Reliability, Verification, Algorithms

We present a symbolic-execution-based algorithm that for a given program and a given program location in it produces a nontrivial necessary condition on input values to drive the program execution to the given location. The algorithm is based on computation of loop summaries for loops along acyclic paths leading to the target location. We also propose an application of necessary conditions in contemporary bug-finding and test-generation tools. Experimental results on several small benchmarks show that the presented tech-nique can in some cases significantly improve performance of the tools