Re: [gentoo-dev] [PATCH] boost-utils.eclass -- for building against newest boost.

[Michał Górny]

On Tue, 28 Aug 2012 10:10:01 +0200
Tiziano Müller <dev-zero@g.o> wrote:

> Am Dienstag, den 28.08.2012, 10:06 +0200 schrieb Michał Górny:
> > On Tue, 28 Aug 2012 06:26:02 +0200
> > Arfrever Frehtes Taifersar Arahesis <arfrever.fta@×××××.com> wrote:
> >
> > > 2012-08-28 00:19:28 Michał Górny napisał(a):
> > > > --- /dev/null
> > > > +++ b/gx86/eclass/boost-utils.eclass
> > > > @@ -0,0 +1,43 @@
> > > > +# Copyright 1999-2012 Gentoo Foundation
> > > > +# Distributed under the terms of the GNU General Public
> > > > License v2 +# $Header: $
> > > > +
> > > > +if [[ ! ${_BOOST_ECLASS} ]]; then
> > > > +
> > > > +# @ECLASS: boost-utils.eclass
> > > > +# @MAINTAINER:
> > > > +# mgorny@g.o
> > >
> > > It is better to copy list of maintainers from
> > > gentoo-x86/dev-libs/boost/metadata.xml.
> > >
> > > > +# @BLURB: helper functions for packages using Boost C++ library
> > > > +# @DESCRIPTION:
> > > > +# Helper functions to be used when building packages using the
> > > > Boost C++ +# library collection.
> > > > +
> > > > +case ${EAPI:-0} in
> > > > +	0|1|2|3|4) ;;
> > > > +	*) die "${ECLASS}.eclass API in EAPI ${EAPI} not yet
> > > > established." +esac
> > >
> > > Please accept all EAPIs.
> >
> > These are EAPIs which are allowed throughout the tree, sorry. Feel
> > free to ping Council about adding non-standard EAPIs to eclasses.
> >
> > > > +inherit versionator
> > > > +
> > > > +# @FUNCTION: boost-utils_get_best_slot
> > > > +# @DESCRIPTION:
> > > > +# Get newest SLOT (major version) of Boost.
> > > > +boost-utils_get_best_slot() {
> > > > +	local pkg=dev-libs/boost
> > > > +	local atom=$(best_version ${pkg})
> > > > +	get_version_component_range 1-2 ${atom#${pkg}}
> > > > +}
> > > > +
> > > > +# @FUNCTION: boost-utils_get_includedir
> > > > +# @DESCRIPTION:
> > > > +# Get correct includedir for best Boost version. Outputs the
> > > > sole path +# (without -I).
> > > > +boost-utils_get_includedir() {
> > > > +	local slot=$(boost-utils_get_best_slot)
> > > > +	has "${EAPI:-0}" 0 1 2 && ! use prefix && EPREFIX=
> > > > +
> > > > +	echo -n "${EPREFIX}/usr/include/boost-${slot/./_}"
> > > > +}
> > >
> > > There needs to be a way to specify maximal accepted slot of Boost.
> > > Examples of some possibilities:
> > > * BOOST_MAX_SLOT="1.49" global variable
> > > * '--max 1.49' arguments for boost-utils_get_* functions
> >
> > I'd rather wait with that till Tiziano expresses his opinion. I
> > think the policy ought to be 'always prefer newest version' but I
> > guess that's hard with boost.
> >
>
> one of the points of having a slotted boost (besides solving the
> rebuild when API/ABI breakages occur) is that a package may also use
> an older boost slot (currently it only would make sense if we'd
> backport the glibc-2.16 patches but that's a different story). So I'd
> prefer if we'd have a BOOST_MAX_SLOT variable.

Do we want to support using random old versions of boost then or just
the newest supported SLOT? If the latter, we could get away without
using best_version, and just request devs to depend on specific boost
slot then.

-- 
Best regards,
Michał Górny