Automatic backward compatibility analysis of software component binary interfaces

This paper discusses a problem of ensuring backward compatibility when developing software components (e.g., libraries) and their consistent combinations (software platforms). Linux environment is considered as the main example. Breakage of the compatibility may result in crashing or incorrect behavior (at binary level) or inability to build (at source level) of applications targeted at an old version of a dependent software component when the applications are used with a new version of the component. The paper describes typical issues that cause compatibility problems (focusing on binary level problems) and presents a new method for automated verification for such issues (focusing on changes in structure of interfaces) for components developed in C/C++. Existing means can detect only a small fraction of all possible backward compatibility problems while the suggested method can verify a broad spectrum of them. The method is based on comparison of function signatures and type definitions obtained from library header files in addition to analyzing symbols in library binaries. This paper also describes an automated verification tool that implements the suggested method and presents some results of its practical usage.