Expose well-known Symbols to C++ API.

src/api.cc

Index: src/api.cc
diff --git a/src/api.cc b/src/api.cc
index 9093f4dd30d1c1023468da715d84a212953cbd26..ef0e4f2d28654c4a4c5fe331c028b0be6608fe49 100644
--- a/src/api.cc
+++ b/src/api.cc
@@ -6192,6 +6192,25 @@ Local<Symbol> v8::Symbol::ForApi(Isolate* isolate, Local<String> name) {
 }
 
 
+Local<Symbol> v8::Symbol::ForInternal(Isolate* isolate, Local<String> name) {
+  i::Isolate* i_isolate = reinterpret_cast<i::Isolate*>(isolate);
+  i::Handle<i::String> i_name = Utils::OpenHandle(*name);
+  i::Handle<i::JSObject> registry = i_isolate->GetSymbolRegistry();
+  i::Handle<i::String> part = i_isolate->factory()->for_intern_string();

[arv (Not doing code reviews), 2014/08/19 02:02:25]

Maybe it is time to refactor this into a function that is used by the 3 API
functions?

[yhirano, 2014/08/19 02:17:55]

Done.

+  i::Handle<i::JSObject> symbols = i::Handle<i::JSObject>::cast(
+      i::Object::GetPropertyOrElement(registry, part).ToHandleChecked());
+  i::Handle<i::Object> symbol =
+      i::Object::GetPropertyOrElement(symbols, i_name).ToHandleChecked();
+  if (!symbol->IsSymbol()) {
+    DCHECK(symbol->IsUndefined());
+    symbol = i_isolate->factory()->NewSymbol();
+    i::Handle<i::Symbol>::cast(symbol)->set_name(*i_name);
+    i::JSObject::SetProperty(symbols, i_name, symbol, i::STRICT).Assert();
+  }
+  return Utils::ToLocal(i::Handle<i::Symbol>::cast(symbol));
+}
+
+
 Local<Private> v8::Private::New(Isolate* isolate, Local<String> name) {
   i::Isolate* i_isolate = reinterpret_cast<i::Isolate*>(isolate);
   EnsureInitializedForIsolate(i_isolate, "v8::Private::New()");