1 /* Target-struct-independent code to start (run) and stop an inferior
4 Copyright (C) 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995,
5 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007,
6 2008, 2009, 2010 Free Software Foundation, Inc.
8 This file is part of GDB.
10 This program is free software; you can redistribute it and/or modify
11 it under the terms of the GNU General Public License as published by
12 the Free Software Foundation; either version 3 of the License, or
13 (at your option) any later version.
15 This program is distributed in the hope that it will be useful,
16 but WITHOUT ANY WARRANTY; without even the implied warranty of
17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 GNU General Public License for more details.
20 You should have received a copy of the GNU General Public License
21 along with this program. If not, see <http://www.gnu.org/licenses/>. */
24 #include "gdb_string.h"
29 #include "exceptions.h"
30 #include "breakpoint.h"
34 #include "cli/cli-script.h"
36 #include "gdbthread.h"
48 #include "gdb_assert.h"
49 #include "mi/mi-common.h"
50 #include "event-top.h"
52 #include "inline-frame.h"
54 #include "tracepoint.h"
56 /* Prototypes for local functions */
58 static void signals_info (char *, int);
60 static void handle_command (char *, int);
62 static void sig_print_info (enum target_signal);
64 static void sig_print_header (void);
66 static void resume_cleanups (void *);
68 static int hook_stop_stub (void *);
70 static int restore_selected_frame (void *);
72 static int follow_fork (void);
74 static void set_schedlock_func (char *args, int from_tty,
75 struct cmd_list_element *c);
77 static int currently_stepping (struct thread_info *tp);
79 static int currently_stepping_or_nexting_callback (struct thread_info *tp,
82 static void xdb_handle_command (char *args, int from_tty);
84 static int prepare_to_proceed (int);
86 void _initialize_infrun (void);
88 void nullify_last_target_wait_ptid (void);
90 /* When set, stop the 'step' command if we enter a function which has
91 no line number information. The normal behavior is that we step
92 over such function. */
93 int step_stop_if_no_debug = 0;
95 show_step_stop_if_no_debug (struct ui_file *file, int from_tty,
96 struct cmd_list_element *c, const char *value)
98 fprintf_filtered (file, _("Mode of the step operation is %s.\n"), value);
101 /* In asynchronous mode, but simulating synchronous execution. */
103 int sync_execution = 0;
105 /* wait_for_inferior and normal_stop use this to notify the user
106 when the inferior stopped in a different thread than it had been
109 static ptid_t previous_inferior_ptid;
111 /* Default behavior is to detach newly forked processes (legacy). */
114 int debug_displaced = 0;
116 show_debug_displaced (struct ui_file *file, int from_tty,
117 struct cmd_list_element *c, const char *value)
119 fprintf_filtered (file, _("Displace stepping debugging is %s.\n"), value);
122 static int debug_infrun = 0;
124 show_debug_infrun (struct ui_file *file, int from_tty,
125 struct cmd_list_element *c, const char *value)
127 fprintf_filtered (file, _("Inferior debugging is %s.\n"), value);
130 /* If the program uses ELF-style shared libraries, then calls to
131 functions in shared libraries go through stubs, which live in a
132 table called the PLT (Procedure Linkage Table). The first time the
133 function is called, the stub sends control to the dynamic linker,
134 which looks up the function's real address, patches the stub so
135 that future calls will go directly to the function, and then passes
136 control to the function.
138 If we are stepping at the source level, we don't want to see any of
139 this --- we just want to skip over the stub and the dynamic linker.
140 The simple approach is to single-step until control leaves the
143 However, on some systems (e.g., Red Hat's 5.2 distribution) the
144 dynamic linker calls functions in the shared C library, so you
145 can't tell from the PC alone whether the dynamic linker is still
146 running. In this case, we use a step-resume breakpoint to get us
147 past the dynamic linker, as if we were using "next" to step over a
150 in_solib_dynsym_resolve_code() says whether we're in the dynamic
151 linker code or not. Normally, this means we single-step. However,
152 if SKIP_SOLIB_RESOLVER then returns non-zero, then its value is an
153 address where we can place a step-resume breakpoint to get past the
154 linker's symbol resolution function.
156 in_solib_dynsym_resolve_code() can generally be implemented in a
157 pretty portable way, by comparing the PC against the address ranges
158 of the dynamic linker's sections.
160 SKIP_SOLIB_RESOLVER is generally going to be system-specific, since
161 it depends on internal details of the dynamic linker. It's usually
162 not too hard to figure out where to put a breakpoint, but it
163 certainly isn't portable. SKIP_SOLIB_RESOLVER should do plenty of
164 sanity checking. If it can't figure things out, returning zero and
165 getting the (possibly confusing) stepping behavior is better than
166 signalling an error, which will obscure the change in the
169 /* This function returns TRUE if pc is the address of an instruction
170 that lies within the dynamic linker (such as the event hook, or the
173 This function must be used only when a dynamic linker event has
174 been caught, and the inferior is being stepped out of the hook, or
175 undefined results are guaranteed. */
177 #ifndef SOLIB_IN_DYNAMIC_LINKER
178 #define SOLIB_IN_DYNAMIC_LINKER(pid,pc) 0
182 /* Tables of how to react to signals; the user sets them. */
184 static unsigned char *signal_stop;
185 static unsigned char *signal_print;
186 static unsigned char *signal_program;
188 #define SET_SIGS(nsigs,sigs,flags) \
190 int signum = (nsigs); \
191 while (signum-- > 0) \
192 if ((sigs)[signum]) \
193 (flags)[signum] = 1; \
196 #define UNSET_SIGS(nsigs,sigs,flags) \
198 int signum = (nsigs); \
199 while (signum-- > 0) \
200 if ((sigs)[signum]) \
201 (flags)[signum] = 0; \
204 /* Value to pass to target_resume() to cause all threads to resume */
206 #define RESUME_ALL minus_one_ptid
208 /* Command list pointer for the "stop" placeholder. */
210 static struct cmd_list_element *stop_command;
212 /* Function inferior was in as of last step command. */
214 static struct symbol *step_start_function;
216 /* Nonzero if we want to give control to the user when we're notified
217 of shared library events by the dynamic linker. */
218 static int stop_on_solib_events;
220 show_stop_on_solib_events (struct ui_file *file, int from_tty,
221 struct cmd_list_element *c, const char *value)
223 fprintf_filtered (file, _("Stopping for shared library events is %s.\n"),
227 /* Nonzero means expecting a trace trap
228 and should stop the inferior and return silently when it happens. */
232 /* Save register contents here when executing a "finish" command or are
233 about to pop a stack dummy frame, if-and-only-if proceed_to_finish is set.
234 Thus this contains the return value from the called function (assuming
235 values are returned in a register). */
237 struct regcache *stop_registers;
239 /* Nonzero after stop if current stack frame should be printed. */
241 static int stop_print_frame;
243 /* This is a cached copy of the pid/waitstatus of the last event
244 returned by target_wait()/deprecated_target_wait_hook(). This
245 information is returned by get_last_target_status(). */
246 static ptid_t target_last_wait_ptid;
247 static struct target_waitstatus target_last_waitstatus;
249 static void context_switch (ptid_t ptid);
251 void init_thread_stepping_state (struct thread_info *tss);
253 void init_infwait_state (void);
255 static const char follow_fork_mode_child[] = "child";
256 static const char follow_fork_mode_parent[] = "parent";
258 static const char *follow_fork_mode_kind_names[] = {
259 follow_fork_mode_child,
260 follow_fork_mode_parent,
264 static const char *follow_fork_mode_string = follow_fork_mode_parent;
266 show_follow_fork_mode_string (struct ui_file *file, int from_tty,
267 struct cmd_list_element *c, const char *value)
269 fprintf_filtered (file, _("\
270 Debugger response to a program call of fork or vfork is \"%s\".\n"),
275 /* Tell the target to follow the fork we're stopped at. Returns true
276 if the inferior should be resumed; false, if the target for some
277 reason decided it's best not to resume. */
282 int follow_child = (follow_fork_mode_string == follow_fork_mode_child);
283 int should_resume = 1;
284 struct thread_info *tp;
286 /* Copy user stepping state to the new inferior thread. FIXME: the
287 followed fork child thread should have a copy of most of the
288 parent thread structure's run control related fields, not just these.
289 Initialized to avoid "may be used uninitialized" warnings from gcc. */
290 struct breakpoint *step_resume_breakpoint = NULL;
291 CORE_ADDR step_range_start = 0;
292 CORE_ADDR step_range_end = 0;
293 struct frame_id step_frame_id = { 0 };
298 struct target_waitstatus wait_status;
300 /* Get the last target status returned by target_wait(). */
301 get_last_target_status (&wait_ptid, &wait_status);
303 /* If not stopped at a fork event, then there's nothing else to
305 if (wait_status.kind != TARGET_WAITKIND_FORKED
306 && wait_status.kind != TARGET_WAITKIND_VFORKED)
309 /* Check if we switched over from WAIT_PTID, since the event was
311 if (!ptid_equal (wait_ptid, minus_one_ptid)
312 && !ptid_equal (inferior_ptid, wait_ptid))
314 /* We did. Switch back to WAIT_PTID thread, to tell the
315 target to follow it (in either direction). We'll
316 afterwards refuse to resume, and inform the user what
318 switch_to_thread (wait_ptid);
323 tp = inferior_thread ();
325 /* If there were any forks/vforks that were caught and are now to be
326 followed, then do so now. */
327 switch (tp->pending_follow.kind)
329 case TARGET_WAITKIND_FORKED:
330 case TARGET_WAITKIND_VFORKED:
332 ptid_t parent, child;
334 /* If the user did a next/step, etc, over a fork call,
335 preserve the stepping state in the fork child. */
336 if (follow_child && should_resume)
338 step_resume_breakpoint
339 = clone_momentary_breakpoint (tp->step_resume_breakpoint);
340 step_range_start = tp->step_range_start;
341 step_range_end = tp->step_range_end;
342 step_frame_id = tp->step_frame_id;
344 /* For now, delete the parent's sr breakpoint, otherwise,
345 parent/child sr breakpoints are considered duplicates,
346 and the child version will not be installed. Remove
347 this when the breakpoints module becomes aware of
348 inferiors and address spaces. */
349 delete_step_resume_breakpoint (tp);
350 tp->step_range_start = 0;
351 tp->step_range_end = 0;
352 tp->step_frame_id = null_frame_id;
355 parent = inferior_ptid;
356 child = tp->pending_follow.value.related_pid;
358 /* Tell the target to do whatever is necessary to follow
359 either parent or child. */
360 if (target_follow_fork (follow_child))
362 /* Target refused to follow, or there's some other reason
363 we shouldn't resume. */
368 /* This pending follow fork event is now handled, one way
369 or another. The previous selected thread may be gone
370 from the lists by now, but if it is still around, need
371 to clear the pending follow request. */
372 tp = find_thread_ptid (parent);
374 tp->pending_follow.kind = TARGET_WAITKIND_SPURIOUS;
376 /* This makes sure we don't try to apply the "Switched
377 over from WAIT_PID" logic above. */
378 nullify_last_target_wait_ptid ();
380 /* If we followed the child, switch to it... */
383 switch_to_thread (child);
385 /* ... and preserve the stepping state, in case the
386 user was stepping over the fork call. */
389 tp = inferior_thread ();
390 tp->step_resume_breakpoint = step_resume_breakpoint;
391 tp->step_range_start = step_range_start;
392 tp->step_range_end = step_range_end;
393 tp->step_frame_id = step_frame_id;
397 /* If we get here, it was because we're trying to
398 resume from a fork catchpoint, but, the user
399 has switched threads away from the thread that
400 forked. In that case, the resume command
401 issued is most likely not applicable to the
402 child, so just warn, and refuse to resume. */
404 Not resuming: switched threads before following fork child.\n"));
407 /* Reset breakpoints in the child as appropriate. */
408 follow_inferior_reset_breakpoints ();
411 switch_to_thread (parent);
415 case TARGET_WAITKIND_SPURIOUS:
416 /* Nothing to follow. */
419 internal_error (__FILE__, __LINE__,
420 "Unexpected pending_follow.kind %d\n",
421 tp->pending_follow.kind);
425 return should_resume;
429 follow_inferior_reset_breakpoints (void)
431 struct thread_info *tp = inferior_thread ();
433 /* Was there a step_resume breakpoint? (There was if the user
434 did a "next" at the fork() call.) If so, explicitly reset its
437 step_resumes are a form of bp that are made to be per-thread.
438 Since we created the step_resume bp when the parent process
439 was being debugged, and now are switching to the child process,
440 from the breakpoint package's viewpoint, that's a switch of
441 "threads". We must update the bp's notion of which thread
442 it is for, or it'll be ignored when it triggers. */
444 if (tp->step_resume_breakpoint)
445 breakpoint_re_set_thread (tp->step_resume_breakpoint);
447 /* Reinsert all breakpoints in the child. The user may have set
448 breakpoints after catching the fork, in which case those
449 were never set in the child, but only in the parent. This makes
450 sure the inserted breakpoints match the breakpoint list. */
452 breakpoint_re_set ();
453 insert_breakpoints ();
456 /* The child has exited or execed: resume threads of the parent the
457 user wanted to be executing. */
460 proceed_after_vfork_done (struct thread_info *thread,
463 int pid = * (int *) arg;
465 if (ptid_get_pid (thread->ptid) == pid
466 && is_running (thread->ptid)
467 && !is_executing (thread->ptid)
468 && !thread->stop_requested
469 && thread->stop_signal == TARGET_SIGNAL_0)
472 fprintf_unfiltered (gdb_stdlog,
473 "infrun: resuming vfork parent thread %s\n",
474 target_pid_to_str (thread->ptid));
476 switch_to_thread (thread->ptid);
477 clear_proceed_status ();
478 proceed ((CORE_ADDR) -1, TARGET_SIGNAL_DEFAULT, 0);
484 /* Called whenever we notice an exec or exit event, to handle
485 detaching or resuming a vfork parent. */
488 handle_vfork_child_exec_or_exit (int exec)
490 struct inferior *inf = current_inferior ();
492 if (inf->vfork_parent)
494 int resume_parent = -1;
496 /* This exec or exit marks the end of the shared memory region
497 between the parent and the child. If the user wanted to
498 detach from the parent, now is the time. */
500 if (inf->vfork_parent->pending_detach)
502 struct thread_info *tp;
503 struct cleanup *old_chain;
504 struct program_space *pspace;
505 struct address_space *aspace;
507 /* follow-fork child, detach-on-fork on */
509 old_chain = make_cleanup_restore_current_thread ();
511 /* We're letting loose of the parent. */
512 tp = any_live_thread_of_process (inf->vfork_parent->pid);
513 switch_to_thread (tp->ptid);
515 /* We're about to detach from the parent, which implicitly
516 removes breakpoints from its address space. There's a
517 catch here: we want to reuse the spaces for the child,
518 but, parent/child are still sharing the pspace at this
519 point, although the exec in reality makes the kernel give
520 the child a fresh set of new pages. The problem here is
521 that the breakpoints module being unaware of this, would
522 likely chose the child process to write to the parent
523 address space. Swapping the child temporarily away from
524 the spaces has the desired effect. Yes, this is "sort
527 pspace = inf->pspace;
528 aspace = inf->aspace;
532 if (debug_infrun || info_verbose)
534 target_terminal_ours ();
537 fprintf_filtered (gdb_stdlog,
538 "Detaching vfork parent process %d after child exec.\n",
539 inf->vfork_parent->pid);
541 fprintf_filtered (gdb_stdlog,
542 "Detaching vfork parent process %d after child exit.\n",
543 inf->vfork_parent->pid);
546 target_detach (NULL, 0);
549 inf->pspace = pspace;
550 inf->aspace = aspace;
552 do_cleanups (old_chain);
556 /* We're staying attached to the parent, so, really give the
557 child a new address space. */
558 inf->pspace = add_program_space (maybe_new_address_space ());
559 inf->aspace = inf->pspace->aspace;
561 set_current_program_space (inf->pspace);
563 resume_parent = inf->vfork_parent->pid;
565 /* Break the bonds. */
566 inf->vfork_parent->vfork_child = NULL;
570 struct cleanup *old_chain;
571 struct program_space *pspace;
573 /* If this is a vfork child exiting, then the pspace and
574 aspaces were shared with the parent. Since we're
575 reporting the process exit, we'll be mourning all that is
576 found in the address space, and switching to null_ptid,
577 preparing to start a new inferior. But, since we don't
578 want to clobber the parent's address/program spaces, we
579 go ahead and create a new one for this exiting
582 /* Switch to null_ptid, so that clone_program_space doesn't want
583 to read the selected frame of a dead process. */
584 old_chain = save_inferior_ptid ();
585 inferior_ptid = null_ptid;
587 /* This inferior is dead, so avoid giving the breakpoints
588 module the option to write through to it (cloning a
589 program space resets breakpoints). */
592 pspace = add_program_space (maybe_new_address_space ());
593 set_current_program_space (pspace);
595 clone_program_space (pspace, inf->vfork_parent->pspace);
596 inf->pspace = pspace;
597 inf->aspace = pspace->aspace;
599 /* Put back inferior_ptid. We'll continue mourning this
601 do_cleanups (old_chain);
603 resume_parent = inf->vfork_parent->pid;
604 /* Break the bonds. */
605 inf->vfork_parent->vfork_child = NULL;
608 inf->vfork_parent = NULL;
610 gdb_assert (current_program_space == inf->pspace);
612 if (non_stop && resume_parent != -1)
614 /* If the user wanted the parent to be running, let it go
616 struct cleanup *old_chain = make_cleanup_restore_current_thread ();
619 fprintf_unfiltered (gdb_stdlog, "infrun: resuming vfork parent process %d\n",
622 iterate_over_threads (proceed_after_vfork_done, &resume_parent);
624 do_cleanups (old_chain);
629 /* Enum strings for "set|show displaced-stepping". */
631 static const char follow_exec_mode_new[] = "new";
632 static const char follow_exec_mode_same[] = "same";
633 static const char *follow_exec_mode_names[] =
635 follow_exec_mode_new,
636 follow_exec_mode_same,
640 static const char *follow_exec_mode_string = follow_exec_mode_same;
642 show_follow_exec_mode_string (struct ui_file *file, int from_tty,
643 struct cmd_list_element *c, const char *value)
645 fprintf_filtered (file, _("Follow exec mode is \"%s\".\n"), value);
648 /* EXECD_PATHNAME is assumed to be non-NULL. */
651 follow_exec (ptid_t pid, char *execd_pathname)
653 struct thread_info *th = inferior_thread ();
654 struct inferior *inf = current_inferior ();
656 /* This is an exec event that we actually wish to pay attention to.
657 Refresh our symbol table to the newly exec'd program, remove any
660 If there are breakpoints, they aren't really inserted now,
661 since the exec() transformed our inferior into a fresh set
664 We want to preserve symbolic breakpoints on the list, since
665 we have hopes that they can be reset after the new a.out's
666 symbol table is read.
668 However, any "raw" breakpoints must be removed from the list
669 (e.g., the solib bp's), since their address is probably invalid
672 And, we DON'T want to call delete_breakpoints() here, since
673 that may write the bp's "shadow contents" (the instruction
674 value that was overwritten witha TRAP instruction). Since
675 we now have a new a.out, those shadow contents aren't valid. */
677 mark_breakpoints_out ();
679 update_breakpoints_after_exec ();
681 /* If there was one, it's gone now. We cannot truly step-to-next
682 statement through an exec(). */
683 th->step_resume_breakpoint = NULL;
684 th->step_range_start = 0;
685 th->step_range_end = 0;
687 /* The target reports the exec event to the main thread, even if
688 some other thread does the exec, and even if the main thread was
689 already stopped --- if debugging in non-stop mode, it's possible
690 the user had the main thread held stopped in the previous image
691 --- release it now. This is the same behavior as step-over-exec
692 with scheduler-locking on in all-stop mode. */
693 th->stop_requested = 0;
695 /* What is this a.out's name? */
696 printf_unfiltered (_("%s is executing new program: %s\n"),
697 target_pid_to_str (inferior_ptid),
700 /* We've followed the inferior through an exec. Therefore, the
701 inferior has essentially been killed & reborn. */
703 gdb_flush (gdb_stdout);
705 breakpoint_init_inferior (inf_execd);
707 if (gdb_sysroot && *gdb_sysroot)
709 char *name = alloca (strlen (gdb_sysroot)
710 + strlen (execd_pathname)
712 strcpy (name, gdb_sysroot);
713 strcat (name, execd_pathname);
714 execd_pathname = name;
717 /* Reset the shared library package. This ensures that we get a
718 shlib event when the child reaches "_start", at which point the
719 dld will have had a chance to initialize the child. */
720 /* Also, loading a symbol file below may trigger symbol lookups, and
721 we don't want those to be satisfied by the libraries of the
722 previous incarnation of this process. */
723 no_shared_libraries (NULL, 0);
725 if (follow_exec_mode_string == follow_exec_mode_new)
727 struct program_space *pspace;
729 /* The user wants to keep the old inferior and program spaces
730 around. Create a new fresh one, and switch to it. */
732 inf = add_inferior (current_inferior ()->pid);
733 pspace = add_program_space (maybe_new_address_space ());
734 inf->pspace = pspace;
735 inf->aspace = pspace->aspace;
737 exit_inferior_num_silent (current_inferior ()->num);
739 set_current_inferior (inf);
740 set_current_program_space (pspace);
743 gdb_assert (current_program_space == inf->pspace);
745 /* That a.out is now the one to use. */
746 exec_file_attach (execd_pathname, 0);
748 /* Load the main file's symbols. */
749 symbol_file_add_main (execd_pathname, 0);
751 #ifdef SOLIB_CREATE_INFERIOR_HOOK
752 SOLIB_CREATE_INFERIOR_HOOK (PIDGET (inferior_ptid));
754 solib_create_inferior_hook (0);
757 jit_inferior_created_hook ();
759 /* Reinsert all breakpoints. (Those which were symbolic have
760 been reset to the proper address in the new a.out, thanks
761 to symbol_file_command...) */
762 insert_breakpoints ();
764 /* The next resume of this inferior should bring it to the shlib
765 startup breakpoints. (If the user had also set bp's on
766 "main" from the old (parent) process, then they'll auto-
767 matically get reset there in the new process.) */
770 /* Non-zero if we just simulating a single-step. This is needed
771 because we cannot remove the breakpoints in the inferior process
772 until after the `wait' in `wait_for_inferior'. */
773 static int singlestep_breakpoints_inserted_p = 0;
775 /* The thread we inserted single-step breakpoints for. */
776 static ptid_t singlestep_ptid;
778 /* PC when we started this single-step. */
779 static CORE_ADDR singlestep_pc;
781 /* If another thread hit the singlestep breakpoint, we save the original
782 thread here so that we can resume single-stepping it later. */
783 static ptid_t saved_singlestep_ptid;
784 static int stepping_past_singlestep_breakpoint;
786 /* If not equal to null_ptid, this means that after stepping over breakpoint
787 is finished, we need to switch to deferred_step_ptid, and step it.
789 The use case is when one thread has hit a breakpoint, and then the user
790 has switched to another thread and issued 'step'. We need to step over
791 breakpoint in the thread which hit the breakpoint, but then continue
792 stepping the thread user has selected. */
793 static ptid_t deferred_step_ptid;
795 /* Displaced stepping. */
797 /* In non-stop debugging mode, we must take special care to manage
798 breakpoints properly; in particular, the traditional strategy for
799 stepping a thread past a breakpoint it has hit is unsuitable.
800 'Displaced stepping' is a tactic for stepping one thread past a
801 breakpoint it has hit while ensuring that other threads running
802 concurrently will hit the breakpoint as they should.
804 The traditional way to step a thread T off a breakpoint in a
805 multi-threaded program in all-stop mode is as follows:
807 a0) Initially, all threads are stopped, and breakpoints are not
809 a1) We single-step T, leaving breakpoints uninserted.
810 a2) We insert breakpoints, and resume all threads.
812 In non-stop debugging, however, this strategy is unsuitable: we
813 don't want to have to stop all threads in the system in order to
814 continue or step T past a breakpoint. Instead, we use displaced
817 n0) Initially, T is stopped, other threads are running, and
818 breakpoints are inserted.
819 n1) We copy the instruction "under" the breakpoint to a separate
820 location, outside the main code stream, making any adjustments
821 to the instruction, register, and memory state as directed by
823 n2) We single-step T over the instruction at its new location.
824 n3) We adjust the resulting register and memory state as directed
825 by T's architecture. This includes resetting T's PC to point
826 back into the main instruction stream.
829 This approach depends on the following gdbarch methods:
831 - gdbarch_max_insn_length and gdbarch_displaced_step_location
832 indicate where to copy the instruction, and how much space must
833 be reserved there. We use these in step n1.
835 - gdbarch_displaced_step_copy_insn copies a instruction to a new
836 address, and makes any necessary adjustments to the instruction,
837 register contents, and memory. We use this in step n1.
839 - gdbarch_displaced_step_fixup adjusts registers and memory after
840 we have successfuly single-stepped the instruction, to yield the
841 same effect the instruction would have had if we had executed it
842 at its original address. We use this in step n3.
844 - gdbarch_displaced_step_free_closure provides cleanup.
846 The gdbarch_displaced_step_copy_insn and
847 gdbarch_displaced_step_fixup functions must be written so that
848 copying an instruction with gdbarch_displaced_step_copy_insn,
849 single-stepping across the copied instruction, and then applying
850 gdbarch_displaced_insn_fixup should have the same effects on the
851 thread's memory and registers as stepping the instruction in place
852 would have. Exactly which responsibilities fall to the copy and
853 which fall to the fixup is up to the author of those functions.
855 See the comments in gdbarch.sh for details.
857 Note that displaced stepping and software single-step cannot
858 currently be used in combination, although with some care I think
859 they could be made to. Software single-step works by placing
860 breakpoints on all possible subsequent instructions; if the
861 displaced instruction is a PC-relative jump, those breakpoints
862 could fall in very strange places --- on pages that aren't
863 executable, or at addresses that are not proper instruction
864 boundaries. (We do generally let other threads run while we wait
865 to hit the software single-step breakpoint, and they might
866 encounter such a corrupted instruction.) One way to work around
867 this would be to have gdbarch_displaced_step_copy_insn fully
868 simulate the effect of PC-relative instructions (and return NULL)
869 on architectures that use software single-stepping.
