Identification of Misleading Location Information in Compiler Diagnoses

The location of compilation errors are usually reported by compilers to facilitate quick fixing of such compiler errors. However, sometimes such location information could be incorrect or misleading, which significantly reduces the chance of quick fixing. To this end, in this paper, we propose an automated approach, called iMiLi, to identify misleading location information in compiler diagnoses. We generate potentially illegal programs (called mutants) by mutating legal programs, and compile such mutants. If the compiler generates error diagnoses on a mutant, we extract the location information from the resulting diagnoses. The location information is suspicious if it does not point to the source code where the associated mutation is conducted. Then we propose heuristics for each kind of mutation operators to exclude such suspicious but correct location information. We evaluate the proposed approach on a state-of-the-practice compiler (i.e., Eclipse Compiler for Java, known as ECJ). iMiLi successfully identifies seven categories of incorrect/misleading location information in diagnoses of ECJ.