1 /* Target-struct-independent code to start (run) and stop an inferior
4 Copyright (C) 1986-2013 Free Software Foundation, Inc.
6 This file is part of GDB.
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program. If not, see <http://www.gnu.org/licenses/>. */
22 #include "gdb_string.h"
27 #include "exceptions.h"
28 #include "breakpoint.h"
32 #include "cli/cli-script.h"
34 #include "gdbthread.h"
46 #include "dictionary.h"
48 #include "gdb_assert.h"
49 #include "mi/mi-common.h"
50 #include "event-top.h"
52 #include "record-full.h"
53 #include "inline-frame.h"
55 #include "tracepoint.h"
56 #include "continuations.h"
61 #include "completer.h"
62 #include "target-descriptions.h"
64 /* Prototypes for local functions */
66 static void signals_info (char *, int);
68 static void handle_command (char *, int);
70 static void sig_print_info (enum gdb_signal);
72 static void sig_print_header (void);
74 static void resume_cleanups (void *);
76 static int hook_stop_stub (void *);
78 static int restore_selected_frame (void *);
80 static int follow_fork (void);
82 static void set_schedlock_func (char *args, int from_tty,
83 struct cmd_list_element *c);
85 static int currently_stepping (struct thread_info *tp);
87 static int currently_stepping_or_nexting_callback (struct thread_info *tp,
90 static void xdb_handle_command (char *args, int from_tty);
92 static int prepare_to_proceed (int);
94 static void print_exited_reason (int exitstatus);
96 static void print_signal_exited_reason (enum gdb_signal siggnal);
98 static void print_no_history_reason (void);
100 static void print_signal_received_reason (enum gdb_signal siggnal);
102 static void print_end_stepping_range_reason (void);
104 void _initialize_infrun (void);
106 void nullify_last_target_wait_ptid (void);
108 static void insert_hp_step_resume_breakpoint_at_frame (struct frame_info *);
110 static void insert_step_resume_breakpoint_at_caller (struct frame_info *);
112 static void insert_longjmp_resume_breakpoint (struct gdbarch *, CORE_ADDR);
114 /* When set, stop the 'step' command if we enter a function which has
115 no line number information. The normal behavior is that we step
116 over such function. */
117 int step_stop_if_no_debug = 0;
119 show_step_stop_if_no_debug (struct ui_file *file, int from_tty,
120 struct cmd_list_element *c, const char *value)
122 fprintf_filtered (file, _("Mode of the step operation is %s.\n"), value);
125 /* In asynchronous mode, but simulating synchronous execution. */
127 int sync_execution = 0;
129 /* wait_for_inferior and normal_stop use this to notify the user
130 when the inferior stopped in a different thread than it had been
133 static ptid_t previous_inferior_ptid;
135 /* Default behavior is to detach newly forked processes (legacy). */
138 int debug_displaced = 0;
140 show_debug_displaced (struct ui_file *file, int from_tty,
141 struct cmd_list_element *c, const char *value)
143 fprintf_filtered (file, _("Displace stepping debugging is %s.\n"), value);
146 unsigned int debug_infrun = 0;
148 show_debug_infrun (struct ui_file *file, int from_tty,
149 struct cmd_list_element *c, const char *value)
151 fprintf_filtered (file, _("Inferior debugging is %s.\n"), value);
155 /* Support for disabling address space randomization. */
157 int disable_randomization = 1;
160 show_disable_randomization (struct ui_file *file, int from_tty,
161 struct cmd_list_element *c, const char *value)
163 if (target_supports_disable_randomization ())
164 fprintf_filtered (file,
165 _("Disabling randomization of debuggee's "
166 "virtual address space is %s.\n"),
169 fputs_filtered (_("Disabling randomization of debuggee's "
170 "virtual address space is unsupported on\n"
171 "this platform.\n"), file);
175 set_disable_randomization (char *args, int from_tty,
176 struct cmd_list_element *c)
178 if (!target_supports_disable_randomization ())
179 error (_("Disabling randomization of debuggee's "
180 "virtual address space is unsupported on\n"
185 /* If the program uses ELF-style shared libraries, then calls to
186 functions in shared libraries go through stubs, which live in a
187 table called the PLT (Procedure Linkage Table). The first time the
188 function is called, the stub sends control to the dynamic linker,
189 which looks up the function's real address, patches the stub so
190 that future calls will go directly to the function, and then passes
191 control to the function.
193 If we are stepping at the source level, we don't want to see any of
194 this --- we just want to skip over the stub and the dynamic linker.
195 The simple approach is to single-step until control leaves the
198 However, on some systems (e.g., Red Hat's 5.2 distribution) the
199 dynamic linker calls functions in the shared C library, so you
200 can't tell from the PC alone whether the dynamic linker is still
201 running. In this case, we use a step-resume breakpoint to get us
202 past the dynamic linker, as if we were using "next" to step over a
205 in_solib_dynsym_resolve_code() says whether we're in the dynamic
206 linker code or not. Normally, this means we single-step. However,
207 if SKIP_SOLIB_RESOLVER then returns non-zero, then its value is an
208 address where we can place a step-resume breakpoint to get past the
209 linker's symbol resolution function.
211 in_solib_dynsym_resolve_code() can generally be implemented in a
212 pretty portable way, by comparing the PC against the address ranges
213 of the dynamic linker's sections.
215 SKIP_SOLIB_RESOLVER is generally going to be system-specific, since
216 it depends on internal details of the dynamic linker. It's usually
217 not too hard to figure out where to put a breakpoint, but it
218 certainly isn't portable. SKIP_SOLIB_RESOLVER should do plenty of
219 sanity checking. If it can't figure things out, returning zero and
220 getting the (possibly confusing) stepping behavior is better than
221 signalling an error, which will obscure the change in the
224 /* This function returns TRUE if pc is the address of an instruction
225 that lies within the dynamic linker (such as the event hook, or the
228 This function must be used only when a dynamic linker event has
229 been caught, and the inferior is being stepped out of the hook, or
230 undefined results are guaranteed. */
232 #ifndef SOLIB_IN_DYNAMIC_LINKER
233 #define SOLIB_IN_DYNAMIC_LINKER(pid,pc) 0
236 /* "Observer mode" is somewhat like a more extreme version of
237 non-stop, in which all GDB operations that might affect the
238 target's execution have been disabled. */
240 static int non_stop_1 = 0;
242 int observer_mode = 0;
243 static int observer_mode_1 = 0;
246 set_observer_mode (char *args, int from_tty,
247 struct cmd_list_element *c)
249 extern int pagination_enabled;
251 if (target_has_execution)
253 observer_mode_1 = observer_mode;
254 error (_("Cannot change this setting while the inferior is running."));
257 observer_mode = observer_mode_1;
259 may_write_registers = !observer_mode;
260 may_write_memory = !observer_mode;
261 may_insert_breakpoints = !observer_mode;
262 may_insert_tracepoints = !observer_mode;
263 /* We can insert fast tracepoints in or out of observer mode,
264 but enable them if we're going into this mode. */
266 may_insert_fast_tracepoints = 1;
267 may_stop = !observer_mode;
268 update_target_permissions ();
270 /* Going *into* observer mode we must force non-stop, then
271 going out we leave it that way. */
274 target_async_permitted = 1;
275 pagination_enabled = 0;
276 non_stop = non_stop_1 = 1;
280 printf_filtered (_("Observer mode is now %s.\n"),
281 (observer_mode ? "on" : "off"));
285 show_observer_mode (struct ui_file *file, int from_tty,
286 struct cmd_list_element *c, const char *value)
288 fprintf_filtered (file, _("Observer mode is %s.\n"), value);
291 /* This updates the value of observer mode based on changes in
292 permissions. Note that we are deliberately ignoring the values of
293 may-write-registers and may-write-memory, since the user may have
294 reason to enable these during a session, for instance to turn on a
295 debugging-related global. */
298 update_observer_mode (void)
302 newval = (!may_insert_breakpoints
303 && !may_insert_tracepoints
304 && may_insert_fast_tracepoints
308 /* Let the user know if things change. */
309 if (newval != observer_mode)
310 printf_filtered (_("Observer mode is now %s.\n"),
311 (newval ? "on" : "off"));
313 observer_mode = observer_mode_1 = newval;
316 /* Tables of how to react to signals; the user sets them. */
318 static unsigned char *signal_stop;
319 static unsigned char *signal_print;
320 static unsigned char *signal_program;
322 /* Table of signals that are registered with "catch signal". A
323 non-zero entry indicates that the signal is caught by some "catch
324 signal" command. This has size GDB_SIGNAL_LAST, to accommodate all
326 static unsigned char *signal_catch;
328 /* Table of signals that the target may silently handle.
329 This is automatically determined from the flags above,
330 and simply cached here. */
331 static unsigned char *signal_pass;
333 #define SET_SIGS(nsigs,sigs,flags) \
335 int signum = (nsigs); \
336 while (signum-- > 0) \
337 if ((sigs)[signum]) \
338 (flags)[signum] = 1; \
341 #define UNSET_SIGS(nsigs,sigs,flags) \
343 int signum = (nsigs); \
344 while (signum-- > 0) \
345 if ((sigs)[signum]) \
346 (flags)[signum] = 0; \
349 /* Update the target's copy of SIGNAL_PROGRAM. The sole purpose of
350 this function is to avoid exporting `signal_program'. */
353 update_signals_program_target (void)
355 target_program_signals ((int) GDB_SIGNAL_LAST, signal_program);
358 /* Value to pass to target_resume() to cause all threads to resume. */
360 #define RESUME_ALL minus_one_ptid
362 /* Command list pointer for the "stop" placeholder. */
364 static struct cmd_list_element *stop_command;
366 /* Function inferior was in as of last step command. */
368 static struct symbol *step_start_function;
370 /* Nonzero if we want to give control to the user when we're notified
371 of shared library events by the dynamic linker. */
372 int stop_on_solib_events;
374 show_stop_on_solib_events (struct ui_file *file, int from_tty,
375 struct cmd_list_element *c, const char *value)
377 fprintf_filtered (file, _("Stopping for shared library events is %s.\n"),
381 /* Nonzero means expecting a trace trap
382 and should stop the inferior and return silently when it happens. */
386 /* Save register contents here when executing a "finish" command or are
387 about to pop a stack dummy frame, if-and-only-if proceed_to_finish is set.
388 Thus this contains the return value from the called function (assuming
389 values are returned in a register). */
391 struct regcache *stop_registers;
393 /* Nonzero after stop if current stack frame should be printed. */
395 static int stop_print_frame;
397 /* This is a cached copy of the pid/waitstatus of the last event
398 returned by target_wait()/deprecated_target_wait_hook(). This
399 information is returned by get_last_target_status(). */
400 static ptid_t target_last_wait_ptid;
401 static struct target_waitstatus target_last_waitstatus;
403 static void context_switch (ptid_t ptid);
405 void init_thread_stepping_state (struct thread_info *tss);
407 static void init_infwait_state (void);
409 static const char follow_fork_mode_child[] = "child";
410 static const char follow_fork_mode_parent[] = "parent";
412 static const char *const follow_fork_mode_kind_names[] = {
413 follow_fork_mode_child,
414 follow_fork_mode_parent,
418 static const char *follow_fork_mode_string = follow_fork_mode_parent;
420 show_follow_fork_mode_string (struct ui_file *file, int from_tty,
421 struct cmd_list_element *c, const char *value)
423 fprintf_filtered (file,
424 _("Debugger response to a program "
425 "call of fork or vfork is \"%s\".\n"),
430 /* Tell the target to follow the fork we're stopped at. Returns true
431 if the inferior should be resumed; false, if the target for some
432 reason decided it's best not to resume. */
437 int follow_child = (follow_fork_mode_string == follow_fork_mode_child);
438 int should_resume = 1;
439 struct thread_info *tp;
441 /* Copy user stepping state to the new inferior thread. FIXME: the
442 followed fork child thread should have a copy of most of the
443 parent thread structure's run control related fields, not just these.
444 Initialized to avoid "may be used uninitialized" warnings from gcc. */
445 struct breakpoint *step_resume_breakpoint = NULL;
446 struct breakpoint *exception_resume_breakpoint = NULL;
447 CORE_ADDR step_range_start = 0;
448 CORE_ADDR step_range_end = 0;
449 struct frame_id step_frame_id = { 0 };
454 struct target_waitstatus wait_status;
456 /* Get the last target status returned by target_wait(). */
457 get_last_target_status (&wait_ptid, &wait_status);
459 /* If not stopped at a fork event, then there's nothing else to
461 if (wait_status.kind != TARGET_WAITKIND_FORKED
462 && wait_status.kind != TARGET_WAITKIND_VFORKED)
465 /* Check if we switched over from WAIT_PTID, since the event was
467 if (!ptid_equal (wait_ptid, minus_one_ptid)
468 && !ptid_equal (inferior_ptid, wait_ptid))
470 /* We did. Switch back to WAIT_PTID thread, to tell the
471 target to follow it (in either direction). We'll
472 afterwards refuse to resume, and inform the user what
474 switch_to_thread (wait_ptid);
479 tp = inferior_thread ();
481 /* If there were any forks/vforks that were caught and are now to be
482 followed, then do so now. */
483 switch (tp->pending_follow.kind)
485 case TARGET_WAITKIND_FORKED:
486 case TARGET_WAITKIND_VFORKED:
488 ptid_t parent, child;
490 /* If the user did a next/step, etc, over a fork call,
491 preserve the stepping state in the fork child. */
492 if (follow_child && should_resume)
494 step_resume_breakpoint = clone_momentary_breakpoint
495 (tp->control.step_resume_breakpoint);
496 step_range_start = tp->control.step_range_start;
497 step_range_end = tp->control.step_range_end;
498 step_frame_id = tp->control.step_frame_id;
499 exception_resume_breakpoint
500 = clone_momentary_breakpoint (tp->control.exception_resume_breakpoint);
502 /* For now, delete the parent's sr breakpoint, otherwise,
503 parent/child sr breakpoints are considered duplicates,
504 and the child version will not be installed. Remove
505 this when the breakpoints module becomes aware of
506 inferiors and address spaces. */
507 delete_step_resume_breakpoint (tp);
508 tp->control.step_range_start = 0;
509 tp->control.step_range_end = 0;
510 tp->control.step_frame_id = null_frame_id;
511 delete_exception_resume_breakpoint (tp);
514 parent = inferior_ptid;
515 child = tp->pending_follow.value.related_pid;
517 /* Tell the target to do whatever is necessary to follow
518 either parent or child. */
519 if (target_follow_fork (follow_child))
521 /* Target refused to follow, or there's some other reason
522 we shouldn't resume. */
527 /* This pending follow fork event is now handled, one way
528 or another. The previous selected thread may be gone
529 from the lists by now, but if it is still around, need
530 to clear the pending follow request. */
531 tp = find_thread_ptid (parent);
533 tp->pending_follow.kind = TARGET_WAITKIND_SPURIOUS;
535 /* This makes sure we don't try to apply the "Switched
536 over from WAIT_PID" logic above. */
537 nullify_last_target_wait_ptid ();
539 /* If we followed the child, switch to it... */
542 switch_to_thread (child);
544 /* ... and preserve the stepping state, in case the
545 user was stepping over the fork call. */
548 tp = inferior_thread ();
549 tp->control.step_resume_breakpoint
550 = step_resume_breakpoint;
551 tp->control.step_range_start = step_range_start;
552 tp->control.step_range_end = step_range_end;
553 tp->control.step_frame_id = step_frame_id;
554 tp->control.exception_resume_breakpoint
555 = exception_resume_breakpoint;
559 /* If we get here, it was because we're trying to
560 resume from a fork catchpoint, but, the user
561 has switched threads away from the thread that
562 forked. In that case, the resume command
563 issued is most likely not applicable to the
564 child, so just warn, and refuse to resume. */
565 warning (_("Not resuming: switched threads "
566 "before following fork child.\n"));
569 /* Reset breakpoints in the child as appropriate. */
570 follow_inferior_reset_breakpoints ();
573 switch_to_thread (parent);
577 case TARGET_WAITKIND_SPURIOUS:
578 /* Nothing to follow. */
581 internal_error (__FILE__, __LINE__,
582 "Unexpected pending_follow.kind %d\n",
583 tp->pending_follow.kind);
587 return should_resume;
591 follow_inferior_reset_breakpoints (void)
593 struct thread_info *tp = inferior_thread ();
595 /* Was there a step_resume breakpoint? (There was if the user
596 did a "next" at the fork() call.) If so, explicitly reset its
599 step_resumes are a form of bp that are made to be per-thread.
600 Since we created the step_resume bp when the parent process
601 was being debugged, and now are switching to the child process,
602 from the breakpoint package's viewpoint, that's a switch of
603 "threads". We must update the bp's notion of which thread
604 it is for, or it'll be ignored when it triggers. */
606 if (tp->control.step_resume_breakpoint)
607 breakpoint_re_set_thread (tp->control.step_resume_breakpoint);
609 if (tp->control.exception_resume_breakpoint)
610 breakpoint_re_set_thread (tp->control.exception_resume_breakpoint);
612 /* Reinsert all breakpoints in the child. The user may have set
613 breakpoints after catching the fork, in which case those
614 were never set in the child, but only in the parent. This makes
615 sure the inserted breakpoints match the breakpoint list. */
617 breakpoint_re_set ();
618 insert_breakpoints ();
621 /* The child has exited or execed: resume threads of the parent the
622 user wanted to be executing. */
625 proceed_after_vfork_done (struct thread_info *thread,
628 int pid = * (int *) arg;
630 if (ptid_get_pid (thread->ptid) == pid
631 && is_running (thread->ptid)
632 && !is_executing (thread->ptid)
633 && !thread->stop_requested
634 && thread->suspend.stop_signal == GDB_SIGNAL_0)
637 fprintf_unfiltered (gdb_stdlog,
638 "infrun: resuming vfork parent thread %s\n",
639 target_pid_to_str (thread->ptid));
641 switch_to_thread (thread->ptid);
642 clear_proceed_status ();
643 proceed ((CORE_ADDR) -1, GDB_SIGNAL_DEFAULT, 0);
649 /* Called whenever we notice an exec or exit event, to handle
650 detaching or resuming a vfork parent. */
653 handle_vfork_child_exec_or_exit (int exec)
655 struct inferior *inf = current_inferior ();
657 if (inf->vfork_parent)
659 int resume_parent = -1;
661 /* This exec or exit marks the end of the shared memory region
662 between the parent and the child. If the user wanted to
663 detach from the parent, now is the time. */
665 if (inf->vfork_parent->pending_detach)
667 struct thread_info *tp;
668 struct cleanup *old_chain;
669 struct program_space *pspace;
670 struct address_space *aspace;
672 /* follow-fork child, detach-on-fork on. */
674 inf->vfork_parent->pending_detach = 0;
678 /* If we're handling a child exit, then inferior_ptid
679 points at the inferior's pid, not to a thread. */
680 old_chain = save_inferior_ptid ();
681 save_current_program_space ();
682 save_current_inferior ();
685 old_chain = save_current_space_and_thread ();
687 /* We're letting loose of the parent. */
688 tp = any_live_thread_of_process (inf->vfork_parent->pid);
689 switch_to_thread (tp->ptid);
691 /* We're about to detach from the parent, which implicitly
692 removes breakpoints from its address space. There's a
693 catch here: we want to reuse the spaces for the child,
694 but, parent/child are still sharing the pspace at this
695 point, although the exec in reality makes the kernel give
696 the child a fresh set of new pages. The problem here is
697 that the breakpoints module being unaware of this, would
698 likely chose the child process to write to the parent
699 address space. Swapping the child temporarily away from
700 the spaces has the desired effect. Yes, this is "sort
703 pspace = inf->pspace;
704 aspace = inf->aspace;
708 if (debug_infrun || info_verbose)
710 target_terminal_ours ();
713 fprintf_filtered (gdb_stdlog,
714 "Detaching vfork parent process "
715 "%d after child exec.\n",
716 inf->vfork_parent->pid);
718 fprintf_filtered (gdb_stdlog,
719 "Detaching vfork parent process "
720 "%d after child exit.\n",
721 inf->vfork_parent->pid);
724 target_detach (NULL, 0);
727 inf->pspace = pspace;
728 inf->aspace = aspace;
730 do_cleanups (old_chain);
734 /* We're staying attached to the parent, so, really give the
735 child a new address space. */
736 inf->pspace = add_program_space (maybe_new_address_space ());
737 inf->aspace = inf->pspace->aspace;
739 set_current_program_space (inf->pspace);
741 resume_parent = inf->vfork_parent->pid;
743 /* Break the bonds. */
744 inf->vfork_parent->vfork_child = NULL;
748 struct cleanup *old_chain;
749 struct program_space *pspace;
751 /* If this is a vfork child exiting, then the pspace and
752 aspaces were shared with the parent. Since we're
753 reporting the process exit, we'll be mourning all that is
754 found in the address space, and switching to null_ptid,
755 preparing to start a new inferior. But, since we don't
756 want to clobber the parent's address/program spaces, we
757 go ahead and create a new one for this exiting
760 /* Switch to null_ptid, so that clone_program_space doesn't want
761 to read the selected frame of a dead process. */
762 old_chain = save_inferior_ptid ();
763 inferior_ptid = null_ptid;
765 /* This inferior is dead, so avoid giving the breakpoints
766 module the option to write through to it (cloning a
767 program space resets breakpoints). */
770 pspace = add_program_space (maybe_new_address_space ());
771 set_current_program_space (pspace);
773 inf->symfile_flags = SYMFILE_NO_READ;
774 clone_program_space (pspace, inf->vfork_parent->pspace);
775 inf->pspace = pspace;
776 inf->aspace = pspace->aspace;
778 /* Put back inferior_ptid. We'll continue mourning this
780 do_cleanups (old_chain);
782 resume_parent = inf->vfork_parent->pid;
783 /* Break the bonds. */
784 inf->vfork_parent->vfork_child = NULL;
787 inf->vfork_parent = NULL;
789 gdb_assert (current_program_space == inf->pspace);
791 if (non_stop && resume_parent != -1)
793 /* If the user wanted the parent to be running, let it go
795 struct cleanup *old_chain = make_cleanup_restore_current_thread ();
798 fprintf_unfiltered (gdb_stdlog,
799 "infrun: resuming vfork parent process %d\n",
802 iterate_over_threads (proceed_after_vfork_done, &resume_parent);
804 do_cleanups (old_chain);
809 /* Enum strings for "set|show displaced-stepping". */
811 static const char follow_exec_mode_new[] = "new";
812 static const char follow_exec_mode_same[] = "same";
813 static const char *const follow_exec_mode_names[] =
815 follow_exec_mode_new,
816 follow_exec_mode_same,
820 static const char *follow_exec_mode_string = follow_exec_mode_same;
822 show_follow_exec_mode_string (struct ui_file *file, int from_tty,
823 struct cmd_list_element *c, const char *value)
825 fprintf_filtered (file, _("Follow exec mode is \"%s\".\n"), value);
828 /* EXECD_PATHNAME is assumed to be non-NULL. */
831 follow_exec (ptid_t pid, char *execd_pathname)
833 struct thread_info *th = inferior_thread ();
834 struct inferior *inf = current_inferior ();
836 /* This is an exec event that we actually wish to pay attention to.
837 Refresh our symbol table to the newly exec'd program, remove any
840 If there are breakpoints, they aren't really inserted now,
841 since the exec() transformed our inferior into a fresh set
844 We want to preserve symbolic breakpoints on the list, since
845 we have hopes that they can be reset after the new a.out's
846 symbol table is read.
848 However, any "raw" breakpoints must be removed from the list
849 (e.g., the solib bp's), since their address is probably invalid
852 And, we DON'T want to call delete_breakpoints() here, since
853 that may write the bp's "shadow contents" (the instruction
854 value that was overwritten witha TRAP instruction). Since
855 we now have a new a.out, those shadow contents aren't valid. */
857 mark_breakpoints_out ();
859 update_breakpoints_after_exec ();
861 /* If there was one, it's gone now. We cannot truly step-to-next
862 statement through an exec(). */
863 th->control.step_resume_breakpoint = NULL;
864 th->control.exception_resume_breakpoint = NULL;
865 th->control.step_range_start = 0;
866 th->control.step_range_end = 0;
868 /* The target reports the exec event to the main thread, even if
869 some other thread does the exec, and even if the main thread was
870 already stopped --- if debugging in non-stop mode, it's possible
871 the user had the main thread held stopped in the previous image
872 --- release it now. This is the same behavior as step-over-exec
873 with scheduler-locking on in all-stop mode. */
874 th->stop_requested = 0;
876 /* What is this a.out's name? */
877 printf_unfiltered (_("%s is executing new program: %s\n"),
878 target_pid_to_str (inferior_ptid),
881 /* We've followed the inferior through an exec. Therefore, the
882 inferior has essentially been killed & reborn. */
884 gdb_flush (gdb_stdout);
886 breakpoint_init_inferior (inf_execd);
888 if (gdb_sysroot && *gdb_sysroot)
890 char *name = alloca (strlen (gdb_sysroot)
891 + strlen (execd_pathname)
894 strcpy (name, gdb_sysroot);
895 strcat (name, execd_pathname);
896 execd_pathname = name;
899 /* Reset the shared library package. This ensures that we get a
900 shlib event when the child reaches "_start", at which point the
901 dld will have had a chance to initialize the child. */
902 /* Also, loading a symbol file below may trigger symbol lookups, and
903 we don't want those to be satisfied by the libraries of the
904 previous incarnation of this process. */
905 no_shared_libraries (NULL, 0);
907 if (follow_exec_mode_string == follow_exec_mode_new)
909 struct program_space *pspace;
911 /* The user wants to keep the old inferior and program spaces
912 around. Create a new fresh one, and switch to it. */
914 inf = add_inferior (current_inferior ()->pid);
915 pspace = add_program_space (maybe_new_address_space ());
916 inf->pspace = pspace;
917 inf->aspace = pspace->aspace;
919 exit_inferior_num_silent (current_inferior ()->num);
921 set_current_inferior (inf);
922 set_current_program_space (pspace);
926 /* The old description may no longer be fit for the new image.
927 E.g, a 64-bit process exec'ed a 32-bit process. Clear the
928 old description; we'll read a new one below. No need to do
929 this on "follow-exec-mode new", as the old inferior stays
930 around (its description is later cleared/refetched on
932 target_clear_description ();
935 gdb_assert (current_program_space == inf->pspace);
937 /* That a.out is now the one to use. */
938 exec_file_attach (execd_pathname, 0);
940 /* SYMFILE_DEFER_BP_RESET is used as the proper displacement for PIE
941 (Position Independent Executable) main symbol file will get applied by
942 solib_create_inferior_hook below. breakpoint_re_set would fail to insert
943 the breakpoints with the zero displacement. */
945 symbol_file_add (execd_pathname,
947 | SYMFILE_MAINLINE | SYMFILE_DEFER_BP_RESET),
950 if ((inf->symfile_flags & SYMFILE_NO_READ) == 0)
951 set_initial_language ();
953 /* If the target can specify a description, read it. Must do this
954 after flipping to the new executable (because the target supplied
955 description must be compatible with the executable's
956 architecture, and the old executable may e.g., be 32-bit, while
957 the new one 64-bit), and before anything involving memory or
959 target_find_description ();
961 #ifdef SOLIB_CREATE_INFERIOR_HOOK
962 SOLIB_CREATE_INFERIOR_HOOK (PIDGET (inferior_ptid));
964 solib_create_inferior_hook (0);
967 jit_inferior_created_hook ();
969 breakpoint_re_set ();
971 /* Reinsert all breakpoints. (Those which were symbolic have
972 been reset to the proper address in the new a.out, thanks
973 to symbol_file_command...). */
974 insert_breakpoints ();
976 /* The next resume of this inferior should bring it to the shlib
977 startup breakpoints. (If the user had also set bp's on
978 "main" from the old (parent) process, then they'll auto-
979 matically get reset there in the new process.). */
982 /* Non-zero if we just simulating a single-step. This is needed
983 because we cannot remove the breakpoints in the inferior process
984 until after the `wait' in `wait_for_inferior'. */
985 static int singlestep_breakpoints_inserted_p = 0;
987 /* The thread we inserted single-step breakpoints for. */
988 static ptid_t singlestep_ptid;
990 /* PC when we started this single-step. */
991 static CORE_ADDR singlestep_pc;
993 /* If another thread hit the singlestep breakpoint, we save the original
994 thread here so that we can resume single-stepping it later. */
995 static ptid_t saved_singlestep_ptid;
996 static int stepping_past_singlestep_breakpoint;
998 /* If not equal to null_ptid, this means that after stepping over breakpoint
999 is finished, we need to switch to deferred_step_ptid, and step it.
1001 The use case is when one thread has hit a breakpoint, and then the user
1002 has switched to another thread and issued 'step'. We need to step over
1003 breakpoint in the thread which hit the breakpoint, but then continue
1004 stepping the thread user has selected. */
1005 static ptid_t deferred_step_ptid;
1007 /* Displaced stepping. */
1009 /* In non-stop debugging mode, we must take special care to manage
1010 breakpoints properly; in particular, the traditional strategy for
1011 stepping a thread past a breakpoint it has hit is unsuitable.
1012 'Displaced stepping' is a tactic for stepping one thread past a
1013 breakpoint it has hit while ensuring that other threads running
1014 concurrently will hit the breakpoint as they should.
