Perf4JS: Automatically Fixing Performance Problems in Real-World JavaScript Applications

随着动态语言（例如JavaScript）变得越来越流行，用这些语言编写的应用程序的性能对于确保响应性、高吞吐量和高能效至关重要。不幸的是，目前查找和优化性能瓶颈主要是由少数专业开发人员手动执行的，而且耗时。原因是现有的动态语言程序分析技术受到基本的限制，这些限制使工具无法自动进行有效的代码优化。该项目将研究新颖的程序分析和重构技术，以满足高度动态语言的特定需求。我们期望这些基本的新技术能够实现跨多个领域、语言和软件质量目标的广泛应用。作为一个特定的应用程序，该提案侧重于自动提高实际JavaScript应用程序的性能。为此，我们将开发一些方法来帮助开发人员检测优化机会，通过用高效的代码替换低效的代码来重构它们，并可靠而现实地测量对性能的影响。我们设想计划的工作对蓬勃发展的程序分析和性能分析研究领域产生重大影响。

As dynamic languages, e.g., JavaScript, are becoming more and more prevalent, the performance of applications written in these languages is crucial to ensure responsiveness, high throughput, and energy-efficiency. Unfortunately, finding and optimizing performance bottlenecks currently is a mostly manual and time-consuming process performed by few expert developers. The reason is that existing program analysis techniques for dynamic languages suffer from fundamental limitations that prevent tools from automating effective code optimizations. The proposed project will research novel program analysis and refactoring techniques that address the specific needs of highly dynamic languages. We expect these fundamentally new techniques to enable a wide range of applications across multiple domains, languages, and software quality goals. As a specific application, the proposal focuses on automatically improving the performance of real-world JavaScript applications. To this end, we will develop approaches that help developers to detect optimization opportunities, refactor them by replacing inefficient with efficient code, and by reliably and realistically measuring the effect on performance. We envision that the planned work has a significant impact on the thriving research fields of program analysis and performance analysis.