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:
3427 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_FORKED\n");
3429 /* Check whether the inferior is displaced stepping. */
3431 struct regcache *regcache = get_thread_regcache (ecs->ptid);
3432 struct gdbarch *gdbarch = get_regcache_arch (regcache);
3433 struct displaced_step_inferior_state *displaced
3434 = get_displaced_stepping_state (ptid_get_pid (ecs->ptid));
3436 /* If checking displaced stepping is supported, and thread
3437 ecs->ptid is displaced stepping. */
3438 if (displaced && ptid_equal (displaced->step_ptid, ecs->ptid))
3440 struct inferior *parent_inf
3441 = find_inferior_pid (ptid_get_pid (ecs->ptid));
3442 struct regcache *child_regcache;
3443 CORE_ADDR parent_pc;
3445 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
3446 indicating that the displaced stepping of syscall instruction
3447 has been done. Perform cleanup for parent process here. Note
3448 that this operation also cleans up the child process for vfork,
3449 because their pages are shared. */
3450 displaced_step_fixup (ecs->ptid, GDB_SIGNAL_TRAP);
3452 if (ecs->ws.kind == TARGET_WAITKIND_FORKED)
3454 /* Restore scratch pad for child process. */
3455 displaced_step_restore (displaced, ecs->ws.value.related_pid);
3458 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
3459 the child's PC is also within the scratchpad. Set the child's PC
3460 to the parent's PC value, which has already been fixed up.
3461 FIXME: we use the parent's aspace here, although we're touching
3462 the child, because the child hasn't been added to the inferior
3463 list yet at this point. */
3466 = get_thread_arch_aspace_regcache (ecs->ws.value.related_pid,
3468 parent_inf->aspace);
3469 /* Read PC value of parent process. */
3470 parent_pc = regcache_read_pc (regcache);
3472 if (debug_displaced)
3473 fprintf_unfiltered (gdb_stdlog,
3474 "displaced: write child pc from %s to %s\n",
3476 regcache_read_pc (child_regcache)),
3477 paddress (gdbarch, parent_pc));
3479 regcache_write_pc (child_regcache, parent_pc);
3483 if (!ptid_equal (ecs->ptid, inferior_ptid))
3484 context_switch (ecs->ptid);
3486 /* Immediately detach breakpoints from the child before there's
3487 any chance of letting the user delete breakpoints from the
3488 breakpoint lists. If we don't do this early, it's easy to
3489 leave left over traps in the child, vis: "break foo; catch
3490 fork; c; <fork>; del; c; <child calls foo>". We only follow
3491 the fork on the last `continue', and by that time the
3492 breakpoint at "foo" is long gone from the breakpoint table.
3493 If we vforked, then we don't need to unpatch here, since both
3494 parent and child are sharing the same memory pages; we'll
3495 need to unpatch at follow/detach time instead to be certain
3496 that new breakpoints added between catchpoint hit time and
3497 vfork follow are detached. */
3498 if (ecs->ws.kind != TARGET_WAITKIND_VFORKED)
3500 /* This won't actually modify the breakpoint list, but will
3501 physically remove the breakpoints from the child. */
3502 detach_breakpoints (ecs->ws.value.related_pid);
3505 if (singlestep_breakpoints_inserted_p)
3507 /* Pull the single step breakpoints out of the target. */
3508 remove_single_step_breakpoints ();
3509 singlestep_breakpoints_inserted_p = 0;
3512 /* In case the event is caught by a catchpoint, remember that
3513 the event is to be followed at the next resume of the thread,
3514 and not immediately. */
3515 ecs->event_thread->pending_follow = ecs->ws;
3517 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
3519 ecs->event_thread->control.stop_bpstat
3520 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
3521 stop_pc, ecs->ptid, &ecs->ws);
3523 /* Note that we're interested in knowing the bpstat actually
3524 causes a stop, not just if it may explain the signal.
3525 Software watchpoints, for example, always appear in the
3528 = !bpstat_causes_stop (ecs->event_thread->control.stop_bpstat);
3530 /* If no catchpoint triggered for this, then keep going. */
3531 if (ecs->random_signal)
3537 = (follow_fork_mode_string == follow_fork_mode_child);
3539 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
3541 should_resume = follow_fork ();
3544 child = ecs->ws.value.related_pid;
3546 /* In non-stop mode, also resume the other branch. */
3547 if (non_stop && !detach_fork)
3550 switch_to_thread (parent);
3552 switch_to_thread (child);
3554 ecs->event_thread = inferior_thread ();
3555 ecs->ptid = inferior_ptid;
3560 switch_to_thread (child);
3562 switch_to_thread (parent);
3564 ecs->event_thread = inferior_thread ();
3565 ecs->ptid = inferior_ptid;
3570 stop_stepping (ecs);
3573 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_TRAP;
3574 goto process_event_stop_test;
3576 case TARGET_WAITKIND_VFORK_DONE:
3577 /* Done with the shared memory region. Re-insert breakpoints in
3578 the parent, and keep going. */
3581 fprintf_unfiltered (gdb_stdlog,
3582 "infrun: TARGET_WAITKIND_VFORK_DONE\n");
3584 if (!ptid_equal (ecs->ptid, inferior_ptid))
3585 context_switch (ecs->ptid);
3587 current_inferior ()->waiting_for_vfork_done = 0;
3588 current_inferior ()->pspace->breakpoints_not_allowed = 0;
3589 /* This also takes care of reinserting breakpoints in the
3590 previously locked inferior. */
3594 case TARGET_WAITKIND_EXECD:
3596 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_EXECD\n");
3598 if (!ptid_equal (ecs->ptid, inferior_ptid))
3599 context_switch (ecs->ptid);
3601 singlestep_breakpoints_inserted_p = 0;
3602 cancel_single_step_breakpoints ();
3604 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
3606 /* Do whatever is necessary to the parent branch of the vfork. */
3607 handle_vfork_child_exec_or_exit (1);
3609 /* This causes the eventpoints and symbol table to be reset.
3610 Must do this now, before trying to determine whether to
3612 follow_exec (inferior_ptid, ecs->ws.value.execd_pathname);
3614 ecs->event_thread->control.stop_bpstat
3615 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
3616 stop_pc, ecs->ptid, &ecs->ws);
3618 = !bpstat_explains_signal (ecs->event_thread->control.stop_bpstat);
3620 /* Note that this may be referenced from inside
3621 bpstat_stop_status above, through inferior_has_execd. */
3622 xfree (ecs->ws.value.execd_pathname);
3623 ecs->ws.value.execd_pathname = NULL;
3625 /* If no catchpoint triggered for this, then keep going. */
3626 if (ecs->random_signal)
3628 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
3632 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_TRAP;
3633 goto process_event_stop_test;
3635 /* Be careful not to try to gather much state about a thread
3636 that's in a syscall. It's frequently a losing proposition. */
3637 case TARGET_WAITKIND_SYSCALL_ENTRY:
3639 fprintf_unfiltered (gdb_stdlog,
3640 "infrun: TARGET_WAITKIND_SYSCALL_ENTRY\n");
3641 /* Getting the current syscall number. */
3642 if (handle_syscall_event (ecs) != 0)
3644 goto process_event_stop_test;
3646 /* Before examining the threads further, step this thread to
3647 get it entirely out of the syscall. (We get notice of the
3648 event when the thread is just on the verge of exiting a
3649 syscall. Stepping one instruction seems to get it back
3651 case TARGET_WAITKIND_SYSCALL_RETURN:
3653 fprintf_unfiltered (gdb_stdlog,
3654 "infrun: TARGET_WAITKIND_SYSCALL_RETURN\n");
3655 if (handle_syscall_event (ecs) != 0)
3657 goto process_event_stop_test;
3659 case TARGET_WAITKIND_STOPPED:
3661 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_STOPPED\n");
3662 ecs->event_thread->suspend.stop_signal = ecs->ws.value.sig;
3665 case TARGET_WAITKIND_NO_HISTORY:
3667 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_NO_HISTORY\n");
3668 /* Reverse execution: target ran out of history info. */
3670 /* Pull the single step breakpoints out of the target. */
3671 if (singlestep_breakpoints_inserted_p)
3673 if (!ptid_equal (ecs->ptid, inferior_ptid))
3674 context_switch (ecs->ptid);
3675 remove_single_step_breakpoints ();
3676 singlestep_breakpoints_inserted_p = 0;
3678 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
3679 print_no_history_reason ();
3680 stop_stepping (ecs);
3684 if (ecs->ws.kind == TARGET_WAITKIND_STOPPED)
3686 /* Do we need to clean up the state of a thread that has
3687 completed a displaced single-step? (Doing so usually affects
3688 the PC, so do it here, before we set stop_pc.) */
3689 displaced_step_fixup (ecs->ptid,
3690 ecs->event_thread->suspend.stop_signal);
3692 /* If we either finished a single-step or hit a breakpoint, but
3693 the user wanted this thread to be stopped, pretend we got a
3694 SIG0 (generic unsignaled stop). */
3696 if (ecs->event_thread->stop_requested
3697 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
3698 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
3701 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
3705 struct regcache *regcache = get_thread_regcache (ecs->ptid);
3706 struct gdbarch *gdbarch = get_regcache_arch (regcache);
3707 struct cleanup *old_chain = save_inferior_ptid ();
3709 inferior_ptid = ecs->ptid;
3711 fprintf_unfiltered (gdb_stdlog, "infrun: stop_pc = %s\n",
3712 paddress (gdbarch, stop_pc));
3713 if (target_stopped_by_watchpoint ())
3717 fprintf_unfiltered (gdb_stdlog, "infrun: stopped by watchpoint\n");
3719 if (target_stopped_data_address (¤t_target, &addr))
3720 fprintf_unfiltered (gdb_stdlog,
3721 "infrun: stopped data address = %s\n",
3722 paddress (gdbarch, addr));
3724 fprintf_unfiltered (gdb_stdlog,
3725 "infrun: (no data address available)\n");
3728 do_cleanups (old_chain);
3731 if (stepping_past_singlestep_breakpoint)
3733 gdb_assert (singlestep_breakpoints_inserted_p);
3734 gdb_assert (ptid_equal (singlestep_ptid, ecs->ptid));
3735 gdb_assert (!ptid_equal (singlestep_ptid, saved_singlestep_ptid));
3737 stepping_past_singlestep_breakpoint = 0;
3739 /* We've either finished single-stepping past the single-step
3740 breakpoint, or stopped for some other reason. It would be nice if
3741 we could tell, but we can't reliably. */
3742 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
3745 fprintf_unfiltered (gdb_stdlog,
3746 "infrun: stepping_past_"
3747 "singlestep_breakpoint\n");
3748 /* Pull the single step breakpoints out of the target. */
3749 if (!ptid_equal (ecs->ptid, inferior_ptid))
3750 context_switch (ecs->ptid);
3751 remove_single_step_breakpoints ();
3752 singlestep_breakpoints_inserted_p = 0;
3754 ecs->random_signal = 0;
3755 ecs->event_thread->control.trap_expected = 0;
3757 context_switch (saved_singlestep_ptid);
3758 if (deprecated_context_hook)
3759 deprecated_context_hook (pid_to_thread_id (ecs->ptid));
3761 resume (1, GDB_SIGNAL_0);
3762 prepare_to_wait (ecs);
3767 if (!ptid_equal (deferred_step_ptid, null_ptid))
3769 /* In non-stop mode, there's never a deferred_step_ptid set. */
3770 gdb_assert (!non_stop);
3772 /* If we stopped for some other reason than single-stepping, ignore
3773 the fact that we were supposed to switch back. */
3774 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
3777 fprintf_unfiltered (gdb_stdlog,
3778 "infrun: handling deferred step\n");
3780 /* Pull the single step breakpoints out of the target. */
3781 if (singlestep_breakpoints_inserted_p)
3783 if (!ptid_equal (ecs->ptid, inferior_ptid))
3784 context_switch (ecs->ptid);
3785 remove_single_step_breakpoints ();
3786 singlestep_breakpoints_inserted_p = 0;
3789 ecs->event_thread->control.trap_expected = 0;
3791 context_switch (deferred_step_ptid);
3792 deferred_step_ptid = null_ptid;
3793 /* Suppress spurious "Switching to ..." message. */
3794 previous_inferior_ptid = inferior_ptid;
3796 resume (1, GDB_SIGNAL_0);
3797 prepare_to_wait (ecs);
3801 deferred_step_ptid = null_ptid;
3804 /* See if a thread hit a thread-specific breakpoint that was meant for
3805 another thread. If so, then step that thread past the breakpoint,
3808 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
3810 int thread_hop_needed = 0;
3811 struct address_space *aspace =
3812 get_regcache_aspace (get_thread_regcache (ecs->ptid));
3814 /* Check if a regular breakpoint has been hit before checking
3815 for a potential single step breakpoint. Otherwise, GDB will
3816 not see this breakpoint hit when stepping onto breakpoints. */
3817 if (regular_breakpoint_inserted_here_p (aspace, stop_pc))
3819 ecs->random_signal = 0;
3820 if (!breakpoint_thread_match (aspace, stop_pc, ecs->ptid))
3821 thread_hop_needed = 1;
3823 else if (singlestep_breakpoints_inserted_p)
3825 /* We have not context switched yet, so this should be true
3826 no matter which thread hit the singlestep breakpoint. */
3827 gdb_assert (ptid_equal (inferior_ptid, singlestep_ptid));
3829 fprintf_unfiltered (gdb_stdlog, "infrun: software single step "
3831 target_pid_to_str (ecs->ptid));
3833 ecs->random_signal = 0;
3834 /* The call to in_thread_list is necessary because PTIDs sometimes
3835 change when we go from single-threaded to multi-threaded. If
3836 the singlestep_ptid is still in the list, assume that it is
3837 really different from ecs->ptid. */
3838 if (!ptid_equal (singlestep_ptid, ecs->ptid)
3839 && in_thread_list (singlestep_ptid))
3841 /* If the PC of the thread we were trying to single-step
3842 has changed, discard this event (which we were going
3843 to ignore anyway), and pretend we saw that thread
3844 trap. This prevents us continuously moving the
3845 single-step breakpoint forward, one instruction at a
3846 time. If the PC has changed, then the thread we were
3847 trying to single-step has trapped or been signalled,
3848 but the event has not been reported to GDB yet.
3850 There might be some cases where this loses signal
3851 information, if a signal has arrived at exactly the
3852 same time that the PC changed, but this is the best
3853 we can do with the information available. Perhaps we
3854 should arrange to report all events for all threads
3855 when they stop, or to re-poll the remote looking for
3856 this particular thread (i.e. temporarily enable
3859 CORE_ADDR new_singlestep_pc
3860 = regcache_read_pc (get_thread_regcache (singlestep_ptid));
3862 if (new_singlestep_pc != singlestep_pc)
3864 enum gdb_signal stop_signal;
3867 fprintf_unfiltered (gdb_stdlog, "infrun: unexpected thread,"
3868 " but expected thread advanced also\n");
3870 /* The current context still belongs to
3871 singlestep_ptid. Don't swap here, since that's
3872 the context we want to use. Just fudge our
3873 state and continue. */
3874 stop_signal = ecs->event_thread->suspend.stop_signal;
3875 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
3876 ecs->ptid = singlestep_ptid;
3877 ecs->event_thread = find_thread_ptid (ecs->ptid);
3878 ecs->event_thread->suspend.stop_signal = stop_signal;
3879 stop_pc = new_singlestep_pc;
3884 fprintf_unfiltered (gdb_stdlog,
3885 "infrun: unexpected thread\n");
3887 thread_hop_needed = 1;
3888 stepping_past_singlestep_breakpoint = 1;
3889 saved_singlestep_ptid = singlestep_ptid;
3894 if (thread_hop_needed)
3896 struct regcache *thread_regcache;
3897 int remove_status = 0;
3900 fprintf_unfiltered (gdb_stdlog, "infrun: thread_hop_needed\n");
3902 /* Switch context before touching inferior memory, the
3903 previous thread may have exited. */
3904 if (!ptid_equal (inferior_ptid, ecs->ptid))
3905 context_switch (ecs->ptid);
3907 /* Saw a breakpoint, but it was hit by the wrong thread.
