An Executable Structural Operational Formal Semantics for Python

TL;DR

This paper develops an executable formal semantics for Python using structural operational semantics, enabling sound static analysis and automated interpreter derivation for the language.

Contribution

It introduces a meta-theoretic framework for formalizing structural operational semantics and applies it to Python, facilitating static analysis and interpreter automation.

Findings

Created a formal semantics for Python

Developed a tool-supported framework for semantics formalization

Validated the approach for modern programming languages

Abstract

Python is a popular high-level general-purpose programming language also heavily used by the scientific community. It supports a variety of different programming paradigms and is preferred by many for its ease of use. With the vision of harvesting static analysis techniques like abstract interpretation for Python, we develop a formal semantics for Python. A formal semantics is an important cornerstone for any sound static analysis technique. We base our efforts on the general framework of structural operational semantics yielding a small-step semantics in principle allowing for concurrency and interaction with an environment. The main contributions of this thesis are twofold: first, we develop a meta-theoretic framework for the formalization of structural operational semantics in tandem with the necessary tool support for the automated derivation of interpreters from such formal semantics, and, second, we validate the suitability of this approach for the formalization of modern programming languages developing a semantics for Python.