SLICING CLASS HIERARCHIES IN C++

This paper describes an algorithm for slicing class hierarchies in C+ programs. Given a C++ class hierarchy (a collection of C++ classes an d inheritance relations among them) and a program P that uses the hier archy, the algorithm eliminates from the hierarchy those data members, member functions, classes, and inheritance relations that are unneces sary for ensuring that the semantics of P is maintained. Class slicing is especially useful when the program P is generated from a larger pr ogram P' by a statement slicing algorithm. Such an algorithm eliminate s statements that are irrelevant to a set of slicing criteria-program points of particular interest. There has been considerable previous wo rk on statement slicing, and it will not be the concern of this paper. However, the combination of statement slicing and class slicing for C ++ has two principal applications: First, class slicing can enhance st atement slicing's utility in program debugging and understanding appli cations, by eliminating both executable and declarative program compon ents irrelevant to the slicing criteria. Second, the combination of th e two slicing algorithms can be used to decrease the space requirement s of programs that do not use all the components of a class hierarchy. Such a situation is particularly common in programs that use class li braries.