Automated Verification of Shared Libraries for Backward Binary Compatibility

This paper discusses a problem of ensuring backward binary compatibility when developing shared libraries. Linux (and GCC environment) is used as the main example. Breakage of the compatibility may result in crashing or incorrect behavior of applications built with an old version of a library when they are running with a new one. The paper describes typical issues that cause binary compatibility problems and presents a new method for library verification for such issues. Existing tools 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.