1016 The traditional way to step a thread T off a breakpoint in a
1017 multi-threaded program in all-stop mode is as follows:
1019 a0) Initially, all threads are stopped, and breakpoints are not
1021 a1) We single-step T, leaving breakpoints uninserted.
1022 a2) We insert breakpoints, and resume all threads.
1024 In non-stop debugging, however, this strategy is unsuitable: we
1025 don't want to have to stop all threads in the system in order to
1026 continue or step T past a breakpoint. Instead, we use displaced
1029 n0) Initially, T is stopped, other threads are running, and
1030 breakpoints are inserted.
1031 n1) We copy the instruction "under" the breakpoint to a separate
1032 location, outside the main code stream, making any adjustments
1033 to the instruction, register, and memory state as directed by
1035 n2) We single-step T over the instruction at its new location.
1036 n3) We adjust the resulting register and memory state as directed
1037 by T's architecture. This includes resetting T's PC to point
1038 back into the main instruction stream.
1041 This approach depends on the following gdbarch methods:
1043 - gdbarch_max_insn_length and gdbarch_displaced_step_location
1044 indicate where to copy the instruction, and how much space must
1045 be reserved there. We use these in step n1.
1047 - gdbarch_displaced_step_copy_insn copies a instruction to a new
1048 address, and makes any necessary adjustments to the instruction,
1049 register contents, and memory. We use this in step n1.
1051 - gdbarch_displaced_step_fixup adjusts registers and memory after
1052 we have successfuly single-stepped the instruction, to yield the
1053 same effect the instruction would have had if we had executed it
1054 at its original address. We use this in step n3.
1056 - gdbarch_displaced_step_free_closure provides cleanup.
1058 The gdbarch_displaced_step_copy_insn and
1059 gdbarch_displaced_step_fixup functions must be written so that
1060 copying an instruction with gdbarch_displaced_step_copy_insn,
1061 single-stepping across the copied instruction, and then applying
1062 gdbarch_displaced_insn_fixup should have the same effects on the
1063 thread's memory and registers as stepping the instruction in place
1064 would have. Exactly which responsibilities fall to the copy and
1065 which fall to the fixup is up to the author of those functions.
1067 See the comments in gdbarch.sh for details.
1069 Note that displaced stepping and software single-step cannot
1070 currently be used in combination, although with some care I think
1071 they could be made to. Software single-step works by placing
1072 breakpoints on all possible subsequent instructions; if the
1073 displaced instruction is a PC-relative jump, those breakpoints
1074 could fall in very strange places --- on pages that aren't
1075 executable, or at addresses that are not proper instruction
1076 boundaries. (We do generally let other threads run while we wait
1077 to hit the software single-step breakpoint, and they might
1078 encounter such a corrupted instruction.) One way to work around
1079 this would be to have gdbarch_displaced_step_copy_insn fully
1080 simulate the effect of PC-relative instructions (and return NULL)
1081 on architectures that use software single-stepping.
1083 In non-stop mode, we can have independent and simultaneous step
1084 requests, so more than one thread may need to simultaneously step
1085 over a breakpoint. The current implementation assumes there is
1086 only one scratch space per process. In this case, we have to
1087 serialize access to the scratch space. If thread A wants to step
1088 over a breakpoint, but we are currently waiting for some other
1089 thread to complete a displaced step, we leave thread A stopped and
1090 place it in the displaced_step_request_queue. Whenever a displaced
1091 step finishes, we pick the next thread in the queue and start a new
1092 displaced step operation on it. See displaced_step_prepare and
1093 displaced_step_fixup for details. */
1095 struct displaced_step_request
1098 struct displaced_step_request *next;
1101 /* Per-inferior displaced stepping state. */
1102 struct displaced_step_inferior_state
1104 /* Pointer to next in linked list. */
1105 struct displaced_step_inferior_state *next;
1107 /* The process this displaced step state refers to. */
1110 /* A queue of pending displaced stepping requests. One entry per
1111 thread that needs to do a displaced step. */
1112 struct displaced_step_request *step_request_queue;
1114 /* If this is not null_ptid, this is the thread carrying out a
1115 displaced single-step in process PID. This thread's state will
1116 require fixing up once it has completed its step. */
1119 /* The architecture the thread had when we stepped it. */
1120 struct gdbarch *step_gdbarch;
1122 /* The closure provided gdbarch_displaced_step_copy_insn, to be used
1123 for post-step cleanup. */
1124 struct displaced_step_closure *step_closure;
1126 /* The address of the original instruction, and the copy we
1128 CORE_ADDR step_original, step_copy;
1130 /* Saved contents of copy area. */
1131 gdb_byte *step_saved_copy;
1134 /* The list of states of processes involved in displaced stepping
1136 static struct displaced_step_inferior_state *displaced_step_inferior_states;
1138 /* Get the displaced stepping state of process PID. */
1140 static struct displaced_step_inferior_state *
1141 get_displaced_stepping_state (int pid)
1143 struct displaced_step_inferior_state *state;
1145 for (state = displaced_step_inferior_states;
1147 state = state->next)
1148 if (state->pid == pid)
1154 /* Add a new displaced stepping state for process PID to the displaced
1155 stepping state list, or return a pointer to an already existing
1156 entry, if it already exists. Never returns NULL. */
1158 static struct displaced_step_inferior_state *
1159 add_displaced_stepping_state (int pid)
1161 struct displaced_step_inferior_state *state;
1163 for (state = displaced_step_inferior_states;
1165 state = state->next)
1166 if (state->pid == pid)
1169 state = xcalloc (1, sizeof (*state));
1171 state->next = displaced_step_inferior_states;
1172 displaced_step_inferior_states = state;
1177 /* If inferior is in displaced stepping, and ADDR equals to starting address
1178 of copy area, return corresponding displaced_step_closure. Otherwise,
1181 struct displaced_step_closure*
1182 get_displaced_step_closure_by_addr (CORE_ADDR addr)
1184 struct displaced_step_inferior_state *displaced
1185 = get_displaced_stepping_state (ptid_get_pid (inferior_ptid));
1187 /* If checking the mode of displaced instruction in copy area. */
1188 if (displaced && !ptid_equal (displaced->step_ptid, null_ptid)
1189 && (displaced->step_copy == addr))
1190 return displaced->step_closure;
1195 /* Remove the displaced stepping state of process PID. */
1198 remove_displaced_stepping_state (int pid)
1200 struct displaced_step_inferior_state *it, **prev_next_p;
1202 gdb_assert (pid != 0);
1204 it = displaced_step_inferior_states;
1205 prev_next_p = &displaced_step_inferior_states;
1210 *prev_next_p = it->next;
1215 prev_next_p = &it->next;
1221 infrun_inferior_exit (struct inferior *inf)
1223 remove_displaced_stepping_state (inf->pid);
1226 /* If ON, and the architecture supports it, GDB will use displaced
1227 stepping to step over breakpoints. If OFF, or if the architecture
1228 doesn't support it, GDB will instead use the traditional
1229 hold-and-step approach. If AUTO (which is the default), GDB will
1230 decide which technique to use to step over breakpoints depending on
1231 which of all-stop or non-stop mode is active --- displaced stepping
1232 in non-stop mode; hold-and-step in all-stop mode. */
1234 static enum auto_boolean can_use_displaced_stepping = AUTO_BOOLEAN_AUTO;
1237 show_can_use_displaced_stepping (struct ui_file *file, int from_tty,
1238 struct cmd_list_element *c,
1241 if (can_use_displaced_stepping == AUTO_BOOLEAN_AUTO)
1242 fprintf_filtered (file,
1243 _("Debugger's willingness to use displaced stepping "
1244 "to step over breakpoints is %s (currently %s).\n"),
1245 value, non_stop ? "on" : "off");
1247 fprintf_filtered (file,
1248 _("Debugger's willingness to use displaced stepping "
1249 "to step over breakpoints is %s.\n"), value);
1252 /* Return non-zero if displaced stepping can/should be used to step
1253 over breakpoints. */
1256 use_displaced_stepping (struct gdbarch *gdbarch)
1258 return (((can_use_displaced_stepping == AUTO_BOOLEAN_AUTO && non_stop)
1259 || can_use_displaced_stepping == AUTO_BOOLEAN_TRUE)
1260 && gdbarch_displaced_step_copy_insn_p (gdbarch)
1261 && !RECORD_IS_USED);
1264 /* Clean out any stray displaced stepping state. */
1266 displaced_step_clear (struct displaced_step_inferior_state *displaced)
1268 /* Indicate that there is no cleanup pending. */
1269 displaced->step_ptid = null_ptid;
1271 if (displaced->step_closure)
1273 gdbarch_displaced_step_free_closure (displaced->step_gdbarch,
1274 displaced->step_closure);
1275 displaced->step_closure = NULL;
1280 displaced_step_clear_cleanup (void *arg)
1282 struct displaced_step_inferior_state *state = arg;
1284 displaced_step_clear (state);
1287 /* Dump LEN bytes at BUF in hex to FILE, followed by a newline. */
1289 displaced_step_dump_bytes (struct ui_file *file,
1290 const gdb_byte *buf,
1295 for (i = 0; i < len; i++)
1296 fprintf_unfiltered (file, "%02x ", buf[i]);
1297 fputs_unfiltered ("\n", file);
1300 /* Prepare to single-step, using displaced stepping.
1302 Note that we cannot use displaced stepping when we have a signal to
1303 deliver. If we have a signal to deliver and an instruction to step
1304 over, then after the step, there will be no indication from the
1305 target whether the thread entered a signal handler or ignored the
1306 signal and stepped over the instruction successfully --- both cases
1307 result in a simple SIGTRAP. In the first case we mustn't do a
1308 fixup, and in the second case we must --- but we can't tell which.
1309 Comments in the code for 'random signals' in handle_inferior_event
1310 explain how we handle this case instead.
1312 Returns 1 if preparing was successful -- this thread is going to be
1313 stepped now; or 0 if displaced stepping this thread got queued. */
1315 displaced_step_prepare (ptid_t ptid)
1317 struct cleanup *old_cleanups, *ignore_cleanups;
1318 struct regcache *regcache = get_thread_regcache (ptid);
1319 struct gdbarch *gdbarch = get_regcache_arch (regcache);
1320 CORE_ADDR original, copy;
1322 struct displaced_step_closure *closure;
1323 struct displaced_step_inferior_state *displaced;
1326 /* We should never reach this function if the architecture does not
1327 support displaced stepping. */
1328 gdb_assert (gdbarch_displaced_step_copy_insn_p (gdbarch));
1330 /* We have to displaced step one thread at a time, as we only have
1331 access to a single scratch space per inferior. */
1333 displaced = add_displaced_stepping_state (ptid_get_pid (ptid));
1335 if (!ptid_equal (displaced->step_ptid, null_ptid))
1337 /* Already waiting for a displaced step to finish. Defer this
1338 request and place in queue. */
1339 struct displaced_step_request *req, *new_req;
1341 if (debug_displaced)
1342 fprintf_unfiltered (gdb_stdlog,
1343 "displaced: defering step of %s\n",
1344 target_pid_to_str (ptid));
1346 new_req = xmalloc (sizeof (*new_req));
1347 new_req->ptid = ptid;
1348 new_req->next = NULL;
1350 if (displaced->step_request_queue)
1352 for (req = displaced->step_request_queue;
1356 req->next = new_req;
1359 displaced->step_request_queue = new_req;
1365 if (debug_displaced)
1366 fprintf_unfiltered (gdb_stdlog,
1367 "displaced: stepping %s now\n",
1368 target_pid_to_str (ptid));
1371 displaced_step_clear (displaced);
1373 old_cleanups = save_inferior_ptid ();
1374 inferior_ptid = ptid;
1376 original = regcache_read_pc (regcache);
1378 copy = gdbarch_displaced_step_location (gdbarch);
1379 len = gdbarch_max_insn_length (gdbarch);
1381 /* Save the original contents of the copy area. */
1382 displaced->step_saved_copy = xmalloc (len);
1383 ignore_cleanups = make_cleanup (free_current_contents,
1384 &displaced->step_saved_copy);
1385 status = target_read_memory (copy, displaced->step_saved_copy, len);
1387 throw_error (MEMORY_ERROR,
1388 _("Error accessing memory address %s (%s) for "
1389 "displaced-stepping scratch space."),
1390 paddress (gdbarch, copy), safe_strerror (status));
1391 if (debug_displaced)
1393 fprintf_unfiltered (gdb_stdlog, "displaced: saved %s: ",
1394 paddress (gdbarch, copy));
1395 displaced_step_dump_bytes (gdb_stdlog,
1396 displaced->step_saved_copy,
1400 closure = gdbarch_displaced_step_copy_insn (gdbarch,
1401 original, copy, regcache);
1403 /* We don't support the fully-simulated case at present. */
1404 gdb_assert (closure);
1406 /* Save the information we need to fix things up if the step
1408 displaced->step_ptid = ptid;
1409 displaced->step_gdbarch = gdbarch;
1410 displaced->step_closure = closure;
1411 displaced->step_original = original;
1412 displaced->step_copy = copy;
1414 make_cleanup (displaced_step_clear_cleanup, displaced);
1416 /* Resume execution at the copy. */
1417 regcache_write_pc (regcache, copy);
1419 discard_cleanups (ignore_cleanups);
1421 do_cleanups (old_cleanups);
1423 if (debug_displaced)
1424 fprintf_unfiltered (gdb_stdlog, "displaced: displaced pc to %s\n",
1425 paddress (gdbarch, copy));
1431 write_memory_ptid (ptid_t ptid, CORE_ADDR memaddr,
1432 const gdb_byte *myaddr, int len)
1434 struct cleanup *ptid_cleanup = save_inferior_ptid ();
1436 inferior_ptid = ptid;
1437 write_memory (memaddr, myaddr, len);
1438 do_cleanups (ptid_cleanup);
1441 /* Restore the contents of the copy area for thread PTID. */
1444 displaced_step_restore (struct displaced_step_inferior_state *displaced,
1447 ULONGEST len = gdbarch_max_insn_length (displaced->step_gdbarch);
1449 write_memory_ptid (ptid, displaced->step_copy,
1450 displaced->step_saved_copy, len);
1451 if (debug_displaced)
1452 fprintf_unfiltered (gdb_stdlog, "displaced: restored %s %s\n",
1453 target_pid_to_str (ptid),
1454 paddress (displaced->step_gdbarch,
1455 displaced->step_copy));
1459 displaced_step_fixup (ptid_t event_ptid, enum gdb_signal signal)
1461 struct cleanup *old_cleanups;
1462 struct displaced_step_inferior_state *displaced
1463 = get_displaced_stepping_state (ptid_get_pid (event_ptid));
1465 /* Was any thread of this process doing a displaced step? */
1466 if (displaced == NULL)
1469 /* Was this event for the pid we displaced? */
1470 if (ptid_equal (displaced->step_ptid, null_ptid)
1471 || ! ptid_equal (displaced->step_ptid, event_ptid))
1474 old_cleanups = make_cleanup (displaced_step_clear_cleanup, displaced);
1476 displaced_step_restore (displaced, displaced->step_ptid);
1478 /* Did the instruction complete successfully? */
1479 if (signal == GDB_SIGNAL_TRAP)
1481 /* Fix up the resulting state. */
1482 gdbarch_displaced_step_fixup (displaced->step_gdbarch,
1483 displaced->step_closure,
1484 displaced->step_original,
1485 displaced->step_copy,
1486 get_thread_regcache (displaced->step_ptid));
1490 /* Since the instruction didn't complete, all we can do is
1492 struct regcache *regcache = get_thread_regcache (event_ptid);
1493 CORE_ADDR pc = regcache_read_pc (regcache);
1495 pc = displaced->step_original + (pc - displaced->step_copy);
1496 regcache_write_pc (regcache, pc);
1499 do_cleanups (old_cleanups);
1501 displaced->step_ptid = null_ptid;
1503 /* Are there any pending displaced stepping requests? If so, run
1504 one now. Leave the state object around, since we're likely to
1505 need it again soon. */
1506 while (displaced->step_request_queue)
1508 struct displaced_step_request *head;
1510 struct regcache *regcache;
1511 struct gdbarch *gdbarch;
1512 CORE_ADDR actual_pc;
1513 struct address_space *aspace;
1515 head = displaced->step_request_queue;
1517 displaced->step_request_queue = head->next;
1520 context_switch (ptid);
1522 regcache = get_thread_regcache (ptid);
1523 actual_pc = regcache_read_pc (regcache);
1524 aspace = get_regcache_aspace (regcache);
1526 if (breakpoint_here_p (aspace, actual_pc))
1528 if (debug_displaced)
1529 fprintf_unfiltered (gdb_stdlog,
1530 "displaced: stepping queued %s now\n",
1531 target_pid_to_str (ptid));
1533 displaced_step_prepare (ptid);
1535 gdbarch = get_regcache_arch (regcache);
1537 if (debug_displaced)
1539 CORE_ADDR actual_pc = regcache_read_pc (regcache);
1542 fprintf_unfiltered (gdb_stdlog, "displaced: run %s: ",
1543 paddress (gdbarch, actual_pc));
1544 read_memory (actual_pc, buf, sizeof (buf));
1545 displaced_step_dump_bytes (gdb_stdlog, buf, sizeof (buf));
1548 if (gdbarch_displaced_step_hw_singlestep (gdbarch,
1549 displaced->step_closure))
1550 target_resume (ptid, 1, GDB_SIGNAL_0);
1552 target_resume (ptid, 0, GDB_SIGNAL_0);
1554 /* Done, we're stepping a thread. */
1560 struct thread_info *tp = inferior_thread ();
1562 /* The breakpoint we were sitting under has since been
1564 tp->control.trap_expected = 0;
1566 /* Go back to what we were trying to do. */
1567 step = currently_stepping (tp);
1569 if (debug_displaced)
1570 fprintf_unfiltered (gdb_stdlog,
1571 "displaced: breakpoint is gone: %s, step(%d)\n",
1572 target_pid_to_str (tp->ptid), step);
1574 target_resume (ptid, step, GDB_SIGNAL_0);
1575 tp->suspend.stop_signal = GDB_SIGNAL_0;
1577 /* This request was discarded. See if there's any other
1578 thread waiting for its turn. */
1583 /* Update global variables holding ptids to hold NEW_PTID if they were
1584 holding OLD_PTID. */
1586 infrun_thread_ptid_changed (ptid_t old_ptid, ptid_t new_ptid)
1588 struct displaced_step_request *it;
1589 struct displaced_step_inferior_state *displaced;
1591 if (ptid_equal (inferior_ptid, old_ptid))
1592 inferior_ptid = new_ptid;
1594 if (ptid_equal (singlestep_ptid, old_ptid))
1595 singlestep_ptid = new_ptid;
1597 if (ptid_equal (deferred_step_ptid, old_ptid))
1598 deferred_step_ptid = new_ptid;
1600 for (displaced = displaced_step_inferior_states;
1602 displaced = displaced->next)
1604 if (ptid_equal (displaced->step_ptid, old_ptid))
1605 displaced->step_ptid = new_ptid;
1607 for (it = displaced->step_request_queue; it; it = it->next)
1608 if (ptid_equal (it->ptid, old_ptid))
1609 it->ptid = new_ptid;
1616 /* Things to clean up if we QUIT out of resume (). */
1618 resume_cleanups (void *ignore)
1623 static const char schedlock_off[] = "off";
1624 static const char schedlock_on[] = "on";
1625 static const char schedlock_step[] = "step";
1626 static const char *const scheduler_enums[] = {
1632 static const char *scheduler_mode = schedlock_off;
1634 show_scheduler_mode (struct ui_file *file, int from_tty,
1635 struct cmd_list_element *c, const char *value)
1637 fprintf_filtered (file,
1638 _("Mode for locking scheduler "
1639 "during execution is \"%s\".\n"),
1644 set_schedlock_func (char *args, int from_tty, struct cmd_list_element *c)
1646 if (!target_can_lock_scheduler)
1648 scheduler_mode = schedlock_off;
1649 error (_("Target '%s' cannot support this command."), target_shortname);
1653 /* True if execution commands resume all threads of all processes by
1654 default; otherwise, resume only threads of the current inferior
1656 int sched_multi = 0;
1658 /* Try to setup for software single stepping over the specified location.
1659 Return 1 if target_resume() should use hardware single step.
1661 GDBARCH the current gdbarch.
1662 PC the location to step over. */
1665 maybe_software_singlestep (struct gdbarch *gdbarch, CORE_ADDR pc)
1669 if (execution_direction == EXEC_FORWARD
1670 && gdbarch_software_single_step_p (gdbarch)
1671 && gdbarch_software_single_step (gdbarch, get_current_frame ()))
1674 /* Do not pull these breakpoints until after a `wait' in
1675 `wait_for_inferior'. */
1676 singlestep_breakpoints_inserted_p = 1;
1677 singlestep_ptid = inferior_ptid;
1683 /* Return a ptid representing the set of threads that we will proceed,
1684 in the perspective of the user/frontend. We may actually resume
1685 fewer threads at first, e.g., if a thread is stopped at a
1686 breakpoint that needs stepping-off, but that should not be visible
1687 to the user/frontend, and neither should the frontend/user be
1688 allowed to proceed any of the threads that happen to be stopped for
1689 internal run control handling, if a previous command wanted them
1693 user_visible_resume_ptid (int step)
1695 /* By default, resume all threads of all processes. */
1696 ptid_t resume_ptid = RESUME_ALL;
1698 /* Maybe resume only all threads of the current process. */
1699 if (!sched_multi && target_supports_multi_process ())
1701 resume_ptid = pid_to_ptid (ptid_get_pid (inferior_ptid));
1704 /* Maybe resume a single thread after all. */
1707 /* With non-stop mode on, threads are always handled
1709 resume_ptid = inferior_ptid;
1711 else if ((scheduler_mode == schedlock_on)
1712 || (scheduler_mode == schedlock_step
1713 && (step || singlestep_breakpoints_inserted_p)))
1715 /* User-settable 'scheduler' mode requires solo thread resume. */
1716 resume_ptid = inferior_ptid;
1722 /* Resume the inferior, but allow a QUIT. This is useful if the user
1723 wants to interrupt some lengthy single-stepping operation
1724 (for child processes, the SIGINT goes to the inferior, and so
1725 we get a SIGINT random_signal, but for remote debugging and perhaps
1726 other targets, that's not true).
1728 STEP nonzero if we should step (zero to continue instead).
1729 SIG is the signal to give the inferior (zero for none). */
1731 resume (int step, enum gdb_signal sig)
1733 int should_resume = 1;
1734 struct cleanup *old_cleanups = make_cleanup (resume_cleanups, 0);
1735 struct regcache *regcache = get_current_regcache ();
1736 struct gdbarch *gdbarch = get_regcache_arch (regcache);
1737 struct thread_info *tp = inferior_thread ();
1738 CORE_ADDR pc = regcache_read_pc (regcache);
1739 struct address_space *aspace = get_regcache_aspace (regcache);
1743 if (current_inferior ()->waiting_for_vfork_done)
1745 /* Don't try to single-step a vfork parent that is waiting for
1746 the child to get out of the shared memory region (by exec'ing
1747 or exiting). This is particularly important on software
1748 single-step archs, as the child process would trip on the
1749 software single step breakpoint inserted for the parent
1750 process. Since the parent will not actually execute any
1751 instruction until the child is out of the shared region (such
1752 are vfork's semantics), it is safe to simply continue it.
1753 Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for
1754 the parent, and tell it to `keep_going', which automatically
1755 re-sets it stepping. */
1757 fprintf_unfiltered (gdb_stdlog,
1758 "infrun: resume : clear step\n");
1763 fprintf_unfiltered (gdb_stdlog,
1764 "infrun: resume (step=%d, signal=%d), "
1765 "trap_expected=%d, current thread [%s] at %s\n",
1766 step, sig, tp->control.trap_expected,
1767 target_pid_to_str (inferior_ptid),
1768 paddress (gdbarch, pc));
1770 /* Normally, by the time we reach `resume', the breakpoints are either
1771 removed or inserted, as appropriate. The exception is if we're sitting
1772 at a permanent breakpoint; we need to step over it, but permanent
1773 breakpoints can't be removed. So we have to test for it here. */
1774 if (breakpoint_here_p (aspace, pc) == permanent_breakpoint_here)
1776 if (gdbarch_skip_permanent_breakpoint_p (gdbarch))
1777 gdbarch_skip_permanent_breakpoint (gdbarch, regcache);
1780 The program is stopped at a permanent breakpoint, but GDB does not know\n\
1781 how to step past a permanent breakpoint on this architecture. Try using\n\
1782 a command like `return' or `jump' to continue execution."));
1785 /* If enabled, step over breakpoints by executing a copy of the
1786 instruction at a different address.
1788 We can't use displaced stepping when we have a signal to deliver;
1789 the comments for displaced_step_prepare explain why. The
1790 comments in the handle_inferior event for dealing with 'random
1791 signals' explain what we do instead.
1793 We can't use displaced stepping when we are waiting for vfork_done
1794 event, displaced stepping breaks the vfork child similarly as single
1795 step software breakpoint. */
1796 if (use_displaced_stepping (gdbarch)
1797 && (tp->control.trap_expected
1798 || (step && gdbarch_software_single_step_p (gdbarch)))
1799 && sig == GDB_SIGNAL_0
1800 && !current_inferior ()->waiting_for_vfork_done)
1802 struct displaced_step_inferior_state *displaced;
1804 if (!displaced_step_prepare (inferior_ptid))
1806 /* Got placed in displaced stepping queue. Will be resumed
1807 later when all the currently queued displaced stepping
1808 requests finish. The thread is not executing at this point,
1809 and the call to set_executing will be made later. But we
1810 need to call set_running here, since from frontend point of view,
1811 the thread is running. */
1812 set_running (inferior_ptid, 1);
1813 discard_cleanups (old_cleanups);
1817 /* Update pc to reflect the new address from which we will execute
1818 instructions due to displaced stepping. */
1819 pc = regcache_read_pc (get_thread_regcache (inferior_ptid));
1821 displaced = get_displaced_stepping_state (ptid_get_pid (inferior_ptid));
1822 step = gdbarch_displaced_step_hw_singlestep (gdbarch,
1823 displaced->step_closure);
1826 /* Do we need to do it the hard way, w/temp breakpoints? */
1828 step = maybe_software_singlestep (gdbarch, pc);
1830 /* Currently, our software single-step implementation leads to different
1831 results than hardware single-stepping in one situation: when stepping
1832 into delivering a signal which has an associated signal handler,
1833 hardware single-step will stop at the first instruction of the handler,
1834 while software single-step will simply skip execution of the handler.
1836 For now, this difference in behavior is accepted since there is no
1837 easy way to actually implement single-stepping into a signal handler
1838 without kernel support.
1840 However, there is one scenario where this difference leads to follow-on
1841 problems: if we're stepping off a breakpoint by removing all breakpoints
1842 and then single-stepping. In this case, the software single-step
1843 behavior means that even if there is a *breakpoint* in the signal
1844 handler, GDB still would not stop.
1846 Fortunately, we can at least fix this particular issue. We detect
1847 here the case where we are about to deliver a signal while software
1848 single-stepping with breakpoints removed. In this situation, we
1849 revert the decisions to remove all breakpoints and insert single-
1850 step breakpoints, and instead we install a step-resume breakpoint
1851 at the current address, deliver the signal without stepping, and
1852 once we arrive back at the step-resume breakpoint, actually step
1853 over the breakpoint we originally wanted to step over. */
1854 if (singlestep_breakpoints_inserted_p
1855 && tp->control.trap_expected && sig != GDB_SIGNAL_0)
1857 /* If we have nested signals or a pending signal is delivered
1858 immediately after a handler returns, might might already have
1859 a step-resume breakpoint set on the earlier handler. We cannot
1860 set another step-resume breakpoint; just continue on until the
1861 original breakpoint is hit. */
1862 if (tp->control.step_resume_breakpoint == NULL)
1864 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
1865 tp->step_after_step_resume_breakpoint = 1;
1868 remove_single_step_breakpoints ();
1869 singlestep_breakpoints_inserted_p = 0;
1871 insert_breakpoints ();
1872 tp->control.trap_expected = 0;
1879 /* If STEP is set, it's a request to use hardware stepping
1880 facilities. But in that case, we should never
1881 use singlestep breakpoint. */
1882 gdb_assert (!(singlestep_breakpoints_inserted_p && step));
1884 /* Decide the set of threads to ask the target to resume. Start
1885 by assuming everything will be resumed, than narrow the set
1886 by applying increasingly restricting conditions. */
1887 resume_ptid = user_visible_resume_ptid (step);
1889 /* Maybe resume a single thread after all. */
1890 if (singlestep_breakpoints_inserted_p
1891 && stepping_past_singlestep_breakpoint)
1893 /* The situation here is as follows. In thread T1 we wanted to
1894 single-step. Lacking hardware single-stepping we've
1895 set breakpoint at the PC of the next instruction -- call it
1896 P. After resuming, we've hit that breakpoint in thread T2.
1897 Now we've removed original breakpoint, inserted breakpoint
1898 at P+1, and try to step to advance T2 past breakpoint.
