Re: [XEN PATCH 12/13] xen: address violations of MISRA C:2012 Directive 4.10

[Stefano Stabellini <sstabellini@xxxxxxxxxx>]

On Thu, 31 Aug 2023, Simone Ballarin wrote:
> On 29/08/23 00:51, Stefano Stabellini wrote:
> > On Mon, 28 Aug 2023, Simone Ballarin wrote:
> > > Move or amended inclusion guards to address violations of
> > > MISRA C:2012 Directive 4.10 ("Precautions shall be taken in order
> > > to prevent the contents of a header file being included more than
> > > once").
> > > 
> > > Inclusion guards must appear at the beginning of the headers
> > > (comments are permitted anywhere) and the #if directive cannot
> > > be used for other checks.
> > > 
> > > Mechanical change.
> > > 
> > > Signed-off-by: Simone Ballarin <simone.ballarin@xxxxxxxxxxx>
> > > ---
> > >   xen/include/xen/err.h       | 4 +++-
> > >   xen/include/xen/pci_ids.h   | 5 +++++
> > >   xen/include/xen/softirq.h   | 4 +++-
> > >   xen/include/xen/unaligned.h | 7 ++++---
> > >   xen/include/xen/vmap.h      | 4 +++-
> > >   5 files changed, 18 insertions(+), 6 deletions(-)
> > > 
> > > diff --git a/xen/include/xen/err.h b/xen/include/xen/err.h
> > > index 2f29b57d28..a6323d82d7 100644
> > > --- a/xen/include/xen/err.h
> > > +++ b/xen/include/xen/err.h
> > > @@ -1,5 +1,6 @@
> > > -#if !defined(__XEN_ERR_H__) && !defined(__ASSEMBLY__)
> > > +#if !defined(__XEN_ERR_H__)
> > >   #define __XEN_ERR_H__
> > > +#if !defined(__ASSEMBLY__)
> > 
> > The original pattern was also guarding the header file sufficiently,
> > protecting it from double-inclusion. In fact, it is posing stricter
> > restrictions than usual (not laxer). This change is unnecessary?
> 
> The MISRA directive asks to use one of the two following forms:
> 
> <start-of-file>
> #if !defined ( identifier )
> #define identifier
> /* Contents of file */
> #endif
> <end-of-file>
> 
> <start-of-file>
> #ifndef identifier
> #define identifier
> /* Contents of file */
> #endif
> <end-of-file>
> 
> I do not see any reason for deviating, but if you ask that, I can do it.

Let's follow MISRA's form.