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(event_ptr))
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(event_ptr))
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         Vote thread_vote = eVoteNoOpinion;
835         ThreadPlan *plan_ptr = GetCurrentPlan();
836         while (1)
837         {
838             if (plan_ptr->PlanExplainsStop(event_ptr))
839             {
840                 thread_vote = plan_ptr->ShouldReportStop(event_ptr);
841                 break;
842             }
843             if (PlanIsBasePlan(plan_ptr))
844                 break;
845             else
846                 plan_ptr = GetPreviousPlan(plan_ptr);
847         }
848         if (log)
849             log->Printf ("Thread::ShouldReportStop() tid = 0x%4.4" PRIx64 ": returning vote %i for current plan\n", GetID(), thread_vote);
850 
851         return thread_vote;
852     }
853 }
854 
855 Vote
856 Thread::ShouldReportRun (Event* event_ptr)
857 {
858     StateType thread_state = GetResumeState ();
859 
860     if (thread_state == eStateSuspended
861             || thread_state == eStateInvalid)
862     {
863         return eVoteNoOpinion;
864     }
865 
866     LogSP log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP));
867     if (m_completed_plan_stack.size() > 0)
868     {
869         // Don't use GetCompletedPlan here, since that suppresses private plans.
870         if (log)
871             log->Printf ("Current Plan for thread %d (0x%4.4" PRIx64 "): %s being asked whether we should report run.",
872                          GetIndexID(),
873                          GetID(),
874                          m_completed_plan_stack.back()->GetName());
875 
876         return m_completed_plan_stack.back()->ShouldReportRun (event_ptr);
877     }
878     else
879     {
880         if (log)
881             log->Printf ("Current Plan for thread %d (0x%4.4" PRIx64 "): %s being asked whether we should report run.",
882                          GetIndexID(),
883                          GetID(),
884                          GetCurrentPlan()->GetName());
885 
886         return GetCurrentPlan()->ShouldReportRun (event_ptr);
887      }
888 }
889 
890 bool
891 Thread::MatchesSpec (const ThreadSpec *spec)
892 {
893     if (spec == NULL)
894         return true;
895 
896     return spec->ThreadPassesBasicTests(*this);
897 }
898 
899 void
900 Thread::PushPlan (ThreadPlanSP &thread_plan_sp)
901 {
902     if (thread_plan_sp)
903     {
904         // If the thread plan doesn't already have a tracer, give it its parent's tracer:
905         if (!thread_plan_sp->GetThreadPlanTracer())
906             thread_plan_sp->SetThreadPlanTracer(m_plan_stack.back()->GetThreadPlanTracer());
907         m_plan_stack.push_back (thread_plan_sp);
908 
909         thread_plan_sp->DidPush();
910 
911         LogSP log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP));
912         if (log)
913         {
914             StreamString s;
915             thread_plan_sp->GetDescription (&s, lldb::eDescriptionLevelFull);
916             log->Printf("Pushing plan: \"%s\", tid = 0x%4.4" PRIx64 ".",
917                         s.GetData(),
918                         thread_plan_sp->GetThread().GetID());
919         }
920     }
921 }
922 
923 void
924 Thread::PopPlan ()
925 {
926     LogSP log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP));
927 
928     if (m_plan_stack.size() <= 1)
929         return;
930     else
931     {
932         ThreadPlanSP &plan = m_plan_stack.back();
933         if (log)
934         {
935             log->Printf("Popping plan: \"%s\", tid = 0x%4.4" PRIx64 ".", plan->GetName(), plan->GetThread().GetID());
936         }
937         m_completed_plan_stack.push_back (plan);
938         plan->WillPop();
939         m_plan_stack.pop_back();
940     }
941 }
942 
943 void
944 Thread::DiscardPlan ()
945 {
946     if (m_plan_stack.size() > 1)
947     {
948         ThreadPlanSP &plan = m_plan_stack.back();
949         m_discarded_plan_stack.push_back (plan);
950         plan->WillPop();
951         m_plan_stack.pop_back();
952     }
953 }
954 
955 ThreadPlan *
956 Thread::GetCurrentPlan ()
957 {
958     // There will always be at least the base plan.  If somebody is mucking with a
959     // thread with an empty plan stack, we should assert right away.
