>>>>> On Sat, 03 Dec 2022, Michał Górny wrote:
> --- /dev/null
> +++ b/eclass/app-alternatives.eclass
> @@ -0,0 +1,84 @@
> +# Copyright 2022 Gentoo Authors
> +# Distributed under the terms of the GNU General Public License v2
> +
> +# @ECLASS: app-alternatives.eclass
> +# @MAINTAINER:
> +# Michał Górny <mgo...@gentoo.org>
> +# @AUTHOR:
> +# Michał Górny <mgo...@gentoo.org>
> +# @SUPPORTED_EAPIS: 8
> +# @BLURB: Common logic for app-alternatives/*
> +# @DESCRIPTION:
> +# This eclass provides common logic shared by app-alternatives/*
> +# ebuilds. A global ALTERNATIVES variable needs to be declared
> +# that lists available options and their respective dependencies.
> +# HOMEPAGE, S, LICENSE, SLOT, IUSE, REQUIRED_USE and RDEPEND are set.
> +# A get_alternative() function is provided that prints the determines
Grammar?
> +# the selected alternative and prints its respective flag name.
> +
> +case ${EAPI} in
> + 8) ;;
> + *) die "${ECLASS}: EAPI ${EAPI} unsupported."
${EAPI:-0} here?
> +esac
> +
> +if [[ ! ${_APP_ALTERNATIVES_ECLASS} ]]; then
> +_APP_ALTERNATIVES_ECLASS=1
> +
> +# @ECLASS_VARIABLE: ALTERNATIVES
> +# @PRE_INHERIT
> +# @REQUIRED
> +# @DESCRIPTION:
> +# Array of "flag:dependency" pairs specifying the available
> +# alternatives. The default provider must be listed first.
> +
> +# @FUNCTION: _app-alternatives_set_globals
> +# @INTERNAL
> +# @DESCRIPTION:
> +# Set ebuild metadata variables.
> +_app-alternatives_set_globals() {
> + debug-print-function ${FUNCNAME} "${@}"
> +
> + if [[ $(declare -p ALTERNATIVES) != "declare -a"* ]]; then
The more modern (and presumably, more reliable) check would be:
if [[ ${ALTERNATIVES@a} != *a* ]]; then
Since the eclass supports EAPI 8 only, bash-5.0 is guaranteed, so the
feature will be available.
> + die 'ALTERNATIVES must be an array.'
> + elif [[ ${#ALTERNATIVES[@]} -eq 0 ]]; then
> + die 'ALTERNATIVES must not be empty.'
> + fi
> +
> + HOMEPAGE="https://wiki.gentoo.org/wiki/Project:Base/Alternatives";
> + S=${WORKDIR}
> +
> + LICENSE="CC0-1.0"
> + SLOT="0"
> +
> + # yep, that's a cheap hack adding '+' to the first flag
> + IUSE="+${ALTERNATIVES[*]%%:*}"
> + REQUIRED_USE="^^ ( ${ALTERNATIVES[*]%%:*} )"
> + RDEPEND=""
> +
> + local flag dep
> + for flag in "${ALTERNATIVES[@]}"; do
> + [[ ${flag} != *:* ]] && die "Invalid ALTERNATIVES item: ${flag}"
> + dep=${flag#*:}
> + flag=${flag%%:*}
> + RDEPEND+="
> + ${flag}? ( ${dep} )
> + "
Why two newlines? A single space should be enough.
> + done
> +}
> +_app-alternatives_set_globals
> +
> +# @FUNCTION: get_alternative
> +# @DESCRIPTION:
> +# Get the flag name for the selected alterantive (i.e. the USE flag set).
Typo.
> +get_alternative() {
> + debug-print-function ${FUNCNAME} "${@}"
> +
> + local flag
> + for flag in "${ALTERNATIVES[@]%%:*}"; do
> + usev "${flag}" && return
> + done
> +
> + die "No selected alternative found (REQUIRED_USE ignored?!)"
> +}
> +
> +fi
