FOAL 2004 Proceedings: Foundations of Aspect-Oriented Languages Workshop at AOSD 2004

Aspect-oriented programming is a paradigm in software engineering and FOAL logos courtesy of Luca Cardelli programming languages that promises better support for separation of concerns. The third Foundations of Aspect-Oriented Languages (FOAL) workshop was held at the Third International Conference on Aspect-Oriented Software Development in Lancaster, UK, on March 23, 2004. This workshop was designed to be a forum for research in formal foundations of aspect-oriented programming languages. The call for papers announced the areas of interest for FOAL as including, but not limited to: semantics of aspect-oriented languages, specification and verification for such languages, type systems, static analysis, theory of testing, theory of aspect composition, and theory of aspect translation (compilation) and rewriting. The call for papers welcomed all theoretical and foundational studies of foundations of aspect-oriented languages. The goals of this FOAL workshop were to: � Make progress on the foundations of aspect-oriented programming languages. � Exchange ideas about semantics and formal methods for aspect-oriented programming languages. � Foster interest within the programming language theory and types communities in aspect-oriented programming languages. � Foster interest within the formal methods community in aspect-oriented programming and the problems of reasoning about aspect-oriented programs. The papers at the workshop, which are included in the proceedings, were selected frompapers submitted by researchers worldwide. Due to time limitations at the workshop, not all of the submitted papers were selected for presentation. FOAL also welcomed an invited talk by James Riely (DePaul University), the abstract of which is included below. The workshop was organized by Gary T. Leavens (Iowa State University), Ralf L?ammel (CWI and Vrije Universiteit, Amsterdam), and Curtis Clifton (Iowa State University). The program committee was chaired by L?ammel and included L?ammel, Leavens, Clifton, Lodewijk Bergmans (University of Twente), John Tang Boyland (University of Wisconsin, Milwaukee), William R. Cook (University of Texas at Austin), Tzilla Elrad (Illinois Institute of Technology), Kathleen Fisher (AT&T Labs�Research), Radha Jagadeesan (DePaul University), Shmuel Katz (Technion�Israel Institute of Technology), Shriram Krishnamurthi (Brown University), Mira Mezini (Darmstadt University of Technology), Todd Millstein (University of California, Los Angeles), Benjamin C. Pierce (University of Pennsylvania), Henny Sipma (Stanford University), Mario S?udholt ( ?Ecole des Mines de Nantes), and David Walker (Princeton University). We thank the organizers of AOSD 2004 for hosting the workshop

Composing safely: a type system for aspects

In this paper we present an approach towards safe software composition based on aspect-orientation. Aspects enable the systematic addition of code into existing programs but often they also introduce er- rors. In order to provide safe aspects for software composition we address the verification of the aspect-oriented language paradigm. We construct a basic calculus for aspects with types and prove formally type safety. More precisely, this paper presents the following contributions (a) a fully formalized type system for the Theory of Objects including the proof of type safety, (b) a theory of aspects based on the Theory of Objects including a type system for aspects, and (c) the definition of a notion of type safety for aspects including its proof. The entire theory and proofs are carried out in the theorem prover Isabelle/HOL

A Formalization of Typed Aspects for the ς-calculus in Isabelle/HOL

In this paper we present an approach towards safe software composition based on aspect-orientation. Aspects enable the systematic addition of code into existing programs but often they also introduce errors. In order to provide safe aspects for software composition we address the verification of the aspect-oriented language paradigm. We construct a basic calculus for aspects with types and prove formally type safety. More precisely, this paper presents the following contributions (a) a fully formalized type system for the Theory of Objects including the proof of type safety, (b) a theory of aspects based on the Theory of Objects including a type system for aspects, and (c) the definition of a notion of type safety for aspects including its proof. The entire theory and proofs are carried out in the theorem prover Isabelle/HOL

Improving Reuse of Distributed Transaction Software with Transaction-Aware Aspects

Implementing crosscutting concerns for transactions is difficult, even using Aspect-Oriented Programming Languages (AOPLs) such as AspectJ. Many of these challenges arise because the context of a transaction-related crosscutting concern consists of loosely-coupled abstractions like dynamically-generated identifiers, timestamps, and tentative value sets of distributed resources. Current AOPLs do not provide joinpoints and pointcuts for weaving advice into high-level abstractions or contexts, like transaction contexts. Other challenges stem from the essential complexity in the nature of the data, operations on the data, or the volume of data, and accidental complexity comes from the way that the problem is being solved, even using common transaction frameworks. This dissertation describes an extension to AspectJ, called TransJ, with which developers can implement transaction-related crosscutting concerns in cohesive and loosely-coupled aspects. It also presents a preliminary experiment that provides evidence of improvement in reusability without sacrificing the performance of applications requiring essential transactions. This empirical study is conducted using the extended-quality model for transactional application to define measurements on the transaction software systems. This quality model defines three goals: the first relates to code quality (in terms of its reusability); the second to software performance; and the third concerns software development efficiency. Results from this study show that TransJ can improve the reusability while maintaining performance of TransJ applications requiring transaction for all eight areas addressed by the hypotheses: better encapsulation and separation of concern; loose Coupling, higher-cohesion and less tangling; improving obliviousness; preserving the software efficiency; improving extensibility; and hasten the development process

An aspect oriented approach for security hardening : semantic foundations

Computer security is nowadays a very important field in computer science and security hardening of applications becomes of paramount importance. Aspect oriented programming (AOP) is a relatively new technology that allows separation of concerns such as security, synchronization, logging, etc. This increases the readability, understandability, maintainability, and security of software systems. Furthermore, AOP allows automatic injection of the crosscutting concerns into the application code using a weaving mechanism. This thesis comes to provide theoretical study of using AOP for security hardening of applications. The main contributions of this thesis are the following. We propose a comparative study of AOP approaches from a security perspective. We establish a security appropriateness analysis of AspectJ and we propose new security constructs for this language. Since aspects in AspectJ are weaved (combined) with the Java Virtual Machine Language (JVML) application code, we develop a formal semantics for the JVML. We propose also a semantics for AspectJ that formalizes the advice weaving. We develop a new AOP calculus, n_SAOP, based on lambda calculus extended with security pointcuts. Finally, we implement three new constructs in AspectJ, namely getLocal , setLocal , and dflow , for local variable accesses and data flow analysis. In conclusion, this thesis demonstrates the relevance, importance, and appropriateness of using the AOP programming paradigm in hardening the security of application

Early aspects: aspect-oriented requirements engineering and architecture design

This paper reports on the third Early Aspects: Aspect-Oriented Requirements Engineering and Architecture Design Workshop, which has been held in Lancaster, UK, on March 21, 2004. The workshop included a presentation session and working sessions in which the particular topics on early aspects were discussed. The primary goal of the workshop was to focus on challenges to defining methodical software development processes for aspects from early on in the software life cycle and explore the potential of proposed methods and techniques to scale up to industrial applications