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 // C Includes
11 // C++ Includes
12 // Other libraries and framework includes
13 // Project includes
14 #include "lldb/Breakpoint/BreakpointLocation.h"
15 #include "lldb/Core/Debugger.h"
16 #include "lldb/Core/Log.h"
17 #include "lldb/Core/FormatEntity.h"
18 #include "lldb/Core/Module.h"
19 #include "lldb/Core/State.h"
20 #include "lldb/Core/Stream.h"
21 #include "lldb/Core/StreamString.h"
22 #include "lldb/Core/RegularExpression.h"
23 #include "lldb/Core/ValueObject.h"
24 #include "lldb/Host/Host.h"
25 #include "lldb/Interpreter/OptionValueFileSpecList.h"
26 #include "lldb/Interpreter/OptionValueProperties.h"
27 #include "lldb/Interpreter/Property.h"
28 #include "lldb/Symbol/Function.h"
29 #include "lldb/Target/ABI.h"
30 #include "lldb/Target/DynamicLoader.h"
31 #include "lldb/Target/ExecutionContext.h"
32 #include "lldb/Target/Process.h"
33 #include "lldb/Target/RegisterContext.h"
34 #include "lldb/Target/StopInfo.h"
35 #include "lldb/Target/SystemRuntime.h"
36 #include "lldb/Target/Target.h"
37 #include "lldb/Target/Thread.h"
38 #include "lldb/Target/ThreadPlan.h"
39 #include "lldb/Target/ThreadPlanCallFunction.h"
40 #include "lldb/Target/ThreadPlanBase.h"
41 #include "lldb/Target/ThreadPlanPython.h"
42 #include "lldb/Target/ThreadPlanStepInstruction.h"
43 #include "lldb/Target/ThreadPlanStepOut.h"
44 #include "lldb/Target/ThreadPlanStepOverBreakpoint.h"
45 #include "lldb/Target/ThreadPlanStepThrough.h"
46 #include "lldb/Target/ThreadPlanStepInRange.h"
47 #include "lldb/Target/ThreadPlanStepOverRange.h"
48 #include "lldb/Target/ThreadPlanRunToAddress.h"
49 #include "lldb/Target/ThreadPlanStepUntil.h"
50 #include "lldb/Target/ThreadSpec.h"
51 #include "lldb/Target/Unwind.h"
52 #include "Plugins/Process/Utility/UnwindLLDB.h"
53 #include "Plugins/Process/Utility/UnwindMacOSXFrameBackchain.h"
54 
55 using namespace lldb;
56 using namespace lldb_private;
57 
58 const ThreadPropertiesSP &
59 Thread::GetGlobalProperties()
60 {
61     static ThreadPropertiesSP g_settings_sp;
62     if (!g_settings_sp)
63         g_settings_sp.reset (new ThreadProperties (true));
64     return g_settings_sp;
65 }
66 
67 static PropertyDefinition
68 g_properties[] =
69 {
70     { "step-in-avoid-nodebug", OptionValue::eTypeBoolean, true, true, NULL, NULL, "If true, step-in will not stop in functions with no debug information." },
71     { "step-out-avoid-nodebug", OptionValue::eTypeBoolean, true, false, NULL, NULL, "If true, when step-in/step-out/step-over leave the current frame, they will continue to step out till they come to a function with "
72                                                                                     "debug information.  Passing a frame argument to step-out will override this option." },
73     { "step-avoid-regexp",  OptionValue::eTypeRegex  , true , 0, "^std::", NULL, "A regular expression defining functions step-in won't stop in." },
74     { "step-avoid-libraries",  OptionValue::eTypeFileSpecList  , true , 0, NULL, NULL, "A list of libraries that source stepping won't stop in." },
75     { "trace-thread",       OptionValue::eTypeBoolean, false, false, NULL, NULL, "If true, this thread will single-step and log execution." },
76     {  NULL               , OptionValue::eTypeInvalid, false, 0    , NULL, NULL, NULL  }
77 };
78 
79 enum {
80     ePropertyStepInAvoidsNoDebug,
81     ePropertyStepOutAvoidsNoDebug,
82     ePropertyStepAvoidRegex,
83     ePropertyStepAvoidLibraries,
84     ePropertyEnableThreadTrace
85 };
86 
87 class ThreadOptionValueProperties : public OptionValueProperties
88 {
89 public:
90     ThreadOptionValueProperties (const ConstString &name) :
91         OptionValueProperties (name)
92     {
93     }
94 
95     // This constructor is used when creating ThreadOptionValueProperties when it
96     // is part of a new lldb_private::Thread instance. It will copy all current
97     // global property values as needed
98     ThreadOptionValueProperties (ThreadProperties *global_properties) :
99         OptionValueProperties(*global_properties->GetValueProperties())
100     {
101     }
102 
103     const Property *
104     GetPropertyAtIndex(const ExecutionContext *exe_ctx, bool will_modify, uint32_t idx) const override
105     {
106         // When getting the value for a key from the thread options, we will always
107         // try and grab the setting from the current thread if there is one. Else we just
108         // use the one from this instance.
109         if (exe_ctx)
110         {
111             Thread *thread = exe_ctx->GetThreadPtr();
112             if (thread)
113             {
114                 ThreadOptionValueProperties *instance_properties = static_cast<ThreadOptionValueProperties *>(thread->GetValueProperties().get());
115                 if (this != instance_properties)
116                     return instance_properties->ProtectedGetPropertyAtIndex (idx);
117             }
118         }
119         return ProtectedGetPropertyAtIndex (idx);
120     }
121 };
122 
123 ThreadProperties::ThreadProperties (bool is_global) :
124     Properties ()
125 {
126     if (is_global)
127     {
128         m_collection_sp.reset (new ThreadOptionValueProperties(ConstString("thread")));
129         m_collection_sp->Initialize(g_properties);
130     }
131     else
132         m_collection_sp.reset (new ThreadOptionValueProperties(Thread::GetGlobalProperties().get()));
133 }
134 
135 ThreadProperties::~ThreadProperties() = default;
136 
137 const RegularExpression *
138 ThreadProperties::GetSymbolsToAvoidRegexp()
139 {
140     const uint32_t idx = ePropertyStepAvoidRegex;
141     return m_collection_sp->GetPropertyAtIndexAsOptionValueRegex (NULL, idx);
142 }
143 
144 FileSpecList &
145 ThreadProperties::GetLibrariesToAvoid() const
146 {
147     const uint32_t idx = ePropertyStepAvoidLibraries;
148     OptionValueFileSpecList *option_value = m_collection_sp->GetPropertyAtIndexAsOptionValueFileSpecList (NULL, false, idx);
149     assert(option_value);
150     return option_value->GetCurrentValue();
151 }
152 
153 bool
154 ThreadProperties::GetTraceEnabledState() const
155 {
156     const uint32_t idx = ePropertyEnableThreadTrace;
157     return m_collection_sp->GetPropertyAtIndexAsBoolean (NULL, idx, g_properties[idx].default_uint_value != 0);
158 }
159 
160 bool
161 ThreadProperties::GetStepInAvoidsNoDebug() const
162 {
163     const uint32_t idx = ePropertyStepInAvoidsNoDebug;
164     return m_collection_sp->GetPropertyAtIndexAsBoolean (NULL, idx, g_properties[idx].default_uint_value != 0);
165 }
166 
167 bool
168 ThreadProperties::GetStepOutAvoidsNoDebug() const
169 {
170     const uint32_t idx = ePropertyStepOutAvoidsNoDebug;
171     return m_collection_sp->GetPropertyAtIndexAsBoolean (NULL, idx, g_properties[idx].default_uint_value != 0);
172 }
173 
174 //------------------------------------------------------------------
175 // Thread Event Data
176 //------------------------------------------------------------------
177 
178 const ConstString &
179 Thread::ThreadEventData::GetFlavorString ()
180 {
181     static ConstString g_flavor ("Thread::ThreadEventData");
182     return g_flavor;
183 }
184 
185 Thread::ThreadEventData::ThreadEventData (const lldb::ThreadSP thread_sp) :
186     m_thread_sp (thread_sp),
187     m_stack_id ()
188 {
189 }
190 
191 Thread::ThreadEventData::ThreadEventData (const lldb::ThreadSP thread_sp, const StackID &stack_id) :
192     m_thread_sp (thread_sp),
193     m_stack_id (stack_id)
194 {
195 }
196 
197 Thread::ThreadEventData::ThreadEventData () :
198     m_thread_sp (),
199     m_stack_id ()
200 {
201 }
202 
203 Thread::ThreadEventData::~ThreadEventData() = default;
204 
205 void
206 Thread::ThreadEventData::Dump (Stream *s) const
207 {
208 }
209 
210 const Thread::ThreadEventData *
211 Thread::ThreadEventData::GetEventDataFromEvent (const Event *event_ptr)
212 {
213     if (event_ptr)
214     {
215         const EventData *event_data = event_ptr->GetData();
216         if (event_data && event_data->GetFlavor() == ThreadEventData::GetFlavorString())
217             return static_cast <const ThreadEventData *> (event_ptr->GetData());
218     }
219     return NULL;
220 }
221 
222 ThreadSP
223 Thread::ThreadEventData::GetThreadFromEvent (const Event *event_ptr)
224 {
225     ThreadSP thread_sp;
226     const ThreadEventData *event_data = GetEventDataFromEvent (event_ptr);
227     if (event_data)
228         thread_sp = event_data->GetThread();
229     return thread_sp;
230 }
231 
232 StackID
233 Thread::ThreadEventData::GetStackIDFromEvent (const Event *event_ptr)
234 {
235     StackID stack_id;
236     const ThreadEventData *event_data = GetEventDataFromEvent (event_ptr);
237     if (event_data)
238         stack_id = event_data->GetStackID();
239     return stack_id;
240 }
241 
242 StackFrameSP
243 Thread::ThreadEventData::GetStackFrameFromEvent (const Event *event_ptr)
244 {
245     const ThreadEventData *event_data = GetEventDataFromEvent (event_ptr);
246     StackFrameSP frame_sp;
247     if (event_data)
248     {
249         ThreadSP thread_sp = event_data->GetThread();
250         if (thread_sp)
251         {
252             frame_sp = thread_sp->GetStackFrameList()->GetFrameWithStackID (event_data->GetStackID());
253         }
254     }
255     return frame_sp;
256 }
257 
258 //------------------------------------------------------------------
259 // Thread class
260 //------------------------------------------------------------------
261 
262 ConstString &
263 Thread::GetStaticBroadcasterClass ()
264 {
265     static ConstString class_name ("lldb.thread");
266     return class_name;
267 }
268 
269 Thread::Thread (Process &process, lldb::tid_t tid, bool use_invalid_index_id) :
270     ThreadProperties (false),
271     UserID (tid),
272     Broadcaster(&process.GetTarget().GetDebugger(), Thread::GetStaticBroadcasterClass().AsCString()),
273     m_process_wp (process.shared_from_this()),
274     m_stop_info_sp (),
275     m_stop_info_stop_id (0),
276     m_stop_info_override_stop_id (0),
277     m_index_id (use_invalid_index_id ? LLDB_INVALID_INDEX32 : process.GetNextThreadIndexID(tid)),
278     m_reg_context_sp (),
279     m_state (eStateUnloaded),
280     m_state_mutex (Mutex::eMutexTypeRecursive),
281     m_plan_stack (),
282     m_completed_plan_stack(),
283     m_frame_mutex (Mutex::eMutexTypeRecursive),
284     m_curr_frames_sp (),
285     m_prev_frames_sp (),
286     m_resume_signal (LLDB_INVALID_SIGNAL_NUMBER),
287     m_resume_state (eStateRunning),
288     m_temporary_resume_state (eStateRunning),
289     m_unwinder_ap (),
290     m_destroy_called (false),
291     m_override_should_notify (eLazyBoolCalculate),
292     m_extended_info_fetched (false),
293     m_extended_info ()
294 {
295     Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_OBJECT));
296     if (log)
297         log->Printf ("%p Thread::Thread(tid = 0x%4.4" PRIx64 ")",
298                      static_cast<void*>(this), GetID());
299 
300     CheckInWithManager();
301     QueueFundamentalPlan(true);
302 }
303 
304 Thread::~Thread()
305 {
306     Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_OBJECT));
307     if (log)
308         log->Printf ("%p Thread::~Thread(tid = 0x%4.4" PRIx64 ")",
309                      static_cast<void*>(this), GetID());
310     /// If you hit this assert, it means your derived class forgot to call DoDestroy in its destructor.
