A Comprehensive Study of Code-removal Patches in Automated Program Repair

TL;DR

This paper investigates code-removal patches in automated program repair, revealing their limitations, proposing a taxonomy, and exploring their relationship with developer patches to improve APR techniques.

Contribution

It provides a comprehensive analysis of code-removal patches, identifies scenarios affecting their effectiveness, and introduces a taxonomy to guide future APR research.

Findings

Code-removal patches often fail to fix bugs effectively.

Test suite limitations impact the success of code-removal patches.

A taxonomy of code-removal patches highlights key issues and opportunities.

Abstract

Automatic Program Repair (APR) techniques can promisingly help reducing the cost of debugging. Many relevant APR techniques follow the generate-and-validate approach, that is, the faulty program is iteratively modified with different change operators and then validated with a test suite until a plausible patch is generated. In particular, Kali is a generate-and-validate technique developed to investigate the possibility of generating plausible patches by only removing code. Former studies show that indeed Kali successfully addressed several faults. This paper addresses the case of code-removal patches in automated program repair investigating the reasons and the scenarios that make their creation possible, and the relationship with patches implemented by developers. Our study reveals that code-removal patches are often insufficient to fix bugs, and proposes a comprehensive taxonomy of code-removal patches that provides evidence of the problems that may affect test suites, opening new opportunities for researchers in the field of automatic program repair.