Finding and preventing run-time error handling mistakes

It is difficult to write programs that behave correctly in the presence of run-time errors. Existing programming language features often provide poor support for executing clean-up code and for restoring invariants in such exceptional situations. We present a dataflow analysis for finding a certain class of error-handling mistakes: those that arise from a failure to release resources or to clean up properly along all paths. Many real-world programs violate such resource safety policies because of incorrect error handling. Our flow-sensitive analysis keeps track of outstanding obligations along program paths and does a precise modeling of control flow in the presence of exceptions. Using it, we have found over 800 error handling mistakes almost 4 million lines of Java code. The analysis is unsound and produces false positives, but a few simple filtering rules suffice to remove them in practice. The remaining mistakes were manually verified. These mistakes cause sockets, files an...

• Type: Conference
• Year: 2004
• Where: OOPSLA
• Authors: Westley Weimer, George C. Necula
• Keywords: Error Handling, Keeps Track, OOPSLA 2004, Programming Language Feature