A state model is an abstract state machine that can be in one of various states. Using modelcheckers to generate and analyze property. Testing with model checkers is mostly applied to reactive systems 4, where the software size is within bounds e. Model based testing is an application of model based design for designing and optionally also executing artifacts to perform software testing or system testing. Model checkers generate a state model from your code. If model checkers were designed or adapted to take into account the needs that result from the application to software testing, this could lead to significant improvements with regard to test suite quality and performance. Qsic 07 proceedings of the seventh international conference on quality software pages 2531 october 11 12, 2007 ieee computer society washington, dc, usa 2007 table of contents isbn.
Whereas conventional model checkers require manual effort to create an abstract target model, modern software model checkers remove this overhead by directly analyzing a target c program, and can be utilized as unit testing tools. The use of model checkers for testing offers full automation, a choice of different methods to derive test suites, and is efficient under certain preconditions. Model checking techniques have been proven to be an excellent approach to analyse critical properties of complex systems. However, since software model checkers are not fully mature yet, they have limitations according to the underlying. Automated testing automated combinatorial testing for. Model checkers are formal verification tools, capable of providing counterexamples to violated properties. However, realistic concurrent programs are nonterminating, a property that signi. We chose six existing tools for automatic testcase generation, namely aflfuzz, cpatiger, crestppc,fshell,klee,andprtest,andfourtoolsforsoftwaremodel. Despite the large volume of academic research on software testing and verification, there are relatively. We discuss a couple techniques that alter the specification to force the model checker to output counterexamples that are then used as test cases for the software. The nodes represents states of a program, the edges represent possible.
We show how to apply these powerful computation engines to the problems of test generation and test evaluation for a variety. The primary focus of formal methods is static analysis of specifications and code, but there is also a long tradition of exploiting formal methods for testing. Automation is desirable since the complexity and the effort involved are significant. This is typically associated with hardware or software systems, where the specification contains liveness requirements such as avoidance of livelock as well as safety requirements such as avoidance of states representing. Autogenerating test sequences using model checkers. Model checkers in software testing microform, 2002. These approaches leverage the witness or counterexample generation capability of modelcheckers for constructing test cases. Extending model checkers for hybrid system verification.
Modelcheckers, however, were not originally intended for this task. In contrast to static analysis techniques, testing requires the execution of the program with specific input values to find. The counterexamples generated by model checkers are often better for localizing and correcting failures than discovering failures from testing and simulation because they tend to be very short under 10 input. Test criteria are expressed as temporal properties. Property relevant software testing with modelcheckers. Although model checkers can be used to generate tests 3, 5, existing methods allow the model checker. The model checker then checks that the state model conforms to certain behavioral properties. Normally, these counterexamples are meant to guide an analyst when searching for the root cause of a property violation. Issues in software component testing 1998 citeseerx. Abstract to detect a fault in software, a test case execution must be chosen so intermediate errors propagate to the output. Evaluating model testing and model checking for finding. The approach analyzes both these specification models to generate test cases that are then converted into temporal logic formulae to be model checked on the. Verification and test methods for access control policiesmodels.
Black, issues in software testing with model checkers preprint, submitted to 2003 international conference on dependable systems and networks dsn 2003, san francisco, california, june 2225, 2003. Generating a short, but effective test suite usually needs a lot ofmanual work and expert knowledge. Model checking is a lightweight formal method to check the truth \or falsity\ of statements. Regression testing and testsuite update with modelcheckers gordon fraser 1,2, bernhard k. The ieee software engineering body of knowledge swebok 2004 defines testing as an activity performed for evaluating product quality, and for improving it, by identifying defects and problems bourque and dupuis 2004. The picture on the right depicts the former approach. Existing stateless model checkers are limited to the veri. A comparative study of software model checkers as unit.
