Symbolic execution is a program analysis technique introduced in the 70s that has received renewed interest in recent years, due to algorithmic advances and increased availability of computational power and constraint solving technology. If the correctness criteria for the given program is described by a set of test cases, we will show that. Dec 09, 20 software testingdebugging is extremely time consuming, and hence techniques to automate debugging or program repair are of value. We present a new tool, named dart, for automatically testing software that combines three main techniques. Based on a risk, select a subset of test suite to be executed for this cycle.
Symbolic execution is a program analysis technique that was introduced in the 70s 9,16,26,30,39, and that has found renewed interest in recent years,14,24,28,4244, followed by many other works 10,25,27,35,37,38,46,47 etc. Software testingdebugging is extremely time consuming, and hence techniques to automate debugging or program repair are of value. A feasible execution path is a sequence of true and false, where a value of true respectively false at the thi position in the sequence denotes that the ith conditional statement encountered. In practice, one needs to put a limit on the search for example, a timeout, or a limit on the number of paths, loop. The generated symbolic constraints are solved using yices to generate input that drive the test execution down new, unexplored program paths crest currently only reasons. Verlag 2009 abstract symbolic execution is a wellknown program analysis technique which represents program inputs with symbolic values instead of concrete, initialized, data and. Some insights about symbolic execution i execute programs with symbols. Automata learning for symbolic execution bernhard k. In computer science, symbolic execution also symbolic evaluation is a means of analyzing a program to determine what inputs cause each part of a program to execute. Role of symbolic execution in software testing, debugging. Comprehensively testing software patches with symbolic execution. Symbolic execution is a program analysis technique introduced in the 70s that has received renewed interest in. Symbolic execution is used to reason about a program pathbypath which is an advantage over reasoning about a program inputbyinput as other testing paradigms use e. Symbolic execution for software testing in practice proceedings of.
Moreover, it can alleviate imprecision in symdomization. Symbolic execution for software testing in practice preliminary. Generalized symbolic execution for model checking and testing. Combining symbolic execution and model checking for data. Fast loop boundary coverage testing in symbolic execution. If execution path depends on unknown, we fork symbolic executor at least, conceptually 5. Symbolic execution has become an effective program testing technique, providing a way to automatically generate inputs that trigger software errors ranging from lowlevel program crashes to higher.
Pdf symbolic execution for software testing in practice. It intertwines traditional symbolic execution 16 with concrete execution, and explores as many program paths as possible to generate test cases by solving path constraints. She is an acm distinguished scientist, known for her influential research on software model checking, symbolic execution and assumeguarantee compositional verification, using abstraction and learning. Abstract we present results for the impact project focus area on the topic of symbolic execution as used in software testing.
We have developed symbolic java pathfinder, a symbolic execution framework that implements a nonstandard bytecode interpreter. Modern software systems, which often are concurrent and manipulate complex data structures must be extremely reliable. Symbolic execution for software testing in practice preliminary assessment. She is an acm distinguished scientist, known for her influential research on software model checking, symbolic execution and assumeguarantee compositional verification, using abstraction and learningbased methods. In computer science, symbolic execution also symbolic evaluation is a means of analyzing a. Request pdf symbolic execution for software testing in practice preliminary assessment we present results for the impact project focus area on the topic. Symbolic execution for software testing in practice preliminary assessment conference paper in proceedings international conference on software engineering january 2011 with 338 reads. However, if few inputs take the same path through the program, there is little savings over testing each of the inputs separately. The use of symbolic execution for testing of realtime. Symbolic execution 15, 42 is a well known program analysis technique that allows execution of programs using symbolic input values, instead of actual data, and represents the values of program variables as symbolic expressions. Generalized symbolic execution for model checking and testing sarfraz khurshid1, corina s. Combining symbolic execution and model checking for data flow. Aichernig, roderick bloem, masoud ebrahimi, martin tappler, johannes winter graz university of technology, austria abstractblackbox components conceal parts of software execution paths, which makes systematic testing, e.
Symbolic execution and software testing corina pasareanu nasa ames research center, mo et field, usa symbolic execution is a systematic program analysis technique that has become increasingly popular in recent years, due to algorithmic advances and availability of computational power and constraint solving technology. The use of symbolic execution for testing of realtime safety. I think symbolic execution can be used in many other interesting ways next. Software security introducing symbolic execution youtube. Jul 26, 2016 software testing debugging is extremely time consuming, and hence techniques to automate debugging or program repair are of value. Pasareanu is an associate research professor with cylab at carnegie mellon university, working at the silicon valley campus with nasa ames research center. Symbolic testing and the dissect symbolic evaluation system. Comprehensively testing software patches with symbolic. Research article survey paper case study available symbolic. Katch is based on symbolic execution, a program analysis technique that can systematically explore a programs possible executions.
In software testing, symbolic execution is used to generate a test input for each feasible execution path of a program. In this talk, i will discuss the use of symbolic execution for software testing, debugging and repair. In this talk, i will discuss the use of symbolic execution for. Key laboratory of high confidence software technologies peking university, moe. Symbolic execution for software testing in practice imperial. We describe an approach to testing complex safety critical software that combines unitlevel symbolic execution and systemlevelconcrete execution for generating test cases that satisfy userspeci.
