xref: /freebsd-src/contrib/llvm-project/lldb/source/Target/Thread.cpp (revision 1db9f3b21e39176dd5b67cf8ac378633b172463e)
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(llvm::StringRef 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 = std::make_shared<ThreadOptionValueProperties>("thread");
104     m_collection_sp->Initialize(g_thread_properties);
105   } else
106     m_collection_sp =
107         OptionValueProperties::CreateLocalCopy(Thread::GetGlobalProperties());
108 }
109 
110 ThreadProperties::~ThreadProperties() = default;
111 
112 const RegularExpression *ThreadProperties::GetSymbolsToAvoidRegexp() {
113   const uint32_t idx = ePropertyStepAvoidRegex;
114   return GetPropertyAtIndexAs<const RegularExpression *>(idx);
115 }
116 
117 FileSpecList ThreadProperties::GetLibrariesToAvoid() const {
118   const uint32_t idx = ePropertyStepAvoidLibraries;
119   return GetPropertyAtIndexAs<FileSpecList>(idx, {});
120 }
121 
122 bool ThreadProperties::GetTraceEnabledState() const {
123   const uint32_t idx = ePropertyEnableThreadTrace;
124   return GetPropertyAtIndexAs<bool>(
125       idx, g_thread_properties[idx].default_uint_value != 0);
126 }
127 
128 bool ThreadProperties::GetStepInAvoidsNoDebug() const {
129   const uint32_t idx = ePropertyStepInAvoidsNoDebug;
130   return GetPropertyAtIndexAs<bool>(
131       idx, g_thread_properties[idx].default_uint_value != 0);
132 }
133 
134 bool ThreadProperties::GetStepOutAvoidsNoDebug() const {
135   const uint32_t idx = ePropertyStepOutAvoidsNoDebug;
136   return GetPropertyAtIndexAs<bool>(
137       idx, g_thread_properties[idx].default_uint_value != 0);
138 }
139 
140 uint64_t ThreadProperties::GetMaxBacktraceDepth() const {
141   const uint32_t idx = ePropertyMaxBacktraceDepth;
142   return GetPropertyAtIndexAs<uint64_t>(
143       idx, g_thread_properties[idx].default_uint_value);
144 }
145 
146 // Thread Event Data
147 
148 llvm::StringRef Thread::ThreadEventData::GetFlavorString() {
149   return "Thread::ThreadEventData";
150 }
151 
152 Thread::ThreadEventData::ThreadEventData(const lldb::ThreadSP thread_sp)
153     : m_thread_sp(thread_sp), m_stack_id() {}
154 
155 Thread::ThreadEventData::ThreadEventData(const lldb::ThreadSP thread_sp,
156                                          const StackID &stack_id)
157     : m_thread_sp(thread_sp), m_stack_id(stack_id) {}
158 
159 Thread::ThreadEventData::ThreadEventData() : m_thread_sp(), m_stack_id() {}
160 
161 Thread::ThreadEventData::~ThreadEventData() = default;
162 
163 void Thread::ThreadEventData::Dump(Stream *s) const {}
164 
165 const Thread::ThreadEventData *
166 Thread::ThreadEventData::GetEventDataFromEvent(const Event *event_ptr) {
167   if (event_ptr) {
168     const EventData *event_data = event_ptr->GetData();
169     if (event_data &&
170         event_data->GetFlavor() == ThreadEventData::GetFlavorString())
171       return static_cast<const ThreadEventData *>(event_ptr->GetData());
172   }
173   return nullptr;
174 }
175 
176 ThreadSP Thread::ThreadEventData::GetThreadFromEvent(const Event *event_ptr) {
177   ThreadSP thread_sp;
178   const ThreadEventData *event_data = GetEventDataFromEvent(event_ptr);
179   if (event_data)
180     thread_sp = event_data->GetThread();
181   return thread_sp;
182 }
183 
184 StackID Thread::ThreadEventData::GetStackIDFromEvent(const Event *event_ptr) {
185   StackID stack_id;
186   const ThreadEventData *event_data = GetEventDataFromEvent(event_ptr);
187   if (event_data)
188     stack_id = event_data->GetStackID();
189   return stack_id;
190 }
191 
192 StackFrameSP
193 Thread::ThreadEventData::GetStackFrameFromEvent(const Event *event_ptr) {
194   const ThreadEventData *event_data = GetEventDataFromEvent(event_ptr);
195   StackFrameSP frame_sp;
196   if (event_data) {
197     ThreadSP thread_sp = event_data->GetThread();
198     if (thread_sp) {
199       frame_sp = thread_sp->GetStackFrameList()->GetFrameWithStackID(
200           event_data->GetStackID());
201     }
202   }
203   return frame_sp;
204 }
205 
206 // Thread class
207 
208 ConstString &Thread::GetStaticBroadcasterClass() {
209   static ConstString class_name("lldb.thread");
210   return class_name;
211 }
212 
213 Thread::Thread(Process &process, lldb::tid_t tid, bool use_invalid_index_id)
214     : ThreadProperties(false), UserID(tid),
215       Broadcaster(process.GetTarget().GetDebugger().GetBroadcasterManager(),
216                   Thread::GetStaticBroadcasterClass().AsCString()),
217       m_process_wp(process.shared_from_this()), m_stop_info_sp(),
218       m_stop_info_stop_id(0), m_stop_info_override_stop_id(0),
219       m_should_run_before_public_stop(false),
220       m_index_id(use_invalid_index_id ? LLDB_INVALID_INDEX32
221                                       : process.GetNextThreadIndexID(tid)),
222       m_reg_context_sp(), m_state(eStateUnloaded), m_state_mutex(),
223       m_frame_mutex(), m_curr_frames_sp(), m_prev_frames_sp(),
224       m_resume_signal(LLDB_INVALID_SIGNAL_NUMBER),
225       m_resume_state(eStateRunning), m_temporary_resume_state(eStateRunning),
226       m_unwinder_up(), m_destroy_called(false),
227       m_override_should_notify(eLazyBoolCalculate),
228       m_extended_info_fetched(false), m_extended_info() {
229   Log *log = GetLog(LLDBLog::Object);
230   LLDB_LOGF(log, "%p Thread::Thread(tid = 0x%4.4" PRIx64 ")",
231             static_cast<void *>(this), GetID());
232 
233   CheckInWithManager();
234 }
235 
236 Thread::~Thread() {
237   Log *log = GetLog(LLDBLog::Object);
238   LLDB_LOGF(log, "%p Thread::~Thread(tid = 0x%4.4" PRIx64 ")",
239             static_cast<void *>(this), GetID());
240   /// If you hit this assert, it means your derived class forgot to call
241   /// DoDestroy in its destructor.
242   assert(m_destroy_called);
243 }
244 
245 void Thread::DestroyThread() {
246   m_destroy_called = true;
247   m_stop_info_sp.reset();
248   m_reg_context_sp.reset();
249   m_unwinder_up.reset();
250   std::lock_guard<std::recursive_mutex> guard(m_frame_mutex);
251   m_curr_frames_sp.reset();
252   m_prev_frames_sp.reset();
253 }
254 
255 void Thread::BroadcastSelectedFrameChange(StackID &new_frame_id) {
256   if (EventTypeHasListeners(eBroadcastBitSelectedFrameChanged))
257     BroadcastEvent(eBroadcastBitSelectedFrameChanged,
258                    new ThreadEventData(this->shared_from_this(), new_frame_id));
259 }
260 
261 lldb::StackFrameSP
262 Thread::GetSelectedFrame(SelectMostRelevant select_most_relevant) {
263   StackFrameListSP stack_frame_list_sp(GetStackFrameList());
264   StackFrameSP frame_sp = stack_frame_list_sp->GetFrameAtIndex(
265       stack_frame_list_sp->GetSelectedFrameIndex(select_most_relevant));
266   FrameSelectedCallback(frame_sp.get());
267   return frame_sp;
268 }
269 
270 uint32_t Thread::SetSelectedFrame(lldb_private::StackFrame *frame,
271                                   bool broadcast) {
272   uint32_t ret_value = GetStackFrameList()->SetSelectedFrame(frame);
273   if (broadcast)
274     BroadcastSelectedFrameChange(frame->GetStackID());
275   FrameSelectedCallback(frame);
276   return ret_value;
277 }
278 
279 bool Thread::SetSelectedFrameByIndex(uint32_t frame_idx, bool broadcast) {
280   StackFrameSP frame_sp(GetStackFrameList()->GetFrameAtIndex(frame_idx));
281   if (frame_sp) {
282     GetStackFrameList()->SetSelectedFrame(frame_sp.get());
283     if (broadcast)
284       BroadcastSelectedFrameChange(frame_sp->GetStackID());
285     FrameSelectedCallback(frame_sp.get());
286     return true;
287   } else
288     return false;
289 }
290 
291 bool Thread::SetSelectedFrameByIndexNoisily(uint32_t frame_idx,
292                                             Stream &output_stream) {
293   const bool broadcast = true;
294   bool success = SetSelectedFrameByIndex(frame_idx, broadcast);
295   if (success) {
296     StackFrameSP frame_sp = GetSelectedFrame(DoNoSelectMostRelevantFrame);
297     if (frame_sp) {
298       bool already_shown = false;
299       SymbolContext frame_sc(
300           frame_sp->GetSymbolContext(eSymbolContextLineEntry));
301       const Debugger &debugger = GetProcess()->GetTarget().GetDebugger();
302       if (debugger.GetUseExternalEditor() && frame_sc.line_entry.file &&
303           frame_sc.line_entry.line != 0) {
304         if (llvm::Error e = Host::OpenFileInExternalEditor(
305                 debugger.GetExternalEditor(), frame_sc.line_entry.file,
306                 frame_sc.line_entry.line)) {
307           LLDB_LOG_ERROR(GetLog(LLDBLog::Host), std::move(e),
308                          "OpenFileInExternalEditor failed: {0}");
309         } else {
310           already_shown = true;
311         }
312       }
313 
314       bool show_frame_info = true;
315       bool show_source = !already_shown;
316       FrameSelectedCallback(frame_sp.get());
317       return frame_sp->GetStatus(output_stream, show_frame_info, show_source);
318     }
319     return false;
320   } else
321     return false;
322 }
323 
324 void Thread::FrameSelectedCallback(StackFrame *frame) {
325   if (!frame)
326     return;
327 
328   if (frame->HasDebugInformation() &&
329       (GetProcess()->GetWarningsOptimization() ||
330        GetProcess()->GetWarningsUnsupportedLanguage())) {
331     SymbolContext sc =
332         frame->GetSymbolContext(eSymbolContextFunction | eSymbolContextModule);
333     GetProcess()->PrintWarningOptimization(sc);
334     GetProcess()->PrintWarningUnsupportedLanguage(sc);
335   }
336 }
337 
338 lldb::StopInfoSP Thread::GetStopInfo() {
339   if (m_destroy_called)
340     return m_stop_info_sp;
341 
342   ThreadPlanSP completed_plan_sp(GetCompletedPlan());
343   ProcessSP process_sp(GetProcess());
344   const uint32_t stop_id = process_sp ? process_sp->GetStopID() : UINT32_MAX;
345 
346   // Here we select the stop info according to priorirty: - m_stop_info_sp (if
347   // not trace) - preset value - completed plan stop info - new value with plan
348   // from completed plan stack - m_stop_info_sp (trace stop reason is OK now) -
349   // ask GetPrivateStopInfo to set stop info
350 
351   bool have_valid_stop_info = m_stop_info_sp &&
352       m_stop_info_sp ->IsValid() &&
353       m_stop_info_stop_id == stop_id;
354   bool have_valid_completed_plan = completed_plan_sp && completed_plan_sp->PlanSucceeded();
355   bool plan_failed = completed_plan_sp && !completed_plan_sp->PlanSucceeded();
356   bool plan_overrides_trace =
357     have_valid_stop_info && have_valid_completed_plan
358     && (m_stop_info_sp->GetStopReason() == eStopReasonTrace);
359 
360   if (have_valid_stop_info && !plan_overrides_trace && !plan_failed) {
361     return m_stop_info_sp;
362   } else if (completed_plan_sp) {
363     return StopInfo::CreateStopReasonWithPlan(
364         completed_plan_sp, GetReturnValueObject(), GetExpressionVariable());
365   } else {
366     GetPrivateStopInfo();
367     return m_stop_info_sp;
368   }
369 }
370 
371 void Thread::CalculatePublicStopInfo() {
372   ResetStopInfo();
373   SetStopInfo(GetStopInfo());
374 }
375 
376 lldb::StopInfoSP Thread::GetPrivateStopInfo(bool calculate) {
377   if (!calculate)
378     return m_stop_info_sp;
379 
380   if (m_destroy_called)
381     return m_stop_info_sp;
382 
383   ProcessSP process_sp(GetProcess());
384   if (process_sp) {
385     const uint32_t process_stop_id = process_sp->GetStopID();
386     if (m_stop_info_stop_id != process_stop_id) {
387       // We preserve the old stop info for a variety of reasons:
388       // 1) Someone has already updated it by the time we get here
389       // 2) We didn't get to execute the breakpoint instruction we stopped at
390       // 3) This is a virtual step so we didn't actually run
391       // 4) If this thread wasn't allowed to run the last time round.
