Expose a way to make a "same-origin" realm

src/d8.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.
 
 
 // Defined when linking against shared lib on Windows.
 #if defined(USING_V8_SHARED) && !defined(V8_SHARED)
 #define V8_SHARED
 #endif
 
@@ skipping 505 matching lines @@
 // Realm.global(i) returns the global object of realm i.
 // (Note that properties of global objects cannot be read/written cross-realm.)
 void Shell::RealmGlobal(const v8::FunctionCallbackInfo<v8::Value>& args) {
   PerIsolateData* data = PerIsolateData::Get(args.GetIsolate());
   int index = data->RealmIndexOrThrow(args, 0);
   if (index == -1) return;
   args.GetReturnValue().Set(
       Local<Context>::New(args.GetIsolate(), data->realms_[index])->Global());
 }
 
-
-// Realm.create() creates a new realm and returns its index.
-void Shell::RealmCreate(const v8::FunctionCallbackInfo<v8::Value>& args) {
+MaybeLocal<Context> Shell::CreateRealm(
+    const v8::FunctionCallbackInfo<v8::Value>& args) {
   Isolate* isolate = args.GetIsolate();
   TryCatch try_catch(isolate);
   PerIsolateData* data = PerIsolateData::Get(isolate);
   Global<Context>* old_realms = data->realms_;
   int index = data->realm_count_;
   data->realms_ = new Global<Context>[++data->realm_count_];
   for (int i = 0; i < index; ++i) {
     data->realms_[i].Reset(isolate, old_realms[i]);
     old_realms[i].Reset();
   }
   delete[] old_realms;
   Local<ObjectTemplate> global_template = CreateGlobalTemplate(isolate);
   Local<Context> context = Context::New(isolate, NULL, global_template);
   if (context.IsEmpty()) {
     DCHECK(try_catch.HasCaught());
     try_catch.ReThrow();
-    return;
+    return MaybeLocal<Context>();
   }
   data->realms_[index].Reset(isolate, context);
   args.GetReturnValue().Set(index);
+  return context;
 }
 
+// Realm.create() creates a new realm with a distinct security token
+// and returns its index.
+void Shell::RealmCreate(const v8::FunctionCallbackInfo<v8::Value>& args) {
+  CreateRealm(args);
+}
+
+// Realm.createAllowCrossRealmAccess() creates a new realm with the same
+// security token as the current realm.
+void Shell::RealmCreateAllowCrossRealmAccess(
+    const v8::FunctionCallbackInfo<v8::Value>& args) {
+  Local<Context> context;
+  if (CreateRealm(args).ToLocal(&context)) {
+    context->SetSecurityToken(
+        args.GetIsolate()->GetEnteredContext()->GetSecurityToken());
+  }
+}
 
 // Realm.dispose(i) disposes the reference to the realm i.
 void Shell::RealmDispose(const v8::FunctionCallbackInfo<v8::Value>& args) {
   Isolate* isolate = args.GetIsolate();
   PerIsolateData* data = PerIsolateData::Get(isolate);
   int index = data->RealmIndexOrThrow(args, 0);
   if (index == -1) return;
   if (index == 0 ||
       index == data->realm_current_ || index == data->realm_switch_) {
     Throw(args.GetIsolate(), "Invalid realm index");
@@ skipping 568 matching lines @@
       FunctionTemplate::New(isolate, RealmOwner));
   realm_template->Set(
       String::NewFromUtf8(isolate, "global", NewStringType::kNormal)
           .ToLocalChecked(),
       FunctionTemplate::New(isolate, RealmGlobal));
   realm_template->Set(
       String::NewFromUtf8(isolate, "create", NewStringType::kNormal)
           .ToLocalChecked(),
       FunctionTemplate::New(isolate, RealmCreate));
   realm_template->Set(
+      String::NewFromUtf8(isolate, "createAllowCrossRealmAccess",
+                          NewStringType::kNormal)
+          .ToLocalChecked(),
+      FunctionTemplate::New(isolate, RealmCreateAllowCrossRealmAccess));
+  realm_template->Set(
       String::NewFromUtf8(isolate, "dispose", NewStringType::kNormal)
           .ToLocalChecked(),
       FunctionTemplate::New(isolate, RealmDispose));
   realm_template->Set(
       String::NewFromUtf8(isolate, "switch", NewStringType::kNormal)
           .ToLocalChecked(),
       FunctionTemplate::New(isolate, RealmSwitch));
   realm_template->Set(
       String::NewFromUtf8(isolate, "eval", NewStringType::kNormal)
           .ToLocalChecked(),
@@ skipping 1377 matching lines @@
 }
 
 }  // namespace v8
 
 
 #ifndef GOOGLE3
 int main(int argc, char* argv[]) {
   return v8::Shell::Main(argc, argv);
 }
 #endif