用抽象语法链表示C程序中的表达式

Representing the express in the C program with abstract syntax link list

因为缺少解释器,对程序进行自动分析和测试领域中有很多问题难以解决.设计解释器的一个核心问题是如何表示表达式,使其既便于人工检查也便于计算机自动生成和解释执行表达式.传统的表示方式主要针对编译器进行设计,不适合解释器.为此,综合运算符的特性和常见表示方法的优缺点,提出用抽象语法链EOE*表示表达式,给出了相应的提取和解释执行算法,并成功应用于本项目组开发的解释器中.

Because of lacking interpreter,many problems are difficult to be solved in the fields of analyzing and testing program automatically.As designing interpreter,one of the core problems is representing and interpreting the express in an adequate manner.With it,we hope that the programs could be checked easily by people or by computer,and the relative algorithms of being created and interpreted could be simple.But most of the classical represent methods of intermediate code are more suitable for compiler and not for interpreter.After discussing the features of the operators and the shortcoming of the classical represent methods,this paper presents that using abstract syntax link list（or EOE＊ for short） to represent the express.And then we describe the algorithms for fetching and calculating EOE＊.We have realized it in our interpreter successfully.