392       if (m_stop_info_sp) {
393         if (m_stop_info_sp->IsValid() || IsStillAtLastBreakpointHit() ||
394             GetCurrentPlan()->IsVirtualStep()
395             || GetTemporaryResumeState() == eStateSuspended)
396           SetStopInfo(m_stop_info_sp);
397         else
398           m_stop_info_sp.reset();
399       }
400 
401       if (!m_stop_info_sp) {
402         if (!CalculateStopInfo())
403           SetStopInfo(StopInfoSP());
404       }
405     }
406 
407     // The stop info can be manually set by calling Thread::SetStopInfo() prior
408     // to this function ever getting called, so we can't rely on
409     // "m_stop_info_stop_id != process_stop_id" as the condition for the if
410     // statement below, we must also check the stop info to see if we need to
411     // override it. See the header documentation in
412     // Architecture::OverrideStopInfo() for more information on the stop
413     // info override callback.
414     if (m_stop_info_override_stop_id != process_stop_id) {
415       m_stop_info_override_stop_id = process_stop_id;
416       if (m_stop_info_sp) {
417         if (const Architecture *arch =
418                 process_sp->GetTarget().GetArchitecturePlugin())
419           arch->OverrideStopInfo(*this);
420       }
421     }
422   }
423   return m_stop_info_sp;
424 }
425 
426 lldb::StopReason Thread::GetStopReason() {
427   lldb::StopInfoSP stop_info_sp(GetStopInfo());
428   if (stop_info_sp)
429     return stop_info_sp->GetStopReason();
430   return eStopReasonNone;
431 }
432 
433 bool Thread::StopInfoIsUpToDate() const {
434   ProcessSP process_sp(GetProcess());
435   if (process_sp)
436     return m_stop_info_stop_id == process_sp->GetStopID();
437   else
438     return true; // Process is no longer around so stop info is always up to
439                  // date...
440 }
441 
442 void Thread::ResetStopInfo() {
443   if (m_stop_info_sp) {
444     m_stop_info_sp.reset();
445   }
446 }
447 
448 void Thread::SetStopInfo(const lldb::StopInfoSP &stop_info_sp) {
449   m_stop_info_sp = stop_info_sp;
450   if (m_stop_info_sp) {
451     m_stop_info_sp->MakeStopInfoValid();
452     // If we are overriding the ShouldReportStop, do that here:
453     if (m_override_should_notify != eLazyBoolCalculate)
454       m_stop_info_sp->OverrideShouldNotify(m_override_should_notify ==
455                                            eLazyBoolYes);
456   }
457 
458   ProcessSP process_sp(GetProcess());
459   if (process_sp)
460     m_stop_info_stop_id = process_sp->GetStopID();
461   else
462     m_stop_info_stop_id = UINT32_MAX;
463   Log *log = GetLog(LLDBLog::Thread);
464   LLDB_LOGF(log, "%p: tid = 0x%" PRIx64 ": stop info = %s (stop_id = %u)",
465             static_cast<void *>(this), GetID(),
466             stop_info_sp ? stop_info_sp->GetDescription() : "<NULL>",
467             m_stop_info_stop_id);
468 }
469 
470 void Thread::SetShouldReportStop(Vote vote) {
471   if (vote == eVoteNoOpinion)
472     return;
473   else {
474     m_override_should_notify = (vote == eVoteYes ? eLazyBoolYes : eLazyBoolNo);
475     if (m_stop_info_sp)
476       m_stop_info_sp->OverrideShouldNotify(m_override_should_notify ==
477                                            eLazyBoolYes);
478   }
479 }
480 
481 void Thread::SetStopInfoToNothing() {
482   // Note, we can't just NULL out the private reason, or the native thread
483   // implementation will try to go calculate it again.  For now, just set it to
484   // a Unix Signal with an invalid signal number.
485   SetStopInfo(
486       StopInfo::CreateStopReasonWithSignal(*this, LLDB_INVALID_SIGNAL_NUMBER));
487 }
488 
489 bool Thread::ThreadStoppedForAReason() { return (bool)GetPrivateStopInfo(); }
490 
491 bool Thread::CheckpointThreadState(ThreadStateCheckpoint &saved_state) {
492   saved_state.register_backup_sp.reset();
493   lldb::StackFrameSP frame_sp(GetStackFrameAtIndex(0));
494   if (frame_sp) {
495     lldb::RegisterCheckpointSP reg_checkpoint_sp(
496         new RegisterCheckpoint(RegisterCheckpoint::Reason::eExpression));
497     if (reg_checkpoint_sp) {
498       lldb::RegisterContextSP reg_ctx_sp(frame_sp->GetRegisterContext());
499       if (reg_ctx_sp && reg_ctx_sp->ReadAllRegisterValues(*reg_checkpoint_sp))
500         saved_state.register_backup_sp = reg_checkpoint_sp;
501     }
502   }
503   if (!saved_state.register_backup_sp)
504     return false;
505 
506   saved_state.stop_info_sp = GetStopInfo();
507   ProcessSP process_sp(GetProcess());
508   if (process_sp)
509     saved_state.orig_stop_id = process_sp->GetStopID();
510   saved_state.current_inlined_depth = GetCurrentInlinedDepth();
511   saved_state.m_completed_plan_checkpoint =
512       GetPlans().CheckpointCompletedPlans();
513 
514   return true;
515 }
516 
517 bool Thread::RestoreRegisterStateFromCheckpoint(
518     ThreadStateCheckpoint &saved_state) {
519   if (saved_state.register_backup_sp) {
520     lldb::StackFrameSP frame_sp(GetStackFrameAtIndex(0));
521     if (frame_sp) {
522       lldb::RegisterContextSP reg_ctx_sp(frame_sp->GetRegisterContext());
523       if (reg_ctx_sp) {
524         bool ret =
525             reg_ctx_sp->WriteAllRegisterValues(*saved_state.register_backup_sp);
526 
527         // Clear out all stack frames as our world just changed.
528         ClearStackFrames();
529         reg_ctx_sp->InvalidateIfNeeded(true);
530         if (m_unwinder_up)
531           m_unwinder_up->Clear();
532         return ret;
533       }
534     }
535   }
536   return false;
537 }
538 
539 void Thread::RestoreThreadStateFromCheckpoint(
540     ThreadStateCheckpoint &saved_state) {
541   if (saved_state.stop_info_sp)
542     saved_state.stop_info_sp->MakeStopInfoValid();
543   SetStopInfo(saved_state.stop_info_sp);
544   GetStackFrameList()->SetCurrentInlinedDepth(
545       saved_state.current_inlined_depth);
546   GetPlans().RestoreCompletedPlanCheckpoint(
547       saved_state.m_completed_plan_checkpoint);
548 }
549 
550 StateType Thread::GetState() const {
551   // If any other threads access this we will need a mutex for it
552   std::lock_guard<std::recursive_mutex> guard(m_state_mutex);
553   return m_state;
554 }
555 
556 void Thread::SetState(StateType state) {
557   std::lock_guard<std::recursive_mutex> guard(m_state_mutex);
558   m_state = state;
559 }
560 
561 std::string Thread::GetStopDescription() {
562   StackFrameSP frame_sp = GetStackFrameAtIndex(0);
563 
564   if (!frame_sp)
565     return GetStopDescriptionRaw();
566 
567   auto recognized_frame_sp = frame_sp->GetRecognizedFrame();
568 
569   if (!recognized_frame_sp)
570     return GetStopDescriptionRaw();
571 
572   std::string recognized_stop_description =
573       recognized_frame_sp->GetStopDescription();
574 
575   if (!recognized_stop_description.empty())
576     return recognized_stop_description;
577 
578   return GetStopDescriptionRaw();
579 }
580 
581 std::string Thread::GetStopDescriptionRaw() {
582   StopInfoSP stop_info_sp = GetStopInfo();
583   std::string raw_stop_description;
584   if (stop_info_sp && stop_info_sp->IsValid()) {
585     raw_stop_description = stop_info_sp->GetDescription();
586     assert((!raw_stop_description.empty() ||
587             stop_info_sp->GetStopReason() == eStopReasonNone) &&
588            "StopInfo returned an empty description.");
589   }
590   return raw_stop_description;
591 }
592 
593 void Thread::WillStop() {
594   ThreadPlan *current_plan = GetCurrentPlan();
595 
596   // FIXME: I may decide to disallow threads with no plans.  In which
597   // case this should go to an assert.
