler "
1638 "during execution is \"%s\".\n"),
1643 set_schedlock_func (char *args, int from_tty, struct cmd_list_element *c)
1645 if (!target_can_lock_scheduler)
1647 scheduler_mode = schedlock_off;
1648 error (_("Target '%s' cannot support this command."), target_shortname);
1652 /* True if execution commands resume all threads of all processes by
1653 default; otherwise, resume only threads of the current inferior
1655 int sched_multi = 0;
1657 /* Try to setup for software single stepping over the specified location.
1658 Return 1 if target_resume() should use hardware single step.
1660 GDBARCH the current gdbarch.
1661 PC the location to step over. */
1664 maybe_software_singlestep (struct gdbarch *gdbarch, CORE_ADDR pc)
1668 if (execution_direction == EXEC_FORWARD
1669 && gdbarch_software_single_step_p (gdbarch)
1670 && gdbarch_software_single_step (gdbarch, get_current_frame ()))
1673 /* Do not pull these breakpoints until after a `wait' in
1674 `wait_for_inferior'. */
1675 singlestep_breakpoints_inserted_p = 1;
1676 singlestep_ptid = inferior_ptid;
1682 /* Return a ptid representing the set of threads that we will proceed,
1683 in the perspective of the user/frontend. We may actually resume
1684 fewer threads at first, e.g., if a thread is stopped at a
1685 breakpoint that needs stepping-off, but that should not be visible
1686 to the user/frontend, and neither should the frontend/user be
1687 allowed to proceed any of the threads that happen to be stopped for
1688 internal run control handling, if a previous command wanted them
1692 user_visible_resume_ptid (int step)
1694 /* By default, resume all threads of all processes. */
1695 ptid_t resume_ptid = RESUME_ALL;
1697 /* Maybe resume only all threads of the current process. */
1698 if (!sched_multi && target_supports_multi_process ())
1700 resume_ptid = pid_to_ptid (ptid_get_pid (inferior_ptid));
1703 /* Maybe resume a single thread after all. */
1706 /* With non-stop mode on, threads are always handled
1708 resume_ptid = inferior_ptid;
1710 else if ((scheduler_mode == schedlock_on)
1711 || (scheduler_mode == schedlock_step
1712 && (step || singlestep_breakpoints_inserted_p)))
1714 /* User-settable 'scheduler' mode requires solo thread resume. */
1715 resume_ptid = inferior_ptid;
1721 /* Resume the inferior, but allow a QUIT. This is useful if the user
1722 wants to interrupt some lengthy single-stepping operation
1723 (for child processes, the SIGINT goes to the inferior, and so
1724 we get a SIGINT random_signal, but for remote debugging and perhaps
1725 other targets, that's not true).
1727 STEP nonzero if we should step (zero to continue instead).
1728 SIG is the signal to give the inferior (zero for none). */
1730 resume (int step, enum gdb_signal sig)
1732 int should_resume = 1;
1733 struct cleanup *old_cleanups = make_cleanup (resume_cleanups, 0);
1734 struct regcache *regcache = get_current_regcache ();
1735 struct gdbarch *gdbarch = get_regcache_arch (regcache);
1736 struct thread_info *tp = inferior_thread ();
1737 CORE_ADDR pc = regcache_read_pc (regcache);
1738 struct address_space *aspace = get_regcache_aspace (regcache);
1742 if (current_inferior ()->waiting_for_vfork_done)
1744 /* Don't try to single-step a vfork parent that is waiting for
1745 the child to get out of the shared memory region (by exec'ing
1746 or exiting). This is particularly important on software
1747 single-step archs, as the child process would trip on the
1748 software single step breakpoint inserted for the parent
1749 process. Since the parent will not actually execute any
1750 instruction until the child is out of the shared region (such
1751 are vfork's semantics), it is safe to simply continue it.
1752 Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for
1753 the parent, and tell it to `keep_going', which automatically
1754 re-sets it stepping. */
1756 fprintf_unfiltered (gdb_stdlog,
1757 "infrun: resume : clear step\n");
1762 fprintf_unfiltered (gdb_stdlog,
1763 "infrun: resume (step=%d, signal=%d), "
1764 "trap_expected=%d, current thread [%s] at %s\n",
1765 step, sig, tp->control.trap_expected,
1766 target_pid_to_str (inferior_ptid),
1767 paddress (gdbarch, pc));
1769 /* Normally, by the time we reach `resume', the breakpoints are either
1770 removed or inserted, as appropriate. The exception is if we're sitting
1771 at a permanent breakpoint; we need to step over it, but permanent
1772 breakpoints can't be removed. So we have to test for it here. */
1773 if (breakpoint_here_p (aspace, pc) == permanent_breakpoint_here)
1775 if (gdbarch_skip_permanent_breakpoint_p (gdbarch))
1776 gdbarch_skip_permanent_breakpoint (gdbarch, regcache);
1779 The program is stopped at a permanent breakpoint, but GDB does not know\n\
1780 how to step past a permanent breakpoint on this architecture. Try using\n\
1781 a command like `return' or `jump' to continue execution."));
1784 /* If enabled, step over breakpoints by executing a copy of the
1785 instruction at a different address.
1787 We can't use displaced stepping when we have a signal to deliver;
1788 the comments for displaced_step_prepare explain why. The
1789 comments in the handle_inferior event for dealing with 'random
1790 signals' explain what we do instead.
1792 We can't use displaced stepping when we are waiting for vfork_done
1793 event, displaced stepping breaks the vfork child similarly as single
1794 step software breakpoint. */
1795 if (use_displaced_stepping (gdbarch)
1796 && (tp->control.trap_expected
1797 || (step && gdbarch_software_single_step_p (gdbarch)))
1798 && sig == GDB_SIGNAL_0
1799 && !current_inferior ()->waiting_for_vfork_done)
1801 struct displaced_step_inferior_state *displaced;
1803 if (!displaced_step_prepare (inferior_ptid))
1805 /* Got placed in displaced stepping queue. Will be resumed
1806 later when all the currently queued displaced stepping
1807 requests finish. The thread is not executing at this point,
1808 and the call to set_executing will be made later. But we
1809 need to call set_running here, since from frontend point of view,
1810 the thread is running. */
1811 set_running (inferior_ptid, 1);
1812 discard_cleanups (old_cleanups);
1816 /* Update pc to reflect the new address from which we will execute
1817 instructions due to displaced stepping. */
1818 pc = regcache_read_pc (get_thread_regcache (inferior_ptid));
1820 displaced = get_displaced_stepping_state (ptid_get_pid (inferior_ptid));
1821 step = gdbarch_displaced_step_hw_singlestep (gdbarch,
1822 displaced->step_closure);
1825 /* Do we need to do it the hard way, w/temp breakpoints? */
1827 step = maybe_software_singlestep (gdbarch, pc);
1829 /* Currently, our software single-step implementation leads to different
1830 results than hardware single-stepping in one situation: when stepping
1831 into delivering a signal which has an associated signal handler,
1832 hardware single-step will stop at the first instruction of the handler,
1833 while software single-step will simply skip execution of the handler.
1835 For now, this difference in behavior is accepted since there is no
1836 easy way to actually implement single-stepping into a signal handler
1837 without kernel support.
1839 However, there is one scenario where this difference leads to follow-on
1840 problems: if we're stepping off a breakpoint by removing all breakpoints
1841 and then single-stepping. In this case, the software single-step
1842 behavior means that even if there is a *breakpoint* in the signal
1843 handler, GDB still would not stop.
1845 Fortunately, we can at least fix this particular issue. We detect
1846 here the case where we are about to deliver a signal while software
1847 single-stepping with breakpoints removed. In this situation, we
1848 revert the decisions to remove all breakpoints and insert single-
1849 step breakpoints, and instead we install a step-resume breakpoint
1850 at the current address, deliver the signal without stepping, and
1851 once we arrive back at the step-resume breakpoint, actually step
1852 over the breakpoint we originally wanted to step over. */
1853 if (singlestep_breakpoints_inserted_p
1854 && tp->control.trap_expected && sig != GDB_SIGNAL_0)
1856 /* If we have nested signals or a pending signal is delivered
1857 immediately after a handler returns, might might already have
1858 a step-resume breakpoint set on the earlier handler. We cannot
1859 set another step-resume breakpoint; just continue on until the
1860 original breakpoint is hit. */
1861 if (tp->control.step_resume_breakpoint == NULL)
1863 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
1864 tp->step_after_step_resume_breakpoint = 1;
1867 remove_single_step_breakpoints ();
1868 singlestep_breakpoints_inserted_p = 0;
1870 insert_breakpoints ();
1871 tp->control.trap_expected = 0;
1878 /* If STEP is set, it's a request to use hardware stepping
1879 facilities. But in that case, we should never
1880 use singlestep breakpoint. */
1881 gdb_assert (!(singlestep_breakpoints_inserted_p && step));
1883 /* Decide the set of threads to ask the target to resume. Start
1884 by assuming everything will be resumed, than narrow the set
1885 by applying increasingly restricting conditions. */
1886 resume_ptid = user_visible_resume_ptid (step);
1888 /* Maybe resume a single thread after all. */
1889 if (singlestep_breakpoints_inserted_p
1890 && stepping_past_singlestep_breakpoint)
1892 /* The situation here is as follows. In thread T1 we wanted to
1893 single-step. Lacking hardware single-stepping we've
1894 set breakpoint at the PC of the next instruction -- call it
1895 P. After resuming, we've hit that breakpoint in thread T2.
1896 Now we've removed original breakpoint, inserted breakpoint
1897 at P+1, and try to step to advance T2 past breakpoint.
1898 We need to step only T2, as if T1 is allowed to freely run,
1899 it can run past P, and if other threads are allowed to run,
1900 they can hit breakpoint at P+1, and nested hits of single-step
1901 breakpoints is not something we'd want -- that's complicated
1902 to support, and has no value. */
1903 resume_ptid = inferior_ptid;
1905 else if ((step || singlestep_breakpoints_inserted_p)
1906 && tp->control.trap_expected)
1908 /* We're allowing a thread to run past a breakpoint it has
1909 hit, by single-stepping the thread with the breakpoint
1910 removed. In which case, we need to single-step only this
1911 thread, and keep others stopped, as they can miss this
1912 breakpoint if allowed to run.
1914 The current code actually removes all breakpoints when
1915 doing this, not just the one being stepped over, so if we
1916 let other threads run, we can actually miss any
1917 breakpoint, not just the one at PC. */
1918 resume_ptid = inferior_ptid;
1921 if (gdbarch_cannot_step_breakpoint (gdbarch))
1923 /* Most targets can step a breakpoint instruction, thus
1924 executing it normally. But if this one cannot, just
1925 continue and we will hit it anyway. */
1926 if (step && breakpoint_inserted_here_p (aspace, pc))
1931 && use_displaced_stepping (gdbarch)
1932 && tp->control.trap_expected)
1934 struct regcache *resume_regcache = get_thread_regcache (resume_ptid);
1935 struct gdbarch *resume_gdbarch = get_regcache_arch (resume_regcache);
1936 CORE_ADDR actual_pc = regcache_read_pc (resume_regcache);
1939 fprintf_unfiltered (gdb_stdlog, "displaced: run %s: ",
1940 paddress (resume_gdbarch, actual_pc));
1941 read_memory (actual_pc, buf, sizeof (buf));
1942 displaced_step_dump_bytes (gdb_stdlog, buf, sizeof (buf));
1945 /* Install inferior's terminal modes. */
1946 target_terminal_inferior ();
1948 /* Avoid confusing the next resume, if the next stop/resume
1949 happens to apply to another thread. */
1950 tp->suspend.stop_signal = GDB_SIGNAL_0;
1952 /* Advise target which signals may be handled silently. If we have
1953 removed breakpoints because we are stepping over one (which can
1954 happen only if we are not using displaced stepping), we need to
1955 receive all signals to avoid accidentally skipping a breakpoint
1956 during execution of a signal handler. */
1957 if ((step || singlestep_breakpoints_inserted_p)
1958 && tp->control.trap_expected
1959 && !use_displaced_stepping (gdbarch))
1960 target_pass_signals (0, NULL);
1962 target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
1964 target_resume (resume_ptid, step, sig);
1967 discard_cleanups (old_cleanups);
1972 /* Clear out all variables saying what to do when inferior is continued.
1973 First do this, then set the ones you want, then call `proceed'. */
1976 clear_proceed_status_thread (struct thread_info *tp)
1979 fprintf_unfiltered (gdb_stdlog,
1980 "infrun: clear_proceed_status_thread (%s)\n",
1981 target_pid_to_str (tp->ptid));
1983 tp->control.trap_expected = 0;
1984 tp->control.step_range_start = 0;
1985 tp->control.step_range_end = 0;
1986 tp->control.step_frame_id = null_frame_id;
1987 tp->control.step_stack_frame_id = null_frame_id;
1988 tp->control.step_over_calls = STEP_OVER_UNDEBUGGABLE;
1989 tp->stop_requested = 0;
1991 tp->control.stop_step = 0;
1993 tp->control.proceed_to_finish = 0;
1995 /* Discard any remaining commands or status from previous stop. */
1996 bpstat_clear (&tp->control.stop_bpstat);
2000 clear_proceed_status_callback (struct thread_info *tp, void *data)
2002 if (is_exited (tp->ptid))
2005 clear_proceed_status_thread (tp);
2010 clear_proceed_status (void)
2014 /* In all-stop mode, delete the per-thread status of all
2015 threads, even if inferior_ptid is null_ptid, there may be
2016 threads on the list. E.g., we may be launching a new
2017 process, while selecting the executable. */
2018 iterate_over_threads (clear_proceed_status_callback, NULL);
2021 if (!ptid_equal (inferior_ptid, null_ptid))
2023 struct inferior *inferior;
2027 /* If in non-stop mode, only delete the per-thread status of
2028 the current thread. */
2029 clear_proceed_status_thread (inferior_thread ());
2032 inferior = current_inferior ();
2033 inferior->control.stop_soon = NO_STOP_QUIETLY;
2036 stop_after_trap = 0;
2038 observer_notify_about_to_proceed ();
2042 regcache_xfree (stop_registers);
2043 stop_registers = NULL;
2047 /* Check the current thread against the thread that reported the most recent
2048 event. If a step-over is required return TRUE and set the current thread
2049 to the old thread. Otherwise return FALSE.
2051 This should be suitable for any targets that support threads. */
2054 prepare_to_proceed (int step)
2057 struct target_waitstatus wait_status;
2058 int schedlock_enabled;
2060 /* With non-stop mode on, threads are always handled individually. */
2061 gdb_assert (! non_stop);
2063 /* Get the last target status returned by target_wait(). */
2064 get_last_target_status (&wait_ptid, &wait_status);
2066 /* Make sure we were stopped at a breakpoint. */
2067 if (wait_status.kind != TARGET_WAITKIND_STOPPED
2068 || (wait_status.value.sig != GDB_SIGNAL_TRAP
2069 && wait_status.value.sig != GDB_SIGNAL_ILL
2070 && wait_status.value.sig != GDB_SIGNAL_SEGV
2071 && wait_status.value.sig != GDB_SIGNAL_EMT))
2076 schedlock_enabled = (scheduler_mode == schedlock_on
2077 || (scheduler_mode == schedlock_step
2080 /* Don't switch over to WAIT_PTID if scheduler locking is on. */
2081 if (schedlock_enabled)
2084 /* Don't switch over if we're about to resume some other process
2085 other than WAIT_PTID's, and schedule-multiple is off. */
2087 && ptid_get_pid (wait_ptid) != ptid_get_pid (inferior_ptid))
2090 /* Switched over from WAIT_PID. */
2091 if (!ptid_equal (wait_ptid, minus_one_ptid)
2092 && !ptid_equal (inferior_ptid, wait_ptid))
2094 struct regcache *regcache = get_thread_regcache (wait_ptid);
2096 if (breakpoint_here_p (get_regcache_aspace (regcache),
2097 regcache_read_pc (regcache)))
2099 /* If stepping, remember current thread to switch back to. */
2101 deferred_step_ptid = inferior_ptid;
2103 /* Switch back to WAIT_PID thread. */
2104 switch_to_thread (wait_ptid);
2107 fprintf_unfiltered (gdb_stdlog,
2108 "infrun: prepare_to_proceed (step=%d), "
2109 "switched to [%s]\n",
2110 step, target_pid_to_str (inferior_ptid));
2112 /* We return 1 to indicate that there is a breakpoint here,
2113 so we need to step over it before continuing to avoid
2114 hitting it straight away. */
2122 /* Basic routine for continuing the program in various fashions.
2124 ADDR is the address to resume at, or -1 for resume where stopped.
2125 SIGGNAL is the signal to give it, or 0 for none,
2126 or -1 for act according to how it stopped.
2127 STEP is nonzero if should trap after one instruction.
2128 -1 means return after that and print nothing.
2129 You should probably set various step_... variables
2130 before calling here, if you are stepping.
2132 You should call clear_proceed_status before calling proceed. */
2135 proceed (CORE_ADDR addr, enum gdb_signal siggnal, int step)
2137 struct regcache *regcache;
2138 struct gdbarch *gdbarch;
2139 struct thread_info *tp;
2141 struct address_space *aspace;
2142 /* GDB may force the inferior to step due to various reasons. */
2145 /* If we're stopped at a fork/vfork, follow the branch set by the
2146 "set follow-fork-mode" command; otherwise, we'll just proceed
2147 resuming the current thread. */
2148 if (!follow_fork ())
2150 /* The target for some reason decided not to resume. */
2152 if (target_can_async_p ())
2153 inferior_event_handler (INF_EXEC_COMPLETE, NULL);
2157 /* We'll update this if & when we switch to a new thread. */
2158 previous_inferior_ptid = inferior_ptid;
2160 regcache = get_current_regcache ();
2161 gdbarch = get_regcache_arch (regcache);
2162 aspace = get_regcache_aspace (regcache);
2163 pc = regcache_read_pc (regcache);
2166 step_start_function = find_pc_function (pc);
2168 stop_after_trap = 1;
2170 if (addr == (CORE_ADDR) -1)
2172 if (pc == stop_pc && breakpoint_here_p (aspace, pc)
2173 && execution_direction != EXEC_REVERSE)
2174 /* There is a breakpoint at the address we will resume at,
2175 step one instruction before inserting breakpoints so that
2176 we do not stop right away (and report a second hit at this
2179 Note, we don't do this in reverse, because we won't
2180 actually be executing the breakpoint insn anyway.
2181 We'll be (un-)executing the previous instruction. */
2184 else if (gdbarch_single_step_through_delay_p (gdbarch)
2185 && gdbarch_single_step_through_delay (gdbarch,
2186 get_current_frame ()))
2187 /* We stepped onto an instruction that needs to be stepped
2188 again before re-inserting the breakpoint, do so. */
2193 regcache_write_pc (regcache, addr);
2197 fprintf_unfiltered (gdb_stdlog,
2198 "infrun: proceed (addr=%s, signal=%d, step=%d)\n",
2199 paddress (gdbarch, addr), siggnal, step);
2202 /* In non-stop, each thread is handled individually. The context
2203 must already be set to the right thread here. */
2207 /* In a multi-threaded task we may select another thread and
2208 then continue or step.
2210 But if the old thread was stopped at a breakpoint, it will
2211 immediately cause another breakpoint stop without any
2212 execution (i.e. it will report a breakpoint hit incorrectly).
2213 So we must step over it first.
2215 prepare_to_proceed checks the current thread against the
2216 thread that reported the most recent event. If a step-over
2217 is required it returns TRUE and sets the current thread to
2219 if (prepare_to_proceed (step))
2223 /* prepare_to_proceed may change the current thread. */
2224 tp = inferior_thread ();
2228 tp->control.trap_expected = 1;
2229 /* If displaced stepping is enabled, we can step over the
2230 breakpoint without hitting it, so leave all breakpoints
2231 inserted. Otherwise we need to disable all breakpoints, step
2232 one instruction, and then re-add them when that step is
2234 if (!use_displaced_stepping (gdbarch))
2235 remove_breakpoints ();
2238 /* We can insert breakpoints if we're not trying to step over one,
2239 or if we are stepping over one but we're using displaced stepping
2241 if (! tp->control.trap_expected || use_displaced_stepping (gdbarch))
2242 insert_breakpoints ();
2246 /* Pass the last stop signal to the thread we're resuming,
2247 irrespective of whether the current thread is the thread that
2248 got the last event or not. This was historically GDB's
2249 behaviour before keeping a stop_signal per thread. */
2251 struct thread_info *last_thread;
2253 struct target_waitstatus last_status;
2255 get_last_target_status (&last_ptid, &last_status);
2256 if (!ptid_equal (inferior_ptid, last_ptid)
2257 && !ptid_equal (last_ptid, null_ptid)
2258 && !ptid_equal (last_ptid, minus_one_ptid))
2260 last_thread = find_thread_ptid (last_ptid);
2263 tp->suspend.stop_signal = last_thread->suspend.stop_signal;
2264 last_thread->suspend.stop_signal = GDB_SIGNAL_0;
2269 if (siggnal != GDB_SIGNAL_DEFAULT)
2270 tp->suspend.stop_signal = siggnal;
2271 /* If this signal should not be seen by program,
2272 give it zero. Used for debugging signals. */
2273 else if (!signal_program[tp->suspend.stop_signal])
2274 tp->suspend.stop_signal = GDB_SIGNAL_0;
2276 annotate_starting ();
2278 /* Make sure that output from GDB appears before output from the
2280 gdb_flush (gdb_stdout);
2282 /* Refresh prev_pc value just prior to resuming. This used to be
2283 done in stop_stepping, however, setting prev_pc there did not handle
2284 scenarios such as inferior function calls or returning from
2285 a function via the return command. In those cases, the prev_pc
2286 value was not set properly for subsequent commands. The prev_pc value
2287 is used to initialize the starting line number in the ecs. With an
2288 invalid value, the gdb next command ends up stopping at the position
2289 represented by the next line table entry past our start position.
2290 On platforms that generate one line table entry per line, this
2291 is not a problem. However, on the ia64, the compiler generates
2292 extraneous line table entries that do not increase the line number.
2293 When we issue the gdb next command on the ia64 after an inferior call
2294 or a return command, we often end up a few instructions forward, still
2295 within the original line we started.
