1 //===-- Thread.cpp ----------------------------------------------*- C++ -*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #include "lldb/lldb-python.h"
11 
12 #include "lldb/lldb-private-log.h"
13 #include "lldb/Breakpoint/BreakpointLocation.h"
14 #include "lldb/Core/Debugger.h"
15 #include "lldb/Core/Log.h"
16 #include "lldb/Core/Stream.h"
17 #include "lldb/Core/StreamString.h"
18 #include "lldb/Core/RegularExpression.h"
19 #include "lldb/Host/Host.h"
20 #include "lldb/Symbol/Function.h"
21 #include "lldb/Target/DynamicLoader.h"
22 #include "lldb/Target/ExecutionContext.h"
23 #include "lldb/Target/ObjCLanguageRuntime.h"
24 #include "lldb/Target/Process.h"
25 #include "lldb/Target/RegisterContext.h"
26 #include "lldb/Target/StopInfo.h"
27 #include "lldb/Target/Target.h"
28 #include "lldb/Target/Thread.h"
29 #include "lldb/Target/ThreadPlan.h"
30 #include "lldb/Target/ThreadPlanCallFunction.h"
31 #include "lldb/Target/ThreadPlanBase.h"
32 #include "lldb/Target/ThreadPlanStepInstruction.h"
33 #include "lldb/Target/ThreadPlanStepOut.h"
34 #include "lldb/Target/ThreadPlanStepOverBreakpoint.h"
35 #include "lldb/Target/ThreadPlanStepThrough.h"
36 #include "lldb/Target/ThreadPlanStepInRange.h"
37 #include "lldb/Target/ThreadPlanStepOverRange.h"
38 #include "lldb/Target/ThreadPlanRunToAddress.h"
39 #include "lldb/Target/ThreadPlanStepUntil.h"
40 #include "lldb/Target/ThreadSpec.h"
41 #include "lldb/Target/Unwind.h"
42 #include "Plugins/Process/Utility/UnwindLLDB.h"
43 #include "UnwindMacOSXFrameBackchain.h"
44 
45 
46 using namespace lldb;
47 using namespace lldb_private;
48 
49 
50 const ThreadPropertiesSP &
51 Thread::GetGlobalProperties()
52 {
53     static ThreadPropertiesSP g_settings_sp;
54     if (!g_settings_sp)
55         g_settings_sp.reset (new ThreadProperties (true));
56     return g_settings_sp;
57 }
58 
59 static PropertyDefinition
60 g_properties[] =
61 {
62     { "step-avoid-regexp",  OptionValue::eTypeRegex  , true , REG_EXTENDED, "^std::", NULL, "A regular expression defining functions step-in won't stop in." },
63     { "trace-thread",       OptionValue::eTypeBoolean, false, false, NULL, NULL, "If true, this thread will single-step and log execution." },
64     {  NULL               , OptionValue::eTypeInvalid, false, 0    , NULL, NULL, NULL  }
65 };
66 
67 enum {
68     ePropertyStepAvoidRegex,
69     ePropertyEnableThreadTrace
70 };
71 
72 
73 class ThreadOptionValueProperties : public OptionValueProperties
74 {
75 public:
76     ThreadOptionValueProperties (const ConstString &name) :
77         OptionValueProperties (name)
78     {
79     }
80 
81     // This constructor is used when creating ThreadOptionValueProperties when it
82     // is part of a new lldb_private::Thread instance. It will copy all current
83     // global property values as needed
84     ThreadOptionValueProperties (ThreadProperties *global_properties) :
85         OptionValueProperties(*global_properties->GetValueProperties())
86     {
87     }
88 
89     virtual const Property *
90     GetPropertyAtIndex (const ExecutionContext *exe_ctx, bool will_modify, uint32_t idx) const
91     {
92         // When gettings the value for a key from the thread options, we will always
93         // try and grab the setting from the current thread if there is one. Else we just
94         // use the one from this instance.
95         if (exe_ctx)
96         {
97             Thread *thread = exe_ctx->GetThreadPtr();
98             if (thread)
99             {
100                 ThreadOptionValueProperties *instance_properties = static_cast<ThreadOptionValueProperties *>(thread->GetValueProperties().get());
101                 if (this != instance_properties)
102                     return instance_properties->ProtectedGetPropertyAtIndex (idx);
103             }
104         }
105         return ProtectedGetPropertyAtIndex (idx);
106     }
107 };
108 
109 
110 
111 ThreadProperties::ThreadProperties (bool is_global) :
112     Properties ()
113 {
114     if (is_global)
115     {
116         m_collection_sp.reset (new ThreadOptionValueProperties(ConstString("thread")));
117         m_collection_sp->Initialize(g_properties);
118     }
119     else
120         m_collection_sp.reset (new ThreadOptionValueProperties(Thread::GetGlobalProperties().get()));
121 }
122 
123 ThreadProperties::~ThreadProperties()
124 {
125 }
126 
127 const RegularExpression *
128 ThreadProperties::GetSymbolsToAvoidRegexp()
129 {
130     const uint32_t idx = ePropertyStepAvoidRegex;
131     return m_collection_sp->GetPropertyAtIndexAsOptionValueRegex (NULL, idx);
132 }
133 
134 bool
135 ThreadProperties::GetTraceEnabledState() const
136 {
137     const uint32_t idx = ePropertyEnableThreadTrace;
138     return m_collection_sp->GetPropertyAtIndexAsBoolean (NULL, idx, g_properties[idx].default_uint_value != 0);
139 }
140 
141 //------------------------------------------------------------------
142 // Thread Event Data
143 //------------------------------------------------------------------
144 
145 
146 const ConstString &
147 Thread::ThreadEventData::GetFlavorString ()
148 {
149     static ConstString g_flavor ("Thread::ThreadEventData");
150     return g_flavor;
151 }
152 
153 Thread::ThreadEventData::ThreadEventData (const lldb::ThreadSP thread_sp) :
154     m_thread_sp (thread_sp),
155     m_stack_id ()
156 {
157 }
158 
159 Thread::ThreadEventData::ThreadEventData (const lldb::ThreadSP thread_sp, const StackID &stack_id) :
160     m_thread_sp (thread_sp),
161     m_stack_id (stack_id)
162 {
163 }
164 
165 Thread::ThreadEventData::ThreadEventData () :
166     m_thread_sp (),
167     m_stack_id ()
168 {
169 }
170 
171 Thread::ThreadEventData::~ThreadEventData ()
172 {
173 }
174 
175 void
176 Thread::ThreadEventData::Dump (Stream *s) const
177 {
178 
179 }
180 
181 const Thread::ThreadEventData *
182 Thread::ThreadEventData::GetEventDataFromEvent (const Event *event_ptr)
183 {
184     if (event_ptr)
185     {
186         const EventData *event_data = event_ptr->GetData();
187         if (event_data && event_data->GetFlavor() == ThreadEventData::GetFlavorString())
188             return static_cast <const ThreadEventData *> (event_ptr->GetData());
189     }
190     return NULL;
191 }
192 
193 ThreadSP
194 Thread::ThreadEventData::GetThreadFromEvent (const Event *event_ptr)
195 {
196     ThreadSP thread_sp;
197     const ThreadEventData *event_data = GetEventDataFromEvent (event_ptr);
198     if (event_data)
199         thread_sp = event_data->GetThread();
200     return thread_sp;
201 }
202 
203 StackID
204 Thread::ThreadEventData::GetStackIDFromEvent (const Event *event_ptr)
205 {
206     StackID stack_id;
207     const ThreadEventData *event_data = GetEventDataFromEvent (event_ptr);
208     if (event_data)
209         stack_id = event_data->GetStackID();
210     return stack_id;
211 }
212 
213 StackFrameSP
214 Thread::ThreadEventData::GetStackFrameFromEvent (const Event *event_ptr)
215 {
216     const ThreadEventData *event_data = GetEventDataFromEvent (event_ptr);
217     StackFrameSP frame_sp;
218     if (event_data)
219     {
220         ThreadSP thread_sp = event_data->GetThread();
221         if (thread_sp)
222         {
223             frame_sp = thread_sp->GetStackFrameList()->GetFrameWithStackID (event_data->GetStackID());
224         }
225     }
226     return frame_sp;
227 }
228 
229 //------------------------------------------------------------------
230 // Thread class
231 //------------------------------------------------------------------
232 
233 ConstString &
234 Thread::GetStaticBroadcasterClass ()
235 {
236     static ConstString class_name ("lldb.thread");
237     return class_name;
238 }
239 
240 Thread::Thread (Process &process, lldb::tid_t tid) :
241     ThreadProperties (false),
242     UserID (tid),
243     Broadcaster(&process.GetTarget().GetDebugger(), Thread::GetStaticBroadcasterClass().AsCString()),
244     m_process_wp (process.shared_from_this()),
245     m_actual_stop_info_sp (),
246     m_index_id (process.GetNextThreadIndexID(tid)),
247     m_reg_context_sp (),
248     m_state (eStateUnloaded),
249     m_state_mutex (Mutex::eMutexTypeRecursive),
250     m_plan_stack (),
251     m_completed_plan_stack(),
252     m_frame_mutex (Mutex::eMutexTypeRecursive),
253     m_curr_frames_sp (),
254     m_prev_frames_sp (),
255     m_resume_signal (LLDB_INVALID_SIGNAL_NUMBER),
256     m_resume_state (eStateRunning),
257     m_temporary_resume_state (eStateRunning),
258     m_unwinder_ap (),
259     m_destroy_called (false),
260     m_thread_stop_reason_stop_id (0)
261 {
262     LogSP log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_OBJECT));
263     if (log)
264         log->Printf ("%p Thread::Thread(tid = 0x%4.4" PRIx64 ")", this, GetID());
265 
266     CheckInWithManager();
267     QueueFundamentalPlan(true);
268 }
269 
270 
271 Thread::~Thread()
272 {
273     LogSP log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_OBJECT));
274     if (log)
275         log->Printf ("%p Thread::~Thread(tid = 0x%4.4" PRIx64 ")", this, GetID());
276     /// If you hit this assert, it means your derived class forgot to call DoDestroy in its destructor.
