1 //===-- Thread.cpp --------------------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include "lldb/Target/Thread.h"
10 #include "lldb/Breakpoint/BreakpointLocation.h"
11 #include "lldb/Core/Debugger.h"
12 #include "lldb/Core/FormatEntity.h"
13 #include "lldb/Core/Module.h"
14 #include "lldb/Core/StructuredDataImpl.h"
15 #include "lldb/Core/ValueObject.h"
16 #include "lldb/Host/Host.h"
17 #include "lldb/Interpreter/OptionValueFileSpecList.h"
18 #include "lldb/Interpreter/OptionValueProperties.h"
19 #include "lldb/Interpreter/Property.h"
20 #include "lldb/Symbol/Function.h"
21 #include "lldb/Target/ABI.h"
22 #include "lldb/Target/DynamicLoader.h"
23 #include "lldb/Target/ExecutionContext.h"
24 #include "lldb/Target/LanguageRuntime.h"
25 #include "lldb/Target/Process.h"
26 #include "lldb/Target/RegisterContext.h"
27 #include "lldb/Target/StackFrameRecognizer.h"
28 #include "lldb/Target/StopInfo.h"
29 #include "lldb/Target/SystemRuntime.h"
30 #include "lldb/Target/Target.h"
31 #include "lldb/Target/ThreadPlan.h"
32 #include "lldb/Target/ThreadPlanBase.h"
33 #include "lldb/Target/ThreadPlanCallFunction.h"
34 #include "lldb/Target/ThreadPlanPython.h"
35 #include "lldb/Target/ThreadPlanRunToAddress.h"
36 #include "lldb/Target/ThreadPlanStack.h"
37 #include "lldb/Target/ThreadPlanStepInRange.h"
38 #include "lldb/Target/ThreadPlanStepInstruction.h"
39 #include "lldb/Target/ThreadPlanStepOut.h"
40 #include "lldb/Target/ThreadPlanStepOverBreakpoint.h"
41 #include "lldb/Target/ThreadPlanStepOverRange.h"
42 #include "lldb/Target/ThreadPlanStepThrough.h"
43 #include "lldb/Target/ThreadPlanStepUntil.h"
44 #include "lldb/Target/ThreadSpec.h"
45 #include "lldb/Target/UnwindLLDB.h"
46 #include "lldb/Utility/Log.h"
47 #include "lldb/Utility/RegularExpression.h"
48 #include "lldb/Utility/State.h"
49 #include "lldb/Utility/Stream.h"
50 #include "lldb/Utility/StreamString.h"
51 #include "lldb/lldb-enumerations.h"
52 
53 #include <memory>
54 
55 using namespace lldb;
56 using namespace lldb_private;
57 
58 const ThreadPropertiesSP &Thread::GetGlobalProperties() {
59   // NOTE: intentional leak so we don't crash if global destructor chain gets
60   // called as other threads still use the result of this function
61   static ThreadPropertiesSP *g_settings_sp_ptr =
62       new ThreadPropertiesSP(new ThreadProperties(true));
63   return *g_settings_sp_ptr;
64 }
65 
66 #define LLDB_PROPERTIES_thread
67 #include "TargetProperties.inc"
68 
69 enum {
70 #define LLDB_PROPERTIES_thread
71 #include "TargetPropertiesEnum.inc"
72 };
73 
74 class ThreadOptionValueProperties : public OptionValueProperties {
75 public:
76   ThreadOptionValueProperties(ConstString name)
77       : OptionValueProperties(name) {}
78 
79   // This constructor is used when creating ThreadOptionValueProperties when it
80   // is part of a new lldb_private::Thread instance. It will copy all current
81   // global property values as needed
82   ThreadOptionValueProperties(ThreadProperties *global_properties)
83       : OptionValueProperties(*global_properties->GetValueProperties()) {}
84 
85   const Property *GetPropertyAtIndex(const ExecutionContext *exe_ctx,
86                                      bool will_modify,
87                                      uint32_t idx) const override {
88     // When getting the value for a key from the thread options, we will always
89     // try and grab the setting from the current thread if there is one. Else
90     // we just use the one from this instance.
91     if (exe_ctx) {
92       Thread *thread = exe_ctx->GetThreadPtr();
93       if (thread) {
94         ThreadOptionValueProperties *instance_properties =
95             static_cast<ThreadOptionValueProperties *>(
96                 thread->GetValueProperties().get());
97         if (this != instance_properties)
98           return instance_properties->ProtectedGetPropertyAtIndex(idx);
99       }
100     }
101     return ProtectedGetPropertyAtIndex(idx);
102   }
103 };
104 
105 ThreadProperties::ThreadProperties(bool is_global) : Properties() {
106   if (is_global) {
107     m_collection_sp =
108         std::make_shared<ThreadOptionValueProperties>(ConstString("thread"));
109     m_collection_sp->Initialize(g_thread_properties);
110   } else
111     m_collection_sp = std::make_shared<ThreadOptionValueProperties>(
112         Thread::GetGlobalProperties().get());
113 }
114 
115 ThreadProperties::~ThreadProperties() = default;
116 
117 const RegularExpression *ThreadProperties::GetSymbolsToAvoidRegexp() {
118   const uint32_t idx = ePropertyStepAvoidRegex;
119   return m_collection_sp->GetPropertyAtIndexAsOptionValueRegex(nullptr, idx);
120 }
121 
122 FileSpecList ThreadProperties::GetLibrariesToAvoid() const {
123   const uint32_t idx = ePropertyStepAvoidLibraries;
124   const OptionValueFileSpecList *option_value =
125       m_collection_sp->GetPropertyAtIndexAsOptionValueFileSpecList(nullptr,
126                                                                    false, idx);
127   assert(option_value);
128   return option_value->GetCurrentValue();
129 }
130 
131 bool ThreadProperties::GetTraceEnabledState() const {
132   const uint32_t idx = ePropertyEnableThreadTrace;
133   return m_collection_sp->GetPropertyAtIndexAsBoolean(
134       nullptr, idx, g_thread_properties[idx].default_uint_value != 0);
135 }
136 
137 bool ThreadProperties::GetStepInAvoidsNoDebug() const {
138   const uint32_t idx = ePropertyStepInAvoidsNoDebug;
139   return m_collection_sp->GetPropertyAtIndexAsBoolean(
140       nullptr, idx, g_thread_properties[idx].default_uint_value != 0);
141 }
142 
143 bool ThreadProperties::GetStepOutAvoidsNoDebug() const {
144   const uint32_t idx = ePropertyStepOutAvoidsNoDebug;
145   return m_collection_sp->GetPropertyAtIndexAsBoolean(
146       nullptr, idx, g_thread_properties[idx].default_uint_value != 0);
147 }
148 
149 uint64_t ThreadProperties::GetMaxBacktraceDepth() const {
150   const uint32_t idx = ePropertyMaxBacktraceDepth;
151   return m_collection_sp->GetPropertyAtIndexAsUInt64(
152       nullptr, idx, g_thread_properties[idx].default_uint_value != 0);
153 }
154 
155 // Thread Event Data
156 
157 ConstString Thread::ThreadEventData::GetFlavorString() {
158   static ConstString g_flavor("Thread::ThreadEventData");
159   return g_flavor;
160 }
161 
162 Thread::ThreadEventData::ThreadEventData(const lldb::ThreadSP thread_sp)
163     : m_thread_sp(thread_sp), m_stack_id() {}
164 
165 Thread::ThreadEventData::ThreadEventData(const lldb::ThreadSP thread_sp,
166                                          const StackID &stack_id)
167     : m_thread_sp(thread_sp), m_stack_id(stack_id) {}
168 
169 Thread::ThreadEventData::ThreadEventData() : m_thread_sp(), m_stack_id() {}
170 
171 Thread::ThreadEventData::~ThreadEventData() = default;
172 
173 void Thread::ThreadEventData::Dump(Stream *s) const {}
174 
175 const Thread::ThreadEventData *
176 Thread::ThreadEventData::GetEventDataFromEvent(const Event *event_ptr) {
177   if (event_ptr) {
178     const EventData *event_data = event_ptr->GetData();
179     if (event_data &&
180         event_data->GetFlavor() == ThreadEventData::GetFlavorString())
181       return static_cast<const ThreadEventData *>(event_ptr->GetData());
182   }
183   return nullptr;
184 }
185 
186 ThreadSP Thread::ThreadEventData::GetThreadFromEvent(const Event *event_ptr) {
187   ThreadSP thread_sp;
188   const ThreadEventData *event_data = GetEventDataFromEvent(event_ptr);
189   if (event_data)
190     thread_sp = event_data->GetThread();
191   return thread_sp;
192 }
193 
194 StackID Thread::ThreadEventData::GetStackIDFromEvent(const Event *event_ptr) {
195   StackID stack_id;
196   const ThreadEventData *event_data = GetEventDataFromEvent(event_ptr);
197   if (event_data)
198     stack_id = event_data->GetStackID();
199   return stack_id;
200 }
201 
202 StackFrameSP
203 Thread::ThreadEventData::GetStackFrameFromEvent(const Event *event_ptr) {
204   const ThreadEventData *event_data = GetEventDataFromEvent(event_ptr);
205   StackFrameSP frame_sp;
206   if (event_data) {
207     ThreadSP thread_sp = event_data->GetThread();
208     if (thread_sp) {
209       frame_sp = thread_sp->GetStackFrameList()->GetFrameWithStackID(
210           event_data->GetStackID());
211     }
212   }
213   return frame_sp;
214 }
215 
216 // Thread class
217 
218 ConstString &Thread::GetStaticBroadcasterClass() {
219   static ConstString class_name("lldb.thread");
220   return class_name;
221 }
222 
223 Thread::Thread(Process &process, lldb::tid_t tid, bool use_invalid_index_id)
224     : ThreadProperties(false), UserID(tid),
225       Broadcaster(process.GetTarget().GetDebugger().GetBroadcasterManager(),
226                   Thread::GetStaticBroadcasterClass().AsCString()),
227       m_process_wp(process.shared_from_this()), m_stop_info_sp(),
228       m_stop_info_stop_id(0), m_stop_info_override_stop_id(0),
229       m_index_id(use_invalid_index_id ? LLDB_INVALID_INDEX32
230                                       : process.GetNextThreadIndexID(tid)),
231       m_reg_context_sp(), m_state(eStateUnloaded), m_state_mutex(),
232       m_frame_mutex(), m_curr_frames_sp(), m_prev_frames_sp(),
233       m_resume_signal(LLDB_INVALID_SIGNAL_NUMBER),
234       m_resume_state(eStateRunning), m_temporary_resume_state(eStateRunning),
235       m_unwinder_up(), m_destroy_called(false),
236       m_override_should_notify(eLazyBoolCalculate),
237       m_extended_info_fetched(false), m_extended_info() {
238   Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_OBJECT));
239   LLDB_LOGF(log, "%p Thread::Thread(tid = 0x%4.4" PRIx64 ")",
240             static_cast<void *>(this), GetID());
241 
242   CheckInWithManager();
243 }
244 
245 Thread::~Thread() {
246   Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_OBJECT));
247   LLDB_LOGF(log, "%p Thread::~Thread(tid = 0x%4.4" PRIx64 ")",
248             static_cast<void *>(this), GetID());
249   /// If you hit this assert, it means your derived class forgot to call
250   /// DoDestroy in its destructor.
