1 /* Target-struct-independent code to start (run) and stop an inferior
4 Copyright (C) 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995,
5 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007,
6 2008, 2009, 2010, 2011 Free Software Foundation, Inc.
8 This file is part of GDB.
10 This program is free software; you can redistribute it and/or modify
11 it under the terms of the GNU General Public License as published by
12 the Free Software Foundation; either version 3 of the License, or
13 (at your option) any later version.
15 This program is distributed in the hope that it will be useful,
16 but WITHOUT ANY WARRANTY; without even the implied warranty of
17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 GNU General Public License for more details.
20 You should have received a copy of the GNU General Public License
21 along with this program. If not, see <http://www.gnu.org/licenses/>. */
24 #include "gdb_string.h"
29 #include "exceptions.h"
30 #include "breakpoint.h"
34 #include "cli/cli-script.h"
36 #include "gdbthread.h"
48 #include "dictionary.h"
50 #include "gdb_assert.h"
51 #include "mi/mi-common.h"
52 #include "event-top.h"
54 #include "inline-frame.h"
56 #include "tracepoint.h"
57 #include "continuations.h"
60 /* Prototypes for local functions */
62 static void signals_info (char *, int);
64 static void handle_command (char *, int);
66 static void sig_print_info (enum target_signal);
68 static void sig_print_header (void);
70 static void resume_cleanups (void *);
72 static int hook_stop_stub (void *);
74 static int restore_selected_frame (void *);
76 static int follow_fork (void);
78 static void set_schedlock_func (char *args, int from_tty,
79 struct cmd_list_element *c);
81 static int currently_stepping (struct thread_info *tp);
83 static int currently_stepping_or_nexting_callback (struct thread_info *tp,
86 static void xdb_handle_command (char *args, int from_tty);
88 static int prepare_to_proceed (int);
90 static void print_exited_reason (int exitstatus);
92 static void print_signal_exited_reason (enum target_signal siggnal);
94 static void print_no_history_reason (void);
96 static void print_signal_received_reason (enum target_signal siggnal);
98 static void print_end_stepping_range_reason (void);
100 void _initialize_infrun (void);
102 void nullify_last_target_wait_ptid (void);
104 static void insert_hp_step_resume_breakpoint_at_frame (struct frame_info *);
106 static void insert_step_resume_breakpoint_at_caller (struct frame_info *);
108 static void insert_longjmp_resume_breakpoint (struct gdbarch *, CORE_ADDR);
110 /* When set, stop the 'step' command if we enter a function which has
111 no line number information. The normal behavior is that we step
112 over such function. */
113 int step_stop_if_no_debug = 0;
115 show_step_stop_if_no_debug (struct ui_file *file, int from_tty,
116 struct cmd_list_element *c, const char *value)
118 fprintf_filtered (file, _("Mode of the step operation is %s.\n"), value);
121 /* In asynchronous mode, but simulating synchronous execution. */
123 int sync_execution = 0;
125 /* wait_for_inferior and normal_stop use this to notify the user
126 when the inferior stopped in a different thread than it had been
129 static ptid_t previous_inferior_ptid;
131 /* Default behavior is to detach newly forked processes (legacy). */
134 int debug_displaced = 0;
136 show_debug_displaced (struct ui_file *file, int from_tty,
137 struct cmd_list_element *c, const char *value)
139 fprintf_filtered (file, _("Displace stepping debugging is %s.\n"), value);
142 int debug_infrun = 0;
144 show_debug_infrun (struct ui_file *file, int from_tty,
145 struct cmd_list_element *c, const char *value)
147 fprintf_filtered (file, _("Inferior debugging is %s.\n"), value);
151 /* Support for disabling address space randomization. */
153 int disable_randomization = 1;
156 show_disable_randomization (struct ui_file *file, int from_tty,
157 struct cmd_list_element *c, const char *value)
159 if (target_supports_disable_randomization ())
160 fprintf_filtered (file,
161 _("Disabling randomization of debuggee's "
162 "virtual address space is %s.\n"),
165 fputs_filtered (_("Disabling randomization of debuggee's "
166 "virtual address space is unsupported on\n"
167 "this platform.\n"), file);
171 set_disable_randomization (char *args, int from_tty,
172 struct cmd_list_element *c)
174 if (!target_supports_disable_randomization ())
175 error (_("Disabling randomization of debuggee's "
176 "virtual address space is unsupported on\n"
181 /* If the program uses ELF-style shared libraries, then calls to
182 functions in shared libraries go through stubs, which live in a
183 table called the PLT (Procedure Linkage Table). The first time the
184 function is called, the stub sends control to the dynamic linker,
185 which looks up the function's real address, patches the stub so
186 that future calls will go directly to the function, and then passes
187 control to the function.
189 If we are stepping at the source level, we don't want to see any of
190 this --- we just want to skip over the stub and the dynamic linker.
191 The simple approach is to single-step until control leaves the
194 However, on some systems (e.g., Red Hat's 5.2 distribution) the
195 dynamic linker calls functions in the shared C library, so you
196 can't tell from the PC alone whether the dynamic linker is still
197 running. In this case, we use a step-resume breakpoint to get us
198 past the dynamic linker, as if we were using "next" to step over a
201 in_solib_dynsym_resolve_code() says whether we're in the dynamic
202 linker code or not. Normally, this means we single-step. However,
203 if SKIP_SOLIB_RESOLVER then returns non-zero, then its value is an
204 address where we can place a step-resume breakpoint to get past the
205 linker's symbol resolution function.
207 in_solib_dynsym_resolve_code() can generally be implemented in a
208 pretty portable way, by comparing the PC against the address ranges
209 of the dynamic linker's sections.
211 SKIP_SOLIB_RESOLVER is generally going to be system-specific, since
212 it depends on internal details of the dynamic linker. It's usually
213 not too hard to figure out where to put a breakpoint, but it
214 certainly isn't portable. SKIP_SOLIB_RESOLVER should do plenty of
215 sanity checking. If it can't figure things out, returning zero and
216 getting the (possibly confusing) stepping behavior is better than
217 signalling an error, which will obscure the change in the
220 /* This function returns TRUE if pc is the address of an instruction
221 that lies within the dynamic linker (such as the event hook, or the
224 This function must be used only when a dynamic linker event has
225 been caught, and the inferior is being stepped out of the hook, or
226 undefined results are guaranteed. */
228 #ifndef SOLIB_IN_DYNAMIC_LINKER
229 #define SOLIB_IN_DYNAMIC_LINKER(pid,pc) 0
232 /* "Observer mode" is somewhat like a more extreme version of
233 non-stop, in which all GDB operations that might affect the
234 target's execution have been disabled. */
236 static int non_stop_1 = 0;
238 int observer_mode = 0;
239 static int observer_mode_1 = 0;
242 set_observer_mode (char *args, int from_tty,
243 struct cmd_list_element *c)
245 extern int pagination_enabled;
247 if (target_has_execution)
249 observer_mode_1 = observer_mode;
250 error (_("Cannot change this setting while the inferior is running."));
253 observer_mode = observer_mode_1;
255 may_write_registers = !observer_mode;
256 may_write_memory = !observer_mode;
257 may_insert_breakpoints = !observer_mode;
258 may_insert_tracepoints = !observer_mode;
259 /* We can insert fast tracepoints in or out of observer mode,
260 but enable them if we're going into this mode. */
262 may_insert_fast_tracepoints = 1;
263 may_stop = !observer_mode;
264 update_target_permissions ();
266 /* Going *into* observer mode we must force non-stop, then
267 going out we leave it that way. */
270 target_async_permitted = 1;
271 pagination_enabled = 0;
272 non_stop = non_stop_1 = 1;
276 printf_filtered (_("Observer mode is now %s.\n"),
277 (observer_mode ? "on" : "off"));
281 show_observer_mode (struct ui_file *file, int from_tty,
282 struct cmd_list_element *c, const char *value)
284 fprintf_filtered (file, _("Observer mode is %s.\n"), value);
287 /* This updates the value of observer mode based on changes in
288 permissions. Note that we are deliberately ignoring the values of
289 may-write-registers and may-write-memory, since the user may have
290 reason to enable these during a session, for instance to turn on a
291 debugging-related global. */
294 update_observer_mode (void)
298 newval = (!may_insert_breakpoints
299 && !may_insert_tracepoints
300 && may_insert_fast_tracepoints
304 /* Let the user know if things change. */
305 if (newval != observer_mode)
306 printf_filtered (_("Observer mode is now %s.\n"),
307 (newval ? "on" : "off"));
309 observer_mode = observer_mode_1 = newval;
312 /* Tables of how to react to signals; the user sets them. */
314 static unsigned char *signal_stop;
315 static unsigned char *signal_print;
316 static unsigned char *signal_program;
318 /* Table of signals that the target may silently handle.
319 This is automatically determined from the flags above,
320 and simply cached here. */
321 static unsigned char *signal_pass;
323 #define SET_SIGS(nsigs,sigs,flags) \
325 int signum = (nsigs); \
326 while (signum-- > 0) \
327 if ((sigs)[signum]) \
328 (flags)[signum] = 1; \
331 #define UNSET_SIGS(nsigs,sigs,flags) \
333 int signum = (nsigs); \
334 while (signum-- > 0) \
335 if ((sigs)[signum]) \
336 (flags)[signum] = 0; \
339 /* Value to pass to target_resume() to cause all threads to resume. */
341 #define RESUME_ALL minus_one_ptid
343 /* Command list pointer for the "stop" placeholder. */
345 static struct cmd_list_element *stop_command;
347 /* Function inferior was in as of last step command. */
349 static struct symbol *step_start_function;
351 /* Nonzero if we want to give control to the user when we're notified
352 of shared library events by the dynamic linker. */
353 int stop_on_solib_events;
355 show_stop_on_solib_events (struct ui_file *file, int from_tty,
356 struct cmd_list_element *c, const char *value)
358 fprintf_filtered (file, _("Stopping for shared library events is %s.\n"),
362 /* Nonzero means expecting a trace trap
363 and should stop the inferior and return silently when it happens. */
367 /* Save register contents here when executing a "finish" command or are
368 about to pop a stack dummy frame, if-and-only-if proceed_to_finish is set.
369 Thus this contains the return value from the called function (assuming
370 values are returned in a register). */
372 struct regcache *stop_registers;
374 /* Nonzero after stop if current stack frame should be printed. */
376 static int stop_print_frame;
378 /* This is a cached copy of the pid/waitstatus of the last event
379 returned by target_wait()/deprecated_target_wait_hook(). This
380 information is returned by get_last_target_status(). */
381 static ptid_t target_last_wait_ptid;
382 static struct target_waitstatus target_last_waitstatus;
384 static void context_switch (ptid_t ptid);
386 void init_thread_stepping_state (struct thread_info *tss);
388 void init_infwait_state (void);
390 static const char follow_fork_mode_child[] = "child";
391 static const char follow_fork_mode_parent[] = "parent";
393 static const char *follow_fork_mode_kind_names[] = {
394 follow_fork_mode_child,
395 follow_fork_mode_parent,
399 static const char *follow_fork_mode_string = follow_fork_mode_parent;
401 show_follow_fork_mode_string (struct ui_file *file, int from_tty,
402 struct cmd_list_element *c, const char *value)
404 fprintf_filtered (file,
405 _("Debugger response to a program "
406 "call of fork or vfork is \"%s\".\n"),
411 /* Tell the target to follow the fork we're stopped at. Returns true
412 if the inferior should be resumed; false, if the target for some
413 reason decided it's best not to resume. */
418 int follow_child = (follow_fork_mode_string == follow_fork_mode_child);
419 int should_resume = 1;
420 struct thread_info *tp;
422 /* Copy user stepping state to the new inferior thread. FIXME: the
423 followed fork child thread should have a copy of most of the
424 parent thread structure's run control related fields, not just these.
425 Initialized to avoid "may be used uninitialized" warnings from gcc. */
426 struct breakpoint *step_resume_breakpoint = NULL;
427 struct breakpoint *exception_resume_breakpoint = NULL;
428 CORE_ADDR step_range_start = 0;
429 CORE_ADDR step_range_end = 0;
430 struct frame_id step_frame_id = { 0 };
435 struct target_waitstatus wait_status;
437 /* Get the last target status returned by target_wait(). */
438 get_last_target_status (&wait_ptid, &wait_status);
440 /* If not stopped at a fork event, then there's nothing else to
442 if (wait_status.kind != TARGET_WAITKIND_FORKED
443 && wait_status.kind != TARGET_WAITKIND_VFORKED)
446 /* Check if we switched over from WAIT_PTID, since the event was
448 if (!ptid_equal (wait_ptid, minus_one_ptid)
449 && !ptid_equal (inferior_ptid, wait_ptid))
451 /* We did. Switch back to WAIT_PTID thread, to tell the
452 target to follow it (in either direction). We'll
453 afterwards refuse to resume, and inform the user what
455 switch_to_thread (wait_ptid);
460 tp = inferior_thread ();
462 /* If there were any forks/vforks that were caught and are now to be
463 followed, then do so now. */
464 switch (tp->pending_follow.kind)
466 case TARGET_WAITKIND_FORKED:
467 case TARGET_WAITKIND_VFORKED:
469 ptid_t parent, child;
471 /* If the user did a next/step, etc, over a fork call,
472 preserve the stepping state in the fork child. */
473 if (follow_child && should_resume)
475 step_resume_breakpoint = clone_momentary_breakpoint
476 (tp->control.step_resume_breakpoint);
477 step_range_start = tp->control.step_range_start;
478 step_range_end = tp->control.step_range_end;
479 step_frame_id = tp->control.step_frame_id;
480 exception_resume_breakpoint
481 = clone_momentary_breakpoint (tp->control.exception_resume_breakpoint);
483 /* For now, delete the parent's sr breakpoint, otherwise,
484 parent/child sr breakpoints are considered duplicates,
485 and the child version will not be installed. Remove
486 this when the breakpoints module becomes aware of
487 inferiors and address spaces. */
488 delete_step_resume_breakpoint (tp);
489 tp->control.step_range_start = 0;
490 tp->control.step_range_end = 0;
491 tp->control.step_frame_id = null_frame_id;
492 delete_exception_resume_breakpoint (tp);
495 parent = inferior_ptid;
496 child = tp->pending_follow.value.related_pid;
498 /* Tell the target to do whatever is necessary to follow
499 either parent or child. */
500 if (target_follow_fork (follow_child))
502 /* Target refused to follow, or there's some other reason
503 we shouldn't resume. */
508 /* This pending follow fork event is now handled, one way
509 or another. The previous selected thread may be gone
510 from the lists by now, but if it is still around, need
511 to clear the pending follow request. */
512 tp = find_thread_ptid (parent);
514 tp->pending_follow.kind = TARGET_WAITKIND_SPURIOUS;
516 /* This makes sure we don't try to apply the "Switched
517 over from WAIT_PID" logic above. */
518 nullify_last_target_wait_ptid ();
520 /* If we followed the child, switch to it... */
523 switch_to_thread (child);
525 /* ... and preserve the stepping state, in case the
526 user was stepping over the fork call. */
529 tp = inferior_thread ();
530 tp->control.step_resume_breakpoint
531 = step_resume_breakpoint;
532 tp->control.step_range_start = step_range_start;
533 tp->control.step_range_end = step_range_end;
534 tp->control.step_frame_id = step_frame_id;
535 tp->control.exception_resume_breakpoint
536 = exception_resume_breakpoint;
540 /* If we get here, it was because we're trying to
541 resume from a fork catchpoint, but, the user
542 has switched threads away from the thread that
543 forked. In that case, the resume command
544 issued is most likely not applicable to the
545 child, so just warn, and refuse to resume. */
546 warning (_("Not resuming: switched threads "
547 "before following fork child.\n"));
550 /* Reset breakpoints in the child as appropriate. */
551 follow_inferior_reset_breakpoints ();
554 switch_to_thread (parent);
558 case TARGET_WAITKIND_SPURIOUS:
559 /* Nothing to follow. */
562 internal_error (__FILE__, __LINE__,
563 "Unexpected pending_follow.kind %d\n",
564 tp->pending_follow.kind);
568 return should_resume;
572 follow_inferior_reset_breakpoints (void)
574 struct thread_info *tp = inferior_thread ();
576 /* Was there a step_resume breakpoint? (There was if the user
577 did a "next" at the fork() call.) If so, explicitly reset its
580 step_resumes are a form of bp that are made to be per-thread.
581 Since we created the step_resume bp when the parent process
582 was being debugged, and now are switching to the child process,
583 from the breakpoint package's viewpoint, that's a switch of
584 "threads". We must update the bp's notion of which thread
585 it is for, or it'll be ignored when it triggers. */
587 if (tp->control.step_resume_breakpoint)
588 breakpoint_re_set_thread (tp->control.step_resume_breakpoint);
590 if (tp->control.exception_resume_breakpoint)
591 breakpoint_re_set_thread (tp->control.exception_resume_breakpoint);
593 /* Reinsert all breakpoints in the child. The user may have set
594 breakpoints after catching the fork, in which case those
595 were never set in the child, but only in the parent. This makes
596 sure the inserted breakpoints match the breakpoint list. */
598 breakpoint_re_set ();
599 insert_breakpoints ();
602 /* The child has exited or execed: resume threads of the parent the
603 user wanted to be executing. */
606 proceed_after_vfork_done (struct thread_info *thread,
609 int pid = * (int *) arg;
611 if (ptid_get_pid (thread->ptid) == pid
612 && is_running (thread->ptid)
613 && !is_executing (thread->ptid)
614 && !thread->stop_requested
615 && thread->suspend.stop_signal == TARGET_SIGNAL_0)
618 fprintf_unfiltered (gdb_stdlog,
619 "infrun: resuming vfork parent thread %s\n",
620 target_pid_to_str (thread->ptid));
622 switch_to_thread (thread->ptid);
623 clear_proceed_status ();
624 proceed ((CORE_ADDR) -1, TARGET_SIGNAL_DEFAULT, 0);
630 /* Called whenever we notice an exec or exit event, to handle
631 detaching or resuming a vfork parent. */
634 handle_vfork_child_exec_or_exit (int exec)
636 struct inferior *inf = current_inferior ();
638 if (inf->vfork_parent)
640 int resume_parent = -1;
642 /* This exec or exit marks the end of the shared memory region
643 between the parent and the child. If the user wanted to
644 detach from the parent, now is the time. */
646 if (inf->vfork_parent->pending_detach)
648 struct thread_info *tp;
649 struct cleanup *old_chain;
650 struct program_space *pspace;
651 struct address_space *aspace;
653 /* follow-fork child, detach-on-fork on. */
655 old_chain = make_cleanup_restore_current_thread ();
657 /* We're letting loose of the parent. */
658 tp = any_live_thread_of_process (inf->vfork_parent->pid);
659 switch_to_thread (tp->ptid);
661 /* We're about to detach from the parent, which implicitly
662 removes breakpoints from its address space. There's a
663 catch here: we want to reuse the spaces for the child,
664 but, parent/child are still sharing the pspace at this
665 point, although the exec in reality makes the kernel give
666 the child a fresh set of new pages. The problem here is
667 that the breakpoints module being unaware of this, would
668 likely chose the child process to write to the parent
669 address space. Swapping the child temporarily away from
670 the spaces has the desired effect. Yes, this is "sort
673 pspace = inf->pspace;
674 aspace = inf->aspace;
678 if (debug_infrun || info_verbose)
680 target_terminal_ours ();
683 fprintf_filtered (gdb_stdlog,
684 "Detaching vfork parent process "
685 "%d after child exec.\n",
686 inf->vfork_parent->pid);
688 fprintf_filtered (gdb_stdlog,
689 "Detaching vfork parent process "
690 "%d after child exit.\n",
691 inf->vfork_parent->pid);
694 target_detach (NULL, 0);
697 inf->pspace = pspace;
698 inf->aspace = aspace;
700 do_cleanups (old_chain);
704 /* We're staying attached to the parent, so, really give the
705 child a new address space. */
706 inf->pspace = add_program_space (maybe_new_address_space ());
707 inf->aspace = inf->pspace->aspace;
709 set_current_program_space (inf->pspace);
711 resume_parent = inf->vfork_parent->pid;
713 /* Break the bonds. */
714 inf->vfork_parent->vfork_child = NULL;
718 struct cleanup *old_chain;
719 struct program_space *pspace;
721 /* If this is a vfork child exiting, then the pspace and
722 aspaces were shared with the parent. Since we're
723 reporting the process exit, we'll be mourning all that is
724 found in the address space, and switching to null_ptid,
725 preparing to start a new inferior. But, since we don't
726 want to clobber the parent's address/program spaces, we
727 go ahead and create a new one for this exiting
730 /* Switch to null_ptid, so that clone_program_space doesn't want
731 to read the selected frame of a dead process. */
732 old_chain = save_inferior_ptid ();
733 inferior_ptid = null_ptid;
735 /* This inferior is dead, so avoid giving the breakpoints
736 module the option to write through to it (cloning a
737 program space resets breakpoints). */
740 pspace = add_program_space (maybe_new_address_space ());
741 set_current_program_space (pspace);
743 clone_program_space (pspace, inf->vfork_parent->pspace);
744 inf->pspace = pspace;
745 inf->aspace = pspace->aspace;
747 /* Put back inferior_ptid. We'll continue mourning this
749 do_cleanups (old_chain);
751 resume_parent = inf->vfork_parent->pid;
752 /* Break the bonds. */
753 inf->vfork_parent->vfork_child = NULL;
756 inf->vfork_parent = NULL;
758 gdb_assert (current_program_space == inf->pspace);
760 if (non_stop && resume_parent != -1)
762 /* If the user wanted the parent to be running, let it go
764 struct cleanup *old_chain = make_cleanup_restore_current_thread ();
767 fprintf_unfiltered (gdb_stdlog,
768 "infrun: resuming vfork parent process %d\n",
771 iterate_over_threads (proceed_after_vfork_done, &resume_parent);
773 do_cleanups (old_chain);
778 /* Enum strings for "set|show displaced-stepping". */
780 static const char follow_exec_mode_new[] = "new";
781 static const char follow_exec_mode_same[] = "same";
782 static const char *follow_exec_mode_names[] =
784 follow_exec_mode_new,
785 follow_exec_mode_same,
789 static const char *follow_exec_mode_string = follow_exec_mode_same;
791 show_follow_exec_mode_string (struct ui_file *file, int from_tty,
792 struct cmd_list_element *c, const char *value)
794 fprintf_filtered (file, _("Follow exec mode is \"%s\".\n"), value);
797 /* EXECD_PATHNAME is assumed to be non-NULL. */
800 follow_exec (ptid_t pid, char *execd_pathname)
802 struct thread_info *th = inferior_thread ();
803 struct inferior *inf = current_inferior ();
805 /* This is an exec event that we actually wish to pay attention to.
806 Refresh our symbol table to the newly exec'd program, remove any
809 If there are breakpoints, they aren't really inserted now,
810 since the exec() transformed our inferior into a fresh set
813 We want to preserve symbolic breakpoints on the list, since
814 we have hopes that they can be reset after the new a.out's
815 symbol table is read.
817 However, any "raw" breakpoints must be removed from the list
818 (e.g., the solib bp's), since their address is probably invalid
821 And, we DON'T want to call delete_breakpoints() here, since
822 that may write the bp's "shadow contents" (the instruction
823 value that was overwritten witha TRAP instruction). Since
824 we now have a new a.out, those shadow contents aren't valid. */
826 mark_breakpoints_out ();
828 update_breakpoints_after_exec ();
830 /* If there was one, it's gone now. We cannot truly step-to-next
831 statement through an exec(). */
832 th->control.step_resume_breakpoint = NULL;
833 th->control.exception_resume_breakpoint = NULL;
834 th->control.step_range_start = 0;
835 th->control.step_range_end = 0;
837 /* The target reports the exec event to the main thread, even if
838 some other thread does the exec, and even if the main thread was
839 already stopped --- if debugging in non-stop mode, it's possible
840 the user had the main thread held stopped in the previous image
841 --- release it now. This is the same behavior as step-over-exec
842 with scheduler-locking on in all-stop mode. */
843 th->stop_requested = 0;
845 /* What is this a.out's name? */
846 printf_unfiltered (_("%s is executing new program: %s\n"),
847 target_pid_to_str (inferior_ptid),
850 /* We've followed the inferior through an exec. Therefore, the
851 inferior has essentially been killed & reborn. */
853 gdb_flush (gdb_stdout);
855 breakpoint_init_inferior (inf_execd);
857 if (gdb_sysroot && *gdb_sysroot)
859 char *name = alloca (strlen (gdb_sysroot)
860 + strlen (execd_pathname)
863 strcpy (name, gdb_sysroot);
864 strcat (name, execd_pathname);
865 execd_pathname = name;
868 /* Reset the shared library package. This ensures that we get a
869 shlib event when the child reaches "_start", at which point the
870 dld will have had a chance to initialize the child. */
871 /* Also, loading a symbol file below may trigger symbol lookups, and
872 we don't want those to be satisfied by the libraries of the
873 previous incarnation of this process. */
874 no_shared_libraries (NULL, 0);
876 if (follow_exec_mode_string == follow_exec_mode_new)
878 struct program_space *pspace;
880 /* The user wants to keep the old inferior and program spaces
881 around. Create a new fresh one, and switch to it. */
883 inf = add_inferior (current_inferior ()->pid);
884 pspace = add_program_space (maybe_new_address_space ());
885 inf->pspace = pspace;
886 inf->aspace = pspace->aspace;
888 exit_inferior_num_silent (current_inferior ()->num);
890 set_current_inferior (inf);
891 set_current_program_space (pspace);
894 gdb_assert (current_program_space == inf->pspace);
896 /* That a.out is now the one to use. */
897 exec_file_attach (execd_pathname, 0);
899 /* SYMFILE_DEFER_BP_RESET is used as the proper displacement for PIE
900 (Position Independent Executable) main symbol file will get applied by
901 solib_create_inferior_hook below. breakpoint_re_set would fail to insert
902 the breakpoints with the zero displacement. */
904 symbol_file_add (execd_pathname, SYMFILE_MAINLINE | SYMFILE_DEFER_BP_RESET,
907 set_initial_language ();
909 #ifdef SOLIB_CREATE_INFERIOR_HOOK
910 SOLIB_CREATE_INFERIOR_HOOK (PIDGET (inferior_ptid));
912 solib_create_inferior_hook (0);
915 jit_inferior_created_hook ();
917 breakpoint_re_set ();
919 /* Reinsert all breakpoints. (Those which were symbolic have
920 been reset to the proper address in the new a.out, thanks
921 to symbol_file_command...). */
922 insert_breakpoints ();
924 /* The next resume of this inferior should bring it to the shlib
925 startup breakpoints. (If the user had also set bp's on
926 "main" from the old (parent) process, then they'll auto-
927 matically get reset there in the new process.). */
930 /* Non-zero if we just simulating a single-step. This is needed
931 because we cannot remove the breakpoints in the inferior process
932 until after the `wait' in `wait_for_inferior'. */
933 static int singlestep_breakpoints_inserted_p = 0;
935 /* The thread we inserted single-step breakpoints for. */
936 static ptid_t singlestep_ptid;
938 /* PC when we started this single-step. */
939 static CORE_ADDR singlestep_pc;
941 /* If another thread hit the singlestep breakpoint, we save the original
942 thread here so that we can resume single-stepping it later. */
943 static ptid_t saved_singlestep_ptid;
944 static int stepping_past_singlestep_breakpoint;
946 /* If not equal to null_ptid, this means that after stepping over breakpoint
947 is finished, we need to switch to deferred_step_ptid, and step it.
949 The use case is when one thread has hit a breakpoint, and then the user
950 has switched to another thread and issued 'step'. We need to step over
951 breakpoint in the thread which hit the breakpoint, but then continue
952 stepping the thread user has selected. */
953 static ptid_t deferred_step_ptid;
955 /* Displaced stepping. */
957 /* In non-stop debugging mode, we must take special care to manage
958 breakpoints properly; in particular, the traditional strategy for
959 stepping a thread past a breakpoint it has hit is unsuitable.
960 'Displaced stepping' is a tactic for stepping one thread past a
961 breakpoint it has hit while ensuring that other threads running
962 concurrently will hit the breakpoint as they should.
964 The traditional way to step a thread T off a breakpoint in a
965 multi-threaded program in all-stop mode is as follows:
967 a0) Initially, all threads are stopped, and breakpoints are not
969 a1) We single-step T, leaving breakpoints uninserted.
970 a2) We insert breakpoints, and resume all threads.
972 In non-stop debugging, however, this strategy is unsuitable: we
973 don't want to have to stop all threads in the system in order to
974 continue or step T past a breakpoint. Instead, we use displaced
977 n0) Initially, T is stopped, other threads are running, and
978 breakpoints are inserted.
979 n1) We copy the instruction "under" the breakpoint to a separate
980 location, outside the main code stream, making any adjustments
981 to the instruction, register, and memory state as directed by
983 n2) We single-step T over the instruction at its new location.
