Component design of retargetable program analysis tools that reuse intermediate representations

Interactive program analysis tools are often tailored to one particular representation of programs, making adaptation to a new language costly. One way to ease adaptability is to introduce an intermediate abstraction-an adaptation layer-between an existing language representation and the program analysis tool. This adaptation layer translates the tool's queries into queries on the particular representation. Our experiments with this approach on the StarTool program analysis tool resulted in low-cost retargets for C, Tcl/Tk, and Ada. Required adjustments to the approach, however, led to insights for improving a client's retargetability. First, retargeting was eased by having our tool import a tool-centric (i.e.,client-centric) interface rather than a general-purpose, language-neutral representation interface. Second, our adaptation layer exports two interfaces, a representation interface supporting queries on the represented program and a language interface that the client queries to configure itself suitably for the given language. Straightforward object-oriented extensions enhance reuse and ease the development of multilanguage tools