251   assert(m_destroy_called);
252 }
253 
254 void Thread::DestroyThread() {
255   m_destroy_called = true;
256   m_stop_info_sp.reset();
257   m_reg_context_sp.reset();
258   m_unwinder_up.reset();
259   std::lock_guard<std::recursive_mutex> guard(m_frame_mutex);
260   m_curr_frames_sp.reset();
261   m_prev_frames_sp.reset();
262 }
263 
264 void Thread::BroadcastSelectedFrameChange(StackID &new_frame_id) {
265   if (EventTypeHasListeners(eBroadcastBitSelectedFrameChanged))
266     BroadcastEvent(eBroadcastBitSelectedFrameChanged,
267                    new ThreadEventData(this->shared_from_this(), new_frame_id));
268 }
269 
270 lldb::StackFrameSP Thread::GetSelectedFrame() {
271   StackFrameListSP stack_frame_list_sp(GetStackFrameList());
272   StackFrameSP frame_sp = stack_frame_list_sp->GetFrameAtIndex(
273       stack_frame_list_sp->GetSelectedFrameIndex());
274   FrameSelectedCallback(frame_sp.get());
275   return frame_sp;
276 }
277 
278 uint32_t Thread::SetSelectedFrame(lldb_private::StackFrame *frame,
279                                   bool broadcast) {
280   uint32_t ret_value = GetStackFrameList()->SetSelectedFrame(frame);
281   if (broadcast)
282     BroadcastSelectedFrameChange(frame->GetStackID());
283   FrameSelectedCallback(frame);
284   return ret_value;
285 }
286 
287 bool Thread::SetSelectedFrameByIndex(uint32_t frame_idx, bool broadcast) {
288   StackFrameSP frame_sp(GetStackFrameList()->GetFrameAtIndex(frame_idx));
289   if (frame_sp) {
290     GetStackFrameList()->SetSelectedFrame(frame_sp.get());
291     if (broadcast)
292       BroadcastSelectedFrameChange(frame_sp->GetStackID());
293     FrameSelectedCallback(frame_sp.get());
294     return true;
295   } else
296     return false;
297 }
298 
299 bool Thread::SetSelectedFrameByIndexNoisily(uint32_t frame_idx,
300                                             Stream &output_stream) {
301   const bool broadcast = true;
302   bool success = SetSelectedFrameByIndex(frame_idx, broadcast);
303   if (success) {
304     StackFrameSP frame_sp = GetSelectedFrame();
305     if (frame_sp) {
306       bool already_shown = false;
307       SymbolContext frame_sc(
308           frame_sp->GetSymbolContext(eSymbolContextLineEntry));
309       if (GetProcess()->GetTarget().GetDebugger().GetUseExternalEditor() &&
310           frame_sc.line_entry.file && frame_sc.line_entry.line != 0) {
311         already_shown = Host::OpenFileInExternalEditor(
312             frame_sc.line_entry.file, frame_sc.line_entry.line);
313       }
314 
315       bool show_frame_info = true;
316       bool show_source = !already_shown;
317       FrameSelectedCallback(frame_sp.get());
318       return frame_sp->GetStatus(output_stream, show_frame_info, show_source);
319     }
320     return false;
321   } else
322     return false;
323 }
324 
325 void Thread::FrameSelectedCallback(StackFrame *frame) {
326   if (!frame)
327     return;
328 
329   if (frame->HasDebugInformation() &&
330       (GetProcess()->GetWarningsOptimization() ||
331        GetProcess()->GetWarningsUnsupportedLanguage())) {
332     SymbolContext sc =
333         frame->GetSymbolContext(eSymbolContextFunction | eSymbolContextModule);
334     GetProcess()->PrintWarningOptimization(sc);
335     GetProcess()->PrintWarningUnsupportedLanguage(sc);
336   }
337 }
338 
339 lldb::StopInfoSP Thread::GetStopInfo() {
340   if (m_destroy_called)
341     return m_stop_info_sp;
342 
343   ThreadPlanSP completed_plan_sp(GetCompletedPlan());
344   ProcessSP process_sp(GetProcess());
345   const uint32_t stop_id = process_sp ? process_sp->GetStopID() : UINT32_MAX;
346 
347   // Here we select the stop info according to priorirty: - m_stop_info_sp (if
348   // not trace) - preset value - completed plan stop info - new value with plan
349   // from completed plan stack - m_stop_info_sp (trace stop reason is OK now) -
350   // ask GetPrivateStopInfo to set stop info
351 
352   bool have_valid_stop_info = m_stop_info_sp &&
353       m_stop_info_sp ->IsValid() &&
354       m_stop_info_stop_id == stop_id;
355   bool have_valid_completed_plan = completed_plan_sp && completed_plan_sp->PlanSucceeded();
356   bool plan_failed = completed_plan_sp && !completed_plan_sp->PlanSucceeded();
357   bool plan_overrides_trace =
358     have_valid_stop_info && have_valid_completed_plan
359     && (m_stop_info_sp->GetStopReason() == eStopReasonTrace);
360 
361   if (have_valid_stop_info && !plan_overrides_trace && !plan_failed) {
362     return m_stop_info_sp;
363   } else if (completed_plan_sp) {
364     return StopInfo::CreateStopReasonWithPlan(
365         completed_plan_sp, GetReturnValueObject(), GetExpressionVariable());
366   } else {
367     GetPrivateStopInfo();
368     return m_stop_info_sp;
369   }
370 }
371 
372 void Thread::CalculatePublicStopInfo() {
373   ResetStopInfo();
374   SetStopInfo(GetStopInfo());
375 }
376 
377 lldb::StopInfoSP Thread::GetPrivateStopInfo() {
378   if (m_destroy_called)
379     return m_stop_info_sp;
380 
381   ProcessSP process_sp(GetProcess());
382   if (process_sp) {
383     const uint32_t process_stop_id = process_sp->GetStopID();
384     if (m_stop_info_stop_id != process_stop_id) {
385       if (m_stop_info_sp) {
386         if (m_stop_info_sp->IsValid() || IsStillAtLastBreakpointHit() ||
387             GetCurrentPlan()->IsVirtualStep())
388           SetStopInfo(m_stop_info_sp);
389         else
390           m_stop_info_sp.reset();
391       }
392 
393       if (!m_stop_info_sp) {
394         if (!CalculateStopInfo())
395           SetStopInfo(StopInfoSP());
396       }
397     }
398 
399     // The stop info can be manually set by calling Thread::SetStopInfo() prior
400     // to this function ever getting called, so we can't rely on
401     // "m_stop_info_stop_id != process_stop_id" as the condition for the if
402     // statement below, we must also check the stop info to see if we need to
403     // override it. See the header documentation in
404     // Architecture::OverrideStopInfo() for more information on the stop
405     // info override callback.
406     if (m_stop_info_override_stop_id != process_stop_id) {
407       m_stop_info_override_stop_id = process_stop_id;
408       if (m_stop_info_sp) {
409         if (const Architecture *arch =
410                 process_sp->GetTarget().GetArchitecturePlugin())
411           arch->OverrideStopInfo(*this);
412       }
413     }
414   }
415   return m_stop_info_sp;
416 }
417 
418 lldb::StopReason Thread::GetStopReason() {
419   lldb::StopInfoSP stop_info_sp(GetStopInfo());
420   if (stop_info_sp)
421     return stop_info_sp->GetStopReason();
422   return eStopReasonNone;
423 }
424 
425 bool Thread::StopInfoIsUpToDate() const {
426   ProcessSP process_sp(GetProcess());
427   if (process_sp)
428     return m_stop_info_stop_id == process_sp->GetStopID();
429   else
430     return true; // Process is no longer around so stop info is always up to
431                  // date...
432 }
433 
434 void Thread::ResetStopInfo() {
435   if (m_stop_info_sp) {
436     m_stop_info_sp.reset();
437   }
438 }
439 
440 void Thread::SetStopInfo(const lldb::StopInfoSP &stop_info_sp) {
441   m_stop_info_sp = stop_info_sp;
442   if (m_stop_info_sp) {
443     m_stop_info_sp->MakeStopInfoValid();
444     // If we are overriding the ShouldReportStop, do that here:
445     if (m_override_should_notify != eLazyBoolCalculate)
446       m_stop_info_sp->OverrideShouldNotify(m_override_should_notify ==
447                                            eLazyBoolYes);
448   }
449 
450   ProcessSP process_sp(GetProcess());
451   if (process_sp)
452     m_stop_info_stop_id = process_sp->GetStopID();
453   else
454     m_stop_info_stop_id = UINT32_MAX;
455   Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_THREAD));
456   LLDB_LOGF(log, "%p: tid = 0x%" PRIx64 ": stop info = %s (stop_id = %u)",
457             static_cast<void *>(this), GetID(),
458             stop_info_sp ? stop_info_sp->GetDescription() : "<NULL>",
459             m_stop_info_stop_id);
460 }
461 
462 void Thread::SetShouldReportStop(Vote vote) {
463   if (vote == eVoteNoOpinion)
464     return;
465   else {
466     m_override_should_notify = (vote == eVoteYes ? eLazyBoolYes : eLazyBoolNo);
467     if (m_stop_info_sp)
468       m_stop_info_sp->OverrideShouldNotify(m_override_should_notify ==
469                                            eLazyBoolYes);
470   }
471 }
472 
473 void Thread::SetStopInfoToNothing() {
474   // Note, we can't just NULL out the private reason, or the native thread
475   // implementation will try to go calculate it again.  For now, just set it to
476   // a Unix Signal with an invalid signal number.
