Re: [PATCH 05/14] kernel-doc: public/features.h

[Jan Beulich <jbeulich@xxxxxxxx>]

On 07.08.2020 23:52, Stefano Stabellini wrote:
> On Fri, 7 Aug 2020, Jan Beulich wrote:
>> On 07.08.2020 01:49, Stefano Stabellini wrote:
>>> @@ -41,19 +41,25 @@
>>>   * XENFEAT_dom0 MUST be set if the guest is to be booted as dom0,
>>>   */
>>>  
>>> -/*
>>> - * If set, the guest does not need to write-protect its pagetables, and can
>>> - * update them via direct writes.
>>> +/**
>>> + * DOC: XENFEAT_writable_page_tables
>>> + *
>>> + * If set, the guest does not need to write-protect its pagetables, and
>>> + * can update them via direct writes.
>>>   */
>>>  #define XENFEAT_writable_page_tables       0
>>
>> I dislike such redundancy (and it's more noticable here than with
>> the struct-s). Is there really no way for the tool to find the
>> right item, the more that in the cover letter you say that you
>> even need to get the placement right, i.e. there can't be e.g.
>> intervening #define-s?
> 
> Let me clarify that the right placement (nothing between the comment and
> the following structure) is important for structs, typedefs, etc., but
> not for "DOC". DOC is freeform and doesn't have to be followed by
> anything specifically.
> 
> 
> In regards to the redundancy, there is only another option, that I
> didn't choose because it leads to worse documents being generated.
> However, they are still readable, so if the agreement is to use the
> other format, I would be OK with it.
> 
> 
> The other format is the keyword "macro" (this one would have to have the
> right placement, straight on top of the #define):
> 
> /**
>  * macro XENFEAT_writable_page_tables
>  *
>  * If set, the guest does not need to write-protect its pagetables, and
>  * can update them via direct writes.
>  */
> 
> 
> Which could be further simplified to:
> 
> /**
>  * macro
>  *
>  * If set, the guest does not need to write-protect its pagetables, and
>  * can update them via direct writes.
>  */
> 
> 
> In terms of redundancy, that's the best we can do.
> 
> The reason why I say it is not optimal is that with DOC the pleudo-html
> generated via sphinx is:
> 
> ---
> * XENFEAT_writable_page_tables *
> 
> If set, the guest does not need to write-protect its pagetables, and
> can update them via direct writes.
> ---
> 
> While with macro, two () parenthesis gets added to the title, and also an
> empty "Parameters" section gets added, like this:
> 
> ---
> * XENFEAT_writable_page_tables() *
> 
> ** Parameters **
> 
> ** Description **
> 
> If set, the guest does not need to write-protect its pagetables, and
> can update them via direct writes.
> ---
> 
> 
> I think it could be confusing to the user: it looks like a macro with
> parameters, which is not what we want.

Agreed, so ...

> For that reason, I think we should stick with "DOC" for now.

... if there are no (better) alternatives we'll have to live with the
redundancy.

Jan