Re: [PATCH] kvm: x86: mmu: Add cast to negated bitmasks in update_permission_bitmask()

[Joe Perches]

On Tue, 2018-06-19 at 14:10 -0700, Matthias Kaehlcke wrote:
> On Tue, Jun 19, 2018 at 12:11:27PM -0700, Joe Perches wrote:
> > -Wconstant-conversion is only issued when a *constant value* is assigned to
> an incompatible type.
> 
> > Trying to allow a "make W=3" to be compiler warning message free
> > is also silly.
> > 
> > I think it's better to make the warning emitted only at a W=3
> > level instead.
> 
> Another difference with -Wsign-conversion is that enabling it would
> probably result in thousands of warnings. Do you have evidence that
> there is a significant number of spurious -Wconstant-conversion
> warnings?

Not my issue really.  You're advocating for
making the code more complex/ugly for a condition
where the result is identical.

Do you have evidence this is the only location in
an allyesconfig compilation?