A Compositional Semantics for Verified Separate Compilation and Linking

Abstract

Recent ground-breaking efforts such as CompCert have made a convincing case that mechanized verification of the compiler correctness for realistic C programs is both viable and practical. Unfortunately, existing verified compilers can only handle whole programs-this severely limits their applicability and prevents the linking of verified C programs with verified external libraries. In this paper, we present a novel compositional semantics for reasoning about open modules and for supporting verified separate compilation and linking. More specifically, we replace external function calls with explicit events in the behavioral semantics. We then develop a verified linking operator that makes lazy substitutions on (potentially reacting) behaviors by replacing each external function call event with a behavior simulating the requested function. Finally, we show how our new semantics can be applied to build a refinement infrastructure that supports both vertical composition and horizontal composition.

Game Semantics for Interface Middleweight Java

“…Apart from the foundational value found in the latter statement, there is practical value, namely that game semantics could play the role of a more generally applicable semantics for open code: be it programs-in-context, libraries with external dependencies, code distributed over a network, etc. Evidence of this can be located in open trace models used for low-level languages which are based, each to a different extent, on the game semantics approach [14,19,42,44].…”

Game semantics for interface middleweight Java

“…Apart from the foundational value found in the latter statement, there is practical value, namely that game semantics could play the role of a more generally applicable semantics for open code: be it programs-in-context, libraries with external dependencies, code distributed over a network, etc. Evidence of this can be located in open trace models used for low-level languages which are based, each to a different extent, on the game semantics approach [14,19,42,44].…”

CompCertO: compiling certified open C components

“…Unfortunately, traditional approaches to compositional semantics fare poorly in the presence of advanced language features, or of the kind of abstraction involved in the compilation process. For CompCert, early attempts along these lines have proven challenging [21,23].…”