Research Of Program Static Analyzer Based On Incremental Techniques

Software maintenance is the process of modifying the software system or component after delivery to correct faults, to improve performance or other attributes, or adapt to a change in the environment, or make it more maintainable. It is the longest phase, and also highest time-cost. It is reported that program comprehension may cost 47%-62% during the whole software maintenance. Therefore, to enhance the efficiency of program comprehension will be in favor of controlling the maintenance cost, which makes a great practical significance.It is a crucial step in enhancing the efficiency and reducing the maintenance cost by using some assistant tools when program comprehension. However, because of the diversity of comprehension tasks, objective systems, and operation systems, some tools usually developed for only one task or run under only one platform. Thus, for program comprehension tools being adaptive to multitask, running under cross platform, the main tasks we have done are as follows:(1)According to the characteristics of C/C++ programming, pointed out the definitions of entities, attributes and relationships between the entities; then on the basis, constructed a new conception model, giving the scope of information extraction.(2)Studied on Lex and Yacc about lexical analysis and error handling, put forward the mechanisms of information extraction and error recovery, which has resolved the problems of extraction manner as well as error handling.(3)During software maintenance, sometimes needs to modify the program files. Avoiding reanalysis every time, applied incremental techniques to parsing, semantic analysis and data flow analysis, in order to update information base quickly.(4)With the aid of the Linux-like environment called Cygwin, code migration from Linux to Windows is researched, which provided the possibility of the analyzer running under cross platform.