871 In non-stop mode, we can have independent and simultaneous step
872 requests, so more than one thread may need to simultaneously step
873 over a breakpoint. The current implementation assumes there is
874 only one scratch space per process. In this case, we have to
875 serialize access to the scratch space. If thread A wants to step
876 over a breakpoint, but we are currently waiting for some other
877 thread to complete a displaced step, we leave thread A stopped and
878 place it in the displaced_step_request_queue. Whenever a displaced
879 step finishes, we pick the next thread in the queue and start a new
880 displaced step operation on it. See displaced_step_prepare and
881 displaced_step_fixup for details. */
883 struct displaced_step_request
886 struct displaced_step_request *next;
889 /* Per-inferior displaced stepping state. */
890 struct displaced_step_inferior_state
892 /* Pointer to next in linked list. */
893 struct displaced_step_inferior_state *next;
895 /* The process this displaced step state refers to. */
898 /* A queue of pending displaced stepping requests. One entry per
899 thread that needs to do a displaced step. */
900 struct displaced_step_request *step_request_queue;
902 /* If this is not null_ptid, this is the thread carrying out a
903 displaced single-step in process PID. This thread's state will
904 require fixing up once it has completed its step. */
907 /* The architecture the thread had when we stepped it. */
908 struct gdbarch *step_gdbarch;
910 /* The closure provided gdbarch_displaced_step_copy_insn, to be used
911 for post-step cleanup. */
912 struct displaced_step_closure *step_closure;
914 /* The address of the original instruction, and the copy we
916 CORE_ADDR step_original, step_copy;
918 /* Saved contents of copy area. */
919 gdb_byte *step_saved_copy;
922 /* The list of states of processes involved in displaced stepping
924 static struct displaced_step_inferior_state *displaced_step_inferior_states;
926 /* Get the displaced stepping state of process PID. */
928 static struct displaced_step_inferior_state *
929 get_displaced_stepping_state (int pid)
931 struct displaced_step_inferior_state *state;
933 for (state = displaced_step_inferior_states;
936 if (state->pid == pid)
942 /* Add a new displaced stepping state for process PID to the displaced
943 stepping state list, or return a pointer to an already existing
944 entry, if it already exists. Never returns NULL. */
946 static struct displaced_step_inferior_state *
947 add_displaced_stepping_state (int pid)
949 struct displaced_step_inferior_state *state;
951 for (state = displaced_step_inferior_states;
954 if (state->pid == pid)
957 state = xcalloc (1, sizeof (*state));
959 state->next = displaced_step_inferior_states;
960 displaced_step_inferior_states = state;
965 /* Remove the displaced stepping state of process PID. */
968 remove_displaced_stepping_state (int pid)
970 struct displaced_step_inferior_state *it, **prev_next_p;
972 gdb_assert (pid != 0);
974 it = displaced_step_inferior_states;
975 prev_next_p = &displaced_step_inferior_states;
980 *prev_next_p = it->next;
985 prev_next_p = &it->next;
991 infrun_inferior_exit (struct inferior *inf)
993 remove_displaced_stepping_state (inf->pid);
996 /* Enum strings for "set|show displaced-stepping". */
998 static const char can_use_displaced_stepping_auto[] = "auto";
999 static const char can_use_displaced_stepping_on[] = "on";
1000 static const char can_use_displaced_stepping_off[] = "off";
1001 static const char *can_use_displaced_stepping_enum[] =
1003 can_use_displaced_stepping_auto,
1004 can_use_displaced_stepping_on,
1005 can_use_displaced_stepping_off,
1009 /* If ON, and the architecture supports it, GDB will use displaced
1010 stepping to step over breakpoints. If OFF, or if the architecture
1011 doesn't support it, GDB will instead use the traditional
1012 hold-and-step approach. If AUTO (which is the default), GDB will
1013 decide which technique to use to step over breakpoints depending on
1014 which of all-stop or non-stop mode is active --- displaced stepping
1015 in non-stop mode; hold-and-step in all-stop mode. */
1017 static const char *can_use_displaced_stepping =
1018 can_use_displaced_stepping_auto;
1021 show_can_use_displaced_stepping (struct ui_file *file, int from_tty,
1022 struct cmd_list_element *c,
1025 if (can_use_displaced_stepping == can_use_displaced_stepping_auto)
1026 fprintf_filtered (file, _("\
1027 Debugger's willingness to use displaced stepping to step over \
1028 breakpoints is %s (currently %s).\n"),
1029 value, non_stop ? "on" : "off");
1031 fprintf_filtered (file, _("\
1032 Debugger's willingness to use displaced stepping to step over \
1033 breakpoints is %s.\n"), value);
1036 /* Return non-zero if displaced stepping can/should be used to step
1037 over breakpoints. */
1040 use_displaced_stepping (struct gdbarch *gdbarch)
1042 return (((can_use_displaced_stepping == can_use_displaced_stepping_auto
1044 || can_use_displaced_stepping == can_use_displaced_stepping_on)
1045 && gdbarch_displaced_step_copy_insn_p (gdbarch)
1046 && !RECORD_IS_USED);
1049 /* Clean out any stray displaced stepping state. */
1051 displaced_step_clear (struct displaced_step_inferior_state *displaced)
1053 /* Indicate that there is no cleanup pending. */
1054 displaced->step_ptid = null_ptid;
1056 if (displaced->step_closure)
1058 gdbarch_displaced_step_free_closure (displaced->step_gdbarch,
1059 displaced->step_closure);
1060 displaced->step_closure = NULL;
1065 displaced_step_clear_cleanup (void *arg)
1067 struct displaced_step_inferior_state *state = arg;
1069 displaced_step_clear (state);
1072 /* Dump LEN bytes at BUF in hex to FILE, followed by a newline. */
1074 displaced_step_dump_bytes (struct ui_file *file,
1075 const gdb_byte *buf,
1080 for (i = 0; i < len; i++)
1081 fprintf_unfiltered (file, "%02x ", buf[i]);
1082 fputs_unfiltered ("\n", file);
1085 /* Prepare to single-step, using displaced stepping.
1087 Note that we cannot use displaced stepping when we have a signal to
1088 deliver. If we have a signal to deliver and an instruction to step
1089 over, then after the step, there will be no indication from the
1090 target whether the thread entered a signal handler or ignored the
1091 signal and stepped over the instruction successfully --- both cases
1092 result in a simple SIGTRAP. In the first case we mustn't do a
1093 fixup, and in the second case we must --- but we can't tell which.
1094 Comments in the code for 'random signals' in handle_inferior_event
1095 explain how we handle this case instead.
1097 Returns 1 if preparing was successful -- this thread is going to be
1098 stepped now; or 0 if displaced stepping this thread got queued. */
1100 displaced_step_prepare (ptid_t ptid)
1102 struct cleanup *old_cleanups, *ignore_cleanups;
1103 struct regcache *regcache = get_thread_regcache (ptid);
1104 struct gdbarch *gdbarch = get_regcache_arch (regcache);
1105 CORE_ADDR original, copy;
1107 struct displaced_step_closure *closure;
1108 struct displaced_step_inferior_state *displaced;
1110 /* We should never reach this function if the architecture does not
1111 support displaced stepping. */
1112 gdb_assert (gdbarch_displaced_step_copy_insn_p (gdbarch));
1114 /* We have to displaced step one thread at a time, as we only have
1115 access to a single scratch space per inferior. */
1117 displaced = add_displaced_stepping_state (ptid_get_pid (ptid));
1119 if (!ptid_equal (displaced->step_ptid, null_ptid))
1121 /* Already waiting for a displaced step to finish. Defer this
1122 request and place in queue. */
1123 struct displaced_step_request *req, *new_req;
1125 if (debug_displaced)
1126 fprintf_unfiltered (gdb_stdlog,
1127 "displaced: defering step of %s\n",
1128 target_pid_to_str (ptid));
1130 new_req = xmalloc (sizeof (*new_req));
1131 new_req->ptid = ptid;
1132 new_req->next = NULL;
1134 if (displaced->step_request_queue)
1136 for (req = displaced->step_request_queue;
1140 req->next = new_req;
1143 displaced->step_request_queue = new_req;
1149 if (debug_displaced)
1150 fprintf_unfiltered (gdb_stdlog,
1151 "displaced: stepping %s now\n",
1152 target_pid_to_str (ptid));
1155 displaced_step_clear (displaced);
1157 old_cleanups = save_inferior_ptid ();
1158 inferior_ptid = ptid;
1160 original = regcache_read_pc (regcache);
1162 copy = gdbarch_displaced_step_location (gdbarch);
1163 len = gdbarch_max_insn_length (gdbarch);
1165 /* Save the original contents of the copy area. */
1166 displaced->step_saved_copy = xmalloc (len);
1167 ignore_cleanups = make_cleanup (free_current_contents,
1168 &displaced->step_saved_copy);
1169 read_memory (copy, displaced->step_saved_copy, len);
1170 if (debug_displaced)
1172 fprintf_unfiltered (gdb_stdlog, "displaced: saved %s: ",
1173 paddress (gdbarch, copy));
1174 displaced_step_dump_bytes (gdb_stdlog,
1175 displaced->step_saved_copy,
1179 closure = gdbarch_displaced_step_copy_insn (gdbarch,
1180 original, copy, regcache);
1182 /* We don't support the fully-simulated case at present. */
1183 gdb_assert (closure);
1185 /* Save the information we need to fix things up if the step
1187 displaced->step_ptid = ptid;
1188 displaced->step_gdbarch = gdbarch;
1189 displaced->step_closure = closure;
1190 displaced->step_original = original;
1191 displaced->step_copy = copy;
1193 make_cleanup (displaced_step_clear_cleanup, displaced);
1195 /* Resume execution at the copy. */
1196 regcache_write_pc (regcache, copy);
1198 discard_cleanups (ignore_cleanups);
1200 do_cleanups (old_cleanups);
1202 if (debug_displaced)
1203 fprintf_unfiltered (gdb_stdlog, "displaced: displaced pc to %s\n",
1204 paddress (gdbarch, copy));
1210 write_memory_ptid (ptid_t ptid, CORE_ADDR memaddr, const gdb_byte *myaddr, int len)
1212 struct cleanup *ptid_cleanup = save_inferior_ptid ();
1213 inferior_ptid = ptid;
1214 write_memory (memaddr, myaddr, len);
1215 do_cleanups (ptid_cleanup);
1219 displaced_step_fixup (ptid_t event_ptid, enum target_signal signal)
1221 struct cleanup *old_cleanups;
1222 struct displaced_step_inferior_state *displaced
1223 = get_displaced_stepping_state (ptid_get_pid (event_ptid));
1225 /* Was any thread of this process doing a displaced step? */
1226 if (displaced == NULL)
1229 /* Was this event for the pid we displaced? */
1230 if (ptid_equal (displaced->step_ptid, null_ptid)
1231 || ! ptid_equal (displaced->step_ptid, event_ptid))
1234 old_cleanups = make_cleanup (displaced_step_clear_cleanup, displaced);
1236 /* Restore the contents of the copy area. */
1238 ULONGEST len = gdbarch_max_insn_length (displaced->step_gdbarch);
1239 write_memory_ptid (displaced->step_ptid, displaced->step_copy,
1240 displaced->step_saved_copy, len);
1241 if (debug_displaced)
1242 fprintf_unfiltered (gdb_stdlog, "displaced: restored %s\n",
1243 paddress (displaced->step_gdbarch,
1244 displaced->step_copy));
1247 /* Did the instruction complete successfully? */
1248 if (signal == TARGET_SIGNAL_TRAP)
1250 /* Fix up the resulting state. */
1251 gdbarch_displaced_step_fixup (displaced->step_gdbarch,
1252 displaced->step_closure,
1253 displaced->step_original,
1254 displaced->step_copy,
1255 get_thread_regcache (displaced->step_ptid));
1259 /* Since the instruction didn't complete, all we can do is
1261 struct regcache *regcache = get_thread_regcache (event_ptid);
1262 CORE_ADDR pc = regcache_read_pc (regcache);
1263 pc = displaced->step_original + (pc - displaced->step_copy);
1264 regcache_write_pc (regcache, pc);
1267 do_cleanups (old_cleanups);
1269 displaced->step_ptid = null_ptid;
1271 /* Are there any pending displaced stepping requests? If so, run
1272 one now. Leave the state object around, since we're likely to
1273 need it again soon. */
1274 while (displaced->step_request_queue)
1276 struct displaced_step_request *head;
1278 struct regcache *regcache;
1279 struct gdbarch *gdbarch;
1280 CORE_ADDR actual_pc;
1281 struct address_space *aspace;
1283 head = displaced->step_request_queue;
1285 displaced->step_request_queue = head->next;
1288 context_switch (ptid);
1290 regcache = get_thread_regcache (ptid);
1291 actual_pc = regcache_read_pc (regcache);
1292 aspace = get_regcache_aspace (regcache);
1294 if (breakpoint_here_p (aspace, actual_pc))
1296 if (debug_displaced)
1297 fprintf_unfiltered (gdb_stdlog,
1298 "displaced: stepping queued %s now\n",
1299 target_pid_to_str (ptid));
1301 displaced_step_prepare (ptid);
1303 gdbarch = get_regcache_arch (regcache);
1305 if (debug_displaced)
1307 CORE_ADDR actual_pc = regcache_read_pc (regcache);
1310 fprintf_unfiltered (gdb_stdlog, "displaced: run %s: ",
1311 paddress (gdbarch, actual_pc));
1312 read_memory (actual_pc, buf, sizeof (buf));
1313 displaced_step_dump_bytes (gdb_stdlog, buf, sizeof (buf));
1316 if (gdbarch_displaced_step_hw_singlestep (gdbarch,
1317 displaced->step_closure))
1318 target_resume (ptid, 1, TARGET_SIGNAL_0);
1320 target_resume (ptid, 0, TARGET_SIGNAL_0);
1322 /* Done, we're stepping a thread. */
1328 struct thread_info *tp = inferior_thread ();
1330 /* The breakpoint we were sitting under has since been
1332 tp->trap_expected = 0;
1334 /* Go back to what we were trying to do. */
1335 step = currently_stepping (tp);
1337 if (debug_displaced)
1338 fprintf_unfiltered (gdb_stdlog, "breakpoint is gone %s: step(%d)\n",
1339 target_pid_to_str (tp->ptid), step);
1341 target_resume (ptid, step, TARGET_SIGNAL_0);
1342 tp->stop_signal = TARGET_SIGNAL_0;
1344 /* This request was discarded. See if there's any other
1345 thread waiting for its turn. */
1350 /* Update global variables holding ptids to hold NEW_PTID if they were
1351 holding OLD_PTID. */
1353 infrun_thread_ptid_changed (ptid_t old_ptid, ptid_t new_ptid)
1355 struct displaced_step_request *it;
1356 struct displaced_step_inferior_state *displaced;
1358 if (ptid_equal (inferior_ptid, old_ptid))
1359 inferior_ptid = new_ptid;
1361 if (ptid_equal (singlestep_ptid, old_ptid))
1362 singlestep_ptid = new_ptid;
1364 if (ptid_equal (deferred_step_ptid, old_ptid))
1365 deferred_step_ptid = new_ptid;
1367 for (displaced = displaced_step_inferior_states;
1369 displaced = displaced->next)
1371 if (ptid_equal (displaced->step_ptid, old_ptid))
1372 displaced->step_ptid = new_ptid;
1374 for (it = displaced->step_request_queue; it; it = it->next)
1375 if (ptid_equal (it->ptid, old_ptid))
1376 it->ptid = new_ptid;
1383 /* Things to clean up if we QUIT out of resume (). */
1385 resume_cleanups (void *ignore)
1390 static const char schedlock_off[] = "off";
1391 static const char schedlock_on[] = "on";
1392 static const char schedlock_step[] = "step";
1393 static const char *scheduler_enums[] = {
1399 static const char *scheduler_mode = schedlock_off;
1401 show_scheduler_mode (struct ui_file *file, int from_tty,
1402 struct cmd_list_element *c, const char *value)
1404 fprintf_filtered (file, _("\
1405 Mode for locking scheduler during execution is \"%s\".\n"),
1410 set_schedlock_func (char *args, int from_tty, struct cmd_list_element *c)
1412 if (!target_can_lock_scheduler)
1414 scheduler_mode = schedlock_off;
1415 error (_("Target '%s' cannot support this command."), target_shortname);
1419 /* True if execution commands resume all threads of all processes by
1420 default; otherwise, resume only threads of the current inferior
1422 int sched_multi = 0;
1424 /* Try to setup for software single stepping over the specified location.
1425 Return 1 if target_resume() should use hardware single step.
1427 GDBARCH the current gdbarch.
1428 PC the location to step over. */
1431 maybe_software_singlestep (struct gdbarch *gdbarch, CORE_ADDR pc)
1435 if (gdbarch_software_single_step_p (gdbarch)
1436 && gdbarch_software_single_step (gdbarch, get_current_frame ()))
1439 /* Do not pull these breakpoints until after a `wait' in
1440 `wait_for_inferior' */
1441 singlestep_breakpoints_inserted_p = 1;
1442 singlestep_ptid = inferior_ptid;
1448 /* Resume the inferior, but allow a QUIT. This is useful if the user
1449 wants to interrupt some lengthy single-stepping operation
1450 (for child processes, the SIGINT goes to the inferior, and so
1451 we get a SIGINT random_signal, but for remote debugging and perhaps
1452 other targets, that's not true).
1454 STEP nonzero if we should step (zero to continue instead).
1455 SIG is the signal to give the inferior (zero for none). */
1457 resume (int step, enum target_signal sig)
1459 int should_resume = 1;
1460 struct cleanup *old_cleanups = make_cleanup (resume_cleanups, 0);
1461 struct regcache *regcache = get_current_regcache ();
1462 struct gdbarch *gdbarch = get_regcache_arch (regcache);
1463 struct thread_info *tp = inferior_thread ();
1464 CORE_ADDR pc = regcache_read_pc (regcache);
1465 struct address_space *aspace = get_regcache_aspace (regcache);
1470 fprintf_unfiltered (gdb_stdlog,
1471 "infrun: resume (step=%d, signal=%d), "
1472 "trap_expected=%d\n",
1473 step, sig, tp->trap_expected);
1475 /* Normally, by the time we reach `resume', the breakpoints are either
1476 removed or inserted, as appropriate. The exception is if we're sitting
1477 at a permanent breakpoint; we need to step over it, but permanent
1478 breakpoints can't be removed. So we have to test for it here. */
1479 if (breakpoint_here_p (aspace, pc) == permanent_breakpoint_here)
1481 if (gdbarch_skip_permanent_breakpoint_p (gdbarch))
1482 gdbarch_skip_permanent_breakpoint (gdbarch, regcache);
1485 The program is stopped at a permanent breakpoint, but GDB does not know\n\
1486 how to step past a permanent breakpoint on this architecture. Try using\n\
1487 a command like `return' or `jump' to continue execution."));
1490 /* If enabled, step over breakpoints by executing a copy of the
1491 instruction at a different address.
1493 We can't use displaced stepping when we have a signal to deliver;
1494 the comments for displaced_step_prepare explain why. The
1495 comments in the handle_inferior event for dealing with 'random
1496 signals' explain what we do instead. */
1497 if (use_displaced_stepping (gdbarch)
1498 && (tp->trap_expected
1499 || (step && gdbarch_software_single_step_p (gdbarch)))
1500 && sig == TARGET_SIGNAL_0)
1502 struct displaced_step_inferior_state *displaced;
1504 if (!displaced_step_prepare (inferior_ptid))
1506 /* Got placed in displaced stepping queue. Will be resumed
1507 later when all the currently queued displaced stepping
1508 requests finish. The thread is not executing at this point,
1509 and the call to set_executing will be made later. But we
1510 need to call set_running here, since from frontend point of view,
1511 the thread is running. */
1512 set_running (inferior_ptid, 1);
1513 discard_cleanups (old_cleanups);
1517 displaced = get_displaced_stepping_state (ptid_get_pid (inferior_ptid));
1518 step = gdbarch_displaced_step_hw_singlestep (gdbarch,
1519 displaced->step_closure);
1522 /* Do we need to do it the hard way, w/temp breakpoints? */
1524 step = maybe_software_singlestep (gdbarch, pc);
1530 /* If STEP is set, it's a request to use hardware stepping
1531 facilities. But in that case, we should never
1532 use singlestep breakpoint. */
1533 gdb_assert (!(singlestep_breakpoints_inserted_p && step));
1535 /* Decide the set of threads to ask the target to resume. Start
1536 by assuming everything will be resumed, than narrow the set
1537 by applying increasingly restricting conditions. */
1539 /* By default, resume all threads of all processes. */
1540 resume_ptid = RESUME_ALL;
1542 /* Maybe resume only all threads of the current process. */
1543 if (!sched_multi && target_supports_multi_process ())
1545 resume_ptid = pid_to_ptid (ptid_get_pid (inferior_ptid));
1548 /* Maybe resume a single thread after all. */
1549 if (singlestep_breakpoints_inserted_p
1550 && stepping_past_singlestep_breakpoint)
1552 /* The situation here is as follows. In thread T1 we wanted to
1553 single-step. Lacking hardware single-stepping we've
1554 set breakpoint at the PC of the next instruction -- call it
1555 P. After resuming, we've hit that breakpoint in thread T2.
1556 Now we've removed original breakpoint, inserted breakpoint
1557 at P+1, and try to step to advance T2 past breakpoint.
1558 We need to step only T2, as if T1 is allowed to freely run,
1559 it can run past P, and if other threads are allowed to run,
1560 they can hit breakpoint at P+1, and nested hits of single-step
1561 breakpoints is not something we'd want -- that's complicated
1562 to support, and has no value. */
1563 resume_ptid = inferior_ptid;
1565 else if ((step || singlestep_breakpoints_inserted_p)
1566 && tp->trap_expected)
1568 /* We're allowing a thread to run past a breakpoint it has
1569 hit, by single-stepping the thread with the breakpoint
1570 removed. In which case, we need to single-step only this
1571 thread, and keep others stopped, as they can miss this
1572 breakpoint if allowed to run.
1574 The current code actually removes all breakpoints when
1575 doing this, not just the one being stepped over, so if we
1576 let other threads run, we can actually miss any
1577 breakpoint, not just the one at PC. */
1578 resume_ptid = inferior_ptid;
1582 /* With non-stop mode on, threads are always handled
1584 resume_ptid = inferior_ptid;
1586 else if ((scheduler_mode == schedlock_on)
1587 || (scheduler_mode == schedlock_step
1588 && (step || singlestep_breakpoints_inserted_p)))
1590 /* User-settable 'scheduler' mode requires solo thread resume. */
1591 resume_ptid = inferior_ptid;
1594 if (gdbarch_cannot_step_breakpoint (gdbarch))
1596 /* Most targets can step a breakpoint instruction, thus
1597 executing it normally. But if this one cannot, just
1598 continue and we will hit it anyway. */
1599 if (step && breakpoint_inserted_here_p (aspace, pc))
1604 && use_displaced_stepping (gdbarch)
1605 && tp->trap_expected)
1607 struct regcache *resume_regcache = get_thread_regcache (resume_ptid);
1608 struct gdbarch *resume_gdbarch = get_regcache_arch (resume_regcache);
1609 CORE_ADDR actual_pc = regcache_read_pc (resume_regcache);
1612 fprintf_unfiltered (gdb_stdlog, "displaced: run %s: ",
1613 paddress (resume_gdbarch, actual_pc));
1614 read_memory (actual_pc, buf, sizeof (buf));
1615 displaced_step_dump_bytes (gdb_stdlog, buf, sizeof (buf));
1618 /* Install inferior's terminal modes. */
1619 target_terminal_inferior ();
1621 /* Avoid confusing the next resume, if the next stop/resume
1622 happens to apply to another thread. */
1623 tp->stop_signal = TARGET_SIGNAL_0;
1625 target_resume (resume_ptid, step, sig);
1628 discard_cleanups (old_cleanups);
1633 /* Clear out all variables saying what to do when inferior is continued.
1634 First do this, then set the ones you want, then call `proceed'. */
1637 clear_proceed_status_thread (struct thread_info *tp)
1640 fprintf_unfiltered (gdb_stdlog,
1641 "infrun: clear_proceed_status_thread (%s)\n",
1642 target_pid_to_str (tp->ptid));
1644 tp->trap_expected = 0;
1645 tp->step_range_start = 0;
1646 tp->step_range_end = 0;
1647 tp->step_frame_id = null_frame_id;
1648 tp->step_stack_frame_id = null_frame_id;
1649 tp->step_over_calls = STEP_OVER_UNDEBUGGABLE;
1650 tp->stop_requested = 0;
1654 tp->proceed_to_finish = 0;
1656 /* Discard any remaining commands or status from previous stop. */
1657 bpstat_clear (&tp->stop_bpstat);
1661 clear_proceed_status_callback (struct thread_info *tp, void *data)
1663 if (is_exited (tp->ptid))
1666 clear_proceed_status_thread (tp);
1671 clear_proceed_status (void)
1675 /* In all-stop mode, delete the per-thread status of all
1676 threads, even if inferior_ptid is null_ptid, there may be
1677 threads on the list. E.g., we may be launching a new
1678 process, while selecting the executable. */
1679 iterate_over_threads (clear_proceed_status_callback, NULL);
1682 if (!ptid_equal (inferior_ptid, null_ptid))
1684 struct inferior *inferior;
1688 /* If in non-stop mode, only delete the per-thread status of
1689 the current thread. */
1690 clear_proceed_status_thread (inferior_thread ());
1693 inferior = current_inferior ();
1694 inferior->stop_soon = NO_STOP_QUIETLY;
1697 stop_after_trap = 0;
1699 observer_notify_about_to_proceed ();
1703 regcache_xfree (stop_registers);
1704 stop_registers = NULL;
1708 /* Check the current thread against the thread that reported the most recent
1709 event. If a step-over is required return TRUE and set the current thread
1710 to the old thread. Otherwise return FALSE.
1712 This should be suitable for any targets that support threads. */
1715 prepare_to_proceed (int step)
1718 struct target_waitstatus wait_status;
1719 int schedlock_enabled;
1721 /* With non-stop mode on, threads are always handled individually. */
1722 gdb_assert (! non_stop);
1724 /* Get the last target status returned by target_wait(). */
1725 get_last_target_status (&wait_ptid, &wait_status);
1727 /* Make sure we were stopped at a breakpoint. */
1728 if (wait_status.kind != TARGET_WAITKIND_STOPPED
1729 || (wait_status.value.sig != TARGET_SIGNAL_TRAP
1730 && wait_status.value.sig != TARGET_SIGNAL_ILL
1731 && wait_status.value.sig != TARGET_SIGNAL_SEGV
1732 && wait_status.value.sig != TARGET_SIGNAL_EMT))
1737 schedlock_enabled = (scheduler_mode == schedlock_on
1738 || (scheduler_mode == schedlock_step
1741 /* Don't switch over to WAIT_PTID if scheduler locking is on. */
1742 if (schedlock_enabled)
1745 /* Don't switch over if we're about to resume some other process
1746 other than WAIT_PTID's, and schedule-multiple is off. */
1748 && ptid_get_pid (wait_ptid) != ptid_get_pid (inferior_ptid))
1751 /* Switched over from WAIT_PID. */
1752 if (!ptid_equal (wait_ptid, minus_one_ptid)
1753 && !ptid_equal (inferior_ptid, wait_ptid))
1755 struct regcache *regcache = get_thread_regcache (wait_ptid);
1757 if (breakpoint_here_p (get_regcache_aspace (regcache),
1758 regcache_read_pc (regcache)))
1760 /* If stepping, remember current thread to switch back to. */
1762 deferred_step_ptid = inferior_ptid;
1764 /* Switch back to WAIT_PID thread. */
1765 switch_to_thread (wait_ptid);
1767 /* We return 1 to indicate that there is a breakpoint here,
1768 so we need to step over it before continuing to avoid
1769 hitting it straight away. */
1777 /* Basic routine for continuing the program in various fashions.
