Introduce python-r1, a new (and simpler) eclass for Python-related packages.

2 files changed, 226 insertions, 1 deletions

diff --git a/eclass/ChangeLog b/eclass/ChangeLog
index f9fea9444513..5b28f9404262 100644
--- a/eclass/ChangeLog
+++ b/eclass/ChangeLog
@@ -1,6 +1,9 @@
 # ChangeLog for eclass directory
 # Copyright 1999-2012 Gentoo Foundation; Distributed under the GPL v2
-# $Header: /var/cvsroot/gentoo-x86/eclass/ChangeLog,v 1.441 2012/10/13 22:54:37 johu Exp $
+# $Header: /var/cvsroot/gentoo-x86/eclass/ChangeLog,v 1.442 2012/10/14 10:51:28 mgorny Exp $
+
+  14 Oct 2012; Michał Górny <mgorny@gentoo.org> +python-r1.eclass:
+  Introduce python-r1, a new (and simpler) eclass for Python-related packages.
 
   13 Oct 2012; Johannes Huber <johu@gentoo.org> kde4-meta-pkg.eclass:
   Change LICENSE to 'metapackage' for kde meta packages, bug #438278.
diff --git a/eclass/python-r1.eclass b/eclass/python-r1.eclass
new file mode 100644
index 000000000000..4b5cc695cecb
--- /dev/null
+++ b/eclass/python-r1.eclass
@@ -0,0 +1,222 @@
+# Copyright 1999-2012 Gentoo Foundation
+# Distributed under the terms of the GNU General Public License v2
+# $Header: /var/cvsroot/gentoo-x86/eclass/python-r1.eclass,v 1.1 2012/10/14 10:51:28 mgorny Exp $
+
+# @ECLASS: python-r1
+# @MAINTAINER:
+# Michał Górny <mgorny@gentoo.org>
+# Python herd <python@gentoo.org>
+# @AUTHOR:
+# Author: Michał Górny <mgorny@gentoo.org>
+# Based on work of: Krzysztof Pawlik <nelchael@gentoo.org>
+# @BLURB: A common, simple eclass for Python packages.
+# @DESCRIPTION:
+# A common eclass providing helper functions to build and install
+# packages supporting being installed for multiple Python
+# implementations.
+#
+# This eclass sets correct IUSE and REQUIRED_USE. It exports PYTHON_DEPS
+# and PYTHON_USEDEP so you can create correct dependencies for your
+# package easily. It also provides methods to easily run a command for
+# each enabled Python implementation and duplicate the sources for them.
+
+case "${EAPI}" in
+	0|1|2|3)
+		die "Unsupported EAPI=${EAPI} (too old) for ${ECLASS}"
+		;;
+	4)
+		# EAPI=4 needed for REQUIRED_USE
+		;;
+	*)
+		die "Unsupported EAPI=${EAPI} (unknown) for ${ECLASS}"
+		;;
+esac
+
+# @ECLASS-VARIABLE: _PYTHON_ALL_IMPLS
+# @INTERNAL
+# @DESCRIPTION:
+# All supported Python implementations, most preferred last.
+_PYTHON_ALL_IMPLS=(
+	jython2_5
+	pypy1_8 pypy1_9
+	python3_1 python3_2
+	python2_5 python2_6 python2_7
+)
+
+# @ECLASS-VARIABLE: PYTHON_COMPAT
+# @DESCRIPTION:
+# This variable contains a list of Python implementations the package
+# supports. It must be set before the `inherit' call.  The default is to
+# enable all implementations. It has to be an array.
+if ! declare -p PYTHON_COMPAT &>/dev/null; then
+	PYTHON_COMPAT=( "${_PYTHON_ALL_IMPLS[@]}" )
+fi
+
+# @ECLASS-VARIABLE: PYTHON_REQ_USE
+# @DEFAULT_UNSET
+# @DESCRIPTION:
+# The list of USEflags required to be enabled on the chosen Python
+# implementations, formed as a USE-dependency string. It should be valid
+# for all implementations in PYTHON_COMPAT, so it may be necessary to
+# use USE defaults.
+#
+# Example:
+# @CODE
+# PYTHON_REQ_USE="gdbm,ncurses(-)?"
+# @CODE
+#
+# Will cause the Python dependencies to look like:
+# @CODE
+# python_targets_pythonX_Y? (
+#   dev-lang/python:X_Y[gdbm,ncurses(-)?] )
+# @CODE
+
+# @ECLASS-VARIABLE: PYTHON_DEPS
+# @DESCRIPTION:
+# This is an eclass-generated Python dependency string for all
+# implementations listed in PYTHON_COMPAT. It should be used
+# in RDEPEND and/or DEPEND like:
+#
+# @CODE
+# RDEPEND="${PYTHON_DEPS}
+#   dev-foo/mydep"
+# DEPEND="${RDEPEND}"
+# @CODE
+
+# @ECLASS-VARIABLE: PYTHON_USEDEP
+# @DESCRIPTION:
+# This is an eclass-generated USE-dependency string which can be used to
