On Mon, Sep 05, 2016 at 02:08:20PM +0000, Bernd Edlinger wrote:
> On 09/05/16 14:03, Marek Polacek wrote:
> > On Fri, Sep 02, 2016 at 03:51:49PM +0000, Bernd Edlinger wrote:
> >> Hi,
> >>
> >> > + r += !a == ~b;
> >> > + r += !a == ~(int) b;
> >>
> >> I don't understand why ~b should not be warned at -Wall.
> >
> > Yeah, there was an RFE for this but I'm not finding it.
> >
>
> I certainly agree that the warning is compeletely misleading here:
>
> test.c: In function 'f':
> test.c:10:11: warning: logical not is only applied to the left hand side
> of comparison [-Wlogical-not-parentheses]
> r += !a == ~b;
> ^~
> test.c:10:8: note: add parentheses around left hand side expression to
> silence this warning
> r += !a == ~b;
> ^~
> ( )
>
> this will not fix it, but make it worse.
> I think a better warning would be
> warning: ~ on boolean value, did you mean ! ?
Could you please open a PR? I'll take care of it.
Still not sure about other operations. I guess no one would
object to warning on bool1 % bool2, but should we warn for
bool1 + bool2?
Marek
