1 /* Target-struct-independent code to start (run) and stop an inferior
4 Copyright (C) 1986-2012 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"
62 /* Prototypes for local functions */
64 static void signals_info (char *, int);
66 static void handle_command (char *, int);
68 static void sig_print_info (enum gdb_signal);
70 static void sig_print_header (void);
72 static void resume_cleanups (void *);
74 static int hook_stop_stub (void *);
76 static int restore_selected_frame (void *);
78 static int follow_fork (void);
80 static void set_schedlock_func (char *args, int from_tty,
81 struct cmd_list_element *c);
83 static int currently_stepping (struct thread_info *tp);
85 static int currently_stepping_or_nexting_callback (struct thread_info *tp,
88 static void xdb_handle_command (char *args, int from_tty);
90 static int prepare_to_proceed (int);
92 static void print_exited_reason (int exitstatus);
94 static void print_signal_exited_reason (enum gdb_signal siggnal);
96 static void print_no_history_reason (void);
98 static void print_signal_received_reason (enum gdb_signal siggnal);
100 static void print_end_stepping_range_reason (void);
102 void _initialize_infrun (void);
104 void nullify_last_target_wait_ptid (void);
106 static void insert_hp_step_resume_breakpoint_at_frame (struct frame_info *);
108 static void insert_step_resume_breakpoint_at_caller (struct frame_info *);
110 static void insert_longjmp_resume_breakpoint (struct gdbarch *, CORE_ADDR);
112 /* When set, stop the 'step' command if we enter a function which has
113 no line number information. The normal behavior is that we step
114 over such function. */
115 int step_stop_if_no_debug = 0;
117 show_step_stop_if_no_debug (struct ui_file *file, int from_tty,
118 struct cmd_list_element *c, const char *value)
120 fprintf_filtered (file, _("Mode of the step operation is %s.\n"), value);
123 /* In asynchronous mode, but simulating synchronous execution. */
125 int sync_execution = 0;
127 /* wait_for_inferior and normal_stop use this to notify the user
128 when the inferior stopped in a different thread than it had been
131 static ptid_t previous_inferior_ptid;
133 /* Default behavior is to detach newly forked processes (legacy). */
136 int debug_displaced = 0;
138 show_debug_displaced (struct ui_file *file, int from_tty,
139 struct cmd_list_element *c, const char *value)
141 fprintf_filtered (file, _("Displace stepping debugging is %s.\n"), value);
144 unsigned int debug_infrun = 0;
146 show_debug_infrun (struct ui_file *file, int from_tty,
147 struct cmd_list_element *c, const char *value)
149 fprintf_filtered (file, _("Inferior debugging is %s.\n"), value);
153 /* Support for disabling address space randomization. */
155 int disable_randomization = 1;
158 show_disable_randomization (struct ui_file *file, int from_tty,
159 struct cmd_list_element *c, const char *value)
161 if (target_supports_disable_randomization ())
162 fprintf_filtered (file,
163 _("Disabling randomization of debuggee's "
164 "virtual address space is %s.\n"),
167 fputs_filtered (_("Disabling randomization of debuggee's "
168 "virtual address space is unsupported on\n"
169 "this platform.\n"), file);
173 set_disable_randomization (char *args, int from_tty,
174 struct cmd_list_element *c)
176 if (!target_supports_disable_randomization ())
177 error (_("Disabling randomization of debuggee's "
178 "virtual address space is unsupported on\n"
183 /* If the program uses ELF-style shared libraries, then calls to
184 functions in shared libraries go through stubs, which live in a
185 table called the PLT (Procedure Linkage Table). The first time the
186 function is called, the stub sends control to the dynamic linker,
187 which looks up the function's real address, patches the stub so
188 that future calls will go directly to the function, and then passes
189 control to the function.
191 If we are stepping at the source level, we don't want to see any of
192 this --- we just want to skip over the stub and the dynamic linker.
193 The simple approach is to single-step until control leaves the
196 However, on some systems (e.g., Red Hat's 5.2 distribution) the
197 dynamic linker calls functions in the shared C library, so you
198 can't tell from the PC alone whether the dynamic linker is still
199 running. In this case, we use a step-resume breakpoint to get us
200 past the dynamic linker, as if we were using "next" to step over a
203 in_solib_dynsym_resolve_code() says whether we're in the dynamic
204 linker code or not. Normally, this means we single-step. However,
205 if SKIP_SOLIB_RESOLVER then returns non-zero, then its value is an
206 address where we can place a step-resume breakpoint to get past the
207 linker's symbol resolution function.
209 in_solib_dynsym_resolve_code() can generally be implemented in a
210 pretty portable way, by comparing the PC against the address ranges
211 of the dynamic linker's sections.
213 SKIP_SOLIB_RESOLVER is generally going to be system-specific, since
214 it depends on internal details of the dynamic linker. It's usually
215 not too hard to figure out where to put a breakpoint, but it
216 certainly isn't portable. SKIP_SOLIB_RESOLVER should do plenty of
217 sanity checking. If it can't figure things out, returning zero and
218 getting the (possibly confusing) stepping behavior is better than
219 signalling an error, which will obscure the change in the
222 /* This function returns TRUE if pc is the address of an instruction
223 that lies within the dynamic linker (such as the event hook, or the
226 This function must be used only when a dynamic linker event has
227 been caught, and the inferior is being stepped out of the hook, or
228 undefined results are guaranteed. */
230 #ifndef SOLIB_IN_DYNAMIC_LINKER
231 #define SOLIB_IN_DYNAMIC_LINKER(pid,pc) 0
234 /* "Observer mode" is somewhat like a more extreme version of
235 non-stop, in which all GDB operations that might affect the
236 target's execution have been disabled. */
238 static int non_stop_1 = 0;
240 int observer_mode = 0;
241 static int observer_mode_1 = 0;
244 set_observer_mode (char *args, int from_tty,
245 struct cmd_list_element *c)
247 extern int pagination_enabled;
249 if (target_has_execution)
251 observer_mode_1 = observer_mode;
252 error (_("Cannot change this setting while the inferior is running."));
255 observer_mode = observer_mode_1;
257 may_write_registers = !observer_mode;
258 may_write_memory = !observer_mode;
259 may_insert_breakpoints = !observer_mode;
260 may_insert_tracepoints = !observer_mode;
261 /* We can insert fast tracepoints in or out of observer mode,
262 but enable them if we're going into this mode. */
264 may_insert_fast_tracepoints = 1;
265 may_stop = !observer_mode;
266 update_target_permissions ();
268 /* Going *into* observer mode we must force non-stop, then
269 going out we leave it that way. */
272 target_async_permitted = 1;
273 pagination_enabled = 0;
274 non_stop = non_stop_1 = 1;
278 printf_filtered (_("Observer mode is now %s.\n"),
279 (observer_mode ? "on" : "off"));
283 show_observer_mode (struct ui_file *file, int from_tty,
284 struct cmd_list_element *c, const char *value)
286 fprintf_filtered (file, _("Observer mode is %s.\n"), value);
289 /* This updates the value of observer mode based on changes in
290 permissions. Note that we are deliberately ignoring the values of
291 may-write-registers and may-write-memory, since the user may have
292 reason to enable these during a session, for instance to turn on a
293 debugging-related global. */
296 update_observer_mode (void)
300 newval = (!may_insert_breakpoints
301 && !may_insert_tracepoints
302 && may_insert_fast_tracepoints
306 /* Let the user know if things change. */
307 if (newval != observer_mode)
308 printf_filtered (_("Observer mode is now %s.\n"),
309 (newval ? "on" : "off"));
311 observer_mode = observer_mode_1 = newval;
314 /* Tables of how to react to signals; the user sets them. */
316 static unsigned char *signal_stop;
317 static unsigned char *signal_print;
318 static unsigned char *signal_program;
320 /* Table of signals that the target may silently handle.
321 This is automatically determined from the flags above,
322 and simply cached here. */
323 static unsigned char *signal_pass;
325 #define SET_SIGS(nsigs,sigs,flags) \
327 int signum = (nsigs); \
328 while (signum-- > 0) \
329 if ((sigs)[signum]) \
330 (flags)[signum] = 1; \
333 #define UNSET_SIGS(nsigs,sigs,flags) \
335 int signum = (nsigs); \
336 while (signum-- > 0) \
337 if ((sigs)[signum]) \
338 (flags)[signum] = 0; \
341 /* Update the target's copy of SIGNAL_PROGRAM. The sole purpose of
342 this function is to avoid exporting `signal_program'. */
345 update_signals_program_target (void)
347 target_program_signals ((int) GDB_SIGNAL_LAST, signal_program);
350 /* Value to pass to target_resume() to cause all threads to resume. */
352 #define RESUME_ALL minus_one_ptid
354 /* Command list pointer for the "stop" placeholder. */
356 static struct cmd_list_element *stop_command;
358 /* Function inferior was in as of last step command. */
360 static struct symbol *step_start_function;
362 /* Nonzero if we want to give control to the user when we're notified
363 of shared library events by the dynamic linker. */
364 int stop_on_solib_events;
366 show_stop_on_solib_events (struct ui_file *file, int from_tty,
367 struct cmd_list_element *c, const char *value)
369 fprintf_filtered (file, _("Stopping for shared library events is %s.\n"),
373 /* Nonzero means expecting a trace trap
374 and should stop the inferior and return silently when it happens. */
378 /* Save register contents here when executing a "finish" command or are
379 about to pop a stack dummy frame, if-and-only-if proceed_to_finish is set.
380 Thus this contains the return value from the called function (assuming
381 values are returned in a register). */
383 struct regcache *stop_registers;
385 /* Nonzero after stop if current stack frame should be printed. */
387 static int stop_print_frame;
389 /* This is a cached copy of the pid/waitstatus of the last event
390 returned by target_wait()/deprecated_target_wait_hook(). This
391 information is returned by get_last_target_status(). */
392 static ptid_t target_last_wait_ptid;
393 static struct target_waitstatus target_last_waitstatus;
395 static void context_switch (ptid_t ptid);
397 void init_thread_stepping_state (struct thread_info *tss);
399 void init_infwait_state (void);
401 static const char follow_fork_mode_child[] = "child";
402 static const char follow_fork_mode_parent[] = "parent";
404 static const char *const follow_fork_mode_kind_names[] = {
405 follow_fork_mode_child,
406 follow_fork_mode_parent,
410 static const char *follow_fork_mode_string = follow_fork_mode_parent;
412 show_follow_fork_mode_string (struct ui_file *file, int from_tty,
413 struct cmd_list_element *c, const char *value)
415 fprintf_filtered (file,
416 _("Debugger response to a program "
417 "call of fork or vfork is \"%s\".\n"),
422 /* Tell the target to follow the fork we're stopped at. Returns true
423 if the inferior should be resumed; false, if the target for some
424 reason decided it's best not to resume. */
429 int follow_child = (follow_fork_mode_string == follow_fork_mode_child);
430 int should_resume = 1;
431 struct thread_info *tp;
433 /* Copy user stepping state to the new inferior thread. FIXME: the
434 followed fork child thread should have a copy of most of the
435 parent thread structure's run control related fields, not just these.
436 Initialized to avoid "may be used uninitialized" warnings from gcc. */
437 struct breakpoint *step_resume_breakpoint = NULL;
438 struct breakpoint *exception_resume_breakpoint = NULL;
439 CORE_ADDR step_range_start = 0;
440 CORE_ADDR step_range_end = 0;
441 struct frame_id step_frame_id = { 0 };
446 struct target_waitstatus wait_status;
448 /* Get the last target status returned by target_wait(). */
449 get_last_target_status (&wait_ptid, &wait_status);
451 /* If not stopped at a fork event, then there's nothing else to
453 if (wait_status.kind != TARGET_WAITKIND_FORKED
454 && wait_status.kind != TARGET_WAITKIND_VFORKED)
457 /* Check if we switched over from WAIT_PTID, since the event was
459 if (!ptid_equal (wait_ptid, minus_one_ptid)
460 && !ptid_equal (inferior_ptid, wait_ptid))
462 /* We did. Switch back to WAIT_PTID thread, to tell the
463 target to follow it (in either direction). We'll
464 afterwards refuse to resume, and inform the user what
466 switch_to_thread (wait_ptid);
471 tp = inferior_thread ();
473 /* If there were any forks/vforks that were caught and are now to be
474 followed, then do so now. */
475 switch (tp->pending_follow.kind)
477 case TARGET_WAITKIND_FORKED:
478 case TARGET_WAITKIND_VFORKED:
480 ptid_t parent, child;
482 /* If the user did a next/step, etc, over a fork call,
483 preserve the stepping state in the fork child. */
484 if (follow_child && should_resume)
486 step_resume_breakpoint = clone_momentary_breakpoint
487 (tp->control.step_resume_breakpoint);
488 step_range_start = tp->control.step_range_start;
489 step_range_end = tp->control.step_range_end;
490 step_frame_id = tp->control.step_frame_id;
491 exception_resume_breakpoint
492 = clone_momentary_breakpoint (tp->control.exception_resume_breakpoint);
494 /* For now, delete the parent's sr breakpoint, otherwise,
495 parent/child sr breakpoints are considered duplicates,
496 and the child version will not be installed. Remove
497 this when the breakpoints module becomes aware of
498 inferiors and address spaces. */
499 delete_step_resume_breakpoint (tp);
500 tp->control.step_range_start = 0;
501 tp->control.step_range_end = 0;
502 tp->control.step_frame_id = null_frame_id;
503 delete_exception_resume_breakpoint (tp);
506 parent = inferior_ptid;
507 child = tp->pending_follow.value.related_pid;
509 /* Tell the target to do whatever is necessary to follow
510 either parent or child. */
511 if (target_follow_fork (follow_child))
513 /* Target refused to follow, or there's some other reason
514 we shouldn't resume. */
519 /* This pending follow fork event is now handled, one way
520 or another. The previous selected thread may be gone
521 from the lists by now, but if it is still around, need
522 to clear the pending follow request. */
523 tp = find_thread_ptid (parent);
525 tp->pending_follow.kind = TARGET_WAITKIND_SPURIOUS;
527 /* This makes sure we don't try to apply the "Switched
528 over from WAIT_PID" logic above. */
529 nullify_last_target_wait_ptid ();
531 /* If we followed the child, switch to it... */
534 switch_to_thread (child);
536 /* ... and preserve the stepping state, in case the
537 user was stepping over the fork call. */
540 tp = inferior_thread ();
541 tp->control.step_resume_breakpoint
542 = step_resume_breakpoint;
543 tp->control.step_range_start = step_range_start;
544 tp->control.step_range_end = step_range_end;
545 tp->control.step_frame_id = step_frame_id;
546 tp->control.exception_resume_breakpoint
547 = exception_resume_breakpoint;
551 /* If we get here, it was because we're trying to
552 resume from a fork catchpoint, but, the user
553 has switched threads away from the thread that
554 forked. In that case, the resume command
555 issued is most likely not applicable to the
556 child, so just warn, and refuse to resume. */
557 warning (_("Not resuming: switched threads "
558 "before following fork child.\n"));
561 /* Reset breakpoints in the child as appropriate. */
562 follow_inferior_reset_breakpoints ();
565 switch_to_thread (parent);
569 case TARGET_WAITKIND_SPURIOUS:
570 /* Nothing to follow. */
573 internal_error (__FILE__, __LINE__,
574 "Unexpected pending_follow.kind %d\n",
575 tp->pending_follow.kind);
579 return should_resume;
583 follow_inferior_reset_breakpoints (void)
585 struct thread_info *tp = inferior_thread ();
587 /* Was there a step_resume breakpoint? (There was if the user
588 did a "next" at the fork() call.) If so, explicitly reset its
591 step_resumes are a form of bp that are made to be per-thread.
592 Since we created the step_resume bp when the parent process
593 was being debugged, and now are switching to the child process,
594 from the breakpoint package's viewpoint, that's a switch of
595 "threads". We must update the bp's notion of which thread
596 it is for, or it'll be ignored when it triggers. */
598 if (tp->control.step_resume_breakpoint)
599 breakpoint_re_set_thread (tp->control.step_resume_breakpoint);
601 if (tp->control.exception_resume_breakpoint)
602 breakpoint_re_set_thread (tp->control.exception_resume_breakpoint);
604 /* Reinsert all breakpoints in the child. The user may have set
605 breakpoints after catching the fork, in which case those
606 were never set in the child, but only in the parent. This makes
607 sure the inserted breakpoints match the breakpoint list. */
609 breakpoint_re_set ();
610 insert_breakpoints ();
613 /* The child has exited or execed: resume threads of the parent the
614 user wanted to be executing. */
617 proceed_after_vfork_done (struct thread_info *thread,
620 int pid = * (int *) arg;
622 if (ptid_get_pid (thread->ptid) == pid
623 && is_running (thread->ptid)
624 && !is_executing (thread->ptid)
625 && !thread->stop_requested
626 && thread->suspend.stop_signal == GDB_SIGNAL_0)
629 fprintf_unfiltered (gdb_stdlog,
630 "infrun: resuming vfork parent thread %s\n",
631 target_pid_to_str (thread->ptid));
633 switch_to_thread (thread->ptid);
634 clear_proceed_status ();
635 proceed ((CORE_ADDR) -1, GDB_SIGNAL_DEFAULT, 0);
641 /* Called whenever we notice an exec or exit event, to handle
642 detaching or resuming a vfork parent. */
645 handle_vfork_child_exec_or_exit (int exec)
647 struct inferior *inf = current_inferior ();
649 if (inf->vfork_parent)
651 int resume_parent = -1;
653 /* This exec or exit marks the end of the shared memory region
654 between the parent and the child. If the user wanted to
655 detach from the parent, now is the time. */
657 if (inf->vfork_parent->pending_detach)
659 struct thread_info *tp;
660 struct cleanup *old_chain;
661 struct program_space *pspace;
662 struct address_space *aspace;
664 /* follow-fork child, detach-on-fork on. */
666 old_chain = make_cleanup_restore_current_thread ();
668 /* We're letting loose of the parent. */
669 tp = any_live_thread_of_process (inf->vfork_parent->pid);
670 switch_to_thread (tp->ptid);
672 /* We're about to detach from the parent, which implicitly
673 removes breakpoints from its address space. There's a
674 catch here: we want to reuse the spaces for the child,
675 but, parent/child are still sharing the pspace at this
676 point, although the exec in reality makes the kernel give
677 the child a fresh set of new pages. The problem here is
678 that the breakpoints module being unaware of this, would
679 likely chose the child process to write to the parent
680 address space. Swapping the child temporarily away from
681 the spaces has the desired effect. Yes, this is "sort
684 pspace = inf->pspace;
685 aspace = inf->aspace;
689 if (debug_infrun || info_verbose)
691 target_terminal_ours ();
694 fprintf_filtered (gdb_stdlog,
695 "Detaching vfork parent process "
696 "%d after child exec.\n",
697 inf->vfork_parent->pid);
699 fprintf_filtered (gdb_stdlog,
700 "Detaching vfork parent process "
701 "%d after child exit.\n",
702 inf->vfork_parent->pid);
705 target_detach (NULL, 0);
708 inf->pspace = pspace;
709 inf->aspace = aspace;
711 do_cleanups (old_chain);
715 /* We're staying attached to the parent, so, really give the
716 child a new address space. */
717 inf->pspace = add_program_space (maybe_new_address_space ());
718 inf->aspace = inf->pspace->aspace;
720 set_current_program_space (inf->pspace);
722 resume_parent = inf->vfork_parent->pid;
724 /* Break the bonds. */
725 inf->vfork_parent->vfork_child = NULL;
729 struct cleanup *old_chain;
730 struct program_space *pspace;
732 /* If this is a vfork child exiting, then the pspace and
733 aspaces were shared with the parent. Since we're
734 reporting the process exit, we'll be mourning all that is
735 found in the address space, and switching to null_ptid,
736 preparing to start a new inferior. But, since we don't
737 want to clobber the parent's address/program spaces, we
738 go ahead and create a new one for this exiting
741 /* Switch to null_ptid, so that clone_program_space doesn't want
742 to read the selected frame of a dead process. */
743 old_chain = save_inferior_ptid ();
744 inferior_ptid = null_ptid;
746 /* This inferior is dead, so avoid giving the breakpoints
747 module the option to write through to it (cloning a
748 program space resets breakpoints). */
751 pspace = add_program_space (maybe_new_address_space ());
752 set_current_program_space (pspace);
754 inf->symfile_flags = SYMFILE_NO_READ;
755 clone_program_space (pspace, inf->vfork_parent->pspace);
756 inf->pspace = pspace;
757 inf->aspace = pspace->aspace;
759 /* Put back inferior_ptid. We'll continue mourning this
761 do_cleanups (old_chain);
763 resume_parent = inf->vfork_parent->pid;
764 /* Break the bonds. */
765 inf->vfork_parent->vfork_child = NULL;
768 inf->vfork_parent = NULL;
770 gdb_assert (current_program_space == inf->pspace);
772 if (non_stop && resume_parent != -1)
774 /* If the user wanted the parent to be running, let it go
776 struct cleanup *old_chain = make_cleanup_restore_current_thread ();
779 fprintf_unfiltered (gdb_stdlog,
780 "infrun: resuming vfork parent process %d\n",
783 iterate_over_threads (proceed_after_vfork_done, &resume_parent);
785 do_cleanups (old_chain);
790 /* Enum strings for "set|show displaced-stepping". */
792 static const char follow_exec_mode_new[] = "new";
793 static const char follow_exec_mode_same[] = "same";
794 static const char *const follow_exec_mode_names[] =
796 follow_exec_mode_new,
797 follow_exec_mode_same,
801 static const char *follow_exec_mode_string = follow_exec_mode_same;
803 show_follow_exec_mode_string (struct ui_file *file, int from_tty,
804 struct cmd_list_element *c, const char *value)
806 fprintf_filtered (file, _("Follow exec mode is \"%s\".\n"), value);
809 /* EXECD_PATHNAME is assumed to be non-NULL. */
812 follow_exec (ptid_t pid, char *execd_pathname)
814 struct thread_info *th = inferior_thread ();
815 struct inferior *inf = current_inferior ();
817 /* This is an exec event that we actually wish to pay attention to.
818 Refresh our symbol table to the newly exec'd program, remove any
821 If there are breakpoints, they aren't really inserted now,
822 since the exec() transformed our inferior into a fresh set
825 We want to preserve symbolic breakpoints on the list, since
826 we have hopes that they can be reset after the new a.out's
827 symbol table is read.
829 However, any "raw" breakpoints must be removed from the list
830 (e.g., the solib bp's), since their address is probably invalid
833 And, we DON'T want to call delete_breakpoints() here, since
834 that may write the bp's "shadow contents" (the instruction
835 value that was overwritten witha TRAP instruction). Since
836 we now have a new a.out, those shadow contents aren't valid. */
838 mark_breakpoints_out ();
840 update_breakpoints_after_exec ();
842 /* If there was one, it's gone now. We cannot truly step-to-next
843 statement through an exec(). */
844 th->control.step_resume_breakpoint = NULL;
845 th->control.exception_resume_breakpoint = NULL;
846 th->control.step_range_start = 0;
847 th->control.step_range_end = 0;
849 /* The target reports the exec event to the main thread, even if
850 some other thread does the exec, and even if the main thread was
851 already stopped --- if debugging in non-stop mode, it's possible
852 the user had the main thread held stopped in the previous image
853 --- release it now. This is the same behavior as step-over-exec
854 with scheduler-locking on in all-stop mode. */
855 th->stop_requested = 0;
857 /* What is this a.out's name? */
858 printf_unfiltered (_("%s is executing new program: %s\n"),
859 target_pid_to_str (inferior_ptid),
862 /* We've followed the inferior through an exec. Therefore, the
863 inferior has essentially been killed & reborn. */
865 gdb_flush (gdb_stdout);
867 breakpoint_init_inferior (inf_execd);
869 if (gdb_sysroot && *gdb_sysroot)
871 char *name = alloca (strlen (gdb_sysroot)
872 + strlen (execd_pathname)
875 strcpy (name, gdb_sysroot);
876 strcat (name, execd_pathname);
877 execd_pathname = name;
880 /* Reset the shared library package. This ensures that we get a
881 shlib event when the child reaches "_start", at which point the
882 dld will have had a chance to initialize the child. */
883 /* Also, loading a symbol file below may trigger symbol lookups, and
884 we don't want those to be satisfied by the libraries of the
885 previous incarnation of this process. */
886 no_shared_libraries (NULL, 0);
888 if (follow_exec_mode_string == follow_exec_mode_new)
890 struct program_space *pspace;
892 /* The user wants to keep the old inferior and program spaces
893 around. Create a new fresh one, and switch to it. */
895 inf = add_inferior (current_inferior ()->pid);
896 pspace = add_program_space (maybe_new_address_space ());
897 inf->pspace = pspace;
898 inf->aspace = pspace->aspace;
900 exit_inferior_num_silent (current_inferior ()->num);
902 set_current_inferior (inf);
903 set_current_program_space (pspace);
906 gdb_assert (current_program_space == inf->pspace);
908 /* That a.out is now the one to use. */
909 exec_file_attach (execd_pathname, 0);
911 /* SYMFILE_DEFER_BP_RESET is used as the proper displacement for PIE
912 (Position Independent Executable) main symbol file will get applied by
913 solib_create_inferior_hook below. breakpoint_re_set would fail to insert
914 the breakpoints with the zero displacement. */
916 symbol_file_add (execd_pathname,
918 | SYMFILE_MAINLINE | SYMFILE_DEFER_BP_RESET),
921 if ((inf->symfile_flags & SYMFILE_NO_READ) == 0)
922 set_initial_language ();
924 #ifdef SOLIB_CREATE_INFERIOR_HOOK
925 SOLIB_CREATE_INFERIOR_HOOK (PIDGET (inferior_ptid));
927 solib_create_inferior_hook (0);
930 jit_inferior_created_hook ();
932 breakpoint_re_set ();
934 /* Reinsert all breakpoints. (Those which were symbolic have
935 been reset to the proper address in the new a.out, thanks
936 to symbol_file_command...). */
937 insert_breakpoints ();
939 /* The next resume of this inferior should bring it to the shlib
940 startup breakpoints. (If the user had also set bp's on
941 "main" from the old (parent) process, then they'll auto-
942 matically get reset there in the new process.). */
945 /* Non-zero if we just simulating a single-step. This is needed
946 because we cannot remove the breakpoints in the inferior process
947 until after the `wait' in `wait_for_inferior'. */
948 static int singlestep_breakpoints_inserted_p = 0;
950 /* The thread we inserted single-step breakpoints for. */
951 static ptid_t singlestep_ptid;
953 /* PC when we started this single-step. */
954 static CORE_ADDR singlestep_pc;
956 /* If another thread hit the singlestep breakpoint, we save the original
957 thread here so that we can resume single-stepping it later. */
958 static ptid_t saved_singlestep_ptid;
959 static int stepping_past_singlestep_breakpoint;
961 /* If not equal to null_ptid, this means that after stepping over breakpoint
962 is finished, we need to switch to deferred_step_ptid, and step it.
964 The use case is when one thread has hit a breakpoint, and then the user
965 has switched to another thread and issued 'step'. We need to step over
966 breakpoint in the thread which hit the breakpoint, but then continue
967 stepping the thread user has selected. */
968 static ptid_t deferred_step_ptid;
970 /* Displaced stepping. */
972 /* In non-stop debugging mode, we must take special care to manage
973 breakpoints properly; in particular, the traditional strategy for
974 stepping a thread past a breakpoint it has hit is unsuitable.
975 'Displaced stepping' is a tactic for stepping one thread past a
976 breakpoint it has hit while ensuring that other threads running
977 concurrently will hit the breakpoint as they should.
979 The traditional way to step a thread T off a breakpoint in a
980 multi-threaded program in all-stop mode is as follows:
982 a0) Initially, all threads are stopped, and breakpoints are not
984 a1) We single-step T, leaving breakpoints uninserted.
985 a2) We insert breakpoints, and resume all threads.
987 In non-stop debugging, however, this strategy is unsuitable: we
988 don't want to have to stop all threads in the system in order to
989 continue or step T past a breakpoint. Instead, we use displaced
992 n0) Initially, T is stopped, other threads are running, and
993 breakpoints are inserted.
994 n1) We copy the instruction "under" the breakpoint to a separate
995 location, outside the main code stream, making any adjustments
996 to the instruction, register, and memory state as directed by
998 n2) We single-step T over the instruction at its new location.
999 n3) We adjust the resulting register and memory state as directed
1000 by T's architecture. This includes resetting T's PC to point
1001 back into the main instruction stream.
1004 This approach depends on the following gdbarch methods:
1006 - gdbarch_max_insn_length and gdbarch_displaced_step_location
1007 indicate where to copy the instruction, and how much space must
1008 be reserved there. We use these in step n1.
1010 - gdbarch_displaced_step_copy_insn copies a instruction to a new
1011 address, and makes any necessary adjustments to the instruction,
1012 register contents, and memory. We use this in step n1.
1014 - gdbarch_displaced_step_fixup adjusts registers and memory after
1015 we have successfuly single-stepped the instruction, to yield the
1016 same effect the instruction would have had if we had executed it
1017 at its original address. We use this in step n3.