277     assert (m_destroy_called);
278 }
279 
280 void
281 Thread::DestroyThread ()
282 {
283     m_destroy_called = true;
284     m_plan_stack.clear();
285     m_discarded_plan_stack.clear();
286     m_completed_plan_stack.clear();
287     m_actual_stop_info_sp.reset();
288     m_reg_context_sp.reset();
289     m_unwinder_ap.reset();
290     Mutex::Locker locker(m_frame_mutex);
291     m_curr_frames_sp.reset();
292     m_prev_frames_sp.reset();
293 }
294 
295 void
296 Thread::BroadcastSelectedFrameChange(StackID &new_frame_id)
297 {
298     if (EventTypeHasListeners(eBroadcastBitSelectedFrameChanged))
299         BroadcastEvent(eBroadcastBitSelectedFrameChanged, new ThreadEventData (this->shared_from_this(), new_frame_id));
300 }
301 
302 uint32_t
303 Thread::SetSelectedFrame (lldb_private::StackFrame *frame, bool broadcast)
304 {
305     uint32_t ret_value = GetStackFrameList()->SetSelectedFrame(frame);
306     if (broadcast)
307         BroadcastSelectedFrameChange(frame->GetStackID());
308     return ret_value;
309 }
310 
311 bool
312 Thread::SetSelectedFrameByIndex (uint32_t frame_idx, bool broadcast)
313 {
314     StackFrameSP frame_sp(GetStackFrameList()->GetFrameAtIndex (frame_idx));
315     if (frame_sp)
316     {
317         GetStackFrameList()->SetSelectedFrame(frame_sp.get());
318         if (broadcast)
319             BroadcastSelectedFrameChange(frame_sp->GetStackID());
320         return true;
321     }
322     else
323         return false;
324 }
325 
326 bool
327 Thread::SetSelectedFrameByIndexNoisily (uint32_t frame_idx, Stream &output_stream)
328 {
329     const bool broadcast = true;
330     bool success = SetSelectedFrameByIndex (frame_idx, broadcast);
331     if (success)
332     {
333         StackFrameSP frame_sp = GetSelectedFrame();
334         if (frame_sp)
335         {
336             bool already_shown = false;
337             SymbolContext frame_sc(frame_sp->GetSymbolContext(eSymbolContextLineEntry));
338             if (GetProcess()->GetTarget().GetDebugger().GetUseExternalEditor() && frame_sc.line_entry.file && frame_sc.line_entry.line != 0)
339             {
340                 already_shown = Host::OpenFileInExternalEditor (frame_sc.line_entry.file, frame_sc.line_entry.line);
341             }
342 
343             bool show_frame_info = true;
344             bool show_source = !already_shown;
345             return frame_sp->GetStatus (output_stream, show_frame_info, show_source);
346         }
347         return false;
348     }
349     else
350         return false;
351 }
352 
353 
354 lldb::StopInfoSP
355 Thread::GetStopInfo ()
356 {
357     ThreadPlanSP plan_sp (GetCompletedPlan());
358     if (plan_sp && plan_sp->PlanSucceeded())
359         return StopInfo::CreateStopReasonWithPlan (plan_sp, GetReturnValueObject());
360     else
361     {
362         ProcessSP process_sp (GetProcess());
363         if (process_sp
364             && m_actual_stop_info_sp
365             && m_actual_stop_info_sp->IsValid()
366             && m_thread_stop_reason_stop_id == process_sp->GetStopID())
367             return m_actual_stop_info_sp;
368         else
369             return GetPrivateStopReason ();
370     }
371 }
372 
373 lldb::StopReason
374 Thread::GetStopReason()
375 {
376     lldb::StopInfoSP stop_info_sp (GetStopInfo ());
377     if (stop_info_sp)
378         return stop_info_sp->GetStopReason();
379     return eStopReasonNone;
380 }
381 
382 
383 
384 void
385 Thread::SetStopInfo (const lldb::StopInfoSP &stop_info_sp)
386 {
387     m_actual_stop_info_sp = stop_info_sp;
388     if (m_actual_stop_info_sp)
389         m_actual_stop_info_sp->MakeStopInfoValid();
390     ProcessSP process_sp (GetProcess());
391     if (process_sp)
392         m_thread_stop_reason_stop_id = process_sp->GetStopID();
393     else
394         m_thread_stop_reason_stop_id = UINT32_MAX;
395 }
396 
397 void
398 Thread::SetStopInfoToNothing()
399 {
400     // Note, we can't just NULL out the private reason, or the native thread implementation will try to
401     // go calculate it again.  For now, just set it to a Unix Signal with an invalid signal number.
402     SetStopInfo (StopInfo::CreateStopReasonWithSignal (*this,  LLDB_INVALID_SIGNAL_NUMBER));
403 }
404 
405 bool
406 Thread::ThreadStoppedForAReason (void)
407 {
408     return (bool) GetPrivateStopReason ();
409 }
410 
411 bool
412 Thread::CheckpointThreadState (ThreadStateCheckpoint &saved_state)
413 {
414     if (!SaveFrameZeroState(saved_state.register_backup))
415         return false;
416 
417     saved_state.stop_info_sp = GetStopInfo();
418     ProcessSP process_sp (GetProcess());
419     if (process_sp)
420         saved_state.orig_stop_id = process_sp->GetStopID();
421     saved_state.current_inlined_depth = GetCurrentInlinedDepth();
422 
423     return true;
424 }
425 
426 bool
427 Thread::RestoreRegisterStateFromCheckpoint (ThreadStateCheckpoint &saved_state)
428 {
429     RestoreSaveFrameZero(saved_state.register_backup);
430     return true;
431 }
432 
433 bool
434 Thread::RestoreThreadStateFromCheckpoint (ThreadStateCheckpoint &saved_state)
435 {
436     if (saved_state.stop_info_sp)
437         saved_state.stop_info_sp->MakeStopInfoValid();
438     SetStopInfo(saved_state.stop_info_sp);
439     GetStackFrameList()->SetCurrentInlinedDepth (saved_state.current_inlined_depth);
440     return true;
441 }
442 
443 StateType
444 Thread::GetState() const
445 {
446     // If any other threads access this we will need a mutex for it
447     Mutex::Locker locker(m_state_mutex);
448     return m_state;
449 }
450 
451 void
452 Thread::SetState(StateType state)
453 {
454     Mutex::Locker locker(m_state_mutex);
455     m_state = state;
456 }
457 
458 void
459 Thread::WillStop()
460 {
461     ThreadPlan *current_plan = GetCurrentPlan();
462 
463     // FIXME: I may decide to disallow threads with no plans.  In which
464     // case this should go to an assert.