3910 if (singlestep_breakpoints_inserted_p)
3912 /* Pull the single step breakpoints out of the target. */
3913 remove_single_step_breakpoints ();
3914 singlestep_breakpoints_inserted_p = 0;
3917 /* If the arch can displace step, don't remove the
3919 thread_regcache = get_thread_regcache (ecs->ptid);
3920 if (!use_displaced_stepping (get_regcache_arch (thread_regcache)))
3921 remove_status = remove_breakpoints ();
3923 /* Did we fail to remove breakpoints? If so, try
3924 to set the PC past the bp. (There's at least
3925 one situation in which we can fail to remove
3926 the bp's: On HP-UX's that use ttrace, we can't
3927 change the address space of a vforking child
3928 process until the child exits (well, okay, not
3929 then either :-) or execs. */
3930 if (remove_status != 0)
3931 error (_("Cannot step over breakpoint hit in wrong thread"));
3936 /* Only need to require the next event from this
3937 thread in all-stop mode. */
3938 waiton_ptid = ecs->ptid;
3939 infwait_state = infwait_thread_hop_state;
3942 ecs->event_thread->stepping_over_breakpoint = 1;
3947 else if (singlestep_breakpoints_inserted_p)
3949 ecs->random_signal = 0;
3953 ecs->random_signal = 1;
3955 /* See if something interesting happened to the non-current thread. If
3956 so, then switch to that thread. */
3957 if (!ptid_equal (ecs->ptid, inferior_ptid))
3960 fprintf_unfiltered (gdb_stdlog, "infrun: context switch\n");
3962 context_switch (ecs->ptid);
3964 if (deprecated_context_hook)
3965 deprecated_context_hook (pid_to_thread_id (ecs->ptid));
3968 /* At this point, get hold of the now-current thread's frame. */
3969 frame = get_current_frame ();
3970 gdbarch = get_frame_arch (frame);
3972 if (singlestep_breakpoints_inserted_p)
3974 /* Pull the single step breakpoints out of the target. */
3975 remove_single_step_breakpoints ();
3976 singlestep_breakpoints_inserted_p = 0;
3979 if (stepped_after_stopped_by_watchpoint)
3980 stopped_by_watchpoint = 0;
3982 stopped_by_watchpoint = watchpoints_triggered (&ecs->ws);
3984 /* If necessary, step over this watchpoint. We'll be back to display
3986 if (stopped_by_watchpoint
3987 && (target_have_steppable_watchpoint
3988 || gdbarch_have_nonsteppable_watchpoint (gdbarch)))
3990 /* At this point, we are stopped at an instruction which has
3991 attempted to write to a piece of memory under control of
3992 a watchpoint. The instruction hasn't actually executed
3993 yet. If we were to evaluate the watchpoint expression
3994 now, we would get the old value, and therefore no change
3995 would seem to have occurred.
3997 In order to make watchpoints work `right', we really need
3998 to complete the memory write, and then evaluate the
3999 watchpoint expression. We do this by single-stepping the
4002 It may not be necessary to disable the watchpoint to stop over
4003 it. For example, the PA can (with some kernel cooperation)
4004 single step over a watchpoint without disabling the watchpoint.
4006 It is far more common to need to disable a watchpoint to step
4007 the inferior over it. If we have non-steppable watchpoints,
4008 we must disable the current watchpoint; it's simplest to
4009 disable all watchpoints and breakpoints. */
4012 if (!target_have_steppable_watchpoint)
4014 remove_breakpoints ();
4015 /* See comment in resume why we need to stop bypassing signals
4016 while breakpoints have been removed. */
4017 target_pass_signals (0, NULL);
4020 hw_step = maybe_software_singlestep (gdbarch, stop_pc);
4021 target_resume (ecs->ptid, hw_step, GDB_SIGNAL_0);
4022 waiton_ptid = ecs->ptid;
4023 if (target_have_steppable_watchpoint)
4024 infwait_state = infwait_step_watch_state;
4026 infwait_state = infwait_nonstep_watch_state;
4027 prepare_to_wait (ecs);
4031 clear_stop_func (ecs);
4032 ecs->event_thread->stepping_over_breakpoint = 0;
4033 bpstat_clear (&ecs->event_thread->control.stop_bpstat);
4034 ecs->event_thread->control.stop_step = 0;
4035 stop_print_frame = 1;
4036 ecs->random_signal = 0;
4037 stopped_by_random_signal = 0;
4039 /* Hide inlined functions starting here, unless we just performed stepi or
4040 nexti. After stepi and nexti, always show the innermost frame (not any
4041 inline function call sites). */
4042 if (ecs->event_thread->control.step_range_end != 1)
4044 struct address_space *aspace =
4045 get_regcache_aspace (get_thread_regcache (ecs->ptid));
4047 /* skip_inline_frames is expensive, so we avoid it if we can
4048 determine that the address is one where functions cannot have
4049 been inlined. This improves performance with inferiors that
4050 load a lot of shared libraries, because the solib event
4051 breakpoint is defined as the address of a function (i.e. not
4052 inline). Note that we have to check the previous PC as well
4053 as the current one to catch cases when we have just
4054 single-stepped off a breakpoint prior to reinstating it.
4055 Note that we're assuming that the code we single-step to is
4056 not inline, but that's not definitive: there's nothing
4057 preventing the event breakpoint function from containing
4058 inlined code, and the single-step ending up there. If the
4059 user had set a breakpoint on that inlined code, the missing
4060 skip_inline_frames call would break things. Fortunately
4061 that's an extremely unlikely scenario. */
4062 if (!pc_at_non_inline_function (aspace, stop_pc, &ecs->ws)
4063 && !(ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
4064 && ecs->event_thread->control.trap_expected
4065 && pc_at_non_inline_function (aspace,
4066 ecs->event_thread->prev_pc,
4069 skip_inline_frames (ecs->ptid);
4071 /* Re-fetch current thread's frame in case that invalidated
4073 frame = get_current_frame ();
4074 gdbarch = get_frame_arch (frame);
4078 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
4079 && ecs->event_thread->control.trap_expected
4080 && gdbarch_single_step_through_delay_p (gdbarch)
4081 && currently_stepping (ecs->event_thread))
4083 /* We're trying to step off a breakpoint. Turns out that we're
4084 also on an instruction that needs to be stepped multiple
4085 times before it's been fully executing. E.g., architectures
4086 with a delay slot. It needs to be stepped twice, once for
4087 the instruction and once for the delay slot. */
4088 int step_through_delay
4089 = gdbarch_single_step_through_delay (gdbarch, frame);
4091 if (debug_infrun && step_through_delay)
4092 fprintf_unfiltered (gdb_stdlog, "infrun: step through delay\n");
4093 if (ecs->event_thread->control.step_range_end == 0
4094 && step_through_delay)
4096 /* The user issued a continue when stopped at a breakpoint.
4097 Set up for another trap and get out of here. */
4098 ecs->event_thread->stepping_over_breakpoint = 1;
4102 else if (step_through_delay)
4104 /* The user issued a step when stopped at a breakpoint.
4105 Maybe we should stop, maybe we should not - the delay
4106 slot *might* correspond to a line of source. In any
4107 case, don't decide that here, just set
4108 ecs->stepping_over_breakpoint, making sure we
4109 single-step again before breakpoints are re-inserted. */
4110 ecs->event_thread->stepping_over_breakpoint = 1;
4114 /* Look at the cause of the stop, and decide what to do.
4115 The alternatives are:
4116 1) stop_stepping and return; to really stop and return to the debugger,
4117 2) keep_going and return to start up again
4118 (set ecs->event_thread->stepping_over_breakpoint to 1 to single step once)
4119 3) set ecs->random_signal to 1, and the decision between 1 and 2
4120 will be made according to the signal handling tables. */
4122 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
4123 || stop_soon == STOP_QUIETLY || stop_soon == STOP_QUIETLY_NO_SIGSTOP
4124 || stop_soon == STOP_QUIETLY_REMOTE)
4126 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
4130 fprintf_unfiltered (gdb_stdlog, "infrun: stopped\n");
4131 stop_print_frame = 0;
4132 stop_stepping (ecs);
4136 /* This is originated from start_remote(), start_inferior() and
4137 shared libraries hook functions. */
4138 if (stop_soon == STOP_QUIETLY || stop_soon == STOP_QUIETLY_REMOTE)
4141 fprintf_unfiltered (gdb_stdlog, "infrun: quietly stopped\n");
4142 stop_stepping (ecs);
4146 /* This originates from attach_command(). We need to overwrite
4147 the stop_signal here, because some kernels don't ignore a
4148 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
4149 See more comments in inferior.h. On the other hand, if we
4150 get a non-SIGSTOP, report it to the user - assume the backend
4151 will handle the SIGSTOP if it should show up later.
4153 Also consider that the attach is complete when we see a
4154 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
4155 target extended-remote report it instead of a SIGSTOP
4156 (e.g. gdbserver). We already rely on SIGTRAP being our
4157 signal, so this is no exception.
4159 Also consider that the attach is complete when we see a
4160 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
4161 the target to stop all threads of the inferior, in case the
4162 low level attach operation doesn't stop them implicitly. If
4163 they weren't stopped implicitly, then the stub will report a
4164 GDB_SIGNAL_0, meaning: stopped for no particular reason
4165 other than GDB's request. */
4166 if (stop_soon == STOP_QUIETLY_NO_SIGSTOP
4167 && (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_STOP
4168 || ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
4169 || ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_0))
4171 stop_stepping (ecs);
4172 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
4176 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
4177 handles this event. */
4178 ecs->event_thread->control.stop_bpstat
4179 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
4180 stop_pc, ecs->ptid, &ecs->ws);
4182 /* Following in case break condition called a
4184 stop_print_frame = 1;
4186 /* This is where we handle "moribund" watchpoints. Unlike
4187 software breakpoints traps, hardware watchpoint traps are
4188 always distinguishable from random traps. If no high-level
4189 watchpoint is associated with the reported stop data address
4190 anymore, then the bpstat does not explain the signal ---
4191 simply make sure to ignore it if `stopped_by_watchpoint' is
4195 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
4196 && !bpstat_explains_signal (ecs->event_thread->control.stop_bpstat)
4197 && stopped_by_watchpoint)
4198 fprintf_unfiltered (gdb_stdlog,
4199 "infrun: no user watchpoint explains "
4200 "watchpoint SIGTRAP, ignoring\n");
4202 /* NOTE: cagney/2003-03-29: These two checks for a random signal
4203 at one stage in the past included checks for an inferior
4204 function call's call dummy's return breakpoint. The original
4205 comment, that went with the test, read:
4207 ``End of a stack dummy. Some systems (e.g. Sony news) give
4208 another signal besides SIGTRAP, so check here as well as
4211 If someone ever tries to get call dummys on a
4212 non-executable stack to work (where the target would stop
4213 with something like a SIGSEGV), then those tests might need
4214 to be re-instated. Given, however, that the tests were only
4215 enabled when momentary breakpoints were not being used, I
4216 suspect that it won't be the case.
4218 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
4219 be necessary for call dummies on a non-executable stack on
4222 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
4224 = !(bpstat_explains_signal (ecs->event_thread->control.stop_bpstat)
4225 || stopped_by_watchpoint
4226 || ecs->event_thread->control.trap_expected
4227 || (ecs->event_thread->control.step_range_end
4228 && (ecs->event_thread->control.step_resume_breakpoint
4232 ecs->random_signal = !bpstat_explains_signal
4233 (ecs->event_thread->control.stop_bpstat);
4234 if (!ecs->random_signal)
4235 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_TRAP;
4239 /* When we reach this point, we've pretty much decided
4240 that the reason for stopping must've been a random
4241 (unexpected) signal. */
4244 ecs->random_signal = 1;
4246 process_event_stop_test:
4248 /* Re-fetch current thread's frame in case we did a
4249 "goto process_event_stop_test" above. */
4250 frame = get_current_frame ();
4251 gdbarch = get_frame_arch (frame);
4253 /* For the program's own signals, act according to
4254 the signal handling tables. */
4256 if (ecs->random_signal)
4258 /* Signal not for debugging purposes. */
4260 struct inferior *inf = find_inferior_pid (ptid_get_pid (ecs->ptid));
4263 fprintf_unfiltered (gdb_stdlog, "infrun: random signal %d\n",
4264 ecs->event_thread->suspend.stop_signal);
4266 stopped_by_random_signal = 1;
4268 if (signal_print[ecs->event_thread->suspend.stop_signal])
4271 target_terminal_ours_for_output ();
4272 print_signal_received_reason
4273 (ecs->event_thread->suspend.stop_signal);
4275 /* Always stop on signals if we're either just gaining control
4276 of the program, or the user explicitly requested this thread
4277 to remain stopped. */
4278 if (stop_soon != NO_STOP_QUIETLY
4279 || ecs->event_thread->stop_requested
4281 && signal_stop_state (ecs->event_thread->suspend.stop_signal)))
4283 stop_stepping (ecs);
4286 /* If not going to stop, give terminal back
4287 if we took it away. */
4289 target_terminal_inferior ();
4291 /* Clear the signal if it should not be passed. */
4292 if (signal_program[ecs->event_thread->suspend.stop_signal] == 0)
4293 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
4295 if (ecs->event_thread->prev_pc == stop_pc
4296 && ecs->event_thread->control.trap_expected
4297 && ecs->event_thread->control.step_resume_breakpoint == NULL)
4299 /* We were just starting a new sequence, attempting to
4300 single-step off of a breakpoint and expecting a SIGTRAP.
4301 Instead this signal arrives. This signal will take us out
4302 of the stepping range so GDB needs to remember to, when
4303 the signal handler returns, resume stepping off that
4305 /* To simplify things, "continue" is forced to use the same
4306 code paths as single-step - set a breakpoint at the
4307 signal return address and then, once hit, step off that
4310 fprintf_unfiltered (gdb_stdlog,
4311 "infrun: signal arrived while stepping over "
4314 insert_hp_step_resume_breakpoint_at_frame (frame);
4315 ecs->event_thread->step_after_step_resume_breakpoint = 1;
4316 /* Reset trap_expected to ensure breakpoints are re-inserted. */
4317 ecs->event_thread->control.trap_expected = 0;
4322 if (ecs->event_thread->control.step_range_end != 0
4323 && ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_0
4324 && (ecs->event_thread->control.step_range_start <= stop_pc
4325 && stop_pc < ecs->event_thread->control.step_range_end)
4326 && frame_id_eq (get_stack_frame_id (frame),
4327 ecs->event_thread->control.step_stack_frame_id)
4328 && ecs->event_thread->control.step_resume_breakpoint == NULL)
4330 /* The inferior is about to take a signal that will take it
4331 out of the single step range. Set a breakpoint at the
4332 current PC (which is presumably where the signal handler
4333 will eventually return) and then allow the inferior to
4336 Note that this is only needed for a signal delivered
4337 while in the single-step range. Nested signals aren't a
4338 problem as they eventually all return. */
4340 fprintf_unfiltered (gdb_stdlog,
4341 "infrun: signal may take us out of "
4342 "single-step range\n");
4344 insert_hp_step_resume_breakpoint_at_frame (frame);
4345 /* Reset trap_expected to ensure breakpoints are re-inserted. */
4346 ecs->event_thread->control.trap_expected = 0;
4351 /* Note: step_resume_breakpoint may be non-NULL. This occures
4352 when either there's a nested signal, or when there's a
4353 pending signal enabled just as the signal handler returns
4354 (leaving the inferior at the step-resume-breakpoint without
4355 actually executing it). Either way continue until the
4356 breakpoint is really hit. */
4360 /* Handle cases caused by hitting a breakpoint. */
4362 CORE_ADDR jmp_buf_pc;
4363 struct bpstat_what what;
4365 what = bpstat_what (ecs->event_thread->control.stop_bpstat);
4367 if (what.call_dummy)
4369 stop_stack_dummy = what.call_dummy;
4372 /* If we hit an internal event that triggers symbol changes, the
4373 current frame will be invalidated within bpstat_what (e.g.,
4374 if we hit an internal solib event). Re-fetch it. */
4375 frame = get_current_frame ();
4376 gdbarch = get_frame_arch (frame);
4378 switch (what.main_action)
4380 case BPSTAT_WHAT_SET_LONGJMP_RESUME:
4381 /* If we hit the breakpoint at longjmp while stepping, we
4382 install a momentary breakpoint at the target of the
4386 fprintf_unfiltered (gdb_stdlog,
4387 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME\n");
4389 ecs->event_thread->stepping_over_breakpoint = 1;
4391 if (what.is_longjmp)
4393 struct value *arg_value;
4395 /* If we set the longjmp breakpoint via a SystemTap
4396 probe, then use it to extract the arguments. The
4397 destination PC is the third argument to the
4399 arg_value = probe_safe_evaluate_at_pc (frame, 2);
4401 jmp_buf_pc = value_as_address (arg_value);
4402 else if (!gdbarch_get_longjmp_target_p (gdbarch)
4403 || !gdbarch_get_longjmp_target (gdbarch,
4404 frame, &jmp_buf_pc))
4407 fprintf_unfiltered (gdb_stdlog,
4408 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME "
4409 "(!gdbarch_get_longjmp_target)\n");
4414 /* Insert a breakpoint at resume address. */
4415 insert_longjmp_resume_breakpoint (gdbarch, jmp_buf_pc);
4418 check_exception_resume (ecs, frame);
4422 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME:
4424 struct frame_info *init_frame;
4426 /* There are several cases to consider.