960     assert (!m_plan_stack.empty());
961 
962     return m_plan_stack.back().get();
963 }
964 
965 ThreadPlanSP
966 Thread::GetCompletedPlan ()
967 {
968     ThreadPlanSP empty_plan_sp;
969     if (!m_completed_plan_stack.empty())
970     {
971         for (int i = m_completed_plan_stack.size() - 1; i >= 0; i--)
972         {
973             ThreadPlanSP completed_plan_sp;
974             completed_plan_sp = m_completed_plan_stack[i];
975             if (!completed_plan_sp->GetPrivate ())
976             return completed_plan_sp;
977         }
978     }
979     return empty_plan_sp;
980 }
981 
982 ValueObjectSP
983 Thread::GetReturnValueObject ()
984 {
985     if (!m_completed_plan_stack.empty())
986     {
987         for (int i = m_completed_plan_stack.size() - 1; i >= 0; i--)
988         {
989             ValueObjectSP return_valobj_sp;
990             return_valobj_sp = m_completed_plan_stack[i]->GetReturnValueObject();
991             if (return_valobj_sp)
992             return return_valobj_sp;
993         }
994     }
995     return ValueObjectSP();
996 }
997 
998 bool
999 Thread::IsThreadPlanDone (ThreadPlan *plan)
1000 {
1001     if (!m_completed_plan_stack.empty())
1002     {
1003         for (int i = m_completed_plan_stack.size() - 1; i >= 0; i--)
1004         {
1005             if (m_completed_plan_stack[i].get() == plan)
1006                 return true;
1007         }
1008     }
1009     return false;
1010 }
1011 
1012 bool
1013 Thread::WasThreadPlanDiscarded (ThreadPlan *plan)
1014 {
1015     if (!m_discarded_plan_stack.empty())
1016     {
1017         for (int i = m_discarded_plan_stack.size() - 1; i >= 0; i--)
1018         {
1019             if (m_discarded_plan_stack[i].get() == plan)
1020                 return true;
1021         }
1022     }
1023     return false;
1024 }
1025 
1026 ThreadPlan *
1027 Thread::GetPreviousPlan (ThreadPlan *current_plan)
1028 {
1029     if (current_plan == NULL)
1030         return NULL;
1031 
1032     int stack_size = m_completed_plan_stack.size();
1033     for (int i = stack_size - 1; i > 0; i--)
1034     {
1035         if (current_plan == m_completed_plan_stack[i].get())
1036             return m_completed_plan_stack[i-1].get();
1037     }
1038 
1039     if (stack_size > 0 && m_completed_plan_stack[0].get() == current_plan)
1040     {
1041         if (m_plan_stack.size() > 0)
1042             return m_plan_stack.back().get();
1043         else
1044             return NULL;
1045     }
1046 
1047     stack_size = m_plan_stack.size();
1048     for (int i = stack_size - 1; i > 0; i--)
1049     {
1050         if (current_plan == m_plan_stack[i].get())
1051             return m_plan_stack[i-1].get();
1052     }
1053     return NULL;
1054 }
1055 
1056 void
1057 Thread::QueueThreadPlan (ThreadPlanSP &thread_plan_sp, bool abort_other_plans)
1058 {
1059     if (abort_other_plans)
1060        DiscardThreadPlans(true);
1061 
1062     PushPlan (thread_plan_sp);
1063 }
1064 
1065 
1066 void
1067 Thread::EnableTracer (bool value, bool single_stepping)
1068 {
1069     int stack_size = m_plan_stack.size();
1070     for (int i = 0; i < stack_size; i++)
1071     {
1072         if (m_plan_stack[i]->GetThreadPlanTracer())
1073         {
1074             m_plan_stack[i]->GetThreadPlanTracer()->EnableTracing(value);
1075             m_plan_stack[i]->GetThreadPlanTracer()->EnableSingleStep(single_stepping);
1076         }
1077     }
1078 }
1079 
1080 void
1081 Thread::SetTracer (lldb::ThreadPlanTracerSP &tracer_sp)
1082 {
1083     int stack_size = m_plan_stack.size();
1084     for (int i = 0; i < stack_size; i++)
1085         m_plan_stack[i]->SetThreadPlanTracer(tracer_sp);
1086 }
1087 
1088 void
1089 Thread::DiscardThreadPlansUpToPlan (lldb::ThreadPlanSP &up_to_plan_sp)
1090 {
1091     DiscardThreadPlansUpToPlan (up_to_plan_sp.get());
1092 }
1093 
1094 void
1095 Thread::DiscardThreadPlansUpToPlan (ThreadPlan *up_to_plan_ptr)
1096 {
1097     LogSP log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP));
1098     if (log)
1099     {
1100         log->Printf("Discarding thread plans for thread tid = 0x%4.4" PRIx64 ", up to %p", GetID(), up_to_plan_ptr);
1101     }
1102 
1103     int stack_size = m_plan_stack.size();
1104 
1105     // If the input plan is NULL, discard all plans.  Otherwise make sure this plan is in the
1106     // stack, and if so discard up to and including it.
