Re: [kvm-unit-tests PATCH] s390x: unify header guards

[Cornelia Huck <cohuck@redhat.com>]

Thomas Huth <thuth@redhat.com> writes:

> On 01/06/2021 18.15, Cornelia Huck wrote:
>> Let's unify the header guards to _ASM_S390X_FILE_H_ respectively
>> _S390X_FILE_H_. This makes it more obvious what the file is
>> about, and avoids possible name space collisions.
>> 
>> Signed-off-by: Cornelia Huck <cohuck@redhat.com>
>> ---
>> 
>> Only did s390x for now; the other archs seem to be inconsistent in
>> places as well, and I can also try to tackle them if it makes sense.
> ...
>> diff --git a/lib/s390x/asm/bitops.h b/lib/s390x/asm/bitops.h
>> index 792881ec3249..61cd38fd36b7 100644
>> --- a/lib/s390x/asm/bitops.h
>> +++ b/lib/s390x/asm/bitops.h
>> @@ -8,8 +8,8 @@
>>    *    Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>,
>>    *
>>    */
>> -#ifndef _ASMS390X_BITOPS_H_
>> -#define _ASMS390X_BITOPS_H_
>> +#ifndef _ASM_S390X_BITOPS_H_
>> +#define _ASM_S390X_BITOPS_H_
>
> Why not the other way round (S390X_ASM_BITOPS_H) ?

Most existing guards were this way around, I don't really have a
preference here, we should just agree on one format :)

>
>  > diff --git a/s390x/sthyi.h b/s390x/sthyi.h
>  > index bbd74c6197c3..eb92fdd2f2b2 100644
>  > --- a/s390x/sthyi.h
>  > +++ b/s390x/sthyi.h
>  > @@ -7,8 +7,8 @@
>  >   * Authors:
>  >   *    Janosch Frank <frankja@linux.vnet.ibm.com>
>  >   */
>  > -#ifndef _STHYI_H_
>  > -#define _STHYI_H_
>  > +#ifndef _S390X_STHYI_H_
>  > +#define _S390X_STHYI_H_
>
> While we're at it: Do we also want to drop the leading (and trailing) 
> underscores here? ... since leading underscore followed by a capital letter 
> is a reserved namespace in C and you should normally not use these in nice 
> programs...? I think I'm ok with keeping the underscores in the files in the 
> lib folder (since these are our core libraries, similar to the system and 
> libc headers on a normal system), but in files that are not part of the lib 
> folder, we should rather avoid them.

Hm, I actually ended up _adding_ some underscores in various places... I
can certainly drop them for !lib.

What about the following structure:

- in lib/<arch>/asm/: _ARCH_ASM_FILE_H_
- in lib/<arch>/: _ARCH_FILE_H_
- in lib/linux/: _LINUX_FILE_H_
- in lib/: _FILE_H_
(lib/libfdt is imported code, leave untouched)
- in <arch>/: ARCH_FILE_H