1899 We need to step only T2, as if T1 is allowed to freely run,
1900 it can run past P, and if other threads are allowed to run,
1901 they can hit breakpoint at P+1, and nested hits of single-step
1902 breakpoints is not something we'd want -- that's complicated
1903 to support, and has no value. */
1904 resume_ptid = inferior_ptid;
1906 else if ((step || singlestep_breakpoints_inserted_p)
1907 && tp->control.trap_expected)
1909 /* We're allowing a thread to run past a breakpoint it has
1910 hit, by single-stepping the thread with the breakpoint
1911 removed. In which case, we need to single-step only this
1912 thread, and keep others stopped, as they can miss this
1913 breakpoint if allowed to run.
1915 The current code actually removes all breakpoints when
1916 doing this, not just the one being stepped over, so if we
1917 let other threads run, we can actually miss any
1918 breakpoint, not just the one at PC. */
1919 resume_ptid = inferior_ptid;
1922 if (gdbarch_cannot_step_breakpoint (gdbarch))
1924 /* Most targets can step a breakpoint instruction, thus
1925 executing it normally. But if this one cannot, just
1926 continue and we will hit it anyway. */
1927 if (step && breakpoint_inserted_here_p (aspace, pc))
1932 && use_displaced_stepping (gdbarch)
1933 && tp->control.trap_expected)
1935 struct regcache *resume_regcache = get_thread_regcache (resume_ptid);
1936 struct gdbarch *resume_gdbarch = get_regcache_arch (resume_regcache);
1937 CORE_ADDR actual_pc = regcache_read_pc (resume_regcache);
1940 fprintf_unfiltered (gdb_stdlog, "displaced: run %s: ",
1941 paddress (resume_gdbarch, actual_pc));
1942 read_memory (actual_pc, buf, sizeof (buf));
1943 displaced_step_dump_bytes (gdb_stdlog, buf, sizeof (buf));
1946 /* Install inferior's terminal modes. */
1947 target_terminal_inferior ();
1949 /* Avoid confusing the next resume, if the next stop/resume
1950 happens to apply to another thread. */
1951 tp->suspend.stop_signal = GDB_SIGNAL_0;
1953 /* Advise target which signals may be handled silently. If we have
1954 removed breakpoints because we are stepping over one (which can
1955 happen only if we are not using displaced stepping), we need to
1956 receive all signals to avoid accidentally skipping a breakpoint
1957 during execution of a signal handler. */
1958 if ((step || singlestep_breakpoints_inserted_p)
1959 && tp->control.trap_expected
1960 && !use_displaced_stepping (gdbarch))
1961 target_pass_signals (0, NULL);
1963 target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
1965 target_resume (resume_ptid, step, sig);
1968 discard_cleanups (old_cleanups);
1973 /* Clear out all variables saying what to do when inferior is continued.
1974 First do this, then set the ones you want, then call `proceed'. */
1977 clear_proceed_status_thread (struct thread_info *tp)
1980 fprintf_unfiltered (gdb_stdlog,
1981 "infrun: clear_proceed_status_thread (%s)\n",
1982 target_pid_to_str (tp->ptid));
1984 tp->control.trap_expected = 0;
1985 tp->control.step_range_start = 0;
1986 tp->control.step_range_end = 0;
1987 tp->control.step_frame_id = null_frame_id;
1988 tp->control.step_stack_frame_id = null_frame_id;
1989 tp->control.step_over_calls = STEP_OVER_UNDEBUGGABLE;
1990 tp->stop_requested = 0;
1992 tp->control.stop_step = 0;
1994 tp->control.proceed_to_finish = 0;
1996 /* Discard any remaining commands or status from previous stop. */
1997 bpstat_clear (&tp->control.stop_bpstat);
2001 clear_proceed_status_callback (struct thread_info *tp, void *data)
2003 if (is_exited (tp->ptid))
2006 clear_proceed_status_thread (tp);
2011 clear_proceed_status (void)
2015 /* In all-stop mode, delete the per-thread status of all
2016 threads, even if inferior_ptid is null_ptid, there may be
2017 threads on the list. E.g., we may be launching a new
2018 process, while selecting the executable. */
2019 iterate_over_threads (clear_proceed_status_callback, NULL);
2022 if (!ptid_equal (inferior_ptid, null_ptid))
2024 struct inferior *inferior;
2028 /* If in non-stop mode, only delete the per-thread status of
2029 the current thread. */
2030 clear_proceed_status_thread (inferior_thread ());
2033 inferior = current_inferior ();
2034 inferior->control.stop_soon = NO_STOP_QUIETLY;
2037 stop_after_trap = 0;
2039 observer_notify_about_to_proceed ();
2043 regcache_xfree (stop_registers);
2044 stop_registers = NULL;
2048 /* Check the current thread against the thread that reported the most recent
2049 event. If a step-over is required return TRUE and set the current thread
2050 to the old thread. Otherwise return FALSE.
2052 This should be suitable for any targets that support threads. */
2055 prepare_to_proceed (int step)
2058 struct target_waitstatus wait_status;
2059 int schedlock_enabled;
2061 /* With non-stop mode on, threads are always handled individually. */
2062 gdb_assert (! non_stop);
2064 /* Get the last target status returned by target_wait(). */
2065 get_last_target_status (&wait_ptid, &wait_status);
2067 /* Make sure we were stopped at a breakpoint. */
2068 if (wait_status.kind != TARGET_WAITKIND_STOPPED
2069 || (wait_status.value.sig != GDB_SIGNAL_TRAP
2070 && wait_status.value.sig != GDB_SIGNAL_ILL
2071 && wait_status.value.sig != GDB_SIGNAL_SEGV
2072 && wait_status.value.sig != GDB_SIGNAL_EMT))
2077 schedlock_enabled = (scheduler_mode == schedlock_on
2078 || (scheduler_mode == schedlock_step
2081 /* Don't switch over to WAIT_PTID if scheduler locking is on. */
2082 if (schedlock_enabled)
2085 /* Don't switch over if we're about to resume some other process
2086 other than WAIT_PTID's, and schedule-multiple is off. */
2088 && ptid_get_pid (wait_ptid) != ptid_get_pid (inferior_ptid))
2091 /* Switched over from WAIT_PID. */
2092 if (!ptid_equal (wait_ptid, minus_one_ptid)
2093 && !ptid_equal (inferior_ptid, wait_ptid))
2095 struct regcache *regcache = get_thread_regcache (wait_ptid);
2097 if (breakpoint_here_p (get_regcache_aspace (regcache),
2098 regcache_read_pc (regcache)))
2100 /* If stepping, remember current thread to switch back to. */
2102 deferred_step_ptid = inferior_ptid;
2104 /* Switch back to WAIT_PID thread. */
2105 switch_to_thread (wait_ptid);
2108 fprintf_unfiltered (gdb_stdlog,
2109 "infrun: prepare_to_proceed (step=%d), "
2110 "switched to [%s]\n",
2111 step, target_pid_to_str (inferior_ptid));
2113 /* We return 1 to indicate that there is a breakpoint here,
2114 so we need to step over it before continuing to avoid
2115 hitting it straight away. */
2123 /* Basic routine for continuing the program in various fashions.
2125 ADDR is the address to resume at, or -1 for resume where stopped.
2126 SIGGNAL is the signal to give it, or 0 for none,
2127 or -1 for act according to how it stopped.
2128 STEP is nonzero if should trap after one instruction.
2129 -1 means return after that and print nothing.
2130 You should probably set various step_... variables
2131 before calling here, if you are stepping.
2133 You should call clear_proceed_status before calling proceed. */
2136 proceed (CORE_ADDR addr, enum gdb_signal siggnal, int step)
2138 struct regcache *regcache;
2139 struct gdbarch *gdbarch;
2140 struct thread_info *tp;
2142 struct address_space *aspace;
2143 /* GDB may force the inferior to step due to various reasons. */
2146 /* If we're stopped at a fork/vfork, follow the branch set by the
2147 "set follow-fork-mode" command; otherwise, we'll just proceed
2148 resuming the current thread. */
2149 if (!follow_fork ())
2151 /* The target for some reason decided not to resume. */
2153 if (target_can_async_p ())
2154 inferior_event_handler (INF_EXEC_COMPLETE, NULL);
2158 /* We'll update this if & when we switch to a new thread. */
2159 previous_inferior_ptid = inferior_ptid;
2161 regcache = get_current_regcache ();
2162 gdbarch = get_regcache_arch (regcache);
2163 aspace = get_regcache_aspace (regcache);
2164 pc = regcache_read_pc (regcache);
2167 step_start_function = find_pc_function (pc);
2169 stop_after_trap = 1;
2171 if (addr == (CORE_ADDR) -1)
2173 if (pc == stop_pc && breakpoint_here_p (aspace, pc)
2174 && execution_direction != EXEC_REVERSE)
2175 /* There is a breakpoint at the address we will resume at,
2176 step one instruction before inserting breakpoints so that
2177 we do not stop right away (and report a second hit at this
2180 Note, we don't do this in reverse, because we won't
2181 actually be executing the breakpoint insn anyway.
2182 We'll be (un-)executing the previous instruction. */
2185 else if (gdbarch_single_step_through_delay_p (gdbarch)
2186 && gdbarch_single_step_through_delay (gdbarch,
2187 get_current_frame ()))
2188 /* We stepped onto an instruction that needs to be stepped
2189 again before re-inserting the breakpoint, do so. */
2194 regcache_write_pc (regcache, addr);
2198 fprintf_unfiltered (gdb_stdlog,
2199 "infrun: proceed (addr=%s, signal=%d, step=%d)\n",
2200 paddress (gdbarch, addr), siggnal, step);
2203 /* In non-stop, each thread is handled individually. The context
2204 must already be set to the right thread here. */
2208 /* In a multi-threaded task we may select another thread and
2209 then continue or step.
2211 But if the old thread was stopped at a breakpoint, it will
2212 immediately cause another breakpoint stop without any
2213 execution (i.e. it will report a breakpoint hit incorrectly).
2214 So we must step over it first.
2216 prepare_to_proceed checks the current thread against the
2217 thread that reported the most recent event. If a step-over
2218 is required it returns TRUE and sets the current thread to
2220 if (prepare_to_proceed (step))
2224 /* prepare_to_proceed may change the current thread. */
2225 tp = inferior_thread ();
2229 tp->control.trap_expected = 1;
2230 /* If displaced stepping is enabled, we can step over the
2231 breakpoint without hitting it, so leave all breakpoints
2232 inserted. Otherwise we need to disable all breakpoints, step
2233 one instruction, and then re-add them when that step is
2235 if (!use_displaced_stepping (gdbarch))
2236 remove_breakpoints ();
2239 /* We can insert breakpoints if we're not trying to step over one,
2240 or if we are stepping over one but we're using displaced stepping
2242 if (! tp->control.trap_expected || use_displaced_stepping (gdbarch))
2243 insert_breakpoints ();
2247 /* Pass the last stop signal to the thread we're resuming,
2248 irrespective of whether the current thread is the thread that
2249 got the last event or not. This was historically GDB's
2250 behaviour before keeping a stop_signal per thread. */
2252 struct thread_info *last_thread;
2254 struct target_waitstatus last_status;
2256 get_last_target_status (&last_ptid, &last_status);
2257 if (!ptid_equal (inferior_ptid, last_ptid)
2258 && !ptid_equal (last_ptid, null_ptid)
2259 && !ptid_equal (last_ptid, minus_one_ptid))
2261 last_thread = find_thread_ptid (last_ptid);
2264 tp->suspend.stop_signal = last_thread->suspend.stop_signal;
2265 last_thread->suspend.stop_signal = GDB_SIGNAL_0;
2270 if (siggnal != GDB_SIGNAL_DEFAULT)
2271 tp->suspend.stop_signal = siggnal;
2272 /* If this signal should not be seen by program,
2273 give it zero. Used for debugging signals. */
2274 else if (!signal_program[tp->suspend.stop_signal])
2275 tp->suspend.stop_signal = GDB_SIGNAL_0;
2277 annotate_starting ();
2279 /* Make sure that output from GDB appears before output from the
2281 gdb_flush (gdb_stdout);
2283 /* Refresh prev_pc value just prior to resuming. This used to be
2284 done in stop_stepping, however, setting prev_pc there did not handle
2285 scenarios such as inferior function calls or returning from
2286 a function via the return command. In those cases, the prev_pc
2287 value was not set properly for subsequent commands. The prev_pc value
2288 is used to initialize the starting line number in the ecs. With an
2289 invalid value, the gdb next command ends up stopping at the position
2290 represented by the next line table entry past our start position.
2291 On platforms that generate one line table entry per line, this
2292 is not a problem. However, on the ia64, the compiler generates
2293 extraneous line table entries that do not increase the line number.
2294 When we issue the gdb next command on the ia64 after an inferior call
2295 or a return command, we often end up a few instructions forward, still
2296 within the original line we started.
2298 An attempt was made to refresh the prev_pc at the same time the
2299 execution_control_state is initialized (for instance, just before
2300 waiting for an inferior event). But this approach did not work
2301 because of platforms that use ptrace, where the pc register cannot
2302 be read unless the inferior is stopped. At that point, we are not
2303 guaranteed the inferior is stopped and so the regcache_read_pc() call
2304 can fail. Setting the prev_pc value here ensures the value is updated
2305 correctly when the inferior is stopped. */
2306 tp->prev_pc = regcache_read_pc (get_current_regcache ());
2308 /* Fill in with reasonable starting values. */
2309 init_thread_stepping_state (tp);
2311 /* Reset to normal state. */
2312 init_infwait_state ();
2314 /* Resume inferior. */
2315 resume (force_step || step || bpstat_should_step (),
2316 tp->suspend.stop_signal);
2318 /* Wait for it to stop (if not standalone)
2319 and in any case decode why it stopped, and act accordingly. */
2320 /* Do this only if we are not using the event loop, or if the target
2321 does not support asynchronous execution. */
2322 if (!target_can_async_p ())
2324 wait_for_inferior ();
2330 /* Start remote-debugging of a machine over a serial link. */
2333 start_remote (int from_tty)
2335 struct inferior *inferior;
2337 inferior = current_inferior ();
2338 inferior->control.stop_soon = STOP_QUIETLY_REMOTE;
2340 /* Always go on waiting for the target, regardless of the mode. */
2341 /* FIXME: cagney/1999-09-23: At present it isn't possible to
2342 indicate to wait_for_inferior that a target should timeout if
2343 nothing is returned (instead of just blocking). Because of this,
2344 targets expecting an immediate response need to, internally, set
2345 things up so that the target_wait() is forced to eventually
2347 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
2348 differentiate to its caller what the state of the target is after
2349 the initial open has been performed. Here we're assuming that
2350 the target has stopped. It should be possible to eventually have
2351 target_open() return to the caller an indication that the target
2352 is currently running and GDB state should be set to the same as
2353 for an async run. */
2354 wait_for_inferior ();
2356 /* Now that the inferior has stopped, do any bookkeeping like
2357 loading shared libraries. We want to do this before normal_stop,
2358 so that the displayed frame is up to date. */
2359 post_create_inferior (¤t_target, from_tty);
2364 /* Initialize static vars when a new inferior begins. */
2367 init_wait_for_inferior (void)
2369 /* These are meaningless until the first time through wait_for_inferior. */
2371 breakpoint_init_inferior (inf_starting);
2373 clear_proceed_status ();
2375 stepping_past_singlestep_breakpoint = 0;
2376 deferred_step_ptid = null_ptid;
2378 target_last_wait_ptid = minus_one_ptid;
2380 previous_inferior_ptid = inferior_ptid;
2381 init_infwait_state ();
2383 /* Discard any skipped inlined frames. */
2384 clear_inline_frame_state (minus_one_ptid);
2388 /* This enum encodes possible reasons for doing a target_wait, so that
2389 wfi can call target_wait in one place. (Ultimately the call will be
2390 moved out of the infinite loop entirely.) */
2394 infwait_normal_state,
2395 infwait_thread_hop_state,
2396 infwait_step_watch_state,
2397 infwait_nonstep_watch_state
2400 /* The PTID we'll do a target_wait on.*/
2403 /* Current inferior wait state. */
2404 static enum infwait_states infwait_state;
2406 /* Data to be passed around while handling an event. This data is
2407 discarded between events. */
2408 struct execution_control_state
2411 /* The thread that got the event, if this was a thread event; NULL
2413 struct thread_info *event_thread;
2415 struct target_waitstatus ws;
2417 int stop_func_filled_in;
2418 CORE_ADDR stop_func_start;
2419 CORE_ADDR stop_func_end;
2420 const char *stop_func_name;
2424 static void handle_inferior_event (struct execution_control_state *ecs);
2426 static void handle_step_into_function (struct gdbarch *gdbarch,
2427 struct execution_control_state *ecs);
2428 static void handle_step_into_function_backward (struct gdbarch *gdbarch,
2429 struct execution_control_state *ecs);
2430 static void check_exception_resume (struct execution_control_state *,
2431 struct frame_info *);
2433 static void stop_stepping (struct execution_control_state *ecs);
2434 static void prepare_to_wait (struct execution_control_state *ecs);
2435 static void keep_going (struct execution_control_state *ecs);
2437 /* Callback for iterate over threads. If the thread is stopped, but
2438 the user/frontend doesn't know about that yet, go through
2439 normal_stop, as if the thread had just stopped now. ARG points at
2440 a ptid. If PTID is MINUS_ONE_PTID, applies to all threads. If
2441 ptid_is_pid(PTID) is true, applies to all threads of the process
2442 pointed at by PTID. Otherwise, apply only to the thread pointed by
2446 infrun_thread_stop_requested_callback (struct thread_info *info, void *arg)
2448 ptid_t ptid = * (ptid_t *) arg;
2450 if ((ptid_equal (info->ptid, ptid)
2451 || ptid_equal (minus_one_ptid, ptid)
2452 || (ptid_is_pid (ptid)
2453 && ptid_get_pid (ptid) == ptid_get_pid (info->ptid)))
2454 && is_running (info->ptid)
2455 && !is_executing (info->ptid))
2457 struct cleanup *old_chain;
2458 struct execution_control_state ecss;
2459 struct execution_control_state *ecs = &ecss;
2461 memset (ecs, 0, sizeof (*ecs));
2463 old_chain = make_cleanup_restore_current_thread ();
2465 /* Go through handle_inferior_event/normal_stop, so we always
2466 have consistent output as if the stop event had been
2468 ecs->ptid = info->ptid;
2469 ecs->event_thread = find_thread_ptid (info->ptid);
2470 ecs->ws.kind = TARGET_WAITKIND_STOPPED;
2471 ecs->ws.value.sig = GDB_SIGNAL_0;
2473 handle_inferior_event (ecs);
2475 if (!ecs->wait_some_more)
2477 struct thread_info *tp;
2481 /* Finish off the continuations. */
2482 tp = inferior_thread ();
2483 do_all_intermediate_continuations_thread (tp, 1);
2484 do_all_continuations_thread (tp, 1);
2487 do_cleanups (old_chain);
2493 /* This function is attached as a "thread_stop_requested" observer.
2494 Cleanup local state that assumed the PTID was to be resumed, and
2495 report the stop to the frontend. */
2498 infrun_thread_stop_requested (ptid_t ptid)
2500 struct displaced_step_inferior_state *displaced;
2502 /* PTID was requested to stop. Remove it from the displaced
2503 stepping queue, so we don't try to resume it automatically. */
2505 for (displaced = displaced_step_inferior_states;
2507 displaced = displaced->next)
2509 struct displaced_step_request *it, **prev_next_p;
2511 it = displaced->step_request_queue;
2512 prev_next_p = &displaced->step_request_queue;
2515 if (ptid_match (it->ptid, ptid))
2517 *prev_next_p = it->next;
2523 prev_next_p = &it->next;
2530 iterate_over_threads (infrun_thread_stop_requested_callback, &ptid);
2534 infrun_thread_thread_exit (struct thread_info *tp, int silent)
2536 if (ptid_equal (target_last_wait_ptid, tp->ptid))
2537 nullify_last_target_wait_ptid ();
2540 /* Callback for iterate_over_threads. */
2543 delete_step_resume_breakpoint_callback (struct thread_info *info, void *data)
2545 if (is_exited (info->ptid))
2548 delete_step_resume_breakpoint (info);
2549 delete_exception_resume_breakpoint (info);
2553 /* In all-stop, delete the step resume breakpoint of any thread that
2554 had one. In non-stop, delete the step resume breakpoint of the
2555 thread that just stopped. */
2558 delete_step_thread_step_resume_breakpoint (void)
2560 if (!target_has_execution
2561 || ptid_equal (inferior_ptid, null_ptid))
2562 /* If the inferior has exited, we have already deleted the step
2563 resume breakpoints out of GDB's lists. */
2568 /* If in non-stop mode, only delete the step-resume or
2569 longjmp-resume breakpoint of the thread that just stopped
2571 struct thread_info *tp = inferior_thread ();
2573 delete_step_resume_breakpoint (tp);
2574 delete_exception_resume_breakpoint (tp);
2577 /* In all-stop mode, delete all step-resume and longjmp-resume
2578 breakpoints of any thread that had them. */
2579 iterate_over_threads (delete_step_resume_breakpoint_callback, NULL);
2582 /* A cleanup wrapper. */
2585 delete_step_thread_step_resume_breakpoint_cleanup (void *arg)
2587 delete_step_thread_step_resume_breakpoint ();
2590 /* Pretty print the results of target_wait, for debugging purposes. */
2593 print_target_wait_results (ptid_t waiton_ptid, ptid_t result_ptid,
2594 const struct target_waitstatus *ws)
2596 char *status_string = target_waitstatus_to_string (ws);
2597 struct ui_file *tmp_stream = mem_fileopen ();
2600 /* The text is split over several lines because it was getting too long.
2601 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
2602 output as a unit; we want only one timestamp printed if debug_timestamp
2605 fprintf_unfiltered (tmp_stream,
2606 "infrun: target_wait (%d", PIDGET (waiton_ptid));
2607 if (PIDGET (waiton_ptid) != -1)
2608 fprintf_unfiltered (tmp_stream,
2609 " [%s]", target_pid_to_str (waiton_ptid));
2610 fprintf_unfiltered (tmp_stream, ", status) =\n");
2611 fprintf_unfiltered (tmp_stream,
2612 "infrun: %d [%s],\n",
2613 PIDGET (result_ptid), target_pid_to_str (result_ptid));
2614 fprintf_unfiltered (tmp_stream,
2618 text = ui_file_xstrdup (tmp_stream, NULL);
2620 /* This uses %s in part to handle %'s in the text, but also to avoid
2621 a gcc error: the format attribute requires a string literal. */
2622 fprintf_unfiltered (gdb_stdlog, "%s", text);
2624 xfree (status_string);
2626 ui_file_delete (tmp_stream);
2629 /* Prepare and stabilize the inferior for detaching it. E.g.,
2630 detaching while a thread is displaced stepping is a recipe for
2631 crashing it, as nothing would readjust the PC out of the scratch
2635 prepare_for_detach (void)
2637 struct inferior *inf = current_inferior ();
2638 ptid_t pid_ptid = pid_to_ptid (inf->pid);
2639 struct cleanup *old_chain_1;
2640 struct displaced_step_inferior_state *displaced;
2642 displaced = get_displaced_stepping_state (inf->pid);
2644 /* Is any thread of this process displaced stepping? If not,
2645 there's nothing else to do. */
2646 if (displaced == NULL || ptid_equal (displaced->step_ptid, null_ptid))
2650 fprintf_unfiltered (gdb_stdlog,
2651 "displaced-stepping in-process while detaching");
2653 old_chain_1 = make_cleanup_restore_integer (&inf->detaching);
2656 while (!ptid_equal (displaced->step_ptid, null_ptid))
2658 struct cleanup *old_chain_2;
2659 struct execution_control_state ecss;
2660 struct execution_control_state *ecs;
2663 memset (ecs, 0, sizeof (*ecs));
2665 overlay_cache_invalid = 1;
2667 if (deprecated_target_wait_hook)
2668 ecs->ptid = deprecated_target_wait_hook (pid_ptid, &ecs->ws, 0);
2670 ecs->ptid = target_wait (pid_ptid, &ecs->ws, 0);
2673 print_target_wait_results (pid_ptid, ecs->ptid, &ecs->ws);
2675 /* If an error happens while handling the event, propagate GDB's
2676 knowledge of the executing state to the frontend/user running
2678 old_chain_2 = make_cleanup (finish_thread_state_cleanup,
2681 /* Now figure out what to do with the result of the result. */
2682 handle_inferior_event (ecs);
2684 /* No error, don't finish the state yet. */
2685 discard_cleanups (old_chain_2);
2687 /* Breakpoints and watchpoints are not installed on the target
2688 at this point, and signals are passed directly to the
2689 inferior, so this must mean the process is gone. */
2690 if (!ecs->wait_some_more)
2692 discard_cleanups (old_chain_1);
2693 error (_("Program exited while detaching"));
2697 discard_cleanups (old_chain_1);
2700 /* Wait for control to return from inferior to debugger.
2702 If inferior gets a signal, we may decide to start it up again
2703 instead of returning. That is why there is a loop in this function.
2704 When this function actually returns it means the inferior
2705 should be left stopped and GDB should read more commands. */
2708 wait_for_inferior (void)
2710 struct cleanup *old_cleanups;
2714 (gdb_stdlog, "infrun: wait_for_inferior ()\n");
2717 make_cleanup (delete_step_thread_step_resume_breakpoint_cleanup, NULL);
2721 struct execution_control_state ecss;
2722 struct execution_control_state *ecs = &ecss;
2723 struct cleanup *old_chain;
2725 memset (ecs, 0, sizeof (*ecs));
2727 overlay_cache_invalid = 1;
2729 if (deprecated_target_wait_hook)
2730 ecs->ptid = deprecated_target_wait_hook (waiton_ptid, &ecs->ws, 0);
2732 ecs->ptid = target_wait (waiton_ptid, &ecs->ws, 0);
2735 print_target_wait_results (waiton_ptid, ecs->ptid, &ecs->ws);
2737 /* If an error happens while handling the event, propagate GDB's
2738 knowledge of the executing state to the frontend/user running
2740 old_chain = make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
2742 /* Now figure out what to do with the result of the result. */
2743 handle_inferior_event (ecs);
2745 /* No error, don't finish the state yet. */
2746 discard_cleanups (old_chain);
2748 if (!ecs->wait_some_more)
2752 do_cleanups (old_cleanups);
2755 /* Asynchronous version of wait_for_inferior. It is called by the
2756 event loop whenever a change of state is detected on the file
2757 descriptor corresponding to the target. It can be called more than
2758 once to complete a single execution command. In such cases we need
2759 to keep the state in a global variable ECSS. If it is the last time
2760 that this function is called for a single execution command, then
2761 report to the user that the inferior has stopped, and do the
2762 necessary cleanups. */
2765 fetch_inferior_event (void *client_data)
2767 struct execution_control_state ecss;
2768 struct execution_control_state *ecs = &ecss;
2769 struct cleanup *old_chain = make_cleanup (null_cleanup, NULL);
2770 struct cleanup *ts_old_chain;
2771 int was_sync = sync_execution;
2774 memset (ecs, 0, sizeof (*ecs));
2776 /* We're handling a live event, so make sure we're doing live
2777 debugging. If we're looking at traceframes while the target is
2778 running, we're going to need to get back to that mode after
2779 handling the event. */
2782 make_cleanup_restore_current_traceframe ();
2783 set_current_traceframe (-1);
2787 /* In non-stop mode, the user/frontend should not notice a thread
2788 switch due to internal events. Make sure we reverse to the
2789 user selected thread and frame after handling the event and
2790 running any breakpoint commands. */
2791 make_cleanup_restore_current_thread ();
2793 overlay_cache_invalid = 1;
2795 make_cleanup_restore_integer (&execution_direction);
2796 execution_direction = target_execution_direction ();
2798 if (deprecated_target_wait_hook)
2800 deprecated_target_wait_hook (waiton_ptid, &ecs->ws, TARGET_WNOHANG);
2802 ecs->ptid = target_wait (waiton_ptid, &ecs->ws, TARGET_WNOHANG);
2805 print_target_wait_results (waiton_ptid, ecs->ptid, &ecs->ws);
2807 /* If an error happens while handling the event, propagate GDB's
2808 knowledge of the executing state to the frontend/user running
2811 ts_old_chain = make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
2813 ts_old_chain = make_cleanup (finish_thread_state_cleanup, &ecs->ptid);
2815 /* Get executed before make_cleanup_restore_current_thread above to apply
2816 still for the thread which has thrown the exception. */
2817 make_bpstat_clear_actions_cleanup ();
2819 /* Now figure out what to do with the result of the result. */
2820 handle_inferior_event (ecs);
2822 if (!ecs->wait_some_more)
2824 struct inferior *inf = find_inferior_pid (ptid_get_pid (ecs->ptid));
2826 delete_step_thread_step_resume_breakpoint ();
2828 /* We may not find an inferior if this was a process exit. */
2829 if (inf == NULL || inf->control.stop_soon == NO_STOP_QUIETLY)
2832 if (target_has_execution
2833 && ecs->ws.kind != TARGET_WAITKIND_NO_RESUMED
2834 && ecs->ws.kind != TARGET_WAITKIND_EXITED
2835 && ecs->ws.kind != TARGET_WAITKIND_SIGNALLED
2836 && ecs->event_thread->step_multi
2837 && ecs->event_thread->control.stop_step)
2838 inferior_event_handler (INF_EXEC_CONTINUE, NULL);
2841 inferior_event_handler (INF_EXEC_COMPLETE, NULL);
2846 /* No error, don't finish the thread states yet. */
2847 discard_cleanups (ts_old_chain);
2849 /* Revert thread and frame. */
2850 do_cleanups (old_chain);
2852 /* If the inferior was in sync execution mode, and now isn't,
2853 restore the prompt (a synchronous execution command has finished,
2854 and we're ready for input). */
2855 if (interpreter_async && was_sync && !sync_execution)
2856 display_gdb_prompt (0);
2860 && exec_done_display_p
2861 && (ptid_equal (inferior_ptid, null_ptid)
2862 || !is_running (inferior_ptid)))
2863 printf_unfiltered (_("completed.\n"));
2866 /* Record the frame and location we're currently stepping through. */
2868 set_step_info (struct frame_info *frame, struct symtab_and_line sal)
2870 struct thread_info *tp = inferior_thread ();
2872 tp->control.step_frame_id = get_frame_id (frame);
2873 tp->control.step_stack_frame_id = get_stack_frame_id (frame);
2875 tp->current_symtab = sal.symtab;
2876 tp->current_line = sal.line;
2879 /* Clear context switchable stepping state. */
2882 init_thread_stepping_state (struct thread_info *tss)
2884 tss->stepping_over_breakpoint = 0;
2885 tss->step_after_step_resume_breakpoint = 0;
2888 /* Return the cached copy of the last pid/waitstatus returned by
2889 target_wait()/deprecated_target_wait_hook(). The data is actually
2890 cached by handle_inferior_event(), which gets called immediately
2891 after target_wait()/deprecated_target_wait_hook(). */
2894 get_last_target_status (ptid_t *ptidp, struct target_waitstatus *status)
2896 *ptidp = target_last_wait_ptid;
2897 *status = target_last_waitstatus;
2901 nullify_last_target_wait_ptid (void)
2903 target_last_wait_ptid = minus_one_ptid;
2906 /* Switch thread contexts. */
2909 context_switch (ptid_t ptid)
2911 if (debug_infrun && !ptid_equal (ptid, inferior_ptid))
2913 fprintf_unfiltered (gdb_stdlog, "infrun: Switching context from %s ",
2914 target_pid_to_str (inferior_ptid));
2915 fprintf_unfiltered (gdb_stdlog, "to %s\n",
2916 target_pid_to_str (ptid));
2919 switch_to_thread (ptid);
2923 adjust_pc_after_break (struct execution_control_state *ecs)
2925 struct regcache *regcache;
2926 struct gdbarch *gdbarch;
2927 struct address_space *aspace;
2928 CORE_ADDR breakpoint_pc;
2930 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
2931 we aren't, just return.