4428 1. The initiating frame no longer exists. In this case
4429 we must stop, because the exception or longjmp has gone
4432 2. The initiating frame exists, and is the same as the
4433 current frame. We stop, because the exception or
4434 longjmp has been caught.
4436 3. The initiating frame exists and is different from
4437 the current frame. This means the exception or longjmp
4438 has been caught beneath the initiating frame, so keep
4441 4. longjmp breakpoint has been placed just to protect
4442 against stale dummy frames and user is not interested
4443 in stopping around longjmps. */
4446 fprintf_unfiltered (gdb_stdlog,
4447 "infrun: BPSTAT_WHAT_CLEAR_LONGJMP_RESUME\n");
4449 gdb_assert (ecs->event_thread->control.exception_resume_breakpoint
4451 delete_exception_resume_breakpoint (ecs->event_thread);
4453 if (what.is_longjmp)
4455 check_longjmp_breakpoint_for_call_dummy (ecs->event_thread->num);
4457 if (!frame_id_p (ecs->event_thread->initiating_frame))
4465 init_frame = frame_find_by_id (ecs->event_thread->initiating_frame);
4469 struct frame_id current_id
4470 = get_frame_id (get_current_frame ());
4471 if (frame_id_eq (current_id,
4472 ecs->event_thread->initiating_frame))
4474 /* Case 2. Fall through. */
4484 /* For Cases 1 and 2, remove the step-resume breakpoint,
4486 delete_step_resume_breakpoint (ecs->event_thread);
4488 ecs->event_thread->control.stop_step = 1;
4489 print_end_stepping_range_reason ();
4490 stop_stepping (ecs);
4494 case BPSTAT_WHAT_SINGLE:
4496 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_SINGLE\n");
4497 ecs->event_thread->stepping_over_breakpoint = 1;
4498 /* Still need to check other stuff, at least the case where
4499 we are stepping and step out of the right range. */
4502 case BPSTAT_WHAT_STEP_RESUME:
4504 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STEP_RESUME\n");
4506 delete_step_resume_breakpoint (ecs->event_thread);
4507 if (ecs->event_thread->control.proceed_to_finish
4508 && execution_direction == EXEC_REVERSE)
4510 struct thread_info *tp = ecs->event_thread;
4512 /* We are finishing a function in reverse, and just hit
4513 the step-resume breakpoint at the start address of
4514 the function, and we're almost there -- just need to
4515 back up by one more single-step, which should take us
4516 back to the function call. */
4517 tp->control.step_range_start = tp->control.step_range_end = 1;
4521 fill_in_stop_func (gdbarch, ecs);
4522 if (stop_pc == ecs->stop_func_start
4523 && execution_direction == EXEC_REVERSE)
4525 /* We are stepping over a function call in reverse, and
4526 just hit the step-resume breakpoint at the start
4527 address of the function. Go back to single-stepping,
4528 which should take us back to the function call. */
4529 ecs->event_thread->stepping_over_breakpoint = 1;
4535 case BPSTAT_WHAT_STOP_NOISY:
4537 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_NOISY\n");
4538 stop_print_frame = 1;
4540 /* We are about to nuke the step_resume_breakpointt via the
4541 cleanup chain, so no need to worry about it here. */
4543 stop_stepping (ecs);
4546 case BPSTAT_WHAT_STOP_SILENT:
4548 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_SILENT\n");
4549 stop_print_frame = 0;
4551 /* We are about to nuke the step_resume_breakpoin via the
4552 cleanup chain, so no need to worry about it here. */
4554 stop_stepping (ecs);
4557 case BPSTAT_WHAT_HP_STEP_RESUME:
4559 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_HP_STEP_RESUME\n");
4561 delete_step_resume_breakpoint (ecs->event_thread);
4562 if (ecs->event_thread->step_after_step_resume_breakpoint)
4564 /* Back when the step-resume breakpoint was inserted, we
4565 were trying to single-step off a breakpoint. Go back
4567 ecs->event_thread->step_after_step_resume_breakpoint = 0;
4568 ecs->event_thread->stepping_over_breakpoint = 1;
4574 case BPSTAT_WHAT_KEEP_CHECKING:
4579 /* We come here if we hit a breakpoint but should not
4580 stop for it. Possibly we also were stepping
4581 and should stop for that. So fall through and
4582 test for stepping. But, if not stepping,
4585 /* In all-stop mode, if we're currently stepping but have stopped in
4586 some other thread, we need to switch back to the stepped thread. */
4589 struct thread_info *tp;
4591 tp = iterate_over_threads (currently_stepping_or_nexting_callback,
4595 /* However, if the current thread is blocked on some internal
4596 breakpoint, and we simply need to step over that breakpoint
4597 to get it going again, do that first. */
4598 if ((ecs->event_thread->control.trap_expected
4599 && ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_TRAP)
4600 || ecs->event_thread->stepping_over_breakpoint)
4606 /* If the stepping thread exited, then don't try to switch
4607 back and resume it, which could fail in several different
4608 ways depending on the target. Instead, just keep going.
4610 We can find a stepping dead thread in the thread list in
4613 - The target supports thread exit events, and when the
4614 target tries to delete the thread from the thread list,
4615 inferior_ptid pointed at the exiting thread. In such
4616 case, calling delete_thread does not really remove the
4617 thread from the list; instead, the thread is left listed,
4618 with 'exited' state.
4620 - The target's debug interface does not support thread
4621 exit events, and so we have no idea whatsoever if the
4622 previously stepping thread is still alive. For that
4623 reason, we need to synchronously query the target
4625 if (is_exited (tp->ptid)
4626 || !target_thread_alive (tp->ptid))
4629 fprintf_unfiltered (gdb_stdlog,
4630 "infrun: not switching back to "
4631 "stepped thread, it has vanished\n");
4633 delete_thread (tp->ptid);
4638 /* Otherwise, we no longer expect a trap in the current thread.
4639 Clear the trap_expected flag before switching back -- this is
4640 what keep_going would do as well, if we called it. */
4641 ecs->event_thread->control.trap_expected = 0;
4644 fprintf_unfiltered (gdb_stdlog,
4645 "infrun: switching back to stepped thread\n");
4647 ecs->event_thread = tp;
4648 ecs->ptid = tp->ptid;
4649 context_switch (ecs->ptid);
4655 if (ecs->event_thread->control.step_resume_breakpoint)
4658 fprintf_unfiltered (gdb_stdlog,
4659 "infrun: step-resume breakpoint is inserted\n");
4661 /* Having a step-resume breakpoint overrides anything
4662 else having to do with stepping commands until
4663 that breakpoint is reached. */
4668 if (ecs->event_thread->control.step_range_end == 0)
4671 fprintf_unfiltered (gdb_stdlog, "infrun: no stepping, continue\n");
4672 /* Likewise if we aren't even stepping. */
4677 /* Re-fetch current thread's frame in case the code above caused
4678 the frame cache to be re-initialized, making our FRAME variable
4679 a dangling pointer. */
4680 frame = get_current_frame ();
4681 gdbarch = get_frame_arch (frame);
4682 fill_in_stop_func (gdbarch, ecs);
4684 /* If stepping through a line, keep going if still within it.
4686 Note that step_range_end is the address of the first instruction
4687 beyond the step range, and NOT the address of the last instruction
4690 Note also that during reverse execution, we may be stepping
4691 through a function epilogue and therefore must detect when
4692 the current-frame changes in the middle of a line. */
4694 if (stop_pc >= ecs->event_thread->control.step_range_start
4695 && stop_pc < ecs->event_thread->control.step_range_end
4696 && (execution_direction != EXEC_REVERSE
4697 || frame_id_eq (get_frame_id (frame),
4698 ecs->event_thread->control.step_frame_id)))
4702 (gdb_stdlog, "infrun: stepping inside range [%s-%s]\n",
4703 paddress (gdbarch, ecs->event_thread->control.step_range_start),
4704 paddress (gdbarch, ecs->event_thread->control.step_range_end));
4706 /* When stepping backward, stop at beginning of line range
4707 (unless it's the function entry point, in which case
4708 keep going back to the call point). */
4709 if (stop_pc == ecs->event_thread->control.step_range_start
4710 && stop_pc != ecs->stop_func_start
4711 && execution_direction == EXEC_REVERSE)
4713 ecs->event_thread->control.stop_step = 1;
4714 print_end_stepping_range_reason ();
4715 stop_stepping (ecs);
4723 /* We stepped out of the stepping range. */
4725 /* If we are stepping at the source level and entered the runtime
4726 loader dynamic symbol resolution code...
4728 EXEC_FORWARD: we keep on single stepping until we exit the run
4729 time loader code and reach the callee's address.
4731 EXEC_REVERSE: we've already executed the callee (backward), and
4732 the runtime loader code is handled just like any other
4733 undebuggable function call. Now we need only keep stepping
4734 backward through the trampoline code, and that's handled further
4735 down, so there is nothing for us to do here. */
4737 if (execution_direction != EXEC_REVERSE
4738 && ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
4739 && in_solib_dynsym_resolve_code (stop_pc))
4741 CORE_ADDR pc_after_resolver =
4742 gdbarch_skip_solib_resolver (gdbarch, stop_pc);
4745 fprintf_unfiltered (gdb_stdlog,
4746 "infrun: stepped into dynsym resolve code\n");
4748 if (pc_after_resolver)
4750 /* Set up a step-resume breakpoint at the address
4751 indicated by SKIP_SOLIB_RESOLVER. */
4752 struct symtab_and_line sr_sal;
4755 sr_sal.pc = pc_after_resolver;
4756 sr_sal.pspace = get_frame_program_space (frame);
4758 insert_step_resume_breakpoint_at_sal (gdbarch,
4759 sr_sal, null_frame_id);
4766 if (ecs->event_thread->control.step_range_end != 1
4767 && (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
4768 || ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
4769 && get_frame_type (frame) == SIGTRAMP_FRAME)
4772 fprintf_unfiltered (gdb_stdlog,
4773 "infrun: stepped into signal trampoline\n");
4774 /* The inferior, while doing a "step" or "next", has ended up in
4775 a signal trampoline (either by a signal being delivered or by
4776 the signal handler returning). Just single-step until the
4777 inferior leaves the trampoline (either by calling the handler
4783 /* If we're in the return path from a shared library trampoline,
4784 we want to proceed through the trampoline when stepping. */
4785 /* macro/2012-04-25: This needs to come before the subroutine
4786 call check below as on some targets return trampolines look
4787 like subroutine calls (MIPS16 return thunks). */
4788 if (gdbarch_in_solib_return_trampoline (gdbarch,
4789 stop_pc, ecs->stop_func_name)
4790 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE)
4792 /* Determine where this trampoline returns. */
4793 CORE_ADDR real_stop_pc;
4795 real_stop_pc = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc);
4798 fprintf_unfiltered (gdb_stdlog,
4799 "infrun: stepped into solib return tramp\n");
4801 /* Only proceed through if we know where it's going. */
4804 /* And put the step-breakpoint there and go until there. */
4805 struct symtab_and_line sr_sal;
4807 init_sal (&sr_sal); /* initialize to zeroes */
4808 sr_sal.pc = real_stop_pc;
4809 sr_sal.section = find_pc_overlay (sr_sal.pc);
4810 sr_sal.pspace = get_frame_program_space (frame);
4812 /* Do not specify what the fp should be when we stop since
4813 on some machines the prologue is where the new fp value
4815 insert_step_resume_breakpoint_at_sal (gdbarch,
4816 sr_sal, null_frame_id);
4818 /* Restart without fiddling with the step ranges or
4825 /* Check for subroutine calls. The check for the current frame
4826 equalling the step ID is not necessary - the check of the
4827 previous frame's ID is sufficient - but it is a common case and
4828 cheaper than checking the previous frame's ID.
4830 NOTE: frame_id_eq will never report two invalid frame IDs as
4831 being equal, so to get into this block, both the current and
4832 previous frame must have valid frame IDs. */
4833 /* The outer_frame_id check is a heuristic to detect stepping
4834 through startup code. If we step over an instruction which
4835 sets the stack pointer from an invalid value to a valid value,
4836 we may detect that as a subroutine call from the mythical
4837 "outermost" function. This could be fixed by marking
4838 outermost frames as !stack_p,code_p,special_p. Then the
4839 initial outermost frame, before sp was valid, would
4840 have code_addr == &_start. See the comment in frame_id_eq
4842 if (!frame_id_eq (get_stack_frame_id (frame),
4843 ecs->event_thread->control.step_stack_frame_id)
4844 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
4845 ecs->event_thread->control.step_stack_frame_id)
4846 && (!frame_id_eq (ecs->event_thread->control.step_stack_frame_id,
4848 || step_start_function != find_pc_function (stop_pc))))
4850 CORE_ADDR real_stop_pc;
4853 fprintf_unfiltered (gdb_stdlog, "infrun: stepped into subroutine\n");
4855 if ((ecs->event_thread->control.step_over_calls == STEP_OVER_NONE)
4856 || ((ecs->event_thread->control.step_range_end == 1)
4857 && in_prologue (gdbarch, ecs->event_thread->prev_pc,
4858 ecs->stop_func_start)))
4860 /* I presume that step_over_calls is only 0 when we're
4861 supposed to be stepping at the assembly language level
4862 ("stepi"). Just stop. */
4863 /* Also, maybe we just did a "nexti" inside a prolog, so we
4864 thought it was a subroutine call but it was not. Stop as
4866 /* And this works the same backward as frontward. MVS */
4867 ecs->event_thread->control.stop_step = 1;
4868 print_end_stepping_range_reason ();
4869 stop_stepping (ecs);
4873 /* Reverse stepping through solib trampolines. */
4875 if (execution_direction == EXEC_REVERSE
4876 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE
4877 && (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc)
4878 || (ecs->stop_func_start == 0
4879 && in_solib_dynsym_resolve_code (stop_pc))))
4881 /* Any solib trampoline code can be handled in reverse
4882 by simply continuing to single-step. We have already
4883 executed the solib function (backwards), and a few
4884 steps will take us back through the trampoline to the
4890 if (ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
4892 /* We're doing a "next".