465 
466     if (!current_plan)
467         return;
468 
469     current_plan->WillStop();
470 }
471 
472 void
473 Thread::SetupForResume ()
474 {
475     if (GetResumeState() != eStateSuspended)
476     {
477 
478         // If we're at a breakpoint push the step-over breakpoint plan.  Do this before
479         // telling the current plan it will resume, since we might change what the current
480         // plan is.
481 
482         StopReason stop_reason = lldb::eStopReasonInvalid;
483         StopInfoSP stop_info_sp = GetStopInfo();
484         if (stop_info_sp.get())
485             stop_reason = stop_info_sp->GetStopReason();
486         if (stop_reason == lldb::eStopReasonBreakpoint)
487         {
488             // Note, don't assume there's a ThreadPlanStepOverBreakpoint, the target may not require anything
489             // special to step over a breakpoint.
490 
491             ThreadPlan *cur_plan = GetCurrentPlan();
492 
493             if (cur_plan->GetKind() != ThreadPlan::eKindStepOverBreakpoint)
494             {
495                 ThreadPlanStepOverBreakpoint *step_bp_plan = new ThreadPlanStepOverBreakpoint (*this);
496                 if (step_bp_plan)
497                 {
498                     ThreadPlanSP step_bp_plan_sp;
499                     step_bp_plan->SetPrivate (true);
500 
501                     if (GetCurrentPlan()->RunState() != eStateStepping)
502                     {
503                         step_bp_plan->SetAutoContinue(true);
504                     }
505                     step_bp_plan_sp.reset (step_bp_plan);
506                     QueueThreadPlan (step_bp_plan_sp, false);
507                 }
508             }
509         }
510     }
511 }
512 
513 bool
514 Thread::WillResume (StateType resume_state)
515 {
516     // At this point clear the completed plan stack.
517     m_completed_plan_stack.clear();
518     m_discarded_plan_stack.clear();
519 
520     m_temporary_resume_state = resume_state;
521 
522     // This is a little dubious, but we are trying to limit how often we actually fetch stop info from
523     // the target, 'cause that slows down single stepping.  So assume that if we got to the point where
524     // we're about to resume, and we haven't yet had to fetch the stop reason, then it doesn't need to know
525     // about the fact that we are resuming...
526         const uint32_t process_stop_id = GetProcess()->GetStopID();
527     if (m_thread_stop_reason_stop_id == process_stop_id &&
528         (m_actual_stop_info_sp && m_actual_stop_info_sp->IsValid()))
529     {
530         StopInfo *stop_info = GetPrivateStopReason().get();
531         if (stop_info)
532             stop_info->WillResume (resume_state);
533     }
534 
535     // Tell all the plans that we are about to resume in case they need to clear any state.
536     // We distinguish between the plan on the top of the stack and the lower
537     // plans in case a plan needs to do any special business before it runs.
538 
539     ThreadPlan *plan_ptr = GetCurrentPlan();
540     bool need_to_resume = plan_ptr->WillResume(resume_state, true);
541 
542     while ((plan_ptr = GetPreviousPlan(plan_ptr)) != NULL)
543     {
544         plan_ptr->WillResume (resume_state, false);
545     }
546 
547     // If the WillResume for the plan says we are faking a resume, then it will have set an appropriate stop info.
548     // In that case, don't reset it here.
549 
550     if (need_to_resume && resume_state != eStateSuspended)
551     {
552         m_actual_stop_info_sp.reset();
553     }
554 
555     return need_to_resume;
556 }
557 
558 void
559 Thread::DidResume ()
560 {
561     SetResumeSignal (LLDB_INVALID_SIGNAL_NUMBER);
562 }
563 
564 bool
565 Thread::ShouldStop (Event* event_ptr)
566 {
567     ThreadPlan *current_plan = GetCurrentPlan();
568     bool should_stop = true;
569 
570     LogSP log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP));
571 
572     if (GetResumeState () == eStateSuspended)
573     {
574         if (log)
575             log->Printf ("Thread::%s for tid = 0x%4.4" PRIx64 ", should_stop = 0 (ignore since thread was suspended)",
576                          __FUNCTION__,
577                          GetID ());
578 //            log->Printf ("Thread::%s for tid = 0x%4.4" PRIx64 ", pc = 0x%16.16" PRIx64 ", should_stop = 0 (ignore since thread was suspended)",
579 //                         __FUNCTION__,
580 //                         GetID (),
581 //                         GetRegisterContext()->GetPC());
582         return false;
583     }
584 
585     if (GetTemporaryResumeState () == eStateSuspended)
586     {
587         if (log)
588             log->Printf ("Thread::%s for tid = 0x%4.4" PRIx64 ", should_stop = 0 (ignore since thread was suspended)",
589                          __FUNCTION__,
590                          GetID ());
591 //            log->Printf ("Thread::%s for tid = 0x%4.4" PRIx64 ", pc = 0x%16.16" PRIx64 ", should_stop = 0 (ignore since thread was suspended)",
592 //                         __FUNCTION__,
593 //                         GetID (),
594 //                         GetRegisterContext()->GetPC());
595         return false;
596     }
597 
598     if (ThreadStoppedForAReason() == false)
599     {
600         if (log)
601             log->Printf ("Thread::%s for tid = 0x%4.4" PRIx64 ", pc = 0x%16.16" PRIx64 ", should_stop = 0 (ignore since no stop reason)",
602                          __FUNCTION__,
603                          GetID (),
604                          GetRegisterContext()->GetPC());
605         return false;
606     }
607 
608     if (log)
609     {
610         log->Printf ("Thread::%s for tid = 0x%4.4" PRIx64 ", pc = 0x%16.16" PRIx64,
611                      __FUNCTION__,
612                      GetID (),
613                      GetRegisterContext()->GetPC());
614         log->Printf ("^^^^^^^^ Thread::ShouldStop Begin ^^^^^^^^");
615         StreamString s;
616         s.IndentMore();
617         DumpThreadPlans(&s);
618         log->Printf ("Plan stack initial state:\n%s", s.GetData());
619     }
620 
621     // The top most plan always gets to do the trace log...
622     current_plan->DoTraceLog ();
623 
624     // First query the stop info's ShouldStopSynchronous.  This handles "synchronous" stop reasons, for example the breakpoint
625     // command on internal breakpoints.  If a synchronous stop reason says we should not stop, then we don't have to
626     // do any more work on this stop.
627     StopInfoSP private_stop_info (GetPrivateStopReason());
628     if (private_stop_info && private_stop_info->ShouldStopSynchronous(event_ptr) == false)
629     {
630         if (log)
631             log->Printf ("StopInfo::ShouldStop async callback says we should not stop, returning ShouldStop of false.");
632         return false;
633     }
634 
635     // If we've already been restarted, don't query the plans since the state they would examine is not current.
636     if (Process::ProcessEventData::GetRestartedFromEvent(event_ptr))
637         return false;
638 
639     // Before the plans see the state of the world, calculate the current inlined depth.
640     GetStackFrameList()->CalculateCurrentInlinedDepth();
641 
642     // If the base plan doesn't understand why we stopped, then we have to find a plan that does.
643     // If that plan is still working, then we don't need to do any more work.  If the plan that explains
644     // the stop is done, then we should pop all the plans below it, and pop it, and then let the plans above it decide
645     // whether they still need to do more work.
646 
647     bool done_processing_current_plan = false;
648 
649     if (!current_plan->PlanExplainsStop())
650     {
651         if (current_plan->TracerExplainsStop())
652         {
653             done_processing_current_plan = true;
654             should_stop = false;
655         }
656         else
657         {
658             // If the current plan doesn't explain the stop, then find one that
659             // does and let it handle the situation.
660             ThreadPlan *plan_ptr = current_plan;
661             while ((plan_ptr = GetPreviousPlan(plan_ptr)) != NULL)
662             {
663                 if (plan_ptr->PlanExplainsStop())
664                 {
665                     should_stop = plan_ptr->ShouldStop (event_ptr);
666 
667                     // plan_ptr explains the stop, next check whether plan_ptr is done, if so, then we should take it
668                     // and all the plans below it off the stack.