598 
599   if (!current_plan)
600     return;
601 
602   current_plan->WillStop();
603 }
604 
605 void Thread::SetupForResume() {
606   if (GetResumeState() != eStateSuspended) {
607     // If we're at a breakpoint push the step-over breakpoint plan.  Do this
608     // before telling the current plan it will resume, since we might change
609     // what the current plan is.
610 
611     lldb::RegisterContextSP reg_ctx_sp(GetRegisterContext());
612     if (reg_ctx_sp) {
613       const addr_t thread_pc = reg_ctx_sp->GetPC();
614       BreakpointSiteSP bp_site_sp =
615           GetProcess()->GetBreakpointSiteList().FindByAddress(thread_pc);
616       if (bp_site_sp) {
617         // Note, don't assume there's a ThreadPlanStepOverBreakpoint, the
618         // target may not require anything special to step over a breakpoint.
619 
620         ThreadPlan *cur_plan = GetCurrentPlan();
621 
622         bool push_step_over_bp_plan = false;
623         if (cur_plan->GetKind() == ThreadPlan::eKindStepOverBreakpoint) {
624           ThreadPlanStepOverBreakpoint *bp_plan =
625               (ThreadPlanStepOverBreakpoint *)cur_plan;
626           if (bp_plan->GetBreakpointLoadAddress() != thread_pc)
627             push_step_over_bp_plan = true;
628         } else
629           push_step_over_bp_plan = true;
630 
631         if (push_step_over_bp_plan) {
632           ThreadPlanSP step_bp_plan_sp(new ThreadPlanStepOverBreakpoint(*this));
633           if (step_bp_plan_sp) {
634             step_bp_plan_sp->SetPrivate(true);
635 
636             if (GetCurrentPlan()->RunState() != eStateStepping) {
637               ThreadPlanStepOverBreakpoint *step_bp_plan =
638                   static_cast<ThreadPlanStepOverBreakpoint *>(
639                       step_bp_plan_sp.get());
640               step_bp_plan->SetAutoContinue(true);
641             }
642             QueueThreadPlan(step_bp_plan_sp, false);
643           }
644         }
645       }
646     }
647   }
648 }
649 
650 bool Thread::ShouldResume(StateType resume_state) {
651   // At this point clear the completed plan stack.
652   GetPlans().WillResume();
653   m_override_should_notify = eLazyBoolCalculate;
654 
655   StateType prev_resume_state = GetTemporaryResumeState();
656 
657   SetTemporaryResumeState(resume_state);
658 
659   lldb::ThreadSP backing_thread_sp(GetBackingThread());
660   if (backing_thread_sp)
661     backing_thread_sp->SetTemporaryResumeState(resume_state);
662 
663   // Make sure m_stop_info_sp is valid.  Don't do this for threads we suspended
664   // in the previous run.
665   if (prev_resume_state != eStateSuspended)
666     GetPrivateStopInfo();
667 
668   // This is a little dubious, but we are trying to limit how often we actually
669   // fetch stop info from the target, 'cause that slows down single stepping.
670   // So assume that if we got to the point where we're about to resume, and we
671   // haven't yet had to fetch the stop reason, then it doesn't need to know
672   // about the fact that we are resuming...
673   const uint32_t process_stop_id = GetProcess()->GetStopID();
674   if (m_stop_info_stop_id == process_stop_id &&
675       (m_stop_info_sp && m_stop_info_sp->IsValid())) {
676     StopInfo *stop_info = GetPrivateStopInfo().get();
677     if (stop_info)
678       stop_info->WillResume(resume_state);
679   }
680 
681   // Tell all the plans that we are about to resume in case they need to clear
682   // any state. We distinguish between the plan on the top of the stack and the
683   // lower plans in case a plan needs to do any special business before it
684   // runs.
685 
686   bool need_to_resume = false;
687   ThreadPlan *plan_ptr = GetCurrentPlan();
688   if (plan_ptr) {
689     need_to_resume = plan_ptr->WillResume(resume_state, true);
690 
691     while ((plan_ptr = GetPreviousPlan(plan_ptr)) != nullptr) {
692       plan_ptr->WillResume(resume_state, false);
693     }
694 
695     // If the WillResume for the plan says we are faking a resume, then it will
696     // have set an appropriate stop info. In that case, don't reset it here.
697 
698     if (need_to_resume && resume_state != eStateSuspended) {
699       m_stop_info_sp.reset();
700     }
701   }
702 
703   if (need_to_resume) {
704     ClearStackFrames();
705     // Let Thread subclasses do any special work they need to prior to resuming
706     WillResume(resume_state);
707   }
708 
709   return need_to_resume;
710 }
711 
712 void Thread::DidResume() {
713   SetResumeSignal(LLDB_INVALID_SIGNAL_NUMBER);
714   // This will get recomputed each time when we stop.
715   SetShouldRunBeforePublicStop(false);
716 }
717 
718 void Thread::DidStop() { SetState(eStateStopped); }
719 
720 bool Thread::ShouldStop(Event *event_ptr) {
721   ThreadPlan *current_plan = GetCurrentPlan();
722 
723   bool should_stop = true;
724 
725   Log *log = GetLog(LLDBLog::Step);
726 
727   if (GetResumeState() == eStateSuspended) {
728     LLDB_LOGF(log,
729               "Thread::%s for tid = 0x%4.4" PRIx64 " 0x%4.4" PRIx64
730               ", should_stop = 0 (ignore since thread was suspended)",
731               __FUNCTION__, GetID(), GetProtocolID());
732     return false;
733   }
734 
735   if (GetTemporaryResumeState() == eStateSuspended) {
736     LLDB_LOGF(log,
737               "Thread::%s for tid = 0x%4.4" PRIx64 " 0x%4.4" PRIx64
738               ", should_stop = 0 (ignore since thread was suspended)",
739               __FUNCTION__, GetID(), GetProtocolID());
740     return false;
741   }
742 
743   // Based on the current thread plan and process stop info, check if this
744   // thread caused the process to stop. NOTE: this must take place before the
745   // plan is moved from the current plan stack to the completed plan stack.
746   if (!ThreadStoppedForAReason()) {
747     LLDB_LOGF(log,
748               "Thread::%s for tid = 0x%4.4" PRIx64 " 0x%4.4" PRIx64
749               ", pc = 0x%16.16" PRIx64
750               ", should_stop = 0 (ignore since no stop reason)",
751               __FUNCTION__, GetID(), GetProtocolID(),
752               GetRegisterContext() ? GetRegisterContext()->GetPC()
753                                    : LLDB_INVALID_ADDRESS);
754     return false;
755   }
756 
757   // Clear the "must run me before stop" if it was set:
758   SetShouldRunBeforePublicStop(false);
759 
760   if (log) {
761     LLDB_LOGF(log,
762               "Thread::%s(%p) for tid = 0x%4.4" PRIx64 " 0x%4.4" PRIx64
763               ", pc = 0x%16.16" PRIx64,
764               __FUNCTION__, static_cast<void *>(this), GetID(), GetProtocolID(),
765               GetRegisterContext() ? GetRegisterContext()->GetPC()
766                                    : LLDB_INVALID_ADDRESS);
767     LLDB_LOGF(log, "^^^^^^^^ Thread::ShouldStop Begin ^^^^^^^^");
768     StreamString s;
769     s.IndentMore();
770     GetProcess()->DumpThreadPlansForTID(
771         s, GetID(), eDescriptionLevelVerbose, true /* internal */,
772         false /* condense_trivial */, true /* skip_unreported */);
773     LLDB_LOGF(log, "Plan stack initial state:\n%s", s.GetData());
774   }
775 
776   // The top most plan always gets to do the trace log...
777   current_plan->DoTraceLog();
778 
779   // First query the stop info's ShouldStopSynchronous.  This handles
780   // "synchronous" stop reasons, for example the breakpoint command on internal
781   // breakpoints.  If a synchronous stop reason says we should not stop, then
782   // we don't have to do any more work on this stop.
783   StopInfoSP private_stop_info(GetPrivateStopInfo());
784   if (private_stop_info &&
785       !private_stop_info->ShouldStopSynchronous(event_ptr)) {
786     LLDB_LOGF(log, "StopInfo::ShouldStop async callback says we should not "
787                    "stop, returning ShouldStop of false.");
788     return false;
789   }
790 
791   // If we've already been restarted, don't query the plans since the state
792   // they would examine is not current.
793   if (Process::ProcessEventData::GetRestartedFromEvent(event_ptr))
794     return false;
795 
796   // Before the plans see the state of the world, calculate the current inlined
797   // depth.
798   GetStackFrameList()->CalculateCurrentInlinedDepth();
799 
800   // If the base plan doesn't understand why we stopped, then we have to find a
801   // plan that does. If that plan is still working, then we don't need to do
802   // any more work.  If the plan that explains the stop is done, then we should
803   // pop all the plans below it, and pop it, and then let the plans above it
804   // decide whether they still need to do more work.
805 
806   bool done_processing_current_plan = false;
807 
808   if (!current_plan->PlanExplainsStop(event_ptr)) {
809     if (current_plan->TracerExplainsStop()) {
810       done_processing_current_plan = true;
811       should_stop = false;
812     } else {
813       // If the current plan doesn't explain the stop, then find one that does
814       // and let it handle the situation.
815       ThreadPlan *plan_ptr = current_plan;
816       while ((plan_ptr = GetPreviousPlan(plan_ptr)) != nullptr) {
817         if (plan_ptr->PlanExplainsStop(event_ptr)) {
818           LLDB_LOGF(log, "Plan %s explains stop.", plan_ptr->GetName());
819 
820           should_stop = plan_ptr->ShouldStop(event_ptr);
821 
822           // plan_ptr explains the stop, next check whether plan_ptr is done,
823           // if so, then we should take it and all the plans below it off the
824           // stack.
825 
826           if (plan_ptr->MischiefManaged()) {
827             // We're going to pop the plans up to and including the plan that
828             // explains the stop.