2297 An attempt was made to refresh the prev_pc at the same time the
2298 execution_control_state is initialized (for instance, just before
2299 waiting for an inferior event). But this approach did not work
2300 because of platforms that use ptrace, where the pc register cannot
2301 be read unless the inferior is stopped. At that point, we are not
2302 guaranteed the inferior is stopped and so the regcache_read_pc() call
2303 can fail. Setting the prev_pc value here ensures the value is updated
2304 correctly when the inferior is stopped. */
2305 tp->prev_pc = regcache_read_pc (get_current_regcache ());
2307 /* Fill in with reasonable starting values. */
2308 init_thread_stepping_state (tp);
2310 /* Reset to normal state. */
2311 init_infwait_state ();
2313 /* Resume inferior. */
2314 resume (force_step || step || bpstat_should_step (),
2315 tp->suspend.stop_signal);
2317 /* Wait for it to stop (if not standalone)
2318 and in any case decode why it stopped, and act accordingly. */
2319 /* Do this only if we are not using the event loop, or if the target
2320 does not support asynchronous execution. */
2321 if (!target_can_async_p ())
2323 wait_for_inferior ();
2329 /* Start remote-debugging of a machine over a serial link. */
2332 start_remote (int from_tty)
2334 struct inferior *inferior;
2336 inferior = current_inferior ();
2337 inferior->control.stop_soon = STOP_QUIETLY_REMOTE;
2339 /* Always go on waiting for the target, regardless of the mode. */
2340 /* FIXME: cagney/1999-09-23: At present it isn't possible to
2341 indicate to wait_for_inferior that a target should timeout if
2342 nothing is returned (instead of just blocking). Because of this,
2343 targets expecting an immediate response need to, internally, set
2344 things up so that the target_wait() is forced to eventually
2346 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
2347 differentiate to its caller what the state of the target is after
2348 the initial open has been performed. Here we're assuming that
2349 the target has stopped. It should be possible to eventually have
2350 target_open() return to the caller an indication that the target
2351 is currently running and GDB state should be set to the same as
2352 for an async run. */
2353 wait_for_inferior ();
2355 /* Now that the inferior has stopped, do any bookkeeping like
2356 loading shared libraries. We want to do this before normal_stop,
2357 so that the displayed frame is up to date. */
2358 post_create_inferior (¤t_target, from_tty);
2363 /* Initialize static vars when a new inferior begins. */
2366 init_wait_for_inferior (void)
2368 /* These are meaningless until the first time through wait_for_inferior. */
2370 breakpoint_init_inferior (inf_starting);
2372 clear_proceed_status ();
2374 stepping_past_singlestep_breakpoint = 0;
2375 deferred_step_ptid = null_ptid;
2377 target_last_wait_ptid = minus_one_ptid;
2379 previous_inferior_ptid = inferior_ptid;
2380 init_infwait_state ();
2382 /* Discard any skipped inlined frames. */
2383 clear_inline_frame_state (minus_one_ptid);
2387 /* This enum encodes possible reasons for doing a target_wait, so that
2388 wfi can call target_wait in one place. (Ultimately the call will be
2389 moved out of the infinite loop entirely.) */
2393 infwait_normal_state,
2394 infwait_thread_hop_state,
2395 infwait_step_watch_state,
2396 infwait_nonstep_watch_state
2399 /* The PTID we'll do a target_wait on.*/
2402 /* Current inferior wait state. */
2403 static enum infwait_states infwait_state;
2405 /* Data to be passed around while handling an event. This data is
2406 discarded between events. */
2407 struct execution_control_state
2410 /* The thread that got the event, if this was a thread event; NULL
2412 struct thread_info *event_thread;
2414 struct target_waitstatus ws;
2416 int stop_func_filled_in;
2417 CORE_ADDR stop_func_start;
2418 CORE_ADDR stop_func_end;
2419 const char *stop_func_name;
2423 static void handle_inferior_event (struct execution_control_state *ecs);
2425 static void handle_step_into_function (struct gdbarch *gdbarch,
2426 struct execution_control_state *ecs);
2427 static void handle_step_into_function_backward (struct gdbarch *gdbarch,
2428 struct execution_control_state *ecs);
2429 static void check_exception_resume (struct execution_control_state *,
2430 struct frame_info *);
2432 static void stop_stepping (struct execution_control_state *ecs);
2433 static void prepare_to_wait (struct execution_control_state *ecs);
2434 static void keep_going (struct execution_control_state *ecs);
2436 /* Callback for iterate over threads. If the thread is stopped, but
2437 the user/frontend doesn't know about that yet, go through
2438 normal_stop, as if the thread had just stopped now. ARG points at
2439 a ptid. If PTID is MINUS_ONE_PTID, applies to all threads. If
2440 ptid_is_pid(PTID) is true, applies to all threads of the process
2441 pointed at by PTID. Otherwise, apply only to the thread pointed by
2445 infrun_thread_stop_requested_callback (struct thread_info *info, void *arg)
2447 ptid_t ptid = * (ptid_t *) arg;
2449 if ((ptid_equal (info->ptid, ptid)
2450 || ptid_equal (minus_one_ptid, ptid)
2451 || (ptid_is_pid (ptid)
2452 && ptid_get_pid (ptid) == ptid_get_pid (info->ptid)))
2453 && is_running (info->ptid)
2454 && !is_executing (info->ptid))
2456 struct cleanup *old_chain;
2457 struct execution_control_state ecss;
2458 struct execution_control_state *ecs = &ecss;
2460 memset (ecs, 0, sizeof (*ecs));
2462 old_chain = make_cleanup_restore_current_thread ();
2464 /* Go through handle_inferior_event/normal_stop, so we always
2465 have consistent output as if the stop event had been
2467 ecs->ptid = info->ptid;
2468 ecs->event_thread = find_thread_ptid (info->ptid);
2469 ecs->ws.kind = TARGET_WAITKIND_STOPPED;
2470 ecs->ws.value.sig = GDB_SIGNAL_0;
2472 handle_inferior_event (ecs);
2474 if (!ecs->wait_some_more)
2476 struct thread_info *tp;
2480 /* Finish off the continuations. */
2481 tp = inferior_thread ();
2482 do_all_intermediate_continuations_thread (tp, 1);
2483 do_all_continuations_thread (tp, 1);
2486 do_cleanups (old_chain);
2492 /* This function is attached as a "thread_stop_requested" observer.
2493 Cleanup local state that assumed the PTID was to be resumed, and
2494 report the stop to the frontend. */
2497 infrun_thread_stop_requested (ptid_t ptid)
2499 struct displaced_step_inferior_state *displaced;
2501 /* PTID was requested to stop. Remove it from the displaced
2502 stepping queue, so we don't try to resume it automatically. */
2504 for (displaced = displaced_step_inferior_states;
2506 displaced = displaced->next)
2508 struct displaced_step_request *it, **prev_next_p;
2510 it = displaced->step_request_queue;
2511 prev_next_p = &displaced->step_request_queue;
2514 if (ptid_match (it->ptid, ptid))
2516 *prev_next_p = it->next;
2522 prev_next_p = &it->next;
2529 iterate_over_threads (infrun_thread_stop_requested_callback, &ptid);
2533 infrun_thread_thread_exit (struct thread_info *tp, int silent)
2535 if (ptid_equal (target_last_wait_ptid, tp->ptid))
2536 nullify_last_target_wait_ptid ();
2539 /* Callback for iterate_over_threads. */
2542 delete_step_resume_breakpoint_callback (struct thread_info *info, void *data)
2544 if (is_exited (info->ptid))
2547 delete_step_resume_breakpoint (info);
2548 delete_exception_resume_breakpoint (info);
2552 /* In all-stop, delete the step resume breakpoint of any thread that
2553 had one. In non-stop, delete the step resume breakpoint of the
2554 thread that just stopped. */
2557 delete_step_thread_step_resume_breakpoint (void)
2559 if (!target_has_execution
2560 || ptid_equal (inferior_ptid, null_ptid))
2561 /* If the inferior has exited, we have already deleted the step
2562 resume breakpoints out of GDB's lists. */
2567 /* If in non-stop mode, only delete the step-resume or
2568 longjmp-resume breakpoint of the thread that just stopped
2570 struct thread_info *tp = inferior_thread ();
2572 delete_step_resume_breakpoint (tp);
2573 delete_exception_resume_breakpoint (tp);
2576 /* In all-stop mode, delete all step-resume and longjmp-resume
2577 breakpoints of any thread that had them. */
2578 iterate_over_threads (delete_step_resume_breakpoint_callback, NULL);
2581 /* A cleanup wrapper. */
2584 delete_step_thread_step_resume_breakpoint_cleanup (void *arg)
2586 delete_step_thread_step_resume_breakpoint ();
2589 /* Pretty print the results of target_wait, for debugging purposes. */
2592 print_target_wait_results (ptid_t waiton_ptid, ptid_t result_ptid,
2593 const struct target_waitstatus *ws)
2595 char *status_string = target_waitstatus_to_string (ws);
2596 struct ui_file *tmp_stream = mem_fileopen ();
2599 /* The text is split over several lines because it was getting too long.
2600 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
2601 output as a unit; we want only one timestamp printed if debug_timestamp
2604 fprintf_unfiltered (tmp_stream,
2605 "infrun: target_wait (%d", PIDGET (waiton_ptid));
2606 if (PIDGET (waiton_ptid) != -1)
2607 fprintf_unfiltered (tmp_stream,
2608 " [%s]", target_pid_to_str (waiton_ptid));
2609 fprintf_unfiltered (tmp_stream, ", status) =\n");
2610 fprintf_unfiltered (tmp_stream,
2611 "infrun: %d [%s],\n",
2612 PIDGET (result_ptid), target_pid_to_str (result_ptid));
2613 fprintf_unfiltered (tmp_stream,
2617 text = ui_file_xstrdup (tmp_stream, NULL);
2619 /* This uses %s in part to handle %'s in the text, but also to avoid
2620 a gcc error: the format attribute requires a string literal. */
2621 fprintf_unfiltered (gdb_stdlog, "%s", text);
2623 xfree (status_string);
2625 ui_file_delete (tmp_stream);
2628 /* Prepare and stabilize the inferior for detaching it. E.g.,
2629 detaching while a thread is displaced stepping is a recipe for
2630 crashing it, as nothing would readjust the PC out of the scratch
2634 prepare_for_detach (void)
2636 struct inferior *inf = current_inferior ();
2637 ptid_t pid_ptid = pid_to_ptid (inf->pid);
2638 struct cleanup *old_chain_1;
2639 struct displaced_step_inferior_state *displaced;
2641 displaced = get_displaced_stepping_state (inf->pid);
2643 /* Is any thread of this process displaced stepping? If not,
2644 there's nothing else to do. */
2645 if (displaced == NULL || ptid_equal (displaced->step_ptid, null_ptid))
2649 fprintf_unfiltered (gdb_stdlog,
2650 "displaced-stepping in-process while detaching");
2652 old_chain_1 = make_cleanup_restore_integer (&inf->detaching);
2655 while (!ptid_equal (displaced->step_ptid, null_ptid))
2657 struct cleanup *old_chain_2;
2658 struct execution_control_state ecss;
2659 struct execution_control_state *ecs;
2662 memset (ecs, 0, sizeof (*ecs));
2664 overlay_cache_invalid = 1;
2666 if (deprecated_target_wait_hook)
2667 ecs->ptid = deprecated_target_wait_hook (pid_ptid, &ecs->ws, 0);
2669 ecs->ptid = target_wait (pid_ptid, &ecs->ws, 0);
2672 print_target_wait_results (pid_ptid, ecs->ptid, &ecs->ws);
2674 /* If an error happens while handling the event, propagate GDB's
2675 knowledge of the executing state to the frontend/user running
2677 old_chain_2 = make_cleanup (finish_thread_state_cleanup,
2680 /* Now figure out what to do with the result of the result. */
2681 handle_inferior_event (ecs);
2683 /* No error, don't finish the state yet. */
2684 discard_cleanups (old_chain_2);
2686 /* Breakpoints and watchpoints are not installed on the target
2687 at this point, and signals are passed directly to the
2688 inferior, so this must mean the process is gone. */
2689 if (!ecs->wait_some_more)
2691 discard_cleanups (old_chain_1);
2692 error (_("Program exited while detaching"));
2696 discard_cleanups (old_chain_1);
2699 /* Wait for control to return from inferior to debugger.
2701 If inferior gets a signal, we may decide to start it up again
2702 instead of returning. That is why there is a loop in this function.
2703 When this function actually returns it means the inferior
2704 should be left stopped and GDB should read more commands. */
2707 wait_for_inferior (void)
2709 struct cleanup *old_cleanups;
2713 (gdb_stdlog, "infrun: wait_for_inferior ()\n");
2716 make_cleanup (delete_step_thread_step_resume_breakpoint_cleanup, NULL);
2720 struct execution_control_state ecss;
2721 struct execution_control_state *ecs = &ecss;
2722 struct cleanup *old_chain;
2724 memset (ecs, 0, sizeof (*ecs));
2726 overlay_cache_invalid = 1;
2728 if (deprecated_target_wait_hook)
2729 ecs->ptid = deprecated_target_wait_hook (waiton_ptid, &ecs->ws, 0);
2731 ecs->ptid = target_wait (waiton_ptid, &ecs->ws, 0);
2734 print_target_wait_results (waiton_ptid, ecs->ptid, &ecs->ws);
2736 /* If an error happens while handling the event, propagate GDB's
2737 knowledge of the executing state to the frontend/user running
2739 old_chain = make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
2741 /* Now figure out what to do with the result of the result. */
2742 handle_inferior_event (ecs);
2744 /* No error, don't finish the state yet. */
2745 discard_cleanups (old_chain);
2747 if (!ecs->wait_some_more)
2751 do_cleanups (old_cleanups);
2754 /* Asynchronous version of wait_for_inferior. It is called by the
2755 event loop whenever a change of state is detected on the file
2756 descriptor corresponding to the target. It can be called more than
2757 once to complete a single execution command. In such cases we need
2758 to keep the state in a global variable ECSS. If it is the last time
2759 that this function is called for a single execution command, then
2760 report to the user that the inferior has stopped, and do the
2761 necessary cleanups. */
2764 fetch_inferior_event (void *client_data)
2766 struct execution_control_state ecss;
2767 struct execution_control_state *ecs = &ecss;
2768 struct cleanup *old_chain = make_cleanup (null_cleanup, NULL);
2769 struct cleanup *ts_old_chain;
2770 int was_sync = sync_execution;
2773 memset (ecs, 0, sizeof (*ecs));
2775 /* We're handling a live event, so make sure we're doing live
2776 debugging. If we're looking at traceframes while the target is
2777 running, we're going to need to get back to that mode after
2778 handling the event. */
2781 make_cleanup_restore_current_traceframe ();
2782 set_current_traceframe (-1);
2786 /* In non-stop mode, the user/frontend should not notice a thread
2787 switch due to internal events. Make sure we reverse to the
2788 user selected thread and frame after handling the event and
2789 running any breakpoint commands. */
2790 make_cleanup_restore_current_thread ();
2792 overlay_cache_invalid = 1;
2794 make_cleanup_restore_integer (&execution_direction);
2795 execution_direction = target_execution_direction ();
2797 if (deprecated_target_wait_hook)
2799 deprecated_target_wait_hook (waiton_ptid, &ecs->ws, TARGET_WNOHANG);
2801 ecs->ptid = target_wait (waiton_ptid, &ecs->ws, TARGET_WNOHANG);
2804 print_target_wait_results (waiton_ptid, ecs->ptid, &ecs->ws);
2806 /* If an error happens while handling the event, propagate GDB's
2807 knowledge of the executing state to the frontend/user running
2810 ts_old_chain = make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
2812 ts_old_chain = make_cleanup (finish_thread_state_cleanup, &ecs->ptid);
2814 /* Get executed before make_cleanup_restore_current_thread above to apply
2815 still for the thread which has thrown the exception. */
2816 make_bpstat_clear_actions_cleanup ();
2818 /* Now figure out what to do with the result of the result. */
2819 handle_inferior_event (ecs);
2821 if (!ecs->wait_some_more)
2823 struct inferior *inf = find_inferior_pid (ptid_get_pid (ecs->ptid));
2825 delete_step_thread_step_resume_breakpoint ();
2827 /* We may not find an inferior if this was a process exit. */
2828 if (inf == NULL || inf->control.stop_soon == NO_STOP_QUIETLY)
2831 if (target_has_execution
2832 && ecs->ws.kind != TARGET_WAITKIND_NO_RESUMED
2833 && ecs->ws.kind != TARGET_WAITKIND_EXITED
2834 && ecs->ws.kind != TARGET_WAITKIND_SIGNALLED
2835 && ecs->event_thread->step_multi
2836 && ecs->event_thread->control.stop_step)
2837 inferior_event_handler (INF_EXEC_CONTINUE, NULL);
2840 inferior_event_handler (INF_EXEC_COMPLETE, NULL);
2845 /* No error, don't finish the thread states yet. */
2846 discard_cleanups (ts_old_chain);
2848 /* Revert thread and frame. */
2849 do_cleanups (old_chain);
2851 /* If the inferior was in sync execution mode, and now isn't,
2852 restore the prompt (a synchronous execution command has finished,
2853 and we're ready for input). */
2854 if (interpreter_async && was_sync && !sync_execution)
2855 display_gdb_prompt (0);
2859 && exec_done_display_p
2860 && (ptid_equal (inferior_ptid, null_ptid)
2861 || !is_running (inferior_ptid)))
2862 printf_unfiltered (_("completed.\n"));
2865 /* Record the frame and location we're currently stepping through. */
2867 set_step_info (struct frame_info *frame, struct symtab_and_line sal)
2869 struct thread_info *tp = inferior_thread ();
2871 tp->control.step_frame_id = get_frame_id (frame);
2872 tp->control.step_stack_frame_id = get_stack_frame_id (frame);
2874 tp->current_symtab = sal.symtab;
2875 tp->current_line = sal.line;
2878 /* Clear context switchable stepping state. */
2881 init_thread_stepping_state (struct thread_info *tss)
2883 tss->stepping_over_breakpoint = 0;
2884 tss->step_after_step_resume_breakpoint = 0;
2887 /* Return the cached copy of the last pid/waitstatus returned by
2888 target_wait()/deprecated_target_wait_hook(). The data is actually
2889 cached by handle_inferior_event(), which gets called immediately
2890 after target_wait()/deprecated_target_wait_hook(). */
2893 get_last_target_status (ptid_t *ptidp, struct target_waitstatus *status)
2895 *ptidp = target_last_wait_ptid;
2896 *status = target_last_waitstatus;
2900 nullify_last_target_wait_ptid (void)
2902 target_last_wait_ptid = minus_one_ptid;
2905 /* Switch thread contexts. */
2908 context_switch (ptid_t ptid)
2910 if (debug_infrun && !ptid_equal (ptid, inferior_ptid))
2912 fprintf_unfiltered (gdb_stdlog, "infrun: Switching context from %s ",
2913 target_pid_to_str (inferior_ptid));
2914 fprintf_unfiltered (gdb_stdlog, "to %s\n",
2915 target_pid_to_str (ptid));
2918 switch_to_thread (ptid);
2922 adjust_pc_after_break (struct execution_control_state *ecs)
2924 struct regcache *regcache;
2925 struct gdbarch *gdbarch;
2926 struct address_space *aspace;
2927 CORE_ADDR breakpoint_pc;
2929 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
2930 we aren't, just return.
2932 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
2933 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
2934 implemented by software breakpoints should be handled through the normal
2937 NOTE drow/2004-01-31: On some targets, breakpoints may generate
2938 different signals (SIGILL or SIGEMT for instance), but it is less
2939 clear where the PC is pointing afterwards. It may not match
2940 gdbarch_decr_pc_after_break. I don't know any specific target that
2941 generates these signals at breakpoints (the code has been in GDB since at
2942 least 1992) so I can not guess how to handle them here.
2944 In earlier versions of GDB, a target with
2945 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
2946 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
2947 target with both of these set in GDB history, and it seems unlikely to be
2948 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
2950 if (ecs->ws.kind != TARGET_WAITKIND_STOPPED)
2953 if (ecs->ws.value.sig != GDB_SIGNAL_TRAP)
2956 /* In reverse execution, when a breakpoint is hit, the instruction
2957 under it has already been de-executed. The reported PC always
2958 points at the breakpoint address, so adjusting it further would
2959 be wrong. E.g., consider this case on a decr_pc_after_break == 1
2962 B1 0x08000000 : INSN1
2963 B2 0x08000001 : INSN2
2965 PC -> 0x08000003 : INSN4
2967 Say you're stopped at 0x08000003 as above. Reverse continuing
2968 from that point should hit B2 as below. Reading the PC when the
2969 SIGTRAP is reported should read 0x08000001 and INSN2 should have
2970 been de-executed already.
2972 B1 0x08000000 : INSN1
2973 B2 PC -> 0x08000001 : INSN2
2977 We can't apply the same logic as for forward execution, because
2978 we would wrongly adjust the PC to 0x08000000, since there's a
2979 breakpoint at PC - 1. We'd then report a hit on B1, although
2980 INSN1 hadn't been de-executed yet. Doing nothing is the correct
2982 if (execution_direction == EXEC_REVERSE)
2985 /* If this target does not decrement the PC after breakpoints, then
2986 we have nothing to do. */
2987 regcache = get_thread_regcache (ecs->ptid);
2988 gdbarch = get_regcache_arch (regcache);
2989 if (gdbarch_decr_pc_after_break (gdbarch) == 0)
2992 aspace = get_regcache_aspace (regcache);
2994 /* Find the location where (if we've hit a breakpoint) the
2995 breakpoint would be. */
2996 breakpoint_pc = regcache_read_pc (regcache)
2997 - gdbarch_decr_pc_after_break (gdbarch);
2999 /* Check whether there actually is a software breakpoint inserted at
3002 If in non-stop mode, a race condition is possible where we've
3003 removed a breakpoint, but stop events for that breakpoint were
3004 already queued and arrive later. To suppress those spurious
3005 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
3006 and retire them after a number of stop events are reported. */
3007 if (software_breakpoint_inserted_here_p (aspace, breakpoint_pc)
3008 || (non_stop && moribund_breakpoint_here_p (aspace, breakpoint_pc)))
3010 struct cleanup *old_cleanups = NULL;
3013 old_cleanups = record_gdb_operation_disable_set ();
3015 /* When using hardware single-step, a SIGTRAP is reported for both
3016 a completed single-step and a software breakpoint. Need to
3017 differentiate between the two, as the latter needs adjusting
3018 but the former does not.
3020 The SIGTRAP can be due to a completed hardware single-step only if
3021 - we didn't insert software single-step breakpoints
3022 - the thread to be examined is still the current thread
3023 - this thread is currently being stepped
3025 If any of these events did not occur, we must have stopped due
3026 to hitting a software breakpoint, and have to back up to the
3029 As a special case, we could have hardware single-stepped a
3030 software breakpoint. In this case (prev_pc == breakpoint_pc),
3031 we also need to back up to the breakpoint address. */
3033 if (singlestep_breakpoints_inserted_p
3034 || !ptid_equal (ecs->ptid, inferior_ptid)
3035 || !currently_stepping (ecs->event_thread)
3036 || ecs->event_thread->prev_pc == breakpoint_pc)
3037 regcache_write_pc (regcache, breakpoint_pc);
3040 do_cleanups (old_cleanups);
3045 init_infwait_state (void)
3047 waiton_ptid = pid_to_ptid (-1);
3048 infwait_state = infwait_normal_state;
3052 stepped_in_from (struct frame_info *frame, struct frame_id step_frame_id)
3054 for (frame = get_prev_frame (frame);
3056 frame = get_prev_frame (frame))
3058 if (frame_id_eq (get_frame_id (frame), step_frame_id))
3060 if (get_frame_type (frame) != INLINE_FRAME)
3067 /* Auxiliary function that handles syscall entry/return events.
