A Study of Java's Binary Compatibility

In this paper, we investigate Java's approach to release-torelease binary compatibility and argue that it is restricted in two ways. First, binary compatibility is coupled to the mechanism for resolving references, ensuring binary compatibility of new releases of a base component with existing clients (components that use and/or inherit from the base component) only if existing clients are never recompiled. Second, some release-to-release modi cations to a base component that might cause its clients to malfunction are not at all considered. We conclude that proper change management should be the responsibility of a dedicated module of the language, a Change Manager. We present a framework for analyzing Java binaries to detect incompatible changes. The framework will be one part of the independent change management module. Another part will be responsible for reestablishing compatibility when possible.