Interfacing Hoare Logic and Type Systems for Foundational Proof-Carrying Code

In this paper, we introduce a Foundational Proof-Carrying Code (FPCC) framework for constructing certified code packages from typed assembly language that will interface with a similarly certified runtime system. Our framework permits the typed assembly language to have a “foreign function” interface, in which stubs, initially provided when the program is being written, are eventually compiled and linked to code that may have been written in a language with a different type system, or even certified directly in the FPCC logic using a proof assistant. We have increased the potential scalability and flexibility of our FPCC system by providing a way to integrate programs compiled from different source type systems. In the process, we are explicitly manipulating the interface between Hoare logic and a syntactic type system.