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/Core/ValueObjectConstResult.h"
17 #include "lldb/Host/Host.h"
18 #include "lldb/Interpreter/OptionValueFileSpecList.h"
19 #include "lldb/Interpreter/OptionValueProperties.h"
20 #include "lldb/Interpreter/Property.h"
21 #include "lldb/Symbol/Function.h"
22 #include "lldb/Target/ABI.h"
23 #include "lldb/Target/DynamicLoader.h"
24 #include "lldb/Target/ExecutionContext.h"
25 #include "lldb/Target/LanguageRuntime.h"
26 #include "lldb/Target/Process.h"
27 #include "lldb/Target/RegisterContext.h"
28 #include "lldb/Target/StackFrameRecognizer.h"
29 #include "lldb/Target/StopInfo.h"
30 #include "lldb/Target/SystemRuntime.h"
31 #include "lldb/Target/Target.h"
32 #include "lldb/Target/ThreadPlan.h"
33 #include "lldb/Target/ThreadPlanBase.h"
34 #include "lldb/Target/ThreadPlanCallFunction.h"
35 #include "lldb/Target/ThreadPlanPython.h"
36 #include "lldb/Target/ThreadPlanRunToAddress.h"
37 #include "lldb/Target/ThreadPlanStack.h"
38 #include "lldb/Target/ThreadPlanStepInRange.h"
39 #include "lldb/Target/ThreadPlanStepInstruction.h"
40 #include "lldb/Target/ThreadPlanStepOut.h"
41 #include "lldb/Target/ThreadPlanStepOverBreakpoint.h"
42 #include "lldb/Target/ThreadPlanStepOverRange.h"
43 #include "lldb/Target/ThreadPlanStepThrough.h"
44 #include "lldb/Target/ThreadPlanStepUntil.h"
45 #include "lldb/Target/ThreadSpec.h"
46 #include "lldb/Target/UnwindLLDB.h"
47 #include "lldb/Utility/LLDBLog.h"
48 #include "lldb/Utility/Log.h"
49 #include "lldb/Utility/RegularExpression.h"
50 #include "lldb/Utility/State.h"
51 #include "lldb/Utility/Stream.h"
52 #include "lldb/Utility/StreamString.h"
53 #include "lldb/lldb-enumerations.h"
54 
55 #include <memory>
56 #include <optional>
57 
58 using namespace lldb;
59 using namespace lldb_private;
60 
61 ThreadProperties &Thread::GetGlobalProperties() {
62   // NOTE: intentional leak so we don't crash if global destructor chain gets
63   // called as other threads still use the result of this function
64   static ThreadProperties *g_settings_ptr = new ThreadProperties(true);
65   return *g_settings_ptr;
66 }
67 
68 #define LLDB_PROPERTIES_thread
69 #include "TargetProperties.inc"
70 
71 enum {
72 #define LLDB_PROPERTIES_thread
73 #include "TargetPropertiesEnum.inc"
74 };
75 
76 class ThreadOptionValueProperties
77     : public Cloneable<ThreadOptionValueProperties, OptionValueProperties> {
78 public:
79   ThreadOptionValueProperties(ConstString name) : Cloneable(name) {}
80 
81   const Property *
82   GetPropertyAtIndex(size_t idx,
83                      const ExecutionContext *exe_ctx) const override {
84     // When getting the value for a key from the thread options, we will always
85     // try and grab the setting from the current thread if there is one. Else
86     // we just use the one from this instance.
87     if (exe_ctx) {
88       Thread *thread = exe_ctx->GetThreadPtr();
89       if (thread) {
90         ThreadOptionValueProperties *instance_properties =
91             static_cast<ThreadOptionValueProperties *>(
92                 thread->GetValueProperties().get());
93         if (this != instance_properties)
94           return instance_properties->ProtectedGetPropertyAtIndex(idx);
95       }
96     }
97     return ProtectedGetPropertyAtIndex(idx);
98   }
99 };
100 
101 ThreadProperties::ThreadProperties(bool is_global) : Properties() {
102   if (is_global) {
103     m_collection_sp =
104         std::make_shared<ThreadOptionValueProperties>(ConstString("thread"));
105     m_collection_sp->Initialize(g_thread_properties);
106   } else
107     m_collection_sp =
108         OptionValueProperties::CreateLocalCopy(Thread::GetGlobalProperties());
109 }
110 
111 ThreadProperties::~ThreadProperties() = default;
112 
113 const RegularExpression *ThreadProperties::GetSymbolsToAvoidRegexp() {
114   const uint32_t idx = ePropertyStepAvoidRegex;
115   return GetPropertyAtIndexAs<const RegularExpression *>(idx);
116 }
117 
118 FileSpecList ThreadProperties::GetLibrariesToAvoid() const {
119   const uint32_t idx = ePropertyStepAvoidLibraries;
120   return GetPropertyAtIndexAs<FileSpecList>(idx, {});
121 }
122 
123 bool ThreadProperties::GetTraceEnabledState() const {
124   const uint32_t idx = ePropertyEnableThreadTrace;
125   return GetPropertyAtIndexAs<bool>(
126       idx, g_thread_properties[idx].default_uint_value != 0);
127 }
128 
129 bool ThreadProperties::GetStepInAvoidsNoDebug() const {
130   const uint32_t idx = ePropertyStepInAvoidsNoDebug;
131   return GetPropertyAtIndexAs<bool>(
132       idx, g_thread_properties[idx].default_uint_value != 0);
133 }
134 
135 bool ThreadProperties::GetStepOutAvoidsNoDebug() const {
136   const uint32_t idx = ePropertyStepOutAvoidsNoDebug;
137   return GetPropertyAtIndexAs<bool>(
138       idx, g_thread_properties[idx].default_uint_value != 0);
139 }
140 
141 uint64_t ThreadProperties::GetMaxBacktraceDepth() const {
142   const uint32_t idx = ePropertyMaxBacktraceDepth;
143   return GetPropertyAtIndexAs<uint64_t>(
144       idx, g_thread_properties[idx].default_uint_value);
145 }
146 
147 // Thread Event Data
148 
149 llvm::StringRef Thread::ThreadEventData::GetFlavorString() {
150   return "Thread::ThreadEventData";
151 }
152 
153 Thread::ThreadEventData::ThreadEventData(const lldb::ThreadSP thread_sp)
154     : m_thread_sp(thread_sp), m_stack_id() {}
155 
156 Thread::ThreadEventData::ThreadEventData(const lldb::ThreadSP thread_sp,
157                                          const StackID &stack_id)
158     : m_thread_sp(thread_sp), m_stack_id(stack_id) {}
159 
160 Thread::ThreadEventData::ThreadEventData() : m_thread_sp(), m_stack_id() {}
161 
162 Thread::ThreadEventData::~ThreadEventData() = default;
163 
164 void Thread::ThreadEventData::Dump(Stream *s) const {}
165 
166 const Thread::ThreadEventData *
167 Thread::ThreadEventData::GetEventDataFromEvent(const Event *event_ptr) {
168   if (event_ptr) {
169     const EventData *event_data = event_ptr->GetData();
170     if (event_data &&
171         event_data->GetFlavor() == ThreadEventData::GetFlavorString())
172       return static_cast<const ThreadEventData *>(event_ptr->GetData());
173   }
174   return nullptr;
175 }
176 
177 ThreadSP Thread::ThreadEventData::GetThreadFromEvent(const Event *event_ptr) {
178   ThreadSP thread_sp;
179   const ThreadEventData *event_data = GetEventDataFromEvent(event_ptr);
180   if (event_data)
181     thread_sp = event_data->GetThread();
182   return thread_sp;
183 }
184 
185 StackID Thread::ThreadEventData::GetStackIDFromEvent(const Event *event_ptr) {
186   StackID stack_id;
187   const ThreadEventData *event_data = GetEventDataFromEvent(event_ptr);
188   if (event_data)
189     stack_id = event_data->GetStackID();
190   return stack_id;
191 }
192 
193 StackFrameSP
194 Thread::ThreadEventData::GetStackFrameFromEvent(const Event *event_ptr) {
195   const ThreadEventData *event_data = GetEventDataFromEvent(event_ptr);
196   StackFrameSP frame_sp;
197   if (event_data) {
198     ThreadSP thread_sp = event_data->GetThread();
199     if (thread_sp) {
200       frame_sp = thread_sp->GetStackFrameList()->GetFrameWithStackID(
201           event_data->GetStackID());
202     }
203   }
204   return frame_sp;
205 }
206 
207 // Thread class
208 
209 ConstString &Thread::GetStaticBroadcasterClass() {
210   static ConstString class_name("lldb.thread");
211   return class_name;
212 }
213 
214 Thread::Thread(Process &process, lldb::tid_t tid, bool use_invalid_index_id)
215     : ThreadProperties(false), UserID(tid),
216       Broadcaster(process.GetTarget().GetDebugger().GetBroadcasterManager(),
217                   Thread::GetStaticBroadcasterClass().AsCString()),
218       m_process_wp(process.shared_from_this()), m_stop_info_sp(),
219       m_stop_info_stop_id(0), m_stop_info_override_stop_id(0),
220       m_should_run_before_public_stop(false),
221       m_index_id(use_invalid_index_id ? LLDB_INVALID_INDEX32
222                                       : process.GetNextThreadIndexID(tid)),
223       m_reg_context_sp(), m_state(eStateUnloaded), m_state_mutex(),
224       m_frame_mutex(), m_curr_frames_sp(), m_prev_frames_sp(),
225       m_resume_signal(LLDB_INVALID_SIGNAL_NUMBER),
226       m_resume_state(eStateRunning), m_temporary_resume_state(eStateRunning),
227       m_unwinder_up(), m_destroy_called(false),
228       m_override_should_notify(eLazyBoolCalculate),
229       m_extended_info_fetched(false), m_extended_info() {
230   Log *log = GetLog(LLDBLog::Object);
231   LLDB_LOGF(log, "%p Thread::Thread(tid = 0x%4.4" PRIx64 ")",
232             static_cast<void *>(this), GetID());
233 
234   CheckInWithManager();
235 }
236 
237 Thread::~Thread() {
238   Log *log = GetLog(LLDBLog::Object);
239   LLDB_LOGF(log, "%p Thread::~Thread(tid = 0x%4.4" PRIx64 ")",
240             static_cast<void *>(this), GetID());
241   /// If you hit this assert, it means your derived class forgot to call
242   /// DoDestroy in its destructor.
