Re: [XEN PATCH 09/13] xen/common: address violations of MISRA C:2012 Directive 4.10

[Simone Ballarin <simone.ballarin@xxxxxxxxxxx>]

On 29/08/23 08:50, Jan Beulich wrote:
> On 28.08.2023 15:20, Simone Ballarin wrote:
> > Add 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").
> >
> > Also C files, if included somewhere, need to comply with the guideline.
> >
> > Mechanical change.
> >
> > Signed-off-by: Simone Ballarin <simone.ballarin@xxxxxxxxxxx>
> > ---
> >   xen/common/compat/grant_table.c | 7 +++++++
> >   xen/common/coverage/gcc_4_7.c   | 5 +++++
> >   xen/common/decompress.h         | 5 +++++
> >   xen/common/event_channel.h      | 5 +++++
> >   xen/common/multicall.c          | 5 +++++
> >   5 files changed, 27 insertions(+)
> As already said in reply to another patch, imo .c files shouldn't gain such
> guards. These are commonly referred to as "header guards" for a reason.
This is the MISRA's definition of "header file" (MISRA C:2012 Revision 
1, Appendix J):
  "A header file is any file that is the subject of a #include
   directive.
   Note: the filename extension is not significant."

So, the guards are required if we want to comply with the directive, 
otherwise we can raise a deviation.
The danger of multi-inclusion also exists for .c files, why do you want 
to avoid guards for them?
> > --- a/xen/common/compat/grant_table.c
> > +++ b/xen/common/compat/grant_table.c
> > @@ -3,6 +3,10 @@
> >    *
> >    */
> >   
> > +
> Nit: No double blank lines please.
>
> > +#ifndef __COMMON_COMPAT_GRANT_TABLE_C__
> > +#define __COMMON_COMPAT_GRANT_TABLE_C__
> > +
> >   #include <xen/hypercall.h>
> >   #include <compat/grant_table.h>
> >   
> > @@ -331,6 +335,9 @@ int compat_grant_table_op(
> >       return rc;
> >   }
> >   
> > +
> Again here (at least).
>
> Jan
--
Simone Ballarin, M.Sc.

Field Application Engineer, BUGSENG (https://bugseng.com)