3068 It returns 1 if the inferior should keep going (and GDB
3069 should ignore the event), or 0 if the event deserves to be
3073 handle_syscall_event (struct execution_control_state *ecs)
3075 struct regcache *regcache;
3076 struct gdbarch *gdbarch;
3079 if (!ptid_equal (ecs->ptid, inferior_ptid))
3080 context_switch (ecs->ptid);
3082 regcache = get_thread_regcache (ecs->ptid);
3083 gdbarch = get_regcache_arch (regcache);
3084 syscall_number = ecs->ws.value.syscall_number;
3085 stop_pc = regcache_read_pc (regcache);
3087 if (catch_syscall_enabled () > 0
3088 && catching_syscall_number (syscall_number) > 0)
3090 enum bpstat_signal_value sval;
3093 fprintf_unfiltered (gdb_stdlog, "infrun: syscall number = '%d'\n",
3096 ecs->event_thread->control.stop_bpstat
3097 = bpstat_stop_status (get_regcache_aspace (regcache),
3098 stop_pc, ecs->ptid, &ecs->ws);
3100 sval = bpstat_explains_signal (ecs->event_thread->control.stop_bpstat);
3101 ecs->random_signal = sval == BPSTAT_SIGNAL_NO;
3103 if (!ecs->random_signal)
3105 /* Catchpoint hit. */
3106 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_TRAP;
3111 /* If no catchpoint triggered for this, then keep going. */
3112 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
3117 /* Clear the supplied execution_control_state's stop_func_* fields. */
3120 clear_stop_func (struct execution_control_state *ecs)
3122 ecs->stop_func_filled_in = 0;
3123 ecs->stop_func_start = 0;
3124 ecs->stop_func_end = 0;
3125 ecs->stop_func_name = NULL;
3128 /* Lazily fill in the execution_control_state's stop_func_* fields. */
3131 fill_in_stop_func (struct gdbarch *gdbarch,
3132 struct execution_control_state *ecs)
3134 if (!ecs->stop_func_filled_in)
3136 /* Don't care about return value; stop_func_start and stop_func_name
3137 will both be 0 if it doesn't work. */
3138 find_pc_partial_function (stop_pc, &ecs->stop_func_name,
3139 &ecs->stop_func_start, &ecs->stop_func_end);
3140 ecs->stop_func_start
3141 += gdbarch_deprecated_function_start_offset (gdbarch);
3143 ecs->stop_func_filled_in = 1;
3147 /* Given an execution control state that has been freshly filled in
3148 by an event from the inferior, figure out what it means and take
3149 appropriate action. */
3152 handle_inferior_event (struct execution_control_state *ecs)
3154 struct frame_info *frame;
3155 struct gdbarch *gdbarch;
3156 int stopped_by_watchpoint;
3157 int stepped_after_stopped_by_watchpoint = 0;
3158 struct symtab_and_line stop_pc_sal;
3159 enum stop_kind stop_soon;
3161 if (ecs->ws.kind == TARGET_WAITKIND_IGNORE)
3163 /* We had an event in the inferior, but we are not interested in
3164 handling it at this level. The lower layers have already
3165 done what needs to be done, if anything.
3167 One of the possible circumstances for this is when the
3168 inferior produces output for the console. The inferior has
3169 not stopped, and we are ignoring the event. Another possible
3170 circumstance is any event which the lower level knows will be
3171 reported multiple times without an intervening resume. */
3173 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_IGNORE\n");
3174 prepare_to_wait (ecs);
3178 if (ecs->ws.kind == TARGET_WAITKIND_NO_RESUMED
3179 && target_can_async_p () && !sync_execution)
3181 /* There were no unwaited-for children left in the target, but,
3182 we're not synchronously waiting for events either. Just
3183 ignore. Otherwise, if we were running a synchronous
3184 execution command, we need to cancel it and give the user
3185 back the terminal. */
3187 fprintf_unfiltered (gdb_stdlog,
3188 "infrun: TARGET_WAITKIND_NO_RESUMED (ignoring)\n");
3189 prepare_to_wait (ecs);
3193 if (ecs->ws.kind != TARGET_WAITKIND_EXITED
3194 && ecs->ws.kind != TARGET_WAITKIND_SIGNALLED
3195 && ecs->ws.kind != TARGET_WAITKIND_NO_RESUMED)
3197 struct inferior *inf = find_inferior_pid (ptid_get_pid (ecs->ptid));
3200 stop_soon = inf->control.stop_soon;
3203 stop_soon = NO_STOP_QUIETLY;
3205 /* Cache the last pid/waitstatus. */
3206 target_last_wait_ptid = ecs->ptid;
3207 target_last_waitstatus = ecs->ws;
3209 /* Always clear state belonging to the previous time we stopped. */
3210 stop_stack_dummy = STOP_NONE;
3212 if (ecs->ws.kind == TARGET_WAITKIND_NO_RESUMED)
3214 /* No unwaited-for children left. IOW, all resumed children
3217 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_NO_RESUMED\n");
3219 stop_print_frame = 0;
3220 stop_stepping (ecs);
3224 if (ecs->ws.kind != TARGET_WAITKIND_EXITED
3225 && ecs->ws.kind != TARGET_WAITKIND_SIGNALLED)
3227 ecs->event_thread = find_thread_ptid (ecs->ptid);
3228 /* If it's a new thread, add it to the thread database. */
3229 if (ecs->event_thread == NULL)
3230 ecs->event_thread = add_thread (ecs->ptid);
3233 /* Dependent on valid ECS->EVENT_THREAD. */
3234 adjust_pc_after_break (ecs);
3236 /* Dependent on the current PC value modified by adjust_pc_after_break. */
3237 reinit_frame_cache ();
3239 breakpoint_retire_moribund ();
3241 /* First, distinguish signals caused by the debugger from signals
3242 that have to do with the program's own actions. Note that
3243 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
3244 on the operating system version. Here we detect when a SIGILL or
3245 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
3246 something similar for SIGSEGV, since a SIGSEGV will be generated
3247 when we're trying to execute a breakpoint instruction on a
3248 non-executable stack. This happens for call dummy breakpoints
3249 for architectures like SPARC that place call dummies on the
3251 if (ecs->ws.kind == TARGET_WAITKIND_STOPPED
3252 && (ecs->ws.value.sig == GDB_SIGNAL_ILL
3253 || ecs->ws.value.sig == GDB_SIGNAL_SEGV
3254 || ecs->ws.value.sig == GDB_SIGNAL_EMT))
3256 struct regcache *regcache = get_thread_regcache (ecs->ptid);
3258 if (breakpoint_inserted_here_p (get_regcache_aspace (regcache),
3259 regcache_read_pc (regcache)))
3262 fprintf_unfiltered (gdb_stdlog,
3263 "infrun: Treating signal as SIGTRAP\n");
3264 ecs->ws.value.sig = GDB_SIGNAL_TRAP;
3268 /* Mark the non-executing threads accordingly. In all-stop, all
3269 threads of all processes are stopped when we get any event
3270 reported. In non-stop mode, only the event thread stops. If
3271 we're handling a process exit in non-stop mode, there's nothing
3272 to do, as threads of the dead process are gone, and threads of
3273 any other process were left running. */
3275 set_executing (minus_one_ptid, 0);
3276 else if (ecs->ws.kind != TARGET_WAITKIND_SIGNALLED
3277 && ecs->ws.kind != TARGET_WAITKIND_EXITED)
3278 set_executing (ecs->ptid, 0);
3280 switch (infwait_state)
3282 case infwait_thread_hop_state:
3284 fprintf_unfiltered (gdb_stdlog, "infrun: infwait_thread_hop_state\n");
3287 case infwait_normal_state:
3289 fprintf_unfiltered (gdb_stdlog, "infrun: infwait_normal_state\n");
3292 case infwait_step_watch_state:
3294 fprintf_unfiltered (gdb_stdlog,
3295 "infrun: infwait_step_watch_state\n");
3297 stepped_after_stopped_by_watchpoint = 1;
3300 case infwait_nonstep_watch_state:
3302 fprintf_unfiltered (gdb_stdlog,
3303 "infrun: infwait_nonstep_watch_state\n");
3304 insert_breakpoints ();
3306 /* FIXME-maybe: is this cleaner than setting a flag? Does it
3307 handle things like signals arriving and other things happening
3308 in combination correctly? */
3309 stepped_after_stopped_by_watchpoint = 1;
3313 internal_error (__FILE__, __LINE__, _("bad switch"));
3316 infwait_state = infwait_normal_state;
3317 waiton_ptid = pid_to_ptid (-1);
3319 switch (ecs->ws.kind)
3321 case TARGET_WAITKIND_LOADED:
3323 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_LOADED\n");
3324 /* Ignore gracefully during startup of the inferior, as it might
3325 be the shell which has just loaded some objects, otherwise
3326 add the symbols for the newly loaded objects. Also ignore at
3327 the beginning of an attach or remote session; we will query
3328 the full list of libraries once the connection is
3330 if (stop_soon == NO_STOP_QUIETLY)
3332 struct regcache *regcache;
3333 enum bpstat_signal_value sval;
3335 if (!ptid_equal (ecs->ptid, inferior_ptid))
3336 context_switch (ecs->ptid);
3337 regcache = get_thread_regcache (ecs->ptid);
3339 handle_solib_event ();
3341 ecs->event_thread->control.stop_bpstat
3342 = bpstat_stop_status (get_regcache_aspace (regcache),
3343 stop_pc, ecs->ptid, &ecs->ws);
3346 = bpstat_explains_signal (ecs->event_thread->control.stop_bpstat);
3347 ecs->random_signal = sval == BPSTAT_SIGNAL_NO;
3349 if (!ecs->random_signal)
3351 /* A catchpoint triggered. */
3352 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_TRAP;
3353 goto process_event_stop_test;
3356 /* If requested, stop when the dynamic linker notifies
3357 gdb of events. This allows the user to get control
3358 and place breakpoints in initializer routines for
3359 dynamically loaded objects (among other things). */
3360 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
3361 if (stop_on_solib_events)
3363 /* Make sure we print "Stopped due to solib-event" in
3365 stop_print_frame = 1;
3367 stop_stepping (ecs);
3372 /* If we are skipping through a shell, or through shared library
3373 loading that we aren't interested in, resume the program. If
3374 we're running the program normally, also resume. But stop if
3375 we're attaching or setting up a remote connection. */
3376 if (stop_soon == STOP_QUIETLY || stop_soon == NO_STOP_QUIETLY)
3378 if (!ptid_equal (ecs->ptid, inferior_ptid))
3379 context_switch (ecs->ptid);
3381 /* Loading of shared libraries might have changed breakpoint
3382 addresses. Make sure new breakpoints are inserted. */
3383 if (stop_soon == NO_STOP_QUIETLY
3384 && !breakpoints_always_inserted_mode ())
3385 insert_breakpoints ();
3386 resume (0, GDB_SIGNAL_0);
3387 prepare_to_wait (ecs);
3393 case TARGET_WAITKIND_SPURIOUS:
3395 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_SPURIOUS\n");
3396 if (!ptid_equal (ecs->ptid, inferior_ptid))
3397 context_switch (ecs->ptid);
3398 resume (0, GDB_SIGNAL_0);
3399 prepare_to_wait (ecs);
3402 case TARGET_WAITKIND_EXITED:
3403 case TARGET_WAITKIND_SIGNALLED:
3406 if (ecs->ws.kind == TARGET_WAITKIND_EXITED)
3407 fprintf_unfiltered (gdb_stdlog,
3408 "infrun: TARGET_WAITKIND_EXITED\n");
3410 fprintf_unfiltered (gdb_stdlog,
3411 "infrun: TARGET_WAITKIND_SIGNALLED\n");
3414 inferior_ptid = ecs->ptid;
3415 set_current_inferior (find_inferior_pid (ptid_get_pid (ecs->ptid)));
3416 set_current_program_space (current_inferior ()->pspace);
3417 handle_vfork_child_exec_or_exit (0);
3418 target_terminal_ours (); /* Must do this before mourn anyway. */
3420 if (ecs->ws.kind == TARGET_WAITKIND_EXITED)
3422 /* Record the exit code in the convenience variable $_exitcode, so
3423 that the user can inspect this again later. */
3424 set_internalvar_integer (lookup_internalvar ("_exitcode"),
3425 (LONGEST) ecs->ws.value.integer);
3427 /* Also record this in the inferior itself. */
3428 current_inferior ()->has_exit_code = 1;
3429 current_inferior ()->exit_code = (LONGEST) ecs->ws.value.integer;
3431 print_exited_reason (ecs->ws.value.integer);
3434 print_signal_exited_reason (ecs->ws.value.sig);
3436 gdb_flush (gdb_stdout);
3437 target_mourn_inferior ();
3438 singlestep_breakpoints_inserted_p = 0;
3439 cancel_single_step_breakpoints ();
3440 stop_print_frame = 0;
3441 stop_stepping (ecs);
3444 /* The following are the only cases in which we keep going;
3445 the above cases end in a continue or goto. */
3446 case TARGET_WAITKIND_FORKED:
3447 case TARGET_WAITKIND_VFORKED:
3450 if (ecs->ws.kind == TARGET_WAITKIND_FORKED)
3451 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_FORKED\n");
3453 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_VFORKED\n");
3456 /* Check whether the inferior is displaced stepping. */
3458 struct regcache *regcache = get_thread_regcache (ecs->ptid);
3459 struct gdbarch *gdbarch = get_regcache_arch (regcache);
3460 struct displaced_step_inferior_state *displaced
3461 = get_displaced_stepping_state (ptid_get_pid (ecs->ptid));
3463 /* If checking displaced stepping is supported, and thread
3464 ecs->ptid is displaced stepping. */
3465 if (displaced && ptid_equal (displaced->step_ptid, ecs->ptid))
3467 struct inferior *parent_inf
3468 = find_inferior_pid (ptid_get_pid (ecs->ptid));
3469 struct regcache *child_regcache;
3470 CORE_ADDR parent_pc;
3472 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
3473 indicating that the displaced stepping of syscall instruction
3474 has been done. Perform cleanup for parent process here. Note
3475 that this operation also cleans up the child process for vfork,
3476 because their pages are shared. */
3477 displaced_step_fixup (ecs->ptid, GDB_SIGNAL_TRAP);
3479 if (ecs->ws.kind == TARGET_WAITKIND_FORKED)
3481 /* Restore scratch pad for child process. */
3482 displaced_step_restore (displaced, ecs->ws.value.related_pid);
3485 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
3486 the child's PC is also within the scratchpad. Set the child's PC
3487 to the parent's PC value, which has already been fixed up.
3488 FIXME: we use the parent's aspace here, although we're touching
3489 the child, because the child hasn't been added to the inferior
3490 list yet at this point. */
3493 = get_thread_arch_aspace_regcache (ecs->ws.value.related_pid,
3495 parent_inf->aspace);
3496 /* Read PC value of parent process. */
3497 parent_pc = regcache_read_pc (regcache);
3499 if (debug_displaced)
3500 fprintf_unfiltered (gdb_stdlog,
3501 "displaced: write child pc from %s to %s\n",
3503 regcache_read_pc (child_regcache)),
3504 paddress (gdbarch, parent_pc));
3506 regcache_write_pc (child_regcache, parent_pc);
3510 if (!ptid_equal (ecs->ptid, inferior_ptid))
3511 context_switch (ecs->ptid);
3513 /* Immediately detach breakpoints from the child before there's
3514 any chance of letting the user delete breakpoints from the
3515 breakpoint lists. If we don't do this early, it's easy to
3516 leave left over traps in the child, vis: "break foo; catch
3517 fork; c; <fork>; del; c; <child calls foo>". We only follow
3518 the fork on the last `continue', and by that time the
3519 breakpoint at "foo" is long gone from the breakpoint table.
3520 If we vforked, then we don't need to unpatch here, since both
3521 parent and child are sharing the same memory pages; we'll
3522 need to unpatch at follow/detach time instead to be certain
3523 that new breakpoints added between catchpoint hit time and
3524 vfork follow are detached. */
3525 if (ecs->ws.kind != TARGET_WAITKIND_VFORKED)
3527 /* This won't actually modify the breakpoint list, but will
3528 physically remove the breakpoints from the child. */
3529 detach_breakpoints (ecs->ws.value.related_pid);
3532 if (singlestep_breakpoints_inserted_p)
3534 /* Pull the single step breakpoints out of the target. */
3535 remove_single_step_breakpoints ();
3536 singlestep_breakpoints_inserted_p = 0;
3539 /* In case the event is caught by a catchpoint, remember that
3540 the event is to be followed at the next resume of the thread,
3541 and not immediately. */
3542 ecs->event_thread->pending_follow = ecs->ws;
3544 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
3546 ecs->event_thread->control.stop_bpstat
3547 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
3548 stop_pc, ecs->ptid, &ecs->ws);
3550 /* Note that we're interested in knowing the bpstat actually
3551 causes a stop, not just if it may explain the signal.
3552 Software watchpoints, for example, always appear in the
3555 = !bpstat_causes_stop (ecs->event_thread->control.stop_bpstat);
3557 /* If no catchpoint triggered for this, then keep going. */
3558 if (ecs->random_signal)
3564 = (follow_fork_mode_string == follow_fork_mode_child);
3566 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
3568 should_resume = follow_fork ();
3571 child = ecs->ws.value.related_pid;
3573 /* In non-stop mode, also resume the other branch. */
3574 if (non_stop && !detach_fork)
3577 switch_to_thread (parent);
3579 switch_to_thread (child);
3581 ecs->event_thread = inferior_thread ();
3582 ecs->ptid = inferior_ptid;
3587 switch_to_thread (child);
3589 switch_to_thread (parent);
3591 ecs->event_thread = inferior_thread ();
3592 ecs->ptid = inferior_ptid;
3597 stop_stepping (ecs);
3600 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_TRAP;
3601 goto process_event_stop_test;
3603 case TARGET_WAITKIND_VFORK_DONE:
3604 /* Done with the shared memory region. Re-insert breakpoints in
3605 the parent, and keep going. */
3608 fprintf_unfiltered (gdb_stdlog,
3609 "infrun: TARGET_WAITKIND_VFORK_DONE\n");
3611 if (!ptid_equal (ecs->ptid, inferior_ptid))
3612 context_switch (ecs->ptid);
3614 current_inferior ()->waiting_for_vfork_done = 0;
3615 current_inferior ()->pspace->breakpoints_not_allowed = 0;
3616 /* This also takes care of reinserting breakpoints in the
3617 previously locked inferior. */
3621 case TARGET_WAITKIND_EXECD:
3623 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_EXECD\n");
3625 if (!ptid_equal (ecs->ptid, inferior_ptid))
3626 context_switch (ecs->ptid);
3628 singlestep_breakpoints_inserted_p = 0;
3629 cancel_single_step_breakpoints ();
3631 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
3633 /* Do whatever is necessary to the parent branch of the vfork. */
3634 handle_vfork_child_exec_or_exit (1);
3636 /* This causes the eventpoints and symbol table to be reset.
3637 Must do this now, before trying to determine whether to
3639 follow_exec (inferior_ptid, ecs->ws.value.execd_pathname);
3641 ecs->event_thread->control.stop_bpstat
3642 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
3643 stop_pc, ecs->ptid, &ecs->ws);
3645 = (bpstat_explains_signal (ecs->event_thread->control.stop_bpstat)
3646 == BPSTAT_SIGNAL_NO);
3648 /* Note that this may be referenced from inside
3649 bpstat_stop_status above, through inferior_has_execd. */
3650 xfree (ecs->ws.value.execd_pathname);
3651 ecs->ws.value.execd_pathname = NULL;
3653 /* If no catchpoint triggered for this, then keep going. */
3654 if (ecs->random_signal)
3656 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
3660 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_TRAP;
3661 goto process_event_stop_test;
3663 /* Be careful not to try to gather much state about a thread
3664 that's in a syscall. It's frequently a losing proposition. */
3665 case TARGET_WAITKIND_SYSCALL_ENTRY:
3667 fprintf_unfiltered (gdb_stdlog,
3668 "infrun: TARGET_WAITKIND_SYSCALL_ENTRY\n");
3669 /* Getting the current syscall number. */
3670 if (handle_syscall_event (ecs) != 0)
3672 goto process_event_stop_test;
3674 /* Before examining the threads further, step this thread to
3675 get it entirely out of the syscall. (We get notice of the
3676 event when the thread is just on the verge of exiting a
3677 syscall. Stepping one instruction seems to get it back
3679 case TARGET_WAITKIND_SYSCALL_RETURN:
3681 fprintf_unfiltered (gdb_stdlog,
3682 "infrun: TARGET_WAITKIND_SYSCALL_RETURN\n");
3683 if (handle_syscall_event (ecs) != 0)
3685 goto process_event_stop_test;
3687 case TARGET_WAITKIND_STOPPED:
3689 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_STOPPED\n");
3690 ecs->event_thread->suspend.stop_signal = ecs->ws.value.sig;
3693 case TARGET_WAITKIND_NO_HISTORY:
3695 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_NO_HISTORY\n");
3696 /* Reverse execution: target ran out of history info. */
3698 /* Pull the single step breakpoints out of the target. */
3699 if (singlestep_breakpoints_inserted_p)
3701 if (!ptid_equal (ecs->ptid, inferior_ptid))
3702 context_switch (ecs->ptid);
3703 remove_single_step_breakpoints ();
3704 singlestep_breakpoints_inserted_p = 0;
3706 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
3707 print_no_history_reason ();
3708 stop_stepping (ecs);
3712 if (ecs->ws.kind == TARGET_WAITKIND_STOPPED)
3714 /* Do we need to clean up the state of a thread that has
3715 completed a displaced single-step? (Doing so usually affects
3716 the PC, so do it here, before we set stop_pc.) */
3717 displaced_step_fixup (ecs->ptid,
3718 ecs->event_thread->suspend.stop_signal);
3720 /* If we either finished a single-step or hit a breakpoint, but
3721 the user wanted this thread to be stopped, pretend we got a
3722 SIG0 (generic unsignaled stop). */
3724 if (ecs->event_thread->stop_requested
3725 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
3726 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
3729 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
3733 struct regcache *regcache = get_thread_regcache (ecs->ptid);
3734 struct gdbarch *gdbarch = get_regcache_arch (regcache);
3735 struct cleanup *old_chain = save_inferior_ptid ();
3737 inferior_ptid = ecs->ptid;
3739 fprintf_unfiltered (gdb_stdlog, "infrun: stop_pc = %s\n",
3740 paddress (gdbarch, stop_pc));
3741 if (target_stopped_by_watchpoint ())
3745 fprintf_unfiltered (gdb_stdlog, "infrun: stopped by watchpoint\n");
3747 if (target_stopped_data_address (¤t_target, &addr))
3748 fprintf_unfiltered (gdb_stdlog,
3749 "infrun: stopped data address = %s\n",
3750 paddress (gdbarch, addr));
3752 fprintf_unfiltered (gdb_stdlog,
3753 "infrun: (no data address available)\n");
3756 do_cleanups (old_chain);
3759 if (stepping_past_singlestep_breakpoint)
3761 gdb_assert (singlestep_breakpoints_inserted_p);
3762 gdb_assert (ptid_equal (singlestep_ptid, ecs->ptid));
3763 gdb_assert (!ptid_equal (singlestep_ptid, saved_singlestep_ptid));
3765 stepping_past_singlestep_breakpoint = 0;
3767 /* We've either finished single-stepping past the single-step
3768 breakpoint, or stopped for some other reason. It would be nice if
3769 we could tell, but we can't reliably. */
3770 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
3773 fprintf_unfiltered (gdb_stdlog,
3774 "infrun: stepping_past_"
3775 "singlestep_breakpoint\n");
3776 /* Pull the single step breakpoints out of the target. */
3777 if (!ptid_equal (ecs->ptid, inferior_ptid))
3778 context_switch (ecs->ptid);
3779 remove_single_step_breakpoints ();
3780 singlestep_breakpoints_inserted_p = 0;
3782 ecs->random_signal = 0;
3783 ecs->event_thread->control.trap_expected = 0;
3785 context_switch (saved_singlestep_ptid);
3786 if (deprecated_context_hook)
3787 deprecated_context_hook (pid_to_thread_id (saved_singlestep_ptid));
3789 resume (1, GDB_SIGNAL_0);
3790 prepare_to_wait (ecs);
3795 if (!ptid_equal (deferred_step_ptid, null_ptid))
3797 /* In non-stop mode, there's never a deferred_step_ptid set. */
3798 gdb_assert (!non_stop);
3800 /* If we stopped for some other reason than single-stepping, ignore
3801 the fact that we were supposed to switch back. */
3802 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
3805 fprintf_unfiltered (gdb_stdlog,
3806 "infrun: handling deferred step\n");
3808 /* Pull the single step breakpoints out of the target. */
3809 if (singlestep_breakpoints_inserted_p)
3811 if (!ptid_equal (ecs->ptid, inferior_ptid))
3812 context_switch (ecs->ptid);
3813 remove_single_step_breakpoints ();
3814 singlestep_breakpoints_inserted_p = 0;
3817 ecs->event_thread->control.trap_expected = 0;
3819 context_switch (deferred_step_ptid);
3820 deferred_step_ptid = null_ptid;
3821 /* Suppress spurious "Switching to ..." message. */
3822 previous_inferior_ptid = inferior_ptid;
3824 resume (1, GDB_SIGNAL_0);
3825 prepare_to_wait (ecs);
3829 deferred_step_ptid = null_ptid;
3832 /* See if a thread hit a thread-specific breakpoint that was meant for
3833 another thread. If so, then step that thread past the breakpoint,
3836 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
3838 int thread_hop_needed = 0;
3839 struct address_space *aspace =
3840 get_regcache_aspace (get_thread_regcache (ecs->ptid));
3842 /* Check if a regular breakpoint has been hit before checking
3843 for a potential single step breakpoint. Otherwise, GDB will
3844 not see this breakpoint hit when stepping onto breakpoints. */
3845 if (regular_breakpoint_inserted_here_p (aspace, stop_pc))
3847 ecs->random_signal = 0;
3848 if (!breakpoint_thread_match (aspace, stop_pc, ecs->ptid))
3849 thread_hop_needed = 1;
3851 else if (singlestep_breakpoints_inserted_p)
3853 /* We have not context switched yet, so this should be true
3854 no matter which thread hit the singlestep breakpoint. */
3855 gdb_assert (ptid_equal (inferior_ptid, singlestep_ptid));
3857 fprintf_unfiltered (gdb_stdlog, "infrun: software single step "
3859 target_pid_to_str (ecs->ptid));
3861 ecs->random_signal = 0;
3862 /* The call to in_thread_list is necessary because PTIDs sometimes
3863 change when we go from single-threaded to multi-threaded. If
3864 the singlestep_ptid is still in the list, assume that it is
3865 really different from ecs->ptid. */
3866 if (!ptid_equal (singlestep_ptid, ecs->ptid)
3867 && in_thread_list (singlestep_ptid))
3869 /* If the PC of the thread we were trying to single-step
3870 has changed, discard this event (which we were going
3871 to ignore anyway), and pretend we saw that thread
3872 trap. This prevents us continuously moving the
3873 single-step breakpoint forward, one instruction at a
3874 time. If the PC has changed, then the thread we were
3875 trying to single-step has trapped or been signalled,
3876 but the event has not been reported to GDB yet.