243   assert(m_destroy_called);
244 }
245 
246 void Thread::DestroyThread() {
247   m_destroy_called = true;
248   m_stop_info_sp.reset();
249   m_reg_context_sp.reset();
250   m_unwinder_up.reset();
251   std::lock_guard<std::recursive_mutex> guard(m_frame_mutex);
252   m_curr_frames_sp.reset();
253   m_prev_frames_sp.reset();
254 }
255 
256 void Thread::BroadcastSelectedFrameChange(StackID &new_frame_id) {
257   if (EventTypeHasListeners(eBroadcastBitSelectedFrameChanged))
258     BroadcastEvent(eBroadcastBitSelectedFrameChanged,
259                    new ThreadEventData(this->shared_from_this(), new_frame_id));
260 }
261 
262 lldb::StackFrameSP
263 Thread::GetSelectedFrame(SelectMostRelevant select_most_relevant) {
264   StackFrameListSP stack_frame_list_sp(GetStackFrameList());
265   StackFrameSP frame_sp = stack_frame_list_sp->GetFrameAtIndex(
266       stack_frame_list_sp->GetSelectedFrameIndex(select_most_relevant));
267   FrameSelectedCallback(frame_sp.get());
268   return frame_sp;
269 }
270 
271 uint32_t Thread::SetSelectedFrame(lldb_private::StackFrame *frame,
272                                   bool broadcast) {
273   uint32_t ret_value = GetStackFrameList()->SetSelectedFrame(frame);
274   if (broadcast)
275     BroadcastSelectedFrameChange(frame->GetStackID());
276   FrameSelectedCallback(frame);
277   return ret_value;
278 }
279 
280 bool Thread::SetSelectedFrameByIndex(uint32_t frame_idx, bool broadcast) {
281   StackFrameSP frame_sp(GetStackFrameList()->GetFrameAtIndex(frame_idx));
282   if (frame_sp) {
283     GetStackFrameList()->SetSelectedFrame(frame_sp.get());
284     if (broadcast)
285       BroadcastSelectedFrameChange(frame_sp->GetStackID());
286     FrameSelectedCallback(frame_sp.get());
287     return true;
288   } else
289     return false;
290 }
291 
292 bool Thread::SetSelectedFrameByIndexNoisily(uint32_t frame_idx,
293                                             Stream &output_stream) {
294   const bool broadcast = true;
295   bool success = SetSelectedFrameByIndex(frame_idx, broadcast);
296   if (success) {
297     StackFrameSP frame_sp = GetSelectedFrame(DoNoSelectMostRelevantFrame);
298     if (frame_sp) {
299       bool already_shown = false;
300       SymbolContext frame_sc(
301           frame_sp->GetSymbolContext(eSymbolContextLineEntry));
302       const Debugger &debugger = GetProcess()->GetTarget().GetDebugger();
303       if (debugger.GetUseExternalEditor() && frame_sc.line_entry.file &&
304           frame_sc.line_entry.line != 0) {
305         if (llvm::Error e = Host::OpenFileInExternalEditor(
306                 debugger.GetExternalEditor(), frame_sc.line_entry.file,
307                 frame_sc.line_entry.line)) {
308           LLDB_LOG_ERROR(GetLog(LLDBLog::Host), std::move(e),
309                          "OpenFileInExternalEditor failed: {0}");
310         } else {
311           already_shown = true;
312         }
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(bool calculate) {
378   if (!calculate)
379     return m_stop_info_sp;
380 
381   if (m_destroy_called)
382     return m_stop_info_sp;
383 
384   ProcessSP process_sp(GetProcess());
385   if (process_sp) {
386     const uint32_t process_stop_id = process_sp->GetStopID();
387     if (m_stop_info_stop_id != process_stop_id) {
388       // We preserve the old stop info for a variety of reasons:
389       // 1) Someone has already updated it by the time we get here
390       // 2) We didn't get to execute the breakpoint instruction we stopped at
391       // 3) This is a virtual step so we didn't actually run
392       // 4) If this thread wasn't allowed to run the last time round.
393       if (m_stop_info_sp) {
394         if (m_stop_info_sp->IsValid() || IsStillAtLastBreakpointHit() ||
395             GetCurrentPlan()->IsVirtualStep()
396             || GetTemporaryResumeState() == eStateSuspended)
397           SetStopInfo(m_stop_info_sp);
398         else
399           m_stop_info_sp.reset();
400       }
401 
402       if (!m_stop_info_sp) {
403         if (!CalculateStopInfo())
404           SetStopInfo(StopInfoSP());
405       }
406     }
407 
408     // The stop info can be manually set by calling Thread::SetStopInfo() prior
409     // to this function ever getting called, so we can't rely on
410     // "m_stop_info_stop_id != process_stop_id" as the condition for the if
411     // statement below, we must also check the stop info to see if we need to
412     // override it. See the header documentation in
413     // Architecture::OverrideStopInfo() for more information on the stop
414     // info override callback.
415     if (m_stop_info_override_stop_id != process_stop_id) {
416       m_stop_info_override_stop_id = process_stop_id;
417       if (m_stop_info_sp) {
418         if (const Architecture *arch =
419                 process_sp->GetTarget().GetArchitecturePlugin())
420           arch->OverrideStopInfo(*this);
421       }
422     }
423   }
424   return m_stop_info_sp;
425 }
426 
427 lldb::StopReason Thread::GetStopReason() {
428   lldb::StopInfoSP stop_info_sp(GetStopInfo());
429   if (stop_info_sp)
430     return stop_info_sp->GetStopReason();
431   return eStopReasonNone;
432 }
433 
434 bool Thread::StopInfoIsUpToDate() const {
435   ProcessSP process_sp(GetProcess());
436   if (process_sp)
437     return m_stop_info_stop_id == process_sp->GetStopID();
438   else
439     return true; // Process is no longer around so stop info is always up to
440                  // date...
441 }
442 
443 void Thread::ResetStopInfo() {
444   if (m_stop_info_sp) {
445     m_stop_info_sp.reset();
446   }
447 }
448 
449 void Thread::SetStopInfo(const lldb::StopInfoSP &stop_info_sp) {
450   m_stop_info_sp = stop_info_sp;
451   if (m_stop_info_sp) {
452     m_stop_info_sp->MakeStopInfoValid();
453     // If we are overriding the ShouldReportStop, do that here:
454     if (m_override_should_notify != eLazyBoolCalculate)
455       m_stop_info_sp->OverrideShouldNotify(m_override_should_notify ==
456                                            eLazyBoolYes);
457   }
458 
459   ProcessSP process_sp(GetProcess());
460   if (process_sp)
461     m_stop_info_stop_id = process_sp->GetStopID();
462   else
463     m_stop_info_stop_id = UINT32_MAX;
464   Log *log = GetLog(LLDBLog::Thread);
465   LLDB_LOGF(log, "%p: tid = 0x%" PRIx64 ": stop info = %s (stop_id = %u)",
466             static_cast<void *>(this), GetID(),
467             stop_info_sp ? stop_info_sp->GetDescription() : "<NULL>",
468             m_stop_info_stop_id);
469 }
470 
471 void Thread::SetShouldReportStop(Vote vote) {
472   if (vote == eVoteNoOpinion)
473     return;
474   else {
475     m_override_should_notify = (vote == eVoteYes ? eLazyBoolYes : eLazyBoolNo);
476     if (m_stop_info_sp)
477       m_stop_info_sp->OverrideShouldNotify(m_override_should_notify ==
478                                            eLazyBoolYes);
479   }
480 }
481 
482 void Thread::SetStopInfoToNothing() {
483   // Note, we can't just NULL out the private reason, or the native thread
484   // implementation will try to go calculate it again.  For now, just set it to
485   // a Unix Signal with an invalid signal number.
486   SetStopInfo(
487       StopInfo::CreateStopReasonWithSignal(*this, LLDB_INVALID_SIGNAL_NUMBER));
488 }
489 
490 bool Thread::ThreadStoppedForAReason() { return (bool)GetPrivateStopInfo(); }
491 
492 bool Thread::CheckpointThreadState(ThreadStateCheckpoint &saved_state) {
493   saved_state.register_backup_sp.reset();
494   lldb::StackFrameSP frame_sp(GetStackFrameAtIndex(0));
495   if (frame_sp) {
496     lldb::RegisterCheckpointSP reg_checkpoint_sp(
497         new RegisterCheckpoint(RegisterCheckpoint::Reason::eExpression));
498     if (reg_checkpoint_sp) {
499       lldb::RegisterContextSP reg_ctx_sp(frame_sp->GetRegisterContext());
500       if (reg_ctx_sp && reg_ctx_sp->ReadAllRegisterValues(*reg_checkpoint_sp))
501         saved_state.register_backup_sp = reg_checkpoint_sp;
502     }
503   }
504   if (!saved_state.register_backup_sp)
505     return false;
506 
507   saved_state.stop_info_sp = GetStopInfo();
508   ProcessSP process_sp(GetProcess());
509   if (process_sp)
510     saved_state.orig_stop_id = process_sp->GetStopID();
511   saved_state.current_inlined_depth = GetCurrentInlinedDepth();
512   saved_state.m_completed_plan_checkpoint =
513       GetPlans().CheckpointCompletedPlans();
514 
515   return true;
516 }
517 
518 bool Thread::RestoreRegisterStateFromCheckpoint(
519     ThreadStateCheckpoint &saved_state) {
520   if (saved_state.register_backup_sp) {
521     lldb::StackFrameSP frame_sp(GetStackFrameAtIndex(0));
522     if (frame_sp) {
523       lldb::RegisterContextSP reg_ctx_sp(frame_sp->GetRegisterContext());
524       if (reg_ctx_sp) {
525         bool ret =
526             reg_ctx_sp->WriteAllRegisterValues(*saved_state.register_backup_sp);
527 
528         // Clear out all stack frames as our world just changed.