1019 - gdbarch_displaced_step_free_closure provides cleanup.
1021 The gdbarch_displaced_step_copy_insn and
1022 gdbarch_displaced_step_fixup functions must be written so that
1023 copying an instruction with gdbarch_displaced_step_copy_insn,
1024 single-stepping across the copied instruction, and then applying
1025 gdbarch_displaced_insn_fixup should have the same effects on the
1026 thread's memory and registers as stepping the instruction in place
1027 would have. Exactly which responsibilities fall to the copy and
1028 which fall to the fixup is up to the author of those functions.
1030 See the comments in gdbarch.sh for details.
1032 Note that displaced stepping and software single-step cannot
1033 currently be used in combination, although with some care I think
1034 they could be made to. Software single-step works by placing
1035 breakpoints on all possible subsequent instructions; if the
1036 displaced instruction is a PC-relative jump, those breakpoints
1037 could fall in very strange places --- on pages that aren't
1038 executable, or at addresses that are not proper instruction
1039 boundaries. (We do generally let other threads run while we wait
1040 to hit the software single-step breakpoint, and they might
1041 encounter such a corrupted instruction.) One way to work around
1042 this would be to have gdbarch_displaced_step_copy_insn fully
1043 simulate the effect of PC-relative instructions (and return NULL)
1044 on architectures that use software single-stepping.
1046 In non-stop mode, we can have independent and simultaneous step
1047 requests, so more than one thread may need to simultaneously step
1048 over a breakpoint. The current implementation assumes there is
1049 only one scratch space per process. In this case, we have to
1050 serialize access to the scratch space. If thread A wants to step
1051 over a breakpoint, but we are currently waiting for some other
1052 thread to complete a displaced step, we leave thread A stopped and
1053 place it in the displaced_step_request_queue. Whenever a displaced
1054 step finishes, we pick the next thread in the queue and start a new
1055 displaced step operation on it. See displaced_step_prepare and
1056 displaced_step_fixup for details. */
1058 struct displaced_step_request
1061 struct displaced_step_request *next;
1064 /* Per-inferior displaced stepping state. */
1065 struct displaced_step_inferior_state
1067 /* Pointer to next in linked list. */
1068 struct displaced_step_inferior_state *next;
1070 /* The process this displaced step state refers to. */
1073 /* A queue of pending displaced stepping requests. One entry per
1074 thread that needs to do a displaced step. */
1075 struct displaced_step_request *step_request_queue;
1077 /* If this is not null_ptid, this is the thread carrying out a
1078 displaced single-step in process PID. This thread's state will
1079 require fixing up once it has completed its step. */
1082 /* The architecture the thread had when we stepped it. */
1083 struct gdbarch *step_gdbarch;
1085 /* The closure provided gdbarch_displaced_step_copy_insn, to be used
1086 for post-step cleanup. */
1087 struct displaced_step_closure *step_closure;
1089 /* The address of the original instruction, and the copy we
1091 CORE_ADDR step_original, step_copy;
1093 /* Saved contents of copy area. */
1094 gdb_byte *step_saved_copy;
1097 /* The list of states of processes involved in displaced stepping
1099 static struct displaced_step_inferior_state *displaced_step_inferior_states;
1101 /* Get the displaced stepping state of process PID. */
1103 static struct displaced_step_inferior_state *
1104 get_displaced_stepping_state (int pid)
1106 struct displaced_step_inferior_state *state;
1108 for (state = displaced_step_inferior_states;
1110 state = state->next)
1111 if (state->pid == pid)
1117 /* Add a new displaced stepping state for process PID to the displaced
1118 stepping state list, or return a pointer to an already existing
1119 entry, if it already exists. Never returns NULL. */
1121 static struct displaced_step_inferior_state *
1122 add_displaced_stepping_state (int pid)
1124 struct displaced_step_inferior_state *state;
1126 for (state = displaced_step_inferior_states;
1128 state = state->next)
1129 if (state->pid == pid)
1132 state = xcalloc (1, sizeof (*state));
1134 state->next = displaced_step_inferior_states;
1135 displaced_step_inferior_states = state;
1140 /* If inferior is in displaced stepping, and ADDR equals to starting address
1141 of copy area, return corresponding displaced_step_closure. Otherwise,
1144 struct displaced_step_closure*
1145 get_displaced_step_closure_by_addr (CORE_ADDR addr)
1147 struct displaced_step_inferior_state *displaced
1148 = get_displaced_stepping_state (ptid_get_pid (inferior_ptid));
1150 /* If checking the mode of displaced instruction in copy area. */
1151 if (displaced && !ptid_equal (displaced->step_ptid, null_ptid)
1152 && (displaced->step_copy == addr))
1153 return displaced->step_closure;
1158 /* Remove the displaced stepping state of process PID. */
1161 remove_displaced_stepping_state (int pid)
1163 struct displaced_step_inferior_state *it, **prev_next_p;
1165 gdb_assert (pid != 0);
1167 it = displaced_step_inferior_states;
1168 prev_next_p = &displaced_step_inferior_states;
1173 *prev_next_p = it->next;
1178 prev_next_p = &it->next;
1184 infrun_inferior_exit (struct inferior *inf)
1186 remove_displaced_stepping_state (inf->pid);
1189 /* If ON, and the architecture supports it, GDB will use displaced
1190 stepping to step over breakpoints. If OFF, or if the architecture
1191 doesn't support it, GDB will instead use the traditional
1192 hold-and-step approach. If AUTO (which is the default), GDB will
1193 decide which technique to use to step over breakpoints depending on
1194 which of all-stop or non-stop mode is active --- displaced stepping
1195 in non-stop mode; hold-and-step in all-stop mode. */
1197 static enum auto_boolean can_use_displaced_stepping = AUTO_BOOLEAN_AUTO;
1200 show_can_use_displaced_stepping (struct ui_file *file, int from_tty,
1201 struct cmd_list_element *c,
1204 if (can_use_displaced_stepping == AUTO_BOOLEAN_AUTO)
1205 fprintf_filtered (file,
1206 _("Debugger's willingness to use displaced stepping "
1207 "to step over breakpoints is %s (currently %s).\n"),
1208 value, non_stop ? "on" : "off");
1210 fprintf_filtered (file,
1211 _("Debugger's willingness to use displaced stepping "
1212 "to step over breakpoints is %s.\n"), value);
1215 /* Return non-zero if displaced stepping can/should be used to step
1216 over breakpoints. */
1219 use_displaced_stepping (struct gdbarch *gdbarch)
1221 return (((can_use_displaced_stepping == AUTO_BOOLEAN_AUTO && non_stop)
1222 || can_use_displaced_stepping == AUTO_BOOLEAN_TRUE)
1223 && gdbarch_displaced_step_copy_insn_p (gdbarch)
1224 && !RECORD_IS_USED);
1227 /* Clean out any stray displaced stepping state. */
1229 displaced_step_clear (struct displaced_step_inferior_state *displaced)
1231 /* Indicate that there is no cleanup pending. */
1232 displaced->step_ptid = null_ptid;
1234 if (displaced->step_closure)
1236 gdbarch_displaced_step_free_closure (displaced->step_gdbarch,
1237 displaced->step_closure);
1238 displaced->step_closure = NULL;
1243 displaced_step_clear_cleanup (void *arg)
1245 struct displaced_step_inferior_state *state = arg;
1247 displaced_step_clear (state);
1250 /* Dump LEN bytes at BUF in hex to FILE, followed by a newline. */
1252 displaced_step_dump_bytes (struct ui_file *file,
1253 const gdb_byte *buf,
1258 for (i = 0; i < len; i++)
1259 fprintf_unfiltered (file, "%02x ", buf[i]);
1260 fputs_unfiltered ("\n", file);
1263 /* Prepare to single-step, using displaced stepping.
1265 Note that we cannot use displaced stepping when we have a signal to
1266 deliver. If we have a signal to deliver and an instruction to step
1267 over, then after the step, there will be no indication from the
1268 target whether the thread entered a signal handler or ignored the
1269 signal and stepped over the instruction successfully --- both cases
1270 result in a simple SIGTRAP. In the first case we mustn't do a
1271 fixup, and in the second case we must --- but we can't tell which.
1272 Comments in the code for 'random signals' in handle_inferior_event
1273 explain how we handle this case instead.
1275 Returns 1 if preparing was successful -- this thread is going to be
1276 stepped now; or 0 if displaced stepping this thread got queued. */
1278 displaced_step_prepare (ptid_t ptid)
1280 struct cleanup *old_cleanups, *ignore_cleanups;
1281 struct regcache *regcache = get_thread_regcache (ptid);
1282 struct gdbarch *gdbarch = get_regcache_arch (regcache);
1283 CORE_ADDR original, copy;
1285 struct displaced_step_closure *closure;
1286 struct displaced_step_inferior_state *displaced;
1289 /* We should never reach this function if the architecture does not
1290 support displaced stepping. */
1291 gdb_assert (gdbarch_displaced_step_copy_insn_p (gdbarch));
1293 /* We have to displaced step one thread at a time, as we only have
1294 access to a single scratch space per inferior. */
1296 displaced = add_displaced_stepping_state (ptid_get_pid (ptid));
1298 if (!ptid_equal (displaced->step_ptid, null_ptid))
1300 /* Already waiting for a displaced step to finish. Defer this
1301 request and place in queue. */
1302 struct displaced_step_request *req, *new_req;
1304 if (debug_displaced)
1305 fprintf_unfiltered (gdb_stdlog,
1306 "displaced: defering step of %s\n",
1307 target_pid_to_str (ptid));
1309 new_req = xmalloc (sizeof (*new_req));
1310 new_req->ptid = ptid;
1311 new_req->next = NULL;
1313 if (displaced->step_request_queue)
1315 for (req = displaced->step_request_queue;
1319 req->next = new_req;
1322 displaced->step_request_queue = new_req;
1328 if (debug_displaced)
1329 fprintf_unfiltered (gdb_stdlog,
1330 "displaced: stepping %s now\n",
1331 target_pid_to_str (ptid));
1334 displaced_step_clear (displaced);
1336 old_cleanups = save_inferior_ptid ();
1337 inferior_ptid = ptid;
1339 original = regcache_read_pc (regcache);
1341 copy = gdbarch_displaced_step_location (gdbarch);
1342 len = gdbarch_max_insn_length (gdbarch);
1344 /* Save the original contents of the copy area. */
1345 displaced->step_saved_copy = xmalloc (len);
1346 ignore_cleanups = make_cleanup (free_current_contents,
1347 &displaced->step_saved_copy);
1348 status = target_read_memory (copy, displaced->step_saved_copy, len);
1350 throw_error (MEMORY_ERROR,
1351 _("Error accessing memory address %s (%s) for "
1352 "displaced-stepping scratch space."),
1353 paddress (gdbarch, copy), safe_strerror (status));
1354 if (debug_displaced)
1356 fprintf_unfiltered (gdb_stdlog, "displaced: saved %s: ",
1357 paddress (gdbarch, copy));
1358 displaced_step_dump_bytes (gdb_stdlog,
1359 displaced->step_saved_copy,
1363 closure = gdbarch_displaced_step_copy_insn (gdbarch,
1364 original, copy, regcache);
1366 /* We don't support the fully-simulated case at present. */
1367 gdb_assert (closure);
1369 /* Save the information we need to fix things up if the step
1371 displaced->step_ptid = ptid;
1372 displaced->step_gdbarch = gdbarch;
1373 displaced->step_closure = closure;
1374 displaced->step_original = original;
1375 displaced->step_copy = copy;
1377 make_cleanup (displaced_step_clear_cleanup, displaced);
1379 /* Resume execution at the copy. */
1380 regcache_write_pc (regcache, copy);
1382 discard_cleanups (ignore_cleanups);
1384 do_cleanups (old_cleanups);
1386 if (debug_displaced)
1387 fprintf_unfiltered (gdb_stdlog, "displaced: displaced pc to %s\n",
1388 paddress (gdbarch, copy));
1394 write_memory_ptid (ptid_t ptid, CORE_ADDR memaddr,
1395 const gdb_byte *myaddr, int len)
1397 struct cleanup *ptid_cleanup = save_inferior_ptid ();
1399 inferior_ptid = ptid;
1400 write_memory (memaddr, myaddr, len);
1401 do_cleanups (ptid_cleanup);
1404 /* Restore the contents of the copy area for thread PTID. */
1407 displaced_step_restore (struct displaced_step_inferior_state *displaced,
1410 ULONGEST len = gdbarch_max_insn_length (displaced->step_gdbarch);
1412 write_memory_ptid (ptid, displaced->step_copy,
1413 displaced->step_saved_copy, len);
1414 if (debug_displaced)
1415 fprintf_unfiltered (gdb_stdlog, "displaced: restored %s %s\n",
1416 target_pid_to_str (ptid),
1417 paddress (displaced->step_gdbarch,
1418 displaced->step_copy));
1422 displaced_step_fixup (ptid_t event_ptid, enum gdb_signal signal)
1424 struct cleanup *old_cleanups;
1425 struct displaced_step_inferior_state *displaced
1426 = get_displaced_stepping_state (ptid_get_pid (event_ptid));
1428 /* Was any thread of this process doing a displaced step? */
1429 if (displaced == NULL)
1432 /* Was this event for the pid we displaced? */
1433 if (ptid_equal (displaced->step_ptid, null_ptid)
1434 || ! ptid_equal (displaced->step_ptid, event_ptid))
1437 old_cleanups = make_cleanup (displaced_step_clear_cleanup, displaced);
1439 displaced_step_restore (displaced, displaced->step_ptid);
1441 /* Did the instruction complete successfully? */
1442 if (signal == GDB_SIGNAL_TRAP)
1444 /* Fix up the resulting state. */
1445 gdbarch_displaced_step_fixup (displaced->step_gdbarch,
1446 displaced->step_closure,
1447 displaced->step_original,
1448 displaced->step_copy,
1449 get_thread_regcache (displaced->step_ptid));
1453 /* Since the instruction didn't complete, all we can do is
1455 struct regcache *regcache = get_thread_regcache (event_ptid);
1456 CORE_ADDR pc = regcache_read_pc (regcache);
1458 pc = displaced->step_original + (pc - displaced->step_copy);
1459 regcache_write_pc (regcache, pc);
1462 do_cleanups (old_cleanups);
1464 displaced->step_ptid = null_ptid;
1466 /* Are there any pending displaced stepping requests? If so, run
1467 one now. Leave the state object around, since we're likely to
1468 need it again soon. */
1469 while (displaced->step_request_queue)
1471 struct displaced_step_request *head;
1473 struct regcache *regcache;
1474 struct gdbarch *gdbarch;
1475 CORE_ADDR actual_pc;
1476 struct address_space *aspace;
1478 head = displaced->step_request_queue;
1480 displaced->step_request_queue = head->next;
1483 context_switch (ptid);
1485 regcache = get_thread_regcache (ptid);
1486 actual_pc = regcache_read_pc (regcache);
1487 aspace = get_regcache_aspace (regcache);
1489 if (breakpoint_here_p (aspace, actual_pc))
1491 if (debug_displaced)
1492 fprintf_unfiltered (gdb_stdlog,
1493 "displaced: stepping queued %s now\n",
1494 target_pid_to_str (ptid));
1496 displaced_step_prepare (ptid);
1498 gdbarch = get_regcache_arch (regcache);
1500 if (debug_displaced)
1502 CORE_ADDR actual_pc = regcache_read_pc (regcache);
1505 fprintf_unfiltered (gdb_stdlog, "displaced: run %s: ",
1506 paddress (gdbarch, actual_pc));
1507 read_memory (actual_pc, buf, sizeof (buf));
1508 displaced_step_dump_bytes (gdb_stdlog, buf, sizeof (buf));
1511 if (gdbarch_displaced_step_hw_singlestep (gdbarch,
1512 displaced->step_closure))
1513 target_resume (ptid, 1, GDB_SIGNAL_0);
1515 target_resume (ptid, 0, GDB_SIGNAL_0);
1517 /* Done, we're stepping a thread. */
1523 struct thread_info *tp = inferior_thread ();
1525 /* The breakpoint we were sitting under has since been
1527 tp->control.trap_expected = 0;
1529 /* Go back to what we were trying to do. */
1530 step = currently_stepping (tp);
1532 if (debug_displaced)
1533 fprintf_unfiltered (gdb_stdlog,
1534 "displaced: breakpoint is gone: %s, step(%d)\n",
1535 target_pid_to_str (tp->ptid), step);
1537 target_resume (ptid, step, GDB_SIGNAL_0);
1538 tp->suspend.stop_signal = GDB_SIGNAL_0;
1540 /* This request was discarded. See if there's any other
1541 thread waiting for its turn. */
1546 /* Update global variables holding ptids to hold NEW_PTID if they were
1547 holding OLD_PTID. */
1549 infrun_thread_ptid_changed (ptid_t old_ptid, ptid_t new_ptid)
1551 struct displaced_step_request *it;
1552 struct displaced_step_inferior_state *displaced;
1554 if (ptid_equal (inferior_ptid, old_ptid))
1555 inferior_ptid = new_ptid;
1557 if (ptid_equal (singlestep_ptid, old_ptid))
1558 singlestep_ptid = new_ptid;
1560 if (ptid_equal (deferred_step_ptid, old_ptid))
1561 deferred_step_ptid = new_ptid;
1563 for (displaced = displaced_step_inferior_states;
1565 displaced = displaced->next)
1567 if (ptid_equal (displaced->step_ptid, old_ptid))
1568 displaced->step_ptid = new_ptid;
1570 for (it = displaced->step_request_queue; it; it = it->next)
1571 if (ptid_equal (it->ptid, old_ptid))
1572 it->ptid = new_ptid;
1579 /* Things to clean up if we QUIT out of resume (). */
1581 resume_cleanups (void *ignore)
1586 static const char schedlock_off[] = "off";
1587 static const char schedlock_on[] = "on";
1588 static const char schedlock_step[] = "step";
1589 static const char *const scheduler_enums[] = {
1595 static const char *scheduler_mode = schedlock_off;
1597 show_scheduler_mode (struct ui_file *file, int from_tty,
1598 struct cmd_list_element *c, const char *value)
1600 fprintf_filtered (file,
1601 _("Mode for locking scheduler "
1602 "during execution is \"%s\".\n"),
1607 set_schedlock_func (char *args, int from_tty, struct cmd_list_element *c)
1609 if (!target_can_lock_scheduler)
1611 scheduler_mode = schedlock_off;
1612 error (_("Target '%s' cannot support this command."), target_shortname);
1616 /* True if execution commands resume all threads of all processes by
1617 default; otherwise, resume only threads of the current inferior
1619 int sched_multi = 0;
1621 /* Try to setup for software single stepping over the specified location.
1622 Return 1 if target_resume() should use hardware single step.
1624 GDBARCH the current gdbarch.
1625 PC the location to step over. */
1628 maybe_software_singlestep (struct gdbarch *gdbarch, CORE_ADDR pc)
1632 if (execution_direction == EXEC_FORWARD
1633 && gdbarch_software_single_step_p (gdbarch)
1634 && gdbarch_software_single_step (gdbarch, get_current_frame ()))
1637 /* Do not pull these breakpoints until after a `wait' in
1638 `wait_for_inferior'. */
1639 singlestep_breakpoints_inserted_p = 1;
1640 singlestep_ptid = inferior_ptid;
1646 /* Return a ptid representing the set of threads that we will proceed,
1647 in the perspective of the user/frontend. We may actually resume
1648 fewer threads at first, e.g., if a thread is stopped at a
1649 breakpoint that needs stepping-off, but that should not be visible
1650 to the user/frontend, and neither should the frontend/user be
1651 allowed to proceed any of the threads that happen to be stopped for
1652 internal run control handling, if a previous command wanted them
1656 user_visible_resume_ptid (int step)
1658 /* By default, resume all threads of all processes. */
1659 ptid_t resume_ptid = RESUME_ALL;
1661 /* Maybe resume only all threads of the current process. */
1662 if (!sched_multi && target_supports_multi_process ())
1664 resume_ptid = pid_to_ptid (ptid_get_pid (inferior_ptid));
1667 /* Maybe resume a single thread after all. */
1670 /* With non-stop mode on, threads are always handled
1672 resume_ptid = inferior_ptid;
1674 else if ((scheduler_mode == schedlock_on)
1675 || (scheduler_mode == schedlock_step
1676 && (step || singlestep_breakpoints_inserted_p)))
1678 /* User-settable 'scheduler' mode requires solo thread resume. */
1679 resume_ptid = inferior_ptid;
1685 /* Resume the inferior, but allow a QUIT. This is useful if the user
1686 wants to interrupt some lengthy single-stepping operation
1687 (for child processes, the SIGINT goes to the inferior, and so
1688 we get a SIGINT random_signal, but for remote debugging and perhaps
1689 other targets, that's not true).
1691 STEP nonzero if we should step (zero to continue instead).
1692 SIG is the signal to give the inferior (zero for none). */
1694 resume (int step, enum gdb_signal sig)
1696 int should_resume = 1;
1697 struct cleanup *old_cleanups = make_cleanup (resume_cleanups, 0);
1698 struct regcache *regcache = get_current_regcache ();
1699 struct gdbarch *gdbarch = get_regcache_arch (regcache);
1700 struct thread_info *tp = inferior_thread ();
1701 CORE_ADDR pc = regcache_read_pc (regcache);
1702 struct address_space *aspace = get_regcache_aspace (regcache);
1706 if (current_inferior ()->waiting_for_vfork_done)
1708 /* Don't try to single-step a vfork parent that is waiting for
1709 the child to get out of the shared memory region (by exec'ing
1710 or exiting). This is particularly important on software
1711 single-step archs, as the child process would trip on the
1712 software single step breakpoint inserted for the parent
1713 process. Since the parent will not actually execute any
1714 instruction until the child is out of the shared region (such
1715 are vfork's semantics), it is safe to simply continue it.
1716 Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for
1717 the parent, and tell it to `keep_going', which automatically
1718 re-sets it stepping. */
1720 fprintf_unfiltered (gdb_stdlog,
1721 "infrun: resume : clear step\n");
1726 fprintf_unfiltered (gdb_stdlog,
1727 "infrun: resume (step=%d, signal=%d), "
1728 "trap_expected=%d, current thread [%s] at %s\n",
1729 step, sig, tp->control.trap_expected,
1730 target_pid_to_str (inferior_ptid),
1731 paddress (gdbarch, pc));
1733 /* Normally, by the time we reach `resume', the breakpoints are either
1734 removed or inserted, as appropriate. The exception is if we're sitting
1735 at a permanent breakpoint; we need to step over it, but permanent
1736 breakpoints can't be removed. So we have to test for it here. */
1737 if (breakpoint_here_p (aspace, pc) == permanent_breakpoint_here)
1739 if (gdbarch_skip_permanent_breakpoint_p (gdbarch))
1740 gdbarch_skip_permanent_breakpoint (gdbarch, regcache);
1743 The program is stopped at a permanent breakpoint, but GDB does not know\n\
1744 how to step past a permanent breakpoint on this architecture. Try using\n\
1745 a command like `return' or `jump' to continue execution."));
1748 /* If enabled, step over breakpoints by executing a copy of the
1749 instruction at a different address.
1751 We can't use displaced stepping when we have a signal to deliver;
1752 the comments for displaced_step_prepare explain why. The
1753 comments in the handle_inferior event for dealing with 'random
1754 signals' explain what we do instead.
1756 We can't use displaced stepping when we are waiting for vfork_done
1757 event, displaced stepping breaks the vfork child similarly as single
1758 step software breakpoint. */
1759 if (use_displaced_stepping (gdbarch)
1760 && (tp->control.trap_expected
1761 || (step && gdbarch_software_single_step_p (gdbarch)))
1762 && sig == GDB_SIGNAL_0
1763 && !current_inferior ()->waiting_for_vfork_done)
1765 struct displaced_step_inferior_state *displaced;
1767 if (!displaced_step_prepare (inferior_ptid))
1769 /* Got placed in displaced stepping queue. Will be resumed
1770 later when all the currently queued displaced stepping
1771 requests finish. The thread is not executing at this point,
1772 and the call to set_executing will be made later. But we
1773 need to call set_running here, since from frontend point of view,
1774 the thread is running. */
1775 set_running (inferior_ptid, 1);
1776 discard_cleanups (old_cleanups);
1780 /* Update pc to reflect the new address from which we will execute
1781 instructions due to displaced stepping. */
1782 pc = regcache_read_pc (get_thread_regcache (inferior_ptid));
1784 displaced = get_displaced_stepping_state (ptid_get_pid (inferior_ptid));
1785 step = gdbarch_displaced_step_hw_singlestep (gdbarch,
1786 displaced->step_closure);
1789 /* Do we need to do it the hard way, w/temp breakpoints? */
1791 step = maybe_software_singlestep (gdbarch, pc);
1793 /* Currently, our software single-step implementation leads to different
1794 results than hardware single-stepping in one situation: when stepping
1795 into delivering a signal which has an associated signal handler,
1796 hardware single-step will stop at the first instruction of the handler,
1797 while software single-step will simply skip execution of the handler.
1799 For now, this difference in behavior is accepted since there is no
1800 easy way to actually implement single-stepping into a signal handler
1801 without kernel support.
1803 However, there is one scenario where this difference leads to follow-on
1804 problems: if we're stepping off a breakpoint by removing all breakpoints
1805 and then single-stepping. In this case, the software single-step
1806 behavior means that even if there is a *breakpoint* in the signal
1807 handler, GDB still would not stop.
1809 Fortunately, we can at least fix this particular issue. We detect
1810 here the case where we are about to deliver a signal while software
1811 single-stepping with breakpoints removed. In this situation, we
1812 revert the decisions to remove all breakpoints and insert single-
1813 step breakpoints, and instead we install a step-resume breakpoint
1814 at the current address, deliver the signal without stepping, and
1815 once we arrive back at the step-resume breakpoint, actually step
1816 over the breakpoint we originally wanted to step over. */
1817 if (singlestep_breakpoints_inserted_p
1818 && tp->control.trap_expected && sig != GDB_SIGNAL_0)
1820 /* If we have nested signals or a pending signal is delivered
1821 immediately after a handler returns, might might already have
1822 a step-resume breakpoint set on the earlier handler. We cannot
1823 set another step-resume breakpoint; just continue on until the
1824 original breakpoint is hit. */
1825 if (tp->control.step_resume_breakpoint == NULL)
1827 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
1828 tp->step_after_step_resume_breakpoint = 1;
1831 remove_single_step_breakpoints ();
1832 singlestep_breakpoints_inserted_p = 0;
1834 insert_breakpoints ();
1835 tp->control.trap_expected = 0;
1842 /* If STEP is set, it's a request to use hardware stepping
1843 facilities. But in that case, we should never
1844 use singlestep breakpoint. */
1845 gdb_assert (!(singlestep_breakpoints_inserted_p && step));
1847 /* Decide the set of threads to ask the target to resume. Start
1848 by assuming everything will be resumed, than narrow the set
1849 by applying increasingly restricting conditions. */
1850 resume_ptid = user_visible_resume_ptid (step);
1852 /* Maybe resume a single thread after all. */
1853 if (singlestep_breakpoints_inserted_p
1854 && stepping_past_singlestep_breakpoint)
1856 /* The situation here is as follows. In thread T1 we wanted to
1857 single-step. Lacking hardware single-stepping we've
1858 set breakpoint at the PC of the next instruction -- call it
1859 P. After resuming, we've hit that breakpoint in thread T2.
1860 Now we've removed original breakpoint, inserted breakpoint
1861 at P+1, and try to step to advance T2 past breakpoint.
1862 We need to step only T2, as if T1 is allowed to freely run,
1863 it can run past P, and if other threads are allowed to run,
1864 they can hit breakpoint at P+1, and nested hits of single-step
1865 breakpoints is not something we'd want -- that's complicated
1866 to support, and has no value. */
1867 resume_ptid = inferior_ptid;
1869 else if ((step || singlestep_breakpoints_inserted_p)
1870 && tp->control.trap_expected)
1872 /* We're allowing a thread to run past a breakpoint it has
1873 hit, by single-stepping the thread with the breakpoint
1874 removed. In which case, we need to single-step only this
1875 thread, and keep others stopped, as they can miss this
1876 breakpoint if allowed to run.