1779 ADDR is the address to resume at, or -1 for resume where stopped.
1780 SIGGNAL is the signal to give it, or 0 for none,
1781 or -1 for act according to how it stopped.
1782 STEP is nonzero if should trap after one instruction.
1783 -1 means return after that and print nothing.
1784 You should probably set various step_... variables
1785 before calling here, if you are stepping.
1787 You should call clear_proceed_status before calling proceed. */
1790 proceed (CORE_ADDR addr, enum target_signal siggnal, int step)
1792 struct regcache *regcache;
1793 struct gdbarch *gdbarch;
1794 struct thread_info *tp;
1796 struct address_space *aspace;
1799 /* If we're stopped at a fork/vfork, follow the branch set by the
1800 "set follow-fork-mode" command; otherwise, we'll just proceed
1801 resuming the current thread. */
1802 if (!follow_fork ())
1804 /* The target for some reason decided not to resume. */
1809 regcache = get_current_regcache ();
1810 gdbarch = get_regcache_arch (regcache);
1811 aspace = get_regcache_aspace (regcache);
1812 pc = regcache_read_pc (regcache);
1815 step_start_function = find_pc_function (pc);
1817 stop_after_trap = 1;
1819 if (addr == (CORE_ADDR) -1)
1821 if (pc == stop_pc && breakpoint_here_p (aspace, pc)
1822 && execution_direction != EXEC_REVERSE)
1823 /* There is a breakpoint at the address we will resume at,
1824 step one instruction before inserting breakpoints so that
1825 we do not stop right away (and report a second hit at this
1828 Note, we don't do this in reverse, because we won't
1829 actually be executing the breakpoint insn anyway.
1830 We'll be (un-)executing the previous instruction. */
1833 else if (gdbarch_single_step_through_delay_p (gdbarch)
1834 && gdbarch_single_step_through_delay (gdbarch,
1835 get_current_frame ()))
1836 /* We stepped onto an instruction that needs to be stepped
1837 again before re-inserting the breakpoint, do so. */
1842 regcache_write_pc (regcache, addr);
1846 fprintf_unfiltered (gdb_stdlog,
1847 "infrun: proceed (addr=%s, signal=%d, step=%d)\n",
1848 paddress (gdbarch, addr), siggnal, step);
1850 /* We're handling a live event, so make sure we're doing live
1851 debugging. If we're looking at traceframes while the target is
1852 running, we're going to need to get back to that mode after
1853 handling the event. */
1856 make_cleanup_restore_current_traceframe ();
1857 set_traceframe_number (-1);
1861 /* In non-stop, each thread is handled individually. The context
1862 must already be set to the right thread here. */
1866 /* In a multi-threaded task we may select another thread and
1867 then continue or step.
1869 But if the old thread was stopped at a breakpoint, it will
1870 immediately cause another breakpoint stop without any
1871 execution (i.e. it will report a breakpoint hit incorrectly).
1872 So we must step over it first.
1874 prepare_to_proceed checks the current thread against the
1875 thread that reported the most recent event. If a step-over
1876 is required it returns TRUE and sets the current thread to
1878 if (prepare_to_proceed (step))
1882 /* prepare_to_proceed may change the current thread. */
1883 tp = inferior_thread ();
1887 tp->trap_expected = 1;
1888 /* If displaced stepping is enabled, we can step over the
1889 breakpoint without hitting it, so leave all breakpoints
1890 inserted. Otherwise we need to disable all breakpoints, step
1891 one instruction, and then re-add them when that step is
1893 if (!use_displaced_stepping (gdbarch))
1894 remove_breakpoints ();
1897 /* We can insert breakpoints if we're not trying to step over one,
1898 or if we are stepping over one but we're using displaced stepping
1900 if (! tp->trap_expected || use_displaced_stepping (gdbarch))
1901 insert_breakpoints ();
1905 /* Pass the last stop signal to the thread we're resuming,
1906 irrespective of whether the current thread is the thread that
1907 got the last event or not. This was historically GDB's
1908 behaviour before keeping a stop_signal per thread. */
1910 struct thread_info *last_thread;
1912 struct target_waitstatus last_status;
1914 get_last_target_status (&last_ptid, &last_status);
1915 if (!ptid_equal (inferior_ptid, last_ptid)
1916 && !ptid_equal (last_ptid, null_ptid)
1917 && !ptid_equal (last_ptid, minus_one_ptid))
1919 last_thread = find_thread_ptid (last_ptid);
1922 tp->stop_signal = last_thread->stop_signal;
1923 last_thread->stop_signal = TARGET_SIGNAL_0;
1928 if (siggnal != TARGET_SIGNAL_DEFAULT)
1929 tp->stop_signal = siggnal;
1930 /* If this signal should not be seen by program,
1931 give it zero. Used for debugging signals. */
1932 else if (!signal_program[tp->stop_signal])
1933 tp->stop_signal = TARGET_SIGNAL_0;
1935 annotate_starting ();
1937 /* Make sure that output from GDB appears before output from the
1939 gdb_flush (gdb_stdout);
1941 /* Refresh prev_pc value just prior to resuming. This used to be
1942 done in stop_stepping, however, setting prev_pc there did not handle
1943 scenarios such as inferior function calls or returning from
1944 a function via the return command. In those cases, the prev_pc
1945 value was not set properly for subsequent commands. The prev_pc value
1946 is used to initialize the starting line number in the ecs. With an
1947 invalid value, the gdb next command ends up stopping at the position
1948 represented by the next line table entry past our start position.
1949 On platforms that generate one line table entry per line, this
1950 is not a problem. However, on the ia64, the compiler generates
1951 extraneous line table entries that do not increase the line number.
1952 When we issue the gdb next command on the ia64 after an inferior call
1953 or a return command, we often end up a few instructions forward, still
1954 within the original line we started.
1956 An attempt was made to refresh the prev_pc at the same time the
1957 execution_control_state is initialized (for instance, just before
1958 waiting for an inferior event). But this approach did not work
1959 because of platforms that use ptrace, where the pc register cannot
1960 be read unless the inferior is stopped. At that point, we are not
1961 guaranteed the inferior is stopped and so the regcache_read_pc() call
1962 can fail. Setting the prev_pc value here ensures the value is updated
1963 correctly when the inferior is stopped. */
1964 tp->prev_pc = regcache_read_pc (get_current_regcache ());
1966 /* Fill in with reasonable starting values. */
1967 init_thread_stepping_state (tp);
1969 /* Reset to normal state. */
1970 init_infwait_state ();
1972 /* Resume inferior. */
1973 resume (oneproc || step || bpstat_should_step (), tp->stop_signal);
1975 /* Wait for it to stop (if not standalone)
1976 and in any case decode why it stopped, and act accordingly. */
1977 /* Do this only if we are not using the event loop, or if the target
1978 does not support asynchronous execution. */
1979 if (!target_can_async_p ())
1981 wait_for_inferior (0);
1987 /* Start remote-debugging of a machine over a serial link. */
1990 start_remote (int from_tty)
1992 struct inferior *inferior;
1993 init_wait_for_inferior ();
1995 inferior = current_inferior ();
1996 inferior->stop_soon = STOP_QUIETLY_REMOTE;
1998 /* Always go on waiting for the target, regardless of the mode. */
1999 /* FIXME: cagney/1999-09-23: At present it isn't possible to
2000 indicate to wait_for_inferior that a target should timeout if
2001 nothing is returned (instead of just blocking). Because of this,
2002 targets expecting an immediate response need to, internally, set
2003 things up so that the target_wait() is forced to eventually
2005 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
2006 differentiate to its caller what the state of the target is after
2007 the initial open has been performed. Here we're assuming that
2008 the target has stopped. It should be possible to eventually have
2009 target_open() return to the caller an indication that the target
2010 is currently running and GDB state should be set to the same as
2011 for an async run. */
2012 wait_for_inferior (0);
2014 /* Now that the inferior has stopped, do any bookkeeping like
2015 loading shared libraries. We want to do this before normal_stop,
2016 so that the displayed frame is up to date. */
2017 post_create_inferior (¤t_target, from_tty);
2022 /* Initialize static vars when a new inferior begins. */
2025 init_wait_for_inferior (void)
2027 /* These are meaningless until the first time through wait_for_inferior. */
2029 breakpoint_init_inferior (inf_starting);
2031 clear_proceed_status ();
2033 stepping_past_singlestep_breakpoint = 0;
2034 deferred_step_ptid = null_ptid;
2036 target_last_wait_ptid = minus_one_ptid;
2038 previous_inferior_ptid = null_ptid;
2039 init_infwait_state ();
2041 /* Discard any skipped inlined frames. */
2042 clear_inline_frame_state (minus_one_ptid);
2046 /* This enum encodes possible reasons for doing a target_wait, so that
2047 wfi can call target_wait in one place. (Ultimately the call will be
2048 moved out of the infinite loop entirely.) */
2052 infwait_normal_state,
2053 infwait_thread_hop_state,
2054 infwait_step_watch_state,
2055 infwait_nonstep_watch_state
2058 /* Why did the inferior stop? Used to print the appropriate messages
2059 to the interface from within handle_inferior_event(). */
2060 enum inferior_stop_reason
2062 /* Step, next, nexti, stepi finished. */
2064 /* Inferior terminated by signal. */
2066 /* Inferior exited. */
2068 /* Inferior received signal, and user asked to be notified. */
2070 /* Reverse execution -- target ran out of history info. */
2074 /* The PTID we'll do a target_wait on.*/
2077 /* Current inferior wait state. */
2078 enum infwait_states infwait_state;
2080 /* Data to be passed around while handling an event. This data is
2081 discarded between events. */
2082 struct execution_control_state
2085 /* The thread that got the event, if this was a thread event; NULL
2087 struct thread_info *event_thread;
2089 struct target_waitstatus ws;
2091 CORE_ADDR stop_func_start;
2092 CORE_ADDR stop_func_end;
2093 char *stop_func_name;
2094 int new_thread_event;
2098 static void handle_inferior_event (struct execution_control_state *ecs);
2100 static void handle_step_into_function (struct gdbarch *gdbarch,
2101 struct execution_control_state *ecs);
2102 static void handle_step_into_function_backward (struct gdbarch *gdbarch,
2103 struct execution_control_state *ecs);
2104 static void insert_step_resume_breakpoint_at_frame (struct frame_info *step_frame);
2105 static void insert_step_resume_breakpoint_at_caller (struct frame_info *);
2106 static void insert_step_resume_breakpoint_at_sal (struct gdbarch *gdbarch,
2107 struct symtab_and_line sr_sal,
2108 struct frame_id sr_id);
2109 static void insert_longjmp_resume_breakpoint (struct gdbarch *, CORE_ADDR);
2111 static void stop_stepping (struct execution_control_state *ecs);
2112 static void prepare_to_wait (struct execution_control_state *ecs);
2113 static void keep_going (struct execution_control_state *ecs);
2114 static void print_stop_reason (enum inferior_stop_reason stop_reason,
2117 /* Callback for iterate over threads. If the thread is stopped, but
2118 the user/frontend doesn't know about that yet, go through
2119 normal_stop, as if the thread had just stopped now. ARG points at
2120 a ptid. If PTID is MINUS_ONE_PTID, applies to all threads. If
2121 ptid_is_pid(PTID) is true, applies to all threads of the process
2122 pointed at by PTID. Otherwise, apply only to the thread pointed by
2126 infrun_thread_stop_requested_callback (struct thread_info *info, void *arg)
2128 ptid_t ptid = * (ptid_t *) arg;
2130 if ((ptid_equal (info->ptid, ptid)
2131 || ptid_equal (minus_one_ptid, ptid)
2132 || (ptid_is_pid (ptid)
2133 && ptid_get_pid (ptid) == ptid_get_pid (info->ptid)))
2134 && is_running (info->ptid)
2135 && !is_executing (info->ptid))
2137 struct cleanup *old_chain;
2138 struct execution_control_state ecss;
2139 struct execution_control_state *ecs = &ecss;
2141 memset (ecs, 0, sizeof (*ecs));
2143 old_chain = make_cleanup_restore_current_thread ();
2145 switch_to_thread (info->ptid);
2147 /* Go through handle_inferior_event/normal_stop, so we always
2148 have consistent output as if the stop event had been
2150 ecs->ptid = info->ptid;
2151 ecs->event_thread = find_thread_ptid (info->ptid);
2152 ecs->ws.kind = TARGET_WAITKIND_STOPPED;
2153 ecs->ws.value.sig = TARGET_SIGNAL_0;
2155 handle_inferior_event (ecs);
2157 if (!ecs->wait_some_more)
2159 struct thread_info *tp;
2163 /* Finish off the continuations. The continations
2164 themselves are responsible for realising the thread
2165 didn't finish what it was supposed to do. */
2166 tp = inferior_thread ();
2167 do_all_intermediate_continuations_thread (tp);
2168 do_all_continuations_thread (tp);
2171 do_cleanups (old_chain);
2177 /* This function is attached as a "thread_stop_requested" observer.
2178 Cleanup local state that assumed the PTID was to be resumed, and
2179 report the stop to the frontend. */
2182 infrun_thread_stop_requested (ptid_t ptid)
2184 struct displaced_step_inferior_state *displaced;
2186 /* PTID was requested to stop. Remove it from the displaced
2187 stepping queue, so we don't try to resume it automatically. */
2189 for (displaced = displaced_step_inferior_states;
2191 displaced = displaced->next)
2193 struct displaced_step_request *it, **prev_next_p;
2195 it = displaced->step_request_queue;
2196 prev_next_p = &displaced->step_request_queue;
2199 if (ptid_match (it->ptid, ptid))
2201 *prev_next_p = it->next;
2207 prev_next_p = &it->next;
2214 iterate_over_threads (infrun_thread_stop_requested_callback, &ptid);
2218 infrun_thread_thread_exit (struct thread_info *tp, int silent)
2220 if (ptid_equal (target_last_wait_ptid, tp->ptid))
2221 nullify_last_target_wait_ptid ();
2224 /* Callback for iterate_over_threads. */
2227 delete_step_resume_breakpoint_callback (struct thread_info *info, void *data)
2229 if (is_exited (info->ptid))
2232 delete_step_resume_breakpoint (info);
2236 /* In all-stop, delete the step resume breakpoint of any thread that
2237 had one. In non-stop, delete the step resume breakpoint of the
2238 thread that just stopped. */
2241 delete_step_thread_step_resume_breakpoint (void)
2243 if (!target_has_execution
2244 || ptid_equal (inferior_ptid, null_ptid))
2245 /* If the inferior has exited, we have already deleted the step
2246 resume breakpoints out of GDB's lists. */
2251 /* If in non-stop mode, only delete the step-resume or
2252 longjmp-resume breakpoint of the thread that just stopped
2254 struct thread_info *tp = inferior_thread ();
2255 delete_step_resume_breakpoint (tp);
2258 /* In all-stop mode, delete all step-resume and longjmp-resume
2259 breakpoints of any thread that had them. */
2260 iterate_over_threads (delete_step_resume_breakpoint_callback, NULL);
2263 /* A cleanup wrapper. */
2266 delete_step_thread_step_resume_breakpoint_cleanup (void *arg)
2268 delete_step_thread_step_resume_breakpoint ();
2271 /* Pretty print the results of target_wait, for debugging purposes. */
2274 print_target_wait_results (ptid_t waiton_ptid, ptid_t result_ptid,
2275 const struct target_waitstatus *ws)
2277 char *status_string = target_waitstatus_to_string (ws);
2278 struct ui_file *tmp_stream = mem_fileopen ();
2281 /* The text is split over several lines because it was getting too long.
2282 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
2283 output as a unit; we want only one timestamp printed if debug_timestamp
2286 fprintf_unfiltered (tmp_stream,
2287 "infrun: target_wait (%d", PIDGET (waiton_ptid));
2288 if (PIDGET (waiton_ptid) != -1)
2289 fprintf_unfiltered (tmp_stream,
2290 " [%s]", target_pid_to_str (waiton_ptid));
2291 fprintf_unfiltered (tmp_stream, ", status) =\n");
2292 fprintf_unfiltered (tmp_stream,
2293 "infrun: %d [%s],\n",
2294 PIDGET (result_ptid), target_pid_to_str (result_ptid));
2295 fprintf_unfiltered (tmp_stream,
2299 text = ui_file_xstrdup (tmp_stream, NULL);
2301 /* This uses %s in part to handle %'s in the text, but also to avoid
2302 a gcc error: the format attribute requires a string literal. */
2303 fprintf_unfiltered (gdb_stdlog, "%s", text);
2305 xfree (status_string);
2307 ui_file_delete (tmp_stream);
2310 /* Prepare and stabilize the inferior for detaching it. E.g.,
2311 detaching while a thread is displaced stepping is a recipe for
2312 crashing it, as nothing would readjust the PC out of the scratch
2316 prepare_for_detach (void)
2318 struct inferior *inf = current_inferior ();
2319 ptid_t pid_ptid = pid_to_ptid (inf->pid);
2320 struct cleanup *old_chain_1;
2321 struct displaced_step_inferior_state *displaced;
2323 displaced = get_displaced_stepping_state (inf->pid);
2325 /* Is any thread of this process displaced stepping? If not,
2326 there's nothing else to do. */
2327 if (displaced == NULL || ptid_equal (displaced->step_ptid, null_ptid))
2331 fprintf_unfiltered (gdb_stdlog,
2332 "displaced-stepping in-process while detaching");
2334 old_chain_1 = make_cleanup_restore_integer (&inf->detaching);
2337 while (!ptid_equal (displaced->step_ptid, null_ptid))
2339 struct cleanup *old_chain_2;
2340 struct execution_control_state ecss;
2341 struct execution_control_state *ecs;
2344 memset (ecs, 0, sizeof (*ecs));
2346 overlay_cache_invalid = 1;
2348 /* We have to invalidate the registers BEFORE calling
2349 target_wait because they can be loaded from the target while
2350 in target_wait. This makes remote debugging a bit more
2351 efficient for those targets that provide critical registers
2352 as part of their normal status mechanism. */
2354 registers_changed ();
2356 if (deprecated_target_wait_hook)
2357 ecs->ptid = deprecated_target_wait_hook (pid_ptid, &ecs->ws, 0);
2359 ecs->ptid = target_wait (pid_ptid, &ecs->ws, 0);
2362 print_target_wait_results (pid_ptid, ecs->ptid, &ecs->ws);
2364 /* If an error happens while handling the event, propagate GDB's
2365 knowledge of the executing state to the frontend/user running
2367 old_chain_2 = make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
2369 /* In non-stop mode, each thread is handled individually.
2370 Switch early, so the global state is set correctly for this
2373 && ecs->ws.kind != TARGET_WAITKIND_EXITED
2374 && ecs->ws.kind != TARGET_WAITKIND_SIGNALLED)
2375 context_switch (ecs->ptid);
2377 /* Now figure out what to do with the result of the result. */
2378 handle_inferior_event (ecs);
2380 /* No error, don't finish the state yet. */
2381 discard_cleanups (old_chain_2);
2383 /* Breakpoints and watchpoints are not installed on the target
2384 at this point, and signals are passed directly to the
2385 inferior, so this must mean the process is gone. */
2386 if (!ecs->wait_some_more)
2388 discard_cleanups (old_chain_1);
2389 error (_("Program exited while detaching"));
2393 discard_cleanups (old_chain_1);
2396 /* Wait for control to return from inferior to debugger.
2398 If TREAT_EXEC_AS_SIGTRAP is non-zero, then handle EXEC signals
2399 as if they were SIGTRAP signals. This can be useful during
2400 the startup sequence on some targets such as HP/UX, where
2401 we receive an EXEC event instead of the expected SIGTRAP.
2403 If inferior gets a signal, we may decide to start it up again
2404 instead of returning. That is why there is a loop in this function.
2405 When this function actually returns it means the inferior
2406 should be left stopped and GDB should read more commands. */
2409 wait_for_inferior (int treat_exec_as_sigtrap)
2411 struct cleanup *old_cleanups;
2412 struct execution_control_state ecss;
2413 struct execution_control_state *ecs;
2417 (gdb_stdlog, "infrun: wait_for_inferior (treat_exec_as_sigtrap=%d)\n",
2418 treat_exec_as_sigtrap);
2421 make_cleanup (delete_step_thread_step_resume_breakpoint_cleanup, NULL);
2424 memset (ecs, 0, sizeof (*ecs));
2426 /* We'll update this if & when we switch to a new thread. */
2427 previous_inferior_ptid = inferior_ptid;
2431 struct cleanup *old_chain;
2433 /* We have to invalidate the registers BEFORE calling target_wait
2434 because they can be loaded from the target while in target_wait.
2435 This makes remote debugging a bit more efficient for those
2436 targets that provide critical registers as part of their normal
2437 status mechanism. */
2439 overlay_cache_invalid = 1;
2440 registers_changed ();
2442 if (deprecated_target_wait_hook)
2443 ecs->ptid = deprecated_target_wait_hook (waiton_ptid, &ecs->ws, 0);
2445 ecs->ptid = target_wait (waiton_ptid, &ecs->ws, 0);
2448 print_target_wait_results (waiton_ptid, ecs->ptid, &ecs->ws);
2450 if (treat_exec_as_sigtrap && ecs->ws.kind == TARGET_WAITKIND_EXECD)
2452 xfree (ecs->ws.value.execd_pathname);
2453 ecs->ws.kind = TARGET_WAITKIND_STOPPED;
2454 ecs->ws.value.sig = TARGET_SIGNAL_TRAP;
2457 /* If an error happens while handling the event, propagate GDB's
2458 knowledge of the executing state to the frontend/user running
2460 old_chain = make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
2462 if (ecs->ws.kind == TARGET_WAITKIND_SYSCALL_ENTRY
2463 || ecs->ws.kind == TARGET_WAITKIND_SYSCALL_RETURN)
2464 ecs->ws.value.syscall_number = UNKNOWN_SYSCALL;
2466 /* Now figure out what to do with the result of the result. */
2467 handle_inferior_event (ecs);
2469 /* No error, don't finish the state yet. */
2470 discard_cleanups (old_chain);
2472 if (!ecs->wait_some_more)
2476 do_cleanups (old_cleanups);
2479 /* Asynchronous version of wait_for_inferior. It is called by the
2480 event loop whenever a change of state is detected on the file
2481 descriptor corresponding to the target. It can be called more than
2482 once to complete a single execution command. In such cases we need
2483 to keep the state in a global variable ECSS. If it is the last time
2484 that this function is called for a single execution command, then
2485 report to the user that the inferior has stopped, and do the
2486 necessary cleanups. */
2489 fetch_inferior_event (void *client_data)
2491 struct execution_control_state ecss;
2492 struct execution_control_state *ecs = &ecss;
2493 struct cleanup *old_chain = make_cleanup (null_cleanup, NULL);
2494 struct cleanup *ts_old_chain;
2495 int was_sync = sync_execution;
2497 memset (ecs, 0, sizeof (*ecs));
2499 /* We'll update this if & when we switch to a new thread. */
2500 previous_inferior_ptid = inferior_ptid;
2503 /* In non-stop mode, the user/frontend should not notice a thread
2504 switch due to internal events. Make sure we reverse to the
2505 user selected thread and frame after handling the event and
2506 running any breakpoint commands. */
2507 make_cleanup_restore_current_thread ();
2509 /* We have to invalidate the registers BEFORE calling target_wait
2510 because they can be loaded from the target while in target_wait.
2511 This makes remote debugging a bit more efficient for those
2512 targets that provide critical registers as part of their normal
2513 status mechanism. */
2515 overlay_cache_invalid = 1;
2516 registers_changed ();
2518 if (deprecated_target_wait_hook)
2520 deprecated_target_wait_hook (waiton_ptid, &ecs->ws, TARGET_WNOHANG);
2522 ecs->ptid = target_wait (waiton_ptid, &ecs->ws, TARGET_WNOHANG);
2525 print_target_wait_results (waiton_ptid, ecs->ptid, &ecs->ws);
2528 && ecs->ws.kind != TARGET_WAITKIND_IGNORE
2529 && ecs->ws.kind != TARGET_WAITKIND_EXITED
2530 && ecs->ws.kind != TARGET_WAITKIND_SIGNALLED)
2531 /* In non-stop mode, each thread is handled individually. Switch
2532 early, so the global state is set correctly for this
2534 context_switch (ecs->ptid);
2536 /* If an error happens while handling the event, propagate GDB's
2537 knowledge of the executing state to the frontend/user running
2540 ts_old_chain = make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
2542 ts_old_chain = make_cleanup (finish_thread_state_cleanup, &ecs->ptid);
2544 /* Now figure out what to do with the result of the result. */
2545 handle_inferior_event (ecs);
2547 if (!ecs->wait_some_more)
2549 struct inferior *inf = find_inferior_pid (ptid_get_pid (ecs->ptid));
2551 delete_step_thread_step_resume_breakpoint ();
2553 /* We may not find an inferior if this was a process exit. */
2554 if (inf == NULL || inf->stop_soon == NO_STOP_QUIETLY)
2557 if (target_has_execution
2558 && ecs->ws.kind != TARGET_WAITKIND_EXITED
2559 && ecs->ws.kind != TARGET_WAITKIND_SIGNALLED
2560 && ecs->event_thread->step_multi
2561 && ecs->event_thread->stop_step)
2562 inferior_event_handler (INF_EXEC_CONTINUE, NULL);
2564 inferior_event_handler (INF_EXEC_COMPLETE, NULL);
2567 /* No error, don't finish the thread states yet. */
2568 discard_cleanups (ts_old_chain);
2570 /* Revert thread and frame. */
2571 do_cleanups (old_chain);
2573 /* If the inferior was in sync execution mode, and now isn't,
2574 restore the prompt. */
2575 if (was_sync && !sync_execution)
2576 display_gdb_prompt (0);
2579 /* Record the frame and location we're currently stepping through. */
2581 set_step_info (struct frame_info *frame, struct symtab_and_line sal)
2583 struct thread_info *tp = inferior_thread ();
2585 tp->step_frame_id = get_frame_id (frame);
2586 tp->step_stack_frame_id = get_stack_frame_id (frame);
2588 tp->current_symtab = sal.symtab;
2589 tp->current_line = sal.line;
2592 /* Clear context switchable stepping state. */
2595 init_thread_stepping_state (struct thread_info *tss)
2597 tss->stepping_over_breakpoint = 0;
2598 tss->step_after_step_resume_breakpoint = 0;
2599 tss->stepping_through_solib_after_catch = 0;
2600 tss->stepping_through_solib_catchpoints = NULL;
2603 /* Return the cached copy of the last pid/waitstatus returned by
2604 target_wait()/deprecated_target_wait_hook(). The data is actually
2605 cached by handle_inferior_event(), which gets called immediately
2606 after target_wait()/deprecated_target_wait_hook(). */
2609 get_last_target_status (ptid_t *ptidp, struct target_waitstatus *status)
2611 *ptidp = target_last_wait_ptid;
2612 *status = target_last_waitstatus;
2616 nullify_last_target_wait_ptid (void)
2618 target_last_wait_ptid = minus_one_ptid;
2621 /* Switch thread contexts. */
2624 context_switch (ptid_t ptid)
2628 fprintf_unfiltered (gdb_stdlog, "infrun: Switching context from %s ",
2629 target_pid_to_str (inferior_ptid));
2630 fprintf_unfiltered (gdb_stdlog, "to %s\n",
2631 target_pid_to_str (ptid));
2634 switch_to_thread (ptid);
2638 adjust_pc_after_break (struct execution_control_state *ecs)
2640 struct regcache *regcache;
2641 struct gdbarch *gdbarch;
2642 struct address_space *aspace;
2643 CORE_ADDR breakpoint_pc;
2645 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
2646 we aren't, just return.