311     assert (m_destroy_called);
312 }
313 
314 void
315 Thread::DestroyThread ()
316 {
317     // Tell any plans on the plan stacks that the thread is being destroyed since
318     // any plans that have a thread go away in the middle of might need
319     // to do cleanup, or in some cases NOT do cleanup...
320     for (auto plan : m_plan_stack)
321         plan->ThreadDestroyed();
322 
323     for (auto plan : m_discarded_plan_stack)
324         plan->ThreadDestroyed();
325 
326     for (auto plan : m_completed_plan_stack)
327         plan->ThreadDestroyed();
328 
329     m_destroy_called = true;
330     m_plan_stack.clear();
331     m_discarded_plan_stack.clear();
332     m_completed_plan_stack.clear();
333 
334     // Push a ThreadPlanNull on the plan stack.  That way we can continue assuming that the
335     // plan stack is never empty, but if somebody errantly asks questions of a destroyed thread
336     // without checking first whether it is destroyed, they won't crash.
337     ThreadPlanSP null_plan_sp(new ThreadPlanNull (*this));
338     m_plan_stack.push_back (null_plan_sp);
339 
340     m_stop_info_sp.reset();
341     m_reg_context_sp.reset();
342     m_unwinder_ap.reset();
343     Mutex::Locker locker(m_frame_mutex);
344     m_curr_frames_sp.reset();
345     m_prev_frames_sp.reset();
346 }
347 
348 void
349 Thread::BroadcastSelectedFrameChange(StackID &new_frame_id)
350 {
351     if (EventTypeHasListeners(eBroadcastBitSelectedFrameChanged))
352         BroadcastEvent(eBroadcastBitSelectedFrameChanged, new ThreadEventData (this->shared_from_this(), new_frame_id));
353 }
354 
355 lldb::StackFrameSP
356 Thread::GetSelectedFrame()
357 {
358     StackFrameListSP stack_frame_list_sp(GetStackFrameList());
359     StackFrameSP frame_sp = stack_frame_list_sp->GetFrameAtIndex (stack_frame_list_sp->GetSelectedFrameIndex());
360     FunctionOptimizationWarning (frame_sp.get());
361     return frame_sp;
362 }
363 
364 uint32_t
365 Thread::SetSelectedFrame (lldb_private::StackFrame *frame, bool broadcast)
366 {
367     uint32_t ret_value = GetStackFrameList()->SetSelectedFrame(frame);
368     if (broadcast)
369         BroadcastSelectedFrameChange(frame->GetStackID());
370     FunctionOptimizationWarning (frame);
371     return ret_value;
372 }
373 
374 bool
375 Thread::SetSelectedFrameByIndex (uint32_t frame_idx, bool broadcast)
376 {
377     StackFrameSP frame_sp(GetStackFrameList()->GetFrameAtIndex (frame_idx));
378     if (frame_sp)
379     {
380         GetStackFrameList()->SetSelectedFrame(frame_sp.get());
381         if (broadcast)
382             BroadcastSelectedFrameChange(frame_sp->GetStackID());
383         FunctionOptimizationWarning (frame_sp.get());
384         return true;
385     }
386     else
387         return false;
388 }
389 
390 bool
391 Thread::SetSelectedFrameByIndexNoisily (uint32_t frame_idx, Stream &output_stream)
392 {
393     const bool broadcast = true;
394     bool success = SetSelectedFrameByIndex (frame_idx, broadcast);
395     if (success)
396     {
397         StackFrameSP frame_sp = GetSelectedFrame();
398         if (frame_sp)
399         {
400             bool already_shown = false;
401             SymbolContext frame_sc(frame_sp->GetSymbolContext(eSymbolContextLineEntry));
402             if (GetProcess()->GetTarget().GetDebugger().GetUseExternalEditor() && frame_sc.line_entry.file && frame_sc.line_entry.line != 0)
403             {
404                 already_shown = Host::OpenFileInExternalEditor (frame_sc.line_entry.file, frame_sc.line_entry.line);
405             }
406 
407             bool show_frame_info = true;
408             bool show_source = !already_shown;
409             FunctionOptimizationWarning (frame_sp.get());
410             return frame_sp->GetStatus (output_stream, show_frame_info, show_source);
411         }
412         return false;
413     }
414     else
415         return false;
416 }
417 
418 void
419 Thread::FunctionOptimizationWarning (StackFrame *frame)
420 {
421     if (frame && frame->HasDebugInformation() && GetProcess()->GetWarningsOptimization() == true)
422     {
423         SymbolContext sc = frame->GetSymbolContext (eSymbolContextFunction | eSymbolContextModule);
424         GetProcess()->PrintWarningOptimization (sc);
425     }
426 }
427 
428 lldb::StopInfoSP
429 Thread::GetStopInfo ()
430 {
431     if (m_destroy_called)
432         return m_stop_info_sp;
433 
434     ThreadPlanSP plan_sp (GetCompletedPlan());
435     ProcessSP process_sp (GetProcess());
436     const uint32_t stop_id = process_sp ? process_sp->GetStopID() : UINT32_MAX;
437     if (plan_sp && plan_sp->PlanSucceeded())
438     {
439         return StopInfo::CreateStopReasonWithPlan (plan_sp, GetReturnValueObject(), GetExpressionVariable());
440     }
441     else
442     {
443         if ((m_stop_info_stop_id == stop_id) ||   // Stop info is valid, just return what we have (even if empty)
444             (m_stop_info_sp && m_stop_info_sp->IsValid()))  // Stop info is valid, just return what we have
445         {
446             return m_stop_info_sp;
447         }
448         else
449         {
450             GetPrivateStopInfo ();
451             return m_stop_info_sp;
452         }
453     }
454 }
455 
456 lldb::StopInfoSP
457 Thread::GetPrivateStopInfo ()
458 {
459     if (m_destroy_called)
460         return m_stop_info_sp;
461 
462     ProcessSP process_sp (GetProcess());
463     if (process_sp)
464     {
465         const uint32_t process_stop_id = process_sp->GetStopID();
466         if (m_stop_info_stop_id != process_stop_id)
467         {
468             if (m_stop_info_sp)
469             {
470                 if (m_stop_info_sp->IsValid()
471                     || IsStillAtLastBreakpointHit()
472                     || GetCurrentPlan()->IsVirtualStep())
473                     SetStopInfo (m_stop_info_sp);
474                 else
475                     m_stop_info_sp.reset();
476             }
477 
478             if (!m_stop_info_sp)
479             {
480                 if (CalculateStopInfo() == false)
481                     SetStopInfo (StopInfoSP());
482             }
483         }
484 
485         // The stop info can be manually set by calling Thread::SetStopInfo()
486         // prior to this function ever getting called, so we can't rely on
487         // "m_stop_info_stop_id != process_stop_id" as the condition for
488         // the if statement below, we must also check the stop info to see
489         // if we need to override it. See the header documentation in
490         // Process::GetStopInfoOverrideCallback() for more information on
491         // the stop info override callback.
492         if (m_stop_info_override_stop_id != process_stop_id)
493         {
494             m_stop_info_override_stop_id = process_stop_id;
495             if (m_stop_info_sp)
496             {
497                 ArchSpec::StopInfoOverrideCallbackType callback = GetProcess()->GetStopInfoOverrideCallback();
498                 if (callback)
499                     callback(*this);
500             }
501         }
502     }
503     return m_stop_info_sp;
504 }
505 
506 lldb::StopReason
507 Thread::GetStopReason()
508 {
509     lldb::StopInfoSP stop_info_sp (GetStopInfo ());
510     if (stop_info_sp)
511         return stop_info_sp->GetStopReason();
512     return eStopReasonNone;
513 }
514 
515 bool
516 Thread::StopInfoIsUpToDate() const
517 {
518     ProcessSP process_sp (GetProcess());
519     if (process_sp)
520         return m_stop_info_stop_id == process_sp->GetStopID();
521     else
522         return true; // Process is no longer around so stop info is always up to date...
523 }
524 
525 void
526 Thread::SetStopInfo (const lldb::StopInfoSP &stop_info_sp)
527 {
528     m_stop_info_sp = stop_info_sp;
529     if (m_stop_info_sp)
530     {
531         m_stop_info_sp->MakeStopInfoValid();
532         // If we are overriding the ShouldReportStop, do that here:
533         if (m_override_should_notify != eLazyBoolCalculate)
534             m_stop_info_sp->OverrideShouldNotify (m_override_should_notify == eLazyBoolYes);
535     }
536 
537     ProcessSP process_sp (GetProcess());
538     if (process_sp)
539         m_stop_info_stop_id = process_sp->GetStopID();
540     else
541         m_stop_info_stop_id = UINT32_MAX;
542     Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_THREAD));
543     if (log)
544         log->Printf("%p: tid = 0x%" PRIx64 ": stop info = %s (stop_id = %u)",
545                     static_cast<void*>(this), GetID(),
546                     stop_info_sp ? stop_info_sp->GetDescription() : "<NULL>",
547                     m_stop_info_stop_id);
548 }
549 
550 void
551 Thread::SetShouldReportStop (Vote vote)
552 {
553     if (vote == eVoteNoOpinion)
554         return;
555     else
556     {
557         m_override_should_notify = (vote == eVoteYes ? eLazyBoolYes : eLazyBoolNo);
558         if (m_stop_info_sp)
559             m_stop_info_sp->OverrideShouldNotify (m_override_should_notify == eLazyBoolYes);
560     }
561 }
562 
563 void
564 Thread::SetStopInfoToNothing()
565 {
566     // Note, we can't just NULL out the private reason, or the native thread implementation will try to
567     // go calculate it again.  For now, just set it to a Unix Signal with an invalid signal number.
568     SetStopInfo (StopInfo::CreateStopReasonWithSignal (*this,  LLDB_INVALID_SIGNAL_NUMBER));
569 }
570 
571 bool
572 Thread::ThreadStoppedForAReason (void)
573 {
574     return (bool) GetPrivateStopInfo ();
575 }
576 
577 bool
578 Thread::CheckpointThreadState (ThreadStateCheckpoint &saved_state)
579 {
580     saved_state.register_backup_sp.reset();
581     lldb::StackFrameSP frame_sp(GetStackFrameAtIndex (0));
582     if (frame_sp)
583     {
584         lldb::RegisterCheckpointSP reg_checkpoint_sp(new RegisterCheckpoint(RegisterCheckpoint::Reason::eExpression));
585         if (reg_checkpoint_sp)
586         {
587             lldb::RegisterContextSP reg_ctx_sp (frame_sp->GetRegisterContext());
588             if (reg_ctx_sp && reg_ctx_sp->ReadAllRegisterValues (*reg_checkpoint_sp))
589                 saved_state.register_backup_sp = reg_checkpoint_sp;
590         }
591     }
592     if (!saved_state.register_backup_sp)
593         return false;
594 
595     saved_state.stop_info_sp = GetStopInfo();
596     ProcessSP process_sp (GetProcess());
597     if (process_sp)
598         saved_state.orig_stop_id = process_sp->GetStopID();
599     saved_state.current_inlined_depth = GetCurrentInlinedDepth();
600 
601     return true;
602 }
603 
604 bool
605 Thread::RestoreRegisterStateFromCheckpoint (ThreadStateCheckpoint &saved_state)
606 {
607     if (saved_state.register_backup_sp)
608     {
609         lldb::StackFrameSP frame_sp(GetStackFrameAtIndex (0));
610         if (frame_sp)
611         {
612             lldb::RegisterContextSP reg_ctx_sp (frame_sp->GetRegisterContext());
613             if (reg_ctx_sp)
614             {
615                 bool ret = reg_ctx_sp->WriteAllRegisterValues (*saved_state.register_backup_sp);
616 
617                 // Clear out all stack frames as our world just changed.
