Minhaz F. Zibran

Evaluating Code Clone Genealogies at Release Level: An Empirical Study

Code clone genealogies show how clone groups evolve with the evolution of the associated software system, and thus could provide important insights on the maintenance implications of clones. In this paper, we provide an in-depth empirical study for evaluating clone genealogies in evolving open source systems at the release level. We develop a clone genealogy extractor, examine 17 open source C, Java, C++ and C# systems of diverse varieties and study different dimensions of how clone groups evolve with the evolution of the software systems. Our study shows that majority of the clone groups of the clone genealogies either propagate without any syntactic changes or change consistently in the subsequent releases, and that many of the genealogies remain alive during the evolution. These findings seem to be consistent with the findings of a previous study that clones may not be as detrimental in software maintenance as believed to be (at least by many of us), and that instead of aggressively refactoring clones, we should possibly focus on tracking and managing clones during the evolution of software systems.

The vision of software clone management: Past, present, and future (Keynote paper)

Duplicated code or code clones are a kind of code smell that have both positive and negative impacts on the development and maintenance of software systems. Software clone research in the past mostly focused on the detection and analysis of code clones, while research in recent years extends to the whole spectrum of clone management. In the last decade, three surveys appeared in the literature, which cover the detection, analysis, and evolutionary characteristics of code clones. This paper presents a comprehensive survey on the state of the art in clone management, with in-depth investigation of clone management activities (e.g., tracing, refactoring, cost-benefit analysis) beyond the detection and analysis. This is the first survey on clone management, where we point to the achievements so far, and reveal avenues for further research necessary towards an integrated clone management system. We believe that we have done a good job in surveying the area of clone management and that this work may serve as a roadmap for future research in the area.

Analyzing and Forecasting Near-Miss Clones in Evolving Software: An Empirical Study

Effort for development and maintenance of complex large software is believed to have dependency on the amount of duplicated code fragments (code clones) present in code-bases. For example, clones need to be carefully and consistently maintained and/or refactored for preventing accidental error propagation. Thus it is important to understand the proportion and evolution of clones in evolving software systems for cost estimation or the like. This paper presents a study on the evolution of near-miss clones at release level in medium to large open source software systems of different types (operating systems, database systems, editors, etc.) written in three different programming languages namely C, C#, and Java. Using a hybrid clone detector, NiCad, we detected both exact and near-miss clones at different levels of similarity. Applying statistical methods we investigated, from different dimensions, the evolution of both exact and near-miss clones, and also forecasted the amount of clones in future releases of the software systems. Our study offers significant insights into the existence and evolution of code clones and their relationships with programming language or paradigm and program size.

Useful, But Usable? Factors Affecting the Usability of APIs

Software development today has been largely dependent on the use of API libraries, frameworks, and reusable components. However, the API usability issues often increase the development cost (e.g., time, effort) and lower code quality. In this regard, we study 1,513 bug-posts across five different bug repositories, using both qualitative and quantitative analysis. We identify the API usability issues that are reflected in the bug-posts from the API users, and distinguish relative significance of the usability factors. Moreover, from the lessons learned by manual investigation of the bug-posts, we provide further insight into the most frequent API usability issues.

Towards flexible code clone detection, management, and refactoring in IDE

In this paper, we propose an IDE-based clone management system to flexibly detect, manage, and refactor both exact and near-miss code clones. Using a k-difference hybrid suffix tree algorithm we can efficiently detect both exact and near-miss clones. We have implemented the algorithm as a plugin to the Eclipse IDE, and have been extending this for real-time code clone management with semi-automated refactoring support during the actual development process.

IDE-based real-time focused search for near-miss clones

Code clone is a well-known code smell that needs to be detected and managed during the software development process. However, the existing clone detectors have one or more of the three shortcomings: (a) limitation in detecting Type-3 clones, (b) they come as stand-alone tools separate from IDE and thus cannot support clone-aware development, (c) they overwhelm the developer with all clones from the entire code-base, instead of a focused search for clones of a selected code segment of the developers interest. This paper presents our IDE-integrated clone search tool, that addresses all the above issues. For clone detection, we adapt a suffix-tree-based hybrid algorithm. Through an asymptotic analysis, we show that our approach for clone detection is both time and memory efficient. Moreover, using three separate empirical studies, we demonstrate that our tool is flexibly usable for searching exact (Type-1) and near-miss (Type-2 and Type-3) clones with high precision and recall.

Leveraging automated sentiment analysis in software engineering

Automated sentiment analysis in software engineering textual artifacts has long been suffering from inaccuracies in those few tools available for the purpose. We conduct an in-depth qualitative study to identify the difficulties responsible for such low accuracy. Majority of the exposed difficulties are then carefully addressed in developing SentiStrength-SE, a tool for improved sentiment analysis especially designed for application in the software engineering domain. Using a benchmark dataset consisting of 5,600 manually annotated JIRA issue comments, we carry out both quantitative and qualitative evaluations of our tool. SentiStrength-SE achieves 73.85% precision and 85% recall, which are significantly higher than a state-of-the-art sentiment analysis tool we compare with.

Evaluating the conventional wisdom in clone removal: a genealogy-based empirical study

Clone management has drawn immense interest from the research community in recent years. It is recognized that a deep understanding of how code clones change and are refactored is necessary for devising effective clone management tools and techniques. This paper presents an empirical study based on the clone genealogies from a significant number of releases of six software systems, to characterize the patterns of clone change and removal in evolving software systems. With a blend of qualitative analysis, quantitative analysis and statistical tests of significance, we address a number of research questions. Our findings reveal insights into the removal of individual clone fragments and provide empirical evidence in support of conventional clone evolution wisdom. The results can be used to devise informed clone management tools and techniques.

Near-miss clone patterns in web applications: An empirical study with industrial systems

Dynamic web pages composed of inter-woven (tangled) source code written in multiple programming languages (e.g., HTML, PHP, JavaScript, CSS) makes it difficult to analyze and manage clones in web applications. Despite more than a decade of research on software clones, there are not many studies towards the investigation of code clones in web applications. In this paper, we present an in-depth study on the patterns (i.e., forking and templating) of exact and near-miss code clones in two industrial dynamic web applications having distinct architecture. The findings of our study confirm the believed patterns for cloning and suggest that specialized techniques and tool support are necessary for effectively managing clones in the tangled source code of dynamic web applications.

An Internet framework to bring coherence between WAP and HTTP ensuring better mobile Internet security

To bring coherence between wireless access protocol (WAP) and hyper text transfer protocol (HTTP), in this paper, we have proposed an enhanced Internet framework, which incorporates a new markup language and a browser compatible with both of the access control protocols. This markup language and the browser enables co-existence of both hyper text markup language (HTML) and wireless markup language (WML) contents in a single source file, whereas the browser incorporates the ability to hold contents compliant with both HTTP and WAP. The proposed framework also bridges the security gap that is present in the existing mobile Internet framework