Inspecting rewriting logic computations (in a parametric and stepwise way)

The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-642-54624-2_12Trace inspection is concerned with techniques that allow the trace content to be searched for specific components. This paper presents a rich and highly dynamic, parameterized technique for the trace inspection of Rewriting Logic theories that allows the non-deterministic execution of a given unconditional rewrite theory to be followed up in different ways. Using this technique, an analyst can browse, slice, filter, or search the traces as they come to life during the program execution. Starting from a selected state in the computation tree, the navigation of the trace is driven by a user-defined, inspection criterion that specifies the required exploration mode. By selecting different inspection criteria, one can automatically derive a family of practical algorithms such as program steppers and more sophisticated dynamic trace slicers that facilitate the dynamic detection of control and data dependencies across the computation tree. Our methodology, which is implemented in the Anima graphical tool, allows users to capture the impact of a given criterion thereby facilitating the detection of improper program behaviors.This work has been partially supported by the EU (FEDER), the Spanish MEC project ref. TIN2010-21062-C02-02, the Spanish MICINN complementary action ref. TIN2009-07495-E, and by Generalitat Valenciana ref. PROMETEO2011/052. This work was carried out during the tenure of D. Ballis’ ERCIM “Alain Bensoussan ”Postdoctoral Fellowship. The research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement n. 246016. F. Frechina was supported by FPU-ME grant AP2010-5681.Alpuente Frasnedo, M.; Ballis, D.; Frechina, F.; Sapiña Sanchis, J. (2014). Inspecting rewriting logic computations (in a parametric and stepwise way). En Specification, algebra, and software: essays dedicated to Kokichi Futatsugi. Springer Verlag (Germany). 229-255. https://doi.org/10.1007/978-3-642-54624-2_12S229255Alpuente, M., Ballis, D., Baggi, M., Falaschi, M.: A Fold/Unfold Transformation Framework for Rewrite Theories extended to CCT. In: Proc. PEPM 2010, pp. 43–52. ACM (2010)Alpuente, M., Ballis, D., Espert, J., Romero, D.: Model-checking Web Applications with Web-TLR. In: Bouajjani, A., Chin, W.-N. (eds.) ATVA 2010. LNCS, vol. 6252, pp. 341–346. Springer, Heidelberg (2010)Alpuente, M., Ballis, D., Espert, J., Romero, D.: Backward Trace Slicing for Rewriting Logic Theories. In: Bjørner, N., Sofronie-Stokkermans, V. (eds.) CADE 2011. LNCS, vol. 6803, pp. 34–48. Springer, Heidelberg (2011)Alpuente, M., Ballis, D., Frechina, F., Sapiña, J.: Slicing-Based Trace Analysis of Rewriting Logic Specifications with iJulienne. In: Felleisen, M., Gardner, P. (eds.) ESOP 2013. LNCS, vol. 7792, pp. 121–124. Springer, Heidelberg (2013)Alpuente, M., Ballis, D., Frechina, F., Romero, D.: Using Conditional Trace Slicing for improving Maude programs. Science of Computer Programming (2013) (to appear)Alpuente, M., Ballis, D., Romero, D.: A Rewriting Logic Approach to the Formal Specification and Verification of Web applications. Science of Computer Programming (2013) (to appear)Baggi, M., Ballis, D., Falaschi, M.: Quantitative Pathway Logic for Computational Biology. In: Degano, P., Gorrieri, R. (eds.) CMSB 2009. LNCS, vol. 5688, pp. 68–82. Springer, Heidelberg (2009)Bruni, R., Meseguer, J.: Semantic Foundations for Generalized Rewrite Theories. Theoretical Computer Science 360(1-3), 386–414 (2006)Clavel, M., Durán, F., Eker, S., Lincoln, P., Martí-Oliet, N., Meseguer, J., Talcott, C.: Maude Manual (Version 2.6). Technical report, SRI Int’l Computer Science Laboratory (2011), http://maude.cs.uiuc.edu/maude2-manual/Clements, J., Flatt, M., Felleisen, M.: Modeling an Algebraic Stepper. In: Sands, D. (ed.) ESOP 2001. LNCS, vol. 2028, pp. 320–334. Springer, Heidelberg (2001)Durán, F., Meseguer, J.: A Maude Coherence Checker Tool for Conditional Order-Sorted Rewrite Theories. In: Ölveczky, P.C. (ed.) WRLA 2010. LNCS, vol. 6381, pp. 86–103. Springer, Heidelberg (2010)Eker, S.: Associative-Commutative Matching via Bipartite Graph Matching. The Computer Journal 38(5), 381–399 (1995)Eker, S.: Associative-Commutative Rewriting on Large Terms. In: Nieuwenhuis, R. (ed.) RTA 2003. LNCS, vol. 2706, pp. 14–29. Springer, Heidelberg (2003)Klop, J.W.: Term Rewriting Systems. In: Abramsky, S., Gabbay, D., Maibaum, T. (eds.) Handbook of Logic in Computer Science, vol. I, pp. 1–112. Oxford University Press (1992)Martí-Oliet, N., Meseguer, J.: Rewriting Logic: Roadmap and Bibliography. Theoretical Computer Science 285(2), 121–154 (2002)Meseguer, J.: Conditional Rewriting Logic as a Unified Model of Concurrency. Theoretical Computer Science 96(1), 73–155 (1992)Meseguer, J.: The Temporal Logic of Rewriting: A Gentle Introduction. In: Degano, P., De Nicola, R., Meseguer, J. (eds.) Montanari Festschrift. LNCS, vol. 5065, pp. 354–382. Springer, Heidelberg (2008)Plotkin, G.D.: The Origins of Structural Operational Semantics. The Journal of Logic and Algebraic Programming 60-61(1), 3–15 (2004)Riesco, A., Verdejo, A., Caballero, R., Martí-Oliet, N.: Declarative Debugging of Rewriting Logic Specifications. In: Corradini, A., Montanari, U. (eds.) WADT 2008. LNCS, vol. 5486, pp. 308–325. Springer, Heidelberg (2009)Riesco, A., Verdejo, A., Martí-Oliet, N.: Declarative Debugging of Missing Answers for Maude. In: Proc. RTA 2010. LIPIcs, vol. 6, pp. 277–294 (2010)TeReSe. Term Rewriting Systems. Cambridge University Press (2003

