From Bug Reports to Workarounds: The Real-World Impact of Compiler Bugs

Compilers are essential in daily development, but their bugs can introduce hidden bugs to many software projects. As compiler bugs are important, researchers have conducted various empirical studies to understand their characteristics. Most of the prior studies analyze only the bug reports and patches of compilers. From such sources, they analyze the root causes, locations, and repairs of compiler bugs. Their findings are useful for understanding compiler bugs themselves, but to the best of our knowledge, the impact of compiler bugs is rarely explored. For example, before compiler bugs are fixed, programmers would bypass such bugs, but no prior study analyzes the workarounds for compiler bugs. To complement the prior studies, in this paper, we analyze how the bugs of two mainstream compilers, gcc and llvm, affect real development. Besides the bug reports and patches of compilers, in this study, from 603 GitHub projects, we collect 806 commits whose messages mention compiler bugs. From the dataset, we analyze how compiler bugs affect real projects. Furthermore, we manually analyze 219 commits whose messages explicitly mention compiler bugs. Our results lead to eight useful findings for programmers, compiler developers, and researchers. For instance, based on our findings, we suggest that it is critical to analyze the long-term impact of compiler bugs. Our story about a gcc bug confirms that compiler bugs can affect the compilations of projects even after these compiler bugs have already been fixed.