Most FunctionObjects do not actually need their custom jsCall members. They will only call the functions from the vtable anyway. FunctionObject can therefore be split into a static and a dynamic variant. Only the dyanmic variant needs to carry (and invoke) the extra pointer. The jsCallWithMetaTypes pointer is completely pointless because none of the dynamic functions actually implement it. Furthermore, the QV4::Function and QV4::ExecutionContext pointers in FunctionObject are only needed by actual JavaScript functions. The builtins that like to be dynamic functions never need them. Therefore, split out another class for this. In the generic FunctionObject, we need the capability to decide at run time whether the function shall be a constructor or not. Add a flag to replace the check for jsCallAsConstructor. Also, where we can, avoid the pessimization of checking whether a function is a constructor before trying to call it as constructor. Rather have the default implementation throw the exception. As a side effect, for most functions we don't need an ExecutionContext anymore. The engine is enough. Task-number: QTBUG-124662 Change-Id: Iac657fa71288dd6ec230a33de2986ba3bcf4628c Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>