Pass in the prototype to CreateApiFunction rather than setting it on the result.

src/factory.cc

Index: src/factory.cc
diff --git a/src/factory.cc b/src/factory.cc
index 4ca8734100fcb4ce056fe3ad6650a7caac59e374..8307cfa196ab3835f7f57b7185f58ab77c92148b 100644
--- a/src/factory.cc
+++ b/src/factory.cc
@@ -1239,19 +1239,30 @@ Handle<Object> Factory::NewError(const char* constructor,
 }
 
 
-Handle<JSFunction> Factory::NewFunction(Handle<String> name,
+Handle<JSFunction> Factory::NewFunction(MaybeHandle<Object> maybe_prototype,
+                                        Handle<String> name,
                                         InstanceType type,
                                         int instance_size,
                                         Handle<Code> code,
                                         bool force_initial_map) {
   // Allocate the function
-  Handle<JSFunction> function = NewFunction(name, code, the_hole_value());
+  Handle<JSFunction> function = NewFunction(name, code, maybe_prototype);
 
-  if (force_initial_map ||
-      type != JS_OBJECT_TYPE ||
-      instance_size != JSObject::kHeaderSize) {
+  Handle<Object> prototype;
+  if (maybe_prototype.ToHandle(&prototype) &&
+      (force_initial_map ||
+       type != JS_OBJECT_TYPE ||
+       instance_size != JSObject::kHeaderSize)) {
     Handle<Map> initial_map = NewMap(type, instance_size);
-    Handle<JSObject> prototype = NewFunctionPrototype(function);
+    if (prototype->IsJSObject()) {
+      JSObject::SetLocalPropertyIgnoreAttributes(
+          Handle<JSObject>::cast(prototype),
+          constructor_string(),
+          function,
+          DONT_ENUM).Assert();
+    } else if (!function->shared()->is_generator()) {
+      prototype = NewFunctionPrototype(function);
+    }
     initial_map->set_prototype(*prototype);
     function->set_initial_map(*initial_map);
     initial_map->set_constructor(*function);
@@ -1264,6 +1275,16 @@ Handle<JSFunction> Factory::NewFunction(Handle<String> name,
 }
 
 
+Handle<JSFunction> Factory::NewFunction(Handle<String> name,
+                                        InstanceType type,
+                                        int instance_size,
+                                        Handle<Code> code,
+                                        bool force_initial_map) {
+  return NewFunction(
+      the_hole_value(), name, type, instance_size, code, force_initial_map);
+}
+
+
 Handle<JSFunction> Factory::NewFunctionWithPrototype(Handle<String> name,
                                                      InstanceType type,
                                                      int instance_size,
@@ -2041,7 +2062,9 @@ Handle<JSObject> Factory::NewArgumentsObject(Handle<Object> callee,
 
 
 Handle<JSFunction> Factory::CreateApiFunction(
-    Handle<FunctionTemplateInfo> obj, ApiInstanceType instance_type) {
+    Handle<FunctionTemplateInfo> obj,
+    Handle<Object> prototype,
+    ApiInstanceType instance_type) {
   Handle<Code> code = isolate()->builtins()->HandleApiCall();
   Handle<Code> construct_stub = isolate()->builtins()->JSConstructStubApi();
 
@@ -2077,20 +2100,28 @@ Handle<JSFunction> Factory::CreateApiFunction(
       break;
   }
 
+  MaybeHandle<Object> maybe_prototype = prototype;
+  if (obj->remove_prototype()) maybe_prototype = MaybeHandle<Object>();
+
   Handle<JSFunction> result = NewFunction(
-      Factory::empty_string(), type, instance_size, code, true);
+      maybe_prototype, Factory::empty_string(), type,
+      instance_size, code, true);
 
-  // Set length.
   result->shared()->set_length(obj->length());
-
-  // Set class name.
-  Handle<Object> class_name = Handle<Object>(obj->class_name(), isolate());
+  Handle<Object> class_name(obj->class_name(), isolate());
   if (class_name->IsString()) {
     result->shared()->set_instance_class_name(*class_name);
     result->shared()->set_name(*class_name);
   }
+  result->shared()->set_function_data(*obj);
+  result->shared()->set_construct_stub(*construct_stub);
+  result->shared()->DontAdaptArguments();
+
+  if (obj->remove_prototype()) return result;

[Igor Sheludko, 2014/04/28 15:00:38]

Does it make sense to put ASSERT(result->shared()->IsApiFunction()); before
return here?

[Toon Verwaest, 2014/04/29 09:41:13]

Done.

+  // Down from here is only valid for API functions that can be used as a
+  // constructor (don't set the "remove prototype" flag).
 
-  Handle<Map> map = Handle<Map>(result->initial_map());
+  Handle<Map> map(result->initial_map());
 
   // Mark as undetectable if needed.
   if (obj->undetectable()) {
@@ -2120,10 +2151,6 @@ Handle<JSFunction> Factory::CreateApiFunction(
     map->set_has_instance_call_handler();
   }
 
-  result->shared()->set_function_data(*obj);
-  result->shared()->set_construct_stub(*construct_stub);
-  result->shared()->DontAdaptArguments();
-
   // Recursively copy parent instance templates' accessors,
   // 'data' may be modified.
   int max_number_of_additional_properties = 0;