1107 
1108     if (up_to_plan_ptr == NULL)
1109     {
1110         for (int i = stack_size - 1; i > 0; i--)
1111             DiscardPlan();
1112     }
1113     else
1114     {
1115         bool found_it = false;
1116         for (int i = stack_size - 1; i > 0; i--)
1117         {
1118             if (m_plan_stack[i].get() == up_to_plan_ptr)
1119                 found_it = true;
1120         }
1121         if (found_it)
1122         {
1123             bool last_one = false;
1124             for (int i = stack_size - 1; i > 0 && !last_one ; i--)
1125             {
1126                 if (GetCurrentPlan() == up_to_plan_ptr)
1127                     last_one = true;
1128                 DiscardPlan();
1129             }
1130         }
1131     }
1132     return;
1133 }
1134 
1135 void
1136 Thread::DiscardThreadPlans(bool force)
1137 {
1138     LogSP log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP));
1139     if (log)
1140     {
1141         log->Printf("Discarding thread plans for thread (tid = 0x%4.4" PRIx64 ", force %d)", GetID(), force);
1142     }
1143 
1144     if (force)
1145     {
1146         int stack_size = m_plan_stack.size();
1147         for (int i = stack_size - 1; i > 0; i--)
1148         {
1149             DiscardPlan();
1150         }
1151         return;
1152     }
1153 
1154     while (1)
1155     {
1156 
1157         int master_plan_idx;
1158         bool discard = true;
1159 
1160         // Find the first master plan, see if it wants discarding, and if yes discard up to it.
1161         for (master_plan_idx = m_plan_stack.size() - 1; master_plan_idx >= 0; master_plan_idx--)
1162         {
1163             if (m_plan_stack[master_plan_idx]->IsMasterPlan())
1164             {
1165                 discard = m_plan_stack[master_plan_idx]->OkayToDiscard();
1166                 break;
1167             }
1168         }
1169 
1170         if (discard)
1171         {
1172             // First pop all the dependent plans:
1173             for (int i = m_plan_stack.size() - 1; i > master_plan_idx; i--)
1174             {
1175 
1176                 // FIXME: Do we need a finalize here, or is the rule that "PrepareForStop"
1177                 // for the plan leaves it in a state that it is safe to pop the plan
1178                 // with no more notice?
1179                 DiscardPlan();
1180             }
1181 
1182             // Now discard the master plan itself.
1183             // The bottom-most plan never gets discarded.  "OkayToDiscard" for it means
1184             // discard it's dependent plans, but not it...
1185             if (master_plan_idx > 0)
1186             {
1187                 DiscardPlan();
1188             }
1189         }
1190         else
1191         {
1192             // If the master plan doesn't want to get discarded, then we're done.
1193             break;
1194         }
1195 
1196     }
1197 }
1198 
1199 bool
1200 Thread::PlanIsBasePlan (ThreadPlan *plan_ptr)
1201 {
1202     if (plan_ptr->IsBasePlan())
1203         return true;
1204     else if (m_plan_stack.size() == 0)
1205         return false;
1206     else
1207        return m_plan_stack[0].get() == plan_ptr;
1208 }
1209 
1210 Error
1211 Thread::UnwindInnermostExpression()
1212 {
1213     Error error;
1214     int stack_size = m_plan_stack.size();
1215 
1216     // If the input plan is NULL, discard all plans.  Otherwise make sure this plan is in the
1217     // stack, and if so discard up to and including it.