4894 Normal (forward) execution: set a breakpoint at the
4895 callee's return address (the address at which the caller
4898 Reverse (backward) execution. set the step-resume
4899 breakpoint at the start of the function that we just
4900 stepped into (backwards), and continue to there. When we
4901 get there, we'll need to single-step back to the caller. */
4903 if (execution_direction == EXEC_REVERSE)
4905 /* If we're already at the start of the function, we've either
4906 just stepped backward into a single instruction function,
4907 or stepped back out of a signal handler to the first instruction
4908 of the function. Just keep going, which will single-step back
4910 if (ecs->stop_func_start != stop_pc)
4912 struct symtab_and_line sr_sal;
4914 /* Normal function call return (static or dynamic). */
4916 sr_sal.pc = ecs->stop_func_start;
4917 sr_sal.pspace = get_frame_program_space (frame);
4918 insert_step_resume_breakpoint_at_sal (gdbarch,
4919 sr_sal, null_frame_id);
4923 insert_step_resume_breakpoint_at_caller (frame);
4929 /* If we are in a function call trampoline (a stub between the
4930 calling routine and the real function), locate the real
4931 function. That's what tells us (a) whether we want to step
4932 into it at all, and (b) what prologue we want to run to the
4933 end of, if we do step into it. */
4934 real_stop_pc = skip_language_trampoline (frame, stop_pc);
4935 if (real_stop_pc == 0)
4936 real_stop_pc = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc);
4937 if (real_stop_pc != 0)
4938 ecs->stop_func_start = real_stop_pc;
4940 if (real_stop_pc != 0 && in_solib_dynsym_resolve_code (real_stop_pc))
4942 struct symtab_and_line sr_sal;
4945 sr_sal.pc = ecs->stop_func_start;
4946 sr_sal.pspace = get_frame_program_space (frame);
4948 insert_step_resume_breakpoint_at_sal (gdbarch,
4949 sr_sal, null_frame_id);
4954 /* If we have line number information for the function we are
4955 thinking of stepping into and the function isn't on the skip
4958 If there are several symtabs at that PC (e.g. with include
4959 files), just want to know whether *any* of them have line
4960 numbers. find_pc_line handles this. */
4962 struct symtab_and_line tmp_sal;
4964 tmp_sal = find_pc_line (ecs->stop_func_start, 0);
4965 if (tmp_sal.line != 0
4966 && !function_pc_is_marked_for_skip (ecs->stop_func_start))
4968 if (execution_direction == EXEC_REVERSE)
4969 handle_step_into_function_backward (gdbarch, ecs);
4971 handle_step_into_function (gdbarch, ecs);
4976 /* If we have no line number and the step-stop-if-no-debug is
4977 set, we stop the step so that the user has a chance to switch
4978 in assembly mode. */
4979 if (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
4980 && step_stop_if_no_debug)
4982 ecs->event_thread->control.stop_step = 1;
4983 print_end_stepping_range_reason ();
4984 stop_stepping (ecs);
4988 if (execution_direction == EXEC_REVERSE)
4990 /* If we're already at the start of the function, we've either just
4991 stepped backward into a single instruction function without line
4992 number info, or stepped back out of a signal handler to the first
4993 instruction of the function without line number info. Just keep
4994 going, which will single-step back to the caller. */
4995 if (ecs->stop_func_start != stop_pc)
4997 /* Set a breakpoint at callee's start address.
4998 From there we can step once and be back in the caller. */
4999 struct symtab_and_line sr_sal;
5002 sr_sal.pc = ecs->stop_func_start;
5003 sr_sal.pspace = get_frame_program_space (frame);
5004 insert_step_resume_breakpoint_at_sal (gdbarch,
5005 sr_sal, null_frame_id);
5009 /* Set a breakpoint at callee's return address (the address
5010 at which the caller will resume). */
5011 insert_step_resume_breakpoint_at_caller (frame);
5017 /* Reverse stepping through solib trampolines. */
5019 if (execution_direction == EXEC_REVERSE
5020 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE)
5022 if (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc)
5023 || (ecs->stop_func_start == 0
5024 && in_solib_dynsym_resolve_code (stop_pc)))
5026 /* Any solib trampoline code can be handled in reverse
5027 by simply continuing to single-step. We have already
5028 executed the solib function (backwards), and a few
5029 steps will take us back through the trampoline to the
5034 else if (in_solib_dynsym_resolve_code (stop_pc))
5036 /* Stepped backward into the solib dynsym resolver.
5037 Set a breakpoint at its start and continue, then
5038 one more step will take us out. */
5039 struct symtab_and_line sr_sal;
5042 sr_sal.pc = ecs->stop_func_start;
5043 sr_sal.pspace = get_frame_program_space (frame);
5044 insert_step_resume_breakpoint_at_sal (gdbarch,
5045 sr_sal, null_frame_id);
5051 stop_pc_sal = find_pc_line (stop_pc, 0);
5053 /* NOTE: tausq/2004-05-24: This if block used to be done before all
5054 the trampoline processing logic, however, there are some trampolines
5055 that have no names, so we should do trampoline handling first. */
5056 if (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
5057 && ecs->stop_func_name == NULL
5058 && stop_pc_sal.line == 0)
5061 fprintf_unfiltered (gdb_stdlog,
5062 "infrun: stepped into undebuggable function\n");
5064 /* The inferior just stepped into, or returned to, an
5065 undebuggable function (where there is no debugging information
5066 and no line number corresponding to the address where the
5067 inferior stopped). Since we want to skip this kind of code,
5068 we keep going until the inferior returns from this
5069 function - unless the user has asked us not to (via
5070 set step-mode) or we no longer know how to get back
5071 to the call site. */
5072 if (step_stop_if_no_debug
5073 || !frame_id_p (frame_unwind_caller_id (frame)))
5075 /* If we have no line number and the step-stop-if-no-debug
5076 is set, we stop the step so that the user has a chance to
5077 switch in assembly mode. */
5078 ecs->event_thread->control.stop_step = 1;
5079 print_end_stepping_range_reason ();
5080 stop_stepping (ecs);
5085 /* Set a breakpoint at callee's return address (the address
5086 at which the caller will resume). */
5087 insert_step_resume_breakpoint_at_caller (frame);
5093 if (ecs->event_thread->control.step_range_end == 1)
5095 /* It is stepi or nexti. We always want to stop stepping after
5098 fprintf_unfiltered (gdb_stdlog, "infrun: stepi/nexti\n");
5099 ecs->event_thread->control.stop_step = 1;
5100 print_end_stepping_range_reason ();
5101 stop_stepping (ecs);
5105 if (stop_pc_sal.line == 0)
5107 /* We have no line number information. That means to stop
5108 stepping (does this always happen right after one instruction,
5109 when we do "s" in a function with no line numbers,
5110 or can this happen as a result of a return or longjmp?). */
5112 fprintf_unfiltered (gdb_stdlog, "infrun: no line number info\n");
5113 ecs->event_thread->control.stop_step = 1;
5114 print_end_stepping_range_reason ();
5115 stop_stepping (ecs);
5119 /* Look for "calls" to inlined functions, part one. If the inline
5120 frame machinery detected some skipped call sites, we have entered
5121 a new inline function. */
5123 if (frame_id_eq (get_frame_id (get_current_frame ()),
5124 ecs->event_thread->control.step_frame_id)
5125 && inline_skipped_frames (ecs->ptid))
5127 struct symtab_and_line call_sal;
5130 fprintf_unfiltered (gdb_stdlog,
5131 "infrun: stepped into inlined function\n");
5133 find_frame_sal (get_current_frame (), &call_sal);
5135 if (ecs->event_thread->control.step_over_calls != STEP_OVER_ALL)
5137 /* For "step", we're going to stop. But if the call site
5138 for this inlined function is on the same source line as
5139 we were previously stepping, go down into the function
5140 first. Otherwise stop at the call site. */
5142 if (call_sal.line == ecs->event_thread->current_line
5143 && call_sal.symtab == ecs->event_thread->current_symtab)
5144 step_into_inline_frame (ecs->ptid);
5146 ecs->event_thread->control.stop_step = 1;
5147 print_end_stepping_range_reason ();
5148 stop_stepping (ecs);
5153 /* For "next", we should stop at the call site if it is on a
5154 different source line. Otherwise continue through the
5155 inlined function. */
5156 if (call_sal.line == ecs->event_thread->current_line
5157 && call_sal.symtab == ecs->event_thread->current_symtab)
5161 ecs->event_thread->control.stop_step = 1;
5162 print_end_stepping_range_reason ();
5163 stop_stepping (ecs);
5169 /* Look for "calls" to inlined functions, part two. If we are still
5170 in the same real function we were stepping through, but we have
5171 to go further up to find the exact frame ID, we are stepping
5172 through a more inlined call beyond its call site. */
5174 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
5175 && !frame_id_eq (get_frame_id (get_current_frame ()),
5176 ecs->event_thread->control.step_frame_id)
5177 && stepped_in_from (get_current_frame (),
5178 ecs->event_thread->control.step_frame_id))
5181 fprintf_unfiltered (gdb_stdlog,
5182 "infrun: stepping through inlined function\n");
5184 if (ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
5188 ecs->event_thread->control.stop_step = 1;
5189 print_end_stepping_range_reason ();
5190 stop_stepping (ecs);
5195 if ((stop_pc == stop_pc_sal.pc)
5196 && (ecs->event_thread->current_line != stop_pc_sal.line
5197 || ecs->event_thread->current_symtab != stop_pc_sal.symtab))
5199 /* We are at the start of a different line. So stop. Note that
5200 we don't stop if we step into the middle of a different line.
5201 That is said to make things like for (;;) statements work
5204 fprintf_unfiltered (gdb_stdlog,
5205 "infrun: stepped to a different line\n");
5206 ecs->event_thread->control.stop_step = 1;
5207 print_end_stepping_range_reason ();
5208 stop_stepping (ecs);
5212 /* We aren't done stepping.
5214 Optimize by setting the stepping range to the line.
5215 (We might not be in the original line, but if we entered a
5216 new line in mid-statement, we continue stepping. This makes
5217 things like for(;;) statements work better.) */
5219 ecs->event_thread->control.step_range_start = stop_pc_sal.pc;
5220 ecs->event_thread->control.step_range_end = stop_pc_sal.end;
5221 set_step_info (frame, stop_pc_sal);
5224 fprintf_unfiltered (gdb_stdlog, "infrun: keep going\n");
5228 /* Is thread TP in the middle of single-stepping? */
5231 currently_stepping (struct thread_info *tp)
5233 return ((tp->control.step_range_end
5234 && tp->control.step_resume_breakpoint == NULL)
5235 || tp->control.trap_expected
5236 || bpstat_should_step ());
5239 /* Returns true if any thread *but* the one passed in "data" is in the
5240 middle of stepping or of handling a "next". */
5243 currently_stepping_or_nexting_callback (struct thread_info *tp, void *data)
5248 return (tp->control.step_range_end
5249 || tp->control.trap_expected);
5252 /* Inferior has stepped into a subroutine call with source code that
5253 we should not step over. Do step to the first line of code in
5257 handle_step_into_function (struct gdbarch *gdbarch,
5258 struct execution_control_state *ecs)
5261 struct symtab_and_line stop_func_sal, sr_sal;
5263 fill_in_stop_func (gdbarch, ecs);
5265 s = find_pc_symtab (stop_pc);
5266 if (s && s->language != language_asm)
5267 ecs->stop_func_start = gdbarch_skip_prologue (gdbarch,
5268 ecs->stop_func_start);
5270 stop_func_sal = find_pc_line (ecs->stop_func_start, 0);
5271 /* Use the step_resume_break to step until the end of the prologue,
5272 even if that involves jumps (as it seems to on the vax under
5274 /* If the prologue ends in the middle of a source line, continue to
5275 the end of that source line (if it is still within the function).
5276 Otherwise, just go to end of prologue. */
5277 if (stop_func_sal.end
5278 && stop_func_sal.pc != ecs->stop_func_start
5279 && stop_func_sal.end < ecs->stop_func_end)
5280 ecs->stop_func_start = stop_func_sal.end;
5282 /* Architectures which require breakpoint adjustment might not be able
5283 to place a breakpoint at the computed address. If so, the test
5284 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
5285 ecs->stop_func_start to an address at which a breakpoint may be
5286 legitimately placed.
5288 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
5289 made, GDB will enter an infinite loop when stepping through
5290 optimized code consisting of VLIW instructions which contain
5291 subinstructions corresponding to different source lines. On
5292 FR-V, it's not permitted to place a breakpoint on any but the
5293 first subinstruction of a VLIW instruction. When a breakpoint is
5294 set, GDB will adjust the breakpoint address to the beginning of
5295 the VLIW instruction. Thus, we need to make the corresponding
5296 adjustment here when computing the stop address. */
5298 if (gdbarch_adjust_breakpoint_address_p (gdbarch))
5300 ecs->stop_func_start
5301 = gdbarch_adjust_breakpoint_address (gdbarch,
5302 ecs->stop_func_start);
5305 if (ecs->stop_func_start == stop_pc)
5307 /* We are already there: stop now. */
5308 ecs->event_thread->control.stop_step = 1;
5309 print_end_stepping_range_reason ();
5310 stop_stepping (ecs);
5315 /* Put the step-breakpoint there and go until there. */
5316 init_sal (&sr_sal); /* initialize to zeroes */
5317 sr_sal.pc = ecs->stop_func_start;
5318 sr_sal.section = find_pc_overlay (ecs->stop_func_start);
5319 sr_sal.pspace = get_frame_program_space (get_current_frame ());
5321 /* Do not specify what the fp should be when we stop since on
5322 some machines the prologue is where the new fp value is
5324 insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal, null_frame_id);
5326 /* And make sure stepping stops right away then. */
5327 ecs->event_thread->control.step_range_end
5328 = ecs->event_thread->control.step_range_start;
5333 /* Inferior has stepped backward into a subroutine call with source
5334 code that we should not step over. Do step to the beginning of the
5335 last line of code in it. */
5338 handle_step_into_function_backward (struct gdbarch *gdbarch,
5339 struct execution_control_state *ecs)
5342 struct symtab_and_line stop_func_sal;
5344 fill_in_stop_func (gdbarch, ecs);
5346 s = find_pc_symtab (stop_pc);
5347 if (s && s->language != language_asm)
5348 ecs->stop_func_start = gdbarch_skip_prologue (gdbarch,
5349 ecs->stop_func_start);
5351 stop_func_sal = find_pc_line (stop_pc, 0);
5353 /* OK, we're just going to keep stepping here. */
5354 if (stop_func_sal.pc == stop_pc)
5356 /* We're there already. Just stop stepping now. */
5357 ecs->event_thread->control.stop_step = 1;
5358 print_end_stepping_range_reason ();
5359 stop_stepping (ecs);
5363 /* Else just reset the step range and keep going.
