gstreamer-meson.eclass: New eclass required for gstreamer-1.18.0+

Gstreamer switched to meson in 1.16.0 and removed autotools support in 1.18.0,
this eclass is an update of gstreamer.eclass.

One significant change is that we lost the gstreamer_system_link function.

Differences from version 1:
- Move to EAPI-7, including moving deps from DEPEND to BDEPEND when appropriate
- Port python script to perl, this allows to avoid having to add PYTHON_COMPAT
  into a python-unrelated eclass
- Drop errorneous MULTILIB_USEDEP on virtual/pkgconfig
- Fix running tests: defining multilib_src_test, media-libs/gstreamer[test] dep
- Fix ebuild emesonargs being ignored
- Remove legacy prune_libtool_files
- virtualx wrapped for testing

Differences from version 2:
- Get list of plugins from meson_options.txt instead of hard-coding them,
  this adds GST_PLUGINS_NOAUTO for ones managed by the ebuild
- Fix @AUTHOR order
- Sort inherits
- remove stray semicolon in test
- Add virtx to tests
- Remove gstreamer_environment_reset
- Put GST_ORG_MODULE conditions into gstreamer_multilib_src_{compile,install}
- QA warn when IUSE=orc is defined but the option is absent
- Pass gst_debug/examples/nls/tests options only when declared
- Use code similar to orc for introspection

Closes: https://bugs.gentoo.org/690468
Signed-off-by: Haelwenn (lanodan) Monnier <contact@hacktivis.me>
Signed-off-by: Sam James <sam@gentoo.org>