529         ClearStackFrames();
530         reg_ctx_sp->InvalidateIfNeeded(true);
531         if (m_unwinder_up)
532           m_unwinder_up->Clear();
533         return ret;
534       }
535     }
536   }
537   return false;
538 }
539 
540 void Thread::RestoreThreadStateFromCheckpoint(
541     ThreadStateCheckpoint &saved_state) {
542   if (saved_state.stop_info_sp)
543     saved_state.stop_info_sp->MakeStopInfoValid();
544   SetStopInfo(saved_state.stop_info_sp);
545   GetStackFrameList()->SetCurrentInlinedDepth(
546       saved_state.current_inlined_depth);
547   GetPlans().RestoreCompletedPlanCheckpoint(
548       saved_state.m_completed_plan_checkpoint);
549 }
550 
551 StateType Thread::GetState() const {
552   // If any other threads access this we will need a mutex for it
553   std::lock_guard<std::recursive_mutex> guard(m_state_mutex);
554   return m_state;
555 }
556 
557 void Thread::SetState(StateType state) {
558   std::lock_guard<std::recursive_mutex> guard(m_state_mutex);
559   m_state = state;
560 }
561 
562 std::string Thread::GetStopDescription() {
563   StackFrameSP frame_sp = GetStackFrameAtIndex(0);
564 
565   if (!frame_sp)
566     return GetStopDescriptionRaw();
567 
568   auto recognized_frame_sp = frame_sp->GetRecognizedFrame();
569 
570   if (!recognized_frame_sp)
571     return GetStopDescriptionRaw();
572 
573   std::string recognized_stop_description =
574       recognized_frame_sp->GetStopDescription();
575 
576   if (!recognized_stop_description.empty())
577     return recognized_stop_description;
578 
579   return GetStopDescriptionRaw();
580 }
581 
582 std::string Thread::GetStopDescriptionRaw() {
583   StopInfoSP stop_info_sp = GetStopInfo();
584   std::string raw_stop_description;
585   if (stop_info_sp && stop_info_sp->IsValid()) {
586     raw_stop_description = stop_info_sp->GetDescription();
587     assert((!raw_stop_description.empty() ||
588             stop_info_sp->GetStopReason() == eStopReasonNone) &&
589            "StopInfo returned an empty description.");
590   }
591   return raw_stop_description;
592 }
593 
594 void Thread::WillStop() {
595   ThreadPlan *current_plan = GetCurrentPlan();
596 
597   // FIXME: I may decide to disallow threads with no plans.  In which
598   // case this should go to an assert.
599 
600   if (!current_plan)
601     return;
602 
603   current_plan->WillStop();
604 }
605 
606 void Thread::SetupForResume() {
607   if (GetResumeState() != eStateSuspended) {
608     // If we're at a breakpoint push the step-over breakpoint plan.  Do this
609     // before telling the current plan it will resume, since we might change
610     // what the current plan is.
611 
612     lldb::RegisterContextSP reg_ctx_sp(GetRegisterContext());
613     if (reg_ctx_sp) {
614       const addr_t thread_pc = reg_ctx_sp->GetPC();
615       BreakpointSiteSP bp_site_sp =
616           GetProcess()->GetBreakpointSiteList().FindByAddress(thread_pc);
617       if (bp_site_sp) {
618         // Note, don't assume there's a ThreadPlanStepOverBreakpoint, the
619         // target may not require anything special to step over a breakpoint.
620 
621         ThreadPlan *cur_plan = GetCurrentPlan();
622 
623         bool push_step_over_bp_plan = false;
624         if (cur_plan->GetKind() == ThreadPlan::eKindStepOverBreakpoint) {
625           ThreadPlanStepOverBreakpoint *bp_plan =
626               (ThreadPlanStepOverBreakpoint *)cur_plan;
627           if (bp_plan->GetBreakpointLoadAddress() != thread_pc)
628             push_step_over_bp_plan = true;
629         } else
630           push_step_over_bp_plan = true;
631 
632         if (push_step_over_bp_plan) {
633           ThreadPlanSP step_bp_plan_sp(new ThreadPlanStepOverBreakpoint(*this));
634           if (step_bp_plan_sp) {
635             step_bp_plan_sp->SetPrivate(true);
636 
637             if (GetCurrentPlan()->RunState() != eStateStepping) {
638               ThreadPlanStepOverBreakpoint *step_bp_plan =
639                   static_cast<ThreadPlanStepOverBreakpoint *>(
640                       step_bp_plan_sp.get());
641               step_bp_plan->SetAutoContinue(true);
642             }
643             QueueThreadPlan(step_bp_plan_sp, false);
644           }
645         }
646       }
647     }
648   }
649 }
650 
651 bool Thread::ShouldResume(StateType resume_state) {
652   // At this point clear the completed plan stack.
653   GetPlans().WillResume();
654   m_override_should_notify = eLazyBoolCalculate;
655 
656   StateType prev_resume_state = GetTemporaryResumeState();
657 
658   SetTemporaryResumeState(resume_state);
659 
660   lldb::ThreadSP backing_thread_sp(GetBackingThread());
661   if (backing_thread_sp)
662     backing_thread_sp->SetTemporaryResumeState(resume_state);
663 
664   // Make sure m_stop_info_sp is valid.  Don't do this for threads we suspended
665   // in the previous run.
666   if (prev_resume_state != eStateSuspended)
667     GetPrivateStopInfo();
668 
669   // This is a little dubious, but we are trying to limit how often we actually
670   // fetch stop info from the target, 'cause that slows down single stepping.
671   // So assume that if we got to the point where we're about to resume, and we
672   // haven't yet had to fetch the stop reason, then it doesn't need to know
673   // about the fact that we are resuming...
674   const uint32_t process_stop_id = GetProcess()->GetStopID();
675   if (m_stop_info_stop_id == process_stop_id &&
676       (m_stop_info_sp && m_stop_info_sp->IsValid())) {
677     StopInfo *stop_info = GetPrivateStopInfo().get();
678     if (stop_info)
679       stop_info->WillResume(resume_state);
680   }
681 
682   // Tell all the plans that we are about to resume in case they need to clear
683   // any state. We distinguish between the plan on the top of the stack and the
684   // lower plans in case a plan needs to do any special business before it
685   // runs.
686 
687   bool need_to_resume = false;
688   ThreadPlan *plan_ptr = GetCurrentPlan();
689   if (plan_ptr) {
690     need_to_resume = plan_ptr->WillResume(resume_state, true);
691 
692     while ((plan_ptr = GetPreviousPlan(plan_ptr)) != nullptr) {
693       plan_ptr->WillResume(resume_state, false);
694     }
695 
696     // If the WillResume for the plan says we are faking a resume, then it will
697     // have set an appropriate stop info. In that case, don't reset it here.
698 
699     if (need_to_resume && resume_state != eStateSuspended) {
700       m_stop_info_sp.reset();
701     }
702   }
703 
704   if (need_to_resume) {
705     ClearStackFrames();
706     // Let Thread subclasses do any special work they need to prior to resuming
707     WillResume(resume_state);
708   }
709 
710   return need_to_resume;
711 }
712 
713 void Thread::DidResume() {
714   SetResumeSignal(LLDB_INVALID_SIGNAL_NUMBER);
715   // This will get recomputed each time when we stop.
716   SetShouldRunBeforePublicStop(false);
717 }
718 
719 void Thread::DidStop() { SetState(eStateStopped); }
720 
721 bool Thread::ShouldStop(Event *event_ptr) {
722   ThreadPlan *current_plan = GetCurrentPlan();
723 
724   bool should_stop = true;
725 
726   Log *log = GetLog(LLDBLog::Step);
727 
728   if (GetResumeState() == eStateSuspended) {
729     LLDB_LOGF(log,
730               "Thread::%s for tid = 0x%4.4" PRIx64 " 0x%4.4" PRIx64
731               ", should_stop = 0 (ignore since thread was suspended)",
732               __FUNCTION__, GetID(), GetProtocolID());
733     return false;
734   }
735 
736   if (GetTemporaryResumeState() == eStateSuspended) {
737     LLDB_LOGF(log,
738               "Thread::%s for tid = 0x%4.4" PRIx64 " 0x%4.4" PRIx64
739               ", should_stop = 0 (ignore since thread was suspended)",
740               __FUNCTION__, GetID(), GetProtocolID());
741     return false;
742   }
743 
744   // Based on the current thread plan and process stop info, check if this
745   // thread caused the process to stop. NOTE: this must take place before the
746   // plan is moved from the current plan stack to the completed plan stack.
747   if (!ThreadStoppedForAReason()) {
748     LLDB_LOGF(log,
749               "Thread::%s for tid = 0x%4.4" PRIx64 " 0x%4.4" PRIx64
750               ", pc = 0x%16.16" PRIx64
751               ", should_stop = 0 (ignore since no stop reason)",
752               __FUNCTION__, GetID(), GetProtocolID(),
753               GetRegisterContext() ? GetRegisterContext()->GetPC()
754                                    : LLDB_INVALID_ADDRESS);
755     return false;
756   }
757 
758   // Clear the "must run me before stop" if it was set:
759   SetShouldRunBeforePublicStop(false);
760 
761   if (log) {
762     LLDB_LOGF(log,
763               "Thread::%s(%p) for tid = 0x%4.4" PRIx64 " 0x%4.4" PRIx64
764               ", pc = 0x%16.16" PRIx64,
765               __FUNCTION__, static_cast<void *>(this), GetID(), GetProtocolID(),
766               GetRegisterContext() ? GetRegisterContext()->GetPC()
767                                    : LLDB_INVALID_ADDRESS);
768     LLDB_LOGF(log, "^^^^^^^^ Thread::ShouldStop Begin ^^^^^^^^");
769     StreamString s;
770     s.IndentMore();
771     GetProcess()->DumpThreadPlansForTID(
772         s, GetID(), eDescriptionLevelVerbose, true /* internal */,
773         false /* condense_trivial */, true /* skip_unreported */);
774     LLDB_LOGF(log, "Plan stack initial state:\n%s", s.GetData());
775   }
776 
777   // The top most plan always gets to do the trace log...
778   current_plan->DoTraceLog();
779 
780   // First query the stop info's ShouldStopSynchronous.  This handles
781   // "synchronous" stop reasons, for example the breakpoint command on internal
782   // breakpoints.  If a synchronous stop reason says we should not stop, then
783   // we don't have to do any more work on this stop.
784   StopInfoSP private_stop_info(GetPrivateStopInfo());
785   if (private_stop_info &&
786       !private_stop_info->ShouldStopSynchronous(event_ptr)) {
787     LLDB_LOGF(log, "StopInfo::ShouldStop async callback says we should not "
788                    "stop, returning ShouldStop of false.");
789     return false;
790   }
791 
792   // If we've already been restarted, don't query the plans since the state
793   // they would examine is not current.
794   if (Process::ProcessEventData::GetRestartedFromEvent(event_ptr))
795     return false;
796 
797   // Before the plans see the state of the world, calculate the current inlined
798   // depth.
799   GetStackFrameList()->CalculateCurrentInlinedDepth();
800 
801   // If the base plan doesn't understand why we stopped, then we have to find a
802   // plan that does. If that plan is still working, then we don't need to do
803   // any more work.  If the plan that explains the stop is done, then we should
804   // pop all the plans below it, and pop it, and then let the plans above it
805   // decide whether they still need to do more work.
806 
807   bool done_processing_current_plan = false;
808 
809   if (!current_plan->PlanExplainsStop(event_ptr)) {
810     if (current_plan->TracerExplainsStop()) {
811       done_processing_current_plan = true;
812       should_stop = false;
813     } else {
814       // If the current plan doesn't explain the stop, then find one that does
815       // and let it handle the situation.
