Software Component Technologies and Space Applications

In the near future, software systems will be more reconfigurable than hardware. This will be possible through the advent of software component technologies which have been prototyped in universities and research labs. In this paper, we outline the foundations for those technologies and suggest how they might impact software for space applications

Features, modularity, and variation points

A feature interaction algebra (FIA) is an abstract model of features, feature interactions, and their compositions. A structured document algebra (SDA) defines modules with variation points and how such modules compose. We present both FIA and SDA in this paper, and homomorphisms that relate FIA expresssions to SDA expressions. Doing so separates fundamental concepts of Software Product Lines (SPLs) that have previously been conflated and misunderstood. Our work also justifies observations and relationships that have been used in prior work on feature-based SPLs

Automated analysis of feature models: challenges ahead

Ministerio de Ciencia y Tecnología TIC 2003-02737-C02-01Ministerio de Ciencia y Tecnología TIN2006-0047

Automated analysis of feature models: challenges ahead

Ministerio de Ciencia y Tecnología TIC 2003-02737-C02-01Ministerio de Ciencia y Tecnología TIN2006-0047

Integrating the common variability language with multilanguage annotations for web engineering

Web applications development involves managing a high diversity of files and resources like code, pages or style sheets, implemented in different languages. To deal with the automatic generation of custom-made configurations of web applications, industry usually adopts annotation-based approaches even though the majority of studies encourage the use of composition-based approaches to implement Software Product Lines. Recent work tries to combine both approaches to get the complementary benefits. However, technological companies are reticent to adopt new development paradigms such as feature-oriented programming or aspect-oriented programming. Moreover, it is extremely difficult, or even impossible, to apply these programming models to web applications, mainly because of their multilingual nature, since their development involves multiple types of source code (Java, Groovy, JavaScript), templates (HTML, Markdown, XML), style sheet files (CSS and its variants, such as SCSS), and other files (JSON, YML, shell scripts). We propose to use the Common Variability Language as a composition-based approach and integrate annotations to manage fine grained variability of a Software Product Line for web applications. In this paper, we (i) show that existing composition and annotation-based approaches, including some well-known combinations, are not appropriate to model and implement the variability of web applications; and (ii) present a combined approach that effectively integrates annotations into a composition-based approach for web applications. We implement our approach and show its applicability with an industrial real-world system.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Transforming numerical feature models into propositional formulas and the universal variability language

Real-world Software Product Lines (SPLs) need Numerical Feature Models (NFMs) whose features have not only boolean values that satisfy boolean constraints but also have numeric attributes that satisfy arithmetic constraints. An essential operation on NFMs finds near-optimal performing products, which requires counting the number of SPL products. Typical constraint satisfaction solvers perform poorly on counting and sampling. Nemo (Numbers, features, models) is a tool that supports NFMs by bit-blasting, the technique that encodes arithmetic expressions as boolean clauses. The newest version, Nemo2, translates NFMs to propositional formulas and the Universal Variability Language (UVL). By doing so, products can be counted efficiently by #SAT and Binary Decision Tree solvers, enabling finding near-optimal products. This article evaluates Nemo2 with a large set of synthetic and colossal real-world NFMs, including complex arithmetic constraints and counting and sampling experiments. We empirically demonstrate the viability of Nemo2 when counting and sampling large and complex SPLs.Munoz, Pinto and Fuentes work is supported by the European Union’s H2020 research and innovation programme under grant agreement DAEMON 101017109, by the projects co-financed by FEDER, Spain funds LEIA UMA18-FEDERJA-15, IRIS PID2021- 122812OB-I00 (MCI/AEI), and the PRE2019-087496 grant from the Ministerio de Ciencia e Innovación. Funding for open access charge: Universidad de Málaga / CBUA

Automatic Code Generation for Actuator Interfacing from a Declarative Specification

Abstract -Common software design practices use objectoriented (OO) frameworks that structure software in terms of objects, classes, and package; designers then create programs by inheritance and composition of classes and objects. Operational Software Components for Advanced Robotics (OSCAR) is one such framework for robot control software with abstractions for generalized kinematics, dynamics, performance criteria, decision making, and hardware interfacing. Even with OSCAR, writing new programs still requires a significant amount of manual labor. Feature-Oriented Programming (FOP) is method for software design that models and specifies programs in terms of features, where a feature encapsulates the common design decisions that occur in a domain. A set of features then forms a domain model for a Product Line Architecture. Product variants in this product line can then be generated from a declarative specification. FOP and related technologies are emerging software engineering techniques for automatically generating prorams. Our research applies FOP to robot controller software. As an example, the domain of hardware interfacing is analyzed and 41 features identified. A GUI for specifying and generating programs is presented as well. Analysis of features shows 200 possible different programs could be generated

Fitting the Pieces Together: A Machine-Checked Model of Safe Composition

ABSTRACT Programs of a software product line can be synthesized by composing features which implement a unit of program functionality. In most product lines, only some combination of features are meaningful; feature models express the highlevel domain constraints that govern feature compatibility. Product line developers also face the problem of safe composition -whether every product allowed by a feature model is type-safe when compiled and run. To study the problem of safe composition, we present Lightweight Feature Java (LFJ), an extension of Lightweight Java with support for features. We define a constraint-based type system for LFJ and prove its soundness using a full formalization of LFJ in Coq. In LFJ, soundness means that any composition of features that satisfies the typing constraints will generate a well-formed LJ program. If the constraints of a feature model imply these typing constraints then all programs allowed by the feature model are type-safe