Object Type Hierarchies Analysis to Identify Crosscutting Concerns

In Object Oriented (OO) systems inheritance, implementations and type nesting relation-ships are used as one of the principal way to implement static crosscutting. Thus Type Hier-archies are one of the cause introducing the scattering and tangling of code in the components along the hierarchies. This paper presents an approach based on the analysis of type hierarchies to automatically identify the scattered and tangled Type Fragments (i.e. a portion of a type in terms of its members and relationships) implementing crosscutting concerns in OO systems. The approach defines a model to represent Concerns as sets of Type Fragments and a stepped process to identify the Type Fragments composing each Concern and to perform a crosscutting analysis among them. This information is useful and needed to re-engineer the crosscutting concerns into aspects, or to migrate an existing object oriented system towards the aspect oriented paradigm. The approach has been applied to several software systems producing valid results, presented and discussed in the paper, about its feasibility and effectiveness.