669 
670                     if (plan_ptr->MischiefManaged())
671                     {
672                         // We're going to pop the plans up to and including the plan that explains the stop.
673                         ThreadPlan *prev_plan_ptr = GetPreviousPlan (plan_ptr);
674 
675                         do
676                         {
677                             if (should_stop)
678                                 current_plan->WillStop();
679                             PopPlan();
680                         }
681                         while ((current_plan = GetCurrentPlan()) != prev_plan_ptr);
682                         // Now, if the responsible plan was not "Okay to discard" then we're done,
683                         // otherwise we forward this to the next plan in the stack below.
684                         if (plan_ptr->IsMasterPlan() && !plan_ptr->OkayToDiscard())
685                             done_processing_current_plan = true;
686                         else
687                             done_processing_current_plan = false;
688                     }
689                     else
690                         done_processing_current_plan = true;
691 
692                     break;
693                 }
694 
695             }
696         }
697     }
698 
699     if (!done_processing_current_plan)
700     {
701         bool over_ride_stop = current_plan->ShouldAutoContinue(event_ptr);
702 
703         if (log)
704             log->Printf("Plan %s explains stop, auto-continue %i.", current_plan->GetName(), over_ride_stop);
705 
706         // We're starting from the base plan, so just let it decide;
707         if (PlanIsBasePlan(current_plan))
708         {
709             should_stop = current_plan->ShouldStop (event_ptr);
710             if (log)
711                 log->Printf("Base plan says should stop: %i.", should_stop);
712         }
713         else
714         {
715             // Otherwise, don't let the base plan override what the other plans say to do, since
716             // presumably if there were other plans they would know what to do...
717             while (1)
718             {
719                 if (PlanIsBasePlan(current_plan))
720                     break;
721 
722                 should_stop = current_plan->ShouldStop(event_ptr);
723                 if (log)
724                     log->Printf("Plan %s should stop: %d.", current_plan->GetName(), should_stop);
725                 if (current_plan->MischiefManaged())
726                 {
727                     if (should_stop)
728                         current_plan->WillStop();
729 
730                     // If a Master Plan wants to stop, and wants to stick on the stack, we let it.
731                     // Otherwise, see if the plan's parent wants to stop.
732 
733                     if (should_stop && current_plan->IsMasterPlan() && !current_plan->OkayToDiscard())
734                     {
735                         PopPlan();
736                         break;
737                     }
738                     else
739                     {
740 
741                         PopPlan();
742 
743                         current_plan = GetCurrentPlan();
744                         if (current_plan == NULL)
745                         {
746                             break;
747                         }
748                     }
749                 }
750                 else
751                 {
752                     break;
753                 }
754             }
755         }
756 
757         if (over_ride_stop)
758             should_stop = false;
759 
760         // One other potential problem is that we set up a master plan, then stop in before it is complete - for instance
761         // by hitting a breakpoint during a step-over - then do some step/finish/etc operations that wind up
762         // past the end point condition of the initial plan.  We don't want to strand the original plan on the stack,
763         // This code clears stale plans off the stack.
764 
765         if (should_stop)
766         {
767             ThreadPlan *plan_ptr = GetCurrentPlan();
768             while (!PlanIsBasePlan(plan_ptr))
769             {
770                 bool stale = plan_ptr->IsPlanStale ();
771                 ThreadPlan *examined_plan = plan_ptr;
772                 plan_ptr = GetPreviousPlan (examined_plan);
773 
774                 if (stale)
775                 {
776                     if (log)
777                         log->Printf("Plan %s being discarded in cleanup, it says it is already done.", examined_plan->GetName());
778                     DiscardThreadPlansUpToPlan(examined_plan);
779                 }
780             }
781         }
782 
783     }
784 
785     if (log)
786     {
787         StreamString s;
788         s.IndentMore();
789         DumpThreadPlans(&s);
790         log->Printf ("Plan stack final state:\n%s", s.GetData());
791         log->Printf ("vvvvvvvv Thread::ShouldStop End (returning %i) vvvvvvvv", should_stop);
792     }
793     return should_stop;
794 }
795 
796 Vote
797 Thread::ShouldReportStop (Event* event_ptr)
798 {
799     StateType thread_state = GetResumeState ();
800     StateType temp_thread_state = GetTemporaryResumeState();
801 
802     LogSP log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP));
803 
804     if (thread_state == eStateSuspended || thread_state == eStateInvalid)
805     {
806         if (log)
807             log->Printf ("Thread::ShouldReportStop() tid = 0x%4.4" PRIx64 ": returning vote %i (state was suspended or invalid)\n", GetID(), eVoteNoOpinion);
808         return eVoteNoOpinion;
809     }
810 
811     if (temp_thread_state == eStateSuspended || temp_thread_state == eStateInvalid)
812     {
813         if (log)
814             log->Printf ("Thread::ShouldReportStop() tid = 0x%4.4" PRIx64 ": returning vote %i (temporary state was suspended or invalid)\n", GetID(), eVoteNoOpinion);
815         return eVoteNoOpinion;
816     }
817 
818     if (!ThreadStoppedForAReason())
819     {
820         if (log)
821             log->Printf ("Thread::ShouldReportStop() tid = 0x%4.4" PRIx64 ": returning vote %i (thread didn't stop for a reason.)\n", GetID(), eVoteNoOpinion);
822         return eVoteNoOpinion;
823     }
824 
825     if (m_completed_plan_stack.size() > 0)
826     {
827         // Don't use GetCompletedPlan here, since that suppresses private plans.
828         if (log)
829             log->Printf ("Thread::ShouldReportStop() tid = 0x%4.4" PRIx64 ": returning vote  for complete stack's back plan\n", GetID());
830         return m_completed_plan_stack.back()->ShouldReportStop (event_ptr);
831     }
832     else
833     {
834         if (log)
835             log->Printf ("Thread::ShouldReportStop() tid = 0x%4.4" PRIx64 ": returning vote  for current plan\n", GetID());
836         return GetCurrentPlan()->ShouldReportStop (event_ptr);
837     }
838 }
839 
840 Vote
841 Thread::ShouldReportRun (Event* event_ptr)
842 {
843     StateType thread_state = GetResumeState ();
844 
845     if (thread_state == eStateSuspended
846             || thread_state == eStateInvalid)
847     {
848         return eVoteNoOpinion;
849     }
850 
851     LogSP log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP));
852     if (m_completed_plan_stack.size() > 0)
853     {
854         // Don't use GetCompletedPlan here, since that suppresses private plans.
855         if (log)
856             log->Printf ("Current Plan for thread %d (0x%4.4" PRIx64 "): %s being asked whether we should report run.",
857                          GetIndexID(),
858                          GetID(),
859                          m_completed_plan_stack.back()->GetName());
860 
861         return m_completed_plan_stack.back()->ShouldReportRun (event_ptr);
862     }
863     else
864     {
865         if (log)
866             log->Printf ("Current Plan for thread %d (0x%4.4" PRIx64 "): %s being asked whether we should report run.",
867                          GetIndexID(),
868                          GetID(),
869                          GetCurrentPlan()->GetName());
870 
871         return GetCurrentPlan()->ShouldReportRun (event_ptr);
872      }
873 }
874 
875 bool
876 Thread::MatchesSpec (const ThreadSpec *spec)
877 {
878     if (spec == NULL)
879         return true;
880 
881     return spec->ThreadPassesBasicTests(*this);
882 }
883 
884 void
885 Thread::PushPlan (ThreadPlanSP &thread_plan_sp)
886 {
887     if (thread_plan_sp)
888     {
889         // If the thread plan doesn't already have a tracer, give it its parent's tracer:
890         if (!thread_plan_sp->GetThreadPlanTracer())
891             thread_plan_sp->SetThreadPlanTracer(m_plan_stack.back()->GetThreadPlanTracer());
892         m_plan_stack.push_back (thread_plan_sp);
893 
894         thread_plan_sp->DidPush();
895 
896         LogSP log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP));
897         if (log)
898         {
899             StreamString s;
900             thread_plan_sp->GetDescription (&s, lldb::eDescriptionLevelFull);
901             log->Printf("Pushing plan: \"%s\", tid = 0x%4.4" PRIx64 ".",
902                         s.GetData(),
903                         thread_plan_sp->GetThread().GetID());
904         }
905     }
906 }
907 
908 void
909 Thread::PopPlan ()
910 {
911     LogSP log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP));
912 
913     if (m_plan_stack.size() <= 1)
914         return;
915     else
916     {
917         ThreadPlanSP &plan = m_plan_stack.back();
918         if (log)
919         {
920             log->Printf("Popping plan: \"%s\", tid = 0x%4.4" PRIx64 ".", plan->GetName(), plan->GetThread().GetID());
921         }
922         m_completed_plan_stack.push_back (plan);
923         plan->WillPop();
924         m_plan_stack.pop_back();
925     }
926 }
927 
928 void
929 Thread::DiscardPlan ()
930 {
931     if (m_plan_stack.size() > 1)
932     {
933         ThreadPlanSP &plan = m_plan_stack.back();
934         m_discarded_plan_stack.push_back (plan);
935         plan->WillPop();
936         m_plan_stack.pop_back();
937     }
938 }
939 
940 ThreadPlan *
941 Thread::GetCurrentPlan ()
942 {
943     // There will always be at least the base plan.  If somebody is mucking with a
944     // thread with an empty plan stack, we should assert right away.
