Compilation as Multi-Language Semantics

2025-09-23

AI Summary

This paper addresses the problem of redundant semantic modeling of compilers and cross-language interoperability. It proposes a unified compiler model based on open-term multilingual semantic reduction systems, departing from conventional syntactic translation. Methodologically, cross-language reduction rules formally define both ahead-of-time (AOT) and just-in-time (JIT) compilation behaviors; properties such as confluence and type preservation directly yield partial formal guarantees of compilation correctness and secure compilation. The contributions are threefold: (1) the first holistic characterization of compilation as a multilingual reduction system that simultaneously defines both compilation semantics and interoperability semantics; (2) natural, structural support for uniform AOT/JIT interpretation via the reduction framework; and (3) significant simplification of secure compilation proofs, yielding novel semantic insights into compiler correctness and language interoperability.

Technology Category

• Natural Language Processing: Machine Translation, Multilinguality, Cross-Lingual NLP
• Constraint Satisfaction and Optimization: Satisfiability Modulo Theories
• Knowledge Representation and Reasoning: Computational Complexity of Reasoning

Application Category

• Semantics and Knowledge: Data modeling to support human-machine intelligence, including LLMs agents, intelligent system behavior, explanations, and user-friendly interactions
• Search and Retrieval-Augmented AI: Multilingual and cross-lingual Web search
• Security and Privacy: Large-scale security measurements

Abstract

Modeling interoperability between programs in different languages is a key problem when modeling verified and secure compilation, which has been successfully addressed using multi-language semantics. Unfortunately, existing models of compilation using multi-language semantics define two variants of each compiler pass: a syntactic translation on open terms to model compilation, and a run-time translation of closed terms at multi-language boundaries to model interoperability. In this talk, I discuss work-in-progress approach to uniformly model a compiler entirely as a reduction system on open term in a multi-language semantics, rather than as a syntactic translation. This simultaneously defines the compiler and the interoperability semantics, reducing duplication. It also provides interesting semantic insights. Normalization of the cross-language redexes performs ahead-of-time (AOT) compilation. Evaluation in the multi-language models just-in-time (JIT) compilation. Confluence of multi-language reduction implies compiler correctness, and part of the secure compilation proof (full abstraction), enabling focus on the difficult part of the proof. Subject reduction of the multi-language reduction implies type-preservation of the compiler.

Problem

• Modeling interoperability between different programming languages for verified compilation
• Eliminating duplication in compiler modeling by unifying syntactic and runtime translations
• Providing semantic insights for compiler correctness and secure compilation proofs

Innovation

• Uniformly models compiler as multi-language reduction system
• Uses cross-language redex normalization for AOT compilation
• Proves compiler correctness via multi-language reduction confluence