477   SetStopInfo(
478       StopInfo::CreateStopReasonWithSignal(*this, LLDB_INVALID_SIGNAL_NUMBER));
479 }
480 
481 bool Thread::ThreadStoppedForAReason(void) {
482   return (bool)GetPrivateStopInfo();
483 }
484 
485 bool Thread::CheckpointThreadState(ThreadStateCheckpoint &saved_state) {
486   saved_state.register_backup_sp.reset();
487   lldb::StackFrameSP frame_sp(GetStackFrameAtIndex(0));
488   if (frame_sp) {
489     lldb::RegisterCheckpointSP reg_checkpoint_sp(
490         new RegisterCheckpoint(RegisterCheckpoint::Reason::eExpression));
491     if (reg_checkpoint_sp) {
492       lldb::RegisterContextSP reg_ctx_sp(frame_sp->GetRegisterContext());
493       if (reg_ctx_sp && reg_ctx_sp->ReadAllRegisterValues(*reg_checkpoint_sp))
494         saved_state.register_backup_sp = reg_checkpoint_sp;
495     }
496   }
497   if (!saved_state.register_backup_sp)
498     return false;
499 
500   saved_state.stop_info_sp = GetStopInfo();
501   ProcessSP process_sp(GetProcess());
502   if (process_sp)
503     saved_state.orig_stop_id = process_sp->GetStopID();
504   saved_state.current_inlined_depth = GetCurrentInlinedDepth();
505   saved_state.m_completed_plan_checkpoint =
506       GetPlans().CheckpointCompletedPlans();
507 
508   return true;
509 }
510 
511 bool Thread::RestoreRegisterStateFromCheckpoint(
512     ThreadStateCheckpoint &saved_state) {
513   if (saved_state.register_backup_sp) {
514     lldb::StackFrameSP frame_sp(GetStackFrameAtIndex(0));
515     if (frame_sp) {
516       lldb::RegisterContextSP reg_ctx_sp(frame_sp->GetRegisterContext());
517       if (reg_ctx_sp) {
518         bool ret =
519             reg_ctx_sp->WriteAllRegisterValues(*saved_state.register_backup_sp);
520 
521         // Clear out all stack frames as our world just changed.
522         ClearStackFrames();
523         reg_ctx_sp->InvalidateIfNeeded(true);
524         if (m_unwinder_up)
525           m_unwinder_up->Clear();
526         return ret;
527       }
528     }
529   }
530   return false;
531 }
532 
533 void Thread::RestoreThreadStateFromCheckpoint(
534     ThreadStateCheckpoint &saved_state) {
535   if (saved_state.stop_info_sp)
536     saved_state.stop_info_sp->MakeStopInfoValid();
537   SetStopInfo(saved_state.stop_info_sp);
538   GetStackFrameList()->SetCurrentInlinedDepth(
539       saved_state.current_inlined_depth);
540   GetPlans().RestoreCompletedPlanCheckpoint(
541       saved_state.m_completed_plan_checkpoint);
542 }
543 
544 StateType Thread::GetState() const {
545   // If any other threads access this we will need a mutex for it
546   std::lock_guard<std::recursive_mutex> guard(m_state_mutex);
547   return m_state;
548 }
549 
550 void Thread::SetState(StateType state) {
551   std::lock_guard<std::recursive_mutex> guard(m_state_mutex);
552   m_state = state;
553 }
554 
555 std::string Thread::GetStopDescription() {
556   StackFrameSP frame_sp = GetStackFrameAtIndex(0);
557 
558   if (!frame_sp)
559     return GetStopDescriptionRaw();
560 
561   auto recognized_frame_sp = frame_sp->GetRecognizedFrame();
562 
563   if (!recognized_frame_sp)
564     return GetStopDescriptionRaw();
565 
566   std::string recognized_stop_description =
567       recognized_frame_sp->GetStopDescription();
568 
569   if (!recognized_stop_description.empty())
570     return recognized_stop_description;
571 
572   return GetStopDescriptionRaw();
573 }
574 
575 std::string Thread::GetStopDescriptionRaw() {
576   StopInfoSP stop_info_sp = GetStopInfo();
577   std::string raw_stop_description;
578   if (stop_info_sp && stop_info_sp->IsValid()) {
579     raw_stop_description = stop_info_sp->GetDescription();
580     assert((!raw_stop_description.empty() ||
581             stop_info_sp->GetStopReason() == eStopReasonNone) &&
582            "StopInfo returned an empty description.");
583   }
584   return raw_stop_description;
585 }
586 
587 void Thread::SelectMostRelevantFrame() {
588   Log *log = lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_THREAD);
589 
590   auto frames_list_sp = GetStackFrameList();
591 
592   // Only the top frame should be recognized.
593   auto frame_sp = frames_list_sp->GetFrameAtIndex(0);
594 
595   auto recognized_frame_sp = frame_sp->GetRecognizedFrame();
596 
597   if (!recognized_frame_sp) {
598     LLDB_LOG(log, "Frame #0 not recognized");
599     return;
600   }
601 
602   if (StackFrameSP most_relevant_frame_sp =
603           recognized_frame_sp->GetMostRelevantFrame()) {
604     LLDB_LOG(log, "Found most relevant frame at index {0}",
605              most_relevant_frame_sp->GetFrameIndex());
606     SetSelectedFrame(most_relevant_frame_sp.get());
607   } else {
608     LLDB_LOG(log, "No relevant frame!");
609   }
610 }
611 
612 void Thread::WillStop() {
613   ThreadPlan *current_plan = GetCurrentPlan();
614 
615   SelectMostRelevantFrame();
616 
617   // FIXME: I may decide to disallow threads with no plans.  In which
618   // case this should go to an assert.
619 
620   if (!current_plan)
621     return;
622 
623   current_plan->WillStop();
624 }
625 
626 void Thread::SetupForResume() {
627   if (GetResumeState() != eStateSuspended) {
628     // If we're at a breakpoint push the step-over breakpoint plan.  Do this
629     // before telling the current plan it will resume, since we might change
630     // what the current plan is.
631 
632     lldb::RegisterContextSP reg_ctx_sp(GetRegisterContext());
633     if (reg_ctx_sp) {
634       const addr_t thread_pc = reg_ctx_sp->GetPC();
635       BreakpointSiteSP bp_site_sp =
636           GetProcess()->GetBreakpointSiteList().FindByAddress(thread_pc);
637       if (bp_site_sp) {
638         // Note, don't assume there's a ThreadPlanStepOverBreakpoint, the
639         // target may not require anything special to step over a breakpoint.
640 
641         ThreadPlan *cur_plan = GetCurrentPlan();
642 
643         bool push_step_over_bp_plan = false;
644         if (cur_plan->GetKind() == ThreadPlan::eKindStepOverBreakpoint) {
645           ThreadPlanStepOverBreakpoint *bp_plan =
646               (ThreadPlanStepOverBreakpoint *)cur_plan;
647           if (bp_plan->GetBreakpointLoadAddress() != thread_pc)
648             push_step_over_bp_plan = true;
649         } else
650           push_step_over_bp_plan = true;
651 
652         if (push_step_over_bp_plan) {
653           ThreadPlanSP step_bp_plan_sp(new ThreadPlanStepOverBreakpoint(*this));
654           if (step_bp_plan_sp) {
655             step_bp_plan_sp->SetPrivate(true);
656 
657             if (GetCurrentPlan()->RunState() != eStateStepping) {
658               ThreadPlanStepOverBreakpoint *step_bp_plan =
659                   static_cast<ThreadPlanStepOverBreakpoint *>(
660                       step_bp_plan_sp.get());
661               step_bp_plan->SetAutoContinue(true);
662             }
663             QueueThreadPlan(step_bp_plan_sp, false);
664           }
665         }
666       }
667     }
668   }
669 }
670 
671 bool Thread::ShouldResume(StateType resume_state) {
672   // At this point clear the completed plan stack.
673   GetPlans().WillResume();
674   m_override_should_notify = eLazyBoolCalculate;
675 
676   StateType prev_resume_state = GetTemporaryResumeState();
677 
678   SetTemporaryResumeState(resume_state);
679 
680   lldb::ThreadSP backing_thread_sp(GetBackingThread());
681   if (backing_thread_sp)
682     backing_thread_sp->SetTemporaryResumeState(resume_state);
683 
684   // Make sure m_stop_info_sp is valid.  Don't do this for threads we suspended
685   // in the previous run.
686   if (prev_resume_state != eStateSuspended)
687     GetPrivateStopInfo();
688 
689   // This is a little dubious, but we are trying to limit how often we actually
690   // fetch stop info from the target, 'cause that slows down single stepping.
691   // So assume that if we got to the point where we're about to resume, and we
692   // haven't yet had to fetch the stop reason, then it doesn't need to know
693   // about the fact that we are resuming...
694   const uint32_t process_stop_id = GetProcess()->GetStopID();
695   if (m_stop_info_stop_id == process_stop_id &&
696       (m_stop_info_sp && m_stop_info_sp->IsValid())) {
697     StopInfo *stop_info = GetPrivateStopInfo().get();
698     if (stop_info)
699       stop_info->WillResume(resume_state);
700   }
701 
702   // Tell all the plans that we are about to resume in case they need to clear
703   // any state. We distinguish between the plan on the top of the stack and the
704   // lower plans in case a plan needs to do any special business before it
705   // runs.
706 
707   bool need_to_resume = false;
708   ThreadPlan *plan_ptr = GetCurrentPlan();
709   if (plan_ptr) {
710     need_to_resume = plan_ptr->WillResume(resume_state, true);
711 
712     while ((plan_ptr = GetPreviousPlan(plan_ptr)) != nullptr) {
713       plan_ptr->WillResume(resume_state, false);
714     }
715 
716     // If the WillResume for the plan says we are faking a resume, then it will
717     // have set an appropriate stop info. In that case, don't reset it here.
718 
719     if (need_to_resume && resume_state != eStateSuspended) {
720       m_stop_info_sp.reset();
721     }
722   }
723 
724   if (need_to_resume) {
725     ClearStackFrames();
726     // Let Thread subclasses do any special work they need to prior to resuming
727     WillResume(resume_state);
728   }
729 
730   return need_to_resume;
731 }
732 
733 void Thread::DidResume() { SetResumeSignal(LLDB_INVALID_SIGNAL_NUMBER); }
734 
735 void Thread::DidStop() { SetState(eStateStopped); }
736 
737 bool Thread::ShouldStop(Event *event_ptr) {
738   ThreadPlan *current_plan = GetCurrentPlan();
739 
740   bool should_stop = true;
741 
742   Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP));
743 
744   if (GetResumeState() == eStateSuspended) {
745     LLDB_LOGF(log,
746               "Thread::%s for tid = 0x%4.4" PRIx64 " 0x%4.4" PRIx64
747               ", should_stop = 0 (ignore since thread was suspended)",
748               __FUNCTION__, GetID(), GetProtocolID());
749     return false;
750   }
751 
752   if (GetTemporaryResumeState() == eStateSuspended) {
753     LLDB_LOGF(log,
754               "Thread::%s for tid = 0x%4.4" PRIx64 " 0x%4.4" PRIx64
755               ", should_stop = 0 (ignore since thread was suspended)",
756               __FUNCTION__, GetID(), GetProtocolID());
757     return false;
758   }
759 
760   // Based on the current thread plan and process stop info, check if this
761   // thread caused the process to stop. NOTE: this must take place before the
762   // plan is moved from the current plan stack to the completed plan stack.