618                 ClearStackFrames();
619                 reg_ctx_sp->InvalidateIfNeeded(true);
620                 if (m_unwinder_ap.get())
621                     m_unwinder_ap->Clear();
622                 return ret;
623             }
624         }
625     }
626     return false;
627 }
628 
629 bool
630 Thread::RestoreThreadStateFromCheckpoint (ThreadStateCheckpoint &saved_state)
631 {
632     if (saved_state.stop_info_sp)
633         saved_state.stop_info_sp->MakeStopInfoValid();
634     SetStopInfo(saved_state.stop_info_sp);
635     GetStackFrameList()->SetCurrentInlinedDepth (saved_state.current_inlined_depth);
636     return true;
637 }
638 
639 StateType
640 Thread::GetState() const
641 {
642     // If any other threads access this we will need a mutex for it
643     Mutex::Locker locker(m_state_mutex);
644     return m_state;
645 }
646 
647 void
648 Thread::SetState(StateType state)
649 {
650     Mutex::Locker locker(m_state_mutex);
651     m_state = state;
652 }
653 
654 void
655 Thread::WillStop()
656 {
657     ThreadPlan *current_plan = GetCurrentPlan();
658 
659     // FIXME: I may decide to disallow threads with no plans.  In which
660     // case this should go to an assert.
661 
662     if (!current_plan)
663         return;
664 
665     current_plan->WillStop();
666 }
667 
668 void
669 Thread::SetupForResume ()
670 {
671     if (GetResumeState() != eStateSuspended)
672     {
673         // If we're at a breakpoint push the step-over breakpoint plan.  Do this before
674         // telling the current plan it will resume, since we might change what the current
675         // plan is.
676 
677         lldb::RegisterContextSP reg_ctx_sp (GetRegisterContext());
678         if (reg_ctx_sp)
679         {
680             const addr_t thread_pc = reg_ctx_sp->GetPC();
681             BreakpointSiteSP bp_site_sp = GetProcess()->GetBreakpointSiteList().FindByAddress(thread_pc);
682             if (bp_site_sp)
683             {
684                 // Note, don't assume there's a ThreadPlanStepOverBreakpoint, the target may not require anything
685                 // special to step over a breakpoint.
686 
687                 ThreadPlan *cur_plan = GetCurrentPlan();
688 
689                 bool push_step_over_bp_plan = false;
690                 if (cur_plan->GetKind() == ThreadPlan::eKindStepOverBreakpoint)
691                 {
692                     ThreadPlanStepOverBreakpoint *bp_plan = (ThreadPlanStepOverBreakpoint *)cur_plan;
693                     if (bp_plan->GetBreakpointLoadAddress() != thread_pc)
694                         push_step_over_bp_plan = true;
695                 }
696                 else
697                     push_step_over_bp_plan = true;
698 
699                 if (push_step_over_bp_plan)
700                 {
701                     ThreadPlanSP step_bp_plan_sp (new ThreadPlanStepOverBreakpoint (*this));
702                     if (step_bp_plan_sp)
703                     {
704                         ;
705                         step_bp_plan_sp->SetPrivate (true);
706 
707                         if (GetCurrentPlan()->RunState() != eStateStepping)
708                         {
709                             ThreadPlanStepOverBreakpoint *step_bp_plan
710                                     = static_cast<ThreadPlanStepOverBreakpoint *>(step_bp_plan_sp.get());
711                             step_bp_plan->SetAutoContinue(true);
712                         }
713                         QueueThreadPlan (step_bp_plan_sp, false);
714                     }
715                 }
716             }
717         }
718     }
719 }
720 
721 bool
722 Thread::ShouldResume (StateType resume_state)
723 {
724     // At this point clear the completed plan stack.
725     m_completed_plan_stack.clear();
726     m_discarded_plan_stack.clear();
727     m_override_should_notify = eLazyBoolCalculate;
728 
729     m_temporary_resume_state = resume_state;
730 
731     lldb::ThreadSP backing_thread_sp (GetBackingThread ());
732     if (backing_thread_sp)
733         backing_thread_sp->m_temporary_resume_state = resume_state;
734 
735     // Make sure m_stop_info_sp is valid
736     GetPrivateStopInfo();
737 
738     // This is a little dubious, but we are trying to limit how often we actually fetch stop info from
739     // the target, 'cause that slows down single stepping.  So assume that if we got to the point where
740     // we're about to resume, and we haven't yet had to fetch the stop reason, then it doesn't need to know
741     // about the fact that we are resuming...
742     const uint32_t process_stop_id = GetProcess()->GetStopID();
743     if (m_stop_info_stop_id == process_stop_id &&
744         (m_stop_info_sp && m_stop_info_sp->IsValid()))
745     {
746         StopInfo *stop_info = GetPrivateStopInfo().get();
747         if (stop_info)
748             stop_info->WillResume (resume_state);
749     }
750 
751     // Tell all the plans that we are about to resume in case they need to clear any state.
752     // We distinguish between the plan on the top of the stack and the lower
753     // plans in case a plan needs to do any special business before it runs.
754 
755     bool need_to_resume = false;
756     ThreadPlan *plan_ptr = GetCurrentPlan();
757     if (plan_ptr)
758     {
759         need_to_resume = plan_ptr->WillResume(resume_state, true);
760 
761         while ((plan_ptr = GetPreviousPlan(plan_ptr)) != NULL)
762         {
763             plan_ptr->WillResume (resume_state, false);
764         }
765 
766         // If the WillResume for the plan says we are faking a resume, then it will have set an appropriate stop info.
767         // In that case, don't reset it here.
768 
769         if (need_to_resume && resume_state != eStateSuspended)
770         {
771             m_stop_info_sp.reset();
772         }
773     }
774 
775     if (need_to_resume)
776     {
777         ClearStackFrames();
778         // Let Thread subclasses do any special work they need to prior to resuming
779         WillResume (resume_state);
780     }
781 
782     return need_to_resume;
783 }
784 
785 void
786 Thread::DidResume ()
787 {
788     SetResumeSignal (LLDB_INVALID_SIGNAL_NUMBER);
789 }
790 
791 void
792 Thread::DidStop ()
793 {
794     SetState (eStateStopped);
795 }
796 
797 bool
798 Thread::ShouldStop (Event* event_ptr)
799 {
800     ThreadPlan *current_plan = GetCurrentPlan();
801 
802     bool should_stop = true;
803 
804     Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP));
805 
806     if (GetResumeState () == eStateSuspended)
807     {
808         if (log)
809             log->Printf ("Thread::%s for tid = 0x%4.4" PRIx64 " 0x%4.4" PRIx64 ", should_stop = 0 (ignore since thread was suspended)",
810                          __FUNCTION__, GetID (), GetProtocolID());
811         return false;
812     }
813 
814     if (GetTemporaryResumeState () == eStateSuspended)
815     {
816         if (log)
817             log->Printf ("Thread::%s for tid = 0x%4.4" PRIx64 " 0x%4.4" PRIx64 ", should_stop = 0 (ignore since thread was suspended)",
818                          __FUNCTION__, GetID (), GetProtocolID());
819         return false;
820     }
821 
822     // Based on the current thread plan and process stop info, check if this
823     // thread caused the process to stop. NOTE: this must take place before
824     // the plan is moved from the current plan stack to the completed plan
825     // stack.
826     if (ThreadStoppedForAReason() == false)
827     {
828         if (log)
829             log->Printf ("Thread::%s for tid = 0x%4.4" PRIx64 " 0x%4.4" PRIx64 ", pc = 0x%16.16" PRIx64 ", should_stop = 0 (ignore since no stop reason)",
830                          __FUNCTION__, GetID (), GetProtocolID(),
831                          GetRegisterContext() ? GetRegisterContext()->GetPC() : LLDB_INVALID_ADDRESS);
832         return false;
833     }
834 
835     if (log)
836     {
837         log->Printf ("Thread::%s(%p) for tid = 0x%4.4" PRIx64 " 0x%4.4" PRIx64 ", pc = 0x%16.16" PRIx64,
838                      __FUNCTION__, static_cast<void*>(this), GetID (),
839                      GetProtocolID (),
840                      GetRegisterContext()
841                         ? GetRegisterContext()->GetPC()
842                         : LLDB_INVALID_ADDRESS);
843         log->Printf ("^^^^^^^^ Thread::ShouldStop Begin ^^^^^^^^");
844         StreamString s;
845         s.IndentMore();
846         DumpThreadPlans(&s);
847         log->Printf ("Plan stack initial state:\n%s", s.GetData());
848     }
849 
850     // The top most plan always gets to do the trace log...
851     current_plan->DoTraceLog ();
852 
853     // First query the stop info's ShouldStopSynchronous.  This handles "synchronous" stop reasons, for example the breakpoint
854     // command on internal breakpoints.  If a synchronous stop reason says we should not stop, then we don't have to
855     // do any more work on this stop.
856     StopInfoSP private_stop_info (GetPrivateStopInfo());
857     if (private_stop_info && private_stop_info->ShouldStopSynchronous(event_ptr) == false)
858     {
859         if (log)
860             log->Printf ("StopInfo::ShouldStop async callback says we should not stop, returning ShouldStop of false.");
861         return false;
862     }
863 
864     // If we've already been restarted, don't query the plans since the state they would examine is not current.
865     if (Process::ProcessEventData::GetRestartedFromEvent(event_ptr))
866         return false;
867 
868     // Before the plans see the state of the world, calculate the current inlined depth.
869     GetStackFrameList()->CalculateCurrentInlinedDepth();
870 
871     // If the base plan doesn't understand why we stopped, then we have to find a plan that does.
872     // If that plan is still working, then we don't need to do any more work.  If the plan that explains
873     // the stop is done, then we should pop all the plans below it, and pop it, and then let the plans above it decide
874     // whether they still need to do more work.
875 
876     bool done_processing_current_plan = false;
877 
878     if (!current_plan->PlanExplainsStop(event_ptr))
879     {
880         if (current_plan->TracerExplainsStop())
881         {
882             done_processing_current_plan = true;
883             should_stop = false;
884         }
885         else
886         {
887             // If the current plan doesn't explain the stop, then find one that
888             // does and let it handle the situation.
889             ThreadPlan *plan_ptr = current_plan;
890             while ((plan_ptr = GetPreviousPlan(plan_ptr)) != NULL)
891             {
892                 if (plan_ptr->PlanExplainsStop(event_ptr))
893                 {
894                     should_stop = plan_ptr->ShouldStop (event_ptr);
895 
896                     // plan_ptr explains the stop, next check whether plan_ptr is done, if so, then we should take it
897                     // and all the plans below it off the stack.
898 
899                     if (plan_ptr->MischiefManaged())
900                     {
901                         // We're going to pop the plans up to and including the plan that explains the stop.