984 n3) We adjust the resulting register and memory state as directed
985 by T's architecture. This includes resetting T's PC to point
986 back into the main instruction stream.
989 This approach depends on the following gdbarch methods:
991 - gdbarch_max_insn_length and gdbarch_displaced_step_location
992 indicate where to copy the instruction, and how much space must
993 be reserved there. We use these in step n1.
995 - gdbarch_displaced_step_copy_insn copies a instruction to a new
996 address, and makes any necessary adjustments to the instruction,
997 register contents, and memory. We use this in step n1.
999 - gdbarch_displaced_step_fixup adjusts registers and memory after
1000 we have successfuly single-stepped the instruction, to yield the
1001 same effect the instruction would have had if we had executed it
1002 at its original address. We use this in step n3.
1004 - gdbarch_displaced_step_free_closure provides cleanup.
1006 The gdbarch_displaced_step_copy_insn and
1007 gdbarch_displaced_step_fixup functions must be written so that
1008 copying an instruction with gdbarch_displaced_step_copy_insn,
1009 single-stepping across the copied instruction, and then applying
1010 gdbarch_displaced_insn_fixup should have the same effects on the
1011 thread's memory and registers as stepping the instruction in place
1012 would have. Exactly which responsibilities fall to the copy and
1013 which fall to the fixup is up to the author of those functions.
1015 See the comments in gdbarch.sh for details.
1017 Note that displaced stepping and software single-step cannot
1018 currently be used in combination, although with some care I think
1019 they could be made to. Software single-step works by placing
1020 breakpoints on all possible subsequent instructions; if the
1021 displaced instruction is a PC-relative jump, those breakpoints
1022 could fall in very strange places --- on pages that aren't
1023 executable, or at addresses that are not proper instruction
1024 boundaries. (We do generally let other threads run while we wait
1025 to hit the software single-step breakpoint, and they might
1026 encounter such a corrupted instruction.) One way to work around
1027 this would be to have gdbarch_displaced_step_copy_insn fully
1028 simulate the effect of PC-relative instructions (and return NULL)
1029 on architectures that use software single-stepping.
1031 In non-stop mode, we can have independent and simultaneous step
1032 requests, so more than one thread may need to simultaneously step
1033 over a breakpoint. The current implementation assumes there is
1034 only one scratch space per process. In this case, we have to
1035 serialize access to the scratch space. If thread A wants to step
1036 over a breakpoint, but we are currently waiting for some other
1037 thread to complete a displaced step, we leave thread A stopped and
1038 place it in the displaced_step_request_queue. Whenever a displaced
1039 step finishes, we pick the next thread in the queue and start a new
1040 displaced step operation on it. See displaced_step_prepare and
1041 displaced_step_fixup for details. */
1043 struct displaced_step_request
1046 struct displaced_step_request *next;
1049 /* Per-inferior displaced stepping state. */
1050 struct displaced_step_inferior_state
1052 /* Pointer to next in linked list. */
1053 struct displaced_step_inferior_state *next;
1055 /* The process this displaced step state refers to. */
1058 /* A queue of pending displaced stepping requests. One entry per
1059 thread that needs to do a displaced step. */
1060 struct displaced_step_request *step_request_queue;
1062 /* If this is not null_ptid, this is the thread carrying out a
1063 displaced single-step in process PID. This thread's state will
1064 require fixing up once it has completed its step. */
1067 /* The architecture the thread had when we stepped it. */
1068 struct gdbarch *step_gdbarch;
1070 /* The closure provided gdbarch_displaced_step_copy_insn, to be used
1071 for post-step cleanup. */
1072 struct displaced_step_closure *step_closure;
1074 /* The address of the original instruction, and the copy we
1076 CORE_ADDR step_original, step_copy;
1078 /* Saved contents of copy area. */
1079 gdb_byte *step_saved_copy;
1082 /* The list of states of processes involved in displaced stepping
1084 static struct displaced_step_inferior_state *displaced_step_inferior_states;
1086 /* Get the displaced stepping state of process PID. */
1088 static struct displaced_step_inferior_state *
1089 get_displaced_stepping_state (int pid)
1091 struct displaced_step_inferior_state *state;
1093 for (state = displaced_step_inferior_states;
1095 state = state->next)
1096 if (state->pid == pid)
1102 /* Add a new displaced stepping state for process PID to the displaced
1103 stepping state list, or return a pointer to an already existing
1104 entry, if it already exists. Never returns NULL. */
1106 static struct displaced_step_inferior_state *
1107 add_displaced_stepping_state (int pid)
1109 struct displaced_step_inferior_state *state;
1111 for (state = displaced_step_inferior_states;
1113 state = state->next)
1114 if (state->pid == pid)
1117 state = xcalloc (1, sizeof (*state));
1119 state->next = displaced_step_inferior_states;
1120 displaced_step_inferior_states = state;
1125 /* If inferior is in displaced stepping, and ADDR equals to starting address
1126 of copy area, return corresponding displaced_step_closure. Otherwise,
1129 struct displaced_step_closure*
1130 get_displaced_step_closure_by_addr (CORE_ADDR addr)
1132 struct displaced_step_inferior_state *displaced
1133 = get_displaced_stepping_state (ptid_get_pid (inferior_ptid));
1135 /* If checking the mode of displaced instruction in copy area. */
1136 if (displaced && !ptid_equal (displaced->step_ptid, null_ptid)
1137 && (displaced->step_copy == addr))
1138 return displaced->step_closure;
1143 /* Remove the displaced stepping state of process PID. */
1146 remove_displaced_stepping_state (int pid)
1148 struct displaced_step_inferior_state *it, **prev_next_p;
1150 gdb_assert (pid != 0);
1152 it = displaced_step_inferior_states;
1153 prev_next_p = &displaced_step_inferior_states;
1158 *prev_next_p = it->next;
1163 prev_next_p = &it->next;
1169 infrun_inferior_exit (struct inferior *inf)
1171 remove_displaced_stepping_state (inf->pid);
1174 /* Enum strings for "set|show displaced-stepping". */
1176 static const char can_use_displaced_stepping_auto[] = "auto";
1177 static const char can_use_displaced_stepping_on[] = "on";
1178 static const char can_use_displaced_stepping_off[] = "off";
1179 static const char *can_use_displaced_stepping_enum[] =
1181 can_use_displaced_stepping_auto,
1182 can_use_displaced_stepping_on,
1183 can_use_displaced_stepping_off,
1187 /* If ON, and the architecture supports it, GDB will use displaced
1188 stepping to step over breakpoints. If OFF, or if the architecture
1189 doesn't support it, GDB will instead use the traditional
1190 hold-and-step approach. If AUTO (which is the default), GDB will
1191 decide which technique to use to step over breakpoints depending on
1192 which of all-stop or non-stop mode is active --- displaced stepping
1193 in non-stop mode; hold-and-step in all-stop mode. */
1195 static const char *can_use_displaced_stepping =
1196 can_use_displaced_stepping_auto;
1199 show_can_use_displaced_stepping (struct ui_file *file, int from_tty,
1200 struct cmd_list_element *c,
1203 if (can_use_displaced_stepping == can_use_displaced_stepping_auto)
1204 fprintf_filtered (file,
1205 _("Debugger's willingness to use displaced stepping "
1206 "to step over breakpoints is %s (currently %s).\n"),
1207 value, non_stop ? "on" : "off");
1209 fprintf_filtered (file,
1210 _("Debugger's willingness to use displaced stepping "
1211 "to step over breakpoints is %s.\n"), value);
1214 /* Return non-zero if displaced stepping can/should be used to step
1215 over breakpoints. */
1218 use_displaced_stepping (struct gdbarch *gdbarch)
1220 return (((can_use_displaced_stepping == can_use_displaced_stepping_auto
1222 || can_use_displaced_stepping == can_use_displaced_stepping_on)
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;
1288 /* We should never reach this function if the architecture does not
1289 support displaced stepping. */
1290 gdb_assert (gdbarch_displaced_step_copy_insn_p (gdbarch));
1292 /* We have to displaced step one thread at a time, as we only have
1293 access to a single scratch space per inferior. */
1295 displaced = add_displaced_stepping_state (ptid_get_pid (ptid));
1297 if (!ptid_equal (displaced->step_ptid, null_ptid))
1299 /* Already waiting for a displaced step to finish. Defer this
1300 request and place in queue. */
1301 struct displaced_step_request *req, *new_req;
1303 if (debug_displaced)
1304 fprintf_unfiltered (gdb_stdlog,
1305 "displaced: defering step of %s\n",
1306 target_pid_to_str (ptid));
1308 new_req = xmalloc (sizeof (*new_req));
1309 new_req->ptid = ptid;
1310 new_req->next = NULL;
1312 if (displaced->step_request_queue)
1314 for (req = displaced->step_request_queue;
1318 req->next = new_req;
1321 displaced->step_request_queue = new_req;
1327 if (debug_displaced)
1328 fprintf_unfiltered (gdb_stdlog,
1329 "displaced: stepping %s now\n",
1330 target_pid_to_str (ptid));
1333 displaced_step_clear (displaced);
1335 old_cleanups = save_inferior_ptid ();
1336 inferior_ptid = ptid;
1338 original = regcache_read_pc (regcache);
1340 copy = gdbarch_displaced_step_location (gdbarch);
1341 len = gdbarch_max_insn_length (gdbarch);
1343 /* Save the original contents of the copy area. */
1344 displaced->step_saved_copy = xmalloc (len);
1345 ignore_cleanups = make_cleanup (free_current_contents,
1346 &displaced->step_saved_copy);
1347 read_memory (copy, displaced->step_saved_copy, len);
1348 if (debug_displaced)
1350 fprintf_unfiltered (gdb_stdlog, "displaced: saved %s: ",
1351 paddress (gdbarch, copy));
1352 displaced_step_dump_bytes (gdb_stdlog,
1353 displaced->step_saved_copy,
1357 closure = gdbarch_displaced_step_copy_insn (gdbarch,
1358 original, copy, regcache);
1360 /* We don't support the fully-simulated case at present. */
1361 gdb_assert (closure);
1363 /* Save the information we need to fix things up if the step
1365 displaced->step_ptid = ptid;
1366 displaced->step_gdbarch = gdbarch;
1367 displaced->step_closure = closure;
1368 displaced->step_original = original;
1369 displaced->step_copy = copy;
1371 make_cleanup (displaced_step_clear_cleanup, displaced);
1373 /* Resume execution at the copy. */
1374 regcache_write_pc (regcache, copy);
1376 discard_cleanups (ignore_cleanups);
1378 do_cleanups (old_cleanups);
1380 if (debug_displaced)
1381 fprintf_unfiltered (gdb_stdlog, "displaced: displaced pc to %s\n",
1382 paddress (gdbarch, copy));
1388 write_memory_ptid (ptid_t ptid, CORE_ADDR memaddr,
1389 const gdb_byte *myaddr, int len)
1391 struct cleanup *ptid_cleanup = save_inferior_ptid ();
1393 inferior_ptid = ptid;
1394 write_memory (memaddr, myaddr, len);
1395 do_cleanups (ptid_cleanup);
1398 /* Restore the contents of the copy area for thread PTID. */
1401 displaced_step_restore (struct displaced_step_inferior_state *displaced,
1404 ULONGEST len = gdbarch_max_insn_length (displaced->step_gdbarch);
1406 write_memory_ptid (ptid, displaced->step_copy,
1407 displaced->step_saved_copy, len);
1408 if (debug_displaced)
1409 fprintf_unfiltered (gdb_stdlog, "displaced: restored %s %s\n",
1410 target_pid_to_str (ptid),
1411 paddress (displaced->step_gdbarch,
1412 displaced->step_copy));
1416 displaced_step_fixup (ptid_t event_ptid, enum target_signal signal)
1418 struct cleanup *old_cleanups;
1419 struct displaced_step_inferior_state *displaced
1420 = get_displaced_stepping_state (ptid_get_pid (event_ptid));
1422 /* Was any thread of this process doing a displaced step? */
1423 if (displaced == NULL)
1426 /* Was this event for the pid we displaced? */
1427 if (ptid_equal (displaced->step_ptid, null_ptid)
1428 || ! ptid_equal (displaced->step_ptid, event_ptid))
1431 old_cleanups = make_cleanup (displaced_step_clear_cleanup, displaced);
1433 displaced_step_restore (displaced, displaced->step_ptid);
1435 /* Did the instruction complete successfully? */
1436 if (signal == TARGET_SIGNAL_TRAP)
1438 /* Fix up the resulting state. */
1439 gdbarch_displaced_step_fixup (displaced->step_gdbarch,
1440 displaced->step_closure,
1441 displaced->step_original,
1442 displaced->step_copy,
1443 get_thread_regcache (displaced->step_ptid));
1447 /* Since the instruction didn't complete, all we can do is
1449 struct regcache *regcache = get_thread_regcache (event_ptid);
1450 CORE_ADDR pc = regcache_read_pc (regcache);
1452 pc = displaced->step_original + (pc - displaced->step_copy);
1453 regcache_write_pc (regcache, pc);
1456 do_cleanups (old_cleanups);
1458 displaced->step_ptid = null_ptid;
1460 /* Are there any pending displaced stepping requests? If so, run
1461 one now. Leave the state object around, since we're likely to
1462 need it again soon. */
1463 while (displaced->step_request_queue)
1465 struct displaced_step_request *head;
1467 struct regcache *regcache;
1468 struct gdbarch *gdbarch;
1469 CORE_ADDR actual_pc;
1470 struct address_space *aspace;
1472 head = displaced->step_request_queue;
1474 displaced->step_request_queue = head->next;
1477 context_switch (ptid);
1479 regcache = get_thread_regcache (ptid);
1480 actual_pc = regcache_read_pc (regcache);
1481 aspace = get_regcache_aspace (regcache);
1483 if (breakpoint_here_p (aspace, actual_pc))
1485 if (debug_displaced)
1486 fprintf_unfiltered (gdb_stdlog,
1487 "displaced: stepping queued %s now\n",
1488 target_pid_to_str (ptid));
1490 displaced_step_prepare (ptid);
1492 gdbarch = get_regcache_arch (regcache);
1494 if (debug_displaced)
1496 CORE_ADDR actual_pc = regcache_read_pc (regcache);
1499 fprintf_unfiltered (gdb_stdlog, "displaced: run %s: ",
1500 paddress (gdbarch, actual_pc));
1501 read_memory (actual_pc, buf, sizeof (buf));
1502 displaced_step_dump_bytes (gdb_stdlog, buf, sizeof (buf));
1505 if (gdbarch_displaced_step_hw_singlestep (gdbarch,
1506 displaced->step_closure))
1507 target_resume (ptid, 1, TARGET_SIGNAL_0);
1509 target_resume (ptid, 0, TARGET_SIGNAL_0);
1511 /* Done, we're stepping a thread. */
1517 struct thread_info *tp = inferior_thread ();
1519 /* The breakpoint we were sitting under has since been
1521 tp->control.trap_expected = 0;
1523 /* Go back to what we were trying to do. */
1524 step = currently_stepping (tp);
1526 if (debug_displaced)
1527 fprintf_unfiltered (gdb_stdlog,
1528 "breakpoint is gone %s: step(%d)\n",
1529 target_pid_to_str (tp->ptid), step);
1531 target_resume (ptid, step, TARGET_SIGNAL_0);
1532 tp->suspend.stop_signal = TARGET_SIGNAL_0;
1534 /* This request was discarded. See if there's any other
1535 thread waiting for its turn. */
1540 /* Update global variables holding ptids to hold NEW_PTID if they were
1541 holding OLD_PTID. */
1543 infrun_thread_ptid_changed (ptid_t old_ptid, ptid_t new_ptid)
1545 struct displaced_step_request *it;
1546 struct displaced_step_inferior_state *displaced;
1548 if (ptid_equal (inferior_ptid, old_ptid))
1549 inferior_ptid = new_ptid;
1551 if (ptid_equal (singlestep_ptid, old_ptid))
1552 singlestep_ptid = new_ptid;
1554 if (ptid_equal (deferred_step_ptid, old_ptid))
1555 deferred_step_ptid = new_ptid;
1557 for (displaced = displaced_step_inferior_states;
1559 displaced = displaced->next)
1561 if (ptid_equal (displaced->step_ptid, old_ptid))
1562 displaced->step_ptid = new_ptid;
1564 for (it = displaced->step_request_queue; it; it = it->next)
1565 if (ptid_equal (it->ptid, old_ptid))
1566 it->ptid = new_ptid;
1573 /* Things to clean up if we QUIT out of resume (). */
1575 resume_cleanups (void *ignore)
1580 static const char schedlock_off[] = "off";
1581 static const char schedlock_on[] = "on";
1582 static const char schedlock_step[] = "step";
1583 static const char *scheduler_enums[] = {
1589 static const char *scheduler_mode = schedlock_off;
1591 show_scheduler_mode (struct ui_file *file, int from_tty,
1592 struct cmd_list_element *c, const char *value)
1594 fprintf_filtered (file,
1595 _("Mode for locking scheduler "
1596 "during execution is \"%s\".\n"),
1601 set_schedlock_func (char *args, int from_tty, struct cmd_list_element *c)
1603 if (!target_can_lock_scheduler)
1605 scheduler_mode = schedlock_off;
1606 error (_("Target '%s' cannot support this command."), target_shortname);
1610 /* True if execution commands resume all threads of all processes by
1611 default; otherwise, resume only threads of the current inferior
1613 int sched_multi = 0;
1615 /* Try to setup for software single stepping over the specified location.
1616 Return 1 if target_resume() should use hardware single step.
1618 GDBARCH the current gdbarch.
1619 PC the location to step over. */
1622 maybe_software_singlestep (struct gdbarch *gdbarch, CORE_ADDR pc)
1626 if (execution_direction == EXEC_FORWARD
1627 && gdbarch_software_single_step_p (gdbarch)
1628 && gdbarch_software_single_step (gdbarch, get_current_frame ()))
1631 /* Do not pull these breakpoints until after a `wait' in
1632 `wait_for_inferior'. */
1633 singlestep_breakpoints_inserted_p = 1;
1634 singlestep_ptid = inferior_ptid;
1640 /* Return a ptid representing the set of threads that we will proceed,
1641 in the perspective of the user/frontend. We may actually resume
1642 fewer threads at first, e.g., if a thread is stopped at a
1643 breakpoint that needs stepping-off, but that should not be visible
1644 to the user/frontend, and neither should the frontend/user be
1645 allowed to proceed any of the threads that happen to be stopped for
1646 internal run control handling, if a previous command wanted them
1650 user_visible_resume_ptid (int step)
1652 /* By default, resume all threads of all processes. */
1653 ptid_t resume_ptid = RESUME_ALL;
1655 /* Maybe resume only all threads of the current process. */
1656 if (!sched_multi && target_supports_multi_process ())
1658 resume_ptid = pid_to_ptid (ptid_get_pid (inferior_ptid));
1661 /* Maybe resume a single thread after all. */
1664 /* With non-stop mode on, threads are always handled
1666 resume_ptid = inferior_ptid;
1668 else if ((scheduler_mode == schedlock_on)
1669 || (scheduler_mode == schedlock_step
1670 && (step || singlestep_breakpoints_inserted_p)))
1672 /* User-settable 'scheduler' mode requires solo thread resume. */
1673 resume_ptid = inferior_ptid;
1679 /* Resume the inferior, but allow a QUIT. This is useful if the user
1680 wants to interrupt some lengthy single-stepping operation
1681 (for child processes, the SIGINT goes to the inferior, and so
1682 we get a SIGINT random_signal, but for remote debugging and perhaps
1683 other targets, that's not true).
1685 STEP nonzero if we should step (zero to continue instead).
1686 SIG is the signal to give the inferior (zero for none). */
1688 resume (int step, enum target_signal sig)
1690 int should_resume = 1;
1691 struct cleanup *old_cleanups = make_cleanup (resume_cleanups, 0);
1692 struct regcache *regcache = get_current_regcache ();
1693 struct gdbarch *gdbarch = get_regcache_arch (regcache);
1694 struct thread_info *tp = inferior_thread ();
1695 CORE_ADDR pc = regcache_read_pc (regcache);
1696 struct address_space *aspace = get_regcache_aspace (regcache);
1700 if (current_inferior ()->waiting_for_vfork_done)
1702 /* Don't try to single-step a vfork parent that is waiting for
1703 the child to get out of the shared memory region (by exec'ing
1704 or exiting). This is particularly important on software
1705 single-step archs, as the child process would trip on the
1706 software single step breakpoint inserted for the parent
1707 process. Since the parent will not actually execute any
1708 instruction until the child is out of the shared region (such
1709 are vfork's semantics), it is safe to simply continue it.
1710 Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for
1711 the parent, and tell it to `keep_going', which automatically
1712 re-sets it stepping. */
1714 fprintf_unfiltered (gdb_stdlog,
1715 "infrun: resume : clear step\n");
1720 fprintf_unfiltered (gdb_stdlog,
1721 "infrun: resume (step=%d, signal=%d), "
1722 "trap_expected=%d, current thread [%s] at %s\n",
1723 step, sig, tp->control.trap_expected,
1724 target_pid_to_str (inferior_ptid),
1725 paddress (gdbarch, pc));
1727 /* Normally, by the time we reach `resume', the breakpoints are either
1728 removed or inserted, as appropriate. The exception is if we're sitting
1729 at a permanent breakpoint; we need to step over it, but permanent
1730 breakpoints can't be removed. So we have to test for it here. */
1731 if (breakpoint_here_p (aspace, pc) == permanent_breakpoint_here)
1733 if (gdbarch_skip_permanent_breakpoint_p (gdbarch))
1734 gdbarch_skip_permanent_breakpoint (gdbarch, regcache);
1737 The program is stopped at a permanent breakpoint, but GDB does not know\n\
1738 how to step past a permanent breakpoint on this architecture. Try using\n\
1739 a command like `return' or `jump' to continue execution."));
1742 /* If enabled, step over breakpoints by executing a copy of the
1743 instruction at a different address.
1745 We can't use displaced stepping when we have a signal to deliver;
1746 the comments for displaced_step_prepare explain why. The
1747 comments in the handle_inferior event for dealing with 'random
1748 signals' explain what we do instead.
1750 We can't use displaced stepping when we are waiting for vfork_done
1751 event, displaced stepping breaks the vfork child similarly as single
1752 step software breakpoint. */
1753 if (use_displaced_stepping (gdbarch)
1754 && (tp->control.trap_expected
1755 || (step && gdbarch_software_single_step_p (gdbarch)))
1756 && sig == TARGET_SIGNAL_0
1757 && !current_inferior ()->waiting_for_vfork_done)
1759 struct displaced_step_inferior_state *displaced;
1761 if (!displaced_step_prepare (inferior_ptid))
1763 /* Got placed in displaced stepping queue. Will be resumed
1764 later when all the currently queued displaced stepping
1765 requests finish. The thread is not executing at this point,
1766 and the call to set_executing will be made later. But we
1767 need to call set_running here, since from frontend point of view,
1768 the thread is running. */
1769 set_running (inferior_ptid, 1);
1770 discard_cleanups (old_cleanups);
1774 displaced = get_displaced_stepping_state (ptid_get_pid (inferior_ptid));
1775 step = gdbarch_displaced_step_hw_singlestep (gdbarch,
1776 displaced->step_closure);
1779 /* Do we need to do it the hard way, w/temp breakpoints? */
1781 step = maybe_software_singlestep (gdbarch, pc);
1783 /* Currently, our software single-step implementation leads to different
1784 results than hardware single-stepping in one situation: when stepping
1785 into delivering a signal which has an associated signal handler,
1786 hardware single-step will stop at the first instruction of the handler,
1787 while software single-step will simply skip execution of the handler.
1789 For now, this difference in behavior is accepted since there is no
1790 easy way to actually implement single-stepping into a signal handler
1791 without kernel support.
1793 However, there is one scenario where this difference leads to follow-on
1794 problems: if we're stepping off a breakpoint by removing all breakpoints
1795 and then single-stepping. In this case, the software single-step
1796 behavior means that even if there is a *breakpoint* in the signal
1797 handler, GDB still would not stop.
1799 Fortunately, we can at least fix this particular issue. We detect
1800 here the case where we are about to deliver a signal while software
1801 single-stepping with breakpoints removed. In this situation, we
1802 revert the decisions to remove all breakpoints and insert single-
1803 step breakpoints, and instead we install a step-resume breakpoint
1804 at the current address, deliver the signal without stepping, and
1805 once we arrive back at the step-resume breakpoint, actually step
1806 over the breakpoint we originally wanted to step over. */
1807 if (singlestep_breakpoints_inserted_p
1808 && tp->control.trap_expected && sig != TARGET_SIGNAL_0)
1810 /* If we have nested signals or a pending signal is delivered
1811 immediately after a handler returns, might might already have
1812 a step-resume breakpoint set on the earlier handler. We cannot
1813 set another step-resume breakpoint; just continue on until the
1814 original breakpoint is hit. */
1815 if (tp->control.step_resume_breakpoint == NULL)
1817 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
1818 tp->step_after_step_resume_breakpoint = 1;
1821 remove_single_step_breakpoints ();
1822 singlestep_breakpoints_inserted_p = 0;
1824 insert_breakpoints ();
1825 tp->control.trap_expected = 0;
1832 /* If STEP is set, it's a request to use hardware stepping
1833 facilities. But in that case, we should never
1834 use singlestep breakpoint. */
1835 gdb_assert (!(singlestep_breakpoints_inserted_p && step));
1837 /* Decide the set of threads to ask the target to resume. Start
1838 by assuming everything will be resumed, than narrow the set
1839 by applying increasingly restricting conditions. */
1840 resume_ptid = user_visible_resume_ptid (step);
1842 /* Maybe resume a single thread after all. */
1843 if (singlestep_breakpoints_inserted_p
1844 && stepping_past_singlestep_breakpoint)
1846 /* The situation here is as follows. In thread T1 we wanted to
1847 single-step. Lacking hardware single-stepping we've
1848 set breakpoint at the PC of the next instruction -- call it
1849 P. After resuming, we've hit that breakpoint in thread T2.
1850 Now we've removed original breakpoint, inserted breakpoint
1851 at P+1, and try to step to advance T2 past breakpoint.
1852 We need to step only T2, as if T1 is allowed to freely run,
1853 it can run past P, and if other threads are allowed to run,
1854 they can hit breakpoint at P+1, and nested hits of single-step
1855 breakpoints is not something we'd want -- that's complicated
1856 to support, and has no value. */
1857 resume_ptid = inferior_ptid;
1859 else if ((step || singlestep_breakpoints_inserted_p)
1860 && tp->control.trap_expected)
1862 /* We're allowing a thread to run past a breakpoint it has
1863 hit, by single-stepping the thread with the breakpoint
1864 removed. In which case, we need to single-step only this
1865 thread, and keep others stopped, as they can miss this
1866 breakpoint if allowed to run.
1868 The current code actually removes all breakpoints when
1869 doing this, not just the one being stepped over, so if we
1870 let other threads run, we can actually miss any
1871 breakpoint, not just the one at PC. */
1872 resume_ptid = inferior_ptid;
1875 if (gdbarch_cannot_step_breakpoint (gdbarch))
1877 /* Most targets can step a breakpoint instruction, thus
1878 executing it normally. But if this one cannot, just
1879 continue and we will hit it anyway. */
1880 if (step && breakpoint_inserted_here_p (aspace, pc))
1885 && use_displaced_stepping (gdbarch)
1886 && tp->control.trap_expected)
1888 struct regcache *resume_regcache = get_thread_regcache (resume_ptid);
1889 struct gdbarch *resume_gdbarch = get_regcache_arch (resume_regcache);
1890 CORE_ADDR actual_pc = regcache_read_pc (resume_regcache);
1893 fprintf_unfiltered (gdb_stdlog, "displaced: run %s: ",
1894 paddress (resume_gdbarch, actual_pc));
1895 read_memory (actual_pc, buf, sizeof (buf));
1896 displaced_step_dump_bytes (gdb_stdlog, buf, sizeof (buf));
1899 /* Install inferior's terminal modes. */
1900 target_terminal_inferior ();
1902 /* Avoid confusing the next resume, if the next stop/resume
1903 happens to apply to another thread. */
1904 tp->suspend.stop_signal = TARGET_SIGNAL_0;
1906 /* Advise target which signals may be handled silently. If we have
1907 removed breakpoints because we are stepping over one (which can
1908 happen only if we are not using displaced stepping), we need to
1909 receive all signals to avoid accidentally skipping a breakpoint
1910 during execution of a signal handler. */
1911 if ((step || singlestep_breakpoints_inserted_p)
1912 && tp->control.trap_expected
1913 && !use_displaced_stepping (gdbarch))
1914 target_pass_signals (0, NULL);
1916 target_pass_signals ((int) TARGET_SIGNAL_LAST, signal_pass);
1918 target_resume (resume_ptid, step, sig);
1921 discard_cleanups (old_cleanups);
1926 /* Clear out all variables saying what to do when inferior is continued.