829             ThreadPlan *prev_plan_ptr = GetPreviousPlan(plan_ptr);
830 
831             do {
832               if (should_stop)
833                 current_plan->WillStop();
834               PopPlan();
835             } while ((current_plan = GetCurrentPlan()) != prev_plan_ptr);
836             // Now, if the responsible plan was not "Okay to discard" then
837             // we're done, otherwise we forward this to the next plan in the
838             // stack below.
839             done_processing_current_plan =
840                 (plan_ptr->IsControllingPlan() && !plan_ptr->OkayToDiscard());
841           } else {
842             bool should_force_run = plan_ptr->ShouldRunBeforePublicStop();
843             if (should_force_run) {
844               SetShouldRunBeforePublicStop(true);
845               should_stop = false;
846             }
847             done_processing_current_plan = true;
848           }
849           break;
850         }
851       }
852     }
853   }
854 
855   if (!done_processing_current_plan) {
856     bool override_stop = false;
857 
858     // We're starting from the base plan, so just let it decide;
859     if (current_plan->IsBasePlan()) {
860       should_stop = current_plan->ShouldStop(event_ptr);
861       LLDB_LOGF(log, "Base plan says should stop: %i.", should_stop);
862     } else {
863       // Otherwise, don't let the base plan override what the other plans say
864       // to do, since presumably if there were other plans they would know what
865       // to do...
866       while (true) {
867         if (current_plan->IsBasePlan())
868           break;
869 
870         should_stop = current_plan->ShouldStop(event_ptr);
871         LLDB_LOGF(log, "Plan %s should stop: %d.", current_plan->GetName(),
872                   should_stop);
873         if (current_plan->MischiefManaged()) {
874           if (should_stop)
875             current_plan->WillStop();
876 
877           if (current_plan->ShouldAutoContinue(event_ptr)) {
878             override_stop = true;
879             LLDB_LOGF(log, "Plan %s auto-continue: true.",
880                       current_plan->GetName());
881           }
882 
883           // If a Controlling Plan wants to stop, we let it. Otherwise, see if
884           // the plan's parent wants to stop.
885 
886           PopPlan();
887           if (should_stop && current_plan->IsControllingPlan() &&
888               !current_plan->OkayToDiscard()) {
889             break;
890           }
891 
892           current_plan = GetCurrentPlan();
893           if (current_plan == nullptr) {
894             break;
895           }
896         } else {
897           break;
898         }
899       }
900     }
901 
902     if (override_stop)
903       should_stop = false;
904   }
905 
906   // One other potential problem is that we set up a controlling plan, then stop
907   // in before it is complete - for instance by hitting a breakpoint during a
908   // step-over - then do some step/finish/etc operations that wind up past the
909   // end point condition of the initial plan.  We don't want to strand the
910   // original plan on the stack, This code clears stale plans off the stack.
911 
912   if (should_stop) {
913     ThreadPlan *plan_ptr = GetCurrentPlan();
914 
915     // Discard the stale plans and all plans below them in the stack, plus move
916     // the completed plans to the completed plan stack
917     while (!plan_ptr->IsBasePlan()) {
918       bool stale = plan_ptr->IsPlanStale();
919       ThreadPlan *examined_plan = plan_ptr;
920       plan_ptr = GetPreviousPlan(examined_plan);
921 
922       if (stale) {
923         LLDB_LOGF(
924             log,
925             "Plan %s being discarded in cleanup, it says it is already done.",
926             examined_plan->GetName());
927         while (GetCurrentPlan() != examined_plan) {
928           DiscardPlan();
929         }
930         if (examined_plan->IsPlanComplete()) {
931           // plan is complete but does not explain the stop (example: step to a
932           // line with breakpoint), let us move the plan to
933           // completed_plan_stack anyway
934           PopPlan();
935         } else
936           DiscardPlan();
937       }
938     }
939   }
940 
941   if (log) {
942     StreamString s;
943     s.IndentMore();
944     GetProcess()->DumpThreadPlansForTID(
945         s, GetID(), eDescriptionLevelVerbose, true /* internal */,
946         false /* condense_trivial */, true /* skip_unreported */);
947     LLDB_LOGF(log, "Plan stack final state:\n%s", s.GetData());
948     LLDB_LOGF(log, "vvvvvvvv Thread::ShouldStop End (returning %i) vvvvvvvv",
949               should_stop);
950   }
951   return should_stop;
952 }
953 
954 Vote Thread::ShouldReportStop(Event *event_ptr) {
955   StateType thread_state = GetResumeState();
956   StateType temp_thread_state = GetTemporaryResumeState();
957 
958   Log *log = GetLog(LLDBLog::Step);
959 
960   if (thread_state == eStateSuspended || thread_state == eStateInvalid) {
961     LLDB_LOGF(log,
962               "Thread::ShouldReportStop() tid = 0x%4.4" PRIx64
963               ": returning vote %i (state was suspended or invalid)",
964               GetID(), eVoteNoOpinion);
965     return eVoteNoOpinion;
966   }
967 
968   if (temp_thread_state == eStateSuspended ||
969       temp_thread_state == eStateInvalid) {
970     LLDB_LOGF(log,
971               "Thread::ShouldReportStop() tid = 0x%4.4" PRIx64
972               ": returning vote %i (temporary state was suspended or invalid)",
973               GetID(), eVoteNoOpinion);
974     return eVoteNoOpinion;
975   }
976 
977   if (!ThreadStoppedForAReason()) {
978     LLDB_LOGF(log,
979               "Thread::ShouldReportStop() tid = 0x%4.4" PRIx64
980               ": returning vote %i (thread didn't stop for a reason.)",
981               GetID(), eVoteNoOpinion);
982     return eVoteNoOpinion;
983   }
984 
985   if (GetPlans().AnyCompletedPlans()) {
986     // Pass skip_private = false to GetCompletedPlan, since we want to ask
987     // the last plan, regardless of whether it is private or not.
988     LLDB_LOGF(log,
989               "Thread::ShouldReportStop() tid = 0x%4.4" PRIx64
990               ": returning vote for complete stack's back plan",
991               GetID());
992     return GetPlans().GetCompletedPlan(false)->ShouldReportStop(event_ptr);
993   } else {
994     Vote thread_vote = eVoteNoOpinion;
995     ThreadPlan *plan_ptr = GetCurrentPlan();
996     while (true) {
997       if (plan_ptr->PlanExplainsStop(event_ptr)) {
998         thread_vote = plan_ptr->ShouldReportStop(event_ptr);
999         break;
1000       }
1001       if (plan_ptr->IsBasePlan())
1002         break;
1003       else
1004         plan_ptr = GetPreviousPlan(plan_ptr);
1005     }
1006     LLDB_LOGF(log,
1007               "Thread::ShouldReportStop() tid = 0x%4.4" PRIx64
1008               ": returning vote %i for current plan",
1009               GetID(), thread_vote);
1010 
1011     return thread_vote;
1012   }
1013 }
1014 
1015 Vote Thread::ShouldReportRun(Event *event_ptr) {
1016   StateType thread_state = GetResumeState();
1017 
1018   if (thread_state == eStateSuspended || thread_state == eStateInvalid) {
1019     return eVoteNoOpinion;
1020   }
1021 
1022   Log *log = GetLog(LLDBLog::Step);
1023   if (GetPlans().AnyCompletedPlans()) {
1024     // Pass skip_private = false to GetCompletedPlan, since we want to ask
1025     // the last plan, regardless of whether it is private or not.
1026     LLDB_LOGF(log,
1027               "Current Plan for thread %d(%p) (0x%4.4" PRIx64
1028               ", %s): %s being asked whether we should report run.",
1029               GetIndexID(), static_cast<void *>(this), GetID(),
1030               StateAsCString(GetTemporaryResumeState()),
1031               GetCompletedPlan()->GetName());
1032 
1033     return GetPlans().GetCompletedPlan(false)->ShouldReportRun(event_ptr);
1034   } else {
1035     LLDB_LOGF(log,
1036               "Current Plan for thread %d(%p) (0x%4.4" PRIx64
1037               ", %s): %s being asked whether we should report run.",
1038               GetIndexID(), static_cast<void *>(this), GetID(),
1039               StateAsCString(GetTemporaryResumeState()),
1040               GetCurrentPlan()->GetName());
1041 
1042     return GetCurrentPlan()->ShouldReportRun(event_ptr);
1043   }
1044 }
1045 
1046 bool Thread::MatchesSpec(const ThreadSpec *spec) {
1047   return (spec == nullptr) ? true : spec->ThreadPassesBasicTests(*this);
1048 }
1049 
1050 ThreadPlanStack &Thread::GetPlans() const {
1051   ThreadPlanStack *plans = GetProcess()->FindThreadPlans(GetID());
1052   if (plans)
1053     return *plans;
1054 
1055   // History threads don't have a thread plan, but they do ask get asked to
1056   // describe themselves, which usually involves pulling out the stop reason.
1057   // That in turn will check for a completed plan on the ThreadPlanStack.
1058   // Instead of special-casing at that point, we return a Stack with a
1059   // ThreadPlanNull as its base plan.  That will give the right answers to the
1060   // queries GetDescription makes, and only assert if you try to run the thread.
1061   if (!m_null_plan_stack_up)
1062     m_null_plan_stack_up = std::make_unique<ThreadPlanStack>(*this, true);
1063   return *m_null_plan_stack_up;
1064 }
1065 
1066 void Thread::PushPlan(ThreadPlanSP thread_plan_sp) {
1067   assert(thread_plan_sp && "Don't push an empty thread plan.");
1068 
1069   Log *log = GetLog(LLDBLog::Step);
1070   if (log) {
1071     StreamString s;
1072     thread_plan_sp->GetDescription(&s, lldb::eDescriptionLevelFull);
1073     LLDB_LOGF(log, "Thread::PushPlan(0x%p): \"%s\", tid = 0x%4.4" PRIx64 ".",
1074               static_cast<void *>(this), s.GetData(),
1075               thread_plan_sp->GetThread().GetID());
1076   }
1077 
1078   GetPlans().PushPlan(std::move(thread_plan_sp));
1079 }
1080 
1081 void Thread::PopPlan() {
1082   Log *log = GetLog(LLDBLog::Step);
1083   ThreadPlanSP popped_plan_sp = GetPlans().PopPlan();
1084   if (log) {
1085     LLDB_LOGF(log, "Popping plan: \"%s\", tid = 0x%4.4" PRIx64 ".",
1086               popped_plan_sp->GetName(), popped_plan_sp->GetThread().GetID());
1087   }
1088 }
1089 
1090 void Thread::DiscardPlan() {
1091   Log *log = GetLog(LLDBLog::Step);
1092   ThreadPlanSP discarded_plan_sp = GetPlans().DiscardPlan();
1093 
1094   LLDB_LOGF(log, "Discarding plan: \"%s\", tid = 0x%4.4" PRIx64 ".",
1095             discarded_plan_sp->GetName(),
1096             discarded_plan_sp->GetThread().GetID());
1097 }
1098 
1099 void Thread::AutoCompleteThreadPlans(CompletionRequest &request) const {
1100   const ThreadPlanStack &plans = GetPlans();
1101   if (!plans.AnyPlans())
1102     return;
1103 
1104   // Iterate from the second plan (index: 1) to skip the base plan.
