Re: -Wuninitialized issues

[Mark Mitchell <mark at codesourcery dot com>]

Jeffrey A Law wrote:

> Again, the problem I have with the notion that we want to get
> consistent answers is that doing so, is going to give us a lot of
> false positives.  That IMHO is a huge step backwards if that's how
> we make -Wuninitialized work.

You're right that it's the users that matter, and bug reports give us
some visibility into what annoyed people.

The false-positive case I remember seeing most often was the:

  if (b) {
    x = 1;
  }
  ...
  if (b) {
    use(x);
  }

I don't remember very many people complaining about other tricky cases;
I certainly don't remember anyone complaining about:

  if (f())
    x = 1;
  use(x);

warning when f could be proven to return a non-zero value.

However, I'll freely admit this is just my notoriously fallible memory
at work here; I've not reviewed the PRs.

In any case, it does seem like you're moving in a direction that would
give us a mode where warnings would perhaps oscillate between your two
classes, but not come and go completely.  I think that's pretty good.

-- 
Mark Mitchell
CodeSourcery, LLC
mark@codesourcery.com
(916) 791-8304