1927 First do this, then set the ones you want, then call `proceed'. */
1930 clear_proceed_status_thread (struct thread_info *tp)
1933 fprintf_unfiltered (gdb_stdlog,
1934 "infrun: clear_proceed_status_thread (%s)\n",
1935 target_pid_to_str (tp->ptid));
1937 tp->control.trap_expected = 0;
1938 tp->control.step_range_start = 0;
1939 tp->control.step_range_end = 0;
1940 tp->control.step_frame_id = null_frame_id;
1941 tp->control.step_stack_frame_id = null_frame_id;
1942 tp->control.step_over_calls = STEP_OVER_UNDEBUGGABLE;
1943 tp->stop_requested = 0;
1945 tp->control.stop_step = 0;
1947 tp->control.proceed_to_finish = 0;
1949 /* Discard any remaining commands or status from previous stop. */
1950 bpstat_clear (&tp->control.stop_bpstat);
1954 clear_proceed_status_callback (struct thread_info *tp, void *data)
1956 if (is_exited (tp->ptid))
1959 clear_proceed_status_thread (tp);
1964 clear_proceed_status (void)
1968 /* In all-stop mode, delete the per-thread status of all
1969 threads, even if inferior_ptid is null_ptid, there may be
1970 threads on the list. E.g., we may be launching a new
1971 process, while selecting the executable. */
1972 iterate_over_threads (clear_proceed_status_callback, NULL);
1975 if (!ptid_equal (inferior_ptid, null_ptid))
1977 struct inferior *inferior;
1981 /* If in non-stop mode, only delete the per-thread status of
1982 the current thread. */
1983 clear_proceed_status_thread (inferior_thread ());
1986 inferior = current_inferior ();
1987 inferior->control.stop_soon = NO_STOP_QUIETLY;
1990 stop_after_trap = 0;
1992 observer_notify_about_to_proceed ();
1996 regcache_xfree (stop_registers);
1997 stop_registers = NULL;
2001 /* Check the current thread against the thread that reported the most recent
2002 event. If a step-over is required return TRUE and set the current thread
2003 to the old thread. Otherwise return FALSE.
2005 This should be suitable for any targets that support threads. */
2008 prepare_to_proceed (int step)
2011 struct target_waitstatus wait_status;
2012 int schedlock_enabled;
2014 /* With non-stop mode on, threads are always handled individually. */
2015 gdb_assert (! non_stop);
2017 /* Get the last target status returned by target_wait(). */
2018 get_last_target_status (&wait_ptid, &wait_status);
2020 /* Make sure we were stopped at a breakpoint. */
2021 if (wait_status.kind != TARGET_WAITKIND_STOPPED
2022 || (wait_status.value.sig != TARGET_SIGNAL_TRAP
2023 && wait_status.value.sig != TARGET_SIGNAL_ILL
2024 && wait_status.value.sig != TARGET_SIGNAL_SEGV
2025 && wait_status.value.sig != TARGET_SIGNAL_EMT))
2030 schedlock_enabled = (scheduler_mode == schedlock_on
2031 || (scheduler_mode == schedlock_step
2034 /* Don't switch over to WAIT_PTID if scheduler locking is on. */
2035 if (schedlock_enabled)
2038 /* Don't switch over if we're about to resume some other process
2039 other than WAIT_PTID's, and schedule-multiple is off. */
2041 && ptid_get_pid (wait_ptid) != ptid_get_pid (inferior_ptid))
2044 /* Switched over from WAIT_PID. */
2045 if (!ptid_equal (wait_ptid, minus_one_ptid)
2046 && !ptid_equal (inferior_ptid, wait_ptid))
2048 struct regcache *regcache = get_thread_regcache (wait_ptid);
2050 if (breakpoint_here_p (get_regcache_aspace (regcache),
2051 regcache_read_pc (regcache)))
2053 /* If stepping, remember current thread to switch back to. */
2055 deferred_step_ptid = inferior_ptid;
2057 /* Switch back to WAIT_PID thread. */
2058 switch_to_thread (wait_ptid);
2061 fprintf_unfiltered (gdb_stdlog,
2062 "infrun: prepare_to_proceed (step=%d), "
2063 "switched to [%s]\n",
2064 step, target_pid_to_str (inferior_ptid));
2066 /* We return 1 to indicate that there is a breakpoint here,
2067 so we need to step over it before continuing to avoid
2068 hitting it straight away. */
2076 /* Basic routine for continuing the program in various fashions.
2078 ADDR is the address to resume at, or -1 for resume where stopped.
2079 SIGGNAL is the signal to give it, or 0 for none,
2080 or -1 for act according to how it stopped.
2081 STEP is nonzero if should trap after one instruction.
2082 -1 means return after that and print nothing.
2083 You should probably set various step_... variables
2084 before calling here, if you are stepping.
2086 You should call clear_proceed_status before calling proceed. */
2089 proceed (CORE_ADDR addr, enum target_signal siggnal, int step)
2091 struct regcache *regcache;
2092 struct gdbarch *gdbarch;
2093 struct thread_info *tp;
2095 struct address_space *aspace;
2098 /* If we're stopped at a fork/vfork, follow the branch set by the
2099 "set follow-fork-mode" command; otherwise, we'll just proceed
2100 resuming the current thread. */
2101 if (!follow_fork ())
2103 /* The target for some reason decided not to resume. */
2105 if (target_can_async_p ())
2106 inferior_event_handler (INF_EXEC_COMPLETE, NULL);
2110 /* We'll update this if & when we switch to a new thread. */
2111 previous_inferior_ptid = inferior_ptid;
2113 regcache = get_current_regcache ();
2114 gdbarch = get_regcache_arch (regcache);
2115 aspace = get_regcache_aspace (regcache);
2116 pc = regcache_read_pc (regcache);
2119 step_start_function = find_pc_function (pc);
2121 stop_after_trap = 1;
2123 if (addr == (CORE_ADDR) -1)
2125 if (pc == stop_pc && breakpoint_here_p (aspace, pc)
2126 && execution_direction != EXEC_REVERSE)
2127 /* There is a breakpoint at the address we will resume at,
2128 step one instruction before inserting breakpoints so that
2129 we do not stop right away (and report a second hit at this
2132 Note, we don't do this in reverse, because we won't
2133 actually be executing the breakpoint insn anyway.
2134 We'll be (un-)executing the previous instruction. */
2137 else if (gdbarch_single_step_through_delay_p (gdbarch)
2138 && gdbarch_single_step_through_delay (gdbarch,
2139 get_current_frame ()))
2140 /* We stepped onto an instruction that needs to be stepped
2141 again before re-inserting the breakpoint, do so. */
2146 regcache_write_pc (regcache, addr);
2150 fprintf_unfiltered (gdb_stdlog,
2151 "infrun: proceed (addr=%s, signal=%d, step=%d)\n",
2152 paddress (gdbarch, addr), siggnal, step);
2155 /* In non-stop, each thread is handled individually. The context
2156 must already be set to the right thread here. */
2160 /* In a multi-threaded task we may select another thread and
2161 then continue or step.
2163 But if the old thread was stopped at a breakpoint, it will
2164 immediately cause another breakpoint stop without any
2165 execution (i.e. it will report a breakpoint hit incorrectly).
2166 So we must step over it first.
2168 prepare_to_proceed checks the current thread against the
2169 thread that reported the most recent event. If a step-over
2170 is required it returns TRUE and sets the current thread to
2172 if (prepare_to_proceed (step))
2176 /* prepare_to_proceed may change the current thread. */
2177 tp = inferior_thread ();
2181 tp->control.trap_expected = 1;
2182 /* If displaced stepping is enabled, we can step over the
2183 breakpoint without hitting it, so leave all breakpoints
2184 inserted. Otherwise we need to disable all breakpoints, step
2185 one instruction, and then re-add them when that step is
2187 if (!use_displaced_stepping (gdbarch))
2188 remove_breakpoints ();
2191 /* We can insert breakpoints if we're not trying to step over one,
2192 or if we are stepping over one but we're using displaced stepping
2194 if (! tp->control.trap_expected || use_displaced_stepping (gdbarch))
2195 insert_breakpoints ();
2199 /* Pass the last stop signal to the thread we're resuming,
2200 irrespective of whether the current thread is the thread that
2201 got the last event or not. This was historically GDB's
2202 behaviour before keeping a stop_signal per thread. */
2204 struct thread_info *last_thread;
2206 struct target_waitstatus last_status;
2208 get_last_target_status (&last_ptid, &last_status);
2209 if (!ptid_equal (inferior_ptid, last_ptid)
2210 && !ptid_equal (last_ptid, null_ptid)
2211 && !ptid_equal (last_ptid, minus_one_ptid))
2213 last_thread = find_thread_ptid (last_ptid);
2216 tp->suspend.stop_signal = last_thread->suspend.stop_signal;
2217 last_thread->suspend.stop_signal = TARGET_SIGNAL_0;
2222 if (siggnal != TARGET_SIGNAL_DEFAULT)
2223 tp->suspend.stop_signal = siggnal;
2224 /* If this signal should not be seen by program,
2225 give it zero. Used for debugging signals. */
2226 else if (!signal_program[tp->suspend.stop_signal])
2227 tp->suspend.stop_signal = TARGET_SIGNAL_0;
2229 annotate_starting ();
2231 /* Make sure that output from GDB appears before output from the
2233 gdb_flush (gdb_stdout);
2235 /* Refresh prev_pc value just prior to resuming. This used to be
2236 done in stop_stepping, however, setting prev_pc there did not handle
2237 scenarios such as inferior function calls or returning from
2238 a function via the return command. In those cases, the prev_pc
2239 value was not set properly for subsequent commands. The prev_pc value
2240 is used to initialize the starting line number in the ecs. With an
2241 invalid value, the gdb next command ends up stopping at the position
2242 represented by the next line table entry past our start position.
2243 On platforms that generate one line table entry per line, this
2244 is not a problem. However, on the ia64, the compiler generates
2245 extraneous line table entries that do not increase the line number.
2246 When we issue the gdb next command on the ia64 after an inferior call
2247 or a return command, we often end up a few instructions forward, still
2248 within the original line we started.
2250 An attempt was made to refresh the prev_pc at the same time the
2251 execution_control_state is initialized (for instance, just before
2252 waiting for an inferior event). But this approach did not work
2253 because of platforms that use ptrace, where the pc register cannot
2254 be read unless the inferior is stopped. At that point, we are not
2255 guaranteed the inferior is stopped and so the regcache_read_pc() call
2256 can fail. Setting the prev_pc value here ensures the value is updated
2257 correctly when the inferior is stopped. */
2258 tp->prev_pc = regcache_read_pc (get_current_regcache ());
2260 /* Fill in with reasonable starting values. */
2261 init_thread_stepping_state (tp);
2263 /* Reset to normal state. */
2264 init_infwait_state ();
2266 /* Resume inferior. */
2267 resume (oneproc || step || bpstat_should_step (), tp->suspend.stop_signal);
2269 /* Wait for it to stop (if not standalone)
2270 and in any case decode why it stopped, and act accordingly. */
2271 /* Do this only if we are not using the event loop, or if the target
2272 does not support asynchronous execution. */
2273 if (!target_can_async_p ())
2275 wait_for_inferior ();
2281 /* Start remote-debugging of a machine over a serial link. */
2284 start_remote (int from_tty)
2286 struct inferior *inferior;
2288 inferior = current_inferior ();
2289 inferior->control.stop_soon = STOP_QUIETLY_REMOTE;
2291 /* Always go on waiting for the target, regardless of the mode. */
2292 /* FIXME: cagney/1999-09-23: At present it isn't possible to
2293 indicate to wait_for_inferior that a target should timeout if
2294 nothing is returned (instead of just blocking). Because of this,
2295 targets expecting an immediate response need to, internally, set
2296 things up so that the target_wait() is forced to eventually
2298 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
2299 differentiate to its caller what the state of the target is after
2300 the initial open has been performed. Here we're assuming that
2301 the target has stopped. It should be possible to eventually have
2302 target_open() return to the caller an indication that the target
2303 is currently running and GDB state should be set to the same as
2304 for an async run. */
2305 wait_for_inferior ();
2307 /* Now that the inferior has stopped, do any bookkeeping like
2308 loading shared libraries. We want to do this before normal_stop,
2309 so that the displayed frame is up to date. */
2310 post_create_inferior (¤t_target, from_tty);
2315 /* Initialize static vars when a new inferior begins. */
2318 init_wait_for_inferior (void)
2320 /* These are meaningless until the first time through wait_for_inferior. */
2322 breakpoint_init_inferior (inf_starting);
2324 clear_proceed_status ();
2326 stepping_past_singlestep_breakpoint = 0;
2327 deferred_step_ptid = null_ptid;
2329 target_last_wait_ptid = minus_one_ptid;
2331 previous_inferior_ptid = inferior_ptid;
2332 init_infwait_state ();
2334 /* Discard any skipped inlined frames. */
2335 clear_inline_frame_state (minus_one_ptid);
2339 /* This enum encodes possible reasons for doing a target_wait, so that
2340 wfi can call target_wait in one place. (Ultimately the call will be
2341 moved out of the infinite loop entirely.) */
2345 infwait_normal_state,
2346 infwait_thread_hop_state,
2347 infwait_step_watch_state,
2348 infwait_nonstep_watch_state
2351 /* The PTID we'll do a target_wait on.*/
2354 /* Current inferior wait state. */
2355 enum infwait_states infwait_state;
2357 /* Data to be passed around while handling an event. This data is
2358 discarded between events. */
2359 struct execution_control_state
2362 /* The thread that got the event, if this was a thread event; NULL
2364 struct thread_info *event_thread;
2366 struct target_waitstatus ws;
2368 int stop_func_filled_in;
2369 CORE_ADDR stop_func_start;
2370 CORE_ADDR stop_func_end;
2371 char *stop_func_name;
2372 int new_thread_event;
2376 static void handle_inferior_event (struct execution_control_state *ecs);
2378 static void handle_step_into_function (struct gdbarch *gdbarch,
2379 struct execution_control_state *ecs);
2380 static void handle_step_into_function_backward (struct gdbarch *gdbarch,
2381 struct execution_control_state *ecs);
2382 static void check_exception_resume (struct execution_control_state *,
2383 struct frame_info *, struct symbol *);
2385 static void stop_stepping (struct execution_control_state *ecs);
2386 static void prepare_to_wait (struct execution_control_state *ecs);
2387 static void keep_going (struct execution_control_state *ecs);
2389 /* Callback for iterate over threads. If the thread is stopped, but
2390 the user/frontend doesn't know about that yet, go through
2391 normal_stop, as if the thread had just stopped now. ARG points at
2392 a ptid. If PTID is MINUS_ONE_PTID, applies to all threads. If
2393 ptid_is_pid(PTID) is true, applies to all threads of the process
2394 pointed at by PTID. Otherwise, apply only to the thread pointed by
2398 infrun_thread_stop_requested_callback (struct thread_info *info, void *arg)
2400 ptid_t ptid = * (ptid_t *) arg;
2402 if ((ptid_equal (info->ptid, ptid)
2403 || ptid_equal (minus_one_ptid, ptid)
2404 || (ptid_is_pid (ptid)
2405 && ptid_get_pid (ptid) == ptid_get_pid (info->ptid)))
2406 && is_running (info->ptid)
2407 && !is_executing (info->ptid))
2409 struct cleanup *old_chain;
2410 struct execution_control_state ecss;
2411 struct execution_control_state *ecs = &ecss;
2413 memset (ecs, 0, sizeof (*ecs));
2415 old_chain = make_cleanup_restore_current_thread ();
2417 switch_to_thread (info->ptid);
2419 /* Go through handle_inferior_event/normal_stop, so we always
2420 have consistent output as if the stop event had been
2422 ecs->ptid = info->ptid;
2423 ecs->event_thread = find_thread_ptid (info->ptid);
2424 ecs->ws.kind = TARGET_WAITKIND_STOPPED;
2425 ecs->ws.value.sig = TARGET_SIGNAL_0;
2427 handle_inferior_event (ecs);
2429 if (!ecs->wait_some_more)
2431 struct thread_info *tp;
2435 /* Finish off the continuations. */
2436 tp = inferior_thread ();
2437 do_all_intermediate_continuations_thread (tp, 1);
2438 do_all_continuations_thread (tp, 1);
2441 do_cleanups (old_chain);
2447 /* This function is attached as a "thread_stop_requested" observer.
2448 Cleanup local state that assumed the PTID was to be resumed, and
2449 report the stop to the frontend. */
2452 infrun_thread_stop_requested (ptid_t ptid)
2454 struct displaced_step_inferior_state *displaced;
2456 /* PTID was requested to stop. Remove it from the displaced
2457 stepping queue, so we don't try to resume it automatically. */
2459 for (displaced = displaced_step_inferior_states;
2461 displaced = displaced->next)
2463 struct displaced_step_request *it, **prev_next_p;
2465 it = displaced->step_request_queue;
2466 prev_next_p = &displaced->step_request_queue;
2469 if (ptid_match (it->ptid, ptid))
2471 *prev_next_p = it->next;
2477 prev_next_p = &it->next;
2484 iterate_over_threads (infrun_thread_stop_requested_callback, &ptid);
2488 infrun_thread_thread_exit (struct thread_info *tp, int silent)
2490 if (ptid_equal (target_last_wait_ptid, tp->ptid))
2491 nullify_last_target_wait_ptid ();
2494 /* Callback for iterate_over_threads. */
2497 delete_step_resume_breakpoint_callback (struct thread_info *info, void *data)
2499 if (is_exited (info->ptid))
2502 delete_step_resume_breakpoint (info);
2503 delete_exception_resume_breakpoint (info);
2507 /* In all-stop, delete the step resume breakpoint of any thread that
2508 had one. In non-stop, delete the step resume breakpoint of the
2509 thread that just stopped. */
2512 delete_step_thread_step_resume_breakpoint (void)
2514 if (!target_has_execution
2515 || ptid_equal (inferior_ptid, null_ptid))
2516 /* If the inferior has exited, we have already deleted the step
2517 resume breakpoints out of GDB's lists. */
2522 /* If in non-stop mode, only delete the step-resume or
2523 longjmp-resume breakpoint of the thread that just stopped
2525 struct thread_info *tp = inferior_thread ();
2527 delete_step_resume_breakpoint (tp);
2528 delete_exception_resume_breakpoint (tp);
2531 /* In all-stop mode, delete all step-resume and longjmp-resume
2532 breakpoints of any thread that had them. */
2533 iterate_over_threads (delete_step_resume_breakpoint_callback, NULL);
2536 /* A cleanup wrapper. */
2539 delete_step_thread_step_resume_breakpoint_cleanup (void *arg)
2541 delete_step_thread_step_resume_breakpoint ();
2544 /* Pretty print the results of target_wait, for debugging purposes. */
2547 print_target_wait_results (ptid_t waiton_ptid, ptid_t result_ptid,
2548 const struct target_waitstatus *ws)
2550 char *status_string = target_waitstatus_to_string (ws);
2551 struct ui_file *tmp_stream = mem_fileopen ();
2554 /* The text is split over several lines because it was getting too long.
2555 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
2556 output as a unit; we want only one timestamp printed if debug_timestamp
2559 fprintf_unfiltered (tmp_stream,
2560 "infrun: target_wait (%d", PIDGET (waiton_ptid));
2561 if (PIDGET (waiton_ptid) != -1)
2562 fprintf_unfiltered (tmp_stream,
2563 " [%s]", target_pid_to_str (waiton_ptid));
2564 fprintf_unfiltered (tmp_stream, ", status) =\n");
2565 fprintf_unfiltered (tmp_stream,
2566 "infrun: %d [%s],\n",
2567 PIDGET (result_ptid), target_pid_to_str (result_ptid));
2568 fprintf_unfiltered (tmp_stream,
2572 text = ui_file_xstrdup (tmp_stream, NULL);
2574 /* This uses %s in part to handle %'s in the text, but also to avoid
2575 a gcc error: the format attribute requires a string literal. */
2576 fprintf_unfiltered (gdb_stdlog, "%s", text);
2578 xfree (status_string);
2580 ui_file_delete (tmp_stream);
2583 /* Prepare and stabilize the inferior for detaching it. E.g.,
2584 detaching while a thread is displaced stepping is a recipe for
2585 crashing it, as nothing would readjust the PC out of the scratch
2589 prepare_for_detach (void)
2591 struct inferior *inf = current_inferior ();
2592 ptid_t pid_ptid = pid_to_ptid (inf->pid);
2593 struct cleanup *old_chain_1;
2594 struct displaced_step_inferior_state *displaced;
2596 displaced = get_displaced_stepping_state (inf->pid);
2598 /* Is any thread of this process displaced stepping? If not,
2599 there's nothing else to do. */
2600 if (displaced == NULL || ptid_equal (displaced->step_ptid, null_ptid))
2604 fprintf_unfiltered (gdb_stdlog,
2605 "displaced-stepping in-process while detaching");
2607 old_chain_1 = make_cleanup_restore_integer (&inf->detaching);
2610 while (!ptid_equal (displaced->step_ptid, null_ptid))
2612 struct cleanup *old_chain_2;
2613 struct execution_control_state ecss;
2614 struct execution_control_state *ecs;
2617 memset (ecs, 0, sizeof (*ecs));
2619 overlay_cache_invalid = 1;
2621 if (deprecated_target_wait_hook)
2622 ecs->ptid = deprecated_target_wait_hook (pid_ptid, &ecs->ws, 0);
2624 ecs->ptid = target_wait (pid_ptid, &ecs->ws, 0);
2627 print_target_wait_results (pid_ptid, ecs->ptid, &ecs->ws);
2629 /* If an error happens while handling the event, propagate GDB's
2630 knowledge of the executing state to the frontend/user running
2632 old_chain_2 = make_cleanup (finish_thread_state_cleanup,
2635 /* In non-stop mode, each thread is handled individually.
2636 Switch early, so the global state is set correctly for this
2639 && ecs->ws.kind != TARGET_WAITKIND_EXITED
2640 && ecs->ws.kind != TARGET_WAITKIND_SIGNALLED)
2641 context_switch (ecs->ptid);
2643 /* Now figure out what to do with the result of the result. */
2644 handle_inferior_event (ecs);
2646 /* No error, don't finish the state yet. */
2647 discard_cleanups (old_chain_2);
2649 /* Breakpoints and watchpoints are not installed on the target
2650 at this point, and signals are passed directly to the
2651 inferior, so this must mean the process is gone. */
2652 if (!ecs->wait_some_more)
2654 discard_cleanups (old_chain_1);
2655 error (_("Program exited while detaching"));
2659 discard_cleanups (old_chain_1);
2662 /* Wait for control to return from inferior to debugger.
2664 If inferior gets a signal, we may decide to start it up again
2665 instead of returning. That is why there is a loop in this function.
2666 When this function actually returns it means the inferior
2667 should be left stopped and GDB should read more commands. */
2670 wait_for_inferior (void)
2672 struct cleanup *old_cleanups;
2673 struct execution_control_state ecss;
2674 struct execution_control_state *ecs;
2678 (gdb_stdlog, "infrun: wait_for_inferior ()\n");
2681 make_cleanup (delete_step_thread_step_resume_breakpoint_cleanup, NULL);
2684 memset (ecs, 0, sizeof (*ecs));
2688 struct cleanup *old_chain;
2690 overlay_cache_invalid = 1;
2692 if (deprecated_target_wait_hook)
2693 ecs->ptid = deprecated_target_wait_hook (waiton_ptid, &ecs->ws, 0);
2695 ecs->ptid = target_wait (waiton_ptid, &ecs->ws, 0);
2698 print_target_wait_results (waiton_ptid, ecs->ptid, &ecs->ws);
2700 /* If an error happens while handling the event, propagate GDB's
2701 knowledge of the executing state to the frontend/user running
2703 old_chain = make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
2705 if (ecs->ws.kind == TARGET_WAITKIND_SYSCALL_ENTRY
2706 || ecs->ws.kind == TARGET_WAITKIND_SYSCALL_RETURN)
2707 ecs->ws.value.syscall_number = UNKNOWN_SYSCALL;
2709 /* Now figure out what to do with the result of the result. */
2710 handle_inferior_event (ecs);
2712 /* No error, don't finish the state yet. */
2713 discard_cleanups (old_chain);
2715 if (!ecs->wait_some_more)
2719 do_cleanups (old_cleanups);
2722 /* Asynchronous version of wait_for_inferior. It is called by the
2723 event loop whenever a change of state is detected on the file
2724 descriptor corresponding to the target. It can be called more than
2725 once to complete a single execution command. In such cases we need
2726 to keep the state in a global variable ECSS. If it is the last time
2727 that this function is called for a single execution command, then
2728 report to the user that the inferior has stopped, and do the
2729 necessary cleanups. */
2732 fetch_inferior_event (void *client_data)
2734 struct execution_control_state ecss;
2735 struct execution_control_state *ecs = &ecss;
2736 struct cleanup *old_chain = make_cleanup (null_cleanup, NULL);
2737 struct cleanup *ts_old_chain;
2738 int was_sync = sync_execution;
2741 memset (ecs, 0, sizeof (*ecs));
2743 /* We're handling a live event, so make sure we're doing live
2744 debugging. If we're looking at traceframes while the target is
2745 running, we're going to need to get back to that mode after
2746 handling the event. */
2749 make_cleanup_restore_current_traceframe ();
2750 set_current_traceframe (-1);
2754 /* In non-stop mode, the user/frontend should not notice a thread
2755 switch due to internal events. Make sure we reverse to the
2756 user selected thread and frame after handling the event and
2757 running any breakpoint commands. */
2758 make_cleanup_restore_current_thread ();
2760 overlay_cache_invalid = 1;
2762 make_cleanup_restore_integer (&execution_direction);
2763 execution_direction = target_execution_direction ();
2765 if (deprecated_target_wait_hook)
2767 deprecated_target_wait_hook (waiton_ptid, &ecs->ws, TARGET_WNOHANG);
2769 ecs->ptid = target_wait (waiton_ptid, &ecs->ws, TARGET_WNOHANG);
2772 print_target_wait_results (waiton_ptid, ecs->ptid, &ecs->ws);
2775 && ecs->ws.kind != TARGET_WAITKIND_IGNORE
2776 && ecs->ws.kind != TARGET_WAITKIND_EXITED
2777 && ecs->ws.kind != TARGET_WAITKIND_SIGNALLED)
2778 /* In non-stop mode, each thread is handled individually. Switch
2779 early, so the global state is set correctly for this
2781 context_switch (ecs->ptid);
2783 /* If an error happens while handling the event, propagate GDB's
2784 knowledge of the executing state to the frontend/user running
2787 ts_old_chain = make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
2789 ts_old_chain = make_cleanup (finish_thread_state_cleanup, &ecs->ptid);
2791 /* Get executed before make_cleanup_restore_current_thread above to apply
2792 still for the thread which has thrown the exception. */
2793 make_bpstat_clear_actions_cleanup ();
2795 /* Now figure out what to do with the result of the result. */
2796 handle_inferior_event (ecs);
2798 if (!ecs->wait_some_more)
2800 struct inferior *inf = find_inferior_pid (ptid_get_pid (ecs->ptid));
2802 delete_step_thread_step_resume_breakpoint ();
2804 /* We may not find an inferior if this was a process exit. */
2805 if (inf == NULL || inf->control.stop_soon == NO_STOP_QUIETLY)
2808 if (target_has_execution
2809 && ecs->ws.kind != TARGET_WAITKIND_EXITED
2810 && ecs->ws.kind != TARGET_WAITKIND_SIGNALLED
2811 && ecs->event_thread->step_multi
2812 && ecs->event_thread->control.stop_step)
2813 inferior_event_handler (INF_EXEC_CONTINUE, NULL);
2816 inferior_event_handler (INF_EXEC_COMPLETE, NULL);
2821 /* No error, don't finish the thread states yet. */
2822 discard_cleanups (ts_old_chain);
2824 /* Revert thread and frame. */
2825 do_cleanups (old_chain);
2827 /* If the inferior was in sync execution mode, and now isn't,
2828 restore the prompt (a synchronous execution command has finished,
2829 and we're ready for input). */
2830 if (interpreter_async && was_sync && !sync_execution)
2831 display_gdb_prompt (0);
2835 && exec_done_display_p
2836 && (ptid_equal (inferior_ptid, null_ptid)
2837 || !is_running (inferior_ptid)))
2838 printf_unfiltered (_("completed.\n"));
2841 /* Record the frame and location we're currently stepping through. */
2843 set_step_info (struct frame_info *frame, struct symtab_and_line sal)
2845 struct thread_info *tp = inferior_thread ();
2847 tp->control.step_frame_id = get_frame_id (frame);
2848 tp->control.step_stack_frame_id = get_stack_frame_id (frame);
2850 tp->current_symtab = sal.symtab;
2851 tp->current_line = sal.line;
2854 /* Clear context switchable stepping state. */
2857 init_thread_stepping_state (struct thread_info *tss)
2859 tss->stepping_over_breakpoint = 0;
2860 tss->step_after_step_resume_breakpoint = 0;
2863 /* Return the cached copy of the last pid/waitstatus returned by
2864 target_wait()/deprecated_target_wait_hook(). The data is actually
2865 cached by handle_inferior_event(), which gets called immediately
2866 after target_wait()/deprecated_target_wait_hook(). */
2869 get_last_target_status (ptid_t *ptidp, struct target_waitstatus *status)
2871 *ptidp = target_last_wait_ptid;
2872 *status = target_last_waitstatus;
2876 nullify_last_target_wait_ptid (void)
2878 target_last_wait_ptid = minus_one_ptid;
2881 /* Switch thread contexts. */
2884 context_switch (ptid_t ptid)
2886 if (debug_infrun && !ptid_equal (ptid, inferior_ptid))
2888 fprintf_unfiltered (gdb_stdlog, "infrun: Switching context from %s ",
2889 target_pid_to_str (inferior_ptid));
2890 fprintf_unfiltered (gdb_stdlog, "to %s\n",
2891 target_pid_to_str (ptid));
2894 switch_to_thread (ptid);
2898 adjust_pc_after_break (struct execution_control_state *ecs)
2900 struct regcache *regcache;
2901 struct gdbarch *gdbarch;
2902 struct address_space *aspace;
2903 CORE_ADDR breakpoint_pc;
2905 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
2906 we aren't, just return.