2648 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
2649 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
2650 implemented by software breakpoints should be handled through the normal
2653 NOTE drow/2004-01-31: On some targets, breakpoints may generate
2654 different signals (SIGILL or SIGEMT for instance), but it is less
2655 clear where the PC is pointing afterwards. It may not match
2656 gdbarch_decr_pc_after_break. I don't know any specific target that
2657 generates these signals at breakpoints (the code has been in GDB since at
2658 least 1992) so I can not guess how to handle them here.
2660 In earlier versions of GDB, a target with
2661 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
2662 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
2663 target with both of these set in GDB history, and it seems unlikely to be
2664 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
2666 if (ecs->ws.kind != TARGET_WAITKIND_STOPPED)
2669 if (ecs->ws.value.sig != TARGET_SIGNAL_TRAP)
2672 /* In reverse execution, when a breakpoint is hit, the instruction
2673 under it has already been de-executed. The reported PC always
2674 points at the breakpoint address, so adjusting it further would
2675 be wrong. E.g., consider this case on a decr_pc_after_break == 1
2678 B1 0x08000000 : INSN1
2679 B2 0x08000001 : INSN2
2681 PC -> 0x08000003 : INSN4
2683 Say you're stopped at 0x08000003 as above. Reverse continuing
2684 from that point should hit B2 as below. Reading the PC when the
2685 SIGTRAP is reported should read 0x08000001 and INSN2 should have
2686 been de-executed already.
2688 B1 0x08000000 : INSN1
2689 B2 PC -> 0x08000001 : INSN2
2693 We can't apply the same logic as for forward execution, because
2694 we would wrongly adjust the PC to 0x08000000, since there's a
2695 breakpoint at PC - 1. We'd then report a hit on B1, although
2696 INSN1 hadn't been de-executed yet. Doing nothing is the correct
2698 if (execution_direction == EXEC_REVERSE)
2701 /* If this target does not decrement the PC after breakpoints, then
2702 we have nothing to do. */
2703 regcache = get_thread_regcache (ecs->ptid);
2704 gdbarch = get_regcache_arch (regcache);
2705 if (gdbarch_decr_pc_after_break (gdbarch) == 0)
2708 aspace = get_regcache_aspace (regcache);
2710 /* Find the location where (if we've hit a breakpoint) the
2711 breakpoint would be. */
2712 breakpoint_pc = regcache_read_pc (regcache)
2713 - gdbarch_decr_pc_after_break (gdbarch);
2715 /* Check whether there actually is a software breakpoint inserted at
2718 If in non-stop mode, a race condition is possible where we've
2719 removed a breakpoint, but stop events for that breakpoint were
2720 already queued and arrive later. To suppress those spurious
2721 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
2722 and retire them after a number of stop events are reported. */
2723 if (software_breakpoint_inserted_here_p (aspace, breakpoint_pc)
2724 || (non_stop && moribund_breakpoint_here_p (aspace, breakpoint_pc)))
2726 struct cleanup *old_cleanups = NULL;
2728 old_cleanups = record_gdb_operation_disable_set ();
2730 /* When using hardware single-step, a SIGTRAP is reported for both
2731 a completed single-step and a software breakpoint. Need to
2732 differentiate between the two, as the latter needs adjusting
2733 but the former does not.
2735 The SIGTRAP can be due to a completed hardware single-step only if
2736 - we didn't insert software single-step breakpoints
2737 - the thread to be examined is still the current thread
2738 - this thread is currently being stepped
2740 If any of these events did not occur, we must have stopped due
2741 to hitting a software breakpoint, and have to back up to the
2744 As a special case, we could have hardware single-stepped a
2745 software breakpoint. In this case (prev_pc == breakpoint_pc),
2746 we also need to back up to the breakpoint address. */
2748 if (singlestep_breakpoints_inserted_p
2749 || !ptid_equal (ecs->ptid, inferior_ptid)
2750 || !currently_stepping (ecs->event_thread)
2751 || ecs->event_thread->prev_pc == breakpoint_pc)
2752 regcache_write_pc (regcache, breakpoint_pc);
2755 do_cleanups (old_cleanups);
2760 init_infwait_state (void)
2762 waiton_ptid = pid_to_ptid (-1);
2763 infwait_state = infwait_normal_state;
2767 error_is_running (void)
2770 Cannot execute this command while the selected thread is running."));
2774 ensure_not_running (void)
2776 if (is_running (inferior_ptid))
2777 error_is_running ();
2781 stepped_in_from (struct frame_info *frame, struct frame_id step_frame_id)
2783 for (frame = get_prev_frame (frame);
2785 frame = get_prev_frame (frame))
2787 if (frame_id_eq (get_frame_id (frame), step_frame_id))
2789 if (get_frame_type (frame) != INLINE_FRAME)
2796 /* Auxiliary function that handles syscall entry/return events.
2797 It returns 1 if the inferior should keep going (and GDB
2798 should ignore the event), or 0 if the event deserves to be
2802 handle_syscall_event (struct execution_control_state *ecs)
2804 struct regcache *regcache;
2805 struct gdbarch *gdbarch;
2808 if (!ptid_equal (ecs->ptid, inferior_ptid))
2809 context_switch (ecs->ptid);
2811 regcache = get_thread_regcache (ecs->ptid);
2812 gdbarch = get_regcache_arch (regcache);
2813 syscall_number = gdbarch_get_syscall_number (gdbarch, ecs->ptid);
2814 stop_pc = regcache_read_pc (regcache);
2816 target_last_waitstatus.value.syscall_number = syscall_number;
2818 if (catch_syscall_enabled () > 0
2819 && catching_syscall_number (syscall_number) > 0)
2822 fprintf_unfiltered (gdb_stdlog, "infrun: syscall number = '%d'\n",
2825 ecs->event_thread->stop_bpstat
2826 = bpstat_stop_status (get_regcache_aspace (regcache),
2827 stop_pc, ecs->ptid);
2828 ecs->random_signal = !bpstat_explains_signal (ecs->event_thread->stop_bpstat);
2830 if (!ecs->random_signal)
2832 /* Catchpoint hit. */
2833 ecs->event_thread->stop_signal = TARGET_SIGNAL_TRAP;
2838 /* If no catchpoint triggered for this, then keep going. */
2839 ecs->event_thread->stop_signal = TARGET_SIGNAL_0;
2844 /* Given an execution control state that has been freshly filled in
2845 by an event from the inferior, figure out what it means and take
2846 appropriate action. */
2849 handle_inferior_event (struct execution_control_state *ecs)
2851 struct frame_info *frame;
2852 struct gdbarch *gdbarch;
2853 int sw_single_step_trap_p = 0;
2854 int stopped_by_watchpoint;
2855 int stepped_after_stopped_by_watchpoint = 0;
2856 struct symtab_and_line stop_pc_sal;
2857 enum stop_kind stop_soon;
2859 if (ecs->ws.kind == TARGET_WAITKIND_IGNORE)
2861 /* We had an event in the inferior, but we are not interested in
2862 handling it at this level. The lower layers have already
2863 done what needs to be done, if anything.
2865 One of the possible circumstances for this is when the
2866 inferior produces output for the console. The inferior has
2867 not stopped, and we are ignoring the event. Another possible
2868 circumstance is any event which the lower level knows will be
2869 reported multiple times without an intervening resume. */
2871 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_IGNORE\n");
2872 prepare_to_wait (ecs);
2876 if (ecs->ws.kind != TARGET_WAITKIND_EXITED
2877 && ecs->ws.kind != TARGET_WAITKIND_SIGNALLED)
2879 struct inferior *inf = find_inferior_pid (ptid_get_pid (ecs->ptid));
2881 stop_soon = inf->stop_soon;
2884 stop_soon = NO_STOP_QUIETLY;
2886 /* Cache the last pid/waitstatus. */
2887 target_last_wait_ptid = ecs->ptid;
2888 target_last_waitstatus = ecs->ws;
2890 /* Always clear state belonging to the previous time we stopped. */
2891 stop_stack_dummy = STOP_NONE;
2893 /* If it's a new process, add it to the thread database */
2895 ecs->new_thread_event = (!ptid_equal (ecs->ptid, inferior_ptid)
2896 && !ptid_equal (ecs->ptid, minus_one_ptid)
2897 && !in_thread_list (ecs->ptid));
2899 if (ecs->ws.kind != TARGET_WAITKIND_EXITED
2900 && ecs->ws.kind != TARGET_WAITKIND_SIGNALLED && ecs->new_thread_event)
2901 add_thread (ecs->ptid);
2903 ecs->event_thread = find_thread_ptid (ecs->ptid);
2905 /* Dependent on valid ECS->EVENT_THREAD. */
2906 adjust_pc_after_break (ecs);
2908 /* Dependent on the current PC value modified by adjust_pc_after_break. */
2909 reinit_frame_cache ();
2911 breakpoint_retire_moribund ();
2913 /* First, distinguish signals caused by the debugger from signals
2914 that have to do with the program's own actions. Note that
2915 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
2916 on the operating system version. Here we detect when a SIGILL or
2917 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
2918 something similar for SIGSEGV, since a SIGSEGV will be generated
2919 when we're trying to execute a breakpoint instruction on a
2920 non-executable stack. This happens for call dummy breakpoints
2921 for architectures like SPARC that place call dummies on the
2923 if (ecs->ws.kind == TARGET_WAITKIND_STOPPED
2924 && (ecs->ws.value.sig == TARGET_SIGNAL_ILL
2925 || ecs->ws.value.sig == TARGET_SIGNAL_SEGV
2926 || ecs->ws.value.sig == TARGET_SIGNAL_EMT))
2928 struct regcache *regcache = get_thread_regcache (ecs->ptid);
2930 if (breakpoint_inserted_here_p (get_regcache_aspace (regcache),
2931 regcache_read_pc (regcache)))
2934 fprintf_unfiltered (gdb_stdlog,
2935 "infrun: Treating signal as SIGTRAP\n");
2936 ecs->ws.value.sig = TARGET_SIGNAL_TRAP;
2940 /* Mark the non-executing threads accordingly. In all-stop, all
2941 threads of all processes are stopped when we get any event
2942 reported. In non-stop mode, only the event thread stops. If
2943 we're handling a process exit in non-stop mode, there's nothing
2944 to do, as threads of the dead process are gone, and threads of
2945 any other process were left running. */
2947 set_executing (minus_one_ptid, 0);
2948 else if (ecs->ws.kind != TARGET_WAITKIND_SIGNALLED
2949 && ecs->ws.kind != TARGET_WAITKIND_EXITED)
2950 set_executing (inferior_ptid, 0);
2952 switch (infwait_state)
2954 case infwait_thread_hop_state:
2956 fprintf_unfiltered (gdb_stdlog, "infrun: infwait_thread_hop_state\n");
2959 case infwait_normal_state:
2961 fprintf_unfiltered (gdb_stdlog, "infrun: infwait_normal_state\n");
2964 case infwait_step_watch_state:
2966 fprintf_unfiltered (gdb_stdlog,
2967 "infrun: infwait_step_watch_state\n");
2969 stepped_after_stopped_by_watchpoint = 1;
2972 case infwait_nonstep_watch_state:
2974 fprintf_unfiltered (gdb_stdlog,
2975 "infrun: infwait_nonstep_watch_state\n");
2976 insert_breakpoints ();
2978 /* FIXME-maybe: is this cleaner than setting a flag? Does it
2979 handle things like signals arriving and other things happening
2980 in combination correctly? */
2981 stepped_after_stopped_by_watchpoint = 1;
2985 internal_error (__FILE__, __LINE__, _("bad switch"));
2988 infwait_state = infwait_normal_state;
2989 waiton_ptid = pid_to_ptid (-1);
2991 switch (ecs->ws.kind)
2993 case TARGET_WAITKIND_LOADED:
2995 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_LOADED\n");
2996 /* Ignore gracefully during startup of the inferior, as it might
2997 be the shell which has just loaded some objects, otherwise
2998 add the symbols for the newly loaded objects. Also ignore at
2999 the beginning of an attach or remote session; we will query
3000 the full list of libraries once the connection is
3002 if (stop_soon == NO_STOP_QUIETLY)
3004 /* Check for any newly added shared libraries if we're
3005 supposed to be adding them automatically. Switch
3006 terminal for any messages produced by
3007 breakpoint_re_set. */
3008 target_terminal_ours_for_output ();
3009 /* NOTE: cagney/2003-11-25: Make certain that the target
3010 stack's section table is kept up-to-date. Architectures,
3011 (e.g., PPC64), use the section table to perform
3012 operations such as address => section name and hence
3013 require the table to contain all sections (including
3014 those found in shared libraries). */
3016 SOLIB_ADD (NULL, 0, ¤t_target, auto_solib_add);
3018 solib_add (NULL, 0, ¤t_target, auto_solib_add);
3020 target_terminal_inferior ();
3022 /* If requested, stop when the dynamic linker notifies
3023 gdb of events. This allows the user to get control
3024 and place breakpoints in initializer routines for
3025 dynamically loaded objects (among other things). */
3026 if (stop_on_solib_events)
3028 /* Make sure we print "Stopped due to solib-event" in
3030 stop_print_frame = 1;
3032 stop_stepping (ecs);
3036 /* NOTE drow/2007-05-11: This might be a good place to check
3037 for "catch load". */
3040 /* If we are skipping through a shell, or through shared library
3041 loading that we aren't interested in, resume the program. If
3042 we're running the program normally, also resume. But stop if
3043 we're attaching or setting up a remote connection. */
3044 if (stop_soon == STOP_QUIETLY || stop_soon == NO_STOP_QUIETLY)
3046 /* Loading of shared libraries might have changed breakpoint
3047 addresses. Make sure new breakpoints are inserted. */
3048 if (stop_soon == NO_STOP_QUIETLY
3049 && !breakpoints_always_inserted_mode ())
3050 insert_breakpoints ();
3051 resume (0, TARGET_SIGNAL_0);
3052 prepare_to_wait (ecs);
3058 case TARGET_WAITKIND_SPURIOUS:
3060 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_SPURIOUS\n");
3061 resume (0, TARGET_SIGNAL_0);
3062 prepare_to_wait (ecs);
3065 case TARGET_WAITKIND_EXITED:
3067 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_EXITED\n");
3068 inferior_ptid = ecs->ptid;
3069 set_current_inferior (find_inferior_pid (ptid_get_pid (ecs->ptid)));
3070 set_current_program_space (current_inferior ()->pspace);
3071 handle_vfork_child_exec_or_exit (0);
3072 target_terminal_ours (); /* Must do this before mourn anyway */
3073 print_stop_reason (EXITED, ecs->ws.value.integer);
3075 /* Record the exit code in the convenience variable $_exitcode, so
3076 that the user can inspect this again later. */
3077 set_internalvar_integer (lookup_internalvar ("_exitcode"),
3078 (LONGEST) ecs->ws.value.integer);
3079 gdb_flush (gdb_stdout);
3080 target_mourn_inferior ();
3081 singlestep_breakpoints_inserted_p = 0;
3082 stop_print_frame = 0;
3083 stop_stepping (ecs);
3086 case TARGET_WAITKIND_SIGNALLED:
3088 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_SIGNALLED\n");
3089 inferior_ptid = ecs->ptid;
3090 set_current_inferior (find_inferior_pid (ptid_get_pid (ecs->ptid)));
3091 set_current_program_space (current_inferior ()->pspace);
3092 handle_vfork_child_exec_or_exit (0);
3093 stop_print_frame = 0;
3094 target_terminal_ours (); /* Must do this before mourn anyway */
3096 /* Note: By definition of TARGET_WAITKIND_SIGNALLED, we shouldn't
3097 reach here unless the inferior is dead. However, for years
3098 target_kill() was called here, which hints that fatal signals aren't
3099 really fatal on some systems. If that's true, then some changes
3101 target_mourn_inferior ();
3103 print_stop_reason (SIGNAL_EXITED, ecs->ws.value.sig);
3104 singlestep_breakpoints_inserted_p = 0;
3105 stop_stepping (ecs);
3108 /* The following are the only cases in which we keep going;
3109 the above cases end in a continue or goto. */
3110 case TARGET_WAITKIND_FORKED:
3111 case TARGET_WAITKIND_VFORKED:
3113 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_FORKED\n");
3115 if (!ptid_equal (ecs->ptid, inferior_ptid))
3117 context_switch (ecs->ptid);
3118 reinit_frame_cache ();
3121 /* Immediately detach breakpoints from the child before there's
3122 any chance of letting the user delete breakpoints from the
3123 breakpoint lists. If we don't do this early, it's easy to
3124 leave left over traps in the child, vis: "break foo; catch
3125 fork; c; <fork>; del; c; <child calls foo>". We only follow
3126 the fork on the last `continue', and by that time the
3127 breakpoint at "foo" is long gone from the breakpoint table.
3128 If we vforked, then we don't need to unpatch here, since both
3129 parent and child are sharing the same memory pages; we'll
3130 need to unpatch at follow/detach time instead to be certain
3131 that new breakpoints added between catchpoint hit time and
3132 vfork follow are detached. */
3133 if (ecs->ws.kind != TARGET_WAITKIND_VFORKED)
3135 int child_pid = ptid_get_pid (ecs->ws.value.related_pid);
3137 /* This won't actually modify the breakpoint list, but will
3138 physically remove the breakpoints from the child. */
3139 detach_breakpoints (child_pid);
3142 /* In case the event is caught by a catchpoint, remember that
3143 the event is to be followed at the next resume of the thread,
3144 and not immediately. */
3145 ecs->event_thread->pending_follow = ecs->ws;
3147 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
3149 ecs->event_thread->stop_bpstat
3150 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
3151 stop_pc, ecs->ptid);
3153 /* Note that we're interested in knowing the bpstat actually
3154 causes a stop, not just if it may explain the signal.
3155 Software watchpoints, for example, always appear in the
3157 ecs->random_signal = !bpstat_causes_stop (ecs->event_thread->stop_bpstat);
3159 /* If no catchpoint triggered for this, then keep going. */
3160 if (ecs->random_signal)
3165 int follow_child = (follow_fork_mode_string == follow_fork_mode_child);
3167 ecs->event_thread->stop_signal = TARGET_SIGNAL_0;
3169 should_resume = follow_fork ();
3172 child = ecs->ws.value.related_pid;
3174 /* In non-stop mode, also resume the other branch. */
3175 if (non_stop && !detach_fork)
3178 switch_to_thread (parent);
3180 switch_to_thread (child);
3182 ecs->event_thread = inferior_thread ();
3183 ecs->ptid = inferior_ptid;
3188 switch_to_thread (child);
3190 switch_to_thread (parent);
3192 ecs->event_thread = inferior_thread ();
3193 ecs->ptid = inferior_ptid;
3198 stop_stepping (ecs);
3201 ecs->event_thread->stop_signal = TARGET_SIGNAL_TRAP;
3202 goto process_event_stop_test;
3204 case TARGET_WAITKIND_VFORK_DONE:
3205 /* Done with the shared memory region. Re-insert breakpoints in
3206 the parent, and keep going. */
3209 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_VFORK_DONE\n");
3211 if (!ptid_equal (ecs->ptid, inferior_ptid))
3212 context_switch (ecs->ptid);
3214 current_inferior ()->waiting_for_vfork_done = 0;
3215 current_inferior ()->pspace->breakpoints_not_allowed = 0;
3216 /* This also takes care of reinserting breakpoints in the
3217 previously locked inferior. */
3221 case TARGET_WAITKIND_EXECD:
3223 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_EXECD\n");
3225 if (!ptid_equal (ecs->ptid, inferior_ptid))
3227 context_switch (ecs->ptid);
3228 reinit_frame_cache ();
3231 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
3233 /* Do whatever is necessary to the parent branch of the vfork. */
3234 handle_vfork_child_exec_or_exit (1);
3236 /* This causes the eventpoints and symbol table to be reset.
3237 Must do this now, before trying to determine whether to
3239 follow_exec (inferior_ptid, ecs->ws.value.execd_pathname);
3241 ecs->event_thread->stop_bpstat
3242 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
3243 stop_pc, ecs->ptid);
3244 ecs->random_signal = !bpstat_explains_signal (ecs->event_thread->stop_bpstat);
3246 /* Note that this may be referenced from inside
3247 bpstat_stop_status above, through inferior_has_execd. */
3248 xfree (ecs->ws.value.execd_pathname);
3249 ecs->ws.value.execd_pathname = NULL;
3251 /* If no catchpoint triggered for this, then keep going. */
3252 if (ecs->random_signal)
3254 ecs->event_thread->stop_signal = TARGET_SIGNAL_0;
3258 ecs->event_thread->stop_signal = TARGET_SIGNAL_TRAP;
3259 goto process_event_stop_test;
3261 /* Be careful not to try to gather much state about a thread
3262 that's in a syscall. It's frequently a losing proposition. */
3263 case TARGET_WAITKIND_SYSCALL_ENTRY:
3265 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_SYSCALL_ENTRY\n");
3266 /* Getting the current syscall number */
3267 if (handle_syscall_event (ecs) != 0)
3269 goto process_event_stop_test;
3271 /* Before examining the threads further, step this thread to
3272 get it entirely out of the syscall. (We get notice of the
3273 event when the thread is just on the verge of exiting a
3274 syscall. Stepping one instruction seems to get it back
3276 case TARGET_WAITKIND_SYSCALL_RETURN:
3278 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_SYSCALL_RETURN\n");
3279 if (handle_syscall_event (ecs) != 0)
3281 goto process_event_stop_test;
3283 case TARGET_WAITKIND_STOPPED:
3285 fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_STOPPED\n");
3286 ecs->event_thread->stop_signal = ecs->ws.value.sig;
3289 case TARGET_WAITKIND_NO_HISTORY:
3290 /* Reverse execution: target ran out of history info. */
3291 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
3292 print_stop_reason (NO_HISTORY, 0);
3293 stop_stepping (ecs);
3297 if (ecs->new_thread_event)
3300 /* Non-stop assumes that the target handles adding new threads
3301 to the thread list. */
3302 internal_error (__FILE__, __LINE__, "\
3303 targets should add new threads to the thread list themselves in non-stop mode.");
3305 /* We may want to consider not doing a resume here in order to
3306 give the user a chance to play with the new thread. It might
3307 be good to make that a user-settable option. */
3309 /* At this point, all threads are stopped (happens automatically
3310 in either the OS or the native code). Therefore we need to
3311 continue all threads in order to make progress. */
3313 if (!ptid_equal (ecs->ptid, inferior_ptid))
3314 context_switch (ecs->ptid);
3315 target_resume (RESUME_ALL, 0, TARGET_SIGNAL_0);
3316 prepare_to_wait (ecs);
3320 if (ecs->ws.kind == TARGET_WAITKIND_STOPPED)
3322 /* Do we need to clean up the state of a thread that has
3323 completed a displaced single-step? (Doing so usually affects
3324 the PC, so do it here, before we set stop_pc.) */
3325 displaced_step_fixup (ecs->ptid, ecs->event_thread->stop_signal);
3327 /* If we either finished a single-step or hit a breakpoint, but
3328 the user wanted this thread to be stopped, pretend we got a
3329 SIG0 (generic unsignaled stop). */
3331 if (ecs->event_thread->stop_requested
3332 && ecs->event_thread->stop_signal == TARGET_SIGNAL_TRAP)
3333 ecs->event_thread->stop_signal = TARGET_SIGNAL_0;
3336 stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
3340 struct regcache *regcache = get_thread_regcache (ecs->ptid);
3341 struct gdbarch *gdbarch = get_regcache_arch (regcache);
3342 struct cleanup *old_chain = save_inferior_ptid ();
3344 inferior_ptid = ecs->ptid;
3346 fprintf_unfiltered (gdb_stdlog, "infrun: stop_pc = %s\n",
3347 paddress (gdbarch, stop_pc));
3348 if (target_stopped_by_watchpoint ())
3351 fprintf_unfiltered (gdb_stdlog, "infrun: stopped by watchpoint\n");
3353 if (target_stopped_data_address (¤t_target, &addr))
3354 fprintf_unfiltered (gdb_stdlog,
3355 "infrun: stopped data address = %s\n",
3356 paddress (gdbarch, addr));
3358 fprintf_unfiltered (gdb_stdlog,
3359 "infrun: (no data address available)\n");
3362 do_cleanups (old_chain);
3365 if (stepping_past_singlestep_breakpoint)
3367 gdb_assert (singlestep_breakpoints_inserted_p);
3368 gdb_assert (ptid_equal (singlestep_ptid, ecs->ptid));
3369 gdb_assert (!ptid_equal (singlestep_ptid, saved_singlestep_ptid));
3371 stepping_past_singlestep_breakpoint = 0;
3373 /* We've either finished single-stepping past the single-step
3374 breakpoint, or stopped for some other reason. It would be nice if
3375 we could tell, but we can't reliably. */
3376 if (ecs->event_thread->stop_signal == TARGET_SIGNAL_TRAP)
3379 fprintf_unfiltered (gdb_stdlog, "infrun: stepping_past_singlestep_breakpoint\n");
3380 /* Pull the single step breakpoints out of the target. */
3381 remove_single_step_breakpoints ();
3382 singlestep_breakpoints_inserted_p = 0;
3384 ecs->random_signal = 0;
3385 ecs->event_thread->trap_expected = 0;
3387 context_switch (saved_singlestep_ptid);
3388 if (deprecated_context_hook)
3389 deprecated_context_hook (pid_to_thread_id (ecs->ptid));
3391 resume (1, TARGET_SIGNAL_0);
3392 prepare_to_wait (ecs);
3397 if (!ptid_equal (deferred_step_ptid, null_ptid))
3399 /* In non-stop mode, there's never a deferred_step_ptid set. */
3400 gdb_assert (!non_stop);
3402 /* If we stopped for some other reason than single-stepping, ignore
3403 the fact that we were supposed to switch back. */
3404 if (ecs->event_thread->stop_signal == TARGET_SIGNAL_TRAP)
3407 fprintf_unfiltered (gdb_stdlog,
3408 "infrun: handling deferred step\n");
3410 /* Pull the single step breakpoints out of the target. */
3411 if (singlestep_breakpoints_inserted_p)
3413 remove_single_step_breakpoints ();
3414 singlestep_breakpoints_inserted_p = 0;
3417 /* Note: We do not call context_switch at this point, as the
3418 context is already set up for stepping the original thread. */
3419 switch_to_thread (deferred_step_ptid);
3420 deferred_step_ptid = null_ptid;
3421 /* Suppress spurious "Switching to ..." message. */
3422 previous_inferior_ptid = inferior_ptid;
3424 resume (1, TARGET_SIGNAL_0);
3425 prepare_to_wait (ecs);
3429 deferred_step_ptid = null_ptid;
3432 /* See if a thread hit a thread-specific breakpoint that was meant for
3433 another thread. If so, then step that thread past the breakpoint,
3436 if (ecs->event_thread->stop_signal == TARGET_SIGNAL_TRAP)
3438 int thread_hop_needed = 0;
3439 struct address_space *aspace =
3440 get_regcache_aspace (get_thread_regcache (ecs->ptid));
3442 /* Check if a regular breakpoint has been hit before checking
3443 for a potential single step breakpoint. Otherwise, GDB will
3444 not see this breakpoint hit when stepping onto breakpoints. */
3445 if (regular_breakpoint_inserted_here_p (aspace, stop_pc))
3447 ecs->random_signal = 0;
3448 if (!breakpoint_thread_match (aspace, stop_pc, ecs->ptid))
3449 thread_hop_needed = 1;
3451 else if (singlestep_breakpoints_inserted_p)
3453 /* We have not context switched yet, so this should be true
3454 no matter which thread hit the singlestep breakpoint. */
3455 gdb_assert (ptid_equal (inferior_ptid, singlestep_ptid));
3457 fprintf_unfiltered (gdb_stdlog, "infrun: software single step "
3459 target_pid_to_str (ecs->ptid));
3461 ecs->random_signal = 0;
3462 /* The call to in_thread_list is necessary because PTIDs sometimes
3463 change when we go from single-threaded to multi-threaded. If
3464 the singlestep_ptid is still in the list, assume that it is
3465 really different from ecs->ptid. */
3466 if (!ptid_equal (singlestep_ptid, ecs->ptid)
3467 && in_thread_list (singlestep_ptid))
3469 /* If the PC of the thread we were trying to single-step
3470 has changed, discard this event (which we were going
3471 to ignore anyway), and pretend we saw that thread
3472 trap. This prevents us continuously moving the
3473 single-step breakpoint forward, one instruction at a
3474 time. If the PC has changed, then the thread we were
3475 trying to single-step has trapped or been signalled,
3476 but the event has not been reported to GDB yet.
