diff options
| -rw-r--r-- | eclass/llvm.eclass | 139 |
1 files changed, 139 insertions, 0 deletions
diff --git a/eclass/llvm.eclass b/eclass/llvm.eclass new file mode 100644 index 000000000000..bde050b96851 --- /dev/null +++ b/eclass/llvm.eclass @@ -0,0 +1,139 @@ +# Copyright 1999-2017 Gentoo Foundation +# Distributed under the terms of the GNU General Public License v2 +# $Id$ + +# @ECLASS: llvm.eclass +# @MAINTAINER: +# Michał Górny <mgorny@gentoo.org> +# @AUTHOR: +# Michał Górny <mgorny@gentoo.org> +# @BLURB: Utility functions to build against slotted LLVM +# @DESCRIPTION: +# The llvm.eclass provides utility functions that can be used to build +# against specific version of slotted LLVM (with fallback to :0 for old +# versions). +# +# This eclass does not generate dependency strings. You need to write +# a proper dependency string yourself to guarantee that appropriate +# version of LLVM is installed. +# +# Example use for a package supporting LLVM 3.8 to 5: +# @CODE +# inherit cmake-utils llvm +# +# RDEPEND=" +# <sys-devel/llvm-6_rc:= +# || ( +# sys-devel/llvm:5 +# sys-devel/llvm:4 +# >=sys-devel/llvm-3.8:0 +# ) +# " +# +# LLVM_MAX_SLOT=5 +# +# # only if you need to define one explicitly +# pkg_setup() { +# llvm_pkg_setup +# do-something-else +# } +# @CODE + +case "${EAPI:-0}" in + 0|1|2|3|4|5) + die "Unsupported EAPI=${EAPI:-0} (too old) for ${ECLASS}" + ;; + 6) + ;; + *) + die "Unsupported EAPI=${EAPI} (unknown) for ${ECLASS}" + ;; +esac + +EXPORT_FUNCTIONS pkg_setup + +if [[ ! ${_LLVM_ECLASS} ]]; then + +# @ECLASS-VARIABLE: LLVM_MAX_SLOT +# @DEFAULT_UNSET +# @DESCRIPTION: +# Highest LLVM slot supported by the package. Needs to be set before +# llvm_pkg_setup is called. If unset, no upper bound is assumed. + +# @ECLASS-VARIABLE: _LLVM_KNOWN_SLOTS +# @INTERNAL +# @DESCRIPTION: +# Correct values of LLVM slots, newest first. +declare -g -r _LLVM_KNOWN_SLOTS=( 5 4 ) + +# @FUNCTION: get_llvm_prefix +# @USAGE: [<max_slot>] +# @DESCRIPTION: +# Prints the absolute path to an LLVM install prefix corresponding to +# the newest installed version of LLVM that is not newer than +# <max_slot>. If no <max_slot> is specified, there is no upper limit. +# +# Note that the function does not support lower-bound version, so you +# need to provide correct dependencies to ensure that a new enough +# version will be always installed. Otherwise, the function could return +# a version lower than required. +get_llvm_prefix() { + debug-print-function ${FUNCNAME} "${@}" + + local max_slot=${1} + local slot + for slot in "${_LLVM_KNOWN_SLOTS[@]}"; do + # skip higher slots + if [[ -n ${max_slot} ]]; then + if [[ ${max_slot} == ${slot} ]]; then + max_slot= + else + continue + fi + fi + + local p=${EPREFIX}/usr/lib/llvm/${slot} + if [[ -x ${p}/bin/llvm-config ]]; then + echo "${p}" + return + fi + done + + # max_slot should have been unset in the iteration + if [[ -n ${max_slot} ]]; then + die "${FUNCNAME}: invalid max_slot=${max_slot}" + fi + + # fallback to :0 + # assume it's always <= 4 (the lower max_slot allowed) + p=${EPREFIX}/usr + if [[ -x ${p}/bin/llvm-config ]]; then + echo "${p}" + return + fi + + die "No LLVM slot${1:+ <= ${1}} found in PATH!" +} + +# @FUNCTION: llvm_pkg_setup +# @DESCRIPTION: +# Prepend the executable directory corresponding to the newest +# installed LLVM version that is not newer than ${LLVM_MAX_SLOT} +# to PATH. If LLVM_MAX_SLOT is unset or empty, the newest installed +# slot will be used. +# +# The PATH manipulation is only done for source builds. The function +# is a no-op when installing a binary package. +# +# If any other behavior is desired, the contents of the function +# should be inlined into the ebuild and modified as necessary. +llvm_pkg_setup() { + debug-print-function ${FUNCNAME} "${@}" + + if [[ ${MERGE_TYPE} != binary ]]; then + export PATH=$(get_llvm_prefix ${LLVM_MAX_SLOT})/bin:${PATH} + fi +} + +_LLVM_ECLASS=1 +fi |