1878 The current code actually removes all breakpoints when
1879 doing this, not just the one being stepped over, so if we
1880 let other threads run, we can actually miss any
1881 breakpoint, not just the one at PC. */
1882 resume_ptid = inferior_ptid;
1885 if (gdbarch_cannot_step_breakpoint (gdbarch))
1887 /* Most targets can step a breakpoint instruction, thus
1888 executing it normally. But if this one cannot, just
1889 continue and we will hit it anyway. */
1890 if (step && breakpoint_inserted_here_p (aspace, pc))
1895 && use_displaced_stepping (gdbarch)
1896 && tp->control.trap_expected)
1898 struct regcache *resume_regcache = get_thread_regcache (resume_ptid);
1899 struct gdbarch *resume_gdbarch = get_regcache_arch (resume_regcache);
1900 CORE_ADDR actual_pc = regcache_read_pc (resume_regcache);
1903 fprintf_unfiltered (gdb_stdlog, "displaced: run %s: ",
1904 paddress (resume_gdbarch, actual_pc));
1905 read_memory (actual_pc, buf, sizeof (buf));
1906 displaced_step_dump_bytes (gdb_stdlog, buf, sizeof (buf));
1909 /* Install inferior's terminal modes. */
1910 target_terminal_inferior ();
1912 /* Avoid confusing the next resume, if the next stop/resume
1913 happens to apply to another thread. */
1914 tp->suspend.stop_signal = GDB_SIGNAL_0;
1916 /* Advise target which signals may be handled silently. If we have
1917 removed breakpoints because we are stepping over one (which can
1918 happen only if we are not using displaced stepping), we need to
1919 receive all signals to avoid accidentally skipping a breakpoint
1920 during execution of a signal handler. */
1921 if ((step || singlestep_breakpoints_inserted_p)
1922 && tp->control.trap_expected
1923 && !use_displaced_stepping (gdbarch))
1924 target_pass_signals (0, NULL);
1926 target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
1928 target_resume (resume_ptid, step, sig);
1931 discard_cleanups (old_cleanups);
1936 /* Clear out all variables saying what to do when inferior is continued.
1937 First do this, then set the ones you want, then call `proceed'. */
1940 clear_proceed_status_thread (struct thread_info *tp)
1943 fprintf_unfiltered (gdb_stdlog,
1944 "infrun: clear_proceed_status_thread (%s)\n",
1945 target_pid_to_str (tp->ptid));
1947 tp->control.trap_expected = 0;
1948 tp->control.step_range_start = 0;
1949 tp->control.step_range_end = 0;
1950 tp->control.step_frame_id = null_frame_id;
1951 tp->control.step_stack_frame_id = null_frame_id;
1952 tp->control.step_over_calls = STEP_OVER_UNDEBUGGABLE;
1953 tp->stop_requested = 0;
1955 tp->control.stop_step = 0;
1957 tp->control.proceed_to_finish = 0;
1959 /* Discard any remaining commands or status from previous stop. */
1960 bpstat_clear (&tp->control.stop_bpstat);
1964 clear_proceed_status_callback (struct thread_info *tp, void *data)
1966 if (is_exited (tp->ptid))
1969 clear_proceed_status_thread (tp);
1974 clear_proceed_status (void)
1978 /* In all-stop mode, delete the per-thread status of all
1979 threads, even if inferior_ptid is null_ptid, there may be
1980 threads on the list. E.g., we may be launching a new
1981 process, while selecting the executable. */
1982 iterate_over_threads (clear_proceed_status_callback, NULL);
1985 if (!ptid_equal (inferior_ptid, null_ptid))
1987 struct inferior *inferior;
1991 /* If in non-stop mode, only delete the per-thread status of
1992 the current thread. */
1993 clear_proceed_status_thread (inferior_thread ());
1996 inferior = current_inferior ();
1997 inferior->control.stop_soon = NO_STOP_QUIETLY;
2000 stop_after_trap = 0;
2002 observer_notify_about_to_proceed ();
2006 regcache_xfree (stop_registers);
2007 stop_registers = NULL;
2011 /* Check the current thread against the thread that reported the most recent
2012 event. If a step-over is required return TRUE and set the current thread
2013 to the old thread. Otherwise return FALSE.
2015 This should be suitable for any targets that support threads. */
2018 prepare_to_proceed (int step)
2021 struct target_waitstatus wait_status;
2022 int schedlock_enabled;
2024 /* With non-stop mode on, threads are always handled individually. */
2025 gdb_assert (! non_stop);
2027 /* Get the last target status returned by target_wait(). */
2028 get_last_target_status (&wait_ptid, &wait_status);
2030 /* Make sure we were stopped at a breakpoint. */
2031 if (wait_status.kind != TARGET_WAITKIND_STOPPED
2032 || (wait_status.value.sig != GDB_SIGNAL_TRAP
2033 && wait_status.value.sig != GDB_SIGNAL_ILL
2034 && wait_status.value.sig != GDB_SIGNAL_SEGV
2035 && wait_status.value.sig != GDB_SIGNAL_EMT))
2040 schedlock_enabled = (scheduler_mode == schedlock_on
2041 || (scheduler_mode == schedlock_step
2044 /* Don't switch over to WAIT_PTID if scheduler locking is on. */
2045 if (schedlock_enabled)
2048 /* Don't switch over if we're about to resume some other process
2049 other than WAIT_PTID's, and schedule-multiple is off. */
2051 && ptid_get_pid (wait_ptid) != ptid_get_pid (inferior_ptid))
2054 /* Switched over from WAIT_PID. */
2055 if (!ptid_equal (wait_ptid, minus_one_ptid)
2056 && !ptid_equal (inferior_ptid, wait_ptid))
2058 struct regcache *regcache = get_thread_regcache (wait_ptid);
2060 if (breakpoint_here_p (get_regcache_aspace (regcache),
2061 regcache_read_pc (regcache)))
2063 /* If stepping, remember current thread to switch back to. */
2065 deferred_step_ptid = inferior_ptid;
2067 /* Switch back to WAIT_PID thread. */
2068 switch_to_thread (wait_ptid);
2071 fprintf_unfiltered (gdb_stdlog,
2072 "infrun: prepare_to_proceed (step=%d), "
2073 "switched to [%s]\n",
2074 step, target_pid_to_str (inferior_ptid));
2076 /* We return 1 to indicate that there is a breakpoint here,
2077 so we need to step over it before continuing to avoid
2078 hitting it straight away. */
2086 /* Basic routine for continuing the program in various fashions.
2088 ADDR is the address to resume at, or -1 for resume where stopped.
2089 SIGGNAL is the signal to give it, or 0 for none,
2090 or -1 for act according to how it stopped.
2091 STEP is nonzero if should trap after one instruction.
2092 -1 means return after that and print nothing.
2093 You should probably set various step_... variables
2094 before calling here, if you are stepping.
2096 You should call clear_proceed_status before calling proceed. */
2099 proceed (CORE_ADDR addr, enum gdb_signal siggnal, int step)
2101 struct regcache *regcache;
2102 struct gdbarch *gdbarch;
2103 struct thread_info *tp;
2105 struct address_space *aspace;
2108 /* If we're stopped at a fork/vfork, follow the branch set by the
2109 "set follow-fork-mode" command; otherwise, we'll just proceed
2110 resuming the current thread. */
2111 if (!follow_fork ())
2113 /* The target for some reason decided not to resume. */
2115 if (target_can_async_p ())
2116 inferior_event_handler (INF_EXEC_COMPLETE, NULL);
2120 /* We'll update this if & when we switch to a new thread. */
2121 previous_inferior_ptid = inferior_ptid;
2123 regcache = get_current_regcache ();
2124 gdbarch = get_regcache_arch (regcache);
2125 aspace = get_regcache_aspace (regcache);
2126 pc = regcache_read_pc (regcache);
2129 step_start_function = find_pc_function (pc);
2131 stop_after_trap = 1;
2133 if (addr == (CORE_ADDR) -1)
2135 if (pc == stop_pc && breakpoint_here_p (aspace, pc)
2136 && execution_direction != EXEC_REVERSE)
2137 /* There is a breakpoint at the address we will resume at,
2138 step one instruction before inserting breakpoints so that
2139 we do not stop right away (and report a second hit at this
2142 Note, we don't do this in reverse, because we won't
2143 actually be executing the breakpoint insn anyway.
2144 We'll be (un-)executing the previous instruction. */
2147 else if (gdbarch_single_step_through_delay_p (gdbarch)
2148 && gdbarch_single_step_through_delay (gdbarch,
2149 get_current_frame ()))
2150 /* We stepped onto an instruction that needs to be stepped
2151 again before re-inserting the breakpoint, do so. */
2156 regcache_write_pc (regcache, addr);
2160 fprintf_unfiltered (gdb_stdlog,
2161 "infrun: proceed (addr=%s, signal=%d, step=%d)\n",
2162 paddress (gdbarch, addr), siggnal, step);
2165 /* In non-stop, each thread is handled individually. The context
2166 must already be set to the right thread here. */
2170 /* In a multi-threaded task we may select another thread and
2171 then continue or step.
2173 But if the old thread was stopped at a breakpoint, it will
2174 immediately cause another breakpoint stop without any
2175 execution (i.e. it will report a breakpoint hit incorrectly).
2176 So we must step over it first.
2178 prepare_to_proceed checks the current thread against the
2179 thread that reported the most recent event. If a step-over
2180 is required it returns TRUE and sets the current thread to
2182 if (prepare_to_proceed (step))
2186 /* prepare_to_proceed may change the current thread. */
2187 tp = inferior_thread ();
2191 tp->control.trap_expected = 1;
2192 /* If displaced stepping is enabled, we can step over the
2193 breakpoint without hitting it, so leave all breakpoints
2194 inserted. Otherwise we need to disable all breakpoints, step
2195 one instruction, and then re-add them when that step is
2197 if (!use_displaced_stepping (gdbarch))
2198 remove_breakpoints ();
2201 /* We can insert breakpoints if we're not trying to step over one,
2202 or if we are stepping over one but we're using displaced stepping
2204 if (! tp->control.trap_expected || use_displaced_stepping (gdbarch))
2205 insert_breakpoints ();
2209 /* Pass the last stop signal to the thread we're resuming,
2210 irrespective of whether the current thread is the thread that
2211 got the last event or not. This was historically GDB's
2212 behaviour before keeping a stop_signal per thread. */
2214 struct thread_info *last_thread;
2216 struct target_waitstatus last_status;
2218 get_last_target_status (&last_ptid, &last_status);
2219 if (!ptid_equal (inferior_ptid, last_ptid)
2220 && !ptid_equal (last_ptid, null_ptid)
2221 && !ptid_equal (last_ptid, minus_one_ptid))
2223 last_thread = find_thread_ptid (last_ptid);
2226 tp->suspend.stop_signal = last_thread->suspend.stop_signal;
2227 last_thread->suspend.stop_signal = GDB_SIGNAL_0;
2232 if (siggnal != GDB_SIGNAL_DEFAULT)
2233 tp->suspend.stop_signal = siggnal;
2234 /* If this signal should not be seen by program,
2235 give it zero. Used for debugging signals. */
2236 else if (!signal_program[tp->suspend.stop_signal])
2237 tp->suspend.stop_signal = GDB_SIGNAL_0;
2239 annotate_starting ();
2241 /* Make sure that output from GDB appears before output from the
2243 gdb_flush (gdb_stdout);
2245 /* Refresh prev_pc value just prior to resuming. This used to be
2246 done in stop_stepping, however, setting prev_pc there did not handle
2247 scenarios such as inferior function calls or returning from
2248 a function via the return command. In those cases, the prev_pc
2249 value was not set properly for subsequent commands. The prev_pc value
2250 is used to initialize the starting line number in the ecs. With an
2251 invalid value, the gdb next command ends up stopping at the position
2252 represented by the next line table entry past our start position.
2253 On platforms that generate one line table entry per line, this
2254 is not a problem. However, on the ia64, the compiler generates
2255 extraneous line table entries that do not increase the line number.
2256 When we issue the gdb next command on the ia64 after an inferior call
2257 or a return command, we often end up a few instructions forward, still
2258 within the original line we started.
2260 An attempt was made to refresh the prev_pc at the same time the
2261 execution_control_state is initialized (for instance, just before
2262 waiting for an inferior event). But this approach did not work
2263 because of platforms that use ptrace, where the pc register cannot
2264 be read unless the inferior is stopped. At that point, we are not
2265 guaranteed the inferior is stopped and so the regcache_read_pc() call
2266 can fail. Setting the prev_pc value here ensures the value is updated
2267 correctly when the inferior is stopped. */
2268 tp->prev_pc = regcache_read_pc (get_current_regcache ());
2270 /* Fill in with reasonable starting values. */
2271 init_thread_stepping_state (tp);
2273 /* Reset to normal state. */
2274 init_infwait_state ();
2276 /* Resume inferior. */
2277 resume (oneproc || step || bpstat_should_step (), tp->suspend.stop_signal);
2279 /* Wait for it to stop (if not standalone)
2280 and in any case decode why it stopped, and act accordingly. */
2281 /* Do this only if we are not using the event loop, or if the target
2282 does not support asynchronous execution. */
2283 if (!target_can_async_p ())
2285 wait_for_inferior ();
2291 /* Start remote-debugging of a machine over a serial link. */
2294 start_remote (int from_tty)
2296 struct inferior *inferior;
2298 inferior = current_inferior ();
2299 inferior->control.stop_soon = STOP_QUIETLY_REMOTE;
2301 /* Always go on waiting for the target, regardless of the mode. */
2302 /* FIXME: cagney/1999-09-23: At present it isn't possible to
2303 indicate to wait_for_inferior that a target should timeout if
2304 nothing is returned (instead of just blocking). Because of this,
2305 targets expecting an immediate response need to, internally, set
2306 things up so that the target_wait() is forced to eventually
2308 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
2309 differentiate to its caller what the state of the target is after
2310 the initial open has been performed. Here we're assuming that
2311 the target has stopped. It should be possible to eventually have
2312 target_open() return to the caller an indication that the target
2313 is currently running and GDB state should be set to the same as
2314 for an async run. */
2315 wait_for_inferior ();
2317 /* Now that the inferior has stopped, do any bookkeeping like
2318 loading shared libraries. We want to do this before normal_stop,
2319 so that the displayed frame is up to date. */
2320 post_create_inferior (¤t_target, from_tty);
2325 /* Initialize static vars when a new inferior begins. */
2328 init_wait_for_inferior (void)
2330 /* These are meaningless until the first time through wait_for_inferior. */
2332 breakpoint_init_inferior (inf_starting);
2334 clear_proceed_status ();
2336 stepping_past_singlestep_breakpoint = 0;
2337 deferred_step_ptid = null_ptid;
2339 target_last_wait_ptid = minus_one_ptid;
2341 previous_inferior_ptid = inferior_ptid;
2342 init_infwait_state ();
2344 /* Discard any skipped inlined frames. */
2345 clear_inline_frame_state (minus_one_ptid);
2349 /* This enum encodes possible reasons for doing a target_wait, so that
2350 wfi can call target_wait in one place. (Ultimately the call will be
2351 moved out of the infinite loop entirely.) */
2355 infwait_normal_state,
2356 infwait_thread_hop_state,
2357 infwait_step_watch_state,
2358 infwait_nonstep_watch_state
2361 /* The PTID we'll do a target_wait on.*/
2364 /* Current inferior wait state. */
2365 enum infwait_states infwait_state;
2367 /* Data to be passed around while handling an event. This data is
2368 discarded between events. */
2369 struct execution_control_state
2372 /* The thread that got the event, if this was a thread event; NULL
2374 struct thread_info *event_thread;
2376 struct target_waitstatus ws;
2378 int stop_func_filled_in;
2379 CORE_ADDR stop_func_start;
2380 CORE_ADDR stop_func_end;
2381 const char *stop_func_name;
2385 static void handle_inferior_event (struct execution_control_state *ecs);
2387 static void handle_step_into_function (struct gdbarch *gdbarch,
2388 struct execution_control_state *ecs);
2389 static void handle_step_into_function_backward (struct gdbarch *gdbarch,
2390 struct execution_control_state *ecs);
2391 static void check_exception_resume (struct execution_control_state *,
2392 struct frame_info *);
2394 static void stop_stepping (struct execution_control_state *ecs);
2395 static void prepare_to_wait (struct execution_control_state *ecs);
2396 static void keep_going (struct execution_control_state *ecs);
2398 /* Callback for iterate over threads. If the thread is stopped, but
2399 the user/frontend doesn't know about that yet, go through
2400 normal_stop, as if the thread had just stopped now. ARG points at
2401 a ptid. If PTID is MINUS_ONE_PTID, applies to all threads. If
2402 ptid_is_pid(PTID) is true, applies to all threads of the process
2403 pointed at by PTID. Otherwise, apply only to the thread pointed by
2407 infrun_thread_stop_requested_callback (struct thread_info *info, void *arg)
2409 ptid_t ptid = * (ptid_t *) arg;
2411 if ((ptid_equal (info->ptid, ptid)
2412 || ptid_equal (minus_one_ptid, ptid)
2413 || (ptid_is_pid (ptid)
2414 && ptid_get_pid (ptid) == ptid_get_pid (info->ptid)))
2415 && is_running (info->ptid)
2416 && !is_executing (info->ptid))
2418 struct cleanup *old_chain;
2419 struct execution_control_state ecss;
2420 struct execution_control_state *ecs = &ecss;
2422 memset (ecs, 0, sizeof (*ecs));
2424 old_chain = make_cleanup_restore_current_thread ();
2426 /* Go through handle_inferior_event/normal_stop, so we always
2427 have consistent output as if the stop event had been
2429 ecs->ptid = info->ptid;
2430 ecs->event_thread = find_thread_ptid (info->ptid);
2431 ecs->ws.kind = TARGET_WAITKIND_STOPPED;
2432 ecs->ws.value.sig = GDB_SIGNAL_0;
2434 handle_inferior_event (ecs);
2436 if (!ecs->wait_some_more)
2438 struct thread_info *tp;
2442 /* Finish off the continuations. */
2443 tp = inferior_thread ();
2444 do_all_intermediate_continuations_thread (tp, 1);
2445 do_all_continuations_thread (tp, 1);
2448 do_cleanups (old_chain);
2454 /* This function is attached as a "thread_stop_requested" observer.
2455 Cleanup local state that assumed the PTID was to be resumed, and
2456 report the stop to the frontend. */
2459 infrun_thread_stop_requested (ptid_t ptid)
2461 struct displaced_step_inferior_state *displaced;
2463 /* PTID was requested to stop. Remove it from the displaced
2464 stepping queue, so we don't try to resume it automatically. */
2466 for (displaced = displaced_step_inferior_states;
2468 displaced = displaced->next)
2470 struct displaced_step_request *it, **prev_next_p;
2472 it = displaced->step_request_queue;
2473 prev_next_p = &displaced->step_request_queue;
2476 if (ptid_match (it->ptid, ptid))
2478 *prev_next_p = it->next;
2484 prev_next_p = &it->next;
2491 iterate_over_threads (infrun_thread_stop_requested_callback, &ptid);
2495 infrun_thread_thread_exit (struct thread_info *tp, int silent)
2497 if (ptid_equal (target_last_wait_ptid, tp->ptid))
2498 nullify_last_target_wait_ptid ();
2501 /* Callback for iterate_over_threads. */
2504 delete_step_resume_breakpoint_callback (struct thread_info *info, void *data)
2506 if (is_exited (info->ptid))
2509 delete_step_resume_breakpoint (info);
2510 delete_exception_resume_breakpoint (info);
2514 /* In all-stop, delete the step resume breakpoint of any thread that
2515 had one. In non-stop, delete the step resume breakpoint of the
2516 thread that just stopped. */
2519 delete_step_thread_step_resume_breakpoint (void)
2521 if (!target_has_execution
2522 || ptid_equal (inferior_ptid, null_ptid))
2523 /* If the inferior has exited, we have already deleted the step
2524 resume breakpoints out of GDB's lists. */
2529 /* If in non-stop mode, only delete the step-resume or
2530 longjmp-resume breakpoint of the thread that just stopped
2532 struct thread_info *tp = inferior_thread ();
2534 delete_step_resume_breakpoint (tp);
2535 delete_exception_resume_breakpoint (tp);
2538 /* In all-stop mode, delete all step-resume and longjmp-resume
2539 breakpoints of any thread that had them. */
2540 iterate_over_threads (delete_step_resume_breakpoint_callback, NULL);
2543 /* A cleanup wrapper. */
2546 delete_step_thread_step_resume_breakpoint_cleanup (void *arg)
2548 delete_step_thread_step_resume_breakpoint ();
2551 /* Pretty print the results of target_wait, for debugging purposes. */
2554 print_target_wait_results (ptid_t waiton_ptid, ptid_t result_ptid,
2555 const struct target_waitstatus *ws)
2557 char *status_string = target_waitstatus_to_string (ws);
2558 struct ui_file *tmp_stream = mem_fileopen ();
2561 /* The text is split over several lines because it was getting too long.
2562 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
2563 output as a unit; we want only one timestamp printed if debug_timestamp
2566 fprintf_unfiltered (tmp_stream,
2567 "infrun: target_wait (%d", PIDGET (waiton_ptid));
2568 if (PIDGET (waiton_ptid) != -1)
2569 fprintf_unfiltered (tmp_stream,
2570 " [%s]", target_pid_to_str (waiton_ptid));
2571 fprintf_unfiltered (tmp_stream, ", status) =\n");
2572 fprintf_unfiltered (tmp_stream,
2573 "infrun: %d [%s],\n",
2574 PIDGET (result_ptid), target_pid_to_str (result_ptid));
2575 fprintf_unfiltered (tmp_stream,
2579 text = ui_file_xstrdup (tmp_stream, NULL);
2581 /* This uses %s in part to handle %'s in the text, but also to avoid
2582 a gcc error: the format attribute requires a string literal. */
2583 fprintf_unfiltered (gdb_stdlog, "%s", text);
2585 xfree (status_string);
2587 ui_file_delete (tmp_stream);
2590 /* Prepare and stabilize the inferior for detaching it. E.g.,
2591 detaching while a thread is displaced stepping is a recipe for
2592 crashing it, as nothing would readjust the PC out of the scratch
2596 prepare_for_detach (void)
2598 struct inferior *inf = current_inferior ();
2599 ptid_t pid_ptid = pid_to_ptid (inf->pid);
2600 struct cleanup *old_chain_1;
2601 struct displaced_step_inferior_state *displaced;
2603 displaced = get_displaced_stepping_state (inf->pid);
2605 /* Is any thread of this process displaced stepping? If not,
2606 there's nothing else to do. */
2607 if (displaced == NULL || ptid_equal (displaced->step_ptid, null_ptid))
2611 fprintf_unfiltered (gdb_stdlog,
2612 "displaced-stepping in-process while detaching");
2614 old_chain_1 = make_cleanup_restore_integer (&inf->detaching);
2617 while (!ptid_equal (displaced->step_ptid, null_ptid))
2619 struct cleanup *old_chain_2;
2620 struct execution_control_state ecss;
2621 struct execution_control_state *ecs;
2624 memset (ecs, 0, sizeof (*ecs));
2626 overlay_cache_invalid = 1;
2628 if (deprecated_target_wait_hook)
2629 ecs->ptid = deprecated_target_wait_hook (pid_ptid, &ecs->ws, 0);
2631 ecs->ptid = target_wait (pid_ptid, &ecs->ws, 0);
2634 print_target_wait_results (pid_ptid, ecs->ptid, &ecs->ws);
2636 /* If an error happens while handling the event, propagate GDB's
2637 knowledge of the executing state to the frontend/user running
2639 old_chain_2 = make_cleanup (finish_thread_state_cleanup,
2642 /* Now figure out what to do with the result of the result. */
2643 handle_inferior_event (ecs);
2645 /* No error, don't finish the state yet. */
2646 discard_cleanups (old_chain_2);
2648 /* Breakpoints and watchpoints are not installed on the target
2649 at this point, and signals are passed directly to the
2650 inferior, so this must mean the process is gone. */
2651 if (!ecs->wait_some_more)
2653 discard_cleanups (old_chain_1);
2654 error (_("Program exited while detaching"));
2658 discard_cleanups (old_chain_1);
2661 /* Wait for control to return from inferior to debugger.
2663 If inferior gets a signal, we may decide to start it up again
2664 instead of returning. That is why there is a loop in this function.
2665 When this function actually returns it means the inferior
2666 should be left stopped and GDB should read more commands. */
2669 wait_for_inferior (void)
2671 struct cleanup *old_cleanups;
2675 (gdb_stdlog, "infrun: wait_for_inferior ()\n");
2678 make_cleanup (delete_step_thread_step_resume_breakpoint_cleanup, NULL);
2682 struct execution_control_state ecss;
2683 struct execution_control_state *ecs = &ecss;
2684 struct cleanup *old_chain;
2686 memset (ecs, 0, sizeof (*ecs));
2688 overlay_cache_invalid = 1;
2690 if (deprecated_target_wait_hook)
2691 ecs->ptid = deprecated_target_wait_hook (waiton_ptid, &ecs->ws, 0);
2693 ecs->ptid = target_wait (waiton_ptid, &ecs->ws, 0);
2696 print_target_wait_results (waiton_ptid, ecs->ptid, &ecs->ws);
2698 /* If an error happens while handling the event, propagate GDB's
2699 knowledge of the executing state to the frontend/user running
2701 old_chain = make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
2703 /* Now figure out what to do with the result of the result. */
2704 handle_inferior_event (ecs);
2706 /* No error, don't finish the state yet. */
2707 discard_cleanups (old_chain);
2709 if (!ecs->wait_some_more)
2713 do_cleanups (old_cleanups);
2716 /* Asynchronous version of wait_for_inferior. It is called by the
2717 event loop whenever a change of state is detected on the file
2718 descriptor corresponding to the target. It can be called more than
2719 once to complete a single execution command. In such cases we need
2720 to keep the state in a global variable ECSS. If it is the last time
2721 that this function is called for a single execution command, then
2722 report to the user that the inferior has stopped, and do the
2723 necessary cleanups. */
2726 fetch_inferior_event (void *client_data)
2728 struct execution_control_state ecss;
2729 struct execution_control_state *ecs = &ecss;
2730 struct cleanup *old_chain = make_cleanup (null_cleanup, NULL);
2731 struct cleanup *ts_old_chain;
2732 int was_sync = sync_execution;
2735 memset (ecs, 0, sizeof (*ecs));
2737 /* We're handling a live event, so make sure we're doing live
2738 debugging. If we're looking at traceframes while the target is
2739 running, we're going to need to get back to that mode after
2740 handling the event. */
2743 make_cleanup_restore_current_traceframe ();
2744 set_current_traceframe (-1);
2748 /* In non-stop mode, the user/frontend should not notice a thread
2749 switch due to internal events. Make sure we reverse to the
2750 user selected thread and frame after handling the event and
2751 running any breakpoint commands. */
2752 make_cleanup_restore_current_thread ();
2754 overlay_cache_invalid = 1;
2756 make_cleanup_restore_integer (&execution_direction);
2757 execution_direction = target_execution_direction ();
2759 if (deprecated_target_wait_hook)
2761 deprecated_target_wait_hook (waiton_ptid, &ecs->ws, TARGET_WNOHANG);
2763 ecs->ptid = target_wait (waiton_ptid, &ecs->ws, TARGET_WNOHANG);
2766 print_target_wait_results (waiton_ptid, ecs->ptid, &ecs->ws);
2768 /* If an error happens while handling the event, propagate GDB's
2769 knowledge of the executing state to the frontend/user running
2772 ts_old_chain = make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
2774 ts_old_chain = make_cleanup (finish_thread_state_cleanup, &ecs->ptid);
2776 /* Get executed before make_cleanup_restore_current_thread above to apply
2777 still for the thread which has thrown the exception. */
2778 make_bpstat_clear_actions_cleanup ();
2780 /* Now figure out what to do with the result of the result. */
2781 handle_inferior_event (ecs);
2783 if (!ecs->wait_some_more)
2785 struct inferior *inf = find_inferior_pid (ptid_get_pid (ecs->ptid));
2787 delete_step_thread_step_resume_breakpoint ();
2789 /* We may not find an inferior if this was a process exit. */
2790 if (inf == NULL || inf->control.stop_soon == NO_STOP_QUIETLY)
2793 if (target_has_execution
2794 && ecs->ws.kind != TARGET_WAITKIND_NO_RESUMED
2795 && ecs->ws.kind != TARGET_WAITKIND_EXITED
2796 && ecs->ws.kind != TARGET_WAITKIND_SIGNALLED
2797 && ecs->event_thread->step_multi
2798 && ecs->event_thread->control.stop_step)
2799 inferior_event_handler (INF_EXEC_CONTINUE, NULL);
2802 inferior_event_handler (INF_EXEC_COMPLETE, NULL);
2807 /* No error, don't finish the thread states yet. */
2808 discard_cleanups (ts_old_chain);
2810 /* Revert thread and frame. */
2811 do_cleanups (old_chain);
2813 /* If the inferior was in sync execution mode, and now isn't,
2814 restore the prompt (a synchronous execution command has finished,
2815 and we're ready for input). */
2816 if (interpreter_async && was_sync && !sync_execution)
2817 display_gdb_prompt (0);
2821 && exec_done_display_p
2822 && (ptid_equal (inferior_ptid, null_ptid)
2823 || !is_running (inferior_ptid)))
2824 printf_unfiltered (_("completed.\n"));
2827 /* Record the frame and location we're currently stepping through. */
2829 set_step_info (struct frame_info *frame, struct symtab_and_line sal)
2831 struct thread_info *tp = inferior_thread ();
2833 tp->control.step_frame_id = get_frame_id (frame);
2834 tp->control.step_stack_frame_id = get_stack_frame_id (frame);
2836 tp->current_symtab = sal.symtab;
2837 tp->current_line = sal.line;
2840 /* Clear context switchable stepping state. */
2843 init_thread_stepping_state (struct thread_info *tss)
2845 tss->stepping_over_breakpoint = 0;
2846 tss->step_after_step_resume_breakpoint = 0;
2849 /* Return the cached copy of the last pid/waitstatus returned by
2850 target_wait()/deprecated_target_wait_hook(). The data is actually
2851 cached by handle_inferior_event(), which gets called immediately
2852 after target_wait()/deprecated_target_wait_hook(). */
2855 get_last_target_status (ptid_t *ptidp, struct target_waitstatus *status)
2857 *ptidp = target_last_wait_ptid;
2858 *status = target_last_waitstatus;
2862 nullify_last_target_wait_ptid (void)
2864 target_last_wait_ptid = minus_one_ptid;
2867 /* Switch thread contexts. */
2870 context_switch (ptid_t ptid)
2872 if (debug_infrun && !ptid_equal (ptid, inferior_ptid))
2874 fprintf_unfiltered (gdb_stdlog, "infrun: Switching context from %s ",
2875 target_pid_to_str (inferior_ptid));
2876 fprintf_unfiltered (gdb_stdlog, "to %s\n",
2877 target_pid_to_str (ptid));
2880 switch_to_thread (ptid);
2884 adjust_pc_after_break (struct execution_control_state *ecs)
2886 struct regcache *regcache;
2887 struct gdbarch *gdbarch;
2888 struct address_space *aspace;
2889 CORE_ADDR breakpoint_pc;
2891 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
2892 we aren't, just return.