763   if (!ThreadStoppedForAReason()) {
764     LLDB_LOGF(log,
765               "Thread::%s for tid = 0x%4.4" PRIx64 " 0x%4.4" PRIx64
766               ", pc = 0x%16.16" PRIx64
767               ", should_stop = 0 (ignore since no stop reason)",
768               __FUNCTION__, GetID(), GetProtocolID(),
769               GetRegisterContext() ? GetRegisterContext()->GetPC()
770                                    : LLDB_INVALID_ADDRESS);
771     return false;
772   }
773 
774   if (log) {
775     LLDB_LOGF(log,
776               "Thread::%s(%p) for tid = 0x%4.4" PRIx64 " 0x%4.4" PRIx64
777               ", pc = 0x%16.16" PRIx64,
778               __FUNCTION__, static_cast<void *>(this), GetID(), GetProtocolID(),
779               GetRegisterContext() ? GetRegisterContext()->GetPC()
780                                    : LLDB_INVALID_ADDRESS);
781     LLDB_LOGF(log, "^^^^^^^^ Thread::ShouldStop Begin ^^^^^^^^");
782     StreamString s;
783     s.IndentMore();
784     GetProcess()->DumpThreadPlansForTID(
785         s, GetID(), eDescriptionLevelVerbose, true /* internal */,
786         false /* condense_trivial */, true /* skip_unreported */);
787     LLDB_LOGF(log, "Plan stack initial state:\n%s", s.GetData());
788   }
789 
790   // The top most plan always gets to do the trace log...
791   current_plan->DoTraceLog();
792 
793   // First query the stop info's ShouldStopSynchronous.  This handles
794   // "synchronous" stop reasons, for example the breakpoint command on internal
795   // breakpoints.  If a synchronous stop reason says we should not stop, then
796   // we don't have to do any more work on this stop.
797   StopInfoSP private_stop_info(GetPrivateStopInfo());
798   if (private_stop_info &&
799       !private_stop_info->ShouldStopSynchronous(event_ptr)) {
800     LLDB_LOGF(log, "StopInfo::ShouldStop async callback says we should not "
801                    "stop, returning ShouldStop of false.");
802     return false;
803   }
804 
805   // If we've already been restarted, don't query the plans since the state
806   // they would examine is not current.
807   if (Process::ProcessEventData::GetRestartedFromEvent(event_ptr))
808     return false;
809 
810   // Before the plans see the state of the world, calculate the current inlined
811   // depth.
812   GetStackFrameList()->CalculateCurrentInlinedDepth();
813 
814   // If the base plan doesn't understand why we stopped, then we have to find a
815   // plan that does. If that plan is still working, then we don't need to do
816   // any more work.  If the plan that explains the stop is done, then we should
817   // pop all the plans below it, and pop it, and then let the plans above it
818   // decide whether they still need to do more work.
819 
820   bool done_processing_current_plan = false;
821 
822   if (!current_plan->PlanExplainsStop(event_ptr)) {
823     if (current_plan->TracerExplainsStop()) {
824       done_processing_current_plan = true;
825       should_stop = false;
826     } else {
827       // If the current plan doesn't explain the stop, then find one that does
828       // and let it handle the situation.
829       ThreadPlan *plan_ptr = current_plan;
830       while ((plan_ptr = GetPreviousPlan(plan_ptr)) != nullptr) {
831         if (plan_ptr->PlanExplainsStop(event_ptr)) {
832           should_stop = plan_ptr->ShouldStop(event_ptr);
833 
834           // plan_ptr explains the stop, next check whether plan_ptr is done,
835           // if so, then we should take it and all the plans below it off the
836           // stack.
837 
838           if (plan_ptr->MischiefManaged()) {
839             // We're going to pop the plans up to and including the plan that
840             // explains the stop.
841             ThreadPlan *prev_plan_ptr = GetPreviousPlan(plan_ptr);
842 
843             do {
844               if (should_stop)
845                 current_plan->WillStop();
846               PopPlan();
847             } while ((current_plan = GetCurrentPlan()) != prev_plan_ptr);
848             // Now, if the responsible plan was not "Okay to discard" then
849             // we're done, otherwise we forward this to the next plan in the
850             // stack below.
851             done_processing_current_plan =
852                 (plan_ptr->IsMasterPlan() && !plan_ptr->OkayToDiscard());
853           } else
854             done_processing_current_plan = true;
855 
856           break;
857         }
858       }
859     }
860   }
861 
862   if (!done_processing_current_plan) {
863     bool over_ride_stop = current_plan->ShouldAutoContinue(event_ptr);
864 
865     LLDB_LOGF(log, "Plan %s explains stop, auto-continue %i.",
866               current_plan->GetName(), over_ride_stop);
867 
868     // We're starting from the base plan, so just let it decide;
869     if (current_plan->IsBasePlan()) {
870       should_stop = current_plan->ShouldStop(event_ptr);
871       LLDB_LOGF(log, "Base plan says should stop: %i.", should_stop);
872     } else {
873       // Otherwise, don't let the base plan override what the other plans say
874       // to do, since presumably if there were other plans they would know what
875       // to do...
876       while (true) {
877         if (current_plan->IsBasePlan())
878           break;
879 
880         should_stop = current_plan->ShouldStop(event_ptr);
881         LLDB_LOGF(log, "Plan %s should stop: %d.", current_plan->GetName(),
882                   should_stop);
883         if (current_plan->MischiefManaged()) {
884           if (should_stop)
885             current_plan->WillStop();
886 
887           // If a Master Plan wants to stop, and wants to stick on the stack,
888           // we let it. Otherwise, see if the plan's parent wants to stop.
889 
890           if (should_stop && current_plan->IsMasterPlan() &&
891               !current_plan->OkayToDiscard()) {
892             PopPlan();
893             break;
894           } else {
895             PopPlan();
896 
897             current_plan = GetCurrentPlan();
898             if (current_plan == nullptr) {
899               break;
900             }
901           }
902         } else {
903           break;
904         }
905       }
906     }
907 
908     if (over_ride_stop)
909       should_stop = false;
910   }
911 
912   // One other potential problem is that we set up a master plan, then stop in
913   // before it is complete - for instance by hitting a breakpoint during a
914   // step-over - then do some step/finish/etc operations that wind up past the
915   // end point condition of the initial plan.  We don't want to strand the
916   // original plan on the stack, This code clears stale plans off the stack.
917 
918   if (should_stop) {
919     ThreadPlan *plan_ptr = GetCurrentPlan();
920 
921     // Discard the stale plans and all plans below them in the stack, plus move
922     // the completed plans to the completed plan stack
923     while (!plan_ptr->IsBasePlan()) {
924       bool stale = plan_ptr->IsPlanStale();
925       ThreadPlan *examined_plan = plan_ptr;
926       plan_ptr = GetPreviousPlan(examined_plan);
927 
928       if (stale) {
929         LLDB_LOGF(
930             log,
931             "Plan %s being discarded in cleanup, it says it is already done.",
932             examined_plan->GetName());
933         while (GetCurrentPlan() != examined_plan) {
934           DiscardPlan();
935         }
936         if (examined_plan->IsPlanComplete()) {
937           // plan is complete but does not explain the stop (example: step to a
938           // line with breakpoint), let us move the plan to
939           // completed_plan_stack anyway
940           PopPlan();
941         } else
942           DiscardPlan();
943       }
944     }
945   }
946 
947   if (log) {
948     StreamString s;
949     s.IndentMore();
950     GetProcess()->DumpThreadPlansForTID(
951         s, GetID(), eDescriptionLevelVerbose, true /* internal */,
952         false /* condense_trivial */, true /* skip_unreported */);
953     LLDB_LOGF(log, "Plan stack final state:\n%s", s.GetData());
954     LLDB_LOGF(log, "vvvvvvvv Thread::ShouldStop End (returning %i) vvvvvvvv",
955               should_stop);
956   }
957   return should_stop;
958 }
959 
960 Vote Thread::ShouldReportStop(Event *event_ptr) {
961   StateType thread_state = GetResumeState();
962   StateType temp_thread_state = GetTemporaryResumeState();
963 
964   Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP));
965 
966   if (thread_state == eStateSuspended || thread_state == eStateInvalid) {
967     LLDB_LOGF(log,
968               "Thread::ShouldReportStop() tid = 0x%4.4" PRIx64
969               ": returning vote %i (state was suspended or invalid)",
970               GetID(), eVoteNoOpinion);
971     return eVoteNoOpinion;
972   }
973 
974   if (temp_thread_state == eStateSuspended ||
975       temp_thread_state == eStateInvalid) {
976     LLDB_LOGF(log,
977               "Thread::ShouldReportStop() tid = 0x%4.4" PRIx64
978               ": returning vote %i (temporary state was suspended or invalid)",
979               GetID(), eVoteNoOpinion);
980     return eVoteNoOpinion;
981   }
982 
983   if (!ThreadStoppedForAReason()) {
984     LLDB_LOGF(log,
985               "Thread::ShouldReportStop() tid = 0x%4.4" PRIx64
986               ": returning vote %i (thread didn't stop for a reason.)",
987               GetID(), eVoteNoOpinion);
988     return eVoteNoOpinion;
989   }
990 
991   if (GetPlans().AnyCompletedPlans()) {
992     // Pass skip_private = false to GetCompletedPlan, since we want to ask
993     // the last plan, regardless of whether it is private or not.
994     LLDB_LOGF(log,
995               "Thread::ShouldReportStop() tid = 0x%4.4" PRIx64
996               ": returning vote  for complete stack's back plan",
997               GetID());
998     return GetPlans().GetCompletedPlan(false)->ShouldReportStop(event_ptr);
999   } else {
1000     Vote thread_vote = eVoteNoOpinion;
1001     ThreadPlan *plan_ptr = GetCurrentPlan();
1002     while (true) {
1003       if (plan_ptr->PlanExplainsStop(event_ptr)) {
1004         thread_vote = plan_ptr->ShouldReportStop(event_ptr);
1005         break;
1006       }
1007       if (plan_ptr->IsBasePlan())
1008         break;
1009       else
1010         plan_ptr = GetPreviousPlan(plan_ptr);
1011     }
1012     LLDB_LOGF(log,
1013               "Thread::ShouldReportStop() tid = 0x%4.4" PRIx64
1014               ": returning vote %i for current plan",
1015               GetID(), thread_vote);
1016 
1017     return thread_vote;
1018   }
1019 }
1020 
1021 Vote Thread::ShouldReportRun(Event *event_ptr) {
1022   StateType thread_state = GetResumeState();
1023 
1024   if (thread_state == eStateSuspended || thread_state == eStateInvalid) {
1025     return eVoteNoOpinion;
1026   }
1027 
1028   Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP));
1029   if (GetPlans().AnyCompletedPlans()) {
1030     // Pass skip_private = false to GetCompletedPlan, since we want to ask
1031     // the last plan, regardless of whether it is private or not.
