Design of flexible static program analyzers with PQL

摘要

Static program analyzers (SPA) are interactive tools that enhancenprogram understanding during maintenance by answering queries aboutnprograms. Depending on the maintenance task in hand, SPAs must processndifferent source programs and answer different types of program queries.nFlexibility is, therefore, a desirable property of SPAs. The authorndescribes a program query language, called PQL, that facilitates thendesign of flexible SPAs. PQL is a conceptual level, sourcenlanguage-independent notation to specify program queries and programnviews. In PQL, one can query global program design as well as search forndetail code patterns. PQL queries are answered automatically by a querynevaluation mechanism built into an SPA. Program design models and POLnform the core of an SPA conceptual model. He based the SPA'snarchitecture on this conceptual model. By separating the conceptualnmodel from the implementation decisions, one can design SPAs that arencustomizable to the needs of the maintenance project at hand. Dependingnon criteria such as efficiency of query evaluation or simplicity of thenSPA design, one can implement the same functional specifications of annSPA on a variety of program representations to meet the requiredncriteria. Apart from its role in the design of SPAs, the conceptualnmodel also allows one to rigorously study SPA functionality in thencontext of the underlying maintenance process and programmer behaviornmodels, in isolation from tool implementation details