llvm.org.eclass: New eclass to help maintaining LLVM

llvm.org eclass is meant to provide helper routines for maintaining
LLVM packages.  It takes care of covering the differences between
release, prerelease and git ebuilds in a unified API.  This will make
maintenance much easier.

Initially, the eclass takes care of fetching and unpacking the archives.
Later on, I will work on moving some more common stuff there.

Signed-off-by: Michał Górny <mgorny@gentoo.org>

1 files changed, 198 insertions, 0 deletions

diff --git a/eclass/llvm.org.eclass b/eclass/llvm.org.eclass
new file mode 100644
index 000000000000..5a704c1d9805
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+++ b/eclass/llvm.org.eclass
@@ -0,0 +1,198 @@
+# Copyright 2019 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+# @ECLASS: llvm.org.eclass
+# @MAINTAINER:
+# Michał Górny <mgorny@gentoo.org>
+# @AUTHOR:
+# Michał Górny <mgorny@gentoo.org>
+# @BLURB: Common bits for fetching & unpacking llvm.org projects
+# @DESCRIPTION:
+# The llvm.org eclass provides common code to fetch and unpack parts
+# of the llvm.org project tree.  It takes care of handling both git
+# checkouts and source tarballs, making it possible to unify the code
+# of live and release ebuilds and effectively reduce the work needed
+# to package new releases/RCs/branches.
+#
+# In order to use this eclass, the ebuild needs to declare
+# LLVM_COMPONENTS and then call llvm.org_set_globals.  If tests require
+# additional components, they need to be listed in LLVM_TEST_COMPONENTS.
+# The eclass exports an implementation of src_unpack() phase.
+#
+# Example:
+# @CODE
+# inherit llvm.org
+#
+# LLVM_COMPONENTS=( lld )
+# LLVM_TEST_COMPONENTS=( llvm/utils/lit )
+# llvm.org_set_globals
+# @CODE
+
+case "${EAPI:-0}" in
+	7)
+		;;
+	*)
+		die "Unsupported EAPI=${EAPI} for ${ECLASS}"
+		;;
+esac
+
+
+# == internal control bits ==
+
+# @ECLASS-VARIABLE: _LLVM_MASTER_MAJOR
+# @INTERNAL
+# @DESCRIPTION:
+# The major version of current LLVM trunk.  Used to determine
+# the correct branch to use.
+_LLVM_MASTER_MAJOR=10
+
+# @ECLASS-VARIABLE: _LLVM_SOURCE_TYPE
+# @INTERNAL
+# @DESCRIPTION:
+# Source type to use: 'git' or 'tar'.
+if [[ -z ${_LLVM_SOURCE_TYPE+1} ]]; then
+	if [[ ${PV} == *.9999 ]]; then
+		_LLVM_SOURCE_TYPE=git
+	else
+		_LLVM_SOURCE_TYPE=tar
+	fi
+fi
+
+[[ ${_LLVM_SOURCE_TYPE} == git ]] && inherit git-r3
+
+[[ ${PV} == ${_LLVM_MASTER_MAJOR}.* && ${_LLVM_SOURCE_TYPE} == tar ]] &&
+	die "${ECLASS}: Release ebuild for master branch?!"
+
+
+# == control variables ==
+
+# @ECLASS-VARIABLE: LLVM_COMPONENTS
+# @REQUIRED
+# @DESCRIPTION:
+# List of components needed unconditionally.  Specified as bash array
+# with paths relative to llvm-project git.  Automatically translated
+# for tarball releases.
+#
+# The first path specified is used to construct default S.
+
+# @ECLASS-VARIABLE: LLVM_TEST_COMPONENTS
+# @DEFAULT_UNSET
+# @DESCRIPTION:
