Hello, Two questions regarding analysis groups that ``chain'' their results, like AliasAnalysis. (1) I have an analysis group, let's call it Provider. I also have two implementations of it: ProviderA and ProviderB. The "writing a pass" document suggests using: au.addRequiredTransitive< Provider >(); Within the getAnalysisUsage() method of both ProviderA and ProviderB. But... I'm doing something wrong, and I get an infinite recursion. (2) ALSO, I'm confused. Should I get the previous results using: Provider &previous = getAnalysis< Provider >(); But that returns a reference, so how could the last pass in the chain call it if it doesn't exist? Or, am I supposed to implement a terminal pass, similar to NoAA? -- Nick Johnson