5364 No step-resume breakpoint, they don't work for
5365 epilogues, which can have multiple entry paths. */
5366 ecs->event_thread->control.step_range_start = stop_func_sal.pc;
5367 ecs->event_thread->control.step_range_end = stop_func_sal.end;
5373 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
5374 This is used to both functions and to skip over code. */
5377 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch *gdbarch,
5378 struct symtab_and_line sr_sal,
5379 struct frame_id sr_id,
5380 enum bptype sr_type)
5382 /* There should never be more than one step-resume or longjmp-resume
5383 breakpoint per thread, so we should never be setting a new
5384 step_resume_breakpoint when one is already active. */
5385 gdb_assert (inferior_thread ()->control.step_resume_breakpoint == NULL);
5386 gdb_assert (sr_type == bp_step_resume || sr_type == bp_hp_step_resume);
5389 fprintf_unfiltered (gdb_stdlog,
5390 "infrun: inserting step-resume breakpoint at %s\n",
5391 paddress (gdbarch, sr_sal.pc));
5393 inferior_thread ()->control.step_resume_breakpoint
5394 = set_momentary_breakpoint (gdbarch, sr_sal, sr_id, sr_type);
5398 insert_step_resume_breakpoint_at_sal (struct gdbarch *gdbarch,
5399 struct symtab_and_line sr_sal,
5400 struct frame_id sr_id)
5402 insert_step_resume_breakpoint_at_sal_1 (gdbarch,
5407 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
5408 This is used to skip a potential signal handler.
5410 This is called with the interrupted function's frame. The signal
5411 handler, when it returns, will resume the interrupted function at
5415 insert_hp_step_resume_breakpoint_at_frame (struct frame_info *return_frame)
5417 struct symtab_and_line sr_sal;
5418 struct gdbarch *gdbarch;
5420 gdb_assert (return_frame != NULL);
5421 init_sal (&sr_sal); /* initialize to zeros */
5423 gdbarch = get_frame_arch (return_frame);
5424 sr_sal.pc = gdbarch_addr_bits_remove (gdbarch, get_frame_pc (return_frame));
5425 sr_sal.section = find_pc_overlay (sr_sal.pc);
5426 sr_sal.pspace = get_frame_program_space (return_frame);
5428 insert_step_resume_breakpoint_at_sal_1 (gdbarch, sr_sal,
5429 get_stack_frame_id (return_frame),
5433 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
5434 is used to skip a function after stepping into it (for "next" or if
5435 the called function has no debugging information).
5437 The current function has almost always been reached by single
5438 stepping a call or return instruction. NEXT_FRAME belongs to the
5439 current function, and the breakpoint will be set at the caller's
5442 This is a separate function rather than reusing
5443 insert_hp_step_resume_breakpoint_at_frame in order to avoid
5444 get_prev_frame, which may stop prematurely (see the implementation
5445 of frame_unwind_caller_id for an example). */
5448 insert_step_resume_breakpoint_at_caller (struct frame_info *next_frame)
5450 struct symtab_and_line sr_sal;
5451 struct gdbarch *gdbarch;
5453 /* We shouldn't have gotten here if we don't know where the call site
5455 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame)));
5457 init_sal (&sr_sal); /* initialize to zeros */
5459 gdbarch = frame_unwind_caller_arch (next_frame);
5460 sr_sal.pc = gdbarch_addr_bits_remove (gdbarch,
5461 frame_unwind_caller_pc (next_frame));
5462 sr_sal.section = find_pc_overlay (sr_sal.pc);
5463 sr_sal.pspace = frame_unwind_program_space (next_frame);
5465 insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal,
5466 frame_unwind_caller_id (next_frame));
5469 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
5470 new breakpoint at the target of a jmp_buf. The handling of
5471 longjmp-resume uses the same mechanisms used for handling
5472 "step-resume" breakpoints. */
5475 insert_longjmp_resume_breakpoint (struct gdbarch *gdbarch, CORE_ADDR pc)
5477 /* There should never be more than one longjmp-resume breakpoint per
5478 thread, so we should never be setting a new
5479 longjmp_resume_breakpoint when one is already active. */
5480 gdb_assert (inferior_thread ()->control.exception_resume_breakpoint == NULL);
5483 fprintf_unfiltered (gdb_stdlog,
5484 "infrun: inserting longjmp-resume breakpoint at %s\n",
5485 paddress (gdbarch, pc));
5487 inferior_thread ()->control.exception_resume_breakpoint =
5488 set_momentary_breakpoint_at_pc (gdbarch, pc, bp_longjmp_resume);
5491 /* Insert an exception resume breakpoint. TP is the thread throwing
5492 the exception. The block B is the block of the unwinder debug hook
5493 function. FRAME is the frame corresponding to the call to this
5494 function. SYM is the symbol of the function argument holding the
5495 target PC of the exception. */
5498 insert_exception_resume_breakpoint (struct thread_info *tp,
5500 struct frame_info *frame,
5503 volatile struct gdb_exception e;
5505 /* We want to ignore errors here. */
5506 TRY_CATCH (e, RETURN_MASK_ERROR)
5508 struct symbol *vsym;
5509 struct value *value;
5511 struct breakpoint *bp;
5513 vsym = lookup_symbol (SYMBOL_LINKAGE_NAME (sym), b, VAR_DOMAIN, NULL);
5514 value = read_var_value (vsym, frame);
5515 /* If the value was optimized out, revert to the old behavior. */
5516 if (! value_optimized_out (value))
5518 handler = value_as_address (value);
5521 fprintf_unfiltered (gdb_stdlog,
5522 "infrun: exception resume at %lx\n",
5523 (unsigned long) handler);
5525 bp = set_momentary_breakpoint_at_pc (get_frame_arch (frame),
5526 handler, bp_exception_resume);
5528 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
5531 bp->thread = tp->num;
5532 inferior_thread ()->control.exception_resume_breakpoint = bp;
5537 /* A helper for check_exception_resume that sets an
5538 exception-breakpoint based on a SystemTap probe. */
5541 insert_exception_resume_from_probe (struct thread_info *tp,
5542 const struct probe *probe,
5543 struct frame_info *frame)
5545 struct value *arg_value;
5547 struct breakpoint *bp;
5549 arg_value = probe_safe_evaluate_at_pc (frame, 1);
5553 handler = value_as_address (arg_value);
5556 fprintf_unfiltered (gdb_stdlog,
5557 "infrun: exception resume at %s\n",
5558 paddress (get_objfile_arch (probe->objfile),
5561 bp = set_momentary_breakpoint_at_pc (get_frame_arch (frame),
5562 handler, bp_exception_resume);
5563 bp->thread = tp->num;
5564 inferior_thread ()->control.exception_resume_breakpoint = bp;
5567 /* This is called when an exception has been intercepted. Check to
5568 see whether the exception's destination is of interest, and if so,
5569 set an exception resume breakpoint there. */
5572 check_exception_resume (struct execution_control_state *ecs,
5573 struct frame_info *frame)
5575 volatile struct gdb_exception e;
5576 const struct probe *probe;
5577 struct symbol *func;
5579 /* First see if this exception unwinding breakpoint was set via a
5580 SystemTap probe point. If so, the probe has two arguments: the
5581 CFA and the HANDLER. We ignore the CFA, extract the handler, and
5582 set a breakpoint there. */
5583 probe = find_probe_by_pc (get_frame_pc (frame));
5586 insert_exception_resume_from_probe (ecs->event_thread, probe, frame);
5590 func = get_frame_function (frame);
5594 TRY_CATCH (e, RETURN_MASK_ERROR)
5597 struct block_iterator iter;
5601 /* The exception breakpoint is a thread-specific breakpoint on
5602 the unwinder's debug hook, declared as:
5604 void _Unwind_DebugHook (void *cfa, void *handler);
5606 The CFA argument indicates the frame to which control is
5607 about to be transferred. HANDLER is the destination PC.
5609 We ignore the CFA and set a temporary breakpoint at HANDLER.
5610 This is not extremely efficient but it avoids issues in gdb
5611 with computing the DWARF CFA, and it also works even in weird
5612 cases such as throwing an exception from inside a signal
5615 b = SYMBOL_BLOCK_VALUE (func);
5616 ALL_BLOCK_SYMBOLS (b, iter, sym)
5618 if (!SYMBOL_IS_ARGUMENT (sym))
5625 insert_exception_resume_breakpoint (ecs->event_thread,
5634 stop_stepping (struct execution_control_state *ecs)
5637 fprintf_unfiltered (gdb_stdlog, "infrun: stop_stepping\n");
5639 /* Let callers know we don't want to wait for the inferior anymore. */
5640 ecs->wait_some_more = 0;
5643 /* This function handles various cases where we need to continue
5644 waiting for the inferior. */
5645 /* (Used to be the keep_going: label in the old wait_for_inferior). */
5648 keep_going (struct execution_control_state *ecs)
5650 /* Make sure normal_stop is called if we get a QUIT handled before
5652 struct cleanup *old_cleanups = make_cleanup (resume_cleanups, 0);
5654 /* Save the pc before execution, to compare with pc after stop. */
5655 ecs->event_thread->prev_pc
5656 = regcache_read_pc (get_thread_regcache (ecs->ptid));
5658 /* If we did not do break;, it means we should keep running the
5659 inferior and not return to debugger. */
5661 if (ecs->event_thread->control.trap_expected
5662 && ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_TRAP)
5664 /* We took a signal (which we are supposed to pass through to
5665 the inferior, else we'd not get here) and we haven't yet
5666 gotten our trap. Simply continue. */
5668 discard_cleanups (old_cleanups);
5669 resume (currently_stepping (ecs->event_thread),
5670 ecs->event_thread->suspend.stop_signal);
5674 /* Either the trap was not expected, but we are continuing
5675 anyway (the user asked that this signal be passed to the
5678 The signal was SIGTRAP, e.g. it was our signal, but we
5679 decided we should resume from it.
5681 We're going to run this baby now!
5683 Note that insert_breakpoints won't try to re-insert
5684 already inserted breakpoints. Therefore, we don't
5685 care if breakpoints were already inserted, or not. */
5687 if (ecs->event_thread->stepping_over_breakpoint)
5689 struct regcache *thread_regcache = get_thread_regcache (ecs->ptid);
5691 if (!use_displaced_stepping (get_regcache_arch (thread_regcache)))
5692 /* Since we can't do a displaced step, we have to remove
5693 the breakpoint while we step it. To keep things
5694 simple, we remove them all. */
5695 remove_breakpoints ();
5699 volatile struct gdb_exception e;
5701 /* Stop stepping when inserting breakpoints
5703 TRY_CATCH (e, RETURN_MASK_ERROR)
5705 insert_breakpoints ();
5709 exception_print (gdb_stderr, e);
5710 stop_stepping (ecs);
5715 ecs->event_thread->control.trap_expected
5716 = ecs->event_thread->stepping_over_breakpoint;
5718 /* Do not deliver SIGNAL_TRAP (except when the user explicitly
5719 specifies that such a signal should be delivered to the
5722 Typically, this would occure when a user is debugging a
5723 target monitor on a simulator: the target monitor sets a
5724 breakpoint; the simulator encounters this break-point and
5725 halts the simulation handing control to GDB; GDB, noteing
5726 that the break-point isn't valid, returns control back to the
5727 simulator; the simulator then delivers the hardware
5728 equivalent of a SIGNAL_TRAP to the program being debugged. */
5730 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5731 && !signal_program[ecs->event_thread->suspend.stop_signal])
5732 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5734 discard_cleanups (old_cleanups);
5735 resume (currently_stepping (ecs->event_thread),
5736 ecs->event_thread->suspend.stop_signal);
5739 prepare_to_wait (ecs);
5742 /* This function normally comes after a resume, before
5743 handle_inferior_event exits. It takes care of any last bits of
5744 housekeeping, and sets the all-important wait_some_more flag. */
5747 prepare_to_wait (struct execution_control_state *ecs)
5750 fprintf_unfiltered (gdb_stdlog, "infrun: prepare_to_wait\n");
5752 /* This is the old end of the while loop. Let everybody know we
5753 want to wait for the inferior some more and get called again
5755 ecs->wait_some_more = 1;
5758 /* Several print_*_reason functions to print why the inferior has stopped.
5759 We always print something when the inferior exits, or receives a signal.
5760 The rest of the cases are dealt with later on in normal_stop and
5761 print_it_typical. Ideally there should be a call to one of these
5762 print_*_reason functions functions from handle_inferior_event each time
5763 stop_stepping is called. */
5765 /* Print why the inferior has stopped.
5766 We are done with a step/next/si/ni command, print why the inferior has
5767 stopped. For now print nothing. Print a message only if not in the middle
5768 of doing a "step n" operation for n > 1. */
5771 print_end_stepping_range_reason (void)
5773 if ((!inferior_thread ()->step_multi
5774 || !inferior_thread ()->control.stop_step)
5775 && ui_out_is_mi_like_p (current_uiout))
5776 ui_out_field_string (current_uiout, "reason",
5777 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE));
5780 /* The inferior was terminated by a signal, print why it stopped. */
5783 print_signal_exited_reason (enum gdb_signal siggnal)
5785 struct ui_out *uiout = current_uiout;
5787 annotate_signalled ();
5788 if (ui_out_is_mi_like_p (uiout))
5790 (uiout, "reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED));
5791 ui_out_text (uiout, "\nProgram terminated with signal ");
5792 annotate_signal_name ();
5793 ui_out_field_string (uiout, "signal-name",
5794 gdb_signal_to_name (siggnal));
5795 annotate_signal_name_end ();
5796 ui_out_text (uiout, ", ");
5797 annotate_signal_string ();
5798 ui_out_field_string (uiout, "signal-meaning",
5799 gdb_signal_to_string (siggnal));
5800 annotate_signal_string_end ();
5801 ui_out_text (uiout, ".\n");
5802 ui_out_text (uiout, "The program no longer exists.\n");
5805 /* The inferior program is finished, print why it stopped. */
5808 print_exited_reason (int exitstatus)
5810 struct inferior *inf = current_inferior ();
5811 const char *pidstr = target_pid_to_str (pid_to_ptid (inf->pid));
5812 struct ui_out *uiout = current_uiout;
5814 annotate_exited (exitstatus);
5817 if (ui_out_is_mi_like_p (uiout))
5818 ui_out_field_string (uiout, "reason",
5819 async_reason_lookup (EXEC_ASYNC_EXITED));
5820 ui_out_text (uiout, "[Inferior ");
5821 ui_out_text (uiout, plongest (inf->num));
5822 ui_out_text (uiout, " (");
5823 ui_out_text (uiout, pidstr);
5824 ui_out_text (uiout, ") exited with code ");
5825 ui_out_field_fmt (uiout, "exit-code", "0%o", (unsigned int) exitstatus);
5826 ui_out_text (uiout, "]\n");
5830 if (ui_out_is_mi_like_p (uiout))
5832 (uiout, "reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY));
5833 ui_out_text (uiout, "[Inferior ");
5834 ui_out_text (uiout, plongest (inf->num));
5835 ui_out_text (uiout, " (");
5836 ui_out_text (uiout, pidstr);
5837 ui_out_text (uiout, ") exited normally]\n");
5839 /* Support the --return-child-result option. */
5840 return_child_result_value = exitstatus;
5843 /* Signal received, print why the inferior has stopped. The signal table
5844 tells us to print about it. */
5847 print_signal_received_reason (enum gdb_signal siggnal)
5849 struct ui_out *uiout = current_uiout;
5853 if (siggnal == GDB_SIGNAL_0 && !ui_out_is_mi_like_p (uiout))
5855 struct thread_info *t = inferior_thread ();
5857 ui_out_text (uiout, "\n[");
5858 ui_out_field_string (uiout, "thread-name",
5859 target_pid_to_str (t->ptid));
5860 ui_out_field_fmt (uiout, "thread-id", "] #%d", t->num);
5861 ui_out_text (uiout, " stopped");
5865 ui_out_text (uiout, "\nProgram received signal ");
5866 annotate_signal_name ();
5867 if (ui_out_is_mi_like_p (uiout))
5869 (uiout, "reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED));
5870 ui_out_field_string (uiout, "signal-name",
5871 gdb_signal_to_name (siggnal));
5872 annotate_signal_name_end ();
5873 ui_out_text (uiout, ", ");
5874 annotate_signal_string ();
5875 ui_out_field_string (uiout, "signal-meaning",
5876 gdb_signal_to_string (siggnal));
5877 annotate_signal_string_end ();
5879 ui_out_text (uiout, ".\n");
5882 /* Reverse execution: target ran out of history info, print why the inferior
5886 print_no_history_reason (void)
5888 ui_out_text (current_uiout, "\nNo more reverse-execution history.\n");
5891 /* Here to return control to GDB when the inferior stops for real.
5892 Print appropriate messages, remove breakpoints, give terminal our modes.
5894 STOP_PRINT_FRAME nonzero means print the executing frame
5895 (pc, function, args, file, line number and line text).
