Re: [gentoo-dev] Re: [RFC] multilib-build.eclass and restricting unsupported ABIs

[Thomas Sachau]

Alexis Ballier schrieb:
> On Sun, 03 Mar 2013 16:47:43 +0100
> Thomas Sachau <tommy@g.o> wrote:
>
>> Alexis Ballier schrieb:
>>> On Sun, 03 Mar 2013 14:02:58 +0100
>>> Thomas Sachau <tommy@g.o> wrote:
>>>>
>>>> Once the eclass has per-ABI header
>>>
>>> I think this is needed.
>>>
>>>> and binaries support,
>>>
>>> but here, could you enlighten me on its use cases ? I can't imagine
>>> why having multi binaries support would be useful.
>>>
>>> Alexis.
>>>
>>
>>
>> At least some binaries do have abi-specific output, which is used by
>> other applications. As a good example of this, have a look at qmake
>> and qmake based build systems.
>
> hmm, qmake doesnt seem to be the perfect example: how do you handle
> this?
>
> - install qmake-${abi}

ok

> - ln -s qmake-${DEFAULT_ABI} qmake

Just the same as with headers:

You dont symlink the headers for the default ABI, but instead a wrapper
is placed, which does then call/include the real target, so in this
case, qmake is then a symlink to the abiwrapper, which does execute the
real abi-specific binary, depending on the current ABI.
We can of course place this abiwrapper in every place, where it is
needed instead of the symlink, but having one central and package
provided wrapper instead is easier to maintain and update.

> - modify eqmake4 to call the right qmake when doing multilib?

not needed at all (with multilib-portage), since when any package calls
qmake to get any abi-specific details, the abiwrapper executes the
binary, that matches the ABI and you get the right details for your ABI.

-- 

Thomas Sachau
Gentoo Linux Developer