一种基于分支条件的对象状态机自动提取方法.PDF

小 型 微 型 计 算 机 系 统 2007 年 月 第 期 Journal of Chinese Computer Systems Vol.28 No. 2007 一种基于分支条件的对象状态机自动提取方法 吴 浩，彭 鑫，赵文耘 （复旦大学计算机科学与工程系软件工程实验室，上海 200433 ） E-mail ：wuhao@, pengxin@, wyzhao@ 摘 要：对象行为协议对于辅助其他开发者理解并正确使用对象所提供的外部行为具有十分重要的意义。然而相关文档 却常常缺失或存在不一致，需要通过逆向分析的方法进行恢复。针对这一问题，本文提出了一种基于驱动执行和动态分析 的对象状态机（Object State Machine，OSM ）提取方法。该方法从源代码中提取包含类属性的条件表达式，以其在运行时 刻的取值情况及程序异常信息作为状态标识，并通过驱动执行的方式获取运行时的状态转换信息，然后分析运行时信息逐 步构造对象状态机。该方法已实现为相应的原型系统，初步实验结果表明通过该方法可以高效、准确地恢复对象行为协议。 关键词：对象状态机；行为协议；条件提取；状态分析；驱动式调用 An Automatic Extraction Method of Object State Machine Base on Condition Expressions WU Hao ，PENG Xin ，ZHAO Wen-yun （Department of Computer Science and Engineering, Fudan University, Shanghai 200433, China ） Abstract: Object behavior protocols are of great significance in guiding developers to understand and properly use the external functions provided by the object. Nevertheless, the related documents are often missed or inconsistent. Therefore, reverse analysis is used to recover the protocols. To achieve this goal, this paper presents a new method to extract Object State Machine (OSM) based on intentional method invoking and dynamic analysis. This method firstly extracts condition expressions containing class attributes from source code and defines states to be the sets of values of expressions at run-time as well as the exceptions; then gets states transition information by intentional method invoking; and finally uses the sates and the states transition information to construct object state machine. The corresponding prototype system has been realized and the preliminary experimental results show that this method can efficiently and accurately recovers behavior protocols. Key words: Object State Machine, Object behavior protocols, Conditions extraction, State analysis, intention