Expose well-known Symbols to C++ API.

src/api.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/api.h"
 
 #include <string.h>  // For memcpy, strlen.
 #ifdef V8_USE_ADDRESS_SANITIZER
 #include <sanitizer/asan_interface.h>
 #endif  // V8_USE_ADDRESS_SANITIZER
@@ skipping 6134 matching lines @@
   i::Isolate* i_isolate = reinterpret_cast<i::Isolate*>(isolate);
   EnsureInitializedForIsolate(i_isolate, "v8::Symbol::New()");
   LOG_API(i_isolate, "Symbol::New()");
   ENTER_V8(i_isolate);
   i::Handle<i::Symbol> result = i_isolate->factory()->NewSymbol();
   if (!name.IsEmpty()) result->set_name(*Utils::OpenHandle(*name));
   return Utils::ToLocal(result);
 }
 
 
+static i::Handle<i::Symbol> SymbolFor(i::Isolate* isolate,
+                                      i::Handle<i::String> name,
+                                      i::Handle<i::String> part) {
+  i::Handle<i::JSObject> registry = isolate->GetSymbolRegistry();
+  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, name).ToHandleChecked();
+  if (!symbol->IsSymbol()) {
+    DCHECK(symbol->IsUndefined());
+    symbol = isolate->factory()->NewSymbol();
+    i::Handle<i::Symbol>::cast(symbol)->set_name(*name);
+    i::JSObject::SetProperty(symbols, name, symbol, i::STRICT).Assert();
+  }
+  return i::Handle<i::Symbol>::cast(symbol);
+}
+
+
 Local<Symbol> v8::Symbol::For(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_string();
-  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));
+  return Utils::ToLocal(SymbolFor(i_isolate, i_name, part));
 }
 
 
 Local<Symbol> v8::Symbol::ForApi(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_api_string();
-  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));
+  return Utils::ToLocal(SymbolFor(i_isolate, i_name, part));
 }
 
 
+static Local<Symbol> GetWellKnownSymbol(Isolate* isolate, const char* name) {
+  i::Isolate* i_isolate = reinterpret_cast<i::Isolate*>(isolate);
+  i::Handle<i::String> i_name =
+      Utils::OpenHandle(*String::NewFromUtf8(isolate, name));
+  i::Handle<i::String> part = i_isolate->factory()->for_intern_string();
+  return Utils::ToLocal(SymbolFor(i_isolate, i_name, part));
+}
+
+
+Local<Symbol> v8::Symbol::GetIterator(Isolate* isolate) {
+  return GetWellKnownSymbol(isolate, "Symbol.iterator");
+}
+
+
+Local<Symbol> v8::Symbol::GetUnscopables(Isolate* isolate) {
+  return GetWellKnownSymbol(isolate, "Symbol.unscopables");
+}
+
+
 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()");
   LOG_API(i_isolate, "Private::New()");
   ENTER_V8(i_isolate);
   i::Handle<i::Symbol> symbol = i_isolate->factory()->NewPrivateSymbol();
   if (!name.IsEmpty()) symbol->set_name(*Utils::OpenHandle(*name));
   Local<Symbol> result = Utils::ToLocal(symbol);
   return v8::Handle<Private>(reinterpret_cast<Private*>(*result));
 }
@@ skipping 1440 matching lines @@
   Isolate* isolate = reinterpret_cast<Isolate*>(info.GetIsolate());
   Address callback_address =
       reinterpret_cast<Address>(reinterpret_cast<intptr_t>(callback));
   VMState<EXTERNAL> state(isolate);
   ExternalCallbackScope call_scope(isolate, callback_address);
   callback(info);
 }
 
 
 } }  // namespace v8::internal