2933 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
2934 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
2935 implemented by software breakpoints should be handled through the normal
2938 NOTE drow/2004-01-31: On some targets, breakpoints may generate
2939 different signals (SIGILL or SIGEMT for instance), but it is less
2940 clear where the PC is pointing afterwards. It may not match
2941 gdbarch_decr_pc_after_break. I don't know any specific target that
2942 generates these signals at breakpoints (the code has been in GDB since at
2943 least 1992) so I can not guess how to handle them here.
2945 In earlier versions of GDB, a target with
2946 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
2947 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
2948 target with both of these set in GDB history, and it seems unlikely to be
2949 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
2951 if (ecs->ws.kind != TARGET_WAITKIND_STOPPED)
2954 if (ecs->ws.value.sig != GDB_SIGNAL_TRAP)
2957 /* In reverse execution, when a breakpoint is hit, the instruction
2958 under it has already been de-executed. The reported PC always
2959 points at the breakpoint address, so adjusting it further would
2960 be wrong. E.g., consider this case on a decr_pc_after_break == 1
2963 B1 0x08000000 : INSN1
2964 B2 0x08000001 : INSN2
2966 PC -> 0x08000003 : INSN4
2968 Say you're stopped at 0x08000003 as above. Reverse continuing
2969 from that point should hit B2 as below. Reading the PC when the
2970 SIGTRAP is reported should read 0x08000001 and INSN2 should have
2971 been de-executed already.
2973 B1 0x08000000 : INSN1
2974 B2 PC -> 0x08000001 : INSN2
2978 We can't apply the same logic as for forward execution, because
2979 we would wrongly adjust the PC to 0x08000000, since there's a
2980 breakpoint at PC - 1. We'd then report a hit on B1, although
2981 INSN1 hadn't been de-executed yet. Doing nothing is the correct
2983 if (execution_direction == EXEC_REVERSE)
2986 /* If this target does not decrement the PC after breakpoints, then
2987 we have nothing to do. */
2988 regcache = get_thread_regcache (ecs->ptid);
2989 gdbarch = get_regcache_arch (regcache);
2990 if (gdbarch_decr_pc_after_break (gdbarch) == 0)
2993 aspace = get_regcache_aspace (regcache);
2995 /* Find the location where (if we've hit a breakpoint) the
2996 breakpoint would be. */
2997 breakpoint_pc = regcache_read_pc (regcache)
2998 - gdbarch_decr_pc_after_break (gdbarch);
3000 /* Check whether there actually is a software breakpoint inserted at
3003 If in non-stop mode, a race condition is possible where we've
3004 removed a breakpoint, but stop events for that breakpoint were
3005 already queued and arrive later. To suppress those spurious
3006 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
3007 and retire them after a number of stop events are reported. */
3008 if (software_breakpoint_inserted_here_p (aspace, breakpoint_pc)
3009 || (non_stop && moribund_breakpoint_here_p (aspace, breakpoint_pc)))
3011 struct cleanup *old_cleanups = NULL;
3014 old_cleanups = record_gdb_operation_disable_set ();
3016 /* When using hardware single-step, a SIGTRAP is reported for both
3017 a completed single-step and a software breakpoint. Need to
3018 differentiate between the two, as the latter needs adjusting
3019 but the former does not.
3021 The SIGTRAP can be due to a completed hardware single-step only if
3022 - we didn't insert software single-step breakpoints
3023 - the thread to be examined is still the current thread
3024 - this thread is currently being stepped
3026 If any of these events did not occur, we must have stopped due
3027 to hitting a software breakpoint, and have to back up to the
3030 As a special case, we could have hardware single-stepped a
3031 software breakpoint. In this case (prev_pc == breakpoint_pc),
3032 we also need to back up to the breakpoint address. */
3034 if (singlestep_breakpoints_inserted_p
3035 || !ptid_equal (ecs->ptid, inferior_ptid)
3036 || !currently_stepping (ecs->event_thread)
3037 || ecs->event_thread->prev_pc == breakpoint_pc)
3038 regcache_write_pc (regcache, breakpoint_pc);
3041 do_cleanups (old_cleanups);
3046 init_infwait_state (void)
3048 waiton_ptid = pid_to_ptid (-1);
3049 infwait_state = infwait_normal_state;
3053 stepped_in_from (struct frame_info *frame, struct frame_id step_frame_id)
3055 for (frame = get_prev_frame (frame);
3057 frame = get_prev_frame (frame))
3059 if (frame_id_eq (get_frame_id (frame), step_frame_id))
3061 if (get_frame_type (frame) != INLINE_FRAME)
3068 /* Auxiliary function that handles syscall entry/return events.
3069 It returns 1 if the inferior should keep going (and GDB
3070 should ignore the event), or 0 if the event deserves to be
3074 handle_syscall_event (struct execution_control_state *ecs)
3076 struct regcache *regcache;
3079 if (!ptid_equal (ecs->ptid, inferior_ptid))
3080 context_switch (ecs->ptid);
3082 regcache = get_thread_regcache (ecs->ptid);
3083 syscall_number = ecs->ws.value.syscall_number;
3084 stop_pc = regcache_read_pc (regcache);
3086 if (catch_syscall_enabled () > 0
3087 && catching_syscall_number (syscall_number) > 0)
3089 enum bpstat_signal_value sval;
3092 fprintf_unfiltered (gdb_stdlog, "infrun: syscall number = '%d'\n",
3095 ecs->event_thread->control.stop_bpstat
3096 = bpstat_stop_status (get_regcache_aspace (regcache),
3097 stop_pc, ecs->ptid, &ecs->ws);
3099 sval = bpstat_explains_signal (ecs->event_thread->control.stop_bpstat);
3100 ecs->random_signal = sval == BPSTAT_SIGNAL_NO;
3102 if (!ecs->random_signal)
3104 /* Catchpoint hit. */
3105 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_TRAP;
3110 /* If no catchpoint triggered for this, then keep going. */
3111 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
3116 /* Clear the supplied execution_control_state's stop_func_* fields. */
3119 clear_stop_func (struct execution_control_state *ecs)
3121 ecs->stop_func_filled_in = 0;
3122 ecs->stop_func_start = 0;
3123 ecs->stop_func_end = 0;
3124 ecs->stop_func_name = NULL;
3127 /* Lazily fill in the execution_control_state's stop_func_* fields. */
3130 fill_in_stop_func (struct gdbarch *gdbarch,
3131 struct execution_control_state *ecs)
3133 if (!ecs->stop_func_filled_in)
3135 /* Don't care about return value; stop_func_start and stop_func_name
3136 will both be 0 if it doesn't work. */
3137 find_pc_partial_function (stop_pc, &ecs->stop_func_name,
3138 &ecs->stop_func_start, &ecs->stop_func_end);
3139 ecs->stop_func_start
3140 += gdbarch_deprecated_function_start_offset (gdbarch);
3142 ecs->stop_func_filled_in = 1;
3146 /* Given an execution control state that has been freshly filled in
3147 by an event from the inferior, figure out what it means and take
3148 appropriate action. */
3151 handle_inferior_event (struct execution_control_state *ecs)
3153 struct frame_info *frame;
3154 struct gdbarch *gdbarch;
3155 int stopped_by_watchpoint;
3156 int stepped_after_stopped_by_watchpoint = 0;
3157 struct symtab_and_line stop_pc_sal;
3158 enum stop_kind stop_soon;
3160 if (ecs->ws.kind == TARGET_WAITKIND_IGNORE)
3162 /* We had an event in the inferior, but we are not interested in
3163 handling it at this level. The lower layers have already
3164 done what needs to be done, if anything.
3166 One of the possible circumstances for this is when the
3167 inferior produces output for the console. The inferior has
3168 not stopped, and we are ignoring the event. Another possible
3169 circumstance is any event which the lower level knows will be
3170 reported multiple times without an intervening resume. */
3172 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_IGNORE\n");
3173 prepare_to_wait (ecs);
3177 if (ecs->ws.kind == TARGET_WAITKIND_NO_RESUMED
3178 && target_can_async_p () && !sync_execution)
3180 /* There were no unwaited-for children left in the target, but,
3181 we're not synchronously waiting for events either. Just
3182 ignore. Otherwise, if we were running a synchronous
3183 execution command, we need to cancel it and give the user
3184 back the terminal. */
3186 fprintf_unfiltered (gdb_stdlog,
3187 "infrun: TARGET_WAITKIND_NO_RESUMED (ignoring)\n");
3188 prepare_to_wait (ecs);
3192 if (ecs->ws.kind != TARGET_WAITKIND_EXITED
3193 && ecs->ws.kind != TARGET_WAITKIND_SIGNALLED
3194 && ecs->ws.kind != TARGET_WAITKIND_NO_RESUMED)
3196 struct inferior *inf = find_inferior_pid (ptid_get_pid (ecs->ptid));
3199 stop_soon = inf->control.stop_soon;
3202 stop_soon = NO_STOP_QUIETLY;
3204 /* Cache the last pid/waitstatus. */
3205 target_last_wait_ptid = ecs->ptid;
3206 target_last_waitstatus = ecs->ws;
3208 /* Always clear state belonging to the previous time we stopped. */
3209 stop_stack_dummy = STOP_NONE;
3211 if (ecs->ws.kind == TARGET_WAITKIND_NO_RESUMED)
3213 /* No unwaited-for children left. IOW, all resumed children
3216 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_NO_RESUMED\n");
3218 stop_print_frame = 0;
3219 stop_stepping (ecs);
3223 if (ecs->ws.kind != TARGET_WAITKIND_EXITED
3224 && ecs->ws.kind != TARGET_WAITKIND_SIGNALLED)
3226 ecs->event_thread = find_thread_ptid (ecs->ptid);
3227 /* If it's a new thread, add it to the thread database. */
3228 if (ecs->event_thread == NULL)
3229 ecs->event_thread = add_thread (ecs->ptid);
3232 /* Dependent on valid ECS->EVENT_THREAD. */
3233 adjust_pc_after_break (ecs);
3235 /* Dependent on the current PC value modified by adjust_pc_after_break. */
3236 reinit_frame_cache ();
3238 breakpoint_retire_moribund ();
3240 /* First, distinguish signals caused by the debugger from signals
3241 that have to do with the program's own actions. Note that
3242 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
3243 on the operating system version. Here we detect when a SIGILL or
3244 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
3245 something similar for SIGSEGV, since a SIGSEGV will be generated
3246 when we're trying to execute a breakpoint instruction on a
3247 non-executable stack. This happens for call dummy breakpoints
3248 for architectures like SPARC that place call dummies on the
3250 if (ecs->ws.kind == TARGET_WAITKIND_STOPPED
3251 && (ecs->ws.value.sig == GDB_SIGNAL_ILL
3252 || ecs->ws.value.sig == GDB_SIGNAL_SEGV
3253 || ecs->ws.value.sig == GDB_SIGNAL_EMT))
3255 struct regcache *regcache = get_thread_regcache (ecs->ptid);
3257 if (breakpoint_inserted_here_p (get_regcache_aspace (regcache),
3258 regcache_read_pc (regcache)))
3261 fprintf_unfiltered (gdb_stdlog,
3262 "infrun: Treating signal as SIGTRAP\n");
3263 ecs->ws.value.sig = GDB_SIGNAL_TRAP;
3267 /* Mark the non-executing threads accordingly. In all-stop, all
3268 threads of all processes are stopped when we get any event
3269 reported. In non-stop mode, only the event thread stops. If
3270 we're handling a process exit in non-stop mode, there's nothing
3271 to do, as threads of the dead process are gone, and threads of
3272 any other process were left running. */
3274 set_executing (minus_one_ptid, 0);
3275 else if (ecs->ws.kind != TARGET_WAITKIND_SIGNALLED
3276 && ecs->ws.kind != TARGET_WAITKIND_EXITED)
3277 set_executing (ecs->ptid, 0);
3279 switch (infwait_state)
3281 case infwait_thread_hop_state:
3283 fprintf_unfiltered (gdb_stdlog, "infrun: infwait_thread_hop_state\n");
3286 case infwait_normal_state:
3288 fprintf_unfiltered (gdb_stdlog, "infrun: infwait_normal_state\n");
3291 case infwait_step_watch_state:
3293 fprintf_unfiltered (gdb_stdlog,
3294 "infrun: infwait_step_watch_state\n");
3296 stepped_after_stopped_by_watchpoint = 1;
3299 case infwait_nonstep_watch_state:
3301 fprintf_unfiltered (gdb_stdlog,
3302 "infrun: infwait_nonstep_watch_state\n");
3303 insert_breakpoints ();
3305 /* FIXME-maybe: is this cleaner than setting a flag? Does it
3306 handle things like signals arriving and other things happening
3307 in combination correctly? */
3308 stepped_after_stopped_by_watchpoint = 1;
3312 internal_error (__FILE__, __LINE__, _("bad switch"));
3315 infwait_state = infwait_normal_state;
3316 waiton_ptid = pid_to_ptid (-1);
3318 switch (ecs->ws.kind)
3320 case TARGET_WAITKIND_LOADED:
3322 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_LOADED\n");
3323 /* Ignore gracefully during startup of the inferior, as it might
3324 be the shell which has just loaded some objects, otherwise
3325 add the symbols for the newly loaded objects. Also ignore at
3326 the beginning of an attach or remote session; we will query
3327 the full list of libraries once the connection is
3329 if (stop_soon == NO_STOP_QUIETLY)
3331 struct regcache *regcache;
3332 enum bpstat_signal_value sval;
3334 if (!ptid_equal (ecs->ptid, inferior_ptid))
3335 context_switch (ecs->ptid);
3336 regcache = get_thread_regcache (ecs->ptid);
3338 handle_solib_event ();
3340 ecs->event_thread->control.stop_bpstat
3341 = bpstat_stop_status (get_regcache_aspace (regcache),
3342 stop_pc, ecs->ptid, &ecs->ws);
3345 = bpstat_explains_signal (ecs->event_thread->control.stop_bpstat);
3346 ecs->random_signal = sval == BPSTAT_SIGNAL_NO;
3348 if (!ecs->random_signal)
3350 /* A catchpoint triggered. */
3351 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_TRAP;
3352 goto process_event_stop_test;
3355 /* If requested, stop when the dynamic linker notifies
3356 gdb of events. This allows the user to get control
3357 and place breakpoints in initializer routines for
3358 dynamically loaded objects (among other things). */
3359 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
3360 if (stop_on_solib_events)
3362 /* Make sure we print "Stopped due to solib-event" in
3364 stop_print_frame = 1;
3366 stop_stepping (ecs);
3371 /* If we are skipping through a shell, or through shared library
3372 loading that we aren't interested in, resume the program. If
3373 we're running the program normally, also resume. But stop if
3374 we're attaching or setting up a remote connection. */
3375 if (stop_soon == STOP_QUIETLY || stop_soon == NO_STOP_QUIETLY)
3377 if (!ptid_equal (ecs->ptid, inferior_ptid))
3378 context_switch (ecs->ptid);
3380 /* Loading of shared libraries might have changed breakpoint
3381 addresses. Make sure new breakpoints are inserted. */
3382 if (stop_soon == NO_STOP_QUIETLY
3383 && !breakpoints_always_inserted_mode ())
3384 insert_breakpoints ();
3385 resume (0, GDB_SIGNAL_0);
3386 prepare_to_wait (ecs);
3392 case TARGET_WAITKIND_SPURIOUS:
3394 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_SPURIOUS\n");
3395 if (!ptid_equal (ecs->ptid, inferior_ptid))
3396 context_switch (ecs->ptid);
3397 resume (0, GDB_SIGNAL_0);
3398 prepare_to_wait (ecs);
3401 case TARGET_WAITKIND_EXITED:
3402 case TARGET_WAITKIND_SIGNALLED:
3405 if (ecs->ws.kind == TARGET_WAITKIND_EXITED)
3406 fprintf_unfiltered (gdb_stdlog,
3407 "infrun: TARGET_WAITKIND_EXITED\n");
3409 fprintf_unfiltered (gdb_stdlog,
3410 "infrun: TARGET_WAITKIND_SIGNALLED\n");
3413 inferior_ptid = ecs->ptid;
3414 set_current_inferior (find_inferior_pid (ptid_get_pid (ecs->ptid)));
3415 set_current_program_space (current_inferior ()->pspace);
3416 handle_vfork_child_exec_or_exit (0);
3417 target_terminal_ours (); /* Must do this before mourn anyway. */
3419 if (ecs->ws.kind == TARGET_WAITKIND_EXITED)
3421 /* Record the exit code in the convenience variable $_exitcode, so
3422 that the user can inspect this again later. */
3423 set_internalvar_integer (lookup_internalvar ("_exitcode"),
3424 (LONGEST) ecs->ws.value.integer);
3426 /* Also record this in the inferior itself. */
3427 current_inferior ()->has_exit_code = 1;
3428 current_inferior ()->exit_code = (LONGEST) ecs->ws.value.integer;
3430 print_exited_reason (ecs->ws.value.integer);
3433 print_signal_exited_reason (ecs->ws.value.sig);
3435 gdb_flush (gdb_stdout);
3436 target_mourn_inferior ();
3437 singlestep_breakpoints_inserted_p = 0;
3438 cancel_single_step_breakpoints ();
3439 stop_print_frame = 0;
3440 stop_stepping (ecs);
3443 /* The following are the only cases in which we keep going;
3444 the above cases end in a continue or goto. */
3445 case TARGET_WAITKIND_FORKED:
3446 case TARGET_WAITKIND_VFORKED:
3449 if (ecs->ws.kind == TARGET_WAITKIND_FORKED)
3450 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_FORKED\n");
3452 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_VFORKED\n");
3455 /* Check whether the inferior is displaced stepping. */
3457 struct regcache *regcache = get_thread_regcache (ecs->ptid);
3458 struct gdbarch *gdbarch = get_regcache_arch (regcache);
3459 struct displaced_step_inferior_state *displaced
3460 = get_displaced_stepping_state (ptid_get_pid (ecs->ptid));
3462 /* If checking displaced stepping is supported, and thread
3463 ecs->ptid is displaced stepping. */
3464 if (displaced && ptid_equal (displaced->step_ptid, ecs->ptid))
3466 struct inferior *parent_inf
3467 = find_inferior_pid (ptid_get_pid (ecs->ptid));
3468 struct regcache *child_regcache;
3469 CORE_ADDR parent_pc;
3471 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
3472 indicating that the displaced stepping of syscall instruction
3473 has been done. Perform cleanup for parent process here. Note
3474 that this operation also cleans up the child process for vfork,
3475 because their pages are shared. */
3476 displaced_step_fixup (ecs->ptid, GDB_SIGNAL_TRAP);
3478 if (ecs->ws.kind == TARGET_WAITKIND_FORKED)
3480 /* Restore scratch pad for child process. */
3481 displaced_step_restore (displaced, ecs->ws.value.related_pid);
3484 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
3485 the child's PC is also within the scratchpad. Set the child's PC
3486 to the parent's PC value, which has already been fixed up.
3487 FIXME: we use the parent's aspace here, although we're touching
3488 the child, because the child hasn't been added to the inferior
3489 list yet at this point. */
3492 = get_thread_arch_aspace_regcache (ecs->ws.value.related_pid,
3494 parent_inf->aspace);
3495 /* Read PC value of parent process. */
3496 parent_pc = regcache_read_pc (regcache);
3498 if (debug_displaced)
3499 fprintf_unfiltered (gdb_stdlog,
3500 "displaced: write child pc from %s to %s\n",
3502 regcache_read_pc (child_regcache)),
3503 paddress (gdbarch, parent_pc));
3505 regcache_write_pc (child_regcache, parent_pc);
3509 if (!ptid_equal (ecs->ptid, inferior_ptid))
3510 context_switch (ecs->ptid);
3512 /* Immediately detach breakpoints from the child before there's
3513 any chance of letting the user delete breakpoints from the
3514 breakpoint lists. If we don't do this early, it's easy to
3515 leave left over traps in the child, vis: "break foo; catch
3516 fork; c; <fork>; del; c; <child calls foo>". We only follow
3517 the fork on the last `continue', and by that time the
3518 breakpoint at "foo" is long gone from the breakpoint table.
3519 If we vforked, then we don't need to unpatch here, since both
3520 parent and child are sharing the same memory pages; we'll
3521 need to unpatch at follow/detach time instead to be certain
3522 that new breakpoints added between catchpoint hit time and
3523 vfork follow are detached. */
3524 if (ecs->ws.kind != TARGET_WAITKIND_VFORKED)
3526 /* This won't actually modify the breakpoint list, but will
3527 physically remove the breakpoints from the child. */
3528 detach_breakpoints (ecs->ws.value.related_pid);
3531 if (singlestep_breakpoints_inserted_p)
3533 /* Pull the single step breakpoints out of the target. */
3534 remove_single_step_breakpoints ();
3535 singlestep_breakpoints_inserted_p = 0;
3538 /* In case the event is caught by a catchpoint, remember that
3539 the event is to be followed at the next resume of the thread,
3540 and not immediately. */
3541 ecs->event_thread->pending_follow = ecs->ws;
3543 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
3545 ecs->event_thread->control.stop_bpstat
3546 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
3547 stop_pc, ecs->ptid, &ecs->ws);
3549 /* Note that we're interested in knowing the bpstat actually
3550 causes a stop, not just if it may explain the signal.
3551 Software watchpoints, for example, always appear in the
3554 = !bpstat_causes_stop (ecs->event_thread->control.stop_bpstat);
3556 /* If no catchpoint triggered for this, then keep going. */
3557 if (ecs->random_signal)
3563 = (follow_fork_mode_string == follow_fork_mode_child);
3565 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
3567 should_resume = follow_fork ();
3570 child = ecs->ws.value.related_pid;
3572 /* In non-stop mode, also resume the other branch. */
3573 if (non_stop && !detach_fork)
3576 switch_to_thread (parent);
3578 switch_to_thread (child);
3580 ecs->event_thread = inferior_thread ();
3581 ecs->ptid = inferior_ptid;
3586 switch_to_thread (child);
3588 switch_to_thread (parent);
3590 ecs->event_thread = inferior_thread ();
3591 ecs->ptid = inferior_ptid;
3596 stop_stepping (ecs);
3599 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_TRAP;
3600 goto process_event_stop_test;
3602 case TARGET_WAITKIND_VFORK_DONE:
3603 /* Done with the shared memory region. Re-insert breakpoints in
3604 the parent, and keep going. */
3607 fprintf_unfiltered (gdb_stdlog,
3608 "infrun: TARGET_WAITKIND_VFORK_DONE\n");
3610 if (!ptid_equal (ecs->ptid, inferior_ptid))
3611 context_switch (ecs->ptid);
3613 current_inferior ()->waiting_for_vfork_done = 0;
3614 current_inferior ()->pspace->breakpoints_not_allowed = 0;
3615 /* This also takes care of reinserting breakpoints in the
3616 previously locked inferior. */
3620 case TARGET_WAITKIND_EXECD:
3622 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_EXECD\n");
3624 if (!ptid_equal (ecs->ptid, inferior_ptid))
3625 context_switch (ecs->ptid);
3627 singlestep_breakpoints_inserted_p = 0;
3628 cancel_single_step_breakpoints ();
3630 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
3632 /* Do whatever is necessary to the parent branch of the vfork. */
3633 handle_vfork_child_exec_or_exit (1);
3635 /* This causes the eventpoints and symbol table to be reset.
