Features and object capabilities: reconciling two visions of modularity

The prevalence of threats and attacks in modern systems demands programming techniques that help developers maintain security and privacy. In particular, frameworks for composing components written by multiple parties must enable the authors of each component to erect safeguards against intrusion by other components. Object-capability systems have been particularly prominent for enabling encapsulation in such contexts. We describe the program structures dictated by object capabilities and compare these against those that ensue from feature-oriented programming. We argue that the scalability offered by the latter appears to clash with the precision of authority designation demanded by the former. In addition to presenting this position from first principles, we illustrate it with a case study. We then offer a vision of how this conflict might be reconciled, and discuss some of the issues that need to be considered in bridging this mismatch. Our findings suggest a significant avenue for research at the intersection of software engineering and security.