2908 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
2909 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
2910 implemented by software breakpoints should be handled through the normal
2913 NOTE drow/2004-01-31: On some targets, breakpoints may generate
2914 different signals (SIGILL or SIGEMT for instance), but it is less
2915 clear where the PC is pointing afterwards. It may not match
2916 gdbarch_decr_pc_after_break. I don't know any specific target that
2917 generates these signals at breakpoints (the code has been in GDB since at
2918 least 1992) so I can not guess how to handle them here.
2920 In earlier versions of GDB, a target with
2921 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
2922 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
2923 target with both of these set in GDB history, and it seems unlikely to be
2924 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
2926 if (ecs->ws.kind != TARGET_WAITKIND_STOPPED)
2929 if (ecs->ws.value.sig != TARGET_SIGNAL_TRAP)
2932 /* In reverse execution, when a breakpoint is hit, the instruction
2933 under it has already been de-executed. The reported PC always
2934 points at the breakpoint address, so adjusting it further would
2935 be wrong. E.g., consider this case on a decr_pc_after_break == 1
2938 B1 0x08000000 : INSN1
2939 B2 0x08000001 : INSN2
2941 PC -> 0x08000003 : INSN4
2943 Say you're stopped at 0x08000003 as above. Reverse continuing
2944 from that point should hit B2 as below. Reading the PC when the
2945 SIGTRAP is reported should read 0x08000001 and INSN2 should have
2946 been de-executed already.
2948 B1 0x08000000 : INSN1
2949 B2 PC -> 0x08000001 : INSN2
2953 We can't apply the same logic as for forward execution, because
2954 we would wrongly adjust the PC to 0x08000000, since there's a
2955 breakpoint at PC - 1. We'd then report a hit on B1, although
2956 INSN1 hadn't been de-executed yet. Doing nothing is the correct
2958 if (execution_direction == EXEC_REVERSE)
2961 /* If this target does not decrement the PC after breakpoints, then
2962 we have nothing to do. */
2963 regcache = get_thread_regcache (ecs->ptid);
2964 gdbarch = get_regcache_arch (regcache);
2965 if (gdbarch_decr_pc_after_break (gdbarch) == 0)
2968 aspace = get_regcache_aspace (regcache);
2970 /* Find the location where (if we've hit a breakpoint) the
2971 breakpoint would be. */
2972 breakpoint_pc = regcache_read_pc (regcache)
2973 - gdbarch_decr_pc_after_break (gdbarch);
2975 /* Check whether there actually is a software breakpoint inserted at
2978 If in non-stop mode, a race condition is possible where we've
2979 removed a breakpoint, but stop events for that breakpoint were
2980 already queued and arrive later. To suppress those spurious
2981 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
2982 and retire them after a number of stop events are reported. */
2983 if (software_breakpoint_inserted_here_p (aspace, breakpoint_pc)
2984 || (non_stop && moribund_breakpoint_here_p (aspace, breakpoint_pc)))
2986 struct cleanup *old_cleanups = NULL;
2989 old_cleanups = record_gdb_operation_disable_set ();
2991 /* When using hardware single-step, a SIGTRAP is reported for both
2992 a completed single-step and a software breakpoint. Need to
2993 differentiate between the two, as the latter needs adjusting
2994 but the former does not.
2996 The SIGTRAP can be due to a completed hardware single-step only if
2997 - we didn't insert software single-step breakpoints
2998 - the thread to be examined is still the current thread
2999 - this thread is currently being stepped
3001 If any of these events did not occur, we must have stopped due
3002 to hitting a software breakpoint, and have to back up to the
3005 As a special case, we could have hardware single-stepped a
3006 software breakpoint. In this case (prev_pc == breakpoint_pc),
3007 we also need to back up to the breakpoint address. */
3009 if (singlestep_breakpoints_inserted_p
3010 || !ptid_equal (ecs->ptid, inferior_ptid)
3011 || !currently_stepping (ecs->event_thread)
3012 || ecs->event_thread->prev_pc == breakpoint_pc)
3013 regcache_write_pc (regcache, breakpoint_pc);
3016 do_cleanups (old_cleanups);
3021 init_infwait_state (void)
3023 waiton_ptid = pid_to_ptid (-1);
3024 infwait_state = infwait_normal_state;
3028 error_is_running (void)
3030 error (_("Cannot execute this command while "
3031 "the selected thread is running."));
3035 ensure_not_running (void)
3037 if (is_running (inferior_ptid))
3038 error_is_running ();
3042 stepped_in_from (struct frame_info *frame, struct frame_id step_frame_id)
3044 for (frame = get_prev_frame (frame);
3046 frame = get_prev_frame (frame))
3048 if (frame_id_eq (get_frame_id (frame), step_frame_id))
3050 if (get_frame_type (frame) != INLINE_FRAME)
3057 /* Auxiliary function that handles syscall entry/return events.
3058 It returns 1 if the inferior should keep going (and GDB
3059 should ignore the event), or 0 if the event deserves to be
3063 handle_syscall_event (struct execution_control_state *ecs)
3065 struct regcache *regcache;
3066 struct gdbarch *gdbarch;
3069 if (!ptid_equal (ecs->ptid, inferior_ptid))
3070 context_switch (ecs->ptid);
3072 regcache = get_thread_regcache (ecs->ptid);
3073 gdbarch = get_regcache_arch (regcache);
3074 syscall_number = gdbarch_get_syscall_number (gdbarch, ecs->ptid);
3075 stop_pc = regcache_read_pc (regcache);
3077 target_last_waitstatus.value.syscall_number = syscall_number;
3079 if (catch_syscall_enabled () > 0
3080 && catching_syscall_number (syscall_number) > 0)
3083 fprintf_unfiltered (gdb_stdlog, "infrun: syscall number = '%d'\n",
3086 ecs->event_thread->control.stop_bpstat
3087 = bpstat_stop_status (get_regcache_aspace (regcache),
3088 stop_pc, ecs->ptid);
3090 = !bpstat_explains_signal (ecs->event_thread->control.stop_bpstat);
3092 if (!ecs->random_signal)
3094 /* Catchpoint hit. */
3095 ecs->event_thread->suspend.stop_signal = TARGET_SIGNAL_TRAP;
3100 /* If no catchpoint triggered for this, then keep going. */
3101 ecs->event_thread->suspend.stop_signal = TARGET_SIGNAL_0;
3106 /* Clear the supplied execution_control_state's stop_func_* fields. */
3109 clear_stop_func (struct execution_control_state *ecs)
3111 ecs->stop_func_filled_in = 0;
3112 ecs->stop_func_start = 0;
3113 ecs->stop_func_end = 0;
3114 ecs->stop_func_name = NULL;
3117 /* Lazily fill in the execution_control_state's stop_func_* fields. */
3120 fill_in_stop_func (struct gdbarch *gdbarch,
3121 struct execution_control_state *ecs)
3123 if (!ecs->stop_func_filled_in)
3125 /* Don't care about return value; stop_func_start and stop_func_name
3126 will both be 0 if it doesn't work. */
3127 find_pc_partial_function (stop_pc, &ecs->stop_func_name,
3128 &ecs->stop_func_start, &ecs->stop_func_end);
3129 ecs->stop_func_start
3130 += gdbarch_deprecated_function_start_offset (gdbarch);
3132 ecs->stop_func_filled_in = 1;
3136 /* Given an execution control state that has been freshly filled in
3137 by an event from the inferior, figure out what it means and take
3138 appropriate action. */
3141 handle_inferior_event (struct execution_control_state *ecs)
3143 struct frame_info *frame;
3144 struct gdbarch *gdbarch;
3145 int stopped_by_watchpoint;
3146 int stepped_after_stopped_by_watchpoint = 0;
3147 struct symtab_and_line stop_pc_sal;
3148 enum stop_kind stop_soon;
3150 if (ecs->ws.kind == TARGET_WAITKIND_IGNORE)
3152 /* We had an event in the inferior, but we are not interested in
3153 handling it at this level. The lower layers have already
3154 done what needs to be done, if anything.
3156 One of the possible circumstances for this is when the
3157 inferior produces output for the console. The inferior has
3158 not stopped, and we are ignoring the event. Another possible
3159 circumstance is any event which the lower level knows will be
3160 reported multiple times without an intervening resume. */
3162 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_IGNORE\n");
3163 prepare_to_wait (ecs);
3167 if (ecs->ws.kind != TARGET_WAITKIND_EXITED
3168 && ecs->ws.kind != TARGET_WAITKIND_SIGNALLED)
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 it's a new process, add it to the thread database. */
3187 ecs->new_thread_event = (!ptid_equal (ecs->ptid, inferior_ptid)
3188 && !ptid_equal (ecs->ptid, minus_one_ptid)
3189 && !in_thread_list (ecs->ptid));
3191 if (ecs->ws.kind != TARGET_WAITKIND_EXITED
3192 && ecs->ws.kind != TARGET_WAITKIND_SIGNALLED && ecs->new_thread_event)
3193 add_thread (ecs->ptid);
3195 ecs->event_thread = find_thread_ptid (ecs->ptid);
3197 /* Dependent on valid ECS->EVENT_THREAD. */
3198 adjust_pc_after_break (ecs);
3200 /* Dependent on the current PC value modified by adjust_pc_after_break. */
3201 reinit_frame_cache ();
3203 breakpoint_retire_moribund ();
3205 /* First, distinguish signals caused by the debugger from signals
3206 that have to do with the program's own actions. Note that
3207 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
3208 on the operating system version. Here we detect when a SIGILL or
3209 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
3210 something similar for SIGSEGV, since a SIGSEGV will be generated
3211 when we're trying to execute a breakpoint instruction on a
3212 non-executable stack. This happens for call dummy breakpoints
3213 for architectures like SPARC that place call dummies on the
3215 if (ecs->ws.kind == TARGET_WAITKIND_STOPPED
3216 && (ecs->ws.value.sig == TARGET_SIGNAL_ILL
3217 || ecs->ws.value.sig == TARGET_SIGNAL_SEGV
3218 || ecs->ws.value.sig == TARGET_SIGNAL_EMT))
3220 struct regcache *regcache = get_thread_regcache (ecs->ptid);
3222 if (breakpoint_inserted_here_p (get_regcache_aspace (regcache),
3223 regcache_read_pc (regcache)))
3226 fprintf_unfiltered (gdb_stdlog,
3227 "infrun: Treating signal as SIGTRAP\n");
3228 ecs->ws.value.sig = TARGET_SIGNAL_TRAP;
3232 /* Mark the non-executing threads accordingly. In all-stop, all
3233 threads of all processes are stopped when we get any event
3234 reported. In non-stop mode, only the event thread stops. If
3235 we're handling a process exit in non-stop mode, there's nothing
3236 to do, as threads of the dead process are gone, and threads of
3237 any other process were left running. */
3239 set_executing (minus_one_ptid, 0);
3240 else if (ecs->ws.kind != TARGET_WAITKIND_SIGNALLED
3241 && ecs->ws.kind != TARGET_WAITKIND_EXITED)
3242 set_executing (inferior_ptid, 0);
3244 switch (infwait_state)
3246 case infwait_thread_hop_state:
3248 fprintf_unfiltered (gdb_stdlog, "infrun: infwait_thread_hop_state\n");
3251 case infwait_normal_state:
3253 fprintf_unfiltered (gdb_stdlog, "infrun: infwait_normal_state\n");
3256 case infwait_step_watch_state:
3258 fprintf_unfiltered (gdb_stdlog,
3259 "infrun: infwait_step_watch_state\n");
3261 stepped_after_stopped_by_watchpoint = 1;
3264 case infwait_nonstep_watch_state:
3266 fprintf_unfiltered (gdb_stdlog,
3267 "infrun: infwait_nonstep_watch_state\n");
3268 insert_breakpoints ();
3270 /* FIXME-maybe: is this cleaner than setting a flag? Does it
3271 handle things like signals arriving and other things happening
3272 in combination correctly? */
3273 stepped_after_stopped_by_watchpoint = 1;
3277 internal_error (__FILE__, __LINE__, _("bad switch"));
3280 infwait_state = infwait_normal_state;
3281 waiton_ptid = pid_to_ptid (-1);
3283 switch (ecs->ws.kind)
3285 case TARGET_WAITKIND_LOADED:
3287 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_LOADED\n");
3288 /* Ignore gracefully during startup of the inferior, as it might
3289 be the shell which has just loaded some objects, otherwise
3290 add the symbols for the newly loaded objects. Also ignore at
3291 the beginning of an attach or remote session; we will query
3292 the full list of libraries once the connection is
3294 if (stop_soon == NO_STOP_QUIETLY)
3296 /* Check for any newly added shared libraries if we're
3297 supposed to be adding them automatically. Switch
3298 terminal for any messages produced by
3299 breakpoint_re_set. */
3300 target_terminal_ours_for_output ();
3301 /* NOTE: cagney/2003-11-25: Make certain that the target
3302 stack's section table is kept up-to-date. Architectures,
3303 (e.g., PPC64), use the section table to perform
3304 operations such as address => section name and hence
3305 require the table to contain all sections (including
3306 those found in shared libraries). */
3308 SOLIB_ADD (NULL, 0, ¤t_target, auto_solib_add);
3310 solib_add (NULL, 0, ¤t_target, auto_solib_add);
3312 target_terminal_inferior ();
3314 /* If requested, stop when the dynamic linker notifies
3315 gdb of events. This allows the user to get control
3316 and place breakpoints in initializer routines for
3317 dynamically loaded objects (among other things). */
3318 if (stop_on_solib_events)
3320 /* Make sure we print "Stopped due to solib-event" in
3322 stop_print_frame = 1;
3324 stop_stepping (ecs);
3328 /* NOTE drow/2007-05-11: This might be a good place to check
3329 for "catch load". */
3332 /* If we are skipping through a shell, or through shared library
3333 loading that we aren't interested in, resume the program. If
3334 we're running the program normally, also resume. But stop if
3335 we're attaching or setting up a remote connection. */
3336 if (stop_soon == STOP_QUIETLY || stop_soon == NO_STOP_QUIETLY)
3338 /* Loading of shared libraries might have changed breakpoint
3339 addresses. Make sure new breakpoints are inserted. */
3340 if (stop_soon == NO_STOP_QUIETLY
3341 && !breakpoints_always_inserted_mode ())
3342 insert_breakpoints ();
3343 resume (0, TARGET_SIGNAL_0);
3344 prepare_to_wait (ecs);
3350 case TARGET_WAITKIND_SPURIOUS:
3352 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_SPURIOUS\n");
3353 resume (0, TARGET_SIGNAL_0);
3354 prepare_to_wait (ecs);
3357 case TARGET_WAITKIND_EXITED:
3359 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_EXITED\n");
3360 inferior_ptid = ecs->ptid;
3361 set_current_inferior (find_inferior_pid (ptid_get_pid (ecs->ptid)));
3362 set_current_program_space (current_inferior ()->pspace);
3363 handle_vfork_child_exec_or_exit (0);
3364 target_terminal_ours (); /* Must do this before mourn anyway. */
3365 print_exited_reason (ecs->ws.value.integer);
3367 /* Record the exit code in the convenience variable $_exitcode, so
3368 that the user can inspect this again later. */
3369 set_internalvar_integer (lookup_internalvar ("_exitcode"),
3370 (LONGEST) ecs->ws.value.integer);
3372 /* Also record this in the inferior itself. */
3373 current_inferior ()->has_exit_code = 1;
3374 current_inferior ()->exit_code = (LONGEST) ecs->ws.value.integer;
3376 gdb_flush (gdb_stdout);
3377 target_mourn_inferior ();
3378 singlestep_breakpoints_inserted_p = 0;
3379 cancel_single_step_breakpoints ();
3380 stop_print_frame = 0;
3381 stop_stepping (ecs);
3384 case TARGET_WAITKIND_SIGNALLED:
3386 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_SIGNALLED\n");
3387 inferior_ptid = ecs->ptid;
3388 set_current_inferior (find_inferior_pid (ptid_get_pid (ecs->ptid)));
3389 set_current_program_space (current_inferior ()->pspace);
3390 handle_vfork_child_exec_or_exit (0);
3391 stop_print_frame = 0;
3392 target_terminal_ours (); /* Must do this before mourn anyway. */
3394 /* Note: By definition of TARGET_WAITKIND_SIGNALLED, we shouldn't
3395 reach here unless the inferior is dead. However, for years
3396 target_kill() was called here, which hints that fatal signals aren't
3397 really fatal on some systems. If that's true, then some changes
3399 target_mourn_inferior ();
3401 print_signal_exited_reason (ecs->ws.value.sig);
3402 singlestep_breakpoints_inserted_p = 0;
3403 cancel_single_step_breakpoints ();
3404 stop_stepping (ecs);
3407 /* The following are the only cases in which we keep going;
3408 the above cases end in a continue or goto. */
3409 case TARGET_WAITKIND_FORKED:
3410 case TARGET_WAITKIND_VFORKED:
3412 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_FORKED\n");
3414 /* Check whether the inferior is displaced stepping. */
3416 struct regcache *regcache = get_thread_regcache (ecs->ptid);
3417 struct gdbarch *gdbarch = get_regcache_arch (regcache);
3418 struct displaced_step_inferior_state *displaced
3419 = get_displaced_stepping_state (ptid_get_pid (ecs->ptid));
3421 /* If checking displaced stepping is supported, and thread
3422 ecs->ptid is displaced stepping. */
3423 if (displaced && ptid_equal (displaced->step_ptid, ecs->ptid))
3425 struct inferior *parent_inf
3426 = find_inferior_pid (ptid_get_pid (ecs->ptid));
3427 struct regcache *child_regcache;
3428 CORE_ADDR parent_pc;
3430 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
3431 indicating that the displaced stepping of syscall instruction
3432 has been done. Perform cleanup for parent process here. Note
3433 that this operation also cleans up the child process for vfork,
3434 because their pages are shared. */
3435 displaced_step_fixup (ecs->ptid, TARGET_SIGNAL_TRAP);
3437 if (ecs->ws.kind == TARGET_WAITKIND_FORKED)
3439 /* Restore scratch pad for child process. */
3440 displaced_step_restore (displaced, ecs->ws.value.related_pid);
3443 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
3444 the child's PC is also within the scratchpad. Set the child's PC
3445 to the parent's PC value, which has already been fixed up.
3446 FIXME: we use the parent's aspace here, although we're touching
3447 the child, because the child hasn't been added to the inferior
3448 list yet at this point. */
3451 = get_thread_arch_aspace_regcache (ecs->ws.value.related_pid,
3453 parent_inf->aspace);
3454 /* Read PC value of parent process. */
3455 parent_pc = regcache_read_pc (regcache);
3457 if (debug_displaced)
3458 fprintf_unfiltered (gdb_stdlog,
3459 "displaced: write child pc from %s to %s\n",
3461 regcache_read_pc (child_regcache)),
3462 paddress (gdbarch, parent_pc));
3464 regcache_write_pc (child_regcache, parent_pc);
3468 if (!ptid_equal (ecs->ptid, inferior_ptid))
3470 context_switch (ecs->ptid);
3471 reinit_frame_cache ();
3474 /* Immediately detach breakpoints from the child before there's
3475 any chance of letting the user delete breakpoints from the
3476 breakpoint lists. If we don't do this early, it's easy to
3477 leave left over traps in the child, vis: "break foo; catch
3478 fork; c; <fork>; del; c; <child calls foo>". We only follow
3479 the fork on the last `continue', and by that time the
3480 breakpoint at "foo" is long gone from the breakpoint table.
3481 If we vforked, then we don't need to unpatch here, since both
3482 parent and child are sharing the same memory pages; we'll
3483 need to unpatch at follow/detach time instead to be certain
3484 that new breakpoints added between catchpoint hit time and
3485 vfork follow are detached. */
3486 if (ecs->ws.kind != TARGET_WAITKIND_VFORKED)
3488 int child_pid = ptid_get_pid (ecs->ws.value.related_pid);
3490 /* This won't actually modify the breakpoint list, but will
3491 physically remove the breakpoints from the child. */
3492 detach_breakpoints (child_pid);
3495 if (singlestep_breakpoints_inserted_p)
3497 /* Pull the single step breakpoints out of the target. */
3498 remove_single_step_breakpoints ();
3499 singlestep_breakpoints_inserted_p = 0;
3502 /* In case the event is caught by a catchpoint, remember that
3503 the event is to be followed at the next resume of the thread,
3504 and not immediately. */
3505 ecs->event_thread->pending_follow = ecs->ws;
3507 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
3509 ecs->event_thread->control.stop_bpstat
3510 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
3511 stop_pc, ecs->ptid);
3513 /* Note that we're interested in knowing the bpstat actually
3514 causes a stop, not just if it may explain the signal.
3515 Software watchpoints, for example, always appear in the
3518 = !bpstat_causes_stop (ecs->event_thread->control.stop_bpstat);
3520 /* If no catchpoint triggered for this, then keep going. */
3521 if (ecs->random_signal)
3527 = (follow_fork_mode_string == follow_fork_mode_child);
3529 ecs->event_thread->suspend.stop_signal = TARGET_SIGNAL_0;
3531 should_resume = follow_fork ();
3534 child = ecs->ws.value.related_pid;
3536 /* In non-stop mode, also resume the other branch. */
3537 if (non_stop && !detach_fork)
3540 switch_to_thread (parent);
3542 switch_to_thread (child);
3544 ecs->event_thread = inferior_thread ();
3545 ecs->ptid = inferior_ptid;
3550 switch_to_thread (child);
3552 switch_to_thread (parent);
3554 ecs->event_thread = inferior_thread ();
3555 ecs->ptid = inferior_ptid;
3560 stop_stepping (ecs);
3563 ecs->event_thread->suspend.stop_signal = TARGET_SIGNAL_TRAP;
3564 goto process_event_stop_test;
3566 case TARGET_WAITKIND_VFORK_DONE:
3567 /* Done with the shared memory region. Re-insert breakpoints in
3568 the parent, and keep going. */
3571 fprintf_unfiltered (gdb_stdlog,
3572 "infrun: TARGET_WAITKIND_VFORK_DONE\n");
3574 if (!ptid_equal (ecs->ptid, inferior_ptid))
3575 context_switch (ecs->ptid);
3577 current_inferior ()->waiting_for_vfork_done = 0;
3578 current_inferior ()->pspace->breakpoints_not_allowed = 0;
3579 /* This also takes care of reinserting breakpoints in the
3580 previously locked inferior. */
3584 case TARGET_WAITKIND_EXECD:
3586 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_EXECD\n");
3588 if (!ptid_equal (ecs->ptid, inferior_ptid))
3590 context_switch (ecs->ptid);
3591 reinit_frame_cache ();
3594 singlestep_breakpoints_inserted_p = 0;
3595 cancel_single_step_breakpoints ();
3597 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
3599 /* Do whatever is necessary to the parent branch of the vfork. */
3600 handle_vfork_child_exec_or_exit (1);
3602 /* This causes the eventpoints and symbol table to be reset.
