Re: [PATCH v6 2/4] xen: change <asm/bug.h> to <xen/bug.h>

[Oleksii <oleksii.kurochko@xxxxxxxxx>]

On Wed, 2023-03-08 at 16:27 +0100, Jan Beulich wrote:
> On 07.03.2023 16:50, Oleksii Kurochko wrote:
> > --- a/xen/arch/arm/include/asm/bug.h
> > +++ b/xen/arch/arm/include/asm/bug.h
> > @@ -1,6 +1,8 @@
> >  #ifndef __ARM_BUG_H__
> >  #define __ARM_BUG_H__
> >  
> > +#include <xen/types.h>
> > +
> >  #if defined(CONFIG_ARM_32)
> >  # include <asm/arm32/bug.h>
> >  #elif defined(CONFIG_ARM_64)
> > @@ -9,10 +11,16 @@
> >  # error "unknown ARM variant"
> >  #endif
> >  
> > +#undef BUG_DISP_WIDTH
> > +#undef BUG_LINE_LO_WIDTH
> > +#undef BUG_LINE_HI_WIDTH
> 
> Why? For Arm ...
> 
> >  #define BUG_DISP_WIDTH    24
> >  #define BUG_LINE_LO_WIDTH (31 - BUG_DISP_WIDTH)
> >  #define BUG_LINE_HI_WIDTH (31 - BUG_DISP_WIDTH)
> 
> ... you could purge these as unused, even in a standalone prereq
> patch.
> And on x86 ...
> 
> > --- a/xen/arch/x86/include/asm/bug.h
> > +++ b/xen/arch/x86/include/asm/bug.h
> > @@ -1,19 +1,18 @@
> >  #ifndef __X86_BUG_H__
> >  #define __X86_BUG_H__
> >  
> > +#undef BUG_DISP_WIDTH
> > +#undef BUG_LINE_LO_WIDTH
> > +#undef BUG_LINE_HI_WIDTH
> > +
> >  #define BUG_DISP_WIDTH    24
> >  #define BUG_LINE_LO_WIDTH (31 - BUG_DISP_WIDTH)
> >  #define BUG_LINE_HI_WIDTH (31 - BUG_DISP_WIDTH)
> 
> ... there's no reason to #undef just to the #define again to the same
> values. All of this would be removed in a subsequent patch anyway,
> and
> it's less code churn (with code nevertheless being correct) if you
> get
> rid of the #define-s right away (as iirc you had it in an earlier
> version). If you agree then with these adjustments
> Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>

It won't be compilation issue (redefinition) in the current one case
because defines are the same as in <xen/bug.h> so it is possible to not
add #undef in this patch.

~ Oleksii