On Tuesday 01 November 2005 13:17, Jeffrey A Law wrote: > Possibly a useful thing to have, but I don't think we want to put > the burden of detecting uninitialized variables onto each > optimizer :-) > Heh. Indeed.
> I think false positives are inevitable if we attempt to solve the > problems Mark is complaining about. That's part of the reason why > I think this needs to be switch controlled. > Agreed. > Your example is probably derived from C code which looks something > like this: > Yeah, it's gcc.dg/m-un-1.c, IIRC. > Clearly the message could be better, but it's easy to see how this > warning distinguishes itself from the "blah may be used uninitialized in > this function" warning we give in other cases. We clearly state that > it appeared to be used uninitialized, but optimizations changed that > assessment. > Sounds good. We won't get perfect answers, which is fine given the nature of the problem. However, I would like, to get *consistent* answers. If we decide to re-organize the optimization pipeline, we should not be getting different -Wuninitialized behaviour. Perhaps that's an easier problem to solve. For instance, for GCC bootstraps we could ignore the warning when it's from "... but was later optimized away ...".