902                         ThreadPlan *prev_plan_ptr = GetPreviousPlan (plan_ptr);
903 
904                         do
905                         {
906                             if (should_stop)
907                                 current_plan->WillStop();
908                             PopPlan();
909                         }
910                         while ((current_plan = GetCurrentPlan()) != prev_plan_ptr);
911                         // Now, if the responsible plan was not "Okay to discard" then we're done,
912                         // otherwise we forward this to the next plan in the stack below.
913                         if (plan_ptr->IsMasterPlan() && !plan_ptr->OkayToDiscard())
914                             done_processing_current_plan = true;
915                         else
916                             done_processing_current_plan = false;
917                     }
918                     else
919                         done_processing_current_plan = true;
920 
921                     break;
922                 }
923             }
924         }
925     }
926 
927     if (!done_processing_current_plan)
928     {
929         bool over_ride_stop = current_plan->ShouldAutoContinue(event_ptr);
930 
931         if (log)
932             log->Printf("Plan %s explains stop, auto-continue %i.",
933                         current_plan->GetName(), over_ride_stop);
934 
935         // We're starting from the base plan, so just let it decide;
936         if (PlanIsBasePlan(current_plan))
937         {
938             should_stop = current_plan->ShouldStop (event_ptr);
939             if (log)
940                 log->Printf("Base plan says should stop: %i.", should_stop);
941         }
942         else
943         {
944             // Otherwise, don't let the base plan override what the other plans say to do, since
945             // presumably if there were other plans they would know what to do...
946             while (1)
947             {
948                 if (PlanIsBasePlan(current_plan))
949                     break;
950 
951                 should_stop = current_plan->ShouldStop(event_ptr);
952                 if (log)
953                     log->Printf("Plan %s should stop: %d.",
954                                 current_plan->GetName(), should_stop);
955                 if (current_plan->MischiefManaged())
956                 {
957                     if (should_stop)
958                         current_plan->WillStop();
959 
960                     // If a Master Plan wants to stop, and wants to stick on the stack, we let it.
961                     // Otherwise, see if the plan's parent wants to stop.
962 
963                     if (should_stop && current_plan->IsMasterPlan() && !current_plan->OkayToDiscard())
964                     {
965                         PopPlan();
966                         break;
967                     }
968                     else
969                     {
970                         PopPlan();
971 
972                         current_plan = GetCurrentPlan();
973                         if (current_plan == NULL)
974                         {
975                             break;
976                         }
977                     }
978                 }
979                 else
980                 {
981                     break;
982                 }
983             }
984         }
985 
986         if (over_ride_stop)
987             should_stop = false;
988     }
989 
990     // One other potential problem is that we set up a master plan, then stop in before it is complete - for instance
991     // by hitting a breakpoint during a step-over - then do some step/finish/etc operations that wind up
992     // past the end point condition of the initial plan.  We don't want to strand the original plan on the stack,
993     // This code clears stale plans off the stack.
994 
995     if (should_stop)
996     {
997         ThreadPlan *plan_ptr = GetCurrentPlan();
998         while (!PlanIsBasePlan(plan_ptr))
999         {
1000             bool stale = plan_ptr->IsPlanStale ();
1001             ThreadPlan *examined_plan = plan_ptr;
1002             plan_ptr = GetPreviousPlan (examined_plan);
1003 
1004             if (stale)
1005             {
1006                 if (log)
1007                     log->Printf("Plan %s being discarded in cleanup, it says it is already done.",
1008                                 examined_plan->GetName());
1009                 DiscardThreadPlansUpToPlan(examined_plan);
1010             }
1011         }
1012     }
1013 
1014     if (log)
1015     {
1016         StreamString s;
1017         s.IndentMore();
1018         DumpThreadPlans(&s);
1019         log->Printf ("Plan stack final state:\n%s", s.GetData());
1020         log->Printf ("vvvvvvvv Thread::ShouldStop End (returning %i) vvvvvvvv", should_stop);
1021     }
1022     return should_stop;
1023 }
1024 
1025 Vote
1026 Thread::ShouldReportStop (Event* event_ptr)
1027 {
1028     StateType thread_state = GetResumeState ();
1029     StateType temp_thread_state = GetTemporaryResumeState();
1030 
1031     Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP));
1032 
1033     if (thread_state == eStateSuspended || thread_state == eStateInvalid)
1034     {
1035         if (log)
1036             log->Printf ("Thread::ShouldReportStop() tid = 0x%4.4" PRIx64 ": returning vote %i (state was suspended or invalid)", GetID(), eVoteNoOpinion);
1037         return eVoteNoOpinion;
1038     }
1039 
1040     if (temp_thread_state == eStateSuspended || temp_thread_state == eStateInvalid)
1041     {
1042         if (log)
1043             log->Printf ("Thread::ShouldReportStop() tid = 0x%4.4" PRIx64 ": returning vote %i (temporary state was suspended or invalid)", GetID(), eVoteNoOpinion);
1044         return eVoteNoOpinion;
1045     }
1046 
1047     if (!ThreadStoppedForAReason())
1048     {
1049         if (log)
1050             log->Printf ("Thread::ShouldReportStop() tid = 0x%4.4" PRIx64 ": returning vote %i (thread didn't stop for a reason.)", GetID(), eVoteNoOpinion);
1051         return eVoteNoOpinion;
1052     }
1053 
1054     if (m_completed_plan_stack.size() > 0)
1055     {
1056         // Don't use GetCompletedPlan here, since that suppresses private plans.
1057         if (log)
1058             log->Printf ("Thread::ShouldReportStop() tid = 0x%4.4" PRIx64 ": returning vote  for complete stack's back plan", GetID());
1059         return m_completed_plan_stack.back()->ShouldReportStop (event_ptr);
1060     }
1061     else
1062     {
1063         Vote thread_vote = eVoteNoOpinion;
1064         ThreadPlan *plan_ptr = GetCurrentPlan();
1065         while (1)
1066         {
1067             if (plan_ptr->PlanExplainsStop(event_ptr))
1068             {
1069                 thread_vote = plan_ptr->ShouldReportStop(event_ptr);
1070                 break;
1071             }
1072             if (PlanIsBasePlan(plan_ptr))
1073                 break;
1074             else
1075                 plan_ptr = GetPreviousPlan(plan_ptr);
1076         }
1077         if (log)
1078             log->Printf ("Thread::ShouldReportStop() tid = 0x%4.4" PRIx64 ": returning vote %i for current plan", GetID(), thread_vote);
1079 
1080         return thread_vote;
1081     }
1082 }
1083 
1084 Vote
1085 Thread::ShouldReportRun (Event* event_ptr)
1086 {
1087     StateType thread_state = GetResumeState ();
1088 
1089     if (thread_state == eStateSuspended
1090             || thread_state == eStateInvalid)
1091     {
1092         return eVoteNoOpinion;
1093     }
1094 
1095     Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP));
1096     if (m_completed_plan_stack.size() > 0)
1097     {
1098         // Don't use GetCompletedPlan here, since that suppresses private plans.
1099         if (log)
1100             log->Printf ("Current Plan for thread %d(%p) (0x%4.4" PRIx64 ", %s): %s being asked whether we should report run.",
1101                          GetIndexID(), static_cast<void*>(this), GetID(),
1102                          StateAsCString(GetTemporaryResumeState()),
1103                          m_completed_plan_stack.back()->GetName());
1104 
1105         return m_completed_plan_stack.back()->ShouldReportRun (event_ptr);
1106     }
1107     else
1108     {
1109         if (log)
1110             log->Printf ("Current Plan for thread %d(%p) (0x%4.4" PRIx64 ", %s): %s being asked whether we should report run.",
1111                          GetIndexID(), static_cast<void*>(this), GetID(),
1112                          StateAsCString(GetTemporaryResumeState()),
1113                          GetCurrentPlan()->GetName());
1114 
1115         return GetCurrentPlan()->ShouldReportRun (event_ptr);
1116      }
1117 }
1118 
1119 bool
1120 Thread::MatchesSpec (const ThreadSpec *spec)
1121 {
1122     if (spec == NULL)
1123         return true;
1124 
1125     return spec->ThreadPassesBasicTests(*this);
1126 }
1127 
1128 void
1129 Thread::PushPlan (ThreadPlanSP &thread_plan_sp)
1130 {
1131     if (thread_plan_sp)
1132     {
1133         // If the thread plan doesn't already have a tracer, give it its parent's tracer:
1134         if (!thread_plan_sp->GetThreadPlanTracer())
1135             thread_plan_sp->SetThreadPlanTracer(m_plan_stack.back()->GetThreadPlanTracer());
1136         m_plan_stack.push_back (thread_plan_sp);
1137 
1138         thread_plan_sp->DidPush();
1139 
1140         Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP));
1141         if (log)
1142         {
1143             StreamString s;
1144             thread_plan_sp->GetDescription (&s, lldb::eDescriptionLevelFull);
1145             log->Printf("Thread::PushPlan(0x%p): \"%s\", tid = 0x%4.4" PRIx64 ".",
1146                         static_cast<void*>(this), s.GetData(),
1147                         thread_plan_sp->GetThread().GetID());
1148         }
1149     }
1150 }
1151 
1152 void
1153 Thread::PopPlan ()
1154 {
1155     Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP));
1156 
1157     if (m_plan_stack.size() <= 1)
1158         return;
1159     else
1160     {
1161         ThreadPlanSP &plan = m_plan_stack.back();
1162         if (log)
1163         {
1164             log->Printf("Popping plan: \"%s\", tid = 0x%4.4" PRIx64 ".", plan->GetName(), plan->GetThread().GetID());
1165         }
1166         m_completed_plan_stack.push_back (plan);
1167         plan->WillPop();
1168         m_plan_stack.pop_back();
1169     }
1170 }
1171 
1172 void
1173 Thread::DiscardPlan ()
1174 {
1175     Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP));
1176     if (m_plan_stack.size() > 1)
1177     {
1178         ThreadPlanSP &plan = m_plan_stack.back();
1179         if (log)
1180             log->Printf("Discarding plan: \"%s\", tid = 0x%4.4" PRIx64 ".", plan->GetName(), plan->GetThread().GetID());
1181 
1182         m_discarded_plan_stack.push_back (plan);
1183         plan->WillPop();
1184         m_plan_stack.pop_back();
1185     }
1186 }
1187 
1188 ThreadPlan *
1189 Thread::GetCurrentPlan ()
1190 {
1191     // There will always be at least the base plan.  If somebody is mucking with a
1192     // thread with an empty plan stack, we should assert right away.