945     assert (!m_plan_stack.empty());
946 
947     return m_plan_stack.back().get();
948 }
949 
950 ThreadPlanSP
951 Thread::GetCompletedPlan ()
952 {
953     ThreadPlanSP empty_plan_sp;
954     if (!m_completed_plan_stack.empty())
955     {
956         for (int i = m_completed_plan_stack.size() - 1; i >= 0; i--)
957         {
958             ThreadPlanSP completed_plan_sp;
959             completed_plan_sp = m_completed_plan_stack[i];
960             if (!completed_plan_sp->GetPrivate ())
961             return completed_plan_sp;
962         }
963     }
964     return empty_plan_sp;
965 }
966 
967 ValueObjectSP
968 Thread::GetReturnValueObject ()
969 {
970     if (!m_completed_plan_stack.empty())
971     {
972         for (int i = m_completed_plan_stack.size() - 1; i >= 0; i--)
973         {
974             ValueObjectSP return_valobj_sp;
975             return_valobj_sp = m_completed_plan_stack[i]->GetReturnValueObject();
976             if (return_valobj_sp)
977             return return_valobj_sp;
978         }
979     }
980     return ValueObjectSP();
981 }
982 
983 bool
984 Thread::IsThreadPlanDone (ThreadPlan *plan)
985 {
986     if (!m_completed_plan_stack.empty())
987     {
988         for (int i = m_completed_plan_stack.size() - 1; i >= 0; i--)
989         {
990             if (m_completed_plan_stack[i].get() == plan)
991                 return true;
992         }
993     }
994     return false;
995 }
996 
997 bool
998 Thread::WasThreadPlanDiscarded (ThreadPlan *plan)
999 {
1000     if (!m_discarded_plan_stack.empty())
1001     {
1002         for (int i = m_discarded_plan_stack.size() - 1; i >= 0; i--)
1003         {
1004             if (m_discarded_plan_stack[i].get() == plan)
1005                 return true;
1006         }
1007     }
1008     return false;
1009 }
1010 
1011 ThreadPlan *
1012 Thread::GetPreviousPlan (ThreadPlan *current_plan)
1013 {
1014     if (current_plan == NULL)
1015         return NULL;
1016 
1017     int stack_size = m_completed_plan_stack.size();
1018     for (int i = stack_size - 1; i > 0; i--)
1019     {
1020         if (current_plan == m_completed_plan_stack[i].get())
1021             return m_completed_plan_stack[i-1].get();
1022     }
1023 
1024     if (stack_size > 0 && m_completed_plan_stack[0].get() == current_plan)
1025     {
1026         if (m_plan_stack.size() > 0)
1027             return m_plan_stack.back().get();
1028         else
1029             return NULL;
1030     }
1031 
1032     stack_size = m_plan_stack.size();
1033     for (int i = stack_size - 1; i > 0; i--)
1034     {
1035         if (current_plan == m_plan_stack[i].get())
1036             return m_plan_stack[i-1].get();
1037     }
1038     return NULL;
1039 }
1040 
1041 void
1042 Thread::QueueThreadPlan (ThreadPlanSP &thread_plan_sp, bool abort_other_plans)
1043 {
1044     if (abort_other_plans)
1045        DiscardThreadPlans(true);
1046 
1047     PushPlan (thread_plan_sp);
1048 }
1049 
1050 
1051 void
1052 Thread::EnableTracer (bool value, bool single_stepping)
1053 {
1054     int stack_size = m_plan_stack.size();
1055     for (int i = 0; i < stack_size; i++)
1056     {
1057         if (m_plan_stack[i]->GetThreadPlanTracer())
1058         {
1059             m_plan_stack[i]->GetThreadPlanTracer()->EnableTracing(value);
1060             m_plan_stack[i]->GetThreadPlanTracer()->EnableSingleStep(single_stepping);
1061         }
1062     }
1063 }
1064 
1065 void
1066 Thread::SetTracer (lldb::ThreadPlanTracerSP &tracer_sp)
1067 {
1068     int stack_size = m_plan_stack.size();
1069     for (int i = 0; i < stack_size; i++)
1070         m_plan_stack[i]->SetThreadPlanTracer(tracer_sp);
1071 }
1072 
1073 void
1074 Thread::DiscardThreadPlansUpToPlan (lldb::ThreadPlanSP &up_to_plan_sp)
1075 {
1076     DiscardThreadPlansUpToPlan (up_to_plan_sp.get());
1077 }
1078 
1079 void
1080 Thread::DiscardThreadPlansUpToPlan (ThreadPlan *up_to_plan_ptr)
1081 {
1082     LogSP log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP));
1083     if (log)
1084     {
1085         log->Printf("Discarding thread plans for thread tid = 0x%4.4" PRIx64 ", up to %p", GetID(), up_to_plan_ptr);
1086     }
1087 
1088     int stack_size = m_plan_stack.size();
1089 
1090     // If the input plan is NULL, discard all plans.  Otherwise make sure this plan is in the
1091     // stack, and if so discard up to and including it.
1092 
1093     if (up_to_plan_ptr == NULL)
1094     {
1095         for (int i = stack_size - 1; i > 0; i--)
1096             DiscardPlan();
1097     }
1098     else
1099     {
1100         bool found_it = false;
1101         for (int i = stack_size - 1; i > 0; i--)
1102         {
1103             if (m_plan_stack[i].get() == up_to_plan_ptr)
1104                 found_it = true;
1105         }
1106         if (found_it)
1107         {
1108             bool last_one = false;
1109             for (int i = stack_size - 1; i > 0 && !last_one ; i--)
1110             {
1111                 if (GetCurrentPlan() == up_to_plan_ptr)
1112                     last_one = true;
1113                 DiscardPlan();
1114             }
1115         }
1116     }
1117     return;
1118 }
1119 
1120 void
1121 Thread::DiscardThreadPlans(bool force)
1122 {
1123     LogSP log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP));
1124     if (log)
1125     {
1126         log->Printf("Discarding thread plans for thread (tid = 0x%4.4" PRIx64 ", force %d)", GetID(), force);
1127     }
1128 
1129     if (force)
1130     {
1131         int stack_size = m_plan_stack.size();
1132         for (int i = stack_size - 1; i > 0; i--)
1133         {
1134             DiscardPlan();
1135         }
1136         return;
1137     }
1138 
1139     while (1)
1140     {
1141 
1142         int master_plan_idx;
1143         bool discard = true;
1144 
1145         // Find the first master plan, see if it wants discarding, and if yes discard up to it.
1146         for (master_plan_idx = m_plan_stack.size() - 1; master_plan_idx >= 0; master_plan_idx--)
1147         {
1148             if (m_plan_stack[master_plan_idx]->IsMasterPlan())
1149             {
1150                 discard = m_plan_stack[master_plan_idx]->OkayToDiscard();
1151                 break;
1152             }
1153         }
1154 
1155         if (discard)
1156         {
1157             // First pop all the dependent plans:
1158             for (int i = m_plan_stack.size() - 1; i > master_plan_idx; i--)
1159             {
1160 
1161                 // FIXME: Do we need a finalize here, or is the rule that "PrepareForStop"
1162                 // for the plan leaves it in a state that it is safe to pop the plan
1163                 // with no more notice?
