Abstract-In Open Source System (OSS) development, software components are often imported and reused; for this reason we might expect that files are copied in multiple projects (file clones). In this paper, we propose a file clone detection tool called FCFinder and show the analysis performed with it on the FreeBSD Ports Collection, a large OSS project collection. We found many file clones among similar or related projects, which are systematically introduced from base projects.

Embedded software frequently uses interrupts for timer or I/O processing. If a memory area is used by both an interrupt handler and other routines at the same time, the embedded system has the potential to fail because of unexpected data in the memory. To detect the race conditions of memory, this paper proposes a method of interrupt testing on a CPU emulator. The method consists of two features: one is interrupt generation at the instruction points that possibly causes race conditions; the other is replacing input value from external device to control interrupt handlers. An interrupt is generated just after the program reads or writes data on memory for the purpose of covering all possibility of sharing memory between the interrupt handler and other routines. Sequence of input value from the external device is prepared by hand before program execution. We have applied our method to testing for a race condition of uClinux. The experience of detecting race conditions has shown the mechanism causes interrupts at necessary and sufficient timing compared with random interrupt testing. Also, it is easy to substitute values in memory to detect race conditions.

Abstract-An identifier is one of the crucial elements for program readability. Method names in an object-oriented program are important identifiers because method names are used for understanding the behavior of the methods without reading a part of the program. It is well-known that each method name should consist of a verb and objects according to general guidelines. However, it is not easy to name methods consistently since each of the developers may have a different understanding of the verbs and objects used in the method names. As a first step to enable developers to name methods consistently and easily, we focus on the verbs used in the method names.In this paper, we present a technique to recommend candidate verbs for a method name so that developers can use consistent verbs for method names. Given a method, we recommend a list of verbs used in many other methods similar to the given method, by using association rules. We have extracted association rules from 445 OSS projects and applied these rules to two projects. As a result, the extracted rules could recommend the current verbs in the top 10 candidates for 60.6% of the methods covered by our approach. Furthermore, we have identified four meaningful groups of rules for verb recommendation.

Abstract-An identifier is an important key in mapping program elements onto domain knowledge for the purpose of program comprehension. Therefore, if identifiers in a program have inappropriate names, developers can waste a lot of time trying to understand the program. This paper proposes a method for extracting and gathering verb-object (V-O) relations, as good examples of naming, from source code written in an object-oriented programming language. For each of several application domains, dictionaries containing the V-O relations are built and evaluated by software developers. The evaluation results confirm that the relations in the dictionaries are adequate in many cases.

FOSS (Free and Open Source Software) is repeatedly modied and reused by other FOSS or proprietary software systems. They are released to others under specic licenses whose terms and conditions are usually written on the sourcecode les as program comments. There are a few researches which automatically analyze the licenses in a FOSS release, but there is no statistical study on the evolution of licenses along the evolution of FOSS. In this paper, we analyze licenses through FreeBSD, OpenBSD, Eclipse, and ArgoUML evolution, using our license analysis tool Ninka, and discuss characteristics on the evolution of the license used in those systems.

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Comprehensibility of source code is strongly affected by identifier names, therefore software developers need to give good (e.g. meaningful but short) names to identifiers. On the other hand, giving a good name is sometimes a difficult and timeconsuming task even for experienced developers. To support naming identifiers, several techniques for recommending identifier name candidates have been proposed. These techniques, however, still have challenges on the goodness of suggested candidates and limitations on applicable situations. This paper proposes a new approach to recommending method names by applying graph embedding techniques to the method call graph. The evaluation experiment confirms that the proposed technique can suggest more appropriate method name candidates in difficult situations than the state of the art approach.

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