2894 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
2895 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
2896 implemented by software breakpoints should be handled through the normal
2899 NOTE drow/2004-01-31: On some targets, breakpoints may generate
2900 different signals (SIGILL or SIGEMT for instance), but it is less
2901 clear where the PC is pointing afterwards. It may not match
2902 gdbarch_decr_pc_after_break. I don't know any specific target that
2903 generates these signals at breakpoints (the code has been in GDB since at
2904 least 1992) so I can not guess how to handle them here.
2906 In earlier versions of GDB, a target with
2907 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
2908 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
2909 target with both of these set in GDB history, and it seems unlikely to be
2910 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
2912 if (ecs->ws.kind != TARGET_WAITKIND_STOPPED)
2915 if (ecs->ws.value.sig != GDB_SIGNAL_TRAP)
2918 /* In reverse execution, when a breakpoint is hit, the instruction
2919 under it has already been de-executed. The reported PC always
2920 points at the breakpoint address, so adjusting it further would
2921 be wrong. E.g., consider this case on a decr_pc_after_break == 1
2924 B1 0x08000000 : INSN1
2925 B2 0x08000001 : INSN2
2927 PC -> 0x08000003 : INSN4
2929 Say you're stopped at 0x08000003 as above. Reverse continuing
2930 from that point should hit B2 as below. Reading the PC when the
2931 SIGTRAP is reported should read 0x08000001 and INSN2 should have
2932 been de-executed already.
2934 B1 0x08000000 : INSN1
2935 B2 PC -> 0x08000001 : INSN2
2939 We can't apply the same logic as for forward execution, because
2940 we would wrongly adjust the PC to 0x08000000, since there's a
2941 breakpoint at PC - 1. We'd then report a hit on B1, although
2942 INSN1 hadn't been de-executed yet. Doing nothing is the correct
2944 if (execution_direction == EXEC_REVERSE)
2947 /* If this target does not decrement the PC after breakpoints, then
2948 we have nothing to do. */
2949 regcache = get_thread_regcache (ecs->ptid);
2950 gdbarch = get_regcache_arch (regcache);
2951 if (gdbarch_decr_pc_after_break (gdbarch) == 0)
2954 aspace = get_regcache_aspace (regcache);
2956 /* Find the location where (if we've hit a breakpoint) the
2957 breakpoint would be. */
2958 breakpoint_pc = regcache_read_pc (regcache)
2959 - gdbarch_decr_pc_after_break (gdbarch);
2961 /* Check whether there actually is a software breakpoint inserted at
2964 If in non-stop mode, a race condition is possible where we've
2965 removed a breakpoint, but stop events for that breakpoint were
2966 already queued and arrive later. To suppress those spurious
2967 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
2968 and retire them after a number of stop events are reported. */
2969 if (software_breakpoint_inserted_here_p (aspace, breakpoint_pc)
2970 || (non_stop && moribund_breakpoint_here_p (aspace, breakpoint_pc)))
2972 struct cleanup *old_cleanups = NULL;
2975 old_cleanups = record_gdb_operation_disable_set ();
2977 /* When using hardware single-step, a SIGTRAP is reported for both
2978 a completed single-step and a software breakpoint. Need to
2979 differentiate between the two, as the latter needs adjusting
2980 but the former does not.
2982 The SIGTRAP can be due to a completed hardware single-step only if
2983 - we didn't insert software single-step breakpoints
2984 - the thread to be examined is still the current thread
2985 - this thread is currently being stepped
2987 If any of these events did not occur, we must have stopped due
2988 to hitting a software breakpoint, and have to back up to the
2991 As a special case, we could have hardware single-stepped a
2992 software breakpoint. In this case (prev_pc == breakpoint_pc),
2993 we also need to back up to the breakpoint address. */
2995 if (singlestep_breakpoints_inserted_p
2996 || !ptid_equal (ecs->ptid, inferior_ptid)
2997 || !currently_stepping (ecs->event_thread)
2998 || ecs->event_thread->prev_pc == breakpoint_pc)
2999 regcache_write_pc (regcache, breakpoint_pc);
3002 do_cleanups (old_cleanups);
3007 init_infwait_state (void)
3009 waiton_ptid = pid_to_ptid (-1);
3010 infwait_state = infwait_normal_state;
3014 error_is_running (void)
3016 error (_("Cannot execute this command while "
3017 "the selected thread is running."));
3021 ensure_not_running (void)
3023 if (is_running (inferior_ptid))
3024 error_is_running ();
3028 stepped_in_from (struct frame_info *frame, struct frame_id step_frame_id)
3030 for (frame = get_prev_frame (frame);
3032 frame = get_prev_frame (frame))
3034 if (frame_id_eq (get_frame_id (frame), step_frame_id))
3036 if (get_frame_type (frame) != INLINE_FRAME)
3043 /* Auxiliary function that handles syscall entry/return events.
3044 It returns 1 if the inferior should keep going (and GDB
3045 should ignore the event), or 0 if the event deserves to be
3049 handle_syscall_event (struct execution_control_state *ecs)
3051 struct regcache *regcache;
3052 struct gdbarch *gdbarch;
3055 if (!ptid_equal (ecs->ptid, inferior_ptid))
3056 context_switch (ecs->ptid);
3058 regcache = get_thread_regcache (ecs->ptid);
3059 gdbarch = get_regcache_arch (regcache);
3060 syscall_number = ecs->ws.value.syscall_number;
3061 stop_pc = regcache_read_pc (regcache);
3063 if (catch_syscall_enabled () > 0
3064 && catching_syscall_number (syscall_number) > 0)
3067 fprintf_unfiltered (gdb_stdlog, "infrun: syscall number = '%d'\n",
3070 ecs->event_thread->control.stop_bpstat
3071 = bpstat_stop_status (get_regcache_aspace (regcache),
3072 stop_pc, ecs->ptid, &ecs->ws);
3074 = !bpstat_explains_signal (ecs->event_thread->control.stop_bpstat);
3076 if (!ecs->random_signal)
3078 /* Catchpoint hit. */
3079 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_TRAP;
3084 /* If no catchpoint triggered for this, then keep going. */
3085 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
3090 /* Clear the supplied execution_control_state's stop_func_* fields. */
3093 clear_stop_func (struct execution_control_state *ecs)
3095 ecs->stop_func_filled_in = 0;
3096 ecs->stop_func_start = 0;
3097 ecs->stop_func_end = 0;
3098 ecs->stop_func_name = NULL;
3101 /* Lazily fill in the execution_control_state's stop_func_* fields. */
3104 fill_in_stop_func (struct gdbarch *gdbarch,
3105 struct execution_control_state *ecs)
3107 if (!ecs->stop_func_filled_in)
3109 /* Don't care about return value; stop_func_start and stop_func_name
3110 will both be 0 if it doesn't work. */
3111 find_pc_partial_function (stop_pc, &ecs->stop_func_name,
3112 &ecs->stop_func_start, &ecs->stop_func_end);
3113 ecs->stop_func_start
3114 += gdbarch_deprecated_function_start_offset (gdbarch);
3116 ecs->stop_func_filled_in = 1;
3120 /* Given an execution control state that has been freshly filled in
3121 by an event from the inferior, figure out what it means and take
3122 appropriate action. */
3125 handle_inferior_event (struct execution_control_state *ecs)
3127 struct frame_info *frame;
3128 struct gdbarch *gdbarch;
3129 int stopped_by_watchpoint;
3130 int stepped_after_stopped_by_watchpoint = 0;
3131 struct symtab_and_line stop_pc_sal;
3132 enum stop_kind stop_soon;
3134 if (ecs->ws.kind == TARGET_WAITKIND_IGNORE)
3136 /* We had an event in the inferior, but we are not interested in
3137 handling it at this level. The lower layers have already
3138 done what needs to be done, if anything.
3140 One of the possible circumstances for this is when the
3141 inferior produces output for the console. The inferior has
3142 not stopped, and we are ignoring the event. Another possible
3143 circumstance is any event which the lower level knows will be
3144 reported multiple times without an intervening resume. */
3146 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_IGNORE\n");
3147 prepare_to_wait (ecs);
3151 if (ecs->ws.kind == TARGET_WAITKIND_NO_RESUMED
3152 && target_can_async_p () && !sync_execution)
3154 /* There were no unwaited-for children left in the target, but,
3155 we're not synchronously waiting for events either. Just
3156 ignore. Otherwise, if we were running a synchronous
3157 execution command, we need to cancel it and give the user
3158 back the terminal. */
3160 fprintf_unfiltered (gdb_stdlog,
3161 "infrun: TARGET_WAITKIND_NO_RESUMED (ignoring)\n");
3162 prepare_to_wait (ecs);
3166 if (ecs->ws.kind != TARGET_WAITKIND_EXITED
3167 && ecs->ws.kind != TARGET_WAITKIND_SIGNALLED
3168 && ecs->ws.kind != TARGET_WAITKIND_NO_RESUMED)
3170 struct inferior *inf = find_inferior_pid (ptid_get_pid (ecs->ptid));
3173 stop_soon = inf->control.stop_soon;
3176 stop_soon = NO_STOP_QUIETLY;
3178 /* Cache the last pid/waitstatus. */
3179 target_last_wait_ptid = ecs->ptid;
3180 target_last_waitstatus = ecs->ws;
3182 /* Always clear state belonging to the previous time we stopped. */
3183 stop_stack_dummy = STOP_NONE;
3185 if (ecs->ws.kind == TARGET_WAITKIND_NO_RESUMED)
3187 /* No unwaited-for children left. IOW, all resumed children
3190 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_NO_RESUMED\n");
3192 stop_print_frame = 0;
3193 stop_stepping (ecs);
3197 if (ecs->ws.kind != TARGET_WAITKIND_EXITED
3198 && ecs->ws.kind != TARGET_WAITKIND_SIGNALLED)
3200 ecs->event_thread = find_thread_ptid (ecs->ptid);
3201 /* If it's a new thread, add it to the thread database. */
3202 if (ecs->event_thread == NULL)
3203 ecs->event_thread = add_thread (ecs->ptid);
3206 /* Dependent on valid ECS->EVENT_THREAD. */
3207 adjust_pc_after_break (ecs);
3209 /* Dependent on the current PC value modified by adjust_pc_after_break. */
3210 reinit_frame_cache ();
3212 breakpoint_retire_moribund ();
3214 /* First, distinguish signals caused by the debugger from signals
3215 that have to do with the program's own actions. Note that
3216 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
3217 on the operating system version. Here we detect when a SIGILL or
3218 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
3219 something similar for SIGSEGV, since a SIGSEGV will be generated
3220 when we're trying to execute a breakpoint instruction on a
3221 non-executable stack. This happens for call dummy breakpoints
3222 for architectures like SPARC that place call dummies on the
3224 if (ecs->ws.kind == TARGET_WAITKIND_STOPPED
3225 && (ecs->ws.value.sig == GDB_SIGNAL_ILL
3226 || ecs->ws.value.sig == GDB_SIGNAL_SEGV
3227 || ecs->ws.value.sig == GDB_SIGNAL_EMT))
3229 struct regcache *regcache = get_thread_regcache (ecs->ptid);
3231 if (breakpoint_inserted_here_p (get_regcache_aspace (regcache),
3232 regcache_read_pc (regcache)))
3235 fprintf_unfiltered (gdb_stdlog,
3236 "infrun: Treating signal as SIGTRAP\n");
3237 ecs->ws.value.sig = GDB_SIGNAL_TRAP;
3241 /* Mark the non-executing threads accordingly. In all-stop, all
3242 threads of all processes are stopped when we get any event
3243 reported. In non-stop mode, only the event thread stops. If
3244 we're handling a process exit in non-stop mode, there's nothing
3245 to do, as threads of the dead process are gone, and threads of
3246 any other process were left running. */
3248 set_executing (minus_one_ptid, 0);
3249 else if (ecs->ws.kind != TARGET_WAITKIND_SIGNALLED
3250 && ecs->ws.kind != TARGET_WAITKIND_EXITED)
3251 set_executing (ecs->ptid, 0);
3253 switch (infwait_state)
3255 case infwait_thread_hop_state:
3257 fprintf_unfiltered (gdb_stdlog, "infrun: infwait_thread_hop_state\n");
3260 case infwait_normal_state:
3262 fprintf_unfiltered (gdb_stdlog, "infrun: infwait_normal_state\n");
3265 case infwait_step_watch_state:
3267 fprintf_unfiltered (gdb_stdlog,
3268 "infrun: infwait_step_watch_state\n");
3270 stepped_after_stopped_by_watchpoint = 1;
3273 case infwait_nonstep_watch_state:
3275 fprintf_unfiltered (gdb_stdlog,
3276 "infrun: infwait_nonstep_watch_state\n");
3277 insert_breakpoints ();
3279 /* FIXME-maybe: is this cleaner than setting a flag? Does it
3280 handle things like signals arriving and other things happening
3281 in combination correctly? */
3282 stepped_after_stopped_by_watchpoint = 1;
3286 internal_error (__FILE__, __LINE__, _("bad switch"));
3289 infwait_state = infwait_normal_state;
3290 waiton_ptid = pid_to_ptid (-1);
3292 switch (ecs->ws.kind)
3294 case TARGET_WAITKIND_LOADED:
3296 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_LOADED\n");
3297 /* Ignore gracefully during startup of the inferior, as it might
3298 be the shell which has just loaded some objects, otherwise
3299 add the symbols for the newly loaded objects. Also ignore at
3300 the beginning of an attach or remote session; we will query
3301 the full list of libraries once the connection is
3303 if (stop_soon == NO_STOP_QUIETLY)
3305 struct regcache *regcache;
3307 if (!ptid_equal (ecs->ptid, inferior_ptid))
3308 context_switch (ecs->ptid);
3309 regcache = get_thread_regcache (ecs->ptid);
3311 handle_solib_event ();
3313 ecs->event_thread->control.stop_bpstat
3314 = bpstat_stop_status (get_regcache_aspace (regcache),
3315 stop_pc, ecs->ptid, &ecs->ws);
3317 = !bpstat_explains_signal (ecs->event_thread->control.stop_bpstat);
3319 if (!ecs->random_signal)
3321 /* A catchpoint triggered. */
3322 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_TRAP;
3323 goto process_event_stop_test;
3326 /* If requested, stop when the dynamic linker notifies
3327 gdb of events. This allows the user to get control
3328 and place breakpoints in initializer routines for
3329 dynamically loaded objects (among other things). */
3330 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
3331 if (stop_on_solib_events)
3333 /* Make sure we print "Stopped due to solib-event" in
3335 stop_print_frame = 1;
3337 stop_stepping (ecs);
3342 /* If we are skipping through a shell, or through shared library
3343 loading that we aren't interested in, resume the program. If
3344 we're running the program normally, also resume. But stop if
3345 we're attaching or setting up a remote connection. */
3346 if (stop_soon == STOP_QUIETLY || stop_soon == NO_STOP_QUIETLY)
3348 if (!ptid_equal (ecs->ptid, inferior_ptid))
3349 context_switch (ecs->ptid);
3351 /* Loading of shared libraries might have changed breakpoint
3352 addresses. Make sure new breakpoints are inserted. */
3353 if (stop_soon == NO_STOP_QUIETLY
3354 && !breakpoints_always_inserted_mode ())
3355 insert_breakpoints ();
3356 resume (0, GDB_SIGNAL_0);
3357 prepare_to_wait (ecs);
3363 case TARGET_WAITKIND_SPURIOUS:
3365 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_SPURIOUS\n");
3366 if (!ptid_equal (ecs->ptid, inferior_ptid))
3367 context_switch (ecs->ptid);
3368 resume (0, GDB_SIGNAL_0);
3369 prepare_to_wait (ecs);
3372 case TARGET_WAITKIND_EXITED:
3374 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_EXITED\n");
3375 inferior_ptid = ecs->ptid;
3376 set_current_inferior (find_inferior_pid (ptid_get_pid (ecs->ptid)));
3377 set_current_program_space (current_inferior ()->pspace);
3378 handle_vfork_child_exec_or_exit (0);
3379 target_terminal_ours (); /* Must do this before mourn anyway. */
3380 print_exited_reason (ecs->ws.value.integer);
3382 /* Record the exit code in the convenience variable $_exitcode, so
3383 that the user can inspect this again later. */
3384 set_internalvar_integer (lookup_internalvar ("_exitcode"),
3385 (LONGEST) ecs->ws.value.integer);
3387 /* Also record this in the inferior itself. */
3388 current_inferior ()->has_exit_code = 1;
3389 current_inferior ()->exit_code = (LONGEST) ecs->ws.value.integer;
3391 gdb_flush (gdb_stdout);
3392 target_mourn_inferior ();
3393 singlestep_breakpoints_inserted_p = 0;
3394 cancel_single_step_breakpoints ();
3395 stop_print_frame = 0;
3396 stop_stepping (ecs);
3399 case TARGET_WAITKIND_SIGNALLED:
3401 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_SIGNALLED\n");
3402 inferior_ptid = ecs->ptid;
3403 set_current_inferior (find_inferior_pid (ptid_get_pid (ecs->ptid)));
3404 set_current_program_space (current_inferior ()->pspace);
3405 handle_vfork_child_exec_or_exit (0);
3406 stop_print_frame = 0;
3407 target_terminal_ours (); /* Must do this before mourn anyway. */
3409 /* Note: By definition of TARGET_WAITKIND_SIGNALLED, we shouldn't
3410 reach here unless the inferior is dead. However, for years
3411 target_kill() was called here, which hints that fatal signals aren't
3412 really fatal on some systems. If that's true, then some changes
3414 target_mourn_inferior ();
3416 print_signal_exited_reason (ecs->ws.value.sig);
3417 singlestep_breakpoints_inserted_p = 0;
3418 cancel_single_step_breakpoints ();
3419 stop_stepping (ecs);
3422 /* The following are the only cases in which we keep going;
3423 the above cases end in a continue or goto. */
3424 case TARGET_WAITKIND_FORKED:
3425 case TARGET_WAITKIND_VFORKED:
3428 if (ecs->ws.kind == TARGET_WAITKIND_FORKED)
3429 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_FORKED\n");
3431 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_VFORKED\n");
3434 /* Check whether the inferior is displaced stepping. */
3436 struct regcache *regcache = get_thread_regcache (ecs->ptid);
3437 struct gdbarch *gdbarch = get_regcache_arch (regcache);
3438 struct displaced_step_inferior_state *displaced
3439 = get_displaced_stepping_state (ptid_get_pid (ecs->ptid));
3441 /* If checking displaced stepping is supported, and thread
3442 ecs->ptid is displaced stepping. */
3443 if (displaced && ptid_equal (displaced->step_ptid, ecs->ptid))
3445 struct inferior *parent_inf
3446 = find_inferior_pid (ptid_get_pid (ecs->ptid));
3447 struct regcache *child_regcache;
3448 CORE_ADDR parent_pc;
3450 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
3451 indicating that the displaced stepping of syscall instruction
3452 has been done. Perform cleanup for parent process here. Note
3453 that this operation also cleans up the child process for vfork,
3454 because their pages are shared. */
3455 displaced_step_fixup (ecs->ptid, GDB_SIGNAL_TRAP);
3457 if (ecs->ws.kind == TARGET_WAITKIND_FORKED)
3459 /* Restore scratch pad for child process. */
3460 displaced_step_restore (displaced, ecs->ws.value.related_pid);
3463 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
3464 the child's PC is also within the scratchpad. Set the child's PC
3465 to the parent's PC value, which has already been fixed up.
3466 FIXME: we use the parent's aspace here, although we're touching
3467 the child, because the child hasn't been added to the inferior
3468 list yet at this point. */
3471 = get_thread_arch_aspace_regcache (ecs->ws.value.related_pid,
3473 parent_inf->aspace);
3474 /* Read PC value of parent process. */
3475 parent_pc = regcache_read_pc (regcache);
3477 if (debug_displaced)
3478 fprintf_unfiltered (gdb_stdlog,
3479 "displaced: write child pc from %s to %s\n",
3481 regcache_read_pc (child_regcache)),
3482 paddress (gdbarch, parent_pc));
3484 regcache_write_pc (child_regcache, parent_pc);
3488 if (!ptid_equal (ecs->ptid, inferior_ptid))
3489 context_switch (ecs->ptid);
3491 /* Immediately detach breakpoints from the child before there's
3492 any chance of letting the user delete breakpoints from the
3493 breakpoint lists. If we don't do this early, it's easy to
3494 leave left over traps in the child, vis: "break foo; catch
3495 fork; c; <fork>; del; c; <child calls foo>". We only follow
3496 the fork on the last `continue', and by that time the
3497 breakpoint at "foo" is long gone from the breakpoint table.
3498 If we vforked, then we don't need to unpatch here, since both
3499 parent and child are sharing the same memory pages; we'll
3500 need to unpatch at follow/detach time instead to be certain
3501 that new breakpoints added between catchpoint hit time and
3502 vfork follow are detached. */
3503 if (ecs->ws.kind != TARGET_WAITKIND_VFORKED)
3505 /* This won't actually modify the breakpoint list, but will
3506 physically remove the breakpoints from the child. */
3507 detach_breakpoints (ecs->ws.value.related_pid);
3510 if (singlestep_breakpoints_inserted_p)
3512 /* Pull the single step breakpoints out of the target. */
3513 remove_single_step_breakpoints ();
3514 singlestep_breakpoints_inserted_p = 0;
3517 /* In case the event is caught by a catchpoint, remember that
3518 the event is to be followed at the next resume of the thread,
3519 and not immediately. */
3520 ecs->event_thread->pending_follow = ecs->ws;
3522 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
3524 ecs->event_thread->control.stop_bpstat
3525 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
3526 stop_pc, ecs->ptid, &ecs->ws);
3528 /* Note that we're interested in knowing the bpstat actually
3529 causes a stop, not just if it may explain the signal.
3530 Software watchpoints, for example, always appear in the
3533 = !bpstat_causes_stop (ecs->event_thread->control.stop_bpstat);
3535 /* If no catchpoint triggered for this, then keep going. */
3536 if (ecs->random_signal)
3542 = (follow_fork_mode_string == follow_fork_mode_child);
3544 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
3546 should_resume = follow_fork ();
3549 child = ecs->ws.value.related_pid;
3551 /* In non-stop mode, also resume the other branch. */
3552 if (non_stop && !detach_fork)
3555 switch_to_thread (parent);
3557 switch_to_thread (child);
3559 ecs->event_thread = inferior_thread ();
3560 ecs->ptid = inferior_ptid;
3565 switch_to_thread (child);
3567 switch_to_thread (parent);
3569 ecs->event_thread = inferior_thread ();
3570 ecs->ptid = inferior_ptid;
3575 stop_stepping (ecs);
3578 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_TRAP;
3579 goto process_event_stop_test;
3581 case TARGET_WAITKIND_VFORK_DONE:
3582 /* Done with the shared memory region. Re-insert breakpoints in
3583 the parent, and keep going. */
3586 fprintf_unfiltered (gdb_stdlog,
3587 "infrun: TARGET_WAITKIND_VFORK_DONE\n");
3589 if (!ptid_equal (ecs->ptid, inferior_ptid))
3590 context_switch (ecs->ptid);
3592 current_inferior ()->waiting_for_vfork_done = 0;
3593 current_inferior ()->pspace->breakpoints_not_allowed = 0;
3594 /* This also takes care of reinserting breakpoints in the
3595 previously locked inferior. */
3599 case TARGET_WAITKIND_EXECD:
3601 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_EXECD\n");
3603 if (!ptid_equal (ecs->ptid, inferior_ptid))
3604 context_switch (ecs->ptid);
3606 singlestep_breakpoints_inserted_p = 0;
3607 cancel_single_step_breakpoints ();
3609 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
3611 /* Do whatever is necessary to the parent branch of the vfork. */
3612 handle_vfork_child_exec_or_exit (1);
3614 /* This causes the eventpoints and symbol table to be reset.
