8 research outputs found
A Transformational Approach to Resource Analysis with Typed-Norms
In order to automatically infer the resource consumption of programs, analyzers track how data sizes change along a program s execution. Typically, analyzers measure the sizes of data by applying norms which are mappings from data to natural numbers that represent the sizes of the corresponding data. When norms are defined by taking type information into account, they are named typed-norms. The main contribution of this paper is a transformational approach to resource analysis with typed-norms. The analysis is based on a transformation of the program into an intermediate abstract program in which each variable is abstracted with respect to all considered norms which are valid for its type. We also sketch a simple analysis that can be used to automatically infer the required, useful, typed-norms from programs.This work was funded partially by the EU project FP7-ICT-610582 ENVISAGE: Engineering Virtualized Services (http://www.envisage-project.eu) and by the Spanish projects TIN2008-05624 and TIN2012-38137. Raúl Gutiérrez is also partially supported by a Juan de la Cierva Fellowship from the Spanish MINECO, ref. JCI-2012-13528.Albert Albiol, EM.; Genaim, S.; Gutiérrez Gil, R. (2014). A Transformational Approach to Resource Analysis with Typed-Norms. Lecture Notes in Computer Science. 8901:38-53. https://doi.org/10.1007/978-3-319-14125-1_3S38538901Albert, E., Arenas, P., Genaim, S., Gómez-Zamalloa, M., Puebla, G.: Cost Analysis of Concurrent OO Programs. In: Yang, H. (ed.) APLAS 2011. LNCS, vol. 7078, pp. 238–254. Springer, Heidelberg (2011)Albert, E., Arenas, P., Genaim, S., Puebla, G., Zanardini, D.: Cost Analysis of Java Bytecode. In: De Nicola, R. (ed.) ESOP 2007. LNCS, vol. 4421, pp. 157–172. Springer, Heidelberg (2007)Albert, E., Arenas, P., Genaim, S., Puebla, G., Zanardini, D.: Removing Useless Variables in Cost Analysis of Java Bytecode. In: Proc. of SAC 2008, pp. 368–375. ACM (2008)Alonso, D., Arenas, P., Genaim, S.: Handling Non-linear Operations in the Value Analysis of COSTA. In: Proc. of BYTECODE 2011. ENTCS, vol. 279, pp. 3–17. Elsevier (2011)Bossi, A., Cocco, N., Fabris, M.: Proving Termination of Logic Programs by Exploiting Term Properties. In: Proc. of TAPSOFT 1991. LNCS, vol. 494, pp. 153–180. Springer (1991)Bruynooghe, M., Codish, M., Gallagher, J., Genaim, S., Vanhoof, W.: Termination Analysis of Logic Programs through Combination of Type-Based norms. TOPLAS 29(2), Art. 10 (2007)Claessen, K., Hughes, J.: QuickCheck: A Lightweight Tool for Random Testing of Haskell Programs. In: Proc. of ICFP 2000, pp. 268–279. ACM (2000)Fähndrich, M.: Static Verification for Code Contracts. In: Cousot, R., Martel, M. (eds.) SAS 2010. LNCS, vol. 6337, pp. 2–5. Springer, Heidelberg (2010)Genaim, S., Codish, M., Gallagher, J.P., Lagoon, V.: Combining Norms to Prove Termination. In: Cortesi, A. (ed.) VMCAI 2002. LNCS, vol. 2294, pp. 123–138. Springer, Heidelberg (2002)Johnsen, E.B., Hähnle, R., Schäfer, J., Schlatte, R., Steffen, M.: ABS: A Core Language for Abstract Behavioral Specification. In: Aichernig, B.K., de Boer, F.S., Bonsangue, M.M. (eds.) Formal Methods for Components and Objects. LNCS, vol. 6957, pp. 142–164. Springer, Heidelberg (2011)King, A., Shen, K., Benoy, F.: Lower-bound Time-complexity Analysis of Logic Programs. In: Proc. of ILPS 1997, pp. 261–275. MIT Press (1997)Serrano, A., Lopez-Garcia, P., Bueno, F., Hermenegildo, M.: Sized Type Analysis for Logic Programs. In: Tech. Comms. of ICLP 2013. Cambridge U. Press (2013) (to appear)Spoto, F., Mesnard, F., Payet, É.: A Termination Analyser for Java Bytecode based on Path-Length. TOPLAS 32(3), Art. 8 (2010)Vallée-Rai, R., Hendren, L., Sundaresan, V., Lam, P., Gagnon, E., Co, P.: Soot - a Java Optimization Framework. In: Proc. of CASCON 1999. pp. 125–135. IBM (1999)Vasconcelos, P.: Space Cost Analysis using Sized Types. Ph.D. thesis, School of CS, University of St. Andrews (2008)Vasconcelos, P.B., Hammond, K.: Inferring Cost Equations for Recursive, Polymorphic and Higher-Order Functional Programs. In: Trinder, P., Michaelson, G.J., Peña, R. (eds.) IFL 2003. LNCS, vol. 3145, pp. 86–101. Springer, Heidelberg (2004)Wegbreit, B.: Mechanical Program Analysis. Commun. ACM 18(9), 528–539 (1975
Climbing the Software Assurance Ladder - Practical Formal Verification for Reliable Software
There is a strong link between software quality and software reliability. By decreasing the probability of imperfection in the software, we can augment its reliability guarantees. At one extreme, software with one unknown bug is not reliable. At the other extreme, perfect software is fully reliable. Formal verification with SPARK has been used for years to get as close as possible to zero-defect software. We present the well-established processes surrounding the use of SPARK at Altran UK, as well as the deployment experiments performed at Thales to finetune the gradual insertion of formal verification techniques in existing processes. Experience of both long-term and new users helped us define adoption and usage guidelines for SPARK based on five levels of increasing assurance that map well with industrial needs in practice
Putting the Semantics into Semantic Versioning
The long-standing aspiration for software reuse has made astonishing strides
in the past few years. Many modern software development ecosystems now come
with rich sets of publicly-available components contributed by the community.