3636 Must do this now, before trying to determine whether to
3638 follow_exec (inferior_ptid, ecs->ws.value.execd_pathname);
3640 ecs->event_thread->control.stop_bpstat
3641 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
3642 stop_pc, ecs->ptid, &ecs->ws);
3644 = (bpstat_explains_signal (ecs->event_thread->control.stop_bpstat)
3645 == BPSTAT_SIGNAL_NO);
3647 /* Note that this may be referenced from inside
3648 bpstat_stop_status above, through inferior_has_execd. */
3649 xfree (ecs->ws.value.execd_pathname);
3650 ecs->ws.value.execd_pathname = NULL;
3652 /* If no catchpoint triggered for this, then keep going. */
3653 if (ecs->random_signal)
3655 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
3659 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_TRAP;
3660 goto process_event_stop_test;
3662 /* Be careful not to try to gather much state about a thread
3663 that's in a syscall. It's frequently a losing proposition. */
3664 case TARGET_WAITKIND_SYSCALL_ENTRY:
3666 fprintf_unfiltered (gdb_stdlog,
3667 "infrun: TARGET_WAITKIND_SYSCALL_ENTRY\n");
3668 /* Getting the current syscall number. */
3669 if (handle_syscall_event (ecs) != 0)
3671 goto process_event_stop_test;
3673 /* Before examining the threads further, step this thread to
3674 get it entirely out of the syscall. (We get notice of the
3675 event when the thread is just on the verge of exiting a
3676 syscall. Stepping one instruction seems to get it back
3678 case TARGET_WAITKIND_SYSCALL_RETURN:
3680 fprintf_unfiltered (gdb_stdlog,
3681 "infrun: TARGET_WAITKIND_SYSCALL_RETURN\n");
3682 if (handle_syscall_event (ecs) != 0)
3684 goto process_event_stop_test;
3686 case TARGET_WAITKIND_STOPPED:
3688 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_STOPPED\n");
3689 ecs->event_thread->suspend.stop_signal = ecs->ws.value.sig;
3692 case TARGET_WAITKIND_NO_HISTORY:
3694 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_NO_HISTORY\n");
3695 /* Reverse execution: target ran out of history info. */
3697 /* Pull the single step breakpoints out of the target. */
3698 if (singlestep_breakpoints_inserted_p)
3700 if (!ptid_equal (ecs->ptid, inferior_ptid))
3701 context_switch (ecs->ptid);
3702 remove_single_step_breakpoints ();
3703 singlestep_breakpoints_inserted_p = 0;
3705 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
3706 print_no_history_reason ();
3707 stop_stepping (ecs);
3711 if (ecs->ws.kind == TARGET_WAITKIND_STOPPED)
3713 /* Do we need to clean up the state of a thread that has
3714 completed a displaced single-step? (Doing so usually affects
3715 the PC, so do it here, before we set stop_pc.) */
3716 displaced_step_fixup (ecs->ptid,
3717 ecs->event_thread->suspend.stop_signal);
3719 /* If we either finished a single-step or hit a breakpoint, but
3720 the user wanted this thread to be stopped, pretend we got a
3721 SIG0 (generic unsignaled stop). */
3723 if (ecs->event_thread->stop_requested
3724 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
3725 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
3728 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
3732 struct regcache *regcache = get_thread_regcache (ecs->ptid);
3733 struct gdbarch *gdbarch = get_regcache_arch (regcache);
3734 struct cleanup *old_chain = save_inferior_ptid ();
3736 inferior_ptid = ecs->ptid;
3738 fprintf_unfiltered (gdb_stdlog, "infrun: stop_pc = %s\n",
3739 paddress (gdbarch, stop_pc));
3740 if (target_stopped_by_watchpoint ())
3744 fprintf_unfiltered (gdb_stdlog, "infrun: stopped by watchpoint\n");
3746 if (target_stopped_data_address (¤t_target, &addr))
3747 fprintf_unfiltered (gdb_stdlog,
3748 "infrun: stopped data address = %s\n",
3749 paddress (gdbarch, addr));
3751 fprintf_unfiltered (gdb_stdlog,
3752 "infrun: (no data address available)\n");
3755 do_cleanups (old_chain);
3758 if (stepping_past_singlestep_breakpoint)
3760 gdb_assert (singlestep_breakpoints_inserted_p);
3761 gdb_assert (ptid_equal (singlestep_ptid, ecs->ptid));
3762 gdb_assert (!ptid_equal (singlestep_ptid, saved_singlestep_ptid));
3764 stepping_past_singlestep_breakpoint = 0;
3766 /* We've either finished single-stepping past the single-step
3767 breakpoint, or stopped for some other reason. It would be nice if
3768 we could tell, but we can't reliably. */
3769 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
3772 fprintf_unfiltered (gdb_stdlog,
3773 "infrun: stepping_past_"
3774 "singlestep_breakpoint\n");
3775 /* Pull the single step breakpoints out of the target. */
3776 if (!ptid_equal (ecs->ptid, inferior_ptid))
3777 context_switch (ecs->ptid);
3778 remove_single_step_breakpoints ();
3779 singlestep_breakpoints_inserted_p = 0;
3781 ecs->random_signal = 0;
3782 ecs->event_thread->control.trap_expected = 0;
3784 context_switch (saved_singlestep_ptid);
3785 if (deprecated_context_hook)
3786 deprecated_context_hook (pid_to_thread_id (saved_singlestep_ptid));
3788 resume (1, GDB_SIGNAL_0);
3789 prepare_to_wait (ecs);
3794 if (!ptid_equal (deferred_step_ptid, null_ptid))
3796 /* In non-stop mode, there's never a deferred_step_ptid set. */
3797 gdb_assert (!non_stop);
3799 /* If we stopped for some other reason than single-stepping, ignore
3800 the fact that we were supposed to switch back. */
3801 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
3804 fprintf_unfiltered (gdb_stdlog,
3805 "infrun: handling deferred step\n");
3807 /* Pull the single step breakpoints out of the target. */
3808 if (singlestep_breakpoints_inserted_p)
3810 if (!ptid_equal (ecs->ptid, inferior_ptid))
3811 context_switch (ecs->ptid);
3812 remove_single_step_breakpoints ();
3813 singlestep_breakpoints_inserted_p = 0;
3816 ecs->event_thread->control.trap_expected = 0;
3818 context_switch (deferred_step_ptid);
3819 deferred_step_ptid = null_ptid;
3820 /* Suppress spurious "Switching to ..." message. */
3821 previous_inferior_ptid = inferior_ptid;
3823 resume (1, GDB_SIGNAL_0);
3824 prepare_to_wait (ecs);
3828 deferred_step_ptid = null_ptid;
3831 /* See if a thread hit a thread-specific breakpoint that was meant for
3832 another thread. If so, then step that thread past the breakpoint,
3835 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
3837 int thread_hop_needed = 0;
3838 struct address_space *aspace =
3839 get_regcache_aspace (get_thread_regcache (ecs->ptid));
3841 /* Check if a regular breakpoint has been hit before checking
3842 for a potential single step breakpoint. Otherwise, GDB will
3843 not see this breakpoint hit when stepping onto breakpoints. */
3844 if (regular_breakpoint_inserted_here_p (aspace, stop_pc))
3846 ecs->random_signal = 0;
3847 if (!breakpoint_thread_match (aspace, stop_pc, ecs->ptid))
3848 thread_hop_needed = 1;
3850 else if (singlestep_breakpoints_inserted_p)
3852 /* We have not context switched yet, so this should be true
3853 no matter which thread hit the singlestep breakpoint. */
3854 gdb_assert (ptid_equal (inferior_ptid, singlestep_ptid));
3856 fprintf_unfiltered (gdb_stdlog, "infrun: software single step "
3858 target_pid_to_str (ecs->ptid));
3860 ecs->random_signal = 0;
3861 /* The call to in_thread_list is necessary because PTIDs sometimes
3862 change when we go from single-threaded to multi-threaded. If
3863 the singlestep_ptid is still in the list, assume that it is
3864 really different from ecs->ptid. */
3865 if (!ptid_equal (singlestep_ptid, ecs->ptid)
3866 && in_thread_list (singlestep_ptid))
3868 /* If the PC of the thread we were trying to single-step
3869 has changed, discard this event (which we were going
3870 to ignore anyway), and pretend we saw that thread
3871 trap. This prevents us continuously moving the
3872 single-step breakpoint forward, one instruction at a
3873 time. If the PC has changed, then the thread we were
3874 trying to single-step has trapped or been signalled,
3875 but the event has not been reported to GDB yet.
3877 There might be some cases where this loses signal
3878 information, if a signal has arrived at exactly the
3879 same time that the PC changed, but this is the best
3880 we can do with the information available. Perhaps we
3881 should arrange to report all events for all threads
3882 when they stop, or to re-poll the remote looking for
3883 this particular thread (i.e. temporarily enable
3886 CORE_ADDR new_singlestep_pc
3887 = regcache_read_pc (get_thread_regcache (singlestep_ptid));
3889 if (new_singlestep_pc != singlestep_pc)
3891 enum gdb_signal stop_signal;
3894 fprintf_unfiltered (gdb_stdlog, "infrun: unexpected thread,"
3895 " but expected thread advanced also\n");
3897 /* The current context still belongs to
3898 singlestep_ptid. Don't swap here, since that's
3899 the context we want to use. Just fudge our
3900 state and continue. */
3901 stop_signal = ecs->event_thread->suspend.stop_signal;
3902 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
3903 ecs->ptid = singlestep_ptid;
3904 ecs->event_thread = find_thread_ptid (ecs->ptid);
3905 ecs->event_thread->suspend.stop_signal = stop_signal;
3906 stop_pc = new_singlestep_pc;
3911 fprintf_unfiltered (gdb_stdlog,
3912 "infrun: unexpected thread\n");
3914 thread_hop_needed = 1;
3915 stepping_past_singlestep_breakpoint = 1;
3916 saved_singlestep_ptid = singlestep_ptid;
3921 if (thread_hop_needed)
3923 struct regcache *thread_regcache;
3924 int remove_status = 0;
3927 fprintf_unfiltered (gdb_stdlog, "infrun: thread_hop_needed\n");
3929 /* Switch context before touching inferior memory, the
3930 previous thread may have exited. */
3931 if (!ptid_equal (inferior_ptid, ecs->ptid))
3932 context_switch (ecs->ptid);
3934 /* Saw a breakpoint, but it was hit by the wrong thread.
3937 if (singlestep_breakpoints_inserted_p)
3939 /* Pull the single step breakpoints out of the target. */
3940 remove_single_step_breakpoints ();
3941 singlestep_breakpoints_inserted_p = 0;
3944 /* If the arch can displace step, don't remove the
3946 thread_regcache = get_thread_regcache (ecs->ptid);
3947 if (!use_displaced_stepping (get_regcache_arch (thread_regcache)))
3948 remove_status = remove_breakpoints ();
3950 /* Did we fail to remove breakpoints? If so, try
3951 to set the PC past the bp. (There's at least
3952 one situation in which we can fail to remove
3953 the bp's: On HP-UX's that use ttrace, we can't
3954 change the address space of a vforking child
3955 process until the child exits (well, okay, not
3956 then either :-) or execs. */
3957 if (remove_status != 0)
3958 error (_("Cannot step over breakpoint hit in wrong thread"));
3963 /* Only need to require the next event from this
3964 thread in all-stop mode. */
3965 waiton_ptid = ecs->ptid;
3966 infwait_state = infwait_thread_hop_state;
3969 ecs->event_thread->stepping_over_breakpoint = 1;
3974 else if (singlestep_breakpoints_inserted_p)
3976 ecs->random_signal = 0;
3980 ecs->random_signal = 1;
3982 /* See if something interesting happened to the non-current thread. If
3983 so, then switch to that thread. */
3984 if (!ptid_equal (ecs->ptid, inferior_ptid))
3987 fprintf_unfiltered (gdb_stdlog, "infrun: context switch\n");
3989 context_switch (ecs->ptid);
3991 if (deprecated_context_hook)
3992 deprecated_context_hook (pid_to_thread_id (ecs->ptid));
3995 /* At this point, get hold of the now-current thread's frame. */
3996 frame = get_current_frame ();
3997 gdbarch = get_frame_arch (frame);
3999 if (singlestep_breakpoints_inserted_p)
4001 /* Pull the single step breakpoints out of the target. */
4002 remove_single_step_breakpoints ();
4003 singlestep_breakpoints_inserted_p = 0;
4006 if (stepped_after_stopped_by_watchpoint)
4007 stopped_by_watchpoint = 0;
4009 stopped_by_watchpoint = watchpoints_triggered (&ecs->ws);
4011 /* If necessary, step over this watchpoint. We'll be back to display
4013 if (stopped_by_watchpoint
4014 && (target_have_steppable_watchpoint
4015 || gdbarch_have_nonsteppable_watchpoint (gdbarch)))
4017 /* At this point, we are stopped at an instruction which has
4018 attempted to write to a piece of memory under control of
4019 a watchpoint. The instruction hasn't actually executed
4020 yet. If we were to evaluate the watchpoint expression
4021 now, we would get the old value, and therefore no change
4022 would seem to have occurred.
4024 In order to make watchpoints work `right', we really need
4025 to complete the memory write, and then evaluate the
4026 watchpoint expression. We do this by single-stepping the
4029 It may not be necessary to disable the watchpoint to stop over
4030 it. For example, the PA can (with some kernel cooperation)
4031 single step over a watchpoint without disabling the watchpoint.
4033 It is far more common to need to disable a watchpoint to step
4034 the inferior over it. If we have non-steppable watchpoints,
4035 we must disable the current watchpoint; it's simplest to
4036 disable all watchpoints and breakpoints. */
4039 if (!target_have_steppable_watchpoint)
4041 remove_breakpoints ();
4042 /* See comment in resume why we need to stop bypassing signals
4043 while breakpoints have been removed. */
4044 target_pass_signals (0, NULL);
4047 hw_step = maybe_software_singlestep (gdbarch, stop_pc);
4048 target_resume (ecs->ptid, hw_step, GDB_SIGNAL_0);
4049 waiton_ptid = ecs->ptid;
4050 if (target_have_steppable_watchpoint)
4051 infwait_state = infwait_step_watch_state;
4053 infwait_state = infwait_nonstep_watch_state;
4054 prepare_to_wait (ecs);
4058 clear_stop_func (ecs);
4059 ecs->event_thread->stepping_over_breakpoint = 0;
4060 bpstat_clear (&ecs->event_thread->control.stop_bpstat);
4061 ecs->event_thread->control.stop_step = 0;
4062 stop_print_frame = 1;
4063 ecs->random_signal = 0;
4064 stopped_by_random_signal = 0;
4066 /* Hide inlined functions starting here, unless we just performed stepi or
4067 nexti. After stepi and nexti, always show the innermost frame (not any
4068 inline function call sites). */
4069 if (ecs->event_thread->control.step_range_end != 1)
4071 struct address_space *aspace =
4072 get_regcache_aspace (get_thread_regcache (ecs->ptid));
4074 /* skip_inline_frames is expensive, so we avoid it if we can
4075 determine that the address is one where functions cannot have
4076 been inlined. This improves performance with inferiors that
4077 load a lot of shared libraries, because the solib event
4078 breakpoint is defined as the address of a function (i.e. not
4079 inline). Note that we have to check the previous PC as well
4080 as the current one to catch cases when we have just
4081 single-stepped off a breakpoint prior to reinstating it.
4082 Note that we're assuming that the code we single-step to is
4083 not inline, but that's not definitive: there's nothing
4084 preventing the event breakpoint function from containing
4085 inlined code, and the single-step ending up there. If the
4086 user had set a breakpoint on that inlined code, the missing
4087 skip_inline_frames call would break things. Fortunately
4088 that's an extremely unlikely scenario. */
4089 if (!pc_at_non_inline_function (aspace, stop_pc, &ecs->ws)
4090 && !(ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
4091 && ecs->event_thread->control.trap_expected
4092 && pc_at_non_inline_function (aspace,
4093 ecs->event_thread->prev_pc,
4096 skip_inline_frames (ecs->ptid);
4098 /* Re-fetch current thread's frame in case that invalidated
4100 frame = get_current_frame ();
4101 gdbarch = get_frame_arch (frame);
4105 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
4106 && ecs->event_thread->control.trap_expected
4107 && gdbarch_single_step_through_delay_p (gdbarch)
4108 && currently_stepping (ecs->event_thread))
4110 /* We're trying to step off a breakpoint. Turns out that we're
4111 also on an instruction that needs to be stepped multiple
4112 times before it's been fully executing. E.g., architectures
4113 with a delay slot. It needs to be stepped twice, once for
4114 the instruction and once for the delay slot. */
4115 int step_through_delay
4116 = gdbarch_single_step_through_delay (gdbarch, frame);
4118 if (debug_infrun && step_through_delay)
4119 fprintf_unfiltered (gdb_stdlog, "infrun: step through delay\n");
4120 if (ecs->event_thread->control.step_range_end == 0
4121 && step_through_delay)
4123 /* The user issued a continue when stopped at a breakpoint.
4124 Set up for another trap and get out of here. */
4125 ecs->event_thread->stepping_over_breakpoint = 1;
4129 else if (step_through_delay)
4131 /* The user issued a step when stopped at a breakpoint.
4132 Maybe we should stop, maybe we should not - the delay
4133 slot *might* correspond to a line of source. In any
4134 case, don't decide that here, just set
4135 ecs->stepping_over_breakpoint, making sure we
4136 single-step again before breakpoints are re-inserted. */
4137 ecs->event_thread->stepping_over_breakpoint = 1;
4141 /* Look at the cause of the stop, and decide what to do.
4142 The alternatives are:
4143 1) stop_stepping and return; to really stop and return to the debugger,
4144 2) keep_going and return to start up again
4145 (set ecs->event_thread->stepping_over_breakpoint to 1 to single step once)
4146 3) set ecs->random_signal to 1, and the decision between 1 and 2
4147 will be made according to the signal handling tables. */
4149 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
4153 fprintf_unfiltered (gdb_stdlog, "infrun: stopped\n");
4154 stop_print_frame = 0;
4155 stop_stepping (ecs);
4159 /* This is originated from start_remote(), start_inferior() and
4160 shared libraries hook functions. */
4161 if (stop_soon == STOP_QUIETLY || stop_soon == STOP_QUIETLY_REMOTE)
4164 fprintf_unfiltered (gdb_stdlog, "infrun: quietly stopped\n");
4165 stop_stepping (ecs);
4169 /* This originates from attach_command(). We need to overwrite
4170 the stop_signal here, because some kernels don't ignore a
4171 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
4172 See more comments in inferior.h. On the other hand, if we
4173 get a non-SIGSTOP, report it to the user - assume the backend
4174 will handle the SIGSTOP if it should show up later.
4176 Also consider that the attach is complete when we see a
4177 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
4178 target extended-remote report it instead of a SIGSTOP
4179 (e.g. gdbserver). We already rely on SIGTRAP being our
4180 signal, so this is no exception.
4182 Also consider that the attach is complete when we see a
4183 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
4184 the target to stop all threads of the inferior, in case the
4185 low level attach operation doesn't stop them implicitly. If
4186 they weren't stopped implicitly, then the stub will report a
4187 GDB_SIGNAL_0, meaning: stopped for no particular reason
4188 other than GDB's request. */
4189 if (stop_soon == STOP_QUIETLY_NO_SIGSTOP
4190 && (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_STOP
4191 || ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
4192 || ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_0))
4194 stop_stepping (ecs);
4195 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
4199 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
4200 handles this event. */
4201 ecs->event_thread->control.stop_bpstat
4202 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
4203 stop_pc, ecs->ptid, &ecs->ws);
4205 /* Following in case break condition called a
4207 stop_print_frame = 1;
4209 /* This is where we handle "moribund" watchpoints. Unlike
4210 software breakpoints traps, hardware watchpoint traps are
4211 always distinguishable from random traps. If no high-level
4212 watchpoint is associated with the reported stop data address
4213 anymore, then the bpstat does not explain the signal ---
4214 simply make sure to ignore it if `stopped_by_watchpoint' is
4218 && ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
4219 && (bpstat_explains_signal (ecs->event_thread->control.stop_bpstat)
4220 == BPSTAT_SIGNAL_NO)
4221 && stopped_by_watchpoint)
4222 fprintf_unfiltered (gdb_stdlog,
4223 "infrun: no user watchpoint explains "
4224 "watchpoint SIGTRAP, ignoring\n");
4226 /* NOTE: cagney/2003-03-29: These two checks for a random signal
4227 at one stage in the past included checks for an inferior
4228 function call's call dummy's return breakpoint. The original
4229 comment, that went with the test, read:
4231 ``End of a stack dummy. Some systems (e.g. Sony news) give
4232 another signal besides SIGTRAP, so check here as well as
4235 If someone ever tries to get call dummys on a
4236 non-executable stack to work (where the target would stop
4237 with something like a SIGSEGV), then those tests might need
4238 to be re-instated. Given, however, that the tests were only
4239 enabled when momentary breakpoints were not being used, I
4240 suspect that it won't be the case.
4242 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
4243 be necessary for call dummies on a non-executable stack on
4246 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
4248 = !((bpstat_explains_signal (ecs->event_thread->control.stop_bpstat)
4249 != BPSTAT_SIGNAL_NO)
4250 || stopped_by_watchpoint
4251 || ecs->event_thread->control.trap_expected
4252 || (ecs->event_thread->control.step_range_end
4253 && (ecs->event_thread->control.step_resume_breakpoint
4257 enum bpstat_signal_value sval;
4259 sval = bpstat_explains_signal (ecs->event_thread->control.stop_bpstat);
4260 ecs->random_signal = (sval == BPSTAT_SIGNAL_NO);
4262 if (sval == BPSTAT_SIGNAL_HIDE)
4263 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_TRAP;
4266 process_event_stop_test:
4268 /* Re-fetch current thread's frame in case we did a
4269 "goto process_event_stop_test" above. */
4270 frame = get_current_frame ();
4271 gdbarch = get_frame_arch (frame);
4273 /* For the program's own signals, act according to
4274 the signal handling tables. */
4276 if (ecs->random_signal)
4278 /* Signal not for debugging purposes. */
4280 struct inferior *inf = find_inferior_pid (ptid_get_pid (ecs->ptid));
4283 fprintf_unfiltered (gdb_stdlog, "infrun: random signal %d\n",
4284 ecs->event_thread->suspend.stop_signal);
4286 stopped_by_random_signal = 1;
4288 if (signal_print[ecs->event_thread->suspend.stop_signal])
4291 target_terminal_ours_for_output ();
4292 print_signal_received_reason
4293 (ecs->event_thread->suspend.stop_signal);
4295 /* Always stop on signals if we're either just gaining control
4296 of the program, or the user explicitly requested this thread
4297 to remain stopped. */
4298 if (stop_soon != NO_STOP_QUIETLY
4299 || ecs->event_thread->stop_requested
4301 && signal_stop_state (ecs->event_thread->suspend.stop_signal)))
4303 stop_stepping (ecs);
4306 /* If not going to stop, give terminal back
4307 if we took it away. */
4309 target_terminal_inferior ();
4311 /* Clear the signal if it should not be passed. */
4312 if (signal_program[ecs->event_thread->suspend.stop_signal] == 0)
4313 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
4315 if (ecs->event_thread->prev_pc == stop_pc
4316 && ecs->event_thread->control.trap_expected
4317 && ecs->event_thread->control.step_resume_breakpoint == NULL)
4319 /* We were just starting a new sequence, attempting to
4320 single-step off of a breakpoint and expecting a SIGTRAP.
4321 Instead this signal arrives. This signal will take us out
4322 of the stepping range so GDB needs to remember to, when
4323 the signal handler returns, resume stepping off that
4325 /* To simplify things, "continue" is forced to use the same
4326 code paths as single-step - set a breakpoint at the
4327 signal return address and then, once hit, step off that
4330 fprintf_unfiltered (gdb_stdlog,
4331 "infrun: signal arrived while stepping over "
4334 insert_hp_step_resume_breakpoint_at_frame (frame);
4335 ecs->event_thread->step_after_step_resume_breakpoint = 1;
4336 /* Reset trap_expected to ensure breakpoints are re-inserted. */
4337 ecs->event_thread->control.trap_expected = 0;
4342 if (ecs->event_thread->control.step_range_end != 0
4343 && ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_0
4344 && (ecs->event_thread->control.step_range_start <= stop_pc
4345 && stop_pc < ecs->event_thread->control.step_range_end)
4346 && frame_id_eq (get_stack_frame_id (frame),
4347 ecs->event_thread->control.step_stack_frame_id)
4348 && ecs->event_thread->control.step_resume_breakpoint == NULL)
4350 /* The inferior is about to take a signal that will take it
4351 out of the single step range. Set a breakpoint at the
4352 current PC (which is presumably where the signal handler
4353 will eventually return) and then allow the inferior to
4356 Note that this is only needed for a signal delivered
4357 while in the single-step range. Nested signals aren't a
4358 problem as they eventually all return. */
4360 fprintf_unfiltered (gdb_stdlog,
4361 "infrun: signal may take us out of "
4362 "single-step range\n");
4364 insert_hp_step_resume_breakpoint_at_frame (frame);
4365 /* Reset trap_expected to ensure breakpoints are re-inserted. */
4366 ecs->event_thread->control.trap_expected = 0;
4371 /* Note: step_resume_breakpoint may be non-NULL. This occures
4372 when either there's a nested signal, or when there's a
4373 pending signal enabled just as the signal handler returns
4374 (leaving the inferior at the step-resume-breakpoint without
4375 actually executing it). Either way continue until the
4376 breakpoint is really hit. */
4380 /* Handle cases caused by hitting a breakpoint. */
4382 CORE_ADDR jmp_buf_pc;
4383 struct bpstat_what what;
4385 what = bpstat_what (ecs->event_thread->control.stop_bpstat);
4387 if (what.call_dummy)
4389 stop_stack_dummy = what.call_dummy;
4392 /* If we hit an internal event that triggers symbol changes, the
4393 current frame will be invalidated within bpstat_what (e.g.,
4394 if we hit an internal solib event). Re-fetch it. */
4395 frame = get_current_frame ();
4396 gdbarch = get_frame_arch (frame);
4398 switch (what.main_action)
4400 case BPSTAT_WHAT_SET_LONGJMP_RESUME:
4401 /* If we hit the breakpoint at longjmp while stepping, we
4402 install a momentary breakpoint at the target of the
4406 fprintf_unfiltered (gdb_stdlog,
4407 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME\n");
4409 ecs->event_thread->stepping_over_breakpoint = 1;
4411 if (what.is_longjmp)
4413 struct value *arg_value;
4415 /* If we set the longjmp breakpoint via a SystemTap
4416 probe, then use it to extract the arguments. The
4417 destination PC is the third argument to the
4419 arg_value = probe_safe_evaluate_at_pc (frame, 2);
4421 jmp_buf_pc = value_as_address (arg_value);
4422 else if (!gdbarch_get_longjmp_target_p (gdbarch)
4423 || !gdbarch_get_longjmp_target (gdbarch,
4424 frame, &jmp_buf_pc))
4427 fprintf_unfiltered (gdb_stdlog,
4428 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME "
4429 "(!gdbarch_get_longjmp_target)\n");
4434 /* Insert a breakpoint at resume address. */
4435 insert_longjmp_resume_breakpoint (gdbarch, jmp_buf_pc);
4438 check_exception_resume (ecs, frame);
4442 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME:
4444 struct frame_info *init_frame;
4446 /* There are several cases to consider.
4448 1. The initiating frame no longer exists. In this case
4449 we must stop, because the exception or longjmp has gone
4452 2. The initiating frame exists, and is the same as the
4453 current frame. We stop, because the exception or
4454 longjmp has been caught.
4456 3. The initiating frame exists and is different from
4457 the current frame. This means the exception or longjmp
4458 has been caught beneath the initiating frame, so keep
4461 4. longjmp breakpoint has been placed just to protect
4462 against stale dummy frames and user is not interested
4463 in stopping around longjmps. */
4466 fprintf_unfiltered (gdb_stdlog,
4467 "infrun: BPSTAT_WHAT_CLEAR_LONGJMP_RESUME\n");
4469 gdb_assert (ecs->event_thread->control.exception_resume_breakpoint
4471 delete_exception_resume_breakpoint (ecs->event_thread);
4473 if (what.is_longjmp)
4475 check_longjmp_breakpoint_for_call_dummy (ecs->event_thread->num);
4477 if (!frame_id_p (ecs->event_thread->initiating_frame))
4485 init_frame = frame_find_by_id (ecs->event_thread->initiating_frame);
4489 struct frame_id current_id
4490 = get_frame_id (get_current_frame ());
4491 if (frame_id_eq (current_id,
4492 ecs->event_thread->initiating_frame))
4494 /* Case 2. Fall through. */
4504 /* For Cases 1 and 2, remove the step-resume breakpoint,
4506 delete_step_resume_breakpoint (ecs->event_thread);
4508 ecs->event_thread->control.stop_step = 1;
4509 print_end_stepping_range_reason ();
4510 stop_stepping (ecs);
4514 case BPSTAT_WHAT_SINGLE:
4516 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_SINGLE\n");
4517 ecs->event_thread->stepping_over_breakpoint = 1;
4518 /* Still need to check other stuff, at least the case where
4519 we are stepping and step out of the right range. */
4522 case BPSTAT_WHAT_STEP_RESUME:
4524 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STEP_RESUME\n");
4526 delete_step_resume_breakpoint (ecs->event_thread);
4527 if (ecs->event_thread->control.proceed_to_finish
4528 && execution_direction == EXEC_REVERSE)
4530 struct thread_info *tp = ecs->event_thread;
4532 /* We are finishing a function in reverse, and just hit
4533 the step-resume breakpoint at the start address of
4534 the function, and we're almost there -- just need to
4535 back up by one more single-step, which should take us
4536 back to the function call. */
4537 tp->control.step_range_start = tp->control.step_range_end = 1;
4541 fill_in_stop_func (gdbarch, ecs);
4542 if (stop_pc == ecs->stop_func_start
4543 && execution_direction == EXEC_REVERSE)
4545 /* We are stepping over a function call in reverse, and
4546 just hit the step-resume breakpoint at the start
4547 address of the function. Go back to single-stepping,
4548 which should take us back to the function call. */
4549 ecs->event_thread->stepping_over_breakpoint = 1;
4555 case BPSTAT_WHAT_STOP_NOISY:
4557 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_NOISY\n");
4558 stop_print_frame = 1;
4560 /* We are about to nuke the step_resume_breakpointt via the
4561 cleanup chain, so no need to worry about it here. */
4563 stop_stepping (ecs);
4566 case BPSTAT_WHAT_STOP_SILENT:
4568 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_SILENT\n");
4569 stop_print_frame = 0;
4571 /* We are about to nuke the step_resume_breakpoin via the
4572 cleanup chain, so no need to worry about it here. */
4574 stop_stepping (ecs);
4577 case BPSTAT_WHAT_HP_STEP_RESUME:
4579 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_HP_STEP_RESUME\n");
4581 delete_step_resume_breakpoint (ecs->event_thread);
4582 if (ecs->event_thread->step_after_step_resume_breakpoint)
4584 /* Back when the step-resume breakpoint was inserted, we
4585 were trying to single-step off a breakpoint. Go back
4587 ecs->event_thread->step_after_step_resume_breakpoint = 0;
4588 ecs->event_thread->stepping_over_breakpoint = 1;
4594 case BPSTAT_WHAT_KEEP_CHECKING:
4599 /* We come here if we hit a breakpoint but should not
4600 stop for it. Possibly we also were stepping
4601 and should stop for that. So fall through and
4602 test for stepping. But, if not stepping,
4605 /* In all-stop mode, if we're currently stepping but have stopped in
4606 some other thread, we need to switch back to the stepped thread. */
4609 struct thread_info *tp;
4611 tp = iterate_over_threads (currently_stepping_or_nexting_callback,
4615 /* However, if the current thread is blocked on some internal
4616 breakpoint, and we simply need to step over that breakpoint
4617 to get it going again, do that first. */
4618 if ((ecs->event_thread->control.trap_expected
4619 && ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_TRAP)
4620 || ecs->event_thread->stepping_over_breakpoint)
4626 /* If the stepping thread exited, then don't try to switch
4627 back and resume it, which could fail in several different
4628 ways depending on the target. Instead, just keep going.
4630 We can find a stepping dead thread in the thread list in
4633 - The target supports thread exit events, and when the
4634 target tries to delete the thread from the thread list,
4635 inferior_ptid pointed at the exiting thread. In such
4636 case, calling delete_thread does not really remove the
4637 thread from the list; instead, the thread is left listed,
4638 with 'exited' state.
