Verification of High-Level Transformations with Inductive Refinement Types

TL;DR

This paper introduces Rabit, an abstract interpretation tool designed to verify inductive type and shape properties of high-level transformations in languages like Rascal, addressing challenges posed by expressive features such as traversals and pattern matching.

Contribution

It presents a novel approach to verifying properties of complex transformations using abstract interpretation based on operational semantics, specifically tailored for expressive transformation languages.

Findings

Rabit effectively verifies properties of various transformations

The approach handles expressive traversals and pattern matching

Successful evaluation on normalization, desugaring, and code generation transformations

Abstract

High-level transformation languages like Rascal include expressive features for manipulating large abstract syntax trees: first-class traversals, expressive pattern matching, backtracking and generalized iterators. We present the design and implementation of an abstract interpretation tool, Rabit, for verifying inductive type and shape properties for transformations written in such languages. We describe how to perform abstract interpretation based on operational semantics, specifically focusing on the challenges arising when analyzing the expressive traversals and pattern matching. Finally, we evaluate Rabit on a series of transformations (normalization, desugaring, refactoring, code generators, type inference, etc.) showing that we can effectively verify stated properties.