3615 Must do this now, before trying to determine whether to
3617 follow_exec (inferior_ptid, ecs->ws.value.execd_pathname);
3619 ecs->event_thread->control.stop_bpstat
3620 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
3621 stop_pc, ecs->ptid, &ecs->ws);
3623 = !bpstat_explains_signal (ecs->event_thread->control.stop_bpstat);
3625 /* Note that this may be referenced from inside
3626 bpstat_stop_status above, through inferior_has_execd. */
3627 xfree (ecs->ws.value.execd_pathname);
3628 ecs->ws.value.execd_pathname = NULL;
3630 /* If no catchpoint triggered for this, then keep going. */
3631 if (ecs->random_signal)
3633 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
3637 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_TRAP;
3638 goto process_event_stop_test;
3640 /* Be careful not to try to gather much state about a thread
3641 that's in a syscall. It's frequently a losing proposition. */
3642 case TARGET_WAITKIND_SYSCALL_ENTRY:
3644 fprintf_unfiltered (gdb_stdlog,
3645 "infrun: TARGET_WAITKIND_SYSCALL_ENTRY\n");
3646 /* Getting the current syscall number. */
3647 if (handle_syscall_event (ecs) != 0)
3649 goto process_event_stop_test;
3651 /* Before examining the threads further, step this thread to
3652 get it entirely out of the syscall. (We get notice of the
3653 event when the thread is just on the verge of exiting a
3654 syscall. Stepping one instruction seems to get it back
3656 case TARGET_WAITKIND_SYSCALL_RETURN:
3658 fprintf_unfiltered (gdb_stdlog,
3659 "infrun: TARGET_WAITKIND_SYSCALL_RETURN\n");
3660 if (handle_syscall_event (ecs) != 0)
3662 goto process_event_stop_test;
3664 case TARGET_WAITKIND_STOPPED:
3666 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_STOPPED\n");
3667 ecs->event_thread->suspend.stop_signal = ecs->ws.value.sig;
3670 case TARGET_WAITKIND_NO_HISTORY:
3672 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_NO_HISTORY\n");
3673 /* Reverse execution: target ran out of history info. */
3675 /* Pull the single step breakpoints out of the target. */
3676 if (singlestep_breakpoints_inserted_p)
3678 if (!ptid_equal (ecs->ptid, inferior_ptid))
3679 context_switch (ecs->ptid);
3680 remove_single_step_breakpoints ();
3681 singlestep_breakpoints_inserted_p = 0;
3683 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
3684 print_no_history_reason ();
3685 stop_stepping (ecs);
3689 if (ecs->ws.kind == TARGET_WAITKIND_STOPPED)
3691 /* Do we need to clean up the state of a thread that has
3692 completed a displaced single-step? (Doing so usually affects
3693 the PC, so do it here, before we set stop_pc.) */
3694 displaced_step_fixup (ecs->ptid,
3695 ecs->event_thread->suspend.stop_signal);
3697 /* If we either finished a single-step or hit a breakpoint, but
3698 the user wanted this thread to be stopped, pretend we got a
3699 SIG0 (generic unsignaled stop). */
3701 if (ecs->event_thread->stop_requested
3702 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
3703 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
3706 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
3710 struct regcache *regcache = get_thread_regcache (ecs->ptid);
3711 struct gdbarch *gdbarch = get_regcache_arch (regcache);
3712 struct cleanup *old_chain = save_inferior_ptid ();
3714 inferior_ptid = ecs->ptid;
3716 fprintf_unfiltered (gdb_stdlog, "infrun: stop_pc = %s\n",
3717 paddress (gdbarch, stop_pc));
3718 if (target_stopped_by_watchpoint ())
3722 fprintf_unfiltered (gdb_stdlog, "infrun: stopped by watchpoint\n");
3724 if (target_stopped_data_address (¤t_target, &addr))
3725 fprintf_unfiltered (gdb_stdlog,
3726 "infrun: stopped data address = %s\n",
3727 paddress (gdbarch, addr));
3729 fprintf_unfiltered (gdb_stdlog,
3730 "infrun: (no data address available)\n");
3733 do_cleanups (old_chain);
3736 if (stepping_past_singlestep_breakpoint)
3738 gdb_assert (singlestep_breakpoints_inserted_p);
3739 gdb_assert (ptid_equal (singlestep_ptid, ecs->ptid));
3740 gdb_assert (!ptid_equal (singlestep_ptid, saved_singlestep_ptid));
3742 stepping_past_singlestep_breakpoint = 0;
3744 /* We've either finished single-stepping past the single-step
3745 breakpoint, or stopped for some other reason. It would be nice if
3746 we could tell, but we can't reliably. */
3747 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
3750 fprintf_unfiltered (gdb_stdlog,
3751 "infrun: stepping_past_"
3752 "singlestep_breakpoint\n");
3753 /* Pull the single step breakpoints out of the target. */
3754 if (!ptid_equal (ecs->ptid, inferior_ptid))
3755 context_switch (ecs->ptid);
3756 remove_single_step_breakpoints ();
3757 singlestep_breakpoints_inserted_p = 0;
3759 ecs->random_signal = 0;
3760 ecs->event_thread->control.trap_expected = 0;
3762 context_switch (saved_singlestep_ptid);
3763 if (deprecated_context_hook)
3764 deprecated_context_hook (pid_to_thread_id (ecs->ptid));
3766 resume (1, GDB_SIGNAL_0);
3767 prepare_to_wait (ecs);
3772 if (!ptid_equal (deferred_step_ptid, null_ptid))
3774 /* In non-stop mode, there's never a deferred_step_ptid set. */
3775 gdb_assert (!non_stop);
3777 /* If we stopped for some other reason than single-stepping, ignore
3778 the fact that we were supposed to switch back. */
3779 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
3782 fprintf_unfiltered (gdb_stdlog,
3783 "infrun: handling deferred step\n");
3785 /* Pull the single step breakpoints out of the target. */
3786 if (singlestep_breakpoints_inserted_p)
3788 if (!ptid_equal (ecs->ptid, inferior_ptid))
3789 context_switch (ecs->ptid);
3790 remove_single_step_breakpoints ();
3791 singlestep_breakpoints_inserted_p = 0;
3794 ecs->event_thread->control.trap_expected = 0;
3796 context_switch (deferred_step_ptid);
3797 deferred_step_ptid = null_ptid;
3798 /* Suppress spurious "Switching to ..." message. */
3799 previous_inferior_ptid = inferior_ptid;
3801 resume (1, GDB_SIGNAL_0);
3802 prepare_to_wait (ecs);
3806 deferred_step_ptid = null_ptid;
3809 /* See if a thread hit a thread-specific breakpoint that was meant for
3810 another thread. If so, then step that thread past the breakpoint,
3813 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
3815 int thread_hop_needed = 0;
3816 struct address_space *aspace =
3817 get_regcache_aspace (get_thread_regcache (ecs->ptid));
3819 /* Check if a regular breakpoint has been hit before checking
3820 for a potential single step breakpoint. Otherwise, GDB will
3821 not see this breakpoint hit when stepping onto breakpoints. */
3822 if (regular_breakpoint_inserted_here_p (aspace, stop_pc))
3824 ecs->random_signal = 0;
3825 if (!breakpoint_thread_match (aspace, stop_pc, ecs->ptid))
3826 thread_hop_needed = 1;
3828 else if (singlestep_breakpoints_inserted_p)
3830 /* We have not context switched yet, so this should be true
3831 no matter which thread hit the singlestep breakpoint. */
3832 gdb_assert (ptid_equal (inferior_ptid, singlestep_ptid));
3834 fprintf_unfiltered (gdb_stdlog, "infrun: software single step "
3836 target_pid_to_str (ecs->ptid));
3838 ecs->random_signal = 0;
3839 /* The call to in_thread_list is necessary because PTIDs sometimes
3840 change when we go from single-threaded to multi-threaded. If
3841 the singlestep_ptid is still in the list, assume that it is
3842 really different from ecs->ptid. */
3843 if (!ptid_equal (singlestep_ptid, ecs->ptid)
3844 && in_thread_list (singlestep_ptid))
3846 /* If the PC of the thread we were trying to single-step
3847 has changed, discard this event (which we were going
3848 to ignore anyway), and pretend we saw that thread
3849 trap. This prevents us continuously moving the
3850 single-step breakpoint forward, one instruction at a
3851 time. If the PC has changed, then the thread we were
3852 trying to single-step has trapped or been signalled,
3853 but the event has not been reported to GDB yet.
3855 There might be some cases where this loses signal
3856 information, if a signal has arrived at exactly the
3857 same time that the PC changed, but this is the best
3858 we can do with the information available. Perhaps we
3859 should arrange to report all events for all threads
3860 when they stop, or to re-poll the remote looking for
3861 this particular thread (i.e. temporarily enable
3864 CORE_ADDR new_singlestep_pc
3865 = regcache_read_pc (get_thread_regcache (singlestep_ptid));
3867 if (new_singlestep_pc != singlestep_pc)
3869 enum gdb_signal stop_signal;
3872 fprintf_unfiltered (gdb_stdlog, "infrun: unexpected thread,"
3873 " but expected thread advanced also\n");
3875 /* The current context still belongs to
3876 singlestep_ptid. Don't swap here, since that's
3877 the context we want to use. Just fudge our
3878 state and continue. */
3879 stop_signal = ecs->event_thread->suspend.stop_signal;
3880 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
3881 ecs->ptid = singlestep_ptid;
3882 ecs->event_thread = find_thread_ptid (ecs->ptid);
3883 ecs->event_thread->suspend.stop_signal = stop_signal;
3884 stop_pc = new_singlestep_pc;
3889 fprintf_unfiltered (gdb_stdlog,
3890 "infrun: unexpected thread\n");
3892 thread_hop_needed = 1;
3893 stepping_past_singlestep_breakpoint = 1;
3894 saved_singlestep_ptid = singlestep_ptid;
3899 if (thread_hop_needed)
3901 struct regcache *thread_regcache;
3902 int remove_status = 0;
3905 fprintf_unfiltered (gdb_stdlog, "infrun: thread_hop_needed\n");
3907 /* Switch context before touching inferior memory, the
3908 previous thread may have exited. */
3909 if (!ptid_equal (inferior_ptid, ecs->ptid))
3910 context_switch (ecs->ptid);
3912 /* Saw a breakpoint, but it was hit by the wrong thread.
3915 if (singlestep_breakpoints_inserted_p)
3917 /* Pull the single step breakpoints out of the target. */
3918 remove_single_step_breakpoints ();
3919 singlestep_breakpoints_inserted_p = 0;
3922 /* If the arch can displace step, don't remove the
3924 thread_regcache = get_thread_regcache (ecs->ptid);
3925 if (!use_displaced_stepping (get_regcache_arch (thread_regcache)))
3926 remove_status = remove_breakpoints ();
3928 /* Did we fail to remove breakpoints? If so, try
3929 to set the PC past the bp. (There's at least
3930 one situation in which we can fail to remove
3931 the bp's: On HP-UX's that use ttrace, we can't
3932 change the address space of a vforking child
3933 process until the child exits (well, okay, not
3934 then either :-) or execs. */
3935 if (remove_status != 0)
3936 error (_("Cannot step over breakpoint hit in wrong thread"));
3941 /* Only need to require the next event from this
3942 thread in all-stop mode. */
3943 waiton_ptid = ecs->ptid;
3944 infwait_state = infwait_thread_hop_state;
3947 ecs->event_thread->stepping_over_breakpoint = 1;
3952 else if (singlestep_breakpoints_inserted_p)
3954 ecs->random_signal = 0;
3958 ecs->random_signal = 1;
3960 /* See if something interesting happened to the non-current thread. If
3961 so, then switch to that thread. */
3962 if (!ptid_equal (ecs->ptid, inferior_ptid))
3965 fprintf_unfiltered (gdb_stdlog, "infrun: context switch\n");
3967 context_switch (ecs->ptid);
3969 if (deprecated_context_hook)
3970 deprecated_context_hook (pid_to_thread_id (ecs->ptid));
3973 /* At this point, get hold of the now-current thread's frame. */
3974 frame = get_current_frame ();
3975 gdbarch = get_frame_arch (frame);
3977 if (singlestep_breakpoints_inserted_p)
3979 /* Pull the single step breakpoints out of the target. */
3980 remove_single_step_breakpoints ();
3981 singlestep_breakpoints_inserted_p = 0;
3984 if (stepped_after_stopped_by_watchpoint)
3985 stopped_by_watchpoint = 0;
3987 stopped_by_watchpoint = watchpoints_triggered (&ecs->ws);
3989 /* If necessary, step over this watchpoint. We'll be back to display
3991 if (stopped_by_watchpoint
3992 && (target_have_steppable_watchpoint
3993 || gdbarch_have_nonsteppable_watchpoint (gdbarch)))
3995 /* At this point, we are stopped at an instruction which has
3996 attempted to write to a piece of memory under control of
3997 a watchpoint. The instruction hasn't actually executed
3998 yet. If we were to evaluate the watchpoint expression
3999 now, we would get the old value, and therefore no change
4000 would seem to have occurred.
4002 In order to make watchpoints work `right', we really need
4003 to complete the memory write, and then evaluate the
4004 watchpoint expression. We do this by single-stepping the
4007 It may not be necessary to disable the watchpoint to stop over
4008 it. For example, the PA can (with some kernel cooperation)
4009 single step over a watchpoint without disabling the watchpoint.
4011 It is far more common to need to disable a watchpoint to step
4012 the inferior over it. If we have non-steppable watchpoints,
4013 we must disable the current watchpoint; it's simplest to
4014 disable all watchpoints and breakpoints. */
4017 if (!target_have_steppable_watchpoint)
4019 remove_breakpoints ();
4020 /* See comment in resume why we need to stop bypassing signals
4021 while breakpoints have been removed. */
4022 target_pass_signals (0, NULL);
4025 hw_step = maybe_software_singlestep (gdbarch, stop_pc);
4026 target_resume (ecs->ptid, hw_step, GDB_SIGNAL_0);
4027 waiton_ptid = ecs->ptid;
4028 if (target_have_steppable_watchpoint)
4029 infwait_state = infwait_step_watch_state;
4031 infwait_state = infwait_nonstep_watch_state;
4032 prepare_to_wait (ecs);
4036 clear_stop_func (ecs);
4037 ecs->event_thread->stepping_over_breakpoint = 0;
4038 bpstat_clear (&ecs->event_thread->control.stop_bpstat);
4039 ecs->event_thread->control.stop_step = 0;
4040 stop_print_frame = 1;
4041 ecs->random_signal = 0;
4042 stopped_by_random_signal = 0;
4044 /* Hide inlined functions starting here, unless we just performed stepi or
4045 nexti. After stepi and nexti, always show the innermost frame (not any
4046 inline function call sites). */
4047 if (ecs->event_thread->control.step_range_end != 1)
4049 struct address_space *aspace =
4050 get_regcache_aspace (get_thread_regcache (ecs->ptid));
4052 /* skip_inline_frames is expensive, so we avoid it if we can
4053 determine that the address is one where functions cannot have
4054 been inlined. This improves performance with inferiors that
4055 load a lot of shared libraries, because the solib event
4056 breakpoint is defined as the address of a function (i.e. not
4057 inline). Note that we have to check the previous PC as well
4058 as the current one to catch cases when we have just
4059 single-stepped off a breakpoint prior to reinstating it.
4060 Note that we're assuming that the code we single-step to is
4061 not inline, but that's not definitive: there's nothing
4062 preventing the event breakpoint function from containing
4063 inlined code, and the single-step ending up there. If the
4064 user had set a breakpoint on that inlined code, the missing
4065 skip_inline_frames call would break things. Fortunately
4066 that's an extremely unlikely scenario. */
4067 if (!pc_at_non_inline_function (aspace, stop_pc, &ecs->ws)
4068 && !(ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
4069 && ecs->event_thread->control.trap_expected
4070 && pc_at_non_inline_function (aspace,
4071 ecs->event_thread->prev_pc,
4074 skip_inline_frames (ecs->ptid);
4076 /* Re-fetch current thread's frame in case that invalidated
4078 frame = get_current_frame ();
4079 gdbarch = get_frame_arch (frame);
4083 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
4084 && ecs->event_thread->control.trap_expected
4085 && gdbarch_single_step_through_delay_p (gdbarch)
4086 && currently_stepping (ecs->event_thread))
4088 /* We're trying to step off a breakpoint. Turns out that we're
4089 also on an instruction that needs to be stepped multiple
4090 times before it's been fully executing. E.g., architectures
4091 with a delay slot. It needs to be stepped twice, once for
4092 the instruction and once for the delay slot. */
4093 int step_through_delay
4094 = gdbarch_single_step_through_delay (gdbarch, frame);
4096 if (debug_infrun && step_through_delay)
4097 fprintf_unfiltered (gdb_stdlog, "infrun: step through delay\n");
4098 if (ecs->event_thread->control.step_range_end == 0
4099 && step_through_delay)
4101 /* The user issued a continue when stopped at a breakpoint.
4102 Set up for another trap and get out of here. */
4103 ecs->event_thread->stepping_over_breakpoint = 1;
4107 else if (step_through_delay)
4109 /* The user issued a step when stopped at a breakpoint.
4110 Maybe we should stop, maybe we should not - the delay
4111 slot *might* correspond to a line of source. In any
4112 case, don't decide that here, just set
4113 ecs->stepping_over_breakpoint, making sure we
4114 single-step again before breakpoints are re-inserted. */
4115 ecs->event_thread->stepping_over_breakpoint = 1;
4119 /* Look at the cause of the stop, and decide what to do.
4120 The alternatives are:
4121 1) stop_stepping and return; to really stop and return to the debugger,
4122 2) keep_going and return to start up again
4123 (set ecs->event_thread->stepping_over_breakpoint to 1 to single step once)
4124 3) set ecs->random_signal to 1, and the decision between 1 and 2
4125 will be made according to the signal handling tables. */
4127 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
4128 || stop_soon == STOP_QUIETLY || stop_soon == STOP_QUIETLY_NO_SIGSTOP
4129 || stop_soon == STOP_QUIETLY_REMOTE)
4131 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
4135 fprintf_unfiltered (gdb_stdlog, "infrun: stopped\n");
4136 stop_print_frame = 0;
4137 stop_stepping (ecs);
4141 /* This is originated from start_remote(), start_inferior() and
4142 shared libraries hook functions. */
4143 if (stop_soon == STOP_QUIETLY || stop_soon == STOP_QUIETLY_REMOTE)
4146 fprintf_unfiltered (gdb_stdlog, "infrun: quietly stopped\n");
4147 stop_stepping (ecs);
4151 /* This originates from attach_command(). We need to overwrite
4152 the stop_signal here, because some kernels don't ignore a
4153 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
4154 See more comments in inferior.h. On the other hand, if we
4155 get a non-SIGSTOP, report it to the user - assume the backend
4156 will handle the SIGSTOP if it should show up later.
4158 Also consider that the attach is complete when we see a
4159 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
4160 target extended-remote report it instead of a SIGSTOP
4161 (e.g. gdbserver). We already rely on SIGTRAP being our
4162 signal, so this is no exception.
4164 Also consider that the attach is complete when we see a
4165 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
4166 the target to stop all threads of the inferior, in case the
4167 low level attach operation doesn't stop them implicitly. If
4168 they weren't stopped implicitly, then the stub will report a
4169 GDB_SIGNAL_0, meaning: stopped for no particular reason
4170 other than GDB's request. */
4171 if (stop_soon == STOP_QUIETLY_NO_SIGSTOP
4172 && (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_STOP
4173 || ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
4174 || ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_0))
4176 stop_stepping (ecs);
4177 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
4181 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
4182 handles this event. */
4183 ecs->event_thread->control.stop_bpstat
4184 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
4185 stop_pc, ecs->ptid, &ecs->ws);
4187 /* Following in case break condition called a
4189 stop_print_frame = 1;
4191 /* This is where we handle "moribund" watchpoints. Unlike
4192 software breakpoints traps, hardware watchpoint traps are
4193 always distinguishable from random traps. If no high-level
4194 watchpoint is associated with the reported stop data address
4195 anymore, then the bpstat does not explain the signal ---
4196 simply make sure to ignore it if `stopped_by_watchpoint' is
4200 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
4201 && !bpstat_explains_signal (ecs->event_thread->control.stop_bpstat)
4202 && stopped_by_watchpoint)
4203 fprintf_unfiltered (gdb_stdlog,
4204 "infrun: no user watchpoint explains "
4205 "watchpoint SIGTRAP, ignoring\n");
4207 /* NOTE: cagney/2003-03-29: These two checks for a random signal
4208 at one stage in the past included checks for an inferior
4209 function call's call dummy's return breakpoint. The original
4210 comment, that went with the test, read:
4212 ``End of a stack dummy. Some systems (e.g. Sony news) give
4213 another signal besides SIGTRAP, so check here as well as
4216 If someone ever tries to get call dummys on a
4217 non-executable stack to work (where the target would stop
4218 with something like a SIGSEGV), then those tests might need
4219 to be re-instated. Given, however, that the tests were only
4220 enabled when momentary breakpoints were not being used, I
4221 suspect that it won't be the case.
4223 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
4224 be necessary for call dummies on a non-executable stack on
4227 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
4229 = !(bpstat_explains_signal (ecs->event_thread->control.stop_bpstat)
4230 || stopped_by_watchpoint
4231 || ecs->event_thread->control.trap_expected
4232 || (ecs->event_thread->control.step_range_end
4233 && (ecs->event_thread->control.step_resume_breakpoint
4237 ecs->random_signal = !bpstat_explains_signal
4238 (ecs->event_thread->control.stop_bpstat);
4239 if (!ecs->random_signal)
4240 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_TRAP;
4244 /* When we reach this point, we've pretty much decided
4245 that the reason for stopping must've been a random
4246 (unexpected) signal. */
4249 ecs->random_signal = 1;
4251 process_event_stop_test:
4253 /* Re-fetch current thread's frame in case we did a
4254 "goto process_event_stop_test" above. */
4255 frame = get_current_frame ();
4256 gdbarch = get_frame_arch (frame);
4258 /* For the program's own signals, act according to
4259 the signal handling tables. */
4261 if (ecs->random_signal)
4263 /* Signal not for debugging purposes. */
4265 struct inferior *inf = find_inferior_pid (ptid_get_pid (ecs->ptid));
4268 fprintf_unfiltered (gdb_stdlog, "infrun: random signal %d\n",
4269 ecs->event_thread->suspend.stop_signal);
4271 stopped_by_random_signal = 1;
4273 if (signal_print[ecs->event_thread->suspend.stop_signal])
4276 target_terminal_ours_for_output ();
4277 print_signal_received_reason
4278 (ecs->event_thread->suspend.stop_signal);
4280 /* Always stop on signals if we're either just gaining control
4281 of the program, or the user explicitly requested this thread
4282 to remain stopped. */
4283 if (stop_soon != NO_STOP_QUIETLY
4284 || ecs->event_thread->stop_requested
4286 && signal_stop_state (ecs->event_thread->suspend.stop_signal)))
4288 stop_stepping (ecs);
4291 /* If not going to stop, give terminal back
4292 if we took it away. */
4294 target_terminal_inferior ();
4296 /* Clear the signal if it should not be passed. */
4297 if (signal_program[ecs->event_thread->suspend.stop_signal] == 0)
4298 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
4300 if (ecs->event_thread->prev_pc == stop_pc
4301 && ecs->event_thread->control.trap_expected
4302 && ecs->event_thread->control.step_resume_breakpoint == NULL)
4304 /* We were just starting a new sequence, attempting to
4305 single-step off of a breakpoint and expecting a SIGTRAP.
4306 Instead this signal arrives. This signal will take us out
4307 of the stepping range so GDB needs to remember to, when
4308 the signal handler returns, resume stepping off that
4310 /* To simplify things, "continue" is forced to use the same
4311 code paths as single-step - set a breakpoint at the
4312 signal return address and then, once hit, step off that
4315 fprintf_unfiltered (gdb_stdlog,
4316 "infrun: signal arrived while stepping over "
4319 insert_hp_step_resume_breakpoint_at_frame (frame);
4320 ecs->event_thread->step_after_step_resume_breakpoint = 1;
4321 /* Reset trap_expected to ensure breakpoints are re-inserted. */
4322 ecs->event_thread->control.trap_expected = 0;
4327 if (ecs->event_thread->control.step_range_end != 0
4328 && ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_0
4329 && (ecs->event_thread->control.step_range_start <= stop_pc
4330 && stop_pc < ecs->event_thread->control.step_range_end)
4331 && frame_id_eq (get_stack_frame_id (frame),
4332 ecs->event_thread->control.step_stack_frame_id)
4333 && ecs->event_thread->control.step_resume_breakpoint == NULL)
4335 /* The inferior is about to take a signal that will take it
4336 out of the single step range. Set a breakpoint at the
4337 current PC (which is presumably where the signal handler
4338 will eventually return) and then allow the inferior to
4341 Note that this is only needed for a signal delivered
4342 while in the single-step range. Nested signals aren't a
4343 problem as they eventually all return. */
4345 fprintf_unfiltered (gdb_stdlog,
4346 "infrun: signal may take us out of "
4347 "single-step range\n");
4349 insert_hp_step_resume_breakpoint_at_frame (frame);
4350 /* Reset trap_expected to ensure breakpoints are re-inserted. */
4351 ecs->event_thread->control.trap_expected = 0;
4356 /* Note: step_resume_breakpoint may be non-NULL. This occures
4357 when either there's a nested signal, or when there's a
4358 pending signal enabled just as the signal handler returns
4359 (leaving the inferior at the step-resume-breakpoint without
4360 actually executing it). Either way continue until the
4361 breakpoint is really hit. */
4365 /* Handle cases caused by hitting a breakpoint. */
4367 CORE_ADDR jmp_buf_pc;
4368 struct bpstat_what what;
4370 what = bpstat_what (ecs->event_thread->control.stop_bpstat);
4372 if (what.call_dummy)
4374 stop_stack_dummy = what.call_dummy;
4377 /* If we hit an internal event that triggers symbol changes, the
4378 current frame will be invalidated within bpstat_what (e.g.,
4379 if we hit an internal solib event). Re-fetch it. */
4380 frame = get_current_frame ();
4381 gdbarch = get_frame_arch (frame);
4383 switch (what.main_action)
4385 case BPSTAT_WHAT_SET_LONGJMP_RESUME:
4386 /* If we hit the breakpoint at longjmp while stepping, we
4387 install a momentary breakpoint at the target of the
4391 fprintf_unfiltered (gdb_stdlog,
4392 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME\n");
4394 ecs->event_thread->stepping_over_breakpoint = 1;
4396 if (what.is_longjmp)
4398 struct value *arg_value;
4400 /* If we set the longjmp breakpoint via a SystemTap
4401 probe, then use it to extract the arguments. The
4402 destination PC is the third argument to the
4404 arg_value = probe_safe_evaluate_at_pc (frame, 2);
4406 jmp_buf_pc = value_as_address (arg_value);
4407 else if (!gdbarch_get_longjmp_target_p (gdbarch)
4408 || !gdbarch_get_longjmp_target (gdbarch,
4409 frame, &jmp_buf_pc))
4412 fprintf_unfiltered (gdb_stdlog,
4413 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME "
4414 "(!gdbarch_get_longjmp_target)\n");
4419 /* Insert a breakpoint at resume address. */
4420 insert_longjmp_resume_breakpoint (gdbarch, jmp_buf_pc);
4423 check_exception_resume (ecs, frame);
4427 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME:
4429 struct frame_info *init_frame;
4431 /* There are several cases to consider.
4433 1. The initiating frame no longer exists. In this case
4434 we must stop, because the exception or longjmp has gone
4437 2. The initiating frame exists, and is the same as the
4438 current frame. We stop, because the exception or
4439 longjmp has been caught.
4441 3. The initiating frame exists and is different from
4442 the current frame. This means the exception or longjmp
4443 has been caught beneath the initiating frame, so keep
4446 4. longjmp breakpoint has been placed just to protect
4447 against stale dummy frames and user is not interested
4448 in stopping around longjmps. */
4451 fprintf_unfiltered (gdb_stdlog,
4452 "infrun: BPSTAT_WHAT_CLEAR_LONGJMP_RESUME\n");
4454 gdb_assert (ecs->event_thread->control.exception_resume_breakpoint
4456 delete_exception_resume_breakpoint (ecs->event_thread);
4458 if (what.is_longjmp)
4460 check_longjmp_breakpoint_for_call_dummy (ecs->event_thread->num);
4462 if (!frame_id_p (ecs->event_thread->initiating_frame))
4470 init_frame = frame_find_by_id (ecs->event_thread->initiating_frame);
4474 struct frame_id current_id
4475 = get_frame_id (get_current_frame ());
4476 if (frame_id_eq (current_id,
4477 ecs->event_thread->initiating_frame))
4479 /* Case 2. Fall through. */
4489 /* For Cases 1 and 2, remove the step-resume breakpoint,
4491 delete_step_resume_breakpoint (ecs->event_thread);
4493 ecs->event_thread->control.stop_step = 1;
4494 print_end_stepping_range_reason ();
4495 stop_stepping (ecs);
4499 case BPSTAT_WHAT_SINGLE:
4501 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_SINGLE\n");
4502 ecs->event_thread->stepping_over_breakpoint = 1;
4503 /* Still need to check other stuff, at least the case where
4504 we are stepping and step out of the right range. */
4507 case BPSTAT_WHAT_STEP_RESUME:
4509 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STEP_RESUME\n");
4511 delete_step_resume_breakpoint (ecs->event_thread);
4512 if (ecs->event_thread->control.proceed_to_finish
4513 && execution_direction == EXEC_REVERSE)
4515 struct thread_info *tp = ecs->event_thread;
4517 /* We are finishing a function in reverse, and just hit
4518 the step-resume breakpoint at the start address of
4519 the function, and we're almost there -- just need to
4520 back up by one more single-step, which should take us
4521 back to the function call. */
4522 tp->control.step_range_start = tp->control.step_range_end = 1;
4526 fill_in_stop_func (gdbarch, ecs);
4527 if (stop_pc == ecs->stop_func_start
4528 && execution_direction == EXEC_REVERSE)
4530 /* We are stepping over a function call in reverse, and
4531 just hit the step-resume breakpoint at the start
4532 address of the function. Go back to single-stepping,
4533 which should take us back to the function call. */
4534 ecs->event_thread->stepping_over_breakpoint = 1;
4540 case BPSTAT_WHAT_STOP_NOISY:
4542 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_NOISY\n");
4543 stop_print_frame = 1;
4545 /* We are about to nuke the step_resume_breakpointt via the
4546 cleanup chain, so no need to worry about it here. */
4548 stop_stepping (ecs);
4551 case BPSTAT_WHAT_STOP_SILENT:
4553 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_SILENT\n");
4554 stop_print_frame = 0;
4556 /* We are about to nuke the step_resume_breakpoin via the
4557 cleanup chain, so no need to worry about it here. */
4559 stop_stepping (ecs);
4562 case BPSTAT_WHAT_HP_STEP_RESUME:
4564 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_HP_STEP_RESUME\n");
4566 delete_step_resume_breakpoint (ecs->event_thread);
4567 if (ecs->event_thread->step_after_step_resume_breakpoint)
4569 /* Back when the step-resume breakpoint was inserted, we
4570 were trying to single-step off a breakpoint. Go back
4572 ecs->event_thread->step_after_step_resume_breakpoint = 0;
4573 ecs->event_thread->stepping_over_breakpoint = 1;
4579 case BPSTAT_WHAT_KEEP_CHECKING:
4584 /* We come here if we hit a breakpoint but should not
4585 stop for it. Possibly we also were stepping
4586 and should stop for that. So fall through and
4587 test for stepping. But, if not stepping,
4590 /* In all-stop mode, if we're currently stepping but have stopped in
4591 some other thread, we need to switch back to the stepped thread. */
4594 struct thread_info *tp;
4596 tp = iterate_over_threads (currently_stepping_or_nexting_callback,
4600 /* However, if the current thread is blocked on some internal
4601 breakpoint, and we simply need to step over that breakpoint
4602 to get it going again, do that first. */
4603 if ((ecs->event_thread->control.trap_expected
4604 && ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_TRAP)
4605 || ecs->event_thread->stepping_over_breakpoint)
4611 /* If the stepping thread exited, then don't try to switch
4612 back and resume it, which could fail in several different
4613 ways depending on the target. Instead, just keep going.
4615 We can find a stepping dead thread in the thread list in
4618 - The target supports thread exit events, and when the
4619 target tries to delete the thread from the thread list,
4620 inferior_ptid pointed at the exiting thread. In such
4621 case, calling delete_thread does not really remove the
4622 thread from the list; instead, the thread is left listed,
4623 with 'exited' state.
