COTTAGE: A Consistency Based System for Test Data Generation

This paper presents a system, called COTTAGE, for automated test data generation of C programs. The main originality of our system is its ability to handle programs with oat variables as well as boolean and integer variables. It can also deal with arrays and procedure calls. The system is based on our previous work [25, 26]. A test program (with procedure calls) is represented by an Interprocedural Control Flow Graph (ICFG). Path coverage is the core of our approach. Given a speci ed path of the ICFG, a path constraint is derived and solved to obtain a test case. The constraint solving is carried out based on a consistency notion. For statement coverage, paths reaching a speci ed node are dynamically constructed. The COTTAGE system, a 13,000 Java lines software, implements our approach for C programs. For each generated test data, the system also automatically generates an instrumented C program, allowing the user to verify the correctness of the test data. Experimental results, including complex numerical programs from [23], demonstrate the feasability of the method and the efciency of the COTTAGE system, as well as its versatility and exibility to di erent classes of problems (integer and/or oat variables; arrays, procedures, path coverage, statement coverage).