The Frama-C platform, which integrates static analysis and formal proof of C programs, now has a plug-in for run-time execution of annotations. In particular, preconditions and postconditions written using the E-ACSL subset of the ACSL annotation language for C can now be executed thanks to this plug-in. This is a great move in the direction of better integration of proofs and tests for C programs!
As far as I know, this is the first attempt at defining a common annotation language for tests and static analysis / proof for C. The annotation languages for C that I know of cannot be executed: Microsoft’s widely used Standard Annotation Language, the annotation language used by the Escher C Verifier or the one from Microsoft’s VCC.
Note that an important difference between this annotation language and others is that it uses mathematical semantics for operations in annotations. So an addition in annotations cannot overflow. In practice, they are using the GMP library for mathematical integers. Try it for yourself by downloading/installing Frama-C and this plug-in!