1193     if (m_plan_stack.empty())
1194         return NULL;
1195     return m_plan_stack.back().get();
1196 }
1197 
1198 ThreadPlanSP
1199 Thread::GetCompletedPlan ()
1200 {
1201     ThreadPlanSP empty_plan_sp;
1202     if (!m_completed_plan_stack.empty())
1203     {
1204         for (int i = m_completed_plan_stack.size() - 1; i >= 0; i--)
1205         {
1206             ThreadPlanSP completed_plan_sp;
1207             completed_plan_sp = m_completed_plan_stack[i];
1208             if (!completed_plan_sp->GetPrivate ())
1209             return completed_plan_sp;
1210         }
1211     }
1212     return empty_plan_sp;
1213 }
1214 
1215 ValueObjectSP
1216 Thread::GetReturnValueObject ()
1217 {
1218     if (!m_completed_plan_stack.empty())
1219     {
1220         for (int i = m_completed_plan_stack.size() - 1; i >= 0; i--)
1221         {
1222             ValueObjectSP return_valobj_sp;
1223             return_valobj_sp = m_completed_plan_stack[i]->GetReturnValueObject();
1224             if (return_valobj_sp)
1225                 return return_valobj_sp;
1226         }
1227     }
1228     return ValueObjectSP();
1229 }
1230 
1231 ExpressionVariableSP
1232 Thread::GetExpressionVariable ()
1233 {
1234     if (!m_completed_plan_stack.empty())
1235     {
1236         for (int i = m_completed_plan_stack.size() - 1; i >= 0; i--)
1237         {
1238             ExpressionVariableSP expression_variable_sp;
1239             expression_variable_sp = m_completed_plan_stack[i]->GetExpressionVariable();
1240             if (expression_variable_sp)
1241                 return expression_variable_sp;
1242         }
1243     }
1244     return ExpressionVariableSP();
1245 }
1246 
1247 bool
1248 Thread::IsThreadPlanDone (ThreadPlan *plan)
1249 {
1250     if (!m_completed_plan_stack.empty())
1251     {
1252         for (int i = m_completed_plan_stack.size() - 1; i >= 0; i--)
1253         {
1254             if (m_completed_plan_stack[i].get() == plan)
1255                 return true;
1256         }
1257     }
1258     return false;
1259 }
1260 
1261 bool
1262 Thread::WasThreadPlanDiscarded (ThreadPlan *plan)
1263 {
1264     if (!m_discarded_plan_stack.empty())
1265     {
1266         for (int i = m_discarded_plan_stack.size() - 1; i >= 0; i--)
1267         {
1268             if (m_discarded_plan_stack[i].get() == plan)
1269                 return true;
1270         }
1271     }
1272     return false;
1273 }
1274 
1275 ThreadPlan *
1276 Thread::GetPreviousPlan (ThreadPlan *current_plan)
1277 {
1278     if (current_plan == NULL)
1279         return NULL;
1280 
1281     int stack_size = m_completed_plan_stack.size();
1282     for (int i = stack_size - 1; i > 0; i--)
1283     {
1284         if (current_plan == m_completed_plan_stack[i].get())
1285             return m_completed_plan_stack[i-1].get();
1286     }
1287 
1288     if (stack_size > 0 && m_completed_plan_stack[0].get() == current_plan)
1289     {
1290         if (m_plan_stack.size() > 0)
1291             return m_plan_stack.back().get();
1292         else
1293             return NULL;
1294     }
1295 
1296     stack_size = m_plan_stack.size();
1297     for (int i = stack_size - 1; i > 0; i--)
1298     {
1299         if (current_plan == m_plan_stack[i].get())
1300             return m_plan_stack[i-1].get();
1301     }
1302     return NULL;
1303 }
1304 
1305 void
1306 Thread::QueueThreadPlan (ThreadPlanSP &thread_plan_sp, bool abort_other_plans)
1307 {
1308     if (abort_other_plans)
1309        DiscardThreadPlans(true);
1310 
1311     PushPlan (thread_plan_sp);
1312 }
1313 
1314 void
1315 Thread::EnableTracer (bool value, bool single_stepping)
1316 {
1317     int stack_size = m_plan_stack.size();
1318     for (int i = 0; i < stack_size; i++)
1319     {
1320         if (m_plan_stack[i]->GetThreadPlanTracer())
1321         {
1322             m_plan_stack[i]->GetThreadPlanTracer()->EnableTracing(value);
1323             m_plan_stack[i]->GetThreadPlanTracer()->EnableSingleStep(single_stepping);
1324         }
1325     }
1326 }
1327 
1328 void
1329 Thread::SetTracer (lldb::ThreadPlanTracerSP &tracer_sp)
1330 {
1331     int stack_size = m_plan_stack.size();
1332     for (int i = 0; i < stack_size; i++)
1333         m_plan_stack[i]->SetThreadPlanTracer(tracer_sp);
1334 }
1335 
1336 bool
1337 Thread::DiscardUserThreadPlansUpToIndex (uint32_t thread_index)
1338 {
1339     // Count the user thread plans from the back end to get the number of the one we want
1340     // to discard:
1341 
1342     uint32_t idx = 0;
1343     ThreadPlan *up_to_plan_ptr = nullptr;
1344 
1345     for (ThreadPlanSP plan_sp : m_plan_stack)
1346     {
1347         if (plan_sp->GetPrivate())
1348             continue;
1349         if (idx == thread_index)
1350         {
1351             up_to_plan_ptr = plan_sp.get();
1352             break;
1353         }
1354         else
1355             idx++;
1356     }
1357 
1358     if (up_to_plan_ptr == nullptr)
1359         return false;
1360 
1361     DiscardThreadPlansUpToPlan(up_to_plan_ptr);
1362     return true;
1363 }
1364 
1365 void
1366 Thread::DiscardThreadPlansUpToPlan (lldb::ThreadPlanSP &up_to_plan_sp)
1367 {
1368     DiscardThreadPlansUpToPlan (up_to_plan_sp.get());
1369 }
1370 
1371 void
1372 Thread::DiscardThreadPlansUpToPlan (ThreadPlan *up_to_plan_ptr)
1373 {
1374     Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP));
1375     if (log)
1376         log->Printf("Discarding thread plans for thread tid = 0x%4.4" PRIx64 ", up to %p",
1377                     GetID(), static_cast<void*>(up_to_plan_ptr));
1378 
1379     int stack_size = m_plan_stack.size();
1380 
1381     // If the input plan is NULL, discard all plans.  Otherwise make sure this plan is in the
1382     // stack, and if so discard up to and including it.
1383 
1384     if (up_to_plan_ptr == NULL)
1385     {
1386         for (int i = stack_size - 1; i > 0; i--)
1387             DiscardPlan();
1388     }
1389     else
1390     {
1391         bool found_it = false;
1392         for (int i = stack_size - 1; i > 0; i--)
1393         {
1394             if (m_plan_stack[i].get() == up_to_plan_ptr)
1395                 found_it = true;
1396         }
1397         if (found_it)
1398         {
1399             bool last_one = false;
1400             for (int i = stack_size - 1; i > 0 && !last_one ; i--)
1401             {
1402                 if (GetCurrentPlan() == up_to_plan_ptr)
1403                     last_one = true;
1404                 DiscardPlan();
1405             }
1406         }
1407     }
1408 }
1409 
1410 void
1411 Thread::DiscardThreadPlans(bool force)
1412 {
1413     Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP));
1414     if (log)
1415     {
1416         log->Printf("Discarding thread plans for thread (tid = 0x%4.4" PRIx64 ", force %d)", GetID(), force);
1417     }
1418 
1419     if (force)
1420     {
1421         int stack_size = m_plan_stack.size();
1422         for (int i = stack_size - 1; i > 0; i--)
1423         {
1424             DiscardPlan();
1425         }
1426         return;
1427     }
1428 
1429     while (1)
1430     {
1431         int master_plan_idx;
1432         bool discard = true;
1433 
1434         // Find the first master plan, see if it wants discarding, and if yes discard up to it.
1435         for (master_plan_idx = m_plan_stack.size() - 1; master_plan_idx >= 0; master_plan_idx--)
1436         {
1437             if (m_plan_stack[master_plan_idx]->IsMasterPlan())
1438             {
1439                 discard = m_plan_stack[master_plan_idx]->OkayToDiscard();
1440                 break;
1441             }
1442         }
1443 
1444         if (discard)
1445         {
1446             // First pop all the dependent plans:
1447             for (int i = m_plan_stack.size() - 1; i > master_plan_idx; i--)
1448             {
1449                 // FIXME: Do we need a finalize here, or is the rule that "PrepareForStop"
1450                 // for the plan leaves it in a state that it is safe to pop the plan
1451                 // with no more notice?
1452                 DiscardPlan();
1453             }
1454 
1455             // Now discard the master plan itself.
1456             // The bottom-most plan never gets discarded.  "OkayToDiscard" for it means
1457             // discard it's dependent plans, but not it...
1458             if (master_plan_idx > 0)
1459             {
1460                 DiscardPlan();
1461             }
1462         }
1463         else
1464         {
1465             // If the master plan doesn't want to get discarded, then we're done.
1466             break;
1467         }
1468     }
1469 }
1470 
1471 bool
1472 Thread::PlanIsBasePlan (ThreadPlan *plan_ptr)
1473 {
1474     if (plan_ptr->IsBasePlan())
1475         return true;
1476     else if (m_plan_stack.size() == 0)
1477         return false;
1478     else
1479        return m_plan_stack[0].get() == plan_ptr;
1480 }
1481 
1482 Error
1483 Thread::UnwindInnermostExpression()
1484 {
1485     Error error;
1486     int stack_size = m_plan_stack.size();
1487 
1488     // If the input plan is NULL, discard all plans.  Otherwise make sure this plan is in the
1489     // stack, and if so discard up to and including it.