3478 There might be some cases where this loses signal
3479 information, if a signal has arrived at exactly the
3480 same time that the PC changed, but this is the best
3481 we can do with the information available. Perhaps we
3482 should arrange to report all events for all threads
3483 when they stop, or to re-poll the remote looking for
3484 this particular thread (i.e. temporarily enable
3487 CORE_ADDR new_singlestep_pc
3488 = regcache_read_pc (get_thread_regcache (singlestep_ptid));
3490 if (new_singlestep_pc != singlestep_pc)
3492 enum target_signal stop_signal;
3495 fprintf_unfiltered (gdb_stdlog, "infrun: unexpected thread,"
3496 " but expected thread advanced also\n");
3498 /* The current context still belongs to
3499 singlestep_ptid. Don't swap here, since that's
3500 the context we want to use. Just fudge our
3501 state and continue. */
3502 stop_signal = ecs->event_thread->stop_signal;
3503 ecs->event_thread->stop_signal = TARGET_SIGNAL_0;
3504 ecs->ptid = singlestep_ptid;
3505 ecs->event_thread = find_thread_ptid (ecs->ptid);
3506 ecs->event_thread->stop_signal = stop_signal;
3507 stop_pc = new_singlestep_pc;
3512 fprintf_unfiltered (gdb_stdlog,
3513 "infrun: unexpected thread\n");
3515 thread_hop_needed = 1;
3516 stepping_past_singlestep_breakpoint = 1;
3517 saved_singlestep_ptid = singlestep_ptid;
3522 if (thread_hop_needed)
3524 struct regcache *thread_regcache;
3525 int remove_status = 0;
3528 fprintf_unfiltered (gdb_stdlog, "infrun: thread_hop_needed\n");
3530 /* Switch context before touching inferior memory, the
3531 previous thread may have exited. */
3532 if (!ptid_equal (inferior_ptid, ecs->ptid))
3533 context_switch (ecs->ptid);
3535 /* Saw a breakpoint, but it was hit by the wrong thread.
3538 if (singlestep_breakpoints_inserted_p)
3540 /* Pull the single step breakpoints out of the target. */
3541 remove_single_step_breakpoints ();
3542 singlestep_breakpoints_inserted_p = 0;
3545 /* If the arch can displace step, don't remove the
3547 thread_regcache = get_thread_regcache (ecs->ptid);
3548 if (!use_displaced_stepping (get_regcache_arch (thread_regcache)))
3549 remove_status = remove_breakpoints ();
3551 /* Did we fail to remove breakpoints? If so, try
3552 to set the PC past the bp. (There's at least
3553 one situation in which we can fail to remove
3554 the bp's: On HP-UX's that use ttrace, we can't
3555 change the address space of a vforking child
3556 process until the child exits (well, okay, not
3557 then either :-) or execs. */
3558 if (remove_status != 0)
3559 error (_("Cannot step over breakpoint hit in wrong thread"));
3564 /* Only need to require the next event from this
3565 thread in all-stop mode. */
3566 waiton_ptid = ecs->ptid;
3567 infwait_state = infwait_thread_hop_state;
3570 ecs->event_thread->stepping_over_breakpoint = 1;
3575 else if (singlestep_breakpoints_inserted_p)
3577 sw_single_step_trap_p = 1;
3578 ecs->random_signal = 0;
3582 ecs->random_signal = 1;
3584 /* See if something interesting happened to the non-current thread. If
3585 so, then switch to that thread. */
3586 if (!ptid_equal (ecs->ptid, inferior_ptid))
3589 fprintf_unfiltered (gdb_stdlog, "infrun: context switch\n");
3591 context_switch (ecs->ptid);
3593 if (deprecated_context_hook)
3594 deprecated_context_hook (pid_to_thread_id (ecs->ptid));
3597 /* At this point, get hold of the now-current thread's frame. */
3598 frame = get_current_frame ();
3599 gdbarch = get_frame_arch (frame);
3601 if (singlestep_breakpoints_inserted_p)
3603 /* Pull the single step breakpoints out of the target. */
3604 remove_single_step_breakpoints ();
3605 singlestep_breakpoints_inserted_p = 0;
3608 if (stepped_after_stopped_by_watchpoint)
3609 stopped_by_watchpoint = 0;
3611 stopped_by_watchpoint = watchpoints_triggered (&ecs->ws);
3613 /* If necessary, step over this watchpoint. We'll be back to display
3615 if (stopped_by_watchpoint
3616 && (target_have_steppable_watchpoint
3617 || gdbarch_have_nonsteppable_watchpoint (gdbarch)))
3619 /* At this point, we are stopped at an instruction which has
3620 attempted to write to a piece of memory under control of
3621 a watchpoint. The instruction hasn't actually executed
3622 yet. If we were to evaluate the watchpoint expression
3623 now, we would get the old value, and therefore no change
3624 would seem to have occurred.
3626 In order to make watchpoints work `right', we really need
3627 to complete the memory write, and then evaluate the
3628 watchpoint expression. We do this by single-stepping the
3631 It may not be necessary to disable the watchpoint to stop over
3632 it. For example, the PA can (with some kernel cooperation)
3633 single step over a watchpoint without disabling the watchpoint.
3635 It is far more common to need to disable a watchpoint to step
3636 the inferior over it. If we have non-steppable watchpoints,
3637 we must disable the current watchpoint; it's simplest to
3638 disable all watchpoints and breakpoints. */
3641 if (!target_have_steppable_watchpoint)
3642 remove_breakpoints ();
3644 hw_step = maybe_software_singlestep (gdbarch, stop_pc);
3645 target_resume (ecs->ptid, hw_step, TARGET_SIGNAL_0);
3646 waiton_ptid = ecs->ptid;
3647 if (target_have_steppable_watchpoint)
3648 infwait_state = infwait_step_watch_state;
3650 infwait_state = infwait_nonstep_watch_state;
3651 prepare_to_wait (ecs);
3655 ecs->stop_func_start = 0;
3656 ecs->stop_func_end = 0;
3657 ecs->stop_func_name = 0;
3658 /* Don't care about return value; stop_func_start and stop_func_name
3659 will both be 0 if it doesn't work. */
3660 find_pc_partial_function (stop_pc, &ecs->stop_func_name,
3661 &ecs->stop_func_start, &ecs->stop_func_end);
3662 ecs->stop_func_start
3663 += gdbarch_deprecated_function_start_offset (gdbarch);
3664 ecs->event_thread->stepping_over_breakpoint = 0;
3665 bpstat_clear (&ecs->event_thread->stop_bpstat);
3666 ecs->event_thread->stop_step = 0;
3667 stop_print_frame = 1;
3668 ecs->random_signal = 0;
3669 stopped_by_random_signal = 0;
3671 /* Hide inlined functions starting here, unless we just performed stepi or
3672 nexti. After stepi and nexti, always show the innermost frame (not any
3673 inline function call sites). */
3674 if (ecs->event_thread->step_range_end != 1)
3675 skip_inline_frames (ecs->ptid);
3677 if (ecs->event_thread->stop_signal == TARGET_SIGNAL_TRAP
3678 && ecs->event_thread->trap_expected
3679 && gdbarch_single_step_through_delay_p (gdbarch)
3680 && currently_stepping (ecs->event_thread))
3682 /* We're trying to step off a breakpoint. Turns out that we're
3683 also on an instruction that needs to be stepped multiple
3684 times before it's been fully executing. E.g., architectures
3685 with a delay slot. It needs to be stepped twice, once for
3686 the instruction and once for the delay slot. */
3687 int step_through_delay
3688 = gdbarch_single_step_through_delay (gdbarch, frame);
3689 if (debug_infrun && step_through_delay)
3690 fprintf_unfiltered (gdb_stdlog, "infrun: step through delay\n");
3691 if (ecs->event_thread->step_range_end == 0 && step_through_delay)
3693 /* The user issued a continue when stopped at a breakpoint.
3694 Set up for another trap and get out of here. */
3695 ecs->event_thread->stepping_over_breakpoint = 1;
3699 else if (step_through_delay)
3701 /* The user issued a step when stopped at a breakpoint.
3702 Maybe we should stop, maybe we should not - the delay
3703 slot *might* correspond to a line of source. In any
3704 case, don't decide that here, just set
3705 ecs->stepping_over_breakpoint, making sure we
3706 single-step again before breakpoints are re-inserted. */
3707 ecs->event_thread->stepping_over_breakpoint = 1;
3711 /* Look at the cause of the stop, and decide what to do.
3712 The alternatives are:
3713 1) stop_stepping and return; to really stop and return to the debugger,
3714 2) keep_going and return to start up again
3715 (set ecs->event_thread->stepping_over_breakpoint to 1 to single step once)
3716 3) set ecs->random_signal to 1, and the decision between 1 and 2
3717 will be made according to the signal handling tables. */
3719 if (ecs->event_thread->stop_signal == TARGET_SIGNAL_TRAP
3720 || stop_soon == STOP_QUIETLY || stop_soon == STOP_QUIETLY_NO_SIGSTOP
3721 || stop_soon == STOP_QUIETLY_REMOTE)
3723 if (ecs->event_thread->stop_signal == TARGET_SIGNAL_TRAP && stop_after_trap)
3726 fprintf_unfiltered (gdb_stdlog, "infrun: stopped\n");
3727 stop_print_frame = 0;
3728 stop_stepping (ecs);
3732 /* This is originated from start_remote(), start_inferior() and
3733 shared libraries hook functions. */
3734 if (stop_soon == STOP_QUIETLY || stop_soon == STOP_QUIETLY_REMOTE)
3737 fprintf_unfiltered (gdb_stdlog, "infrun: quietly stopped\n");
3738 stop_stepping (ecs);
3742 /* This originates from attach_command(). We need to overwrite
3743 the stop_signal here, because some kernels don't ignore a
3744 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
3745 See more comments in inferior.h. On the other hand, if we
3746 get a non-SIGSTOP, report it to the user - assume the backend
3747 will handle the SIGSTOP if it should show up later.
3749 Also consider that the attach is complete when we see a
3750 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
3751 target extended-remote report it instead of a SIGSTOP
3752 (e.g. gdbserver). We already rely on SIGTRAP being our
3753 signal, so this is no exception.
3755 Also consider that the attach is complete when we see a
3756 TARGET_SIGNAL_0. In non-stop mode, GDB will explicitly tell
3757 the target to stop all threads of the inferior, in case the
3758 low level attach operation doesn't stop them implicitly. If
3759 they weren't stopped implicitly, then the stub will report a
3760 TARGET_SIGNAL_0, meaning: stopped for no particular reason
3761 other than GDB's request. */
3762 if (stop_soon == STOP_QUIETLY_NO_SIGSTOP
3763 && (ecs->event_thread->stop_signal == TARGET_SIGNAL_STOP
3764 || ecs->event_thread->stop_signal == TARGET_SIGNAL_TRAP
3765 || ecs->event_thread->stop_signal == TARGET_SIGNAL_0))
3767 stop_stepping (ecs);
3768 ecs->event_thread->stop_signal = TARGET_SIGNAL_0;
3772 /* See if there is a breakpoint at the current PC. */
3773 ecs->event_thread->stop_bpstat
3774 = bpstat_stop_status (get_regcache_aspace (get_current_regcache ()),
3775 stop_pc, ecs->ptid);
3777 /* Following in case break condition called a
3779 stop_print_frame = 1;
3781 /* This is where we handle "moribund" watchpoints. Unlike
3782 software breakpoints traps, hardware watchpoint traps are
3783 always distinguishable from random traps. If no high-level
3784 watchpoint is associated with the reported stop data address
3785 anymore, then the bpstat does not explain the signal ---
3786 simply make sure to ignore it if `stopped_by_watchpoint' is
3790 && ecs->event_thread->stop_signal == TARGET_SIGNAL_TRAP
3791 && !bpstat_explains_signal (ecs->event_thread->stop_bpstat)
3792 && stopped_by_watchpoint)
3793 fprintf_unfiltered (gdb_stdlog, "\
3794 infrun: no user watchpoint explains watchpoint SIGTRAP, ignoring\n");
3796 /* NOTE: cagney/2003-03-29: These two checks for a random signal
3797 at one stage in the past included checks for an inferior
3798 function call's call dummy's return breakpoint. The original
3799 comment, that went with the test, read:
3801 ``End of a stack dummy. Some systems (e.g. Sony news) give
3802 another signal besides SIGTRAP, so check here as well as
3805 If someone ever tries to get call dummys on a
3806 non-executable stack to work (where the target would stop
3807 with something like a SIGSEGV), then those tests might need
3808 to be re-instated. Given, however, that the tests were only
3809 enabled when momentary breakpoints were not being used, I
3810 suspect that it won't be the case.
3812 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
3813 be necessary for call dummies on a non-executable stack on
3816 if (ecs->event_thread->stop_signal == TARGET_SIGNAL_TRAP)
3818 = !(bpstat_explains_signal (ecs->event_thread->stop_bpstat)
3819 || stopped_by_watchpoint
3820 || ecs->event_thread->trap_expected
3821 || (ecs->event_thread->step_range_end
3822 && ecs->event_thread->step_resume_breakpoint == NULL));
3825 ecs->random_signal = !bpstat_explains_signal (ecs->event_thread->stop_bpstat);
3826 if (!ecs->random_signal)
3827 ecs->event_thread->stop_signal = TARGET_SIGNAL_TRAP;
3831 /* When we reach this point, we've pretty much decided
3832 that the reason for stopping must've been a random
3833 (unexpected) signal. */
3836 ecs->random_signal = 1;
3838 process_event_stop_test:
3840 /* Re-fetch current thread's frame in case we did a
3841 "goto process_event_stop_test" above. */
3842 frame = get_current_frame ();
3843 gdbarch = get_frame_arch (frame);
3845 /* For the program's own signals, act according to
3846 the signal handling tables. */
3848 if (ecs->random_signal)
3850 /* Signal not for debugging purposes. */
3852 struct inferior *inf = find_inferior_pid (ptid_get_pid (ecs->ptid));
3855 fprintf_unfiltered (gdb_stdlog, "infrun: random signal %d\n",
3856 ecs->event_thread->stop_signal);
3858 stopped_by_random_signal = 1;
3860 if (signal_print[ecs->event_thread->stop_signal])
3863 target_terminal_ours_for_output ();
3864 print_stop_reason (SIGNAL_RECEIVED, ecs->event_thread->stop_signal);
3866 /* Always stop on signals if we're either just gaining control
3867 of the program, or the user explicitly requested this thread
3868 to remain stopped. */
3869 if (stop_soon != NO_STOP_QUIETLY
3870 || ecs->event_thread->stop_requested
3872 && signal_stop_state (ecs->event_thread->stop_signal)))
3874 stop_stepping (ecs);
3877 /* If not going to stop, give terminal back
3878 if we took it away. */
3880 target_terminal_inferior ();
3882 /* Clear the signal if it should not be passed. */
3883 if (signal_program[ecs->event_thread->stop_signal] == 0)
3884 ecs->event_thread->stop_signal = TARGET_SIGNAL_0;
3886 if (ecs->event_thread->prev_pc == stop_pc
3887 && ecs->event_thread->trap_expected
3888 && ecs->event_thread->step_resume_breakpoint == NULL)
3890 /* We were just starting a new sequence, attempting to
3891 single-step off of a breakpoint and expecting a SIGTRAP.
3892 Instead this signal arrives. This signal will take us out
3893 of the stepping range so GDB needs to remember to, when
3894 the signal handler returns, resume stepping off that
3896 /* To simplify things, "continue" is forced to use the same
3897 code paths as single-step - set a breakpoint at the
3898 signal return address and then, once hit, step off that
3901 fprintf_unfiltered (gdb_stdlog,
3902 "infrun: signal arrived while stepping over "
3905 insert_step_resume_breakpoint_at_frame (frame);
3906 ecs->event_thread->step_after_step_resume_breakpoint = 1;
3911 if (ecs->event_thread->step_range_end != 0
3912 && ecs->event_thread->stop_signal != TARGET_SIGNAL_0
3913 && (ecs->event_thread->step_range_start <= stop_pc
3914 && stop_pc < ecs->event_thread->step_range_end)
3915 && frame_id_eq (get_stack_frame_id (frame),
3916 ecs->event_thread->step_stack_frame_id)
3917 && ecs->event_thread->step_resume_breakpoint == NULL)
3919 /* The inferior is about to take a signal that will take it
3920 out of the single step range. Set a breakpoint at the
3921 current PC (which is presumably where the signal handler
3922 will eventually return) and then allow the inferior to
3925 Note that this is only needed for a signal delivered
3926 while in the single-step range. Nested signals aren't a
3927 problem as they eventually all return. */
3929 fprintf_unfiltered (gdb_stdlog,
3930 "infrun: signal may take us out of "
3931 "single-step range\n");
3933 insert_step_resume_breakpoint_at_frame (frame);
3938 /* Note: step_resume_breakpoint may be non-NULL. This occures
3939 when either there's a nested signal, or when there's a
3940 pending signal enabled just as the signal handler returns
3941 (leaving the inferior at the step-resume-breakpoint without
3942 actually executing it). Either way continue until the
3943 breakpoint is really hit. */
3948 /* Handle cases caused by hitting a breakpoint. */
3950 CORE_ADDR jmp_buf_pc;
3951 struct bpstat_what what;
3953 what = bpstat_what (ecs->event_thread->stop_bpstat);
3955 if (what.call_dummy)
3957 stop_stack_dummy = what.call_dummy;
3960 switch (what.main_action)
3962 case BPSTAT_WHAT_SET_LONGJMP_RESUME:
3963 /* If we hit the breakpoint at longjmp while stepping, we
3964 install a momentary breakpoint at the target of the
3968 fprintf_unfiltered (gdb_stdlog,
3969 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME\n");
3971 ecs->event_thread->stepping_over_breakpoint = 1;
3973 if (!gdbarch_get_longjmp_target_p (gdbarch)
3974 || !gdbarch_get_longjmp_target (gdbarch, frame, &jmp_buf_pc))
3977 fprintf_unfiltered (gdb_stdlog, "\
3978 infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME (!gdbarch_get_longjmp_target)\n");
3983 /* We're going to replace the current step-resume breakpoint
3984 with a longjmp-resume breakpoint. */
3985 delete_step_resume_breakpoint (ecs->event_thread);
3987 /* Insert a breakpoint at resume address. */
3988 insert_longjmp_resume_breakpoint (gdbarch, jmp_buf_pc);
3993 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME:
3995 fprintf_unfiltered (gdb_stdlog,
3996 "infrun: BPSTAT_WHAT_CLEAR_LONGJMP_RESUME\n");
3998 gdb_assert (ecs->event_thread->step_resume_breakpoint != NULL);
3999 delete_step_resume_breakpoint (ecs->event_thread);
4001 ecs->event_thread->stop_step = 1;
4002 print_stop_reason (END_STEPPING_RANGE, 0);
4003 stop_stepping (ecs);
4006 case BPSTAT_WHAT_SINGLE:
4008 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_SINGLE\n");
4009 ecs->event_thread->stepping_over_breakpoint = 1;
4010 /* Still need to check other stuff, at least the case
4011 where we are stepping and step out of the right range. */
4014 case BPSTAT_WHAT_STOP_NOISY:
4016 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_NOISY\n");
4017 stop_print_frame = 1;
4019 /* We are about to nuke the step_resume_breakpointt via the
4020 cleanup chain, so no need to worry about it here. */
4022 stop_stepping (ecs);
4025 case BPSTAT_WHAT_STOP_SILENT:
4027 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STOP_SILENT\n");
4028 stop_print_frame = 0;
4030 /* We are about to nuke the step_resume_breakpoin via the
4031 cleanup chain, so no need to worry about it here. */
4033 stop_stepping (ecs);
4036 case BPSTAT_WHAT_STEP_RESUME:
4038 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_STEP_RESUME\n");
4040 delete_step_resume_breakpoint (ecs->event_thread);
4041 if (ecs->event_thread->step_after_step_resume_breakpoint)
4043 /* Back when the step-resume breakpoint was inserted, we
4044 were trying to single-step off a breakpoint. Go back
4046 ecs->event_thread->step_after_step_resume_breakpoint = 0;
4047 ecs->event_thread->stepping_over_breakpoint = 1;
4051 if (stop_pc == ecs->stop_func_start
4052 && execution_direction == EXEC_REVERSE)
4054 /* We are stepping over a function call in reverse, and
4055 just hit the step-resume breakpoint at the start
4056 address of the function. Go back to single-stepping,
4057 which should take us back to the function call. */
4058 ecs->event_thread->stepping_over_breakpoint = 1;
4064 case BPSTAT_WHAT_CHECK_SHLIBS:
4067 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_CHECK_SHLIBS\n");
4069 /* Check for any newly added shared libraries if we're
4070 supposed to be adding them automatically. Switch
4071 terminal for any messages produced by
4072 breakpoint_re_set. */
4073 target_terminal_ours_for_output ();
4074 /* NOTE: cagney/2003-11-25: Make certain that the target
4075 stack's section table is kept up-to-date. Architectures,
4076 (e.g., PPC64), use the section table to perform
4077 operations such as address => section name and hence
4078 require the table to contain all sections (including
4079 those found in shared libraries). */
4081 SOLIB_ADD (NULL, 0, ¤t_target, auto_solib_add);
4083 solib_add (NULL, 0, ¤t_target, auto_solib_add);
4085 target_terminal_inferior ();
4087 /* If requested, stop when the dynamic linker notifies
4088 gdb of events. This allows the user to get control
4089 and place breakpoints in initializer routines for
4090 dynamically loaded objects (among other things). */
4091 if (stop_on_solib_events || stop_stack_dummy)
4093 stop_stepping (ecs);
4098 /* We want to step over this breakpoint, then keep going. */
4099 ecs->event_thread->stepping_over_breakpoint = 1;
4105 case BPSTAT_WHAT_CHECK_JIT:
4107 fprintf_unfiltered (gdb_stdlog, "infrun: BPSTAT_WHAT_CHECK_JIT\n");
4109 /* Switch terminal for any messages produced by breakpoint_re_set. */
4110 target_terminal_ours_for_output ();
4112 jit_event_handler (gdbarch);
4114 target_terminal_inferior ();
4116 /* We want to step over this breakpoint, then keep going. */
4117 ecs->event_thread->stepping_over_breakpoint = 1;
4121 case BPSTAT_WHAT_LAST:
4122 /* Not a real code, but listed here to shut up gcc -Wall. */
4124 case BPSTAT_WHAT_KEEP_CHECKING:
4129 /* We come here if we hit a breakpoint but should not
4130 stop for it. Possibly we also were stepping
4131 and should stop for that. So fall through and
4132 test for stepping. But, if not stepping,
4135 /* In all-stop mode, if we're currently stepping but have stopped in
4136 some other thread, we need to switch back to the stepped thread. */
4139 struct thread_info *tp;
4140 tp = iterate_over_threads (currently_stepping_or_nexting_callback,
4144 /* However, if the current thread is blocked on some internal
4145 breakpoint, and we simply need to step over that breakpoint
4146 to get it going again, do that first. */
4147 if ((ecs->event_thread->trap_expected
4148 && ecs->event_thread->stop_signal != TARGET_SIGNAL_TRAP)
4149 || ecs->event_thread->stepping_over_breakpoint)
4155 /* If the stepping thread exited, then don't try to switch
4156 back and resume it, which could fail in several different
4157 ways depending on the target. Instead, just keep going.
4159 We can find a stepping dead thread in the thread list in
4162 - The target supports thread exit events, and when the
4163 target tries to delete the thread from the thread list,
4164 inferior_ptid pointed at the exiting thread. In such
4165 case, calling delete_thread does not really remove the
4166 thread from the list; instead, the thread is left listed,
4167 with 'exited' state.
4169 - The target's debug interface does not support thread
4170 exit events, and so we have no idea whatsoever if the
4171 previously stepping thread is still alive. For that
4172 reason, we need to synchronously query the target
4174 if (is_exited (tp->ptid)
4175 || !target_thread_alive (tp->ptid))
4178 fprintf_unfiltered (gdb_stdlog, "\
4179 infrun: not switching back to stepped thread, it has vanished\n");
4181 delete_thread (tp->ptid);
4186 /* Otherwise, we no longer expect a trap in the current thread.
