Subject: Re: [PATCH] cxl: Fix build failure due to -Wunused-variable behaviour change

From: Torsten Duwe <[email-masked]>
Date: Tue, 1 Dec 2015 15:47:41 +0100

On Thu, Nov 26, 2015 at 10:41:53AM +1100, Michael Ellerman wrote:
> On Wed, 2015-11-25 at 17:16 +0100, Torsten Duwe wrote:
> > On Tue, Sep 15, 2015 at 03:48:34PM +1000, Ian Munsie wrote:
> > > --- a/drivers/misc/cxl/Makefile
> > > +++ b/drivers/misc/cxl/Makefile
> > > @@ -1,4 +1,4 @@
> > > -ccflags-y := -Werror
> > > +ccflags-y := -Werror -Wno-unused-const-variable
> > 
> > JFYI, my gcc-4.3 does not like this switch.
> > What's the minimum compiler version to build this code?
> 
> I build everything with gcc 4.4.4, so if it breaks with that I will notice.
> 
> Does it work if you wrap it in cc-option? eg:
> 
> ccflags-y := -Werror $(call cc-option,-Wno-unused-const-variable)

Yes, now it builds. It also looks cleaner to me: compilers which check
for "unused-const-variable"s should have this switch and the check is disabled.
All other (known :) warnings error out.

	Torsten