1490 
1491     for (int i = stack_size - 1; i > 0; i--)
1492     {
1493         if (m_plan_stack[i]->GetKind() == ThreadPlan::eKindCallFunction)
1494         {
1495             DiscardThreadPlansUpToPlan(m_plan_stack[i].get());
1496             return error;
1497         }
1498     }
1499     error.SetErrorString("No expressions currently active on this thread");
1500     return error;
1501 }
1502 
1503 ThreadPlanSP
1504 Thread::QueueFundamentalPlan (bool abort_other_plans)
1505 {
1506     ThreadPlanSP thread_plan_sp (new ThreadPlanBase(*this));
1507     QueueThreadPlan (thread_plan_sp, abort_other_plans);
1508     return thread_plan_sp;
1509 }
1510 
1511 ThreadPlanSP
1512 Thread::QueueThreadPlanForStepSingleInstruction(bool step_over,
1513                                                 bool abort_other_plans,
1514                                                 bool stop_other_threads)
1515 {
1516     ThreadPlanSP thread_plan_sp (new ThreadPlanStepInstruction (*this, step_over, stop_other_threads, eVoteNoOpinion, eVoteNoOpinion));
1517     QueueThreadPlan (thread_plan_sp, abort_other_plans);
1518     return thread_plan_sp;
1519 }
1520 
1521 ThreadPlanSP
1522 Thread::QueueThreadPlanForStepOverRange(bool abort_other_plans,
1523                                         const AddressRange &range,
1524                                         const SymbolContext &addr_context,
1525                                         lldb::RunMode stop_other_threads,
1526                                         LazyBool step_out_avoids_code_withoug_debug_info)
1527 {
1528     ThreadPlanSP thread_plan_sp;
1529     thread_plan_sp.reset (new ThreadPlanStepOverRange (*this, range, addr_context, stop_other_threads, step_out_avoids_code_withoug_debug_info));
1530 
1531     QueueThreadPlan (thread_plan_sp, abort_other_plans);
1532     return thread_plan_sp;
1533 }
1534 
1535 ThreadPlanSP
1536 Thread::QueueThreadPlanForStepInRange(bool abort_other_plans,
1537                                       const AddressRange &range,
1538                                       const SymbolContext &addr_context,
1539                                       const char *step_in_target,
1540                                       lldb::RunMode stop_other_threads,
1541                                       LazyBool step_in_avoids_code_without_debug_info,
1542                                       LazyBool step_out_avoids_code_without_debug_info)
1543 {
1544     ThreadPlanSP thread_plan_sp (new ThreadPlanStepInRange (*this,
1545                                                              range,
1546                                                              addr_context,
1547                                                              stop_other_threads,
1548                                                              step_in_avoids_code_without_debug_info,
1549                                                              step_out_avoids_code_without_debug_info));
1550     ThreadPlanStepInRange *plan = static_cast<ThreadPlanStepInRange *>(thread_plan_sp.get());
1551 
1552     if (step_in_target)
1553         plan->SetStepInTarget(step_in_target);
1554 
1555     QueueThreadPlan (thread_plan_sp, abort_other_plans);
1556     return thread_plan_sp;
1557 }
1558 
1559 ThreadPlanSP
1560 Thread::QueueThreadPlanForStepOut(bool abort_other_plans,
1561                                   SymbolContext *addr_context,
1562                                   bool first_insn,
1563                                   bool stop_other_threads,
1564                                   Vote stop_vote,
1565                                   Vote run_vote,
1566                                   uint32_t frame_idx,
1567                                   LazyBool step_out_avoids_code_withoug_debug_info)
1568 {
1569     ThreadPlanSP thread_plan_sp (new ThreadPlanStepOut (*this,
1570                                                         addr_context,
1571                                                         first_insn,
1572                                                         stop_other_threads,
1573                                                         stop_vote,
1574                                                         run_vote,
1575                                                         frame_idx,
1576                                                         step_out_avoids_code_withoug_debug_info));
1577 
1578     if (thread_plan_sp->ValidatePlan(NULL))
1579     {
1580         QueueThreadPlan (thread_plan_sp, abort_other_plans);
1581         return thread_plan_sp;
1582     }
1583     else
1584     {
1585         return ThreadPlanSP();
1586     }
1587 }
1588 
1589 ThreadPlanSP
1590 Thread::QueueThreadPlanForStepOutNoShouldStop(bool abort_other_plans,
1591                                               SymbolContext *addr_context,
1592                                               bool first_insn,
1593                                               bool stop_other_threads,
1594                                               Vote stop_vote,
1595                                               Vote run_vote,
1596                                               uint32_t frame_idx)
1597 {
1598     ThreadPlanSP thread_plan_sp(new ThreadPlanStepOut (*this,
1599                                                         addr_context,
1600                                                         first_insn,
1601                                                         stop_other_threads,
1602                                                         stop_vote,
1603                                                         run_vote,
1604                                                         frame_idx,
1605                                                         eLazyBoolNo));
1606 
1607     ThreadPlanStepOut *new_plan = static_cast<ThreadPlanStepOut *>(thread_plan_sp.get());
1608     new_plan->ClearShouldStopHereCallbacks();
1609 
1610     if (thread_plan_sp->ValidatePlan(NULL))
1611     {
1612         QueueThreadPlan (thread_plan_sp, abort_other_plans);
1613         return thread_plan_sp;
1614     }
1615     else
1616     {
1617         return ThreadPlanSP();
1618     }
1619 }
1620 
1621 ThreadPlanSP
1622 Thread::QueueThreadPlanForStepThrough (StackID &return_stack_id, bool abort_other_plans, bool stop_other_threads)
1623 {
1624     ThreadPlanSP thread_plan_sp(new ThreadPlanStepThrough (*this, return_stack_id, stop_other_threads));
1625     if (!thread_plan_sp || !thread_plan_sp->ValidatePlan (NULL))
1626         return ThreadPlanSP();
1627 
1628     QueueThreadPlan (thread_plan_sp, abort_other_plans);
1629     return thread_plan_sp;
1630 }
1631 
1632 ThreadPlanSP
1633 Thread::QueueThreadPlanForRunToAddress (bool abort_other_plans,
1634                                         Address &target_addr,
1635                                         bool stop_other_threads)
1636 {
1637     ThreadPlanSP thread_plan_sp (new ThreadPlanRunToAddress (*this, target_addr, stop_other_threads));
1638     QueueThreadPlan (thread_plan_sp, abort_other_plans);
1639     return thread_plan_sp;
1640 }
1641 
1642 ThreadPlanSP
1643 Thread::QueueThreadPlanForStepUntil (bool abort_other_plans,
1644                                      lldb::addr_t *address_list,
1645                                      size_t num_addresses,
1646                                      bool stop_other_threads,
1647                                      uint32_t frame_idx)
1648 {
1649     ThreadPlanSP thread_plan_sp (new ThreadPlanStepUntil (*this, address_list, num_addresses, stop_other_threads, frame_idx));
1650     QueueThreadPlan (thread_plan_sp, abort_other_plans);
1651     return thread_plan_sp;
1652 
1653 }
1654 
1655 lldb::ThreadPlanSP
1656 Thread::QueueThreadPlanForStepScripted (bool abort_other_plans,
1657                                         const char *class_name,
1658                                         bool stop_other_threads)
1659 {
1660     ThreadPlanSP thread_plan_sp (new ThreadPlanPython (*this, class_name));
1661     QueueThreadPlan (thread_plan_sp, abort_other_plans);
1662     // This seems a little funny, but I don't want to have to split up the constructor and the
1663     // DidPush in the scripted plan, that seems annoying.
1664     // That means the constructor has to be in DidPush.
1665     // So I have to validate the plan AFTER pushing it, and then take it off again...
1666     if (!thread_plan_sp->ValidatePlan(nullptr))
1667     {
1668         DiscardThreadPlansUpToPlan(thread_plan_sp);
1669         return ThreadPlanSP();
1670     }
1671     else
1672         return thread_plan_sp;
1673 }
1674 
1675 uint32_t
1676 Thread::GetIndexID () const
1677 {
1678     return m_index_id;
1679 }
1680 
1681 static void
1682 PrintPlanElement (Stream *s, const ThreadPlanSP &plan, lldb::DescriptionLevel desc_level, int32_t elem_idx)
1683 {
1684         s->IndentMore();
1685         s->Indent();
1686         s->Printf ("Element %d: ", elem_idx);
1687         plan->GetDescription (s, desc_level);
1688         s->EOL();
1689         s->IndentLess();
1690 }
1691 
1692 static void
1693 PrintPlanStack (Stream *s, const std::vector<lldb::ThreadPlanSP> &plan_stack, lldb::DescriptionLevel desc_level, bool include_internal)
1694 {
1695     int32_t print_idx = 0;
1696     for (ThreadPlanSP plan_sp : plan_stack)
1697     {
1698         if (include_internal || !plan_sp->GetPrivate())
1699         {
1700             PrintPlanElement (s, plan_sp, desc_level, print_idx++);
1701         }
1702     }
1703 }
1704 
1705 void
1706 Thread::DumpThreadPlans (Stream *s,
1707                          lldb::DescriptionLevel desc_level,
1708                          bool include_internal,
1709                          bool ignore_boring_threads) const
1710 {
1711     uint32_t stack_size;
1712 
1713     if (ignore_boring_threads)
1714     {
1715         uint32_t stack_size = m_plan_stack.size();
1716         uint32_t completed_stack_size = m_completed_plan_stack.size();
1717         uint32_t discarded_stack_size = m_discarded_plan_stack.size();
1718         if (stack_size == 1 && completed_stack_size == 0 && discarded_stack_size == 0)
1719         {
1720             s->Printf ("thread #%u: tid = 0x%4.4" PRIx64 "\n", GetIndexID(), GetID());
1721             s->IndentMore();
1722             s->Indent();
1723             s->Printf("No active thread plans\n");
1724             s->IndentLess();
1725             return;
1726         }
1727     }
1728 
1729     s->Indent();
1730     s->Printf ("thread #%u: tid = 0x%4.4" PRIx64 ":\n", GetIndexID(), GetID());
1731     s->IndentMore();
1732     s->Indent();
1733     s->Printf ("Active plan stack:\n");
1734     PrintPlanStack (s, m_plan_stack, desc_level, include_internal);
1735 
1736     stack_size = m_completed_plan_stack.size();
1737     if (stack_size > 0)
1738     {
1739         s->Indent();
1740         s->Printf ("Completed Plan Stack:\n");
1741         PrintPlanStack (s, m_completed_plan_stack, desc_level, include_internal);
1742     }
1743 
1744     stack_size = m_discarded_plan_stack.size();
1745     if (stack_size > 0)
1746     {
1747         s->Indent();
1748         s->Printf ("Discarded Plan Stack:\n");
1749         PrintPlanStack (s, m_discarded_plan_stack, desc_level, include_internal);
1750     }
1751 
1752     s->IndentLess();
1753 }
1754 
1755 TargetSP
1756 Thread::CalculateTarget ()
1757 {
1758     TargetSP target_sp;
1759     ProcessSP process_sp(GetProcess());
1760     if (process_sp)
1761         target_sp = process_sp->CalculateTarget();
1762     return target_sp;
1763 
1764 }
1765 
1766 ProcessSP
1767 Thread::CalculateProcess ()
1768 {
1769     return GetProcess();
1770 }
1771 
1772 ThreadSP
1773 Thread::CalculateThread ()
1774 {
1775     return shared_from_this();
1776 }
1777 
1778 StackFrameSP
1779 Thread::CalculateStackFrame ()
1780 {
1781     return StackFrameSP();
1782 }
1783 
1784 void
1785 Thread::CalculateExecutionContext (ExecutionContext &exe_ctx)
1786 {
1787     exe_ctx.SetContext (shared_from_this());
1788 }
1789 
1790 StackFrameListSP
1791 Thread::GetStackFrameList ()
1792 {
1793     StackFrameListSP frame_list_sp;
1794     Mutex::Locker locker(m_frame_mutex);
1795     if (m_curr_frames_sp)
1796     {
1797         frame_list_sp = m_curr_frames_sp;
1798     }
1799     else
1800     {
1801         frame_list_sp.reset(new StackFrameList (*this, m_prev_frames_sp, true));
1802         m_curr_frames_sp = frame_list_sp;
1803     }
1804     return frame_list_sp;
1805 }
1806 
1807 void
1808 Thread::ClearStackFrames ()
1809 {
1810     Mutex::Locker locker(m_frame_mutex);
1811 
1812     Unwind *unwinder = GetUnwinder ();
1813     if (unwinder)
1814         unwinder->Clear();
1815 
1816     // Only store away the old "reference" StackFrameList if we got all its frames:
1817     // FIXME: At some point we can try to splice in the frames we have fetched into
1818     // the new frame as we make it, but let's not try that now.
1819     if (m_curr_frames_sp && m_curr_frames_sp->GetAllFramesFetched())
1820         m_prev_frames_sp.swap (m_curr_frames_sp);
1821     m_curr_frames_sp.reset();
1822 
1823     m_extended_info.reset();
1824     m_extended_info_fetched = false;
1825 }
1826 
1827 lldb::StackFrameSP
1828 Thread::GetFrameWithConcreteFrameIndex (uint32_t unwind_idx)
1829 {
1830     return GetStackFrameList()->GetFrameWithConcreteFrameIndex (unwind_idx);
1831 }
1832 
1833 Error
1834 Thread::ReturnFromFrameWithIndex (uint32_t frame_idx, lldb::ValueObjectSP return_value_sp, bool broadcast)
1835 {
1836     StackFrameSP frame_sp = GetStackFrameAtIndex (frame_idx);
1837     Error return_error;
1838 
1839     if (!frame_sp)
1840     {
1841         return_error.SetErrorStringWithFormat("Could not find frame with index %d in thread 0x%" PRIx64 ".", frame_idx, GetID());
1842     }
1843 
1844     return ReturnFromFrame(frame_sp, return_value_sp, broadcast);
1845 }
1846 
1847 Error
1848 Thread::ReturnFromFrame (lldb::StackFrameSP frame_sp, lldb::ValueObjectSP return_value_sp, bool broadcast)
1849 {
1850     Error return_error;
1851 
1852     if (!frame_sp)
1853     {
1854         return_error.SetErrorString("Can't return to a null frame.");
1855         return return_error;
1856     }
1857 
1858     Thread *thread = frame_sp->GetThread().get();
1859     uint32_t older_frame_idx = frame_sp->GetFrameIndex() + 1;
1860     StackFrameSP older_frame_sp = thread->GetStackFrameAtIndex(older_frame_idx);
1861     if (!older_frame_sp)
1862     {
1863         return_error.SetErrorString("No older frame to return to.");
1864         return return_error;
1865     }
1866 
1867     if (return_value_sp)
1868     {
1869         lldb::ABISP abi = thread->GetProcess()->GetABI();
1870         if (!abi)
1871         {
1872             return_error.SetErrorString("Could not find ABI to set return value.");
1873             return return_error;
1874         }
1875         SymbolContext sc = frame_sp->GetSymbolContext(eSymbolContextFunction);
1876 
1877         // FIXME: ValueObject::Cast doesn't currently work correctly, at least not for scalars.