816       ThreadPlan *plan_ptr = current_plan;
817       while ((plan_ptr = GetPreviousPlan(plan_ptr)) != nullptr) {
818         if (plan_ptr->PlanExplainsStop(event_ptr)) {
819           LLDB_LOGF(log, "Plan %s explains stop.", plan_ptr->GetName());
820 
821           should_stop = plan_ptr->ShouldStop(event_ptr);
822 
823           // plan_ptr explains the stop, next check whether plan_ptr is done,
824           // if so, then we should take it and all the plans below it off the
825           // stack.
826 
827           if (plan_ptr->MischiefManaged()) {
828             // We're going to pop the plans up to and including the plan that
829             // explains the stop.
830             ThreadPlan *prev_plan_ptr = GetPreviousPlan(plan_ptr);
831 
832             do {
833               if (should_stop)
834                 current_plan->WillStop();
835               PopPlan();
836             } while ((current_plan = GetCurrentPlan()) != prev_plan_ptr);
837             // Now, if the responsible plan was not "Okay to discard" then
838             // we're done, otherwise we forward this to the next plan in the
839             // stack below.
840             done_processing_current_plan =
841                 (plan_ptr->IsControllingPlan() && !plan_ptr->OkayToDiscard());
842           } else {
843             bool should_force_run = plan_ptr->ShouldRunBeforePublicStop();
844             if (should_force_run) {
845               SetShouldRunBeforePublicStop(true);
846               should_stop = false;
847             }
848             done_processing_current_plan = true;
849           }
850           break;
851         }
852       }
853     }
854   }
855 
856   if (!done_processing_current_plan) {
857     bool override_stop = false;
858 
859     // We're starting from the base plan, so just let it decide;
860     if (current_plan->IsBasePlan()) {
861       should_stop = current_plan->ShouldStop(event_ptr);
862       LLDB_LOGF(log, "Base plan says should stop: %i.", should_stop);
863     } else {
864       // Otherwise, don't let the base plan override what the other plans say
865       // to do, since presumably if there were other plans they would know what
866       // to do...
867       while (true) {
868         if (current_plan->IsBasePlan())
869           break;
870 
871         should_stop = current_plan->ShouldStop(event_ptr);
872         LLDB_LOGF(log, "Plan %s should stop: %d.", current_plan->GetName(),
873                   should_stop);
874         if (current_plan->MischiefManaged()) {
875           if (should_stop)
876             current_plan->WillStop();
877 
878           if (current_plan->ShouldAutoContinue(event_ptr)) {
879             override_stop = true;
880             LLDB_LOGF(log, "Plan %s auto-continue: true.",
881                       current_plan->GetName());
882           }
883 
884           // If a Controlling Plan wants to stop, we let it. Otherwise, see if
885           // the plan's parent wants to stop.
886 
887           PopPlan();
888           if (should_stop && current_plan->IsControllingPlan() &&
889               !current_plan->OkayToDiscard()) {
890             break;
891           }
892 
893           current_plan = GetCurrentPlan();
894           if (current_plan == nullptr) {
895             break;
896           }
897         } else {
898           break;
899         }
900       }
901     }
902 
903     if (override_stop)
904       should_stop = false;
905   }
906 
907   // One other potential problem is that we set up a controlling plan, then stop
908   // in before it is complete - for instance by hitting a breakpoint during a
909   // step-over - then do some step/finish/etc operations that wind up past the
910   // end point condition of the initial plan.  We don't want to strand the
911   // original plan on the stack, This code clears stale plans off the stack.
912 
913   if (should_stop) {
914     ThreadPlan *plan_ptr = GetCurrentPlan();
915 
916     // Discard the stale plans and all plans below them in the stack, plus move
917     // the completed plans to the completed plan stack
918     while (!plan_ptr->IsBasePlan()) {
919       bool stale = plan_ptr->IsPlanStale();
920       ThreadPlan *examined_plan = plan_ptr;
921       plan_ptr = GetPreviousPlan(examined_plan);
922 
923       if (stale) {
924         LLDB_LOGF(
925             log,
926             "Plan %s being discarded in cleanup, it says it is already done.",
927             examined_plan->GetName());
928         while (GetCurrentPlan() != examined_plan) {
929           DiscardPlan();
930         }
931         if (examined_plan->IsPlanComplete()) {
932           // plan is complete but does not explain the stop (example: step to a
933           // line with breakpoint), let us move the plan to
934           // completed_plan_stack anyway
935           PopPlan();
936         } else
937           DiscardPlan();
938       }
939     }
940   }
941 
942   if (log) {
943     StreamString s;
944     s.IndentMore();
945     GetProcess()->DumpThreadPlansForTID(
946         s, GetID(), eDescriptionLevelVerbose, true /* internal */,
947         false /* condense_trivial */, true /* skip_unreported */);
948     LLDB_LOGF(log, "Plan stack final state:\n%s", s.GetData());
949     LLDB_LOGF(log, "vvvvvvvv Thread::ShouldStop End (returning %i) vvvvvvvv",
950               should_stop);
951   }
952   return should_stop;
953 }
954 
955 Vote Thread::ShouldReportStop(Event *event_ptr) {
956   StateType thread_state = GetResumeState();
957   StateType temp_thread_state = GetTemporaryResumeState();
958 
959   Log *log = GetLog(LLDBLog::Step);
960 
961   if (thread_state == eStateSuspended || thread_state == eStateInvalid) {
962     LLDB_LOGF(log,
963               "Thread::ShouldReportStop() tid = 0x%4.4" PRIx64
964               ": returning vote %i (state was suspended or invalid)",
965               GetID(), eVoteNoOpinion);
966     return eVoteNoOpinion;
967   }
968 
969   if (temp_thread_state == eStateSuspended ||
970       temp_thread_state == eStateInvalid) {
971     LLDB_LOGF(log,
972               "Thread::ShouldReportStop() tid = 0x%4.4" PRIx64
973               ": returning vote %i (temporary state was suspended or invalid)",
974               GetID(), eVoteNoOpinion);
975     return eVoteNoOpinion;
976   }
977 
978   if (!ThreadStoppedForAReason()) {
979     LLDB_LOGF(log,
980               "Thread::ShouldReportStop() tid = 0x%4.4" PRIx64
981               ": returning vote %i (thread didn't stop for a reason.)",
982               GetID(), eVoteNoOpinion);
983     return eVoteNoOpinion;
984   }
985 
986   if (GetPlans().AnyCompletedPlans()) {
987     // Pass skip_private = false to GetCompletedPlan, since we want to ask
988     // the last plan, regardless of whether it is private or not.
989     LLDB_LOGF(log,
990               "Thread::ShouldReportStop() tid = 0x%4.4" PRIx64
991               ": returning vote for complete stack's back plan",
992               GetID());
993     return GetPlans().GetCompletedPlan(false)->ShouldReportStop(event_ptr);
994   } else {
995     Vote thread_vote = eVoteNoOpinion;
996     ThreadPlan *plan_ptr = GetCurrentPlan();
997     while (true) {
998       if (plan_ptr->PlanExplainsStop(event_ptr)) {
999         thread_vote = plan_ptr->ShouldReportStop(event_ptr);
1000         break;
1001       }
1002       if (plan_ptr->IsBasePlan())
1003         break;
1004       else
1005         plan_ptr = GetPreviousPlan(plan_ptr);
1006     }
1007     LLDB_LOGF(log,
1008               "Thread::ShouldReportStop() tid = 0x%4.4" PRIx64
1009               ": returning vote %i for current plan",
1010               GetID(), thread_vote);
1011 
1012     return thread_vote;
1013   }
1014 }
1015 
1016 Vote Thread::ShouldReportRun(Event *event_ptr) {
1017   StateType thread_state = GetResumeState();
1018 
1019   if (thread_state == eStateSuspended || thread_state == eStateInvalid) {
1020     return eVoteNoOpinion;
1021   }
1022 
1023   Log *log = GetLog(LLDBLog::Step);
1024   if (GetPlans().AnyCompletedPlans()) {
1025     // Pass skip_private = false to GetCompletedPlan, since we want to ask
1026     // the last plan, regardless of whether it is private or not.
1027     LLDB_LOGF(log,
1028               "Current Plan for thread %d(%p) (0x%4.4" PRIx64
1029               ", %s): %s being asked whether we should report run.",
1030               GetIndexID(), static_cast<void *>(this), GetID(),
1031               StateAsCString(GetTemporaryResumeState()),
1032               GetCompletedPlan()->GetName());
1033 
1034     return GetPlans().GetCompletedPlan(false)->ShouldReportRun(event_ptr);
1035   } else {
1036     LLDB_LOGF(log,
1037               "Current Plan for thread %d(%p) (0x%4.4" PRIx64
1038               ", %s): %s being asked whether we should report run.",
1039               GetIndexID(), static_cast<void *>(this), GetID(),
1040               StateAsCString(GetTemporaryResumeState()),
1041               GetCurrentPlan()->GetName());
1042 
1043     return GetCurrentPlan()->ShouldReportRun(event_ptr);
1044   }
1045 }
1046 
1047 bool Thread::MatchesSpec(const ThreadSpec *spec) {
1048   return (spec == nullptr) ? true : spec->ThreadPassesBasicTests(*this);
1049 }
1050 
1051 ThreadPlanStack &Thread::GetPlans() const {
1052   ThreadPlanStack *plans = GetProcess()->FindThreadPlans(GetID());
1053   if (plans)
1054     return *plans;
1055 
1056   // History threads don't have a thread plan, but they do ask get asked to
1057   // describe themselves, which usually involves pulling out the stop reason.
1058   // That in turn will check for a completed plan on the ThreadPlanStack.
1059   // Instead of special-casing at that point, we return a Stack with a
1060   // ThreadPlanNull as its base plan.  That will give the right answers to the
1061   // queries GetDescription makes, and only assert if you try to run the thread.