1218 
1219     for (int i = stack_size - 1; i > 0; i--)
1220     {
1221         if (m_plan_stack[i]->GetKind() == ThreadPlan::eKindCallFunction)
1222         {
1223             DiscardThreadPlansUpToPlan(m_plan_stack[i].get());
1224             return error;
1225         }
1226     }
1227     error.SetErrorString("No expressions currently active on this thread");
1228     return error;
1229 }
1230 
1231 
1232 ThreadPlan *
1233 Thread::QueueFundamentalPlan (bool abort_other_plans)
1234 {
1235     ThreadPlanSP thread_plan_sp (new ThreadPlanBase(*this));
1236     QueueThreadPlan (thread_plan_sp, abort_other_plans);
1237     return thread_plan_sp.get();
1238 }
1239 
1240 ThreadPlan *
1241 Thread::QueueThreadPlanForStepSingleInstruction
1242 (
1243     bool step_over,
1244     bool abort_other_plans,
1245     bool stop_other_threads
1246 )
1247 {
1248     ThreadPlanSP thread_plan_sp (new ThreadPlanStepInstruction (*this, step_over, stop_other_threads, eVoteNoOpinion, eVoteNoOpinion));
1249     QueueThreadPlan (thread_plan_sp, abort_other_plans);
1250     return thread_plan_sp.get();
1251 }
1252 
1253 ThreadPlan *
1254 Thread::QueueThreadPlanForStepOverRange
1255 (
1256     bool abort_other_plans,
1257     const AddressRange &range,
1258     const SymbolContext &addr_context,
1259     lldb::RunMode stop_other_threads
1260 )
1261 {
1262     ThreadPlanSP thread_plan_sp;
1263     thread_plan_sp.reset (new ThreadPlanStepOverRange (*this, range, addr_context, stop_other_threads));
1264 
1265     QueueThreadPlan (thread_plan_sp, abort_other_plans);
1266     return thread_plan_sp.get();
1267 }
1268 
1269 ThreadPlan *
1270 Thread::QueueThreadPlanForStepInRange
1271 (
1272     bool abort_other_plans,
1273     const AddressRange &range,
1274     const SymbolContext &addr_context,
1275     const char *step_in_target,
1276     lldb::RunMode stop_other_threads,
1277     bool avoid_code_without_debug_info
1278 )
1279 {
1280     ThreadPlanSP thread_plan_sp;
1281     ThreadPlanStepInRange *plan = new ThreadPlanStepInRange (*this, range, addr_context, stop_other_threads);
1282     if (avoid_code_without_debug_info)
1283         plan->GetFlags().Set (ThreadPlanShouldStopHere::eAvoidNoDebug);
1284     else
1285         plan->GetFlags().Clear (ThreadPlanShouldStopHere::eAvoidNoDebug);
1286     if (step_in_target)
1287         plan->SetStepInTarget(step_in_target);
1288     thread_plan_sp.reset (plan);
1289 
1290     QueueThreadPlan (thread_plan_sp, abort_other_plans);
1291     return thread_plan_sp.get();
1292 }
1293 
1294 
1295 ThreadPlan *
1296 Thread::QueueThreadPlanForStepOverBreakpointPlan (bool abort_other_plans)
1297 {
1298     ThreadPlanSP thread_plan_sp (new ThreadPlanStepOverBreakpoint (*this));
1299     QueueThreadPlan (thread_plan_sp, abort_other_plans);
1300     return thread_plan_sp.get();
1301 }
1302 
1303 ThreadPlan *
1304 Thread::QueueThreadPlanForStepOut
1305 (
1306     bool abort_other_plans,
1307     SymbolContext *addr_context,
1308     bool first_insn,
1309     bool stop_other_threads,
1310     Vote stop_vote,
1311     Vote run_vote,
1312     uint32_t frame_idx
1313 )
1314 {
1315     ThreadPlanSP thread_plan_sp (new ThreadPlanStepOut (*this,
1316                                                         addr_context,
1317                                                         first_insn,
1318                                                         stop_other_threads,
1319                                                         stop_vote,
1320                                                         run_vote,
1321                                                         frame_idx));
1322 
1323     if (thread_plan_sp->ValidatePlan(NULL))
1324     {
1325         QueueThreadPlan (thread_plan_sp, abort_other_plans);
1326         return thread_plan_sp.get();
1327     }
1328     else
1329     {
1330         return NULL;
1331     }
1332 }
1333 
1334 ThreadPlan *
1335 Thread::QueueThreadPlanForStepThrough (StackID &return_stack_id, bool abort_other_plans, bool stop_other_threads)
1336 {
1337     ThreadPlanSP thread_plan_sp(new ThreadPlanStepThrough (*this, return_stack_id, stop_other_threads));
1338     if (!thread_plan_sp || !thread_plan_sp->ValidatePlan (NULL))
1339         return NULL;
1340 
1341     QueueThreadPlan (thread_plan_sp, abort_other_plans);
1342     return thread_plan_sp.get();
1343 }
1344 
1345 ThreadPlan *
1346 Thread::QueueThreadPlanForCallFunction (bool abort_other_plans,
1347                                         Address& function,
1348                                         lldb::addr_t arg,
1349                                         bool stop_other_threads,
1350                                         bool unwind_on_error,
1351                                         bool ignore_breakpoints)
1352 {
1353     ThreadPlanSP thread_plan_sp (new ThreadPlanCallFunction (*this,
