Override property, Proxy class C#

gistfile1.cs

/* Overriding makes sense when you look at the generated IL for overriden fields =) */

public override T OverrideProperty<T>(string propertyName, Type attribute = null, Type [] constructorParams = null, object [] constructorValues = null)
{
    // [ML] - Default to an empty instance 

    constructorParams = constructorParams ?? Type.EmptyTypes;
    constructorValues = constructorValues ?? new object[] { null };

    var type = typeof(T);

    // [ML] - Proxy the class

    var proxyNamespace = new AssemblyName(this.GetType().Namespace + ".Proxied");
    var assembly = AppDomain.CurrentDomain.DefineDynamicAssembly(proxyNamespace, AssemblyBuilderAccess.RunAndSave);
    var module = assembly.DefineDynamicModule(proxyNamespace.Name);
    var proxyType = module.DefineType(type.Name + "Proxy", TypeAttributes.Public | TypeAttributes.BeforeFieldInit, type);

    // [ML] - Override the virtual converted value

    var oldProp = type.GetProperty(propertyName);

    if (oldProp != null && oldProp.GetGetMethod().IsVirtual)
    {
        var newProp = proxyType.DefineProperty(oldProp.Name, oldProp.Attributes, oldProp.PropertyType, null);
        var backingField = proxyType.DefineField(string.Format("<{0}>k__BackingField", propertyName), oldProp.PropertyType, ributes.Private);

        // [ML] - Add the custom attribute
        if (attribute != null)
        {
            var ctor = attribute.GetConstructor(constructorParams);

            if (ctor != null)
            {
                newProp.SetCustomAttribute(new CustomAttributeBuilder(ctor, constructorValues, new FieldInfo[0], new object[0]
            }
        }

        // [ML] - Define a placeholder for a getter and setter of the new override property on the proxy class

        var attributes = MethodAttributes.Virtual | MethodAttributes.Public | MethodAttributes.SpecialName | MethodAttributesig;

        var pGet = proxyType.DefineMethod("get_" + oldProp.Name, attributes, oldProp.PropertyType, Type.EmptyTypes);
        var pSet = proxyType.DefineMethod("set_" + oldProp.Name, attributes, null, new[] {oldProp.PropertyType});

        // [ML] - Give the getter a method body

        ILGenerator pILGet = pGet.GetILGenerator();

        
        pILGet.Emit(OpCodes.Ldarg_0);
        pILGet.Emit(OpCodes.Ldfld, backingField);
        pILGet.Emit(OpCodes.Ret);

        // [ML] - Give the setter a method body

        ILGenerator pILSet = pSet.GetILGenerator();

        pILSet.Emit(OpCodes.Ldarg_0);
        pILSet.Emit(OpCodes.Ldarg_1);
        pILSet.Emit(OpCodes.Stfld, backingField);
        pILSet.Emit(OpCodes.Ret);

        newProp.SetSetMethod(pSet);
        newProp.SetGetMethod(pGet);
    }

    // [ML] - Create and return a an instance

    var newType = proxyType.CreateType();

    return (T)Activator.CreateInstance(newType);
}

41: ... MethodAttributesig - error