1105   ThreadPlanSP p;
1106   uint32_t i = 1;
1107   while ((p = plans.GetPlanByIndex(i, false))) {
1108     StreamString strm;
1109     p->GetDescription(&strm, eDescriptionLevelInitial);
1110     request.TryCompleteCurrentArg(std::to_string(i), strm.GetString());
1111     i++;
1112   }
1113 }
1114 
1115 ThreadPlan *Thread::GetCurrentPlan() const {
1116   return GetPlans().GetCurrentPlan().get();
1117 }
1118 
1119 ThreadPlanSP Thread::GetCompletedPlan() const {
1120   return GetPlans().GetCompletedPlan();
1121 }
1122 
1123 ValueObjectSP Thread::GetReturnValueObject() const {
1124   return GetPlans().GetReturnValueObject();
1125 }
1126 
1127 ExpressionVariableSP Thread::GetExpressionVariable() const {
1128   return GetPlans().GetExpressionVariable();
1129 }
1130 
1131 bool Thread::IsThreadPlanDone(ThreadPlan *plan) const {
1132   return GetPlans().IsPlanDone(plan);
1133 }
1134 
1135 bool Thread::WasThreadPlanDiscarded(ThreadPlan *plan) const {
1136   return GetPlans().WasPlanDiscarded(plan);
1137 }
1138 
1139 bool Thread::CompletedPlanOverridesBreakpoint() const {
1140   return GetPlans().AnyCompletedPlans();
1141 }
1142 
1143 ThreadPlan *Thread::GetPreviousPlan(ThreadPlan *current_plan) const{
1144   return GetPlans().GetPreviousPlan(current_plan);
1145 }
1146 
1147 Status Thread::QueueThreadPlan(ThreadPlanSP &thread_plan_sp,
1148                                bool abort_other_plans) {
1149   Status status;
1150   StreamString s;
1151   if (!thread_plan_sp->ValidatePlan(&s)) {
1152     DiscardThreadPlansUpToPlan(thread_plan_sp);
1153     thread_plan_sp.reset();
1154     status.SetErrorString(s.GetString());
1155     return status;
1156   }
1157 
1158   if (abort_other_plans)
1159     DiscardThreadPlans(true);
1160 
1161   PushPlan(thread_plan_sp);
1162 
1163   // This seems a little funny, but I don't want to have to split up the
1164   // constructor and the DidPush in the scripted plan, that seems annoying.
1165   // That means the constructor has to be in DidPush. So I have to validate the
1166   // plan AFTER pushing it, and then take it off again...
1167   if (!thread_plan_sp->ValidatePlan(&s)) {
1168     DiscardThreadPlansUpToPlan(thread_plan_sp);
1169     thread_plan_sp.reset();
1170     status.SetErrorString(s.GetString());
1171     return status;
1172   }
1173 
1174   return status;
1175 }
1176 
1177 bool Thread::DiscardUserThreadPlansUpToIndex(uint32_t plan_index) {
1178   // Count the user thread plans from the back end to get the number of the one
1179   // we want to discard:
1180 
1181   ThreadPlan *up_to_plan_ptr = GetPlans().GetPlanByIndex(plan_index).get();
1182   if (up_to_plan_ptr == nullptr)
1183     return false;
1184 
1185   DiscardThreadPlansUpToPlan(up_to_plan_ptr);
1186   return true;
1187 }
1188 
1189 void Thread::DiscardThreadPlansUpToPlan(lldb::ThreadPlanSP &up_to_plan_sp) {
1190   DiscardThreadPlansUpToPlan(up_to_plan_sp.get());
1191 }
1192 
1193 void Thread::DiscardThreadPlansUpToPlan(ThreadPlan *up_to_plan_ptr) {
1194   Log *log = GetLog(LLDBLog::Step);
1195   LLDB_LOGF(log,
1196             "Discarding thread plans for thread tid = 0x%4.4" PRIx64
1197             ", up to %p",
1198             GetID(), static_cast<void *>(up_to_plan_ptr));
1199   GetPlans().DiscardPlansUpToPlan(up_to_plan_ptr);
1200 }
1201 
1202 void Thread::DiscardThreadPlans(bool force) {
1203   Log *log = GetLog(LLDBLog::Step);
1204   if (log) {
1205     LLDB_LOGF(log,
1206               "Discarding thread plans for thread (tid = 0x%4.4" PRIx64
1207               ", force %d)",
1208               GetID(), force);
1209   }
1210 
1211   if (force) {
1212     GetPlans().DiscardAllPlans();
1213     return;
1214   }
1215   GetPlans().DiscardConsultingControllingPlans();
1216 }
1217 
1218 Status Thread::UnwindInnermostExpression() {
1219   Status error;
1220   ThreadPlan *innermost_expr_plan = GetPlans().GetInnermostExpression();
1221   if (!innermost_expr_plan) {
1222     error.SetErrorString("No expressions currently active on this thread");
1223     return error;
1224   }
1225   DiscardThreadPlansUpToPlan(innermost_expr_plan);
1226   return error;
1227 }
1228 
1229 ThreadPlanSP Thread::QueueBasePlan(bool abort_other_plans) {
1230   ThreadPlanSP thread_plan_sp(new ThreadPlanBase(*this));
1231   QueueThreadPlan(thread_plan_sp, abort_other_plans);
1232   return thread_plan_sp;
1233 }
1234 
1235 ThreadPlanSP Thread::QueueThreadPlanForStepSingleInstruction(
1236     bool step_over, bool abort_other_plans, bool stop_other_threads,
1237     Status &status) {
1238   ThreadPlanSP thread_plan_sp(new ThreadPlanStepInstruction(
1239       *this, step_over, stop_other_threads, eVoteNoOpinion, eVoteNoOpinion));
1240   status = QueueThreadPlan(thread_plan_sp, abort_other_plans);
1241   return thread_plan_sp;
1242 }
1243 
1244 ThreadPlanSP Thread::QueueThreadPlanForStepOverRange(
1245     bool abort_other_plans, const AddressRange &range,
1246     const SymbolContext &addr_context, lldb::RunMode stop_other_threads,
1247     Status &status, LazyBool step_out_avoids_code_withoug_debug_info) {
1248   ThreadPlanSP thread_plan_sp;
1249   thread_plan_sp = std::make_shared<ThreadPlanStepOverRange>(
1250       *this, range, addr_context, stop_other_threads,
1251       step_out_avoids_code_withoug_debug_info);
1252 
1253   status = QueueThreadPlan(thread_plan_sp, abort_other_plans);
1254   return thread_plan_sp;
1255 }
1256 
1257 // Call the QueueThreadPlanForStepOverRange method which takes an address
1258 // range.
1259 ThreadPlanSP Thread::QueueThreadPlanForStepOverRange(
1260     bool abort_other_plans, const LineEntry &line_entry,
1261     const SymbolContext &addr_context, lldb::RunMode stop_other_threads,
1262     Status &status, LazyBool step_out_avoids_code_withoug_debug_info) {
1263   const bool include_inlined_functions = true;
1264   auto address_range =
1265       line_entry.GetSameLineContiguousAddressRange(include_inlined_functions);
1266   return QueueThreadPlanForStepOverRange(
1267       abort_other_plans, address_range, addr_context, stop_other_threads,
1268       status, step_out_avoids_code_withoug_debug_info);
1269 }
1270 
1271 ThreadPlanSP Thread::QueueThreadPlanForStepInRange(
1272     bool abort_other_plans, const AddressRange &range,
1273     const SymbolContext &addr_context, const char *step_in_target,
1274     lldb::RunMode stop_other_threads, Status &status,
1275     LazyBool step_in_avoids_code_without_debug_info,
1276     LazyBool step_out_avoids_code_without_debug_info) {
1277   ThreadPlanSP thread_plan_sp(new ThreadPlanStepInRange(
1278       *this, range, addr_context, step_in_target, stop_other_threads,
1279       step_in_avoids_code_without_debug_info,
1280       step_out_avoids_code_without_debug_info));
1281   status = QueueThreadPlan(thread_plan_sp, abort_other_plans);
1282   return thread_plan_sp;
1283 }
1284 
1285 // Call the QueueThreadPlanForStepInRange method which takes an address range.
1286 ThreadPlanSP Thread::QueueThreadPlanForStepInRange(
1287     bool abort_other_plans, const LineEntry &line_entry,
1288     const SymbolContext &addr_context, const char *step_in_target,
1289     lldb::RunMode stop_other_threads, Status &status,
1290     LazyBool step_in_avoids_code_without_debug_info,
1291     LazyBool step_out_avoids_code_without_debug_info) {
1292   const bool include_inlined_functions = false;
1293   return QueueThreadPlanForStepInRange(
1294       abort_other_plans,
1295       line_entry.GetSameLineContiguousAddressRange(include_inlined_functions),
1296       addr_context, step_in_target, stop_other_threads, status,
1297       step_in_avoids_code_without_debug_info,
1298       step_out_avoids_code_without_debug_info);
1299 }
1300 
1301 ThreadPlanSP Thread::QueueThreadPlanForStepOut(
1302     bool abort_other_plans, SymbolContext *addr_context, bool first_insn,
1303     bool stop_other_threads, Vote report_stop_vote, Vote report_run_vote,
1304     uint32_t frame_idx, Status &status,
1305     LazyBool step_out_avoids_code_without_debug_info) {
1306   ThreadPlanSP thread_plan_sp(new ThreadPlanStepOut(
1307       *this, addr_context, first_insn, stop_other_threads, report_stop_vote,
1308       report_run_vote, frame_idx, step_out_avoids_code_without_debug_info));
1309 
1310   status = QueueThreadPlan(thread_plan_sp, abort_other_plans);
1311   return thread_plan_sp;
1312 }
1313 
1314 ThreadPlanSP Thread::QueueThreadPlanForStepOutNoShouldStop(
1315     bool abort_other_plans, SymbolContext *addr_context, bool first_insn,
1316     bool stop_other_threads, Vote report_stop_vote, Vote report_run_vote,
1317     uint32_t frame_idx, Status &status, bool continue_to_next_branch) {
1318   const bool calculate_return_value =
1319       false; // No need to calculate the return value here.