5896 BREAKPOINTS_FAILED nonzero means stop was due to error
5897 attempting to insert breakpoints. */
5902 struct target_waitstatus last;
5904 struct cleanup *old_chain = make_cleanup (null_cleanup, NULL);
5906 get_last_target_status (&last_ptid, &last);
5908 /* If an exception is thrown from this point on, make sure to
5909 propagate GDB's knowledge of the executing state to the
5910 frontend/user running state. A QUIT is an easy exception to see
5911 here, so do this before any filtered output. */
5913 make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
5914 else if (last.kind != TARGET_WAITKIND_SIGNALLED
5915 && last.kind != TARGET_WAITKIND_EXITED
5916 && last.kind != TARGET_WAITKIND_NO_RESUMED)
5917 make_cleanup (finish_thread_state_cleanup, &inferior_ptid);
5919 /* In non-stop mode, we don't want GDB to switch threads behind the
5920 user's back, to avoid races where the user is typing a command to
5921 apply to thread x, but GDB switches to thread y before the user
5922 finishes entering the command. */
5924 /* As with the notification of thread events, we want to delay
5925 notifying the user that we've switched thread context until
5926 the inferior actually stops.
5928 There's no point in saying anything if the inferior has exited.
5929 Note that SIGNALLED here means "exited with a signal", not
5930 "received a signal". */
5932 && !ptid_equal (previous_inferior_ptid, inferior_ptid)
5933 && target_has_execution
5934 && last.kind != TARGET_WAITKIND_SIGNALLED
5935 && last.kind != TARGET_WAITKIND_EXITED
5936 && last.kind != TARGET_WAITKIND_NO_RESUMED)
5938 target_terminal_ours_for_output ();
5939 printf_filtered (_("[Switching to %s]\n"),
5940 target_pid_to_str (inferior_ptid));
5941 annotate_thread_changed ();
5942 previous_inferior_ptid = inferior_ptid;
5945 if (last.kind == TARGET_WAITKIND_NO_RESUMED)
5947 gdb_assert (sync_execution || !target_can_async_p ());
5949 target_terminal_ours_for_output ();
5950 printf_filtered (_("No unwaited-for children left.\n"));
5953 if (!breakpoints_always_inserted_mode () && target_has_execution)
5955 if (remove_breakpoints ())
5957 target_terminal_ours_for_output ();
5958 printf_filtered (_("Cannot remove breakpoints because "
5959 "program is no longer writable.\nFurther "
5960 "execution is probably impossible.\n"));
5964 /* If an auto-display called a function and that got a signal,
5965 delete that auto-display to avoid an infinite recursion. */
5967 if (stopped_by_random_signal)
5968 disable_current_display ();
5970 /* Don't print a message if in the middle of doing a "step n"
5971 operation for n > 1 */
5972 if (target_has_execution
5973 && last.kind != TARGET_WAITKIND_SIGNALLED
5974 && last.kind != TARGET_WAITKIND_EXITED
5975 && inferior_thread ()->step_multi
5976 && inferior_thread ()->control.stop_step)
5979 target_terminal_ours ();
5980 async_enable_stdin ();
5982 /* Set the current source location. This will also happen if we
5983 display the frame below, but the current SAL will be incorrect
5984 during a user hook-stop function. */
5985 if (has_stack_frames () && !stop_stack_dummy)
5986 set_current_sal_from_frame (get_current_frame (), 1);
5988 /* Let the user/frontend see the threads as stopped. */
5989 do_cleanups (old_chain);
5991 /* Look up the hook_stop and run it (CLI internally handles problem
5992 of stop_command's pre-hook not existing). */
5994 catch_errors (hook_stop_stub, stop_command,
5995 "Error while running hook_stop:\n", RETURN_MASK_ALL);
5997 if (!has_stack_frames ())
6000 if (last.kind == TARGET_WAITKIND_SIGNALLED
6001 || last.kind == TARGET_WAITKIND_EXITED)
6004 /* Select innermost stack frame - i.e., current frame is frame 0,
6005 and current location is based on that.
6006 Don't do this on return from a stack dummy routine,
6007 or if the program has exited. */
6009 if (!stop_stack_dummy)
6011 select_frame (get_current_frame ());
6013 /* Print current location without a level number, if
6014 we have changed functions or hit a breakpoint.
6015 Print source line if we have one.
6016 bpstat_print() contains the logic deciding in detail
6017 what to print, based on the event(s) that just occurred. */
6019 /* If --batch-silent is enabled then there's no need to print the current
6020 source location, and to try risks causing an error message about
6021 missing source files. */
6022 if (stop_print_frame && !batch_silent)
6026 int do_frame_printing = 1;
6027 struct thread_info *tp = inferior_thread ();
6029 bpstat_ret = bpstat_print (tp->control.stop_bpstat, last.kind);
6033 /* FIXME: cagney/2002-12-01: Given that a frame ID does
6034 (or should) carry around the function and does (or
6035 should) use that when doing a frame comparison. */
6036 if (tp->control.stop_step
6037 && frame_id_eq (tp->control.step_frame_id,
6038 get_frame_id (get_current_frame ()))
6039 && step_start_function == find_pc_function (stop_pc))
6040 source_flag = SRC_LINE; /* Finished step, just
6041 print source line. */
6043 source_flag = SRC_AND_LOC; /* Print location and
6046 case PRINT_SRC_AND_LOC:
6047 source_flag = SRC_AND_LOC; /* Print location and
6050 case PRINT_SRC_ONLY:
6051 source_flag = SRC_LINE;
6054 source_flag = SRC_LINE; /* something bogus */
6055 do_frame_printing = 0;
6058 internal_error (__FILE__, __LINE__, _("Unknown value."));
6061 /* The behavior of this routine with respect to the source
6063 SRC_LINE: Print only source line
6064 LOCATION: Print only location
6065 SRC_AND_LOC: Print location and source line. */
6066 if (do_frame_printing)
6067 print_stack_frame (get_selected_frame (NULL), 0, source_flag);
6069 /* Display the auto-display expressions. */
6074 /* Save the function value return registers, if we care.
6075 We might be about to restore their previous contents. */
6076 if (inferior_thread ()->control.proceed_to_finish
6077 && execution_direction != EXEC_REVERSE)
6079 /* This should not be necessary. */
6081 regcache_xfree (stop_registers);
6083 /* NB: The copy goes through to the target picking up the value of
6084 all the registers. */
6085 stop_registers = regcache_dup (get_current_regcache ());
6088 if (stop_stack_dummy == STOP_STACK_DUMMY)
6090 /* Pop the empty frame that contains the stack dummy.
6091 This also restores inferior state prior to the call
6092 (struct infcall_suspend_state). */
6093 struct frame_info *frame = get_current_frame ();
6095 gdb_assert (get_frame_type (frame) == DUMMY_FRAME);
6097 /* frame_pop() calls reinit_frame_cache as the last thing it
6098 does which means there's currently no selected frame. We
6099 don't need to re-establish a selected frame if the dummy call
6100 returns normally, that will be done by
6101 restore_infcall_control_state. However, we do have to handle
6102 the case where the dummy call is returning after being
6103 stopped (e.g. the dummy call previously hit a breakpoint).
6104 We can't know which case we have so just always re-establish
6105 a selected frame here. */
6106 select_frame (get_current_frame ());
6110 annotate_stopped ();
6112 /* Suppress the stop observer if we're in the middle of:
6114 - a step n (n > 1), as there still more steps to be done.
6116 - a "finish" command, as the observer will be called in
6117 finish_command_continuation, so it can include the inferior
6118 function's return value.
6120 - calling an inferior function, as we pretend we inferior didn't
6121 run at all. The return value of the call is handled by the
6122 expression evaluator, through call_function_by_hand. */
6124 if (!target_has_execution
6125 || last.kind == TARGET_WAITKIND_SIGNALLED
6126 || last.kind == TARGET_WAITKIND_EXITED
6127 || last.kind == TARGET_WAITKIND_NO_RESUMED
6128 || (!(inferior_thread ()->step_multi
6129 && inferior_thread ()->control.stop_step)
6130 && !(inferior_thread ()->control.stop_bpstat
6131 && inferior_thread ()->control.proceed_to_finish)
6132 && !inferior_thread ()->control.in_infcall))
6134 if (!ptid_equal (inferior_ptid, null_ptid))
6135 observer_notify_normal_stop (inferior_thread ()->control.stop_bpstat,
6138 observer_notify_normal_stop (NULL, stop_print_frame);
6141 if (target_has_execution)
6143 if (last.kind != TARGET_WAITKIND_SIGNALLED
6144 && last.kind != TARGET_WAITKIND_EXITED)
6145 /* Delete the breakpoint we stopped at, if it wants to be deleted.
6146 Delete any breakpoint that is to be deleted at the next stop. */
6147 breakpoint_auto_delete (inferior_thread ()->control.stop_bpstat);
6150 /* Try to get rid of automatically added inferiors that are no
6151 longer needed. Keeping those around slows down things linearly.
6152 Note that this never removes the current inferior. */
6157 hook_stop_stub (void *cmd)
6159 execute_cmd_pre_hook ((struct cmd_list_element *) cmd);
6164 signal_stop_state (int signo)
6166 return signal_stop[signo];
6170 signal_print_state (int signo)
6172 return signal_print[signo];
6176 signal_pass_state (int signo)
6178 return signal_program[signo];
6182 signal_cache_update (int signo)
6186 for (signo = 0; signo < (int) GDB_SIGNAL_LAST; signo++)
6187 signal_cache_update (signo);
6192 signal_pass[signo] = (signal_stop[signo] == 0
6193 && signal_print[signo] == 0
6194 && signal_program[signo] == 1);
6198 signal_stop_update (int signo, int state)
6200 int ret = signal_stop[signo];
6202 signal_stop[signo] = state;
6203 signal_cache_update (signo);
6208 signal_print_update (int signo, int state)
6210 int ret = signal_print[signo];
6212 signal_print[signo] = state;
6213 signal_cache_update (signo);
6218 signal_pass_update (int signo, int state)
6220 int ret = signal_program[signo];
6222 signal_program[signo] = state;
6223 signal_cache_update (signo);
6228 sig_print_header (void)
6230 printf_filtered (_("Signal Stop\tPrint\tPass "
6231 "to program\tDescription\n"));
6235 sig_print_info (enum gdb_signal oursig)
6237 const char *name = gdb_signal_to_name (oursig);
6238 int name_padding = 13 - strlen (name);
6240 if (name_padding <= 0)
6243 printf_filtered ("%s", name);
6244 printf_filtered ("%*.*s ", name_padding, name_padding, " ");
6245 printf_filtered ("%s\t", signal_stop[oursig] ? "Yes" : "No");
6246 printf_filtered ("%s\t", signal_print[oursig] ? "Yes" : "No");
6247 printf_filtered ("%s\t\t", signal_program[oursig] ? "Yes" : "No");
6248 printf_filtered ("%s\n", gdb_signal_to_string (oursig));
6251 /* Specify how various signals in the inferior should be handled. */
6254 handle_command (char *args, int from_tty)
6257 int digits, wordlen;
6258 int sigfirst, signum, siglast;
6259 enum gdb_signal oursig;
6262 unsigned char *sigs;
6263 struct cleanup *old_chain;
6267 error_no_arg (_("signal to handle"));
6270 /* Allocate and zero an array of flags for which signals to handle. */
6272 nsigs = (int) GDB_SIGNAL_LAST;
6273 sigs = (unsigned char *) alloca (nsigs);
6274 memset (sigs, 0, nsigs);
6276 /* Break the command line up into args. */
6278 argv = gdb_buildargv (args);
6279 old_chain = make_cleanup_freeargv (argv);
6281 /* Walk through the args, looking for signal oursigs, signal names, and
6282 actions. Signal numbers and signal names may be interspersed with
6283 actions, with the actions being performed for all signals cumulatively
6284 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
6286 while (*argv != NULL)
6288 wordlen = strlen (*argv);
6289 for (digits = 0; isdigit ((*argv)[digits]); digits++)
6293 sigfirst = siglast = -1;
6295 if (wordlen >= 1 && !strncmp (*argv, "all", wordlen))
6297 /* Apply action to all signals except those used by the
6298 debugger. Silently skip those. */
6301 siglast = nsigs - 1;
6303 else if (wordlen >= 1 && !strncmp (*argv, "stop", wordlen))
6305 SET_SIGS (nsigs, sigs, signal_stop);
6306 SET_SIGS (nsigs, sigs, signal_print);
6308 else if (wordlen >= 1 && !strncmp (*argv, "ignore", wordlen))
6310 UNSET_SIGS (nsigs, sigs, signal_program);
6312 else if (wordlen >= 2 && !strncmp (*argv, "print", wordlen))
6314 SET_SIGS (nsigs, sigs, signal_print);
6316 else if (wordlen >= 2 && !strncmp (*argv, "pass", wordlen))
6318 SET_SIGS (nsigs, sigs, signal_program);
6320 else if (wordlen >= 3 && !strncmp (*argv, "nostop", wordlen))
6322 UNSET_SIGS (nsigs, sigs, signal_stop);
6324 else if (wordlen >= 3 && !strncmp (*argv, "noignore", wordlen))
6326 SET_SIGS (nsigs, sigs, signal_program);
6328 else if (wordlen >= 4 && !strncmp (*argv, "noprint", wordlen))
6330 UNSET_SIGS (nsigs, sigs, signal_print);
6331 UNSET_SIGS (nsigs, sigs, signal_stop);
6333 else if (wordlen >= 4 && !strncmp (*argv, "nopass", wordlen))
6335 UNSET_SIGS (nsigs, sigs, signal_program);
6337 else if (digits > 0)
6339 /* It is numeric. The numeric signal refers to our own
6340 internal signal numbering from target.h, not to host/target
6341 signal number. This is a feature; users really should be
6342 using symbolic names anyway, and the common ones like
6343 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
6345 sigfirst = siglast = (int)
6346 gdb_signal_from_command (atoi (*argv));
6347 if ((*argv)[digits] == '-')
6350 gdb_signal_from_command (atoi ((*argv) + digits + 1));
6352 if (sigfirst > siglast)
6354 /* Bet he didn't figure we'd think of this case... */
6362 oursig = gdb_signal_from_name (*argv);
6363 if (oursig != GDB_SIGNAL_UNKNOWN)
6365 sigfirst = siglast = (int) oursig;
6369 /* Not a number and not a recognized flag word => complain. */
6370 error (_("Unrecognized or ambiguous flag word: \"%s\"."), *argv);
6374 /* If any signal numbers or symbol names were found, set flags for
6375 which signals to apply actions to. */
6377 for (signum = sigfirst; signum >= 0 && signum <= siglast; signum++)
6379 switch ((enum gdb_signal) signum)
6381 case GDB_SIGNAL_TRAP:
6382 case GDB_SIGNAL_INT:
6383 if (!allsigs && !sigs[signum])
6385 if (query (_("%s is used by the debugger.\n\
6386 Are you sure you want to change it? "),
6387 gdb_signal_to_name ((enum gdb_signal) signum)))
6393 printf_unfiltered (_("Not confirmed, unchanged.\n"));
6394 gdb_flush (gdb_stdout);
6399 case GDB_SIGNAL_DEFAULT:
6400 case GDB_SIGNAL_UNKNOWN:
6401 /* Make sure that "all" doesn't print these. */
6412 for (signum = 0; signum < nsigs; signum++)
6415 signal_cache_update (-1);
6416 target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
6417 target_program_signals ((int) GDB_SIGNAL_LAST, signal_program);
6421 /* Show the results. */
6422 sig_print_header ();
6423 for (; signum < nsigs; signum++)
6425 sig_print_info (signum);
6431 do_cleanups (old_chain);
6434 /* Complete the "handle" command. */
6436 static VEC (char_ptr) *
6437 handle_completer (struct cmd_list_element *ignore,
6438 char *text, char *word)
6440 VEC (char_ptr) *vec_signals, *vec_keywords, *return_val;
6441 static const char * const keywords[] =
6455 vec_signals = signal_completer (ignore, text, word);
6456 vec_keywords = complete_on_enum (keywords, word, word);
6458 return_val = VEC_merge (char_ptr, vec_signals, vec_keywords);
6459 VEC_free (char_ptr, vec_signals);
6460 VEC_free (char_ptr, vec_keywords);
6465 xdb_handle_command (char *args, int from_tty)
6468 struct cleanup *old_chain;
6471 error_no_arg (_("xdb command"));
6473 /* Break the command line up into args. */
6475 argv = gdb_buildargv (args);
6476 old_chain = make_cleanup_freeargv (argv);
6477 if (argv[1] != (char *) NULL)
6482 bufLen = strlen (argv[0]) + 20;
6483 argBuf = (char *) xmalloc (bufLen);
6487 enum gdb_signal oursig;
6489 oursig = gdb_signal_from_name (argv[0]);
6490 memset (argBuf, 0, bufLen);
6491 if (strcmp (argv[1], "Q") == 0)
6492 sprintf (argBuf, "%s %s", argv[0], "noprint");
6495 if (strcmp (argv[1], "s") == 0)
6497 if (!signal_stop[oursig])
6498 sprintf (argBuf, "%s %s", argv[0], "stop");
6500 sprintf (argBuf, "%s %s", argv[0], "nostop");
6502 else if (strcmp (argv[1], "i") == 0)
6504 if (!signal_program[oursig])
6505 sprintf (argBuf, "%s %s", argv[0], "pass");
6507 sprintf (argBuf, "%s %s", argv[0], "nopass");
6509 else if (strcmp (argv[1], "r") == 0)
6511 if (!signal_print[oursig])
6512 sprintf (argBuf, "%s %s", argv[0], "print");
6514 sprintf (argBuf, "%s %s", argv[0], "noprint");
6520 handle_command (argBuf, from_tty);
6522 printf_filtered (_("Invalid signal handling flag.\n"));
6527 do_cleanups (old_chain);
6531 gdb_signal_from_command (int num)
6533 if (num >= 1 && num <= 15)
6534 return (enum gdb_signal) num;
6535 error (_("Only signals 1-15 are valid as numeric signals.\n\
6536 Use \"info signals\" for a list of symbolic signals."));
6539 /* Print current contents of the tables set by the handle command.
