Based On JAVA The EDPL Compiler Of The Design And Implementation

The software evolution is a very important morph during software life cycle, and it also is a process that the software system constantly adjusts itself to meet the internet opening environment and variation of user's requirement. The software evolution process as the work flow in the software evolution, the purpose is to establish the whole task framework of software evolution and improving the efficiency of software evolution. The main objective of the software evolution process description language is to describe and expand the ability of meta-model of software evolution process and the computer morph.At present, the compiling technique is relatively mature. There is different product for different languages and application is relatively extensive. The main stages of the compiling technology as follows:the lexical analysis phase, the syntax analysis phase, the semantic analysis phase, the intermediate code generation, the object code generation, the code optimization, the symbol table management and the error handling.This paper concisely introduces the function of the software evolution process description language, which adopted the Backus-Naur Form (EBNF) to define the EPDL program syntax rule. A design model of EPDL code complier was presented. It has six stages as follows:the lexical analysis phase, the syntax analysis phase, the semantic analysis phase, the object code generation, the symbol table management and the error handling.The EPDL is an object-oriented software evolution modeling description language, on which based, the research is carried out according to Inheritance of the EPDL, the two following concepts, process inheritance and activity inheritance as well as additive inheritance, absolute inheritance, modified inheritance, refused inheritance are put forwarded, besides, the related syntax rules is defined.According to defined data structure of object code, the storage rules and storage format of object code generation phase is put forwarded. The design and implementation of compiler were described from different aspects:lexical analysis, syntax and semantic analysis, the object code generation, information draws and so on. It concretely describes the process of using JAVA which is an OOP language to realize the EPDL compiler. It is independent of operating system and can be expanded easily.