1032     LLDB_LOGF(log,
1033               "Current Plan for thread %d(%p) (0x%4.4" PRIx64
1034               ", %s): %s being asked whether we should report run.",
1035               GetIndexID(), static_cast<void *>(this), GetID(),
1036               StateAsCString(GetTemporaryResumeState()),
1037               GetCompletedPlan()->GetName());
1038 
1039     return GetPlans().GetCompletedPlan(false)->ShouldReportRun(event_ptr);
1040   } else {
1041     LLDB_LOGF(log,
1042               "Current Plan for thread %d(%p) (0x%4.4" PRIx64
1043               ", %s): %s being asked whether we should report run.",
1044               GetIndexID(), static_cast<void *>(this), GetID(),
1045               StateAsCString(GetTemporaryResumeState()),
1046               GetCurrentPlan()->GetName());
1047 
1048     return GetCurrentPlan()->ShouldReportRun(event_ptr);
1049   }
1050 }
1051 
1052 bool Thread::MatchesSpec(const ThreadSpec *spec) {
1053   return (spec == nullptr) ? true : spec->ThreadPassesBasicTests(*this);
1054 }
1055 
1056 ThreadPlanStack &Thread::GetPlans() const {
1057   ThreadPlanStack *plans = GetProcess()->FindThreadPlans(GetID());
1058   if (plans)
1059     return *plans;
1060 
1061   // History threads don't have a thread plan, but they do ask get asked to
1062   // describe themselves, which usually involves pulling out the stop reason.
1063   // That in turn will check for a completed plan on the ThreadPlanStack.
1064   // Instead of special-casing at that point, we return a Stack with a
1065   // ThreadPlanNull as its base plan.  That will give the right answers to the
1066   // queries GetDescription makes, and only assert if you try to run the thread.
1067   if (!m_null_plan_stack_up)
1068     m_null_plan_stack_up = std::make_unique<ThreadPlanStack>(*this, true);
1069   return *(m_null_plan_stack_up.get());
1070 }
1071 
1072 void Thread::PushPlan(ThreadPlanSP thread_plan_sp) {
1073   assert(thread_plan_sp && "Don't push an empty thread plan.");
1074 
1075   Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP));
1076   if (log) {
1077     StreamString s;
1078     thread_plan_sp->GetDescription(&s, lldb::eDescriptionLevelFull);
1079     LLDB_LOGF(log, "Thread::PushPlan(0x%p): \"%s\", tid = 0x%4.4" PRIx64 ".",
1080               static_cast<void *>(this), s.GetData(),
1081               thread_plan_sp->GetThread().GetID());
1082   }
1083 
1084   GetPlans().PushPlan(std::move(thread_plan_sp));
1085 }
1086 
1087 void Thread::PopPlan() {
1088   Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP));
1089   ThreadPlanSP popped_plan_sp = GetPlans().PopPlan();
1090   if (log) {
1091     LLDB_LOGF(log, "Popping plan: \"%s\", tid = 0x%4.4" PRIx64 ".",
1092               popped_plan_sp->GetName(), popped_plan_sp->GetThread().GetID());
1093   }
1094 }
1095 
1096 void Thread::DiscardPlan() {
1097   Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP));
1098   ThreadPlanSP discarded_plan_sp = GetPlans().PopPlan();
1099 
1100   LLDB_LOGF(log, "Discarding plan: \"%s\", tid = 0x%4.4" PRIx64 ".",
1101             discarded_plan_sp->GetName(),
1102             discarded_plan_sp->GetThread().GetID());
1103 }
1104 
1105 void Thread::AutoCompleteThreadPlans(CompletionRequest &request) const {
1106   const ThreadPlanStack &plans = GetPlans();
1107   if (!plans.AnyPlans())
1108     return;
1109 
1110   // Iterate from the second plan (index: 1) to skip the base plan.
1111   ThreadPlanSP p;
1112   uint32_t i = 1;
1113   while ((p = plans.GetPlanByIndex(i, false))) {
1114     StreamString strm;
1115     p->GetDescription(&strm, eDescriptionLevelInitial);
1116     request.TryCompleteCurrentArg(std::to_string(i), strm.GetString());
1117     i++;
1118   }
1119 }
1120 
1121 ThreadPlan *Thread::GetCurrentPlan() const {
1122   return GetPlans().GetCurrentPlan().get();
1123 }
1124 
1125 ThreadPlanSP Thread::GetCompletedPlan() const {
1126   return GetPlans().GetCompletedPlan();
1127 }
1128 
1129 ValueObjectSP Thread::GetReturnValueObject() const {
1130   return GetPlans().GetReturnValueObject();
1131 }
1132 
1133 ExpressionVariableSP Thread::GetExpressionVariable() const {
1134   return GetPlans().GetExpressionVariable();
1135 }
1136 
1137 bool Thread::IsThreadPlanDone(ThreadPlan *plan) const {
1138   return GetPlans().IsPlanDone(plan);
1139 }
1140 
1141 bool Thread::WasThreadPlanDiscarded(ThreadPlan *plan) const {
1142   return GetPlans().WasPlanDiscarded(plan);
1143 }
1144 
1145 bool Thread::CompletedPlanOverridesBreakpoint() const {
1146   return GetPlans().AnyCompletedPlans();
1147 }
1148 
1149 ThreadPlan *Thread::GetPreviousPlan(ThreadPlan *current_plan) const{
1150   return GetPlans().GetPreviousPlan(current_plan);
1151 }
1152 
1153 Status Thread::QueueThreadPlan(ThreadPlanSP &thread_plan_sp,
1154                                bool abort_other_plans) {
1155   Status status;
1156   StreamString s;
1157   if (!thread_plan_sp->ValidatePlan(&s)) {
1158     DiscardThreadPlansUpToPlan(thread_plan_sp);
1159     thread_plan_sp.reset();
1160     status.SetErrorString(s.GetString());
1161     return status;
1162   }
1163 
1164   if (abort_other_plans)
1165     DiscardThreadPlans(true);
1166 
1167   PushPlan(thread_plan_sp);
1168 
1169   // This seems a little funny, but I don't want to have to split up the
1170   // constructor and the DidPush in the scripted plan, that seems annoying.
1171   // That means the constructor has to be in DidPush. So I have to validate the
1172   // plan AFTER pushing it, and then take it off again...
1173   if (!thread_plan_sp->ValidatePlan(&s)) {
1174     DiscardThreadPlansUpToPlan(thread_plan_sp);
1175     thread_plan_sp.reset();
1176     status.SetErrorString(s.GetString());
1177     return status;
1178   }
1179 
1180   return status;
1181 }
1182 
1183 void Thread::EnableTracer(bool value, bool single_stepping) {
1184   GetPlans().EnableTracer(value, single_stepping);
1185 }
1186 
1187 void Thread::SetTracer(lldb::ThreadPlanTracerSP &tracer_sp) {
1188   GetPlans().SetTracer(tracer_sp);
1189 }
1190 
1191 bool Thread::DiscardUserThreadPlansUpToIndex(uint32_t plan_index) {
1192   // Count the user thread plans from the back end to get the number of the one
1193   // we want to discard:
1194 
1195   ThreadPlan *up_to_plan_ptr = GetPlans().GetPlanByIndex(plan_index).get();
1196   if (up_to_plan_ptr == nullptr)
1197     return false;
1198 
1199   DiscardThreadPlansUpToPlan(up_to_plan_ptr);
1200   return true;
1201 }
1202 
1203 void Thread::DiscardThreadPlansUpToPlan(lldb::ThreadPlanSP &up_to_plan_sp) {
1204   DiscardThreadPlansUpToPlan(up_to_plan_sp.get());
1205 }
1206 
1207 void Thread::DiscardThreadPlansUpToPlan(ThreadPlan *up_to_plan_ptr) {
1208   Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP));
1209   LLDB_LOGF(log,
1210             "Discarding thread plans for thread tid = 0x%4.4" PRIx64
1211             ", up to %p",
1212             GetID(), static_cast<void *>(up_to_plan_ptr));
1213   GetPlans().DiscardPlansUpToPlan(up_to_plan_ptr);
1214 }
1215 
1216 void Thread::DiscardThreadPlans(bool force) {
1217   Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_STEP));
1218   if (log) {
1219     LLDB_LOGF(log,
1220               "Discarding thread plans for thread (tid = 0x%4.4" PRIx64
1221               ", force %d)",
1222               GetID(), force);
1223   }
1224 
1225   if (force) {
1226     GetPlans().DiscardAllPlans();
1227     return;
1228   }
1229   GetPlans().DiscardConsultingMasterPlans();
1230 }
1231 
1232 Status Thread::UnwindInnermostExpression() {
1233   Status error;
1234   ThreadPlan *innermost_expr_plan = GetPlans().GetInnermostExpression();
1235   if (!innermost_expr_plan) {
1236     error.SetErrorString("No expressions currently active on this thread");
1237     return error;
1238   }
1239   DiscardThreadPlansUpToPlan(innermost_expr_plan);
1240   return error;
1241 }
1242 
1243 ThreadPlanSP Thread::QueueFundamentalPlan(bool abort_other_plans) {
1244   ThreadPlanSP thread_plan_sp(new ThreadPlanBase(*this));
1245   QueueThreadPlan(thread_plan_sp, abort_other_plans);
1246   return thread_plan_sp;
1247 }
1248 
1249 ThreadPlanSP Thread::QueueThreadPlanForStepSingleInstruction(
1250     bool step_over, bool abort_other_plans, bool stop_other_threads,
1251     Status &status) {
1252   ThreadPlanSP thread_plan_sp(new ThreadPlanStepInstruction(
1253       *this, step_over, stop_other_threads, eVoteNoOpinion, eVoteNoOpinion));
1254   status = QueueThreadPlan(thread_plan_sp, abort_other_plans);
1255   return thread_plan_sp;
1256 }
1257 
1258 ThreadPlanSP Thread::QueueThreadPlanForStepOverRange(
1259     bool abort_other_plans, const AddressRange &range,
1260     const SymbolContext &addr_context, lldb::RunMode stop_other_threads,
1261     Status &status, LazyBool step_out_avoids_code_withoug_debug_info) {
1262   ThreadPlanSP thread_plan_sp;
1263   thread_plan_sp = std::make_shared<ThreadPlanStepOverRange>(
1264       *this, range, addr_context, stop_other_threads,
1265       step_out_avoids_code_withoug_debug_info);
1266 
1267   status = QueueThreadPlan(thread_plan_sp, abort_other_plans);
1268   return thread_plan_sp;
1269 }
1270 
1271 // Call the QueueThreadPlanForStepOverRange method which takes an address
1272 // range.