Downstream developers can leverage these upstream components, boosting their
productivity.
However, components evolve at their own pace. This imposes obligations on and
yields benefits for downstream developers, especially since changes can be
breaking, requiring additional downstream work to adapt to. Upgrading too late
leaves downstream vulnerable to security issues and missing out on useful
improvements; upgrading too early results in excess work. Semantic versioning
has been proposed as an elegant mechanism to communicate levels of
compatibility, enabling downstream developers to automate dependency upgrades.
While it is questionable whether a version number can adequately characterize
version compatibility in general, we argue that developers would greatly
benefit from tools such as semantic version calculators to help them upgrade
safely. The time is now for the research community to develop such tools: large
component ecosystems exist and are accessible, component interactions have
become observable through automated builds, and recent advances in program
analysis make the development of relevant tools feasible. In particular,
contracts (both traditional and lightweight) are a promising input to semantic
versioning calculators, which can suggest whether an upgrade is likely to be
safe.Comment: to be published as Onward! Essays 202
Event-B in the Institutional Framework: Defining a Semantics, Modularisation Constructs and Interoperability for a Specification Language
Event-B is an industrial-strength specification language for verifying
the properties of a given system’s specification. It is supported by its
Eclipse-based IDE, Rodin, and uses the process of refinement to model
systems at different levels of abstraction. Although a mature formalism,
Event-B has a number of limitations. In this thesis, we demonstrate that
Event-B lacks formally defined modularisation constructs. Additionally,
interoperability between Event-B and other formalisms has been
achieved in an ad hoc manner. Moreover, although a formal language,
Event-B does not have a formal semantics. We address each of these
limitations in this thesis using the theory of institutions.
The theory of institutions provides a category-theoretic way of representing
a formalism. Formalisms that have been represented as institutions
gain access to an array of generic specification-building operators
that can be used to modularise specifications in a formalismindependent
manner. In the theory of institutions, there are constructs
(known as institution (co)morphisms) that provide us with the facility to
create interoperability between formalisms in a mathematically sound
way.
The main contribution of this thesis is the definition of an institution
for Event-B, EVT, which allows us to address its identified limitations.
To this end, we formally define a translational semantics from Event-
B to EVT. We show how specification-building operators can provide
a unified set of modularisation constructs for Event-B. In fact, the institutional
framework that we have incorporated Event-B into is more
accommodating to modularisation than the current state-of-the-art for
Rodin. Furthermore, we present institution morphisms that facilitate interoperability between the respective institutions for Event-B and UML.
This approach is more generic than the current approach to interoperability
for Event-B and in fact, allows access to any formalism or logic
that has already been defined as an institution. Finally, by defining
EVT, we have outlined the steps required in order to include similar
formalisms into the institutional framework. Hence, this thesis acts as a
template for defining an institution for a specification language
Theoretical and Practical Aspects of Typestate
The modelling and enforcement of typestate constraints in object oriented languages has the potential to eliminate a variety of common and difficult to diagnose errors. While the theoretical foundations of typestate are well established in the literature, less attention has been paid to the practical aspects: is the additional complexity justifiable? Can typestate be reasoned about effectively by "real" programmers? To what extent can typestate constraints be inferred, to reduce the burden of large type annotations? This thesis aims to answer these questions and provide a holistic treatment of the subject, with original contributions to both the theorical and practical aspects of typestate