4187 Clear the trap_expected flag before switching back -- this is
4188 what keep_going would do as well, if we called it. */
4189 ecs->event_thread->trap_expected = 0;
4192 fprintf_unfiltered (gdb_stdlog,
4193 "infrun: switching back to stepped thread\n");
4195 ecs->event_thread = tp;
4196 ecs->ptid = tp->ptid;
4197 context_switch (ecs->ptid);
4203 /* Are we stepping to get the inferior out of the dynamic linker's
4204 hook (and possibly the dld itself) after catching a shlib
4206 if (ecs->event_thread->stepping_through_solib_after_catch)
4208 #if defined(SOLIB_ADD)
4209 /* Have we reached our destination? If not, keep going. */
4210 if (SOLIB_IN_DYNAMIC_LINKER (PIDGET (ecs->ptid), stop_pc))
4213 fprintf_unfiltered (gdb_stdlog, "infrun: stepping in dynamic linker\n");
4214 ecs->event_thread->stepping_over_breakpoint = 1;
4220 fprintf_unfiltered (gdb_stdlog, "infrun: step past dynamic linker\n");
4221 /* Else, stop and report the catchpoint(s) whose triggering
4222 caused us to begin stepping. */
4223 ecs->event_thread->stepping_through_solib_after_catch = 0;
4224 bpstat_clear (&ecs->event_thread->stop_bpstat);
4225 ecs->event_thread->stop_bpstat
4226 = bpstat_copy (ecs->event_thread->stepping_through_solib_catchpoints);
4227 bpstat_clear (&ecs->event_thread->stepping_through_solib_catchpoints);
4228 stop_print_frame = 1;
4229 stop_stepping (ecs);
4233 if (ecs->event_thread->step_resume_breakpoint)
4236 fprintf_unfiltered (gdb_stdlog,
4237 "infrun: step-resume breakpoint is inserted\n");
4239 /* Having a step-resume breakpoint overrides anything
4240 else having to do with stepping commands until
4241 that breakpoint is reached. */
4246 if (ecs->event_thread->step_range_end == 0)
4249 fprintf_unfiltered (gdb_stdlog, "infrun: no stepping, continue\n");
4250 /* Likewise if we aren't even stepping. */
4255 /* Re-fetch current thread's frame in case the code above caused
4256 the frame cache to be re-initialized, making our FRAME variable
4257 a dangling pointer. */
4258 frame = get_current_frame ();
4260 /* If stepping through a line, keep going if still within it.
4262 Note that step_range_end is the address of the first instruction
4263 beyond the step range, and NOT the address of the last instruction
4266 Note also that during reverse execution, we may be stepping
4267 through a function epilogue and therefore must detect when
4268 the current-frame changes in the middle of a line. */
4270 if (stop_pc >= ecs->event_thread->step_range_start
4271 && stop_pc < ecs->event_thread->step_range_end
4272 && (execution_direction != EXEC_REVERSE
4273 || frame_id_eq (get_frame_id (frame),
4274 ecs->event_thread->step_frame_id)))
4278 (gdb_stdlog, "infrun: stepping inside range [%s-%s]\n",
4279 paddress (gdbarch, ecs->event_thread->step_range_start),
4280 paddress (gdbarch, ecs->event_thread->step_range_end));
4282 /* When stepping backward, stop at beginning of line range
4283 (unless it's the function entry point, in which case
4284 keep going back to the call point). */
4285 if (stop_pc == ecs->event_thread->step_range_start
4286 && stop_pc != ecs->stop_func_start
4287 && execution_direction == EXEC_REVERSE)
4289 ecs->event_thread->stop_step = 1;
4290 print_stop_reason (END_STEPPING_RANGE, 0);
4291 stop_stepping (ecs);
4299 /* We stepped out of the stepping range. */
4301 /* If we are stepping at the source level and entered the runtime
4302 loader dynamic symbol resolution code...
4304 EXEC_FORWARD: we keep on single stepping until we exit the run
4305 time loader code and reach the callee's address.
4307 EXEC_REVERSE: we've already executed the callee (backward), and
4308 the runtime loader code is handled just like any other
4309 undebuggable function call. Now we need only keep stepping
4310 backward through the trampoline code, and that's handled further
4311 down, so there is nothing for us to do here. */
4313 if (execution_direction != EXEC_REVERSE
4314 && ecs->event_thread->step_over_calls == STEP_OVER_UNDEBUGGABLE
4315 && in_solib_dynsym_resolve_code (stop_pc))
4317 CORE_ADDR pc_after_resolver =
4318 gdbarch_skip_solib_resolver (gdbarch, stop_pc);
4321 fprintf_unfiltered (gdb_stdlog, "infrun: stepped into dynsym resolve code\n");
4323 if (pc_after_resolver)
4325 /* Set up a step-resume breakpoint at the address
4326 indicated by SKIP_SOLIB_RESOLVER. */
4327 struct symtab_and_line sr_sal;
4329 sr_sal.pc = pc_after_resolver;
4330 sr_sal.pspace = get_frame_program_space (frame);
4332 insert_step_resume_breakpoint_at_sal (gdbarch,
4333 sr_sal, null_frame_id);
4340 if (ecs->event_thread->step_range_end != 1
4341 && (ecs->event_thread->step_over_calls == STEP_OVER_UNDEBUGGABLE
4342 || ecs->event_thread->step_over_calls == STEP_OVER_ALL)
4343 && get_frame_type (frame) == SIGTRAMP_FRAME)
4346 fprintf_unfiltered (gdb_stdlog, "infrun: stepped into signal trampoline\n");
4347 /* The inferior, while doing a "step" or "next", has ended up in
4348 a signal trampoline (either by a signal being delivered or by
4349 the signal handler returning). Just single-step until the
4350 inferior leaves the trampoline (either by calling the handler
4356 /* Check for subroutine calls. The check for the current frame
4357 equalling the step ID is not necessary - the check of the
4358 previous frame's ID is sufficient - but it is a common case and
4359 cheaper than checking the previous frame's ID.
4361 NOTE: frame_id_eq will never report two invalid frame IDs as
4362 being equal, so to get into this block, both the current and
4363 previous frame must have valid frame IDs. */
4364 /* The outer_frame_id check is a heuristic to detect stepping
4365 through startup code. If we step over an instruction which
4366 sets the stack pointer from an invalid value to a valid value,
4367 we may detect that as a subroutine call from the mythical
4368 "outermost" function. This could be fixed by marking
4369 outermost frames as !stack_p,code_p,special_p. Then the
4370 initial outermost frame, before sp was valid, would
4371 have code_addr == &_start. See the comment in frame_id_eq
4373 if (!frame_id_eq (get_stack_frame_id (frame),
4374 ecs->event_thread->step_stack_frame_id)
4375 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
4376 ecs->event_thread->step_stack_frame_id)
4377 && (!frame_id_eq (ecs->event_thread->step_stack_frame_id,
4379 || step_start_function != find_pc_function (stop_pc))))
4381 CORE_ADDR real_stop_pc;
4384 fprintf_unfiltered (gdb_stdlog, "infrun: stepped into subroutine\n");
4386 if ((ecs->event_thread->step_over_calls == STEP_OVER_NONE)
4387 || ((ecs->event_thread->step_range_end == 1)
4388 && in_prologue (gdbarch, ecs->event_thread->prev_pc,
4389 ecs->stop_func_start)))
4391 /* I presume that step_over_calls is only 0 when we're
4392 supposed to be stepping at the assembly language level
4393 ("stepi"). Just stop. */
4394 /* Also, maybe we just did a "nexti" inside a prolog, so we
4395 thought it was a subroutine call but it was not. Stop as
4397 /* And this works the same backward as frontward. MVS */
4398 ecs->event_thread->stop_step = 1;
4399 print_stop_reason (END_STEPPING_RANGE, 0);
4400 stop_stepping (ecs);
4404 /* Reverse stepping through solib trampolines. */
4406 if (execution_direction == EXEC_REVERSE
4407 && ecs->event_thread->step_over_calls != STEP_OVER_NONE
4408 && (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc)
4409 || (ecs->stop_func_start == 0
4410 && in_solib_dynsym_resolve_code (stop_pc))))
4412 /* Any solib trampoline code can be handled in reverse
4413 by simply continuing to single-step. We have already
4414 executed the solib function (backwards), and a few
4415 steps will take us back through the trampoline to the
4421 if (ecs->event_thread->step_over_calls == STEP_OVER_ALL)
4423 /* We're doing a "next".
4425 Normal (forward) execution: set a breakpoint at the
4426 callee's return address (the address at which the caller
4429 Reverse (backward) execution. set the step-resume
4430 breakpoint at the start of the function that we just
4431 stepped into (backwards), and continue to there. When we
4432 get there, we'll need to single-step back to the caller. */
4434 if (execution_direction == EXEC_REVERSE)
4436 struct symtab_and_line sr_sal;
4438 /* Normal function call return (static or dynamic). */
4440 sr_sal.pc = ecs->stop_func_start;
4441 sr_sal.pspace = get_frame_program_space (frame);
4442 insert_step_resume_breakpoint_at_sal (gdbarch,
4443 sr_sal, null_frame_id);
4446 insert_step_resume_breakpoint_at_caller (frame);
4452 /* If we are in a function call trampoline (a stub between the
4453 calling routine and the real function), locate the real
4454 function. That's what tells us (a) whether we want to step
4455 into it at all, and (b) what prologue we want to run to the
4456 end of, if we do step into it. */
4457 real_stop_pc = skip_language_trampoline (frame, stop_pc);
4458 if (real_stop_pc == 0)
4459 real_stop_pc = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc);
4460 if (real_stop_pc != 0)
4461 ecs->stop_func_start = real_stop_pc;
4463 if (real_stop_pc != 0 && in_solib_dynsym_resolve_code (real_stop_pc))
4465 struct symtab_and_line sr_sal;
4467 sr_sal.pc = ecs->stop_func_start;
4468 sr_sal.pspace = get_frame_program_space (frame);
4470 insert_step_resume_breakpoint_at_sal (gdbarch,
4471 sr_sal, null_frame_id);
4476 /* If we have line number information for the function we are
4477 thinking of stepping into, step into it.
4479 If there are several symtabs at that PC (e.g. with include
4480 files), just want to know whether *any* of them have line
4481 numbers. find_pc_line handles this. */
4483 struct symtab_and_line tmp_sal;
4485 tmp_sal = find_pc_line (ecs->stop_func_start, 0);
4486 tmp_sal.pspace = get_frame_program_space (frame);
4487 if (tmp_sal.line != 0)
4489 if (execution_direction == EXEC_REVERSE)
4490 handle_step_into_function_backward (gdbarch, ecs);
4492 handle_step_into_function (gdbarch, ecs);
4497 /* If we have no line number and the step-stop-if-no-debug is
4498 set, we stop the step so that the user has a chance to switch
4499 in assembly mode. */
4500 if (ecs->event_thread->step_over_calls == STEP_OVER_UNDEBUGGABLE
4501 && step_stop_if_no_debug)
4503 ecs->event_thread->stop_step = 1;
4504 print_stop_reason (END_STEPPING_RANGE, 0);
4505 stop_stepping (ecs);
4509 if (execution_direction == EXEC_REVERSE)
4511 /* Set a breakpoint at callee's start address.
4512 From there we can step once and be back in the caller. */
4513 struct symtab_and_line sr_sal;
4515 sr_sal.pc = ecs->stop_func_start;
4516 sr_sal.pspace = get_frame_program_space (frame);
4517 insert_step_resume_breakpoint_at_sal (gdbarch,
4518 sr_sal, null_frame_id);
4521 /* Set a breakpoint at callee's return address (the address
4522 at which the caller will resume). */
4523 insert_step_resume_breakpoint_at_caller (frame);
4529 /* Reverse stepping through solib trampolines. */
4531 if (execution_direction == EXEC_REVERSE
4532 && ecs->event_thread->step_over_calls != STEP_OVER_NONE)
4534 if (gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc)
4535 || (ecs->stop_func_start == 0
4536 && in_solib_dynsym_resolve_code (stop_pc)))
4538 /* Any solib trampoline code can be handled in reverse
4539 by simply continuing to single-step. We have already
4540 executed the solib function (backwards), and a few
4541 steps will take us back through the trampoline to the
4546 else if (in_solib_dynsym_resolve_code (stop_pc))
4548 /* Stepped backward into the solib dynsym resolver.
4549 Set a breakpoint at its start and continue, then
4550 one more step will take us out. */
4551 struct symtab_and_line sr_sal;
4553 sr_sal.pc = ecs->stop_func_start;
4554 sr_sal.pspace = get_frame_program_space (frame);
4555 insert_step_resume_breakpoint_at_sal (gdbarch,
4556 sr_sal, null_frame_id);
4562 /* If we're in the return path from a shared library trampoline,
4563 we want to proceed through the trampoline when stepping. */
4564 if (gdbarch_in_solib_return_trampoline (gdbarch,
4565 stop_pc, ecs->stop_func_name))
4567 /* Determine where this trampoline returns. */
4568 CORE_ADDR real_stop_pc;
4569 real_stop_pc = gdbarch_skip_trampoline_code (gdbarch, frame, stop_pc);
4572 fprintf_unfiltered (gdb_stdlog, "infrun: stepped into solib return tramp\n");
4574 /* Only proceed through if we know where it's going. */
4577 /* And put the step-breakpoint there and go until there. */
4578 struct symtab_and_line sr_sal;
4580 init_sal (&sr_sal); /* initialize to zeroes */
4581 sr_sal.pc = real_stop_pc;
4582 sr_sal.section = find_pc_overlay (sr_sal.pc);
4583 sr_sal.pspace = get_frame_program_space (frame);
4585 /* Do not specify what the fp should be when we stop since
4586 on some machines the prologue is where the new fp value
4588 insert_step_resume_breakpoint_at_sal (gdbarch,
4589 sr_sal, null_frame_id);
4591 /* Restart without fiddling with the step ranges or
4598 stop_pc_sal = find_pc_line (stop_pc, 0);
4600 /* NOTE: tausq/2004-05-24: This if block used to be done before all
4601 the trampoline processing logic, however, there are some trampolines
4602 that have no names, so we should do trampoline handling first. */
4603 if (ecs->event_thread->step_over_calls == STEP_OVER_UNDEBUGGABLE
4604 && ecs->stop_func_name == NULL
4605 && stop_pc_sal.line == 0)
4608 fprintf_unfiltered (gdb_stdlog, "infrun: stepped into undebuggable function\n");
4610 /* The inferior just stepped into, or returned to, an
4611 undebuggable function (where there is no debugging information
4612 and no line number corresponding to the address where the
4613 inferior stopped). Since we want to skip this kind of code,
4614 we keep going until the inferior returns from this
4615 function - unless the user has asked us not to (via
4616 set step-mode) or we no longer know how to get back
4617 to the call site. */
4618 if (step_stop_if_no_debug
4619 || !frame_id_p (frame_unwind_caller_id (frame)))
4621 /* If we have no line number and the step-stop-if-no-debug
4622 is set, we stop the step so that the user has a chance to
4623 switch in assembly mode. */
4624 ecs->event_thread->stop_step = 1;
4625 print_stop_reason (END_STEPPING_RANGE, 0);
4626 stop_stepping (ecs);
4631 /* Set a breakpoint at callee's return address (the address
4632 at which the caller will resume). */
4633 insert_step_resume_breakpoint_at_caller (frame);
4639 if (ecs->event_thread->step_range_end == 1)
4641 /* It is stepi or nexti. We always want to stop stepping after
4644 fprintf_unfiltered (gdb_stdlog, "infrun: stepi/nexti\n");
4645 ecs->event_thread->stop_step = 1;
4646 print_stop_reason (END_STEPPING_RANGE, 0);
4647 stop_stepping (ecs);
4651 if (stop_pc_sal.line == 0)
4653 /* We have no line number information. That means to stop
4654 stepping (does this always happen right after one instruction,
4655 when we do "s" in a function with no line numbers,
4656 or can this happen as a result of a return or longjmp?). */
4658 fprintf_unfiltered (gdb_stdlog, "infrun: no line number info\n");
4659 ecs->event_thread->stop_step = 1;
4660 print_stop_reason (END_STEPPING_RANGE, 0);
4661 stop_stepping (ecs);
4665 /* Look for "calls" to inlined functions, part one. If the inline
4666 frame machinery detected some skipped call sites, we have entered
4667 a new inline function. */
4669 if (frame_id_eq (get_frame_id (get_current_frame ()),
4670 ecs->event_thread->step_frame_id)
4671 && inline_skipped_frames (ecs->ptid))
4673 struct symtab_and_line call_sal;
4676 fprintf_unfiltered (gdb_stdlog,
4677 "infrun: stepped into inlined function\n");
4679 find_frame_sal (get_current_frame (), &call_sal);
4681 if (ecs->event_thread->step_over_calls != STEP_OVER_ALL)
4683 /* For "step", we're going to stop. But if the call site
4684 for this inlined function is on the same source line as
4685 we were previously stepping, go down into the function
4686 first. Otherwise stop at the call site. */
4688 if (call_sal.line == ecs->event_thread->current_line
4689 && call_sal.symtab == ecs->event_thread->current_symtab)
4690 step_into_inline_frame (ecs->ptid);
4692 ecs->event_thread->stop_step = 1;
4693 print_stop_reason (END_STEPPING_RANGE, 0);
4694 stop_stepping (ecs);
4699 /* For "next", we should stop at the call site if it is on a
4700 different source line. Otherwise continue through the
4701 inlined function. */
4702 if (call_sal.line == ecs->event_thread->current_line
4703 && call_sal.symtab == ecs->event_thread->current_symtab)
4707 ecs->event_thread->stop_step = 1;
4708 print_stop_reason (END_STEPPING_RANGE, 0);
4709 stop_stepping (ecs);
4715 /* Look for "calls" to inlined functions, part two. If we are still
4716 in the same real function we were stepping through, but we have
4717 to go further up to find the exact frame ID, we are stepping
4718 through a more inlined call beyond its call site. */
4720 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
4721 && !frame_id_eq (get_frame_id (get_current_frame ()),
4722 ecs->event_thread->step_frame_id)
4723 && stepped_in_from (get_current_frame (),
4724 ecs->event_thread->step_frame_id))
4727 fprintf_unfiltered (gdb_stdlog,
4728 "infrun: stepping through inlined function\n");
4730 if (ecs->event_thread->step_over_calls == STEP_OVER_ALL)
4734 ecs->event_thread->stop_step = 1;
4735 print_stop_reason (END_STEPPING_RANGE, 0);
4736 stop_stepping (ecs);
4741 if ((stop_pc == stop_pc_sal.pc)
4742 && (ecs->event_thread->current_line != stop_pc_sal.line
4743 || ecs->event_thread->current_symtab != stop_pc_sal.symtab))
4745 /* We are at the start of a different line. So stop. Note that
4746 we don't stop if we step into the middle of a different line.
4747 That is said to make things like for (;;) statements work
4750 fprintf_unfiltered (gdb_stdlog, "infrun: stepped to a different line\n");
4751 ecs->event_thread->stop_step = 1;
4752 print_stop_reason (END_STEPPING_RANGE, 0);
4753 stop_stepping (ecs);
4757 /* We aren't done stepping.
4759 Optimize by setting the stepping range to the line.
4760 (We might not be in the original line, but if we entered a
4761 new line in mid-statement, we continue stepping. This makes
4762 things like for(;;) statements work better.) */
4764 ecs->event_thread->step_range_start = stop_pc_sal.pc;
4765 ecs->event_thread->step_range_end = stop_pc_sal.end;
4766 set_step_info (frame, stop_pc_sal);
4769 fprintf_unfiltered (gdb_stdlog, "infrun: keep going\n");
4773 /* Is thread TP in the middle of single-stepping? */
4776 currently_stepping (struct thread_info *tp)
4778 return ((tp->step_range_end && tp->step_resume_breakpoint == NULL)
4779 || tp->trap_expected
4780 || tp->stepping_through_solib_after_catch
4781 || bpstat_should_step ());
4784 /* Returns true if any thread *but* the one passed in "data" is in the
4785 middle of stepping or of handling a "next". */
4788 currently_stepping_or_nexting_callback (struct thread_info *tp, void *data)
4793 return (tp->step_range_end
4794 || tp->trap_expected
4795 || tp->stepping_through_solib_after_catch);
4798 /* Inferior has stepped into a subroutine call with source code that
4799 we should not step over. Do step to the first line of code in
4803 handle_step_into_function (struct gdbarch *gdbarch,
4804 struct execution_control_state *ecs)
4807 struct symtab_and_line stop_func_sal, sr_sal;
4809 s = find_pc_symtab (stop_pc);
4810 if (s && s->language != language_asm)
4811 ecs->stop_func_start = gdbarch_skip_prologue (gdbarch,
4812 ecs->stop_func_start);
4814 stop_func_sal = find_pc_line (ecs->stop_func_start, 0);
4815 /* Use the step_resume_break to step until the end of the prologue,
4816 even if that involves jumps (as it seems to on the vax under
4818 /* If the prologue ends in the middle of a source line, continue to
4819 the end of that source line (if it is still within the function).
4820 Otherwise, just go to end of prologue. */
4821 if (stop_func_sal.end
4822 && stop_func_sal.pc != ecs->stop_func_start
4823 && stop_func_sal.end < ecs->stop_func_end)
4824 ecs->stop_func_start = stop_func_sal.end;
4826 /* Architectures which require breakpoint adjustment might not be able
4827 to place a breakpoint at the computed address. If so, the test
4828 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
4829 ecs->stop_func_start to an address at which a breakpoint may be
4830 legitimately placed.
4832 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
4833 made, GDB will enter an infinite loop when stepping through
4834 optimized code consisting of VLIW instructions which contain
4835 subinstructions corresponding to different source lines. On
4836 FR-V, it's not permitted to place a breakpoint on any but the
4837 first subinstruction of a VLIW instruction. When a breakpoint is
4838 set, GDB will adjust the breakpoint address to the beginning of
4839 the VLIW instruction. Thus, we need to make the corresponding
4840 adjustment here when computing the stop address. */
4842 if (gdbarch_adjust_breakpoint_address_p (gdbarch))
4844 ecs->stop_func_start
4845 = gdbarch_adjust_breakpoint_address (gdbarch,
4846 ecs->stop_func_start);
4849 if (ecs->stop_func_start == stop_pc)
4851 /* We are already there: stop now. */
4852 ecs->event_thread->stop_step = 1;
4853 print_stop_reason (END_STEPPING_RANGE, 0);
4854 stop_stepping (ecs);
4859 /* Put the step-breakpoint there and go until there. */
4860 init_sal (&sr_sal); /* initialize to zeroes */
4861 sr_sal.pc = ecs->stop_func_start;
4862 sr_sal.section = find_pc_overlay (ecs->stop_func_start);
4863 sr_sal.pspace = get_frame_program_space (get_current_frame ());
4865 /* Do not specify what the fp should be when we stop since on
4866 some machines the prologue is where the new fp value is
4868 insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal, null_frame_id);
4870 /* And make sure stepping stops right away then. */
4871 ecs->event_thread->step_range_end = ecs->event_thread->step_range_start;
4876 /* Inferior has stepped backward into a subroutine call with source
4877 code that we should not step over. Do step to the beginning of the
4878 last line of code in it. */
4881 handle_step_into_function_backward (struct gdbarch *gdbarch,
4882 struct execution_control_state *ecs)
4885 struct symtab_and_line stop_func_sal;
4887 s = find_pc_symtab (stop_pc);
4888 if (s && s->language != language_asm)
4889 ecs->stop_func_start = gdbarch_skip_prologue (gdbarch,
4890 ecs->stop_func_start);
4892 stop_func_sal = find_pc_line (stop_pc, 0);
4894 /* OK, we're just going to keep stepping here. */
4895 if (stop_func_sal.pc == stop_pc)
4897 /* We're there already. Just stop stepping now. */
4898 ecs->event_thread->stop_step = 1;
4899 print_stop_reason (END_STEPPING_RANGE, 0);
4900 stop_stepping (ecs);
4904 /* Else just reset the step range and keep going.
4905 No step-resume breakpoint, they don't work for
4906 epilogues, which can have multiple entry paths. */
4907 ecs->event_thread->step_range_start = stop_func_sal.pc;
4908 ecs->event_thread->step_range_end = stop_func_sal.end;
4914 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
4915 This is used to both functions and to skip over code. */
4918 insert_step_resume_breakpoint_at_sal (struct gdbarch *gdbarch,
4919 struct symtab_and_line sr_sal,
4920 struct frame_id sr_id)
4922 /* There should never be more than one step-resume or longjmp-resume
4923 breakpoint per thread, so we should never be setting a new
4924 step_resume_breakpoint when one is already active. */
4925 gdb_assert (inferior_thread ()->step_resume_breakpoint == NULL);
4928 fprintf_unfiltered (gdb_stdlog,
4929 "infrun: inserting step-resume breakpoint at %s\n",
4930 paddress (gdbarch, sr_sal.pc));
4932 inferior_thread ()->step_resume_breakpoint
4933 = set_momentary_breakpoint (gdbarch, sr_sal, sr_id, bp_step_resume);
4936 /* Insert a "step-resume breakpoint" at RETURN_FRAME.pc. This is used
4937 to skip a potential signal handler.
4939 This is called with the interrupted function's frame. The signal
4940 handler, when it returns, will resume the interrupted function at
4944 insert_step_resume_breakpoint_at_frame (struct frame_info *return_frame)
4946 struct symtab_and_line sr_sal;
4947 struct gdbarch *gdbarch;
4949 gdb_assert (return_frame != NULL);
4950 init_sal (&sr_sal); /* initialize to zeros */
4952 gdbarch = get_frame_arch (return_frame);
4953 sr_sal.pc = gdbarch_addr_bits_remove (gdbarch, get_frame_pc (return_frame));
4954 sr_sal.section = find_pc_overlay (sr_sal.pc);
4955 sr_sal.pspace = get_frame_program_space (return_frame);
4957 insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal,
4958 get_stack_frame_id (return_frame));
4961 /* Similar to insert_step_resume_breakpoint_at_frame, except
4962 but a breakpoint at the previous frame's PC. This is used to
4963 skip a function after stepping into it (for "next" or if the called
4964 function has no debugging information).