1273 ThreadPlanSP Thread::QueueThreadPlanForStepOverRange(
1274     bool abort_other_plans, const LineEntry &line_entry,
1275     const SymbolContext &addr_context, lldb::RunMode stop_other_threads,
1276     Status &status, LazyBool step_out_avoids_code_withoug_debug_info) {
1277   const bool include_inlined_functions = true;
1278   auto address_range =
1279       line_entry.GetSameLineContiguousAddressRange(include_inlined_functions);
1280   return QueueThreadPlanForStepOverRange(
1281       abort_other_plans, address_range, addr_context, stop_other_threads,
1282       status, step_out_avoids_code_withoug_debug_info);
1283 }
1284 
1285 ThreadPlanSP Thread::QueueThreadPlanForStepInRange(
1286     bool abort_other_plans, const AddressRange &range,
1287     const SymbolContext &addr_context, const char *step_in_target,
1288     lldb::RunMode stop_other_threads, Status &status,
1289     LazyBool step_in_avoids_code_without_debug_info,
1290     LazyBool step_out_avoids_code_without_debug_info) {
1291   ThreadPlanSP thread_plan_sp(new ThreadPlanStepInRange(
1292       *this, range, addr_context, step_in_target, stop_other_threads,
1293       step_in_avoids_code_without_debug_info,
1294       step_out_avoids_code_without_debug_info));
1295   status = QueueThreadPlan(thread_plan_sp, abort_other_plans);
1296   return thread_plan_sp;
1297 }
1298 
1299 // Call the QueueThreadPlanForStepInRange method which takes an address range.
1300 ThreadPlanSP Thread::QueueThreadPlanForStepInRange(
1301     bool abort_other_plans, const LineEntry &line_entry,
1302     const SymbolContext &addr_context, const char *step_in_target,
1303     lldb::RunMode stop_other_threads, Status &status,
1304     LazyBool step_in_avoids_code_without_debug_info,
1305     LazyBool step_out_avoids_code_without_debug_info) {
1306   const bool include_inlined_functions = false;
1307   return QueueThreadPlanForStepInRange(
1308       abort_other_plans,
1309       line_entry.GetSameLineContiguousAddressRange(include_inlined_functions),
1310       addr_context, step_in_target, stop_other_threads, status,
1311       step_in_avoids_code_without_debug_info,
1312       step_out_avoids_code_without_debug_info);
1313 }
1314 
1315 ThreadPlanSP Thread::QueueThreadPlanForStepOut(
1316     bool abort_other_plans, SymbolContext *addr_context, bool first_insn,
1317     bool stop_other_threads, Vote stop_vote, Vote run_vote, uint32_t frame_idx,
1318     Status &status, LazyBool step_out_avoids_code_without_debug_info) {
1319   ThreadPlanSP thread_plan_sp(new ThreadPlanStepOut(
1320       *this, addr_context, first_insn, stop_other_threads, stop_vote, run_vote,
1321       frame_idx, step_out_avoids_code_without_debug_info));
1322 
1323   status = QueueThreadPlan(thread_plan_sp, abort_other_plans);
1324   return thread_plan_sp;
1325 }
1326 
1327 ThreadPlanSP Thread::QueueThreadPlanForStepOutNoShouldStop(
1328     bool abort_other_plans, SymbolContext *addr_context, bool first_insn,
1329     bool stop_other_threads, Vote stop_vote, Vote run_vote, uint32_t frame_idx,
1330     Status &status, bool continue_to_next_branch) {
1331   const bool calculate_return_value =
1332       false; // No need to calculate the return value here.
1333   ThreadPlanSP thread_plan_sp(new ThreadPlanStepOut(
1334       *this, addr_context, first_insn, stop_other_threads, stop_vote, run_vote,
1335       frame_idx, eLazyBoolNo, continue_to_next_branch, calculate_return_value));
1336 
1337   ThreadPlanStepOut *new_plan =
1338       static_cast<ThreadPlanStepOut *>(thread_plan_sp.get());
1339   new_plan->ClearShouldStopHereCallbacks();
1340 
1341   status = QueueThreadPlan(thread_plan_sp, abort_other_plans);
1342   return thread_plan_sp;
1343 }
1344 
1345 ThreadPlanSP Thread::QueueThreadPlanForStepThrough(StackID &return_stack_id,
1346                                                    bool abort_other_plans,
1347                                                    bool stop_other_threads,
1348                                                    Status &status) {
1349   ThreadPlanSP thread_plan_sp(
1350       new ThreadPlanStepThrough(*this, return_stack_id, stop_other_threads));
1351   if (!thread_plan_sp || !thread_plan_sp->ValidatePlan(nullptr))
1352     return ThreadPlanSP();
1353 
1354   status = QueueThreadPlan(thread_plan_sp, abort_other_plans);
1355   return thread_plan_sp;
1356 }
1357 
1358 ThreadPlanSP Thread::QueueThreadPlanForRunToAddress(bool abort_other_plans,
1359                                                     Address &target_addr,
1360                                                     bool stop_other_threads,
1361                                                     Status &status) {
1362   ThreadPlanSP thread_plan_sp(
1363       new ThreadPlanRunToAddress(*this, target_addr, stop_other_threads));
1364 
1365   status = QueueThreadPlan(thread_plan_sp, abort_other_plans);
1366   return thread_plan_sp;
1367 }
1368 
1369 ThreadPlanSP Thread::QueueThreadPlanForStepUntil(
1370     bool abort_other_plans, lldb::addr_t *address_list, size_t num_addresses,
1371     bool stop_other_threads, uint32_t frame_idx, Status &status) {
1372   ThreadPlanSP thread_plan_sp(new ThreadPlanStepUntil(
1373       *this, address_list, num_addresses, stop_other_threads, frame_idx));
1374 
1375   status = QueueThreadPlan(thread_plan_sp, abort_other_plans);
1376   return thread_plan_sp;
1377 }
1378 
1379 lldb::ThreadPlanSP Thread::QueueThreadPlanForStepScripted(
1380     bool abort_other_plans, const char *class_name,
1381     StructuredData::ObjectSP extra_args_sp,  bool stop_other_threads,
1382     Status &status) {
1383 
1384   StructuredDataImpl *extra_args_impl = nullptr;
1385   if (extra_args_sp) {
1386     extra_args_impl = new StructuredDataImpl();
1387     extra_args_impl->SetObjectSP(extra_args_sp);
1388   }
1389 
1390   ThreadPlanSP thread_plan_sp(new ThreadPlanPython(*this, class_name,
1391                                                    extra_args_impl));
1392   thread_plan_sp->SetStopOthers(stop_other_threads);
1393   status = QueueThreadPlan(thread_plan_sp, abort_other_plans);
1394   return thread_plan_sp;
1395 }
1396 
1397 uint32_t Thread::GetIndexID() const { return m_index_id; }
1398 
1399 TargetSP Thread::CalculateTarget() {
1400   TargetSP target_sp;
1401   ProcessSP process_sp(GetProcess());
1402   if (process_sp)
1403     target_sp = process_sp->CalculateTarget();
1404   return target_sp;
1405 }
1406 
1407 ProcessSP Thread::CalculateProcess() { return GetProcess(); }
1408 
1409 ThreadSP Thread::CalculateThread() { return shared_from_this(); }
1410 
1411 StackFrameSP Thread::CalculateStackFrame() { return StackFrameSP(); }
1412 
1413 void Thread::CalculateExecutionContext(ExecutionContext &exe_ctx) {
1414   exe_ctx.SetContext(shared_from_this());
1415 }
1416 
1417 StackFrameListSP Thread::GetStackFrameList() {
1418   std::lock_guard<std::recursive_mutex> guard(m_frame_mutex);
1419 
1420   if (!m_curr_frames_sp)
1421     m_curr_frames_sp =
1422         std::make_shared<StackFrameList>(*this, m_prev_frames_sp, true);
1423 
1424   return m_curr_frames_sp;
1425 }
1426 
1427 void Thread::ClearStackFrames() {
1428   std::lock_guard<std::recursive_mutex> guard(m_frame_mutex);
1429 
1430   GetUnwinder().Clear();
1431 
1432   // Only store away the old "reference" StackFrameList if we got all its
1433   // frames:
1434   // FIXME: At some point we can try to splice in the frames we have fetched
1435   // into
1436   // the new frame as we make it, but let's not try that now.
1437   if (m_curr_frames_sp && m_curr_frames_sp->GetAllFramesFetched())
1438     m_prev_frames_sp.swap(m_curr_frames_sp);
1439   m_curr_frames_sp.reset();
1440 
1441   m_extended_info.reset();
1442   m_extended_info_fetched = false;
1443 }
1444 
1445 lldb::StackFrameSP Thread::GetFrameWithConcreteFrameIndex(uint32_t unwind_idx) {
1446   return GetStackFrameList()->GetFrameWithConcreteFrameIndex(unwind_idx);
1447 }
1448 
1449 Status Thread::ReturnFromFrameWithIndex(uint32_t frame_idx,
1450                                         lldb::ValueObjectSP return_value_sp,
1451                                         bool broadcast) {
1452   StackFrameSP frame_sp = GetStackFrameAtIndex(frame_idx);
1453   Status return_error;
1454 
1455   if (!frame_sp) {
1456     return_error.SetErrorStringWithFormat(
1457         "Could not find frame with index %d in thread 0x%" PRIx64 ".",
1458         frame_idx, GetID());
1459   }
1460 
1461   return ReturnFromFrame(frame_sp, return_value_sp, broadcast);
1462 }
1463 
1464 Status Thread::ReturnFromFrame(lldb::StackFrameSP frame_sp,
1465                                lldb::ValueObjectSP return_value_sp,
1466                                bool broadcast) {
1467   Status return_error;
1468 
1469   if (!frame_sp) {
1470     return_error.SetErrorString("Can't return to a null frame.");
1471     return return_error;
1472   }
1473 
1474   Thread *thread = frame_sp->GetThread().get();
1475   uint32_t older_frame_idx = frame_sp->GetFrameIndex() + 1;
1476   StackFrameSP older_frame_sp = thread->GetStackFrameAtIndex(older_frame_idx);
1477   if (!older_frame_sp) {
1478     return_error.SetErrorString("No older frame to return to.");
1479     return return_error;
1480   }
1481 
1482   if (return_value_sp) {
1483     lldb::ABISP abi = thread->GetProcess()->GetABI();
1484     if (!abi) {
1485       return_error.SetErrorString("Could not find ABI to set return value.");
1486       return return_error;
1487     }
1488     SymbolContext sc = frame_sp->GetSymbolContext(eSymbolContextFunction);
1489 
1490     // FIXME: ValueObject::Cast doesn't currently work correctly, at least not
1491     // for scalars.
1492     // Turn that back on when that works.
