Incremental migration strategies: data flow analysis for wrapping

Incremental migration strategies entail the decomposition of large legacy systems in components that can be independently and selectively replaced; this reduces the costs and risks of a migration program. The legacy components are encapsulated into object wrappers and used (through the wrapper interface) in their original form until new components take up their functions with an acceptable level of reliability. The decomposition of legacy programs in components to be encapsulated in different wrappers involves reengineering activities for creating a new program for each component. Data flow analysis methods are needed for identifying the formal parameters in the interfaces of such programs. We present the approach defined within the project ERCOLE, a research project aiming at migrating legacy systems towards object-oriented platforms.