1 files changed, 367 insertions, 0 deletions

diff --git a/eclass/gstreamer-meson.eclass b/eclass/gstreamer-meson.eclass
new file mode 100644
index 000000000000..c3c97db0690b
--- /dev/null
+++ b/eclass/gstreamer-meson.eclass
@@ -0,0 +1,367 @@
+# Copyright 1999-2021 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+# @ECLASS: gstreamer-meson.eclass
+# @MAINTAINER:
+# gstreamer@gentoo.org
+# @AUTHOR:
+# Haelwenn (lanodan) Monnier <contact@hacktivis.me>
+# Michał Górny <mgorny@gentoo.org>
+# Gilles Dartiguelongue <eva@gentoo.org>
+# Saleem Abdulrasool <compnerd@gentoo.org>
+# foser <foser@gentoo.org>
+# zaheerm <zaheerm@gentoo.org>
+# Steven Newbury
+# @SUPPORTED_EAPIS: 7
+# @BLURB: Helps building core & split gstreamer plugins
+# @DESCRIPTION:
+# Eclass to make external gst-plugins emergable on a per-plugin basis
+# and to solve the problem with gst-plugins generating far too much
+# unneeded dependencies.
+#
+# GStreamer consuming applications should depend on the specific plugins
+# they need as defined in their source code. Usually you can find that
+# out by grepping the source tree for 'factory_make'. If it uses playbin
+# plugin, consider adding media-plugins/gst-plugins-meta dependency, but
+# also list any packages that provide explicitly requested plugins.
+
+# multilib-minimal goes last
+inherit meson multilib toolchain-funcs virtualx xdg-utils multilib-minimal
+
+case "${EAPI:-0}" in
+	7)
+		;;
+	*)
+		die "EAPI=\"${EAPI}\" is not supported"
+		;;
+esac
+
+# @ECLASS-VARIABLE: GST_PLUGINS_ENABLED
+# @DESCRIPTION:
+# Defines the plugins to be built.
+# May be set by an ebuild and contain more than one indentifier, space
+# separated (only src_configure can handle mutiple plugins at this time).
+
+# @ECLASS-VARIABLE: GST_PLUGINS_NOAUTO
+# @DESCRIPTION:
+# Space-separated list defined by the ebuild for plugin options which shouldn't
+# be automatically defined by gstreamer_multilib_src_configure.
+
+# @FUNCTION: gstreamer_get_default_enabled_plugins
+# @INTERNAL
+# @DESCRIPTION:
+# Get the list of plugins to be built by default, meaning the ones with no
+# external dependencies for base packages and the name of the package for
+# split ones.
+gstreamer_get_default_enabled_plugins() {
+	if [[ "${GST_ORG_MODULE}" == "${PN}" ]]; then
+		gstreamer_get_plugins
+		echo "${GST_PLUGINS_NO_EXT_DEPS}" | tr '\n' ' '
+	else
+		echo "${PN/gst-plugins-/}"
+	fi
+}
+
+# @FUNCTION: gstreamer_get_plugins
+# @INTERNAL
+# @DESCRIPTION:
+# Get the list of all plugins, with and without external dependencies.
+# Must be called from src_prepare/src_configure
+gstreamer_get_plugins() {
+	GST_PLUGINS_NO_EXT_DEPS=$(sed -rn \
+		"/^# Feature options for plugins with(out| no) external deps$/,/^#.*$/s;^option\('([^']*)'.*;\1;p" \
+		"${S}/meson_options.txt" || die "Failed to extract options for plugins without external deps"
+	)
+
+	GST_PLUGINS_EXT_DEPS=$(sed -rn \
+		"/^# Feature options for plugins (with|that need) external deps$/,/^#.*$/s;^option\('([^']*)'.*;\1;p" \
+		"${S}/meson_options.txt" || die "Failed to extract options for plugins with external deps"
+	)
+}
+
+# @ECLASS-VARIABLE: GST_PLUGINS_BUILD_DIR
+# @DESCRIPTION:
+# Actual build directories of the plugins.
+# Most often the same as the configure switch name.
+# FIXME: Change into a bash array
+: ${GST_PLUGINS_BUILD_DIR:=${PN/gst-plugins-/}}
+
+# @ECLASS-VARIABLE: GST_TARBALL_SUFFIX
+# @DESCRIPTION:
+# Most projects hosted on gstreamer.freedesktop.org mirrors provide
+# tarballs as tar.bz2 or tar.xz. This eclass defaults to xz. This is
+# because the gstreamer mirrors are moving to only have xz tarballs for
+# new releases.
+: ${GST_TARBALL_SUFFIX:="xz"}
+
+# Even though xz-utils are in @system, they must still be added to BDEPEND; see
+# https://archives.gentoo.org/gentoo-dev/msg_a0d4833eb314d1be5d5802a3b710e0a4.xml
+if [[ ${GST_TARBALL_SUFFIX} == "xz" ]]; then