3878 There might be some cases where this loses signal
3879 information, if a signal has arrived at exactly the
3880 same time that the PC changed, but this is the best
3881 we can do with the information available. Perhaps we
3882 should arrange to report all events for all threads
3883 when they stop, or to re-poll the remote looking for
3884 this particular thread (i.e. temporarily enable
3887 CORE_ADDR new_singlestep_pc
3888 = regcache_read_pc (get_thread_regcache (singlestep_ptid));
3890 if (new_singlestep_pc != singlestep_pc)
3892 enum gdb_signal stop_signal;
3895 fprintf_unfiltered (gdb_stdlog, "infrun: unexpected thread,"
3896 " but expected thread advanced also\n");
3898 /* The current context still belongs to
3899 singlestep_ptid. Don't swap here, since that's
3900 the context we want to use. Just fudge our
3901 state and continue. */
3902 stop_signal = ecs->event_thread->suspend.stop_signal;
3903 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
3904 ecs->ptid = singlestep_ptid;
3905 ecs->event_thread = find_thread_ptid (ecs->ptid);
3906 ecs->event_thread->suspend.stop_signal = stop_signal;
3907 stop_pc = new_singlestep_pc;
3912 fprintf_unfiltered (gdb_stdlog,
3913 "infrun: unexpected thread\n");
3915 thread_hop_needed = 1;
3916 stepping_past_singlestep_breakpoint = 1;
3917 saved_singlestep_ptid = singlestep_ptid;
3922 if (thread_hop_needed)
3924 struct regcache *thread_regcache;
3925 int remove_status = 0;
3928 fprintf_unfiltered (gdb_stdlog, "infrun: thread_hop_needed\n");
3930 /* Switch context before touching inferior memory, the
3931 previous thread may have exited. */
3932 if (!ptid_equal (inferior_ptid, ecs->ptid))
3933 context_switch (ecs->ptid);
3935 /* Saw a breakpoint, but it was hit by the wrong thread.
3938 if (singlestep_breakpoints_inserted_p)
3940 /* Pull the single step breakpoints out of the target. */
3941 remove_single_step_breakpoints ();
3942 singlestep_breakpoints_inserted_p = 0;
3945 /* If the arch can displace step, don't remove the
3947 thread_regcache = get_thread_regcache (ecs->ptid);
3948 if (!use_displaced_stepping (get_regcache_arch (thread_regcache)))
3949 remove_status = remove_breakpoints ();
3951 /* Did we fail to remove breakpoints? If so, try
3952 to set the PC past the bp. (There's at least
3953 one situation in which we can fail to remove
3954 the bp's: On HP-UX's that use ttrace, we can't
3955 change the address space of a vforking child
3956 process until the child exits (well, okay, not
3957 then either :-) or execs. */
3958 if (remove_status != 0)
3959 error (_("Cannot step over breakpoint hit in wrong thread"));
3964 /* Only need to require the next event from this
3965 thread in all-stop mode. */
3966 waiton_ptid = ecs->ptid;
3967 infwait_state = infwait_thread_hop_state;
3970 ecs->event_thread->stepping_over_breakpoint = 1;
3975 else if (singlestep_breakpoints_inserted_p)
3977 ecs->random_signal = 0;
3981 ecs->random_signal = 1;
3983 /* See if something interesting happened to the non-current thread. If
3984 so, then switch to that thread. */
3985 if (!ptid_equal (ecs->ptid, inferior_ptid))
3988 fprintf_unfiltered (gdb_stdlog, "infrun: context switch\n");
3990 context_switch (ecs->ptid);
3992 if (deprecated_context_hook)
3993 deprecated_context_hook (pid_to_thread_id (ecs->ptid));
3996 /* At this point, get hold of the now-current thread's frame. */
3997 frame = get_current_frame ();
3998 gdbarch = get_frame_arch (frame);
4000 if (singlestep_breakpoints_inserted_p)
4002 /* Pull the single step breakpoints out of the target. */
4003 remove_single_step_breakpoints ();
4004 singlestep_breakpoints_inserted_p = 0;
4007 if (stepped_after_stopped_by_watchpoint)
4008 stopped_by_watchpoint = 0;
4010 stopped_by_watchpoint = watchpoints_triggered (&ecs->ws);
4012 /* If necessary, step over this watchpoint. We'll be back to display
4014 if (stopped_by_watchpoint
4015 && (target_have_steppable_watchpoint
4016 || gdbarch_have_nonsteppable_watchpoint (gdbarch)))
4018 /* At this point, we are stopped at an instruction which has
4019 attempted to write to a piece of memory under control of
4020 a watchpoint. The instruction hasn't actually executed
4021 yet. If we were to evaluate the watchpoint expression
4022 now, we would get the old value, and therefore no change
4023 would seem to have occurred.
4025 In order to make watchpoints work `right', we really need
4026 to complete the memory write, and then evaluate the
4027 watchpoint expression. We do this by single-stepping the
4030 It may not be necessary to disable the watchpoint to stop over
4031 it. For example, the PA can (with some kernel cooperation)
4032 single step over a watchpoint without disabling the watchpoint.
4034 It is far more common to need to disable a watchpoint to step
4035 the inferior over it. If we have non-steppable watchpoints,
4036 we must disable the current watchpoint; it's simplest to
4037 disable all watchpoints and breakpoints. */
4040 if (!target_have_steppable_watchpoint)
4042 remove_breakpoints ();
4043 /* See comment in resume why we need to stop bypassing signals
4044 while breakpoints have been removed. */
4045 target_pass_signals (0, NULL);
4048 hw_step = maybe_software_singlestep (gdbarch, stop_pc);
4049 target_resume (ecs->ptid, hw_step, GDB_SIGNAL_0);
4050 waiton_ptid = ecs->ptid;
4051 if (target_have_steppable_watchpoint)
4052 infwait_state = infwait_step_watch_state;
4054 infwait_state = infwait_nonstep_watch_state;
4055 prepare_to_wait (ecs);
4059 clear_stop_func (ecs);
4060 ecs->event_thread->stepping_over_breakpoint = 0;
4061 bpstat_clear (&ecs->event_thread->control.stop_bpstat);
4062 ecs->event_thread->control.stop_step = 0;
4063 stop_print_frame = 1;
4064 ecs->random_signal = 0;
4065 stopped_by_random_signal = 0;
4067 /* Hide inlined functions starting here, unless we just performed stepi or
4068 nexti. After stepi and nexti, always show the innermost frame (not any
4069 inline function call sites). */
4070 if (ecs->event_thread->control.step_range_end != 1)
4072 struct address_space *aspace =
4073 get_regcache_aspace (get_thread_regcache (ecs->ptid));
4075 /* skip_inline_frames is expensive, so we avoid it if we can
4076 determine that the address is one where functions cannot have
4077 been inlined. This improves performance with inferiors that
4078 load a lot of shared libraries, because the solib event
4079 breakpoint is defined as the address of a function (i.e. not
4080 inline). Note that we have to check the previous PC as well
4081 as the current one to catch cases when we have just
4082 single-stepped off a breakpoint prior to reinstating it.
4083 Note that we're assuming that the code we single-step to is
4084 not inline, but that's not definitive: there's nothing
4085 preventing the event breakpoint function from containing
4086 inlined code, and the single-step ending up there. If the
4087 user had set a breakpoint on that inlined code, the missing
4088 skip_inline_frames call would break things. Fortunately
4089 that's an extremely unlikely scenario. */
4090 if (!pc_at_non_inline_function (aspace, stop_pc, &ecs->ws)
4091 && !(ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
4092 && ecs->event_thread->control.trap_expected
4093 && pc_at_non_inline_function (aspace,
4094 ecs->event_thread->prev_pc,
4097 skip_inline_frames (ecs->ptid);
4099 /* Re-fetch current thread's frame in case that invalidated
4101 frame = get_current_frame ();
4102 gdbarch = get_frame_arch (frame);
4106 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
4107 && ecs->event_thread->control.trap_expected
4108 && gdbarch_single_step_through_delay_p (gdbarch)
4109 && currently_stepping (ecs->event_thread))
4111 /* We're trying to step off a breakpoint. Turns out that we're
4112 also on an instruction that needs to be stepped multiple
4113 times before it's been fully executing. E.g., architectures
4114 with a delay slot. It needs to be stepped twice, once for
4115 the instruction and once for the delay slot. */
4116 int step_through_delay
4117 = gdbarch_single_step_through_delay (gdbarch, frame);
4119 if (debug_infrun && step_through_delay)
4120 fprintf_unfiltered (gdb_stdlog, "infrun: step through delay\n");
4121 if (ecs->event_thread->control.step_range_end == 0
4122 && step_through_delay)
4124 /* The user issued a continue when stopped at a breakpoint.
4125 Set up for another trap and get out of here. */
4126 ecs->event_thread->stepping_over_breakpoint = 1;
4130 else if (step_through_delay)
4132 /* The user issued a step when stopped at a breakpoint.
4133 Maybe we should stop, maybe we should not - the delay
4134 slot *might* correspond to a line of source. In any
4135 case, don't decide that here, just set
4136 ecs->stepping_over_breakpoint, making sure we
4137 single-step again before breakpoints are re-inserted. */
4138 ecs->event_thread->stepping_over_breakpoint = 1;
4142 /* Look at the cause of the stop, and decide what to do.
4143 The alternatives are:
4144 1) stop_stepping and return; to really stop and return to the debugger,
4145 2) keep_going and return to start up again
4146 (set ecs->event_thread->stepping_over_breakpoint to 1 to single step once)
4147 3) set ecs->random_signal to 1, and the decision between 1 and 2
4148 will be made according to the signal handling tables. */
4150 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
4154 fprintf_unfiltered (gdb_stdlog, "infrun: stopped\n");
4155 stop_print_frame = 0;
4156 stop_stepping (ecs);
4160 /* This is originated from start_remote(), start_inferior() and
4161 shared libraries hook functions. */
4162 if (stop_soon == STOP_QUIETLY || stop_soon == STOP_QUIETLY_REMOTE)
4165 fprintf_unfiltered (gdb_stdlog, "infrun: quietly stopped\n");
4166 stop_stepping (ecs);
4170 /* This originates from attach_command(). We need to overwrite
4171 the stop_signal here, because some kernels don't ignore a
4172 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
4173 See more comments in inferior.h. On the other hand, if we
4174 get a non-SIGSTOP, report it to the user - assume the backend
4175 will handle the SIGSTOP if it should show up later.
4177 Also consider that the attach is complete when we see a
4178 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
4179 target extended-remote report it instead of a SIGSTOP
4180 (e.g. gdbserver). We already rely on SIGTRAP being our
4181 signal, so this is no exception.
4183 Also consider that the attach is complete when we see a
4184 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
4185 the target to stop all threads of the inferior, in case the
4186 low level attach operation doesn't stop them implicitly. If
4187 they weren't stopped implicitly, then the stub will report a
4188 GDB_SIGNAL_0, meaning: stopped for no particular reason
4189 other than GDB's request. */
4190 if (stop_soon == STOP_QUIETLY_NO_SIGSTOP
4191 && (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_STOP
4192 || ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
4193 || ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_0))
4195 stop_stepping (ecs);
4196 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
4200 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
4201 handles this event. */
4202 ecs->event_thread->control.stop_bpstat
4203 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
4204 stop_pc, ecs->ptid, &ecs->ws);
4206 /* Following in case break condition called a
4208 stop_print_frame = 1;
4210 /* This is where we handle "moribund" watchpoints. Unlike
4211 software breakpoints traps, hardware watchpoint traps are
4212 always distinguishable from random traps. If no high-level
4213 watchpoint is associated with the reported stop data address
4214 anymore, then the bpstat does not explain the signal ---
4215 simply make sure to ignore it if `stopped_by_watchpoint' is
4219 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
4220 && (bpstat_explains_signal (ecs->event_thread->control.stop_bpstat)
4221 == BPSTAT_SIGNAL_NO)
4222 && stopped_by_watchpoint)
4223 fprintf_unfiltered (gdb_stdlog,
4224 "infrun: no user watchpoint explains "
4225 "watchpoint SIGTRAP, ignoring\n");
4227 /* NOTE: cagney/2003-03-29: These two checks for a random signal
4228 at one stage in the past included checks for an inferior
4229 function call's call dummy's return breakpoint. The original
4230 comment, that went with the test, read:
4232 ``End of a stack dummy. Some systems (e.g. Sony news) give
4233 another signal besides SIGTRAP, so check here as well as
4236 If someone ever tries to get call dummys on a
4237 non-executable stack to work (where the target would stop
4238 with something like a SIGSEGV), then those tests might need
4239 to be re-instated. Given, however, that the tests were only
4240 enabled when momentary breakpoints were not being used, I
4241 suspect that it won't be the case.
4243 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
4244 be necessary for call dummies on a non-executable stack on
4247 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
4249 = !((bpstat_explains_signal (ecs->event_thread->control.stop_bpstat)
4250 != BPSTAT_SIGNAL_NO)
4251 || stopped_by_watchpoint
4252 || ecs->event_thread->control.trap_expected
4253 || (ecs->event_thread->control.step_range_end
4254 && (ecs->event_thread->control.step_resume_breakpoint
4258 enum bpstat_signal_value sval;
4260 sval = bpstat_explains_signal (ecs->event_thread->control.stop_bpstat);
4261 ecs->random_signal = (sval == BPSTAT_SIGNAL_NO);
4263 if (sval == BPSTAT_SIGNAL_HIDE)
4264 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_TRAP;
4267 process_event_stop_test:
4269 /* Re-fetch current thread's frame in case we did a
4270 "goto process_event_stop_test" above. */
4271 frame = get_current_frame ();
4272 gdbarch = get_frame_arch (frame);
4274 /* For the program's own signals, act according to
4275 the signal handling tables. */
4277 if (ecs->random_signal)
4279 /* Signal not for debugging purposes. */
4281 struct inferior *inf = find_inferior_pid (ptid_get_pid (ecs->ptid));
4284 fprintf_unfiltered (gdb_stdlog, "infrun: random signal %d\n",
4285 ecs->event_thread->suspend.stop_signal);
4287 stopped_by_random_signal = 1;
4289 if (signal_print[ecs->event_thread->suspend.stop_signal])
4292 target_terminal_ours_for_output ();
4293 print_signal_received_reason
4294 (ecs->event_thread->suspend.stop_signal);
4296 /* Always stop on signals if we're either just gaining control
4297 of the program, or the user explicitly requested this thread
4298 to remain stopped. */
4299 if (stop_soon != NO_STOP_QUIETLY
4300 || ecs->event_thread->stop_requested
4302 && signal_stop_state (ecs->event_thread->suspend.stop_signal)))
4304 stop_stepping (ecs);
4307 /* If not going to stop, give terminal back
4308 if we took it away. */
4310 target_terminal_inferior ();
4312 /* Clear the signal if it should not be passed. */
4313 if (signal_program[ecs->event_thread->suspend.stop_signal] == 0)
4314 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
4316 if (ecs->event_thread->prev_pc == stop_pc
4317 && ecs->event_thread->control.trap_expected
4318 && ecs->event_thread->control.step_resume_breakpoint == NULL)
4320 /* We were just starting a new sequence, attempting to
4321 single-step off of a breakpoint and expecting a SIGTRAP.
4322 Instead this signal arrives. This signal will take us out
4323 of the stepping range so GDB needs to remember to, when
4324 the signal handler returns, resume stepping off that
4326 /* To simplify things, "continue" is forced to use the same
4327 code paths as single-step - set a breakpoint at the
4328 signal return address and then, once hit, step off that
4331 fprintf_unfiltered (gdb_stdlog,
4332 "infrun: signal arrived while stepping over "
4335 insert_hp_step_resume_breakpoint_at_frame (frame);
4336 ecs->event_thread->step_after_step_resume_breakpoint = 1;
4337 /* Reset trap_expected to ensure breakpoints are re-inserted. */
4338 ecs->event_thread->control.trap_expected = 0;
4343 if (ecs->event_thread->control.step_range_end != 0
4344 && ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_0
4345 && (ecs->event_thread->control.step_range_start <= stop_pc
4346 && stop_pc < ecs->event_thread->control.step_range_end)
4347 && frame_id_eq (get_stack_frame_id (frame),
4348 ecs->event_thread->control.step_stack_frame_id)
4349 && ecs->event_thread->control.step_resume_breakpoint == NULL)
4351 /* The inferior is about to take a signal that will take it
4352 out of the single step range. Set a breakpoint at the
4353 current PC (which is presumably where the signal handler
4354 will eventually return) and then allow the inferior to
4357 Note that this is only needed for a signal delivered
4358 while in the single-step range. Nested signals aren't a
4359 problem as they eventually all return. */
4361 fprintf_unfiltered (gdb_stdlog,
4362 "infrun: signal may take us out of "
4363 "single-step range\n");
4365 insert_hp_step_resume_breakpoint_at_frame (frame);
4366 /* Reset trap_expected to ensure breakpoints are re-inserted. */
4367 ecs->event_thread->control.trap_expected = 0;
4372 /* Note: step_resume_breakpoint may be non-NULL. This occures
4373 when either there's a nested signal, or when there's a
4374 pending signal enabled just as the signal handler returns
4375 (leaving the inferior at the step-resume-breakpoint without
4376 actually executing it). Either way continue until the
4377 breakpoint is really hit. */
4381 /* Handle cases caused by hitting a breakpoint. */
4383 CORE_ADDR jmp_buf_pc;
4384 struct bpstat_what what;
4386 what = bpstat_what (ecs->event_thread->control.stop_bpstat);
4388 if (what.call_dummy)
4390 stop_stack_dummy = what.call_dummy;
4393 /* If we hit an internal event that triggers symbol changes, the
4394 current frame will be invalidated within bpstat_what (e.g.,
4395 if we hit an internal solib event). Re-fetch it. */
4396 frame = get_current_frame ();
4397 gdbarch = get_frame_arch (frame);
4399 switch (what.main_action)
4401 case BPSTAT_WHAT_SET_LONGJMP_RESUME:
4402 /* If we hit the breakpoint at longjmp while stepping, we
4403 install a momentary breakpoint at the target of the
4407 fprintf_unfiltered (gdb_stdlog,
4408 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME\n");
4410 ecs->event_thread->stepping_over_breakpoint = 1;
4412 if (what.is_longjmp)
4414 struct value *arg_value;
4416 /* If we set the longjmp breakpoint via a SystemTap
4417 probe, then use it to extract the arguments. The
4418 destination PC is the third argument to the
4420 arg_value = probe_safe_evaluate_at_pc (frame, 2);
4422 jmp_buf_pc = value_as_address (arg_value);
4423 else if (!gdbarch_get_longjmp_target_p (gdbarch)
4424 || !gdbarch_get_longjmp_target (gdbarch,
4425 frame, &jmp_buf_pc))
4428 fprintf_unfiltered (gdb_stdlog,
4429 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME "
4430 "(!gdbarch_get_longjmp_target)\n");
4435 /* Insert a breakpoint at resume address. */
4436 insert_longjmp_resume_breakpoint (gdbarch, jmp_buf_pc);
4439 check_exception_resume (ecs, frame);
4443 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME:
4445 struct frame_info *init_frame;
4447 /* There are several cases to consider.
4449 1. The initiating frame no longer exists. In this case
4450 we must stop, because the exception or longjmp has gone
4453 2. The initiating frame exists, and is the same as the
4454 current frame. We stop, because the exception or
4455 longjmp has been caught.