1062   if (!m_null_plan_stack_up)
1063     m_null_plan_stack_up = std::make_unique<ThreadPlanStack>(*this, true);
1064   return *m_null_plan_stack_up;
1065 }
1066 
1067 void Thread::PushPlan(ThreadPlanSP thread_plan_sp) {
1068   assert(thread_plan_sp && "Don't push an empty thread plan.");
1069 
1070   Log *log = GetLog(LLDBLog::Step);
1071   if (log) {
1072     StreamString s;
1073     thread_plan_sp->GetDescription(&s, lldb::eDescriptionLevelFull);
1074     LLDB_LOGF(log, "Thread::PushPlan(0x%p): \"%s\", tid = 0x%4.4" PRIx64 ".",
1075               static_cast<void *>(this), s.GetData(),
1076               thread_plan_sp->GetThread().GetID());
1077   }
1078 
1079   GetPlans().PushPlan(std::move(thread_plan_sp));
1080 }
1081 
1082 void Thread::PopPlan() {
1083   Log *log = GetLog(LLDBLog::Step);
1084   ThreadPlanSP popped_plan_sp = GetPlans().PopPlan();
1085   if (log) {
1086     LLDB_LOGF(log, "Popping plan: \"%s\", tid = 0x%4.4" PRIx64 ".",
1087               popped_plan_sp->GetName(), popped_plan_sp->GetThread().GetID());
1088   }
1089 }
1090 
1091 void Thread::DiscardPlan() {
1092   Log *log = GetLog(LLDBLog::Step);
1093   ThreadPlanSP discarded_plan_sp = GetPlans().DiscardPlan();
1094 
1095   LLDB_LOGF(log, "Discarding plan: \"%s\", tid = 0x%4.4" PRIx64 ".",
1096             discarded_plan_sp->GetName(),
1097             discarded_plan_sp->GetThread().GetID());
1098 }
1099 
1100 void Thread::AutoCompleteThreadPlans(CompletionRequest &request) const {
1101   const ThreadPlanStack &plans = GetPlans();
1102   if (!plans.AnyPlans())
1103     return;
1104 
1105   // Iterate from the second plan (index: 1) to skip the base plan.
1106   ThreadPlanSP p;
1107   uint32_t i = 1;
1108   while ((p = plans.GetPlanByIndex(i, false))) {
1109     StreamString strm;
1110     p->GetDescription(&strm, eDescriptionLevelInitial);
1111     request.TryCompleteCurrentArg(std::to_string(i), strm.GetString());
1112     i++;
1113   }
1114 }
1115 
1116 ThreadPlan *Thread::GetCurrentPlan() const {
1117   return GetPlans().GetCurrentPlan().get();
1118 }
1119 
1120 ThreadPlanSP Thread::GetCompletedPlan() const {
1121   return GetPlans().GetCompletedPlan();
1122 }
1123 
1124 ValueObjectSP Thread::GetReturnValueObject() const {
1125   return GetPlans().GetReturnValueObject();
1126 }
1127 
1128 ExpressionVariableSP Thread::GetExpressionVariable() const {
1129   return GetPlans().GetExpressionVariable();
1130 }
1131 
1132 bool Thread::IsThreadPlanDone(ThreadPlan *plan) const {
1133   return GetPlans().IsPlanDone(plan);
1134 }
1135 
1136 bool Thread::WasThreadPlanDiscarded(ThreadPlan *plan) const {
1137   return GetPlans().WasPlanDiscarded(plan);
1138 }
1139 
1140 bool Thread::CompletedPlanOverridesBreakpoint() const {
1141   return GetPlans().AnyCompletedPlans();
1142 }
1143 
1144 ThreadPlan *Thread::GetPreviousPlan(ThreadPlan *current_plan) const{
1145   return GetPlans().GetPreviousPlan(current_plan);
1146 }
1147 
1148 Status Thread::QueueThreadPlan(ThreadPlanSP &thread_plan_sp,
1149                                bool abort_other_plans) {
1150   Status status;
1151   StreamString s;
1152   if (!thread_plan_sp->ValidatePlan(&s)) {
1153     DiscardThreadPlansUpToPlan(thread_plan_sp);
1154     thread_plan_sp.reset();
1155     status.SetErrorString(s.GetString());
1156     return status;
1157   }
1158 
1159   if (abort_other_plans)
1160     DiscardThreadPlans(true);
1161 
1162   PushPlan(thread_plan_sp);
1163 
1164   // This seems a little funny, but I don't want to have to split up the
1165   // constructor and the DidPush in the scripted plan, that seems annoying.
1166   // That means the constructor has to be in DidPush. So I have to validate the
1167   // plan AFTER pushing it, and then take it off again...
1168   if (!thread_plan_sp->ValidatePlan(&s)) {
1169     DiscardThreadPlansUpToPlan(thread_plan_sp);
1170     thread_plan_sp.reset();
1171     status.SetErrorString(s.GetString());
1172     return status;
1173   }
1174 
1175   return status;
1176 }
1177 
1178 bool Thread::DiscardUserThreadPlansUpToIndex(uint32_t plan_index) {
1179   // Count the user thread plans from the back end to get the number of the one
1180   // we want to discard:
1181 
1182   ThreadPlan *up_to_plan_ptr = GetPlans().GetPlanByIndex(plan_index).get();
1183   if (up_to_plan_ptr == nullptr)
1184     return false;
1185 
1186   DiscardThreadPlansUpToPlan(up_to_plan_ptr);
1187   return true;
1188 }
1189 
1190 void Thread::DiscardThreadPlansUpToPlan(lldb::ThreadPlanSP &up_to_plan_sp) {
1191   DiscardThreadPlansUpToPlan(up_to_plan_sp.get());
1192 }
1193 
1194 void Thread::DiscardThreadPlansUpToPlan(ThreadPlan *up_to_plan_ptr) {
1195   Log *log = GetLog(LLDBLog::Step);
1196   LLDB_LOGF(log,
1197             "Discarding thread plans for thread tid = 0x%4.4" PRIx64
1198             ", up to %p",
1199             GetID(), static_cast<void *>(up_to_plan_ptr));
1200   GetPlans().DiscardPlansUpToPlan(up_to_plan_ptr);
1201 }
1202 
1203 void Thread::DiscardThreadPlans(bool force) {
1204   Log *log = GetLog(LLDBLog::Step);
1205   if (log) {
1206     LLDB_LOGF(log,
1207               "Discarding thread plans for thread (tid = 0x%4.4" PRIx64
1208               ", force %d)",
1209               GetID(), force);
1210   }
1211 
1212   if (force) {
1213     GetPlans().DiscardAllPlans();
1214     return;
1215   }
1216   GetPlans().DiscardConsultingControllingPlans();
1217 }
1218 
1219 Status Thread::UnwindInnermostExpression() {
1220   Status error;
1221   ThreadPlan *innermost_expr_plan = GetPlans().GetInnermostExpression();
1222   if (!innermost_expr_plan) {
1223     error.SetErrorString("No expressions currently active on this thread");
1224     return error;
1225   }
1226   DiscardThreadPlansUpToPlan(innermost_expr_plan);
1227   return error;
1228 }
1229 
1230 ThreadPlanSP Thread::QueueBasePlan(bool abort_other_plans) {
1231   ThreadPlanSP thread_plan_sp(new ThreadPlanBase(*this));
1232   QueueThreadPlan(thread_plan_sp, abort_other_plans);
1233   return thread_plan_sp;
1234 }
1235 
1236 ThreadPlanSP Thread::QueueThreadPlanForStepSingleInstruction(
1237     bool step_over, bool abort_other_plans, bool stop_other_threads,
1238     Status &status) {
1239   ThreadPlanSP thread_plan_sp(new ThreadPlanStepInstruction(
1240       *this, step_over, stop_other_threads, eVoteNoOpinion, eVoteNoOpinion));
1241   status = QueueThreadPlan(thread_plan_sp, abort_other_plans);
1242   return thread_plan_sp;
1243 }
1244 
1245 ThreadPlanSP Thread::QueueThreadPlanForStepOverRange(
1246     bool abort_other_plans, const AddressRange &range,
1247     const SymbolContext &addr_context, lldb::RunMode stop_other_threads,
1248     Status &status, LazyBool step_out_avoids_code_withoug_debug_info) {
1249   ThreadPlanSP thread_plan_sp;
1250   thread_plan_sp = std::make_shared<ThreadPlanStepOverRange>(
1251       *this, range, addr_context, stop_other_threads,
1252       step_out_avoids_code_withoug_debug_info);
1253 
1254   status = QueueThreadPlan(thread_plan_sp, abort_other_plans);
1255   return thread_plan_sp;
1256 }
1257 
1258 // Call the QueueThreadPlanForStepOverRange method which takes an address
1259 // range.
1260 ThreadPlanSP Thread::QueueThreadPlanForStepOverRange(
1261     bool abort_other_plans, const LineEntry &line_entry,
1262     const SymbolContext &addr_context, lldb::RunMode stop_other_threads,
1263     Status &status, LazyBool step_out_avoids_code_withoug_debug_info) {
1264   const bool include_inlined_functions = true;
1265   auto address_range =
1266       line_entry.GetSameLineContiguousAddressRange(include_inlined_functions);
1267   return QueueThreadPlanForStepOverRange(
1268       abort_other_plans, address_range, addr_context, stop_other_threads,
1269       status, step_out_avoids_code_withoug_debug_info);
1270 }
1271 
1272 ThreadPlanSP Thread::QueueThreadPlanForStepInRange(
1273     bool abort_other_plans, const AddressRange &range,
1274     const SymbolContext &addr_context, const char *step_in_target,
1275     lldb::RunMode stop_other_threads, Status &status,
1276     LazyBool step_in_avoids_code_without_debug_info,
1277     LazyBool step_out_avoids_code_without_debug_info) {
1278   ThreadPlanSP thread_plan_sp(new ThreadPlanStepInRange(
1279       *this, range, addr_context, step_in_target, stop_other_threads,
1280       step_in_avoids_code_without_debug_info,
1281       step_out_avoids_code_without_debug_info));
1282   status = QueueThreadPlan(thread_plan_sp, abort_other_plans);
1283   return thread_plan_sp;
1284 }
1285 
1286 // Call the QueueThreadPlanForStepInRange method which takes an address range.
1287 ThreadPlanSP Thread::QueueThreadPlanForStepInRange(
1288     bool abort_other_plans, const LineEntry &line_entry,
1289     const SymbolContext &addr_context, const char *step_in_target,
1290     lldb::RunMode stop_other_threads, Status &status,
1291     LazyBool step_in_avoids_code_without_debug_info,
1292     LazyBool step_out_avoids_code_without_debug_info) {
1293   const bool include_inlined_functions = false;
1294   return QueueThreadPlanForStepInRange(
1295       abort_other_plans,
1296       line_entry.GetSameLineContiguousAddressRange(include_inlined_functions),
1297       addr_context, step_in_target, stop_other_threads, status,
1298       step_in_avoids_code_without_debug_info,
1299       step_out_avoids_code_without_debug_info);
1300 }
1301 
1302 ThreadPlanSP Thread::QueueThreadPlanForStepOut(
1303     bool abort_other_plans, SymbolContext *addr_context, bool first_insn,
1304     bool stop_other_threads, Vote report_stop_vote, Vote report_run_vote,
1305     uint32_t frame_idx, Status &status,
1306     LazyBool step_out_avoids_code_without_debug_info) {
1307   ThreadPlanSP thread_plan_sp(new ThreadPlanStepOut(
1308       *this, addr_context, first_insn, stop_other_threads, report_stop_vote,
1309       report_run_vote, frame_idx, step_out_avoids_code_without_debug_info));
1310 
1311   status = QueueThreadPlan(thread_plan_sp, abort_other_plans);
1312   return thread_plan_sp;
1313 }
1314 
1315 ThreadPlanSP Thread::QueueThreadPlanForStepOutNoShouldStop(
1316     bool abort_other_plans, SymbolContext *addr_context, bool first_insn,
1317     bool stop_other_threads, Vote report_stop_vote, Vote report_run_vote,
1318     uint32_t frame_idx, Status &status, bool continue_to_next_branch) {
1319   const bool calculate_return_value =
1320       false; // No need to calculate the return value here.
