On 07/29/2015 08:08 AM, Marek Polacek wrote:
As discussed elsewhere, -Wtautological-compare shouldn't warn about
floating-point types because of the way NaN behave.
I've been meaning to commit this one as obvious, but I'm not sure
whether I should also use HONOR_NANS or whether I can safely ignore
that here.
Bootstrapped/regtested on x86_64-linux, ok for trunk?
2015-07-29 Marek Polacek <pola...@redhat.com>
* c-common.c (warn_tautological_cmp): Bail for float types.
* c-c++-common/Wtautological-compare-3.c: New test.
I think it comes down to what we think users are going to expect when
compiling code with NaNs disabled.
One camp would probably say "in my code X == X is always true since I
don't have NaNs." The other might say "whether or not to warn on X == X
should not be dependent on flags such as -ffinite-math-only".
I could easily make a case for either. I'd personally tend to lean
towards the latter.
Jeff