1354                                                              function,
1355                                                              ClangASTType(),
1356                                                              arg,
1357                                                              stop_other_threads,
1358                                                              unwind_on_error,
1359                                                              ignore_breakpoints));
1360     QueueThreadPlan (thread_plan_sp, abort_other_plans);
1361     return thread_plan_sp.get();
1362 }
1363 
1364 ThreadPlan *
1365 Thread::QueueThreadPlanForRunToAddress (bool abort_other_plans,
1366                                         Address &target_addr,
1367                                         bool stop_other_threads)
1368 {
1369     ThreadPlanSP thread_plan_sp (new ThreadPlanRunToAddress (*this, target_addr, stop_other_threads));
1370     QueueThreadPlan (thread_plan_sp, abort_other_plans);
1371     return thread_plan_sp.get();
1372 }
1373 
1374 ThreadPlan *
1375 Thread::QueueThreadPlanForStepUntil (bool abort_other_plans,
1376                                      lldb::addr_t *address_list,
1377                                      size_t num_addresses,
1378                                      bool stop_other_threads,
1379                                      uint32_t frame_idx)
1380 {
1381     ThreadPlanSP thread_plan_sp (new ThreadPlanStepUntil (*this, address_list, num_addresses, stop_other_threads, frame_idx));
1382     QueueThreadPlan (thread_plan_sp, abort_other_plans);
1383     return thread_plan_sp.get();
1384 
1385 }
1386 
1387 uint32_t
1388 Thread::GetIndexID () const
1389 {
1390     return m_index_id;
1391 }
1392 
1393 void
1394 Thread::DumpThreadPlans (lldb_private::Stream *s) const
1395 {
1396     uint32_t stack_size = m_plan_stack.size();
1397     int i;
1398     s->Indent();
1399     s->Printf ("Plan Stack for thread #%u: tid = 0x%4.4" PRIx64 ", stack_size = %d\n", GetIndexID(), GetID(), 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_plan_stack[i]->GetDescription (s, eDescriptionLevelFull);
1406         s->EOL();
1407         s->IndentLess();
1408     }
1409 
1410     stack_size = m_completed_plan_stack.size();
1411     if (stack_size > 0)
1412     {
1413         s->Indent();
1414         s->Printf ("Completed Plan Stack: %d elements.\n", stack_size);
1415         for (i = stack_size - 1; i >= 0; i--)
1416         {
1417             s->IndentMore();
1418             s->Indent();
1419             s->Printf ("Element %d: ", i);
1420             m_completed_plan_stack[i]->GetDescription (s, eDescriptionLevelFull);
1421             s->EOL();
1422             s->IndentLess();
1423         }
1424     }
1425 
1426     stack_size = m_discarded_plan_stack.size();
1427     if (stack_size > 0)
1428     {
1429         s->Indent();
1430         s->Printf ("Discarded Plan Stack: %d elements.\n", stack_size);
1431         for (i = stack_size - 1; i >= 0; i--)
1432         {
1433             s->IndentMore();
1434             s->Indent();
1435             s->Printf ("Element %d: ", i);
1436             m_discarded_plan_stack[i]->GetDescription (s, eDescriptionLevelFull);
1437             s->EOL();
1438             s->IndentLess();
1439         }
1440     }
1441 
1442 }
1443 
1444 TargetSP
1445 Thread::CalculateTarget ()
1446 {
1447     TargetSP target_sp;
1448     ProcessSP process_sp(GetProcess());
1449     if (process_sp)
1450         target_sp = process_sp->CalculateTarget();
1451     return target_sp;
1452 
1453 }
1454 
1455 ProcessSP
1456 Thread::CalculateProcess ()
1457 {
1458     return GetProcess();
1459 }
1460 
1461 ThreadSP
1462 Thread::CalculateThread ()
1463 {
1464     return shared_from_this();
1465 }
1466 
1467 StackFrameSP
1468 Thread::CalculateStackFrame ()
1469 {
1470     return StackFrameSP();
1471 }
1472 
1473 void
1474 Thread::CalculateExecutionContext (ExecutionContext &exe_ctx)
1475 {
1476     exe_ctx.SetContext (shared_from_this());
1477 }
1478 
1479 
1480 StackFrameListSP
1481 Thread::GetStackFrameList ()
1482 {
1483     StackFrameListSP frame_list_sp;
1484     Mutex::Locker locker(m_frame_mutex);
1485     if (m_curr_frames_sp)
1486     {
1487         frame_list_sp = m_curr_frames_sp;
1488     }
1489     else
1490     {
1491         frame_list_sp.reset(new StackFrameList (*this, m_prev_frames_sp, true));
1492         m_curr_frames_sp = frame_list_sp;
1493     }
1494     return frame_list_sp;
1495 }
1496 
1497 void
1498 Thread::ClearStackFrames ()
1499 {
1500     Mutex::Locker locker(m_frame_mutex);
1501 
1502     // Only store away the old "reference" StackFrameList if we got all its frames:
1503     // FIXME: At some point we can try to splice in the frames we have fetched into
1504     // the new frame as we make it, but let's not try that now.
