Re: [gentoo-dev] [RFC] New eclass: mate

[Michał Górny]

Dnia 15 czerwca 2016 06:18:31 CEST, Jason Zaman <perfinion@g.o> napisał(a):
>On Fri, Jun 10, 2016 at 12:52:34PM -0400, NP-Hardass wrote:
>> On 06/09/2016 11:54 PM, Jason Zaman wrote:
>> > On Thu, Jun 09, 2016 at 08:19:43AM -0400, NP-Hardass wrote:
>> >> # @FUNCTION: python_cond_func_wrap
>> >> # @DESCRIPTION: Wraps a function for conditional python use, to
>run for each
>> >> # python implementation in the build directory.
>> >> python_cond_func_wrap() {
>> >> 	if use python; then
>> >> 		python_foreach_impl run_in_build_dir "$@"
>> >> 	else
>> >> 		$@
>> >> 	fi
>> >> }
>> >
>> > I dont see where you inherited the python eclasses? You also
>probably
>> > need to use use_if_iuse (from eutils.eclass) instead since it seems
>like
>> > python might not be in all the ebuilds. Afaik, you're not allowed
>to
>> > call use foo if foo is not in IUSE already
>> I forgot to include a comment in the ebuild, but the intention was
>that
>> the eclass would not inherit python, by design, those wanting to use
>> that should inherit python themselves.  Although, if I should check
>that
>> explicitly, I am unaware of how to do so, and would appreciate advice
>> from someone, if it is possible. I am aware of INHERITED, but the PMS
>> says it shouldn't be exported to ebuilds, so I'm unsure if/how it
>could
>> be used.
>>
>> My hope was that since this is used several times (though, not too
>> many), that I could move this logic into the eclass, but if it would
>be
>> more appropriate to just keep that in each of those ebuilds, I can do
>> that too.
>
>Yeah sounds like keeping this in the eclass is right. Moving duplicated
>code into the ebuilds would be a waste. You are defining the API so
>requiring the ebuild to inherit itself is completely okay. I would add
>a
>little more to the doc above to make it super obvious tho.
>
>I don't know how to check if the python eclasses specifically are
>inherited. I think "python" being in IUSE would be sufficient to check
>tho. so all you'd need to do is inherit eutils and replace the "if use
>python" with "if use_if_iuse python".
>
>If you *really* wanted to check you could perhaps do
>if [[ $(type python_foreach_impl) == function ]]. Seems overkill and I
>wouldn't bother. Having python in iuse is probably enough of a sanity
>check.

You can check for the include guards. This is how python-r1 eclasses detect one another (in order to prevent inheriting multiple of them).

However, note that all fancy checks are allowed in phase scope only, and not in global scope.

>
>-- Jason


-- 
Best regards,
Michał Górny (by phone)