The Design And Implementation Of Front End Of Software Safety Checking Tool

The software safety checking tool studied and discussed in this paper is capable of checking the safety of a program when it is compiled and inspecting safety holes that might exist in the analyzed program as comprehensively as possible, thereby keeping the program from more serious issues when it is executed.The software safety checking tool is composed of a front end and a back end. First of all, this paper discusses the function and significance of building symbol tables and creating abstract syntax trees in the front end of the software safety checking tool. Secondly, the syntax analyzing rules provided by the analyzer automatic production tool ANTLR are studied thoroughly. Based on this, symbol tables are built and abstract syntax trees are created by appending semantic actions and tags in the productions of the syntax analyzing rules with the method of syntax-directed translation. This method fully makes use of the automatic production mechanism provided by ANTLR, thus could enhance the reliability and extendibility of the front end and lay a good foundation for the construction of the back end.Finally, the manifestations of safety holes related to memory resources are analyzed and studied. The front end of this tool is capable of checking these holes by appending semantic actions in the syntax analyzing rules provided by ANTLR and symbol table modules according to some well-designed algorithms. It is practically proved that the front end of this tool can satisfy the need of checking the safety holes above mentioned.