4457 3. The initiating frame exists and is different from
4458 the current frame. This means the exception or longjmp
4459 has been caught beneath the initiating frame, so keep
4462 4. longjmp breakpoint has been placed just to protect
4463 against stale dummy frames and user is not interested
4464 in stopping around longjmps. */
4467 fprintf_unfiltered (gdb_stdlog,
4468 "infrun: BPSTAT_WHAT_CLEAR_LONGJMP_RESUME\n");
4470 gdb_assert (ecs->event_thread->control.exception_resume_breakpoint
4472 delete_exception_resume_breakpoint (ecs->event_thread);
4474 if (what.is_longjmp)
4476 check_longjmp_breakpoint_for_call_dummy (ecs->event_thread->num);
4478 if (!frame_id_p (ecs->event_thread->initiating_frame))
4486 init_frame = frame_find_by_id (ecs->event_thread->initiating_frame);
4490 struct frame_id current_id
4491 = get_frame_id (get_current_frame ());
4492 if (frame_id_eq (current_id,
4493 ecs->event_thread->initiating_frame))
4495 /* Case 2. Fall through. */
4505 /* For Cases 1 and 2, remove the step-resume breakpoint,
4507 delete_step_resume_breakpoint (ecs->event_thread);
4509 ecs->event_thread->control.stop_step = 1;
4510 print_end_stepping_range_reason ();
4511 stop_stepping (ecs);
4515 case BPSTAT_WHAT_SINGLE:
4517 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_SINGLE\n");
4518 ecs->event_thread->stepping_over_breakpoint = 1;
4519 /* Still need to check other stuff, at least the case where
4520 we are stepping and step out of the right range. */
4523 case BPSTAT_WHAT_STEP_RESUME:
4525 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STEP_RESUME\n");
4527 delete_step_resume_breakpoint (ecs->event_thread);
4528 if (ecs->event_thread->control.proceed_to_finish
4529 && execution_direction == EXEC_REVERSE)
4531 struct thread_info *tp = ecs->event_thread;
4533 /* We are finishing a function in reverse, and just hit
4534 the step-resume breakpoint at the start address of
4535 the function, and we're almost there -- just need to
4536 back up by one more single-step, which should take us
4537 back to the function call. */
4538 tp->control.step_range_start = tp->control.step_range_end = 1;
4542 fill_in_stop_func (gdbarch, ecs);
4543 if (stop_pc == ecs->stop_func_start
4544 && execution_direction == EXEC_REVERSE)
4546 /* We are stepping over a function call in reverse, and
4547 just hit the step-resume breakpoint at the start
4548 address of the function. Go back to single-stepping,
4549 which should take us back to the function call. */
4550 ecs->event_thread->stepping_over_breakpoint = 1;
4556 case BPSTAT_WHAT_STOP_NOISY:
4558 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_NOISY\n");
4559 stop_print_frame = 1;
4561 /* We are about to nuke the step_resume_breakpointt via the
4562 cleanup chain, so no need to worry about it here. */
4564 stop_stepping (ecs);
4567 case BPSTAT_WHAT_STOP_SILENT:
4569 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_SILENT\n");
4570 stop_print_frame = 0;
4572 /* We are about to nuke the step_resume_breakpoin via the
4573 cleanup chain, so no need to worry about it here. */
4575 stop_stepping (ecs);
4578 case BPSTAT_WHAT_HP_STEP_RESUME:
4580 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_HP_STEP_RESUME\n");
4582 delete_step_resume_breakpoint (ecs->event_thread);
4583 if (ecs->event_thread->step_after_step_resume_breakpoint)
4585 /* Back when the step-resume breakpoint was inserted, we
4586 were trying to single-step off a breakpoint. Go back
4588 ecs->event_thread->step_after_step_resume_breakpoint = 0;
4589 ecs->event_thread->stepping_over_breakpoint = 1;
4595 case BPSTAT_WHAT_KEEP_CHECKING:
4600 /* We come here if we hit a breakpoint but should not
4601 stop for it. Possibly we also were stepping
4602 and should stop for that. So fall through and
4603 test for stepping. But, if not stepping,
4606 /* In all-stop mode, if we're currently stepping but have stopped in
4607 some other thread, we need to switch back to the stepped thread. */
4610 struct thread_info *tp;
4612 tp = iterate_over_threads (currently_stepping_or_nexting_callback,
4616 /* However, if the current thread is blocked on some internal
4617 breakpoint, and we simply need to step over that breakpoint
4618 to get it going again, do that first. */
4619 if ((ecs->event_thread->control.trap_expected
4620 && ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_TRAP)
4621 || ecs->event_thread->stepping_over_breakpoint)
4627 /* If the stepping thread exited, then don't try to switch
4628 back and resume it, which could fail in several different
4629 ways depending on the target. Instead, just keep going.
4631 We can find a stepping dead thread in the thread list in
4634 - The target supports thread exit events, and when the
4635 target tries to delete the thread from the thread list,
4636 inferior_ptid pointed at the exiting thread. In such
4637 case, calling delete_thread does not really remove the
4638 thread from the list; instead, the thread is left listed,
4639 with 'exited' state.
4641 - The target's debug interface does not support thread
4642 exit events, and so we have no idea whatsoever if the
4643 previously stepping thread is still alive. For that
4644 reason, we need to synchronously query the target
4646 if (is_exited (tp->ptid)
4647 || !target_thread_alive (tp->ptid))
4650 fprintf_unfiltered (gdb_stdlog,
4651 "infrun: not switching back to "
4652 "stepped thread, it has vanished\n");
4654 delete_thread (tp->ptid);
4659 /* Otherwise, we no longer expect a trap in the current thread.
4660 Clear the trap_expected flag before switching back -- this is
4661 what keep_going would do as well, if we called it. */
4662 ecs->event_thread->control.trap_expected = 0;
4665 fprintf_unfiltered (gdb_stdlog,
4666 "infrun: switching back to stepped thread\n");
4668 ecs->event_thread = tp;
4669 ecs->ptid = tp->ptid;
4670 context_switch (ecs->ptid);
4676 if (ecs->event_thread->control.step_resume_breakpoint)
4679 fprintf_unfiltered (gdb_stdlog,
4680 "infrun: step-resume breakpoint is inserted\n");
4682 /* Having a step-resume breakpoint overrides anything
4683 else having to do with stepping commands until
4684 that breakpoint is reached. */
4689 if (ecs->event_thread->control.step_range_end == 0)
4692 fprintf_unfiltered (gdb_stdlog, "infrun: no stepping, continue\n");
4693 /* Likewise if we aren't even stepping. */
4698 /* Re-fetch current thread's frame in case the code above caused
4699 the frame cache to be re-initialized, making our FRAME variable
4700 a dangling pointer. */
4701 frame = get_current_frame ();
4702 gdbarch = get_frame_arch (frame);
4703 fill_in_stop_func (gdbarch, ecs);
4705 /* If stepping through a line, keep going if still within it.
4707 Note that step_range_end is the address of the first instruction
4708 beyond the step range, and NOT the address of the last instruction
4711 Note also that during reverse execution, we may be stepping
4712 through a function epilogue and therefore must detect when
4713 the current-frame changes in the middle of a line. */
4715 if (stop_pc >= ecs->event_thread->control.step_range_start
4716 && stop_pc < ecs->event_thread->control.step_range_end
4717 && (execution_direction != EXEC_REVERSE
4718 || frame_id_eq (get_frame_id (frame),
4719 ecs->event_thread->control.step_frame_id)))
4723 (gdb_stdlog, "infrun: stepping inside range [%s-%s]\n",
4724 paddress (gdbarch, ecs->event_thread->control.step_range_start),
4725 paddress (gdbarch, ecs->event_thread->control.step_range_end));
4727 /* When stepping backward, stop at beginning of line range
4728 (unless it's the function entry point, in which case
4729 keep going back to the call point). */
4730 if (stop_pc == ecs->event_thread->control.step_range_start
4731 && stop_pc != ecs->stop_func_start
4732 && execution_direction == EXEC_REVERSE)
4734 ecs->event_thread->control.stop_step = 1;
4735 print_end_stepping_range_reason ();
4736 stop_stepping (ecs);
4744 /* We stepped out of the stepping range. */
4746 /* If we are stepping at the source level and entered the runtime
4747 loader dynamic symbol resolution code...
4749 EXEC_FORWARD: we keep on single stepping until we exit the run
4750 time loader code and reach the callee's address.
4752 EXEC_REVERSE: we've already executed the callee (backward), and
4753 the runtime loader code is handled just like any other
4754 undebuggable function call. Now we need only keep stepping
4755 backward through the trampoline code, and that's handled further
4756 down, so there is nothing for us to do here. */
4758 if (execution_direction != EXEC_REVERSE
4759 && ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
4760 && in_solib_dynsym_resolve_code (stop_pc))
4762 CORE_ADDR pc_after_resolver =
4763 gdbarch_skip_solib_resolver (gdbarch, stop_pc);
4766 fprintf_unfiltered (gdb_stdlog,
4767 "infrun: stepped into dynsym resolve code\n");
4769 if (pc_after_resolver)
4771 /* Set up a step-resume breakpoint at the address
4772 indicated by SKIP_SOLIB_RESOLVER. */
4773 struct symtab_and_line sr_sal;
4776 sr_sal.pc = pc_after_resolver;
4777 sr_sal.pspace = get_frame_program_space (frame);
4779 insert_step_resume_breakpoint_at_sal (gdbarch,
4780 sr_sal, null_frame_id);
4787 if (ecs->event_thread->control.step_range_end != 1
4788 && (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
4789 || ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
4790 && get_frame_type (frame) == SIGTRAMP_FRAME)
4793 fprintf_unfiltered (gdb_stdlog,
4794 "infrun: stepped into signal trampoline\n");
4795 /* The inferior, while doing a "step" or "next", has ended up in
4796 a signal trampoline (either by a signal being delivered or by
4797 the signal handler returning). Just single-step until the
4798 inferior leaves the trampoline (either by calling the handler
4804 /* If we're in the return path from a shared library trampoline,
4805 we want to proceed through the trampoline when stepping. */
4806 /* macro/2012-04-25: This needs to come before the subroutine
4807 call check below as on some targets return trampolines look
4808 like subroutine calls (MIPS16 return thunks). */
4809 if (gdbarch_in_solib_return_trampoline (gdbarch,
4810 stop_pc, ecs->stop_func_name)
4811 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE)
4813 /* Determine where this trampoline returns. */
4814 CORE_ADDR real_stop_pc;
4816 real_stop_pc = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc);
4819 fprintf_unfiltered (gdb_stdlog,
4820 "infrun: stepped into solib return tramp\n");
4822 /* Only proceed through if we know where it's going. */
4825 /* And put the step-breakpoint there and go until there. */
4826 struct symtab_and_line sr_sal;
4828 init_sal (&sr_sal); /* initialize to zeroes */
4829 sr_sal.pc = real_stop_pc;
4830 sr_sal.section = find_pc_overlay (sr_sal.pc);
4831 sr_sal.pspace = get_frame_program_space (frame);
4833 /* Do not specify what the fp should be when we stop since
4834 on some machines the prologue is where the new fp value
4836 insert_step_resume_breakpoint_at_sal (gdbarch,
4837 sr_sal, null_frame_id);
4839 /* Restart without fiddling with the step ranges or
4846 /* Check for subroutine calls. The check for the current frame
4847 equalling the step ID is not necessary - the check of the
4848 previous frame's ID is sufficient - but it is a common case and
4849 cheaper than checking the previous frame's ID.
4851 NOTE: frame_id_eq will never report two invalid frame IDs as
4852 being equal, so to get into this block, both the current and
4853 previous frame must have valid frame IDs. */
4854 /* The outer_frame_id check is a heuristic to detect stepping
4855 through startup code. If we step over an instruction which
4856 sets the stack pointer from an invalid value to a valid value,
4857 we may detect that as a subroutine call from the mythical
4858 "outermost" function. This could be fixed by marking
4859 outermost frames as !stack_p,code_p,special_p. Then the
4860 initial outermost frame, before sp was valid, would
4861 have code_addr == &_start. See the comment in frame_id_eq
4863 if (!frame_id_eq (get_stack_frame_id (frame),
4864 ecs->event_thread->control.step_stack_frame_id)
4865 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
4866 ecs->event_thread->control.step_stack_frame_id)
4867 && (!frame_id_eq (ecs->event_thread->control.step_stack_frame_id,
4869 || step_start_function != find_pc_function (stop_pc))))
4871 CORE_ADDR real_stop_pc;
4874 fprintf_unfiltered (gdb_stdlog, "infrun: stepped into subroutine\n");
4876 if ((ecs->event_thread->control.step_over_calls == STEP_OVER_NONE)
4877 || ((ecs->event_thread->control.step_range_end == 1)
4878 && in_prologue (gdbarch, ecs->event_thread->prev_pc,
4879 ecs->stop_func_start)))
4881 /* I presume that step_over_calls is only 0 when we're
4882 supposed to be stepping at the assembly language level
4883 ("stepi"). Just stop. */
4884 /* Also, maybe we just did a "nexti" inside a prolog, so we
4885 thought it was a subroutine call but it was not. Stop as
4887 /* And this works the same backward as frontward. MVS */
4888 ecs->event_thread->control.stop_step = 1;
4889 print_end_stepping_range_reason ();
4890 stop_stepping (ecs);
4894 /* Reverse stepping through solib trampolines. */
4896 if (execution_direction == EXEC_REVERSE
4897 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE
4898 && (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc)
4899 || (ecs->stop_func_start == 0
4900 && in_solib_dynsym_resolve_code (stop_pc))))
4902 /* Any solib trampoline code can be handled in reverse
4903 by simply continuing to single-step. We have already
4904 executed the solib function (backwards), and a few
4905 steps will take us back through the trampoline to the
4911 if (ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
4913 /* We're doing a "next".
4915 Normal (forward) execution: set a breakpoint at the
4916 callee's return address (the address at which the caller
4919 Reverse (backward) execution. set the step-resume
4920 breakpoint at the start of the function that we just
4921 stepped into (backwards), and continue to there. When we
4922 get there, we'll need to single-step back to the caller. */
4924 if (execution_direction == EXEC_REVERSE)
4926 /* If we're already at the start of the function, we've either
4927 just stepped backward into a single instruction function,
4928 or stepped back out of a signal handler to the first instruction
4929 of the function. Just keep going, which will single-step back
4931 if (ecs->stop_func_start != stop_pc)
4933 struct symtab_and_line sr_sal;
4935 /* Normal function call return (static or dynamic). */
4937 sr_sal.pc = ecs->stop_func_start;
4938 sr_sal.pspace = get_frame_program_space (frame);
4939 insert_step_resume_breakpoint_at_sal (gdbarch,
4940 sr_sal, null_frame_id);
4944 insert_step_resume_breakpoint_at_caller (frame);
4950 /* If we are in a function call trampoline (a stub between the
4951 calling routine and the real function), locate the real
4952 function. That's what tells us (a) whether we want to step
4953 into it at all, and (b) what prologue we want to run to the
4954 end of, if we do step into it. */
4955 real_stop_pc = skip_language_trampoline (frame, stop_pc);
4956 if (real_stop_pc == 0)
4957 real_stop_pc = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc);
4958 if (real_stop_pc != 0)
4959 ecs->stop_func_start = real_stop_pc;
4961 if (real_stop_pc != 0 && in_solib_dynsym_resolve_code (real_stop_pc))
4963 struct symtab_and_line sr_sal;
4966 sr_sal.pc = ecs->stop_func_start;
4967 sr_sal.pspace = get_frame_program_space (frame);
4969 insert_step_resume_breakpoint_at_sal (gdbarch,
4970 sr_sal, null_frame_id);
4975 /* If we have line number information for the function we are
4976 thinking of stepping into and the function isn't on the skip
4979 If there are several symtabs at that PC (e.g. with include
4980 files), just want to know whether *any* of them have line
4981 numbers. find_pc_line handles this. */
4983 struct symtab_and_line tmp_sal;
4985 tmp_sal = find_pc_line (ecs->stop_func_start, 0);
4986 if (tmp_sal.line != 0
4987 && !function_name_is_marked_for_skip (ecs->stop_func_name,
4990 if (execution_direction == EXEC_REVERSE)
4991 handle_step_into_function_backward (gdbarch, ecs);
4993 handle_step_into_function (gdbarch, ecs);
4998 /* If we have no line number and the step-stop-if-no-debug is
4999 set, we stop the step so that the user has a chance to switch
5000 in assembly mode. */
5001 if (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
5002 && step_stop_if_no_debug)
5004 ecs->event_thread->control.stop_step = 1;
5005 print_end_stepping_range_reason ();
5006 stop_stepping (ecs);
5010 if (execution_direction == EXEC_REVERSE)
5012 /* If we're already at the start of the function, we've either just
5013 stepped backward into a single instruction function without line
5014 number info, or stepped back out of a signal handler to the first
5015 instruction of the function without line number info. Just keep
5016 going, which will single-step back to the caller. */
5017 if (ecs->stop_func_start != stop_pc)
5019 /* Set a breakpoint at callee's start address.
5020 From there we can step once and be back in the caller. */
5021 struct symtab_and_line sr_sal;
5024 sr_sal.pc = ecs->stop_func_start;
5025 sr_sal.pspace = get_frame_program_space (frame);
5026 insert_step_resume_breakpoint_at_sal (gdbarch,
5027 sr_sal, null_frame_id);
5031 /* Set a breakpoint at callee's return address (the address
5032 at which the caller will resume). */
5033 insert_step_resume_breakpoint_at_caller (frame);
5039 /* Reverse stepping through solib trampolines. */
5041 if (execution_direction == EXEC_REVERSE
5042 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE)
5044 if (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc)
5045 || (ecs->stop_func_start == 0
5046 && in_solib_dynsym_resolve_code (stop_pc)))
5048 /* Any solib trampoline code can be handled in reverse
5049 by simply continuing to single-step. We have already
5050 executed the solib function (backwards), and a few
5051 steps will take us back through the trampoline to the
5056 else if (in_solib_dynsym_resolve_code (stop_pc))
5058 /* Stepped backward into the solib dynsym resolver.
5059 Set a breakpoint at its start and continue, then
5060 one more step will take us out. */
5061 struct symtab_and_line sr_sal;
5064 sr_sal.pc = ecs->stop_func_start;
5065 sr_sal.pspace = get_frame_program_space (frame);
5066 insert_step_resume_breakpoint_at_sal (gdbarch,
5067 sr_sal, null_frame_id);
5073 stop_pc_sal = find_pc_line (stop_pc, 0);
5075 /* NOTE: tausq/2004-05-24: This if block used to be done before all
5076 the trampoline processing logic, however, there are some trampolines
5077 that have no names, so we should do trampoline handling first. */
5078 if (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
5079 && ecs->stop_func_name == NULL
5080 && stop_pc_sal.line == 0)
5083 fprintf_unfiltered (gdb_stdlog,
5084 "infrun: stepped into undebuggable function\n");
5086 /* The inferior just stepped into, or returned to, an
5087 undebuggable function (where there is no debugging information
5088 and no line number corresponding to the address where the
5089 inferior stopped). Since we want to skip this kind of code,
5090 we keep going until the inferior returns from this
5091 function - unless the user has asked us not to (via
5092 set step-mode) or we no longer know how to get back
5093 to the call site. */
5094 if (step_stop_if_no_debug
5095 || !frame_id_p (frame_unwind_caller_id (frame)))
5097 /* If we have no line number and the step-stop-if-no-debug
5098 is set, we stop the step so that the user has a chance to
5099 switch in assembly mode. */
5100 ecs->event_thread->control.stop_step = 1;
5101 print_end_stepping_range_reason ();
5102 stop_stepping (ecs);
5107 /* Set a breakpoint at callee's return address (the address
5108 at which the caller will resume). */
5109 insert_step_resume_breakpoint_at_caller (frame);
5115 if (ecs->event_thread->control.step_range_end == 1)
5117 /* It is stepi or nexti. We always want to stop stepping after
5120 fprintf_unfiltered (gdb_stdlog, "infrun: stepi/nexti\n");
5121 ecs->event_thread->control.stop_step = 1;
5122 print_end_stepping_range_reason ();
5123 stop_stepping (ecs);
5127 if (stop_pc_sal.line == 0)
5129 /* We have no line number information. That means to stop
5130 stepping (does this always happen right after one instruction,
5131 when we do "s" in a function with no line numbers,
5132 or can this happen as a result of a return or longjmp?). */
5134 fprintf_unfiltered (gdb_stdlog, "infrun: no line number info\n");
5135 ecs->event_thread->control.stop_step = 1;
5136 print_end_stepping_range_reason ();
5137 stop_stepping (ecs);
5141 /* Look for "calls" to inlined functions, part one. If the inline
5142 frame machinery detected some skipped call sites, we have entered
5143 a new inline function. */
5145 if (frame_id_eq (get_frame_id (get_current_frame ()),
5146 ecs->event_thread->control.step_frame_id)
5147 && inline_skipped_frames (ecs->ptid))
5149 struct symtab_and_line call_sal;
5152 fprintf_unfiltered (gdb_stdlog,
5153 "infrun: stepped into inlined function\n");
5155 find_frame_sal (get_current_frame (), &call_sal);
5157 if (ecs->event_thread->control.step_over_calls != STEP_OVER_ALL)
5159 /* For "step", we're going to stop. But if the call site
5160 for this inlined function is on the same source line as
5161 we were previously stepping, go down into the function
5162 first. Otherwise stop at the call site. */
5164 if (call_sal.line == ecs->event_thread->current_line
5165 && call_sal.symtab == ecs->event_thread->current_symtab)
5166 step_into_inline_frame (ecs->ptid);
5168 ecs->event_thread->control.stop_step = 1;
5169 print_end_stepping_range_reason ();
5170 stop_stepping (ecs);
5175 /* For "next", we should stop at the call site if it is on a
5176 different source line. Otherwise continue through the
5177 inlined function. */
5178 if (call_sal.line == ecs->event_thread->current_line
5179 && call_sal.symtab == ecs->event_thread->current_symtab)
5183 ecs->event_thread->control.stop_step = 1;
5184 print_end_stepping_range_reason ();
5185 stop_stepping (ecs);
5191 /* Look for "calls" to inlined functions, part two. If we are still
5192 in the same real function we were stepping through, but we have
5193 to go further up to find the exact frame ID, we are stepping
5194 through a more inlined call beyond its call site. */
5196 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
5197 && !frame_id_eq (get_frame_id (get_current_frame ()),
5198 ecs->event_thread->control.step_frame_id)
5199 && stepped_in_from (get_current_frame (),
5200 ecs->event_thread->control.step_frame_id))
5203 fprintf_unfiltered (gdb_stdlog,
5204 "infrun: stepping through inlined function\n");
5206 if (ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
5210 ecs->event_thread->control.stop_step = 1;
5211 print_end_stepping_range_reason ();
5212 stop_stepping (ecs);
5217 if ((stop_pc == stop_pc_sal.pc)
5218 && (ecs->event_thread->current_line != stop_pc_sal.line
5219 || ecs->event_thread->current_symtab != stop_pc_sal.symtab))
5221 /* We are at the start of a different line. So stop. Note that
5222 we don't stop if we step into the middle of a different line.
5223 That is said to make things like for (;;) statements work
5226 fprintf_unfiltered (gdb_stdlog,
5227 "infrun: stepped to a different line\n");
5228 ecs->event_thread->control.stop_step = 1;
5229 print_end_stepping_range_reason ();
5230 stop_stepping (ecs);
5234 /* We aren't done stepping.