4966 The current function has almost always been reached by single
4967 stepping a call or return instruction. NEXT_FRAME belongs to the
4968 current function, and the breakpoint will be set at the caller's
4971 This is a separate function rather than reusing
4972 insert_step_resume_breakpoint_at_frame in order to avoid
4973 get_prev_frame, which may stop prematurely (see the implementation
4974 of frame_unwind_caller_id for an example). */
4977 insert_step_resume_breakpoint_at_caller (struct frame_info *next_frame)
4979 struct symtab_and_line sr_sal;
4980 struct gdbarch *gdbarch;
4982 /* We shouldn't have gotten here if we don't know where the call site
4984 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame)));
4986 init_sal (&sr_sal); /* initialize to zeros */
4988 gdbarch = frame_unwind_caller_arch (next_frame);
4989 sr_sal.pc = gdbarch_addr_bits_remove (gdbarch,
4990 frame_unwind_caller_pc (next_frame));
4991 sr_sal.section = find_pc_overlay (sr_sal.pc);
4992 sr_sal.pspace = frame_unwind_program_space (next_frame);
4994 insert_step_resume_breakpoint_at_sal (gdbarch, sr_sal,
4995 frame_unwind_caller_id (next_frame));
4998 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
4999 new breakpoint at the target of a jmp_buf. The handling of
5000 longjmp-resume uses the same mechanisms used for handling
5001 "step-resume" breakpoints. */
5004 insert_longjmp_resume_breakpoint (struct gdbarch *gdbarch, CORE_ADDR pc)
5006 /* There should never be more than one step-resume or longjmp-resume
5007 breakpoint per thread, so we should never be setting a new
5008 longjmp_resume_breakpoint when one is already active. */
5009 gdb_assert (inferior_thread ()->step_resume_breakpoint == NULL);
5012 fprintf_unfiltered (gdb_stdlog,
5013 "infrun: inserting longjmp-resume breakpoint at %s\n",
5014 paddress (gdbarch, pc));
5016 inferior_thread ()->step_resume_breakpoint =
5017 set_momentary_breakpoint_at_pc (gdbarch, pc, bp_longjmp_resume);
5021 stop_stepping (struct execution_control_state *ecs)
5024 fprintf_unfiltered (gdb_stdlog, "infrun: stop_stepping\n");
5026 /* Let callers know we don't want to wait for the inferior anymore. */
5027 ecs->wait_some_more = 0;
5030 /* This function handles various cases where we need to continue
5031 waiting for the inferior. */
5032 /* (Used to be the keep_going: label in the old wait_for_inferior) */
5035 keep_going (struct execution_control_state *ecs)
5037 /* Make sure normal_stop is called if we get a QUIT handled before
5039 struct cleanup *old_cleanups = make_cleanup (resume_cleanups, 0);
5041 /* Save the pc before execution, to compare with pc after stop. */
5042 ecs->event_thread->prev_pc
5043 = regcache_read_pc (get_thread_regcache (ecs->ptid));
5045 /* If we did not do break;, it means we should keep running the
5046 inferior and not return to debugger. */
5048 if (ecs->event_thread->trap_expected
5049 && ecs->event_thread->stop_signal != TARGET_SIGNAL_TRAP)
5051 /* We took a signal (which we are supposed to pass through to
5052 the inferior, else we'd not get here) and we haven't yet
5053 gotten our trap. Simply continue. */
5055 discard_cleanups (old_cleanups);
5056 resume (currently_stepping (ecs->event_thread),
5057 ecs->event_thread->stop_signal);
5061 /* Either the trap was not expected, but we are continuing
5062 anyway (the user asked that this signal be passed to the
5065 The signal was SIGTRAP, e.g. it was our signal, but we
5066 decided we should resume from it.
5068 We're going to run this baby now!
5070 Note that insert_breakpoints won't try to re-insert
5071 already inserted breakpoints. Therefore, we don't
5072 care if breakpoints were already inserted, or not. */
5074 if (ecs->event_thread->stepping_over_breakpoint)
5076 struct regcache *thread_regcache = get_thread_regcache (ecs->ptid);
5077 if (!use_displaced_stepping (get_regcache_arch (thread_regcache)))
5078 /* Since we can't do a displaced step, we have to remove
5079 the breakpoint while we step it. To keep things
5080 simple, we remove them all. */
5081 remove_breakpoints ();
5085 struct gdb_exception e;
5086 /* Stop stepping when inserting breakpoints
5088 TRY_CATCH (e, RETURN_MASK_ERROR)
5090 insert_breakpoints ();
5094 exception_print (gdb_stderr, e);
5095 stop_stepping (ecs);
5100 ecs->event_thread->trap_expected = ecs->event_thread->stepping_over_breakpoint;
5102 /* Do not deliver SIGNAL_TRAP (except when the user explicitly
5103 specifies that such a signal should be delivered to the
5106 Typically, this would occure when a user is debugging a
5107 target monitor on a simulator: the target monitor sets a
5108 breakpoint; the simulator encounters this break-point and
5109 halts the simulation handing control to GDB; GDB, noteing
5110 that the break-point isn't valid, returns control back to the
5111 simulator; the simulator then delivers the hardware
5112 equivalent of a SIGNAL_TRAP to the program being debugged. */
5114 if (ecs->event_thread->stop_signal == TARGET_SIGNAL_TRAP
5115 && !signal_program[ecs->event_thread->stop_signal])
5116 ecs->event_thread->stop_signal = TARGET_SIGNAL_0;
5118 discard_cleanups (old_cleanups);
5119 resume (currently_stepping (ecs->event_thread),
5120 ecs->event_thread->stop_signal);
5123 prepare_to_wait (ecs);
5126 /* This function normally comes after a resume, before
5127 handle_inferior_event exits. It takes care of any last bits of
5128 housekeeping, and sets the all-important wait_some_more flag. */
5131 prepare_to_wait (struct execution_control_state *ecs)
5134 fprintf_unfiltered (gdb_stdlog, "infrun: prepare_to_wait\n");
5136 /* This is the old end of the while loop. Let everybody know we
5137 want to wait for the inferior some more and get called again
5139 ecs->wait_some_more = 1;
5142 /* Print why the inferior has stopped. We always print something when
5143 the inferior exits, or receives a signal. The rest of the cases are
5144 dealt with later on in normal_stop() and print_it_typical(). Ideally
5145 there should be a call to this function from handle_inferior_event()
5146 each time stop_stepping() is called.*/
5148 print_stop_reason (enum inferior_stop_reason stop_reason, int stop_info)
5150 switch (stop_reason)
5152 case END_STEPPING_RANGE:
5153 /* We are done with a step/next/si/ni command. */
5154 /* For now print nothing. */
5155 /* Print a message only if not in the middle of doing a "step n"
5156 operation for n > 1 */
5157 if (!inferior_thread ()->step_multi
5158 || !inferior_thread ()->stop_step)
5159 if (ui_out_is_mi_like_p (uiout))
5162 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE));
5165 /* The inferior was terminated by a signal. */
5166 annotate_signalled ();
5167 if (ui_out_is_mi_like_p (uiout))
5170 async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED));
5171 ui_out_text (uiout, "\nProgram terminated with signal ");
5172 annotate_signal_name ();
5173 ui_out_field_string (uiout, "signal-name",
5174 target_signal_to_name (stop_info));
5175 annotate_signal_name_end ();
5176 ui_out_text (uiout, ", ");
5177 annotate_signal_string ();
5178 ui_out_field_string (uiout, "signal-meaning",
5179 target_signal_to_string (stop_info));
5180 annotate_signal_string_end ();
5181 ui_out_text (uiout, ".\n");
5182 ui_out_text (uiout, "The program no longer exists.\n");
5185 /* The inferior program is finished. */
5186 annotate_exited (stop_info);
5189 if (ui_out_is_mi_like_p (uiout))
5190 ui_out_field_string (uiout, "reason",
5191 async_reason_lookup (EXEC_ASYNC_EXITED));
5192 ui_out_text (uiout, "\nProgram exited with code ");
5193 ui_out_field_fmt (uiout, "exit-code", "0%o",
5194 (unsigned int) stop_info);
5195 ui_out_text (uiout, ".\n");
5199 if (ui_out_is_mi_like_p (uiout))
5202 async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY));
5203 ui_out_text (uiout, "\nProgram exited normally.\n");
5205 /* Support the --return-child-result option. */
5206 return_child_result_value = stop_info;
5208 case SIGNAL_RECEIVED:
5209 /* Signal received. The signal table tells us to print about
5213 if (stop_info == TARGET_SIGNAL_0 && !ui_out_is_mi_like_p (uiout))
5215 struct thread_info *t = inferior_thread ();
5217 ui_out_text (uiout, "\n[");
5218 ui_out_field_string (uiout, "thread-name",
5219 target_pid_to_str (t->ptid));
5220 ui_out_field_fmt (uiout, "thread-id", "] #%d", t->num);
5221 ui_out_text (uiout, " stopped");
5225 ui_out_text (uiout, "\nProgram received signal ");
5226 annotate_signal_name ();
5227 if (ui_out_is_mi_like_p (uiout))
5229 (uiout, "reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED));
5230 ui_out_field_string (uiout, "signal-name",
5231 target_signal_to_name (stop_info));
5232 annotate_signal_name_end ();
5233 ui_out_text (uiout, ", ");
5234 annotate_signal_string ();
5235 ui_out_field_string (uiout, "signal-meaning",
5236 target_signal_to_string (stop_info));
5237 annotate_signal_string_end ();
5239 ui_out_text (uiout, ".\n");
5242 /* Reverse execution: target ran out of history info. */
5243 ui_out_text (uiout, "\nNo more reverse-execution history.\n");
5246 internal_error (__FILE__, __LINE__,
5247 _("print_stop_reason: unrecognized enum value"));
5253 /* Here to return control to GDB when the inferior stops for real.
5254 Print appropriate messages, remove breakpoints, give terminal our modes.
5256 STOP_PRINT_FRAME nonzero means print the executing frame
5257 (pc, function, args, file, line number and line text).
5258 BREAKPOINTS_FAILED nonzero means stop was due to error
5259 attempting to insert breakpoints. */
5264 struct target_waitstatus last;
5266 struct cleanup *old_chain = make_cleanup (null_cleanup, NULL);
5268 get_last_target_status (&last_ptid, &last);
5270 /* If an exception is thrown from this point on, make sure to
5271 propagate GDB's knowledge of the executing state to the
5272 frontend/user running state. A QUIT is an easy exception to see
5273 here, so do this before any filtered output. */
5275 make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
5276 else if (last.kind != TARGET_WAITKIND_SIGNALLED
5277 && last.kind != TARGET_WAITKIND_EXITED)
5278 make_cleanup (finish_thread_state_cleanup, &inferior_ptid);
5280 /* In non-stop mode, we don't want GDB to switch threads behind the
5281 user's back, to avoid races where the user is typing a command to
5282 apply to thread x, but GDB switches to thread y before the user
5283 finishes entering the command. */
5285 /* As with the notification of thread events, we want to delay
5286 notifying the user that we've switched thread context until
5287 the inferior actually stops.
5289 There's no point in saying anything if the inferior has exited.
5290 Note that SIGNALLED here means "exited with a signal", not
5291 "received a signal". */
5293 && !ptid_equal (previous_inferior_ptid, inferior_ptid)
5294 && target_has_execution
5295 && last.kind != TARGET_WAITKIND_SIGNALLED
5296 && last.kind != TARGET_WAITKIND_EXITED)
5298 target_terminal_ours_for_output ();
5299 printf_filtered (_("[Switching to %s]\n"),
5300 target_pid_to_str (inferior_ptid));
5301 annotate_thread_changed ();
5302 previous_inferior_ptid = inferior_ptid;
5305 if (!breakpoints_always_inserted_mode () && target_has_execution)
5307 if (remove_breakpoints ())
5309 target_terminal_ours_for_output ();
5310 printf_filtered (_("\
5311 Cannot remove breakpoints because program is no longer writable.\n\
5312 Further execution is probably impossible.\n"));
5316 /* If an auto-display called a function and that got a signal,
5317 delete that auto-display to avoid an infinite recursion. */
5319 if (stopped_by_random_signal)
5320 disable_current_display ();
5322 /* Don't print a message if in the middle of doing a "step n"
5323 operation for n > 1 */
5324 if (target_has_execution
5325 && last.kind != TARGET_WAITKIND_SIGNALLED
5326 && last.kind != TARGET_WAITKIND_EXITED
5327 && inferior_thread ()->step_multi
5328 && inferior_thread ()->stop_step)
5331 target_terminal_ours ();
5333 /* Set the current source location. This will also happen if we
5334 display the frame below, but the current SAL will be incorrect
5335 during a user hook-stop function. */
5336 if (has_stack_frames () && !stop_stack_dummy)
5337 set_current_sal_from_frame (get_current_frame (), 1);
5339 /* Let the user/frontend see the threads as stopped. */
5340 do_cleanups (old_chain);
5342 /* Look up the hook_stop and run it (CLI internally handles problem
5343 of stop_command's pre-hook not existing). */
5345 catch_errors (hook_stop_stub, stop_command,
5346 "Error while running hook_stop:\n", RETURN_MASK_ALL);
5348 if (!has_stack_frames ())
5351 if (last.kind == TARGET_WAITKIND_SIGNALLED
5352 || last.kind == TARGET_WAITKIND_EXITED)
5355 /* Select innermost stack frame - i.e., current frame is frame 0,
5356 and current location is based on that.
5357 Don't do this on return from a stack dummy routine,
5358 or if the program has exited. */
5360 if (!stop_stack_dummy)
5362 select_frame (get_current_frame ());
5364 /* Print current location without a level number, if
5365 we have changed functions or hit a breakpoint.
5366 Print source line if we have one.
5367 bpstat_print() contains the logic deciding in detail
5368 what to print, based on the event(s) that just occurred. */
5370 /* If --batch-silent is enabled then there's no need to print the current
5371 source location, and to try risks causing an error message about
5372 missing source files. */
5373 if (stop_print_frame && !batch_silent)
5377 int do_frame_printing = 1;
5378 struct thread_info *tp = inferior_thread ();
5380 bpstat_ret = bpstat_print (tp->stop_bpstat);
5384 /* If we had hit a shared library event breakpoint,
5385 bpstat_print would print out this message. If we hit
5386 an OS-level shared library event, do the same
5388 if (last.kind == TARGET_WAITKIND_LOADED)
5390 printf_filtered (_("Stopped due to shared library event\n"));
5391 source_flag = SRC_LINE; /* something bogus */
5392 do_frame_printing = 0;
5396 /* FIXME: cagney/2002-12-01: Given that a frame ID does
5397 (or should) carry around the function and does (or
5398 should) use that when doing a frame comparison. */
5400 && frame_id_eq (tp->step_frame_id,
5401 get_frame_id (get_current_frame ()))
5402 && step_start_function == find_pc_function (stop_pc))
5403 source_flag = SRC_LINE; /* finished step, just print source line */
5405 source_flag = SRC_AND_LOC; /* print location and source line */
5407 case PRINT_SRC_AND_LOC:
5408 source_flag = SRC_AND_LOC; /* print location and source line */
5410 case PRINT_SRC_ONLY:
5411 source_flag = SRC_LINE;
5414 source_flag = SRC_LINE; /* something bogus */
5415 do_frame_printing = 0;
5418 internal_error (__FILE__, __LINE__, _("Unknown value."));
5421 /* The behavior of this routine with respect to the source
5423 SRC_LINE: Print only source line
5424 LOCATION: Print only location
5425 SRC_AND_LOC: Print location and source line */
5426 if (do_frame_printing)
5427 print_stack_frame (get_selected_frame (NULL), 0, source_flag);
5429 /* Display the auto-display expressions. */
5434 /* Save the function value return registers, if we care.
5435 We might be about to restore their previous contents. */
5436 if (inferior_thread ()->proceed_to_finish)
5438 /* This should not be necessary. */
5440 regcache_xfree (stop_registers);
5442 /* NB: The copy goes through to the target picking up the value of
5443 all the registers. */
5444 stop_registers = regcache_dup (get_current_regcache ());
5447 if (stop_stack_dummy == STOP_STACK_DUMMY)
5449 /* Pop the empty frame that contains the stack dummy.
5450 This also restores inferior state prior to the call
5451 (struct inferior_thread_state). */
5452 struct frame_info *frame = get_current_frame ();
5453 gdb_assert (get_frame_type (frame) == DUMMY_FRAME);
5455 /* frame_pop() calls reinit_frame_cache as the last thing it does
5456 which means there's currently no selected frame. We don't need
5457 to re-establish a selected frame if the dummy call returns normally,
5458 that will be done by restore_inferior_status. However, we do have
5459 to handle the case where the dummy call is returning after being
5460 stopped (e.g. the dummy call previously hit a breakpoint). We
5461 can't know which case we have so just always re-establish a
5462 selected frame here. */
5463 select_frame (get_current_frame ());
5467 annotate_stopped ();
5469 /* Suppress the stop observer if we're in the middle of:
5471 - a step n (n > 1), as there still more steps to be done.
5473 - a "finish" command, as the observer will be called in
5474 finish_command_continuation, so it can include the inferior
5475 function's return value.
5477 - calling an inferior function, as we pretend we inferior didn't
5478 run at all. The return value of the call is handled by the
5479 expression evaluator, through call_function_by_hand. */
5481 if (!target_has_execution
5482 || last.kind == TARGET_WAITKIND_SIGNALLED
5483 || last.kind == TARGET_WAITKIND_EXITED
5484 || (!inferior_thread ()->step_multi
5485 && !(inferior_thread ()->stop_bpstat
5486 && inferior_thread ()->proceed_to_finish)
5487 && !inferior_thread ()->in_infcall))
5489 if (!ptid_equal (inferior_ptid, null_ptid))
5490 observer_notify_normal_stop (inferior_thread ()->stop_bpstat,
5493 observer_notify_normal_stop (NULL, stop_print_frame);
5496 if (target_has_execution)
5498 if (last.kind != TARGET_WAITKIND_SIGNALLED
5499 && last.kind != TARGET_WAITKIND_EXITED)
5500 /* Delete the breakpoint we stopped at, if it wants to be deleted.
5501 Delete any breakpoint that is to be deleted at the next stop. */
5502 breakpoint_auto_delete (inferior_thread ()->stop_bpstat);
5505 /* Try to get rid of automatically added inferiors that are no
5506 longer needed. Keeping those around slows down things linearly.
5507 Note that this never removes the current inferior. */
5512 hook_stop_stub (void *cmd)
5514 execute_cmd_pre_hook ((struct cmd_list_element *) cmd);
5519 signal_stop_state (int signo)
5521 return signal_stop[signo];
5525 signal_print_state (int signo)
5527 return signal_print[signo];
5531 signal_pass_state (int signo)
5533 return signal_program[signo];
5537 signal_stop_update (int signo, int state)
5539 int ret = signal_stop[signo];
5540 signal_stop[signo] = state;
5545 signal_print_update (int signo, int state)
5547 int ret = signal_print[signo];
5548 signal_print[signo] = state;
5553 signal_pass_update (int signo, int state)
5555 int ret = signal_program[signo];
5556 signal_program[signo] = state;
5561 sig_print_header (void)
5563 printf_filtered (_("\
5564 Signal Stop\tPrint\tPass to program\tDescription\n"));
5568 sig_print_info (enum target_signal oursig)
5570 const char *name = target_signal_to_name (oursig);
5571 int name_padding = 13 - strlen (name);
5573 if (name_padding <= 0)
5576 printf_filtered ("%s", name);
5577 printf_filtered ("%*.*s ", name_padding, name_padding, " ");
5578 printf_filtered ("%s\t", signal_stop[oursig] ? "Yes" : "No");
5579 printf_filtered ("%s\t", signal_print[oursig] ? "Yes" : "No");
5580 printf_filtered ("%s\t\t", signal_program[oursig] ? "Yes" : "No");
5581 printf_filtered ("%s\n", target_signal_to_string (oursig));
5584 /* Specify how various signals in the inferior should be handled. */
5587 handle_command (char *args, int from_tty)
5590 int digits, wordlen;
5591 int sigfirst, signum, siglast;
5592 enum target_signal oursig;
5595 unsigned char *sigs;
5596 struct cleanup *old_chain;
5600 error_no_arg (_("signal to handle"));
5603 /* Allocate and zero an array of flags for which signals to handle. */
5605 nsigs = (int) TARGET_SIGNAL_LAST;
5606 sigs = (unsigned char *) alloca (nsigs);
5607 memset (sigs, 0, nsigs);
5609 /* Break the command line up into args. */
5611 argv = gdb_buildargv (args);
5612 old_chain = make_cleanup_freeargv (argv);
5614 /* Walk through the args, looking for signal oursigs, signal names, and
5615 actions. Signal numbers and signal names may be interspersed with
5616 actions, with the actions being performed for all signals cumulatively
5617 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
5619 while (*argv != NULL)
5621 wordlen = strlen (*argv);
5622 for (digits = 0; isdigit ((*argv)[digits]); digits++)
5626 sigfirst = siglast = -1;
5628 if (wordlen >= 1 && !strncmp (*argv, "all", wordlen))
5630 /* Apply action to all signals except those used by the
5631 debugger. Silently skip those. */
5634 siglast = nsigs - 1;
5636 else if (wordlen >= 1 && !strncmp (*argv, "stop", wordlen))
5638 SET_SIGS (nsigs, sigs, signal_stop);
5639 SET_SIGS (nsigs, sigs, signal_print);
5641 else if (wordlen >= 1 && !strncmp (*argv, "ignore", wordlen))
5643 UNSET_SIGS (nsigs, sigs, signal_program);
5645 else if (wordlen >= 2 && !strncmp (*argv, "print", wordlen))
5647 SET_SIGS (nsigs, sigs, signal_print);
5649 else if (wordlen >= 2 && !strncmp (*argv, "pass", wordlen))
5651 SET_SIGS (nsigs, sigs, signal_program);
5653 else if (wordlen >= 3 && !strncmp (*argv, "nostop", wordlen))
5655 UNSET_SIGS (nsigs, sigs, signal_stop);
5657 else if (wordlen >= 3 && !strncmp (*argv, "noignore", wordlen))
5659 SET_SIGS (nsigs, sigs, signal_program);
5661 else if (wordlen >= 4 && !strncmp (*argv, "noprint", wordlen))
5663 UNSET_SIGS (nsigs, sigs, signal_print);
5664 UNSET_SIGS (nsigs, sigs, signal_stop);
5666 else if (wordlen >= 4 && !strncmp (*argv, "nopass", wordlen))
5668 UNSET_SIGS (nsigs, sigs, signal_program);
5670 else if (digits > 0)
5672 /* It is numeric. The numeric signal refers to our own
5673 internal signal numbering from target.h, not to host/target
5674 signal number. This is a feature; users really should be
5675 using symbolic names anyway, and the common ones like
5676 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
5678 sigfirst = siglast = (int)
5679 target_signal_from_command (atoi (*argv));
5680 if ((*argv)[digits] == '-')
5683 target_signal_from_command (atoi ((*argv) + digits + 1));
5685 if (sigfirst > siglast)
5687 /* Bet he didn't figure we'd think of this case... */
5695 oursig = target_signal_from_name (*argv);
5696 if (oursig != TARGET_SIGNAL_UNKNOWN)
5698 sigfirst = siglast = (int) oursig;
5702 /* Not a number and not a recognized flag word => complain. */
5703 error (_("Unrecognized or ambiguous flag word: \"%s\"."), *argv);
5707 /* If any signal numbers or symbol names were found, set flags for
5708 which signals to apply actions to. */
5710 for (signum = sigfirst; signum >= 0 && signum <= siglast; signum++)
5712 switch ((enum target_signal) signum)
5714 case TARGET_SIGNAL_TRAP:
5715 case TARGET_SIGNAL_INT:
5716 if (!allsigs && !sigs[signum])
5718 if (query (_("%s is used by the debugger.\n\
5719 Are you sure you want to change it? "), target_signal_to_name ((enum target_signal) signum)))
5725 printf_unfiltered (_("Not confirmed, unchanged.\n"));
5726 gdb_flush (gdb_stdout);
5730 case TARGET_SIGNAL_0:
5731 case TARGET_SIGNAL_DEFAULT:
5732 case TARGET_SIGNAL_UNKNOWN:
5733 /* Make sure that "all" doesn't print these. */
5744 for (signum = 0; signum < nsigs; signum++)
5747 target_notice_signals (inferior_ptid);
5751 /* Show the results. */
5752 sig_print_header ();
5753 for (; signum < nsigs; signum++)
5755 sig_print_info (signum);
5761 do_cleanups (old_chain);
5765 xdb_handle_command (char *args, int from_tty)
5768 struct cleanup *old_chain;
5771 error_no_arg (_("xdb command"));
5773 /* Break the command line up into args. */
5775 argv = gdb_buildargv (args);
5776 old_chain = make_cleanup_freeargv (argv);
5777 if (argv[1] != (char *) NULL)
5782 bufLen = strlen (argv[0]) + 20;
5783 argBuf = (char *) xmalloc (bufLen);
5787 enum target_signal oursig;
5789 oursig = target_signal_from_name (argv[0]);
5790 memset (argBuf, 0, bufLen);
5791 if (strcmp (argv[1], "Q") == 0)
5792 sprintf (argBuf, "%s %s", argv[0], "noprint");
5795 if (strcmp (argv[1], "s") == 0)
5797 if (!signal_stop[oursig])
5798 sprintf (argBuf, "%s %s", argv[0], "stop");
5800 sprintf (argBuf, "%s %s", argv[0], "nostop");
5802 else if (strcmp (argv[1], "i") == 0)
5804 if (!signal_program[oursig])
5805 sprintf (argBuf, "%s %s", argv[0], "pass");
5807 sprintf (argBuf, "%s %s", argv[0], "nopass");
5809 else if (strcmp (argv[1], "r") == 0)
5811 if (!signal_print[oursig])
5812 sprintf (argBuf, "%s %s", argv[0], "print");
5814 sprintf (argBuf, "%s %s", argv[0], "noprint");
5820 handle_command (argBuf, from_tty);
5822 printf_filtered (_("Invalid signal handling flag.\n"));
5827 do_cleanups (old_chain);
5830 /* Print current contents of the tables set by the handle command.
5831 It is possible we should just be printing signals actually used
5832 by the current target (but for things to work right when switching
5833 targets, all signals should be in the signal tables). */
5836 signals_info (char *signum_exp, int from_tty)
5838 enum target_signal oursig;
5839 sig_print_header ();
5843 /* First see if this is a symbol name. */
5844 oursig = target_signal_from_name (signum_exp);
5845 if (oursig == TARGET_SIGNAL_UNKNOWN)
5847 /* No, try numeric. */
5849 target_signal_from_command (parse_and_eval_long (signum_exp));
5851 sig_print_info (oursig);
5855 printf_filtered ("\n");
5856 /* These ugly casts brought to you by the native VAX compiler. */
5857 for (oursig = TARGET_SIGNAL_FIRST;
5858 (int) oursig < (int) TARGET_SIGNAL_LAST;
5859 oursig = (enum target_signal) ((int) oursig + 1))
5863 if (oursig != TARGET_SIGNAL_UNKNOWN
5864 && oursig != TARGET_SIGNAL_DEFAULT && oursig != TARGET_SIGNAL_0)
5865 sig_print_info (oursig);
5868 printf_filtered (_("\nUse the \"handle\" command to change these tables.\n"));
5871 /* The $_siginfo convenience variable is a bit special. We don't know
5872 for sure the type of the value until we actually have a chance to
5873 fetch the data. The type can change depending on gdbarch, so it it
5874 also dependent on which thread you have selected.
