基于字符串的代码克隆检测方法的分析

克隆代码是指在软件源程序中存在的相同或相似的代码片段。克隆代码在很多软件工程中，例如程序理解，代码质量分析，剽窃检测，漏洞查找和病毒检测，都需要通过找出语义或语法上相似的代码片段来实现，目前常用的检测方法有四种：基于文本（text—based）检测，基于字符序列（token-based）的检测，基于语法树（tree-based）的检测和基于关系图（PDG—based）的检测。基于字符序列的克隆检测首先对源程序进行预处理转换，再经过匹配算法得到克隆检测结果：克隆代码的检测是软件分析的一个重要的部分。

Analysis for Code Clone Detection Based on Token Matchings

In source codes, the code clone is usually referred to as a code fragment that is identical or near-identical to another. Many other software engineering tasks, such as program understanding, code quality analysis, plagiarism detection, virus detection and bug detection may require the extraction of syntactically or semantically similar code fragments. There are currently four types of clone detection techniques： text-based technique, token-based technique, tree-based technique and PDG-based technique. Tbe token-based detection technique should preprocess the sources code and then carry out clone detection result by the matching algorithm. Clone code detection is an important part of software analysis.