This paper reports on the design and soundness proof, using the Coq proof assistant, of Verasco, a static analyzer based on abstract interpretation for most of the ISO C 1999 language (excluding recursion and dynamic allocation). Verasco establishes the absence of run-time errors in the analyzed programs. It enjoys a modular architecture that supports the extensible combination of multiple abstract domains, both relational and non-relational. Verasco integrates with the CompCert formally-verified C compiler so that not only the soundness of the analysis results is guaranteed with mathematical certitude, but also the fact that these guarantees carry over to the compiled code.

We consider the verified compilation of high-level managed languages like Java or C# whose intermediate representations provide support for shared-memory synchronization and automatic memory management. In this environment, the interactions between application threads and the language runtime ( e.g. , the garbage collector) are regulated by compiler-injected code snippets. Example of snippets include allocation fast paths among others. In our TOPLAS paper we propose a refinement-based proof methodology that precisely relates concurrent code expressed at different abstraction levels, cognizant throughout of the relaxed memory semantics of the underlying processor. Our technique allows the compiler writer to reason compositionally about the atomicity of low-level concurrent code used to implement managed services. We illustrate our approach with examples taken from the verification of a concurrent garbage collector.

interpretation provides advanced techniques to infer numerical invariants on programs. There is an abundant literature about numerical abstract domains that operate on scalar variables. This work deals with lifting these techniques to a realistic C memory model. We present an abstract memory functor that takes as argument any standard numerical abstract domain, and builds a memory abstract domain that finely tracks properties about memory contents, taking into account union types, pointer arithmetic and type casts. This functor is implemented and verified inside the Coq proof assistant with respect to the CompCert compiler memory model. Using the Coq extraction mechanism, it is fully executable and used by the Verasco C static analyzer.