4640 - The target's debug interface does not support thread
4641 exit events, and so we have no idea whatsoever if the
4642 previously stepping thread is still alive. For that
4643 reason, we need to synchronously query the target
4645 if (is_exited (tp->ptid)
4646 || !target_thread_alive (tp->ptid))
4649 fprintf_unfiltered (gdb_stdlog,
4650 "infrun: not switching back to "
4651 "stepped thread, it has vanished\n");
4653 delete_thread (tp->ptid);
4658 /* Otherwise, we no longer expect a trap in the current thread.
4659 Clear the trap_expected flag before switching back -- this is
4660 what keep_going would do as well, if we called it. */
4661 ecs->event_thread->control.trap_expected = 0;
4664 fprintf_unfiltered (gdb_stdlog,
4665 "infrun: switching back to stepped thread\n");
4667 ecs->event_thread = tp;
4668 ecs->ptid = tp->ptid;
4669 context_switch (ecs->ptid);
4675 if (ecs->event_thread->control.step_resume_breakpoint)
4678 fprintf_unfiltered (gdb_stdlog,
4679 "infrun: step-resume breakpoint is inserted\n");
4681 /* Having a step-resume breakpoint overrides anything
4682 else having to do with stepping commands until
4683 that breakpoint is reached. */
4688 if (ecs->event_thread->control.step_range_end == 0)
4691 fprintf_unfiltered (gdb_stdlog, "infrun: no stepping, continue\n");
4692 /* Likewise if we aren't even stepping. */
4697 /* Re-fetch current thread's frame in case the code above caused
4698 the frame cache to be re-initialized, making our FRAME variable
4699 a dangling pointer. */
4700 frame = get_current_frame ();
4701 gdbarch = get_frame_arch (frame);
4702 fill_in_stop_func (gdbarch, ecs);
4704 /* If stepping through a line, keep going if still within it.
4706 Note that step_range_end is the address of the first instruction
4707 beyond the step range, and NOT the address of the last instruction
4710 Note also that during reverse execution, we may be stepping
4711 through a function epilogue and therefore must detect when
4712 the current-frame changes in the middle of a line. */
4714 if (stop_pc >= ecs->event_thread->control.step_range_start
4715 && stop_pc < ecs->event_thread->control.step_range_end
4716 && (execution_direction != EXEC_REVERSE
4717 || frame_id_eq (get_frame_id (frame),
4718 ecs->event_thread->control.step_frame_id)))
4722 (gdb_stdlog, "infrun: stepping inside range [%s-%s]\n",
4723 paddress (gdbarch, ecs->event_thread->control.step_range_start),
4724 paddress (gdbarch, ecs->event_thread->control.step_range_end));
4726 /* When stepping backward, stop at beginning of line range
4727 (unless it's the function entry point, in which case
4728 keep going back to the call point). */
4729 if (stop_pc == ecs->event_thread->control.step_range_start
4730 && stop_pc != ecs->stop_func_start
4731 && execution_direction == EXEC_REVERSE)
4733 ecs->event_thread->control.stop_step = 1;
4734 print_end_stepping_range_reason ();
4735 stop_stepping (ecs);
4743 /* We stepped out of the stepping range. */
4745 /* If we are stepping at the source level and entered the runtime
4746 loader dynamic symbol resolution code...
4748 EXEC_FORWARD: we keep on single stepping until we exit the run
4749 time loader code and reach the callee's address.
4751 EXEC_REVERSE: we've already executed the callee (backward), and
4752 the runtime loader code is handled just like any other
4753 undebuggable function call. Now we need only keep stepping
4754 backward through the trampoline code, and that's handled further
4755 down, so there is nothing for us to do here. */
4757 if (execution_direction != EXEC_REVERSE
4758 && ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
4759 && in_solib_dynsym_resolve_code (stop_pc))
4761 CORE_ADDR pc_after_resolver =
4762 gdbarch_skip_solib_resolver (gdbarch, stop_pc);
4765 fprintf_unfiltered (gdb_stdlog,
4766 "infrun: stepped into dynsym resolve code\n");
4768 if (pc_after_resolver)
4770 /* Set up a step-resume breakpoint at the address
4771 indicated by SKIP_SOLIB_RESOLVER. */
4772 struct symtab_and_line sr_sal;
4775 sr_sal.pc = pc_after_resolver;
4776 sr_sal.pspace = get_frame_program_space (frame);
4778 insert_step_resume_breakpoint_at_sal (gdbarch,
4779 sr_sal, null_frame_id);
4786 if (ecs->event_thread->control.step_range_end != 1
4787 && (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
4788 || ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
4789 && get_frame_type (frame) == SIGTRAMP_FRAME)
4792 fprintf_unfiltered (gdb_stdlog,
4793 "infrun: stepped into signal trampoline\n");
4794 /* The inferior, while doing a "step" or "next", has ended up in
4795 a signal trampoline (either by a signal being delivered or by
4796 the signal handler returning). Just single-step until the
4797 inferior leaves the trampoline (either by calling the handler
4803 /* If we're in the return path from a shared library trampoline,
4804 we want to proceed through the trampoline when stepping. */
4805 /* macro/2012-04-25: This needs to come before the subroutine
4806 call check below as on some targets return trampolines look
4807 like subroutine calls (MIPS16 return thunks). */
4808 if (gdbarch_in_solib_return_trampoline (gdbarch,
4809 stop_pc, ecs->stop_func_name)
4810 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE)
4812 /* Determine where this trampoline returns. */
4813 CORE_ADDR real_stop_pc;
4815 real_stop_pc = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc);
4818 fprintf_unfiltered (gdb_stdlog,
4819 "infrun: stepped into solib return tramp\n");
4821 /* Only proceed through if we know where it's going. */
4824 /* And put the step-breakpoint there and go until there. */
4825 struct symtab_and_line sr_sal;
4827 init_sal (&sr_sal); /* initialize to zeroes */
4828 sr_sal.pc = real_stop_pc;
4829 sr_sal.section = find_pc_overlay (sr_sal.pc);
4830 sr_sal.pspace = get_frame_program_space (frame);
4832 /* Do not specify what the fp should be when we stop since
4833 on some machines the prologue is where the new fp value
4835 insert_step_resume_breakpoint_at_sal (gdbarch,
4836 sr_sal, null_frame_id);
4838 /* Restart without fiddling with the step ranges or
4845 /* Check for subroutine calls. The check for the current frame
4846 equalling the step ID is not necessary - the check of the
4847 previous frame's ID is sufficient - but it is a common case and
4848 cheaper than checking the previous frame's ID.
4850 NOTE: frame_id_eq will never report two invalid frame IDs as
4851 being equal, so to get into this block, both the current and
4852 previous frame must have valid frame IDs. */
4853 /* The outer_frame_id check is a heuristic to detect stepping
4854 through startup code. If we step over an instruction which
4855 sets the stack pointer from an invalid value to a valid value,
4856 we may detect that as a subroutine call from the mythical
4857 "outermost" function. This could be fixed by marking
4858 outermost frames as !stack_p,code_p,special_p. Then the
4859 initial outermost frame, before sp was valid, would
4860 have code_addr == &_start. See the comment in frame_id_eq
4862 if (!frame_id_eq (get_stack_frame_id (frame),
4863 ecs->event_thread->control.step_stack_frame_id)
4864 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
4865 ecs->event_thread->control.step_stack_frame_id)
4866 && (!frame_id_eq (ecs->event_thread->control.step_stack_frame_id,
4868 || step_start_function != find_pc_function (stop_pc))))
4870 CORE_ADDR real_stop_pc;
4873 fprintf_unfiltered (gdb_stdlog, "infrun: stepped into subroutine\n");
4875 if ((ecs->event_thread->control.step_over_calls == STEP_OVER_NONE)
4876 || ((ecs->event_thread->control.step_range_end == 1)
4877 && in_prologue (gdbarch, ecs->event_thread->prev_pc,
4878 ecs->stop_func_start)))
4880 /* I presume that step_over_calls is only 0 when we're
4881 supposed to be stepping at the assembly language level
4882 ("stepi"). Just stop. */
4883 /* Also, maybe we just did a "nexti" inside a prolog, so we
4884 thought it was a subroutine call but it was not. Stop as
4886 /* And this works the same backward as frontward. MVS */
4887 ecs->event_thread->control.stop_step = 1;
4888 print_end_stepping_range_reason ();
4889 stop_stepping (ecs);
4893 /* Reverse stepping through solib trampolines. */
4895 if (execution_direction == EXEC_REVERSE
4896 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE
4897 && (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc)
4898 || (ecs->stop_func_start == 0
4899 && in_solib_dynsym_resolve_code (stop_pc))))
4901 /* Any solib trampoline code can be handled in reverse
4902 by simply continuing to single-step. We have already
4903 executed the solib function (backwards), and a few
4904 steps will take us back through the trampoline to the
4910 if (ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
4912 /* We're doing a "next".
4914 Normal (forward) execution: set a breakpoint at the
4915 callee's return address (the address at which the caller
4918 Reverse (backward) execution. set the step-resume
4919 breakpoint at the start of the function that we just
4920 stepped into (backwards), and continue to there. When we
4921 get there, we'll need to single-step back to the caller. */
4923 if (execution_direction == EXEC_REVERSE)
4925 /* If we're already at the start of the function, we've either
4926 just stepped backward into a single instruction function,
4927 or stepped back out of a signal handler to the first instruction
4928 of the function. Just keep going, which will single-step back
4930 if (ecs->stop_func_start != stop_pc)
4932 struct symtab_and_line sr_sal;
4934 /* Normal function call return (static or dynamic). */
4936 sr_sal.pc = ecs->stop_func_start;
4937 sr_sal.pspace = get_frame_program_space (frame);
4938 insert_step_resume_breakpoint_at_sal (gdbarch,
4939 sr_sal, null_frame_id);
4943 insert_step_resume_breakpoint_at_caller (frame);
4949 /* If we are in a function call trampoline (a stub between the
4950 calling routine and the real function), locate the real
4951 function. That's what tells us (a) whether we want to step
4952 into it at all, and (b) what prologue we want to run to the
4953 end of, if we do step into it. */
4954 real_stop_pc = skip_language_trampoline (frame, stop_pc);
4955 if (real_stop_pc == 0)
4956 real_stop_pc = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc);
4957 if (real_stop_pc != 0)
4958 ecs->stop_func_start = real_stop_pc;
4960 if (real_stop_pc != 0 && in_solib_dynsym_resolve_code (real_stop_pc))
4962 struct symtab_and_line sr_sal;
4965 sr_sal.pc = ecs->stop_func_start;
4966 sr_sal.pspace = get_frame_program_space (frame);
4968 insert_step_resume_breakpoint_at_sal (gdbarch,
4969 sr_sal, null_frame_id);
4974 /* If we have line number information for the function we are
4975 thinking of stepping into and the function isn't on the skip
4978 If there are several symtabs at that PC (e.g. with include
4979 files), just want to know whether *any* of them have line
4980 numbers. find_pc_line handles this. */
4982 struct symtab_and_line tmp_sal;
4984 tmp_sal = find_pc_line (ecs->stop_func_start, 0);
4985 if (tmp_sal.line != 0
4986 && !function_name_is_marked_for_skip (ecs->stop_func_name,
4989 if (execution_direction == EXEC_REVERSE)
4990 handle_step_into_function_backward (gdbarch, ecs);
4992 handle_step_into_function (gdbarch, ecs);
4997 /* If we have no line number and the step-stop-if-no-debug is
4998 set, we stop the step so that the user has a chance to switch
4999 in assembly mode. */
5000 if (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
5001 && step_stop_if_no_debug)
5003 ecs->event_thread->control.stop_step = 1;
5004 print_end_stepping_range_reason ();
5005 stop_stepping (ecs);
5009 if (execution_direction == EXEC_REVERSE)
5011 /* If we're already at the start of the function, we've either just
5012 stepped backward into a single instruction function without line
5013 number info, or stepped back out of a signal handler to the first
5014 instruction of the function without line number info. Just keep
5015 going, which will single-step back to the caller. */
5016 if (ecs->stop_func_start != stop_pc)
5018 /* Set a breakpoint at callee's start address.
5019 From there we can step once and be back in the caller. */
5020 struct symtab_and_line sr_sal;
5023 sr_sal.pc = ecs->stop_func_start;
5024 sr_sal.pspace = get_frame_program_space (frame);
5025 insert_step_resume_breakpoint_at_sal (gdbarch,
5026 sr_sal, null_frame_id);
5030 /* Set a breakpoint at callee's return address (the address
5031 at which the caller will resume). */
5032 insert_step_resume_breakpoint_at_caller (frame);
5038 /* Reverse stepping through solib trampolines. */
5040 if (execution_direction == EXEC_REVERSE
5041 && ecs->event_thread->control.step_over_calls != STEP_OVER_NONE)
5043 if (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc)
5044 || (ecs->stop_func_start == 0
5045 && in_solib_dynsym_resolve_code (stop_pc)))
5047 /* Any solib trampoline code can be handled in reverse
5048 by simply continuing to single-step. We have already
5049 executed the solib function (backwards), and a few
5050 steps will take us back through the trampoline to the
5055 else if (in_solib_dynsym_resolve_code (stop_pc))
5057 /* Stepped backward into the solib dynsym resolver.
5058 Set a breakpoint at its start and continue, then
5059 one more step will take us out. */
5060 struct symtab_and_line sr_sal;
5063 sr_sal.pc = ecs->stop_func_start;
5064 sr_sal.pspace = get_frame_program_space (frame);
5065 insert_step_resume_breakpoint_at_sal (gdbarch,
5066 sr_sal, null_frame_id);
5072 stop_pc_sal = find_pc_line (stop_pc, 0);
5074 /* NOTE: tausq/2004-05-24: This if block used to be done before all
5075 the trampoline processing logic, however, there are some trampolines
5076 that have no names, so we should do trampoline handling first. */
5077 if (ecs->event_thread->control.step_over_calls == STEP_OVER_UNDEBUGGABLE
5078 && ecs->stop_func_name == NULL
5079 && stop_pc_sal.line == 0)
5082 fprintf_unfiltered (gdb_stdlog,
5083 "infrun: stepped into undebuggable function\n");
5085 /* The inferior just stepped into, or returned to, an
5086 undebuggable function (where there is no debugging information
5087 and no line number corresponding to the address where the
5088 inferior stopped). Since we want to skip this kind of code,
5089 we keep going until the inferior returns from this
5090 function - unless the user has asked us not to (via
5091 set step-mode) or we no longer know how to get back
5092 to the call site. */
5093 if (step_stop_if_no_debug
5094 || !frame_id_p (frame_unwind_caller_id (frame)))
5096 /* If we have no line number and the step-stop-if-no-debug
5097 is set, we stop the step so that the user has a chance to
5098 switch in assembly mode. */
5099 ecs->event_thread->control.stop_step = 1;
5100 print_end_stepping_range_reason ();
5101 stop_stepping (ecs);
5106 /* Set a breakpoint at callee's return address (the address
5107 at which the caller will resume). */
5108 insert_step_resume_breakpoint_at_caller (frame);
5114 if (ecs->event_thread->control.step_range_end == 1)
5116 /* It is stepi or nexti. We always want to stop stepping after
5119 fprintf_unfiltered (gdb_stdlog, "infrun: stepi/nexti\n");
5120 ecs->event_thread->control.stop_step = 1;
5121 print_end_stepping_range_reason ();
5122 stop_stepping (ecs);
5126 if (stop_pc_sal.line == 0)
5128 /* We have no line number information. That means to stop
5129 stepping (does this always happen right after one instruction,
5130 when we do "s" in a function with no line numbers,
5131 or can this happen as a result of a return or longjmp?). */
5133 fprintf_unfiltered (gdb_stdlog, "infrun: no line number info\n");
5134 ecs->event_thread->control.stop_step = 1;
5135 print_end_stepping_range_reason ();
5136 stop_stepping (ecs);
5140 /* Look for "calls" to inlined functions, part one. If the inline
5141 frame machinery detected some skipped call sites, we have entered
5142 a new inline function. */
5144 if (frame_id_eq (get_frame_id (get_current_frame ()),
5145 ecs->event_thread->control.step_frame_id)
5146 && inline_skipped_frames (ecs->ptid))
5148 struct symtab_and_line call_sal;
5151 fprintf_unfiltered (gdb_stdlog,
5152 "infrun: stepped into inlined function\n");
5154 find_frame_sal (get_current_frame (), &call_sal);
5156 if (ecs->event_thread->control.step_over_calls != STEP_OVER_ALL)
5158 /* For "step", we're going to stop. But if the call site
5159 for this inlined function is on the same source line as
5160 we were previously stepping, go down into the function
5161 first. Otherwise stop at the call site. */
5163 if (call_sal.line == ecs->event_thread->current_line
5164 && call_sal.symtab == ecs->event_thread->current_symtab)
5165 step_into_inline_frame (ecs->ptid);
5167 ecs->event_thread->control.stop_step = 1;
5168 print_end_stepping_range_reason ();
5169 stop_stepping (ecs);
5174 /* For "next", we should stop at the call site if it is on a
5175 different source line. Otherwise continue through the
5176 inlined function. */
5177 if (call_sal.line == ecs->event_thread->current_line
5178 && call_sal.symtab == ecs->event_thread->current_symtab)
5182 ecs->event_thread->control.stop_step = 1;
5183 print_end_stepping_range_reason ();
5184 stop_stepping (ecs);
5190 /* Look for "calls" to inlined functions, part two. If we are still
5191 in the same real function we were stepping through, but we have
5192 to go further up to find the exact frame ID, we are stepping
5193 through a more inlined call beyond its call site. */
5195 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
5196 && !frame_id_eq (get_frame_id (get_current_frame ()),
5197 ecs->event_thread->control.step_frame_id)
5198 && stepped_in_from (get_current_frame (),
5199 ecs->event_thread->control.step_frame_id))
5202 fprintf_unfiltered (gdb_stdlog,
5203 "infrun: stepping through inlined function\n");
5205 if (ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
5209 ecs->event_thread->control.stop_step = 1;
5210 print_end_stepping_range_reason ();
5211 stop_stepping (ecs);
5216 if ((stop_pc == stop_pc_sal.pc)
5217 && (ecs->event_thread->current_line != stop_pc_sal.line
5218 || ecs->event_thread->current_symtab != stop_pc_sal.symtab))
5220 /* We are at the start of a different line. So stop. Note that
5221 we don't stop if we step into the middle of a different line.
5222 That is said to make things like for (;;) statements work
5225 fprintf_unfiltered (gdb_stdlog,
5226 "infrun: stepped to a different line\n");
5227 ecs->event_thread->control.stop_step = 1;
5228 print_end_stepping_range_reason ();
5229 stop_stepping (ecs);
5233 /* We aren't done stepping.
5235 Optimize by setting the stepping range to the line.
5236 (We might not be in the original line, but if we entered a
5237 new line in mid-statement, we continue stepping. This makes
5238 things like for(;;) statements work better.) */
5240 ecs->event_thread->control.step_range_start = stop_pc_sal.pc;
5241 ecs->event_thread->control.step_range_end = stop_pc_sal.end;
5242 set_step_info (frame, stop_pc_sal);
5245 fprintf_unfiltered (gdb_stdlog, "infrun: keep going\n");
5249 /* Is thread TP in the middle of single-stepping? */
5252 currently_stepping (struct thread_info *tp)
5254 return ((tp->control.step_range_end
5255 && tp->control.step_resume_breakpoint == NULL)
5256 || tp->control.trap_expected
5257 || bpstat_should_step ());
5260 /* Returns true if any thread *but* the one passed in "data" is in the
5261 middle of stepping or of handling a "next". */
5264 currently_stepping_or_nexting_callback (struct thread_info *tp, void *data)
5269 return (tp->control.step_range_end
5270 || tp->control.trap_expected);
5273 /* Inferior has stepped into a subroutine call with source code that
5274 we should not step over. Do step to the first line of code in
5278 handle_step_into_function (struct gdbarch *gdbarch,
5279 struct execution_control_state *ecs)
5282 struct symtab_and_line stop_func_sal, sr_sal;
5284 fill_in_stop_func (gdbarch, ecs);
5286 s = find_pc_symtab (stop_pc);
5287 if (s && s->language != language_asm)
5288 ecs->stop_func_start = gdbarch_skip_prologue (gdbarch,
5289 ecs->stop_func_start);
5291 stop_func_sal = find_pc_line (ecs->stop_func_start, 0);
5292 /* Use the step_resume_break to step until the end of the prologue,
5293 even if that involves jumps (as it seems to on the vax under
5295 /* If the prologue ends in the middle of a source line, continue to
5296 the end of that source line (if it is still within the function).
5297 Otherwise, just go to end of prologue. */
5298 if (stop_func_sal.end
5299 && stop_func_sal.pc != ecs->stop_func_start
5300 && stop_func_sal.end < ecs->stop_func_end)
5301 ecs->stop_func_start = stop_func_sal.end;
5303 /* Architectures which require breakpoint adjustment might not be able
5304 to place a breakpoint at the computed address. If so, the test
5305 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
5306 ecs->stop_func_start to an address at which a breakpoint may be
5307 legitimately placed.
5309 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
5310 made, GDB will enter an infinite loop when stepping through
5311 optimized code consisting of VLIW instructions which contain
5312 subinstructions corresponding to different source lines. On
5313 FR-V, it's not permitted to place a breakpoint on any but the
5314 first subinstruction of a VLIW instruction. When a breakpoint is
5315 set, GDB will adjust the breakpoint address to the beginning of
5316 the VLIW instruction. Thus, we need to make the corresponding
5317 adjustment here when computing the stop address. */
5319 if (gdbarch_adjust_breakpoint_address_p (gdbarch))
5321 ecs->stop_func_start
5322 = gdbarch_adjust_breakpoint_address (gdbarch,
5323 ecs->stop_func_start);
5326 if (ecs->stop_func_start == stop_pc)
5328 /* We are already there: stop now. */
5329 ecs->event_thread->control.stop_step = 1;
5330 print_end_stepping_range_reason ();
5331 stop_stepping (ecs);
5336 /* Put the step-breakpoint there and go until there. */
5337 init_sal (&sr_sal); /* initialize to zeroes */
5338 sr_sal.pc = ecs->stop_func_start;
5339 sr_sal.section = find_pc_overlay (ecs->stop_func_start);
5340 sr_sal.pspace = get_frame_program_space (get_current_frame ());
5342 /* Do not specify what the fp should be when we stop since on
5343 some machines the prologue is where the new fp value is
5345 insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal, null_frame_id);
5347 /* And make sure stepping stops right away then. */
5348 ecs->event_thread->control.step_range_end
5349 = ecs->event_thread->control.step_range_start;
5354 /* Inferior has stepped backward into a subroutine call with source
5355 code that we should not step over. Do step to the beginning of the
5356 last line of code in it. */
5359 handle_step_into_function_backward (struct gdbarch *gdbarch,
5360 struct execution_control_state *ecs)
5363 struct symtab_and_line stop_func_sal;
5365 fill_in_stop_func (gdbarch, ecs);
5367 s = find_pc_symtab (stop_pc);
5368 if (s && s->language != language_asm)
5369 ecs->stop_func_start = gdbarch_skip_prologue (gdbarch,
5370 ecs->stop_func_start);
5372 stop_func_sal = find_pc_line (stop_pc, 0);
5374 /* OK, we're just going to keep stepping here. */
5375 if (stop_func_sal.pc == stop_pc)
5377 /* We're there already. Just stop stepping now. */
5378 ecs->event_thread->control.stop_step = 1;
5379 print_end_stepping_range_reason ();
5380 stop_stepping (ecs);
5384 /* Else just reset the step range and keep going.
5385 No step-resume breakpoint, they don't work for
5386 epilogues, which can have multiple entry paths. */
5387 ecs->event_thread->control.step_range_start = stop_func_sal.pc;
5388 ecs->event_thread->control.step_range_end = stop_func_sal.end;
5394 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
5395 This is used to both functions and to skip over code. */
5398 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch *gdbarch,
5399 struct symtab_and_line sr_sal,
5400 struct frame_id sr_id,
5401 enum bptype sr_type)
5403 /* There should never be more than one step-resume or longjmp-resume
5404 breakpoint per thread, so we should never be setting a new
5405 step_resume_breakpoint when one is already active. */
5406 gdb_assert (inferior_thread ()->control.step_resume_breakpoint == NULL);
5407 gdb_assert (sr_type == bp_step_resume || sr_type == bp_hp_step_resume);
5410 fprintf_unfiltered (gdb_stdlog,
5411 "infrun: inserting step-resume breakpoint at %s\n",
5412 paddress (gdbarch, sr_sal.pc));
5414 inferior_thread ()->control.step_resume_breakpoint
5415 = set_momentary_breakpoint (gdbarch, sr_sal, sr_id, sr_type);
5419 insert_step_resume_breakpoint_at_sal (struct gdbarch *gdbarch,
5420 struct symtab_and_line sr_sal,
5421 struct frame_id sr_id)
5423 insert_step_resume_breakpoint_at_sal_1 (gdbarch,
5428 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
5429 This is used to skip a potential signal handler.
5431 This is called with the interrupted function's frame. The signal
5432 handler, when it returns, will resume the interrupted function at
5436 insert_hp_step_resume_breakpoint_at_frame (struct frame_info *return_frame)
5438 struct symtab_and_line sr_sal;
5439 struct gdbarch *gdbarch;
5441 gdb_assert (return_frame != NULL);
5442 init_sal (&sr_sal); /* initialize to zeros */
5444 gdbarch = get_frame_arch (return_frame);
5445 sr_sal.pc = gdbarch_addr_bits_remove (gdbarch, get_frame_pc (return_frame));
5446 sr_sal.section = find_pc_overlay (sr_sal.pc);
5447 sr_sal.pspace = get_frame_program_space (return_frame);
5449 insert_step_resume_breakpoint_at_sal_1 (gdbarch, sr_sal,
5450 get_stack_frame_id (return_frame),
5454 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
5455 is used to skip a function after stepping into it (for "next" or if
5456 the called function has no debugging information).
5458 The current function has almost always been reached by single
5459 stepping a call or return instruction. NEXT_FRAME belongs to the
5460 current function, and the breakpoint will be set at the caller's
5463 This is a separate function rather than reusing
5464 insert_hp_step_resume_breakpoint_at_frame in order to avoid
5465 get_prev_frame, which may stop prematurely (see the implementation
5466 of frame_unwind_caller_id for an example). */
5469 insert_step_resume_breakpoint_at_caller (struct frame_info *next_frame)
5471 struct symtab_and_line sr_sal;
5472 struct gdbarch *gdbarch;
5474 /* We shouldn't have gotten here if we don't know where the call site
5476 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame)));
5478 init_sal (&sr_sal); /* initialize to zeros */
5480 gdbarch = frame_unwind_caller_arch (next_frame);
5481 sr_sal.pc = gdbarch_addr_bits_remove (gdbarch,
5482 frame_unwind_caller_pc (next_frame));
5483 sr_sal.section = find_pc_overlay (sr_sal.pc);
5484 sr_sal.pspace = frame_unwind_program_space (next_frame);
5486 insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal,
5487 frame_unwind_caller_id (next_frame));
5490 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
5491 new breakpoint at the target of a jmp_buf. The handling of
5492 longjmp-resume uses the same mechanisms used for handling
5493 "step-resume" breakpoints. */
5496 insert_longjmp_resume_breakpoint (struct gdbarch *gdbarch, CORE_ADDR pc)
5498 /* There should never be more than one longjmp-resume breakpoint per
5499 thread, so we should never be setting a new
5500 longjmp_resume_breakpoint when one is already active. */
5501 gdb_assert (inferior_thread ()->control.exception_resume_breakpoint == NULL);
5504 fprintf_unfiltered (gdb_stdlog,
5505 "infrun: inserting longjmp-resume breakpoint at %s\n",
5506 paddress (gdbarch, pc));
5508 inferior_thread ()->control.exception_resume_breakpoint =
5509 set_momentary_breakpoint_at_pc (gdbarch, pc, bp_longjmp_resume);
5512 /* Insert an exception resume breakpoint. TP is the thread throwing
5513 the exception. The block B is the block of the unwinder debug hook
5514 function. FRAME is the frame corresponding to the call to this
5515 function. SYM is the symbol of the function argument holding the
5516 target PC of the exception. */
5519 insert_exception_resume_breakpoint (struct thread_info *tp,
5521 struct frame_info *frame,
5524 volatile struct gdb_exception e;
5526 /* We want to ignore errors here. */
5527 TRY_CATCH (e, RETURN_MASK_ERROR)
5529 struct symbol *vsym;
5530 struct value *value;
5532 struct breakpoint *bp;
5534 vsym = lookup_symbol (SYMBOL_LINKAGE_NAME (sym), b, VAR_DOMAIN, NULL);
5535 value = read_var_value (vsym, frame);
5536 /* If the value was optimized out, revert to the old behavior. */
5537 if (! value_optimized_out (value))
5539 handler = value_as_address (value);
5542 fprintf_unfiltered (gdb_stdlog,
5543 "infrun: exception resume at %lx\n",
5544 (unsigned long) handler);
5546 bp = set_momentary_breakpoint_at_pc (get_frame_arch (frame),
5547 handler, bp_exception_resume);
5549 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
5552 bp->thread = tp->num;
5553 inferior_thread ()->control.exception_resume_breakpoint = bp;
5558 /* A helper for check_exception_resume that sets an
5559 exception-breakpoint based on a SystemTap probe. */
5562 insert_exception_resume_from_probe (struct thread_info *tp,
5563 const struct probe *probe,
5564 struct frame_info *frame)
5566 struct value *arg_value;
5568 struct breakpoint *bp;
5570 arg_value = probe_safe_evaluate_at_pc (frame, 1);
5574 handler = value_as_address (arg_value);
5577 fprintf_unfiltered (gdb_stdlog,
5578 "infrun: exception resume at %s\n",
5579 paddress (get_objfile_arch (probe->objfile),
5582 bp = set_momentary_breakpoint_at_pc (get_frame_arch (frame),
5583 handler, bp_exception_resume);
5584 bp->thread = tp->num;
5585 inferior_thread ()->control.exception_resume_breakpoint = bp;
5588 /* This is called when an exception has been intercepted. Check to
5589 see whether the exception's destination is of interest, and if so,
5590 set an exception resume breakpoint there. */
5593 check_exception_resume (struct execution_control_state *ecs,
5594 struct frame_info *frame)
5596 volatile struct gdb_exception e;
5597 const struct probe *probe;
5598 struct symbol *func;
5600 /* First see if this exception unwinding breakpoint was set via a
5601 SystemTap probe point. If so, the probe has two arguments: the
5602 CFA and the HANDLER. We ignore the CFA, extract the handler, and
5603 set a breakpoint there. */
5604 probe = find_probe_by_pc (get_frame_pc (frame));
5607 insert_exception_resume_from_probe (ecs->event_thread, probe, frame);
5611 func = get_frame_function (frame);
5615 TRY_CATCH (e, RETURN_MASK_ERROR)
5618 struct block_iterator iter;
5622 /* The exception breakpoint is a thread-specific breakpoint on
5623 the unwinder's debug hook, declared as:
5625 void _Unwind_DebugHook (void *cfa, void *handler);
5627 The CFA argument indicates the frame to which control is
5628 about to be transferred. HANDLER is the destination PC.