1878         // Turn that back on when that works.
1879         if (/* DISABLES CODE */ (0) && sc.function != NULL)
1880         {
1881             Type *function_type = sc.function->GetType();
1882             if (function_type)
1883             {
1884                 CompilerType return_type = sc.function->GetCompilerType().GetFunctionReturnType();
1885                 if (return_type)
1886                 {
1887                     StreamString s;
1888                     return_type.DumpTypeDescription(&s);
1889                     ValueObjectSP cast_value_sp = return_value_sp->Cast(return_type);
1890                     if (cast_value_sp)
1891                     {
1892                         cast_value_sp->SetFormat(eFormatHex);
1893                         return_value_sp = cast_value_sp;
1894                     }
1895                 }
1896             }
1897         }
1898 
1899         return_error = abi->SetReturnValueObject(older_frame_sp, return_value_sp);
1900         if (!return_error.Success())
1901             return return_error;
1902     }
1903 
1904     // Now write the return registers for the chosen frame:
1905     // Note, we can't use ReadAllRegisterValues->WriteAllRegisterValues, since the read & write
1906     // cook their data
1907 
1908     StackFrameSP youngest_frame_sp = thread->GetStackFrameAtIndex(0);
1909     if (youngest_frame_sp)
1910     {
1911         lldb::RegisterContextSP reg_ctx_sp (youngest_frame_sp->GetRegisterContext());
1912         if (reg_ctx_sp)
1913         {
1914             bool copy_success = reg_ctx_sp->CopyFromRegisterContext(older_frame_sp->GetRegisterContext());
1915             if (copy_success)
1916             {
1917                 thread->DiscardThreadPlans(true);
1918                 thread->ClearStackFrames();
1919                 if (broadcast && EventTypeHasListeners(eBroadcastBitStackChanged))
1920                     BroadcastEvent(eBroadcastBitStackChanged, new ThreadEventData (this->shared_from_this()));
1921             }
1922             else
1923             {
1924                 return_error.SetErrorString("Could not reset register values.");
1925             }
1926         }
1927         else
1928         {
1929             return_error.SetErrorString("Frame has no register context.");
1930         }
1931     }
1932     else
1933     {
1934         return_error.SetErrorString("Returned past top frame.");
1935     }
1936     return return_error;
1937 }
1938 
1939 static void DumpAddressList (Stream &s, const std::vector<Address> &list, ExecutionContextScope *exe_scope)
1940 {
1941     for (size_t n=0;n<list.size();n++)
1942     {
1943         s << "\t";
1944         list[n].Dump (&s, exe_scope, Address::DumpStyleResolvedDescription, Address::DumpStyleSectionNameOffset);
1945         s << "\n";
1946     }
1947 }
1948 
1949 Error
1950 Thread::JumpToLine (const FileSpec &file, uint32_t line, bool can_leave_function, std::string *warnings)
1951 {
1952     ExecutionContext exe_ctx (GetStackFrameAtIndex(0));
1953     Target *target = exe_ctx.GetTargetPtr();
1954     TargetSP target_sp = exe_ctx.GetTargetSP();
1955     RegisterContext *reg_ctx = exe_ctx.GetRegisterContext();
1956     StackFrame *frame = exe_ctx.GetFramePtr();
1957     const SymbolContext &sc = frame->GetSymbolContext(eSymbolContextFunction);
1958 
1959     // Find candidate locations.
1960     std::vector<Address> candidates, within_function, outside_function;
1961     target->GetImages().FindAddressesForLine (target_sp, file, line, sc.function, within_function, outside_function);
1962 
1963     // If possible, we try and stay within the current function.
1964     // Within a function, we accept multiple locations (optimized code may do this,
1965     // there's no solution here so we do the best we can).
1966     // However if we're trying to leave the function, we don't know how to pick the
1967     // right location, so if there's more than one then we bail.
1968     if (!within_function.empty())
1969         candidates = within_function;
1970     else if (outside_function.size() == 1 && can_leave_function)
1971         candidates = outside_function;
1972 
1973     // Check if we got anything.
1974     if (candidates.empty())
1975     {
1976         if (outside_function.empty())
1977         {
1978             return Error("Cannot locate an address for %s:%i.",
1979                          file.GetFilename().AsCString(), line);
1980         }
1981         else if (outside_function.size() == 1)
1982         {
1983             return Error("%s:%i is outside the current function.",
1984                          file.GetFilename().AsCString(), line);
1985         }
1986         else
1987         {
1988             StreamString sstr;
1989             DumpAddressList(sstr, outside_function, target);
1990             return Error("%s:%i has multiple candidate locations:\n%s",
1991                          file.GetFilename().AsCString(), line, sstr.GetString().c_str());
1992         }
1993     }
1994 
1995     // Accept the first location, warn about any others.
1996     Address dest = candidates[0];
1997     if (warnings && candidates.size() > 1)
1998     {
1999         StreamString sstr;
2000         sstr.Printf("%s:%i appears multiple times in this function, selecting the first location:\n",
2001                      file.GetFilename().AsCString(), line);
2002         DumpAddressList(sstr, candidates, target);
2003         *warnings = sstr.GetString();
2004     }
2005 
2006     if (!reg_ctx->SetPC (dest))
2007         return Error("Cannot change PC to target address.");
2008 
2009     return Error();
2010 }
2011 
2012 void
2013 Thread::DumpUsingSettingsFormat (Stream &strm, uint32_t frame_idx)
2014 {
2015     ExecutionContext exe_ctx (shared_from_this());
2016     Process *process = exe_ctx.GetProcessPtr();
2017     if (process == NULL)
2018         return;
2019 
2020     StackFrameSP frame_sp;
2021     SymbolContext frame_sc;
2022     if (frame_idx != LLDB_INVALID_FRAME_ID)
2023     {
2024         frame_sp = GetStackFrameAtIndex (frame_idx);
2025         if (frame_sp)
2026         {
2027             exe_ctx.SetFrameSP(frame_sp);
2028             frame_sc = frame_sp->GetSymbolContext(eSymbolContextEverything);
2029         }
2030     }
2031 
2032     const FormatEntity::Entry *thread_format = exe_ctx.GetTargetRef().GetDebugger().GetThreadFormat();
2033     assert (thread_format);
2034 
2035     FormatEntity::Format(*thread_format,
2036                          strm,
2037                          frame_sp ? &frame_sc : NULL,
2038                          &exe_ctx,
2039                          NULL,
2040                          NULL,
2041                          false,
2042                          false);
2043 }
2044 
2045 void
2046 Thread::SettingsInitialize ()
2047 {
2048 }
2049 
2050 void
2051 Thread::SettingsTerminate ()
2052 {
2053 }
2054 
2055 lldb::addr_t
2056 Thread::GetThreadPointer ()
2057 {
2058     return LLDB_INVALID_ADDRESS;
2059 }
2060 
2061 addr_t
2062 Thread::GetThreadLocalData (const ModuleSP module)
2063 {
2064     // The default implementation is to ask the dynamic loader for it.
2065     // This can be overridden for specific platforms.
2066     DynamicLoader *loader = GetProcess()->GetDynamicLoader();
2067     if (loader)
2068         return loader->GetThreadLocalData (module, shared_from_this());
2069     else
2070         return LLDB_INVALID_ADDRESS;
2071 }
2072 
2073 bool
2074 Thread::SafeToCallFunctions ()
2075 {
2076     Process *process = GetProcess().get();
2077     if (process)
2078     {
2079         SystemRuntime *runtime = process->GetSystemRuntime ();
2080         if (runtime)
2081         {
2082             return runtime->SafeToCallFunctionsOnThisThread (shared_from_this());
2083         }
2084     }
2085     return true;
2086 }
2087 
2088 lldb::StackFrameSP
2089 Thread::GetStackFrameSPForStackFramePtr (StackFrame *stack_frame_ptr)
2090 {
2091     return GetStackFrameList()->GetStackFrameSPForStackFramePtr (stack_frame_ptr);
2092 }
2093 
2094 const char *
2095 Thread::StopReasonAsCString (lldb::StopReason reason)
2096 {
2097     switch (reason)
2098     {
2099     case eStopReasonInvalid:       return "invalid";
2100     case eStopReasonNone:          return "none";
2101     case eStopReasonTrace:         return "trace";
2102     case eStopReasonBreakpoint:    return "breakpoint";
2103     case eStopReasonWatchpoint:    return "watchpoint";
2104     case eStopReasonSignal:        return "signal";
2105     case eStopReasonException:     return "exception";
2106     case eStopReasonExec:          return "exec";
2107     case eStopReasonPlanComplete:  return "plan complete";
2108     case eStopReasonThreadExiting: return "thread exiting";
2109     case eStopReasonInstrumentation: return "instrumentation break";
2110     }
2111 
2112     static char unknown_state_string[64];
2113     snprintf(unknown_state_string, sizeof (unknown_state_string), "StopReason = %i", reason);
2114     return unknown_state_string;
2115 }
2116 
2117 const char *
2118 Thread::RunModeAsCString (lldb::RunMode mode)
2119 {
2120     switch (mode)
2121     {
2122     case eOnlyThisThread:     return "only this thread";
2123     case eAllThreads:         return "all threads";
2124     case eOnlyDuringStepping: return "only during stepping";
2125     }
2126 
2127     static char unknown_state_string[64];
2128     snprintf(unknown_state_string, sizeof (unknown_state_string), "RunMode = %i", mode);
2129     return unknown_state_string;
2130 }
2131 
2132 size_t
2133 Thread::GetStatus (Stream &strm, uint32_t start_frame, uint32_t num_frames, uint32_t num_frames_with_source)
2134 {
2135     ExecutionContext exe_ctx (shared_from_this());
2136     Target *target = exe_ctx.GetTargetPtr();
2137     Process *process = exe_ctx.GetProcessPtr();
2138     size_t num_frames_shown = 0;
2139     strm.Indent();
2140     bool is_selected = false;
2141     if (process)
2142     {
2143         if (process->GetThreadList().GetSelectedThread().get() == this)
2144             is_selected = true;
2145     }
2146     strm.Printf("%c ", is_selected ? '*' : ' ');
2147     if (target && target->GetDebugger().GetUseExternalEditor())
2148     {
2149         StackFrameSP frame_sp = GetStackFrameAtIndex(start_frame);
2150         if (frame_sp)
2151         {
2152             SymbolContext frame_sc(frame_sp->GetSymbolContext (eSymbolContextLineEntry));
2153             if (frame_sc.line_entry.line != 0 && frame_sc.line_entry.file)
2154             {
2155                 Host::OpenFileInExternalEditor (frame_sc.line_entry.file, frame_sc.line_entry.line);
2156             }
2157         }
2158     }
2159 
2160     DumpUsingSettingsFormat (strm, start_frame);
2161 
2162     if (num_frames > 0)
2163     {
2164         strm.IndentMore();
2165 
2166         const bool show_frame_info = true;
2167 
2168         const char *selected_frame_marker = NULL;
2169         if (num_frames == 1 || (GetID() != GetProcess()->GetThreadList().GetSelectedThread()->GetID()))
2170             strm.IndentMore ();
2171         else
2172             selected_frame_marker = "* ";
2173 
2174         num_frames_shown = GetStackFrameList ()->GetStatus (strm,
2175                                                             start_frame,
2176                                                             num_frames,
2177                                                             show_frame_info,
2178                                                             num_frames_with_source,
2179                                                             selected_frame_marker);
2180         if (num_frames == 1)
2181             strm.IndentLess();
2182         strm.IndentLess();
2183     }
2184     return num_frames_shown;
2185 }
2186 
2187 bool
2188 Thread::GetDescription (Stream &strm, lldb::DescriptionLevel level, bool print_json_thread, bool print_json_stopinfo)
2189 {
2190     DumpUsingSettingsFormat (strm, 0);
2191     strm.Printf("\n");
2192 
2193     StructuredData::ObjectSP thread_info = GetExtendedInfo();
2194 
2195     if (print_json_thread || print_json_stopinfo)