6540 It is possible we should just be printing signals actually used
6541 by the current target (but for things to work right when switching
6542 targets, all signals should be in the signal tables). */
6545 signals_info (char *signum_exp, int from_tty)
6547 enum gdb_signal oursig;
6549 sig_print_header ();
6553 /* First see if this is a symbol name. */
6554 oursig = gdb_signal_from_name (signum_exp);
6555 if (oursig == GDB_SIGNAL_UNKNOWN)
6557 /* No, try numeric. */
6559 gdb_signal_from_command (parse_and_eval_long (signum_exp));
6561 sig_print_info (oursig);
6565 printf_filtered ("\n");
6566 /* These ugly casts brought to you by the native VAX compiler. */
6567 for (oursig = GDB_SIGNAL_FIRST;
6568 (int) oursig < (int) GDB_SIGNAL_LAST;
6569 oursig = (enum gdb_signal) ((int) oursig + 1))
6573 if (oursig != GDB_SIGNAL_UNKNOWN
6574 && oursig != GDB_SIGNAL_DEFAULT && oursig != GDB_SIGNAL_0)
6575 sig_print_info (oursig);
6578 printf_filtered (_("\nUse the \"handle\" command "
6579 "to change these tables.\n"));
6582 /* Check if it makes sense to read $_siginfo from the current thread
6583 at this point. If not, throw an error. */
6586 validate_siginfo_access (void)
6588 /* No current inferior, no siginfo. */
6589 if (ptid_equal (inferior_ptid, null_ptid))
6590 error (_("No thread selected."));
6592 /* Don't try to read from a dead thread. */
6593 if (is_exited (inferior_ptid))
6594 error (_("The current thread has terminated"));
6596 /* ... or from a spinning thread. */
6597 if (is_running (inferior_ptid))
6598 error (_("Selected thread is running."));
6601 /* The $_siginfo convenience variable is a bit special. We don't know
6602 for sure the type of the value until we actually have a chance to
6603 fetch the data. The type can change depending on gdbarch, so it is
6604 also dependent on which thread you have selected.
6606 1. making $_siginfo be an internalvar that creates a new value on
6609 2. making the value of $_siginfo be an lval_computed value. */
6611 /* This function implements the lval_computed support for reading a
6615 siginfo_value_read (struct value *v)
6617 LONGEST transferred;
6619 validate_siginfo_access ();
6622 target_read (¤t_target, TARGET_OBJECT_SIGNAL_INFO,
6624 value_contents_all_raw (v),
6626 TYPE_LENGTH (value_type (v)));
6628 if (transferred != TYPE_LENGTH (value_type (v)))
6629 error (_("Unable to read siginfo"));
6632 /* This function implements the lval_computed support for writing a
6636 siginfo_value_write (struct value *v, struct value *fromval)
6638 LONGEST transferred;
6640 validate_siginfo_access ();
6642 transferred = target_write (¤t_target,
6643 TARGET_OBJECT_SIGNAL_INFO,
6645 value_contents_all_raw (fromval),
6647 TYPE_LENGTH (value_type (fromval)));
6649 if (transferred != TYPE_LENGTH (value_type (fromval)))
6650 error (_("Unable to write siginfo"));
6653 static const struct lval_funcs siginfo_value_funcs =
6659 /* Return a new value with the correct type for the siginfo object of
6660 the current thread using architecture GDBARCH. Return a void value
6661 if there's no object available. */
6663 static struct value *
6664 siginfo_make_value (struct gdbarch *gdbarch, struct internalvar *var,
6667 if (target_has_stack
6668 && !ptid_equal (inferior_ptid, null_ptid)
6669 && gdbarch_get_siginfo_type_p (gdbarch))
6671 struct type *type = gdbarch_get_siginfo_type (gdbarch);
6673 return allocate_computed_value (type, &siginfo_value_funcs, NULL);
6676 return allocate_value (builtin_type (gdbarch)->builtin_void);
6680 /* infcall_suspend_state contains state about the program itself like its
6681 registers and any signal it received when it last stopped.
6682 This state must be restored regardless of how the inferior function call
6683 ends (either successfully, or after it hits a breakpoint or signal)
6684 if the program is to properly continue where it left off. */
6686 struct infcall_suspend_state
6688 struct thread_suspend_state thread_suspend;
6689 #if 0 /* Currently unused and empty structures are not valid C. */
6690 struct inferior_suspend_state inferior_suspend;
6695 struct regcache *registers;
6697 /* Format of SIGINFO_DATA or NULL if it is not present. */
6698 struct gdbarch *siginfo_gdbarch;
6700 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
6701 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
6702 content would be invalid. */
6703 gdb_byte *siginfo_data;
6706 struct infcall_suspend_state *
6707 save_infcall_suspend_state (void)
6709 struct infcall_suspend_state *inf_state;
6710 struct thread_info *tp = inferior_thread ();
6711 struct inferior *inf = current_inferior ();
6712 struct regcache *regcache = get_current_regcache ();
6713 struct gdbarch *gdbarch = get_regcache_arch (regcache);
6714 gdb_byte *siginfo_data = NULL;
6716 if (gdbarch_get_siginfo_type_p (gdbarch))
6718 struct type *type = gdbarch_get_siginfo_type (gdbarch);
6719 size_t len = TYPE_LENGTH (type);
6720 struct cleanup *back_to;
6722 siginfo_data = xmalloc (len);
6723 back_to = make_cleanup (xfree, siginfo_data);
6725 if (target_read (¤t_target, TARGET_OBJECT_SIGNAL_INFO, NULL,
6726 siginfo_data, 0, len) == len)
6727 discard_cleanups (back_to);
6730 /* Errors ignored. */
6731 do_cleanups (back_to);
6732 siginfo_data = NULL;
6736 inf_state = XZALLOC (struct infcall_suspend_state);
6740 inf_state->siginfo_gdbarch = gdbarch;
6741 inf_state->siginfo_data = siginfo_data;
6744 inf_state->thread_suspend = tp->suspend;
6745 #if 0 /* Currently unused and empty structures are not valid C. */
6746 inf_state->inferior_suspend = inf->suspend;
6749 /* run_inferior_call will not use the signal due to its `proceed' call with
6750 GDB_SIGNAL_0 anyway. */
6751 tp->suspend.stop_signal = GDB_SIGNAL_0;
6753 inf_state->stop_pc = stop_pc;
6755 inf_state->registers = regcache_dup (regcache);
6760 /* Restore inferior session state to INF_STATE. */
6763 restore_infcall_suspend_state (struct infcall_suspend_state *inf_state)
6765 struct thread_info *tp = inferior_thread ();
6766 struct inferior *inf = current_inferior ();
6767 struct regcache *regcache = get_current_regcache ();
6768 struct gdbarch *gdbarch = get_regcache_arch (regcache);
6770 tp->suspend = inf_state->thread_suspend;
6771 #if 0 /* Currently unused and empty structures are not valid C. */
6772 inf->suspend = inf_state->inferior_suspend;
6775 stop_pc = inf_state->stop_pc;
6777 if (inf_state->siginfo_gdbarch == gdbarch)
6779 struct type *type = gdbarch_get_siginfo_type (gdbarch);
6781 /* Errors ignored. */
6782 target_write (¤t_target, TARGET_OBJECT_SIGNAL_INFO, NULL,
6783 inf_state->siginfo_data, 0, TYPE_LENGTH (type));
6786 /* The inferior can be gone if the user types "print exit(0)"
6787 (and perhaps other times). */
6788 if (target_has_execution)
6789 /* NB: The register write goes through to the target. */
6790 regcache_cpy (regcache, inf_state->registers);
6792 discard_infcall_suspend_state (inf_state);
6796 do_restore_infcall_suspend_state_cleanup (void *state)
6798 restore_infcall_suspend_state (state);
6802 make_cleanup_restore_infcall_suspend_state
6803 (struct infcall_suspend_state *inf_state)
6805 return make_cleanup (do_restore_infcall_suspend_state_cleanup, inf_state);
6809 discard_infcall_suspend_state (struct infcall_suspend_state *inf_state)
6811 regcache_xfree (inf_state->registers);
6812 xfree (inf_state->siginfo_data);
6817 get_infcall_suspend_state_regcache (struct infcall_suspend_state *inf_state)
6819 return inf_state->registers;
6822 /* infcall_control_state contains state regarding gdb's control of the
6823 inferior itself like stepping control. It also contains session state like
6824 the user's currently selected frame. */
6826 struct infcall_control_state
6828 struct thread_control_state thread_control;
6829 struct inferior_control_state inferior_control;
6832 enum stop_stack_kind stop_stack_dummy;
6833 int stopped_by_random_signal;
6834 int stop_after_trap;
6836 /* ID if the selected frame when the inferior function call was made. */
6837 struct frame_id selected_frame_id;
6840 /* Save all of the information associated with the inferior<==>gdb
6843 struct infcall_control_state *
6844 save_infcall_control_state (void)
6846 struct infcall_control_state *inf_status = xmalloc (sizeof (*inf_status));
6847 struct thread_info *tp = inferior_thread ();
6848 struct inferior *inf = current_inferior ();
6850 inf_status->thread_control = tp->control;
6851 inf_status->inferior_control = inf->control;
6853 tp->control.step_resume_breakpoint = NULL;
6854 tp->control.exception_resume_breakpoint = NULL;
6856 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
6857 chain. If caller's caller is walking the chain, they'll be happier if we
6858 hand them back the original chain when restore_infcall_control_state is
6860 tp->control.stop_bpstat = bpstat_copy (tp->control.stop_bpstat);
6863 inf_status->stop_stack_dummy = stop_stack_dummy;
6864 inf_status->stopped_by_random_signal = stopped_by_random_signal;
6865 inf_status->stop_after_trap = stop_after_trap;
6867 inf_status->selected_frame_id = get_frame_id (get_selected_frame (NULL));
6873 restore_selected_frame (void *args)
6875 struct frame_id *fid = (struct frame_id *) args;
6876 struct frame_info *frame;
6878 frame = frame_find_by_id (*fid);
6880 /* If inf_status->selected_frame_id is NULL, there was no previously
6884 warning (_("Unable to restore previously selected frame."));
6888 select_frame (frame);
6893 /* Restore inferior session state to INF_STATUS. */
6896 restore_infcall_control_state (struct infcall_control_state *inf_status)
6898 struct thread_info *tp = inferior_thread ();
6899 struct inferior *inf = current_inferior ();
6901 if (tp->control.step_resume_breakpoint)
6902 tp->control.step_resume_breakpoint->disposition = disp_del_at_next_stop;
6904 if (tp->control.exception_resume_breakpoint)
6905 tp->control.exception_resume_breakpoint->disposition
6906 = disp_del_at_next_stop;
6908 /* Handle the bpstat_copy of the chain. */
6909 bpstat_clear (&tp->control.stop_bpstat);
6911 tp->control = inf_status->thread_control;
6912 inf->control = inf_status->inferior_control;
6915 stop_stack_dummy = inf_status->stop_stack_dummy;
6916 stopped_by_random_signal = inf_status->stopped_by_random_signal;
6917 stop_after_trap = inf_status->stop_after_trap;
6919 if (target_has_stack)
6921 /* The point of catch_errors is that if the stack is clobbered,
6922 walking the stack might encounter a garbage pointer and
6923 error() trying to dereference it. */
6925 (restore_selected_frame, &inf_status->selected_frame_id,
6926 "Unable to restore previously selected frame:\n",
6927 RETURN_MASK_ERROR) == 0)
6928 /* Error in restoring the selected frame. Select the innermost
6930 select_frame (get_current_frame ());
6937 do_restore_infcall_control_state_cleanup (void *sts)
6939 restore_infcall_control_state (sts);
6943 make_cleanup_restore_infcall_control_state
6944 (struct infcall_control_state *inf_status)
6946 return make_cleanup (do_restore_infcall_control_state_cleanup, inf_status);
6950 discard_infcall_control_state (struct infcall_control_state *inf_status)
6952 if (inf_status->thread_control.step_resume_breakpoint)
6953 inf_status->thread_control.step_resume_breakpoint->disposition
6954 = disp_del_at_next_stop;
6956 if (inf_status->thread_control.exception_resume_breakpoint)
6957 inf_status->thread_control.exception_resume_breakpoint->disposition
6958 = disp_del_at_next_stop;
6960 /* See save_infcall_control_state for info on stop_bpstat. */
6961 bpstat_clear (&inf_status->thread_control.stop_bpstat);
6967 ptid_match (ptid_t ptid, ptid_t filter)
6969 if (ptid_equal (filter, minus_one_ptid))
6971 if (ptid_is_pid (filter)
6972 && ptid_get_pid (ptid) == ptid_get_pid (filter))
6974 else if (ptid_equal (ptid, filter))
6980 /* restore_inferior_ptid() will be used by the cleanup machinery
6981 to restore the inferior_ptid value saved in a call to
6982 save_inferior_ptid(). */
6985 restore_inferior_ptid (void *arg)
6987 ptid_t *saved_ptid_ptr = arg;
6989 inferior_ptid = *saved_ptid_ptr;
6993 /* Save the value of inferior_ptid so that it may be restored by a
6994 later call to do_cleanups(). Returns the struct cleanup pointer
6995 needed for later doing the cleanup. */
6998 save_inferior_ptid (void)
7000 ptid_t *saved_ptid_ptr;
7002 saved_ptid_ptr = xmalloc (sizeof (ptid_t));
7003 *saved_ptid_ptr = inferior_ptid;
7004 return make_cleanup (restore_inferior_ptid, saved_ptid_ptr);
7008 /* User interface for reverse debugging:
7009 Set exec-direction / show exec-direction commands
7010 (returns error unless target implements to_set_exec_direction method). */
7012 int execution_direction = EXEC_FORWARD;
7013 static const char exec_forward[] = "forward";
7014 static const char exec_reverse[] = "reverse";
7015 static const char *exec_direction = exec_forward;
7016 static const char *const exec_direction_names[] = {
7023 set_exec_direction_func (char *args, int from_tty,
7024 struct cmd_list_element *cmd)
7026 if (target_can_execute_reverse)
7028 if (!strcmp (exec_direction, exec_forward))
7029 execution_direction = EXEC_FORWARD;
7030 else if (!strcmp (exec_direction, exec_reverse))
7031 execution_direction = EXEC_REVERSE;
7035 exec_direction = exec_forward;
7036 error (_("Target does not support this operation."));
7041 show_exec_direction_func (struct ui_file *out, int from_tty,
7042 struct cmd_list_element *cmd, const char *value)
7044 switch (execution_direction) {
7046 fprintf_filtered (out, _("Forward.\n"));
7049 fprintf_filtered (out, _("Reverse.\n"));
7052 internal_error (__FILE__, __LINE__,
7053 _("bogus execution_direction value: %d"),
7054 (int) execution_direction);
7058 /* User interface for non-stop mode. */
7063 set_non_stop (char *args, int from_tty,
7064 struct cmd_list_element *c)
7066 if (target_has_execution)
7068 non_stop_1 = non_stop;
7069 error (_("Cannot change this setting while the inferior is running."));
7072 non_stop = non_stop_1;
7076 show_non_stop (struct ui_file *file, int from_tty,
7077 struct cmd_list_element *c, const char *value)
7079 fprintf_filtered (file,