1320   ThreadPlanSP thread_plan_sp(new ThreadPlanStepOut(
1321       *this, addr_context, first_insn, stop_other_threads, report_stop_vote,
1322       report_run_vote, frame_idx, eLazyBoolNo, continue_to_next_branch,
1323       calculate_return_value));
1324 
1325   ThreadPlanStepOut *new_plan =
1326       static_cast<ThreadPlanStepOut *>(thread_plan_sp.get());
1327   new_plan->ClearShouldStopHereCallbacks();
1328 
1329   status = QueueThreadPlan(thread_plan_sp, abort_other_plans);
1330   return thread_plan_sp;
1331 }
1332 
1333 ThreadPlanSP Thread::QueueThreadPlanForStepThrough(StackID &return_stack_id,
1334                                                    bool abort_other_plans,
1335                                                    bool stop_other_threads,
1336                                                    Status &status) {
1337   ThreadPlanSP thread_plan_sp(
1338       new ThreadPlanStepThrough(*this, return_stack_id, stop_other_threads));
1339   if (!thread_plan_sp || !thread_plan_sp->ValidatePlan(nullptr))
1340     return ThreadPlanSP();
1341 
1342   status = QueueThreadPlan(thread_plan_sp, abort_other_plans);
1343   return thread_plan_sp;
1344 }
1345 
1346 ThreadPlanSP Thread::QueueThreadPlanForRunToAddress(bool abort_other_plans,
1347                                                     Address &target_addr,
1348                                                     bool stop_other_threads,
1349                                                     Status &status) {
1350   ThreadPlanSP thread_plan_sp(
1351       new ThreadPlanRunToAddress(*this, target_addr, stop_other_threads));
1352 
1353   status = QueueThreadPlan(thread_plan_sp, abort_other_plans);
1354   return thread_plan_sp;
1355 }
1356 
1357 ThreadPlanSP Thread::QueueThreadPlanForStepUntil(
1358     bool abort_other_plans, lldb::addr_t *address_list, size_t num_addresses,
1359     bool stop_other_threads, uint32_t frame_idx, Status &status) {
1360   ThreadPlanSP thread_plan_sp(new ThreadPlanStepUntil(
1361       *this, address_list, num_addresses, stop_other_threads, frame_idx));
1362 
1363   status = QueueThreadPlan(thread_plan_sp, abort_other_plans);
1364   return thread_plan_sp;
1365 }
1366 
1367 lldb::ThreadPlanSP Thread::QueueThreadPlanForStepScripted(
1368     bool abort_other_plans, const char *class_name,
1369     StructuredData::ObjectSP extra_args_sp, bool stop_other_threads,
1370     Status &status) {
1371 
1372   ThreadPlanSP thread_plan_sp(new ThreadPlanPython(
1373       *this, class_name, StructuredDataImpl(extra_args_sp)));
1374   thread_plan_sp->SetStopOthers(stop_other_threads);
1375   status = QueueThreadPlan(thread_plan_sp, abort_other_plans);
1376   return thread_plan_sp;
1377 }
1378 
1379 uint32_t Thread::GetIndexID() const { return m_index_id; }
1380 
1381 TargetSP Thread::CalculateTarget() {
1382   TargetSP target_sp;
1383   ProcessSP process_sp(GetProcess());
1384   if (process_sp)
1385     target_sp = process_sp->CalculateTarget();
1386   return target_sp;
1387 }
1388 
1389 ProcessSP Thread::CalculateProcess() { return GetProcess(); }
1390 
1391 ThreadSP Thread::CalculateThread() { return shared_from_this(); }
1392 
1393 StackFrameSP Thread::CalculateStackFrame() { return StackFrameSP(); }
1394 
1395 void Thread::CalculateExecutionContext(ExecutionContext &exe_ctx) {
1396   exe_ctx.SetContext(shared_from_this());
1397 }
1398 
1399 StackFrameListSP Thread::GetStackFrameList() {
1400   std::lock_guard<std::recursive_mutex> guard(m_frame_mutex);
1401 
1402   if (!m_curr_frames_sp)
1403     m_curr_frames_sp =
1404         std::make_shared<StackFrameList>(*this, m_prev_frames_sp, true);
1405 
1406   return m_curr_frames_sp;
1407 }
1408 
1409 void Thread::ClearStackFrames() {
1410   std::lock_guard<std::recursive_mutex> guard(m_frame_mutex);
1411 
1412   GetUnwinder().Clear();
1413 
1414   // Only store away the old "reference" StackFrameList if we got all its
1415   // frames:
1416   // FIXME: At some point we can try to splice in the frames we have fetched
1417   // into
1418   // the new frame as we make it, but let's not try that now.
1419   if (m_curr_frames_sp && m_curr_frames_sp->GetAllFramesFetched())
1420     m_prev_frames_sp.swap(m_curr_frames_sp);
1421   m_curr_frames_sp.reset();
1422 
1423   m_extended_info.reset();
1424   m_extended_info_fetched = false;
1425 }
1426 
1427 lldb::StackFrameSP Thread::GetFrameWithConcreteFrameIndex(uint32_t unwind_idx) {
1428   return GetStackFrameList()->GetFrameWithConcreteFrameIndex(unwind_idx);
1429 }
1430 
1431 Status Thread::ReturnFromFrameWithIndex(uint32_t frame_idx,
1432                                         lldb::ValueObjectSP return_value_sp,
1433                                         bool broadcast) {
1434   StackFrameSP frame_sp = GetStackFrameAtIndex(frame_idx);
1435   Status return_error;
1436 
1437   if (!frame_sp) {
1438     return_error.SetErrorStringWithFormat(
1439         "Could not find frame with index %d in thread 0x%" PRIx64 ".",
1440         frame_idx, GetID());
1441   }
1442 
1443   return ReturnFromFrame(frame_sp, return_value_sp, broadcast);
1444 }
1445 
1446 Status Thread::ReturnFromFrame(lldb::StackFrameSP frame_sp,
1447                                lldb::ValueObjectSP return_value_sp,
1448                                bool broadcast) {
1449   Status return_error;
1450 
1451   if (!frame_sp) {
1452     return_error.SetErrorString("Can't return to a null frame.");
1453     return return_error;
1454   }
1455 
1456   Thread *thread = frame_sp->GetThread().get();
1457   uint32_t older_frame_idx = frame_sp->GetFrameIndex() + 1;
1458   StackFrameSP older_frame_sp = thread->GetStackFrameAtIndex(older_frame_idx);
1459   if (!older_frame_sp) {
1460     return_error.SetErrorString("No older frame to return to.");
1461     return return_error;
1462   }
1463 
1464   if (return_value_sp) {
1465     lldb::ABISP abi = thread->GetProcess()->GetABI();
1466     if (!abi) {
1467       return_error.SetErrorString("Could not find ABI to set return value.");
1468       return return_error;
1469     }
1470     SymbolContext sc = frame_sp->GetSymbolContext(eSymbolContextFunction);
1471 
1472     // FIXME: ValueObject::Cast doesn't currently work correctly, at least not
1473     // for scalars.
1474     // Turn that back on when that works.
1475     if (/* DISABLES CODE */ (false) && sc.function != nullptr) {
1476       Type *function_type = sc.function->GetType();
1477       if (function_type) {
1478         CompilerType return_type =
1479             sc.function->GetCompilerType().GetFunctionReturnType();
1480         if (return_type) {
1481           StreamString s;
1482           return_type.DumpTypeDescription(&s);
1483           ValueObjectSP cast_value_sp = return_value_sp->Cast(return_type);
1484           if (cast_value_sp) {
1485             cast_value_sp->SetFormat(eFormatHex);
1486             return_value_sp = cast_value_sp;
1487           }
1488         }
1489       }
1490     }
1491 
1492     return_error = abi->SetReturnValueObject(older_frame_sp, return_value_sp);
1493     if (!return_error.Success())
1494       return return_error;
1495   }
1496 
1497   // Now write the return registers for the chosen frame: Note, we can't use
1498   // ReadAllRegisterValues->WriteAllRegisterValues, since the read & write cook
1499   // their data
1500 
1501   StackFrameSP youngest_frame_sp = thread->GetStackFrameAtIndex(0);
1502   if (youngest_frame_sp) {
1503     lldb::RegisterContextSP reg_ctx_sp(youngest_frame_sp->GetRegisterContext());
1504     if (reg_ctx_sp) {
1505       bool copy_success = reg_ctx_sp->CopyFromRegisterContext(
1506           older_frame_sp->GetRegisterContext());
1507       if (copy_success) {
1508         thread->DiscardThreadPlans(true);
1509         thread->ClearStackFrames();
1510         if (broadcast && EventTypeHasListeners(eBroadcastBitStackChanged))
1511           BroadcastEvent(eBroadcastBitStackChanged,
1512                          new ThreadEventData(this->shared_from_this()));
1513       } else {
1514         return_error.SetErrorString("Could not reset register values.");
1515       }
1516     } else {
1517       return_error.SetErrorString("Frame has no register context.");
1518     }
1519   } else {
1520     return_error.SetErrorString("Returned past top frame.");
1521   }
1522   return return_error;
1523 }
1524 
1525 static void DumpAddressList(Stream &s, const std::vector<Address> &list,
1526                             ExecutionContextScope *exe_scope) {
1527   for (size_t n = 0; n < list.size(); n++) {
1528     s << "\t";
1529     list[n].Dump(&s, exe_scope, Address::DumpStyleResolvedDescription,
1530                  Address::DumpStyleSectionNameOffset);
1531     s << "\n";
1532   }
1533 }
1534 
1535 Status Thread::JumpToLine(const FileSpec &file, uint32_t line,
1536                           bool can_leave_function, std::string *warnings) {
1537   ExecutionContext exe_ctx(GetStackFrameAtIndex(0));
1538   Target *target = exe_ctx.GetTargetPtr();
1539   TargetSP target_sp = exe_ctx.GetTargetSP();
1540   RegisterContext *reg_ctx = exe_ctx.GetRegisterContext();
1541   StackFrame *frame = exe_ctx.GetFramePtr();
1542   const SymbolContext &sc = frame->GetSymbolContext(eSymbolContextFunction);
1543 
1544   // Find candidate locations.
1545   std::vector<Address> candidates, within_function, outside_function;
1546   target->GetImages().FindAddressesForLine(target_sp, file, line, sc.function,
1547                                            within_function, outside_function);
1548 
1549   // If possible, we try and stay within the current function. Within a
1550   // function, we accept multiple locations (optimized code may do this,
1551   // there's no solution here so we do the best we can). However if we're
1552   // trying to leave the function, we don't know how to pick the right
1553   // location, so if there's more than one then we bail.
