Clippy lints are considered as essential tools for Rust developers, as they can be configured as gate-keeping rules for a Rust project during continuous integration. Despite their availability, little was known about practical application and cost-effectiveness of the lints in reducing code quality issues. In this study, we embark on a comprehensive analysis to unveil the true impact of Clippy lints in the Rust development landscape. The study is structured around three interrelated components, each contributing to the overall effectiveness of Clippy. Firstly, we conduct a comprehensive analysis of Clippy lints in all idiomatic crates-io Rust projects with an average warning density of 21/KLOC. The analysis identifies the most cost-effective lint fixes, offering valuable opportunities for optimizing code quality. Secondly, we actively engage Rust developers through a user survey to garner invaluable feedback on their experiences with Clippy. User insights shed light on two crucial concerns: the prevalence of false positives in warnings and the need for auto-fix support for most warnings. Thirdly, building upon these findings, we engineer three innovative automated refactoring techniques to effectively fix the four most frequent Clippy lints. As a result, the warning density in Rosetta benchmarks has significantly decreased from 195/KLOC to an impressive 18/KLOC, already lower than the average density of the crates-io Rust projects. These results demonstrate tangible benefit and impact of our efforts in enhancing the overall code quality and maintainability for Rust developers.

翻译：Clippy lint被Rust开发者视为必备工具，可在持续集成过程中作为Rust项目的把关规则。尽管这些lint工具已广泛可用，但关于其实际应用及降低代码质量问题成本效益的研究仍十分有限。本研究通过综合分析揭示Clippy lint在Rust开发生态中的真实影响。研究围绕三个相互关联的组成部分展开，每个部分都推动了Clippy整体的有效性：首先，我们对所有符合惯用写法的crates-io Rust项目中的Clippy lint进行综合剖析（平均警告密度为21/KLOC），识别出最具成本效益的lint修复方案，为优化代码质量提供宝贵机遇；其次，通过用户调查积极收集Rust开发者对Clippy使用体验的反馈，用户洞察揭示了两个关键问题——警告中的误报现象盛行以及对大多数警告提供自动修复支持的需求；最后，基于上述发现，我们设计出三种创新性自动重构技术，有效修复四种最常见的Clippy lint。实验结果表明，Rosetta基准测试中的警告密度从195/KLOC显著降至18/KLOC，已低于crates-io Rust项目的平均密度。这些成果充分证明了我们在提升Rust开发者整体代码质量与可维护性方面的实际效益与影响力。