4625 - The target's debug interface does not support thread
4626 exit events, and so we have no idea whatsoever if the
4627 previously stepping thread is still alive. For that
4628 reason, we need to synchronously query the target
4630 if (is_exited (tp->ptid)
4631 || !target_thread_alive (tp->ptid))
4634 fprintf_unfiltered (gdb_stdlog,
4635 "infrun: not switching back to "
4636 "stepped thread, it has vanished\n");
4638 delete_thread (tp->ptid);
4643 /* Otherwise, we no longer expect a trap in the current thread.
4644 Clear the trap_expected flag before switching back -- this is
4645 what keep_going would do as well, if we called it. */
4646 ecs->event_thread->control.trap_expected = 0;
4649 fprintf_unfiltered (gdb_stdlog,
4650 "infrun: switching back to stepped thread\n");
4652 ecs->event_thread = tp;
4653 ecs->ptid = tp->ptid;
4654 context_switch (ecs->ptid);
4660 if (ecs->event_thread->control.step_resume_breakpoint)
4663 fprintf_unfiltered (gdb_stdlog,
4664 "infrun: step-resume breakpoint is inserted\n");
4666 /* Having a step-resume breakpoint overrides anything
4667 else having to do with stepping commands until
4668 that breakpoint is reached. */
4673 if (ecs->event_thread->control.step_range_end == 0)
4676 fprintf_unfiltered (gdb_stdlog, "infrun: no stepping, continue\n");
4677 /* Likewise if we aren't even stepping. */
4682 /* Re-fetch current thread's frame in case the code above caused
4683 the frame cache to be re-initialized, making our FRAME variable
4684 a dangling pointer. */
4685 frame = get_current_frame ();
4686 gdbarch = get_frame_arch (frame);
4687 fill_in_stop_func (gdbarch, ecs);
4689 /* If stepping through a line, keep going if still within it.
4691 Note that step_range_end is the address of the first instruction
4692 beyond the step range, and NOT the address of the last instruction
4695 Note also that during reverse execution, we may be stepping
4696 through a function epilogue and therefore must detect when
4697 the current-frame changes in the middle of a line. */
4699 if (stop_pc >= ecs->event_thread->control.step_range_start
4700 && stop_pc < ecs->event_thread->control.step_range_end
4701 && (execution_direction != EXEC_REVERSE
4702 || frame_id_eq (get_frame_id (frame),
4703 ecs->event_thread->control.step_frame_id)))
4707 (gdb_stdlog, "infrun: stepping inside range [%s-%s]\n",
4708 paddress (gdbarch, ecs->event_thread->control.step_range_start),
4709 paddress (gdbarch, ecs->event_thread->control.step_range_end));
4711 /* When stepping backward, stop at beginning of line range
4712 (unless it's the function entry point, in which case
4713 keep going back to the call point). */
4714 if (stop_pc == ecs->event_thread->control.step_range_start
4715 && stop_pc != ecs->stop_func_start
4716 && execution_direction == EXEC_REVERSE)
4718 ecs->event_thread->control.stop_step = 1;
4719 print_end_stepping_range_reason ();
4720 stop_stepping (ecs);
4728 /* We stepped out of the stepping range. */
4730 /* If we are stepping at the source level and entered the runtime
4731 loader dynamic symbol resolution code...
4733 EXEC_FORWARD: we keep on single stepping until we exit the run
4734 time loader code and reach the callee's address.
4736 EXEC_REVERSE: we've already executed the callee (backward), and
4737 the runtime loader code is handled just like any other
4738 undebuggable function call. Now we need only keep stepping
4739 backward through the trampoline code, and that's handled further
4740 down, so there is nothing for us to do here. */
4742 if (execution_direction != EXEC_REVERSE
4743 && ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
4744 && in_solib_dynsym_resolve_code (stop_pc))
4746 CORE_ADDR pc_after_resolver =
4747 gdbarch_skip_solib_resolver (gdbarch, stop_pc);
4750 fprintf_unfiltered (gdb_stdlog,
4751 "infrun: stepped into dynsym resolve code\n");
4753 if (pc_after_resolver)
4755 /* Set up a step-resume breakpoint at the address
4756 indicated by SKIP_SOLIB_RESOLVER. */
4757 struct symtab_and_line sr_sal;
4760 sr_sal.pc = pc_after_resolver;
4761 sr_sal.pspace = get_frame_program_space (frame);
4763 insert_step_resume_breakpoint_at_sal (gdbarch,
4764 sr_sal, null_frame_id);
4771 if (ecs->event_thread->control.step_range_end != 1
4772 && (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
4773 || ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
4774 && get_frame_type (frame) == SIGTRAMP_FRAME)
4777 fprintf_unfiltered (gdb_stdlog,
4778 "infrun: stepped into signal trampoline\n");
4779 /* The inferior, while doing a "step" or "next", has ended up in
4780 a signal trampoline (either by a signal being delivered or by
4781 the signal handler returning). Just single-step until the
4782 inferior leaves the trampoline (either by calling the handler
4788 /* If we're in the return path from a shared library trampoline,
4789 we want to proceed through the trampoline when stepping. */
4790 /* macro/2012-04-25: This needs to come before the subroutine
4791 call check below as on some targets return trampolines look
4792 like subroutine calls (MIPS16 return thunks). */
4793 if (gdbarch_in_solib_return_trampoline (gdbarch,
4794 stop_pc, ecs->stop_func_name)
4795 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE)
4797 /* Determine where this trampoline returns. */
4798 CORE_ADDR real_stop_pc;
4800 real_stop_pc = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc);
4803 fprintf_unfiltered (gdb_stdlog,
4804 "infrun: stepped into solib return tramp\n");
4806 /* Only proceed through if we know where it's going. */
4809 /* And put the step-breakpoint there and go until there. */
4810 struct symtab_and_line sr_sal;
4812 init_sal (&sr_sal); /* initialize to zeroes */
4813 sr_sal.pc = real_stop_pc;
4814 sr_sal.section = find_pc_overlay (sr_sal.pc);
4815 sr_sal.pspace = get_frame_program_space (frame);
4817 /* Do not specify what the fp should be when we stop since
4818 on some machines the prologue is where the new fp value
4820 insert_step_resume_breakpoint_at_sal (gdbarch,
4821 sr_sal, null_frame_id);
4823 /* Restart without fiddling with the step ranges or
4830 /* Check for subroutine calls. The check for the current frame
4831 equalling the step ID is not necessary - the check of the
4832 previous frame's ID is sufficient - but it is a common case and
4833 cheaper than checking the previous frame's ID.
4835 NOTE: frame_id_eq will never report two invalid frame IDs as
4836 being equal, so to get into this block, both the current and
4837 previous frame must have valid frame IDs. */
4838 /* The outer_frame_id check is a heuristic to detect stepping
4839 through startup code. If we step over an instruction which
4840 sets the stack pointer from an invalid value to a valid value,
4841 we may detect that as a subroutine call from the mythical
4842 "outermost" function. This could be fixed by marking
4843 outermost frames as !stack_p,code_p,special_p. Then the
4844 initial outermost frame, before sp was valid, would
4845 have code_addr == &_start. See the comment in frame_id_eq
4847 if (!frame_id_eq (get_stack_frame_id (frame),
4848 ecs->event_thread->control.step_stack_frame_id)
4849 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
4850 ecs->event_thread->control.step_stack_frame_id)
4851 && (!frame_id_eq (ecs->event_thread->control.step_stack_frame_id,
4853 || step_start_function != find_pc_function (stop_pc))))
4855 CORE_ADDR real_stop_pc;
4858 fprintf_unfiltered (gdb_stdlog, "infrun: stepped into subroutine\n");
4860 if ((ecs->event_thread->control.step_over_calls == STEP_OVER_NONE)
4861 || ((ecs->event_thread->control.step_range_end == 1)
4862 && in_prologue (gdbarch, ecs->event_thread->prev_pc,
4863 ecs->stop_func_start)))
4865 /* I presume that step_over_calls is only 0 when we're
4866 supposed to be stepping at the assembly language level
4867 ("stepi"). Just stop. */
4868 /* Also, maybe we just did a "nexti" inside a prolog, so we
4869 thought it was a subroutine call but it was not. Stop as
4871 /* And this works the same backward as frontward. MVS */
4872 ecs->event_thread->control.stop_step = 1;
4873 print_end_stepping_range_reason ();
4874 stop_stepping (ecs);
4878 /* Reverse stepping through solib trampolines. */
4880 if (execution_direction == EXEC_REVERSE
4881 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE
4882 && (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc)
4883 || (ecs->stop_func_start == 0
4884 && in_solib_dynsym_resolve_code (stop_pc))))
4886 /* Any solib trampoline code can be handled in reverse
4887 by simply continuing to single-step. We have already
4888 executed the solib function (backwards), and a few
4889 steps will take us back through the trampoline to the
4895 if (ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
4897 /* We're doing a "next".
4899 Normal (forward) execution: set a breakpoint at the
4900 callee's return address (the address at which the caller
4903 Reverse (backward) execution. set the step-resume
4904 breakpoint at the start of the function that we just
4905 stepped into (backwards), and continue to there. When we
4906 get there, we'll need to single-step back to the caller. */
4908 if (execution_direction == EXEC_REVERSE)
4910 /* If we're already at the start of the function, we've either
4911 just stepped backward into a single instruction function,
4912 or stepped back out of a signal handler to the first instruction
4913 of the function. Just keep going, which will single-step back
4915 if (ecs->stop_func_start != stop_pc)
4917 struct symtab_and_line sr_sal;
4919 /* Normal function call return (static or dynamic). */
4921 sr_sal.pc = ecs->stop_func_start;
4922 sr_sal.pspace = get_frame_program_space (frame);
4923 insert_step_resume_breakpoint_at_sal (gdbarch,
4924 sr_sal, null_frame_id);
4928 insert_step_resume_breakpoint_at_caller (frame);
4934 /* If we are in a function call trampoline (a stub between the
4935 calling routine and the real function), locate the real
4936 function. That's what tells us (a) whether we want to step
4937 into it at all, and (b) what prologue we want to run to the
4938 end of, if we do step into it. */
4939 real_stop_pc = skip_language_trampoline (frame, stop_pc);
4940 if (real_stop_pc == 0)
4941 real_stop_pc = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc);
4942 if (real_stop_pc != 0)
4943 ecs->stop_func_start = real_stop_pc;
4945 if (real_stop_pc != 0 && in_solib_dynsym_resolve_code (real_stop_pc))
4947 struct symtab_and_line sr_sal;
4950 sr_sal.pc = ecs->stop_func_start;
4951 sr_sal.pspace = get_frame_program_space (frame);
4953 insert_step_resume_breakpoint_at_sal (gdbarch,
4954 sr_sal, null_frame_id);
4959 /* If we have line number information for the function we are
4960 thinking of stepping into and the function isn't on the skip
4963 If there are several symtabs at that PC (e.g. with include
4964 files), just want to know whether *any* of them have line
4965 numbers. find_pc_line handles this. */
4967 struct symtab_and_line tmp_sal;
4969 tmp_sal = find_pc_line (ecs->stop_func_start, 0);
4970 if (tmp_sal.line != 0
4971 && !function_pc_is_marked_for_skip (ecs->stop_func_start))
4973 if (execution_direction == EXEC_REVERSE)
4974 handle_step_into_function_backward (gdbarch, ecs);
4976 handle_step_into_function (gdbarch, ecs);
4981 /* If we have no line number and the step-stop-if-no-debug is
4982 set, we stop the step so that the user has a chance to switch
4983 in assembly mode. */
4984 if (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
4985 && step_stop_if_no_debug)
4987 ecs->event_thread->control.stop_step = 1;
4988 print_end_stepping_range_reason ();
4989 stop_stepping (ecs);
4993 if (execution_direction == EXEC_REVERSE)
4995 /* If we're already at the start of the function, we've either just
4996 stepped backward into a single instruction function without line
4997 number info, or stepped back out of a signal handler to the first
4998 instruction of the function without line number info. Just keep
4999 going, which will single-step back to the caller. */
5000 if (ecs->stop_func_start != stop_pc)
5002 /* Set a breakpoint at callee's start address.
5003 From there we can step once and be back in the caller. */
5004 struct symtab_and_line sr_sal;
5007 sr_sal.pc = ecs->stop_func_start;
5008 sr_sal.pspace = get_frame_program_space (frame);
5009 insert_step_resume_breakpoint_at_sal (gdbarch,
5010 sr_sal, null_frame_id);
5014 /* Set a breakpoint at callee's return address (the address
5015 at which the caller will resume). */
5016 insert_step_resume_breakpoint_at_caller (frame);
5022 /* Reverse stepping through solib trampolines. */
5024 if (execution_direction == EXEC_REVERSE
5025 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE)
5027 if (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc)
5028 || (ecs->stop_func_start == 0
5029 && in_solib_dynsym_resolve_code (stop_pc)))
5031 /* Any solib trampoline code can be handled in reverse
5032 by simply continuing to single-step. We have already
5033 executed the solib function (backwards), and a few
5034 steps will take us back through the trampoline to the
5039 else if (in_solib_dynsym_resolve_code (stop_pc))
5041 /* Stepped backward into the solib dynsym resolver.
5042 Set a breakpoint at its start and continue, then
5043 one more step will take us out. */
5044 struct symtab_and_line sr_sal;
5047 sr_sal.pc = ecs->stop_func_start;
5048 sr_sal.pspace = get_frame_program_space (frame);
5049 insert_step_resume_breakpoint_at_sal (gdbarch,
5050 sr_sal, null_frame_id);
5056 stop_pc_sal = find_pc_line (stop_pc, 0);
5058 /* NOTE: tausq/2004-05-24: This if block used to be done before all
5059 the trampoline processing logic, however, there are some trampolines
5060 that have no names, so we should do trampoline handling first. */
5061 if (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
5062 && ecs->stop_func_name == NULL
5063 && stop_pc_sal.line == 0)
5066 fprintf_unfiltered (gdb_stdlog,
5067 "infrun: stepped into undebuggable function\n");
5069 /* The inferior just stepped into, or returned to, an
5070 undebuggable function (where there is no debugging information
5071 and no line number corresponding to the address where the
5072 inferior stopped). Since we want to skip this kind of code,
5073 we keep going until the inferior returns from this
5074 function - unless the user has asked us not to (via
5075 set step-mode) or we no longer know how to get back
5076 to the call site. */
5077 if (step_stop_if_no_debug
5078 || !frame_id_p (frame_unwind_caller_id (frame)))
5080 /* If we have no line number and the step-stop-if-no-debug
5081 is set, we stop the step so that the user has a chance to
5082 switch in assembly mode. */
5083 ecs->event_thread->control.stop_step = 1;
5084 print_end_stepping_range_reason ();
5085 stop_stepping (ecs);
5090 /* Set a breakpoint at callee's return address (the address
5091 at which the caller will resume). */
5092 insert_step_resume_breakpoint_at_caller (frame);
5098 if (ecs->event_thread->control.step_range_end == 1)
5100 /* It is stepi or nexti. We always want to stop stepping after
5103 fprintf_unfiltered (gdb_stdlog, "infrun: stepi/nexti\n");
5104 ecs->event_thread->control.stop_step = 1;
5105 print_end_stepping_range_reason ();
5106 stop_stepping (ecs);
5110 if (stop_pc_sal.line == 0)
5112 /* We have no line number information. That means to stop
5113 stepping (does this always happen right after one instruction,
5114 when we do "s" in a function with no line numbers,
5115 or can this happen as a result of a return or longjmp?). */
5117 fprintf_unfiltered (gdb_stdlog, "infrun: no line number info\n");
5118 ecs->event_thread->control.stop_step = 1;
5119 print_end_stepping_range_reason ();
5120 stop_stepping (ecs);
5124 /* Look for "calls" to inlined functions, part one. If the inline
5125 frame machinery detected some skipped call sites, we have entered
5126 a new inline function. */
5128 if (frame_id_eq (get_frame_id (get_current_frame ()),
5129 ecs->event_thread->control.step_frame_id)
5130 && inline_skipped_frames (ecs->ptid))
5132 struct symtab_and_line call_sal;
5135 fprintf_unfiltered (gdb_stdlog,
5136 "infrun: stepped into inlined function\n");
5138 find_frame_sal (get_current_frame (), &call_sal);
5140 if (ecs->event_thread->control.step_over_calls != STEP_OVER_ALL)
5142 /* For "step", we're going to stop. But if the call site
5143 for this inlined function is on the same source line as
5144 we were previously stepping, go down into the function
5145 first. Otherwise stop at the call site. */
5147 if (call_sal.line == ecs->event_thread->current_line
5148 && call_sal.symtab == ecs->event_thread->current_symtab)
5149 step_into_inline_frame (ecs->ptid);
5151 ecs->event_thread->control.stop_step = 1;
5152 print_end_stepping_range_reason ();
5153 stop_stepping (ecs);
5158 /* For "next", we should stop at the call site if it is on a
5159 different source line. Otherwise continue through the
5160 inlined function. */
5161 if (call_sal.line == ecs->event_thread->current_line
5162 && call_sal.symtab == ecs->event_thread->current_symtab)
5166 ecs->event_thread->control.stop_step = 1;
5167 print_end_stepping_range_reason ();
5168 stop_stepping (ecs);
5174 /* Look for "calls" to inlined functions, part two. If we are still
5175 in the same real function we were stepping through, but we have
5176 to go further up to find the exact frame ID, we are stepping
5177 through a more inlined call beyond its call site. */
5179 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
5180 && !frame_id_eq (get_frame_id (get_current_frame ()),
5181 ecs->event_thread->control.step_frame_id)
5182 && stepped_in_from (get_current_frame (),
5183 ecs->event_thread->control.step_frame_id))
5186 fprintf_unfiltered (gdb_stdlog,
5187 "infrun: stepping through inlined function\n");
5189 if (ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
5193 ecs->event_thread->control.stop_step = 1;
5194 print_end_stepping_range_reason ();
5195 stop_stepping (ecs);
5200 if ((stop_pc == stop_pc_sal.pc)
5201 && (ecs->event_thread->current_line != stop_pc_sal.line
5202 || ecs->event_thread->current_symtab != stop_pc_sal.symtab))
5204 /* We are at the start of a different line. So stop. Note that
5205 we don't stop if we step into the middle of a different line.
5206 That is said to make things like for (;;) statements work
5209 fprintf_unfiltered (gdb_stdlog,
5210 "infrun: stepped to a different line\n");
5211 ecs->event_thread->control.stop_step = 1;
5212 print_end_stepping_range_reason ();
5213 stop_stepping (ecs);
5217 /* We aren't done stepping.
5219 Optimize by setting the stepping range to the line.
5220 (We might not be in the original line, but if we entered a
5221 new line in mid-statement, we continue stepping. This makes
5222 things like for(;;) statements work better.) */
5224 ecs->event_thread->control.step_range_start = stop_pc_sal.pc;
5225 ecs->event_thread->control.step_range_end = stop_pc_sal.end;
5226 set_step_info (frame, stop_pc_sal);
5229 fprintf_unfiltered (gdb_stdlog, "infrun: keep going\n");
5233 /* Is thread TP in the middle of single-stepping? */
5236 currently_stepping (struct thread_info *tp)
5238 return ((tp->control.step_range_end
5239 && tp->control.step_resume_breakpoint == NULL)
5240 || tp->control.trap_expected
5241 || bpstat_should_step ());
5244 /* Returns true if any thread *but* the one passed in "data" is in the
5245 middle of stepping or of handling a "next". */
5248 currently_stepping_or_nexting_callback (struct thread_info *tp, void *data)
5253 return (tp->control.step_range_end
5254 || tp->control.trap_expected);
5257 /* Inferior has stepped into a subroutine call with source code that
5258 we should not step over. Do step to the first line of code in
5262 handle_step_into_function (struct gdbarch *gdbarch,
5263 struct execution_control_state *ecs)
5266 struct symtab_and_line stop_func_sal, sr_sal;
5268 fill_in_stop_func (gdbarch, ecs);
5270 s = find_pc_symtab (stop_pc);
5271 if (s && s->language != language_asm)
5272 ecs->stop_func_start = gdbarch_skip_prologue (gdbarch,
5273 ecs->stop_func_start);
5275 stop_func_sal = find_pc_line (ecs->stop_func_start, 0);
5276 /* Use the step_resume_break to step until the end of the prologue,
5277 even if that involves jumps (as it seems to on the vax under
5279 /* If the prologue ends in the middle of a source line, continue to
5280 the end of that source line (if it is still within the function).
5281 Otherwise, just go to end of prologue. */
5282 if (stop_func_sal.end
5283 && stop_func_sal.pc != ecs->stop_func_start
5284 && stop_func_sal.end < ecs->stop_func_end)
5285 ecs->stop_func_start = stop_func_sal.end;
5287 /* Architectures which require breakpoint adjustment might not be able
5288 to place a breakpoint at the computed address. If so, the test
5289 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
5290 ecs->stop_func_start to an address at which a breakpoint may be
5291 legitimately placed.
5293 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
5294 made, GDB will enter an infinite loop when stepping through
5295 optimized code consisting of VLIW instructions which contain
5296 subinstructions corresponding to different source lines. On
5297 FR-V, it's not permitted to place a breakpoint on any but the
5298 first subinstruction of a VLIW instruction. When a breakpoint is
5299 set, GDB will adjust the breakpoint address to the beginning of
5300 the VLIW instruction. Thus, we need to make the corresponding
5301 adjustment here when computing the stop address. */
5303 if (gdbarch_adjust_breakpoint_address_p (gdbarch))
5305 ecs->stop_func_start
5306 = gdbarch_adjust_breakpoint_address (gdbarch,
5307 ecs->stop_func_start);
5310 if (ecs->stop_func_start == stop_pc)
5312 /* We are already there: stop now. */
5313 ecs->event_thread->control.stop_step = 1;
5314 print_end_stepping_range_reason ();
5315 stop_stepping (ecs);
5320 /* Put the step-breakpoint there and go until there. */
5321 init_sal (&sr_sal); /* initialize to zeroes */
5322 sr_sal.pc = ecs->stop_func_start;
5323 sr_sal.section = find_pc_overlay (ecs->stop_func_start);
5324 sr_sal.pspace = get_frame_program_space (get_current_frame ());
5326 /* Do not specify what the fp should be when we stop since on
5327 some machines the prologue is where the new fp value is
5329 insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal, null_frame_id);
5331 /* And make sure stepping stops right away then. */
5332 ecs->event_thread->control.step_range_end
5333 = ecs->event_thread->control.step_range_start;
5338 /* Inferior has stepped backward into a subroutine call with source
5339 code that we should not step over. Do step to the beginning of the
5340 last line of code in it. */
5343 handle_step_into_function_backward (struct gdbarch *gdbarch,
5344 struct execution_control_state *ecs)
5347 struct symtab_and_line stop_func_sal;
5349 fill_in_stop_func (gdbarch, ecs);
5351 s = find_pc_symtab (stop_pc);
5352 if (s && s->language != language_asm)
5353 ecs->stop_func_start = gdbarch_skip_prologue (gdbarch,
5354 ecs->stop_func_start);
5356 stop_func_sal = find_pc_line (stop_pc, 0);
5358 /* OK, we're just going to keep stepping here. */
5359 if (stop_func_sal.pc == stop_pc)
5361 /* We're there already. Just stop stepping now. */
5362 ecs->event_thread->control.stop_step = 1;
5363 print_end_stepping_range_reason ();
5364 stop_stepping (ecs);
5368 /* Else just reset the step range and keep going.
5369 No step-resume breakpoint, they don't work for
5370 epilogues, which can have multiple entry paths. */
5371 ecs->event_thread->control.step_range_start = stop_func_sal.pc;
5372 ecs->event_thread->control.step_range_end = stop_func_sal.end;
5378 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
5379 This is used to both functions and to skip over code. */
5382 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch *gdbarch,
5383 struct symtab_and_line sr_sal,
5384 struct frame_id sr_id,
5385 enum bptype sr_type)
5387 /* There should never be more than one step-resume or longjmp-resume
5388 breakpoint per thread, so we should never be setting a new
5389 step_resume_breakpoint when one is already active. */
5390 gdb_assert (inferior_thread ()->control.step_resume_breakpoint == NULL);
5391 gdb_assert (sr_type == bp_step_resume || sr_type == bp_hp_step_resume);
5394 fprintf_unfiltered (gdb_stdlog,
5395 "infrun: inserting step-resume breakpoint at %s\n",
5396 paddress (gdbarch, sr_sal.pc));
5398 inferior_thread ()->control.step_resume_breakpoint
5399 = set_momentary_breakpoint (gdbarch, sr_sal, sr_id, sr_type);
5403 insert_step_resume_breakpoint_at_sal (struct gdbarch *gdbarch,
5404 struct symtab_and_line sr_sal,
5405 struct frame_id sr_id)
5407 insert_step_resume_breakpoint_at_sal_1 (gdbarch,
5412 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
5413 This is used to skip a potential signal handler.
5415 This is called with the interrupted function's frame. The signal
5416 handler, when it returns, will resume the interrupted function at
5420 insert_hp_step_resume_breakpoint_at_frame (struct frame_info *return_frame)
5422 struct symtab_and_line sr_sal;
5423 struct gdbarch *gdbarch;
5425 gdb_assert (return_frame != NULL);
5426 init_sal (&sr_sal); /* initialize to zeros */
5428 gdbarch = get_frame_arch (return_frame);
5429 sr_sal.pc = gdbarch_addr_bits_remove (gdbarch, get_frame_pc (return_frame));
5430 sr_sal.section = find_pc_overlay (sr_sal.pc);
5431 sr_sal.pspace = get_frame_program_space (return_frame);
5433 insert_step_resume_breakpoint_at_sal_1 (gdbarch, sr_sal,
5434 get_stack_frame_id (return_frame),
5438 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
5439 is used to skip a function after stepping into it (for "next" or if
5440 the called function has no debugging information).
5442 The current function has almost always been reached by single
5443 stepping a call or return instruction. NEXT_FRAME belongs to the
5444 current function, and the breakpoint will be set at the caller's
5447 This is a separate function rather than reusing
5448 insert_hp_step_resume_breakpoint_at_frame in order to avoid
5449 get_prev_frame, which may stop prematurely (see the implementation
5450 of frame_unwind_caller_id for an example). */
5453 insert_step_resume_breakpoint_at_caller (struct frame_info *next_frame)
5455 struct symtab_and_line sr_sal;
5456 struct gdbarch *gdbarch;
5458 /* We shouldn't have gotten here if we don't know where the call site
5460 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame)));
5462 init_sal (&sr_sal); /* initialize to zeros */
5464 gdbarch = frame_unwind_caller_arch (next_frame);
5465 sr_sal.pc = gdbarch_addr_bits_remove (gdbarch,
5466 frame_unwind_caller_pc (next_frame));
5467 sr_sal.section = find_pc_overlay (sr_sal.pc);
5468 sr_sal.pspace = frame_unwind_program_space (next_frame);
5470 insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal,
5471 frame_unwind_caller_id (next_frame));
5474 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
5475 new breakpoint at the target of a jmp_buf. The handling of
5476 longjmp-resume uses the same mechanisms used for handling
5477 "step-resume" breakpoints. */
5480 insert_longjmp_resume_breakpoint (struct gdbarch *gdbarch, CORE_ADDR pc)
5482 /* There should never be more than one longjmp-resume breakpoint per
5483 thread, so we should never be setting a new
5484 longjmp_resume_breakpoint when one is already active. */
5485 gdb_assert (inferior_thread ()->control.exception_resume_breakpoint == NULL);
5488 fprintf_unfiltered (gdb_stdlog,
5489 "infrun: inserting longjmp-resume breakpoint at %s\n",
5490 paddress (gdbarch, pc));
5492 inferior_thread ()->control.exception_resume_breakpoint =
5493 set_momentary_breakpoint_at_pc (gdbarch, pc, bp_longjmp_resume);
5496 /* Insert an exception resume breakpoint. TP is the thread throwing
5497 the exception. The block B is the block of the unwinder debug hook
5498 function. FRAME is the frame corresponding to the call to this
5499 function. SYM is the symbol of the function argument holding the
5500 target PC of the exception. */
5503 insert_exception_resume_breakpoint (struct thread_info *tp,
5505 struct frame_info *frame,
5508 volatile struct gdb_exception e;
5510 /* We want to ignore errors here. */
5511 TRY_CATCH (e, RETURN_MASK_ERROR)
5513 struct symbol *vsym;
5514 struct value *value;
5516 struct breakpoint *bp;
5518 vsym = lookup_symbol (SYMBOL_LINKAGE_NAME (sym), b, VAR_DOMAIN, NULL);
5519 value = read_var_value (vsym, frame);
5520 /* If the value was optimized out, revert to the old behavior. */
5521 if (! value_optimized_out (value))
5523 handler = value_as_address (value);
5526 fprintf_unfiltered (gdb_stdlog,
5527 "infrun: exception resume at %lx\n",
5528 (unsigned long) handler);
5530 bp = set_momentary_breakpoint_at_pc (get_frame_arch (frame),
5531 handler, bp_exception_resume);
5533 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
5536 bp->thread = tp->num;
5537 inferior_thread ()->control.exception_resume_breakpoint = bp;
5542 /* A helper for check_exception_resume that sets an
5543 exception-breakpoint based on a SystemTap probe. */
5546 insert_exception_resume_from_probe (struct thread_info *tp,
5547 const struct probe *probe,
5548 struct frame_info *frame)
5550 struct value *arg_value;
5552 struct breakpoint *bp;
5554 arg_value = probe_safe_evaluate_at_pc (frame, 1);
5558 handler = value_as_address (arg_value);
5561 fprintf_unfiltered (gdb_stdlog,
5562 "infrun: exception resume at %s\n",
5563 paddress (get_objfile_arch (probe->objfile),
5566 bp = set_momentary_breakpoint_at_pc (get_frame_arch (frame),
5567 handler, bp_exception_resume);
5568 bp->thread = tp->num;
5569 inferior_thread ()->control.exception_resume_breakpoint = bp;
5572 /* This is called when an exception has been intercepted. Check to
5573 see whether the exception's destination is of interest, and if so,
5574 set an exception resume breakpoint there. */
5577 check_exception_resume (struct execution_control_state *ecs,
5578 struct frame_info *frame)
5580 volatile struct gdb_exception e;
5581 const struct probe *probe;
5582 struct symbol *func;
5584 /* First see if this exception unwinding breakpoint was set via a
5585 SystemTap probe point. If so, the probe has two arguments: the
5586 CFA and the HANDLER. We ignore the CFA, extract the handler, and
5587 set a breakpoint there. */
5588 probe = find_probe_by_pc (get_frame_pc (frame));
5591 insert_exception_resume_from_probe (ecs->event_thread, probe, frame);
5595 func = get_frame_function (frame);
5599 TRY_CATCH (e, RETURN_MASK_ERROR)
5602 struct block_iterator iter;
5606 /* The exception breakpoint is a thread-specific breakpoint on
5607 the unwinder's debug hook, declared as:
5609 void _Unwind_DebugHook (void *cfa, void *handler);
5611 The CFA argument indicates the frame to which control is
5612 about to be transferred. HANDLER is the destination PC.