3603 Must do this now, before trying to determine whether to
3605 follow_exec (inferior_ptid, ecs->ws.value.execd_pathname);
3607 ecs->event_thread->control.stop_bpstat
3608 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
3609 stop_pc, ecs->ptid);
3611 = !bpstat_explains_signal (ecs->event_thread->control.stop_bpstat);
3613 /* Note that this may be referenced from inside
3614 bpstat_stop_status above, through inferior_has_execd. */
3615 xfree (ecs->ws.value.execd_pathname);
3616 ecs->ws.value.execd_pathname = NULL;
3618 /* If no catchpoint triggered for this, then keep going. */
3619 if (ecs->random_signal)
3621 ecs->event_thread->suspend.stop_signal = TARGET_SIGNAL_0;
3625 ecs->event_thread->suspend.stop_signal = TARGET_SIGNAL_TRAP;
3626 goto process_event_stop_test;
3628 /* Be careful not to try to gather much state about a thread
3629 that's in a syscall. It's frequently a losing proposition. */
3630 case TARGET_WAITKIND_SYSCALL_ENTRY:
3632 fprintf_unfiltered (gdb_stdlog,
3633 "infrun: TARGET_WAITKIND_SYSCALL_ENTRY\n");
3634 /* Getting the current syscall number. */
3635 if (handle_syscall_event (ecs) != 0)
3637 goto process_event_stop_test;
3639 /* Before examining the threads further, step this thread to
3640 get it entirely out of the syscall. (We get notice of the
3641 event when the thread is just on the verge of exiting a
3642 syscall. Stepping one instruction seems to get it back
3644 case TARGET_WAITKIND_SYSCALL_RETURN:
3646 fprintf_unfiltered (gdb_stdlog,
3647 "infrun: TARGET_WAITKIND_SYSCALL_RETURN\n");
3648 if (handle_syscall_event (ecs) != 0)
3650 goto process_event_stop_test;
3652 case TARGET_WAITKIND_STOPPED:
3654 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_STOPPED\n");
3655 ecs->event_thread->suspend.stop_signal = ecs->ws.value.sig;
3658 case TARGET_WAITKIND_NO_HISTORY:
3659 /* Reverse execution: target ran out of history info. */
3660 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
3661 print_no_history_reason ();
3662 stop_stepping (ecs);
3666 if (ecs->new_thread_event)
3669 /* Non-stop assumes that the target handles adding new threads
3670 to the thread list. */
3671 internal_error (__FILE__, __LINE__,
3672 "targets should add new threads to the thread "
3673 "list themselves in non-stop mode.");
3675 /* We may want to consider not doing a resume here in order to
3676 give the user a chance to play with the new thread. It might
3677 be good to make that a user-settable option. */
3679 /* At this point, all threads are stopped (happens automatically
3680 in either the OS or the native code). Therefore we need to
3681 continue all threads in order to make progress. */
3683 if (!ptid_equal (ecs->ptid, inferior_ptid))
3684 context_switch (ecs->ptid);
3685 target_resume (RESUME_ALL, 0, TARGET_SIGNAL_0);
3686 prepare_to_wait (ecs);
3690 if (ecs->ws.kind == TARGET_WAITKIND_STOPPED)
3692 /* Do we need to clean up the state of a thread that has
3693 completed a displaced single-step? (Doing so usually affects
3694 the PC, so do it here, before we set stop_pc.) */
3695 displaced_step_fixup (ecs->ptid,
3696 ecs->event_thread->suspend.stop_signal);
3698 /* If we either finished a single-step or hit a breakpoint, but
3699 the user wanted this thread to be stopped, pretend we got a
3700 SIG0 (generic unsignaled stop). */
3702 if (ecs->event_thread->stop_requested
3703 && ecs->event_thread->suspend.stop_signal == TARGET_SIGNAL_TRAP)
3704 ecs->event_thread->suspend.stop_signal = TARGET_SIGNAL_0;
3707 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
3711 struct regcache *regcache = get_thread_regcache (ecs->ptid);
3712 struct gdbarch *gdbarch = get_regcache_arch (regcache);
3713 struct cleanup *old_chain = save_inferior_ptid ();
3715 inferior_ptid = ecs->ptid;
3717 fprintf_unfiltered (gdb_stdlog, "infrun: stop_pc = %s\n",
3718 paddress (gdbarch, stop_pc));
3719 if (target_stopped_by_watchpoint ())
3723 fprintf_unfiltered (gdb_stdlog, "infrun: stopped by watchpoint\n");
3725 if (target_stopped_data_address (¤t_target, &addr))
3726 fprintf_unfiltered (gdb_stdlog,
3727 "infrun: stopped data address = %s\n",
3728 paddress (gdbarch, addr));
3730 fprintf_unfiltered (gdb_stdlog,
3731 "infrun: (no data address available)\n");
3734 do_cleanups (old_chain);
3737 if (stepping_past_singlestep_breakpoint)
3739 gdb_assert (singlestep_breakpoints_inserted_p);
3740 gdb_assert (ptid_equal (singlestep_ptid, ecs->ptid));
3741 gdb_assert (!ptid_equal (singlestep_ptid, saved_singlestep_ptid));
3743 stepping_past_singlestep_breakpoint = 0;
3745 /* We've either finished single-stepping past the single-step
3746 breakpoint, or stopped for some other reason. It would be nice if
3747 we could tell, but we can't reliably. */
3748 if (ecs->event_thread->suspend.stop_signal == TARGET_SIGNAL_TRAP)
3751 fprintf_unfiltered (gdb_stdlog,
3752 "infrun: stepping_past_"
3753 "singlestep_breakpoint\n");
3754 /* Pull the single step breakpoints out of the target. */
3755 remove_single_step_breakpoints ();
3756 singlestep_breakpoints_inserted_p = 0;
3758 ecs->random_signal = 0;
3759 ecs->event_thread->control.trap_expected = 0;
3761 context_switch (saved_singlestep_ptid);
3762 if (deprecated_context_hook)
3763 deprecated_context_hook (pid_to_thread_id (ecs->ptid));
3765 resume (1, TARGET_SIGNAL_0);
3766 prepare_to_wait (ecs);
3771 if (!ptid_equal (deferred_step_ptid, null_ptid))
3773 /* In non-stop mode, there's never a deferred_step_ptid set. */
3774 gdb_assert (!non_stop);
3776 /* If we stopped for some other reason than single-stepping, ignore
3777 the fact that we were supposed to switch back. */
3778 if (ecs->event_thread->suspend.stop_signal == TARGET_SIGNAL_TRAP)
3781 fprintf_unfiltered (gdb_stdlog,
3782 "infrun: handling deferred step\n");
3784 /* Pull the single step breakpoints out of the target. */
3785 if (singlestep_breakpoints_inserted_p)
3787 remove_single_step_breakpoints ();
3788 singlestep_breakpoints_inserted_p = 0;
3791 ecs->event_thread->control.trap_expected = 0;
3793 /* Note: We do not call context_switch at this point, as the
3794 context is already set up for stepping the original thread. */
3795 switch_to_thread (deferred_step_ptid);
3796 deferred_step_ptid = null_ptid;
3797 /* Suppress spurious "Switching to ..." message. */
3798 previous_inferior_ptid = inferior_ptid;
3800 resume (1, TARGET_SIGNAL_0);
3801 prepare_to_wait (ecs);
3805 deferred_step_ptid = null_ptid;
3808 /* See if a thread hit a thread-specific breakpoint that was meant for
3809 another thread. If so, then step that thread past the breakpoint,
3812 if (ecs->event_thread->suspend.stop_signal == TARGET_SIGNAL_TRAP)
3814 int thread_hop_needed = 0;
3815 struct address_space *aspace =
3816 get_regcache_aspace (get_thread_regcache (ecs->ptid));
3818 /* Check if a regular breakpoint has been hit before checking
3819 for a potential single step breakpoint. Otherwise, GDB will
3820 not see this breakpoint hit when stepping onto breakpoints. */
3821 if (regular_breakpoint_inserted_here_p (aspace, stop_pc))
3823 ecs->random_signal = 0;
3824 if (!breakpoint_thread_match (aspace, stop_pc, ecs->ptid))
3825 thread_hop_needed = 1;
3827 else if (singlestep_breakpoints_inserted_p)
3829 /* We have not context switched yet, so this should be true
3830 no matter which thread hit the singlestep breakpoint. */
3831 gdb_assert (ptid_equal (inferior_ptid, singlestep_ptid));
3833 fprintf_unfiltered (gdb_stdlog, "infrun: software single step "
3835 target_pid_to_str (ecs->ptid));
3837 ecs->random_signal = 0;
3838 /* The call to in_thread_list is necessary because PTIDs sometimes
3839 change when we go from single-threaded to multi-threaded. If
3840 the singlestep_ptid is still in the list, assume that it is
3841 really different from ecs->ptid. */
3842 if (!ptid_equal (singlestep_ptid, ecs->ptid)
3843 && in_thread_list (singlestep_ptid))
3845 /* If the PC of the thread we were trying to single-step
3846 has changed, discard this event (which we were going
3847 to ignore anyway), and pretend we saw that thread
3848 trap. This prevents us continuously moving the
3849 single-step breakpoint forward, one instruction at a
3850 time. If the PC has changed, then the thread we were
3851 trying to single-step has trapped or been signalled,
3852 but the event has not been reported to GDB yet.
3854 There might be some cases where this loses signal
3855 information, if a signal has arrived at exactly the
3856 same time that the PC changed, but this is the best
3857 we can do with the information available. Perhaps we
3858 should arrange to report all events for all threads
3859 when they stop, or to re-poll the remote looking for
3860 this particular thread (i.e. temporarily enable
3863 CORE_ADDR new_singlestep_pc
3864 = regcache_read_pc (get_thread_regcache (singlestep_ptid));
3866 if (new_singlestep_pc != singlestep_pc)
3868 enum target_signal stop_signal;
3871 fprintf_unfiltered (gdb_stdlog, "infrun: unexpected thread,"
3872 " but expected thread advanced also\n");
3874 /* The current context still belongs to
3875 singlestep_ptid. Don't swap here, since that's
3876 the context we want to use. Just fudge our
3877 state and continue. */
3878 stop_signal = ecs->event_thread->suspend.stop_signal;
3879 ecs->event_thread->suspend.stop_signal = TARGET_SIGNAL_0;
3880 ecs->ptid = singlestep_ptid;
3881 ecs->event_thread = find_thread_ptid (ecs->ptid);
3882 ecs->event_thread->suspend.stop_signal = stop_signal;
3883 stop_pc = new_singlestep_pc;
3888 fprintf_unfiltered (gdb_stdlog,
3889 "infrun: unexpected thread\n");
3891 thread_hop_needed = 1;
3892 stepping_past_singlestep_breakpoint = 1;
3893 saved_singlestep_ptid = singlestep_ptid;
3898 if (thread_hop_needed)
3900 struct regcache *thread_regcache;
3901 int remove_status = 0;
3904 fprintf_unfiltered (gdb_stdlog, "infrun: thread_hop_needed\n");
3906 /* Switch context before touching inferior memory, the
3907 previous thread may have exited. */
3908 if (!ptid_equal (inferior_ptid, ecs->ptid))
3909 context_switch (ecs->ptid);
3911 /* Saw a breakpoint, but it was hit by the wrong thread.
3914 if (singlestep_breakpoints_inserted_p)
3916 /* Pull the single step breakpoints out of the target. */
3917 remove_single_step_breakpoints ();
3918 singlestep_breakpoints_inserted_p = 0;
3921 /* If the arch can displace step, don't remove the
3923 thread_regcache = get_thread_regcache (ecs->ptid);
3924 if (!use_displaced_stepping (get_regcache_arch (thread_regcache)))
3925 remove_status = remove_breakpoints ();
3927 /* Did we fail to remove breakpoints? If so, try
3928 to set the PC past the bp. (There's at least
3929 one situation in which we can fail to remove
3930 the bp's: On HP-UX's that use ttrace, we can't
3931 change the address space of a vforking child
3932 process until the child exits (well, okay, not
3933 then either :-) or execs. */
3934 if (remove_status != 0)
3935 error (_("Cannot step over breakpoint hit in wrong thread"));
3940 /* Only need to require the next event from this
3941 thread in all-stop mode. */
3942 waiton_ptid = ecs->ptid;
3943 infwait_state = infwait_thread_hop_state;
3946 ecs->event_thread->stepping_over_breakpoint = 1;
3951 else if (singlestep_breakpoints_inserted_p)
3953 ecs->random_signal = 0;
3957 ecs->random_signal = 1;
3959 /* See if something interesting happened to the non-current thread. If
3960 so, then switch to that thread. */
3961 if (!ptid_equal (ecs->ptid, inferior_ptid))
3964 fprintf_unfiltered (gdb_stdlog, "infrun: context switch\n");
3966 context_switch (ecs->ptid);
3968 if (deprecated_context_hook)
3969 deprecated_context_hook (pid_to_thread_id (ecs->ptid));
3972 /* At this point, get hold of the now-current thread's frame. */
3973 frame = get_current_frame ();
3974 gdbarch = get_frame_arch (frame);
3976 if (singlestep_breakpoints_inserted_p)
3978 /* Pull the single step breakpoints out of the target. */
3979 remove_single_step_breakpoints ();
3980 singlestep_breakpoints_inserted_p = 0;
3983 if (stepped_after_stopped_by_watchpoint)
3984 stopped_by_watchpoint = 0;
3986 stopped_by_watchpoint = watchpoints_triggered (&ecs->ws);
3988 /* If necessary, step over this watchpoint. We'll be back to display
3990 if (stopped_by_watchpoint
3991 && (target_have_steppable_watchpoint
3992 || gdbarch_have_nonsteppable_watchpoint (gdbarch)))
3994 /* At this point, we are stopped at an instruction which has
3995 attempted to write to a piece of memory under control of
3996 a watchpoint. The instruction hasn't actually executed
3997 yet. If we were to evaluate the watchpoint expression
3998 now, we would get the old value, and therefore no change
3999 would seem to have occurred.
4001 In order to make watchpoints work `right', we really need
4002 to complete the memory write, and then evaluate the
4003 watchpoint expression. We do this by single-stepping the
4006 It may not be necessary to disable the watchpoint to stop over
4007 it. For example, the PA can (with some kernel cooperation)
4008 single step over a watchpoint without disabling the watchpoint.
4010 It is far more common to need to disable a watchpoint to step
4011 the inferior over it. If we have non-steppable watchpoints,
4012 we must disable the current watchpoint; it's simplest to
4013 disable all watchpoints and breakpoints. */
4016 if (!target_have_steppable_watchpoint)
4018 remove_breakpoints ();
4019 /* See comment in resume why we need to stop bypassing signals
4020 while breakpoints have been removed. */
4021 target_pass_signals (0, NULL);
4024 hw_step = maybe_software_singlestep (gdbarch, stop_pc);
4025 target_resume (ecs->ptid, hw_step, TARGET_SIGNAL_0);
4026 waiton_ptid = ecs->ptid;
4027 if (target_have_steppable_watchpoint)
4028 infwait_state = infwait_step_watch_state;
4030 infwait_state = infwait_nonstep_watch_state;
4031 prepare_to_wait (ecs);
4035 clear_stop_func (ecs);
4036 ecs->event_thread->stepping_over_breakpoint = 0;
4037 bpstat_clear (&ecs->event_thread->control.stop_bpstat);
4038 ecs->event_thread->control.stop_step = 0;
4039 stop_print_frame = 1;
4040 ecs->random_signal = 0;
4041 stopped_by_random_signal = 0;
4043 /* Hide inlined functions starting here, unless we just performed stepi or
4044 nexti. After stepi and nexti, always show the innermost frame (not any
4045 inline function call sites). */
4046 if (ecs->event_thread->control.step_range_end != 1)
4048 struct address_space *aspace =
4049 get_regcache_aspace (get_thread_regcache (ecs->ptid));
4051 /* skip_inline_frames is expensive, so we avoid it if we can
4052 determine that the address is one where functions cannot have
4053 been inlined. This improves performance with inferiors that
4054 load a lot of shared libraries, because the solib event
4055 breakpoint is defined as the address of a function (i.e. not
4056 inline). Note that we have to check the previous PC as well
4057 as the current one to catch cases when we have just
4058 single-stepped off a breakpoint prior to reinstating it.
4059 Note that we're assuming that the code we single-step to is
4060 not inline, but that's not definitive: there's nothing
4061 preventing the event breakpoint function from containing
4062 inlined code, and the single-step ending up there. If the
4063 user had set a breakpoint on that inlined code, the missing
4064 skip_inline_frames call would break things. Fortunately
4065 that's an extremely unlikely scenario. */
4066 if (!pc_at_non_inline_function (aspace, stop_pc)
4067 && !(ecs->event_thread->suspend.stop_signal == TARGET_SIGNAL_TRAP
4068 && ecs->event_thread->control.trap_expected
4069 && pc_at_non_inline_function (aspace,
4070 ecs->event_thread->prev_pc)))
4071 skip_inline_frames (ecs->ptid);
4074 if (ecs->event_thread->suspend.stop_signal == TARGET_SIGNAL_TRAP
4075 && ecs->event_thread->control.trap_expected
4076 && gdbarch_single_step_through_delay_p (gdbarch)
4077 && currently_stepping (ecs->event_thread))
4079 /* We're trying to step off a breakpoint. Turns out that we're
4080 also on an instruction that needs to be stepped multiple
4081 times before it's been fully executing. E.g., architectures
4082 with a delay slot. It needs to be stepped twice, once for
4083 the instruction and once for the delay slot. */
4084 int step_through_delay
4085 = gdbarch_single_step_through_delay (gdbarch, frame);
4087 if (debug_infrun && step_through_delay)
4088 fprintf_unfiltered (gdb_stdlog, "infrun: step through delay\n");
4089 if (ecs->event_thread->control.step_range_end == 0
4090 && step_through_delay)
4092 /* The user issued a continue when stopped at a breakpoint.
4093 Set up for another trap and get out of here. */
4094 ecs->event_thread->stepping_over_breakpoint = 1;
4098 else if (step_through_delay)
4100 /* The user issued a step when stopped at a breakpoint.
4101 Maybe we should stop, maybe we should not - the delay
4102 slot *might* correspond to a line of source. In any
4103 case, don't decide that here, just set
4104 ecs->stepping_over_breakpoint, making sure we
4105 single-step again before breakpoints are re-inserted. */
4106 ecs->event_thread->stepping_over_breakpoint = 1;
4110 /* Look at the cause of the stop, and decide what to do.
4111 The alternatives are:
4112 1) stop_stepping and return; to really stop and return to the debugger,
4113 2) keep_going and return to start up again
4114 (set ecs->event_thread->stepping_over_breakpoint to 1 to single step once)
4115 3) set ecs->random_signal to 1, and the decision between 1 and 2
4116 will be made according to the signal handling tables. */
4118 if (ecs->event_thread->suspend.stop_signal == TARGET_SIGNAL_TRAP
4119 || stop_soon == STOP_QUIETLY || stop_soon == STOP_QUIETLY_NO_SIGSTOP
4120 || stop_soon == STOP_QUIETLY_REMOTE)
4122 if (ecs->event_thread->suspend.stop_signal == TARGET_SIGNAL_TRAP
4126 fprintf_unfiltered (gdb_stdlog, "infrun: stopped\n");
4127 stop_print_frame = 0;
4128 stop_stepping (ecs);
4132 /* This is originated from start_remote(), start_inferior() and
4133 shared libraries hook functions. */
4134 if (stop_soon == STOP_QUIETLY || stop_soon == STOP_QUIETLY_REMOTE)
4137 fprintf_unfiltered (gdb_stdlog, "infrun: quietly stopped\n");
4138 stop_stepping (ecs);
4142 /* This originates from attach_command(). We need to overwrite
4143 the stop_signal here, because some kernels don't ignore a
4144 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
4145 See more comments in inferior.h. On the other hand, if we
4146 get a non-SIGSTOP, report it to the user - assume the backend
4147 will handle the SIGSTOP if it should show up later.
4149 Also consider that the attach is complete when we see a
4150 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
4151 target extended-remote report it instead of a SIGSTOP
4152 (e.g. gdbserver). We already rely on SIGTRAP being our
4153 signal, so this is no exception.
4155 Also consider that the attach is complete when we see a
4156 TARGET_SIGNAL_0. In non-stop mode, GDB will explicitly tell
4157 the target to stop all threads of the inferior, in case the
4158 low level attach operation doesn't stop them implicitly. If
4159 they weren't stopped implicitly, then the stub will report a
4160 TARGET_SIGNAL_0, meaning: stopped for no particular reason
4161 other than GDB's request. */
4162 if (stop_soon == STOP_QUIETLY_NO_SIGSTOP
4163 && (ecs->event_thread->suspend.stop_signal == TARGET_SIGNAL_STOP
4164 || ecs->event_thread->suspend.stop_signal == TARGET_SIGNAL_TRAP
4165 || ecs->event_thread->suspend.stop_signal == TARGET_SIGNAL_0))
4167 stop_stepping (ecs);
4168 ecs->event_thread->suspend.stop_signal = TARGET_SIGNAL_0;
4172 /* See if there is a breakpoint at the current PC. */
4173 ecs->event_thread->control.stop_bpstat
4174 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
4175 stop_pc, ecs->ptid);
4177 /* Following in case break condition called a
4179 stop_print_frame = 1;
4181 /* This is where we handle "moribund" watchpoints. Unlike
4182 software breakpoints traps, hardware watchpoint traps are
4183 always distinguishable from random traps. If no high-level
4184 watchpoint is associated with the reported stop data address
4185 anymore, then the bpstat does not explain the signal ---
4186 simply make sure to ignore it if `stopped_by_watchpoint' is
4190 && ecs->event_thread->suspend.stop_signal == TARGET_SIGNAL_TRAP
4191 && !bpstat_explains_signal (ecs->event_thread->control.stop_bpstat)
4192 && stopped_by_watchpoint)
4193 fprintf_unfiltered (gdb_stdlog,
4194 "infrun: no user watchpoint explains "
4195 "watchpoint SIGTRAP, ignoring\n");
4197 /* NOTE: cagney/2003-03-29: These two checks for a random signal
4198 at one stage in the past included checks for an inferior
4199 function call's call dummy's return breakpoint. The original
4200 comment, that went with the test, read:
4202 ``End of a stack dummy. Some systems (e.g. Sony news) give
4203 another signal besides SIGTRAP, so check here as well as
4206 If someone ever tries to get call dummys on a
4207 non-executable stack to work (where the target would stop
4208 with something like a SIGSEGV), then those tests might need
4209 to be re-instated. Given, however, that the tests were only
4210 enabled when momentary breakpoints were not being used, I
4211 suspect that it won't be the case.
4213 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
4214 be necessary for call dummies on a non-executable stack on
4217 if (ecs->event_thread->suspend.stop_signal == TARGET_SIGNAL_TRAP)
4219 = !(bpstat_explains_signal (ecs->event_thread->control.stop_bpstat)
4220 || stopped_by_watchpoint
4221 || ecs->event_thread->control.trap_expected
4222 || (ecs->event_thread->control.step_range_end
4223 && (ecs->event_thread->control.step_resume_breakpoint
4227 ecs->random_signal = !bpstat_explains_signal
4228 (ecs->event_thread->control.stop_bpstat);
4229 if (!ecs->random_signal)
4230 ecs->event_thread->suspend.stop_signal = TARGET_SIGNAL_TRAP;
4234 /* When we reach this point, we've pretty much decided
4235 that the reason for stopping must've been a random
4236 (unexpected) signal. */
4239 ecs->random_signal = 1;
4241 process_event_stop_test:
4243 /* Re-fetch current thread's frame in case we did a
4244 "goto process_event_stop_test" above. */
4245 frame = get_current_frame ();
4246 gdbarch = get_frame_arch (frame);
4248 /* For the program's own signals, act according to
4249 the signal handling tables. */
4251 if (ecs->random_signal)
4253 /* Signal not for debugging purposes. */
4255 struct inferior *inf = find_inferior_pid (ptid_get_pid (ecs->ptid));
4258 fprintf_unfiltered (gdb_stdlog, "infrun: random signal %d\n",
4259 ecs->event_thread->suspend.stop_signal);
4261 stopped_by_random_signal = 1;
4263 if (signal_print[ecs->event_thread->suspend.stop_signal])
4266 target_terminal_ours_for_output ();
4267 print_signal_received_reason
4268 (ecs->event_thread->suspend.stop_signal);
4270 /* Always stop on signals if we're either just gaining control
4271 of the program, or the user explicitly requested this thread
4272 to remain stopped. */
4273 if (stop_soon != NO_STOP_QUIETLY
4274 || ecs->event_thread->stop_requested
4276 && signal_stop_state (ecs->event_thread->suspend.stop_signal)))
4278 stop_stepping (ecs);
4281 /* If not going to stop, give terminal back
4282 if we took it away. */
4284 target_terminal_inferior ();
4286 /* Clear the signal if it should not be passed. */
4287 if (signal_program[ecs->event_thread->suspend.stop_signal] == 0)
4288 ecs->event_thread->suspend.stop_signal = TARGET_SIGNAL_0;
4290 if (ecs->event_thread->prev_pc == stop_pc
4291 && ecs->event_thread->control.trap_expected
4292 && ecs->event_thread->control.step_resume_breakpoint == NULL)
4294 /* We were just starting a new sequence, attempting to
4295 single-step off of a breakpoint and expecting a SIGTRAP.
4296 Instead this signal arrives. This signal will take us out
4297 of the stepping range so GDB needs to remember to, when
4298 the signal handler returns, resume stepping off that
4300 /* To simplify things, "continue" is forced to use the same
4301 code paths as single-step - set a breakpoint at the
4302 signal return address and then, once hit, step off that
4305 fprintf_unfiltered (gdb_stdlog,
4306 "infrun: signal arrived while stepping over "
4309 insert_hp_step_resume_breakpoint_at_frame (frame);
4310 ecs->event_thread->step_after_step_resume_breakpoint = 1;
4311 /* Reset trap_expected to ensure breakpoints are re-inserted. */
4312 ecs->event_thread->control.trap_expected = 0;
4317 if (ecs->event_thread->control.step_range_end != 0
4318 && ecs->event_thread->suspend.stop_signal != TARGET_SIGNAL_0
4319 && (ecs->event_thread->control.step_range_start <= stop_pc
4320 && stop_pc < ecs->event_thread->control.step_range_end)
4321 && frame_id_eq (get_stack_frame_id (frame),
4322 ecs->event_thread->control.step_stack_frame_id)
4323 && ecs->event_thread->control.step_resume_breakpoint == NULL)
4325 /* The inferior is about to take a signal that will take it
4326 out of the single step range. Set a breakpoint at the
4327 current PC (which is presumably where the signal handler
4328 will eventually return) and then allow the inferior to
4331 Note that this is only needed for a signal delivered
4332 while in the single-step range. Nested signals aren't a
4333 problem as they eventually all return. */
4335 fprintf_unfiltered (gdb_stdlog,
4336 "infrun: signal may take us out of "
4337 "single-step range\n");
4339 insert_hp_step_resume_breakpoint_at_frame (frame);
4340 /* Reset trap_expected to ensure breakpoints are re-inserted. */
4341 ecs->event_thread->control.trap_expected = 0;
4346 /* Note: step_resume_breakpoint may be non-NULL. This occures
4347 when either there's a nested signal, or when there's a
4348 pending signal enabled just as the signal handler returns
4349 (leaving the inferior at the step-resume-breakpoint without
4350 actually executing it). Either way continue until the
4351 breakpoint is really hit. */
4356 /* Handle cases caused by hitting a breakpoint. */
4358 CORE_ADDR jmp_buf_pc;
4359 struct bpstat_what what;
4361 what = bpstat_what (ecs->event_thread->control.stop_bpstat);
4363 if (what.call_dummy)
4365 stop_stack_dummy = what.call_dummy;
4368 /* If we hit an internal event that triggers symbol changes, the
4369 current frame will be invalidated within bpstat_what (e.g., if
4370 we hit an internal solib event). Re-fetch it. */
4371 frame = get_current_frame ();
4372 gdbarch = get_frame_arch (frame);
4374 switch (what.main_action)
4376 case BPSTAT_WHAT_SET_LONGJMP_RESUME:
4377 /* If we hit the breakpoint at longjmp while stepping, we
4378 install a momentary breakpoint at the target of the
4382 fprintf_unfiltered (gdb_stdlog,
4383 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME\n");
4385 ecs->event_thread->stepping_over_breakpoint = 1;
4387 if (what.is_longjmp)
4389 if (!gdbarch_get_longjmp_target_p (gdbarch)
4390 || !gdbarch_get_longjmp_target (gdbarch,
4391 frame, &jmp_buf_pc))
4394 fprintf_unfiltered (gdb_stdlog,
4395 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME "
4396 "(!gdbarch_get_longjmp_target)\n");
4401 /* We're going to replace the current step-resume breakpoint
4402 with a longjmp-resume breakpoint. */
4403 delete_step_resume_breakpoint (ecs->event_thread);
4405 /* Insert a breakpoint at resume address. */
4406 insert_longjmp_resume_breakpoint (gdbarch, jmp_buf_pc);
4410 struct symbol *func = get_frame_function (frame);
4413 check_exception_resume (ecs, frame, func);
4418 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME:
4420 fprintf_unfiltered (gdb_stdlog,
4421 "infrun: BPSTAT_WHAT_CLEAR_LONGJMP_RESUME\n");
4423 if (what.is_longjmp)
4425 gdb_assert (ecs->event_thread->control.step_resume_breakpoint
4427 delete_step_resume_breakpoint (ecs->event_thread);
4431 /* There are several cases to consider.
4433 1. The initiating frame no longer exists. In this case
4434 we must stop, because the exception has gone too far.
4436 2. The initiating frame exists, and is the same as the
4437 current frame. We stop, because the exception has been
4440 3. The initiating frame exists and is different from
4441 the current frame. This means the exception has been
4442 caught beneath the initiating frame, so keep going. */
4443 struct frame_info *init_frame
4444 = frame_find_by_id (ecs->event_thread->initiating_frame);
4446 gdb_assert (ecs->event_thread->control.exception_resume_breakpoint
4448 delete_exception_resume_breakpoint (ecs->event_thread);
4452 struct frame_id current_id
4453 = get_frame_id (get_current_frame ());
4454 if (frame_id_eq (current_id,
4455 ecs->event_thread->initiating_frame))
4457 /* Case 2. Fall through. */
4467 /* For Cases 1 and 2, remove the step-resume breakpoint,
4469 delete_step_resume_breakpoint (ecs->event_thread);
4472 ecs->event_thread->control.stop_step = 1;
4473 print_end_stepping_range_reason ();
4474 stop_stepping (ecs);
4477 case BPSTAT_WHAT_SINGLE:
4479 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_SINGLE\n");
4480 ecs->event_thread->stepping_over_breakpoint = 1;
4481 /* Still need to check other stuff, at least the case
4482 where we are stepping and step out of the right range. */
4485 case BPSTAT_WHAT_STEP_RESUME:
4487 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STEP_RESUME\n");
4489 delete_step_resume_breakpoint (ecs->event_thread);
4490 if (ecs->event_thread->control.proceed_to_finish
4491 && execution_direction == EXEC_REVERSE)
4493 struct thread_info *tp = ecs->event_thread;
4495 /* We are finishing a function in reverse, and just hit
4496 the step-resume breakpoint at the start address of the
4497 function, and we're almost there -- just need to back
4498 up by one more single-step, which should take us back
4499 to the function call. */
4500 tp->control.step_range_start = tp->control.step_range_end = 1;
4504 fill_in_stop_func (gdbarch, ecs);
4505 if (stop_pc == ecs->stop_func_start
4506 && execution_direction == EXEC_REVERSE)
4508 /* We are stepping over a function call in reverse, and
4509 just hit the step-resume breakpoint at the start
4510 address of the function. Go back to single-stepping,
4511 which should take us back to the function call. */
4512 ecs->event_thread->stepping_over_breakpoint = 1;
4518 case BPSTAT_WHAT_STOP_NOISY:
4520 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_NOISY\n");
4521 stop_print_frame = 1;
4523 /* We are about to nuke the step_resume_breakpointt via the
4524 cleanup chain, so no need to worry about it here. */
4526 stop_stepping (ecs);
4529 case BPSTAT_WHAT_STOP_SILENT:
4531 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_SILENT\n");
4532 stop_print_frame = 0;
4534 /* We are about to nuke the step_resume_breakpoin via the
4535 cleanup chain, so no need to worry about it here. */
4537 stop_stepping (ecs);
4540 case BPSTAT_WHAT_HP_STEP_RESUME:
4542 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_HP_STEP_RESUME\n");
4544 delete_step_resume_breakpoint (ecs->event_thread);
4545 if (ecs->event_thread->step_after_step_resume_breakpoint)
4547 /* Back when the step-resume breakpoint was inserted, we
4548 were trying to single-step off a breakpoint. Go back
4550 ecs->event_thread->step_after_step_resume_breakpoint = 0;
4551 ecs->event_thread->stepping_over_breakpoint = 1;
4557 case BPSTAT_WHAT_KEEP_CHECKING:
4562 /* We come here if we hit a breakpoint but should not
4563 stop for it. Possibly we also were stepping
4564 and should stop for that. So fall through and
4565 test for stepping. But, if not stepping,
4568 /* In all-stop mode, if we're currently stepping but have stopped in
4569 some other thread, we need to switch back to the stepped thread. */
4572 struct thread_info *tp;
4574 tp = iterate_over_threads (currently_stepping_or_nexting_callback,
4578 /* However, if the current thread is blocked on some internal
4579 breakpoint, and we simply need to step over that breakpoint
4580 to get it going again, do that first. */
4581 if ((ecs->event_thread->control.trap_expected
4582 && ecs->event_thread->suspend.stop_signal != TARGET_SIGNAL_TRAP)
4583 || ecs->event_thread->stepping_over_breakpoint)
4589 /* If the stepping thread exited, then don't try to switch
4590 back and resume it, which could fail in several different
4591 ways depending on the target. Instead, just keep going.