2196     {
2197         if (thread_info && print_json_thread)
2198         {
2199             thread_info->Dump (strm);
2200             strm.Printf("\n");
2201         }
2202 
2203         if (print_json_stopinfo && m_stop_info_sp)
2204         {
2205             StructuredData::ObjectSP stop_info = m_stop_info_sp->GetExtendedInfo();
2206             if (stop_info)
2207             {
2208                 stop_info->Dump (strm);
2209                 strm.Printf("\n");
2210             }
2211         }
2212 
2213         return true;
2214     }
2215 
2216     if (thread_info)
2217     {
2218         StructuredData::ObjectSP activity = thread_info->GetObjectForDotSeparatedPath("activity");
2219         StructuredData::ObjectSP breadcrumb = thread_info->GetObjectForDotSeparatedPath("breadcrumb");
2220         StructuredData::ObjectSP messages = thread_info->GetObjectForDotSeparatedPath("trace_messages");
2221 
2222         bool printed_activity = false;
2223         if (activity && activity->GetType() == StructuredData::Type::eTypeDictionary)
2224         {
2225             StructuredData::Dictionary *activity_dict = activity->GetAsDictionary();
2226             StructuredData::ObjectSP id = activity_dict->GetValueForKey("id");
2227             StructuredData::ObjectSP name = activity_dict->GetValueForKey("name");
2228             if (name && name->GetType() == StructuredData::Type::eTypeString
2229                 && id && id->GetType() == StructuredData::Type::eTypeInteger)
2230             {
2231                 strm.Printf("  Activity '%s', 0x%" PRIx64 "\n", name->GetAsString()->GetValue().c_str(), id->GetAsInteger()->GetValue());
2232             }
2233             printed_activity = true;
2234         }
2235         bool printed_breadcrumb = false;
2236         if (breadcrumb && breadcrumb->GetType() == StructuredData::Type::eTypeDictionary)
2237         {
2238             if (printed_activity)
2239                 strm.Printf ("\n");
2240             StructuredData::Dictionary *breadcrumb_dict = breadcrumb->GetAsDictionary();
2241             StructuredData::ObjectSP breadcrumb_text = breadcrumb_dict->GetValueForKey ("name");
2242             if (breadcrumb_text && breadcrumb_text->GetType() == StructuredData::Type::eTypeString)
2243             {
2244                 strm.Printf ("  Current Breadcrumb: %s\n", breadcrumb_text->GetAsString()->GetValue().c_str());
2245             }
2246             printed_breadcrumb = true;
2247         }
2248         if (messages && messages->GetType() == StructuredData::Type::eTypeArray)
2249         {
2250             if (printed_breadcrumb)
2251                 strm.Printf("\n");
2252             StructuredData::Array *messages_array = messages->GetAsArray();
2253             const size_t msg_count = messages_array->GetSize();
2254             if (msg_count > 0)
2255             {
2256                 strm.Printf ("  %zu trace messages:\n", msg_count);
2257                 for (size_t i = 0; i < msg_count; i++)
2258                 {
2259                     StructuredData::ObjectSP message = messages_array->GetItemAtIndex(i);
2260                     if (message && message->GetType() == StructuredData::Type::eTypeDictionary)
2261                     {
2262                         StructuredData::Dictionary *message_dict = message->GetAsDictionary();
2263                         StructuredData::ObjectSP message_text = message_dict->GetValueForKey ("message");
2264                         if (message_text && message_text->GetType() == StructuredData::Type::eTypeString)
2265                         {
2266                             strm.Printf ("    %s\n", message_text->GetAsString()->GetValue().c_str());
2267                         }
2268                     }
2269                 }
2270             }
2271         }
2272     }
2273 
2274     return true;
2275 }
2276 
2277 size_t
2278 Thread::GetStackFrameStatus (Stream& strm,
2279                              uint32_t first_frame,
2280                              uint32_t num_frames,
2281                              bool show_frame_info,
2282                              uint32_t num_frames_with_source)
2283 {
2284     return GetStackFrameList()->GetStatus (strm,
2285                                            first_frame,
2286                                            num_frames,
2287                                            show_frame_info,
2288                                            num_frames_with_source);
2289 }
2290 
2291 Unwind *
2292 Thread::GetUnwinder ()
2293 {
2294     if (m_unwinder_ap.get() == NULL)
2295     {
2296         const ArchSpec target_arch (CalculateTarget()->GetArchitecture ());
2297         const llvm::Triple::ArchType machine = target_arch.GetMachine();
2298         switch (machine)
2299         {
2300             case llvm::Triple::x86_64:
2301             case llvm::Triple::x86:
2302             case llvm::Triple::arm:
2303             case llvm::Triple::aarch64:
2304             case llvm::Triple::thumb:
2305             case llvm::Triple::mips:
2306             case llvm::Triple::mipsel:
2307             case llvm::Triple::mips64:
2308             case llvm::Triple::mips64el:
2309             case llvm::Triple::ppc:
2310             case llvm::Triple::ppc64:
2311             case llvm::Triple::hexagon:
2312                 m_unwinder_ap.reset (new UnwindLLDB (*this));
2313                 break;
2314 
2315             default:
2316                 if (target_arch.GetTriple().getVendor() == llvm::Triple::Apple)
2317                     m_unwinder_ap.reset (new UnwindMacOSXFrameBackchain (*this));
2318                 break;
2319         }
2320     }
2321     return m_unwinder_ap.get();
2322 }
2323 
2324 void
2325 Thread::Flush ()
2326 {
2327     ClearStackFrames ();
2328     m_reg_context_sp.reset();
2329 }
2330 
2331 bool
2332 Thread::IsStillAtLastBreakpointHit ()
2333 {
2334     // If we are currently stopped at a breakpoint, always return that stopinfo and don't reset it.
2335     // This allows threads to maintain their breakpoint stopinfo, such as when thread-stepping in
2336     // multithreaded programs.
2337     if (m_stop_info_sp) {
2338         StopReason stop_reason = m_stop_info_sp->GetStopReason();
2339         if (stop_reason == lldb::eStopReasonBreakpoint) {
2340             uint64_t value = m_stop_info_sp->GetValue();
2341             lldb::RegisterContextSP reg_ctx_sp (GetRegisterContext());
2342             if (reg_ctx_sp)
2343             {
2344                 lldb::addr_t pc = reg_ctx_sp->GetPC();
2345                 BreakpointSiteSP bp_site_sp = GetProcess()->GetBreakpointSiteList().FindByAddress(pc);
2346                 if (bp_site_sp &&
2347                     static_cast<break_id_t>(value) == bp_site_sp->GetID())
2348                     return true;
2349             }
2350         }
2351     }
2352     return false;
2353 }
2354 
2355 Error
2356 Thread::StepIn (bool source_step,
2357                 LazyBool step_in_avoids_code_without_debug_info,
2358                 LazyBool step_out_avoids_code_without_debug_info)
2359 
2360 {
2361     Error error;
2362     Process *process = GetProcess().get();
2363     if (StateIsStoppedState (process->GetState(), true))
2364     {
2365         StackFrameSP frame_sp = GetStackFrameAtIndex (0);
2366         ThreadPlanSP new_plan_sp;
2367         const lldb::RunMode run_mode = eOnlyThisThread;
2368         const bool abort_other_plans = false;
2369 
2370         if (source_step && frame_sp && frame_sp->HasDebugInformation ())
2371         {
2372             SymbolContext sc(frame_sp->GetSymbolContext(eSymbolContextEverything));
2373             new_plan_sp = QueueThreadPlanForStepInRange (abort_other_plans,
2374                                                          sc.line_entry.range,
2375                                                          sc,
2376                                                          NULL,
2377                                                          run_mode,
2378                                                          step_in_avoids_code_without_debug_info,
2379                                                          step_out_avoids_code_without_debug_info);
2380         }
2381         else
2382         {
2383             new_plan_sp = QueueThreadPlanForStepSingleInstruction (false,
2384                                                                    abort_other_plans,
2385                                                                    run_mode);
2386         }
2387 
2388         new_plan_sp->SetIsMasterPlan(true);
2389         new_plan_sp->SetOkayToDiscard(false);
2390 
2391         // Why do we need to set the current thread by ID here???
2392         process->GetThreadList().SetSelectedThreadByID (GetID());
2393         error = process->Resume();
2394     }
2395     else
2396     {
2397         error.SetErrorString("process not stopped");
2398     }
2399     return error;
2400 }
2401 
2402 Error
2403 Thread::StepOver (bool source_step,
2404                 LazyBool step_out_avoids_code_without_debug_info)
2405 {
2406     Error error;
2407     Process *process = GetProcess().get();
2408     if (StateIsStoppedState (process->GetState(), true))
2409     {
2410         StackFrameSP frame_sp = GetStackFrameAtIndex (0);
2411         ThreadPlanSP new_plan_sp;
2412 
2413         const lldb::RunMode run_mode = eOnlyThisThread;
2414         const bool abort_other_plans = false;
2415 
2416         if (source_step && frame_sp && frame_sp->HasDebugInformation ())
2417         {
2418             SymbolContext sc(frame_sp->GetSymbolContext(eSymbolContextEverything));
2419             new_plan_sp = QueueThreadPlanForStepOverRange (abort_other_plans,
2420                                                            sc.line_entry.range,
2421                                                            sc,
2422                                                            run_mode,
2423                                                            step_out_avoids_code_without_debug_info);
2424         }
2425         else
2426         {
2427             new_plan_sp = QueueThreadPlanForStepSingleInstruction (true,
2428                                                                    abort_other_plans,
2429                                                                    run_mode);
2430         }
2431 
2432         new_plan_sp->SetIsMasterPlan(true);
2433         new_plan_sp->SetOkayToDiscard(false);
2434 
2435         // Why do we need to set the current thread by ID here???
2436         process->GetThreadList().SetSelectedThreadByID (GetID());
2437         error = process->Resume();
2438     }
2439     else
2440     {
2441         error.SetErrorString("process not stopped");
2442     }
2443     return error;
2444 }
2445 
2446 Error
2447 Thread::StepOut ()
2448 {
2449     Error error;
2450     Process *process = GetProcess().get();
2451     if (StateIsStoppedState (process->GetState(), true))
2452     {
2453         const bool first_instruction = false;
2454         const bool stop_other_threads = false;
2455         const bool abort_other_plans = false;
2456 
2457         ThreadPlanSP new_plan_sp(QueueThreadPlanForStepOut (abort_other_plans,
2458                                                             NULL,
2459                                                             first_instruction,
2460                                                             stop_other_threads,
2461                                                             eVoteYes,
2462                                                             eVoteNoOpinion,
2463                                                             0));
2464 
2465         new_plan_sp->SetIsMasterPlan(true);
2466         new_plan_sp->SetOkayToDiscard(false);
2467 
2468         // Why do we need to set the current thread by ID here???
2469         process->GetThreadList().SetSelectedThreadByID (GetID());
2470         error = process->Resume();
2471     }
2472     else
2473     {
2474         error.SetErrorString("process not stopped");
2475     }
2476     return error;
2477 }
2478