Re: [PATCH 1/3] evaluate: warn on identical exprs around '&&'

[Josh Triplett <josh@joshtriplett.org>]

On Sun, Aug 28, 2011 at 02:53:52PM +1200, Chris Forbes wrote:
> I'm concerned about the potential for false-positives [after
> preprocessing is done] when combining a bunch of flags.
> 
> I'll throw together another patch to add &|^ support, run it against a
> bunch of real codebases, and see how crazy it is.

Fair enough.  I'd hope that doesn't happen, but I can imagine some
scenarios based on preprocessor macros that could cause that.  However,
if you find that it mostly works and occasionally produces false
positives, you might consider providing an off-by-default warning option
to enable it.

Ideally, we'd try to take textual equality into account from before the
preprocessing step, but that seems anywhere from difficult to impossible
depending on the degree of macro insanity.

- Josh Triplett