Make String::Empty inlineable.

include/v8.h

 // Copyright 2012 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 1066 matching lines @@
   // UTF-8 encoded characters.
   V8EXPORT int WriteUtf8(char* buffer,
                          int length = -1,
                          int* nchars_ref = NULL,
                          int options = NO_OPTIONS) const;
 
   /**
    * A zero length string.
    */
   V8EXPORT static v8::Local<v8::String> Empty();
+  inline static v8::Local<v8::String> Empty(Isolate* isolate);
 
   /**
    * Returns true if the string is external
    */
   V8EXPORT bool IsExternal() const;
 
   /**
    * Returns true if the string is both external and ASCII
    */
   V8EXPORT bool IsExternalAscii() const;
@@ skipping 2799 matching lines @@
   static const int kFullStringRepresentationMask = 0x07;
   static const int kExternalTwoByteRepresentationTag = 0x02;
 
   static const int kIsolateStateOffset = 0;
   static const int kIsolateEmbedderDataOffset = 1 * kApiPointerSize;
   static const int kIsolateRootsOffset = 3 * kApiPointerSize;
   static const int kUndefinedValueRootIndex = 5;
   static const int kNullValueRootIndex = 7;
   static const int kTrueValueRootIndex = 8;
   static const int kFalseValueRootIndex = 9;
+  static const int kEmptySymbolRootIndex = 128;
 
   static const int kJSObjectType = 0xaa;
   static const int kFirstNonstringType = 0x80;
   static const int kOddballType = 0x82;
   static const int kForeignType = 0x85;
 
   static const int kUndefinedOddballKind = 5;
   static const int kNullOddballKind = 3;
 
   static inline bool HasHeapObjectTag(internal::Object* value) {
@@ skipping 298 matching lines @@
 
 
 String* String::Cast(v8::Value* value) {
 #ifdef V8_ENABLE_CHECKS
   CheckCast(value);
 #endif
   return static_cast<String*>(value);
 }
 
 
+Local<String> String::Empty(Isolate* isolate) {
+  typedef internal::Object* S;
+  typedef internal::Internals I;
+  if (!I::IsInitialized(isolate)) return Empty();
+  S* slot = I::GetRoot(isolate, I::kEmptySymbolRootIndex);
+  return Local<String>(reinterpret_cast<String*>(slot));
+}
+
+
 String::ExternalStringResource* String::GetExternalStringResource() const {
   typedef internal::Object O;
   typedef internal::Internals I;
   O* obj = *reinterpret_cast<O**>(const_cast<String*>(this));
   String::ExternalStringResource* result;
   if (I::IsExternalTwoByteString(I::GetInstanceType(obj))) {
     void* value = I::ReadField<void*>(obj, I::kStringResourceOffset);
     result = reinterpret_cast<String::ExternalStringResource*>(value);
   } else {
     result = NULL;
@@ skipping 227 matching lines @@
 
 
 }  // namespace v8
 
 
 #undef V8EXPORT
 #undef TYPE_CHECK
 
 
 #endif  // V8_H_