Re: [gentoo-dev] Re: GLEP draf for cross-compile support in multilib profiles

[Michał Górny]

On Sun, 01 Jul 2012 15:30:44 -0700
Zac Medico <zmedico@g.o> wrote:

> On 07/01/2012 02:34 PM, Thomas Sachau wrote:
> > Zac Medico schrieb:
> >> On 07/01/2012 04:29 AM, Thomas Sachau wrote:
> >>> Matt Turner schrieb:
> >>>> On Fri, Jun 29, 2012 at 10:30 AM, Thomas Sachau
> >>>> <tommy@g.o> wrote:
> >>>>>
> >>>>
> >>>> I'm interested in this because I'm regularly annoyed with the
> >>>> emul- packages and also because multilib is pretty important for
> >>>> mips.
> >>>>
> >>>>> If a package has dependencies, then those dependencies are
> >>>>> required to have at least the same targets enabled as the
> >>>>> package
> >>>>
> >>>> That seems like the obvious (but perhaps naive) choice. What
> >>>> about depending on packages that don't install libraries, like
> >>>> x11-proto/ packages or generators like dev-util/indent?
> >>>>
> >>>> Maybe I just don't understand. Would these packages even have
> >>>> ABI flags?
> >>>
> >>> All packages do get the ABI flags (with the needed EAPI or via
> >>> enabled portage feature, which is currently in the multilib
> >>> branch).
> >>>
> >>> If a package does not install anything ABI-specific (no headers,
> >>> no libs and no binaries), then there is no overhead, since it
> >>> will just get compiled/installed for one ABI, even if multiple
> >>> ABI flags are enabled.
> >>
> >> For a package like this that does not install anything
> >> ABI-specific, does the package manager still execute phases for
> >> each enabled ABI, or is there some way for the ebuild to indicate
> >> whether or not its phases need to be executed for each enabled ABI?
> >>
> >
> >
> > This is dynamicly checked at runtime, no need to modify the ebuilds
> > and also no needless compilation, when there is no ABI-specific
> > content.
> >
> > A more detailed answer at package manager level:
> > After the src_install phase for the first requested ABI has been
> > finished, the content of $DESTDIR is checked. If there is no ABI
> > specific content, the other enabled ABIs are skipped and the
> > following steps are done as usual.
>
> In case anyone want some more detail, here's a follow-up question
> from irc:
>
> <zmedico> Tommy[D]: does any ELF executable qualify as "abi specific"
> and trigger builds for all ABIs?
> <Tommy[D]> zmedico: if it goes into any
> of /bin /usr/bin /sbin /usr/sbin and you enable the abiwrapper USE
> flag, yes, otherwise you just request a binary for the default ABI,
> so no need to rebuild everything for no need

How about executables which go into /lib or /libXX?

-- 
Best regards,
Michał Górny