1505     if (m_curr_frames_sp && m_curr_frames_sp->GetAllFramesFetched())
1506         m_prev_frames_sp.swap (m_curr_frames_sp);
1507     m_curr_frames_sp.reset();
1508 }
1509 
1510 lldb::StackFrameSP
1511 Thread::GetFrameWithConcreteFrameIndex (uint32_t unwind_idx)
1512 {
1513     return GetStackFrameList()->GetFrameWithConcreteFrameIndex (unwind_idx);
1514 }
1515 
1516 
1517 Error
1518 Thread::ReturnFromFrameWithIndex (uint32_t frame_idx, lldb::ValueObjectSP return_value_sp, bool broadcast)
1519 {
1520     StackFrameSP frame_sp = GetStackFrameAtIndex (frame_idx);
1521     Error return_error;
1522 
1523     if (!frame_sp)
1524     {
1525         return_error.SetErrorStringWithFormat("Could not find frame with index %d in thread 0x%" PRIx64 ".", frame_idx, GetID());
1526     }
1527 
1528     return ReturnFromFrame(frame_sp, return_value_sp, broadcast);
1529 }
1530 
1531 Error
1532 Thread::ReturnFromFrame (lldb::StackFrameSP frame_sp, lldb::ValueObjectSP return_value_sp, bool broadcast)
1533 {
1534     Error return_error;
1535 
1536     if (!frame_sp)
1537     {
1538         return_error.SetErrorString("Can't return to a null frame.");
1539         return return_error;
1540     }
1541 
1542     Thread *thread = frame_sp->GetThread().get();
1543     uint32_t older_frame_idx = frame_sp->GetFrameIndex() + 1;
1544     StackFrameSP older_frame_sp = thread->GetStackFrameAtIndex(older_frame_idx);
1545     if (!older_frame_sp)
1546     {
1547         return_error.SetErrorString("No older frame to return to.");
1548         return return_error;
1549     }
1550 
1551     if (return_value_sp)
1552     {
1553         lldb::ABISP abi = thread->GetProcess()->GetABI();
1554         if (!abi)
1555         {
1556             return_error.SetErrorString("Could not find ABI to set return value.");
1557             return return_error;
1558         }
1559         SymbolContext sc = frame_sp->GetSymbolContext(eSymbolContextFunction);
1560 
1561         // FIXME: ValueObject::Cast doesn't currently work correctly, at least not for scalars.
1562         // Turn that back on when that works.
1563         if (0 && sc.function != NULL)
1564         {
1565             Type *function_type = sc.function->GetType();
1566             if (function_type)
1567             {
1568                 clang_type_t return_type = sc.function->GetReturnClangType();
1569                 if (return_type)
1570                 {
1571                     ClangASTType ast_type (function_type->GetClangAST(), return_type);
1572                     StreamString s;
1573                     ast_type.DumpTypeDescription(&s);
1574                     ValueObjectSP cast_value_sp = return_value_sp->Cast(ast_type);
1575                     if (cast_value_sp)
1576                     {
1577                         cast_value_sp->SetFormat(eFormatHex);
1578                         return_value_sp = cast_value_sp;
1579                     }
1580                 }
1581             }
1582         }
1583 
1584         return_error = abi->SetReturnValueObject(older_frame_sp, return_value_sp);
1585         if (!return_error.Success())
1586             return return_error;
1587     }
1588 
1589     // Now write the return registers for the chosen frame:
1590     // Note, we can't use ReadAllRegisterValues->WriteAllRegisterValues, since the read & write
1591     // cook their data
1592 
1593     StackFrameSP youngest_frame_sp = thread->GetStackFrameAtIndex(0);
1594     if (youngest_frame_sp)
1595     {
1596         bool copy_success = youngest_frame_sp->GetRegisterContext()->CopyFromRegisterContext(older_frame_sp->GetRegisterContext());
1597         if (copy_success)
1598         {
1599             thread->DiscardThreadPlans(true);
1600             thread->ClearStackFrames();
1601             if (broadcast && EventTypeHasListeners(eBroadcastBitStackChanged))
1602                 BroadcastEvent(eBroadcastBitStackChanged, new ThreadEventData (this->shared_from_this()));
1603         }
1604         else
1605         {
1606             return_error.SetErrorString("Could not reset register values.");
1607         }
1608     }
1609     else
1610     {
1611         return_error.SetErrorString("Returned past top frame.");
1612     }
