Code clones in feature-oriented software product lines

Abstract

Some limitations of object-oriented mechanisms are known to cause code clones (e.g., extension using inheritance). Novel programming paradigms such as feature-oriented programming (FOP) aim at alleviating these limitations. However, it is an open issue whether FOP is really able to avoid code clones or whether it even facilitates (FOP-related) clones. To address this issue, we conduct an empirical analysis on ten feature-oriented software product lines with respect to code cloning. We found that there is a considerable amount of clones in feature-oriented software product lines and that a large fraction of these clones is FOP-related (i.e., caused by limitations of feature-oriented mechanisms). Based on our results, we initiate a discussion on the reasons for FOP-related clones and on how to cope with them. We exemplary show how such clones can be removed by the application of refactoring.

Reusing and converting code clones to aspects - An algorithmic approach

“…Although software engineers have tried to address the issue of cross cutting concerns, the increase in software complexity and size means that there are more and more overlapping concerns in form of duplicate codes scattered across the system. A recent study [19] still shows that between 7% and 23% of source code contains code clones.…”

“…Clone Detection is a technique of looking for functions (or code segments) which are exact copies or mutant copies of another function in the software system [12], [19]. Clone detection techniques can be classified into four main categories: textual, lexical, syntactic, and semantic.…”

“…Code clones can be divided into four distinct types, with types 1, 2, and 3 based on textual similarity, while type 4 code clones are based on functional similarity [17], [18]. Study has shown that around 7% to 23% of the software systems source code contains code clones [19]. There are tools that can detect code clones but the big question is what to do with the clones?…”

Feature-oriented programming with family polymorphism

“…A design-level approach for this aim is a software product line (SPL) and feature-oriented programming (FOP) is known as programming paradigm useful for implementing SPLs. Although FOP enables code reuse among products, a large number of code clones still scatter over feature modules, which are selectable components of a SPL [13]. These code clones are often found in alternative features.…”

“…It is known that a lot of code clones exists in SPLs developed by FOP [13]. The code clones often occur in alternative features because they Permission to make digital or hard copies of all or part of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage and that copies bear this notice and the full citation on the first page.…”