A Static Analysis for Instance-based Confinement in Java

A semantic definition is given for instance-based pointer confinement (alias control); this provides a form of encapsulation suited to many object-oriented designs. A syntax-directed static analysis is defined and proved, using a compositional semantics, to imply semantic confinement. Previous work by the authors, reviewed here, shows that this notion of confinement ensures a strong information-hiding property. The language studied here has features of sequential Java including mutable state, private fields, dynamic binding and inheritance, recursive classes, casts and type tests, and mutually recursive methods.