eclass/cargo.eclass: add cargo_src_configure (revised)

simple src_configure implementation inspired by cmake.eclass
plus some nice improvements to eclass.

Closes: https://bugs.gentoo.org/721936
Signed-off-by: Georgy Yakovlev <gyakovlev@gentoo.org>

1 files changed, 87 insertions, 16 deletions

diff --git a/eclass/cargo.eclass b/eclass/cargo.eclass
index ccbf87aa9a6c..6d341601a112 100644
--- a/eclass/cargo.eclass
+++ b/eclass/cargo.eclass
@@ -22,17 +22,29 @@ esac
 
 inherit multiprocessing toolchain-funcs
 
-EXPORT_FUNCTIONS src_unpack src_compile src_install src_test
+EXPORT_FUNCTIONS src_unpack src_configure src_compile src_install src_test
 
 IUSE="${IUSE} debug"
 
 ECARGO_HOME="${WORKDIR}/cargo_home"
 ECARGO_VENDOR="${ECARGO_HOME}/gentoo"
 
-# @ECLASS-VARIABLE: CARGO_INSTALL_PATH
+# @VARIABLE: myfeatures
+# @DEFAULT_UNSET
 # @DESCRIPTION:
-# Allows overriding the default cwd to run cargo install from
-: ${CARGO_INSTALL_PATH:=.}
+# Optional cargo features defined as bash array.
+# Should be defined before calling cargo_src_configure().
+#
+# Example package that has x11 and wayland as features, and disables default.
+# @CODE
+# src_configure() {
+# 	local myfeatures=(
+#		$(usex X x11 '')
+# 		$(usev wayland)
+# 	)
+# 	cargo_src_configure --no-default-features
+# }
+# @CODE
 
 # @FUNCTION: cargo_crate_uris
 # @DESCRIPTION:
@@ -112,6 +124,7 @@ cargo_live_src_unpack() {
 	mkdir -p "${S}" || die
 
 	pushd "${S}" > /dev/null || die
+	# need to specify CARGO_HOME before cargo_gen_config fired
 	CARGO_HOME="${ECARGO_HOME}" cargo fetch || die
 	CARGO_HOME="${ECARGO_HOME}" cargo vendor "${ECARGO_VENDOR}" || die
 	popd > /dev/null || die
@@ -151,6 +164,56 @@ cargo_gen_config() {
 	EOF
 	# honor NOCOLOR setting
 	[[ "${NOCOLOR}" = true || "${NOCOLOR}" = yes ]] && echo "color = 'never'" >> "${ECARGO_HOME}/config"
+
+	export CARGO_HOME="${ECARGO_HOME}"
+}
+
+# @FUNCTION: cargo_src_configure
+# @DESCRIPTION:
+# Configure cargo package features and arguments.
+# Extra positional arguments supplied to this function
+# will be passed to cargo in all phases.
+# Make sure all cargo subcommands support flags passed here.
+#
+# Example for package that explicitly builds only 'baz' binary and
+# enables 'barfeature' and optional 'foo' feature.
+# will pass '--features barfeature --features foo --bin baz'
+# in src_{compile,test,install}
+#
+# @CODE
+# src_configure() {
+#	local myfeatures=(
+#		barfeature
+#		$(usev foo)
+#	)
+# 	cargo_src_configure --bin baz
+# }
+# @CODE
+#
+# In some cases crates may need '--no-default-features' option,
+# as there is no way to disable single feature, except disabling all.
+# It can be passed directly to cargo_src_configure().
+
+cargo_src_configure() {
+	debug-print-function ${FUNCNAME} "$@"
+
+	[[ -z ${myfeatures} ]] && declare -a myfeatures=()
+	local myfeaturestype=$(declare -p myfeatures 2>&-)
+	if [[ "${myfeaturestype}" != "declare -a myfeatures="* ]]; then
+		die "myfeatures must be declared as array"
+	fi
+
+	# transform array from simple feature list
+	# to multiple cargo args:
+	# --features feature1 --features feature2 ...
+	# this format is chosen because 2 other methods of
+	# listing features (space OR comma separated) require
+	# more fiddling with strings we'd like to avoid here.
+	myfeatures=( ${myfeatures[@]/#/--features } )
+
+	readonly ECARGO_ARGS=( ${myfeatures[@]} ${@} ${ECARGO_EXTRA_ARGS} )
+
+	[[ ${ECARGO_ARGS[@]} ]] && einfo "Configured with: ${ECARGO_ARGS[@]}"
 }
 
 # @FUNCTION: cargo_src_compile
@@ -159,25 +222,32 @@ cargo_gen_config() {
 cargo_src_compile() {
 	debug-print-function ${FUNCNAME} "$@"
 
-	export CARGO_HOME="${ECARGO_HOME}"
+	tc-export AR CC CXX
 
-	tc-export AR CC
-
-	cargo build $(usex debug "" --release) "$@" \
-		|| die "cargo build failed"
+	set -- cargo build $(usex debug "" --release) ${ECARGO_ARGS[@]} "$@"
+	einfo "${@}"
+	"${@}" || die "cargo build failed"
 }
 
 # @FUNCTION: cargo_src_install
 # @DESCRIPTION:
 # Installs the binaries generated by cargo
+# In come case workspaces need alternative --path parameter
+# default is '--path ./' if nothing specified.
+# '--path ./somedir' can be passed directly to cargo_src_install()
+
 cargo_src_install() {
 	debug-print-function ${FUNCNAME} "$@"
 
-	cargo install --path ${CARGO_INSTALL_PATH} \
-		--root="${ED}/usr" $(usex debug --debug "") "$@" \
-		|| die "cargo install failed"
-	rm -f "${ED}/usr/.crates.toml"
-	rm -f "${ED}/usr/.crates2.json"
+	set -- cargo install $(has --path ${@} || echo --path ./) \
+		--root "${ED}/usr" \
+		$(usex debug --debug "") \
+		${ECARGO_ARGS[@]} "$@"
+	einfo "${@}"
+	"${@}" || die "cargo install failed"
+
+	rm -f "${ED}/usr/.crates.toml" || die
+	rm -f "${ED}/usr/.crates2.json" || die
 
 	[ -d "${S}/man" ] && doman "${S}/man" || return 0
 }
@@ -188,8 +258,9 @@ cargo_src_install() {
 cargo_src_test() {
 	debug-print-function ${FUNCNAME} "$@"
 
-	cargo test $(usex debug "" --release) "$@" \
-		|| die "cargo test failed"
+	set -- cargo test $(usex debug "" --release) ${ECARGO_ARGS[@]} "$@"
+	einfo "${@}"
+	"${@}" || die "cargo test failed"
 }
 
 fi