Get information about original function from bound function

src/api.cc

Index: src/api.cc
diff --git a/src/api.cc b/src/api.cc
index 02b6be4d3b7a4622a423d2232b9620796177afa7..8ccea845a639fb7fd7ecface45b9a3529769d1b4 100644
--- a/src/api.cc
+++ b/src/api.cc
@@ -4305,6 +4305,20 @@ int Function::ScriptId() const {
 }
 
 
+Local<v8::Value> Function::GetBoundFunction() const {
+  i::Handle<i::JSFunction> func = Utils::OpenHandle(this);
+  if (!func->shared()->bound()) {
+    return v8::Undefined(reinterpret_cast<v8::Isolate*>(func->GetIsolate()));
+  }
+  i::Handle<i::FixedArray> bound_args = i::Handle<i::FixedArray>(
+      i::FixedArray::cast(func->function_bindings()));
+  i::Handle<i::Object> original(
+      i::JSReceiver::cast(bound_args->get(i::JSFunction::kBoundFunctionIndex)),
+      i::Isolate::Current());

[yurys, 2013/12/12 20:20:50]

func->GetIsolate())

[Alexandra Mikhaylova, 2013/12/18 10:00:28]

Done.

+  return Utils::ToLocal(i::Handle<i::JSFunction>::cast(original));

[yurys, 2013/12/12 20:20:50]

Is it always safe to cast original to JSFunction here?

[Alexandra Mikhaylova, 2013/12/18 10:00:28]

I think it is safe because here we are sure that our function is bound and this
is its original function.

+}
+
+
 int String::Length() const {
   i::Handle<i::String> str = Utils::OpenHandle(this);
   return str->length();