Hi Jan,
> On 30 Apr 2024, at 12:43, Jan Beulich <jbeul...@suse.com> wrote:
>
> On 30.04.2024 13:09, Luca Fancellu wrote:
>> --- a/xen/include/xen/kernel.h
>> +++ b/xen/include/xen/kernel.h
>> @@ -54,6 +54,27 @@
>> typeof_field(type, member) *__mptr = (ptr); \
>> (type *)( (char *)__mptr - offsetof(type,member) );})
>>
>> +/**
>> + * __struct_group() - Create a mirrored named and anonyomous struct
>> + *
>> + * @TAG: The tag name for the named sub-struct (usually empty)
>> + * @NAME: The identifier name of the mirrored sub-struct
>> + * @ATTRS: Any struct attributes (usually empty)
>> + * @MEMBERS: The member declarations for the mirrored structs
>> + *
>> + * Used to create an anonymous union of two structs with identical layout
>> + * and size: one anonymous and one named. The former's members can be used
>> + * normally without sub-struct naming, and the latter can be used to
>> + * reason about the start, end, and size of the group of struct members.
>> + * The named struct can also be explicitly tagged for layer reuse, as well
>> + * as both having struct attributes appended.
>> + */
>> +#define __struct_group(TAG, NAME, ATTRS, MEMBERS...) \
>> + union { \
>> + struct { MEMBERS } ATTRS; \
>> + struct TAG { MEMBERS } ATTRS NAME; \
>> + } ATTRS
>
> Besides my hesitance towards having this construct, can you explain why
> ATTR needs using 3 times, i.e. also on the wrapping union?
The original commit didn’t have the third ATTRS, but afterwards it was
introduced due to
this:
https://patchwork.kernel.org/project/linux-wireless/patch/20231120110607.98956-1-dmanti...@yandex.ru/#25610045
Now, I have to say that for the Origin tag I used the SHA of the commit
introducing the macro
and the SHA doing this modification is different, how are these cases handled?
Cheers,
Luca