5236 Optimize by setting the stepping range to the line.
5237 (We might not be in the original line, but if we entered a
5238 new line in mid-statement, we continue stepping. This makes
5239 things like for(;;) statements work better.) */
5241 ecs->event_thread->control.step_range_start = stop_pc_sal.pc;
5242 ecs->event_thread->control.step_range_end = stop_pc_sal.end;
5243 set_step_info (frame, stop_pc_sal);
5246 fprintf_unfiltered (gdb_stdlog, "infrun: keep going\n");
5250 /* Is thread TP in the middle of single-stepping? */
5253 currently_stepping (struct thread_info *tp)
5255 return ((tp->control.step_range_end
5256 && tp->control.step_resume_breakpoint == NULL)
5257 || tp->control.trap_expected
5258 || bpstat_should_step ());
5261 /* Returns true if any thread *but* the one passed in "data" is in the
5262 middle of stepping or of handling a "next". */
5265 currently_stepping_or_nexting_callback (struct thread_info *tp, void *data)
5270 return (tp->control.step_range_end
5271 || tp->control.trap_expected);
5274 /* Inferior has stepped into a subroutine call with source code that
5275 we should not step over. Do step to the first line of code in
5279 handle_step_into_function (struct gdbarch *gdbarch,
5280 struct execution_control_state *ecs)
5283 struct symtab_and_line stop_func_sal, sr_sal;
5285 fill_in_stop_func (gdbarch, ecs);
5287 s = find_pc_symtab (stop_pc);
5288 if (s && s->language != language_asm)
5289 ecs->stop_func_start = gdbarch_skip_prologue (gdbarch,
5290 ecs->stop_func_start);
5292 stop_func_sal = find_pc_line (ecs->stop_func_start, 0);
5293 /* Use the step_resume_break to step until the end of the prologue,
5294 even if that involves jumps (as it seems to on the vax under
5296 /* If the prologue ends in the middle of a source line, continue to
5297 the end of that source line (if it is still within the function).
5298 Otherwise, just go to end of prologue. */
5299 if (stop_func_sal.end
5300 && stop_func_sal.pc != ecs->stop_func_start
5301 && stop_func_sal.end < ecs->stop_func_end)
5302 ecs->stop_func_start = stop_func_sal.end;
5304 /* Architectures which require breakpoint adjustment might not be able
5305 to place a breakpoint at the computed address. If so, the test
5306 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
5307 ecs->stop_func_start to an address at which a breakpoint may be
5308 legitimately placed.
5310 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
5311 made, GDB will enter an infinite loop when stepping through
5312 optimized code consisting of VLIW instructions which contain
5313 subinstructions corresponding to different source lines. On
5314 FR-V, it's not permitted to place a breakpoint on any but the
5315 first subinstruction of a VLIW instruction. When a breakpoint is
5316 set, GDB will adjust the breakpoint address to the beginning of
5317 the VLIW instruction. Thus, we need to make the corresponding
5318 adjustment here when computing the stop address. */
5320 if (gdbarch_adjust_breakpoint_address_p (gdbarch))
5322 ecs->stop_func_start
5323 = gdbarch_adjust_breakpoint_address (gdbarch,
5324 ecs->stop_func_start);
5327 if (ecs->stop_func_start == stop_pc)
5329 /* We are already there: stop now. */
5330 ecs->event_thread->control.stop_step = 1;
5331 print_end_stepping_range_reason ();
5332 stop_stepping (ecs);
5337 /* Put the step-breakpoint there and go until there. */
5338 init_sal (&sr_sal); /* initialize to zeroes */
5339 sr_sal.pc = ecs->stop_func_start;
5340 sr_sal.section = find_pc_overlay (ecs->stop_func_start);
5341 sr_sal.pspace = get_frame_program_space (get_current_frame ());
5343 /* Do not specify what the fp should be when we stop since on
5344 some machines the prologue is where the new fp value is
5346 insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal, null_frame_id);
5348 /* And make sure stepping stops right away then. */
5349 ecs->event_thread->control.step_range_end
5350 = ecs->event_thread->control.step_range_start;
5355 /* Inferior has stepped backward into a subroutine call with source
5356 code that we should not step over. Do step to the beginning of the
5357 last line of code in it. */
5360 handle_step_into_function_backward (struct gdbarch *gdbarch,
5361 struct execution_control_state *ecs)
5364 struct symtab_and_line stop_func_sal;
5366 fill_in_stop_func (gdbarch, ecs);
5368 s = find_pc_symtab (stop_pc);
5369 if (s && s->language != language_asm)
5370 ecs->stop_func_start = gdbarch_skip_prologue (gdbarch,
5371 ecs->stop_func_start);
5373 stop_func_sal = find_pc_line (stop_pc, 0);
5375 /* OK, we're just going to keep stepping here. */
5376 if (stop_func_sal.pc == stop_pc)
5378 /* We're there already. Just stop stepping now. */
5379 ecs->event_thread->control.stop_step = 1;
5380 print_end_stepping_range_reason ();
5381 stop_stepping (ecs);
5385 /* Else just reset the step range and keep going.
5386 No step-resume breakpoint, they don't work for
5387 epilogues, which can have multiple entry paths. */
5388 ecs->event_thread->control.step_range_start = stop_func_sal.pc;
5389 ecs->event_thread->control.step_range_end = stop_func_sal.end;
5395 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
5396 This is used to both functions and to skip over code. */
5399 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch *gdbarch,
5400 struct symtab_and_line sr_sal,
5401 struct frame_id sr_id,
5402 enum bptype sr_type)
5404 /* There should never be more than one step-resume or longjmp-resume
5405 breakpoint per thread, so we should never be setting a new
5406 step_resume_breakpoint when one is already active. */
5407 gdb_assert (inferior_thread ()->control.step_resume_breakpoint == NULL);
5408 gdb_assert (sr_type == bp_step_resume || sr_type == bp_hp_step_resume);
5411 fprintf_unfiltered (gdb_stdlog,
5412 "infrun: inserting step-resume breakpoint at %s\n",
5413 paddress (gdbarch, sr_sal.pc));
5415 inferior_thread ()->control.step_resume_breakpoint
5416 = set_momentary_breakpoint (gdbarch, sr_sal, sr_id, sr_type);
5420 insert_step_resume_breakpoint_at_sal (struct gdbarch *gdbarch,
5421 struct symtab_and_line sr_sal,
5422 struct frame_id sr_id)
5424 insert_step_resume_breakpoint_at_sal_1 (gdbarch,
5429 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
5430 This is used to skip a potential signal handler.
5432 This is called with the interrupted function's frame. The signal
5433 handler, when it returns, will resume the interrupted function at
5437 insert_hp_step_resume_breakpoint_at_frame (struct frame_info *return_frame)
5439 struct symtab_and_line sr_sal;
5440 struct gdbarch *gdbarch;
5442 gdb_assert (return_frame != NULL);
5443 init_sal (&sr_sal); /* initialize to zeros */
5445 gdbarch = get_frame_arch (return_frame);
5446 sr_sal.pc = gdbarch_addr_bits_remove (gdbarch, get_frame_pc (return_frame));
5447 sr_sal.section = find_pc_overlay (sr_sal.pc);
5448 sr_sal.pspace = get_frame_program_space (return_frame);
5450 insert_step_resume_breakpoint_at_sal_1 (gdbarch, sr_sal,
5451 get_stack_frame_id (return_frame),
5455 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
5456 is used to skip a function after stepping into it (for "next" or if
5457 the called function has no debugging information).
5459 The current function has almost always been reached by single
5460 stepping a call or return instruction. NEXT_FRAME belongs to the
5461 current function, and the breakpoint will be set at the caller's
5464 This is a separate function rather than reusing
5465 insert_hp_step_resume_breakpoint_at_frame in order to avoid
5466 get_prev_frame, which may stop prematurely (see the implementation
5467 of frame_unwind_caller_id for an example). */
5470 insert_step_resume_breakpoint_at_caller (struct frame_info *next_frame)
5472 struct symtab_and_line sr_sal;
5473 struct gdbarch *gdbarch;
5475 /* We shouldn't have gotten here if we don't know where the call site
5477 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame)));
5479 init_sal (&sr_sal); /* initialize to zeros */
5481 gdbarch = frame_unwind_caller_arch (next_frame);
5482 sr_sal.pc = gdbarch_addr_bits_remove (gdbarch,
5483 frame_unwind_caller_pc (next_frame));
5484 sr_sal.section = find_pc_overlay (sr_sal.pc);
5485 sr_sal.pspace = frame_unwind_program_space (next_frame);
5487 insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal,
5488 frame_unwind_caller_id (next_frame));
5491 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
5492 new breakpoint at the target of a jmp_buf. The handling of
5493 longjmp-resume uses the same mechanisms used for handling
5494 "step-resume" breakpoints. */
5497 insert_longjmp_resume_breakpoint (struct gdbarch *gdbarch, CORE_ADDR pc)
5499 /* There should never be more than one longjmp-resume breakpoint per
5500 thread, so we should never be setting a new
5501 longjmp_resume_breakpoint when one is already active. */
5502 gdb_assert (inferior_thread ()->control.exception_resume_breakpoint == NULL);
5505 fprintf_unfiltered (gdb_stdlog,
5506 "infrun: inserting longjmp-resume breakpoint at %s\n",
5507 paddress (gdbarch, pc));
5509 inferior_thread ()->control.exception_resume_breakpoint =
5510 set_momentary_breakpoint_at_pc (gdbarch, pc, bp_longjmp_resume);
5513 /* Insert an exception resume breakpoint. TP is the thread throwing
5514 the exception. The block B is the block of the unwinder debug hook
5515 function. FRAME is the frame corresponding to the call to this
5516 function. SYM is the symbol of the function argument holding the
5517 target PC of the exception. */
5520 insert_exception_resume_breakpoint (struct thread_info *tp,
5522 struct frame_info *frame,
5525 volatile struct gdb_exception e;
5527 /* We want to ignore errors here. */
5528 TRY_CATCH (e, RETURN_MASK_ERROR)
5530 struct symbol *vsym;
5531 struct value *value;
5533 struct breakpoint *bp;
5535 vsym = lookup_symbol (SYMBOL_LINKAGE_NAME (sym), b, VAR_DOMAIN, NULL);
5536 value = read_var_value (vsym, frame);
5537 /* If the value was optimized out, revert to the old behavior. */
5538 if (! value_optimized_out (value))
5540 handler = value_as_address (value);
5543 fprintf_unfiltered (gdb_stdlog,
5544 "infrun: exception resume at %lx\n",
5545 (unsigned long) handler);
5547 bp = set_momentary_breakpoint_at_pc (get_frame_arch (frame),
5548 handler, bp_exception_resume);
5550 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
5553 bp->thread = tp->num;
5554 inferior_thread ()->control.exception_resume_breakpoint = bp;
5559 /* A helper for check_exception_resume that sets an
5560 exception-breakpoint based on a SystemTap probe. */
5563 insert_exception_resume_from_probe (struct thread_info *tp,
5564 const struct probe *probe,
5565 struct frame_info *frame)
5567 struct value *arg_value;
5569 struct breakpoint *bp;
5571 arg_value = probe_safe_evaluate_at_pc (frame, 1);
5575 handler = value_as_address (arg_value);
5578 fprintf_unfiltered (gdb_stdlog,
5579 "infrun: exception resume at %s\n",
5580 paddress (get_objfile_arch (probe->objfile),
5583 bp = set_momentary_breakpoint_at_pc (get_frame_arch (frame),
5584 handler, bp_exception_resume);
5585 bp->thread = tp->num;
5586 inferior_thread ()->control.exception_resume_breakpoint = bp;
5589 /* This is called when an exception has been intercepted. Check to
5590 see whether the exception's destination is of interest, and if so,
5591 set an exception resume breakpoint there. */
5594 check_exception_resume (struct execution_control_state *ecs,
5595 struct frame_info *frame)
5597 volatile struct gdb_exception e;
5598 const struct probe *probe;
5599 struct symbol *func;
5601 /* First see if this exception unwinding breakpoint was set via a
5602 SystemTap probe point. If so, the probe has two arguments: the
5603 CFA and the HANDLER. We ignore the CFA, extract the handler, and
5604 set a breakpoint there. */
5605 probe = find_probe_by_pc (get_frame_pc (frame));
5608 insert_exception_resume_from_probe (ecs->event_thread, probe, frame);
5612 func = get_frame_function (frame);
5616 TRY_CATCH (e, RETURN_MASK_ERROR)
5619 struct block_iterator iter;
5623 /* The exception breakpoint is a thread-specific breakpoint on
5624 the unwinder's debug hook, declared as:
5626 void _Unwind_DebugHook (void *cfa, void *handler);
5628 The CFA argument indicates the frame to which control is
5629 about to be transferred. HANDLER is the destination PC.
5631 We ignore the CFA and set a temporary breakpoint at HANDLER.
5632 This is not extremely efficient but it avoids issues in gdb
5633 with computing the DWARF CFA, and it also works even in weird
5634 cases such as throwing an exception from inside a signal
5637 b = SYMBOL_BLOCK_VALUE (func);
5638 ALL_BLOCK_SYMBOLS (b, iter, sym)
5640 if (!SYMBOL_IS_ARGUMENT (sym))
5647 insert_exception_resume_breakpoint (ecs->event_thread,
5656 stop_stepping (struct execution_control_state *ecs)
5659 fprintf_unfiltered (gdb_stdlog, "infrun: stop_stepping\n");
5661 /* Let callers know we don't want to wait for the inferior anymore. */
5662 ecs->wait_some_more = 0;
5665 /* This function handles various cases where we need to continue
5666 waiting for the inferior. */
5667 /* (Used to be the keep_going: label in the old wait_for_inferior). */
5670 keep_going (struct execution_control_state *ecs)
5672 /* Make sure normal_stop is called if we get a QUIT handled before
5674 struct cleanup *old_cleanups = make_cleanup (resume_cleanups, 0);
5676 /* Save the pc before execution, to compare with pc after stop. */
5677 ecs->event_thread->prev_pc
5678 = regcache_read_pc (get_thread_regcache (ecs->ptid));
5680 /* If we did not do break;, it means we should keep running the
5681 inferior and not return to debugger. */
5683 if (ecs->event_thread->control.trap_expected
5684 && ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_TRAP)
5686 /* We took a signal (which we are supposed to pass through to
5687 the inferior, else we'd not get here) and we haven't yet
5688 gotten our trap. Simply continue. */
5690 discard_cleanups (old_cleanups);
5691 resume (currently_stepping (ecs->event_thread),
5692 ecs->event_thread->suspend.stop_signal);
5696 /* Either the trap was not expected, but we are continuing
5697 anyway (the user asked that this signal be passed to the
5700 The signal was SIGTRAP, e.g. it was our signal, but we
5701 decided we should resume from it.
5703 We're going to run this baby now!
5705 Note that insert_breakpoints won't try to re-insert
5706 already inserted breakpoints. Therefore, we don't
5707 care if breakpoints were already inserted, or not. */
5709 if (ecs->event_thread->stepping_over_breakpoint)
5711 struct regcache *thread_regcache = get_thread_regcache (ecs->ptid);
5713 if (!use_displaced_stepping (get_regcache_arch (thread_regcache)))
5714 /* Since we can't do a displaced step, we have to remove
5715 the breakpoint while we step it. To keep things
5716 simple, we remove them all. */
5717 remove_breakpoints ();
5721 volatile struct gdb_exception e;
5723 /* Stop stepping when inserting breakpoints
5725 TRY_CATCH (e, RETURN_MASK_ERROR)
5727 insert_breakpoints ();
5731 exception_print (gdb_stderr, e);
5732 stop_stepping (ecs);
5737 ecs->event_thread->control.trap_expected
5738 = ecs->event_thread->stepping_over_breakpoint;
5740 /* Do not deliver SIGNAL_TRAP (except when the user explicitly
5741 specifies that such a signal should be delivered to the
5744 Typically, this would occure when a user is debugging a
5745 target monitor on a simulator: the target monitor sets a
5746 breakpoint; the simulator encounters this break-point and
5747 halts the simulation handing control to GDB; GDB, noteing
5748 that the break-point isn't valid, returns control back to the
5749 simulator; the simulator then delivers the hardware
5750 equivalent of a SIGNAL_TRAP to the program being debugged. */
5752 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5753 && !signal_program[ecs->event_thread->suspend.stop_signal])
5754 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5756 discard_cleanups (old_cleanups);
5757 resume (currently_stepping (ecs->event_thread),
5758 ecs->event_thread->suspend.stop_signal);
5761 prepare_to_wait (ecs);
5764 /* This function normally comes after a resume, before
5765 handle_inferior_event exits. It takes care of any last bits of
5766 housekeeping, and sets the all-important wait_some_more flag. */
5769 prepare_to_wait (struct execution_control_state *ecs)
5772 fprintf_unfiltered (gdb_stdlog, "infrun: prepare_to_wait\n");
5774 /* This is the old end of the while loop. Let everybody know we
5775 want to wait for the inferior some more and get called again
5777 ecs->wait_some_more = 1;
5780 /* Several print_*_reason functions to print why the inferior has stopped.
5781 We always print something when the inferior exits, or receives a signal.
5782 The rest of the cases are dealt with later on in normal_stop and
5783 print_it_typical. Ideally there should be a call to one of these
5784 print_*_reason functions functions from handle_inferior_event each time
5785 stop_stepping is called. */
5787 /* Print why the inferior has stopped.
5788 We are done with a step/next/si/ni command, print why the inferior has
5789 stopped. For now print nothing. Print a message only if not in the middle
5790 of doing a "step n" operation for n > 1. */
5793 print_end_stepping_range_reason (void)
5795 if ((!inferior_thread ()->step_multi
5796 || !inferior_thread ()->control.stop_step)
5797 && ui_out_is_mi_like_p (current_uiout))
5798 ui_out_field_string (current_uiout, "reason",
5799 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE));
5802 /* The inferior was terminated by a signal, print why it stopped. */
5805 print_signal_exited_reason (enum gdb_signal siggnal)
5807 struct ui_out *uiout = current_uiout;
5809 annotate_signalled ();
5810 if (ui_out_is_mi_like_p (uiout))
5812 (uiout, "reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED));
5813 ui_out_text (uiout, "\nProgram terminated with signal ");
5814 annotate_signal_name ();
5815 ui_out_field_string (uiout, "signal-name",
5816 gdb_signal_to_name (siggnal));
5817 annotate_signal_name_end ();
5818 ui_out_text (uiout, ", ");
5819 annotate_signal_string ();
5820 ui_out_field_string (uiout, "signal-meaning",
5821 gdb_signal_to_string (siggnal));
5822 annotate_signal_string_end ();
5823 ui_out_text (uiout, ".\n");
5824 ui_out_text (uiout, "The program no longer exists.\n");
5827 /* The inferior program is finished, print why it stopped. */
5830 print_exited_reason (int exitstatus)
5832 struct inferior *inf = current_inferior ();
5833 const char *pidstr = target_pid_to_str (pid_to_ptid (inf->pid));
5834 struct ui_out *uiout = current_uiout;
5836 annotate_exited (exitstatus);
5839 if (ui_out_is_mi_like_p (uiout))
5840 ui_out_field_string (uiout, "reason",
5841 async_reason_lookup (EXEC_ASYNC_EXITED));
5842 ui_out_text (uiout, "[Inferior ");
5843 ui_out_text (uiout, plongest (inf->num));
5844 ui_out_text (uiout, " (");
5845 ui_out_text (uiout, pidstr);
5846 ui_out_text (uiout, ") exited with code ");
5847 ui_out_field_fmt (uiout, "exit-code", "0%o", (unsigned int) exitstatus);
5848 ui_out_text (uiout, "]\n");
5852 if (ui_out_is_mi_like_p (uiout))
5854 (uiout, "reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY));
5855 ui_out_text (uiout, "[Inferior ");
5856 ui_out_text (uiout, plongest (inf->num));
5857 ui_out_text (uiout, " (");
5858 ui_out_text (uiout, pidstr);
5859 ui_out_text (uiout, ") exited normally]\n");
5861 /* Support the --return-child-result option. */
5862 return_child_result_value = exitstatus;
5865 /* Signal received, print why the inferior has stopped. The signal table
5866 tells us to print about it. */
5869 print_signal_received_reason (enum gdb_signal siggnal)
5871 struct ui_out *uiout = current_uiout;
5875 if (siggnal == GDB_SIGNAL_0 && !ui_out_is_mi_like_p (uiout))
5877 struct thread_info *t = inferior_thread ();
5879 ui_out_text (uiout, "\n[");
5880 ui_out_field_string (uiout, "thread-name",
5881 target_pid_to_str (t->ptid));
5882 ui_out_field_fmt (uiout, "thread-id", "] #%d", t->num);
5883 ui_out_text (uiout, " stopped");
5887 ui_out_text (uiout, "\nProgram received signal ");
5888 annotate_signal_name ();
5889 if (ui_out_is_mi_like_p (uiout))
5891 (uiout, "reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED));
5892 ui_out_field_string (uiout, "signal-name",
5893 gdb_signal_to_name (siggnal));
5894 annotate_signal_name_end ();
5895 ui_out_text (uiout, ", ");
5896 annotate_signal_string ();
5897 ui_out_field_string (uiout, "signal-meaning",
5898 gdb_signal_to_string (siggnal));
5899 annotate_signal_string_end ();
5901 ui_out_text (uiout, ".\n");
5904 /* Reverse execution: target ran out of history info, print why the inferior
5908 print_no_history_reason (void)
5910 ui_out_text (current_uiout, "\nNo more reverse-execution history.\n");
5913 /* Here to return control to GDB when the inferior stops for real.
5914 Print appropriate messages, remove breakpoints, give terminal our modes.
5916 STOP_PRINT_FRAME nonzero means print the executing frame
5917 (pc, function, args, file, line number and line text).
5918 BREAKPOINTS_FAILED nonzero means stop was due to error
5919 attempting to insert breakpoints. */
5924 struct target_waitstatus last;
5926 struct cleanup *old_chain = make_cleanup (null_cleanup, NULL);
5928 get_last_target_status (&last_ptid, &last);
5930 /* If an exception is thrown from this point on, make sure to
5931 propagate GDB's knowledge of the executing state to the
5932 frontend/user running state. A QUIT is an easy exception to see
5933 here, so do this before any filtered output. */
5935 make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
5936 else if (last.kind != TARGET_WAITKIND_SIGNALLED
5937 && last.kind != TARGET_WAITKIND_EXITED
5938 && last.kind != TARGET_WAITKIND_NO_RESUMED)
5939 make_cleanup (finish_thread_state_cleanup, &inferior_ptid);
5941 /* In non-stop mode, we don't want GDB to switch threads behind the
5942 user's back, to avoid races where the user is typing a command to
5943 apply to thread x, but GDB switches to thread y before the user
5944 finishes entering the command. */
5946 /* As with the notification of thread events, we want to delay
5947 notifying the user that we've switched thread context until
5948 the inferior actually stops.