1554   if (!within_function.empty())
1555     candidates = within_function;
1556   else if (outside_function.size() == 1 && can_leave_function)
1557     candidates = outside_function;
1558 
1559   // Check if we got anything.
1560   if (candidates.empty()) {
1561     if (outside_function.empty()) {
1562       return Status("Cannot locate an address for %s:%i.",
1563                     file.GetFilename().AsCString(), line);
1564     } else if (outside_function.size() == 1) {
1565       return Status("%s:%i is outside the current function.",
1566                     file.GetFilename().AsCString(), line);
1567     } else {
1568       StreamString sstr;
1569       DumpAddressList(sstr, outside_function, target);
1570       return Status("%s:%i has multiple candidate locations:\n%s",
1571                     file.GetFilename().AsCString(), line, sstr.GetData());
1572     }
1573   }
1574 
1575   // Accept the first location, warn about any others.
1576   Address dest = candidates[0];
1577   if (warnings && candidates.size() > 1) {
1578     StreamString sstr;
1579     sstr.Printf("%s:%i appears multiple times in this function, selecting the "
1580                 "first location:\n",
1581                 file.GetFilename().AsCString(), line);
1582     DumpAddressList(sstr, candidates, target);
1583     *warnings = std::string(sstr.GetString());
1584   }
1585 
1586   if (!reg_ctx->SetPC(dest))
1587     return Status("Cannot change PC to target address.");
1588 
1589   return Status();
1590 }
1591 
1592 bool Thread::DumpUsingFormat(Stream &strm, uint32_t frame_idx,
1593                              const FormatEntity::Entry *format) {
1594   ExecutionContext exe_ctx(shared_from_this());
1595   Process *process = exe_ctx.GetProcessPtr();
1596   if (!process || !format)
1597     return false;
1598 
1599   StackFrameSP frame_sp;
1600   SymbolContext frame_sc;
1601   if (frame_idx != LLDB_INVALID_FRAME_ID) {
1602     frame_sp = GetStackFrameAtIndex(frame_idx);
1603     if (frame_sp) {
1604       exe_ctx.SetFrameSP(frame_sp);
1605       frame_sc = frame_sp->GetSymbolContext(eSymbolContextEverything);
1606     }
1607   }
1608 
1609   return FormatEntity::Format(*format, strm, frame_sp ? &frame_sc : nullptr,
1610                               &exe_ctx, nullptr, nullptr, false, false);
1611 }
1612 
1613 void Thread::DumpUsingSettingsFormat(Stream &strm, uint32_t frame_idx,
1614                                      bool stop_format) {
1615   ExecutionContext exe_ctx(shared_from_this());
1616 
1617   const FormatEntity::Entry *thread_format;
1618   if (stop_format)
1619     thread_format = exe_ctx.GetTargetRef().GetDebugger().GetThreadStopFormat();
1620   else
1621     thread_format = exe_ctx.GetTargetRef().GetDebugger().GetThreadFormat();
1622 
1623   assert(thread_format);
1624 
1625   DumpUsingFormat(strm, frame_idx, thread_format);
1626 }
1627 
1628 void Thread::SettingsInitialize() {}
1629 
1630 void Thread::SettingsTerminate() {}
1631 
1632 lldb::addr_t Thread::GetThreadPointer() {
1633   if (m_reg_context_sp)
1634     return m_reg_context_sp->GetThreadPointer();
1635   return LLDB_INVALID_ADDRESS;
1636 }
1637 
1638 addr_t Thread::GetThreadLocalData(const ModuleSP module,
1639                                   lldb::addr_t tls_file_addr) {
1640   // The default implementation is to ask the dynamic loader for it. This can
1641   // be overridden for specific platforms.
1642   DynamicLoader *loader = GetProcess()->GetDynamicLoader();
1643   if (loader)
1644     return loader->GetThreadLocalData(module, shared_from_this(),
1645                                       tls_file_addr);
1646   else
1647     return LLDB_INVALID_ADDRESS;
1648 }
1649 
1650 bool Thread::SafeToCallFunctions() {
1651   Process *process = GetProcess().get();
1652   if (process) {
1653     DynamicLoader *loader = GetProcess()->GetDynamicLoader();
1654     if (loader && loader->IsFullyInitialized() == false)
1655       return false;
1656 
1657     SystemRuntime *runtime = process->GetSystemRuntime();
1658     if (runtime) {
1659       return runtime->SafeToCallFunctionsOnThisThread(shared_from_this());
1660     }
1661   }
1662   return true;
1663 }
1664 
1665 lldb::StackFrameSP
1666 Thread::GetStackFrameSPForStackFramePtr(StackFrame *stack_frame_ptr) {
1667   return GetStackFrameList()->GetStackFrameSPForStackFramePtr(stack_frame_ptr);
1668 }
1669 
1670 std::string Thread::StopReasonAsString(lldb::StopReason reason) {
1671   switch (reason) {
1672   case eStopReasonInvalid:
1673     return "invalid";
1674   case eStopReasonNone:
1675     return "none";
1676   case eStopReasonTrace:
1677     return "trace";
1678   case eStopReasonBreakpoint:
1679     return "breakpoint";
1680   case eStopReasonWatchpoint:
1681     return "watchpoint";
1682   case eStopReasonSignal:
1683     return "signal";
1684   case eStopReasonException:
1685     return "exception";
1686   case eStopReasonExec:
1687     return "exec";
1688   case eStopReasonFork:
1689     return "fork";
1690   case eStopReasonVFork:
1691     return "vfork";
1692   case eStopReasonVForkDone:
1693     return "vfork done";
1694   case eStopReasonPlanComplete:
1695     return "plan complete";
1696   case eStopReasonThreadExiting:
1697     return "thread exiting";
1698   case eStopReasonInstrumentation:
1699     return "instrumentation break";
1700   case eStopReasonProcessorTrace:
1701     return "processor trace";
1702   }
1703 
1704   return "StopReason = " + std::to_string(reason);
1705 }
1706 
1707 std::string Thread::RunModeAsString(lldb::RunMode mode) {
1708   switch (mode) {
1709   case eOnlyThisThread:
1710     return "only this thread";
1711   case eAllThreads:
1712     return "all threads";
1713   case eOnlyDuringStepping:
1714     return "only during stepping";
1715   }
1716 
1717   return "RunMode = " + std::to_string(mode);
1718 }
1719 
1720 size_t Thread::GetStatus(Stream &strm, uint32_t start_frame,
1721                          uint32_t num_frames, uint32_t num_frames_with_source,
1722                          bool stop_format, bool only_stacks) {
1723 
1724   if (!only_stacks) {
1725     ExecutionContext exe_ctx(shared_from_this());
1726     Target *target = exe_ctx.GetTargetPtr();
1727     Process *process = exe_ctx.GetProcessPtr();
1728     strm.Indent();
1729     bool is_selected = false;
1730     if (process) {
1731       if (process->GetThreadList().GetSelectedThread().get() == this)
1732         is_selected = true;
1733     }
1734     strm.Printf("%c ", is_selected ? '*' : ' ');
1735     if (target && target->GetDebugger().GetUseExternalEditor()) {
1736       StackFrameSP frame_sp = GetStackFrameAtIndex(start_frame);
1737       if (frame_sp) {
1738         SymbolContext frame_sc(
1739             frame_sp->GetSymbolContext(eSymbolContextLineEntry));
1740         if (frame_sc.line_entry.line != 0 && frame_sc.line_entry.file) {
1741           if (llvm::Error e = Host::OpenFileInExternalEditor(
1742                   target->GetDebugger().GetExternalEditor(),
1743                   frame_sc.line_entry.file, frame_sc.line_entry.line)) {
1744             LLDB_LOG_ERROR(GetLog(LLDBLog::Host), std::move(e),
1745                            "OpenFileInExternalEditor failed: {0}");
1746           }
1747         }
1748       }
1749     }
1750 
1751     DumpUsingSettingsFormat(strm, start_frame, stop_format);
1752   }
1753 
1754   size_t num_frames_shown = 0;
1755   if (num_frames > 0) {
1756     strm.IndentMore();
1757 
1758     const bool show_frame_info = true;
1759     const bool show_frame_unique = only_stacks;
1760     const char *selected_frame_marker = nullptr;
1761     if (num_frames == 1 || only_stacks ||
1762         (GetID() != GetProcess()->GetThreadList().GetSelectedThread()->GetID()))
1763       strm.IndentMore();
1764     else
1765       selected_frame_marker = "* ";
1766 
1767     num_frames_shown = GetStackFrameList()->GetStatus(
1768         strm, start_frame, num_frames, show_frame_info, num_frames_with_source,
1769         show_frame_unique, selected_frame_marker);
1770     if (num_frames == 1)
1771       strm.IndentLess();
1772     strm.IndentLess();
1773   }
1774   return num_frames_shown;
1775 }
1776 
1777 bool Thread::GetDescription(Stream &strm, lldb::DescriptionLevel level,
1778                             bool print_json_thread, bool print_json_stopinfo) {
1779   const bool stop_format = false;
1780   DumpUsingSettingsFormat(strm, 0, stop_format);
1781   strm.Printf("\n");
1782 
1783   StructuredData::ObjectSP thread_info = GetExtendedInfo();
1784 
1785   if (print_json_thread || print_json_stopinfo) {
1786     if (thread_info && print_json_thread) {
1787       thread_info->Dump(strm);
1788       strm.Printf("\n");
1789     }
1790 
1791     if (print_json_stopinfo && m_stop_info_sp) {
1792       StructuredData::ObjectSP stop_info = m_stop_info_sp->GetExtendedInfo();
1793       if (stop_info) {
1794         stop_info->Dump(strm);
1795         strm.Printf("\n");
1796       }
1797     }
1798 
1799     return true;
1800   }
1801 
1802   if (thread_info) {
1803     StructuredData::ObjectSP activity =
1804         thread_info->GetObjectForDotSeparatedPath("activity");
1805     StructuredData::ObjectSP breadcrumb =
1806         thread_info->GetObjectForDotSeparatedPath("breadcrumb");
1807     StructuredData::ObjectSP messages =
1808         thread_info->GetObjectForDotSeparatedPath("trace_messages");
1809 
1810     bool printed_activity = false;
1811     if (activity && activity->GetType() == eStructuredDataTypeDictionary) {
1812       StructuredData::Dictionary *activity_dict = activity->GetAsDictionary();
1813       StructuredData::ObjectSP id = activity_dict->GetValueForKey("id");
1814       StructuredData::ObjectSP name = activity_dict->GetValueForKey("name");