4593 We can find a stepping dead thread in the thread list in
4596 - The target supports thread exit events, and when the
4597 target tries to delete the thread from the thread list,
4598 inferior_ptid pointed at the exiting thread. In such
4599 case, calling delete_thread does not really remove the
4600 thread from the list; instead, the thread is left listed,
4601 with 'exited' state.
4603 - The target's debug interface does not support thread
4604 exit events, and so we have no idea whatsoever if the
4605 previously stepping thread is still alive. For that
4606 reason, we need to synchronously query the target
4608 if (is_exited (tp->ptid)
4609 || !target_thread_alive (tp->ptid))
4612 fprintf_unfiltered (gdb_stdlog,
4613 "infrun: not switching back to "
4614 "stepped thread, it has vanished\n");
4616 delete_thread (tp->ptid);
4621 /* Otherwise, we no longer expect a trap in the current thread.
4622 Clear the trap_expected flag before switching back -- this is
4623 what keep_going would do as well, if we called it. */
4624 ecs->event_thread->control.trap_expected = 0;
4627 fprintf_unfiltered (gdb_stdlog,
4628 "infrun: switching back to stepped thread\n");
4630 ecs->event_thread = tp;
4631 ecs->ptid = tp->ptid;
4632 context_switch (ecs->ptid);
4638 if (ecs->event_thread->control.step_resume_breakpoint)
4641 fprintf_unfiltered (gdb_stdlog,
4642 "infrun: step-resume breakpoint is inserted\n");
4644 /* Having a step-resume breakpoint overrides anything
4645 else having to do with stepping commands until
4646 that breakpoint is reached. */
4651 if (ecs->event_thread->control.step_range_end == 0)
4654 fprintf_unfiltered (gdb_stdlog, "infrun: no stepping, continue\n");
4655 /* Likewise if we aren't even stepping. */
4660 /* Re-fetch current thread's frame in case the code above caused
4661 the frame cache to be re-initialized, making our FRAME variable
4662 a dangling pointer. */
4663 frame = get_current_frame ();
4664 gdbarch = get_frame_arch (frame);
4665 fill_in_stop_func (gdbarch, ecs);
4667 /* If stepping through a line, keep going if still within it.
4669 Note that step_range_end is the address of the first instruction
4670 beyond the step range, and NOT the address of the last instruction
4673 Note also that during reverse execution, we may be stepping
4674 through a function epilogue and therefore must detect when
4675 the current-frame changes in the middle of a line. */
4677 if (stop_pc >= ecs->event_thread->control.step_range_start
4678 && stop_pc < ecs->event_thread->control.step_range_end
4679 && (execution_direction != EXEC_REVERSE
4680 || frame_id_eq (get_frame_id (frame),
4681 ecs->event_thread->control.step_frame_id)))
4685 (gdb_stdlog, "infrun: stepping inside range [%s-%s]\n",
4686 paddress (gdbarch, ecs->event_thread->control.step_range_start),
4687 paddress (gdbarch, ecs->event_thread->control.step_range_end));
4689 /* When stepping backward, stop at beginning of line range
4690 (unless it's the function entry point, in which case
4691 keep going back to the call point). */
4692 if (stop_pc == ecs->event_thread->control.step_range_start
4693 && stop_pc != ecs->stop_func_start
4694 && execution_direction == EXEC_REVERSE)
4696 ecs->event_thread->control.stop_step = 1;
4697 print_end_stepping_range_reason ();
4698 stop_stepping (ecs);
4706 /* We stepped out of the stepping range. */
4708 /* If we are stepping at the source level and entered the runtime
4709 loader dynamic symbol resolution code...
4711 EXEC_FORWARD: we keep on single stepping until we exit the run
4712 time loader code and reach the callee's address.
4714 EXEC_REVERSE: we've already executed the callee (backward), and
4715 the runtime loader code is handled just like any other
4716 undebuggable function call. Now we need only keep stepping
4717 backward through the trampoline code, and that's handled further
4718 down, so there is nothing for us to do here. */
4720 if (execution_direction != EXEC_REVERSE
4721 && ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
4722 && in_solib_dynsym_resolve_code (stop_pc))
4724 CORE_ADDR pc_after_resolver =
4725 gdbarch_skip_solib_resolver (gdbarch, stop_pc);
4728 fprintf_unfiltered (gdb_stdlog,
4729 "infrun: stepped into dynsym resolve code\n");
4731 if (pc_after_resolver)
4733 /* Set up a step-resume breakpoint at the address
4734 indicated by SKIP_SOLIB_RESOLVER. */
4735 struct symtab_and_line sr_sal;
4738 sr_sal.pc = pc_after_resolver;
4739 sr_sal.pspace = get_frame_program_space (frame);
4741 insert_step_resume_breakpoint_at_sal (gdbarch,
4742 sr_sal, null_frame_id);
4749 if (ecs->event_thread->control.step_range_end != 1
4750 && (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
4751 || ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
4752 && get_frame_type (frame) == SIGTRAMP_FRAME)
4755 fprintf_unfiltered (gdb_stdlog,
4756 "infrun: stepped into signal trampoline\n");
4757 /* The inferior, while doing a "step" or "next", has ended up in
4758 a signal trampoline (either by a signal being delivered or by
4759 the signal handler returning). Just single-step until the
4760 inferior leaves the trampoline (either by calling the handler
4766 /* Check for subroutine calls. The check for the current frame
4767 equalling the step ID is not necessary - the check of the
4768 previous frame's ID is sufficient - but it is a common case and
4769 cheaper than checking the previous frame's ID.
4771 NOTE: frame_id_eq will never report two invalid frame IDs as
4772 being equal, so to get into this block, both the current and
4773 previous frame must have valid frame IDs. */
4774 /* The outer_frame_id check is a heuristic to detect stepping
4775 through startup code. If we step over an instruction which
4776 sets the stack pointer from an invalid value to a valid value,
4777 we may detect that as a subroutine call from the mythical
4778 "outermost" function. This could be fixed by marking
4779 outermost frames as !stack_p,code_p,special_p. Then the
4780 initial outermost frame, before sp was valid, would
4781 have code_addr == &_start. See the comment in frame_id_eq
4783 if (!frame_id_eq (get_stack_frame_id (frame),
4784 ecs->event_thread->control.step_stack_frame_id)
4785 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
4786 ecs->event_thread->control.step_stack_frame_id)
4787 && (!frame_id_eq (ecs->event_thread->control.step_stack_frame_id,
4789 || step_start_function != find_pc_function (stop_pc))))
4791 CORE_ADDR real_stop_pc;
4794 fprintf_unfiltered (gdb_stdlog, "infrun: stepped into subroutine\n");
4796 if ((ecs->event_thread->control.step_over_calls == STEP_OVER_NONE)
4797 || ((ecs->event_thread->control.step_range_end == 1)
4798 && in_prologue (gdbarch, ecs->event_thread->prev_pc,
4799 ecs->stop_func_start)))
4801 /* I presume that step_over_calls is only 0 when we're
4802 supposed to be stepping at the assembly language level
4803 ("stepi"). Just stop. */
4804 /* Also, maybe we just did a "nexti" inside a prolog, so we
4805 thought it was a subroutine call but it was not. Stop as
4807 /* And this works the same backward as frontward. MVS */
4808 ecs->event_thread->control.stop_step = 1;
4809 print_end_stepping_range_reason ();
4810 stop_stepping (ecs);
4814 /* Reverse stepping through solib trampolines. */
4816 if (execution_direction == EXEC_REVERSE
4817 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE
4818 && (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc)
4819 || (ecs->stop_func_start == 0
4820 && in_solib_dynsym_resolve_code (stop_pc))))
4822 /* Any solib trampoline code can be handled in reverse
4823 by simply continuing to single-step. We have already
4824 executed the solib function (backwards), and a few
4825 steps will take us back through the trampoline to the
4831 if (ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
4833 /* We're doing a "next".
4835 Normal (forward) execution: set a breakpoint at the
4836 callee's return address (the address at which the caller
4839 Reverse (backward) execution. set the step-resume
4840 breakpoint at the start of the function that we just
4841 stepped into (backwards), and continue to there. When we
4842 get there, we'll need to single-step back to the caller. */
4844 if (execution_direction == EXEC_REVERSE)
4846 struct symtab_and_line sr_sal;
4848 /* Normal function call return (static or dynamic). */
4850 sr_sal.pc = ecs->stop_func_start;
4851 sr_sal.pspace = get_frame_program_space (frame);
4852 insert_step_resume_breakpoint_at_sal (gdbarch,
4853 sr_sal, null_frame_id);
4856 insert_step_resume_breakpoint_at_caller (frame);
4862 /* If we are in a function call trampoline (a stub between the
4863 calling routine and the real function), locate the real
4864 function. That's what tells us (a) whether we want to step
4865 into it at all, and (b) what prologue we want to run to the
4866 end of, if we do step into it. */
4867 real_stop_pc = skip_language_trampoline (frame, stop_pc);
4868 if (real_stop_pc == 0)
4869 real_stop_pc = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc);
4870 if (real_stop_pc != 0)
4871 ecs->stop_func_start = real_stop_pc;
4873 if (real_stop_pc != 0 && in_solib_dynsym_resolve_code (real_stop_pc))
4875 struct symtab_and_line sr_sal;
4878 sr_sal.pc = ecs->stop_func_start;
4879 sr_sal.pspace = get_frame_program_space (frame);
4881 insert_step_resume_breakpoint_at_sal (gdbarch,
4882 sr_sal, null_frame_id);
4887 /* If we have line number information for the function we are
4888 thinking of stepping into, step into it.
4890 If there are several symtabs at that PC (e.g. with include
4891 files), just want to know whether *any* of them have line
4892 numbers. find_pc_line handles this. */
4894 struct symtab_and_line tmp_sal;
4896 tmp_sal = find_pc_line (ecs->stop_func_start, 0);
4897 if (tmp_sal.line != 0)
4899 if (execution_direction == EXEC_REVERSE)
4900 handle_step_into_function_backward (gdbarch, ecs);
4902 handle_step_into_function (gdbarch, ecs);
4907 /* If we have no line number and the step-stop-if-no-debug is
4908 set, we stop the step so that the user has a chance to switch
4909 in assembly mode. */
4910 if (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
4911 && step_stop_if_no_debug)
4913 ecs->event_thread->control.stop_step = 1;
4914 print_end_stepping_range_reason ();
4915 stop_stepping (ecs);
4919 if (execution_direction == EXEC_REVERSE)
4921 /* Set a breakpoint at callee's start address.
4922 From there we can step once and be back in the caller. */
4923 struct symtab_and_line sr_sal;
4926 sr_sal.pc = ecs->stop_func_start;
4927 sr_sal.pspace = get_frame_program_space (frame);
4928 insert_step_resume_breakpoint_at_sal (gdbarch,
4929 sr_sal, null_frame_id);
4932 /* Set a breakpoint at callee's return address (the address
4933 at which the caller will resume). */
4934 insert_step_resume_breakpoint_at_caller (frame);
4940 /* Reverse stepping through solib trampolines. */
4942 if (execution_direction == EXEC_REVERSE
4943 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE)
4945 if (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc)
4946 || (ecs->stop_func_start == 0
4947 && in_solib_dynsym_resolve_code (stop_pc)))
4949 /* Any solib trampoline code can be handled in reverse
4950 by simply continuing to single-step. We have already
4951 executed the solib function (backwards), and a few
4952 steps will take us back through the trampoline to the
4957 else if (in_solib_dynsym_resolve_code (stop_pc))
4959 /* Stepped backward into the solib dynsym resolver.
4960 Set a breakpoint at its start and continue, then
4961 one more step will take us out. */
4962 struct symtab_and_line sr_sal;
4965 sr_sal.pc = ecs->stop_func_start;
4966 sr_sal.pspace = get_frame_program_space (frame);
4967 insert_step_resume_breakpoint_at_sal (gdbarch,
4968 sr_sal, null_frame_id);
4974 /* If we're in the return path from a shared library trampoline,
4975 we want to proceed through the trampoline when stepping. */
4976 if (gdbarch_in_solib_return_trampoline (gdbarch,
4977 stop_pc, ecs->stop_func_name))
4979 /* Determine where this trampoline returns. */
4980 CORE_ADDR real_stop_pc;
4982 real_stop_pc = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc);
4985 fprintf_unfiltered (gdb_stdlog,
4986 "infrun: stepped into solib return tramp\n");
4988 /* Only proceed through if we know where it's going. */
4991 /* And put the step-breakpoint there and go until there. */
4992 struct symtab_and_line sr_sal;
4994 init_sal (&sr_sal); /* initialize to zeroes */
4995 sr_sal.pc = real_stop_pc;
4996 sr_sal.section = find_pc_overlay (sr_sal.pc);
4997 sr_sal.pspace = get_frame_program_space (frame);
4999 /* Do not specify what the fp should be when we stop since
5000 on some machines the prologue is where the new fp value
5002 insert_step_resume_breakpoint_at_sal (gdbarch,
5003 sr_sal, null_frame_id);
5005 /* Restart without fiddling with the step ranges or
5012 stop_pc_sal = find_pc_line (stop_pc, 0);
5014 /* NOTE: tausq/2004-05-24: This if block used to be done before all
5015 the trampoline processing logic, however, there are some trampolines
5016 that have no names, so we should do trampoline handling first. */
5017 if (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
5018 && ecs->stop_func_name == NULL
5019 && stop_pc_sal.line == 0)
5022 fprintf_unfiltered (gdb_stdlog,
5023 "infrun: stepped into undebuggable function\n");
5025 /* The inferior just stepped into, or returned to, an
5026 undebuggable function (where there is no debugging information
5027 and no line number corresponding to the address where the
5028 inferior stopped). Since we want to skip this kind of code,
5029 we keep going until the inferior returns from this
5030 function - unless the user has asked us not to (via
5031 set step-mode) or we no longer know how to get back
5032 to the call site. */
5033 if (step_stop_if_no_debug
5034 || !frame_id_p (frame_unwind_caller_id (frame)))
5036 /* If we have no line number and the step-stop-if-no-debug
5037 is set, we stop the step so that the user has a chance to
5038 switch in assembly mode. */
5039 ecs->event_thread->control.stop_step = 1;
5040 print_end_stepping_range_reason ();
5041 stop_stepping (ecs);
5046 /* Set a breakpoint at callee's return address (the address
5047 at which the caller will resume). */
5048 insert_step_resume_breakpoint_at_caller (frame);
5054 if (ecs->event_thread->control.step_range_end == 1)
5056 /* It is stepi or nexti. We always want to stop stepping after
5059 fprintf_unfiltered (gdb_stdlog, "infrun: stepi/nexti\n");
5060 ecs->event_thread->control.stop_step = 1;
5061 print_end_stepping_range_reason ();
5062 stop_stepping (ecs);
5066 if (stop_pc_sal.line == 0)
5068 /* We have no line number information. That means to stop
5069 stepping (does this always happen right after one instruction,
5070 when we do "s" in a function with no line numbers,
5071 or can this happen as a result of a return or longjmp?). */
5073 fprintf_unfiltered (gdb_stdlog, "infrun: no line number info\n");
5074 ecs->event_thread->control.stop_step = 1;
5075 print_end_stepping_range_reason ();
5076 stop_stepping (ecs);
5080 /* Look for "calls" to inlined functions, part one. If the inline
5081 frame machinery detected some skipped call sites, we have entered
5082 a new inline function. */
5084 if (frame_id_eq (get_frame_id (get_current_frame ()),
5085 ecs->event_thread->control.step_frame_id)
5086 && inline_skipped_frames (ecs->ptid))
5088 struct symtab_and_line call_sal;
5091 fprintf_unfiltered (gdb_stdlog,
5092 "infrun: stepped into inlined function\n");
5094 find_frame_sal (get_current_frame (), &call_sal);
5096 if (ecs->event_thread->control.step_over_calls != STEP_OVER_ALL)
5098 /* For "step", we're going to stop. But if the call site
5099 for this inlined function is on the same source line as
5100 we were previously stepping, go down into the function
5101 first. Otherwise stop at the call site. */
5103 if (call_sal.line == ecs->event_thread->current_line
5104 && call_sal.symtab == ecs->event_thread->current_symtab)
5105 step_into_inline_frame (ecs->ptid);
5107 ecs->event_thread->control.stop_step = 1;
5108 print_end_stepping_range_reason ();
5109 stop_stepping (ecs);
5114 /* For "next", we should stop at the call site if it is on a
5115 different source line. Otherwise continue through the
5116 inlined function. */
5117 if (call_sal.line == ecs->event_thread->current_line
5118 && call_sal.symtab == ecs->event_thread->current_symtab)
5122 ecs->event_thread->control.stop_step = 1;
5123 print_end_stepping_range_reason ();
5124 stop_stepping (ecs);
5130 /* Look for "calls" to inlined functions, part two. If we are still
5131 in the same real function we were stepping through, but we have
5132 to go further up to find the exact frame ID, we are stepping
5133 through a more inlined call beyond its call site. */
5135 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
5136 && !frame_id_eq (get_frame_id (get_current_frame ()),
5137 ecs->event_thread->control.step_frame_id)
5138 && stepped_in_from (get_current_frame (),
5139 ecs->event_thread->control.step_frame_id))
5142 fprintf_unfiltered (gdb_stdlog,
5143 "infrun: stepping through inlined function\n");
5145 if (ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
5149 ecs->event_thread->control.stop_step = 1;
5150 print_end_stepping_range_reason ();
5151 stop_stepping (ecs);
5156 if ((stop_pc == stop_pc_sal.pc)
5157 && (ecs->event_thread->current_line != stop_pc_sal.line
5158 || ecs->event_thread->current_symtab != stop_pc_sal.symtab))
5160 /* We are at the start of a different line. So stop. Note that
5161 we don't stop if we step into the middle of a different line.
5162 That is said to make things like for (;;) statements work
5165 fprintf_unfiltered (gdb_stdlog,
5166 "infrun: stepped to a different line\n");
5167 ecs->event_thread->control.stop_step = 1;
5168 print_end_stepping_range_reason ();
5169 stop_stepping (ecs);
5173 /* We aren't done stepping.
5175 Optimize by setting the stepping range to the line.
5176 (We might not be in the original line, but if we entered a
5177 new line in mid-statement, we continue stepping. This makes
5178 things like for(;;) statements work better.) */
5180 ecs->event_thread->control.step_range_start = stop_pc_sal.pc;
5181 ecs->event_thread->control.step_range_end = stop_pc_sal.end;
5182 set_step_info (frame, stop_pc_sal);
5185 fprintf_unfiltered (gdb_stdlog, "infrun: keep going\n");
5189 /* Is thread TP in the middle of single-stepping? */
5192 currently_stepping (struct thread_info *tp)
5194 return ((tp->control.step_range_end
5195 && tp->control.step_resume_breakpoint == NULL)
5196 || tp->control.trap_expected
5197 || bpstat_should_step ());
5200 /* Returns true if any thread *but* the one passed in "data" is in the
5201 middle of stepping or of handling a "next". */
5204 currently_stepping_or_nexting_callback (struct thread_info *tp, void *data)
5209 return (tp->control.step_range_end
5210 || tp->control.trap_expected);
5213 /* Inferior has stepped into a subroutine call with source code that
5214 we should not step over. Do step to the first line of code in
5218 handle_step_into_function (struct gdbarch *gdbarch,
5219 struct execution_control_state *ecs)
5222 struct symtab_and_line stop_func_sal, sr_sal;
5224 fill_in_stop_func (gdbarch, ecs);
5226 s = find_pc_symtab (stop_pc);
5227 if (s && s->language != language_asm)
5228 ecs->stop_func_start = gdbarch_skip_prologue (gdbarch,
5229 ecs->stop_func_start);
5231 stop_func_sal = find_pc_line (ecs->stop_func_start, 0);
5232 /* Use the step_resume_break to step until the end of the prologue,
5233 even if that involves jumps (as it seems to on the vax under
5235 /* If the prologue ends in the middle of a source line, continue to
5236 the end of that source line (if it is still within the function).
5237 Otherwise, just go to end of prologue. */
5238 if (stop_func_sal.end
5239 && stop_func_sal.pc != ecs->stop_func_start
5240 && stop_func_sal.end < ecs->stop_func_end)
5241 ecs->stop_func_start = stop_func_sal.end;
5243 /* Architectures which require breakpoint adjustment might not be able
5244 to place a breakpoint at the computed address. If so, the test
5245 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
5246 ecs->stop_func_start to an address at which a breakpoint may be
5247 legitimately placed.
5249 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
5250 made, GDB will enter an infinite loop when stepping through
5251 optimized code consisting of VLIW instructions which contain
5252 subinstructions corresponding to different source lines. On
5253 FR-V, it's not permitted to place a breakpoint on any but the
5254 first subinstruction of a VLIW instruction. When a breakpoint is
5255 set, GDB will adjust the breakpoint address to the beginning of
5256 the VLIW instruction. Thus, we need to make the corresponding
5257 adjustment here when computing the stop address. */
5259 if (gdbarch_adjust_breakpoint_address_p (gdbarch))
5261 ecs->stop_func_start
5262 = gdbarch_adjust_breakpoint_address (gdbarch,
5263 ecs->stop_func_start);
5266 if (ecs->stop_func_start == stop_pc)
5268 /* We are already there: stop now. */
5269 ecs->event_thread->control.stop_step = 1;
5270 print_end_stepping_range_reason ();
5271 stop_stepping (ecs);
5276 /* Put the step-breakpoint there and go until there. */
5277 init_sal (&sr_sal); /* initialize to zeroes */
5278 sr_sal.pc = ecs->stop_func_start;
5279 sr_sal.section = find_pc_overlay (ecs->stop_func_start);
5280 sr_sal.pspace = get_frame_program_space (get_current_frame ());
5282 /* Do not specify what the fp should be when we stop since on
5283 some machines the prologue is where the new fp value is
5285 insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal, null_frame_id);
5287 /* And make sure stepping stops right away then. */
5288 ecs->event_thread->control.step_range_end
5289 = ecs->event_thread->control.step_range_start;
5294 /* Inferior has stepped backward into a subroutine call with source
5295 code that we should not step over. Do step to the beginning of the
5296 last line of code in it. */
5299 handle_step_into_function_backward (struct gdbarch *gdbarch,
5300 struct execution_control_state *ecs)
5303 struct symtab_and_line stop_func_sal;
5305 fill_in_stop_func (gdbarch, ecs);
5307 s = find_pc_symtab (stop_pc);
5308 if (s && s->language != language_asm)
5309 ecs->stop_func_start = gdbarch_skip_prologue (gdbarch,
5310 ecs->stop_func_start);
5312 stop_func_sal = find_pc_line (stop_pc, 0);
5314 /* OK, we're just going to keep stepping here. */
5315 if (stop_func_sal.pc == stop_pc)
5317 /* We're there already. Just stop stepping now. */
5318 ecs->event_thread->control.stop_step = 1;
5319 print_end_stepping_range_reason ();
5320 stop_stepping (ecs);
5324 /* Else just reset the step range and keep going.
5325 No step-resume breakpoint, they don't work for
5326 epilogues, which can have multiple entry paths. */
5327 ecs->event_thread->control.step_range_start = stop_func_sal.pc;
5328 ecs->event_thread->control.step_range_end = stop_func_sal.end;
5334 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
5335 This is used to both functions and to skip over code. */
5338 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch *gdbarch,
5339 struct symtab_and_line sr_sal,
5340 struct frame_id sr_id,
5341 enum bptype sr_type)
5343 /* There should never be more than one step-resume or longjmp-resume
5344 breakpoint per thread, so we should never be setting a new
5345 step_resume_breakpoint when one is already active. */
5346 gdb_assert (inferior_thread ()->control.step_resume_breakpoint == NULL);
5347 gdb_assert (sr_type == bp_step_resume || sr_type == bp_hp_step_resume);
5350 fprintf_unfiltered (gdb_stdlog,
5351 "infrun: inserting step-resume breakpoint at %s\n",
5352 paddress (gdbarch, sr_sal.pc));
5354 inferior_thread ()->control.step_resume_breakpoint
5355 = set_momentary_breakpoint (gdbarch, sr_sal, sr_id, sr_type);
5359 insert_step_resume_breakpoint_at_sal (struct gdbarch *gdbarch,
5360 struct symtab_and_line sr_sal,
5361 struct frame_id sr_id)
5363 insert_step_resume_breakpoint_at_sal_1 (gdbarch,
5368 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
5369 This is used to skip a potential signal handler.
5371 This is called with the interrupted function's frame. The signal
5372 handler, when it returns, will resume the interrupted function at
5376 insert_hp_step_resume_breakpoint_at_frame (struct frame_info *return_frame)
5378 struct symtab_and_line sr_sal;
5379 struct gdbarch *gdbarch;
5381 gdb_assert (return_frame != NULL);
5382 init_sal (&sr_sal); /* initialize to zeros */
5384 gdbarch = get_frame_arch (return_frame);
5385 sr_sal.pc = gdbarch_addr_bits_remove (gdbarch, get_frame_pc (return_frame));
5386 sr_sal.section = find_pc_overlay (sr_sal.pc);
5387 sr_sal.pspace = get_frame_program_space (return_frame);
5389 insert_step_resume_breakpoint_at_sal_1 (gdbarch, sr_sal,
5390 get_stack_frame_id (return_frame),
5394 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
5395 is used to skip a function after stepping into it (for "next" or if
5396 the called function has no debugging information).
5398 The current function has almost always been reached by single
5399 stepping a call or return instruction. NEXT_FRAME belongs to the
5400 current function, and the breakpoint will be set at the caller's
5403 This is a separate function rather than reusing
5404 insert_hp_step_resume_breakpoint_at_frame in order to avoid
5405 get_prev_frame, which may stop prematurely (see the implementation
5406 of frame_unwind_caller_id for an example). */
5409 insert_step_resume_breakpoint_at_caller (struct frame_info *next_frame)
5411 struct symtab_and_line sr_sal;
5412 struct gdbarch *gdbarch;
5414 /* We shouldn't have gotten here if we don't know where the call site
5416 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame)));
5418 init_sal (&sr_sal); /* initialize to zeros */
5420 gdbarch = frame_unwind_caller_arch (next_frame);
5421 sr_sal.pc = gdbarch_addr_bits_remove (gdbarch,
5422 frame_unwind_caller_pc (next_frame));
5423 sr_sal.section = find_pc_overlay (sr_sal.pc);
5424 sr_sal.pspace = frame_unwind_program_space (next_frame);
5426 insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal,
5427 frame_unwind_caller_id (next_frame));
5430 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
5431 new breakpoint at the target of a jmp_buf. The handling of
5432 longjmp-resume uses the same mechanisms used for handling
5433 "step-resume" breakpoints. */
5436 insert_longjmp_resume_breakpoint (struct gdbarch *gdbarch, CORE_ADDR pc)
5438 /* There should never be more than one step-resume or longjmp-resume
5439 breakpoint per thread, so we should never be setting a new
5440 longjmp_resume_breakpoint when one is already active. */
5441 gdb_assert (inferior_thread ()->control.step_resume_breakpoint == NULL);
5444 fprintf_unfiltered (gdb_stdlog,
5445 "infrun: inserting longjmp-resume breakpoint at %s\n",
5446 paddress (gdbarch, pc));
5448 inferior_thread ()->control.step_resume_breakpoint =
5449 set_momentary_breakpoint_at_pc (gdbarch, pc, bp_longjmp_resume);
5452 /* Insert an exception resume breakpoint. TP is the thread throwing
5453 the exception. The block B is the block of the unwinder debug hook
5454 function. FRAME is the frame corresponding to the call to this
5455 function. SYM is the symbol of the function argument holding the
5456 target PC of the exception. */
5459 insert_exception_resume_breakpoint (struct thread_info *tp,
5461 struct frame_info *frame,
5464 struct gdb_exception e;
5466 /* We want to ignore errors here. */
5467 TRY_CATCH (e, RETURN_MASK_ERROR)
5469 struct symbol *vsym;
5470 struct value *value;
5472 struct breakpoint *bp;
5474 vsym = lookup_symbol (SYMBOL_LINKAGE_NAME (sym), b, VAR_DOMAIN, NULL);
5475 value = read_var_value (vsym, frame);
5476 /* If the value was optimized out, revert to the old behavior. */
5477 if (! value_optimized_out (value))
5479 handler = value_as_address (value);
5482 fprintf_unfiltered (gdb_stdlog,
5483 "infrun: exception resume at %lx\n",
5484 (unsigned long) handler);
5486 bp = set_momentary_breakpoint_at_pc (get_frame_arch (frame),
5487 handler, bp_exception_resume);
5488 bp->thread = tp->num;
5489 inferior_thread ()->control.exception_resume_breakpoint = bp;
5494 /* This is called when an exception has been intercepted. Check to
5495 see whether the exception's destination is of interest, and if so,
5496 set an exception resume breakpoint there. */
5499 check_exception_resume (struct execution_control_state *ecs,
5500 struct frame_info *frame, struct symbol *func)
5502 struct gdb_exception e;
5504 TRY_CATCH (e, RETURN_MASK_ERROR)
5507 struct dict_iterator iter;
5511 /* The exception breakpoint is a thread-specific breakpoint on
5512 the unwinder's debug hook, declared as:
5514 void _Unwind_DebugHook (void *cfa, void *handler);
5516 The CFA argument indicates the frame to which control is
5517 about to be transferred. HANDLER is the destination PC.
