Daniel Dietsch’s research while affiliated with University of Freiburg and other places

... Tools for formal methods are intricate software systems, which often compute abstract models to prove system implementations correct or find errors. There is already a large pool of mature and well-established verification tools (for example, in the area of software verification [1,2,3,4,5]), and automatic tools are heavily used in industrial software-engineering applications [4,6,7,8]. Sometimes such tools are even used as components in meta verifiers [9,10,11,12,13,14]. ...

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FM-Weck: Containerized Execution of Formal-Methods Tools

... An early proof-of-concept implementation [14] of CSeq-DR could only handle basic memory access, achieving modest results (5th place with 6 false positives) at SV-COMP 2022 [3]. GemCutter also relies on program transformation for detecting races [17], but needs one auxiliary variable per global variable in the program, while we only introduce three variables for the whole program; similarly to [14], its analysis beyond basic memory access can be inaccurate. An extension of lazy sequentialisation for deadlock checking is proposed in [35]. ...

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Accurate Static Data Race Detection for C

... Assume we do not know that this error exists and we want to know whether a call to reach_error() is reachable. When we run the formal verifier UAutomizer [24,25] on the program with property "reach_error is never called", it reports an alarm. It also provides a violation witness that represents at least one claimed counterexample to the property. ...

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Fault Localization on Verification Witnesses

... A witness ω ∈ Ω is a certificate produced by a tool to explain its verdict on a verification task. We interpret witnesses more flexibly than verification witnesses [43] for verifiers and also consider test cases as witnesses from test-case generators. Tools that produce witnesses for their analysis results are said to be certifying [44,45]. ...

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The Transformation Game: Joining Forces for Verification

... Deagle [33,65] is a SAT-based bounded model checker built on top of CBMC [12] with an efficient handling of concurrency and a tailored SAT decision procedure; it was the winner in the ConcurrencySafety category at SV-COMP 2023 [4], which subsumes the NoDataRace demo category of the previous edition of the competition. Ultimate GemCutter [45] is based on counterexampleguided abstraction refinement; it ranked first at SV-COMP 2022 [3] for the NoDataRace demo category. Goblint [61,66] is a static analyser for data race checking based on thread-modular abstract interpretation. ...

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Accurate Static Data Race Detection for C

... In this paper we show how to translate bitwise operators more precisely. Our translation is a generalization of the work of Liu et al. [11]. First we describe the translation of the operators &, |,^. ...

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Ultimate Automizer and the Abstraction of Bitwise Operations: (Competition Contribution)

... There are verifiers to validate counterexamples using the witness validation approach, which reproduces the verification results by checking a given counterexample based on the graphml format [12]. For instance, CPAchecker [13] and Ultimate Automizer [14] employ the error-witness-driven program analysis technique to avoid false alarms produced by verifiers, i.e., given a witness for a problematic program path, they re-verify that the witness indeed violates the specification. ...

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DSValidator: An Automated Counterexample Reproducibility Tool for Digital Systems (Tool Demonstration)

... UltimateTaipan 91b1670e [19]. Similar to UltimateAutomizer, UltimateTaipan employs automata-based trace abstraction and CEGAR. ...

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Benchmarking Software Model Checkers on Automotive Code

... This observation is leveraged by many incremental software verification techniques, which aim to speed up the reverification of modified software. For Reducer-based Conditional Verifier [7] Reducer Verifier DG(P,P') condition residual program Fig. 1: Construction of a difference verifier example, there exist techniques that update previously computed state space descriptions [2,39,35,18,27,38], reuse intermediate results [42,1,9,36,16,46,20], or skip the analysis of unchanged behavior [43,34,37,44,29,12,28,6]. However, most approaches are tailored to and coupled with one specific verification approach. ...

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Incorporating Data Dependencies and Properties in Difference Verification with Conditions (Technical Report)

... Extensional theory of arrays. The first experiment evaluates the usefulness of our computed interpolants for the theory of arrays T A within the software model checker Ultimate Automizer 2 [42] which uses interpolants within the trace abstraction scheme [44]. SMTInterpol is tightly integrated into the model checker, but Ultimate Automizer also allows for using other (interpolating) SMT solvers. ...

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SMT solving, interpolation, and quantifiers