5950 There's no point in saying anything if the inferior has exited.
5951 Note that SIGNALLED here means "exited with a signal", not
5952 "received a signal". */
5954 && !ptid_equal (previous_inferior_ptid, inferior_ptid)
5955 && target_has_execution
5956 && last.kind != TARGET_WAITKIND_SIGNALLED
5957 && last.kind != TARGET_WAITKIND_EXITED
5958 && last.kind != TARGET_WAITKIND_NO_RESUMED)
5960 target_terminal_ours_for_output ();
5961 printf_filtered (_("[Switching to %s]\n"),
5962 target_pid_to_str (inferior_ptid));
5963 annotate_thread_changed ();
5964 previous_inferior_ptid = inferior_ptid;
5967 if (last.kind == TARGET_WAITKIND_NO_RESUMED)
5969 gdb_assert (sync_execution || !target_can_async_p ());
5971 target_terminal_ours_for_output ();
5972 printf_filtered (_("No unwaited-for children left.\n"));
5975 if (!breakpoints_always_inserted_mode () && target_has_execution)
5977 if (remove_breakpoints ())
5979 target_terminal_ours_for_output ();
5980 printf_filtered (_("Cannot remove breakpoints because "
5981 "program is no longer writable.\nFurther "
5982 "execution is probably impossible.\n"));
5986 /* If an auto-display called a function and that got a signal,
5987 delete that auto-display to avoid an infinite recursion. */
5989 if (stopped_by_random_signal)
5990 disable_current_display ();
5992 /* Don't print a message if in the middle of doing a "step n"
5993 operation for n > 1 */
5994 if (target_has_execution
5995 && last.kind != TARGET_WAITKIND_SIGNALLED
5996 && last.kind != TARGET_WAITKIND_EXITED
5997 && inferior_thread ()->step_multi
5998 && inferior_thread ()->control.stop_step)
6001 target_terminal_ours ();
6002 async_enable_stdin ();
6004 /* Set the current source location. This will also happen if we
6005 display the frame below, but the current SAL will be incorrect
6006 during a user hook-stop function. */
6007 if (has_stack_frames () && !stop_stack_dummy)
6008 set_current_sal_from_frame (get_current_frame (), 1);
6010 /* Let the user/frontend see the threads as stopped. */
6011 do_cleanups (old_chain);
6013 /* Look up the hook_stop and run it (CLI internally handles problem
6014 of stop_command's pre-hook not existing). */
6016 catch_errors (hook_stop_stub, stop_command,
6017 "Error while running hook_stop:\n", RETURN_MASK_ALL);
6019 if (!has_stack_frames ())
6022 if (last.kind == TARGET_WAITKIND_SIGNALLED
6023 || last.kind == TARGET_WAITKIND_EXITED)
6026 /* Select innermost stack frame - i.e., current frame is frame 0,
6027 and current location is based on that.
6028 Don't do this on return from a stack dummy routine,
6029 or if the program has exited. */
6031 if (!stop_stack_dummy)
6033 select_frame (get_current_frame ());
6035 /* Print current location without a level number, if
6036 we have changed functions or hit a breakpoint.
6037 Print source line if we have one.
6038 bpstat_print() contains the logic deciding in detail
6039 what to print, based on the event(s) that just occurred. */
6041 /* If --batch-silent is enabled then there's no need to print the current
6042 source location, and to try risks causing an error message about
6043 missing source files. */
6044 if (stop_print_frame && !batch_silent)
6048 int do_frame_printing = 1;
6049 struct thread_info *tp = inferior_thread ();
6051 bpstat_ret = bpstat_print (tp->control.stop_bpstat, last.kind);
6055 /* FIXME: cagney/2002-12-01: Given that a frame ID does
6056 (or should) carry around the function and does (or
6057 should) use that when doing a frame comparison. */
6058 if (tp->control.stop_step
6059 && frame_id_eq (tp->control.step_frame_id,
6060 get_frame_id (get_current_frame ()))
6061 && step_start_function == find_pc_function (stop_pc))
6062 source_flag = SRC_LINE; /* Finished step, just
6063 print source line. */
6065 source_flag = SRC_AND_LOC; /* Print location and
6068 case PRINT_SRC_AND_LOC:
6069 source_flag = SRC_AND_LOC; /* Print location and
6072 case PRINT_SRC_ONLY:
6073 source_flag = SRC_LINE;
6076 source_flag = SRC_LINE; /* something bogus */
6077 do_frame_printing = 0;
6080 internal_error (__FILE__, __LINE__, _("Unknown value."));
6083 /* The behavior of this routine with respect to the source
6085 SRC_LINE: Print only source line
6086 LOCATION: Print only location
6087 SRC_AND_LOC: Print location and source line. */
6088 if (do_frame_printing)
6089 print_stack_frame (get_selected_frame (NULL), 0, source_flag);
6091 /* Display the auto-display expressions. */
6096 /* Save the function value return registers, if we care.
6097 We might be about to restore their previous contents. */
6098 if (inferior_thread ()->control.proceed_to_finish
6099 && execution_direction != EXEC_REVERSE)
6101 /* This should not be necessary. */
6103 regcache_xfree (stop_registers);
6105 /* NB: The copy goes through to the target picking up the value of
6106 all the registers. */
6107 stop_registers = regcache_dup (get_current_regcache ());
6110 if (stop_stack_dummy == STOP_STACK_DUMMY)
6112 /* Pop the empty frame that contains the stack dummy.
6113 This also restores inferior state prior to the call
6114 (struct infcall_suspend_state). */
6115 struct frame_info *frame = get_current_frame ();
6117 gdb_assert (get_frame_type (frame) == DUMMY_FRAME);
6119 /* frame_pop() calls reinit_frame_cache as the last thing it
6120 does which means there's currently no selected frame. We
6121 don't need to re-establish a selected frame if the dummy call
6122 returns normally, that will be done by
6123 restore_infcall_control_state. However, we do have to handle
6124 the case where the dummy call is returning after being
6125 stopped (e.g. the dummy call previously hit a breakpoint).
6126 We can't know which case we have so just always re-establish
6127 a selected frame here. */
6128 select_frame (get_current_frame ());
6132 annotate_stopped ();
6134 /* Suppress the stop observer if we're in the middle of:
6136 - a step n (n > 1), as there still more steps to be done.
6138 - a "finish" command, as the observer will be called in
6139 finish_command_continuation, so it can include the inferior
6140 function's return value.
6142 - calling an inferior function, as we pretend we inferior didn't
6143 run at all. The return value of the call is handled by the
6144 expression evaluator, through call_function_by_hand. */
6146 if (!target_has_execution
6147 || last.kind == TARGET_WAITKIND_SIGNALLED
6148 || last.kind == TARGET_WAITKIND_EXITED
6149 || last.kind == TARGET_WAITKIND_NO_RESUMED
6150 || (!(inferior_thread ()->step_multi
6151 && inferior_thread ()->control.stop_step)
6152 && !(inferior_thread ()->control.stop_bpstat
6153 && inferior_thread ()->control.proceed_to_finish)
6154 && !inferior_thread ()->control.in_infcall))
6156 if (!ptid_equal (inferior_ptid, null_ptid))
6157 observer_notify_normal_stop (inferior_thread ()->control.stop_bpstat,
6160 observer_notify_normal_stop (NULL, stop_print_frame);
6163 if (target_has_execution)
6165 if (last.kind != TARGET_WAITKIND_SIGNALLED
6166 && last.kind != TARGET_WAITKIND_EXITED)
6167 /* Delete the breakpoint we stopped at, if it wants to be deleted.
6168 Delete any breakpoint that is to be deleted at the next stop. */
6169 breakpoint_auto_delete (inferior_thread ()->control.stop_bpstat);
6172 /* Try to get rid of automatically added inferiors that are no
6173 longer needed. Keeping those around slows down things linearly.
6174 Note that this never removes the current inferior. */
6179 hook_stop_stub (void *cmd)
6181 execute_cmd_pre_hook ((struct cmd_list_element *) cmd);
6186 signal_stop_state (int signo)
6188 return signal_stop[signo];
6192 signal_print_state (int signo)
6194 return signal_print[signo];
6198 signal_pass_state (int signo)
6200 return signal_program[signo];
6204 signal_cache_update (int signo)
6208 for (signo = 0; signo < (int) GDB_SIGNAL_LAST; signo++)
6209 signal_cache_update (signo);
6214 signal_pass[signo] = (signal_stop[signo] == 0
6215 && signal_print[signo] == 0
6216 && signal_program[signo] == 1
6217 && signal_catch[signo] == 0);
6221 signal_stop_update (int signo, int state)
6223 int ret = signal_stop[signo];
6225 signal_stop[signo] = state;
6226 signal_cache_update (signo);
6231 signal_print_update (int signo, int state)
6233 int ret = signal_print[signo];
6235 signal_print[signo] = state;
6236 signal_cache_update (signo);
6241 signal_pass_update (int signo, int state)
6243 int ret = signal_program[signo];
6245 signal_program[signo] = state;
6246 signal_cache_update (signo);
6250 /* Update the global 'signal_catch' from INFO and notify the
6254 signal_catch_update (const unsigned int *info)
6258 for (i = 0; i < GDB_SIGNAL_LAST; ++i)
6259 signal_catch[i] = info[i] > 0;
6260 signal_cache_update (-1);
6261 target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
6265 sig_print_header (void)
6267 printf_filtered (_("Signal Stop\tPrint\tPass "
6268 "to program\tDescription\n"));
6272 sig_print_info (enum gdb_signal oursig)
6274 const char *name = gdb_signal_to_name (oursig);
6275 int name_padding = 13 - strlen (name);
6277 if (name_padding <= 0)
6280 printf_filtered ("%s", name);
6281 printf_filtered ("%*.*s ", name_padding, name_padding, " ");
6282 printf_filtered ("%s\t", signal_stop[oursig] ? "Yes" : "No");
6283 printf_filtered ("%s\t", signal_print[oursig] ? "Yes" : "No");
6284 printf_filtered ("%s\t\t", signal_program[oursig] ? "Yes" : "No");
6285 printf_filtered ("%s\n", gdb_signal_to_string (oursig));
6288 /* Specify how various signals in the inferior should be handled. */
6291 handle_command (char *args, int from_tty)
6294 int digits, wordlen;
6295 int sigfirst, signum, siglast;
6296 enum gdb_signal oursig;
6299 unsigned char *sigs;
6300 struct cleanup *old_chain;
6304 error_no_arg (_("signal to handle"));
6307 /* Allocate and zero an array of flags for which signals to handle. */
6309 nsigs = (int) GDB_SIGNAL_LAST;
6310 sigs = (unsigned char *) alloca (nsigs);
6311 memset (sigs, 0, nsigs);
6313 /* Break the command line up into args. */
6315 argv = gdb_buildargv (args);
6316 old_chain = make_cleanup_freeargv (argv);
6318 /* Walk through the args, looking for signal oursigs, signal names, and
6319 actions. Signal numbers and signal names may be interspersed with
6320 actions, with the actions being performed for all signals cumulatively
6321 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
6323 while (*argv != NULL)
6325 wordlen = strlen (*argv);
6326 for (digits = 0; isdigit ((*argv)[digits]); digits++)
6330 sigfirst = siglast = -1;
6332 if (wordlen >= 1 && !strncmp (*argv, "all", wordlen))
6334 /* Apply action to all signals except those used by the
6335 debugger. Silently skip those. */
6338 siglast = nsigs - 1;
6340 else if (wordlen >= 1 && !strncmp (*argv, "stop", wordlen))
6342 SET_SIGS (nsigs, sigs, signal_stop);
6343 SET_SIGS (nsigs, sigs, signal_print);
6345 else if (wordlen >= 1 && !strncmp (*argv, "ignore", wordlen))
6347 UNSET_SIGS (nsigs, sigs, signal_program);
6349 else if (wordlen >= 2 && !strncmp (*argv, "print", wordlen))
6351 SET_SIGS (nsigs, sigs, signal_print);
6353 else if (wordlen >= 2 && !strncmp (*argv, "pass", wordlen))
6355 SET_SIGS (nsigs, sigs, signal_program);
6357 else if (wordlen >= 3 && !strncmp (*argv, "nostop", wordlen))
6359 UNSET_SIGS (nsigs, sigs, signal_stop);
6361 else if (wordlen >= 3 && !strncmp (*argv, "noignore", wordlen))
6363 SET_SIGS (nsigs, sigs, signal_program);
6365 else if (wordlen >= 4 && !strncmp (*argv, "noprint", wordlen))
6367 UNSET_SIGS (nsigs, sigs, signal_print);
6368 UNSET_SIGS (nsigs, sigs, signal_stop);
6370 else if (wordlen >= 4 && !strncmp (*argv, "nopass", wordlen))
6372 UNSET_SIGS (nsigs, sigs, signal_program);
6374 else if (digits > 0)
6376 /* It is numeric. The numeric signal refers to our own
6377 internal signal numbering from target.h, not to host/target
6378 signal number. This is a feature; users really should be
6379 using symbolic names anyway, and the common ones like
6380 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
6382 sigfirst = siglast = (int)
6383 gdb_signal_from_command (atoi (*argv));
6384 if ((*argv)[digits] == '-')
6387 gdb_signal_from_command (atoi ((*argv) + digits + 1));
6389 if (sigfirst > siglast)
6391 /* Bet he didn't figure we'd think of this case... */
6399 oursig = gdb_signal_from_name (*argv);
6400 if (oursig != GDB_SIGNAL_UNKNOWN)
6402 sigfirst = siglast = (int) oursig;
6406 /* Not a number and not a recognized flag word => complain. */
6407 error (_("Unrecognized or ambiguous flag word: \"%s\"."), *argv);
6411 /* If any signal numbers or symbol names were found, set flags for
6412 which signals to apply actions to. */
6414 for (signum = sigfirst; signum >= 0 && signum <= siglast; signum++)
6416 switch ((enum gdb_signal) signum)
6418 case GDB_SIGNAL_TRAP:
6419 case GDB_SIGNAL_INT:
6420 if (!allsigs && !sigs[signum])
6422 if (query (_("%s is used by the debugger.\n\
6423 Are you sure you want to change it? "),
6424 gdb_signal_to_name ((enum gdb_signal) signum)))
6430 printf_unfiltered (_("Not confirmed, unchanged.\n"));
6431 gdb_flush (gdb_stdout);
6436 case GDB_SIGNAL_DEFAULT:
6437 case GDB_SIGNAL_UNKNOWN:
6438 /* Make sure that "all" doesn't print these. */
6449 for (signum = 0; signum < nsigs; signum++)
6452 signal_cache_update (-1);
6453 target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
6454 target_program_signals ((int) GDB_SIGNAL_LAST, signal_program);
6458 /* Show the results. */
6459 sig_print_header ();
6460 for (; signum < nsigs; signum++)
6462 sig_print_info (signum);
6468 do_cleanups (old_chain);
6471 /* Complete the "handle" command. */
6473 static VEC (char_ptr) *
6474 handle_completer (struct cmd_list_element *ignore,
6475 char *text, char *word)
6477 VEC (char_ptr) *vec_signals, *vec_keywords, *return_val;
6478 static const char * const keywords[] =
6492 vec_signals = signal_completer (ignore, text, word);
6493 vec_keywords = complete_on_enum (keywords, word, word);
6495 return_val = VEC_merge (char_ptr, vec_signals, vec_keywords);
6496 VEC_free (char_ptr, vec_signals);
6497 VEC_free (char_ptr, vec_keywords);
6502 xdb_handle_command (char *args, int from_tty)
6505 struct cleanup *old_chain;
6508 error_no_arg (_("xdb command"));
6510 /* Break the command line up into args. */
6512 argv = gdb_buildargv (args);
6513 old_chain = make_cleanup_freeargv (argv);
6514 if (argv[1] != (char *) NULL)
6519 bufLen = strlen (argv[0]) + 20;
6520 argBuf = (char *) xmalloc (bufLen);
6524 enum gdb_signal oursig;
6526 oursig = gdb_signal_from_name (argv[0]);
6527 memset (argBuf, 0, bufLen);
6528 if (strcmp (argv[1], "Q") == 0)
6529 sprintf (argBuf, "%s %s", argv[0], "noprint");
6532 if (strcmp (argv[1], "s") == 0)
6534 if (!signal_stop[oursig])
6535 sprintf (argBuf, "%s %s", argv[0], "stop");
6537 sprintf (argBuf, "%s %s", argv[0], "nostop");
6539 else if (strcmp (argv[1], "i") == 0)
6541 if (!signal_program[oursig])
6542 sprintf (argBuf, "%s %s", argv[0], "pass");
6544 sprintf (argBuf, "%s %s", argv[0], "nopass");
6546 else if (strcmp (argv[1], "r") == 0)
6548 if (!signal_print[oursig])
6549 sprintf (argBuf, "%s %s", argv[0], "print");
6551 sprintf (argBuf, "%s %s", argv[0], "noprint");
6557 handle_command (argBuf, from_tty);
6559 printf_filtered (_("Invalid signal handling flag.\n"));
6564 do_cleanups (old_chain);
6568 gdb_signal_from_command (int num)
6570 if (num >= 1 && num <= 15)
6571 return (enum gdb_signal) num;
6572 error (_("Only signals 1-15 are valid as numeric signals.\n\
6573 Use \"info signals\" for a list of symbolic signals."));
6576 /* Print current contents of the tables set by the handle command.
6577 It is possible we should just be printing signals actually used
6578 by the current target (but for things to work right when switching
6579 targets, all signals should be in the signal tables). */
6582 signals_info (char *signum_exp, int from_tty)
6584 enum gdb_signal oursig;
6586 sig_print_header ();
6590 /* First see if this is a symbol name. */
6591 oursig = gdb_signal_from_name (signum_exp);
6592 if (oursig == GDB_SIGNAL_UNKNOWN)
6594 /* No, try numeric. */
6596 gdb_signal_from_command (parse_and_eval_long (signum_exp));
6598 sig_print_info (oursig);
6602 printf_filtered ("\n");
6603 /* These ugly casts brought to you by the native VAX compiler. */
6604 for (oursig = GDB_SIGNAL_FIRST;
6605 (int) oursig < (int) GDB_SIGNAL_LAST;
6606 oursig = (enum gdb_signal) ((int) oursig + 1))
6610 if (oursig != GDB_SIGNAL_UNKNOWN
6611 && oursig != GDB_SIGNAL_DEFAULT && oursig != GDB_SIGNAL_0)
6612 sig_print_info (oursig);
6615 printf_filtered (_("\nUse the \"handle\" command "
6616 "to change these tables.\n"));
6619 /* Check if it makes sense to read $_siginfo from the current thread
6620 at this point. If not, throw an error. */
6623 validate_siginfo_access (void)
6625 /* No current inferior, no siginfo. */
6626 if (ptid_equal (inferior_ptid, null_ptid))
6627 error (_("No thread selected."));
6629 /* Don't try to read from a dead thread. */
6630 if (is_exited (inferior_ptid))
6631 error (_("The current thread has terminated"));
6633 /* ... or from a spinning thread. */
6634 if (is_running (inferior_ptid))
6635 error (_("Selected thread is running."));
6638 /* The $_siginfo convenience variable is a bit special. We don't know
6639 for sure the type of the value until we actually have a chance to
6640 fetch the data. The type can change depending on gdbarch, so it is
6641 also dependent on which thread you have selected.
6643 1. making $_siginfo be an internalvar that creates a new value on
6646 2. making the value of $_siginfo be an lval_computed value. */
6648 /* This function implements the lval_computed support for reading a
6652 siginfo_value_read (struct value *v)
6654 LONGEST transferred;
6656 validate_siginfo_access ();
6659 target_read (¤t_target, TARGET_OBJECT_SIGNAL_INFO,
6661 value_contents_all_raw (v),
6663 TYPE_LENGTH (value_type (v)));
6665 if (transferred != TYPE_LENGTH (value_type (v)))
6666 error (_("Unable to read siginfo"));
6669 /* This function implements the lval_computed support for writing a
6673 siginfo_value_write (struct value *v, struct value *fromval)
6675 LONGEST transferred;
6677 validate_siginfo_access ();
6679 transferred = target_write (¤t_target,
6680 TARGET_OBJECT_SIGNAL_INFO,
6682 value_contents_all_raw (fromval),
6684 TYPE_LENGTH (value_type (fromval)));
6686 if (transferred != TYPE_LENGTH (value_type (fromval)))
6687 error (_("Unable to write siginfo"));
6690 static const struct lval_funcs siginfo_value_funcs =
6696 /* Return a new value with the correct type for the siginfo object of
6697 the current thread using architecture GDBARCH. Return a void value
6698 if there's no object available. */
6700 static struct value *
6701 siginfo_make_value (struct gdbarch *gdbarch, struct internalvar *var,
6704 if (target_has_stack
6705 && !ptid_equal (inferior_ptid, null_ptid)
6706 && gdbarch_get_siginfo_type_p (gdbarch))
6708 struct type *type = gdbarch_get_siginfo_type (gdbarch);
6710 return allocate_computed_value (type, &siginfo_value_funcs, NULL);
6713 return allocate_value (builtin_type (gdbarch)->builtin_void);
6717 /* infcall_suspend_state contains state about the program itself like its
6718 registers and any signal it received when it last stopped.
