Application of SMT in a Meta-Compiler Framework

This technical paper discusses the implementation of a meta-compiler framework called Langkit, which facilitates the specification of type systems for programming languages. The authors, Romain Béguet and Raphaël Amiard, explain how Langkit allows language designers to focus on high-level aspects by using a declarative logic domain-specific language (DSL) for type system specification. The paper outlines the challenges of building compilers, particularly for statically typed languages, and presents Langkit's approach to semantic analysis through a two-stage process that collects constraints and resolves them using a custom solver. The authors detail the advantages of this method, including easier debugging and maintenance of type systems. They also discuss the integration of a DPLL(T) solver backend, which addresses previous combinatorial explosion issues and enhances the generation of human-readable diagnostics for type errors. The paper includes formal definitions and examples of the logic DSL used in Langkit, highlighting its capability to express complex type systems.