Debugging Maude programs via runtime assertion checking and trace slicing

[EN] This is the author’s version of a work that was accepted for publication in . Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Journal of Logical and Algebraic Methods in Programming, [VOL 85, ISSUE 5, (2016)] DOI 10.1016/j.jlamp.2016.03.001.In this paper we propose a dynamic analysis methodology for improving the diagnosis of erroneous Maude programs. The key idea is to combine runtime checking and dynamic trace slicing for automatically catching errors at runtime while reducing the size and complexity of the erroneous traces to be analyzed (i.e., those leading to states failing to satisfy some of the assertions). First, we formalize a technique that is aimed at automatically detecting deviations of the program behavior (symptoms) with respect to two types of user-defined assertions: functional assertions and system assertions. The proposed dynamic checking is provably sound in the sense that all errors flagged are definitely violations of the specifications. Then, upon eventual assertion violations we generate accurate trace slices that help identify the cause of the error. Our methodology is based on (i) a logical notation for specifying assertions that are imposed on execution runs; (ii) a runtime checking technique that dynamically tests the assertions; and (iii) a mechanism based on (equational) least general generalization that automatically derives accurate criteria for slicing from falsified assertions. Finally, we report on an implementation of the proposed technique in the assertion-based, dynamic analyzer ABETS and show how the forward and backward tracking of asserted program properties leads to a thorough trace analysis algorithm that can be used for program diagnosis and debugging. © 2016 Elsevier Inc. All rights reserved.This work has been partially supported by the EU (FEDER) and the Spanish MINECO under grants TIN2015-69175-C4-1-R and TIN2013-45732-C4-1-P, and by Generalitat Valenciana Ref. PROMETEOII/2015/013. F. Frechina was supported by FPU-ME grant AP2010-5681, and J. Sapiña was supported by FPI-UPV grant SP2013-0083 and mobility grant VIIT-3946.Alpuente Frasnedo, M.; Ballis, D.; Frechina, F.; Sapiña-Sanchis, J. (2016). Debugging Maude programs via runtime assertion checking and trace slicing. Journal of Logical and Algebraic Methods in Programming. 85(5):707-736. https://doi.org/10.1016/j.jlamp.2016.03.001S70773685