7080 _("Controlling the inferior in non-stop mode is %s.\n"),
7085 show_schedule_multiple (struct ui_file *file, int from_tty,
7086 struct cmd_list_element *c, const char *value)
7088 fprintf_filtered (file, _("Resuming the execution of threads "
7089 "of all processes is %s.\n"), value);
7092 /* Implementation of `siginfo' variable. */
7094 static const struct internalvar_funcs siginfo_funcs =
7102 _initialize_infrun (void)
7106 struct cmd_list_element *c;
7108 add_info ("signals", signals_info, _("\
7109 What debugger does when program gets various signals.\n\
7110 Specify a signal as argument to print info on that signal only."));
7111 add_info_alias ("handle", "signals", 0);
7113 c = add_com ("handle", class_run, handle_command, _("\
7114 Specify how to handle signals.\n\
7115 Usage: handle SIGNAL [ACTIONS]\n\
7116 Args are signals and actions to apply to those signals.\n\
7117 If no actions are specified, the current settings for the specified signals\n\
7118 will be displayed instead.\n\
7120 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
7121 from 1-15 are allowed for compatibility with old versions of GDB.\n\
7122 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
7123 The special arg \"all\" is recognized to mean all signals except those\n\
7124 used by the debugger, typically SIGTRAP and SIGINT.\n\
7126 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
7127 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
7128 Stop means reenter debugger if this signal happens (implies print).\n\
7129 Print means print a message if this signal happens.\n\
7130 Pass means let program see this signal; otherwise program doesn't know.\n\
7131 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
7132 Pass and Stop may be combined.\n\
7134 Multiple signals may be specified. Signal numbers and signal names\n\
7135 may be interspersed with actions, with the actions being performed for\n\
7136 all signals cumulatively specified."));
7137 set_cmd_completer (c, handle_completer);
7141 add_com ("lz", class_info, signals_info, _("\
7142 What debugger does when program gets various signals.\n\
7143 Specify a signal as argument to print info on that signal only."));
7144 add_com ("z", class_run, xdb_handle_command, _("\
7145 Specify how to handle a signal.\n\
7146 Args are signals and actions to apply to those signals.\n\
7147 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
7148 from 1-15 are allowed for compatibility with old versions of GDB.\n\
7149 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
7150 The special arg \"all\" is recognized to mean all signals except those\n\
7151 used by the debugger, typically SIGTRAP and SIGINT.\n\
7152 Recognized actions include \"s\" (toggles between stop and nostop),\n\
7153 \"r\" (toggles between print and noprint), \"i\" (toggles between pass and \
7154 nopass), \"Q\" (noprint)\n\
7155 Stop means reenter debugger if this signal happens (implies print).\n\
7156 Print means print a message if this signal happens.\n\
7157 Pass means let program see this signal; otherwise program doesn't know.\n\
7158 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
7159 Pass and Stop may be combined."));
7163 stop_command = add_cmd ("stop", class_obscure,
7164 not_just_help_class_command, _("\
7165 There is no `stop' command, but you can set a hook on `stop'.\n\
7166 This allows you to set a list of commands to be run each time execution\n\
7167 of the program stops."), &cmdlist);
7169 add_setshow_zuinteger_cmd ("infrun", class_maintenance, &debug_infrun, _("\
7170 Set inferior debugging."), _("\
7171 Show inferior debugging."), _("\
7172 When non-zero, inferior specific debugging is enabled."),
7175 &setdebuglist, &showdebuglist);
7177 add_setshow_boolean_cmd ("displaced", class_maintenance,
7178 &debug_displaced, _("\
7179 Set displaced stepping debugging."), _("\
7180 Show displaced stepping debugging."), _("\
7181 When non-zero, displaced stepping specific debugging is enabled."),
7183 show_debug_displaced,
7184 &setdebuglist, &showdebuglist);
7186 add_setshow_boolean_cmd ("non-stop", no_class,
7188 Set whether gdb controls the inferior in non-stop mode."), _("\
7189 Show whether gdb controls the inferior in non-stop mode."), _("\
7190 When debugging a multi-threaded program and this setting is\n\
7191 off (the default, also called all-stop mode), when one thread stops\n\
7192 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
7193 all other threads in the program while you interact with the thread of\n\
7194 interest. When you continue or step a thread, you can allow the other\n\
7195 threads to run, or have them remain stopped, but while you inspect any\n\
7196 thread's state, all threads stop.\n\
7198 In non-stop mode, when one thread stops, other threads can continue\n\
7199 to run freely. You'll be able to step each thread independently,\n\
7200 leave it stopped or free to run as needed."),
7206 numsigs = (int) GDB_SIGNAL_LAST;
7207 signal_stop = (unsigned char *) xmalloc (sizeof (signal_stop[0]) * numsigs);
7208 signal_print = (unsigned char *)
7209 xmalloc (sizeof (signal_print[0]) * numsigs);
7210 signal_program = (unsigned char *)
7211 xmalloc (sizeof (signal_program[0]) * numsigs);
7212 signal_pass = (unsigned char *)
7213 xmalloc (sizeof (signal_program[0]) * numsigs);
7214 for (i = 0; i < numsigs; i++)
7217 signal_print[i] = 1;
7218 signal_program[i] = 1;
7221 /* Signals caused by debugger's own actions
7222 should not be given to the program afterwards. */
7223 signal_program[GDB_SIGNAL_TRAP] = 0;
7224 signal_program[GDB_SIGNAL_INT] = 0;
7226 /* Signals that are not errors should not normally enter the debugger. */
7227 signal_stop[GDB_SIGNAL_ALRM] = 0;
7228 signal_print[GDB_SIGNAL_ALRM] = 0;
7229 signal_stop[GDB_SIGNAL_VTALRM] = 0;
7230 signal_print[GDB_SIGNAL_VTALRM] = 0;
7231 signal_stop[GDB_SIGNAL_PROF] = 0;
7232 signal_print[GDB_SIGNAL_PROF] = 0;
7233 signal_stop[GDB_SIGNAL_CHLD] = 0;
7234 signal_print[GDB_SIGNAL_CHLD] = 0;
7235 signal_stop[GDB_SIGNAL_IO] = 0;
7236 signal_print[GDB_SIGNAL_IO] = 0;
7237 signal_stop[GDB_SIGNAL_POLL] = 0;
7238 signal_print[GDB_SIGNAL_POLL] = 0;
7239 signal_stop[GDB_SIGNAL_URG] = 0;
7240 signal_print[GDB_SIGNAL_URG] = 0;
7241 signal_stop[GDB_SIGNAL_WINCH] = 0;
7242 signal_print[GDB_SIGNAL_WINCH] = 0;
7243 signal_stop[GDB_SIGNAL_PRIO] = 0;
7244 signal_print[GDB_SIGNAL_PRIO] = 0;
7246 /* These signals are used internally by user-level thread
7247 implementations. (See signal(5) on Solaris.) Like the above
7248 signals, a healthy program receives and handles them as part of
7249 its normal operation. */
7250 signal_stop[GDB_SIGNAL_LWP] = 0;
7251 signal_print[GDB_SIGNAL_LWP] = 0;
7252 signal_stop[GDB_SIGNAL_WAITING] = 0;
7253 signal_print[GDB_SIGNAL_WAITING] = 0;
7254 signal_stop[GDB_SIGNAL_CANCEL] = 0;
7255 signal_print[GDB_SIGNAL_CANCEL] = 0;
7257 /* Update cached state. */
7258 signal_cache_update (-1);
7260 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support,
7261 &stop_on_solib_events, _("\
7262 Set stopping for shared library events."), _("\
7263 Show stopping for shared library events."), _("\
7264 If nonzero, gdb will give control to the user when the dynamic linker\n\
7265 notifies gdb of shared library events. The most common event of interest\n\
7266 to the user would be loading/unloading of a new library."),
7268 show_stop_on_solib_events,
7269 &setlist, &showlist);
7271 add_setshow_enum_cmd ("follow-fork-mode", class_run,
7272 follow_fork_mode_kind_names,
7273 &follow_fork_mode_string, _("\
7274 Set debugger response to a program call of fork or vfork."), _("\
7275 Show debugger response to a program call of fork or vfork."), _("\
7276 A fork or vfork creates a new process. follow-fork-mode can be:\n\
7277 parent - the original process is debugged after a fork\n\
7278 child - the new process is debugged after a fork\n\
7279 The unfollowed process will continue to run.\n\
7280 By default, the debugger will follow the parent process."),
7282 show_follow_fork_mode_string,
7283 &setlist, &showlist);
7285 add_setshow_enum_cmd ("follow-exec-mode", class_run,
7286 follow_exec_mode_names,
7287 &follow_exec_mode_string, _("\
7288 Set debugger response to a program call of exec."), _("\
7289 Show debugger response to a program call of exec."), _("\
7290 An exec call replaces the program image of a process.\n\
7292 follow-exec-mode can be:\n\
7294 new - the debugger creates a new inferior and rebinds the process\n\
7295 to this new inferior. The program the process was running before\n\
7296 the exec call can be restarted afterwards by restarting the original\n\
7299 same - the debugger keeps the process bound to the same inferior.\n\
7300 The new executable image replaces the previous executable loaded in\n\
7301 the inferior. Restarting the inferior after the exec call restarts\n\
7302 the executable the process was running after the exec call.\n\
7304 By default, the debugger will use the same inferior."),
7306 show_follow_exec_mode_string,
7307 &setlist, &showlist);
7309 add_setshow_enum_cmd ("scheduler-locking", class_run,
7310 scheduler_enums, &scheduler_mode, _("\
7311 Set mode for locking scheduler during execution."), _("\
7312 Show mode for locking scheduler during execution."), _("\
7313 off == no locking (threads may preempt at any time)\n\
7314 on == full locking (no thread except the current thread may run)\n\
7315 step == scheduler locked during every single-step operation.\n\
7316 In this mode, no other thread may run during a step command.\n\
7317 Other threads may run while stepping over a function call ('next')."),
7318 set_schedlock_func, /* traps on target vector */
7319 show_scheduler_mode,
7320 &setlist, &showlist);
7322 add_setshow_boolean_cmd ("schedule-multiple", class_run, &sched_multi, _("\
7323 Set mode for resuming threads of all processes."), _("\
7324 Show mode for resuming threads of all processes."), _("\
7325 When on, execution commands (such as 'continue' or 'next') resume all\n\
7326 threads of all processes. When off (which is the default), execution\n\
7327 commands only resume the threads of the current process. The set of\n\
7328 threads that are resumed is further refined by the scheduler-locking\n\
7329 mode (see help set scheduler-locking)."),
7331 show_schedule_multiple,
7332 &setlist, &showlist);
7334 add_setshow_boolean_cmd ("step-mode", class_run, &step_stop_if_no_debug, _("\
7335 Set mode of the step operation."), _("\
7336 Show mode of the step operation."), _("\
7337 When set, doing a step over a function without debug line information\n\
7338 will stop at the first instruction of that function. Otherwise, the\n\
7339 function is skipped and the step command stops at a different source line."),
7341 show_step_stop_if_no_debug,
7342 &setlist, &showlist);
7344 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run,
7345 &can_use_displaced_stepping, _("\
7346 Set debugger's willingness to use displaced stepping."), _("\
7347 Show debugger's willingness to use displaced stepping."), _("\
7348 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
7349 supported by the target architecture. If off, gdb will not use displaced\n\
7350 stepping to step over breakpoints, even if such is supported by the target\n\
7351 architecture. If auto (which is the default), gdb will use displaced stepping\n\
7352 if the target architecture supports it and non-stop mode is active, but will not\n\
7353 use it in all-stop mode (see help set non-stop)."),
7355 show_can_use_displaced_stepping,
7356 &setlist, &showlist);
7358 add_setshow_enum_cmd ("exec-direction", class_run, exec_direction_names,
7359 &exec_direction, _("Set direction of execution.\n\
7360 Options are 'forward' or 'reverse'."),
7361 _("Show direction of execution (forward/reverse)."),
7362 _("Tells gdb whether to execute forward or backward."),
7363 set_exec_direction_func, show_exec_direction_func,
7364 &setlist, &showlist);
7366 /* Set/show detach-on-fork: user-settable mode. */
7368 add_setshow_boolean_cmd ("detach-on-fork", class_run, &detach_fork, _("\
7369 Set whether gdb will detach the child of a fork."), _("\
7370 Show whether gdb will detach the child of a fork."), _("\
7371 Tells gdb whether to detach the child of a fork."),
7372 NULL, NULL, &setlist, &showlist);
7374 /* Set/show disable address space randomization mode. */
7376 add_setshow_boolean_cmd ("disable-randomization", class_support,
7377 &disable_randomization, _("\
7378 Set disabling of debuggee's virtual address space randomization."), _("\
7379 Show disabling of debuggee's virtual address space randomization."), _("\
7380 When this mode is on (which is the default), randomization of the virtual\n\
7381 address space is disabled. Standalone programs run with the randomization\n\
7382 enabled by default on some platforms."),
7383 &set_disable_randomization,
7384 &show_disable_randomization,
7385 &setlist, &showlist);
7387 /* ptid initializations */
7388 inferior_ptid = null_ptid;
7389 target_last_wait_ptid = minus_one_ptid;
7391 observer_attach_thread_ptid_changed (infrun_thread_ptid_changed);
7392 observer_attach_thread_stop_requested (infrun_thread_stop_requested);
7393 observer_attach_thread_exit (infrun_thread_thread_exit);
7394 observer_attach_inferior_exit (infrun_inferior_exit);
7396 /* Explicitly create without lookup, since that tries to create a
7397 value with a void typed value, and when we get here, gdbarch
7398 isn't initialized yet. At this point, we're quite sure there
7399 isn't another convenience variable of the same name. */
7400 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs, NULL);
7402 add_setshow_boolean_cmd ("observer", no_class,
7403 &observer_mode_1, _("\
7404 Set whether gdb controls the inferior in observer mode."), _("\
7405 Show whether gdb controls the inferior in observer mode."), _("\
7406 In observer mode, GDB can get data from the inferior, but not\n\
7407 affect its execution. Registers and memory may not be changed,\n\
7408 breakpoints may not be set, and the program cannot be interrupted\n\