Accurate Interprocedural Null-Dereference Analysis for Java

Null dereference is a commonly occurring defect in Java programs, and many static-analysis tools identify such defects. However, most of the existing tools perform a limited interprocedural analysis. In this paper, the authors present an interprocedural path-sensitive and context-sensitive analysis for identifying null dereferences. Starting at a dereference statement; the authors' approach performs a backward demand-driven, path-sensitive analysis to identify true and false null-propagation paths precisely. The backward demand-driven analysis avoids an exhaustive program exploration that permits the analysis to scale to large programs. The authors present the results of empirical studies conducted using large open-source and commercial products.