[Checkers] Problems with NonNull checker

[Michael Ernst]

Matt-

> I'm not seeing differences in the qualifiers in Daikon CVS, but
> ~mernst/tmp/nninfer/invariants-java/checkers/quals has old
> definitions.

Right, that may have been old.  I don't usually work on that machine and in
particular haven't updated it since I sent you my mail -- the
trans-Atlantic delay is too irritating for interactive use.

> >  If we could comment this out or use some other mechanism, then I wouldn't
> >  have to have a copy of the qualifiers in Daikon.  (This is the mechanism
> >  that Mahmood was asking about recently.)
> 
> I started working on this a while back and got sidetracked; I'll see
> what state the code is in. Personally, though, I think this is a
> slippery slope. Annotations in comments give us backward
> compatibility, enabling us to compile code in Java 5/6. Optional
> imports have nothing to do with backward compatibility at all, and I
> could imagine this confusing users that have legitimately commented
> imports (rare as they may be).

I agree this isn't high-priority.  (And maybe there is some better
mechanism than the several possibilities I suggested.)  It's OK for me now,
and I was just explaining why the qualifiers were there.

                    -Mike