1493     if (/* DISABLES CODE */ (false) && sc.function != nullptr) {
1494       Type *function_type = sc.function->GetType();
1495       if (function_type) {
1496         CompilerType return_type =
1497             sc.function->GetCompilerType().GetFunctionReturnType();
1498         if (return_type) {
1499           StreamString s;
1500           return_type.DumpTypeDescription(&s);
1501           ValueObjectSP cast_value_sp = return_value_sp->Cast(return_type);
1502           if (cast_value_sp) {
1503             cast_value_sp->SetFormat(eFormatHex);
1504             return_value_sp = cast_value_sp;
1505           }
1506         }
1507       }
1508     }
1509 
1510     return_error = abi->SetReturnValueObject(older_frame_sp, return_value_sp);
1511     if (!return_error.Success())
1512       return return_error;
1513   }
1514 
1515   // Now write the return registers for the chosen frame: Note, we can't use
1516   // ReadAllRegisterValues->WriteAllRegisterValues, since the read & write cook
1517   // their data
1518 
1519   StackFrameSP youngest_frame_sp = thread->GetStackFrameAtIndex(0);
1520   if (youngest_frame_sp) {
1521     lldb::RegisterContextSP reg_ctx_sp(youngest_frame_sp->GetRegisterContext());
1522     if (reg_ctx_sp) {
1523       bool copy_success = reg_ctx_sp->CopyFromRegisterContext(
1524           older_frame_sp->GetRegisterContext());
1525       if (copy_success) {
1526         thread->DiscardThreadPlans(true);
1527         thread->ClearStackFrames();
1528         if (broadcast && EventTypeHasListeners(eBroadcastBitStackChanged))
1529           BroadcastEvent(eBroadcastBitStackChanged,
1530                          new ThreadEventData(this->shared_from_this()));
1531       } else {
1532         return_error.SetErrorString("Could not reset register values.");
1533       }
1534     } else {
1535       return_error.SetErrorString("Frame has no register context.");
1536     }
1537   } else {
1538     return_error.SetErrorString("Returned past top frame.");
1539   }
1540   return return_error;
1541 }
1542 
1543 static void DumpAddressList(Stream &s, const std::vector<Address> &list,
1544                             ExecutionContextScope *exe_scope) {
1545   for (size_t n = 0; n < list.size(); n++) {
1546     s << "\t";
1547     list[n].Dump(&s, exe_scope, Address::DumpStyleResolvedDescription,
1548                  Address::DumpStyleSectionNameOffset);
1549     s << "\n";
1550   }
1551 }
1552 
1553 Status Thread::JumpToLine(const FileSpec &file, uint32_t line,
1554                           bool can_leave_function, std::string *warnings) {
1555   ExecutionContext exe_ctx(GetStackFrameAtIndex(0));
1556   Target *target = exe_ctx.GetTargetPtr();
1557   TargetSP target_sp = exe_ctx.GetTargetSP();
1558   RegisterContext *reg_ctx = exe_ctx.GetRegisterContext();
1559   StackFrame *frame = exe_ctx.GetFramePtr();
1560   const SymbolContext &sc = frame->GetSymbolContext(eSymbolContextFunction);
1561 
1562   // Find candidate locations.
1563   std::vector<Address> candidates, within_function, outside_function;
1564   target->GetImages().FindAddressesForLine(target_sp, file, line, sc.function,
1565                                            within_function, outside_function);
1566 
1567   // If possible, we try and stay within the current function. Within a
1568   // function, we accept multiple locations (optimized code may do this,
1569   // there's no solution here so we do the best we can). However if we're
1570   // trying to leave the function, we don't know how to pick the right
1571   // location, so if there's more than one then we bail.
1572   if (!within_function.empty())
1573     candidates = within_function;
1574   else if (outside_function.size() == 1 && can_leave_function)
1575     candidates = outside_function;
1576 
1577   // Check if we got anything.
1578   if (candidates.empty()) {
1579     if (outside_function.empty()) {
1580       return Status("Cannot locate an address for %s:%i.",
1581                     file.GetFilename().AsCString(), line);
1582     } else if (outside_function.size() == 1) {
1583       return Status("%s:%i is outside the current function.",
1584                     file.GetFilename().AsCString(), line);
1585     } else {
1586       StreamString sstr;
1587       DumpAddressList(sstr, outside_function, target);
1588       return Status("%s:%i has multiple candidate locations:\n%s",
1589                     file.GetFilename().AsCString(), line, sstr.GetData());
1590     }
1591   }
1592 
1593   // Accept the first location, warn about any others.
1594   Address dest = candidates[0];
1595   if (warnings && candidates.size() > 1) {
1596     StreamString sstr;
1597     sstr.Printf("%s:%i appears multiple times in this function, selecting the "
1598                 "first location:\n",
1599                 file.GetFilename().AsCString(), line);
1600     DumpAddressList(sstr, candidates, target);
1601     *warnings = std::string(sstr.GetString());
1602   }
1603 
1604   if (!reg_ctx->SetPC(dest))
1605     return Status("Cannot change PC to target address.");
1606 
1607   return Status();
1608 }
1609 
1610 void Thread::DumpUsingSettingsFormat(Stream &strm, uint32_t frame_idx,
1611                                      bool stop_format) {
1612   ExecutionContext exe_ctx(shared_from_this());
1613   Process *process = exe_ctx.GetProcessPtr();
1614   if (process == nullptr)
1615     return;
1616 
1617   StackFrameSP frame_sp;
1618   SymbolContext frame_sc;
1619   if (frame_idx != LLDB_INVALID_FRAME_ID) {
1620     frame_sp = GetStackFrameAtIndex(frame_idx);
1621     if (frame_sp) {
1622       exe_ctx.SetFrameSP(frame_sp);
1623       frame_sc = frame_sp->GetSymbolContext(eSymbolContextEverything);
1624     }
1625   }
1626 
1627   const FormatEntity::Entry *thread_format;
1628   if (stop_format)
1629     thread_format = exe_ctx.GetTargetRef().GetDebugger().GetThreadStopFormat();
1630   else
1631     thread_format = exe_ctx.GetTargetRef().GetDebugger().GetThreadFormat();
1632 
1633   assert(thread_format);
1634 
1635   FormatEntity::Format(*thread_format, strm, frame_sp ? &frame_sc : nullptr,
1636                        &exe_ctx, nullptr, nullptr, false, false);
1637 }
1638 
1639 void Thread::SettingsInitialize() {}
1640 
1641 void Thread::SettingsTerminate() {}
1642 
1643 lldb::addr_t Thread::GetThreadPointer() { return LLDB_INVALID_ADDRESS; }
1644 
1645 addr_t Thread::GetThreadLocalData(const ModuleSP module,
1646                                   lldb::addr_t tls_file_addr) {
1647   // The default implementation is to ask the dynamic loader for it. This can
1648   // be overridden for specific platforms.
1649   DynamicLoader *loader = GetProcess()->GetDynamicLoader();
1650   if (loader)
1651     return loader->GetThreadLocalData(module, shared_from_this(),
1652                                       tls_file_addr);
1653   else
1654     return LLDB_INVALID_ADDRESS;
1655 }
1656 
1657 bool Thread::SafeToCallFunctions() {
1658   Process *process = GetProcess().get();
1659   if (process) {
1660     SystemRuntime *runtime = process->GetSystemRuntime();
1661     if (runtime) {
1662       return runtime->SafeToCallFunctionsOnThisThread(shared_from_this());
1663     }
1664   }
1665   return true;
1666 }
1667 
1668 lldb::StackFrameSP
1669 Thread::GetStackFrameSPForStackFramePtr(StackFrame *stack_frame_ptr) {
1670   return GetStackFrameList()->GetStackFrameSPForStackFramePtr(stack_frame_ptr);
1671 }
1672 
1673 std::string Thread::StopReasonAsString(lldb::StopReason reason) {
1674   switch (reason) {
1675   case eStopReasonInvalid:
1676     return "invalid";
1677   case eStopReasonNone:
1678     return "none";
1679   case eStopReasonTrace:
1680     return "trace";
1681   case eStopReasonBreakpoint:
1682     return "breakpoint";
1683   case eStopReasonWatchpoint:
1684     return "watchpoint";
1685   case eStopReasonSignal:
1686     return "signal";
1687   case eStopReasonException:
1688     return "exception";
1689   case eStopReasonExec:
1690     return "exec";
1691   case eStopReasonPlanComplete:
1692     return "plan complete";
1693   case eStopReasonThreadExiting:
1694     return "thread exiting";
1695   case eStopReasonInstrumentation:
1696     return "instrumentation break";
1697   }
1698 
1699   return "StopReason = " + std::to_string(reason);
1700 }
1701 
1702 std::string Thread::RunModeAsString(lldb::RunMode mode) {
1703   switch (mode) {
1704   case eOnlyThisThread:
1705     return "only this thread";
1706   case eAllThreads:
1707     return "all threads";
1708   case eOnlyDuringStepping:
1709     return "only during stepping";
1710   }
1711 
1712   return "RunMode = " + std::to_string(mode);
1713 }
1714 
1715 size_t Thread::GetStatus(Stream &strm, uint32_t start_frame,
1716                          uint32_t num_frames, uint32_t num_frames_with_source,
1717                          bool stop_format, bool only_stacks) {
1718 
1719   if (!only_stacks) {
1720     ExecutionContext exe_ctx(shared_from_this());
1721     Target *target = exe_ctx.GetTargetPtr();
1722     Process *process = exe_ctx.GetProcessPtr();
1723     strm.Indent();
1724     bool is_selected = false;
1725     if (process) {
1726       if (process->GetThreadList().GetSelectedThread().get() == this)
1727         is_selected = true;
1728     }
1729     strm.Printf("%c ", is_selected ? '*' : ' ');
1730     if (target && target->GetDebugger().GetUseExternalEditor()) {
1731       StackFrameSP frame_sp = GetStackFrameAtIndex(start_frame);
1732       if (frame_sp) {
1733         SymbolContext frame_sc(
1734             frame_sp->GetSymbolContext(eSymbolContextLineEntry));
1735         if (frame_sc.line_entry.line != 0 && frame_sc.line_entry.file) {
1736           Host::OpenFileInExternalEditor(frame_sc.line_entry.file,
1737                                          frame_sc.line_entry.line);
1738         }
1739       }
1740     }
1741 
1742     DumpUsingSettingsFormat(strm, start_frame, stop_format);
1743   }
1744 
1745   size_t num_frames_shown = 0;
1746   if (num_frames > 0) {
1747     strm.IndentMore();
1748 
1749     const bool show_frame_info = true;
1750     const bool show_frame_unique = only_stacks;
1751     const char *selected_frame_marker = nullptr;
1752     if (num_frames == 1 || only_stacks ||
1753         (GetID() != GetProcess()->GetThreadList().GetSelectedThread()->GetID()))
1754       strm.IndentMore();
1755     else
1756       selected_frame_marker = "* ";
1757 
1758     num_frames_shown = GetStackFrameList()->GetStatus(
