Modularizing error recovery

Error recovery in compilers often involves significant amounts of cognitive effort to identify the code and execution points in the compiler that are related to identifying and handling input-program errors. This is because current implementations fail to explicitly identify error-related control dependencies, and to separately characterize the actions to take when programming errors are detected. As a result, compiler writers need to navigate and understand much of the compiler source in order to replace or extend error recovery actions. In the context of AspectJ compiler (ajc), this paper encapsulates error concerns as aspects yielding improved modularity through: pointcuts that explicitly declare the loci of error detection, and advice that expose the extension points for error handling.