5614 We ignore the CFA and set a temporary breakpoint at HANDLER.
5615 This is not extremely efficient but it avoids issues in gdb
5616 with computing the DWARF CFA, and it also works even in weird
5617 cases such as throwing an exception from inside a signal
5620 b = SYMBOL_BLOCK_VALUE (func);
5621 ALL_BLOCK_SYMBOLS (b, iter, sym)
5623 if (!SYMBOL_IS_ARGUMENT (sym))
5630 insert_exception_resume_breakpoint (ecs->event_thread,
5639 stop_stepping (struct execution_control_state *ecs)
5642 fprintf_unfiltered (gdb_stdlog, "infrun: stop_stepping\n");
5644 /* Let callers know we don't want to wait for the inferior anymore. */
5645 ecs->wait_some_more = 0;
5648 /* This function handles various cases where we need to continue
5649 waiting for the inferior. */
5650 /* (Used to be the keep_going: label in the old wait_for_inferior). */
5653 keep_going (struct execution_control_state *ecs)
5655 /* Make sure normal_stop is called if we get a QUIT handled before
5657 struct cleanup *old_cleanups = make_cleanup (resume_cleanups, 0);
5659 /* Save the pc before execution, to compare with pc after stop. */
5660 ecs->event_thread->prev_pc
5661 = regcache_read_pc (get_thread_regcache (ecs->ptid));
5663 /* If we did not do break;, it means we should keep running the
5664 inferior and not return to debugger. */
5666 if (ecs->event_thread->control.trap_expected
5667 && ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_TRAP)
5669 /* We took a signal (which we are supposed to pass through to
5670 the inferior, else we'd not get here) and we haven't yet
5671 gotten our trap. Simply continue. */
5673 discard_cleanups (old_cleanups);
5674 resume (currently_stepping (ecs->event_thread),
5675 ecs->event_thread->suspend.stop_signal);
5679 /* Either the trap was not expected, but we are continuing
5680 anyway (the user asked that this signal be passed to the
5683 The signal was SIGTRAP, e.g. it was our signal, but we
5684 decided we should resume from it.
5686 We're going to run this baby now!
5688 Note that insert_breakpoints won't try to re-insert
5689 already inserted breakpoints. Therefore, we don't
5690 care if breakpoints were already inserted, or not. */
5692 if (ecs->event_thread->stepping_over_breakpoint)
5694 struct regcache *thread_regcache = get_thread_regcache (ecs->ptid);
5696 if (!use_displaced_stepping (get_regcache_arch (thread_regcache)))
5697 /* Since we can't do a displaced step, we have to remove
5698 the breakpoint while we step it. To keep things
5699 simple, we remove them all. */
5700 remove_breakpoints ();
5704 volatile struct gdb_exception e;
5706 /* Stop stepping when inserting breakpoints
5708 TRY_CATCH (e, RETURN_MASK_ERROR)
5710 insert_breakpoints ();
5714 exception_print (gdb_stderr, e);
5715 stop_stepping (ecs);
5720 ecs->event_thread->control.trap_expected
5721 = ecs->event_thread->stepping_over_breakpoint;
5723 /* Do not deliver SIGNAL_TRAP (except when the user explicitly
5724 specifies that such a signal should be delivered to the
5727 Typically, this would occure when a user is debugging a
5728 target monitor on a simulator: the target monitor sets a
5729 breakpoint; the simulator encounters this break-point and
5730 halts the simulation handing control to GDB; GDB, noteing
5731 that the break-point isn't valid, returns control back to the
5732 simulator; the simulator then delivers the hardware
5733 equivalent of a SIGNAL_TRAP to the program being debugged. */
5735 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5736 && !signal_program[ecs->event_thread->suspend.stop_signal])
5737 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5739 discard_cleanups (old_cleanups);
5740 resume (currently_stepping (ecs->event_thread),
5741 ecs->event_thread->suspend.stop_signal);
5744 prepare_to_wait (ecs);
5747 /* This function normally comes after a resume, before
5748 handle_inferior_event exits. It takes care of any last bits of
5749 housekeeping, and sets the all-important wait_some_more flag. */
5752 prepare_to_wait (struct execution_control_state *ecs)
5755 fprintf_unfiltered (gdb_stdlog, "infrun: prepare_to_wait\n");
5757 /* This is the old end of the while loop. Let everybody know we
5758 want to wait for the inferior some more and get called again
5760 ecs->wait_some_more = 1;
5763 /* Several print_*_reason functions to print why the inferior has stopped.
5764 We always print something when the inferior exits, or receives a signal.
5765 The rest of the cases are dealt with later on in normal_stop and
5766 print_it_typical. Ideally there should be a call to one of these
5767 print_*_reason functions functions from handle_inferior_event each time
5768 stop_stepping is called. */
5770 /* Print why the inferior has stopped.
5771 We are done with a step/next/si/ni command, print why the inferior has
5772 stopped. For now print nothing. Print a message only if not in the middle
5773 of doing a "step n" operation for n > 1. */
5776 print_end_stepping_range_reason (void)
5778 if ((!inferior_thread ()->step_multi
5779 || !inferior_thread ()->control.stop_step)
5780 && ui_out_is_mi_like_p (current_uiout))
5781 ui_out_field_string (current_uiout, "reason",
5782 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE));
5785 /* The inferior was terminated by a signal, print why it stopped. */
5788 print_signal_exited_reason (enum gdb_signal siggnal)
5790 struct ui_out *uiout = current_uiout;
5792 annotate_signalled ();
5793 if (ui_out_is_mi_like_p (uiout))
5795 (uiout, "reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED));
5796 ui_out_text (uiout, "\nProgram terminated with signal ");
5797 annotate_signal_name ();
5798 ui_out_field_string (uiout, "signal-name",
5799 gdb_signal_to_name (siggnal));
5800 annotate_signal_name_end ();
5801 ui_out_text (uiout, ", ");
5802 annotate_signal_string ();
5803 ui_out_field_string (uiout, "signal-meaning",
5804 gdb_signal_to_string (siggnal));
5805 annotate_signal_string_end ();
5806 ui_out_text (uiout, ".\n");
5807 ui_out_text (uiout, "The program no longer exists.\n");
5810 /* The inferior program is finished, print why it stopped. */
5813 print_exited_reason (int exitstatus)
5815 struct inferior *inf = current_inferior ();
5816 const char *pidstr = target_pid_to_str (pid_to_ptid (inf->pid));
5817 struct ui_out *uiout = current_uiout;
5819 annotate_exited (exitstatus);
5822 if (ui_out_is_mi_like_p (uiout))
5823 ui_out_field_string (uiout, "reason",
5824 async_reason_lookup (EXEC_ASYNC_EXITED));
5825 ui_out_text (uiout, "[Inferior ");
5826 ui_out_text (uiout, plongest (inf->num));
5827 ui_out_text (uiout, " (");
5828 ui_out_text (uiout, pidstr);
5829 ui_out_text (uiout, ") exited with code ");
5830 ui_out_field_fmt (uiout, "exit-code", "0%o", (unsigned int) exitstatus);
5831 ui_out_text (uiout, "]\n");
5835 if (ui_out_is_mi_like_p (uiout))
5837 (uiout, "reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY));
5838 ui_out_text (uiout, "[Inferior ");
5839 ui_out_text (uiout, plongest (inf->num));
5840 ui_out_text (uiout, " (");
5841 ui_out_text (uiout, pidstr);
5842 ui_out_text (uiout, ") exited normally]\n");
5844 /* Support the --return-child-result option. */
5845 return_child_result_value = exitstatus;
5848 /* Signal received, print why the inferior has stopped. The signal table
5849 tells us to print about it. */
5852 print_signal_received_reason (enum gdb_signal siggnal)
5854 struct ui_out *uiout = current_uiout;
5858 if (siggnal == GDB_SIGNAL_0 && !ui_out_is_mi_like_p (uiout))
5860 struct thread_info *t = inferior_thread ();
5862 ui_out_text (uiout, "\n[");
5863 ui_out_field_string (uiout, "thread-name",
5864 target_pid_to_str (t->ptid));
5865 ui_out_field_fmt (uiout, "thread-id", "] #%d", t->num);
5866 ui_out_text (uiout, " stopped");
5870 ui_out_text (uiout, "\nProgram received signal ");
5871 annotate_signal_name ();
5872 if (ui_out_is_mi_like_p (uiout))
5874 (uiout, "reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED));
5875 ui_out_field_string (uiout, "signal-name",
5876 gdb_signal_to_name (siggnal));
5877 annotate_signal_name_end ();
5878 ui_out_text (uiout, ", ");
5879 annotate_signal_string ();
5880 ui_out_field_string (uiout, "signal-meaning",
5881 gdb_signal_to_string (siggnal));
5882 annotate_signal_string_end ();
5884 ui_out_text (uiout, ".\n");
5887 /* Reverse execution: target ran out of history info, print why the inferior
5891 print_no_history_reason (void)
5893 ui_out_text (current_uiout, "\nNo more reverse-execution history.\n");
5896 /* Here to return control to GDB when the inferior stops for real.
5897 Print appropriate messages, remove breakpoints, give terminal our modes.
5899 STOP_PRINT_FRAME nonzero means print the executing frame
5900 (pc, function, args, file, line number and line text).
5901 BREAKPOINTS_FAILED nonzero means stop was due to error
5902 attempting to insert breakpoints. */
5907 struct target_waitstatus last;
5909 struct cleanup *old_chain = make_cleanup (null_cleanup, NULL);
5911 get_last_target_status (&last_ptid, &last);
5913 /* If an exception is thrown from this point on, make sure to
5914 propagate GDB's knowledge of the executing state to the
5915 frontend/user running state. A QUIT is an easy exception to see
5916 here, so do this before any filtered output. */
5918 make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
5919 else if (last.kind != TARGET_WAITKIND_SIGNALLED
5920 && last.kind != TARGET_WAITKIND_EXITED
5921 && last.kind != TARGET_WAITKIND_NO_RESUMED)
5922 make_cleanup (finish_thread_state_cleanup, &inferior_ptid);
5924 /* In non-stop mode, we don't want GDB to switch threads behind the
5925 user's back, to avoid races where the user is typing a command to
5926 apply to thread x, but GDB switches to thread y before the user
5927 finishes entering the command. */
5929 /* As with the notification of thread events, we want to delay
5930 notifying the user that we've switched thread context until
5931 the inferior actually stops.
5933 There's no point in saying anything if the inferior has exited.
5934 Note that SIGNALLED here means "exited with a signal", not
5935 "received a signal". */
5937 && !ptid_equal (previous_inferior_ptid, inferior_ptid)
5938 && target_has_execution
5939 && last.kind != TARGET_WAITKIND_SIGNALLED
5940 && last.kind != TARGET_WAITKIND_EXITED
5941 && last.kind != TARGET_WAITKIND_NO_RESUMED)
5943 target_terminal_ours_for_output ();
5944 printf_filtered (_("[Switching to %s]\n"),
5945 target_pid_to_str (inferior_ptid));
5946 annotate_thread_changed ();
5947 previous_inferior_ptid = inferior_ptid;
5950 if (last.kind == TARGET_WAITKIND_NO_RESUMED)
5952 gdb_assert (sync_execution || !target_can_async_p ());
5954 target_terminal_ours_for_output ();
5955 printf_filtered (_("No unwaited-for children left.\n"));
5958 if (!breakpoints_always_inserted_mode () && target_has_execution)
5960 if (remove_breakpoints ())
5962 target_terminal_ours_for_output ();
5963 printf_filtered (_("Cannot remove breakpoints because "
5964 "program is no longer writable.\nFurther "
5965 "execution is probably impossible.\n"));
5969 /* If an auto-display called a function and that got a signal,
5970 delete that auto-display to avoid an infinite recursion. */
5972 if (stopped_by_random_signal)
5973 disable_current_display ();
5975 /* Don't print a message if in the middle of doing a "step n"
5976 operation for n > 1 */
5977 if (target_has_execution
5978 && last.kind != TARGET_WAITKIND_SIGNALLED
5979 && last.kind != TARGET_WAITKIND_EXITED
5980 && inferior_thread ()->step_multi
5981 && inferior_thread ()->control.stop_step)
5984 target_terminal_ours ();
5985 async_enable_stdin ();
5987 /* Set the current source location. This will also happen if we
5988 display the frame below, but the current SAL will be incorrect
5989 during a user hook-stop function. */
5990 if (has_stack_frames () && !stop_stack_dummy)
5991 set_current_sal_from_frame (get_current_frame (), 1);
5993 /* Let the user/frontend see the threads as stopped. */
5994 do_cleanups (old_chain);
5996 /* Look up the hook_stop and run it (CLI internally handles problem
5997 of stop_command's pre-hook not existing). */
5999 catch_errors (hook_stop_stub, stop_command,
6000 "Error while running hook_stop:\n", RETURN_MASK_ALL);
6002 if (!has_stack_frames ())
6005 if (last.kind == TARGET_WAITKIND_SIGNALLED
6006 || last.kind == TARGET_WAITKIND_EXITED)
6009 /* Select innermost stack frame - i.e., current frame is frame 0,
6010 and current location is based on that.
6011 Don't do this on return from a stack dummy routine,
6012 or if the program has exited. */
6014 if (!stop_stack_dummy)
6016 select_frame (get_current_frame ());
6018 /* Print current location without a level number, if
6019 we have changed functions or hit a breakpoint.
6020 Print source line if we have one.
6021 bpstat_print() contains the logic deciding in detail
6022 what to print, based on the event(s) that just occurred. */
6024 /* If --batch-silent is enabled then there's no need to print the current
6025 source location, and to try risks causing an error message about
6026 missing source files. */
6027 if (stop_print_frame && !batch_silent)
6031 int do_frame_printing = 1;
6032 struct thread_info *tp = inferior_thread ();
6034 bpstat_ret = bpstat_print (tp->control.stop_bpstat, last.kind);
6038 /* FIXME: cagney/2002-12-01: Given that a frame ID does
6039 (or should) carry around the function and does (or
6040 should) use that when doing a frame comparison. */
6041 if (tp->control.stop_step
6042 && frame_id_eq (tp->control.step_frame_id,
6043 get_frame_id (get_current_frame ()))
6044 && step_start_function == find_pc_function (stop_pc))
6045 source_flag = SRC_LINE; /* Finished step, just
6046 print source line. */
6048 source_flag = SRC_AND_LOC; /* Print location and
6051 case PRINT_SRC_AND_LOC:
6052 source_flag = SRC_AND_LOC; /* Print location and
6055 case PRINT_SRC_ONLY:
6056 source_flag = SRC_LINE;
6059 source_flag = SRC_LINE; /* something bogus */
6060 do_frame_printing = 0;
6063 internal_error (__FILE__, __LINE__, _("Unknown value."));
6066 /* The behavior of this routine with respect to the source
6068 SRC_LINE: Print only source line
6069 LOCATION: Print only location
6070 SRC_AND_LOC: Print location and source line. */
6071 if (do_frame_printing)
6072 print_stack_frame (get_selected_frame (NULL), 0, source_flag);
6074 /* Display the auto-display expressions. */
6079 /* Save the function value return registers, if we care.
6080 We might be about to restore their previous contents. */
6081 if (inferior_thread ()->control.proceed_to_finish
6082 && execution_direction != EXEC_REVERSE)
6084 /* This should not be necessary. */
6086 regcache_xfree (stop_registers);
6088 /* NB: The copy goes through to the target picking up the value of
6089 all the registers. */
6090 stop_registers = regcache_dup (get_current_regcache ());
6093 if (stop_stack_dummy == STOP_STACK_DUMMY)
6095 /* Pop the empty frame that contains the stack dummy.
6096 This also restores inferior state prior to the call
6097 (struct infcall_suspend_state). */
6098 struct frame_info *frame = get_current_frame ();
6100 gdb_assert (get_frame_type (frame) == DUMMY_FRAME);
6102 /* frame_pop() calls reinit_frame_cache as the last thing it
6103 does which means there's currently no selected frame. We
6104 don't need to re-establish a selected frame if the dummy call
6105 returns normally, that will be done by
6106 restore_infcall_control_state. However, we do have to handle
6107 the case where the dummy call is returning after being
6108 stopped (e.g. the dummy call previously hit a breakpoint).
6109 We can't know which case we have so just always re-establish
6110 a selected frame here. */
6111 select_frame (get_current_frame ());
6115 annotate_stopped ();
6117 /* Suppress the stop observer if we're in the middle of:
6119 - a step n (n > 1), as there still more steps to be done.
6121 - a "finish" command, as the observer will be called in
6122 finish_command_continuation, so it can include the inferior
6123 function's return value.
6125 - calling an inferior function, as we pretend we inferior didn't
6126 run at all. The return value of the call is handled by the
6127 expression evaluator, through call_function_by_hand. */
6129 if (!target_has_execution
6130 || last.kind == TARGET_WAITKIND_SIGNALLED
6131 || last.kind == TARGET_WAITKIND_EXITED
6132 || last.kind == TARGET_WAITKIND_NO_RESUMED
6133 || (!(inferior_thread ()->step_multi
6134 && inferior_thread ()->control.stop_step)
6135 && !(inferior_thread ()->control.stop_bpstat
6136 && inferior_thread ()->control.proceed_to_finish)
6137 && !inferior_thread ()->control.in_infcall))
6139 if (!ptid_equal (inferior_ptid, null_ptid))
6140 observer_notify_normal_stop (inferior_thread ()->control.stop_bpstat,
6143 observer_notify_normal_stop (NULL, stop_print_frame);
6146 if (target_has_execution)
6148 if (last.kind != TARGET_WAITKIND_SIGNALLED
6149 && last.kind != TARGET_WAITKIND_EXITED)
6150 /* Delete the breakpoint we stopped at, if it wants to be deleted.
6151 Delete any breakpoint that is to be deleted at the next stop. */
6152 breakpoint_auto_delete (inferior_thread ()->control.stop_bpstat);
6155 /* Try to get rid of automatically added inferiors that are no
6156 longer needed. Keeping those around slows down things linearly.
6157 Note that this never removes the current inferior. */
6162 hook_stop_stub (void *cmd)
6164 execute_cmd_pre_hook ((struct cmd_list_element *) cmd);
6169 signal_stop_state (int signo)
6171 return signal_stop[signo];
6175 signal_print_state (int signo)
6177 return signal_print[signo];
6181 signal_pass_state (int signo)
6183 return signal_program[signo];
6187 signal_cache_update (int signo)
6191 for (signo = 0; signo < (int) GDB_SIGNAL_LAST; signo++)
6192 signal_cache_update (signo);
6197 signal_pass[signo] = (signal_stop[signo] == 0
6198 && signal_print[signo] == 0
6199 && signal_program[signo] == 1);
6203 signal_stop_update (int signo, int state)
6205 int ret = signal_stop[signo];
6207 signal_stop[signo] = state;
6208 signal_cache_update (signo);
6213 signal_print_update (int signo, int state)
6215 int ret = signal_print[signo];
6217 signal_print[signo] = state;
6218 signal_cache_update (signo);
6223 signal_pass_update (int signo, int state)
6225 int ret = signal_program[signo];
6227 signal_program[signo] = state;
6228 signal_cache_update (signo);
6233 sig_print_header (void)
6235 printf_filtered (_("Signal Stop\tPrint\tPass "
6236 "to program\tDescription\n"));
6240 sig_print_info (enum gdb_signal oursig)
6242 const char *name = gdb_signal_to_name (oursig);
6243 int name_padding = 13 - strlen (name);
6245 if (name_padding <= 0)
6248 printf_filtered ("%s", name);
6249 printf_filtered ("%*.*s ", name_padding, name_padding, " ");
6250 printf_filtered ("%s\t", signal_stop[oursig] ? "Yes" : "No");
6251 printf_filtered ("%s\t", signal_print[oursig] ? "Yes" : "No");
6252 printf_filtered ("%s\t\t", signal_program[oursig] ? "Yes" : "No");
6253 printf_filtered ("%s\n", gdb_signal_to_string (oursig));
6256 /* Specify how various signals in the inferior should be handled. */
6259 handle_command (char *args, int from_tty)
6262 int digits, wordlen;
6263 int sigfirst, signum, siglast;
6264 enum gdb_signal oursig;
6267 unsigned char *sigs;
6268 struct cleanup *old_chain;
6272 error_no_arg (_("signal to handle"));
6275 /* Allocate and zero an array of flags for which signals to handle. */
6277 nsigs = (int) GDB_SIGNAL_LAST;
6278 sigs = (unsigned char *) alloca (nsigs);
6279 memset (sigs, 0, nsigs);
6281 /* Break the command line up into args. */
6283 argv = gdb_buildargv (args);
6284 old_chain = make_cleanup_freeargv (argv);
6286 /* Walk through the args, looking for signal oursigs, signal names, and
6287 actions. Signal numbers and signal names may be interspersed with
6288 actions, with the actions being performed for all signals cumulatively
6289 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
6291 while (*argv != NULL)
6293 wordlen = strlen (*argv);
6294 for (digits = 0; isdigit ((*argv)[digits]); digits++)
6298 sigfirst = siglast = -1;
6300 if (wordlen >= 1 && !strncmp (*argv, "all", wordlen))
6302 /* Apply action to all signals except those used by the
6303 debugger. Silently skip those. */
6306 siglast = nsigs - 1;
6308 else if (wordlen >= 1 && !strncmp (*argv, "stop", wordlen))
6310 SET_SIGS (nsigs, sigs, signal_stop);
6311 SET_SIGS (nsigs, sigs, signal_print);
6313 else if (wordlen >= 1 && !strncmp (*argv, "ignore", wordlen))
6315 UNSET_SIGS (nsigs, sigs, signal_program);
6317 else if (wordlen >= 2 && !strncmp (*argv, "print", wordlen))
6319 SET_SIGS (nsigs, sigs, signal_print);
6321 else if (wordlen >= 2 && !strncmp (*argv, "pass", wordlen))
6323 SET_SIGS (nsigs, sigs, signal_program);
6325 else if (wordlen >= 3 && !strncmp (*argv, "nostop", wordlen))
6327 UNSET_SIGS (nsigs, sigs, signal_stop);
6329 else if (wordlen >= 3 && !strncmp (*argv, "noignore", wordlen))
6331 SET_SIGS (nsigs, sigs, signal_program);
6333 else if (wordlen >= 4 && !strncmp (*argv, "noprint", wordlen))
6335 UNSET_SIGS (nsigs, sigs, signal_print);
6336 UNSET_SIGS (nsigs, sigs, signal_stop);
6338 else if (wordlen >= 4 && !strncmp (*argv, "nopass", wordlen))
6340 UNSET_SIGS (nsigs, sigs, signal_program);
6342 else if (digits > 0)
6344 /* It is numeric. The numeric signal refers to our own
6345 internal signal numbering from target.h, not to host/target
6346 signal number. This is a feature; users really should be
6347 using symbolic names anyway, and the common ones like
6348 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
6350 sigfirst = siglast = (int)
6351 gdb_signal_from_command (atoi (*argv));
6352 if ((*argv)[digits] == '-')
6355 gdb_signal_from_command (atoi ((*argv) + digits + 1));
6357 if (sigfirst > siglast)
6359 /* Bet he didn't figure we'd think of this case... */
6367 oursig = gdb_signal_from_name (*argv);
6368 if (oursig != GDB_SIGNAL_UNKNOWN)
6370 sigfirst = siglast = (int) oursig;
6374 /* Not a number and not a recognized flag word => complain. */
6375 error (_("Unrecognized or ambiguous flag word: \"%s\"."), *argv);
6379 /* If any signal numbers or symbol names were found, set flags for
6380 which signals to apply actions to. */
6382 for (signum = sigfirst; signum >= 0 && signum <= siglast; signum++)
6384 switch ((enum gdb_signal) signum)
6386 case GDB_SIGNAL_TRAP:
6387 case GDB_SIGNAL_INT:
6388 if (!allsigs && !sigs[signum])
6390 if (query (_("%s is used by the debugger.\n\
6391 Are you sure you want to change it? "),
6392 gdb_signal_to_name ((enum gdb_signal) signum)))
6398 printf_unfiltered (_("Not confirmed, unchanged.\n"));
6399 gdb_flush (gdb_stdout);
6404 case GDB_SIGNAL_DEFAULT:
6405 case GDB_SIGNAL_UNKNOWN:
6406 /* Make sure that "all" doesn't print these. */
6417 for (signum = 0; signum < nsigs; signum++)
6420 signal_cache_update (-1);
6421 target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
6422 target_program_signals ((int) GDB_SIGNAL_LAST, signal_program);
6426 /* Show the results. */
6427 sig_print_header ();
6428 for (; signum < nsigs; signum++)
6430 sig_print_info (signum);
6436 do_cleanups (old_chain);
6439 /* Complete the "handle" command. */
6441 static VEC (char_ptr) *
6442 handle_completer (struct cmd_list_element *ignore,
6443 char *text, char *word)
6445 VEC (char_ptr) *vec_signals, *vec_keywords, *return_val;
6446 static const char * const keywords[] =
6460 vec_signals = signal_completer (ignore, text, word);
6461 vec_keywords = complete_on_enum (keywords, word, word);
6463 return_val = VEC_merge (char_ptr, vec_signals, vec_keywords);
6464 VEC_free (char_ptr, vec_signals);
6465 VEC_free (char_ptr, vec_keywords);
6470 xdb_handle_command (char *args, int from_tty)
6473 struct cleanup *old_chain;
6476 error_no_arg (_("xdb command"));
6478 /* Break the command line up into args. */
6480 argv = gdb_buildargv (args);
6481 old_chain = make_cleanup_freeargv (argv);
6482 if (argv[1] != (char *) NULL)
6487 bufLen = strlen (argv[0]) + 20;
6488 argBuf = (char *) xmalloc (bufLen);
6492 enum gdb_signal oursig;
6494 oursig = gdb_signal_from_name (argv[0]);
6495 memset (argBuf, 0, bufLen);
6496 if (strcmp (argv[1], "Q") == 0)
6497 sprintf (argBuf, "%s %s", argv[0], "noprint");
6500 if (strcmp (argv[1], "s") == 0)
6502 if (!signal_stop[oursig])
6503 sprintf (argBuf, "%s %s", argv[0], "stop");
6505 sprintf (argBuf, "%s %s", argv[0], "nostop");
6507 else if (strcmp (argv[1], "i") == 0)
6509 if (!signal_program[oursig])
6510 sprintf (argBuf, "%s %s", argv[0], "pass");
6512 sprintf (argBuf, "%s %s", argv[0], "nopass");
6514 else if (strcmp (argv[1], "r") == 0)
6516 if (!signal_print[oursig])
6517 sprintf (argBuf, "%s %s", argv[0], "print");
6519 sprintf (argBuf, "%s %s", argv[0], "noprint");
6525 handle_command (argBuf, from_tty);
6527 printf_filtered (_("Invalid signal handling flag.\n"));
6532 do_cleanups (old_chain);
6536 gdb_signal_from_command (int num)
6538 if (num >= 1 && num <= 15)
6539 return (enum gdb_signal) num;
6540 error (_("Only signals 1-15 are valid as numeric signals.\n\
6541 Use \"info signals\" for a list of symbolic signals."));
6544 /* Print current contents of the tables set by the handle command.
