Siavash Soleimanifard

Compositional algorithmic verification of software product lines

Software product line engineering allows large software systems to be developed and adapted for varying customer needs. The products of a software product line can be described by means of a hierarchical variability model specifying the commonalities and variabilities between the artifacts of the individual products. The number of products generated by a hierarchical model is exponential in its size, which poses a serious challenge to software product line analysis and verification. For an analysis technique to scale, the effort has to be linear in the size of the model rather than linear in the number of products it generates. Hence, efficient product line verification is only possible if compositional verification techniques are applied that allow the analysis of products to be relativized on the properties of their variation points. In this paper, we propose simple hierarchical variability models (SHVM) with explicit variation points as a novel way to describe a set of products consisting of sets of methods. SHVMs provide a trade---off between expressiveness and a clean and simple model suitable for compositional verification. We generalize a previously developed compositional technique and tool set for the automatic verification of control---flow based temporal safety properties to product lines defined by SHVMs, and prove soundness of the generalization. The desired property relativization is achieved by introducing variation point specifications. We evaluate the proposed technique on a number of test cases.

Algorithmic Verification of Procedural Programs in the Presence of Code Variability

We present a generic framework for verifying temporal safety properties of procedural programs that are dynamically or statically configured by replacing, adapting, or adding new components. To deal with such a variability of a program, we require programmers to provide local specifications for its variable components, and verify the global properties by replacing these specifications with maximal models. Our framework is a generalization of a previously developed framework that abstracts from all program data. In this work, we capture program data and thus significantly increase the range of properties that can be verified. Our framework is generic by being parametric on the set of observed program events and their semantics. We separate program structure from the behavior it induces to facilitate independent component specification and verification. We provide tool support for an instantiation of our framework to programs written in a procedural language with pointers as the only datatype.

ProMoVer: modular verification of temporal safety properties

This paper describes ProMoVer, a tool for fully automated procedure-modular verification of Java programs equipped with method-local and global assertions that specify safety properties of sequences of method invocations. Modularity at the procedure-level is a natural instantiation of the modular verification paradigm, where correctness of global properties is relativized on the local properties of the methods rather than on their implementations, and is based here on the construction of maximal models for a program model that abstracts away from program data. This approach allows global properties to be verified in the presence of code evolution, multiple method implementations (as arising from software product lines), or even unknown method implementations (as in mobile code for open platforms). PROMOVER automates a typical verification scenario for a previously developed tool set for compositional verification of control flow safety properties, and provides appropriate pre- and post-processing. Modularity is exploited by a mechanism for proof reuse that detects and minimizes the verification tasks resulting from changes in the code and the specifications. The verification task is relatively light-weight due to support for abstraction from private methods and automatic extraction of candidate specifications from method implementations. We evaluate the tool on a number of applications from the smart card domain.

Procedure-modular verification of control flow safety properties

This paper describes a novel technique for fully automated procedure-modular verification of Java programs equipped with method-local and global assertions that specify safety properties of sequences of method invocations. Modularity of verification is achieved by relativizing the correctness of global properties on the local properties rather than on the implementations of methods, and is based on the construction of maximal models. Tool support is provided by means of ProMoVer, a tool that is essentially a wrapper around a previously developed tool set for compositional verification of control flow safety properties, where program data is abstracted away completely. We evaluate the technique on a small but realistic case study.

Procedure-modular specification and verification of temporal safety properties

This paper describes ProMoVer, a tool for fully automated procedure-modular verification of Java programs equipped with method-local and global assertions that specify safety properties of sequences of method invocations. Modularity at the procedure-level is a natural instantiation of the modular verification paradigm, where correctness of global properties is relativized on the local properties of the methods rather than on their implementations. Here, it is based on the construction of maximal models for a program model that abstracts away from program data. This approach allows global properties to be verified in the presence of code evolution, multiple method implementations (as arising from software product lines), or even unknown method implementations (as in mobile code for open platforms). ProMoVer automates a typical verification scenario for a previously developed tool set for compositional verification of control flow safety properties, and provides appropriate pre- and post-processing. Both linear-time temporal logic and finite automata are supported as formalisms for expressing local and global safety properties, allowing the user to choose a suitable format for the property at hand. Modularity is exploited by a mechanism for proof reuse that detects and minimizes the verification tasks resulting from changes in the code and the specifications. The verification task is relatively light-weight due to support for abstraction from private methods and automatic extraction of candidate specifications from method implementations. We evaluate the tool on a number of applications from the domains of Java Card and web-based application.

Algorithmic verification of procedural programs in the presence of code variability

We present a generic framework for verifying temporal safety properties of procedural programs that are dynamically or statically configured by replacing, adapting, or adding new components. To deal with such a variability of a program, we require programmers to provide local specifications for its variable components, and verify the global properties by replacing these specifications with maximal models. Our framework is a generalization of a previously developed framework that fully abstracts from program data. In this work, we recapture program data and thus significantly increase the range of properties that can be verified. Our framework is generic by being parametric on the set of observed program events and their semantics. We separate program structure from the behaviour it induces to facilitate independent component specification and verification. To exemplify the use of the framework, we develop three concrete instantiations; in particular, we derive a compositional verification technique for programs written in a procedural language with pointers as the only datatype. A generic framework for compositional verification of procedural programs is proposed.Three instantiations of the framework are developed.Various scenarios for dealing with code variability are presented.