1759         strm, start_frame, num_frames, show_frame_info, num_frames_with_source,
1760         show_frame_unique, selected_frame_marker);
1761     if (num_frames == 1)
1762       strm.IndentLess();
1763     strm.IndentLess();
1764   }
1765   return num_frames_shown;
1766 }
1767 
1768 bool Thread::GetDescription(Stream &strm, lldb::DescriptionLevel level,
1769                             bool print_json_thread, bool print_json_stopinfo) {
1770   const bool stop_format = false;
1771   DumpUsingSettingsFormat(strm, 0, stop_format);
1772   strm.Printf("\n");
1773 
1774   StructuredData::ObjectSP thread_info = GetExtendedInfo();
1775 
1776   if (print_json_thread || print_json_stopinfo) {
1777     if (thread_info && print_json_thread) {
1778       thread_info->Dump(strm);
1779       strm.Printf("\n");
1780     }
1781 
1782     if (print_json_stopinfo && m_stop_info_sp) {
1783       StructuredData::ObjectSP stop_info = m_stop_info_sp->GetExtendedInfo();
1784       if (stop_info) {
1785         stop_info->Dump(strm);
1786         strm.Printf("\n");
1787       }
1788     }
1789 
1790     return true;
1791   }
1792 
1793   if (thread_info) {
1794     StructuredData::ObjectSP activity =
1795         thread_info->GetObjectForDotSeparatedPath("activity");
1796     StructuredData::ObjectSP breadcrumb =
1797         thread_info->GetObjectForDotSeparatedPath("breadcrumb");
1798     StructuredData::ObjectSP messages =
1799         thread_info->GetObjectForDotSeparatedPath("trace_messages");
1800 
1801     bool printed_activity = false;
1802     if (activity && activity->GetType() == eStructuredDataTypeDictionary) {
1803       StructuredData::Dictionary *activity_dict = activity->GetAsDictionary();
1804       StructuredData::ObjectSP id = activity_dict->GetValueForKey("id");
1805       StructuredData::ObjectSP name = activity_dict->GetValueForKey("name");
1806       if (name && name->GetType() == eStructuredDataTypeString && id &&
1807           id->GetType() == eStructuredDataTypeInteger) {
1808         strm.Format("  Activity '{0}', {1:x}\n",
1809                     name->GetAsString()->GetValue(),
1810                     id->GetAsInteger()->GetValue());
1811       }
1812       printed_activity = true;
1813     }
1814     bool printed_breadcrumb = false;
1815     if (breadcrumb && breadcrumb->GetType() == eStructuredDataTypeDictionary) {
1816       if (printed_activity)
1817         strm.Printf("\n");
1818       StructuredData::Dictionary *breadcrumb_dict =
1819           breadcrumb->GetAsDictionary();
1820       StructuredData::ObjectSP breadcrumb_text =
1821           breadcrumb_dict->GetValueForKey("name");
1822       if (breadcrumb_text &&
1823           breadcrumb_text->GetType() == eStructuredDataTypeString) {
1824         strm.Format("  Current Breadcrumb: {0}\n",
1825                     breadcrumb_text->GetAsString()->GetValue());
1826       }
1827       printed_breadcrumb = true;
1828     }
1829     if (messages && messages->GetType() == eStructuredDataTypeArray) {
1830       if (printed_breadcrumb)
1831         strm.Printf("\n");
1832       StructuredData::Array *messages_array = messages->GetAsArray();
1833       const size_t msg_count = messages_array->GetSize();
1834       if (msg_count > 0) {
1835         strm.Printf("  %zu trace messages:\n", msg_count);
1836         for (size_t i = 0; i < msg_count; i++) {
1837           StructuredData::ObjectSP message = messages_array->GetItemAtIndex(i);
1838           if (message && message->GetType() == eStructuredDataTypeDictionary) {
1839             StructuredData::Dictionary *message_dict =
1840                 message->GetAsDictionary();
1841             StructuredData::ObjectSP message_text =
1842                 message_dict->GetValueForKey("message");
1843             if (message_text &&
1844                 message_text->GetType() == eStructuredDataTypeString) {
1845               strm.Format("    {0}\n", message_text->GetAsString()->GetValue());
1846             }
1847           }
1848         }
1849       }
1850     }
1851   }
1852 
1853   return true;
1854 }
1855 
1856 size_t Thread::GetStackFrameStatus(Stream &strm, uint32_t first_frame,
1857                                    uint32_t num_frames, bool show_frame_info,
1858                                    uint32_t num_frames_with_source) {
1859   return GetStackFrameList()->GetStatus(
1860       strm, first_frame, num_frames, show_frame_info, num_frames_with_source);
1861 }
1862 
1863 Unwind &Thread::GetUnwinder() {
1864   if (!m_unwinder_up)
1865     m_unwinder_up = std::make_unique<UnwindLLDB>(*this);
1866   return *m_unwinder_up;
1867 }
1868 
1869 void Thread::Flush() {
1870   ClearStackFrames();
1871   m_reg_context_sp.reset();
1872 }
1873 
1874 bool Thread::IsStillAtLastBreakpointHit() {
1875   // If we are currently stopped at a breakpoint, always return that stopinfo
1876   // and don't reset it. This allows threads to maintain their breakpoint
1877   // stopinfo, such as when thread-stepping in multithreaded programs.
1878   if (m_stop_info_sp) {
1879     StopReason stop_reason = m_stop_info_sp->GetStopReason();
1880     if (stop_reason == lldb::eStopReasonBreakpoint) {
1881       uint64_t value = m_stop_info_sp->GetValue();
1882       lldb::RegisterContextSP reg_ctx_sp(GetRegisterContext());
1883       if (reg_ctx_sp) {
1884         lldb::addr_t pc = reg_ctx_sp->GetPC();
1885         BreakpointSiteSP bp_site_sp =
1886             GetProcess()->GetBreakpointSiteList().FindByAddress(pc);
1887         if (bp_site_sp && static_cast<break_id_t>(value) == bp_site_sp->GetID())
1888           return true;
1889       }
1890     }
1891   }
1892   return false;
1893 }
1894 
1895 Status Thread::StepIn(bool source_step,
1896                       LazyBool step_in_avoids_code_without_debug_info,
1897                       LazyBool step_out_avoids_code_without_debug_info)
1898 
1899 {
1900   Status error;
1901   Process *process = GetProcess().get();
1902   if (StateIsStoppedState(process->GetState(), true)) {
1903     StackFrameSP frame_sp = GetStackFrameAtIndex(0);
1904     ThreadPlanSP new_plan_sp;
1905     const lldb::RunMode run_mode = eOnlyThisThread;
1906     const bool abort_other_plans = false;
1907 
1908     if (source_step && frame_sp && frame_sp->HasDebugInformation()) {
1909       SymbolContext sc(frame_sp->GetSymbolContext(eSymbolContextEverything));
1910       new_plan_sp = QueueThreadPlanForStepInRange(
1911           abort_other_plans, sc.line_entry, sc, nullptr, run_mode, error,
1912           step_in_avoids_code_without_debug_info,
1913           step_out_avoids_code_without_debug_info);
1914     } else {
1915       new_plan_sp = QueueThreadPlanForStepSingleInstruction(
1916           false, abort_other_plans, run_mode, error);
1917     }
1918 
1919     new_plan_sp->SetIsMasterPlan(true);
1920     new_plan_sp->SetOkayToDiscard(false);
1921 
1922     // Why do we need to set the current thread by ID here???
1923     process->GetThreadList().SetSelectedThreadByID(GetID());
1924     error = process->Resume();
1925   } else {
1926     error.SetErrorString("process not stopped");
1927   }
1928   return error;
1929 }
1930 
1931 Status Thread::StepOver(bool source_step,
1932                         LazyBool step_out_avoids_code_without_debug_info) {
1933   Status error;
1934   Process *process = GetProcess().get();
1935   if (StateIsStoppedState(process->GetState(), true)) {
1936     StackFrameSP frame_sp = GetStackFrameAtIndex(0);
1937     ThreadPlanSP new_plan_sp;
1938 
1939     const lldb::RunMode run_mode = eOnlyThisThread;
1940     const bool abort_other_plans = false;
1941 
1942     if (source_step && frame_sp && frame_sp->HasDebugInformation()) {
1943       SymbolContext sc(frame_sp->GetSymbolContext(eSymbolContextEverything));
1944       new_plan_sp = QueueThreadPlanForStepOverRange(
1945           abort_other_plans, sc.line_entry, sc, run_mode, error,
1946           step_out_avoids_code_without_debug_info);
1947     } else {
1948       new_plan_sp = QueueThreadPlanForStepSingleInstruction(
1949           true, abort_other_plans, run_mode, error);
1950     }
1951 
1952     new_plan_sp->SetIsMasterPlan(true);
1953     new_plan_sp->SetOkayToDiscard(false);
1954 
1955     // Why do we need to set the current thread by ID here???
1956     process->GetThreadList().SetSelectedThreadByID(GetID());
1957     error = process->Resume();
1958   } else {
1959     error.SetErrorString("process not stopped");
1960   }
1961   return error;
1962 }
1963 
1964 Status Thread::StepOut() {
1965   Status error;
1966   Process *process = GetProcess().get();
1967   if (StateIsStoppedState(process->GetState(), true)) {
1968     const bool first_instruction = false;
1969     const bool stop_other_threads = false;
1970     const bool abort_other_plans = false;
1971 
1972     ThreadPlanSP new_plan_sp(QueueThreadPlanForStepOut(
1973         abort_other_plans, nullptr, first_instruction, stop_other_threads,
1974         eVoteYes, eVoteNoOpinion, 0, error));
1975 
1976     new_plan_sp->SetIsMasterPlan(true);
1977     new_plan_sp->SetOkayToDiscard(false);
1978 
1979     // Why do we need to set the current thread by ID here???
1980     process->GetThreadList().SetSelectedThreadByID(GetID());
1981     error = process->Resume();
1982   } else {
1983     error.SetErrorString("process not stopped");
1984   }
1985   return error;
1986 }
1987 
1988 ValueObjectSP Thread::GetCurrentException() {
1989   if (auto frame_sp = GetStackFrameAtIndex(0))
1990     if (auto recognized_frame = frame_sp->GetRecognizedFrame())
1991       if (auto e = recognized_frame->GetExceptionObject())
1992         return e;
1993 
1994   // NOTE: Even though this behavior is generalized, only ObjC is actually
1995   // supported at the moment.
1996   for (LanguageRuntime *runtime : GetProcess()->GetLanguageRuntimes()) {
1997     if (auto e = runtime->GetExceptionObjectForThread(shared_from_this()))
1998       return e;
1999   }
2000 
2001   return ValueObjectSP();
2002 }
2003 
2004 ThreadSP Thread::GetCurrentExceptionBacktrace() {
2005   ValueObjectSP exception = GetCurrentException();
2006   if (!exception)
2007     return ThreadSP();
2008 
2009   // NOTE: Even though this behavior is generalized, only ObjC is actually
2010   // supported at the moment.
2011   for (LanguageRuntime *runtime : GetProcess()->GetLanguageRuntimes()) {
2012     if (auto bt = runtime->GetBacktraceThreadFromException(exception))
2013       return bt;
2014   }
2015 
2016   return ThreadSP();
2017 }
2018