1815       if (name && name->GetType() == eStructuredDataTypeString && id &&
1816           id->GetType() == eStructuredDataTypeInteger) {
1817         strm.Format("  Activity '{0}', {1:x}\n",
1818                     name->GetAsString()->GetValue(),
1819                     id->GetUnsignedIntegerValue());
1820       }
1821       printed_activity = true;
1822     }
1823     bool printed_breadcrumb = false;
1824     if (breadcrumb && breadcrumb->GetType() == eStructuredDataTypeDictionary) {
1825       if (printed_activity)
1826         strm.Printf("\n");
1827       StructuredData::Dictionary *breadcrumb_dict =
1828           breadcrumb->GetAsDictionary();
1829       StructuredData::ObjectSP breadcrumb_text =
1830           breadcrumb_dict->GetValueForKey("name");
1831       if (breadcrumb_text &&
1832           breadcrumb_text->GetType() == eStructuredDataTypeString) {
1833         strm.Format("  Current Breadcrumb: {0}\n",
1834                     breadcrumb_text->GetAsString()->GetValue());
1835       }
1836       printed_breadcrumb = true;
1837     }
1838     if (messages && messages->GetType() == eStructuredDataTypeArray) {
1839       if (printed_breadcrumb)
1840         strm.Printf("\n");
1841       StructuredData::Array *messages_array = messages->GetAsArray();
1842       const size_t msg_count = messages_array->GetSize();
1843       if (msg_count > 0) {
1844         strm.Printf("  %zu trace messages:\n", msg_count);
1845         for (size_t i = 0; i < msg_count; i++) {
1846           StructuredData::ObjectSP message = messages_array->GetItemAtIndex(i);
1847           if (message && message->GetType() == eStructuredDataTypeDictionary) {
1848             StructuredData::Dictionary *message_dict =
1849                 message->GetAsDictionary();
1850             StructuredData::ObjectSP message_text =
1851                 message_dict->GetValueForKey("message");
1852             if (message_text &&
1853                 message_text->GetType() == eStructuredDataTypeString) {
1854               strm.Format("    {0}\n", message_text->GetAsString()->GetValue());
1855             }
1856           }
1857         }
1858       }
1859     }
1860   }
1861 
1862   return true;
1863 }
1864 
1865 size_t Thread::GetStackFrameStatus(Stream &strm, uint32_t first_frame,
1866                                    uint32_t num_frames, bool show_frame_info,
1867                                    uint32_t num_frames_with_source) {
1868   return GetStackFrameList()->GetStatus(
1869       strm, first_frame, num_frames, show_frame_info, num_frames_with_source);
1870 }
1871 
1872 Unwind &Thread::GetUnwinder() {
1873   if (!m_unwinder_up)
1874     m_unwinder_up = std::make_unique<UnwindLLDB>(*this);
1875   return *m_unwinder_up;
1876 }
1877 
1878 void Thread::Flush() {
1879   ClearStackFrames();
1880   m_reg_context_sp.reset();
1881 }
1882 
1883 bool Thread::IsStillAtLastBreakpointHit() {
1884   // If we are currently stopped at a breakpoint, always return that stopinfo
1885   // and don't reset it. This allows threads to maintain their breakpoint
1886   // stopinfo, such as when thread-stepping in multithreaded programs.
1887   if (m_stop_info_sp) {
1888     StopReason stop_reason = m_stop_info_sp->GetStopReason();
1889     if (stop_reason == lldb::eStopReasonBreakpoint) {
1890       uint64_t value = m_stop_info_sp->GetValue();
1891       lldb::RegisterContextSP reg_ctx_sp(GetRegisterContext());
1892       if (reg_ctx_sp) {
1893         lldb::addr_t pc = reg_ctx_sp->GetPC();
1894         BreakpointSiteSP bp_site_sp =
1895             GetProcess()->GetBreakpointSiteList().FindByAddress(pc);
1896         if (bp_site_sp && static_cast<break_id_t>(value) == bp_site_sp->GetID())
1897           return true;
1898       }
1899     }
1900   }
1901   return false;
1902 }
1903 
1904 Status Thread::StepIn(bool source_step,
1905                       LazyBool step_in_avoids_code_without_debug_info,
1906                       LazyBool step_out_avoids_code_without_debug_info)
1907 
1908 {
1909   Status error;
1910   Process *process = GetProcess().get();
1911   if (StateIsStoppedState(process->GetState(), true)) {
1912     StackFrameSP frame_sp = GetStackFrameAtIndex(0);
1913     ThreadPlanSP new_plan_sp;
1914     const lldb::RunMode run_mode = eOnlyThisThread;
1915     const bool abort_other_plans = false;
1916 
1917     if (source_step && frame_sp && frame_sp->HasDebugInformation()) {
1918       SymbolContext sc(frame_sp->GetSymbolContext(eSymbolContextEverything));
1919       new_plan_sp = QueueThreadPlanForStepInRange(
1920           abort_other_plans, sc.line_entry, sc, nullptr, run_mode, error,
1921           step_in_avoids_code_without_debug_info,
1922           step_out_avoids_code_without_debug_info);
1923     } else {
1924       new_plan_sp = QueueThreadPlanForStepSingleInstruction(
1925           false, abort_other_plans, run_mode, error);
1926     }
1927 
1928     new_plan_sp->SetIsControllingPlan(true);
1929     new_plan_sp->SetOkayToDiscard(false);
1930 
1931     // Why do we need to set the current thread by ID here???
1932     process->GetThreadList().SetSelectedThreadByID(GetID());
1933     error = process->Resume();
1934   } else {
1935     error.SetErrorString("process not stopped");
1936   }
1937   return error;
1938 }
1939 
1940 Status Thread::StepOver(bool source_step,
1941                         LazyBool step_out_avoids_code_without_debug_info) {
1942   Status error;
1943   Process *process = GetProcess().get();
1944   if (StateIsStoppedState(process->GetState(), true)) {
1945     StackFrameSP frame_sp = GetStackFrameAtIndex(0);
1946     ThreadPlanSP new_plan_sp;
1947 
1948     const lldb::RunMode run_mode = eOnlyThisThread;
1949     const bool abort_other_plans = false;
1950 
1951     if (source_step && frame_sp && frame_sp->HasDebugInformation()) {
1952       SymbolContext sc(frame_sp->GetSymbolContext(eSymbolContextEverything));
1953       new_plan_sp = QueueThreadPlanForStepOverRange(
1954           abort_other_plans, sc.line_entry, sc, run_mode, error,
1955           step_out_avoids_code_without_debug_info);
1956     } else {
1957       new_plan_sp = QueueThreadPlanForStepSingleInstruction(
1958           true, abort_other_plans, run_mode, error);
1959     }
1960 
1961     new_plan_sp->SetIsControllingPlan(true);
1962     new_plan_sp->SetOkayToDiscard(false);
1963 
1964     // Why do we need to set the current thread by ID here???
1965     process->GetThreadList().SetSelectedThreadByID(GetID());
1966     error = process->Resume();
1967   } else {
1968     error.SetErrorString("process not stopped");
1969   }
1970   return error;
1971 }
1972 
1973 Status Thread::StepOut(uint32_t frame_idx) {
1974   Status error;
1975   Process *process = GetProcess().get();
1976   if (StateIsStoppedState(process->GetState(), true)) {
1977     const bool first_instruction = false;
1978     const bool stop_other_threads = false;
1979     const bool abort_other_plans = false;
1980 
1981     ThreadPlanSP new_plan_sp(QueueThreadPlanForStepOut(
1982         abort_other_plans, nullptr, first_instruction, stop_other_threads,
1983         eVoteYes, eVoteNoOpinion, frame_idx, error));
1984 
1985     new_plan_sp->SetIsControllingPlan(true);
1986     new_plan_sp->SetOkayToDiscard(false);
1987 
1988     // Why do we need to set the current thread by ID here???
1989     process->GetThreadList().SetSelectedThreadByID(GetID());
1990     error = process->Resume();
1991   } else {
1992     error.SetErrorString("process not stopped");
1993   }
1994   return error;
1995 }
1996 
1997 ValueObjectSP Thread::GetCurrentException() {
1998   if (auto frame_sp = GetStackFrameAtIndex(0))
1999     if (auto recognized_frame = frame_sp->GetRecognizedFrame())
2000       if (auto e = recognized_frame->GetExceptionObject())
2001         return e;
2002 
2003   // NOTE: Even though this behavior is generalized, only ObjC is actually
2004   // supported at the moment.
2005   for (LanguageRuntime *runtime : GetProcess()->GetLanguageRuntimes()) {
2006     if (auto e = runtime->GetExceptionObjectForThread(shared_from_this()))
2007       return e;
2008   }
2009 
2010   return ValueObjectSP();
2011 }
2012 
2013 ThreadSP Thread::GetCurrentExceptionBacktrace() {
2014   ValueObjectSP exception = GetCurrentException();
2015   if (!exception)
2016     return ThreadSP();
2017 
2018   // NOTE: Even though this behavior is generalized, only ObjC is actually
2019   // supported at the moment.
2020   for (LanguageRuntime *runtime : GetProcess()->GetLanguageRuntimes()) {
2021     if (auto bt = runtime->GetBacktraceThreadFromException(exception))
2022       return bt;
2023   }
2024 
2025   return ThreadSP();
2026 }
2027 
2028 lldb::ValueObjectSP Thread::GetSiginfoValue() {
2029   ProcessSP process_sp = GetProcess();
2030   assert(process_sp);
2031   Target &target = process_sp->GetTarget();
2032   PlatformSP platform_sp = target.GetPlatform();
2033   assert(platform_sp);
2034   ArchSpec arch = target.GetArchitecture();
2035 
2036   CompilerType type = platform_sp->GetSiginfoType(arch.GetTriple());
2037   if (!type.IsValid())
2038     return ValueObjectConstResult::Create(&target, Status("no siginfo_t for the platform"));
2039 
2040   std::optional<uint64_t> type_size = type.GetByteSize(nullptr);
2041   assert(type_size);
2042   llvm::Expected<std::unique_ptr<llvm::MemoryBuffer>> data =
2043       GetSiginfo(*type_size);
2044   if (!data)
2045     return ValueObjectConstResult::Create(&target, Status(data.takeError()));
2046 
2047   DataExtractor data_extractor{data.get()->getBufferStart(), data.get()->getBufferSize(),
2048     process_sp->GetByteOrder(), arch.GetAddressByteSize()};
2049   return ValueObjectConstResult::Create(&target, type, ConstString("__lldb_siginfo"), data_extractor);
2050 }
2051