Practical Static Ownership Inference

There are many proposals for ownership type systems de- signed to control aliasing in object-oriented programs. Most systems re- quire signicant annotation eort and therefore it may be dicult to adopt these systems in software practice. Ownership inference has received less attention, while it is an impor- tant problem because it could ease the annotation eort and facilitate application of ownership type systems in real-world software systems. This paper presents novel static analyses for Java that infers ownership according to two known ownership protocols: the owner-as-dominator protocol, and the owner-as-modier protocol. Our analyses do not re- quire annotations. They are based on the cubic Andersen-style points-to analysis, and therefore, remains relatively inexpensive. We perform experiments on a set of Java programs. The experiments show that the analyses are practical and relatively precise. In addition, the experiments show that ownership occurs frequently in real-world ap- plications, and that the owner-as-dominator protocol and the owner-as- modier protocol capture distinct ownership properties.