[Engineering Paper] Challenges of Implementing Cross Translation Unit Analysis in Clang Static Analyzer

Abstract

Static analysis is a great approach to find bugs and code smells. Some of the errors span across multiple translation units. Unfortunately, separate compilation makes cross translation unit analysis challenging for C family languages. In this paper, we describe a model and an implementation for cross translation unit symbolic execution for C family languages. We were able to extend the scope of the analysis without modifying any of the existing checkers. The analysis is implemented in the open source Clang compiler. We also measured the performance of the approach and the quality of the reports. The solution proved to be scalable to large codebases and the number of findings increased significantly for the evaluated projects. The implementation is already accepted into mainline Clang.