Finding and understanding bugs in software model checkers. Bugfinding capabilities i s aflfuzz t tiger t crestppc l t e t test t cbmc m aseq m cr m d m s mc l total found 1490 605 57 376 236 826 292 830 889 949 844 887 1092 1176 compilable 1115 605 57 376 236 826 292 779 819 830 761 887 930 1014 median cpu time s 11 4. This paper continues this model by exploring the role of model checkers in software testing. Our experience with nonfilesystem flight software modules shows that methods even further removed from traditional static formal methods can be assisted by formal approaches, yet readily adopted by test engineers and. Model checkers are tools that systematically explore the state space of a model to demonstrate the presence of errors or to confirm their absence. Verification is applied to software as a proof method with respect to its requirements. Modelbased testing is an application of modelbased design for designing and optionally also executing artifacts to perform software testing or system testing. Coverage based testcase generation using model checkers. Black, wei ding nistir 6777, national institute of standards and technology, 2002 the primary focus of formal methods is static analysis of specifications and code, but there is also a long tradition of exploiting formal methods for testing. This is typically associated with hardware or software systems, where the.
Model checkers article about model checkers by the free. Home browse by title proceedings qsic 07 improving modelcheckers for software testing. Abstract the primary focus of formal methods is static analysis of specifications and code, but there is also a long tradition of exploiting formal methods for testing. Aichernig 3 and franz wotawa 4 institute for software technology graz university of technology inffeldgasse 16b2 a8010 graz, austria abstract several modelchecker based methods to automated testcase generation have been proposed. Evaluating model testing and model checking for finding requirements violations in simulink models. Issue in software testing with model checkers author. The modelbased approach to software testing encompasses the creation of an abstract model. Issues in using model checkers for test case generation. Testing is an essential, but time and resource consuming activity in the software development process. Software model checking smc is a wellknown automatic program verification technique and frequently adopted for checking safetycritical software. Citeseerx document details isaac councill, lee giles, pradeep teregowda.
The use of modelcheckers for testing offers full automation, a choice of different methods to derive testsuites, and is efficient under certain preconditions. Test generation using model checking department of computer. The model is usually expressed as a directed graph consisting of nodes or vertices and edges. Creating testcases incrementally with modelcheckers.
In modelbased testing, testcases are created for an iut with respect to a model m and a speci. In recent years, automated testcase generation with modelcheckers has seen increasing attention in the research community. About a decade after the initial proposal to use model checkers for the generation of test cases we take a look at the results in this field of research. Various approaches to model checking software 6 hypothesis model checking is an algorithmic approach to analysis of finitestate systems model checking has been originally developed for analysis of hardware designs and communication protocols model checking algorithms and tools have to be tuned to be applicable to analysis of software. For example, a model checker can report a test whenever it finds an interesting state, i. Explains effective use of model checking to generate complete test cases. We claim that the answer is no, and show with experiments on a large benchmark of c programs that software model checkers even find more bugs than testers. Instead of using formal methods, developers test software. Verification and test methods for access control policies. Section 3 defines a formal framework suitable for model checking in which we can discuss the coverage of various software engineering artifacts. Testcase generation with modelcheckers is apromising. Software testing is necessary because verification is often infeasible. Testing with model checkers is a modelbased testing technique.
Use of modelchecking approaches for test generation from requirement models have been proposed by several researchers. Indeed, several drawbacks result from the use of model checkers for test case generation. Model checkers were originally developed to check that state machines conformed to specifications expressed in a temporal logic. A set of atomic propositions is associated with each node. However, little work exists on validating software model checkers, an important problem. Integration of formal analysis into a modelbased software. Creating testcases incrementally with modelcheckers gordon fraser and franz wotawa. The model based approach to software testing encompasses the creation of an abstract model.
Pdf model checkers in software testing researchgate. Improving modelcheckers for software testing abstract. Software model checkers are becoming increasingly popular to assist in the automation of software testing. We believe it is time for a careful comparative evaluation of automatic software test ing against automatic software model checking. Software model checking is the algorithmic analysis of programs to prove. However, automated software testing is commonly used to ensure confidence in the conformance of an. In recent years, automated test case generation with model checkers has seen increasing attention in the research community. Most software developers consider formal methods too hard and tedious to use in practice. Model checkers were originally developed to check that state machines conformed to specifications. This paper continues this tradition by exploring the role of model checkers in software testing. Models can be used to represent the desired behavior of a system under test sut, or to represent testing strategies and a test environment. In computer science, model checking or property checking is a method for checking whether a finitestate model of a system meets a given specification a.
1606 1501 266 1517 353 308 1561 1110 304 1614 1146 244 795 347 903 1632 1493 888 453 698 513 334 491 117 825 646 466 913 426 242 1286 771 1229