Re: [PATCH v2 2/2] x86: Support compiling out human-friendly processor feature names

From: Josh Triplett
Date: Sat Feb 22 2014 - 16:38:03 EST


On Sat, Feb 22, 2014 at 01:18:14PM -0800, H. Peter Anvin wrote:
> On February 22, 2014 1:00:39 PM PST, Josh Triplett <josh@xxxxxxxxxxxxxxxx> wrote:
> >On Sat, Feb 22, 2014 at 09:49:36PM +0100, Borislav Petkov wrote:
> >> On Sat, Feb 22, 2014 at 11:57:10AM -0800, Josh Triplett wrote:
> >> > diff --git a/arch/x86/boot/cpu.c b/arch/x86/boot/cpu.c
> >> > index 6ec6bb6..29207f6 100644
> >> > --- a/arch/x86/boot/cpu.c
> >> > +++ b/arch/x86/boot/cpu.c
> >> > @@ -16,7 +16,9 @@
> >> > */
> >> >
> >> > #include "boot.h"
> >> > +#ifdef CONFIG_X86_FEATURE_NAMES
> >> > #include "cpustr.h"
> >> > +#endif
> >>
> >> You probably could get rid of this ifdef too by moving it into
> >cpustr.h
> >> after teaching arch/x86/boot/mkcpustr.c to issue it...
> >
> >That would require building and running mkcpustr, which doesn't happen
> >when !CONFIG_X86_FEATURE_NAMES. (And it'd require adding ifdefs to
> >mkcpustr instead, which seems counterproductive.)
>
> Didn't that change since v1?

No, even after removing the ifdefs around the build rules as you
suggested (and v3's fixes for the resulting build issues, notably
changing some -y's to -$(CONFIG_X86_FEATURE_NAMES)), the makefiles still
manage to not build mkcpustr or cpustr.h, because nothing depends on it.

I could change the build rules to generate an empty cpustr.h and avoid
this ifdef, but that'd require an additional ifdef block in the Makefile.

- Josh Triplett
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