5630 We ignore the CFA and set a temporary breakpoint at HANDLER.
5631 This is not extremely efficient but it avoids issues in gdb
5632 with computing the DWARF CFA, and it also works even in weird
5633 cases such as throwing an exception from inside a signal
5636 b = SYMBOL_BLOCK_VALUE (func);
5637 ALL_BLOCK_SYMBOLS (b, iter, sym)
5639 if (!SYMBOL_IS_ARGUMENT (sym))
5646 insert_exception_resume_breakpoint (ecs->event_thread,
5655 stop_stepping (struct execution_control_state *ecs)
5658 fprintf_unfiltered (gdb_stdlog, "infrun: stop_stepping\n");
5660 /* Let callers know we don't want to wait for the inferior anymore. */
5661 ecs->wait_some_more = 0;
5664 /* This function handles various cases where we need to continue
5665 waiting for the inferior. */
5666 /* (Used to be the keep_going: label in the old wait_for_inferior). */
5669 keep_going (struct execution_control_state *ecs)
5671 /* Make sure normal_stop is called if we get a QUIT handled before
5673 struct cleanup *old_cleanups = make_cleanup (resume_cleanups, 0);
5675 /* Save the pc before execution, to compare with pc after stop. */
5676 ecs->event_thread->prev_pc
5677 = regcache_read_pc (get_thread_regcache (ecs->ptid));
5679 /* If we did not do break;, it means we should keep running the
5680 inferior and not return to debugger. */
5682 if (ecs->event_thread->control.trap_expected
5683 && ecs->event_thread->suspend.stop_signal != GDB_SIGNAL_TRAP)
5685 /* We took a signal (which we are supposed to pass through to
5686 the inferior, else we'd not get here) and we haven't yet
5687 gotten our trap. Simply continue. */
5689 discard_cleanups (old_cleanups);
5690 resume (currently_stepping (ecs->event_thread),
5691 ecs->event_thread->suspend.stop_signal);
5695 /* Either the trap was not expected, but we are continuing
5696 anyway (the user asked that this signal be passed to the
5699 The signal was SIGTRAP, e.g. it was our signal, but we
5700 decided we should resume from it.
5702 We're going to run this baby now!
5704 Note that insert_breakpoints won't try to re-insert
5705 already inserted breakpoints. Therefore, we don't
5706 care if breakpoints were already inserted, or not. */
5708 if (ecs->event_thread->stepping_over_breakpoint)
5710 struct regcache *thread_regcache = get_thread_regcache (ecs->ptid);
5712 if (!use_displaced_stepping (get_regcache_arch (thread_regcache)))
5713 /* Since we can't do a displaced step, we have to remove
5714 the breakpoint while we step it. To keep things
5715 simple, we remove them all. */
5716 remove_breakpoints ();
5720 volatile struct gdb_exception e;
5722 /* Stop stepping when inserting breakpoints
5724 TRY_CATCH (e, RETURN_MASK_ERROR)
5726 insert_breakpoints ();
5730 exception_print (gdb_stderr, e);
5731 stop_stepping (ecs);
5736 ecs->event_thread->control.trap_expected
5737 = ecs->event_thread->stepping_over_breakpoint;
5739 /* Do not deliver SIGNAL_TRAP (except when the user explicitly
5740 specifies that such a signal should be delivered to the
5743 Typically, this would occure when a user is debugging a
5744 target monitor on a simulator: the target monitor sets a
5745 breakpoint; the simulator encounters this break-point and
5746 halts the simulation handing control to GDB; GDB, noteing
5747 that the break-point isn't valid, returns control back to the
5748 simulator; the simulator then delivers the hardware
5749 equivalent of a SIGNAL_TRAP to the program being debugged. */
5751 if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP
5752 && !signal_program[ecs->event_thread->suspend.stop_signal])
5753 ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
5755 discard_cleanups (old_cleanups);
5756 resume (currently_stepping (ecs->event_thread),
5757 ecs->event_thread->suspend.stop_signal);
5760 prepare_to_wait (ecs);
5763 /* This function normally comes after a resume, before
5764 handle_inferior_event exits. It takes care of any last bits of
5765 housekeeping, and sets the all-important wait_some_more flag. */
5768 prepare_to_wait (struct execution_control_state *ecs)
5771 fprintf_unfiltered (gdb_stdlog, "infrun: prepare_to_wait\n");
5773 /* This is the old end of the while loop. Let everybody know we
5774 want to wait for the inferior some more and get called again
5776 ecs->wait_some_more = 1;
5779 /* Several print_*_reason functions to print why the inferior has stopped.
5780 We always print something when the inferior exits, or receives a signal.
5781 The rest of the cases are dealt with later on in normal_stop and
5782 print_it_typical. Ideally there should be a call to one of these
5783 print_*_reason functions functions from handle_inferior_event each time
5784 stop_stepping is called. */
5786 /* Print why the inferior has stopped.
5787 We are done with a step/next/si/ni command, print why the inferior has
5788 stopped. For now print nothing. Print a message only if not in the middle
5789 of doing a "step n" operation for n > 1. */
5792 print_end_stepping_range_reason (void)
5794 if ((!inferior_thread ()->step_multi
5795 || !inferior_thread ()->control.stop_step)
5796 && ui_out_is_mi_like_p (current_uiout))
5797 ui_out_field_string (current_uiout, "reason",
5798 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE));
5801 /* The inferior was terminated by a signal, print why it stopped. */
5804 print_signal_exited_reason (enum gdb_signal siggnal)
5806 struct ui_out *uiout = current_uiout;
5808 annotate_signalled ();
5809 if (ui_out_is_mi_like_p (uiout))
5811 (uiout, "reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED));
5812 ui_out_text (uiout, "\nProgram terminated with signal ");
5813 annotate_signal_name ();
5814 ui_out_field_string (uiout, "signal-name",
5815 gdb_signal_to_name (siggnal));
5816 annotate_signal_name_end ();
5817 ui_out_text (uiout, ", ");
5818 annotate_signal_string ();
5819 ui_out_field_string (uiout, "signal-meaning",
5820 gdb_signal_to_string (siggnal));
5821 annotate_signal_string_end ();
5822 ui_out_text (uiout, ".\n");
5823 ui_out_text (uiout, "The program no longer exists.\n");
5826 /* The inferior program is finished, print why it stopped. */
5829 print_exited_reason (int exitstatus)
5831 struct inferior *inf = current_inferior ();
5832 const char *pidstr = target_pid_to_str (pid_to_ptid (inf->pid));
5833 struct ui_out *uiout = current_uiout;
5835 annotate_exited (exitstatus);
5838 if (ui_out_is_mi_like_p (uiout))
5839 ui_out_field_string (uiout, "reason",
5840 async_reason_lookup (EXEC_ASYNC_EXITED));
5841 ui_out_text (uiout, "[Inferior ");
5842 ui_out_text (uiout, plongest (inf->num));
5843 ui_out_text (uiout, " (");
5844 ui_out_text (uiout, pidstr);
5845 ui_out_text (uiout, ") exited with code ");
5846 ui_out_field_fmt (uiout, "exit-code", "0%o", (unsigned int) exitstatus);
5847 ui_out_text (uiout, "]\n");
5851 if (ui_out_is_mi_like_p (uiout))
5853 (uiout, "reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY));
5854 ui_out_text (uiout, "[Inferior ");
5855 ui_out_text (uiout, plongest (inf->num));
5856 ui_out_text (uiout, " (");
5857 ui_out_text (uiout, pidstr);
5858 ui_out_text (uiout, ") exited normally]\n");
5860 /* Support the --return-child-result option. */
5861 return_child_result_value = exitstatus;
5864 /* Signal received, print why the inferior has stopped. The signal table
5865 tells us to print about it. */
5868 print_signal_received_reason (enum gdb_signal siggnal)
5870 struct ui_out *uiout = current_uiout;
5874 if (siggnal == GDB_SIGNAL_0 && !ui_out_is_mi_like_p (uiout))
5876 struct thread_info *t = inferior_thread ();
5878 ui_out_text (uiout, "\n[");
5879 ui_out_field_string (uiout, "thread-name",
5880 target_pid_to_str (t->ptid));
5881 ui_out_field_fmt (uiout, "thread-id", "] #%d", t->num);
5882 ui_out_text (uiout, " stopped");
5886 ui_out_text (uiout, "\nProgram received signal ");
5887 annotate_signal_name ();
5888 if (ui_out_is_mi_like_p (uiout))
5890 (uiout, "reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED));
5891 ui_out_field_string (uiout, "signal-name",
5892 gdb_signal_to_name (siggnal));
5893 annotate_signal_name_end ();
5894 ui_out_text (uiout, ", ");
5895 annotate_signal_string ();
5896 ui_out_field_string (uiout, "signal-meaning",
5897 gdb_signal_to_string (siggnal));
5898 annotate_signal_string_end ();
5900 ui_out_text (uiout, ".\n");
5903 /* Reverse execution: target ran out of history info, print why the inferior
5907 print_no_history_reason (void)
5909 ui_out_text (current_uiout, "\nNo more reverse-execution history.\n");
5912 /* Here to return control to GDB when the inferior stops for real.
5913 Print appropriate messages, remove breakpoints, give terminal our modes.
5915 STOP_PRINT_FRAME nonzero means print the executing frame
5916 (pc, function, args, file, line number and line text).
5917 BREAKPOINTS_FAILED nonzero means stop was due to error
5918 attempting to insert breakpoints. */
5923 struct target_waitstatus last;
5925 struct cleanup *old_chain = make_cleanup (null_cleanup, NULL);
5927 get_last_target_status (&last_ptid, &last);
5929 /* If an exception is thrown from this point on, make sure to
5930 propagate GDB's knowledge of the executing state to the
5931 frontend/user running state. A QUIT is an easy exception to see
5932 here, so do this before any filtered output. */
5934 make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
5935 else if (last.kind != TARGET_WAITKIND_SIGNALLED
5936 && last.kind != TARGET_WAITKIND_EXITED
5937 && last.kind != TARGET_WAITKIND_NO_RESUMED)
5938 make_cleanup (finish_thread_state_cleanup, &inferior_ptid);
5940 /* In non-stop mode, we don't want GDB to switch threads behind the
5941 user's back, to avoid races where the user is typing a command to
5942 apply to thread x, but GDB switches to thread y before the user
5943 finishes entering the command. */
5945 /* As with the notification of thread events, we want to delay
5946 notifying the user that we've switched thread context until
5947 the inferior actually stops.
5949 There's no point in saying anything if the inferior has exited.
5950 Note that SIGNALLED here means "exited with a signal", not
5951 "received a signal". */
5953 && !ptid_equal (previous_inferior_ptid, inferior_ptid)
5954 && target_has_execution
5955 && last.kind != TARGET_WAITKIND_SIGNALLED
5956 && last.kind != TARGET_WAITKIND_EXITED
5957 && last.kind != TARGET_WAITKIND_NO_RESUMED)
5959 target_terminal_ours_for_output ();
5960 printf_filtered (_("[Switching to %s]\n"),
5961 target_pid_to_str (inferior_ptid));
5962 annotate_thread_changed ();
5963 previous_inferior_ptid = inferior_ptid;
5966 if (last.kind == TARGET_WAITKIND_NO_RESUMED)
5968 gdb_assert (sync_execution || !target_can_async_p ());
5970 target_terminal_ours_for_output ();
5971 printf_filtered (_("No unwaited-for children left.\n"));
5974 if (!breakpoints_always_inserted_mode () && target_has_execution)
5976 if (remove_breakpoints ())
5978 target_terminal_ours_for_output ();
5979 printf_filtered (_("Cannot remove breakpoints because "
5980 "program is no longer writable.\nFurther "
5981 "execution is probably impossible.\n"));
5985 /* If an auto-display called a function and that got a signal,
5986 delete that auto-display to avoid an infinite recursion. */
5988 if (stopped_by_random_signal)
5989 disable_current_display ();
5991 /* Don't print a message if in the middle of doing a "step n"
5992 operation for n > 1 */
5993 if (target_has_execution
5994 && last.kind != TARGET_WAITKIND_SIGNALLED
5995 && last.kind != TARGET_WAITKIND_EXITED
5996 && inferior_thread ()->step_multi
5997 && inferior_thread ()->control.stop_step)
6000 target_terminal_ours ();
6001 async_enable_stdin ();
6003 /* Set the current source location. This will also happen if we
6004 display the frame below, but the current SAL will be incorrect
6005 during a user hook-stop function. */
6006 if (has_stack_frames () && !stop_stack_dummy)
6007 set_current_sal_from_frame (get_current_frame (), 1);
6009 /* Let the user/frontend see the threads as stopped. */
6010 do_cleanups (old_chain);
6012 /* Look up the hook_stop and run it (CLI internally handles problem
6013 of stop_command's pre-hook not existing). */
6015 catch_errors (hook_stop_stub, stop_command,
6016 "Error while running hook_stop:\n", RETURN_MASK_ALL);
6018 if (!has_stack_frames ())
6021 if (last.kind == TARGET_WAITKIND_SIGNALLED
6022 || last.kind == TARGET_WAITKIND_EXITED)
6025 /* Select innermost stack frame - i.e., current frame is frame 0,
6026 and current location is based on that.
6027 Don't do this on return from a stack dummy routine,
6028 or if the program has exited. */
6030 if (!stop_stack_dummy)
6032 select_frame (get_current_frame ());
6034 /* Print current location without a level number, if
6035 we have changed functions or hit a breakpoint.
6036 Print source line if we have one.
6037 bpstat_print() contains the logic deciding in detail
6038 what to print, based on the event(s) that just occurred. */
6040 /* If --batch-silent is enabled then there's no need to print the current
6041 source location, and to try risks causing an error message about
6042 missing source files. */
6043 if (stop_print_frame && !batch_silent)
6047 int do_frame_printing = 1;
6048 struct thread_info *tp = inferior_thread ();
6050 bpstat_ret = bpstat_print (tp->control.stop_bpstat, last.kind);
6054 /* FIXME: cagney/2002-12-01: Given that a frame ID does
6055 (or should) carry around the function and does (or
6056 should) use that when doing a frame comparison. */
6057 if (tp->control.stop_step
6058 && frame_id_eq (tp->control.step_frame_id,
6059 get_frame_id (get_current_frame ()))
6060 && step_start_function == find_pc_function (stop_pc))
6061 source_flag = SRC_LINE; /* Finished step, just
6062 print source line. */
6064 source_flag = SRC_AND_LOC; /* Print location and
6067 case PRINT_SRC_AND_LOC:
6068 source_flag = SRC_AND_LOC; /* Print location and
6071 case PRINT_SRC_ONLY:
6072 source_flag = SRC_LINE;
6075 source_flag = SRC_LINE; /* something bogus */
6076 do_frame_printing = 0;
6079 internal_error (__FILE__, __LINE__, _("Unknown value."));
6082 /* The behavior of this routine with respect to the source
6084 SRC_LINE: Print only source line
6085 LOCATION: Print only location
6086 SRC_AND_LOC: Print location and source line. */
6087 if (do_frame_printing)
6088 print_stack_frame (get_selected_frame (NULL), 0, source_flag);
6090 /* Display the auto-display expressions. */
6095 /* Save the function value return registers, if we care.
6096 We might be about to restore their previous contents. */
6097 if (inferior_thread ()->control.proceed_to_finish
6098 && execution_direction != EXEC_REVERSE)
6100 /* This should not be necessary. */
6102 regcache_xfree (stop_registers);
6104 /* NB: The copy goes through to the target picking up the value of
6105 all the registers. */
6106 stop_registers = regcache_dup (get_current_regcache ());
6109 if (stop_stack_dummy == STOP_STACK_DUMMY)
6111 /* Pop the empty frame that contains the stack dummy.
6112 This also restores inferior state prior to the call
6113 (struct infcall_suspend_state). */
6114 struct frame_info *frame = get_current_frame ();
6116 gdb_assert (get_frame_type (frame) == DUMMY_FRAME);
6118 /* frame_pop() calls reinit_frame_cache as the last thing it
6119 does which means there's currently no selected frame. We
6120 don't need to re-establish a selected frame if the dummy call
6121 returns normally, that will be done by
6122 restore_infcall_control_state. However, we do have to handle
6123 the case where the dummy call is returning after being
6124 stopped (e.g. the dummy call previously hit a breakpoint).
6125 We can't know which case we have so just always re-establish
6126 a selected frame here. */
6127 select_frame (get_current_frame ());
6131 annotate_stopped ();
6133 /* Suppress the stop observer if we're in the middle of:
6135 - a step n (n > 1), as there still more steps to be done.
6137 - a "finish" command, as the observer will be called in
6138 finish_command_continuation, so it can include the inferior
6139 function's return value.
6141 - calling an inferior function, as we pretend we inferior didn't
6142 run at all. The return value of the call is handled by the
6143 expression evaluator, through call_function_by_hand. */
6145 if (!target_has_execution
6146 || last.kind == TARGET_WAITKIND_SIGNALLED
6147 || last.kind == TARGET_WAITKIND_EXITED
6148 || last.kind == TARGET_WAITKIND_NO_RESUMED
6149 || (!(inferior_thread ()->step_multi
6150 && inferior_thread ()->control.stop_step)
6151 && !(inferior_thread ()->control.stop_bpstat
6152 && inferior_thread ()->control.proceed_to_finish)
6153 && !inferior_thread ()->control.in_infcall))
6155 if (!ptid_equal (inferior_ptid, null_ptid))
6156 observer_notify_normal_stop (inferior_thread ()->control.stop_bpstat,
6159 observer_notify_normal_stop (NULL, stop_print_frame);
6162 if (target_has_execution)
6164 if (last.kind != TARGET_WAITKIND_SIGNALLED
6165 && last.kind != TARGET_WAITKIND_EXITED)
6166 /* Delete the breakpoint we stopped at, if it wants to be deleted.
6167 Delete any breakpoint that is to be deleted at the next stop. */
6168 breakpoint_auto_delete (inferior_thread ()->control.stop_bpstat);
6171 /* Try to get rid of automatically added inferiors that are no
6172 longer needed. Keeping those around slows down things linearly.
6173 Note that this never removes the current inferior. */
6178 hook_stop_stub (void *cmd)
6180 execute_cmd_pre_hook ((struct cmd_list_element *) cmd);
6185 signal_stop_state (int signo)
6187 return signal_stop[signo];
6191 signal_print_state (int signo)
6193 return signal_print[signo];
6197 signal_pass_state (int signo)
6199 return signal_program[signo];
6203 signal_cache_update (int signo)
6207 for (signo = 0; signo < (int) GDB_SIGNAL_LAST; signo++)
6208 signal_cache_update (signo);
6213 signal_pass[signo] = (signal_stop[signo] == 0
6214 && signal_print[signo] == 0
6215 && signal_program[signo] == 1
6216 && signal_catch[signo] == 0);
6220 signal_stop_update (int signo, int state)
6222 int ret = signal_stop[signo];
6224 signal_stop[signo] = state;
6225 signal_cache_update (signo);
6230 signal_print_update (int signo, int state)
6232 int ret = signal_print[signo];
6234 signal_print[signo] = state;
6235 signal_cache_update (signo);
6240 signal_pass_update (int signo, int state)
6242 int ret = signal_program[signo];
6244 signal_program[signo] = state;
6245 signal_cache_update (signo);
6249 /* Update the global 'signal_catch' from INFO and notify the
6253 signal_catch_update (const unsigned int *info)
6257 for (i = 0; i < GDB_SIGNAL_LAST; ++i)
6258 signal_catch[i] = info[i] > 0;
6259 signal_cache_update (-1);
6260 target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
6264 sig_print_header (void)
6266 printf_filtered (_("Signal Stop\tPrint\tPass "
6267 "to program\tDescription\n"));
6271 sig_print_info (enum gdb_signal oursig)
6273 const char *name = gdb_signal_to_name (oursig);
6274 int name_padding = 13 - strlen (name);
6276 if (name_padding <= 0)
6279 printf_filtered ("%s", name);
6280 printf_filtered ("%*.*s ", name_padding, name_padding, " ");
6281 printf_filtered ("%s\t", signal_stop[oursig] ? "Yes" : "No");
6282 printf_filtered ("%s\t", signal_print[oursig] ? "Yes" : "No");
6283 printf_filtered ("%s\t\t", signal_program[oursig] ? "Yes" : "No");
6284 printf_filtered ("%s\n", gdb_signal_to_string (oursig));
6287 /* Specify how various signals in the inferior should be handled. */
6290 handle_command (char *args, int from_tty)
6293 int digits, wordlen;
6294 int sigfirst, signum, siglast;
6295 enum gdb_signal oursig;
6298 unsigned char *sigs;
6299 struct cleanup *old_chain;
6303 error_no_arg (_("signal to handle"));
6306 /* Allocate and zero an array of flags for which signals to handle. */
6308 nsigs = (int) GDB_SIGNAL_LAST;
6309 sigs = (unsigned char *) alloca (nsigs);
6310 memset (sigs, 0, nsigs);
6312 /* Break the command line up into args. */
6314 argv = gdb_buildargv (args);
6315 old_chain = make_cleanup_freeargv (argv);
6317 /* Walk through the args, looking for signal oursigs, signal names, and
6318 actions. Signal numbers and signal names may be interspersed with
6319 actions, with the actions being performed for all signals cumulatively
6320 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
6322 while (*argv != NULL)
6324 wordlen = strlen (*argv);
6325 for (digits = 0; isdigit ((*argv)[digits]); digits++)
6329 sigfirst = siglast = -1;
6331 if (wordlen >= 1 && !strncmp (*argv, "all", wordlen))
6333 /* Apply action to all signals except those used by the
6334 debugger. Silently skip those. */
6337 siglast = nsigs - 1;
6339 else if (wordlen >= 1 && !strncmp (*argv, "stop", wordlen))
6341 SET_SIGS (nsigs, sigs, signal_stop);
6342 SET_SIGS (nsigs, sigs, signal_print);
6344 else if (wordlen >= 1 && !strncmp (*argv, "ignore", wordlen))
6346 UNSET_SIGS (nsigs, sigs, signal_program);
6348 else if (wordlen >= 2 && !strncmp (*argv, "print", wordlen))
6350 SET_SIGS (nsigs, sigs, signal_print);
6352 else if (wordlen >= 2 && !strncmp (*argv, "pass", wordlen))
6354 SET_SIGS (nsigs, sigs, signal_program);
6356 else if (wordlen >= 3 && !strncmp (*argv, "nostop", wordlen))
6358 UNSET_SIGS (nsigs, sigs, signal_stop);
6360 else if (wordlen >= 3 && !strncmp (*argv, "noignore", wordlen))
6362 SET_SIGS (nsigs, sigs, signal_program);
6364 else if (wordlen >= 4 && !strncmp (*argv, "noprint", wordlen))
6366 UNSET_SIGS (nsigs, sigs, signal_print);
6367 UNSET_SIGS (nsigs, sigs, signal_stop);
6369 else if (wordlen >= 4 && !strncmp (*argv, "nopass", wordlen))
6371 UNSET_SIGS (nsigs, sigs, signal_program);
6373 else if (digits > 0)
6375 /* It is numeric. The numeric signal refers to our own
6376 internal signal numbering from target.h, not to host/target
6377 signal number. This is a feature; users really should be
6378 using symbolic names anyway, and the common ones like
6379 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
6381 sigfirst = siglast = (int)
6382 gdb_signal_from_command (atoi (*argv));
6383 if ((*argv)[digits] == '-')
6386 gdb_signal_from_command (atoi ((*argv) + digits + 1));
6388 if (sigfirst > siglast)
6390 /* Bet he didn't figure we'd think of this case... */
6398 oursig = gdb_signal_from_name (*argv);
6399 if (oursig != GDB_SIGNAL_UNKNOWN)
6401 sigfirst = siglast = (int) oursig;
6405 /* Not a number and not a recognized flag word => complain. */
6406 error (_("Unrecognized or ambiguous flag word: \"%s\"."), *argv);
6410 /* If any signal numbers or symbol names were found, set flags for
6411 which signals to apply actions to. */
6413 for (signum = sigfirst; signum >= 0 && signum <= siglast; signum++)
6415 switch ((enum gdb_signal) signum)
6417 case GDB_SIGNAL_TRAP:
6418 case GDB_SIGNAL_INT:
6419 if (!allsigs && !sigs[signum])
6421 if (query (_("%s is used by the debugger.\n\
6422 Are you sure you want to change it? "),
6423 gdb_signal_to_name ((enum gdb_signal) signum)))
6429 printf_unfiltered (_("Not confirmed, unchanged.\n"));
6430 gdb_flush (gdb_stdout);
6435 case GDB_SIGNAL_DEFAULT:
6436 case GDB_SIGNAL_UNKNOWN:
6437 /* Make sure that "all" doesn't print these. */
6448 for (signum = 0; signum < nsigs; signum++)
6451 signal_cache_update (-1);
6452 target_pass_signals ((int) GDB_SIGNAL_LAST, signal_pass);
6453 target_program_signals ((int) GDB_SIGNAL_LAST, signal_program);
6457 /* Show the results. */
6458 sig_print_header ();
6459 for (; signum < nsigs; signum++)
6461 sig_print_info (signum);
6467 do_cleanups (old_chain);
6470 /* Complete the "handle" command. */
6472 static VEC (char_ptr) *
6473 handle_completer (struct cmd_list_element *ignore,
6474 char *text, char *word)
6476 VEC (char_ptr) *vec_signals, *vec_keywords, *return_val;
6477 static const char * const keywords[] =
6491 vec_signals = signal_completer (ignore, text, word);
6492 vec_keywords = complete_on_enum (keywords, word, word);
6494 return_val = VEC_merge (char_ptr, vec_signals, vec_keywords);
6495 VEC_free (char_ptr, vec_signals);
6496 VEC_free (char_ptr, vec_keywords);
6501 xdb_handle_command (char *args, int from_tty)
6504 struct cleanup *old_chain;
6507 error_no_arg (_("xdb command"));
6509 /* Break the command line up into args. */
6511 argv = gdb_buildargv (args);
6512 old_chain = make_cleanup_freeargv (argv);
6513 if (argv[1] != (char *) NULL)
6518 bufLen = strlen (argv[0]) + 20;
6519 argBuf = (char *) xmalloc (bufLen);
6523 enum gdb_signal oursig;
6525 oursig = gdb_signal_from_name (argv[0]);
6526 memset (argBuf, 0, bufLen);
6527 if (strcmp (argv[1], "Q") == 0)
6528 sprintf (argBuf, "%s %s", argv[0], "noprint");
6531 if (strcmp (argv[1], "s") == 0)
6533 if (!signal_stop[oursig])
6534 sprintf (argBuf, "%s %s", argv[0], "stop");
6536 sprintf (argBuf, "%s %s", argv[0], "nostop");
6538 else if (strcmp (argv[1], "i") == 0)
6540 if (!signal_program[oursig])
6541 sprintf (argBuf, "%s %s", argv[0], "pass");
6543 sprintf (argBuf, "%s %s", argv[0], "nopass");
6545 else if (strcmp (argv[1], "r") == 0)
6547 if (!signal_print[oursig])
6548 sprintf (argBuf, "%s %s", argv[0], "print");
6550 sprintf (argBuf, "%s %s", argv[0], "noprint");
6556 handle_command (argBuf, from_tty);
6558 printf_filtered (_("Invalid signal handling flag.\n"));
6563 do_cleanups (old_chain);
6567 gdb_signal_from_command (int num)
6569 if (num >= 1 && num <= 15)
6570 return (enum gdb_signal) num;
6571 error (_("Only signals 1-15 are valid as numeric signals.\n\
6572 Use \"info signals\" for a list of symbolic signals."));
6575 /* Print current contents of the tables set by the handle command.
