Undefined Symbol in Node.js Addon

Question

I am getting an awkward error when creating a Node.js addon.

Error Message:

Error: /media/psf/fluxdb/build/Release/flux.node: undefined symbol: _ZN4flux20SinglyLinkedListWrapIiE11constructorE

I am trying to make a Template ObjectWrap to reuse with various types. The code compiles without error, but when I require the *.node file in JS, I get an undefined symbol error.

Below is my code for the Template class:

using namespace node;
using namespace v8;

namespace flux {

    template <typename T>
    class SinglyLinkedListWrap : public ObjectWrap {
    public:
        static void Init(Handle<Object> exports, const char *symbol) {
            // Prepare constructor template
            Local<FunctionTemplate> tpl = FunctionTemplate::New(New);
            tpl->SetClassName(String::NewSymbol(symbol));
            tpl->InstanceTemplate()->SetInternalFieldCount(1);

            // exports
            constructor = Persistent<Function>::New(tpl->GetFunction());
            exports->Set(String::NewSymbol(symbol), constructor);
        }

    protected:
        SinglyLinkedList<T> *list_;

    private:
        SinglyLinkedListWrap() {
            list_ = new SinglyLinkedList<T>();
        }

        ~SinglyLinkedListWrap() {
            delete list_;
        }

        SinglyLinkedList<T> *list() {
            return list_;
        }

        static Persistent<Function> constructor;

        // new SinglyLinkedList or SinglyLinkedList() call
        static Handle<Value> New(const Arguments& args) {
            HandleScope scope;
            if (args.IsConstructCall()) {
                // Invoked as constructor: `new SinglyLinkedList(...)`
                SinglyLinkedListWrap<T> *obj = new SinglyLinkedListWrap<T>();
                obj->Wrap(args.This());
                return scope.Close(args.This());
            } else {
                // Invoked as plain function `SinglyLinkedList(...)`, turn into construct call.
                const int argc = 1;
                Local<Value> argv[argc] = {args[0]};
                return scope.Close(constructor->NewInstance(argc, argv));
            }
        }
    };

}

Thank you for any help :)

Answer 1

我通过删除构造函数引用并直接使用tpl-> GetFunction（）解决了该问题。