PASTE 2007

Bill Pugh and I will be presenting a paper at PASTE 2007 entitled Finding More Null Pointer Bugs, But Not Too Many. A preprint is available. The paper describes some work that Bill and I did in summer 2006 to improve the null pointer bug-finder in FindBugs. The idea is simple:

1. Perform an backwards intraprocedural dataflow analysis to track values that are guaranteed to be dereferenced on all non-exception forward paths
2. Look for locations within methods (both within basic blocks and on control edges) where a known-null value is guaranteed to be dereferenced

The improved analysis finds more null pointer bugs than our previous null pointer analysis with a low false-positive rate; see paper for details (and try it out by using FindBugs on your Java code).

PASTE happens to be located at FCRC this year, so there's all kinds of cool stuff going on there.