Extend GCMole with poor man's data flow analysis to catch dead raw pointer vars.

src/liveedit.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 509 matching lines @@
 
 
 // Unwraps JSValue object, returning its field "value"
 static Handle<Object> UnwrapJSValue(Handle<JSValue> jsValue) {
   return Handle<Object>(jsValue->value());
 }
 
 
 // Wraps any object into a OpaqueReference, that will hide the object
 // from JavaScript.
-static Handle<JSValue> WrapInJSValue(Object* object) {
+static Handle<JSValue> WrapInJSValue(Handle<Object> object) {
   Handle<JSFunction> constructor =
       Isolate::Current()->opaque_reference_function();
   Handle<JSValue> result =
       Handle<JSValue>::cast(FACTORY->NewJSObject(constructor));
-  result->set_value(object);
+  result->set_value(*object);
   return result;
 }
 
 
 // Simple helper class that creates more or less typed structures over
 // JSArray object. This is an adhoc method of passing structures from C++
 // to JavaScript.
 template<typename S>
 class JSArrayBasedStruct {
  public:
@@ skipping 46 matching lines @@
                             int end_position, int param_num, int parent_index) {
     HandleScope scope;
     this->SetField(kFunctionNameOffset_, name);
     this->SetSmiValueField(kStartPositionOffset_, start_position);
     this->SetSmiValueField(kEndPositionOffset_, end_position);
     this->SetSmiValueField(kParamNumOffset_, param_num);
     this->SetSmiValueField(kParentIndexOffset_, parent_index);
   }
   void SetFunctionCode(Handle<Code> function_code,
       Handle<Object> code_scope_info) {
-    Handle<JSValue> code_wrapper = WrapInJSValue(*function_code);
+    Handle<JSValue> code_wrapper = WrapInJSValue(function_code);
     this->SetField(kCodeOffset_, code_wrapper);
 
-    Handle<JSValue> scope_wrapper = WrapInJSValue(*code_scope_info);
+    Handle<JSValue> scope_wrapper = WrapInJSValue(code_scope_info);
     this->SetField(kCodeScopeInfoOffset_, scope_wrapper);
   }
   void SetOuterScopeInfo(Handle<Object> scope_info_array) {
     this->SetField(kOuterScopeInfoOffset_, scope_info_array);
   }
   void SetSharedFunctionInfo(Handle<SharedFunctionInfo> info) {
-    Handle<JSValue> info_holder = WrapInJSValue(*info);
+    Handle<JSValue> info_holder = WrapInJSValue(info);
     this->SetField(kSharedFunctionInfoOffset_, info_holder);
   }
   int GetParentIndex() {
     return this->GetSmiValueField(kParentIndexOffset_);
   }
   Handle<Code> GetFunctionCode() {
     Handle<Object> raw_result = UnwrapJSValue(Handle<JSValue>(
         JSValue::cast(this->GetField(kCodeOffset_))));
     return Handle<Code>::cast(raw_result);
   }
@@ skipping 36 matching lines @@
   }
 
   explicit SharedInfoWrapper(Handle<JSArray> array)
       : JSArrayBasedStruct<SharedInfoWrapper>(array) {
   }
 
   void SetProperties(Handle<String> name, int start_position, int end_position,
                      Handle<SharedFunctionInfo> info) {
     HandleScope scope;
     this->SetField(kFunctionNameOffset_, name);
-    Handle<JSValue> info_holder = WrapInJSValue(*info);
+    Handle<JSValue> info_holder = WrapInJSValue(info);
     this->SetField(kSharedInfoOffset_, info_holder);
     this->SetSmiValueField(kStartPositionOffset_, start_position);
     this->SetSmiValueField(kEndPositionOffset_, end_position);
   }
   Handle<SharedFunctionInfo> GetInfo() {
     Object* element = this->GetField(kSharedInfoOffset_);
     Handle<JSValue> value_wrapper(JSValue::cast(element));
     Handle<Object> raw_result = UnwrapJSValue(value_wrapper);
     return Handle<SharedFunctionInfo>::cast(raw_result);
   }
@@ skipping 1001 matching lines @@
 
 bool LiveEditFunctionTracker::IsActive(Isolate* isolate) {
   return false;
 }
 
 #endif  // ENABLE_DEBUGGER_SUPPORT
 
 
 
 } }  // namespace v8::internal