1321   ThreadPlanSP thread_plan_sp(new ThreadPlanStepOut(
1322       *this, addr_context, first_insn, stop_other_threads, report_stop_vote,
1323       report_run_vote, frame_idx, eLazyBoolNo, continue_to_next_branch,
1324       calculate_return_value));
1325 
1326   ThreadPlanStepOut *new_plan =
1327       static_cast<ThreadPlanStepOut *>(thread_plan_sp.get());
1328   new_plan->ClearShouldStopHereCallbacks();
1329 
1330   status = QueueThreadPlan(thread_plan_sp, abort_other_plans);
1331   return thread_plan_sp;
1332 }
1333 
1334 ThreadPlanSP Thread::QueueThreadPlanForStepThrough(StackID &return_stack_id,
1335                                                    bool abort_other_plans,
1336                                                    bool stop_other_threads,
1337                                                    Status &status) {
1338   ThreadPlanSP thread_plan_sp(
1339       new ThreadPlanStepThrough(*this, return_stack_id, stop_other_threads));
1340   if (!thread_plan_sp || !thread_plan_sp->ValidatePlan(nullptr))
1341     return ThreadPlanSP();
1342 
1343   status = QueueThreadPlan(thread_plan_sp, abort_other_plans);
1344   return thread_plan_sp;
1345 }
1346 
1347 ThreadPlanSP Thread::QueueThreadPlanForRunToAddress(bool abort_other_plans,
1348                                                     Address &target_addr,
1349                                                     bool stop_other_threads,
1350                                                     Status &status) {
1351   ThreadPlanSP thread_plan_sp(
1352       new ThreadPlanRunToAddress(*this, target_addr, stop_other_threads));
1353 
1354   status = QueueThreadPlan(thread_plan_sp, abort_other_plans);
1355   return thread_plan_sp;
1356 }
1357 
1358 ThreadPlanSP Thread::QueueThreadPlanForStepUntil(
1359     bool abort_other_plans, lldb::addr_t *address_list, size_t num_addresses,
1360     bool stop_other_threads, uint32_t frame_idx, Status &status) {
1361   ThreadPlanSP thread_plan_sp(new ThreadPlanStepUntil(
1362       *this, address_list, num_addresses, stop_other_threads, frame_idx));
1363 
1364   status = QueueThreadPlan(thread_plan_sp, abort_other_plans);
1365   return thread_plan_sp;
1366 }
1367 
1368 lldb::ThreadPlanSP Thread::QueueThreadPlanForStepScripted(
1369     bool abort_other_plans, const char *class_name,
1370     StructuredData::ObjectSP extra_args_sp, bool stop_other_threads,
1371     Status &status) {
1372 
1373   ThreadPlanSP thread_plan_sp(new ThreadPlanPython(
1374       *this, class_name, StructuredDataImpl(extra_args_sp)));
1375   thread_plan_sp->SetStopOthers(stop_other_threads);
1376   status = QueueThreadPlan(thread_plan_sp, abort_other_plans);
1377   return thread_plan_sp;
1378 }
1379 
1380 uint32_t Thread::GetIndexID() const { return m_index_id; }
1381 
1382 TargetSP Thread::CalculateTarget() {
1383   TargetSP target_sp;
1384   ProcessSP process_sp(GetProcess());
1385   if (process_sp)
1386     target_sp = process_sp->CalculateTarget();
1387   return target_sp;
1388 }
1389 
1390 ProcessSP Thread::CalculateProcess() { return GetProcess(); }
1391 
1392 ThreadSP Thread::CalculateThread() { return shared_from_this(); }
1393 
1394 StackFrameSP Thread::CalculateStackFrame() { return StackFrameSP(); }
1395 
1396 void Thread::CalculateExecutionContext(ExecutionContext &exe_ctx) {
1397   exe_ctx.SetContext(shared_from_this());
1398 }
1399 
1400 StackFrameListSP Thread::GetStackFrameList() {
1401   std::lock_guard<std::recursive_mutex> guard(m_frame_mutex);
1402 
1403   if (!m_curr_frames_sp)
1404     m_curr_frames_sp =
1405         std::make_shared<StackFrameList>(*this, m_prev_frames_sp, true);
1406 
1407   return m_curr_frames_sp;
1408 }
1409 
1410 void Thread::ClearStackFrames() {
1411   std::lock_guard<std::recursive_mutex> guard(m_frame_mutex);
1412 
1413   GetUnwinder().Clear();
1414 
1415   // Only store away the old "reference" StackFrameList if we got all its
1416   // frames:
1417   // FIXME: At some point we can try to splice in the frames we have fetched
1418   // into
1419   // the new frame as we make it, but let's not try that now.
1420   if (m_curr_frames_sp && m_curr_frames_sp->GetAllFramesFetched())
1421     m_prev_frames_sp.swap(m_curr_frames_sp);
1422   m_curr_frames_sp.reset();
1423 
1424   m_extended_info.reset();
1425   m_extended_info_fetched = false;
1426 }
1427 
1428 lldb::StackFrameSP Thread::GetFrameWithConcreteFrameIndex(uint32_t unwind_idx) {
1429   return GetStackFrameList()->GetFrameWithConcreteFrameIndex(unwind_idx);
1430 }
1431 
1432 Status Thread::ReturnFromFrameWithIndex(uint32_t frame_idx,
1433                                         lldb::ValueObjectSP return_value_sp,
1434                                         bool broadcast) {
1435   StackFrameSP frame_sp = GetStackFrameAtIndex(frame_idx);
1436   Status return_error;
1437 
1438   if (!frame_sp) {
1439     return_error.SetErrorStringWithFormat(
1440         "Could not find frame with index %d in thread 0x%" PRIx64 ".",
1441         frame_idx, GetID());
1442   }
1443 
1444   return ReturnFromFrame(frame_sp, return_value_sp, broadcast);
1445 }
1446 
1447 Status Thread::ReturnFromFrame(lldb::StackFrameSP frame_sp,
1448                                lldb::ValueObjectSP return_value_sp,
1449                                bool broadcast) {
1450   Status return_error;
1451 
1452   if (!frame_sp) {
1453     return_error.SetErrorString("Can't return to a null frame.");
1454     return return_error;
1455   }
1456 
1457   Thread *thread = frame_sp->GetThread().get();
1458   uint32_t older_frame_idx = frame_sp->GetFrameIndex() + 1;
1459   StackFrameSP older_frame_sp = thread->GetStackFrameAtIndex(older_frame_idx);
1460   if (!older_frame_sp) {
1461     return_error.SetErrorString("No older frame to return to.");
1462     return return_error;
1463   }
1464 
1465   if (return_value_sp) {
1466     lldb::ABISP abi = thread->GetProcess()->GetABI();
1467     if (!abi) {
1468       return_error.SetErrorString("Could not find ABI to set return value.");
1469       return return_error;
1470     }
1471     SymbolContext sc = frame_sp->GetSymbolContext(eSymbolContextFunction);
1472 
1473     // FIXME: ValueObject::Cast doesn't currently work correctly, at least not
1474     // for scalars.
1475     // Turn that back on when that works.
1476     if (/* DISABLES CODE */ (false) && sc.function != nullptr) {
1477       Type *function_type = sc.function->GetType();
1478       if (function_type) {
1479         CompilerType return_type =
1480             sc.function->GetCompilerType().GetFunctionReturnType();
1481         if (return_type) {
1482           StreamString s;
1483           return_type.DumpTypeDescription(&s);
1484           ValueObjectSP cast_value_sp = return_value_sp->Cast(return_type);
1485           if (cast_value_sp) {
1486             cast_value_sp->SetFormat(eFormatHex);
1487             return_value_sp = cast_value_sp;
1488           }
1489         }
1490       }
1491     }
1492 
1493     return_error = abi->SetReturnValueObject(older_frame_sp, return_value_sp);
1494     if (!return_error.Success())
1495       return return_error;
1496   }
1497 
1498   // Now write the return registers for the chosen frame: Note, we can't use
1499   // ReadAllRegisterValues->WriteAllRegisterValues, since the read & write cook
1500   // their data
1501 
1502   StackFrameSP youngest_frame_sp = thread->GetStackFrameAtIndex(0);
1503   if (youngest_frame_sp) {
1504     lldb::RegisterContextSP reg_ctx_sp(youngest_frame_sp->GetRegisterContext());
1505     if (reg_ctx_sp) {
1506       bool copy_success = reg_ctx_sp->CopyFromRegisterContext(
1507           older_frame_sp->GetRegisterContext());
1508       if (copy_success) {
1509         thread->DiscardThreadPlans(true);
1510         thread->ClearStackFrames();
1511         if (broadcast && EventTypeHasListeners(eBroadcastBitStackChanged))
1512           BroadcastEvent(eBroadcastBitStackChanged,
1513                          new ThreadEventData(this->shared_from_this()));
1514       } else {
1515         return_error.SetErrorString("Could not reset register values.");
1516       }
1517     } else {
1518       return_error.SetErrorString("Frame has no register context.");
1519     }
1520   } else {
1521     return_error.SetErrorString("Returned past top frame.");
1522   }
1523   return return_error;
1524 }
1525 
1526 static void DumpAddressList(Stream &s, const std::vector<Address> &list,
1527                             ExecutionContextScope *exe_scope) {
1528   for (size_t n = 0; n < list.size(); n++) {
1529     s << "\t";
1530     list[n].Dump(&s, exe_scope, Address::DumpStyleResolvedDescription,
1531                  Address::DumpStyleSectionNameOffset);
1532     s << "\n";
1533   }
1534 }
1535 
1536 Status Thread::JumpToLine(const FileSpec &file, uint32_t line,
1537                           bool can_leave_function, std::string *warnings) {
1538   ExecutionContext exe_ctx(GetStackFrameAtIndex(0));
1539   Target *target = exe_ctx.GetTargetPtr();
1540   TargetSP target_sp = exe_ctx.GetTargetSP();
1541   RegisterContext *reg_ctx = exe_ctx.GetRegisterContext();
1542   StackFrame *frame = exe_ctx.GetFramePtr();
1543   const SymbolContext &sc = frame->GetSymbolContext(eSymbolContextFunction);
1544 
1545   // Find candidate locations.