6576 It is possible we should just be printing signals actually used
6577 by the current target (but for things to work right when switching
6578 targets, all signals should be in the signal tables). */
6581 signals_info (char *signum_exp, int from_tty)
6583 enum gdb_signal oursig;
6585 sig_print_header ();
6589 /* First see if this is a symbol name. */
6590 oursig = gdb_signal_from_name (signum_exp);
6591 if (oursig == GDB_SIGNAL_UNKNOWN)
6593 /* No, try numeric. */
6595 gdb_signal_from_command (parse_and_eval_long (signum_exp));
6597 sig_print_info (oursig);
6601 printf_filtered ("\n");
6602 /* These ugly casts brought to you by the native VAX compiler. */
6603 for (oursig = GDB_SIGNAL_FIRST;
6604 (int) oursig < (int) GDB_SIGNAL_LAST;
6605 oursig = (enum gdb_signal) ((int) oursig + 1))
6609 if (oursig != GDB_SIGNAL_UNKNOWN
6610 && oursig != GDB_SIGNAL_DEFAULT && oursig != GDB_SIGNAL_0)
6611 sig_print_info (oursig);
6614 printf_filtered (_("\nUse the \"handle\" command "
6615 "to change these tables.\n"));
6618 /* Check if it makes sense to read $_siginfo from the current thread
6619 at this point. If not, throw an error. */
6622 validate_siginfo_access (void)
6624 /* No current inferior, no siginfo. */
6625 if (ptid_equal (inferior_ptid, null_ptid))
6626 error (_("No thread selected."));
6628 /* Don't try to read from a dead thread. */
6629 if (is_exited (inferior_ptid))
6630 error (_("The current thread has terminated"));
6632 /* ... or from a spinning thread. */
6633 if (is_running (inferior_ptid))
6634 error (_("Selected thread is running."));
6637 /* The $_siginfo convenience variable is a bit special. We don't know
6638 for sure the type of the value until we actually have a chance to
6639 fetch the data. The type can change depending on gdbarch, so it is
6640 also dependent on which thread you have selected.
6642 1. making $_siginfo be an internalvar that creates a new value on
6645 2. making the value of $_siginfo be an lval_computed value. */
6647 /* This function implements the lval_computed support for reading a
6651 siginfo_value_read (struct value *v)
6653 LONGEST transferred;
6655 validate_siginfo_access ();
6658 target_read (¤t_target, TARGET_OBJECT_SIGNAL_INFO,
6660 value_contents_all_raw (v),
6662 TYPE_LENGTH (value_type (v)));
6664 if (transferred != TYPE_LENGTH (value_type (v)))
6665 error (_("Unable to read siginfo"));
6668 /* This function implements the lval_computed support for writing a
6672 siginfo_value_write (struct value *v, struct value *fromval)
6674 LONGEST transferred;
6676 validate_siginfo_access ();
6678 transferred = target_write (¤t_target,
6679 TARGET_OBJECT_SIGNAL_INFO,
6681 value_contents_all_raw (fromval),
6683 TYPE_LENGTH (value_type (fromval)));
6685 if (transferred != TYPE_LENGTH (value_type (fromval)))
6686 error (_("Unable to write siginfo"));
6689 static const struct lval_funcs siginfo_value_funcs =
6695 /* Return a new value with the correct type for the siginfo object of
6696 the current thread using architecture GDBARCH. Return a void value
6697 if there's no object available. */
6699 static struct value *
6700 siginfo_make_value (struct gdbarch *gdbarch, struct internalvar *var,
6703 if (target_has_stack
6704 && !ptid_equal (inferior_ptid, null_ptid)
6705 && gdbarch_get_siginfo_type_p (gdbarch))
6707 struct type *type = gdbarch_get_siginfo_type (gdbarch);
6709 return allocate_computed_value (type, &siginfo_value_funcs, NULL);
6712 return allocate_value (builtin_type (gdbarch)->builtin_void);
6716 /* infcall_suspend_state contains state about the program itself like its
6717 registers and any signal it received when it last stopped.
6718 This state must be restored regardless of how the inferior function call
6719 ends (either successfully, or after it hits a breakpoint or signal)
6720 if the program is to properly continue where it left off. */
6722 struct infcall_suspend_state
6724 struct thread_suspend_state thread_suspend;
6725 #if 0 /* Currently unused and empty structures are not valid C. */
6726 struct inferior_suspend_state inferior_suspend;
6731 struct regcache *registers;
6733 /* Format of SIGINFO_DATA or NULL if it is not present. */
6734 struct gdbarch *siginfo_gdbarch;
6736 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
6737 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
6738 content would be invalid. */
6739 gdb_byte *siginfo_data;
6742 struct infcall_suspend_state *
6743 save_infcall_suspend_state (void)
6745 struct infcall_suspend_state *inf_state;
6746 struct thread_info *tp = inferior_thread ();
6748 struct inferior *inf = current_inferior ();
6750 struct regcache *regcache = get_current_regcache ();
6751 struct gdbarch *gdbarch = get_regcache_arch (regcache);
6752 gdb_byte *siginfo_data = NULL;
6754 if (gdbarch_get_siginfo_type_p (gdbarch))
6756 struct type *type = gdbarch_get_siginfo_type (gdbarch);
6757 size_t len = TYPE_LENGTH (type);
6758 struct cleanup *back_to;
6760 siginfo_data = xmalloc (len);
6761 back_to = make_cleanup (xfree, siginfo_data);
6763 if (target_read (¤t_target, TARGET_OBJECT_SIGNAL_INFO, NULL,
6764 siginfo_data, 0, len) == len)
6765 discard_cleanups (back_to);
6768 /* Errors ignored. */
6769 do_cleanups (back_to);
6770 siginfo_data = NULL;
6774 inf_state = XZALLOC (struct infcall_suspend_state);
6778 inf_state->siginfo_gdbarch = gdbarch;
6779 inf_state->siginfo_data = siginfo_data;
6782 inf_state->thread_suspend = tp->suspend;
6783 #if 0 /* Currently unused and empty structures are not valid C. */
6784 inf_state->inferior_suspend = inf->suspend;
6787 /* run_inferior_call will not use the signal due to its `proceed' call with
6788 GDB_SIGNAL_0 anyway. */
6789 tp->suspend.stop_signal = GDB_SIGNAL_0;
6791 inf_state->stop_pc = stop_pc;
6793 inf_state->registers = regcache_dup (regcache);
6798 /* Restore inferior session state to INF_STATE. */
6801 restore_infcall_suspend_state (struct infcall_suspend_state *inf_state)
6803 struct thread_info *tp = inferior_thread ();
6805 struct inferior *inf = current_inferior ();
6807 struct regcache *regcache = get_current_regcache ();
6808 struct gdbarch *gdbarch = get_regcache_arch (regcache);
6810 tp->suspend = inf_state->thread_suspend;
6811 #if 0 /* Currently unused and empty structures are not valid C. */
6812 inf->suspend = inf_state->inferior_suspend;
6815 stop_pc = inf_state->stop_pc;
6817 if (inf_state->siginfo_gdbarch == gdbarch)
6819 struct type *type = gdbarch_get_siginfo_type (gdbarch);
6821 /* Errors ignored. */
6822 target_write (¤t_target, TARGET_OBJECT_SIGNAL_INFO, NULL,
6823 inf_state->siginfo_data, 0, TYPE_LENGTH (type));
6826 /* The inferior can be gone if the user types "print exit(0)"
6827 (and perhaps other times). */
6828 if (target_has_execution)
6829 /* NB: The register write goes through to the target. */
6830 regcache_cpy (regcache, inf_state->registers);
6832 discard_infcall_suspend_state (inf_state);
6836 do_restore_infcall_suspend_state_cleanup (void *state)
6838 restore_infcall_suspend_state (state);
6842 make_cleanup_restore_infcall_suspend_state
6843 (struct infcall_suspend_state *inf_state)
6845 return make_cleanup (do_restore_infcall_suspend_state_cleanup, inf_state);
6849 discard_infcall_suspend_state (struct infcall_suspend_state *inf_state)
6851 regcache_xfree (inf_state->registers);
6852 xfree (inf_state->siginfo_data);
6857 get_infcall_suspend_state_regcache (struct infcall_suspend_state *inf_state)
6859 return inf_state->registers;
6862 /* infcall_control_state contains state regarding gdb's control of the
6863 inferior itself like stepping control. It also contains session state like
6864 the user's currently selected frame. */
6866 struct infcall_control_state
6868 struct thread_control_state thread_control;
6869 struct inferior_control_state inferior_control;
6872 enum stop_stack_kind stop_stack_dummy;
6873 int stopped_by_random_signal;
6874 int stop_after_trap;
6876 /* ID if the selected frame when the inferior function call was made. */
6877 struct frame_id selected_frame_id;
6880 /* Save all of the information associated with the inferior<==>gdb
6883 struct infcall_control_state *
6884 save_infcall_control_state (void)
6886 struct infcall_control_state *inf_status = xmalloc (sizeof (*inf_status));
6887 struct thread_info *tp = inferior_thread ();
6888 struct inferior *inf = current_inferior ();
6890 inf_status->thread_control = tp->control;
6891 inf_status->inferior_control = inf->control;
6893 tp->control.step_resume_breakpoint = NULL;
6894 tp->control.exception_resume_breakpoint = NULL;
6896 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
6897 chain. If caller's caller is walking the chain, they'll be happier if we
6898 hand them back the original chain when restore_infcall_control_state is
6900 tp->control.stop_bpstat = bpstat_copy (tp->control.stop_bpstat);
6903 inf_status->stop_stack_dummy = stop_stack_dummy;
6904 inf_status->stopped_by_random_signal = stopped_by_random_signal;
6905 inf_status->stop_after_trap = stop_after_trap;
6907 inf_status->selected_frame_id = get_frame_id (get_selected_frame (NULL));
6913 restore_selected_frame (void *args)
6915 struct frame_id *fid = (struct frame_id *) args;
6916 struct frame_info *frame;
6918 frame = frame_find_by_id (*fid);
6920 /* If inf_status->selected_frame_id is NULL, there was no previously
6924 warning (_("Unable to restore previously selected frame."));
6928 select_frame (frame);
6933 /* Restore inferior session state to INF_STATUS. */
6936 restore_infcall_control_state (struct infcall_control_state *inf_status)
6938 struct thread_info *tp = inferior_thread ();
6939 struct inferior *inf = current_inferior ();
6941 if (tp->control.step_resume_breakpoint)
6942 tp->control.step_resume_breakpoint->disposition = disp_del_at_next_stop;
6944 if (tp->control.exception_resume_breakpoint)
6945 tp->control.exception_resume_breakpoint->disposition
6946 = disp_del_at_next_stop;
6948 /* Handle the bpstat_copy of the chain. */
6949 bpstat_clear (&tp->control.stop_bpstat);
6951 tp->control = inf_status->thread_control;
6952 inf->control = inf_status->inferior_control;
6955 stop_stack_dummy = inf_status->stop_stack_dummy;
6956 stopped_by_random_signal = inf_status->stopped_by_random_signal;
6957 stop_after_trap = inf_status->stop_after_trap;
6959 if (target_has_stack)
6961 /* The point of catch_errors is that if the stack is clobbered,
6962 walking the stack might encounter a garbage pointer and
6963 error() trying to dereference it. */
6965 (restore_selected_frame, &inf_status->selected_frame_id,
6966 "Unable to restore previously selected frame:\n",
6967 RETURN_MASK_ERROR) == 0)
6968 /* Error in restoring the selected frame. Select the innermost
6970 select_frame (get_current_frame ());
6977 do_restore_infcall_control_state_cleanup (void *sts)
6979 restore_infcall_control_state (sts);
6983 make_cleanup_restore_infcall_control_state
6984 (struct infcall_control_state *inf_status)
6986 return make_cleanup (do_restore_infcall_control_state_cleanup, inf_status);
6990 discard_infcall_control_state (struct infcall_control_state *inf_status)
6992 if (inf_status->thread_control.step_resume_breakpoint)
6993 inf_status->thread_control.step_resume_breakpoint->disposition
6994 = disp_del_at_next_stop;
6996 if (inf_status->thread_control.exception_resume_breakpoint)
6997 inf_status->thread_control.exception_resume_breakpoint->disposition
6998 = disp_del_at_next_stop;
7000 /* See save_infcall_control_state for info on stop_bpstat. */
7001 bpstat_clear (&inf_status->thread_control.stop_bpstat);
7007 ptid_match (ptid_t ptid, ptid_t filter)
7009 if (ptid_equal (filter, minus_one_ptid))
7011 if (ptid_is_pid (filter)
7012 && ptid_get_pid (ptid) == ptid_get_pid (filter))
7014 else if (ptid_equal (ptid, filter))
7020 /* restore_inferior_ptid() will be used by the cleanup machinery
7021 to restore the inferior_ptid value saved in a call to
7022 save_inferior_ptid(). */
7025 restore_inferior_ptid (void *arg)
7027 ptid_t *saved_ptid_ptr = arg;
7029 inferior_ptid = *saved_ptid_ptr;
7033 /* Save the value of inferior_ptid so that it may be restored by a
7034 later call to do_cleanups(). Returns the struct cleanup pointer
7035 needed for later doing the cleanup. */
7038 save_inferior_ptid (void)
7040 ptid_t *saved_ptid_ptr;
7042 saved_ptid_ptr = xmalloc (sizeof (ptid_t));
7043 *saved_ptid_ptr = inferior_ptid;
7044 return make_cleanup (restore_inferior_ptid, saved_ptid_ptr);
7048 /* User interface for reverse debugging:
7049 Set exec-direction / show exec-direction commands
7050 (returns error unless target implements to_set_exec_direction method). */
7052 int execution_direction = EXEC_FORWARD;
7053 static const char exec_forward[] = "forward";
7054 static const char exec_reverse[] = "reverse";
7055 static const char *exec_direction = exec_forward;
7056 static const char *const exec_direction_names[] = {
7063 set_exec_direction_func (char *args, int from_tty,
7064 struct cmd_list_element *cmd)
7066 if (target_can_execute_reverse)
7068 if (!strcmp (exec_direction, exec_forward))
7069 execution_direction = EXEC_FORWARD;
7070 else if (!strcmp (exec_direction, exec_reverse))
7071 execution_direction = EXEC_REVERSE;
7075 exec_direction = exec_forward;
7076 error (_("Target does not support this operation."));
7081 show_exec_direction_func (struct ui_file *out, int from_tty,
7082 struct cmd_list_element *cmd, const char *value)
7084 switch (execution_direction) {
7086 fprintf_filtered (out, _("Forward.\n"));
7089 fprintf_filtered (out, _("Reverse.\n"));
7092 internal_error (__FILE__, __LINE__,
7093 _("bogus execution_direction value: %d"),
7094 (int) execution_direction);
7098 /* User interface for non-stop mode. */
7103 set_non_stop (char *args, int from_tty,
7104 struct cmd_list_element *c)
7106 if (target_has_execution)
7108 non_stop_1 = non_stop;
7109 error (_("Cannot change this setting while the inferior is running."));
7112 non_stop = non_stop_1;
7116 show_non_stop (struct ui_file *file, int from_tty,
7117 struct cmd_list_element *c, const char *value)
7119 fprintf_filtered (file,
7120 _("Controlling the inferior in non-stop mode is %s.\n"),
7125 show_schedule_multiple (struct ui_file *file, int from_tty,
7126 struct cmd_list_element *c, const char *value)
7128 fprintf_filtered (file, _("Resuming the execution of threads "
7129 "of all processes is %s.\n"), value);
7132 /* Implementation of `siginfo' variable. */
7134 static const struct internalvar_funcs siginfo_funcs =
7142 _initialize_infrun (void)
7146 struct cmd_list_element *c;
7148 add_info ("signals", signals_info, _("\
7149 What debugger does when program gets various signals.\n\
7150 Specify a signal as argument to print info on that signal only."));
7151 add_info_alias ("handle", "signals", 0);
7153 c = add_com ("handle", class_run, handle_command, _("\
7154 Specify how to handle signals.\n\
7155 Usage: handle SIGNAL [ACTIONS]\n\
7156 Args are signals and actions to apply to those signals.\n\
7157 If no actions are specified, the current settings for the specified signals\n\
7158 will be displayed instead.\n\
7160 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
7161 from 1-15 are allowed for compatibility with old versions of GDB.\n\
7162 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
7163 The special arg \"all\" is recognized to mean all signals except those\n\
7164 used by the debugger, typically SIGTRAP and SIGINT.\n\
7166 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
7167 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
7168 Stop means reenter debugger if this signal happens (implies print).\n\
7169 Print means print a message if this signal happens.\n\
7170 Pass means let program see this signal; otherwise program doesn't know.\n\
7171 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
7172 Pass and Stop may be combined.\n\
7174 Multiple signals may be specified. Signal numbers and signal names\n\
7175 may be interspersed with actions, with the actions being performed for\n\
7176 all signals cumulatively specified."));
7177 set_cmd_completer (c, handle_completer);
7181 add_com ("lz", class_info, signals_info, _("\
7182 What debugger does when program gets various signals.\n\
7183 Specify a signal as argument to print info on that signal only."));
7184 add_com ("z", class_run, xdb_handle_command, _("\
7185 Specify how to handle a signal.\n\
7186 Args are signals and actions to apply to those signals.\n\
7187 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
7188 from 1-15 are allowed for compatibility with old versions of GDB.\n\
7189 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
7190 The special arg \"all\" is recognized to mean all signals except those\n\
7191 used by the debugger, typically SIGTRAP and SIGINT.\n\
7192 Recognized actions include \"s\" (toggles between stop and nostop),\n\
7193 \"r\" (toggles between print and noprint), \"i\" (toggles between pass and \
7194 nopass), \"Q\" (noprint)\n\
7195 Stop means reenter debugger if this signal happens (implies print).\n\
7196 Print means print a message if this signal happens.\n\
7197 Pass means let program see this signal; otherwise program doesn't know.\n\
7198 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
7199 Pass and Stop may be combined."));
7203 stop_command = add_cmd ("stop", class_obscure,
7204 not_just_help_class_command, _("\
7205 There is no `stop' command, but you can set a hook on `stop'.\n\
7206 This allows you to set a list of commands to be run each time execution\n\
7207 of the program stops."), &cmdlist);
7209 add_setshow_zuinteger_cmd ("infrun", class_maintenance, &debug_infrun, _("\
7210 Set inferior debugging."), _("\
7211 Show inferior debugging."), _("\
7212 When non-zero, inferior specific debugging is enabled."),
7215 &setdebuglist, &showdebuglist);
7217 add_setshow_boolean_cmd ("displaced", class_maintenance,
7218 &debug_displaced, _("\
7219 Set displaced stepping debugging."), _("\
7220 Show displaced stepping debugging."), _("\
7221 When non-zero, displaced stepping specific debugging is enabled."),
7223 show_debug_displaced,
7224 &setdebuglist, &showdebuglist);
7226 add_setshow_boolean_cmd ("non-stop", no_class,
7228 Set whether gdb controls the inferior in non-stop mode."), _("\
7229 Show whether gdb controls the inferior in non-stop mode."), _("\
7230 When debugging a multi-threaded program and this setting is\n\
7231 off (the default, also called all-stop mode), when one thread stops\n\
7232 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
7233 all other threads in the program while you interact with the thread of\n\
7234 interest. When you continue or step a thread, you can allow the other\n\
7235 threads to run, or have them remain stopped, but while you inspect any\n\
7236 thread's state, all threads stop.\n\
7238 In non-stop mode, when one thread stops, other threads can continue\n\
7239 to run freely. You'll be able to step each thread independently,\n\
7240 leave it stopped or free to run as needed."),
7246 numsigs = (int) GDB_SIGNAL_LAST;
7247 signal_stop = (unsigned char *) xmalloc (sizeof (signal_stop[0]) * numsigs);
7248 signal_print = (unsigned char *)
7249 xmalloc (sizeof (signal_print[0]) * numsigs);
7250 signal_program = (unsigned char *)
7251 xmalloc (sizeof (signal_program[0]) * numsigs);
7252 signal_catch = (unsigned char *)
7253 xmalloc (sizeof (signal_catch[0]) * numsigs);
7254 signal_pass = (unsigned char *)
7255 xmalloc (sizeof (signal_program[0]) * numsigs);
7256 for (i = 0; i < numsigs; i++)
7259 signal_print[i] = 1;
7260 signal_program[i] = 1;
7261 signal_catch[i] = 0;
7264 /* Signals caused by debugger's own actions
7265 should not be given to the program afterwards. */
7266 signal_program[GDB_SIGNAL_TRAP] = 0;
7267 signal_program[GDB_SIGNAL_INT] = 0;
7269 /* Signals that are not errors should not normally enter the debugger. */
7270 signal_stop[GDB_SIGNAL_ALRM] = 0;
7271 signal_print[GDB_SIGNAL_ALRM] = 0;
7272 signal_stop[GDB_SIGNAL_VTALRM] = 0;
7273 signal_print[GDB_SIGNAL_VTALRM] = 0;
7274 signal_stop[GDB_SIGNAL_PROF] = 0;
7275 signal_print[GDB_SIGNAL_PROF] = 0;
7276 signal_stop[GDB_SIGNAL_CHLD] = 0;
7277 signal_print[GDB_SIGNAL_CHLD] = 0;
7278 signal_stop[GDB_SIGNAL_IO] = 0;
7279 signal_print[GDB_SIGNAL_IO] = 0;
7280 signal_stop[GDB_SIGNAL_POLL] = 0;
7281 signal_print[GDB_SIGNAL_POLL] = 0;
7282 signal_stop[GDB_SIGNAL_URG] = 0;
7283 signal_print[GDB_SIGNAL_URG] = 0;
7284 signal_stop[GDB_SIGNAL_WINCH] = 0;
7285 signal_print[GDB_SIGNAL_WINCH] = 0;
7286 signal_stop[GDB_SIGNAL_PRIO] = 0;
7287 signal_print[GDB_SIGNAL_PRIO] = 0;
7289 /* These signals are used internally by user-level thread
7290 implementations. (See signal(5) on Solaris.) Like the above
7291 signals, a healthy program receives and handles them as part of
7292 its normal operation. */
7293 signal_stop[GDB_SIGNAL_LWP] = 0;
7294 signal_print[GDB_SIGNAL_LWP] = 0;
7295 signal_stop[GDB_SIGNAL_WAITING] = 0;
7296 signal_print[GDB_SIGNAL_WAITING] = 0;
7297 signal_stop[GDB_SIGNAL_CANCEL] = 0;
7298 signal_print[GDB_SIGNAL_CANCEL] = 0;
7300 /* Update cached state. */
7301 signal_cache_update (-1);
7303 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support,
7304 &stop_on_solib_events, _("\
7305 Set stopping for shared library events."), _("\
7306 Show stopping for shared library events."), _("\
7307 If nonzero, gdb will give control to the user when the dynamic linker\n\
7308 notifies gdb of shared library events. The most common event of interest\n\
7309 to the user would be loading/unloading of a new library."),
7311 show_stop_on_solib_events,
7312 &setlist, &showlist);
7314 add_setshow_enum_cmd ("follow-fork-mode", class_run,
7315 follow_fork_mode_kind_names,
7316 &follow_fork_mode_string, _("\
7317 Set debugger response to a program call of fork or vfork."), _("\
7318 Show debugger response to a program call of fork or vfork."), _("\
7319 A fork or vfork creates a new process. follow-fork-mode can be:\n\
7320 parent - the original process is debugged after a fork\n\
7321 child - the new process is debugged after a fork\n\
7322 The unfollowed process will continue to run.\n\
7323 By default, the debugger will follow the parent process."),
7325 show_follow_fork_mode_string,
7326 &setlist, &showlist);
7328 add_setshow_enum_cmd ("follow-exec-mode", class_run,
7329 follow_exec_mode_names,
7330 &follow_exec_mode_string, _("\
7331 Set debugger response to a program call of exec."), _("\
7332 Show debugger response to a program call of exec."), _("\
7333 An exec call replaces the program image of a process.\n\
7335 follow-exec-mode can be:\n\
7337 new - the debugger creates a new inferior and rebinds the process\n\
7338 to this new inferior. The program the process was running before\n\
7339 the exec call can be restarted afterwards by restarting the original\n\
7342 same - the debugger keeps the process bound to the same inferior.\n\
7343 The new executable image replaces the previous executable loaded in\n\
7344 the inferior. Restarting the inferior after the exec call restarts\n\
7345 the executable the process was running after the exec call.\n\
7347 By default, the debugger will use the same inferior."),
7349 show_follow_exec_mode_string,
7350 &setlist, &showlist);
7352 add_setshow_enum_cmd ("scheduler-locking", class_run,
7353 scheduler_enums, &scheduler_mode, _("\
7354 Set mode for locking scheduler during execution."), _("\
7355 Show mode for locking scheduler during execution."), _("\
7356 off == no locking (threads may preempt at any time)\n\
7357 on == full locking (no thread except the current thread may run)\n\
7358 step == scheduler locked during every single-step operation.\n\
7359 In this mode, no other thread may run during a step command.\n\
7360 Other threads may run while stepping over a function call ('next')."),
7361 set_schedlock_func, /* traps on target vector */
7362 show_scheduler_mode,
7363 &setlist, &showlist);
7365 add_setshow_boolean_cmd ("schedule-multiple", class_run, &sched_multi, _("\
7366 Set mode for resuming threads of all processes."), _("\
7367 Show mode for resuming threads of all processes."), _("\
7368 When on, execution commands (such as 'continue' or 'next') resume all\n\
7369 threads of all processes. When off (which is the default), execution\n\
7370 commands only resume the threads of the current process. The set of\n\
7371 threads that are resumed is further refined by the scheduler-locking\n\
7372 mode (see help set scheduler-locking)."),
7374 show_schedule_multiple,
7375 &setlist, &showlist);
7377 add_setshow_boolean_cmd ("step-mode", class_run, &step_stop_if_no_debug, _("\
7378 Set mode of the step operation."), _("\
7379 Show mode of the step operation."), _("\
7380 When set, doing a step over a function without debug line information\n\
7381 will stop at the first instruction of that function. Otherwise, the\n\
7382 function is skipped and the step command stops at a different source line."),
7384 show_step_stop_if_no_debug,
7385 &setlist, &showlist);
7387 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run,
7388 &can_use_displaced_stepping, _("\
7389 Set debugger's willingness to use displaced stepping."), _("\
7390 Show debugger's willingness to use displaced stepping."), _("\
7391 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
7392 supported by the target architecture. If off, gdb will not use displaced\n\
7393 stepping to step over breakpoints, even if such is supported by the target\n\
7394 architecture. If auto (which is the default), gdb will use displaced stepping\n\
7395 if the target architecture supports it and non-stop mode is active, but will not\n\
7396 use it in all-stop mode (see help set non-stop)."),
7398 show_can_use_displaced_stepping,
7399 &setlist, &showlist);
7401 add_setshow_enum_cmd ("exec-direction", class_run, exec_direction_names,
7402 &exec_direction, _("Set direction of execution.\n\
7403 Options are 'forward' or 'reverse'."),
7404 _("Show direction of execution (forward/reverse)."),
7405 _("Tells gdb whether to execute forward or backward."),
7406 set_exec_direction_func, show_exec_direction_func,
7407 &setlist, &showlist);
7409 /* Set/show detach-on-fork: user-settable mode. */
7411 add_setshow_boolean_cmd ("detach-on-fork", class_run, &detach_fork, _("\
7412 Set whether gdb will detach the child of a fork."), _("\
7413 Show whether gdb will detach the child of a fork."), _("\
7414 Tells gdb whether to detach the child of a fork."),
7415 NULL, NULL, &setlist, &showlist);
7417 /* Set/show disable address space randomization mode. */
7419 add_setshow_boolean_cmd ("disable-randomization", class_support,
7420 &disable_randomization, _("\
7421 Set disabling of debuggee's virtual address space randomization."), _("\
7422 Show disabling of debuggee's virtual address space randomization."), _("\
7423 When this mode is on (which is the default), randomization of the virtual\n\
7424 address space is disabled. Standalone programs run with the randomization\n\
7425 enabled by default on some platforms."),
7426 &set_disable_randomization,
7427 &show_disable_randomization,
7428 &setlist, &showlist);
7430 /* ptid initializations */
7431 inferior_ptid = null_ptid;
7432 target_last_wait_ptid = minus_one_ptid;
7434 observer_attach_thread_ptid_changed (infrun_thread_ptid_changed);
7435 observer_attach_thread_stop_requested (infrun_thread_stop_requested);
7436 observer_attach_thread_exit (infrun_thread_thread_exit);
7437 observer_attach_inferior_exit (infrun_inferior_exit);
7439 /* Explicitly create without lookup, since that tries to create a
7440 value with a void typed value, and when we get here, gdbarch
7441 isn't initialized yet. At this point, we're quite sure there
7442 isn't another convenience variable of the same name. */
7443 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs, NULL);
7445 add_setshow_boolean_cmd ("observer", no_class,
7446 &observer_mode_1, _("\
7447 Set whether gdb controls the inferior in observer mode."), _("\
7448 Show whether gdb controls the inferior in observer mode."), _("\
7449 In observer mode, GDB can get data from the inferior, but not\n\
7450 affect its execution. Registers and memory may not be changed,\n\
7451 breakpoints may not be set, and the program cannot be interrupted\n\