Re: [PATCH] Use __unused.0 instead of __unused for user visible struct members

["Carlos O'Donell" <carlos at redhat dot com>]

On 11/13/2013 11:55 AM, Carlos O'Donell wrote:
> On 11/13/2013 06:09 AM, OndÅej BÃlka wrote:
>> On Tue, Nov 12, 2013 at 11:44:58PM -0500, Carlos O'Donell wrote:
>>> On 11/05/2013 08:54 AM, OndÅej BÃlka wrote:
>>>> On Mon, Oct 28, 2013 at 03:41:18PM +0000, Justin Cormack wrote:
>>>>> On Mon, Oct 28, 2013 at 1:30 PM, Joseph S. Myers
>>>>> <joseph@codesourcery.com> wrote:
>>>>>> On Mon, 28 Oct 2013, Justin Cormack wrote:
>>>>>>
>>>>>>> A patch was submitted for this a while back
>>>>>>> https://sourceware.org/ml/libc-alpha/2012-01/msg00001.html and did not
>>>>>>> get a good reception from the maintainer at the time. Attached is an
>>>>>>> updated version for current glibc head.
>>>>>>
>>>>>> I believe we had consensus on use of __glibc_reserved as a prefix in such
>>>>>> cases (allowing for __glibc_reserved0, __glibc_reserved1 or
>>>>>> __glibc_reserved_foo, __glibc_reserved_bar in cases where more than one
>>>>>> identifier, or a more meaningful name, is needed).
>>>>>
>>>>> OK, that makes sense, found part of that conversation in the archives.
>>>>> Here is a patch (inline and attached) to convert all uses to
>>>>> __glibc_reserved.
>>>>>
>>>>> Justin
>>>>>
>>>> A mechanical change that looks ok,
>>>>
>>>> It needs changelog so I generated following.
>>>
>>> Could you please repost with the patch and final ChangeLog,
>>> TO me, CC libc-alpha, and I'll review.
>>>
>>> Cheers,
>>> Carlos.
>>>
>> Here
> 
> OK to checkin as long as you do 2 more things please:
> 
> 1. Email libc-ports and explain that you've made cross-machine
>    changes and renamed __unused to __glibc_reserved and to look
>    for any unintended breakage.
> 
> 2. Update https://sourceware.org/glibc/wiki/Style_and_Conventions
>    and add an entry on this to explain that we use __glibc_reserved
>    for unused structure entries and that this is done to avoid 
>    __unused which causes problems with BSD sources.
> 
> Thank you for following through with these changes. I've gone
> through them all and looked for anything out of place and didn't
> see anything. I spot checked some headers and uses matched and
> they did.
> 
> I have some apprehension at changing the kernel headers because
> it might complicate synching with the kernel headers, but these
> headers represent a real problem in their use of `__unused` and
> coordinating that not to break when building unmodified BSD
> sources would be the next step. That is to say we should approach
> the Linux kernel guys and explain the UAPI should not use __unused
> and isntead should use __linux_unused or __uapi_unused etc. etc.
> Therefore I'm fine with the changes.

Ondrej,

Ping? 

I'd like to see this go into 2.19 so we can claim our headers will 
work with BSD code that uses __unused :-)

Cheers,
Carlos.