Correct Compilation of Concurrent C Code

Technical Report · Wed Mar 01 04:00:00 EST 2023

DOI:https://doi.org/10.2172/2480189· OSTI ID:2480189

Bender, John Matthew ^[1]

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1. Sandia National Laboratories (SNL-CA), Livermore, CA (United States)

The CompCert compiler represents a landmark effort in program verification as both a piece of verified software and as a compiler for verified C programs. A key shortcoming of CompCert however is that it does not support multithreaded programs. Prior work to add threads to CompCert has either required major rewrites of parts of the proof or only works for well synchronized programs. The problem is that CompCert’s backward simulation derives from a forward simulation via the determinism of the semantics of intermediate representation languages. This makes the proofs in CompCert easier but also makes them incompatible with standard models of multithreading which are non-deterministic. Here we propose an alternate formulation of CompCert’s proof structure that parameterizes the existing single threaded semantics with nondeterministic behavior generated at the multithreading level. While this is an old trick where program equivalence is concerned, performing it in the context of CompCert is quite subtle. Our approach allows for expressive concurrent semantics and does not require major proof rewrites but still results in a global backward simulation for multithreaded programs.

• Research Organization: Sandia National Laboratories (SNL-CA), Livermore, CA (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA)
• DOE Contract Number: NA0003525
• OSTI ID: 2480189
• Report Number(s): SAND--2024-13400
• Country of Publication: United States
• Language: English

Related Subjects

97 MATHEMATICS AND COMPUTING