Re: [RFC] man7/system_data_types.7: Document [unsigned] __int128

[Alejandro Colomar <colomar.6.4.3@gmail.com>]

Hi Jonathan,

On 2020-10-01 12:50, Jonathan Wakely wrote:
>> Ok,  I thought that GCC is part of the GNU project, but I don't know how
>> much...
>> I'll use "When using GCC," :)
> 
> It is, but the GNU project is a large organisation, and has nothing to
> say about non-standard types defined by GCC. Just because GCC is part
> of a larger proejct, doesn't mean the entire project defines
> something.


Ok.
>>   >>         Conforming to: GCC 4.6.0 and later.
>>   >
>>   > It doesn't conform to anything, shouldn't this say "This type is a GNU
>>   > extension." or just "This type is an extension." ?
>>
>> That's what I had first: "Conforming to: GCC extension"
>> Then I thought that I could include the version information,
>> so I changed it to that.
>>
>> Maybe "GCC extension (since GCC 4.6.0)" would be better?
> 
> I don't think that information belongs in the Conforming To section at
> all. The version that added the type is nothing to do with
> conformance, because it's an extension and there is nothing to conform
> to.
> 
> Look at 'man clock_gettime' for comparison. It has a VERSIONS section
> and some individual constants are annotated with "(since Linux
> 2.6.12)". That seems more appropriate for annotating individual types
> within this man page which are not universally available.
> 


Thank you!

Updated:

[[
__int128
       A signed integer type of a fixed width of exactly 128 bits.

       When  using  GCC, it is supported only for targets which have an
       integer mode wide enough to hold 128 bits.

       Versions: GCC 4.6.0 and later.

       Conforming to: GCC extension.

       Notes: This type is available without including any header.

       Bugs: It is not possible to express an integer constant of  type
       __int128  in  implementations  where  long long is less than 128
       bits wide.

       See also the intmax_t, intN_t and  unsigned  __int128  types  in
       this page.
]]

Just one more thing:
Would you say "GCC extension" or "GNU extension"?

Thanks,

Alex