Finding Compiler Bugs through Cross-Language Code Generator and Differential Testing

2025-07-09

AI Summary

This work addresses a novel class of correctness defects in cross-language compilation arising from ambiguous responsibility boundaries among compilers. We propose CrossLangFuzzer, the first cross-compiler vulnerability detection framework tailored for the JVM multi-language ecosystem. Grounded in a unified intermediate representation (IR), it integrates three mutation strategies—LangShuffler, FunctionRemoval, and TypeChanger—to automatically generate cross-language test programs featuring complex type systems and inheritance hierarchies. These tests expose behavioral inconsistencies across compilers via differential testing. Evaluated on Kotlin, Groovy, Scala 2/3, and Java compilers, CrossLangFuzzer identified 24 confirmed vulnerabilities; notably, TypeChanger alone accounted for 11. Our findings systematically uncover failure patterns stemming from compiler miscoordination in multi-language interaction scenarios. This work establishes a novel methodology and empirical foundation for reliability verification of cross-language compilers.

Technology Category

• Natural Language Processing: Machine Translation, Multilinguality, Cross-Lingual NLP
• Computer Vision: Language and Vision
• Knowledge Representation and Reasoning: Knowledge Representation Languages

Application Category

• Search and Retrieval-Augmented AI: Multilingual and cross-lingual Web search
• Web Mining and Content Analysis: Mining multimedia, multimodal, multilingual, cross-lingual Web data
• Systems and Infrastructure for Web, Mobile and WoT: Sustainability and carbon-aware systems for Web, mobile, and WoT

Abstract

Compilers play a central role in translating high-level code into executable programs, making their correctness essential for ensuring code safety and reliability. While extensive research has focused on verifying the correctness of compilers for single-language compilation, the correctness of cross-language compilation - which involves the interaction between two languages and their respective compilers - remains largely unexplored. To fill this research gap, we propose CrossLangFuzzer, a novel framework that introduces a universal intermediate representation (IR) for JVM-based languages and automatically generates cross-language test programs with diverse type parameters and complex inheritance structures. After generating the initial IR, CrossLangFuzzer applies three mutation techniques - LangShuffler, FunctionRemoval, and TypeChanger - to enhance program diversity. By evaluating both the original and mutated programs across multiple compiler versions, CrossLangFuzzer successfully uncovered 10 confirmed bugs in the Kotlin compiler, 4 confirmed bugs in the Groovy compiler, 7 confirmed bugs in the Scala 3 compiler, 2 confirmed bugs in the Scala 2 compiler, and 1 confirmed bug in the Java compiler. Among all mutators, TypeChanger is the most effective, detecting 11 of the 24 compiler bugs. Furthermore, we analyze the symptoms and root causes of cross-compilation bugs, examining the respective responsibilities of language compilers when incorrect behavior occurs during cross-language compilation. To the best of our knowledge, this is the firstwork specifically focused on identifying and diagnosing compiler bugs in cross-language compilation scenarios. Our research helps to understand these challenges and contributes to improving compiler correctness in multi-language environments.

Problem

• Identifying compiler bugs in cross-language compilation scenarios
• Proposing a framework to generate diverse cross-language test programs
• Analyzing symptoms and root causes of cross-compilation bugs

Innovation

• Universal IR for JVM-based cross-language testing
• Mutation techniques enhance program diversity
• Differential testing across compiler versions