Catálogo de publicaciones - libros

Successful software systems must be prepared to evolve or they will die. Although object-oriented software systems are built to last, over time they degrade as much as any legacy software system. As a consequence, one must invest in reengineering efforts to keep further development costs down. Even though software systems and their business contexts may differ in countless ways, the techniques one uses to understand, analyze and transform these systems tend to be very similar. As a consequence, one may identify various that capture best practice in reverse- and re-engineering object-oriented legacy systems. We present a brief outline of a large collection of these patterns that have been mined over several years of experience with object-oriented legacy systems, and we indicate how some of these patterns can be supported by appropriate tools.

is an extensible, optimising compiler for AspectJ. It has been designed as a workbench for experimental research in aspect-oriented programming languages and compilers. We outline a programme of research in these areas, and we review how can help in achieving those research goals.

Code generators based on template expansion techniques are easier to build than purely deductive systems but do not guarantee the same level of assurance: instead of providing “correctness-by-construction”, the correctness of the generated code depends on the correctness of the generator itself. We present an alternative assurance approach, in which the generator is extended to enable Hoare-style safety proofs for each individual generated program. The proofs ensure that the generated code does not “go wrong”, i.e., does not violate certain conditions during its execution.

The crucial step in this approach is to extend the generator in such way that it produces all required annotations (i.e., pre-/postconditions and loop invariants) without compromising the assurance provided by the subsequent verification phase. This is achieved by embedding annotation templates into the code templates, which are then instantiated in parallel by the generator. This is feasible because the structure of the generated code and the possible safety properties are known when the generator is developed. It does not compromise the provided assurance because the annotations only serve as auxiliary lemmas and errors in the annotation templates ultimately lead to unprovable safety obligations.

We have implemented this approach and integrated it into the and program generators. We have then used it to fully automatically prove that code generated by the two systems satisfies both language-specific properties such as array-bounds safety or proper variable initialization-before-use and domain-specific properties such as vector normalization, matrix symmetry, or correct sensor input usage.

Domain-Specific Languages (DSLs) represent a proven approach to raising the abstraction level of programming. They offer high-level constructs and notations dedicated to a domain, structuring program design, easing program writing, masking the intricacies of underlying software layers, and guaranteeing critical properties.

On the one hand, DSLs facilitate a straightforward mapping between a conceptual model and a solution expressed in a specific programming language. On the other hand, DSLs complicate the compilation process because of the gap in the abstraction level between the source and target language. The nature of DSLs make their compilation very different from the compilation of common General-Purpose Languages (GPLs). In fact, a DSL compiler generally produces code written in a GPL; low-level compilation is left to the compiler of the target GPL. In essence, a DSL compiler defines some mapping of the high-level information and features of a DSL into the target GPL and underlying layers ( middleware, protocols, objects, ...).

This paper presents a methodology to develop DSL compilers, centered around the use of generative programming tools. Our approach enables the development of a DSL compiler to be structured on facets that represent dimensions of compilation. Each facet can then be implemented in a modular way, using aspects, annotations and specialization. Because these tools are high level, they match the needs of a DSL, facilitating the development of the DSL compiler, and making it modular and re-targetable.

We illustrate our approach with a DSL for telephony services. The structure of the DSL compiler is presented, as well as practical uses of generative tools for some compilation facets.

We present a domain-specific-language (DSL) for writing instances of a class of filter programs. The values in the language are symbolic and independent of a concrete precision. Efficient code generation is required to fit the program onto a target device limited in both memory and processing power. We construct an interpreter for the DSL in a language specific to the device which contains the semantics of the target instruction set embedded within a declarative meta-language. The compiler is automatically generated from the interpreter through specialisation. This extension of the instruction set allows the construction of an interpreter for the DSL that is both simple and clear. In particular it allows us to declare static representations of the symbolic values, and have the specialisation of the code produce operate upon these values in the instruction set of the target device.

Domain-specific languages (DSL) provides high-level functions making applications easier to write, and to maintain. Unfortunately, many applications are written from scratch and poorly documented, which make them hard to maintain. An ideal solution should be to rewrite them in a appropriate DSL. In this paper, we present (mplate tcher), an automatic tool to recognize high-level functions in source code. Preliminary results show how can be used to reformulate Fortran code into Signal Processing Language (SPL) used in SPIRAL. This opens new possibilities for domain-specific languages.

Domain-specific languages (DSLs) have been proposed as a solution to ease the development of programs within a program family. Sometimes, however, experience with the use of a DSL reveals the presence of subfamilies within the family targeted by the language. We are then faced with the question of how to capture these subfamilies in DSL abstractions. A solution should retain features of the original DSL to leverage existing expertise and support tools.

The Bossa DSL is a language targeted towards the development of kernel process scheduling policies. We have encountered the issue of program subfamilies in using this language to implement an encyclopedic, multi-OS library of scheduling policies. In this paper, we propose that introducing certain kinds of modularity into the language can furnish abstractions appropriate for implementing scheduling policy subfamilies. We present the design of our modular language, Bossa Nova, and assess the language quantitatively and qualitatively.

This paper presents AOP++, a generic aspect-oriented programming framework in C++. It successfully incorporates AOP with object-oriented programming as well as generic programming naturally in the framework of standard C++. It innovatively makes use of C++ templates to express pointcut expressions and match join points at compile time. It innovatively creates a full-fledged aspect weaver by using template metaprogramming techniques to perform aspect weaving. It is notable that AOP++ itself is written completely in standard C++, and requires no language extensions. With the help of AOP++, C++ programmers can facilitate AOP with only a little effort.

Model-driven architecture (MDA) aims at automating software design processes. Design models are divided into platform-indepen- dent models (PIMs) and platform-specific models (PSMs). A model compiler transforms the former models into the latter automatically. We can regard PIMs as a new kind of reusable software component because they can be reused even if a platform is changed. However, a generated PSM is useless if it does not satisfy system limitations such as memory usage and real-time constraints. It is necessary to allow a modeler to customize transformation rules because model modifications for dealing with these limitations may be specific to an application. However, current model compilers do not provide the modeler sufficient customization methods. In order to tackle this problem, we propose a method for constructing an extensible model compiler based on aspect orientation, a mechanism that modularizes crosscutting concerns. Aspect orientation is useful for platform descriptions because it crosscuts many model elements. A modeler can extend model transformation rules by defining new aspects in the process of modeling. In this paper, an aspect-oriented modeling language called AspectM (Aspect for Modeling) for supporting modeling-level aspects is introduced. Using AspectM, a modeler can describe not only crosscutting concerns related to platforms but also other kinds of crosscutting concerns. We believe that MDA is one of the applications of aspect-oriented mechanisms. The contribution of this paper is to show that a model compiler can actually be constructed based on aspect-oriented mechanisms.

This paper presents , a novel language extension to C++ that supports Feature-Oriented Programming (FOP) and Aspect-Oriented Programming (AOP). Besides well-known concepts of FOP languages, contributes several novel FOP language features, in particular multiple inheritance and templates for generic programming. Furthermore, solves several problems regarding incremental software development by adopting AOP concepts. Starting our considerations on solving these problems, we give a summary of drawbacks and weaknesses of current FOP languages in expressing incremental refinements. Specifically, we outline five key problems and present three approaches to solve them: , , and that adopt AOP concepts in different ways. We use as a representative FOP language to explain these three approaches. Finally, we present a case study to clarify the benefits of and its AOP extensions.