Object Model Construction for Inheritance in C++ and Its Applications to Program Analysis

Abstract

Modern object-oriented programming languages such as C++ provide convenient abstractions and data encapsulation mechanisms for software developers. However, these features also complicate testing and static analysis of programs that utilize object-oriented programming concepts. In particular, the C++ language exhibits features such as multiple inheritance, static and dynamic typecasting that make static analyzers for C++ quite hard to implement. In this paper, we present an approach where static analysis is performed by lowering the original C++ program into a semantically equivalent C program. However, unlike existing translation mechanisms that utilize complex pointer arithmetic operations, virtual-base offsets, virtual-function pointer tables, and calls to run-time libraries to model C++ features, our translation is targeted towards making static program analyzers for C++ easier to write and provide more precise results. We have implemented our ideas in a framework for C++ called CILpp that is analogous to the popular C Intermediate Language (CIL) framework. We evaluate the effectiveness of our translation in a bug finding tool that uses abstract interpretation and model checking. The bug finding tool uncovered several previously unknown bugs in C++ open source projects.