MethodDecl

Determine the set of methods that are overridden by the given method. In both Objective-C and C++, a method (aka virtual member function, in C++) can override a virtual method in a base class. For Objective-C, a method is said to override any method in the class’s base class, its protocols, or its categories’ protocols, that has the same selector and is of the same kind (class or instance). If no such method exists, the search continues to the class’s superclass, its protocols, and its categories, and so on. A method from an Objective-C implementation is considered to override the same methods as its corresponding method in the interface.

For C++, a virtual member function overrides any virtual member function with the same signature that occurs in its base classes. With multiple inheritance, a virtual member function can override several virtual member functions coming from different base classes.

In all cases, this will return the immediate overridden method, rather than all of the overridden methods. For example, if a method is originally declared in a class A, then overridden in B (which in inherits from A) and also in C (which inherited from B), then the only overridden method returned from this function when invoked on C’s method will be B’s method. The client may then invoke this function again, given the previously-found overridden methods, to map out the complete method-override set.