1546   std::vector<Address> candidates, within_function, outside_function;
1547   target->GetImages().FindAddressesForLine(target_sp, file, line, sc.function,
1548                                            within_function, outside_function);
1549 
1550   // If possible, we try and stay within the current function. Within a
1551   // function, we accept multiple locations (optimized code may do this,
1552   // there's no solution here so we do the best we can). However if we're
1553   // trying to leave the function, we don't know how to pick the right
1554   // location, so if there's more than one then we bail.
1555   if (!within_function.empty())
1556     candidates = within_function;
1557   else if (outside_function.size() == 1 && can_leave_function)
1558     candidates = outside_function;
1559 
1560   // Check if we got anything.
1561   if (candidates.empty()) {
1562     if (outside_function.empty()) {
1563       return Status("Cannot locate an address for %s:%i.",
1564                     file.GetFilename().AsCString(), line);
1565     } else if (outside_function.size() == 1) {
1566       return Status("%s:%i is outside the current function.",
1567                     file.GetFilename().AsCString(), line);
1568     } else {
1569       StreamString sstr;
1570       DumpAddressList(sstr, outside_function, target);
1571       return Status("%s:%i has multiple candidate locations:\n%s",
1572                     file.GetFilename().AsCString(), line, sstr.GetData());
1573     }
1574   }
1575 
1576   // Accept the first location, warn about any others.
1577   Address dest = candidates[0];
1578   if (warnings && candidates.size() > 1) {
1579     StreamString sstr;
1580     sstr.Printf("%s:%i appears multiple times in this function, selecting the "
1581                 "first location:\n",
1582                 file.GetFilename().AsCString(), line);
1583     DumpAddressList(sstr, candidates, target);
1584     *warnings = std::string(sstr.GetString());
1585   }
1586 
1587   if (!reg_ctx->SetPC(dest))
1588     return Status("Cannot change PC to target address.");
1589 
1590   return Status();
1591 }
1592 
1593 void Thread::DumpUsingSettingsFormat(Stream &strm, uint32_t frame_idx,
1594                                      bool stop_format) {
1595   ExecutionContext exe_ctx(shared_from_this());
1596   Process *process = exe_ctx.GetProcessPtr();
1597   if (process == nullptr)
1598     return;
1599 
1600   StackFrameSP frame_sp;
1601   SymbolContext frame_sc;
1602   if (frame_idx != LLDB_INVALID_FRAME_ID) {
1603     frame_sp = GetStackFrameAtIndex(frame_idx);
1604     if (frame_sp) {
1605       exe_ctx.SetFrameSP(frame_sp);
1606       frame_sc = frame_sp->GetSymbolContext(eSymbolContextEverything);
1607     }
1608   }
1609 
1610   const FormatEntity::Entry *thread_format;
1611   if (stop_format)
1612     thread_format = exe_ctx.GetTargetRef().GetDebugger().GetThreadStopFormat();
1613   else
1614     thread_format = exe_ctx.GetTargetRef().GetDebugger().GetThreadFormat();
1615 
1616   assert(thread_format);
1617 
1618   FormatEntity::Format(*thread_format, strm, frame_sp ? &frame_sc : nullptr,
1619                        &exe_ctx, nullptr, nullptr, false, false);
1620 }
1621 
1622 void Thread::SettingsInitialize() {}
1623 
1624 void Thread::SettingsTerminate() {}
1625 
1626 lldb::addr_t Thread::GetThreadPointer() { return LLDB_INVALID_ADDRESS; }
1627 
1628 addr_t Thread::GetThreadLocalData(const ModuleSP module,
1629                                   lldb::addr_t tls_file_addr) {
1630   // The default implementation is to ask the dynamic loader for it. This can
1631   // be overridden for specific platforms.
1632   DynamicLoader *loader = GetProcess()->GetDynamicLoader();
1633   if (loader)
1634     return loader->GetThreadLocalData(module, shared_from_this(),
1635                                       tls_file_addr);
1636   else
1637     return LLDB_INVALID_ADDRESS;
1638 }
1639 
1640 bool Thread::SafeToCallFunctions() {
1641   Process *process = GetProcess().get();
1642   if (process) {
1643     DynamicLoader *loader = GetProcess()->GetDynamicLoader();
1644     if (loader && loader->IsFullyInitialized() == false)
1645       return false;
1646 
1647     SystemRuntime *runtime = process->GetSystemRuntime();
1648     if (runtime) {
1649       return runtime->SafeToCallFunctionsOnThisThread(shared_from_this());
1650     }
1651   }
1652   return true;
1653 }
1654 
1655 lldb::StackFrameSP
1656 Thread::GetStackFrameSPForStackFramePtr(StackFrame *stack_frame_ptr) {
1657   return GetStackFrameList()->GetStackFrameSPForStackFramePtr(stack_frame_ptr);
1658 }
1659 
1660 std::string Thread::StopReasonAsString(lldb::StopReason reason) {
1661   switch (reason) {
1662   case eStopReasonInvalid:
1663     return "invalid";
1664   case eStopReasonNone:
1665     return "none";
1666   case eStopReasonTrace:
1667     return "trace";
1668   case eStopReasonBreakpoint:
1669     return "breakpoint";
1670   case eStopReasonWatchpoint:
1671     return "watchpoint";
1672   case eStopReasonSignal:
1673     return "signal";
1674   case eStopReasonException:
1675     return "exception";
1676   case eStopReasonExec:
1677     return "exec";
1678   case eStopReasonFork:
1679     return "fork";
1680   case eStopReasonVFork:
1681     return "vfork";
1682   case eStopReasonVForkDone:
1683     return "vfork done";
1684   case eStopReasonPlanComplete:
1685     return "plan complete";
1686   case eStopReasonThreadExiting:
1687     return "thread exiting";
1688   case eStopReasonInstrumentation:
1689     return "instrumentation break";
1690   case eStopReasonProcessorTrace:
1691     return "processor trace";
1692   }
1693 
1694   return "StopReason = " + std::to_string(reason);
1695 }
1696 
1697 std::string Thread::RunModeAsString(lldb::RunMode mode) {
1698   switch (mode) {
1699   case eOnlyThisThread:
1700     return "only this thread";
1701   case eAllThreads:
1702     return "all threads";
1703   case eOnlyDuringStepping:
1704     return "only during stepping";
1705   }
1706 
1707   return "RunMode = " + std::to_string(mode);
1708 }
1709 
1710 size_t Thread::GetStatus(Stream &strm, uint32_t start_frame,
1711                          uint32_t num_frames, uint32_t num_frames_with_source,
1712                          bool stop_format, bool only_stacks) {
1713 
1714   if (!only_stacks) {
1715     ExecutionContext exe_ctx(shared_from_this());
1716     Target *target = exe_ctx.GetTargetPtr();
1717     Process *process = exe_ctx.GetProcessPtr();
1718     strm.Indent();
1719     bool is_selected = false;
1720     if (process) {
1721       if (process->GetThreadList().GetSelectedThread().get() == this)
1722         is_selected = true;
1723     }
1724     strm.Printf("%c ", is_selected ? '*' : ' ');
1725     if (target && target->GetDebugger().GetUseExternalEditor()) {
1726       StackFrameSP frame_sp = GetStackFrameAtIndex(start_frame);
1727       if (frame_sp) {
1728         SymbolContext frame_sc(
1729             frame_sp->GetSymbolContext(eSymbolContextLineEntry));
1730         if (frame_sc.line_entry.line != 0 && frame_sc.line_entry.file) {
1731           if (llvm::Error e = Host::OpenFileInExternalEditor(
1732                   target->GetDebugger().GetExternalEditor(),
1733                   frame_sc.line_entry.file, frame_sc.line_entry.line)) {
1734             LLDB_LOG_ERROR(GetLog(LLDBLog::Host), std::move(e),
1735                            "OpenFileInExternalEditor failed: {0}");
1736           }
1737         }
1738       }
1739     }
1740 
1741     DumpUsingSettingsFormat(strm, start_frame, stop_format);
1742   }
1743 
1744   size_t num_frames_shown = 0;
1745   if (num_frames > 0) {
1746     strm.IndentMore();
1747 
1748     const bool show_frame_info = true;
1749     const bool show_frame_unique = only_stacks;
1750     const char *selected_frame_marker = nullptr;
1751     if (num_frames == 1 || only_stacks ||
1752         (GetID() != GetProcess()->GetThreadList().GetSelectedThread()->GetID()))
1753       strm.IndentMore();
1754     else
1755       selected_frame_marker = "* ";
1756 
1757     num_frames_shown = GetStackFrameList()->GetStatus(
1758         strm, start_frame, num_frames, show_frame_info, num_frames_with_source,
1759         show_frame_unique, selected_frame_marker);
1760     if (num_frames == 1)
1761       strm.IndentLess();
1762     strm.IndentLess();
1763   }
1764   return num_frames_shown;
1765 }
1766 
1767 bool Thread::GetDescription(Stream &strm, lldb::DescriptionLevel level,
1768                             bool print_json_thread, bool print_json_stopinfo) {
1769   const bool stop_format = false;
1770   DumpUsingSettingsFormat(strm, 0, stop_format);
1771   strm.Printf("\n");
1772 
1773   StructuredData::ObjectSP thread_info = GetExtendedInfo();
1774 
1775   if (print_json_thread || print_json_stopinfo) {
1776     if (thread_info && print_json_thread) {
1777       thread_info->Dump(strm);
1778       strm.Printf("\n");
1779     }
1780 
1781     if (print_json_stopinfo && m_stop_info_sp) {
1782       StructuredData::ObjectSP stop_info = m_stop_info_sp->GetExtendedInfo();
1783       if (stop_info) {
1784         stop_info->Dump(strm);
1785         strm.Printf("\n");
1786       }
1787     }
1788 
1789     return true;
1790   }
1791 
1792   if (thread_info) {
1793     StructuredData::ObjectSP activity =
1794         thread_info->GetObjectForDotSeparatedPath("activity");
1795     StructuredData::ObjectSP breadcrumb =
1796         thread_info->GetObjectForDotSeparatedPath("breadcrumb");
1797     StructuredData::ObjectSP messages =
1798         thread_info->GetObjectForDotSeparatedPath("trace_messages");
1799 
1800     bool printed_activity = false;
1801     if (activity && activity->GetType() == eStructuredDataTypeDictionary) {
1802       StructuredData::Dictionary *activity_dict = activity->GetAsDictionary();
1803       StructuredData::ObjectSP id = activity_dict->GetValueForKey("id");