5876 1. making $_siginfo be an internalvar that creates a new value on
5879 2. making the value of $_siginfo be an lval_computed value. */
5881 /* This function implements the lval_computed support for reading a
5885 siginfo_value_read (struct value *v)
5887 LONGEST transferred;
5890 target_read (¤t_target, TARGET_OBJECT_SIGNAL_INFO,
5892 value_contents_all_raw (v),
5894 TYPE_LENGTH (value_type (v)));
5896 if (transferred != TYPE_LENGTH (value_type (v)))
5897 error (_("Unable to read siginfo"));
5900 /* This function implements the lval_computed support for writing a
5904 siginfo_value_write (struct value *v, struct value *fromval)
5906 LONGEST transferred;
5908 transferred = target_write (¤t_target,
5909 TARGET_OBJECT_SIGNAL_INFO,
5911 value_contents_all_raw (fromval),
5913 TYPE_LENGTH (value_type (fromval)));
5915 if (transferred != TYPE_LENGTH (value_type (fromval)))
5916 error (_("Unable to write siginfo"));
5919 static struct lval_funcs siginfo_value_funcs =
5925 /* Return a new value with the correct type for the siginfo object of
5926 the current thread using architecture GDBARCH. Return a void value
5927 if there's no object available. */
5929 static struct value *
5930 siginfo_make_value (struct gdbarch *gdbarch, struct internalvar *var)
5932 if (target_has_stack
5933 && !ptid_equal (inferior_ptid, null_ptid)
5934 && gdbarch_get_siginfo_type_p (gdbarch))
5936 struct type *type = gdbarch_get_siginfo_type (gdbarch);
5937 return allocate_computed_value (type, &siginfo_value_funcs, NULL);
5940 return allocate_value (builtin_type (gdbarch)->builtin_void);
5944 /* Inferior thread state.
5945 These are details related to the inferior itself, and don't include
5946 things like what frame the user had selected or what gdb was doing
5947 with the target at the time.
5948 For inferior function calls these are things we want to restore
5949 regardless of whether the function call successfully completes
5950 or the dummy frame has to be manually popped. */
5952 struct inferior_thread_state
5954 enum target_signal stop_signal;
5956 struct regcache *registers;
5959 struct inferior_thread_state *
5960 save_inferior_thread_state (void)
5962 struct inferior_thread_state *inf_state = XMALLOC (struct inferior_thread_state);
5963 struct thread_info *tp = inferior_thread ();
5965 inf_state->stop_signal = tp->stop_signal;
5966 inf_state->stop_pc = stop_pc;
5968 inf_state->registers = regcache_dup (get_current_regcache ());
5973 /* Restore inferior session state to INF_STATE. */
5976 restore_inferior_thread_state (struct inferior_thread_state *inf_state)
5978 struct thread_info *tp = inferior_thread ();
5980 tp->stop_signal = inf_state->stop_signal;
5981 stop_pc = inf_state->stop_pc;
5983 /* The inferior can be gone if the user types "print exit(0)"
5984 (and perhaps other times). */
5985 if (target_has_execution)
5986 /* NB: The register write goes through to the target. */
5987 regcache_cpy (get_current_regcache (), inf_state->registers);
5988 regcache_xfree (inf_state->registers);
5993 do_restore_inferior_thread_state_cleanup (void *state)
5995 restore_inferior_thread_state (state);
5999 make_cleanup_restore_inferior_thread_state (struct inferior_thread_state *inf_state)
6001 return make_cleanup (do_restore_inferior_thread_state_cleanup, inf_state);
6005 discard_inferior_thread_state (struct inferior_thread_state *inf_state)
6007 regcache_xfree (inf_state->registers);
6012 get_inferior_thread_state_regcache (struct inferior_thread_state *inf_state)
6014 return inf_state->registers;
6017 /* Session related state for inferior function calls.
6018 These are the additional bits of state that need to be restored
6019 when an inferior function call successfully completes. */
6021 struct inferior_status
6025 enum stop_stack_kind stop_stack_dummy;
6026 int stopped_by_random_signal;
6027 int stepping_over_breakpoint;
6028 CORE_ADDR step_range_start;
6029 CORE_ADDR step_range_end;
6030 struct frame_id step_frame_id;
6031 struct frame_id step_stack_frame_id;
6032 enum step_over_calls_kind step_over_calls;
6033 CORE_ADDR step_resume_break_address;
6034 int stop_after_trap;
6037 /* ID if the selected frame when the inferior function call was made. */
6038 struct frame_id selected_frame_id;
6040 int proceed_to_finish;
6044 /* Save all of the information associated with the inferior<==>gdb
6047 struct inferior_status *
6048 save_inferior_status (void)
6050 struct inferior_status *inf_status = XMALLOC (struct inferior_status);
6051 struct thread_info *tp = inferior_thread ();
6052 struct inferior *inf = current_inferior ();
6054 inf_status->stop_step = tp->stop_step;
6055 inf_status->stop_stack_dummy = stop_stack_dummy;
6056 inf_status->stopped_by_random_signal = stopped_by_random_signal;
6057 inf_status->stepping_over_breakpoint = tp->trap_expected;
6058 inf_status->step_range_start = tp->step_range_start;
6059 inf_status->step_range_end = tp->step_range_end;
6060 inf_status->step_frame_id = tp->step_frame_id;
6061 inf_status->step_stack_frame_id = tp->step_stack_frame_id;
6062 inf_status->step_over_calls = tp->step_over_calls;
6063 inf_status->stop_after_trap = stop_after_trap;
6064 inf_status->stop_soon = inf->stop_soon;
6065 /* Save original bpstat chain here; replace it with copy of chain.
6066 If caller's caller is walking the chain, they'll be happier if we
6067 hand them back the original chain when restore_inferior_status is
6069 inf_status->stop_bpstat = tp->stop_bpstat;
6070 tp->stop_bpstat = bpstat_copy (tp->stop_bpstat);
6071 inf_status->proceed_to_finish = tp->proceed_to_finish;
6072 inf_status->in_infcall = tp->in_infcall;
6074 inf_status->selected_frame_id = get_frame_id (get_selected_frame (NULL));
6080 restore_selected_frame (void *args)
6082 struct frame_id *fid = (struct frame_id *) args;
6083 struct frame_info *frame;
6085 frame = frame_find_by_id (*fid);
6087 /* If inf_status->selected_frame_id is NULL, there was no previously
6091 warning (_("Unable to restore previously selected frame."));
6095 select_frame (frame);
6100 /* Restore inferior session state to INF_STATUS. */
6103 restore_inferior_status (struct inferior_status *inf_status)
6105 struct thread_info *tp = inferior_thread ();
6106 struct inferior *inf = current_inferior ();
6108 tp->stop_step = inf_status->stop_step;
6109 stop_stack_dummy = inf_status->stop_stack_dummy;
6110 stopped_by_random_signal = inf_status->stopped_by_random_signal;
6111 tp->trap_expected = inf_status->stepping_over_breakpoint;
6112 tp->step_range_start = inf_status->step_range_start;
6113 tp->step_range_end = inf_status->step_range_end;
6114 tp->step_frame_id = inf_status->step_frame_id;
6115 tp->step_stack_frame_id = inf_status->step_stack_frame_id;
6116 tp->step_over_calls = inf_status->step_over_calls;
6117 stop_after_trap = inf_status->stop_after_trap;
6118 inf->stop_soon = inf_status->stop_soon;
6119 bpstat_clear (&tp->stop_bpstat);
6120 tp->stop_bpstat = inf_status->stop_bpstat;
6121 inf_status->stop_bpstat = NULL;
6122 tp->proceed_to_finish = inf_status->proceed_to_finish;
6123 tp->in_infcall = inf_status->in_infcall;
6125 if (target_has_stack)
6127 /* The point of catch_errors is that if the stack is clobbered,
6128 walking the stack might encounter a garbage pointer and
6129 error() trying to dereference it. */
6131 (restore_selected_frame, &inf_status->selected_frame_id,
6132 "Unable to restore previously selected frame:\n",
6133 RETURN_MASK_ERROR) == 0)
6134 /* Error in restoring the selected frame. Select the innermost
6136 select_frame (get_current_frame ());
6143 do_restore_inferior_status_cleanup (void *sts)
6145 restore_inferior_status (sts);
6149 make_cleanup_restore_inferior_status (struct inferior_status *inf_status)
6151 return make_cleanup (do_restore_inferior_status_cleanup, inf_status);
6155 discard_inferior_status (struct inferior_status *inf_status)
6157 /* See save_inferior_status for info on stop_bpstat. */
6158 bpstat_clear (&inf_status->stop_bpstat);
6163 inferior_has_forked (ptid_t pid, ptid_t *child_pid)
6165 struct target_waitstatus last;
6168 get_last_target_status (&last_ptid, &last);
6170 if (last.kind != TARGET_WAITKIND_FORKED)
6173 if (!ptid_equal (last_ptid, pid))
6176 *child_pid = last.value.related_pid;
6181 inferior_has_vforked (ptid_t pid, ptid_t *child_pid)
6183 struct target_waitstatus last;
6186 get_last_target_status (&last_ptid, &last);
6188 if (last.kind != TARGET_WAITKIND_VFORKED)
6191 if (!ptid_equal (last_ptid, pid))
6194 *child_pid = last.value.related_pid;
6199 inferior_has_execd (ptid_t pid, char **execd_pathname)
6201 struct target_waitstatus last;
6204 get_last_target_status (&last_ptid, &last);
6206 if (last.kind != TARGET_WAITKIND_EXECD)
6209 if (!ptid_equal (last_ptid, pid))
6212 *execd_pathname = xstrdup (last.value.execd_pathname);
6217 inferior_has_called_syscall (ptid_t pid, int *syscall_number)
6219 struct target_waitstatus last;
6222 get_last_target_status (&last_ptid, &last);
6224 if (last.kind != TARGET_WAITKIND_SYSCALL_ENTRY &&
6225 last.kind != TARGET_WAITKIND_SYSCALL_RETURN)
6228 if (!ptid_equal (last_ptid, pid))
6231 *syscall_number = last.value.syscall_number;
6235 /* Oft used ptids */
6237 ptid_t minus_one_ptid;
6239 /* Create a ptid given the necessary PID, LWP, and TID components. */
6242 ptid_build (int pid, long lwp, long tid)
6252 /* Create a ptid from just a pid. */
6255 pid_to_ptid (int pid)
6257 return ptid_build (pid, 0, 0);
6260 /* Fetch the pid (process id) component from a ptid. */
6263 ptid_get_pid (ptid_t ptid)
6268 /* Fetch the lwp (lightweight process) component from a ptid. */
6271 ptid_get_lwp (ptid_t ptid)
6276 /* Fetch the tid (thread id) component from a ptid. */
6279 ptid_get_tid (ptid_t ptid)
6284 /* ptid_equal() is used to test equality of two ptids. */
6287 ptid_equal (ptid_t ptid1, ptid_t ptid2)
6289 return (ptid1.pid == ptid2.pid && ptid1.lwp == ptid2.lwp
6290 && ptid1.tid == ptid2.tid);
6293 /* Returns true if PTID represents a process. */
6296 ptid_is_pid (ptid_t ptid)
6298 if (ptid_equal (minus_one_ptid, ptid))
6300 if (ptid_equal (null_ptid, ptid))
6303 return (ptid_get_lwp (ptid) == 0 && ptid_get_tid (ptid) == 0);
6307 ptid_match (ptid_t ptid, ptid_t filter)
6309 /* Since both parameters have the same type, prevent easy mistakes
6311 gdb_assert (!ptid_equal (ptid, minus_one_ptid)
6312 && !ptid_equal (ptid, null_ptid));
6314 if (ptid_equal (filter, minus_one_ptid))
6316 if (ptid_is_pid (filter)
6317 && ptid_get_pid (ptid) == ptid_get_pid (filter))
6319 else if (ptid_equal (ptid, filter))
6325 /* restore_inferior_ptid() will be used by the cleanup machinery
6326 to restore the inferior_ptid value saved in a call to
6327 save_inferior_ptid(). */
6330 restore_inferior_ptid (void *arg)
6332 ptid_t *saved_ptid_ptr = arg;
6333 inferior_ptid = *saved_ptid_ptr;
6337 /* Save the value of inferior_ptid so that it may be restored by a
6338 later call to do_cleanups(). Returns the struct cleanup pointer
6339 needed for later doing the cleanup. */
6342 save_inferior_ptid (void)
6344 ptid_t *saved_ptid_ptr;
6346 saved_ptid_ptr = xmalloc (sizeof (ptid_t));
6347 *saved_ptid_ptr = inferior_ptid;
6348 return make_cleanup (restore_inferior_ptid, saved_ptid_ptr);
6352 /* User interface for reverse debugging:
6353 Set exec-direction / show exec-direction commands
6354 (returns error unless target implements to_set_exec_direction method). */
6356 enum exec_direction_kind execution_direction = EXEC_FORWARD;
6357 static const char exec_forward[] = "forward";
6358 static const char exec_reverse[] = "reverse";
6359 static const char *exec_direction = exec_forward;
6360 static const char *exec_direction_names[] = {
6367 set_exec_direction_func (char *args, int from_tty,
6368 struct cmd_list_element *cmd)
6370 if (target_can_execute_reverse)
6372 if (!strcmp (exec_direction, exec_forward))
6373 execution_direction = EXEC_FORWARD;
6374 else if (!strcmp (exec_direction, exec_reverse))
6375 execution_direction = EXEC_REVERSE;
6380 show_exec_direction_func (struct ui_file *out, int from_tty,
6381 struct cmd_list_element *cmd, const char *value)
6383 switch (execution_direction) {
6385 fprintf_filtered (out, _("Forward.\n"));
6388 fprintf_filtered (out, _("Reverse.\n"));
6392 fprintf_filtered (out,
6393 _("Forward (target `%s' does not support exec-direction).\n"),
6399 /* User interface for non-stop mode. */
6402 static int non_stop_1 = 0;
6405 set_non_stop (char *args, int from_tty,
6406 struct cmd_list_element *c)
6408 if (target_has_execution)
6410 non_stop_1 = non_stop;
6411 error (_("Cannot change this setting while the inferior is running."));
6414 non_stop = non_stop_1;
6418 show_non_stop (struct ui_file *file, int from_tty,
6419 struct cmd_list_element *c, const char *value)
6421 fprintf_filtered (file,
6422 _("Controlling the inferior in non-stop mode is %s.\n"),
6427 show_schedule_multiple (struct ui_file *file, int from_tty,
6428 struct cmd_list_element *c, const char *value)
6430 fprintf_filtered (file, _("\
6431 Resuming the execution of threads of all processes is %s.\n"), value);
6435 _initialize_infrun (void)
6440 add_info ("signals", signals_info, _("\
6441 What debugger does when program gets various signals.\n\
6442 Specify a signal as argument to print info on that signal only."));
6443 add_info_alias ("handle", "signals", 0);
6445 add_com ("handle", class_run, handle_command, _("\
6446 Specify how to handle a signal.\n\
6447 Args are signals and actions to apply to those signals.\n\
6448 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
6449 from 1-15 are allowed for compatibility with old versions of GDB.\n\
6450 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
6451 The special arg \"all\" is recognized to mean all signals except those\n\
6452 used by the debugger, typically SIGTRAP and SIGINT.\n\
6453 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
6454 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
6455 Stop means reenter debugger if this signal happens (implies print).\n\
6456 Print means print a message if this signal happens.\n\
6457 Pass means let program see this signal; otherwise program doesn't know.\n\
6458 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
6459 Pass and Stop may be combined."));
6462 add_com ("lz", class_info, signals_info, _("\
6463 What debugger does when program gets various signals.\n\
6464 Specify a signal as argument to print info on that signal only."));
6465 add_com ("z", class_run, xdb_handle_command, _("\
6466 Specify how to handle a signal.\n\
6467 Args are signals and actions to apply to those signals.\n\
6468 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
6469 from 1-15 are allowed for compatibility with old versions of GDB.\n\
6470 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
6471 The special arg \"all\" is recognized to mean all signals except those\n\
6472 used by the debugger, typically SIGTRAP and SIGINT.\n\
6473 Recognized actions include \"s\" (toggles between stop and nostop), \n\
6474 \"r\" (toggles between print and noprint), \"i\" (toggles between pass and \
6475 nopass), \"Q\" (noprint)\n\
6476 Stop means reenter debugger if this signal happens (implies print).\n\
6477 Print means print a message if this signal happens.\n\
6478 Pass means let program see this signal; otherwise program doesn't know.\n\
6479 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
6480 Pass and Stop may be combined."));
6484 stop_command = add_cmd ("stop", class_obscure,
6485 not_just_help_class_command, _("\
6486 There is no `stop' command, but you can set a hook on `stop'.\n\
6487 This allows you to set a list of commands to be run each time execution\n\
6488 of the program stops."), &cmdlist);
6490 add_setshow_zinteger_cmd ("infrun", class_maintenance, &debug_infrun, _("\
6491 Set inferior debugging."), _("\
6492 Show inferior debugging."), _("\
6493 When non-zero, inferior specific debugging is enabled."),
6496 &setdebuglist, &showdebuglist);
6498 add_setshow_boolean_cmd ("displaced", class_maintenance, &debug_displaced, _("\
6499 Set displaced stepping debugging."), _("\
6500 Show displaced stepping debugging."), _("\
6501 When non-zero, displaced stepping specific debugging is enabled."),
6503 show_debug_displaced,
6504 &setdebuglist, &showdebuglist);
6506 add_setshow_boolean_cmd ("non-stop", no_class,
6508 Set whether gdb controls the inferior in non-stop mode."), _("\
6509 Show whether gdb controls the inferior in non-stop mode."), _("\
6510 When debugging a multi-threaded program and this setting is\n\
6511 off (the default, also called all-stop mode), when one thread stops\n\
6512 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
6513 all other threads in the program while you interact with the thread of\n\
6514 interest. When you continue or step a thread, you can allow the other\n\
6515 threads to run, or have them remain stopped, but while you inspect any\n\
6516 thread's state, all threads stop.\n\
6518 In non-stop mode, when one thread stops, other threads can continue\n\
6519 to run freely. You'll be able to step each thread independently,\n\
6520 leave it stopped or free to run as needed."),
6526 numsigs = (int) TARGET_SIGNAL_LAST;
6527 signal_stop = (unsigned char *) xmalloc (sizeof (signal_stop[0]) * numsigs);
6528 signal_print = (unsigned char *)
6529 xmalloc (sizeof (signal_print[0]) * numsigs);
6530 signal_program = (unsigned char *)
6531 xmalloc (sizeof (signal_program[0]) * numsigs);
6532 for (i = 0; i < numsigs; i++)
6535 signal_print[i] = 1;
6536 signal_program[i] = 1;
6539 /* Signals caused by debugger's own actions
6540 should not be given to the program afterwards. */
6541 signal_program[TARGET_SIGNAL_TRAP] = 0;
6542 signal_program[TARGET_SIGNAL_INT] = 0;
6544 /* Signals that are not errors should not normally enter the debugger. */
6545 signal_stop[TARGET_SIGNAL_ALRM] = 0;
6546 signal_print[TARGET_SIGNAL_ALRM] = 0;
6547 signal_stop[TARGET_SIGNAL_VTALRM] = 0;
6548 signal_print[TARGET_SIGNAL_VTALRM] = 0;
6549 signal_stop[TARGET_SIGNAL_PROF] = 0;
6550 signal_print[TARGET_SIGNAL_PROF] = 0;
6551 signal_stop[TARGET_SIGNAL_CHLD] = 0;
6552 signal_print[TARGET_SIGNAL_CHLD] = 0;
6553 signal_stop[TARGET_SIGNAL_IO] = 0;
6554 signal_print[TARGET_SIGNAL_IO] = 0;
6555 signal_stop[TARGET_SIGNAL_POLL] = 0;
6556 signal_print[TARGET_SIGNAL_POLL] = 0;
6557 signal_stop[TARGET_SIGNAL_URG] = 0;
6558 signal_print[TARGET_SIGNAL_URG] = 0;
6559 signal_stop[TARGET_SIGNAL_WINCH] = 0;
6560 signal_print[TARGET_SIGNAL_WINCH] = 0;
6562 /* These signals are used internally by user-level thread
6563 implementations. (See signal(5) on Solaris.) Like the above
6564 signals, a healthy program receives and handles them as part of
6565 its normal operation. */
6566 signal_stop[TARGET_SIGNAL_LWP] = 0;
6567 signal_print[TARGET_SIGNAL_LWP] = 0;
6568 signal_stop[TARGET_SIGNAL_WAITING] = 0;
6569 signal_print[TARGET_SIGNAL_WAITING] = 0;
6570 signal_stop[TARGET_SIGNAL_CANCEL] = 0;
6571 signal_print[TARGET_SIGNAL_CANCEL] = 0;
6573 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support,
6574 &stop_on_solib_events, _("\
6575 Set stopping for shared library events."), _("\
6576 Show stopping for shared library events."), _("\
6577 If nonzero, gdb will give control to the user when the dynamic linker\n\
6578 notifies gdb of shared library events. The most common event of interest\n\
6579 to the user would be loading/unloading of a new library."),
6581 show_stop_on_solib_events,
6582 &setlist, &showlist);
6584 add_setshow_enum_cmd ("follow-fork-mode", class_run,
6585 follow_fork_mode_kind_names,
6586 &follow_fork_mode_string, _("\
6587 Set debugger response to a program call of fork or vfork."), _("\
6588 Show debugger response to a program call of fork or vfork."), _("\
6589 A fork or vfork creates a new process. follow-fork-mode can be:\n\
6590 parent - the original process is debugged after a fork\n\
6591 child - the new process is debugged after a fork\n\
6592 The unfollowed process will continue to run.\n\
6593 By default, the debugger will follow the parent process."),
6595 show_follow_fork_mode_string,
6596 &setlist, &showlist);
6598 add_setshow_enum_cmd ("follow-exec-mode", class_run,
6599 follow_exec_mode_names,
6600 &follow_exec_mode_string, _("\
6601 Set debugger response to a program call of exec."), _("\
6602 Show debugger response to a program call of exec."), _("\
6603 An exec call replaces the program image of a process.\n\
6605 follow-exec-mode can be:\n\
6607 new - the debugger creates a new inferior and rebinds the process \n\
6608 to this new inferior. The program the process was running before\n\
6609 the exec call can be restarted afterwards by restarting the original\n\
6612 same - the debugger keeps the process bound to the same inferior.\n\
6613 The new executable image replaces the previous executable loaded in\n\
6614 the inferior. Restarting the inferior after the exec call restarts\n\
6615 the executable the process was running after the exec call.\n\
6617 By default, the debugger will use the same inferior."),
6619 show_follow_exec_mode_string,
6620 &setlist, &showlist);
6622 add_setshow_enum_cmd ("scheduler-locking", class_run,
6623 scheduler_enums, &scheduler_mode, _("\
6624 Set mode for locking scheduler during execution."), _("\
6625 Show mode for locking scheduler during execution."), _("\
6626 off == no locking (threads may preempt at any time)\n\
6627 on == full locking (no thread except the current thread may run)\n\
6628 step == scheduler locked during every single-step operation.\n\
6629 In this mode, no other thread may run during a step command.\n\
6630 Other threads may run while stepping over a function call ('next')."),
6631 set_schedlock_func, /* traps on target vector */
6632 show_scheduler_mode,
6633 &setlist, &showlist);
6635 add_setshow_boolean_cmd ("schedule-multiple", class_run, &sched_multi, _("\
6636 Set mode for resuming threads of all processes."), _("\
6637 Show mode for resuming threads of all processes."), _("\
6638 When on, execution commands (such as 'continue' or 'next') resume all\n\
6639 threads of all processes. When off (which is the default), execution\n\
6640 commands only resume the threads of the current process. The set of\n\
6641 threads that are resumed is further refined by the scheduler-locking\n\
6642 mode (see help set scheduler-locking)."),
6644 show_schedule_multiple,
6645 &setlist, &showlist);
6647 add_setshow_boolean_cmd ("step-mode", class_run, &step_stop_if_no_debug, _("\
6648 Set mode of the step operation."), _("\
6649 Show mode of the step operation."), _("\
6650 When set, doing a step over a function without debug line information\n\
6651 will stop at the first instruction of that function. Otherwise, the\n\
6652 function is skipped and the step command stops at a different source line."),
6654 show_step_stop_if_no_debug,
6655 &setlist, &showlist);
6657 add_setshow_enum_cmd ("displaced-stepping", class_run,
6658 can_use_displaced_stepping_enum,
6659 &can_use_displaced_stepping, _("\
6660 Set debugger's willingness to use displaced stepping."), _("\
6661 Show debugger's willingness to use displaced stepping."), _("\
6662 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
6663 supported by the target architecture. If off, gdb will not use displaced\n\
6664 stepping to step over breakpoints, even if such is supported by the target\n\
6665 architecture. If auto (which is the default), gdb will use displaced stepping\n\
6666 if the target architecture supports it and non-stop mode is active, but will not\n\
6667 use it in all-stop mode (see help set non-stop)."),
6669 show_can_use_displaced_stepping,
6670 &setlist, &showlist);
6672 add_setshow_enum_cmd ("exec-direction", class_run, exec_direction_names,
6673 &exec_direction, _("Set direction of execution.\n\
6674 Options are 'forward' or 'reverse'."),
6675 _("Show direction of execution (forward/reverse)."),
6676 _("Tells gdb whether to execute forward or backward."),
6677 set_exec_direction_func, show_exec_direction_func,
6678 &setlist, &showlist);
6680 /* Set/show detach-on-fork: user-settable mode. */
6682 add_setshow_boolean_cmd ("detach-on-fork", class_run, &detach_fork, _("\
6683 Set whether gdb will detach the child of a fork."), _("\
6684 Show whether gdb will detach the child of a fork."), _("\
6685 Tells gdb whether to detach the child of a fork."),
6686 NULL, NULL, &setlist, &showlist);
6688 /* ptid initializations */
6689 null_ptid = ptid_build (0, 0, 0);
6690 minus_one_ptid = ptid_build (-1, 0, 0);
6691 inferior_ptid = null_ptid;
6692 target_last_wait_ptid = minus_one_ptid;
6694 observer_attach_thread_ptid_changed (infrun_thread_ptid_changed);
6695 observer_attach_thread_stop_requested (infrun_thread_stop_requested);
6696 observer_attach_thread_exit (infrun_thread_thread_exit);
6697 observer_attach_inferior_exit (infrun_inferior_exit);
6699 /* Explicitly create without lookup, since that tries to create a
6700 value with a void typed value, and when we get here, gdbarch
6701 isn't initialized yet. At this point, we're quite sure there
6702 isn't another convenience variable of the same name. */
6703 create_internalvar_type_lazy ("_siginfo", siginfo_make_value);