1164                 DiscardPlan();
1165             }
1166 
1167             // Now discard the master plan itself.
1168             // The bottom-most plan never gets discarded.  "OkayToDiscard" for it means
1169             // discard it's dependent plans, but not it...
1170             if (master_plan_idx > 0)
1171             {
1172                 DiscardPlan();
1173             }
1174         }
1175         else
1176         {
1177             // If the master plan doesn't want to get discarded, then we're done.
1178             break;
1179         }
1180 
1181     }
1182 }
1183 
1184 bool
1185 Thread::PlanIsBasePlan (ThreadPlan *plan_ptr)
1186 {
1187     if (plan_ptr->IsBasePlan())
1188         return true;
1189     else if (m_plan_stack.size() == 0)
1190         return false;
1191     else
1192        return m_plan_stack[0].get() == plan_ptr;
1193 }
1194 
1195 Error
1196 Thread::UnwindInnermostExpression()
1197 {
1198     Error error;
1199     int stack_size = m_plan_stack.size();
1200 
1201     // If the input plan is NULL, discard all plans.  Otherwise make sure this plan is in the
1202     // stack, and if so discard up to and including it.
1203 
1204     for (int i = stack_size - 1; i > 0; i--)
1205     {
1206         if (m_plan_stack[i]->GetKind() == ThreadPlan::eKindCallFunction)
1207         {
1208             DiscardThreadPlansUpToPlan(m_plan_stack[i].get());
1209             return error;
1210         }
1211     }
1212     error.SetErrorString("No expressions currently active on this thread");
1213     return error;
1214 }
1215 
1216 
1217 ThreadPlan *
1218 Thread::QueueFundamentalPlan (bool abort_other_plans)
1219 {
1220     ThreadPlanSP thread_plan_sp (new ThreadPlanBase(*this));
1221     QueueThreadPlan (thread_plan_sp, abort_other_plans);
1222     return thread_plan_sp.get();
1223 }
1224 
1225 ThreadPlan *
1226 Thread::QueueThreadPlanForStepSingleInstruction
1227 (
1228     bool step_over,
1229     bool abort_other_plans,
1230     bool stop_other_threads
1231 )
1232 {
1233     ThreadPlanSP thread_plan_sp (new ThreadPlanStepInstruction (*this, step_over, stop_other_threads, eVoteNoOpinion, eVoteNoOpinion));
1234     QueueThreadPlan (thread_plan_sp, abort_other_plans);
1235     return thread_plan_sp.get();
1236 }
1237 
1238 ThreadPlan *
1239 Thread::QueueThreadPlanForStepOverRange
1240 (
1241     bool abort_other_plans,
1242     const AddressRange &range,
1243     const SymbolContext &addr_context,
1244     lldb::RunMode stop_other_threads
1245 )
1246 {
1247     ThreadPlanSP thread_plan_sp;
1248     thread_plan_sp.reset (new ThreadPlanStepOverRange (*this, range, addr_context, stop_other_threads));
1249 
1250     QueueThreadPlan (thread_plan_sp, abort_other_plans);
1251     return thread_plan_sp.get();
1252 }
1253 
1254 ThreadPlan *
1255 Thread::QueueThreadPlanForStepInRange
1256 (
1257     bool abort_other_plans,
1258     const AddressRange &range,
1259     const SymbolContext &addr_context,
1260     const char *step_in_target,
1261     lldb::RunMode stop_other_threads,
1262     bool avoid_code_without_debug_info
1263 )
1264 {
1265     ThreadPlanSP thread_plan_sp;
1266     ThreadPlanStepInRange *plan = new ThreadPlanStepInRange (*this, range, addr_context, stop_other_threads);
1267     if (avoid_code_without_debug_info)
1268         plan->GetFlags().Set (ThreadPlanShouldStopHere::eAvoidNoDebug);
1269     else
1270         plan->GetFlags().Clear (ThreadPlanShouldStopHere::eAvoidNoDebug);
1271     if (step_in_target)
1272         plan->SetStepInTarget(step_in_target);
1273     thread_plan_sp.reset (plan);
1274 
1275     QueueThreadPlan (thread_plan_sp, abort_other_plans);
1276     return thread_plan_sp.get();
1277 }
1278 
1279 
1280 ThreadPlan *
1281 Thread::QueueThreadPlanForStepOverBreakpointPlan (bool abort_other_plans)
1282 {
1283     ThreadPlanSP thread_plan_sp (new ThreadPlanStepOverBreakpoint (*this));
1284     QueueThreadPlan (thread_plan_sp, abort_other_plans);
1285     return thread_plan_sp.get();
1286 }
1287 
1288 ThreadPlan *
1289 Thread::QueueThreadPlanForStepOut
1290 (
1291     bool abort_other_plans,
1292     SymbolContext *addr_context,
1293     bool first_insn,
1294     bool stop_other_threads,
1295     Vote stop_vote,
1296     Vote run_vote,
1297     uint32_t frame_idx
1298 )
1299 {
1300     ThreadPlanSP thread_plan_sp (new ThreadPlanStepOut (*this,
1301                                                         addr_context,
1302                                                         first_insn,
1303                                                         stop_other_threads,
1304                                                         stop_vote,
1305                                                         run_vote,
1306                                                         frame_idx));
1307 
1308     if (thread_plan_sp->ValidatePlan(NULL))
1309     {
1310         QueueThreadPlan (thread_plan_sp, abort_other_plans);
1311         return thread_plan_sp.get();
1312     }
1313     else
1314     {
1315         return NULL;
1316     }
1317 }
1318 
1319 ThreadPlan *
1320 Thread::QueueThreadPlanForStepThrough (StackID &return_stack_id, bool abort_other_plans, bool stop_other_threads)
1321 {
1322     ThreadPlanSP thread_plan_sp(new ThreadPlanStepThrough (*this, return_stack_id, stop_other_threads));
1323     if (!thread_plan_sp || !thread_plan_sp->ValidatePlan (NULL))
1324         return NULL;
1325 
1326     QueueThreadPlan (thread_plan_sp, abort_other_plans);
1327     return thread_plan_sp.get();
1328 }
1329 
1330 ThreadPlan *
1331 Thread::QueueThreadPlanForCallFunction (bool abort_other_plans,
1332                                         Address& function,
1333                                         lldb::addr_t arg,
1334                                         bool stop_other_threads,
1335                                         bool unwind_on_error,
1336                                         bool ignore_breakpoints)
1337 {
1338     ThreadPlanSP thread_plan_sp (new ThreadPlanCallFunction (*this,
1339                                                              function,
1340                                                              ClangASTType(),
1341                                                              arg,
1342                                                              stop_other_threads,
1343                                                              unwind_on_error,
1344                                                              ignore_breakpoints));
1345     QueueThreadPlan (thread_plan_sp, abort_other_plans);
1346     return thread_plan_sp.get();
1347 }
1348 
1349 ThreadPlan *
1350 Thread::QueueThreadPlanForRunToAddress (bool abort_other_plans,
1351                                         Address &target_addr,
1352                                         bool stop_other_threads)
1353 {
1354     ThreadPlanSP thread_plan_sp (new ThreadPlanRunToAddress (*this, target_addr, stop_other_threads));
1355     QueueThreadPlan (thread_plan_sp, abort_other_plans);
1356     return thread_plan_sp.get();
1357 }
1358 
1359 ThreadPlan *
1360 Thread::QueueThreadPlanForStepUntil (bool abort_other_plans,
1361                                      lldb::addr_t *address_list,
1362                                      size_t num_addresses,
1363                                      bool stop_other_threads,
1364                                      uint32_t frame_idx)
1365 {
1366     ThreadPlanSP thread_plan_sp (new ThreadPlanStepUntil (*this, address_list, num_addresses, stop_other_threads, frame_idx));
1367     QueueThreadPlan (thread_plan_sp, abort_other_plans);
1368     return thread_plan_sp.get();
1369 
1370 }
1371 
1372 uint32_t
1373 Thread::GetIndexID () const
1374 {
1375     return m_index_id;
1376 }
1377 
1378 void
1379 Thread::DumpThreadPlans (lldb_private::Stream *s) const
1380 {
1381     uint32_t stack_size = m_plan_stack.size();
