Mining Billions of AST Nodes to Study Actual and Potential Usage of Java Language Features

By: Robert Dyer, Hridesh Rajan, Hoan Anh Nguyen, and Tien N. Nguyen

Abstract

Programming languages evolve over time, adding additional language features to simplify common tasks and make the language easier to use. For example, the Java Language Specification has four editions and is currently drafting a fifth. While the addition of language features is driven by an assumed need by the community (often with direct requests for such features), there is little empirical evidence demonstrating how these new features are adopted by developers once released. In this paper, we analyze over 31k open-source Java projects representing over 9 million Java files, which when parsed contain over 18 billion AST nodes. We analyze this corpus to find uses of new Java language features over time. Our study gives interesting insights, such as: there are millions of places features could potentially be used but weren’t; developers convert existing code to use new features; and we found almost 200k instances of potential resource handling bugs.

ACM Reference

Dyer, R. et al. 2014. Mining Billions of AST Nodes to Study Actual and Potential Usage of Java Language Features. 36th International Conference on Software Engineering, ICSE, Hyderabad, India - May 31 - June 07 (2014), 779–790.

BibTeX Reference

@inproceedings{DyerRajanNguyenNguyen2014,
  author = {Robert Dyer and Hridesh Rajan and Hoan Anh Nguyen and Tien N. Nguyen},
  title = {Mining Billions of {AST} Nodes to Study Actual and Potential Usage of {Java} Language Features},
  booktitle = {36th International Conference on Software Engineering, ICSE, Hyderabad, India - May 31 - June 07},
  pages = {779--790},
  year = {2014},
  publisher = {{ACM}},
  editor = {Pankaj Jalote and Lionel C. Briand and Andr{\'{e}} van der Hoek},
  doi = {10.1145/2568225.2568295},
  abstract = {
  Programming languages evolve over time, adding additional language features to
  simplify common tasks and make the language easier to use. For example, the
  Java Language Specification has four editions and is currently drafting a
  fifth. While the addition of language features is driven by an assumed need by
  the community (often with direct requests for such features), there is little
  empirical evidence demonstrating how these new features are adopted by
  developers once released. In this paper, we analyze over 31k open-source Java
  projects representing over 9 million Java files, which when parsed contain
  over 18 billion AST nodes. We analyze this corpus to find uses of new Java
  language features over time. Our study gives interesting insights, such as:
  there are millions of places features could potentially be used but weren't;
  developers convert existing code to use new features; and we found almost 200k
  instances of potential resource handling bugs.},
}