1804       StructuredData::ObjectSP name = activity_dict->GetValueForKey("name");
1805       if (name && name->GetType() == eStructuredDataTypeString && id &&
1806           id->GetType() == eStructuredDataTypeInteger) {
1807         strm.Format("  Activity '{0}', {1:x}\n",
1808                     name->GetAsString()->GetValue(),
1809                     id->GetUnsignedIntegerValue());
1810       }
1811       printed_activity = true;
1812     }
1813     bool printed_breadcrumb = false;
1814     if (breadcrumb && breadcrumb->GetType() == eStructuredDataTypeDictionary) {
1815       if (printed_activity)
1816         strm.Printf("\n");
1817       StructuredData::Dictionary *breadcrumb_dict =
1818           breadcrumb->GetAsDictionary();
1819       StructuredData::ObjectSP breadcrumb_text =
1820           breadcrumb_dict->GetValueForKey("name");
1821       if (breadcrumb_text &&
1822           breadcrumb_text->GetType() == eStructuredDataTypeString) {
1823         strm.Format("  Current Breadcrumb: {0}\n",
1824                     breadcrumb_text->GetAsString()->GetValue());
1825       }
1826       printed_breadcrumb = true;
1827     }
1828     if (messages && messages->GetType() == eStructuredDataTypeArray) {
1829       if (printed_breadcrumb)
1830         strm.Printf("\n");
1831       StructuredData::Array *messages_array = messages->GetAsArray();
1832       const size_t msg_count = messages_array->GetSize();
1833       if (msg_count > 0) {
1834         strm.Printf("  %zu trace messages:\n", msg_count);
1835         for (size_t i = 0; i < msg_count; i++) {
1836           StructuredData::ObjectSP message = messages_array->GetItemAtIndex(i);
1837           if (message && message->GetType() == eStructuredDataTypeDictionary) {
1838             StructuredData::Dictionary *message_dict =
1839                 message->GetAsDictionary();
1840             StructuredData::ObjectSP message_text =
1841                 message_dict->GetValueForKey("message");
1842             if (message_text &&
1843                 message_text->GetType() == eStructuredDataTypeString) {
1844               strm.Format("    {0}\n", message_text->GetAsString()->GetValue());
1845             }
1846           }
1847         }
1848       }
1849     }
1850   }
1851 
1852   return true;
1853 }
1854 
1855 size_t Thread::GetStackFrameStatus(Stream &strm, uint32_t first_frame,
1856                                    uint32_t num_frames, bool show_frame_info,
1857                                    uint32_t num_frames_with_source) {
1858   return GetStackFrameList()->GetStatus(
1859       strm, first_frame, num_frames, show_frame_info, num_frames_with_source);
1860 }
1861 
1862 Unwind &Thread::GetUnwinder() {
1863   if (!m_unwinder_up)
1864     m_unwinder_up = std::make_unique<UnwindLLDB>(*this);
1865   return *m_unwinder_up;
1866 }
1867 
1868 void Thread::Flush() {
1869   ClearStackFrames();
1870   m_reg_context_sp.reset();
1871 }
1872 
1873 bool Thread::IsStillAtLastBreakpointHit() {
1874   // If we are currently stopped at a breakpoint, always return that stopinfo
1875   // and don't reset it. This allows threads to maintain their breakpoint
1876   // stopinfo, such as when thread-stepping in multithreaded programs.
1877   if (m_stop_info_sp) {
1878     StopReason stop_reason = m_stop_info_sp->GetStopReason();
1879     if (stop_reason == lldb::eStopReasonBreakpoint) {
1880       uint64_t value = m_stop_info_sp->GetValue();
1881       lldb::RegisterContextSP reg_ctx_sp(GetRegisterContext());
1882       if (reg_ctx_sp) {
1883         lldb::addr_t pc = reg_ctx_sp->GetPC();
1884         BreakpointSiteSP bp_site_sp =
1885             GetProcess()->GetBreakpointSiteList().FindByAddress(pc);
1886         if (bp_site_sp && static_cast<break_id_t>(value) == bp_site_sp->GetID())
1887           return true;
1888       }
1889     }
1890   }
1891   return false;
1892 }
1893 
1894 Status Thread::StepIn(bool source_step,
1895                       LazyBool step_in_avoids_code_without_debug_info,
1896                       LazyBool step_out_avoids_code_without_debug_info)
1897 
1898 {
1899   Status error;
1900   Process *process = GetProcess().get();
1901   if (StateIsStoppedState(process->GetState(), true)) {
1902     StackFrameSP frame_sp = GetStackFrameAtIndex(0);
1903     ThreadPlanSP new_plan_sp;
1904     const lldb::RunMode run_mode = eOnlyThisThread;
1905     const bool abort_other_plans = false;
1906 
1907     if (source_step && frame_sp && frame_sp->HasDebugInformation()) {
1908       SymbolContext sc(frame_sp->GetSymbolContext(eSymbolContextEverything));
1909       new_plan_sp = QueueThreadPlanForStepInRange(
1910           abort_other_plans, sc.line_entry, sc, nullptr, run_mode, error,
1911           step_in_avoids_code_without_debug_info,
1912           step_out_avoids_code_without_debug_info);
1913     } else {
1914       new_plan_sp = QueueThreadPlanForStepSingleInstruction(
1915           false, abort_other_plans, run_mode, error);
1916     }
1917 
1918     new_plan_sp->SetIsControllingPlan(true);
1919     new_plan_sp->SetOkayToDiscard(false);
1920 
1921     // Why do we need to set the current thread by ID here???
1922     process->GetThreadList().SetSelectedThreadByID(GetID());
1923     error = process->Resume();
1924   } else {
1925     error.SetErrorString("process not stopped");
1926   }
1927   return error;
1928 }
1929 
1930 Status Thread::StepOver(bool source_step,
1931                         LazyBool step_out_avoids_code_without_debug_info) {
1932   Status error;
1933   Process *process = GetProcess().get();
1934   if (StateIsStoppedState(process->GetState(), true)) {
1935     StackFrameSP frame_sp = GetStackFrameAtIndex(0);
1936     ThreadPlanSP new_plan_sp;
1937 
1938     const lldb::RunMode run_mode = eOnlyThisThread;
1939     const bool abort_other_plans = false;
1940 
1941     if (source_step && frame_sp && frame_sp->HasDebugInformation()) {
1942       SymbolContext sc(frame_sp->GetSymbolContext(eSymbolContextEverything));
1943       new_plan_sp = QueueThreadPlanForStepOverRange(
1944           abort_other_plans, sc.line_entry, sc, run_mode, error,
1945           step_out_avoids_code_without_debug_info);
1946     } else {
1947       new_plan_sp = QueueThreadPlanForStepSingleInstruction(
1948           true, abort_other_plans, run_mode, error);
1949     }
1950 
1951     new_plan_sp->SetIsControllingPlan(true);
1952     new_plan_sp->SetOkayToDiscard(false);
1953 
1954     // Why do we need to set the current thread by ID here???
1955     process->GetThreadList().SetSelectedThreadByID(GetID());
1956     error = process->Resume();
1957   } else {
1958     error.SetErrorString("process not stopped");
1959   }
1960   return error;
1961 }
1962 
1963 Status Thread::StepOut(uint32_t frame_idx) {
1964   Status error;
1965   Process *process = GetProcess().get();
1966   if (StateIsStoppedState(process->GetState(), true)) {
1967     const bool first_instruction = false;
1968     const bool stop_other_threads = false;
1969     const bool abort_other_plans = false;
1970 
1971     ThreadPlanSP new_plan_sp(QueueThreadPlanForStepOut(
1972         abort_other_plans, nullptr, first_instruction, stop_other_threads,
1973         eVoteYes, eVoteNoOpinion, frame_idx, error));
1974 
1975     new_plan_sp->SetIsControllingPlan(true);
1976     new_plan_sp->SetOkayToDiscard(false);
1977 
1978     // Why do we need to set the current thread by ID here???
1979     process->GetThreadList().SetSelectedThreadByID(GetID());
1980     error = process->Resume();
1981   } else {
1982     error.SetErrorString("process not stopped");
1983   }
1984   return error;
1985 }
1986 
1987 ValueObjectSP Thread::GetCurrentException() {
1988   if (auto frame_sp = GetStackFrameAtIndex(0))
1989     if (auto recognized_frame = frame_sp->GetRecognizedFrame())
1990       if (auto e = recognized_frame->GetExceptionObject())
1991         return e;
1992 
1993   // NOTE: Even though this behavior is generalized, only ObjC is actually
1994   // supported at the moment.
1995   for (LanguageRuntime *runtime : GetProcess()->GetLanguageRuntimes()) {
1996     if (auto e = runtime->GetExceptionObjectForThread(shared_from_this()))
1997       return e;
1998   }
1999 
2000   return ValueObjectSP();
2001 }
2002 
2003 ThreadSP Thread::GetCurrentExceptionBacktrace() {
2004   ValueObjectSP exception = GetCurrentException();
2005   if (!exception)
2006     return ThreadSP();
2007 
2008   // NOTE: Even though this behavior is generalized, only ObjC is actually
2009   // supported at the moment.
2010   for (LanguageRuntime *runtime : GetProcess()->GetLanguageRuntimes()) {
2011     if (auto bt = runtime->GetBacktraceThreadFromException(exception))
2012       return bt;
2013   }
2014 
2015   return ThreadSP();
2016 }
2017 
2018 lldb::ValueObjectSP Thread::GetSiginfoValue() {
2019   ProcessSP process_sp = GetProcess();
2020   assert(process_sp);
2021   Target &target = process_sp->GetTarget();
2022   PlatformSP platform_sp = target.GetPlatform();
2023   assert(platform_sp);
2024   ArchSpec arch = target.GetArchitecture();
2025 
2026   CompilerType type = platform_sp->GetSiginfoType(arch.GetTriple());
2027   if (!type.IsValid())
2028     return ValueObjectConstResult::Create(&target, Status("no siginfo_t for the platform"));
2029 
2030   std::optional<uint64_t> type_size = type.GetByteSize(nullptr);
2031   assert(type_size);
2032   llvm::Expected<std::unique_ptr<llvm::MemoryBuffer>> data =
2033       GetSiginfo(*type_size);
2034   if (!data)
2035     return ValueObjectConstResult::Create(&target, Status(data.takeError()));
2036 
2037   DataExtractor data_extractor{data.get()->getBufferStart(), data.get()->getBufferSize(),
2038     process_sp->GetByteOrder(), arch.GetAddressByteSize()};
2039   return ValueObjectConstResult::Create(&target, type, ConstString("__lldb_siginfo"), data_extractor);
2040 }
2041