Pluggable type systems allow programmers to extend the type system of a programming language to enforce semantic properties defined by the programmer. Pluggable type systems are difficult to deploy in legacy codebases because they require programmers to write type annotations manually. This paper investigates how to use machine learning to infer type qualifiers automatically. We propose a novel representation, NaP-AST, that encodes minimal dataflow hints for the effective inference of type qualifiers. We evaluate several model architectures for inferring type qualifiers, including Graph Transformer Network, Graph Convolutional Network and Large Language Model. We further validated these models by applying them to 12 open-source programs from a prior evaluation of the NullAway pluggable typechecker, lowering warnings in all but one unannotated project. We discovered that GTN shows the best performance, with a recall of .89 and precision of 0.6. Furthermore, we conduct a study to estimate the number of Java classes needed for good performance of the trained model. For our feasibility study, performance improved around 16k classes, and deteriorated due to overfitting around 22k classes.

使用机器学习自动推断类型限定符的可插入式类型系统研究，提出了一种编码最小数据流提示的新型表示方式 NaP-AST，并评估了多种模型架构，包括图变换网络（Graph Transformer Network），图卷积网络（Graph Convolutional Network）和大型语言模型。研究中还验证了这些模型在 12 个开源项目中的性能，并进行了一个可行性研究，结果发现在大约 16k 个类时性能有所提升，在约 22k 个类时由于过拟合而恶化。

用机器学习推断可插拔类型