Introduce boost-utils eclass, to support linking against arbitrary boost version.

2 files changed, 100 insertions, 1 deletions

diff --git a/eclass/ChangeLog b/eclass/ChangeLog
index 9392a724f8fd..0105bb538624 100644
--- a/eclass/ChangeLog
+++ b/eclass/ChangeLog
@@ -1,6 +1,10 @@
 # ChangeLog for eclass directory
 # Copyright 1999-2012 Gentoo Foundation; Distributed under the GPL v2
-# $Header: /var/cvsroot/gentoo-x86/eclass/ChangeLog,v 1.405 2012/09/18 06:41:45 ulm Exp $
+# $Header: /var/cvsroot/gentoo-x86/eclass/ChangeLog,v 1.406 2012/09/19 09:37:53 mgorny Exp $
+
+  19 Sep 2012; Michał Górny <mgorny@gentoo.org> +boost-utils.eclass:
+  Introduce boost-utils eclass, to support linking against arbitrary boost
+  version.
 
   18 Sep 2012; Ulrich Müller <ulm@gentoo.org> bzr.eclass:
   Use lightweight checkout instead of export if EBZR_WORKDIR_CHECKOUT is set;
diff --git a/eclass/boost-utils.eclass b/eclass/boost-utils.eclass
new file mode 100644
index 000000000000..d32385879156
--- /dev/null
+++ b/eclass/boost-utils.eclass
@@ -0,0 +1,95 @@
+# Copyright 1999-2012 Gentoo Foundation
+# Distributed under the terms of the GNU General Public License v2
+# $Header: /var/cvsroot/gentoo-x86/eclass/boost-utils.eclass,v 1.1 2012/09/19 09:37:53 mgorny Exp $
+
+if [[ ! ${_BOOST_ECLASS} ]]; then
+
+# @ECLASS: boost-utils.eclass
+# @MAINTAINER:
+# Michał Górny <mgorny@gentoo.org>
+# Tiziano Müller <dev-zero@gentoo.org>
+# Sebastian Luther <SebastianLuther@gmx.de>
+# Arfrever Frehtes Taifersar Arahesis <arfrever.fta@gmail.com>
+# @BLURB: helper functions for packages using Boost C++ library
+# @DESCRIPTION:
+# Helper functions to be used when building packages using the Boost C++
+# library collection.
+#
+# Please note that this eclass does not set the dependencies for you.
+# You need to do that yourself.
+#
+# For cmake & autotools it is usually necessary to set BOOST_ROOT using
+# boost-utils_export_root. However, other build system may require more
+# hackery or even appending -I$(boost-utils_get_includedir) to CFLAGS
+# and -L$(boost-utils_get_libdir) to LDFLAGS.
+
+case ${EAPI:-0} in
+	0|1|2|3|4) ;;
+	*) die "${ECLASS}.eclass API in EAPI ${EAPI} not yet established."
+esac
+
+inherit multilib versionator
+
+# @ECLASS-VARIABLE: BOOST_MAX_SLOT
+# @DEFAULT_UNSET
+# @DESCRIPTION:
+# The maximal (newest) boost slot supported by the package. If unset,
+# there is no limit (the newest installed version will be used).
+
+# @FUNCTION: boost-utils_get_best_slot
+# @DESCRIPTION:
+# Get newest installed slot of Boost. If BOOST_MAX_SLOT is set, the version
+# returned will be at most in the specified slot.
+boost-utils_get_best_slot() {
+	local pkg=dev-libs/boost
+	[[ ${BOOST_MAX_SLOT} ]] && pkg="<=${pkg}-${BOOST_MAX_SLOT}.9999"
+
+	local cpv=$(best_version ${pkg})
+	get_version_component_range 1-2 ${cpv#${pkg}-}
+}
+
+# @FUNCTION: boost-utils_get_includedir
+# @USAGE: [slot]
+# @DESCRIPTION:
+# Get the includedir for the given Boost slot. If no slot is given,
+# defaults to the newest installed Boost slot (but not newer than
+# BOOST_MAX_SLOT if that variable is set).
+#
+# Outputs the sole path (without -I).
+boost-utils_get_includedir() {
+	local slot=${1:-$(boost-utils_get_best_slot)}
+	has "${EAPI:-0}" 0 1 2 && ! use prefix && EPREFIX=
+
+	echo -n "${EPREFIX}/usr/include/boost-${slot/./_}"
+}
+
+# @FUNCTION: boost-utils_get_libdir
+# @USAGE: [slot]
+# @DESCRIPTION:
+# Get the libdir for the given Boost slot. If no slot is given, defaults
+# to the newest installed Boost slot (but not newer than BOOST_MAX_SLOT
+# if that variable is set).
+#
+# Outputs the sole path (without -L).
+boost-utils_get_libdir() {
+	local slot=${1:-$(boost-utils_get_best_slot)}
+	has "${EAPI:-0}" 0 1 2 && ! use prefix && EPREFIX=
+
+	echo -n "${EPREFIX}/usr/$(get_libdir)/boost-${slot/./_}"
+}
+
+# @FUNCTION: boost-utils_export_root
+# @USAGE: [slot]
+# @DESCRIPTION:
+# Set the BOOST_ROOT variable to includedir for the given Boost slot.
+# If no slot is given, defaults to the newest installed Boost slot(but
+# not newer than BOOST_MAX_SLOT if that variable is set).
+#
+# This variable satisfies both cmake and sys-devel/boost-m4 autoconf
+# macros.
+boost-utils_export_root() {
+	export BOOST_ROOT=$(boost-utils_get_includedir "${@}")
+}
+
+_BOOST_ECLASS=1
+fi # _BOOST_ECLASS