Add support for innerloop Time-Travel Debugging

Author: mrkmarron

deps/chakrashim/include/v8-debug.h

@@ -86,7 +86,7 @@ class V8_EXPORT Debug {
   static void ProcessDebugMessages(Isolate* isolate) {}
   static Local<Context> GetDebugContext(Isolate* isolate);
 
-  static void EnableInspector(bool enableReplayDebug = false);
+  static void EnableInspector(bool enableTTDebug = false);
 
   static void SetLiveEditEnabled(Isolate* isolate, bool enable);
 };

deps/chakrashim/src/inspector/js_protocol.json

@@ -782,6 +782,13 @@
         "domain": "TimeTravel",
         "description": "TimeTravel domain exposes JavaScript time travel capabilities. It allows stepping backwards through execution.",
         "commands": [
+            {
+              "name": "writeTTDLog",
+              "parameters": [
+                    { "name": "uri", "type": "string", "description": "Location to write time-travel log." }
+                ],
+                "description": "Write a TTD log to the given location"
+            },
             {
                 "name": "stepBack",
                 "description": "Steps backwards to the previous statement."

deps/chakrashim/src/inspector/v8-debugger-agent-impl.cc

@@ -668,6 +668,11 @@ void V8DebuggerAgentImpl::reverse(ErrorString* errorString) {
   m_debugger->reverse();
 }
 
+void V8DebuggerAgentImpl::writeTTDLog(ErrorString* errorString, const String16& uri) {
+  if (!assertPaused(errorString)) return;
+  m_debugger->writeTTDLog(uri);
+}
+
 void V8DebuggerAgentImpl::stepBack(ErrorString* errorString) {
   if (!assertPaused(errorString)) return;
   m_scheduledDebuggerStep = StepBack;

deps/chakrashim/src/inspector/v8-debugger-agent-impl.h

@@ -111,6 +111,7 @@ class V8DebuggerAgentImpl : public protocol::Debugger::Backend {
           positions) override;
 
   // Time travel implementations
+  void writeTTDLog(ErrorString*, const String16&);
   void reverse(ErrorString*);
   void stepBack(ErrorString*);
 

deps/chakrashim/src/inspector/v8-debugger.cc

@@ -249,6 +249,12 @@ void V8Debugger::clearStepping() {
   JsDiagSetStepType(JsDiagStepTypeContinue);
 }
 
+void V8Debugger::writeTTDLog(const String16& uri) {
+  DCHECK(isPaused());
+  auto sval = uri.utf8();
+  JsTTDDiagWriteLog(sval.c_str(), sval.length());
+}
+
 void V8Debugger::reverse() {
   DCHECK(isPaused());
   JsDiagSetStepType(JsDiagStepTypeReverseContinue);

deps/chakrashim/src/inspector/v8-debugger.h

@@ -59,6 +59,7 @@ class V8Debugger {
   void clearStepping();
 
   // Time travel
+  void writeTTDLog(const String16& uri);
   void reverse();
   void stepBack();
 

deps/chakrashim/src/inspector/v8-timetravel-agent-impl.cc

@@ -28,7 +28,15 @@ bool V8TimeTravelAgentImpl::checkEnabled(ErrorString* errorString) {
 }
 
 bool V8TimeTravelAgentImpl::enabled() {
-  return jsrt::Inspector::IsReplayDebugEnabled();
+  return jsrt::Inspector::IsTTDebugEnabled();
+}
+
+void V8TimeTravelAgentImpl::writeTTDLog(ErrorString* errorString, const String16& uri) {
+  if(!checkEnabled(errorString)) {
+    return;
+  }
+
+  m_session->debuggerAgent()->writeTTDLog(errorString, uri);
 }
 
 void V8TimeTravelAgentImpl::reverse(ErrorString* errorString) {

deps/chakrashim/src/inspector/v8-timetravel-agent-impl.h

@@ -26,6 +26,7 @@ class V8TimeTravelAgentImpl : public protocol::TimeTravel::Backend {
   ~V8TimeTravelAgentImpl() override;
 
   // Part of the protocol.
+  void writeTTDLog(ErrorString*, const String16&) override;
   void reverse(ErrorString*) override;
   void stepBack(ErrorString*) override;
 

deps/chakrashim/src/jsrtinspector.cc

@@ -26,7 +26,7 @@
 
 namespace v8 {
   extern THREAD_LOCAL bool g_EnableInspector;
-  extern THREAD_LOCAL bool g_EnableReplayDebug;
+  extern THREAD_LOCAL bool g_EnableTTDebug;
 }
 
 namespace jsrt {
@@ -160,8 +160,8 @@ bool Inspector::IsInspectorEnabled() {
   return v8::g_EnableInspector;
 }
 
-bool Inspector::IsReplayDebugEnabled() {
-  return v8::g_EnableReplayDebug;
+bool Inspector::IsTTDebugEnabled() {
+  return v8::g_EnableTTDebug;
 }
 
 void Inspector::StartDebugging(JsRuntimeHandle runtime) {

deps/chakrashim/src/jsrtinspector.h

@@ -30,7 +30,7 @@ class InspectorBreakQueue;
 class Inspector {
  public:
   static bool IsInspectorEnabled();
-  static bool IsReplayDebugEnabled();
+  static bool IsTTDebugEnabled();
   static void StartDebugging(JsRuntimeHandle runtime);
   static void RequestAsyncBreak(JsRuntimeHandle runtime,
                                 v8::InterruptCallback callback,