6545 It is possible we should just be printing signals actually used
6546 by the current target (but for things to work right when switching
6547 targets, all signals should be in the signal tables). */
6550 signals_info (char *signum_exp, int from_tty)
6552 enum gdb_signal oursig;
6554 sig_print_header ();
6558 /* First see if this is a symbol name. */
6559 oursig = gdb_signal_from_name (signum_exp);
6560 if (oursig == GDB_SIGNAL_UNKNOWN)
6562 /* No, try numeric. */
6564 gdb_signal_from_command (parse_and_eval_long (signum_exp));
6566 sig_print_info (oursig);
6570 printf_filtered ("\n");
6571 /* These ugly casts brought to you by the native VAX compiler. */
6572 for (oursig = GDB_SIGNAL_FIRST;
6573 (int) oursig < (int) GDB_SIGNAL_LAST;
6574 oursig = (enum gdb_signal) ((int) oursig + 1))
6578 if (oursig != GDB_SIGNAL_UNKNOWN
6579 && oursig != GDB_SIGNAL_DEFAULT && oursig != GDB_SIGNAL_0)
6580 sig_print_info (oursig);
6583 printf_filtered (_("\nUse the \"handle\" command "
6584 "to change these tables.\n"));
6587 /* Check if it makes sense to read $_siginfo from the current thread
6588 at this point. If not, throw an error. */
6591 validate_siginfo_access (void)
6593 /* No current inferior, no siginfo. */
6594 if (ptid_equal (inferior_ptid, null_ptid))
6595 error (_("No thread selected."));
6597 /* Don't try to read from a dead thread. */
6598 if (is_exited (inferior_ptid))
6599 error (_("The current thread has terminated"));
6601 /* ... or from a spinning thread. */
6602 if (is_running (inferior_ptid))
6603 error (_("Selected thread is running."));
6606 /* The $_siginfo convenience variable is a bit special. We don't know
6607 for sure the type of the value until we actually have a chance to
6608 fetch the data. The type can change depending on gdbarch, so it is
6609 also dependent on which thread you have selected.
6611 1. making $_siginfo be an internalvar that creates a new value on
6614 2. making the value of $_siginfo be an lval_computed value. */
6616 /* This function implements the lval_computed support for reading a
6620 siginfo_value_read (struct value *v)
6622 LONGEST transferred;
6624 validate_siginfo_access ();
6627 target_read (¤t_target, TARGET_OBJECT_SIGNAL_INFO,
6629 value_contents_all_raw (v),
6631 TYPE_LENGTH (value_type (v)));
6633 if (transferred != TYPE_LENGTH (value_type (v)))
6634 error (_("Unable to read siginfo"));
6637 /* This function implements the lval_computed support for writing a
6641 siginfo_value_write (struct value *v, struct value *fromval)
6643 LONGEST transferred;
6645 validate_siginfo_access ();
6647 transferred = target_write (¤t_target,
6648 TARGET_OBJECT_SIGNAL_INFO,
6650 value_contents_all_raw (fromval),
6652 TYPE_LENGTH (value_type (fromval)));
6654 if (transferred != TYPE_LENGTH (value_type (fromval)))
6655 error (_("Unable to write siginfo"));
6658 static const struct lval_funcs siginfo_value_funcs =
6664 /* Return a new value with the correct type for the siginfo object of
6665 the current thread using architecture GDBARCH. Return a void value
6666 if there's no object available. */
6668 static struct value *
6669 siginfo_make_value (struct gdbarch *gdbarch, struct internalvar *var,
6672 if (target_has_stack
6673 && !ptid_equal (inferior_ptid, null_ptid)
6674 && gdbarch_get_siginfo_type_p (gdbarch))
6676 struct type *type = gdbarch_get_siginfo_type (gdbarch);
6678 return allocate_computed_value (type, &siginfo_value_funcs, NULL);
6681 return allocate_value (builtin_type (gdbarch)->builtin_void);
6685 /* infcall_suspend_state contains state about the program itself like its
6686 registers and any signal it received when it last stopped.
6687 This state must be restored regardless of how the inferior function call
6688 ends (either successfully, or after it hits a breakpoint or signal)
6689 if the program is to properly continue where it left off. */
6691 struct infcall_suspend_state
6693 struct thread_suspend_state thread_suspend;
6694 #if 0 /* Currently unused and empty structures are not valid C. */
6695 struct inferior_suspend_state inferior_suspend;
6700 struct regcache *registers;
6702 /* Format of SIGINFO_DATA or NULL if it is not present. */
6703 struct gdbarch *siginfo_gdbarch;
6705 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
6706 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
6707 content would be invalid. */
6708 gdb_byte *siginfo_data;
6711 struct infcall_suspend_state *
6712 save_infcall_suspend_state (void)
6714 struct infcall_suspend_state *inf_state;
6715 struct thread_info *tp = inferior_thread ();
6716 struct inferior *inf = current_inferior ();
6717 struct regcache *regcache = get_current_regcache ();
6718 struct gdbarch *gdbarch = get_regcache_arch (regcache);
6719 gdb_byte *siginfo_data = NULL;
6721 if (gdbarch_get_siginfo_type_p (gdbarch))
6723 struct type *type = gdbarch_get_siginfo_type (gdbarch);
6724 size_t len = TYPE_LENGTH (type);
6725 struct cleanup *back_to;
6727 siginfo_data = xmalloc (len);
6728 back_to = make_cleanup (xfree, siginfo_data);
6730 if (target_read (¤t_target, TARGET_OBJECT_SIGNAL_INFO, NULL,
6731 siginfo_data, 0, len) == len)
6732 discard_cleanups (back_to);
6735 /* Errors ignored. */
6736 do_cleanups (back_to);
6737 siginfo_data = NULL;
6741 inf_state = XZALLOC (struct infcall_suspend_state);
6745 inf_state->siginfo_gdbarch = gdbarch;
6746 inf_state->siginfo_data = siginfo_data;
6749 inf_state->thread_suspend = tp->suspend;
6750 #if 0 /* Currently unused and empty structures are not valid C. */
6751 inf_state->inferior_suspend = inf->suspend;
6754 /* run_inferior_call will not use the signal due to its `proceed' call with
6755 GDB_SIGNAL_0 anyway. */
6756 tp->suspend.stop_signal = GDB_SIGNAL_0;
6758 inf_state->stop_pc = stop_pc;
6760 inf_state->registers = regcache_dup (regcache);
6765 /* Restore inferior session state to INF_STATE. */
6768 restore_infcall_suspend_state (struct infcall_suspend_state *inf_state)
6770 struct thread_info *tp = inferior_thread ();
6771 struct inferior *inf = current_inferior ();
6772 struct regcache *regcache = get_current_regcache ();
6773 struct gdbarch *gdbarch = get_regcache_arch (regcache);
6775 tp->suspend = inf_state->thread_suspend;
6776 #if 0 /* Currently unused and empty structures are not valid C. */
6777 inf->suspend = inf_state->inferior_suspend;
6780 stop_pc = inf_state->stop_pc;
6782 if (inf_state->siginfo_gdbarch == gdbarch)
6784 struct type *type = gdbarch_get_siginfo_type (gdbarch);
6786 /* Errors ignored. */
6787 target_write (¤t_target, TARGET_OBJECT_SIGNAL_INFO, NULL,
6788 inf_state->siginfo_data, 0, TYPE_LENGTH (type));
6791 /* The inferior can be gone if the user types "print exit(0)"
6792 (and perhaps other times). */
6793 if (target_has_execution)
6794 /* NB: The register write goes through to the target. */
6795 regcache_cpy (regcache, inf_state->registers);
6797 discard_infcall_suspend_state (inf_state);
6801 do_restore_infcall_suspend_state_cleanup (void *state)
6803 restore_infcall_suspend_state (state);
6807 make_cleanup_restore_infcall_suspend_state
6808 (struct infcall_suspend_state *inf_state)
6810 return make_cleanup (do_restore_infcall_suspend_state_cleanup, inf_state);
6814 discard_infcall_suspend_state (struct infcall_suspend_state *inf_state)
6816 regcache_xfree (inf_state->registers);
6817 xfree (inf_state->siginfo_data);
6822 get_infcall_suspend_state_regcache (struct infcall_suspend_state *inf_state)
6824 return inf_state->registers;
6827 /* infcall_control_state contains state regarding gdb's control of the
6828 inferior itself like stepping control. It also contains session state like
6829 the user's currently selected frame. */
6831 struct infcall_control_state
6833 struct thread_control_state thread_control;
6834 struct inferior_control_state inferior_control;
6837 enum stop_stack_kind stop_stack_dummy;
6838 int stopped_by_random_signal;
6839 int stop_after_trap;
6841 /* ID if the selected frame when the inferior function call was made. */
6842 struct frame_id selected_frame_id;
6845 /* Save all of the information associated with the inferior<==>gdb
6848 struct infcall_control_state *
6849 save_infcall_control_state (void)
6851 struct infcall_control_state *inf_status = xmalloc (sizeof (*inf_status));
6852 struct thread_info *tp = inferior_thread ();
6853 struct inferior *inf = current_inferior ();
6855 inf_status->thread_control = tp->control;
6856 inf_status->inferior_control = inf->control;
6858 tp->control.step_resume_breakpoint = NULL;
6859 tp->control.exception_resume_breakpoint = NULL;
6861 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
6862 chain. If caller's caller is walking the chain, they'll be happier if we
6863 hand them back the original chain when restore_infcall_control_state is
6865 tp->control.stop_bpstat = bpstat_copy (tp->control.stop_bpstat);
6868 inf_status->stop_stack_dummy = stop_stack_dummy;
6869 inf_status->stopped_by_random_signal = stopped_by_random_signal;
6870 inf_status->stop_after_trap = stop_after_trap;
6872 inf_status->selected_frame_id = get_frame_id (get_selected_frame (NULL));
6878 restore_selected_frame (void *args)
6880 struct frame_id *fid = (struct frame_id *) args;
6881 struct frame_info *frame;
6883 frame = frame_find_by_id (*fid);
6885 /* If inf_status->selected_frame_id is NULL, there was no previously
6889 warning (_("Unable to restore previously selected frame."));
6893 select_frame (frame);
6898 /* Restore inferior session state to INF_STATUS. */
6901 restore_infcall_control_state (struct infcall_control_state *inf_status)
6903 struct thread_info *tp = inferior_thread ();
6904 struct inferior *inf = current_inferior ();
6906 if (tp->control.step_resume_breakpoint)
6907 tp->control.step_resume_breakpoint->disposition = disp_del_at_next_stop;
6909 if (tp->control.exception_resume_breakpoint)
6910 tp->control.exception_resume_breakpoint->disposition
6911 = disp_del_at_next_stop;
6913 /* Handle the bpstat_copy of the chain. */
6914 bpstat_clear (&tp->control.stop_bpstat);
6916 tp->control = inf_status->thread_control;
6917 inf->control = inf_status->inferior_control;
6920 stop_stack_dummy = inf_status->stop_stack_dummy;
6921 stopped_by_random_signal = inf_status->stopped_by_random_signal;
6922 stop_after_trap = inf_status->stop_after_trap;
6924 if (target_has_stack)
6926 /* The point of catch_errors is that if the stack is clobbered,
6927 walking the stack might encounter a garbage pointer and
6928 error() trying to dereference it. */
6930 (restore_selected_frame, &inf_status->selected_frame_id,
6931 "Unable to restore previously selected frame:\n",
6932 RETURN_MASK_ERROR) == 0)
6933 /* Error in restoring the selected frame. Select the innermost
6935 select_frame (get_current_frame ());
6942 do_restore_infcall_control_state_cleanup (void *sts)
6944 restore_infcall_control_state (sts);
6948 make_cleanup_restore_infcall_control_state
6949 (struct infcall_control_state *inf_status)
6951 return make_cleanup (do_restore_infcall_control_state_cleanup, inf_status);
6955 discard_infcall_control_state (struct infcall_control_state *inf_status)
6957 if (inf_status->thread_control.step_resume_breakpoint)
6958 inf_status->thread_control.step_resume_breakpoint->disposition
6959 = disp_del_at_next_stop;
6961 if (inf_status->thread_control.exception_resume_breakpoint)
6962 inf_status->thread_control.exception_resume_breakpoint->disposition
6963 = disp_del_at_next_stop;
6965 /* See save_infcall_control_state for info on stop_bpstat. */
6966 bpstat_clear (&inf_status->thread_control.stop_bpstat);
6972 ptid_match (ptid_t ptid, ptid_t filter)
6974 if (ptid_equal (filter, minus_one_ptid))
6976 if (ptid_is_pid (filter)
6977 && ptid_get_pid (ptid) == ptid_get_pid (filter))
6979 else if (ptid_equal (ptid, filter))
6985 /* restore_inferior_ptid() will be used by the cleanup machinery
6986 to restore the inferior_ptid value saved in a call to
6987 save_inferior_ptid(). */
6990 restore_inferior_ptid (void *arg)
6992 ptid_t *saved_ptid_ptr = arg;
6994 inferior_ptid = *saved_ptid_ptr;
6998 /* Save the value of inferior_ptid so that it may be restored by a
6999 later call to do_cleanups(). Returns the struct cleanup pointer
7000 needed for later doing the cleanup. */
7003 save_inferior_ptid (void)
7005 ptid_t *saved_ptid_ptr;
7007 saved_ptid_ptr = xmalloc (sizeof (ptid_t));
7008 *saved_ptid_ptr = inferior_ptid;
7009 return make_cleanup (restore_inferior_ptid, saved_ptid_ptr);
7013 /* User interface for reverse debugging:
7014 Set exec-direction / show exec-direction commands
7015 (returns error unless target implements to_set_exec_direction method). */
7017 int execution_direction = EXEC_FORWARD;
7018 static const char exec_forward[] = "forward";
7019 static const char exec_reverse[] = "reverse";
7020 static const char *exec_direction = exec_forward;
7021 static const char *const exec_direction_names[] = {
7028 set_exec_direction_func (char *args, int from_tty,
7029 struct cmd_list_element *cmd)
7031 if (target_can_execute_reverse)
7033 if (!strcmp (exec_direction, exec_forward))
7034 execution_direction = EXEC_FORWARD;
7035 else if (!strcmp (exec_direction, exec_reverse))
7036 execution_direction = EXEC_REVERSE;
7040 exec_direction = exec_forward;
7041 error (_("Target does not support this operation."));
7046 show_exec_direction_func (struct ui_file *out, int from_tty,
7047 struct cmd_list_element *cmd, const char *value)
7049 switch (execution_direction) {
7051 fprintf_filtered (out, _("Forward.\n"));
7054 fprintf_filtered (out, _("Reverse.\n"));
7057 internal_error (__FILE__, __LINE__,
7058 _("bogus execution_direction value: %d"),
7059 (int) execution_direction);
7063 /* User interface for non-stop mode. */
7068 set_non_stop (char *args, int from_tty,
7069 struct cmd_list_element *c)
7071 if (target_has_execution)
7073 non_stop_1 = non_stop;
7074 error (_("Cannot change this setting while the inferior is running."));
7077 non_stop = non_stop_1;
7081 show_non_stop (struct ui_file *file, int from_tty,
7082 struct cmd_list_element *c, const char *value)
7084 fprintf_filtered (file,
7085 _("Controlling the inferior in non-stop mode is %s.\n"),
7090 show_schedule_multiple (struct ui_file *file, int from_tty,
7091 struct cmd_list_element *c, const char *value)
7093 fprintf_filtered (file, _("Resuming the execution of threads "
7094 "of all processes is %s.\n"), value);
7097 /* Implementation of `siginfo' variable. */
7099 static const struct internalvar_funcs siginfo_funcs =
7107 _initialize_infrun (void)
7111 struct cmd_list_element *c;
7113 add_info ("signals", signals_info, _("\
7114 What debugger does when program gets various signals.\n\
7115 Specify a signal as argument to print info on that signal only."));
7116 add_info_alias ("handle", "signals", 0);
7118 c = add_com ("handle", class_run, handle_command, _("\
7119 Specify how to handle signals.\n\
7120 Usage: handle SIGNAL [ACTIONS]\n\
7121 Args are signals and actions to apply to those signals.\n\
7122 If no actions are specified, the current settings for the specified signals\n\
7123 will be displayed instead.\n\
7125 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
7126 from 1-15 are allowed for compatibility with old versions of GDB.\n\
7127 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
7128 The special arg \"all\" is recognized to mean all signals except those\n\
7129 used by the debugger, typically SIGTRAP and SIGINT.\n\
7131 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
7132 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
7133 Stop means reenter debugger if this signal happens (implies print).\n\
7134 Print means print a message if this signal happens.\n\
7135 Pass means let program see this signal; otherwise program doesn't know.\n\
7136 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
7137 Pass and Stop may be combined.\n\
7139 Multiple signals may be specified. Signal numbers and signal names\n\
7140 may be interspersed with actions, with the actions being performed for\n\
7141 all signals cumulatively specified."));
7142 set_cmd_completer (c, handle_completer);
7146 add_com ("lz", class_info, signals_info, _("\
7147 What debugger does when program gets various signals.\n\
7148 Specify a signal as argument to print info on that signal only."));
7149 add_com ("z", class_run, xdb_handle_command, _("\
7150 Specify how to handle a signal.\n\
7151 Args are signals and actions to apply to those signals.\n\
7152 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
7153 from 1-15 are allowed for compatibility with old versions of GDB.\n\
7154 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
7155 The special arg \"all\" is recognized to mean all signals except those\n\
7156 used by the debugger, typically SIGTRAP and SIGINT.\n\
7157 Recognized actions include \"s\" (toggles between stop and nostop),\n\
7158 \"r\" (toggles between print and noprint), \"i\" (toggles between pass and \
7159 nopass), \"Q\" (noprint)\n\
7160 Stop means reenter debugger if this signal happens (implies print).\n\
7161 Print means print a message if this signal happens.\n\
7162 Pass means let program see this signal; otherwise program doesn't know.\n\
7163 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
7164 Pass and Stop may be combined."));
7168 stop_command = add_cmd ("stop", class_obscure,
7169 not_just_help_class_command, _("\
7170 There is no `stop' command, but you can set a hook on `stop'.\n\
7171 This allows you to set a list of commands to be run each time execution\n\
7172 of the program stops."), &cmdlist);
7174 add_setshow_zuinteger_cmd ("infrun", class_maintenance, &debug_infrun, _("\
7175 Set inferior debugging."), _("\
7176 Show inferior debugging."), _("\
7177 When non-zero, inferior specific debugging is enabled."),
7180 &setdebuglist, &showdebuglist);
7182 add_setshow_boolean_cmd ("displaced", class_maintenance,
7183 &debug_displaced, _("\
7184 Set displaced stepping debugging."), _("\
7185 Show displaced stepping debugging."), _("\
7186 When non-zero, displaced stepping specific debugging is enabled."),
7188 show_debug_displaced,
7189 &setdebuglist, &showdebuglist);
7191 add_setshow_boolean_cmd ("non-stop", no_class,
7193 Set whether gdb controls the inferior in non-stop mode."), _("\
7194 Show whether gdb controls the inferior in non-stop mode."), _("\
7195 When debugging a multi-threaded program and this setting is\n\
7196 off (the default, also called all-stop mode), when one thread stops\n\
7197 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
7198 all other threads in the program while you interact with the thread of\n\
7199 interest. When you continue or step a thread, you can allow the other\n\
7200 threads to run, or have them remain stopped, but while you inspect any\n\
7201 thread's state, all threads stop.\n\
7203 In non-stop mode, when one thread stops, other threads can continue\n\
7204 to run freely. You'll be able to step each thread independently,\n\
7205 leave it stopped or free to run as needed."),
7211 numsigs = (int) GDB_SIGNAL_LAST;
7212 signal_stop = (unsigned char *) xmalloc (sizeof (signal_stop[0]) * numsigs);
7213 signal_print = (unsigned char *)
7214 xmalloc (sizeof (signal_print[0]) * numsigs);
7215 signal_program = (unsigned char *)
7216 xmalloc (sizeof (signal_program[0]) * numsigs);
7217 signal_pass = (unsigned char *)
7218 xmalloc (sizeof (signal_program[0]) * numsigs);
7219 for (i = 0; i < numsigs; i++)
7222 signal_print[i] = 1;
7223 signal_program[i] = 1;
7226 /* Signals caused by debugger's own actions
7227 should not be given to the program afterwards. */
7228 signal_program[GDB_SIGNAL_TRAP] = 0;
7229 signal_program[GDB_SIGNAL_INT] = 0;
7231 /* Signals that are not errors should not normally enter the debugger. */
7232 signal_stop[GDB_SIGNAL_ALRM] = 0;
7233 signal_print[GDB_SIGNAL_ALRM] = 0;
7234 signal_stop[GDB_SIGNAL_VTALRM] = 0;
7235 signal_print[GDB_SIGNAL_VTALRM] = 0;
7236 signal_stop[GDB_SIGNAL_PROF] = 0;
7237 signal_print[GDB_SIGNAL_PROF] = 0;
7238 signal_stop[GDB_SIGNAL_CHLD] = 0;
7239 signal_print[GDB_SIGNAL_CHLD] = 0;
7240 signal_stop[GDB_SIGNAL_IO] = 0;
7241 signal_print[GDB_SIGNAL_IO] = 0;
7242 signal_stop[GDB_SIGNAL_POLL] = 0;
7243 signal_print[GDB_SIGNAL_POLL] = 0;
7244 signal_stop[GDB_SIGNAL_URG] = 0;
7245 signal_print[GDB_SIGNAL_URG] = 0;
7246 signal_stop[GDB_SIGNAL_WINCH] = 0;
7247 signal_print[GDB_SIGNAL_WINCH] = 0;
7248 signal_stop[GDB_SIGNAL_PRIO] = 0;
7249 signal_print[GDB_SIGNAL_PRIO] = 0;
7251 /* These signals are used internally by user-level thread
7252 implementations. (See signal(5) on Solaris.) Like the above
7253 signals, a healthy program receives and handles them as part of
7254 its normal operation. */
7255 signal_stop[GDB_SIGNAL_LWP] = 0;
7256 signal_print[GDB_SIGNAL_LWP] = 0;
7257 signal_stop[GDB_SIGNAL_WAITING] = 0;
7258 signal_print[GDB_SIGNAL_WAITING] = 0;
7259 signal_stop[GDB_SIGNAL_CANCEL] = 0;
7260 signal_print[GDB_SIGNAL_CANCEL] = 0;
7262 /* Update cached state. */
7263 signal_cache_update (-1);
7265 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support,
7266 &stop_on_solib_events, _("\
7267 Set stopping for shared library events."), _("\
7268 Show stopping for shared library events."), _("\
7269 If nonzero, gdb will give control to the user when the dynamic linker\n\
7270 notifies gdb of shared library events. The most common event of interest\n\
7271 to the user would be loading/unloading of a new library."),
7273 show_stop_on_solib_events,
7274 &setlist, &showlist);
7276 add_setshow_enum_cmd ("follow-fork-mode", class_run,
7277 follow_fork_mode_kind_names,
7278 &follow_fork_mode_string, _("\
7279 Set debugger response to a program call of fork or vfork."), _("\
7280 Show debugger response to a program call of fork or vfork."), _("\
7281 A fork or vfork creates a new process. follow-fork-mode can be:\n\
7282 parent - the original process is debugged after a fork\n\
7283 child - the new process is debugged after a fork\n\
7284 The unfollowed process will continue to run.\n\
7285 By default, the debugger will follow the parent process."),
7287 show_follow_fork_mode_string,
7288 &setlist, &showlist);
7290 add_setshow_enum_cmd ("follow-exec-mode", class_run,
7291 follow_exec_mode_names,
7292 &follow_exec_mode_string, _("\
7293 Set debugger response to a program call of exec."), _("\
7294 Show debugger response to a program call of exec."), _("\
7295 An exec call replaces the program image of a process.\n\
7297 follow-exec-mode can be:\n\
7299 new - the debugger creates a new inferior and rebinds the process\n\
7300 to this new inferior. The program the process was running before\n\
7301 the exec call can be restarted afterwards by restarting the original\n\
7304 same - the debugger keeps the process bound to the same inferior.\n\
7305 The new executable image replaces the previous executable loaded in\n\
7306 the inferior. Restarting the inferior after the exec call restarts\n\
7307 the executable the process was running after the exec call.\n\
7309 By default, the debugger will use the same inferior."),
7311 show_follow_exec_mode_string,
7312 &setlist, &showlist);
7314 add_setshow_enum_cmd ("scheduler-locking", class_run,
7315 scheduler_enums, &scheduler_mode, _("\
7316 Set mode for locking scheduler during execution."), _("\
7317 Show mode for locking scheduler during execution."), _("\
7318 off == no locking (threads may preempt at any time)\n\
7319 on == full locking (no thread except the current thread may run)\n\
7320 step == scheduler locked during every single-step operation.\n\
7321 In this mode, no other thread may run during a step command.\n\
7322 Other threads may run while stepping over a function call ('next')."),
7323 set_schedlock_func, /* traps on target vector */
7324 show_scheduler_mode,
7325 &setlist, &showlist);
7327 add_setshow_boolean_cmd ("schedule-multiple", class_run, &sched_multi, _("\
7328 Set mode for resuming threads of all processes."), _("\
7329 Show mode for resuming threads of all processes."), _("\
7330 When on, execution commands (such as 'continue' or 'next') resume all\n\
7331 threads of all processes. When off (which is the default), execution\n\
7332 commands only resume the threads of the current process. The set of\n\
7333 threads that are resumed is further refined by the scheduler-locking\n\
7334 mode (see help set scheduler-locking)."),
7336 show_schedule_multiple,
7337 &setlist, &showlist);
7339 add_setshow_boolean_cmd ("step-mode", class_run, &step_stop_if_no_debug, _("\
7340 Set mode of the step operation."), _("\
7341 Show mode of the step operation."), _("\
7342 When set, doing a step over a function without debug line information\n\
7343 will stop at the first instruction of that function. Otherwise, the\n\
7344 function is skipped and the step command stops at a different source line."),
7346 show_step_stop_if_no_debug,
7347 &setlist, &showlist);
7349 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run,
7350 &can_use_displaced_stepping, _("\
7351 Set debugger's willingness to use displaced stepping."), _("\
7352 Show debugger's willingness to use displaced stepping."), _("\
7353 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
7354 supported by the target architecture. If off, gdb will not use displaced\n\
7355 stepping to step over breakpoints, even if such is supported by the target\n\
7356 architecture. If auto (which is the default), gdb will use displaced stepping\n\
7357 if the target architecture supports it and non-stop mode is active, but will not\n\
7358 use it in all-stop mode (see help set non-stop)."),
7360 show_can_use_displaced_stepping,
7361 &setlist, &showlist);
7363 add_setshow_enum_cmd ("exec-direction", class_run, exec_direction_names,
7364 &exec_direction, _("Set direction of execution.\n\
7365 Options are 'forward' or 'reverse'."),
7366 _("Show direction of execution (forward/reverse)."),
7367 _("Tells gdb whether to execute forward or backward."),
7368 set_exec_direction_func, show_exec_direction_func,
7369 &setlist, &showlist);
7371 /* Set/show detach-on-fork: user-settable mode. */
7373 add_setshow_boolean_cmd ("detach-on-fork", class_run, &detach_fork, _("\
7374 Set whether gdb will detach the child of a fork."), _("\
7375 Show whether gdb will detach the child of a fork."), _("\
7376 Tells gdb whether to detach the child of a fork."),
7377 NULL, NULL, &setlist, &showlist);
7379 /* Set/show disable address space randomization mode. */
7381 add_setshow_boolean_cmd ("disable-randomization", class_support,
7382 &disable_randomization, _("\
7383 Set disabling of debuggee's virtual address space randomization."), _("\
7384 Show disabling of debuggee's virtual address space randomization."), _("\
7385 When this mode is on (which is the default), randomization of the virtual\n\
7386 address space is disabled. Standalone programs run with the randomization\n\
7387 enabled by default on some platforms."),
7388 &set_disable_randomization,
7389 &show_disable_randomization,
7390 &setlist, &showlist);
7392 /* ptid initializations */
7393 inferior_ptid = null_ptid;
7394 target_last_wait_ptid = minus_one_ptid;
7396 observer_attach_thread_ptid_changed (infrun_thread_ptid_changed);
7397 observer_attach_thread_stop_requested (infrun_thread_stop_requested);
7398 observer_attach_thread_exit (infrun_thread_thread_exit);
7399 observer_attach_inferior_exit (infrun_inferior_exit);
7401 /* Explicitly create without lookup, since that tries to create a
7402 value with a void typed value, and when we get here, gdbarch
7403 isn't initialized yet. At this point, we're quite sure there
7404 isn't another convenience variable of the same name. */
7405 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs, NULL);
7407 add_setshow_boolean_cmd ("observer", no_class,
7408 &observer_mode_1, _("\
7409 Set whether gdb controls the inferior in observer mode."), _("\
7410 Show whether gdb controls the inferior in observer mode."), _("\
7411 In observer mode, GDB can get data from the inferior, but not\n\
7412 affect its execution. Registers and memory may not be changed,\n\
7413 breakpoints may not be set, and the program cannot be interrupted\n\