A Constraint-Pattern Based Method for Reachability Determination

When analyzing programs using static program analysis, we need to determine the reachability of each possible execution path of the programs. Many static analysis tools collect constraints of each path and use SMT solvers to determine the satisfiability of these constraints. The accumulated computing time can be long if we use SMT solvers too many times. In this paper, we propose a constraint-pattern based method for reachability determination to address the limitation of current approaches. We define some constraint-patterns. For each pattern, a carefully designed constraints solving algorithm is presented. Our method contains two steps. Firstly, we collect some information about the constraints in the program to be analyzed. Then we choose the most suitable algorithm for reachability determination based on the information. Secondly, we apply the algorithm in analysis process to speed up satisfiability checking of path constraints. We implement our method based on CPAchecker, a famous software verification tool. The experimental results on some well-known benchmarks show that, with a moderate accuracy, our method is more efficient in comparison with some state-of-the-art SMT solvers.