eclass/cargo: support cargo dependency vendoring

Add support for newer dependency vendoring which allows us to download
the dependencies with the package manager and just have cargo use that
to compile the package.

Signed-off-by: Doug Goldstein <cardoe@gentoo.org>

1 files changed, 38 insertions, 19 deletions

diff --git a/eclass/cargo.eclass b/eclass/cargo.eclass
index 19c66c8d4aa8..f2b2b12149d1 100644
--- a/eclass/cargo.eclass
+++ b/eclass/cargo.eclass
@@ -22,11 +22,7 @@ EXPORT_FUNCTIONS src_unpack src_compile src_install
 IUSE="${IUSE} debug"
 
 ECARGO_HOME="${WORKDIR}/cargo_home"
-#ECARGO_REPO="github.com-88ac128001ac3a9a"
-ECARGO_REPO="github.com-1ecc6299db9ec823"
-ECARGO_INDEX="${ECARGO_HOME}/registry/index/${ECARGO_REPO}"
-ECARGO_SRC="${ECARGO_HOME}/registry/src/${ECARGO_REPO}"
-ECARGO_CACHE="${ECARGO_HOME}/registry/cache/${ECARGO_REPO}"
+ECARGO_VENDOR="${ECARGO_HOME}/gentoo"
 
 # @FUNCTION: cargo_crate_uris
 # @DESCRIPTION:
@@ -47,18 +43,29 @@ cargo_crate_uris() {
 cargo_src_unpack() {
 	debug-print-function ${FUNCNAME} "$@"
 
-	mkdir -p "${ECARGO_INDEX}" || die
-	mkdir -p "${ECARGO_CACHE}" || die
-	mkdir -p "${ECARGO_SRC}" || die
+	mkdir -p "${ECARGO_VENDOR}" || die
 	mkdir -p "${S}" || die
 
 	local archive
 	for archive in ${A}; do
 		case "${archive}" in
 			*.crate)
-				ebegin "Unpacking ${archive}"
-				cp "${DISTDIR}"/${archive} "${ECARGO_CACHE}/" || die
-				tar -xf "${DISTDIR}"/${archive} -C "${ECARGO_SRC}/" || die
+				ebegin "Loading ${archive} into Cargo registry"
+				tar -xf "${DISTDIR}"/${archive} -C "${ECARGO_VENDOR}/" || die
+				# generate sha256sum of the crate itself as cargo needs this
+				shasum=$(sha256sum "${DISTDIR}"/${archive} | cut -d ' ' -f 1)
+				pkg=$(basename ${archive} .crate)
+				cat <<- EOF > ${ECARGO_VENDOR}/${pkg}/.cargo-checksum.json
+				{
+					"package": "${shasum}",
+					"files": {}
+				}
+				EOF
+				# if this is our target package we need it in ${WORKDIR} too
+				# to make ${S} (and handle any revisions too)
+				if [[ ${P} == ${pkg}* ]]; then
+					tar -xf "${DISTDIR}"/${archive} -C "${WORKDIR}" || die
+				fi
 				eend $?
 				;;
 			cargo-snapshot*)
@@ -70,18 +77,29 @@ cargo_src_unpack() {
 				touch "${S}"/target/snapshot/bin/cargo || die
 				eend $?
 				;;
-			cargo-registry*)
-				ebegin "Unpacking ${archive}"
-				tar -xzf "${DISTDIR}"/${archive} -C "${ECARGO_INDEX}" --strip-components 1 || die
-				# prevent cargo from attempting to download this again
-				touch "${ECARGO_INDEX}"/.cargo-index-lock || die
-				eend $?
-				;;
 			*)
 				unpack ${archive}
 				;;
 		esac
 	done
+
+	cargo_gen_config
+}
+
+# @FUNCTION: cargo_gen_config
+# @DESCRIPTION:
+# Generate the $CARGO_HOME/config necessary to use our local registry
+cargo_gen_config() {
+	debug-print-function ${FUNCNAME} "$@"
+
+	cat <<- EOF > ${ECARGO_HOME}/config
+	[source.gentoo]
+	directory = "${ECARGO_VENDOR}"
+
+	[source.crates-io]
+	replace-with = "gentoo"
+	local-registry = "/nonexistant"
+	EOF
 }
 
 # @FUNCTION: cargo_src_compile
@@ -92,7 +110,8 @@ cargo_src_compile() {
 
 	export CARGO_HOME="${ECARGO_HOME}"
 
-	cargo build -v $(usex debug "" --release)
+	cargo build -v $(usex debug "" --release) \
+		|| die "cargo build failed"
 }
 
 # @FUNCTION: cargo_src_install