+# depend on another Python package being built for the same Python
+# implementations. It should be used like:
+#
+# @CODE
+# RDEPEND="dev-python/foo[${PYTHON_USEDEP}]"
+# @CODE
+
+_python_set_globals() {
+	local flags=( "${PYTHON_COMPAT[@]/#/python_targets_}" )
+	local optflags=${flags[@]/%/?}
+
+	IUSE=${flags[*]}
+	REQUIRED_USE="|| ( ${flags[*]} )"
+	PYTHON_USEDEP=${optflags// /,}
+
+	PYTHON_DEPS=
+	local i
+	for i in "${PYTHON_COMPAT[@]}"; do
+		local d
+		case ${i} in
+			python*)
+				d='dev-lang/python';;
+			jython*)
+				d='dev-java/jython';;
+			pypy*)
+				d='dev-python/pypy';;
+			*)
+				die "Invalid implementation: ${i}"
+		esac
+
+		local v=${i##*[a-z]}
+		local usestr
+		[[ ${PYTHON_REQ_USE} ]] && usestr="[${PYTHON_REQ_USE}]"
+		PYTHON_DEPS+=" python_targets_${i}? (
+			${d}:${v/_/.}${usestr} )"
+	done
+}
+_python_set_globals
+
+# @FUNCTION: _python_set_PYTHON
+# @USAGE: <impl>
+# @INTERNAL
+# @DESCRIPTION:
+# Get the Python executable name for the given implementation and set it
+# as ${PYTHON} & ${EPYTHON}. Please note that EPYTHON will contain
+# the 'basename' while PYTHON will contain the full path.
+_python_set_PYTHON() {
+	debug-print-function ${FUNCNAME} "${@}"
+
+	local impl=${1/_/.}
+
+	case "${impl}" in
+		python*|jython*)
+			EPYTHON=${impl}
+			;;
+		pypy*)
+			EPYTHON=pypy-c${impl#pypy}
+			;;
+		*)
+			die "Invalid argument to _python_set_PYTHON: ${1}"
+			;;
+	esac
+	PYTHON=${EPREFIX}/usr/bin/${EPYTHON}
+
+	debug-print "${FUNCNAME}: ${impl} -> ${PYTHON}"
+}
+
+# @FUNCTION: python_copy_sources
+# @DESCRIPTION:
+# Create a single copy of the package sources (${S}) for each enabled
+# Python implementation.
+python_copy_sources() {
+	debug-print-function ${FUNCNAME} "${@}"
+
+	local impl
+	local bdir=${BUILD_DIR:-${S}}
+
+	debug-print "${FUNCNAME}: bdir = ${bdir}"
+	einfo "Will copy sources from ${S}"
+	# the order is irrelevant here
+	for impl in "${PYTHON_COMPAT[@]}"; do
+		if use "python_targets_${impl}"
+		then
+			local BUILD_DIR=${bdir%%/}-${impl}
+
+			einfo "${impl}: copying to ${BUILD_DIR}"
+			debug-print "${FUNCNAME}: [${impl}] cp ${S} => ${BUILD_DIR}"
+			cp -pr "${S}" "${BUILD_DIR}" || die
+		fi
+	done
+}
+
+# @FUNCTION: python_foreach_impl
+# @USAGE: <command> [<args>...]
+# @DESCRIPTION:
+# Run the given command for each of the enabled Python implementations.
+# If additional parameters are passed, they will be passed through
+# to the command. If the command fails, python_foreach_impl dies.
+# If necessary, use ':' to force a successful return.
+#
+# Before the command is run, EPYTHON is set to the name of the current
+# Python implementation, PYTHON is set to the correct Python executable
+# name and exported, and BUILD_DIR is set to a 'default' build directory
+# for given implementation (e.g. ${BUILD_DIR:-${S}}-python2_7).
+#
+# The command is run inside the build directory. If it doesn't exist
+# yet, it is created (as an empty directory!). If your build system does
+# not support out-of-source builds, you will likely want to use
+# python_copy_sources first.
+python_foreach_impl() {
+	debug-print-function ${FUNCNAME} "${@}"
+
+	local impl
+	local bdir=${BUILD_DIR:-${S}}
+
+	debug-print "${FUNCNAME}: bdir = ${bdir}"
+	for impl in "${_PYTHON_ALL_IMPLS[@]}"; do
+		if has "${impl}" "${PYTHON_COMPAT[@]}" && use "python_targets_${impl}"
+		then
+			local EPYTHON PYTHON
+			_python_set_PYTHON "${impl}"
+			local BUILD_DIR=${bdir%%/}-${impl}
+			export PYTHON
+
+			debug-print "${FUNCNAME}: [${impl}] build_dir = ${BUILD_DIR}"
+
+			mkdir -p "${BUILD_DIR}" || die
+			pushd "${BUILD_DIR}" &>/dev/null || die
+			einfo "${EPYTHON}: running ${@}"
+			"${@}" || die "${EPYTHON}: ${1} failed"
+			popd &>/dev/null || die
+		fi
+	done
+}