[gentoo-dev] [PATCH v2 3/5] meson.eclass: refactor src_configure into a setter function

[Eli Schwartz <eschwartz93@gmail.com>]

This is necessary in order to get at the implementation of `meson setup`
from other eclasses, which do not simply call meson_src_configure. The
intended use case is distutils-r1, where a python build backend wraps
meson and needs its arguments while calling meson on its own.

This allows distutils-r1 to invoke `setup_meson_src_configure` followed
by gpep517, and get access to:
- the preparation which needs to be done, including setting up the
  environment
- the array of setup arguments

Signed-off-by: Eli Schwartz <eschwartz93@gmail.com>
---

v2: new patch

 eclass/meson.eclass | 49 +++++++++++++++++++++++++++------------------
 1 file changed, 29 insertions(+), 20 deletions(-)

diff --git a/eclass/meson.eclass b/eclass/meson.eclass
index e1963e552710..620381ed7079 100644
--- a/eclass/meson.eclass
+++ b/eclass/meson.eclass
@@ -277,15 +277,12 @@ meson_feature() {
 	usex "$1" "-D${2-$1}=enabled" "-D${2-$1}=disabled"
 }
 
-# @FUNCTION: meson_src_configure
-# @USAGE: [extra meson arguments]
+# @FUNCTION: setup_meson_src_configure
 # @DESCRIPTION:
-# This is the meson_src_configure function.
-meson_src_configure() {
-	debug-print-function ${FUNCNAME} "$@"
-
-	[[ -n "${NINJA_DEPEND}" ]] || ewarn "Unknown value '${NINJA}' for \${NINJA}"
-
+# Calculate the command line which meson should use, and other relevant
+# variables. Invoke via "${mesonargs[@]}" in the calling environment.
+# This function is called from meson_src_configure.
+setup_meson_src_configure() {
 	local ltoflags=()
 	if tc-is-lto; then
 		# We want to connect -flto in *FLAGS to the dedicated meson option,
@@ -344,8 +341,7 @@ meson_src_configure() {
 		: "${BUILD_PKG_CONFIG_PATH:=${PKG_CONFIG_PATH}}"
 	fi
 
-	local mesonargs=(
-		meson setup
+	mesonargs=(
 		--libdir "$(get_libdir)"
 		--localstatedir "${EPREFIX}/var/lib"
 		--prefix "${EPREFIX}/usr"
@@ -390,12 +386,6 @@ meson_src_configure() {
 
 		# Arguments from user
 		"${MYMESONARGS[@]}"
-
-		# Source directory
-		"${EMESON_SOURCE:-${S}}"
-
-		# Build directory
-		"${BUILD_DIR}"
 	)
 
 	# Used by symbolextractor.py
@@ -407,13 +397,32 @@ meson_src_configure() {
 	python_export_utf8_locale
 
 	# https://bugs.gentoo.org/721786
-	local -x BOOST_INCLUDEDIR="${BOOST_INCLUDEDIR-${EPREFIX}/usr/include}"
-	local -x BOOST_LIBRARYDIR="${BOOST_LIBRARYDIR-${EPREFIX}/usr/$(get_libdir)}"
+	export BOOST_INCLUDEDIR="${BOOST_INCLUDEDIR-${EPREFIX}/usr/include}"
+	export BOOST_LIBRARYDIR="${BOOST_LIBRARYDIR-${EPREFIX}/usr/$(get_libdir)}"
+}
+
+# @FUNCTION: meson_src_configure
+# @USAGE: [extra meson arguments]
+# @DESCRIPTION:
+# This is the meson_src_configure function.
+meson_src_configure() {
+	debug-print-function ${FUNCNAME} "$@"
+
+	[[ -n "${NINJA_DEPEND}" ]] || ewarn "Unknown value '${NINJA}' for \${NINJA}"
 
 	(
+		setup_meson_src_configure "$@"
+		mesonargs+=(
+			# Source directory
+			"${EMESON_SOURCE:-${S}}"
+
+			# Build directory
+			"${BUILD_DIR}"
+		)
+
 		export -n {C,CPP,CXX,F,OBJC,OBJCXX,LD}FLAGS PKG_CONFIG_{LIBDIR,PATH}
-		echo "${mesonargs[@]}" >&2
-		"${mesonargs[@]}"
+		echo meson setup "${mesonargs[@]}" >&2
+		meson setup "${mesonargs[@]}"
 	) || die
 }
 
-- 
2.43.0