Assertion-based Analysis via Slicing with ABETS

[EN] We present ABETS, an assertion-based, dynamic analyzer that helps diagnose errors in Maude programs. ABETS uses slicing to automatically create reduced versions of both a run's execution trace and executed program, reduced versions in which any information that is not relevant to the bug currently being diagnosed is removed. In addition, ABETS employs runtime assertion checking to automate the identification of bugs so that whenever an assertion is violated, the system automatically infers accurate slicing criteria from the failure. We summarize the main services provided by ABETS, which also include a novel assertionbased facility for program repair that generates suitable program fixes when a state invariant is violated. Finally, we provide an experimental evaluation that shows the performance and effectiveness of the system.This work has been partially supported by the EU (FEDER) and Spanish MINECO grant TIN2015-69175-C4-1-R, and by Generalitat Valenciana PROMETEOII/2015/013. J. Sapina was supported by FPI-UPV grant SP2013-0083.Alpuente Frasnedo, M.; Frechina, F.; Sapiña Sanchis, J.; Ballis, D. (2016). Assertion-based Analysis via Slicing with ABETS. Theory and Practice of Logic Programming. 16(5):515-532. https://doi.org/10.1017/S1471068416000375S51553216

Debugging of Web Applications with Web-TLR

Web-TLR is a Web verification engine that is based on the well-established Rewriting Logic--Maude/LTLR tandem for Web system specification and model-checking. In Web-TLR, Web applications are expressed as rewrite theories that can be formally verified by using the Maude built-in LTLR model-checker. Whenever a property is refuted, a counterexample trace is delivered that reveals an undesired, erroneous navigation sequence. Unfortunately, the analysis (or even the simple inspection) of such counterexamples may be unfeasible because of the size and complexity of the traces under examination. In this paper, we endow Web-TLR with a new Web debugging facility that supports the efficient manipulation of counterexample traces. This facility is based on a backward trace-slicing technique for rewriting logic theories that allows the pieces of information that we are interested to be traced back through inverse rewrite sequences. The slicing process drastically simplifies the computation trace by dropping useless data that do not influence the final result. By using this facility, the Web engineer can focus on the relevant fragments of the failing application, which greatly reduces the manual debugging effort and also decreases the number of iterative verifications.Comment: In Proceedings WWV 2011, arXiv:1108.208

Exploring Conditional Rewriting Logic Computations

[EN] Trace exploration is concerned with techniques that allow computation traces to be dynamically searched for specific contents. Depending on whether the exploration is carried backward or forward, trace exploration techniques allow provenance tracking or impact tracking to be done. The aim of provenance tracking is to show how (parts of) a program output depends on (parts of) its input and to help estimate which input data need to be modified to accomplish a change in the outcome. The aim of impact tracking is to identify the scope and potential consequences of changing the program input. Rewriting Logic (RWL) is a logic of change that supplements (an extension of) the equational logic by adding rewrite rules that are used to describe (nondeterministic) transitions between states. In this paper, we present a rich and highly dynamic, parameterized technique for the forward inspection of RWL computations that allows the nondeterministic execution of a given conditional rewrite theory to be followed up in different ways. With this technique, an analyst can browse, slice, filter, or search the traces as they come to life during the program execution. The navigation of the trace is driven by a user-defined, inspection criterion that specifies the required exploration mode. By selecting different inspection criteria, one can automatically derive a family of practical algorithms such as program steppers and more sophisticatedThis work has been partially supported by the EU (FEDER) and the Spanish MEC project Ref. TIN2010-21062-C02-02, the Spanish MICINN complementary action Ref. TIN2009-07495-E, and by Generalitat Valenciana Ref. PROMETEO2011/052. This work was carried out during the tenure of D. Ballis' ERCIM "Alain Bensoussan" Postdoctoral Fellowship. The research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement N. 246016. F. Frechina was supported by FPU-ME grant AP2010-5681, and J. Sapina was supported by FPI-UPV grant SP2013-0083.Alpuente Frasnedo, M.; Ballis, D.; Frechina Navarro, F.; Sapiña Sanchis, J. (2015). Exploring Conditional Rewriting Logic Computations. Journal of Symbolic Computation. 69:3-39. https://doi.org/10.1016/j.jsc.2014.09.028S3396

Parametric Exploration of Rewriting Logic Computations ∗

This paper presents a parameterized technique for the inspection of Rewriting Logic computations that allows the non-deterministic execution of a given rewrite theory to be followed up in different ways. Starting from a selected state in the computation tree, the exploration is driven by a user-defined, inspection criterion that specifies the exploration mode. By selecting different inspection criteria, one can automatically derive useful debugging facilities such as program steppers and more sophisticated dynamic trace slicers that facilitate the detection of control and data dependencies across the computation tree. Our methodology, which is implemented in the Anima graphical tool, allows users to capture the impact of a given criterion, validate input data, and detect improper program behaviors.