[gentoo-dev] [PATCH 1/8] Initial version of multibuild eclass.

["Michał Górny" <mgorny@gentoo.org>]

Based on the code from python-r1.
---
 gx86/eclass/multibuild.eclass | 172 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 172 insertions(+)
 create mode 100644 gx86/eclass/multibuild.eclass

diff --git a/gx86/eclass/multibuild.eclass b/gx86/eclass/multibuild.eclass
new file mode 100644
index 0000000..716d34f
--- /dev/null
+++ b/gx86/eclass/multibuild.eclass
@@ -0,0 +1,172 @@
+# Copyright 1999-2013 Gentoo Foundation
+# Distributed under the terms of the GNU General Public License v2
+# $Header: $
+
+# @ECLASS: multibuild
+# @MAINTAINER:
+# Michał Górny <mgorny@gentoo.org>
+# @AUTHOR:
+# Author: Michał Górny <mgorny@gentoo.org>
+# @BLURB: A generic eclass for building multiple variants of packages.
+# @DESCRIPTION:
+# The multibuild eclass aims to provide a generic framework for building
+# multiple 'variants' of a package (e.g. multilib, Python
+# implementations).
+
+case "${EAPI:-0}" in
+	0|1|2|3|4)
+		die "Unsupported EAPI=${EAPI:-0} (too old) for ${ECLASS}"
+		;;
+	5)
+		;;
+	*)
+		die "Unsupported EAPI=${EAPI} (unknown) for ${ECLASS}"
+		;;
+esac
+
+if [[ ! ${_MULTIBUILD} ]]; then
+
+inherit multiprocessing
+
+# @ECLASS-VARIABLE: MULTIBUILD_VARIANTS
+# @DESCRIPTION:
+# An array specifying all enabled variants which multilib_foreach* will
+# execute the process for.
+#
+# In ebuild, it can be set in global scope. Eclasses should set it
+# locally in function scope to support nesting properly.
+#
+# Example:
+# @CODE
+# python_foreach_impl() {
+#	local MULTIBUILD_VARIANTS=( python{2_5,2_6,2_7} ... )
+#	multibuild_foreach_impl python_compile
+# }
+# @CODE
+
+# @ECLASS-VARIABLE: MULTIBUILD_VARIANT
+# @DESCRIPTION:
+# The current variant which the function was executed for.
+#
+# Example value:
+# @CODE
+# python2_6
+# @CODE
+
+# @ECLASS-VARIABLE: MULTIBUILD_ID
+# @DESCRIPTION:
+# The unique identifier for a multibuild run. In a simple run, it is
+# equal to MULTIBUILD_VARIANT. In a nested multibuild environment, it
+# contains the complete selection tree.
+#
+# It can be used to create variant-unique directories and files.
+#
+# Example value:
+# @CODE
+# amd64-double
+# @CODE
+
+# @ECLASS-VARIABLE: BUILD_DIR
+# @DESCRIPTION:
+# The current build directory. In global scope, it is supposed to
+# contain an 'initial' build directory; if unset, it defaults to ${S}.
+#
+# multibuild_foreach() sets BUILD_DIR locally to variant-specific build
+# directories based on the initial value of BUILD_DIR.
+#
+# Example value:
+# @CODE
+# ${WORKDIR}/foo-1.3-python2_6
+# @CODE
+
+# @FUNCTION: multibuild_foreach
+# @USAGE: [<argv>...]
+# @DESCRIPTION:
+# Run the passed command repeatedly for each of the enabled package
+# variants.
+#
+# Each of the runs will have variant-specific BUILD_DIR set, and output
+# teed to a separate log in ${T}.
+#
+# The function returns 0 if all commands return 0, or the first non-zero
+# exit status otherwise. However, it performs all the invocations
+# nevertheless. It is preferred to call 'die' inside of the passed
+# function.
+multibuild_foreach() {
+	debug-print-function ${FUNCNAME} "${@}"
+
+	[[ ${MULTIBUILD_VARIANTS} ]] \
+		|| die "MULTIBUILD_VARIANTS need to be set"
+
+	local bdir=${BUILD_DIR:-${S}}
+	local prev_id=${MULTIBUILD_ID:+${MULTIBUILD_ID}-}
+	local ret=0 lret=0 v
+
+	debug-print "${FUNCNAME}: initial build_dir = ${bdir}"
+
+	for v in "${MULTIBUILD_VARIANTS[@]}"; do
+		local MULTIBUILD_VARIANT=${v}
+		local MULTIBUILD_ID=${prev_id}${v}
+		local BUILD_DIR=${bdir%%/}-${v}
+
+		einfo "${v}: running ${@}" \
+			| tee -a "${T}/build-${MULTIBUILD_ID}.log"
+
+		# _multibuild_parallel() does redirection internally.
+		# this is a hidden API to avoid writing multilib_foreach twice.
+		if [[ ${1} == _multibuild_parallel ]]; then
+			"${@}"
+		else
+			"${@}" 2>&1 | tee -a "${T}/build-${MULTIBUILD_ID}.log"
+		fi
+		lret=${?}
+	done
+	[[ ${ret} -eq 0 && ${lret} -ne 0 ]] && ret=${lret}
+
+	return ${ret}
+}
+
+# @FUNCTION: multibuild_parallel_foreach
+# @USAGE: [<argv>...]
+# @DESCRIPTION:
+# Run the passed command repeatedly for each of the enabled package
+# variants alike multibuild_foreach. Multiple invocations of the command
+# will be performed in parallel, up to MULTIBUILD_JOBS tasks.
+#
+# The function returns 0 if all commands return 0, or the first non-zero
+# exit status otherwise. However, it performs all the invocations
+# nevertheless. It is preferred to call 'die' inside of the passed
+# function.
+multibuild_parallel_foreach() {
+	debug-print-function ${FUNCNAME} "${@}"
+
+	local ret lret
+
+	_multibuild_parallel() {
+		(
+			multijob_child_init
+			"${@}" 2>&1 | tee -a "${T}/build-${MULTIBUILD_ID}.log"
+			exit ${PIPESTATUS[0]}
+		) &
+		multijob_post_fork
+	}
+
+	local opts
+	if [[ ${MULTIBUILD_JOBS} ]]; then
+		opts=-j${MULTIBUILD_JOBS}
+	else
+		opts=${MAKEOPTS}
+	fi
+
+	multijob_init "${opts}"
+	multibuild_foreach _multibuild_parallel "${@}"
+	ret=${?}
+	multijob_finish
+	lret=${?}
+
+	[[ ${ret} -eq 0 ]] && ret=${lret}
+	return ${ret}
+}
+
+_MULTIBUILD=1
+fi
-- 
1.8.1.4