Google tech talks november, 16 2007 this talk describes techniques that use model checking and symbolic execution for test input generation. Symbolic execution has become an effective program testing technique, providing a way to automatically generate inputs that trigger software errors ranging from low. In proceedings of the 23rd ieeeacm international conference on automated software engineering ase 2008, laquila, italy, pp. Assign the test cases in each test suite to testers for execution. In this article, we survey the main aspects of symbolic execution and discuss the most prominent techniques employed for instance in software testing and computer security applications. None are aimed at commercial dp software and no symbolic execution testing system has previously been built to analyse cobol source programs. We present results for the impact project focus area on the topic of symbolic execution as used in software testing. Concolic testing a portmanteau of concrete and symbolic is a hybrid software verification technique that performs symbolic execution, a classical technique that treats program variables as symbolic variables, along a concrete execution testing on particular inputs path. Crest works by inserting instrumentation code using cil into a target program to perform symbolic execution concurrently with the concrete execution. Symbolic execution and software testing part 1 corina pasareanu. In the last two decades, automation has had a significant impact on software testing and analysis. Symbolic execution as empirical studies tool web application security checker enhancement to abstractionbased static analysis program synthesis tool all of these take advantage of sym exec strengths, and try to avoid drawbacks 7. Program testing techniques using simulated execution.
Test execution is the process of executing the code and comparing the expected and actual results. The execution requires a selection of paths that are exercised by a set of data values. Dynamic symbolic execution 14, 15 dse is a widely accepted and effective approach for automatic test data generation. Symbolic execution and model checking for testing youtube. Aug 30, 2016 importantly, we take a build security in mentality, considering techniques at each phase of the development cycle that can be used to strengthen the security of software systems. A survey of new trends in symbolic execution for software testing and analysis cs pasareanu, w visser international journal on software tools for technology transfer 11 4, 339, 2009. Efficient symbolic execution for software testing johannes kinder royal holloway, university of london joint work with. Symbolic execution for software testing in practice preliminary assessment joint work with cristian cadar, sarfraz khurshid, corina pasareanu, koushik sen, nikolai tillmann and willem visser proceedings of icse2011 international conference on software engineering, impact track, pages 10661071, honolulu, may 2011. Learning to accelerate symbolic execution via code. An execution path is a sequence of true and false, where a value of true respectively false at the ith position in the sequence denotes that the ith conditional statement encountered along the.
Symbolic execution is a program analysis technique that was introduced in the. By reusing the previously calculated results captured from. That means execute the program symbolically rather than concretely which maintains a path condition that is updated whenever a branch instruction is encountered. Role of symbolic execution in software testing, debugging and.
Sep 19, 2016 in response to such poor culture of testing software patches, we have designed katch, a system whose goal is to automatically generate inputs that exercise the lines of code of a patch. Selecta formal system for testing and debugging programs by symbolic execution. Improving structural testing of objectoriented programs via integrating evolutionary testing and symbolic execution. Symbolic execution is a software testing technique that is useful to aid the generation of test data and in proving the program quality. Let us now make a list of all things that are important to understanding the test execution phase. Abstract state matching is used to avoid generation of. Modern symbolic execution austin cory bart cs6304 program analysis 11102015. Our discussion is mainly focused on forward symbolic execution, where a symbolic engine analyzes. These concrete values can be thought of as concrete test cases that can, e.
Symbolic execution the symbolic execution of a program is described in this section in an ideal sense, and then, in section 6, a particular practical system which has been built an ap proximation to the ideal is discussed. Symbolic execution is a promising approach for software analyzing and testing, but it still suffers from scalability issues, in which a significant challenge is how to handle loop caused path explosion. Automated testing techniques, such as symbolic execution, concolic testing, and feedbackdirected fuzzing, have found numerous critical faults, security vulnerabilities, and performance bottlenecks in mature and welltested software systems. Software testing is the most commonly used technique for validating the quality of software, but it is typically a mostly manual process that accounts for a large fraction of software development and maintenance. This paper proposes a new approach to mitigate the scalability problem brought by loops in symbolic execution. Symbolic execution is one of the many techniques that can be used to automate software testing by automatically generating test cases that achieve high coverage. Research article survey paper case study available. We provide a twofold generalization of traditional symbolic execution based approaches. This section briefly describes symbol, a symbolic execution testing system for cobol, built by the author. Symbolic execution is used in conjunction with an automated theorem prover or constraint solver based. Another successful approach, which was explored in the context of concolic testing, is to interleave symbolic exploration with random testing.
Symbolic execution symbolic execution is a software testing technique that is useful to aid the generation of test data and in proving the program quality. Symbolic execution is now the underlying technique of several popular. Test generation using symbolic execution semantic scholar. The software reliability group at imperial college london has invested a significant amount of effort in the last few years on devising techniques and tools for comprehensively testing software patches. Symbolic execution for software testing in practice. Symbolic execution is used to reason about a program pathbypath which is an. An interpreter follows the program, assuming symbolic values for inputs rather than obtaining actual inputs as normal execution of the program would. Symbolic execution and recent applications to worstcase. Symbolic execution is a program analysis technique introduced in the 70s.
Following factors are to be considered for a test execution process. The main focus of our work has been on developing dynamic symbolic execution techniques that automatically detect bugs and augment program. Generalized symbolic execution for model checking and. Combining unitlevel symbolic execution and systemlevel.
We present a novel framework based on symbolic execution, for automated checking of such systems. Symbolic execution is a program analysis technique used in automated software testing. Symbolic execution cs252r spring 2011 contains content from slides by jeff foster. Symbolic execution umd department of computer science. A survey of new trends in symbolic execution for software. In software testing, symbolic execution is used to generate a test input for each execution path of a program. A survey of new trends in symbolic execution for software testing and analysis. Symbolic execution is one of the many techniques that can be used to automate.
49 1296 211 1328 535 1197 1257 463 506 1505 706 1496 1096 1095 450 673 1108 232 1116 649 892 1122 81 657 464 1251 1028 842 795 57 1472 365 604