1613     return return_error;
1614 }
1615 
1616 void
1617 Thread::DumpUsingSettingsFormat (Stream &strm, uint32_t frame_idx)
1618 {
1619     ExecutionContext exe_ctx (shared_from_this());
1620     Process *process = exe_ctx.GetProcessPtr();
1621     if (process == NULL)
1622         return;
1623 
1624     StackFrameSP frame_sp;
1625     SymbolContext frame_sc;
1626     if (frame_idx != LLDB_INVALID_INDEX32)
1627     {
1628         frame_sp = GetStackFrameAtIndex (frame_idx);
1629         if (frame_sp)
1630         {
1631             exe_ctx.SetFrameSP(frame_sp);
1632             frame_sc = frame_sp->GetSymbolContext(eSymbolContextEverything);
1633         }
1634     }
1635 
1636     const char *thread_format = exe_ctx.GetTargetRef().GetDebugger().GetThreadFormat();
1637     assert (thread_format);
1638     const char *end = NULL;
1639     Debugger::FormatPrompt (thread_format,
1640                             frame_sp ? &frame_sc : NULL,
1641                             &exe_ctx,
1642                             NULL,
1643                             strm,
1644                             &end);
1645 }
1646 
1647 void
1648 Thread::SettingsInitialize ()
1649 {
1650 }
1651 
1652 void
1653 Thread::SettingsTerminate ()
1654 {
1655 }
1656 
1657 lldb::StackFrameSP
1658 Thread::GetStackFrameSPForStackFramePtr (StackFrame *stack_frame_ptr)
1659 {
1660     return GetStackFrameList()->GetStackFrameSPForStackFramePtr (stack_frame_ptr);
1661 }
1662 
1663 const char *
1664 Thread::StopReasonAsCString (lldb::StopReason reason)
1665 {
1666     switch (reason)
1667     {
1668     case eStopReasonInvalid:       return "invalid";
1669     case eStopReasonNone:          return "none";
1670     case eStopReasonTrace:         return "trace";
1671     case eStopReasonBreakpoint:    return "breakpoint";
1672     case eStopReasonWatchpoint:    return "watchpoint";
1673     case eStopReasonSignal:        return "signal";
1674     case eStopReasonException:     return "exception";
1675     case eStopReasonExec:          return "exec";
1676     case eStopReasonPlanComplete:  return "plan complete";
1677     case eStopReasonThreadExiting: return "thread exiting";
1678     }
1679 
1680 
1681     static char unknown_state_string[64];
1682     snprintf(unknown_state_string, sizeof (unknown_state_string), "StopReason = %i", reason);
1683     return unknown_state_string;
1684 }
1685 
1686 const char *
1687 Thread::RunModeAsCString (lldb::RunMode mode)
1688 {
1689     switch (mode)
1690     {
1691     case eOnlyThisThread:     return "only this thread";
1692     case eAllThreads:         return "all threads";
1693     case eOnlyDuringStepping: return "only during stepping";
1694     }
1695 
1696     static char unknown_state_string[64];
1697     snprintf(unknown_state_string, sizeof (unknown_state_string), "RunMode = %i", mode);
1698     return unknown_state_string;
1699 }
1700 
1701 size_t
1702 Thread::GetStatus (Stream &strm, uint32_t start_frame, uint32_t num_frames, uint32_t num_frames_with_source)
1703 {
1704     ExecutionContext exe_ctx (shared_from_this());
1705     Target *target = exe_ctx.GetTargetPtr();
1706     Process *process = exe_ctx.GetProcessPtr();
1707     size_t num_frames_shown = 0;
1708     strm.Indent();
1709     bool is_selected = false;
1710     if (process)
1711     {
1712         if (process->GetThreadList().GetSelectedThread().get() == this)
1713             is_selected = true;
1714     }
1715     strm.Printf("%c ", is_selected ? '*' : ' ');
1716     if (target && target->GetDebugger().GetUseExternalEditor())
1717     {
1718         StackFrameSP frame_sp = GetStackFrameAtIndex(start_frame);
1719         if (frame_sp)
1720         {
1721             SymbolContext frame_sc(frame_sp->GetSymbolContext (eSymbolContextLineEntry));
1722             if (frame_sc.line_entry.line != 0 && frame_sc.line_entry.file)
1723             {
1724                 Host::OpenFileInExternalEditor (frame_sc.line_entry.file, frame_sc.line_entry.line);
1725             }
1726         }
1727     }
1728 
1729     DumpUsingSettingsFormat (strm, start_frame);
1730 
1731     if (num_frames > 0)
1732     {
1733         strm.IndentMore();
1734 
1735         const bool show_frame_info = true;