6719 This state must be restored regardless of how the inferior function call
6720 ends (either successfully, or after it hits a breakpoint or signal)
6721 if the program is to properly continue where it left off. */
6723 struct infcall_suspend_state
6725 struct thread_suspend_state thread_suspend;
6726 #if 0 /* Currently unused and empty structures are not valid C. */
6727 struct inferior_suspend_state inferior_suspend;
6732 struct regcache *registers;
6734 /* Format of SIGINFO_DATA or NULL if it is not present. */
6735 struct gdbarch *siginfo_gdbarch;
6737 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
6738 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
6739 content would be invalid. */
6740 gdb_byte *siginfo_data;
6743 struct infcall_suspend_state *
6744 save_infcall_suspend_state (void)
6746 struct infcall_suspend_state *inf_state;
6747 struct thread_info *tp = inferior_thread ();
6748 struct inferior *inf = current_inferior ();
6749 struct regcache *regcache = get_current_regcache ();
6750 struct gdbarch *gdbarch = get_regcache_arch (regcache);
6751 gdb_byte *siginfo_data = NULL;
6753 if (gdbarch_get_siginfo_type_p (gdbarch))
6755 struct type *type = gdbarch_get_siginfo_type (gdbarch);
6756 size_t len = TYPE_LENGTH (type);
6757 struct cleanup *back_to;
6759 siginfo_data = xmalloc (len);
6760 back_to = make_cleanup (xfree, siginfo_data);
6762 if (target_read (¤t_target, TARGET_OBJECT_SIGNAL_INFO, NULL,
6763 siginfo_data, 0, len) == len)
6764 discard_cleanups (back_to);
6767 /* Errors ignored. */
6768 do_cleanups (back_to);
6769 siginfo_data = NULL;
6773 inf_state = XZALLOC (struct infcall_suspend_state);
6777 inf_state->siginfo_gdbarch = gdbarch;
6778 inf_state->siginfo_data = siginfo_data;
6781 inf_state->thread_suspend = tp->suspend;
6782 #if 0 /* Currently unused and empty structures are not valid C. */
6783 inf_state->inferior_suspend = inf->suspend;
6786 /* run_inferior_call will not use the signal due to its `proceed' call with
6787 GDB_SIGNAL_0 anyway. */
6788 tp->suspend.stop_signal = GDB_SIGNAL_0;
6790 inf_state->stop_pc = stop_pc;
6792 inf_state->registers = regcache_dup (regcache);
6797 /* Restore inferior session state to INF_STATE. */
6800 restore_infcall_suspend_state (struct infcall_suspend_state *inf_state)
6802 struct thread_info *tp = inferior_thread ();
6803 struct inferior *inf = current_inferior ();
6804 struct regcache *regcache = get_current_regcache ();
6805 struct gdbarch *gdbarch = get_regcache_arch (regcache);
6807 tp->suspend = inf_state->thread_suspend;
6808 #if 0 /* Currently unused and empty structures are not valid C. */
6809 inf->suspend = inf_state->inferior_suspend;
6812 stop_pc = inf_state->stop_pc;
6814 if (inf_state->siginfo_gdbarch == gdbarch)
6816 struct type *type = gdbarch_get_siginfo_type (gdbarch);
6818 /* Errors ignored. */
6819 target_write (¤t_target, TARGET_OBJECT_SIGNAL_INFO, NULL,
6820 inf_state->siginfo_data, 0, TYPE_LENGTH (type));
6823 /* The inferior can be gone if the user types "print exit(0)"
6824 (and perhaps other times). */
6825 if (target_has_execution)
6826 /* NB: The register write goes through to the target. */
6827 regcache_cpy (regcache, inf_state->registers);
6829 discard_infcall_suspend_state (inf_state);
6833 do_restore_infcall_suspend_state_cleanup (void *state)
6835 restore_infcall_suspend_state (state);
6839 make_cleanup_restore_infcall_suspend_state
6840 (struct infcall_suspend_state *inf_state)
6842 return make_cleanup (do_restore_infcall_suspend_state_cleanup, inf_state);
6846 discard_infcall_suspend_state (struct infcall_suspend_state *inf_state)
6848 regcache_xfree (inf_state->registers);
6849 xfree (inf_state->siginfo_data);
6854 get_infcall_suspend_state_regcache (struct infcall_suspend_state *inf_state)
6856 return inf_state->registers;
6859 /* infcall_control_state contains state regarding gdb's control of the
6860 inferior itself like stepping control. It also contains session state like
6861 the user's currently selected frame. */
6863 struct infcall_control_state
6865 struct thread_control_state thread_control;
6866 struct inferior_control_state inferior_control;
6869 enum stop_stack_kind stop_stack_dummy;
6870 int stopped_by_random_signal;
6871 int stop_after_trap;
6873 /* ID if the selected frame when the inferior function call was made. */
6874 struct frame_id selected_frame_id;
6877 /* Save all of the information associated with the inferior<==>gdb
6880 struct infcall_control_state *
6881 save_infcall_control_state (void)
6883 struct infcall_control_state *inf_status = xmalloc (sizeof (*inf_status));
6884 struct thread_info *tp = inferior_thread ();
6885 struct inferior *inf = current_inferior ();
6887 inf_status->thread_control = tp->control;
6888 inf_status->inferior_control = inf->control;
6890 tp->control.step_resume_breakpoint = NULL;
6891 tp->control.exception_resume_breakpoint = NULL;
6893 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
6894 chain. If caller's caller is walking the chain, they'll be happier if we
6895 hand them back the original chain when restore_infcall_control_state is
6897 tp->control.stop_bpstat = bpstat_copy (tp->control.stop_bpstat);
6900 inf_status->stop_stack_dummy = stop_stack_dummy;
6901 inf_status->stopped_by_random_signal = stopped_by_random_signal;
6902 inf_status->stop_after_trap = stop_after_trap;
6904 inf_status->selected_frame_id = get_frame_id (get_selected_frame (NULL));
6910 restore_selected_frame (void *args)
6912 struct frame_id *fid = (struct frame_id *) args;
6913 struct frame_info *frame;
6915 frame = frame_find_by_id (*fid);
6917 /* If inf_status->selected_frame_id is NULL, there was no previously
6921 warning (_("Unable to restore previously selected frame."));
6925 select_frame (frame);
6930 /* Restore inferior session state to INF_STATUS. */
6933 restore_infcall_control_state (struct infcall_control_state *inf_status)
6935 struct thread_info *tp = inferior_thread ();
6936 struct inferior *inf = current_inferior ();
6938 if (tp->control.step_resume_breakpoint)
6939 tp->control.step_resume_breakpoint->disposition = disp_del_at_next_stop;
6941 if (tp->control.exception_resume_breakpoint)
6942 tp->control.exception_resume_breakpoint->disposition
6943 = disp_del_at_next_stop;
6945 /* Handle the bpstat_copy of the chain. */
6946 bpstat_clear (&tp->control.stop_bpstat);
6948 tp->control = inf_status->thread_control;
6949 inf->control = inf_status->inferior_control;
6952 stop_stack_dummy = inf_status->stop_stack_dummy;
6953 stopped_by_random_signal = inf_status->stopped_by_random_signal;
6954 stop_after_trap = inf_status->stop_after_trap;
6956 if (target_has_stack)
6958 /* The point of catch_errors is that if the stack is clobbered,
6959 walking the stack might encounter a garbage pointer and
6960 error() trying to dereference it. */
6962 (restore_selected_frame, &inf_status->selected_frame_id,
6963 "Unable to restore previously selected frame:\n",
6964 RETURN_MASK_ERROR) == 0)
6965 /* Error in restoring the selected frame. Select the innermost
6967 select_frame (get_current_frame ());
6974 do_restore_infcall_control_state_cleanup (void *sts)
6976 restore_infcall_control_state (sts);
6980 make_cleanup_restore_infcall_control_state
6981 (struct infcall_control_state *inf_status)
6983 return make_cleanup (do_restore_infcall_control_state_cleanup, inf_status);
6987 discard_infcall_control_state (struct infcall_control_state *inf_status)
6989 if (inf_status->thread_control.step_resume_breakpoint)
6990 inf_status->thread_control.step_resume_breakpoint->disposition
6991 = disp_del_at_next_stop;
6993 if (inf_status->thread_control.exception_resume_breakpoint)
6994 inf_status->thread_control.exception_resume_breakpoint->disposition
6995 = disp_del_at_next_stop;
6997 /* See save_infcall_control_state for info on stop_bpstat. */
6998 bpstat_clear (&inf_status->thread_control.stop_bpstat);
7004 ptid_match (ptid_t ptid, ptid_t filter)
7006 if (ptid_equal (filter, minus_one_ptid))
7008 if (ptid_is_pid (filter)
7009 && ptid_get_pid (ptid) == ptid_get_pid (filter))
7011 else if (ptid_equal (ptid, filter))
7017 /* restore_inferior_ptid() will be used by the cleanup machinery
7018 to restore the inferior_ptid value saved in a call to
7019 save_inferior_ptid(). */
7022 restore_inferior_ptid (void *arg)
7024 ptid_t *saved_ptid_ptr = arg;
7026 inferior_ptid = *saved_ptid_ptr;
7030 /* Save the value of inferior_ptid so that it may be restored by a
7031 later call to do_cleanups(). Returns the struct cleanup pointer
7032 needed for later doing the cleanup. */
7035 save_inferior_ptid (void)
7037 ptid_t *saved_ptid_ptr;
7039 saved_ptid_ptr = xmalloc (sizeof (ptid_t));
7040 *saved_ptid_ptr = inferior_ptid;
7041 return make_cleanup (restore_inferior_ptid, saved_ptid_ptr);
7045 /* User interface for reverse debugging:
7046 Set exec-direction / show exec-direction commands
7047 (returns error unless target implements to_set_exec_direction method). */
7049 int execution_direction = EXEC_FORWARD;
7050 static const char exec_forward[] = "forward";
7051 static const char exec_reverse[] = "reverse";
7052 static const char *exec_direction = exec_forward;
7053 static const char *const exec_direction_names[] = {
7060 set_exec_direction_func (char *args, int from_tty,
7061 struct cmd_list_element *cmd)
7063 if (target_can_execute_reverse)
7065 if (!strcmp (exec_direction, exec_forward))
7066 execution_direction = EXEC_FORWARD;
7067 else if (!strcmp (exec_direction, exec_reverse))
7068 execution_direction = EXEC_REVERSE;
7072 exec_direction = exec_forward;
7073 error (_("Target does not support this operation."));
7078 show_exec_direction_func (struct ui_file *out, int from_tty,
7079 struct cmd_list_element *cmd, const char *value)
7081 switch (execution_direction) {
7083 fprintf_filtered (out, _("Forward.\n"));
7086 fprintf_filtered (out, _("Reverse.\n"));
7089 internal_error (__FILE__, __LINE__,
7090 _("bogus execution_direction value: %d"),
7091 (int) execution_direction);
7095 /* User interface for non-stop mode. */
7100 set_non_stop (char *args, int from_tty,
7101 struct cmd_list_element *c)
7103 if (target_has_execution)
7105 non_stop_1 = non_stop;
7106 error (_("Cannot change this setting while the inferior is running."));
7109 non_stop = non_stop_1;
7113 show_non_stop (struct ui_file *file, int from_tty,
7114 struct cmd_list_element *c, const char *value)
7116 fprintf_filtered (file,
7117 _("Controlling the inferior in non-stop mode is %s.\n"),
7122 show_schedule_multiple (struct ui_file *file, int from_tty,
7123 struct cmd_list_element *c, const char *value)
7125 fprintf_filtered (file, _("Resuming the execution of threads "
7126 "of all processes is %s.\n"), value);
7129 /* Implementation of `siginfo' variable. */
7131 static const struct internalvar_funcs siginfo_funcs =
7139 _initialize_infrun (void)
7143 struct cmd_list_element *c;
7145 add_info ("signals", signals_info, _("\
7146 What debugger does when program gets various signals.\n\
7147 Specify a signal as argument to print info on that signal only."));
7148 add_info_alias ("handle", "signals", 0);
7150 c = add_com ("handle", class_run, handle_command, _("\
7151 Specify how to handle signals.\n\
7152 Usage: handle SIGNAL [ACTIONS]\n\
7153 Args are signals and actions to apply to those signals.\n\
7154 If no actions are specified, the current settings for the specified signals\n\
7155 will be displayed instead.\n\
7157 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
7158 from 1-15 are allowed for compatibility with old versions of GDB.\n\
7159 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
7160 The special arg \"all\" is recognized to mean all signals except those\n\
7161 used by the debugger, typically SIGTRAP and SIGINT.\n\
7163 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
7164 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
7165 Stop means reenter debugger if this signal happens (implies print).\n\
7166 Print means print a message if this signal happens.\n\
7167 Pass means let program see this signal; otherwise program doesn't know.\n\
7168 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
7169 Pass and Stop may be combined.\n\
7171 Multiple signals may be specified. Signal numbers and signal names\n\
7172 may be interspersed with actions, with the actions being performed for\n\
7173 all signals cumulatively specified."));
7174 set_cmd_completer (c, handle_completer);
7178 add_com ("lz", class_info, signals_info, _("\
7179 What debugger does when program gets various signals.\n\
7180 Specify a signal as argument to print info on that signal only."));
7181 add_com ("z", class_run, xdb_handle_command, _("\
7182 Specify how to handle a signal.\n\
7183 Args are signals and actions to apply to those signals.\n\
7184 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
7185 from 1-15 are allowed for compatibility with old versions of GDB.\n\
7186 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
7187 The special arg \"all\" is recognized to mean all signals except those\n\
7188 used by the debugger, typically SIGTRAP and SIGINT.\n\
7189 Recognized actions include \"s\" (toggles between stop and nostop),\n\
7190 \"r\" (toggles between print and noprint), \"i\" (toggles between pass and \
7191 nopass), \"Q\" (noprint)\n\
7192 Stop means reenter debugger if this signal happens (implies print).\n\
7193 Print means print a message if this signal happens.\n\
7194 Pass means let program see this signal; otherwise program doesn't know.\n\
7195 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
7196 Pass and Stop may be combined."));
7200 stop_command = add_cmd ("stop", class_obscure,
7201 not_just_help_class_command, _("\
7202 There is no `stop' command, but you can set a hook on `stop'.\n\
7203 This allows you to set a list of commands to be run each time execution\n\
7204 of the program stops."), &cmdlist);
7206 add_setshow_zuinteger_cmd ("infrun", class_maintenance, &debug_infrun, _("\
7207 Set inferior debugging."), _("\
7208 Show inferior debugging."), _("\
7209 When non-zero, inferior specific debugging is enabled."),
7212 &setdebuglist, &showdebuglist);
7214 add_setshow_boolean_cmd ("displaced", class_maintenance,
7215 &debug_displaced, _("\
7216 Set displaced stepping debugging."), _("\
7217 Show displaced stepping debugging."), _("\
7218 When non-zero, displaced stepping specific debugging is enabled."),
7220 show_debug_displaced,
7221 &setdebuglist, &showdebuglist);
7223 add_setshow_boolean_cmd ("non-stop", no_class,
7225 Set whether gdb controls the inferior in non-stop mode."), _("\
7226 Show whether gdb controls the inferior in non-stop mode."), _("\
7227 When debugging a multi-threaded program and this setting is\n\
7228 off (the default, also called all-stop mode), when one thread stops\n\
7229 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
7230 all other threads in the program while you interact with the thread of\n\
7231 interest. When you continue or step a thread, you can allow the other\n\
7232 threads to run, or have them remain stopped, but while you inspect any\n\
7233 thread's state, all threads stop.\n\
7235 In non-stop mode, when one thread stops, other threads can continue\n\
7236 to run freely. You'll be able to step each thread independently,\n\
7237 leave it stopped or free to run as needed."),
7243 numsigs = (int) GDB_SIGNAL_LAST;
7244 signal_stop = (unsigned char *) xmalloc (sizeof (signal_stop[0]) * numsigs);
7245 signal_print = (unsigned char *)
7246 xmalloc (sizeof (signal_print[0]) * numsigs);
7247 signal_program = (unsigned char *)
7248 xmalloc (sizeof (signal_program[0]) * numsigs);
7249 signal_catch = (unsigned char *)
7250 xmalloc (sizeof (signal_catch[0]) * numsigs);
7251 signal_pass = (unsigned char *)
7252 xmalloc (sizeof (signal_program[0]) * numsigs);
7253 for (i = 0; i < numsigs; i++)
7256 signal_print[i] = 1;
7257 signal_program[i] = 1;
7258 signal_catch[i] = 0;
7261 /* Signals caused by debugger's own actions
7262 should not be given to the program afterwards. */
7263 signal_program[GDB_SIGNAL_TRAP] = 0;
7264 signal_program[GDB_SIGNAL_INT] = 0;
7266 /* Signals that are not errors should not normally enter the debugger. */
7267 signal_stop[GDB_SIGNAL_ALRM] = 0;
7268 signal_print[GDB_SIGNAL_ALRM] = 0;
7269 signal_stop[GDB_SIGNAL_VTALRM] = 0;
7270 signal_print[GDB_SIGNAL_VTALRM] = 0;
7271 signal_stop[GDB_SIGNAL_PROF] = 0;
7272 signal_print[GDB_SIGNAL_PROF] = 0;
7273 signal_stop[GDB_SIGNAL_CHLD] = 0;
7274 signal_print[GDB_SIGNAL_CHLD] = 0;
7275 signal_stop[GDB_SIGNAL_IO] = 0;
7276 signal_print[GDB_SIGNAL_IO] = 0;
7277 signal_stop[GDB_SIGNAL_POLL] = 0;
7278 signal_print[GDB_SIGNAL_POLL] = 0;
7279 signal_stop[GDB_SIGNAL_URG] = 0;
7280 signal_print[GDB_SIGNAL_URG] = 0;
7281 signal_stop[GDB_SIGNAL_WINCH] = 0;
7282 signal_print[GDB_SIGNAL_WINCH] = 0;
7283 signal_stop[GDB_SIGNAL_PRIO] = 0;
7284 signal_print[GDB_SIGNAL_PRIO] = 0;
7286 /* These signals are used internally by user-level thread
7287 implementations. (See signal(5) on Solaris.) Like the above
7288 signals, a healthy program receives and handles them as part of
7289 its normal operation. */
7290 signal_stop[GDB_SIGNAL_LWP] = 0;
7291 signal_print[GDB_SIGNAL_LWP] = 0;
7292 signal_stop[GDB_SIGNAL_WAITING] = 0;
7293 signal_print[GDB_SIGNAL_WAITING] = 0;
7294 signal_stop[GDB_SIGNAL_CANCEL] = 0;
7295 signal_print[GDB_SIGNAL_CANCEL] = 0;
7297 /* Update cached state. */
7298 signal_cache_update (-1);
7300 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support,
7301 &stop_on_solib_events, _("\
7302 Set stopping for shared library events."), _("\
7303 Show stopping for shared library events."), _("\
7304 If nonzero, gdb will give control to the user when the dynamic linker\n\
7305 notifies gdb of shared library events. The most common event of interest\n\
7306 to the user would be loading/unloading of a new library."),
7308 show_stop_on_solib_events,
7309 &setlist, &showlist);
7311 add_setshow_enum_cmd ("follow-fork-mode", class_run,
7312 follow_fork_mode_kind_names,
7313 &follow_fork_mode_string, _("\
7314 Set debugger response to a program call of fork or vfork."), _("\
7315 Show debugger response to a program call of fork or vfork."), _("\
7316 A fork or vfork creates a new process. follow-fork-mode can be:\n\
7317 parent - the original process is debugged after a fork\n\
7318 child - the new process is debugged after a fork\n\
7319 The unfollowed process will continue to run.\n\
7320 By default, the debugger will follow the parent process."),
7322 show_follow_fork_mode_string,
7323 &setlist, &showlist);
7325 add_setshow_enum_cmd ("follow-exec-mode", class_run,
7326 follow_exec_mode_names,
7327 &follow_exec_mode_string, _("\
7328 Set debugger response to a program call of exec."), _("\
7329 Show debugger response to a program call of exec."), _("\
7330 An exec call replaces the program image of a process.\n\
7332 follow-exec-mode can be:\n\
7334 new - the debugger creates a new inferior and rebinds the process\n\
7335 to this new inferior. The program the process was running before\n\
7336 the exec call can be restarted afterwards by restarting the original\n\
7339 same - the debugger keeps the process bound to the same inferior.\n\
7340 The new executable image replaces the previous executable loaded in\n\
7341 the inferior. Restarting the inferior after the exec call restarts\n\
7342 the executable the process was running after the exec call.\n\
7344 By default, the debugger will use the same inferior."),
7346 show_follow_exec_mode_string,
7347 &setlist, &showlist);
7349 add_setshow_enum_cmd ("scheduler-locking", class_run,
7350 scheduler_enums, &scheduler_mode, _("\
7351 Set mode for locking scheduler during execution."), _("\
7352 Show mode for locking scheduler during execution."), _("\
7353 off == no locking (threads may preempt at any time)\n\
7354 on == full locking (no thread except the current thread may run)\n\
7355 step == scheduler locked during every single-step operation.\n\
7356 In this mode, no other thread may run during a step command.\n\
7357 Other threads may run while stepping over a function call ('next')."),
7358 set_schedlock_func, /* traps on target vector */
7359 show_scheduler_mode,
7360 &setlist, &showlist);
7362 add_setshow_boolean_cmd ("schedule-multiple", class_run, &sched_multi, _("\
7363 Set mode for resuming threads of all processes."), _("\
7364 Show mode for resuming threads of all processes."), _("\
7365 When on, execution commands (such as 'continue' or 'next') resume all\n\
7366 threads of all processes. When off (which is the default), execution\n\
7367 commands only resume the threads of the current process. The set of\n\
7368 threads that are resumed is further refined by the scheduler-locking\n\
7369 mode (see help set scheduler-locking)."),
7371 show_schedule_multiple,
7372 &setlist, &showlist);
7374 add_setshow_boolean_cmd ("step-mode", class_run, &step_stop_if_no_debug, _("\
7375 Set mode of the step operation."), _("\
7376 Show mode of the step operation."), _("\
7377 When set, doing a step over a function without debug line information\n\
7378 will stop at the first instruction of that function. Otherwise, the\n\
7379 function is skipped and the step command stops at a different source line."),
7381 show_step_stop_if_no_debug,
7382 &setlist, &showlist);
7384 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run,
7385 &can_use_displaced_stepping, _("\
7386 Set debugger's willingness to use displaced stepping."), _("\
7387 Show debugger's willingness to use displaced stepping."), _("\
7388 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
7389 supported by the target architecture. If off, gdb will not use displaced\n\
7390 stepping to step over breakpoints, even if such is supported by the target\n\
7391 architecture. If auto (which is the default), gdb will use displaced stepping\n\
7392 if the target architecture supports it and non-stop mode is active, but will not\n\
7393 use it in all-stop mode (see help set non-stop)."),
7395 show_can_use_displaced_stepping,
7396 &setlist, &showlist);
7398 add_setshow_enum_cmd ("exec-direction", class_run, exec_direction_names,
7399 &exec_direction, _("Set direction of execution.\n\
7400 Options are 'forward' or 'reverse'."),
7401 _("Show direction of execution (forward/reverse)."),
7402 _("Tells gdb whether to execute forward or backward."),
7403 set_exec_direction_func, show_exec_direction_func,
7404 &setlist, &showlist);
7406 /* Set/show detach-on-fork: user-settable mode. */
7408 add_setshow_boolean_cmd ("detach-on-fork", class_run, &detach_fork, _("\
7409 Set whether gdb will detach the child of a fork."), _("\
7410 Show whether gdb will detach the child of a fork."), _("\
7411 Tells gdb whether to detach the child of a fork."),
7412 NULL, NULL, &setlist, &showlist);
7414 /* Set/show disable address space randomization mode. */
7416 add_setshow_boolean_cmd ("disable-randomization", class_support,
7417 &disable_randomization, _("\
7418 Set disabling of debuggee's virtual address space randomization."), _("\
7419 Show disabling of debuggee's virtual address space randomization."), _("\
7420 When this mode is on (which is the default), randomization of the virtual\n\
7421 address space is disabled. Standalone programs run with the randomization\n\
7422 enabled by default on some platforms."),
7423 &set_disable_randomization,
7424 &show_disable_randomization,
7425 &setlist, &showlist);
7427 /* ptid initializations */
7428 inferior_ptid = null_ptid;
7429 target_last_wait_ptid = minus_one_ptid;
7431 observer_attach_thread_ptid_changed (infrun_thread_ptid_changed);
7432 observer_attach_thread_stop_requested (infrun_thread_stop_requested);
7433 observer_attach_thread_exit (infrun_thread_thread_exit);
7434 observer_attach_inferior_exit (infrun_inferior_exit);
7436 /* Explicitly create without lookup, since that tries to create a
7437 value with a void typed value, and when we get here, gdbarch
7438 isn't initialized yet. At this point, we're quite sure there
7439 isn't another convenience variable of the same name. */
7440 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs, NULL);
7442 add_setshow_boolean_cmd ("observer", no_class,
7443 &observer_mode_1, _("\
7444 Set whether gdb controls the inferior in observer mode."), _("\
7445 Show whether gdb controls the inferior in observer mode."), _("\
7446 In observer mode, GDB can get data from the inferior, but not\n\
7447 affect its execution. Registers and memory may not be changed,\n\
7448 breakpoints may not be set, and the program cannot be interrupted\n\