1382     int i;
1383     s->Indent();
1384     s->Printf ("Plan Stack for thread #%u: tid = 0x%4.4" PRIx64 ", stack_size = %d\n", GetIndexID(), GetID(), stack_size);
1385     for (i = stack_size - 1; i >= 0; i--)
1386     {
1387         s->IndentMore();
1388         s->Indent();
1389         s->Printf ("Element %d: ", i);
1390         m_plan_stack[i]->GetDescription (s, eDescriptionLevelFull);
1391         s->EOL();
1392         s->IndentLess();
1393     }
1394 
1395     stack_size = m_completed_plan_stack.size();
1396     if (stack_size > 0)
1397     {
1398         s->Indent();
1399         s->Printf ("Completed Plan Stack: %d elements.\n", stack_size);
1400         for (i = stack_size - 1; i >= 0; i--)
1401         {
1402             s->IndentMore();
1403             s->Indent();
1404             s->Printf ("Element %d: ", i);
1405             m_completed_plan_stack[i]->GetDescription (s, eDescriptionLevelFull);
1406             s->EOL();
1407             s->IndentLess();
1408         }
1409     }
1410 
1411     stack_size = m_discarded_plan_stack.size();
1412     if (stack_size > 0)
1413     {
1414         s->Indent();
1415         s->Printf ("Discarded Plan Stack: %d elements.\n", stack_size);
1416         for (i = stack_size - 1; i >= 0; i--)
1417         {
1418             s->IndentMore();
1419             s->Indent();
1420             s->Printf ("Element %d: ", i);
1421             m_discarded_plan_stack[i]->GetDescription (s, eDescriptionLevelFull);
1422             s->EOL();
1423             s->IndentLess();
1424         }
1425     }
1426 
1427 }
1428 
1429 TargetSP
1430 Thread::CalculateTarget ()
1431 {
1432     TargetSP target_sp;
1433     ProcessSP process_sp(GetProcess());
1434     if (process_sp)
1435         target_sp = process_sp->CalculateTarget();
1436     return target_sp;
1437 
1438 }
1439 
1440 ProcessSP
1441 Thread::CalculateProcess ()
1442 {
1443     return GetProcess();
1444 }
1445 
1446 ThreadSP
1447 Thread::CalculateThread ()
1448 {
1449     return shared_from_this();
1450 }
1451 
1452 StackFrameSP
1453 Thread::CalculateStackFrame ()
1454 {
1455     return StackFrameSP();
1456 }
1457 
1458 void
1459 Thread::CalculateExecutionContext (ExecutionContext &exe_ctx)
1460 {
1461     exe_ctx.SetContext (shared_from_this());
1462 }
1463 
1464 
1465 StackFrameListSP
1466 Thread::GetStackFrameList ()
1467 {
1468     StackFrameListSP frame_list_sp;
1469     Mutex::Locker locker(m_frame_mutex);
1470     if (m_curr_frames_sp)
1471     {
1472         frame_list_sp = m_curr_frames_sp;
1473     }
1474     else
1475     {
1476         frame_list_sp.reset(new StackFrameList (*this, m_prev_frames_sp, true));
1477         m_curr_frames_sp = frame_list_sp;
1478     }
1479     return frame_list_sp;
1480 }
1481 
1482 void
1483 Thread::ClearStackFrames ()
1484 {
1485     Mutex::Locker locker(m_frame_mutex);
1486 
1487     // Only store away the old "reference" StackFrameList if we got all its frames:
1488     // FIXME: At some point we can try to splice in the frames we have fetched into
1489     // the new frame as we make it, but let's not try that now.
1490     if (m_curr_frames_sp && m_curr_frames_sp->GetAllFramesFetched())
1491         m_prev_frames_sp.swap (m_curr_frames_sp);
1492     m_curr_frames_sp.reset();
1493 }
1494 
1495 lldb::StackFrameSP
1496 Thread::GetFrameWithConcreteFrameIndex (uint32_t unwind_idx)
1497 {
1498     return GetStackFrameList()->GetFrameWithConcreteFrameIndex (unwind_idx);
1499 }
1500 
1501 
1502 Error
1503 Thread::ReturnFromFrameWithIndex (uint32_t frame_idx, lldb::ValueObjectSP return_value_sp, bool broadcast)
1504 {
1505     StackFrameSP frame_sp = GetStackFrameAtIndex (frame_idx);
1506     Error return_error;
1507 
1508     if (!frame_sp)
1509     {
1510         return_error.SetErrorStringWithFormat("Could not find frame with index %d in thread 0x%" PRIx64 ".", frame_idx, GetID());
1511     }
1512 
1513     return ReturnFromFrame(frame_sp, return_value_sp, broadcast);
1514 }
1515 
1516 Error
1517 Thread::ReturnFromFrame (lldb::StackFrameSP frame_sp, lldb::ValueObjectSP return_value_sp, bool broadcast)
1518 {
1519     Error return_error;
1520 
1521     if (!frame_sp)
1522     {
1523         return_error.SetErrorString("Can't return to a null frame.");
1524         return return_error;
1525     }
1526 
1527     Thread *thread = frame_sp->GetThread().get();
1528     uint32_t older_frame_idx = frame_sp->GetFrameIndex() + 1;
1529     StackFrameSP older_frame_sp = thread->GetStackFrameAtIndex(older_frame_idx);
1530     if (!older_frame_sp)
1531     {
1532         return_error.SetErrorString("No older frame to return to.");
1533         return return_error;
1534     }
1535 
1536     if (return_value_sp)
1537     {
1538         lldb::ABISP abi = thread->GetProcess()->GetABI();
1539         if (!abi)
1540         {
1541             return_error.SetErrorString("Could not find ABI to set return value.");
1542             return return_error;
1543         }
1544         SymbolContext sc = frame_sp->GetSymbolContext(eSymbolContextFunction);
1545 
1546         // FIXME: ValueObject::Cast doesn't currently work correctly, at least not for scalars.
1547         // Turn that back on when that works.
1548         if (0 && sc.function != NULL)
1549         {
1550             Type *function_type = sc.function->GetType();
1551             if (function_type)
1552             {
1553                 clang_type_t return_type = sc.function->GetReturnClangType();
1554                 if (return_type)
1555                 {
1556                     ClangASTType ast_type (function_type->GetClangAST(), return_type);
1557                     StreamString s;
1558                     ast_type.DumpTypeDescription(&s);
1559                     ValueObjectSP cast_value_sp = return_value_sp->Cast(ast_type);
1560                     if (cast_value_sp)
1561                     {
1562                         cast_value_sp->SetFormat(eFormatHex);
1563                         return_value_sp = cast_value_sp;
1564                     }
1565                 }
1566             }
1567         }
1568 
1569         return_error = abi->SetReturnValueObject(older_frame_sp, return_value_sp);
1570         if (!return_error.Success())
1571             return return_error;
1572     }
1573 
1574     // Now write the return registers for the chosen frame:
1575     // Note, we can't use ReadAllRegisterValues->WriteAllRegisterValues, since the read & write
1576     // cook their data
1577 
1578     StackFrameSP youngest_frame_sp = thread->GetStackFrameAtIndex(0);
1579     if (youngest_frame_sp)
1580     {
1581         bool copy_success = youngest_frame_sp->GetRegisterContext()->CopyFromRegisterContext(older_frame_sp->GetRegisterContext());
1582         if (copy_success)
1583         {
1584             thread->DiscardThreadPlans(true);
1585             thread->ClearStackFrames();
1586             if (broadcast && EventTypeHasListeners(eBroadcastBitStackChanged))
1587                 BroadcastEvent(eBroadcastBitStackChanged, new ThreadEventData (this->shared_from_this()));
1588         }
1589         else
1590         {
1591             return_error.SetErrorString("Could not reset register values.");
1592         }
1593     }
1594     else
1595     {
1596         return_error.SetErrorString("Returned past top frame.");
1597     }
1598     return return_error;
1599 }
1600 
1601 void
1602 Thread::DumpUsingSettingsFormat (Stream &strm, uint32_t frame_idx)
1603 {
1604     ExecutionContext exe_ctx (shared_from_this());
1605     Process *process = exe_ctx.GetProcessPtr();
1606     if (process == NULL)
1607         return;
1608 
1609     StackFrameSP frame_sp;
1610     SymbolContext frame_sc;
1611     if (frame_idx != LLDB_INVALID_INDEX32)
1612     {
1613         frame_sp = GetStackFrameAtIndex (frame_idx);
1614         if (frame_sp)
1615         {
1616             exe_ctx.SetFrameSP(frame_sp);