+# List of additional components needed for tests.
+
+
+# == global scope logic ==
+
+# @FUNCTION: _llvm.org_get_archives
+# @USAGE: <components>
+# @INTERNAL
+# @DESCRIPTION:
+# Set 'archives' array to list of unique archive filenames
+# for components passed as parameters.
+_llvm.org_get_archives() {
+	local c
+	archives=()
+
+	for c; do
+		local cn=${c%%/*}
+		case ${cn} in
+			clang) cn=cfe;;
+		esac
+
+		local a=${cn}-${PV}.src.tar.xz
+		has "${a}" "${archives[@]}" || archives+=( "${a}" )
+	done
+}
+
+# @FUNCTION: llvm.org_set_globals
+# @DESCRIPTION:
+# Set global variables.  This must be called after setting LLVM_*
+# variables used by the eclass.
+llvm.org_set_globals() {
+	if [[ $(declare -p LLVM_COMPONENTS) != "declare -a"* ]]; then
+		die 'LLVM_COMPONENTS must be an array.'
+	fi
+	if declare -p LLVM_TEST_COMPONENTS &>/dev/null; then
+		if [[ $(declare -p LLVM_TEST_COMPONENTS) != "declare -a"* ]]; then
+			die 'LLVM_TEST_COMPONENTS must be an array.'
+		fi
+	fi
+
+	if [[ ${_LLVM_SOURCE_TYPE} == git ]]; then
+		EGIT_REPO_URI="https://github.com/llvm/llvm-project.git"
+
+		[[ ${PV} != ${_LLVM_MASTER_MAJOR}.* ]] &&
+			EGIT_BRANCH="release/${PV%%.*}.x"
+	elif [[ ${_LLVM_SOURCE_TYPE} == tar ]]; then
+		local a archives=()
+		_llvm.org_get_archives "${LLVM_COMPONENTS[@]}"
+		for a in "${archives[@]}"; do
+			SRC_URI+="
+				https://releases.llvm.org/${PV}/${a}"
+		done
+	else
+		die "Invalid _LLVM_SOURCE_TYPE: ${LLVM_SOURCE_TYPE}"
+	fi
+
+	S=${WORKDIR}/${LLVM_COMPONENTS[0]}
+
+	if [[ -n ${LLVM_TEST_COMPONENTS+1} ]]; then
+		IUSE+=" test"
+		RESTRICT+=" !test? ( test )"
+
+		if [[ ${_LLVM_SOURCE_TYPE} == tar ]]; then
+			SRC_URI+="
+				test? ("
+
+			_llvm.org_get_archives "${LLVM_TEST_COMPONENTS[@]}"
+			for a in "${archives[@]}"; do
+				SRC_URI+="
+					https://releases.llvm.org/${PV}/${a}"
+			done
+
+			SRC_URI+="
+				)"
+		fi
+	fi
+
+	_LLVM_ORG_SET_GLOBALS_CALLED=1
+}
+
+
+# == phase functions ==
+
+EXPORT_FUNCTIONS src_unpack
+
+# @FUNCTION: llvm.org_src_unpack
+# @DESCRIPTION:
+# Unpack or checkout requested LLVM components.
+llvm.org_src_unpack() {
+	if [[ ! ${_LLVM_ORG_SET_GLOBALS_CALLED} ]]; then
+		die "llvm.org_set_globals must be called in global scope"
+	fi
+
+	local components=( "${LLVM_COMPONENTS[@]}" )
+	if [[ ${LLVM_TEST_COMPONENTS+1} ]] && use test; then
+		components+=( "${LLVM_TEST_COMPONENTS[@]}" )
+	fi
+
+	if [[ ${_LLVM_SOURCE_TYPE} == git ]]; then
+		git-r3_fetch
+		git-r3_checkout '' . '' "${components[@]}"
+	else
+		local c archives
+		# TODO: optimize this
+		for c in "${components[@]}"; do
+			local top_dir=${c%%/*}
+			_llvm.org_get_archives "${c}"
+			local sub_path=${archives[0]%.tar.xz}
+			[[ ${c} == */* ]] && sub_path+=/${c#*/}
+
+			ebegin "Unpacking ${sub_path} from ${archives[0]}"
+			mkdir -p "${top_dir}" || die
+			tar -C "${top_dir}" -x -J -o --strip-components 1 \
+				-f "${DISTDIR}/${archives[0]}" "${sub_path}" || die
+			eend
+		done
+	fi
+}