1736         strm.IndentMore ();
1737         num_frames_shown = GetStackFrameList ()->GetStatus (strm,
1738                                                             start_frame,
1739                                                             num_frames,
1740                                                             show_frame_info,
1741                                                             num_frames_with_source);
1742         strm.IndentLess();
1743         strm.IndentLess();
1744     }
1745     return num_frames_shown;
1746 }
1747 
1748 size_t
1749 Thread::GetStackFrameStatus (Stream& strm,
1750                              uint32_t first_frame,
1751                              uint32_t num_frames,
1752                              bool show_frame_info,
1753                              uint32_t num_frames_with_source)
1754 {
1755     return GetStackFrameList()->GetStatus (strm,
1756                                            first_frame,
1757                                            num_frames,
1758                                            show_frame_info,
1759                                            num_frames_with_source);
1760 }
1761 
1762 bool
1763 Thread::SaveFrameZeroState (RegisterCheckpoint &checkpoint)
1764 {
1765     lldb::StackFrameSP frame_sp(GetStackFrameAtIndex (0));
1766     if (frame_sp)
1767     {
1768         checkpoint.SetStackID(frame_sp->GetStackID());
1769         return frame_sp->GetRegisterContext()->ReadAllRegisterValues (checkpoint.GetData());
1770     }
1771     return false;
1772 }
1773 
1774 bool
1775 Thread::RestoreSaveFrameZero (const RegisterCheckpoint &checkpoint)
1776 {
1777     return ResetFrameZeroRegisters (checkpoint.GetData());
1778 }
1779 
1780 bool
1781 Thread::ResetFrameZeroRegisters (lldb::DataBufferSP register_data_sp)
1782 {
1783     lldb::StackFrameSP frame_sp(GetStackFrameAtIndex (0));
1784     if (frame_sp)
1785     {
1786         bool ret = frame_sp->GetRegisterContext()->WriteAllRegisterValues (register_data_sp);
1787 
1788         // Clear out all stack frames as our world just changed.
1789         ClearStackFrames();
1790         frame_sp->GetRegisterContext()->InvalidateIfNeeded(true);
1791         if (m_unwinder_ap.get())
1792             m_unwinder_ap->Clear();
1793 
1794         return ret;
1795     }
1796     return false;
1797 }
1798 
1799 Unwind *
1800 Thread::GetUnwinder ()
1801 {
1802     if (m_unwinder_ap.get() == NULL)
1803     {
1804         const ArchSpec target_arch (CalculateTarget()->GetArchitecture ());
1805         const llvm::Triple::ArchType machine = target_arch.GetMachine();
1806         switch (machine)
1807         {
1808             case llvm::Triple::x86_64:
1809             case llvm::Triple::x86:
1810             case llvm::Triple::arm:
1811             case llvm::Triple::thumb:
1812                 m_unwinder_ap.reset (new UnwindLLDB (*this));
1813                 break;
1814 
1815             default:
1816                 if (target_arch.GetTriple().getVendor() == llvm::Triple::Apple)
1817                     m_unwinder_ap.reset (new UnwindMacOSXFrameBackchain (*this));
1818                 break;
1819         }
1820     }
1821     return m_unwinder_ap.get();
1822 }
1823 
1824 
1825 void
1826 Thread::Flush ()
1827 {
1828     ClearStackFrames ();
1829     m_reg_context_sp.reset();
1830 }
1831 
1832 bool
1833 Thread::IsStillAtLastBreakpointHit ()
1834 {
1835     // If we are currently stopped at a breakpoint, always return that stopinfo and don't reset it.
1836     // This allows threads to maintain their breakpoint stopinfo, such as when thread-stepping in
1837     // multithreaded programs.
1838     if (m_actual_stop_info_sp) {
1839         StopReason stop_reason = m_actual_stop_info_sp->GetStopReason();
1840         if (stop_reason == lldb::eStopReasonBreakpoint) {
1841             uint64_t value = m_actual_stop_info_sp->GetValue();
1842             lldb::addr_t pc = GetRegisterContext()->GetPC();
1843             BreakpointSiteSP bp_site_sp = GetProcess()->GetBreakpointSiteList().FindByAddress(pc);
1844             if (bp_site_sp && value == bp_site_sp->GetID())
1845                 return true;
1846         }
1847     }
1848     return false;
1849 }
1850