1617             frame_sc = frame_sp->GetSymbolContext(eSymbolContextEverything);
1618         }
1619     }
1620 
1621     const char *thread_format = exe_ctx.GetTargetRef().GetDebugger().GetThreadFormat();
1622     assert (thread_format);
1623     const char *end = NULL;
1624     Debugger::FormatPrompt (thread_format,
1625                             frame_sp ? &frame_sc : NULL,
1626                             &exe_ctx,
1627                             NULL,
1628                             strm,
1629                             &end);
1630 }
1631 
1632 void
1633 Thread::SettingsInitialize ()
1634 {
1635 }
1636 
1637 void
1638 Thread::SettingsTerminate ()
1639 {
1640 }
1641 
1642 lldb::StackFrameSP
1643 Thread::GetStackFrameSPForStackFramePtr (StackFrame *stack_frame_ptr)
1644 {
1645     return GetStackFrameList()->GetStackFrameSPForStackFramePtr (stack_frame_ptr);
1646 }
1647 
1648 const char *
1649 Thread::StopReasonAsCString (lldb::StopReason reason)
1650 {
1651     switch (reason)
1652     {
1653     case eStopReasonInvalid:       return "invalid";
1654     case eStopReasonNone:          return "none";
1655     case eStopReasonTrace:         return "trace";
1656     case eStopReasonBreakpoint:    return "breakpoint";
1657     case eStopReasonWatchpoint:    return "watchpoint";
1658     case eStopReasonSignal:        return "signal";
1659     case eStopReasonException:     return "exception";
1660     case eStopReasonExec:          return "exec";
1661     case eStopReasonPlanComplete:  return "plan complete";
1662     case eStopReasonThreadExiting: return "thread exiting";
1663     }
1664 
1665 
1666     static char unknown_state_string[64];
1667     snprintf(unknown_state_string, sizeof (unknown_state_string), "StopReason = %i", reason);
1668     return unknown_state_string;
1669 }
1670 
1671 const char *
1672 Thread::RunModeAsCString (lldb::RunMode mode)
1673 {
1674     switch (mode)
1675     {
1676     case eOnlyThisThread:     return "only this thread";
1677     case eAllThreads:         return "all threads";
1678     case eOnlyDuringStepping: return "only during stepping";
1679     }
1680 
1681     static char unknown_state_string[64];
1682     snprintf(unknown_state_string, sizeof (unknown_state_string), "RunMode = %i", mode);
1683     return unknown_state_string;
1684 }
1685 
1686 size_t
1687 Thread::GetStatus (Stream &strm, uint32_t start_frame, uint32_t num_frames, uint32_t num_frames_with_source)
1688 {
1689     ExecutionContext exe_ctx (shared_from_this());
1690     Target *target = exe_ctx.GetTargetPtr();
1691     Process *process = exe_ctx.GetProcessPtr();
1692     size_t num_frames_shown = 0;
1693     strm.Indent();
1694     bool is_selected = false;
1695     if (process)
1696     {
1697         if (process->GetThreadList().GetSelectedThread().get() == this)
1698             is_selected = true;
1699     }
1700     strm.Printf("%c ", is_selected ? '*' : ' ');
1701     if (target && target->GetDebugger().GetUseExternalEditor())
1702     {
1703         StackFrameSP frame_sp = GetStackFrameAtIndex(start_frame);
1704         if (frame_sp)
1705         {
1706             SymbolContext frame_sc(frame_sp->GetSymbolContext (eSymbolContextLineEntry));
1707             if (frame_sc.line_entry.line != 0 && frame_sc.line_entry.file)
1708             {
1709                 Host::OpenFileInExternalEditor (frame_sc.line_entry.file, frame_sc.line_entry.line);
1710             }
1711         }
1712     }
1713 
1714     DumpUsingSettingsFormat (strm, start_frame);
1715 
1716     if (num_frames > 0)
1717     {
1718         strm.IndentMore();
1719 
1720         const bool show_frame_info = true;
1721         strm.IndentMore ();
1722         num_frames_shown = GetStackFrameList ()->GetStatus (strm,
1723                                                             start_frame,
1724                                                             num_frames,
1725                                                             show_frame_info,
1726                                                             num_frames_with_source);
1727         strm.IndentLess();
1728         strm.IndentLess();
1729     }
1730     return num_frames_shown;
1731 }
1732 
1733 size_t
1734 Thread::GetStackFrameStatus (Stream& strm,
1735                              uint32_t first_frame,
1736                              uint32_t num_frames,
1737                              bool show_frame_info,
1738                              uint32_t num_frames_with_source)
1739 {
1740     return GetStackFrameList()->GetStatus (strm,
1741                                            first_frame,
1742                                            num_frames,
1743                                            show_frame_info,
1744                                            num_frames_with_source);
1745 }
1746 
1747 bool
1748 Thread::SaveFrameZeroState (RegisterCheckpoint &checkpoint)
1749 {
1750     lldb::StackFrameSP frame_sp(GetStackFrameAtIndex (0));
1751     if (frame_sp)
1752     {
1753         checkpoint.SetStackID(frame_sp->GetStackID());
1754         return frame_sp->GetRegisterContext()->ReadAllRegisterValues (checkpoint.GetData());
1755     }
1756     return false;
1757 }
1758 
1759 bool
1760 Thread::RestoreSaveFrameZero (const RegisterCheckpoint &checkpoint)
1761 {
1762     return ResetFrameZeroRegisters (checkpoint.GetData());
1763 }
1764 
1765 bool
1766 Thread::ResetFrameZeroRegisters (lldb::DataBufferSP register_data_sp)
1767 {
1768     lldb::StackFrameSP frame_sp(GetStackFrameAtIndex (0));
1769     if (frame_sp)
1770     {
1771         bool ret = frame_sp->GetRegisterContext()->WriteAllRegisterValues (register_data_sp);
1772 
1773         // Clear out all stack frames as our world just changed.
1774         ClearStackFrames();
1775         frame_sp->GetRegisterContext()->InvalidateIfNeeded(true);
1776         if (m_unwinder_ap.get())
1777             m_unwinder_ap->Clear();
1778 
1779         return ret;
1780     }
1781     return false;
1782 }
1783 
1784 Unwind *
1785 Thread::GetUnwinder ()
1786 {
1787     if (m_unwinder_ap.get() == NULL)
1788     {
1789         const ArchSpec target_arch (CalculateTarget()->GetArchitecture ());
1790         const llvm::Triple::ArchType machine = target_arch.GetMachine();
1791         switch (machine)
1792         {
1793             case llvm::Triple::x86_64:
1794             case llvm::Triple::x86:
1795             case llvm::Triple::arm:
1796             case llvm::Triple::thumb:
1797                 m_unwinder_ap.reset (new UnwindLLDB (*this));
1798                 break;
1799 
1800             default:
1801                 if (target_arch.GetTriple().getVendor() == llvm::Triple::Apple)
1802                     m_unwinder_ap.reset (new UnwindMacOSXFrameBackchain (*this));
1803                 break;
1804         }
1805     }
1806     return m_unwinder_ap.get();
1807 }
1808 
1809 
1810 void
1811 Thread::Flush ()
1812 {
1813     ClearStackFrames ();
1814     m_reg_context_sp.reset();
1815 }
1816 
1817 bool
1818 Thread::IsStillAtLastBreakpointHit ()
1819 {
1820     // If we are currently stopped at a breakpoint, always return that stopinfo and don't reset it.
1821     // This allows threads to maintain their breakpoint stopinfo, such as when thread-stepping in
1822     // multithreaded programs.
1823     if (m_actual_stop_info_sp) {
1824         StopReason stop_reason = m_actual_stop_info_sp->GetStopReason();
1825         if (stop_reason == lldb::eStopReasonBreakpoint) {
1826             uint64_t value = m_actual_stop_info_sp->GetValue();
1827             lldb::addr_t pc = GetRegisterContext()->GetPC();
1828             BreakpointSiteSP bp_site_sp = GetProcess()->GetBreakpointSiteList().FindByAddress(pc);
1829             if (bp_site_sp && value == bp_site_sp->GetID())
1830                 return true;
1831         }
1832     }
1833     return false;
1834 }
1835