+	BDEPEND="${BDEPEND} app-arch/xz-utils"
+fi
+
+# @ECLASS-VARIABLE: GST_ORG_MODULE
+# @DESCRIPTION:
+# Name of the module as hosted on gstreamer.freedesktop.org mirrors.
+# Leave unset if package name matches module name.
+: ${GST_ORG_MODULE:=${PN}}
+
+# @ECLASS-VARIABLE: GST_ORG_PVP
+# @INTERNAL
+# @DESCRIPTION:
+# Major and minor numbers of the version number.
+: ${GST_ORG_PVP:=$(ver_cut 1-2)}
+
+
+DESCRIPTION="${BUILD_GST_PLUGINS} plugin for gstreamer"
+HOMEPAGE="https://gstreamer.freedesktop.org/"
+SRC_URI="https://gstreamer.freedesktop.org/src/${GST_ORG_MODULE}/${GST_ORG_MODULE}-${PV}.tar.${GST_TARBALL_SUFFIX}"
+S="${WORKDIR}/${GST_ORG_MODULE}-${PV}"
+
+LICENSE="GPL-2"
+case ${GST_ORG_PVP} in
+	1.*) SLOT="1.0"; GST_MIN_PV="1.2.4-r1" ;;
+	*) die "Unkown gstreamer release."
+esac
+
+RDEPEND="
+	>=dev-libs/glib-2.40.0:2[${MULTILIB_USEDEP}]
+	>=media-libs/gstreamer-${GST_MIN_PV}:${SLOT}[${MULTILIB_USEDEP}]
+"
+BDEPEND="
+	>=sys-apps/sed-4
+	virtual/pkgconfig
+	virtual/perl-JSON-PP
+"
+
+# Export common multilib phases.
+multilib_src_configure() { gstreamer_multilib_src_configure; }
+multilib_src_compile() { gstreamer_multilib_src_compile; }
+multilib_src_install() { gstreamer_multilib_src_install; }
+
+if [[ "${PN}" != "${GST_ORG_MODULE}" ]]; then
+	# Do not run test phase for invididual plugin ebuilds.
+	RESTRICT="test"
+	RDEPEND="${RDEPEND}
+		>=media-libs/${GST_ORG_MODULE}-${PV}:${SLOT}[${MULTILIB_USEDEP}]"
+
+	# Export multilib phases used for split builds.
+	multilib_src_install_all() { gstreamer_multilib_src_install_all; }
+else
+	local extra_deps=""
+
+	IUSE="nls test"
+	RESTRICT="!test? ( test )"
+	if [[ "${PN}" != "gstreamer" ]]; then
+		BDEPEND="${BDEPEND}
+			nls? ( >=sys-devel/gettext-0.17 )
+			test? ( media-libs/gstreamer[test] )
+		"
+	else
+		BDEPEND="${BDEPEND}
+			nls? ( >=sys-devel/gettext-0.17 )
+		"
+	fi
+
+	multilib_src_test() { gstreamer_multilib_src_test; }
+fi
+
+DEPEND="${DEPEND} ${RDEPEND}"
+
+# @FUNCTION: gstreamer_get_plugin_dir
+# @USAGE: gstreamer_get_plugin_dir [<build_dir>]
+# @INTERNAL
+# @DESCRIPTION:
+# Finds plugin build directory and output it.
+# Defaults to ${GST_PLUGINS_BUILD_DIR} if argument is not provided
+gstreamer_get_plugin_dir() {
+	local build_dir=${1:-${GST_PLUGINS_BUILD_DIR}}
+
+	if [[ ! -d ${S}/ext/${build_dir} ]]; then
+		if [[ ! -d ${S}/sys/${build_dir} ]]; then
+			ewarn "No such plugin directory"
+			die
+		fi
+		einfo "Got system plugin in ${build_dir}..." >&2
+		echo sys/${build_dir}
+	else
+		einfo "Got external plugin in ${build_dir}..." >&2
+		echo ext/${build_dir}
+	fi
+}
+
+# @VARIABLE: GST_PLUGINS_ENOAUTO
+# @INTERNAL
+# @DESCRIPTION:
+# Contains false-positives.
+# - gst-plugins-bad puts "shm" in external deps
+GST_PLUGINS_ENOAUTO="shm"
+
+# @FUNCTION: gstreamer_multilib_src_configure
+# @DESCRIPTION:
+# Handles logic common to configuring gstreamer plugins
+gstreamer_multilib_src_configure() {
+	local plugin gst_conf=( ) EMESON_SOURCE=${EMESON_SOURCE:-${S}}
+
+	gstreamer_get_plugins
+	xdg_environment_reset
+
+	GST_PLUGINS_ENABLED=${GST_PLUGINS_ENABLED:-$(gstreamer_get_default_enabled_plugins)}
+
+	for plugin in ${GST_PLUGINS_NO_EXT_DEPS} ${GST_PLUGINS_EXT_DEPS} ; do
+		if has ${plugin} ${GST_PLUGINS_NOAUTO} ${GST_PLUGINS_ENOAUTO}; then
+			: # noop
+		elif has ${plugin} ${GST_PLUGINS_ENABLED} ; then
+			gst_conf+=( -D${plugin}=enabled )
+		else
+			gst_conf+=( -D${plugin}=disabled )
+		fi
+	done
+
+	if grep -q "option('orc'" "${EMESON_SOURCE}"/meson_options.txt ; then
+		if in_iuse orc ; then
+			gst_conf+=( -Dorc=$(usex orc enabled disabled) )
+		else
+			gst_conf+=( -Dorc=disabled )
+			eqawarn "QA: IUSE=orc is missing while plugin supports it"
+		fi
+	else
+		if in_iuse orc ; then
+			eqawarn "QA: IUSE=orc is present while plugin does not support it"
+		fi
+	fi
+
+	if grep -q "option('introspection'" "${EMESON_SOURCE}"/meson_options.txt ; then
