Re: [PATCH] gpiolib: acpi: use correct format characters

From: Nick Desaulniers
Date: Fri Mar 18 2022 - 14:38:01 EST


On Fri, Mar 18, 2022 at 11:25 AM Bill Wendling <morbo@xxxxxxxxxx> wrote:
>
> On Fri, Mar 18, 2022 at 11:01 AM Nick Desaulniers
> <ndesaulniers@xxxxxxxxxx> wrote:
> >
> > On Fri, Mar 18, 2022 at 7:04 AM Andy Shevchenko
> > <andriy.shevchenko@xxxxxxxxxxxxxxx> wrote:
> > >
> > > On Thu, Mar 17, 2022 at 11:11:21AM -0700, Nick Desaulniers wrote:
> > > > Our goal is to enable -Wformat for CC=clang. Please see also:
> > > > commit cbacb5ab0aa0 ("docs: printk-formats: Stop encouraging use of
> > > > unnecessary %h[xudi] and %hh[xudi]")
> > >
> > > Not that I agree on that commit for %h[h]x
> > >
> > > signed char ch = -1;
> > > printf("%x\n", ch);
> > > printf("%hhx\n", ch);
> >
> > Will print:
> > ffffffff
> > ff
> >
> I noticed this. My first thought was to do something akin to:
>
> printf("%x\n", (u8)ch);
>
> but went the route of removing the "h" qualifiers to be more in line
> with previous fixes. I will be happy to change this patch if that's
> what you would prefer.

Should we add a note diagnostic to clang suggesting the explicit cast
as one method of silencing the warning?
--
Thanks,
~Nick Desaulniers