5519 We ignore the CFA and set a temporary breakpoint at HANDLER.
5520 This is not extremely efficient but it avoids issues in gdb
5521 with computing the DWARF CFA, and it also works even in weird
5522 cases such as throwing an exception from inside a signal
5525 b = SYMBOL_BLOCK_VALUE (func);
5526 ALL_BLOCK_SYMBOLS (b, iter, sym)
5528 if (!SYMBOL_IS_ARGUMENT (sym))
5535 insert_exception_resume_breakpoint (ecs->event_thread,
5544 stop_stepping (struct execution_control_state *ecs)
5547 fprintf_unfiltered (gdb_stdlog, "infrun: stop_stepping\n");
5549 /* Let callers know we don't want to wait for the inferior anymore. */
5550 ecs->wait_some_more = 0;
5553 /* This function handles various cases where we need to continue
5554 waiting for the inferior. */
5555 /* (Used to be the keep_going: label in the old wait_for_inferior). */
5558 keep_going (struct execution_control_state *ecs)
5560 /* Make sure normal_stop is called if we get a QUIT handled before
5562 struct cleanup *old_cleanups = make_cleanup (resume_cleanups, 0);
5564 /* Save the pc before execution, to compare with pc after stop. */
5565 ecs->event_thread->prev_pc
5566 = regcache_read_pc (get_thread_regcache (ecs->ptid));
5568 /* If we did not do break;, it means we should keep running the
5569 inferior and not return to debugger. */
5571 if (ecs->event_thread->control.trap_expected
5572 && ecs->event_thread->suspend.stop_signal != TARGET_SIGNAL_TRAP)
5574 /* We took a signal (which we are supposed to pass through to
5575 the inferior, else we'd not get here) and we haven't yet
5576 gotten our trap. Simply continue. */
5578 discard_cleanups (old_cleanups);
5579 resume (currently_stepping (ecs->event_thread),
5580 ecs->event_thread->suspend.stop_signal);
5584 /* Either the trap was not expected, but we are continuing
5585 anyway (the user asked that this signal be passed to the
5588 The signal was SIGTRAP, e.g. it was our signal, but we
5589 decided we should resume from it.
5591 We're going to run this baby now!
5593 Note that insert_breakpoints won't try to re-insert
5594 already inserted breakpoints. Therefore, we don't
5595 care if breakpoints were already inserted, or not. */
5597 if (ecs->event_thread->stepping_over_breakpoint)
5599 struct regcache *thread_regcache = get_thread_regcache (ecs->ptid);
5601 if (!use_displaced_stepping (get_regcache_arch (thread_regcache)))
5602 /* Since we can't do a displaced step, we have to remove
5603 the breakpoint while we step it. To keep things
5604 simple, we remove them all. */
5605 remove_breakpoints ();
5609 struct gdb_exception e;
5611 /* Stop stepping when inserting breakpoints
5613 TRY_CATCH (e, RETURN_MASK_ERROR)
5615 insert_breakpoints ();
5619 exception_print (gdb_stderr, e);
5620 stop_stepping (ecs);
5625 ecs->event_thread->control.trap_expected
5626 = ecs->event_thread->stepping_over_breakpoint;
5628 /* Do not deliver SIGNAL_TRAP (except when the user explicitly
5629 specifies that such a signal should be delivered to the
5632 Typically, this would occure when a user is debugging a
5633 target monitor on a simulator: the target monitor sets a
5634 breakpoint; the simulator encounters this break-point and
5635 halts the simulation handing control to GDB; GDB, noteing
5636 that the break-point isn't valid, returns control back to the
5637 simulator; the simulator then delivers the hardware
5638 equivalent of a SIGNAL_TRAP to the program being debugged. */
5640 if (ecs->event_thread->suspend.stop_signal == TARGET_SIGNAL_TRAP
5641 && !signal_program[ecs->event_thread->suspend.stop_signal])
5642 ecs->event_thread->suspend.stop_signal = TARGET_SIGNAL_0;
5644 discard_cleanups (old_cleanups);
5645 resume (currently_stepping (ecs->event_thread),
5646 ecs->event_thread->suspend.stop_signal);
5649 prepare_to_wait (ecs);
5652 /* This function normally comes after a resume, before
5653 handle_inferior_event exits. It takes care of any last bits of
5654 housekeeping, and sets the all-important wait_some_more flag. */
5657 prepare_to_wait (struct execution_control_state *ecs)
5660 fprintf_unfiltered (gdb_stdlog, "infrun: prepare_to_wait\n");
5662 /* This is the old end of the while loop. Let everybody know we
5663 want to wait for the inferior some more and get called again
5665 ecs->wait_some_more = 1;
5668 /* Several print_*_reason functions to print why the inferior has stopped.
5669 We always print something when the inferior exits, or receives a signal.
5670 The rest of the cases are dealt with later on in normal_stop and
5671 print_it_typical. Ideally there should be a call to one of these
5672 print_*_reason functions functions from handle_inferior_event each time
5673 stop_stepping is called. */
5675 /* Print why the inferior has stopped.
5676 We are done with a step/next/si/ni command, print why the inferior has
5677 stopped. For now print nothing. Print a message only if not in the middle
5678 of doing a "step n" operation for n > 1. */
5681 print_end_stepping_range_reason (void)
5683 if ((!inferior_thread ()->step_multi
5684 || !inferior_thread ()->control.stop_step)
5685 && ui_out_is_mi_like_p (current_uiout))
5686 ui_out_field_string (current_uiout, "reason",
5687 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE));
5690 /* The inferior was terminated by a signal, print why it stopped. */
5693 print_signal_exited_reason (enum target_signal siggnal)
5695 struct ui_out *uiout = current_uiout;
5697 annotate_signalled ();
5698 if (ui_out_is_mi_like_p (uiout))
5700 (uiout, "reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED));
5701 ui_out_text (uiout, "\nProgram terminated with signal ");
5702 annotate_signal_name ();
5703 ui_out_field_string (uiout, "signal-name",
5704 target_signal_to_name (siggnal));
5705 annotate_signal_name_end ();
5706 ui_out_text (uiout, ", ");
5707 annotate_signal_string ();
5708 ui_out_field_string (uiout, "signal-meaning",
5709 target_signal_to_string (siggnal));
5710 annotate_signal_string_end ();
5711 ui_out_text (uiout, ".\n");
5712 ui_out_text (uiout, "The program no longer exists.\n");
5715 /* The inferior program is finished, print why it stopped. */
5718 print_exited_reason (int exitstatus)
5720 struct inferior *inf = current_inferior ();
5721 const char *pidstr = target_pid_to_str (pid_to_ptid (inf->pid));
5722 struct ui_out *uiout = current_uiout;
5724 annotate_exited (exitstatus);
5727 if (ui_out_is_mi_like_p (uiout))
5728 ui_out_field_string (uiout, "reason",
5729 async_reason_lookup (EXEC_ASYNC_EXITED));
5730 ui_out_text (uiout, "[Inferior ");
5731 ui_out_text (uiout, plongest (inf->num));
5732 ui_out_text (uiout, " (");
5733 ui_out_text (uiout, pidstr);
5734 ui_out_text (uiout, ") exited with code ");
5735 ui_out_field_fmt (uiout, "exit-code", "0%o", (unsigned int) exitstatus);
5736 ui_out_text (uiout, "]\n");
5740 if (ui_out_is_mi_like_p (uiout))
5742 (uiout, "reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY));
5743 ui_out_text (uiout, "[Inferior ");
5744 ui_out_text (uiout, plongest (inf->num));
5745 ui_out_text (uiout, " (");
5746 ui_out_text (uiout, pidstr);
5747 ui_out_text (uiout, ") exited normally]\n");
5749 /* Support the --return-child-result option. */
5750 return_child_result_value = exitstatus;
5753 /* Signal received, print why the inferior has stopped. The signal table
5754 tells us to print about it. */
5757 print_signal_received_reason (enum target_signal siggnal)
5759 struct ui_out *uiout = current_uiout;
5763 if (siggnal == TARGET_SIGNAL_0 && !ui_out_is_mi_like_p (uiout))
5765 struct thread_info *t = inferior_thread ();
5767 ui_out_text (uiout, "\n[");
5768 ui_out_field_string (uiout, "thread-name",
5769 target_pid_to_str (t->ptid));
5770 ui_out_field_fmt (uiout, "thread-id", "] #%d", t->num);
5771 ui_out_text (uiout, " stopped");
5775 ui_out_text (uiout, "\nProgram received signal ");
5776 annotate_signal_name ();
5777 if (ui_out_is_mi_like_p (uiout))
5779 (uiout, "reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED));
5780 ui_out_field_string (uiout, "signal-name",
5781 target_signal_to_name (siggnal));
5782 annotate_signal_name_end ();
5783 ui_out_text (uiout, ", ");
5784 annotate_signal_string ();
5785 ui_out_field_string (uiout, "signal-meaning",
5786 target_signal_to_string (siggnal));
5787 annotate_signal_string_end ();
5789 ui_out_text (uiout, ".\n");
5792 /* Reverse execution: target ran out of history info, print why the inferior
5796 print_no_history_reason (void)
5798 ui_out_text (current_uiout, "\nNo more reverse-execution history.\n");
5801 /* Here to return control to GDB when the inferior stops for real.
5802 Print appropriate messages, remove breakpoints, give terminal our modes.
5804 STOP_PRINT_FRAME nonzero means print the executing frame
5805 (pc, function, args, file, line number and line text).
5806 BREAKPOINTS_FAILED nonzero means stop was due to error
5807 attempting to insert breakpoints. */
5812 struct target_waitstatus last;
5814 struct cleanup *old_chain = make_cleanup (null_cleanup, NULL);
5816 get_last_target_status (&last_ptid, &last);
5818 /* If an exception is thrown from this point on, make sure to
5819 propagate GDB's knowledge of the executing state to the
5820 frontend/user running state. A QUIT is an easy exception to see
5821 here, so do this before any filtered output. */
5823 make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
5824 else if (last.kind != TARGET_WAITKIND_SIGNALLED
5825 && last.kind != TARGET_WAITKIND_EXITED)
5826 make_cleanup (finish_thread_state_cleanup, &inferior_ptid);
5828 /* In non-stop mode, we don't want GDB to switch threads behind the
5829 user's back, to avoid races where the user is typing a command to
5830 apply to thread x, but GDB switches to thread y before the user
5831 finishes entering the command. */
5833 /* As with the notification of thread events, we want to delay
5834 notifying the user that we've switched thread context until
5835 the inferior actually stops.
5837 There's no point in saying anything if the inferior has exited.
5838 Note that SIGNALLED here means "exited with a signal", not
5839 "received a signal". */
5841 && !ptid_equal (previous_inferior_ptid, inferior_ptid)
5842 && target_has_execution
5843 && last.kind != TARGET_WAITKIND_SIGNALLED
5844 && last.kind != TARGET_WAITKIND_EXITED)
5846 target_terminal_ours_for_output ();
5847 printf_filtered (_("[Switching to %s]\n"),
5848 target_pid_to_str (inferior_ptid));
5849 annotate_thread_changed ();
5850 previous_inferior_ptid = inferior_ptid;
5853 if (!breakpoints_always_inserted_mode () && target_has_execution)
5855 if (remove_breakpoints ())
5857 target_terminal_ours_for_output ();
5858 printf_filtered (_("Cannot remove breakpoints because "
5859 "program is no longer writable.\nFurther "
5860 "execution is probably impossible.\n"));
5864 /* If an auto-display called a function and that got a signal,
5865 delete that auto-display to avoid an infinite recursion. */
5867 if (stopped_by_random_signal)
5868 disable_current_display ();
5870 /* Don't print a message if in the middle of doing a "step n"
5871 operation for n > 1 */
5872 if (target_has_execution
5873 && last.kind != TARGET_WAITKIND_SIGNALLED
5874 && last.kind != TARGET_WAITKIND_EXITED
5875 && inferior_thread ()->step_multi
5876 && inferior_thread ()->control.stop_step)
5879 target_terminal_ours ();
5880 async_enable_stdin ();
5882 /* Set the current source location. This will also happen if we
5883 display the frame below, but the current SAL will be incorrect
5884 during a user hook-stop function. */
5885 if (has_stack_frames () && !stop_stack_dummy)
5886 set_current_sal_from_frame (get_current_frame (), 1);
5888 /* Let the user/frontend see the threads as stopped. */
5889 do_cleanups (old_chain);
5891 /* Look up the hook_stop and run it (CLI internally handles problem
5892 of stop_command's pre-hook not existing). */
5894 catch_errors (hook_stop_stub, stop_command,
5895 "Error while running hook_stop:\n", RETURN_MASK_ALL);
5897 if (!has_stack_frames ())
5900 if (last.kind == TARGET_WAITKIND_SIGNALLED
5901 || last.kind == TARGET_WAITKIND_EXITED)
5904 /* Select innermost stack frame - i.e., current frame is frame 0,
5905 and current location is based on that.
5906 Don't do this on return from a stack dummy routine,
5907 or if the program has exited. */
5909 if (!stop_stack_dummy)
5911 select_frame (get_current_frame ());
5913 /* Print current location without a level number, if
5914 we have changed functions or hit a breakpoint.
5915 Print source line if we have one.
5916 bpstat_print() contains the logic deciding in detail
5917 what to print, based on the event(s) that just occurred. */
5919 /* If --batch-silent is enabled then there's no need to print the current
5920 source location, and to try risks causing an error message about
5921 missing source files. */
5922 if (stop_print_frame && !batch_silent)
5926 int do_frame_printing = 1;
5927 struct thread_info *tp = inferior_thread ();
5929 bpstat_ret = bpstat_print (tp->control.stop_bpstat);
5933 /* If we had hit a shared library event breakpoint,
5934 bpstat_print would print out this message. If we hit
5935 an OS-level shared library event, do the same
5937 if (last.kind == TARGET_WAITKIND_LOADED)
5939 printf_filtered (_("Stopped due to shared library event\n"));
5940 source_flag = SRC_LINE; /* something bogus */
5941 do_frame_printing = 0;
5945 /* FIXME: cagney/2002-12-01: Given that a frame ID does
5946 (or should) carry around the function and does (or
5947 should) use that when doing a frame comparison. */
5948 if (tp->control.stop_step
5949 && frame_id_eq (tp->control.step_frame_id,
5950 get_frame_id (get_current_frame ()))
5951 && step_start_function == find_pc_function (stop_pc))
5952 source_flag = SRC_LINE; /* Finished step, just
5953 print source line. */
5955 source_flag = SRC_AND_LOC; /* Print location and
5958 case PRINT_SRC_AND_LOC:
5959 source_flag = SRC_AND_LOC; /* Print location and
5962 case PRINT_SRC_ONLY:
5963 source_flag = SRC_LINE;
5966 source_flag = SRC_LINE; /* something bogus */
5967 do_frame_printing = 0;
5970 internal_error (__FILE__, __LINE__, _("Unknown value."));
5973 /* The behavior of this routine with respect to the source
5975 SRC_LINE: Print only source line
5976 LOCATION: Print only location
5977 SRC_AND_LOC: Print location and source line. */
5978 if (do_frame_printing)
5979 print_stack_frame (get_selected_frame (NULL), 0, source_flag);
5981 /* Display the auto-display expressions. */
5986 /* Save the function value return registers, if we care.
5987 We might be about to restore their previous contents. */
5988 if (inferior_thread ()->control.proceed_to_finish
5989 && execution_direction != EXEC_REVERSE)
5991 /* This should not be necessary. */
5993 regcache_xfree (stop_registers);
5995 /* NB: The copy goes through to the target picking up the value of
5996 all the registers. */
5997 stop_registers = regcache_dup (get_current_regcache ());
6000 if (stop_stack_dummy == STOP_STACK_DUMMY)
6002 /* Pop the empty frame that contains the stack dummy.
6003 This also restores inferior state prior to the call
6004 (struct infcall_suspend_state). */
6005 struct frame_info *frame = get_current_frame ();
6007 gdb_assert (get_frame_type (frame) == DUMMY_FRAME);
6009 /* frame_pop() calls reinit_frame_cache as the last thing it
6010 does which means there's currently no selected frame. We
6011 don't need to re-establish a selected frame if the dummy call
6012 returns normally, that will be done by
6013 restore_infcall_control_state. However, we do have to handle
6014 the case where the dummy call is returning after being
6015 stopped (e.g. the dummy call previously hit a breakpoint).
6016 We can't know which case we have so just always re-establish
6017 a selected frame here. */
6018 select_frame (get_current_frame ());
6022 annotate_stopped ();
6024 /* Suppress the stop observer if we're in the middle of:
6026 - a step n (n > 1), as there still more steps to be done.
6028 - a "finish" command, as the observer will be called in
6029 finish_command_continuation, so it can include the inferior
6030 function's return value.
6032 - calling an inferior function, as we pretend we inferior didn't
6033 run at all. The return value of the call is handled by the
6034 expression evaluator, through call_function_by_hand. */
6036 if (!target_has_execution
6037 || last.kind == TARGET_WAITKIND_SIGNALLED
6038 || last.kind == TARGET_WAITKIND_EXITED
6039 || (!inferior_thread ()->step_multi
6040 && !(inferior_thread ()->control.stop_bpstat
6041 && inferior_thread ()->control.proceed_to_finish)
6042 && !inferior_thread ()->control.in_infcall))
6044 if (!ptid_equal (inferior_ptid, null_ptid))
6045 observer_notify_normal_stop (inferior_thread ()->control.stop_bpstat,
6048 observer_notify_normal_stop (NULL, stop_print_frame);
6051 if (target_has_execution)
6053 if (last.kind != TARGET_WAITKIND_SIGNALLED
6054 && last.kind != TARGET_WAITKIND_EXITED)
6055 /* Delete the breakpoint we stopped at, if it wants to be deleted.
6056 Delete any breakpoint that is to be deleted at the next stop. */
6057 breakpoint_auto_delete (inferior_thread ()->control.stop_bpstat);
6060 /* Try to get rid of automatically added inferiors that are no
6061 longer needed. Keeping those around slows down things linearly.
6062 Note that this never removes the current inferior. */
6067 hook_stop_stub (void *cmd)
6069 execute_cmd_pre_hook ((struct cmd_list_element *) cmd);
6074 signal_stop_state (int signo)
6076 return signal_stop[signo];
6080 signal_print_state (int signo)
6082 return signal_print[signo];
6086 signal_pass_state (int signo)
6088 return signal_program[signo];
6092 signal_cache_update (int signo)
6096 for (signo = 0; signo < (int) TARGET_SIGNAL_LAST; signo++)
6097 signal_cache_update (signo);
6102 signal_pass[signo] = (signal_stop[signo] == 0
6103 && signal_print[signo] == 0
6104 && signal_program[signo] == 1);
6108 signal_stop_update (int signo, int state)
6110 int ret = signal_stop[signo];
6112 signal_stop[signo] = state;
6113 signal_cache_update (signo);
6118 signal_print_update (int signo, int state)
6120 int ret = signal_print[signo];
6122 signal_print[signo] = state;
6123 signal_cache_update (signo);
6128 signal_pass_update (int signo, int state)
6130 int ret = signal_program[signo];
6132 signal_program[signo] = state;
6133 signal_cache_update (signo);
6138 sig_print_header (void)
6140 printf_filtered (_("Signal Stop\tPrint\tPass "
6141 "to program\tDescription\n"));
6145 sig_print_info (enum target_signal oursig)
6147 const char *name = target_signal_to_name (oursig);
6148 int name_padding = 13 - strlen (name);
6150 if (name_padding <= 0)
6153 printf_filtered ("%s", name);
6154 printf_filtered ("%*.*s ", name_padding, name_padding, " ");
6155 printf_filtered ("%s\t", signal_stop[oursig] ? "Yes" : "No");
6156 printf_filtered ("%s\t", signal_print[oursig] ? "Yes" : "No");
6157 printf_filtered ("%s\t\t", signal_program[oursig] ? "Yes" : "No");
6158 printf_filtered ("%s\n", target_signal_to_string (oursig));
6161 /* Specify how various signals in the inferior should be handled. */
6164 handle_command (char *args, int from_tty)
6167 int digits, wordlen;
6168 int sigfirst, signum, siglast;
6169 enum target_signal oursig;
6172 unsigned char *sigs;
6173 struct cleanup *old_chain;
6177 error_no_arg (_("signal to handle"));
6180 /* Allocate and zero an array of flags for which signals to handle. */
6182 nsigs = (int) TARGET_SIGNAL_LAST;
6183 sigs = (unsigned char *) alloca (nsigs);
6184 memset (sigs, 0, nsigs);
6186 /* Break the command line up into args. */
6188 argv = gdb_buildargv (args);
6189 old_chain = make_cleanup_freeargv (argv);
6191 /* Walk through the args, looking for signal oursigs, signal names, and
6192 actions. Signal numbers and signal names may be interspersed with
6193 actions, with the actions being performed for all signals cumulatively
6194 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
6196 while (*argv != NULL)
6198 wordlen = strlen (*argv);
6199 for (digits = 0; isdigit ((*argv)[digits]); digits++)
6203 sigfirst = siglast = -1;
6205 if (wordlen >= 1 && !strncmp (*argv, "all", wordlen))
6207 /* Apply action to all signals except those used by the
6208 debugger. Silently skip those. */
6211 siglast = nsigs - 1;
6213 else if (wordlen >= 1 && !strncmp (*argv, "stop", wordlen))
6215 SET_SIGS (nsigs, sigs, signal_stop);
6216 SET_SIGS (nsigs, sigs, signal_print);
6218 else if (wordlen >= 1 && !strncmp (*argv, "ignore", wordlen))
6220 UNSET_SIGS (nsigs, sigs, signal_program);
6222 else if (wordlen >= 2 && !strncmp (*argv, "print", wordlen))
6224 SET_SIGS (nsigs, sigs, signal_print);
6226 else if (wordlen >= 2 && !strncmp (*argv, "pass", wordlen))
6228 SET_SIGS (nsigs, sigs, signal_program);
6230 else if (wordlen >= 3 && !strncmp (*argv, "nostop", wordlen))
6232 UNSET_SIGS (nsigs, sigs, signal_stop);
6234 else if (wordlen >= 3 && !strncmp (*argv, "noignore", wordlen))
6236 SET_SIGS (nsigs, sigs, signal_program);
6238 else if (wordlen >= 4 && !strncmp (*argv, "noprint", wordlen))
6240 UNSET_SIGS (nsigs, sigs, signal_print);
6241 UNSET_SIGS (nsigs, sigs, signal_stop);
6243 else if (wordlen >= 4 && !strncmp (*argv, "nopass", wordlen))
6245 UNSET_SIGS (nsigs, sigs, signal_program);
6247 else if (digits > 0)
6249 /* It is numeric. The numeric signal refers to our own
6250 internal signal numbering from target.h, not to host/target
6251 signal number. This is a feature; users really should be
6252 using symbolic names anyway, and the common ones like
6253 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
6255 sigfirst = siglast = (int)
6256 target_signal_from_command (atoi (*argv));
6257 if ((*argv)[digits] == '-')
6260 target_signal_from_command (atoi ((*argv) + digits + 1));
6262 if (sigfirst > siglast)
6264 /* Bet he didn't figure we'd think of this case... */
6272 oursig = target_signal_from_name (*argv);
6273 if (oursig != TARGET_SIGNAL_UNKNOWN)
6275 sigfirst = siglast = (int) oursig;
6279 /* Not a number and not a recognized flag word => complain. */
6280 error (_("Unrecognized or ambiguous flag word: \"%s\"."), *argv);
6284 /* If any signal numbers or symbol names were found, set flags for
6285 which signals to apply actions to. */
6287 for (signum = sigfirst; signum >= 0 && signum <= siglast; signum++)
6289 switch ((enum target_signal) signum)
6291 case TARGET_SIGNAL_TRAP:
6292 case TARGET_SIGNAL_INT:
6293 if (!allsigs && !sigs[signum])
6295 if (query (_("%s is used by the debugger.\n\
6296 Are you sure you want to change it? "),
6297 target_signal_to_name ((enum target_signal) signum)))
6303 printf_unfiltered (_("Not confirmed, unchanged.\n"));
6304 gdb_flush (gdb_stdout);
6308 case TARGET_SIGNAL_0:
6309 case TARGET_SIGNAL_DEFAULT:
6310 case TARGET_SIGNAL_UNKNOWN:
6311 /* Make sure that "all" doesn't print these. */
6322 for (signum = 0; signum < nsigs; signum++)
6325 signal_cache_update (-1);
6326 target_pass_signals ((int) TARGET_SIGNAL_LAST, signal_pass);
6330 /* Show the results. */
6331 sig_print_header ();
6332 for (; signum < nsigs; signum++)
6334 sig_print_info (signum);
6340 do_cleanups (old_chain);
6344 xdb_handle_command (char *args, int from_tty)
6347 struct cleanup *old_chain;
6350 error_no_arg (_("xdb command"));
6352 /* Break the command line up into args. */
6354 argv = gdb_buildargv (args);
6355 old_chain = make_cleanup_freeargv (argv);
6356 if (argv[1] != (char *) NULL)
6361 bufLen = strlen (argv[0]) + 20;
6362 argBuf = (char *) xmalloc (bufLen);
6366 enum target_signal oursig;
6368 oursig = target_signal_from_name (argv[0]);
6369 memset (argBuf, 0, bufLen);
6370 if (strcmp (argv[1], "Q") == 0)
6371 sprintf (argBuf, "%s %s", argv[0], "noprint");
6374 if (strcmp (argv[1], "s") == 0)
6376 if (!signal_stop[oursig])
6377 sprintf (argBuf, "%s %s", argv[0], "stop");
6379 sprintf (argBuf, "%s %s", argv[0], "nostop");
6381 else if (strcmp (argv[1], "i") == 0)
6383 if (!signal_program[oursig])
6384 sprintf (argBuf, "%s %s", argv[0], "pass");
6386 sprintf (argBuf, "%s %s", argv[0], "nopass");
6388 else if (strcmp (argv[1], "r") == 0)
6390 if (!signal_print[oursig])
6391 sprintf (argBuf, "%s %s", argv[0], "print");
6393 sprintf (argBuf, "%s %s", argv[0], "noprint");
6399 handle_command (argBuf, from_tty);
6401 printf_filtered (_("Invalid signal handling flag.\n"));
6406 do_cleanups (old_chain);
6409 /* Print current contents of the tables set by the handle command.
6410 It is possible we should just be printing signals actually used
6411 by the current target (but for things to work right when switching
6412 targets, all signals should be in the signal tables). */
6415 signals_info (char *signum_exp, int from_tty)
6417 enum target_signal oursig;
6419 sig_print_header ();
6423 /* First see if this is a symbol name. */
6424 oursig = target_signal_from_name (signum_exp);
6425 if (oursig == TARGET_SIGNAL_UNKNOWN)
6427 /* No, try numeric. */
6429 target_signal_from_command (parse_and_eval_long (signum_exp));
6431 sig_print_info (oursig);
6435 printf_filtered ("\n");
6436 /* These ugly casts brought to you by the native VAX compiler. */
6437 for (oursig = TARGET_SIGNAL_FIRST;
6438 (int) oursig < (int) TARGET_SIGNAL_LAST;
6439 oursig = (enum target_signal) ((int) oursig + 1))
6443 if (oursig != TARGET_SIGNAL_UNKNOWN
6444 && oursig != TARGET_SIGNAL_DEFAULT && oursig != TARGET_SIGNAL_0)
6445 sig_print_info (oursig);
6448 printf_filtered (_("\nUse the \"handle\" command "
6449 "to change these tables.\n"));
6452 /* Check if it makes sense to read $_siginfo from the current thread
6453 at this point. If not, throw an error. */
6456 validate_siginfo_access (void)
6458 /* No current inferior, no siginfo. */
6459 if (ptid_equal (inferior_ptid, null_ptid))
6460 error (_("No thread selected."));
6462 /* Don't try to read from a dead thread. */
6463 if (is_exited (inferior_ptid))
6464 error (_("The current thread has terminated"));
6466 /* ... or from a spinning thread. */
6467 if (is_running (inferior_ptid))
6468 error (_("Selected thread is running."));
6471 /* The $_siginfo convenience variable is a bit special. We don't know
6472 for sure the type of the value until we actually have a chance to
6473 fetch the data. The type can change depending on gdbarch, so it is
6474 also dependent on which thread you have selected.