+		if in_iuse introspection ; then
+			gst_conf+=( -Dintrospection=$(multilib_native_usex introspection enabled disabled) )
+		else
+			gst_conf+=( -Dintrospection=disabled )
+			eqawarn "QA: IUSE=introspection is missing while plugin supports it"
+		fi
+	else
+		if in_iuse introspection ; then
+			eqawarn "QA: IUSE=introspection is present while plugin does not support it"
+		fi
+	fi
+
+	if grep -q "option('maintainer-mode'" "${EMESON_SOURCE}"/meson_options.txt ; then
+		gst_conf+=( -Dmaintainer-mode=disabled )
+	fi
+
+	if grep -q "option('schemas-compile'" "${EMESON_SOURCE}"/meson_options.txt ; then
+		gst_conf+=( -Dschemas-compile=disabled )
+	fi
+
+	if grep -q "option('examples'" "${EMESON_SOURCE}"/meson_options.txt ; then
+		gst_conf+=( -Dexamples=disabled )
+	fi
+
+	if [[ ${PN} == ${GST_ORG_MODULE} ]]; then
+		if grep -q "option('nls'" "${EMESON_SOURCE}"/meson_options.txt ; then
+			gst_conf+=( $(meson_feature nls) )
+		fi
+
+		if grep -q "option('tests'" "${EMESON_SOURCE}"/meson_options.txt ; then
+			gst_conf+=( $(meson_feature test tests) )
+		fi
+	fi
+
+	einfo "Configuring to build ${GST_PLUGINS_ENABLED} plugin(s) ..."
+	gst_conf+=(
+		-Dpackage-name="Gentoo GStreamer ebuild"
+		-Dpackage-origin="https://www.gentoo.org"
+		"${@}"
+	)
+	meson_src_configure "${gst_conf[@]}"
+}
+
+
+# @FUNCTION: _gstreamer_get_target_filename
+# @INTERNAL
+# @DESCRIPTION:
+# Looks for first argument being present as a substring in install targets
+# Got ported from python to perl for greater language-stability
+_gstreamer_get_target_filename() {
+	cat >"${WORKDIR}/_gstreamer_get_target_filename.pl" <<"EOF"
+#!/usr/bin/env perl
+use strict;
+use utf8;
+use JSON::PP;
+
+open(my $targets_file, '<:encoding(UTF-8)', 'meson-info/intro-targets.json') || die $!;
+my $data = decode_json <$targets_file>;
+close($targets_file) || die $!;
+
+if(!$ARGV[0]) {
+	die "Requires a target as argument";
+}
+
+foreach my $target (@{$data}) {
+	if($target->{'installed'}
+		and (index($target->{'filename'}[0], $ARGV[0]) != -1)
+	) {
+		printf "%s:%s\n", $target->{'filename'}[0], $target->{'install_filename'}[0];
+	}
+}
+EOF
+
+	chmod +x "${WORKDIR}/_gstreamer_get_target_filename.pl" || die
+
+	perl "${WORKDIR}/_gstreamer_get_target_filename.pl" $@ \
+		|| die "Failed to extract target filenames from meson-info"
+}
+
+# @FUNCTION: gstreamer_multilib_src_compile
+# @DESCRIPTION:
+# Compiles requested gstreamer plugin.
+gstreamer_multilib_src_compile() {
+	if [[ "${PN}" == "${GST_ORG_MODULE}" ]]; then
+		eninja
+	else
+		local plugin_dir plugin
+
+		for plugin_dir in ${GST_PLUGINS_BUILD_DIR} ; do
+			plugin=$(_gstreamer_get_target_filename $(gstreamer_get_plugin_dir ${plugin_dir}))
+			plugin_path="${plugin%%:*}"
+			eninja "${plugin_path/"${BUILD_DIR}/"}"
+		done
+	fi
+}
+
+# @FUNCTION: gstreamer_multilib_src_test
+# @DESCRIPTION:
+# Tests the gstreamer plugin (non-split)
+gstreamer_multilib_src_test() {
+	GST_GL_WINDOW=x11 virtx eninja test
+}
+
+# @FUNCTION: gstreamer_multilib_src_install
+# @DESCRIPTION:
+# Installs requested gstreamer plugin.
+gstreamer_multilib_src_install() {
+	if [[ "${PN}" == "${GST_ORG_MODULE}" ]]; then
+		DESTDIR="${D}" eninja install
+	else
+		local plugin_dir plugin
+
+		for plugin_dir in ${GST_PLUGINS_BUILD_DIR} ; do
+			for plugin in $(_gstreamer_get_target_filename $(gstreamer_get_plugin_dir ${plugin_dir})); do
+				local install_filename="${plugin##*:}"
+				insinto "${install_filename%/*}"
+				doins "${plugin%%:*}"
+			done
+		done
+	fi
+}
+
+# @FUNCTION: gstreamer_multilib_src_install_all
+# @DESCRIPTION:
+# Installs documentation for requested gstreamer plugin
+gstreamer_multilib_src_install_all() {
+	local plugin_dir
+
+	for plugin_dir in ${GST_PLUGINS_BUILD_DIR} ; do
+		local dir=$(gstreamer_get_plugin_dir ${plugin_dir})
+		[[ -e ${dir}/README ]] && dodoc "${dir}"/README
+	done
+}