6476 1. making $_siginfo be an internalvar that creates a new value on
6479 2. making the value of $_siginfo be an lval_computed value. */
6481 /* This function implements the lval_computed support for reading a
6485 siginfo_value_read (struct value *v)
6487 LONGEST transferred;
6489 validate_siginfo_access ();
6492 target_read (¤t_target, TARGET_OBJECT_SIGNAL_INFO,
6494 value_contents_all_raw (v),
6496 TYPE_LENGTH (value_type (v)));
6498 if (transferred != TYPE_LENGTH (value_type (v)))
6499 error (_("Unable to read siginfo"));
6502 /* This function implements the lval_computed support for writing a
6506 siginfo_value_write (struct value *v, struct value *fromval)
6508 LONGEST transferred;
6510 validate_siginfo_access ();
6512 transferred = target_write (¤t_target,
6513 TARGET_OBJECT_SIGNAL_INFO,
6515 value_contents_all_raw (fromval),
6517 TYPE_LENGTH (value_type (fromval)));
6519 if (transferred != TYPE_LENGTH (value_type (fromval)))
6520 error (_("Unable to write siginfo"));
6523 static const struct lval_funcs siginfo_value_funcs =
6529 /* Return a new value with the correct type for the siginfo object of
6530 the current thread using architecture GDBARCH. Return a void value
6531 if there's no object available. */
6533 static struct value *
6534 siginfo_make_value (struct gdbarch *gdbarch, struct internalvar *var)
6536 if (target_has_stack
6537 && !ptid_equal (inferior_ptid, null_ptid)
6538 && gdbarch_get_siginfo_type_p (gdbarch))
6540 struct type *type = gdbarch_get_siginfo_type (gdbarch);
6542 return allocate_computed_value (type, &siginfo_value_funcs, NULL);
6545 return allocate_value (builtin_type (gdbarch)->builtin_void);
6549 /* infcall_suspend_state contains state about the program itself like its
6550 registers and any signal it received when it last stopped.
6551 This state must be restored regardless of how the inferior function call
6552 ends (either successfully, or after it hits a breakpoint or signal)
6553 if the program is to properly continue where it left off. */
6555 struct infcall_suspend_state
6557 struct thread_suspend_state thread_suspend;
6558 struct inferior_suspend_state inferior_suspend;
6562 struct regcache *registers;
6564 /* Format of SIGINFO_DATA or NULL if it is not present. */
6565 struct gdbarch *siginfo_gdbarch;
6567 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
6568 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
6569 content would be invalid. */
6570 gdb_byte *siginfo_data;
6573 struct infcall_suspend_state *
6574 save_infcall_suspend_state (void)
6576 struct infcall_suspend_state *inf_state;
6577 struct thread_info *tp = inferior_thread ();
6578 struct inferior *inf = current_inferior ();
6579 struct regcache *regcache = get_current_regcache ();
6580 struct gdbarch *gdbarch = get_regcache_arch (regcache);
6581 gdb_byte *siginfo_data = NULL;
6583 if (gdbarch_get_siginfo_type_p (gdbarch))
6585 struct type *type = gdbarch_get_siginfo_type (gdbarch);
6586 size_t len = TYPE_LENGTH (type);
6587 struct cleanup *back_to;
6589 siginfo_data = xmalloc (len);
6590 back_to = make_cleanup (xfree, siginfo_data);
6592 if (target_read (¤t_target, TARGET_OBJECT_SIGNAL_INFO, NULL,
6593 siginfo_data, 0, len) == len)
6594 discard_cleanups (back_to);
6597 /* Errors ignored. */
6598 do_cleanups (back_to);
6599 siginfo_data = NULL;
6603 inf_state = XZALLOC (struct infcall_suspend_state);
6607 inf_state->siginfo_gdbarch = gdbarch;
6608 inf_state->siginfo_data = siginfo_data;
6611 inf_state->thread_suspend = tp->suspend;
6612 inf_state->inferior_suspend = inf->suspend;
6614 /* run_inferior_call will not use the signal due to its `proceed' call with
6615 TARGET_SIGNAL_0 anyway. */
6616 tp->suspend.stop_signal = TARGET_SIGNAL_0;
6618 inf_state->stop_pc = stop_pc;
6620 inf_state->registers = regcache_dup (regcache);
6625 /* Restore inferior session state to INF_STATE. */
6628 restore_infcall_suspend_state (struct infcall_suspend_state *inf_state)
6630 struct thread_info *tp = inferior_thread ();
6631 struct inferior *inf = current_inferior ();
6632 struct regcache *regcache = get_current_regcache ();
6633 struct gdbarch *gdbarch = get_regcache_arch (regcache);
6635 tp->suspend = inf_state->thread_suspend;
6636 inf->suspend = inf_state->inferior_suspend;
6638 stop_pc = inf_state->stop_pc;
6640 if (inf_state->siginfo_gdbarch == gdbarch)
6642 struct type *type = gdbarch_get_siginfo_type (gdbarch);
6643 size_t len = TYPE_LENGTH (type);
6645 /* Errors ignored. */
6646 target_write (¤t_target, TARGET_OBJECT_SIGNAL_INFO, NULL,
6647 inf_state->siginfo_data, 0, len);
6650 /* The inferior can be gone if the user types "print exit(0)"
6651 (and perhaps other times). */
6652 if (target_has_execution)
6653 /* NB: The register write goes through to the target. */
6654 regcache_cpy (regcache, inf_state->registers);
6656 discard_infcall_suspend_state (inf_state);
6660 do_restore_infcall_suspend_state_cleanup (void *state)
6662 restore_infcall_suspend_state (state);
6666 make_cleanup_restore_infcall_suspend_state
6667 (struct infcall_suspend_state *inf_state)
6669 return make_cleanup (do_restore_infcall_suspend_state_cleanup, inf_state);
6673 discard_infcall_suspend_state (struct infcall_suspend_state *inf_state)
6675 regcache_xfree (inf_state->registers);
6676 xfree (inf_state->siginfo_data);
6681 get_infcall_suspend_state_regcache (struct infcall_suspend_state *inf_state)
6683 return inf_state->registers;
6686 /* infcall_control_state contains state regarding gdb's control of the
6687 inferior itself like stepping control. It also contains session state like
6688 the user's currently selected frame. */
6690 struct infcall_control_state
6692 struct thread_control_state thread_control;
6693 struct inferior_control_state inferior_control;
6696 enum stop_stack_kind stop_stack_dummy;
6697 int stopped_by_random_signal;
6698 int stop_after_trap;
6700 /* ID if the selected frame when the inferior function call was made. */
6701 struct frame_id selected_frame_id;
6704 /* Save all of the information associated with the inferior<==>gdb
6707 struct infcall_control_state *
6708 save_infcall_control_state (void)
6710 struct infcall_control_state *inf_status = xmalloc (sizeof (*inf_status));
6711 struct thread_info *tp = inferior_thread ();
6712 struct inferior *inf = current_inferior ();
6714 inf_status->thread_control = tp->control;
6715 inf_status->inferior_control = inf->control;
6717 tp->control.step_resume_breakpoint = NULL;
6718 tp->control.exception_resume_breakpoint = NULL;
6720 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
6721 chain. If caller's caller is walking the chain, they'll be happier if we
6722 hand them back the original chain when restore_infcall_control_state is
6724 tp->control.stop_bpstat = bpstat_copy (tp->control.stop_bpstat);
6727 inf_status->stop_stack_dummy = stop_stack_dummy;
6728 inf_status->stopped_by_random_signal = stopped_by_random_signal;
6729 inf_status->stop_after_trap = stop_after_trap;
6731 inf_status->selected_frame_id = get_frame_id (get_selected_frame (NULL));
6737 restore_selected_frame (void *args)
6739 struct frame_id *fid = (struct frame_id *) args;
6740 struct frame_info *frame;
6742 frame = frame_find_by_id (*fid);
6744 /* If inf_status->selected_frame_id is NULL, there was no previously
6748 warning (_("Unable to restore previously selected frame."));
6752 select_frame (frame);
6757 /* Restore inferior session state to INF_STATUS. */
6760 restore_infcall_control_state (struct infcall_control_state *inf_status)
6762 struct thread_info *tp = inferior_thread ();
6763 struct inferior *inf = current_inferior ();
6765 if (tp->control.step_resume_breakpoint)
6766 tp->control.step_resume_breakpoint->disposition = disp_del_at_next_stop;
6768 if (tp->control.exception_resume_breakpoint)
6769 tp->control.exception_resume_breakpoint->disposition
6770 = disp_del_at_next_stop;
6772 /* Handle the bpstat_copy of the chain. */
6773 bpstat_clear (&tp->control.stop_bpstat);
6775 tp->control = inf_status->thread_control;
6776 inf->control = inf_status->inferior_control;
6779 stop_stack_dummy = inf_status->stop_stack_dummy;
6780 stopped_by_random_signal = inf_status->stopped_by_random_signal;
6781 stop_after_trap = inf_status->stop_after_trap;
6783 if (target_has_stack)
6785 /* The point of catch_errors is that if the stack is clobbered,
6786 walking the stack might encounter a garbage pointer and
6787 error() trying to dereference it. */
6789 (restore_selected_frame, &inf_status->selected_frame_id,
6790 "Unable to restore previously selected frame:\n",
6791 RETURN_MASK_ERROR) == 0)
6792 /* Error in restoring the selected frame. Select the innermost
6794 select_frame (get_current_frame ());
6801 do_restore_infcall_control_state_cleanup (void *sts)
6803 restore_infcall_control_state (sts);
6807 make_cleanup_restore_infcall_control_state
6808 (struct infcall_control_state *inf_status)
6810 return make_cleanup (do_restore_infcall_control_state_cleanup, inf_status);
6814 discard_infcall_control_state (struct infcall_control_state *inf_status)
6816 if (inf_status->thread_control.step_resume_breakpoint)
6817 inf_status->thread_control.step_resume_breakpoint->disposition
6818 = disp_del_at_next_stop;
6820 if (inf_status->thread_control.exception_resume_breakpoint)
6821 inf_status->thread_control.exception_resume_breakpoint->disposition
6822 = disp_del_at_next_stop;
6824 /* See save_infcall_control_state for info on stop_bpstat. */
6825 bpstat_clear (&inf_status->thread_control.stop_bpstat);
6831 inferior_has_forked (ptid_t pid, ptid_t *child_pid)
6833 struct target_waitstatus last;
6836 get_last_target_status (&last_ptid, &last);
6838 if (last.kind != TARGET_WAITKIND_FORKED)
6841 if (!ptid_equal (last_ptid, pid))
6844 *child_pid = last.value.related_pid;
6849 inferior_has_vforked (ptid_t pid, ptid_t *child_pid)
6851 struct target_waitstatus last;
6854 get_last_target_status (&last_ptid, &last);
6856 if (last.kind != TARGET_WAITKIND_VFORKED)
6859 if (!ptid_equal (last_ptid, pid))
6862 *child_pid = last.value.related_pid;
6867 inferior_has_execd (ptid_t pid, char **execd_pathname)
6869 struct target_waitstatus last;
6872 get_last_target_status (&last_ptid, &last);
6874 if (last.kind != TARGET_WAITKIND_EXECD)
6877 if (!ptid_equal (last_ptid, pid))
6880 *execd_pathname = xstrdup (last.value.execd_pathname);
6885 inferior_has_called_syscall (ptid_t pid, int *syscall_number)
6887 struct target_waitstatus last;
6890 get_last_target_status (&last_ptid, &last);
6892 if (last.kind != TARGET_WAITKIND_SYSCALL_ENTRY &&
6893 last.kind != TARGET_WAITKIND_SYSCALL_RETURN)
6896 if (!ptid_equal (last_ptid, pid))
6899 *syscall_number = last.value.syscall_number;
6904 ptid_match (ptid_t ptid, ptid_t filter)
6906 if (ptid_equal (filter, minus_one_ptid))
6908 if (ptid_is_pid (filter)
6909 && ptid_get_pid (ptid) == ptid_get_pid (filter))
6911 else if (ptid_equal (ptid, filter))
6917 /* restore_inferior_ptid() will be used by the cleanup machinery
6918 to restore the inferior_ptid value saved in a call to
6919 save_inferior_ptid(). */
6922 restore_inferior_ptid (void *arg)
6924 ptid_t *saved_ptid_ptr = arg;
6926 inferior_ptid = *saved_ptid_ptr;
6930 /* Save the value of inferior_ptid so that it may be restored by a
6931 later call to do_cleanups(). Returns the struct cleanup pointer
6932 needed for later doing the cleanup. */
6935 save_inferior_ptid (void)
6937 ptid_t *saved_ptid_ptr;
6939 saved_ptid_ptr = xmalloc (sizeof (ptid_t));
6940 *saved_ptid_ptr = inferior_ptid;
6941 return make_cleanup (restore_inferior_ptid, saved_ptid_ptr);
6945 /* User interface for reverse debugging:
6946 Set exec-direction / show exec-direction commands
6947 (returns error unless target implements to_set_exec_direction method). */
6949 int execution_direction = EXEC_FORWARD;
6950 static const char exec_forward[] = "forward";
6951 static const char exec_reverse[] = "reverse";
6952 static const char *exec_direction = exec_forward;
6953 static const char *exec_direction_names[] = {
6960 set_exec_direction_func (char *args, int from_tty,
6961 struct cmd_list_element *cmd)
6963 if (target_can_execute_reverse)
6965 if (!strcmp (exec_direction, exec_forward))
6966 execution_direction = EXEC_FORWARD;
6967 else if (!strcmp (exec_direction, exec_reverse))
6968 execution_direction = EXEC_REVERSE;
6972 exec_direction = exec_forward;
6973 error (_("Target does not support this operation."));
6978 show_exec_direction_func (struct ui_file *out, int from_tty,
6979 struct cmd_list_element *cmd, const char *value)
6981 switch (execution_direction) {
6983 fprintf_filtered (out, _("Forward.\n"));
6986 fprintf_filtered (out, _("Reverse.\n"));
6989 internal_error (__FILE__, __LINE__,
6990 _("bogus execution_direction value: %d"),
6991 (int) execution_direction);
6995 /* User interface for non-stop mode. */
7000 set_non_stop (char *args, int from_tty,
7001 struct cmd_list_element *c)
7003 if (target_has_execution)
7005 non_stop_1 = non_stop;
7006 error (_("Cannot change this setting while the inferior is running."));
7009 non_stop = non_stop_1;
7013 show_non_stop (struct ui_file *file, int from_tty,
7014 struct cmd_list_element *c, const char *value)
7016 fprintf_filtered (file,
7017 _("Controlling the inferior in non-stop mode is %s.\n"),
7022 show_schedule_multiple (struct ui_file *file, int from_tty,
7023 struct cmd_list_element *c, const char *value)
7025 fprintf_filtered (file, _("Resuming the execution of threads "
7026 "of all processes is %s.\n"), value);
7030 _initialize_infrun (void)
7035 add_info ("signals", signals_info, _("\
7036 What debugger does when program gets various signals.\n\
7037 Specify a signal as argument to print info on that signal only."));
7038 add_info_alias ("handle", "signals", 0);
7040 add_com ("handle", class_run, handle_command, _("\
7041 Specify how to handle a signal.\n\
7042 Args are signals and actions to apply to those signals.\n\
7043 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
7044 from 1-15 are allowed for compatibility with old versions of GDB.\n\
7045 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
7046 The special arg \"all\" is recognized to mean all signals except those\n\
7047 used by the debugger, typically SIGTRAP and SIGINT.\n\
7048 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
7049 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
7050 Stop means reenter debugger if this signal happens (implies print).\n\
7051 Print means print a message if this signal happens.\n\
7052 Pass means let program see this signal; otherwise program doesn't know.\n\
7053 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
7054 Pass and Stop may be combined."));
7057 add_com ("lz", class_info, signals_info, _("\
7058 What debugger does when program gets various signals.\n\
7059 Specify a signal as argument to print info on that signal only."));
7060 add_com ("z", class_run, xdb_handle_command, _("\
7061 Specify how to handle a signal.\n\
7062 Args are signals and actions to apply to those signals.\n\
7063 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
7064 from 1-15 are allowed for compatibility with old versions of GDB.\n\
7065 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
7066 The special arg \"all\" is recognized to mean all signals except those\n\
7067 used by the debugger, typically SIGTRAP and SIGINT.\n\
7068 Recognized actions include \"s\" (toggles between stop and nostop),\n\
7069 \"r\" (toggles between print and noprint), \"i\" (toggles between pass and \
7070 nopass), \"Q\" (noprint)\n\
7071 Stop means reenter debugger if this signal happens (implies print).\n\
7072 Print means print a message if this signal happens.\n\
7073 Pass means let program see this signal; otherwise program doesn't know.\n\
7074 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
7075 Pass and Stop may be combined."));
7079 stop_command = add_cmd ("stop", class_obscure,
7080 not_just_help_class_command, _("\
7081 There is no `stop' command, but you can set a hook on `stop'.\n\
7082 This allows you to set a list of commands to be run each time execution\n\
7083 of the program stops."), &cmdlist);
7085 add_setshow_zinteger_cmd ("infrun", class_maintenance, &debug_infrun, _("\
7086 Set inferior debugging."), _("\
7087 Show inferior debugging."), _("\
7088 When non-zero, inferior specific debugging is enabled."),
7091 &setdebuglist, &showdebuglist);
7093 add_setshow_boolean_cmd ("displaced", class_maintenance,
7094 &debug_displaced, _("\
7095 Set displaced stepping debugging."), _("\
7096 Show displaced stepping debugging."), _("\
7097 When non-zero, displaced stepping specific debugging is enabled."),
7099 show_debug_displaced,
7100 &setdebuglist, &showdebuglist);
7102 add_setshow_boolean_cmd ("non-stop", no_class,
7104 Set whether gdb controls the inferior in non-stop mode."), _("\
7105 Show whether gdb controls the inferior in non-stop mode."), _("\
7106 When debugging a multi-threaded program and this setting is\n\
7107 off (the default, also called all-stop mode), when one thread stops\n\
7108 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
7109 all other threads in the program while you interact with the thread of\n\
7110 interest. When you continue or step a thread, you can allow the other\n\
7111 threads to run, or have them remain stopped, but while you inspect any\n\
7112 thread's state, all threads stop.\n\
7114 In non-stop mode, when one thread stops, other threads can continue\n\
7115 to run freely. You'll be able to step each thread independently,\n\
7116 leave it stopped or free to run as needed."),
7122 numsigs = (int) TARGET_SIGNAL_LAST;
7123 signal_stop = (unsigned char *) xmalloc (sizeof (signal_stop[0]) * numsigs);
7124 signal_print = (unsigned char *)
7125 xmalloc (sizeof (signal_print[0]) * numsigs);
7126 signal_program = (unsigned char *)
7127 xmalloc (sizeof (signal_program[0]) * numsigs);
7128 signal_pass = (unsigned char *)
7129 xmalloc (sizeof (signal_program[0]) * numsigs);
7130 for (i = 0; i < numsigs; i++)
7133 signal_print[i] = 1;
7134 signal_program[i] = 1;
7137 /* Signals caused by debugger's own actions
7138 should not be given to the program afterwards. */
7139 signal_program[TARGET_SIGNAL_TRAP] = 0;
7140 signal_program[TARGET_SIGNAL_INT] = 0;
7142 /* Signals that are not errors should not normally enter the debugger. */
7143 signal_stop[TARGET_SIGNAL_ALRM] = 0;
7144 signal_print[TARGET_SIGNAL_ALRM] = 0;
7145 signal_stop[TARGET_SIGNAL_VTALRM] = 0;
7146 signal_print[TARGET_SIGNAL_VTALRM] = 0;
7147 signal_stop[TARGET_SIGNAL_PROF] = 0;
7148 signal_print[TARGET_SIGNAL_PROF] = 0;
7149 signal_stop[TARGET_SIGNAL_CHLD] = 0;
7150 signal_print[TARGET_SIGNAL_CHLD] = 0;
7151 signal_stop[TARGET_SIGNAL_IO] = 0;
7152 signal_print[TARGET_SIGNAL_IO] = 0;
7153 signal_stop[TARGET_SIGNAL_POLL] = 0;
7154 signal_print[TARGET_SIGNAL_POLL] = 0;
7155 signal_stop[TARGET_SIGNAL_URG] = 0;
7156 signal_print[TARGET_SIGNAL_URG] = 0;
7157 signal_stop[TARGET_SIGNAL_WINCH] = 0;
7158 signal_print[TARGET_SIGNAL_WINCH] = 0;
7159 signal_stop[TARGET_SIGNAL_PRIO] = 0;
7160 signal_print[TARGET_SIGNAL_PRIO] = 0;
7162 /* These signals are used internally by user-level thread
7163 implementations. (See signal(5) on Solaris.) Like the above
7164 signals, a healthy program receives and handles them as part of
7165 its normal operation. */
7166 signal_stop[TARGET_SIGNAL_LWP] = 0;
7167 signal_print[TARGET_SIGNAL_LWP] = 0;
7168 signal_stop[TARGET_SIGNAL_WAITING] = 0;
7169 signal_print[TARGET_SIGNAL_WAITING] = 0;
7170 signal_stop[TARGET_SIGNAL_CANCEL] = 0;
7171 signal_print[TARGET_SIGNAL_CANCEL] = 0;
7173 /* Update cached state. */
7174 signal_cache_update (-1);
7176 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support,
7177 &stop_on_solib_events, _("\
7178 Set stopping for shared library events."), _("\
7179 Show stopping for shared library events."), _("\
7180 If nonzero, gdb will give control to the user when the dynamic linker\n\
7181 notifies gdb of shared library events. The most common event of interest\n\
7182 to the user would be loading/unloading of a new library."),
7184 show_stop_on_solib_events,
7185 &setlist, &showlist);
7187 add_setshow_enum_cmd ("follow-fork-mode", class_run,
7188 follow_fork_mode_kind_names,
7189 &follow_fork_mode_string, _("\
7190 Set debugger response to a program call of fork or vfork."), _("\
7191 Show debugger response to a program call of fork or vfork."), _("\
7192 A fork or vfork creates a new process. follow-fork-mode can be:\n\
7193 parent - the original process is debugged after a fork\n\
7194 child - the new process is debugged after a fork\n\
7195 The unfollowed process will continue to run.\n\
7196 By default, the debugger will follow the parent process."),
7198 show_follow_fork_mode_string,
7199 &setlist, &showlist);
7201 add_setshow_enum_cmd ("follow-exec-mode", class_run,
7202 follow_exec_mode_names,
7203 &follow_exec_mode_string, _("\
7204 Set debugger response to a program call of exec."), _("\
7205 Show debugger response to a program call of exec."), _("\
7206 An exec call replaces the program image of a process.\n\
7208 follow-exec-mode can be:\n\
7210 new - the debugger creates a new inferior and rebinds the process\n\
7211 to this new inferior. The program the process was running before\n\
7212 the exec call can be restarted afterwards by restarting the original\n\
7215 same - the debugger keeps the process bound to the same inferior.\n\
7216 The new executable image replaces the previous executable loaded in\n\
7217 the inferior. Restarting the inferior after the exec call restarts\n\
7218 the executable the process was running after the exec call.\n\
7220 By default, the debugger will use the same inferior."),
7222 show_follow_exec_mode_string,
7223 &setlist, &showlist);
7225 add_setshow_enum_cmd ("scheduler-locking", class_run,
7226 scheduler_enums, &scheduler_mode, _("\
7227 Set mode for locking scheduler during execution."), _("\
7228 Show mode for locking scheduler during execution."), _("\
7229 off == no locking (threads may preempt at any time)\n\
7230 on == full locking (no thread except the current thread may run)\n\
7231 step == scheduler locked during every single-step operation.\n\
7232 In this mode, no other thread may run during a step command.\n\
7233 Other threads may run while stepping over a function call ('next')."),
7234 set_schedlock_func, /* traps on target vector */
7235 show_scheduler_mode,
7236 &setlist, &showlist);
7238 add_setshow_boolean_cmd ("schedule-multiple", class_run, &sched_multi, _("\
7239 Set mode for resuming threads of all processes."), _("\
7240 Show mode for resuming threads of all processes."), _("\
7241 When on, execution commands (such as 'continue' or 'next') resume all\n\
7242 threads of all processes. When off (which is the default), execution\n\
7243 commands only resume the threads of the current process. The set of\n\
7244 threads that are resumed is further refined by the scheduler-locking\n\
7245 mode (see help set scheduler-locking)."),
7247 show_schedule_multiple,
7248 &setlist, &showlist);
7250 add_setshow_boolean_cmd ("step-mode", class_run, &step_stop_if_no_debug, _("\
7251 Set mode of the step operation."), _("\
7252 Show mode of the step operation."), _("\
7253 When set, doing a step over a function without debug line information\n\
7254 will stop at the first instruction of that function. Otherwise, the\n\
7255 function is skipped and the step command stops at a different source line."),
7257 show_step_stop_if_no_debug,
7258 &setlist, &showlist);
7260 add_setshow_enum_cmd ("displaced-stepping", class_run,
7261 can_use_displaced_stepping_enum,
7262 &can_use_displaced_stepping, _("\
7263 Set debugger's willingness to use displaced stepping."), _("\
7264 Show debugger's willingness to use displaced stepping."), _("\
7265 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
7266 supported by the target architecture. If off, gdb will not use displaced\n\
7267 stepping to step over breakpoints, even if such is supported by the target\n\
7268 architecture. If auto (which is the default), gdb will use displaced stepping\n\
7269 if the target architecture supports it and non-stop mode is active, but will not\n\
7270 use it in all-stop mode (see help set non-stop)."),
7272 show_can_use_displaced_stepping,
7273 &setlist, &showlist);
7275 add_setshow_enum_cmd ("exec-direction", class_run, exec_direction_names,
7276 &exec_direction, _("Set direction of execution.\n\
7277 Options are 'forward' or 'reverse'."),
7278 _("Show direction of execution (forward/reverse)."),
7279 _("Tells gdb whether to execute forward or backward."),
7280 set_exec_direction_func, show_exec_direction_func,
7281 &setlist, &showlist);
7283 /* Set/show detach-on-fork: user-settable mode. */
7285 add_setshow_boolean_cmd ("detach-on-fork", class_run, &detach_fork, _("\
7286 Set whether gdb will detach the child of a fork."), _("\
7287 Show whether gdb will detach the child of a fork."), _("\
7288 Tells gdb whether to detach the child of a fork."),
7289 NULL, NULL, &setlist, &showlist);
7291 /* Set/show disable address space randomization mode. */
7293 add_setshow_boolean_cmd ("disable-randomization", class_support,
7294 &disable_randomization, _("\
7295 Set disabling of debuggee's virtual address space randomization."), _("\
7296 Show disabling of debuggee's virtual address space randomization."), _("\
7297 When this mode is on (which is the default), randomization of the virtual\n\
7298 address space is disabled. Standalone programs run with the randomization\n\
7299 enabled by default on some platforms."),
7300 &set_disable_randomization,
7301 &show_disable_randomization,
7302 &setlist, &showlist);
7304 /* ptid initializations */
7305 inferior_ptid = null_ptid;
7306 target_last_wait_ptid = minus_one_ptid;
7308 observer_attach_thread_ptid_changed (infrun_thread_ptid_changed);
7309 observer_attach_thread_stop_requested (infrun_thread_stop_requested);
7310 observer_attach_thread_exit (infrun_thread_thread_exit);
7311 observer_attach_inferior_exit (infrun_inferior_exit);
7313 /* Explicitly create without lookup, since that tries to create a
7314 value with a void typed value, and when we get here, gdbarch
7315 isn't initialized yet. At this point, we're quite sure there
7316 isn't another convenience variable of the same name. */
7317 create_internalvar_type_lazy ("_siginfo", siginfo_make_value);
7319 add_setshow_boolean_cmd ("observer", no_class,
7320 &observer_mode_1, _("\
7321 Set whether gdb controls the inferior in observer mode."), _("\
7322 Show whether gdb controls the inferior in observer mode."), _("\
7323 In observer mode, GDB can get data from the inferior, but not\n\
7324 affect its execution. Registers and memory may not be changed,\n\
7325 breakpoints may not be set, and the program cannot be interrupted\n\