dev-lang/rust: bump to 1.45.0

move a lot of deps to BDEPEND

Bug: https://bugs.gentoo.org/703744
Bug: https://bugs.gentoo.org/683420
Bug: https://bugs.gentoo.org/731764
Package-Manager: Portage-2.3.103, Repoman-2.3.23
Signed-off-by: Georgy Yakovlev <gyakovlev@gentoo.org>

2 files changed, 518 insertions, 0 deletions

diff --git a/dev-lang/rust/Manifest b/dev-lang/rust/Manifest
index 14c802240e22..cdb786770d79 100644
--- a/dev-lang/rust/Manifest
+++ b/dev-lang/rust/Manifest
@@ -54,7 +54,22 @@ DIST rust-1.43.1-powerpc64le-unknown-linux-gnu.tar.xz 112921244 BLAKE2B 9fa67664
 DIST rust-1.43.1-s390x-unknown-linux-gnu.tar.xz 119547480 BLAKE2B 8ce0d64e2d47f23cb927f3ea3a0f469e3cafc191ac1d47e580bce6cf0b35887484542f7d1b857d9bace5f696a072adb7e17e8c5f64af9bf1fbcc305707a15f9f SHA512 f087e50a91b1cc4a12bf15aea1cefbda9b89518febcecc0d56ea7d0a6a682be06cff7777d0a0b4812e96f3fb3295e7799bf200c1599c88cb7083a78d5002f14a
 DIST rust-1.43.1-x86_64-unknown-linux-gnu.tar.xz 112817212 BLAKE2B c6153889d9872ed5a60bfc43bc8c98e71654fffdd79ce775c3eb4376ed4714c5532e6aaecb769e447f3ae0bb7a11aed75754a5e879404742cb0813080dcf67eb SHA512 2fc573ca2826d9f03044f746ae4d7715b4e31b9ac933289607aa3449a538bb4dfd519540576a1d0d286c0d754a7ba6ce38beef6aded1090d3af3091b6ba2a9ee
 DIST rust-1.43.1-x86_64-unknown-linux-musl.tar.xz 103345832 BLAKE2B c16930854ea5e825e1338fdde3966e24d3505230891ab4e10160c5482298996768d8cee9890eadd486bfca41ebd5c9f38f7b7ead35a7848e59e409df8eaf9bdf SHA512 9f6ce2a5eaf98dc20b4ed88dbe60e8fb014ef3e7e82f5c31a28cf0f916d996271929cadeaf39a869f548aafb311f022acb408d51d4312c849c71843bc37ca202
+DIST rust-1.44.1-aarch64-unknown-linux-gnu.tar.xz 101259004 BLAKE2B c00274660698c5e980a6fe28839f96783989bc5f102025a5e2b63466928f697afc3c70ff8efd00b525ea4b88823585e801690e6c05b246abf5600af80f911a07 SHA512 97a67addb5995f504d7326a500d1b40c52cc6e6e6f6e946adabcf825ce9b64272232a24bc30ce36e3ea63ccda4b980f3b7b61b0e88a8554f021b731ad79a35f1
+DIST rust-1.44.1-arm-unknown-linux-gnueabi.tar.xz 107474900 BLAKE2B 1b21f28b12507cba83ede592670b715365b1ca1fa311dc70108404bc7fa199914716cf7e5560a682ccf4f37bfaf91357f547456a032b4914e75543fdb7e8e84f SHA512 5bb406cc999317a15988b434c3de53d11e3823359fd3dd798de8195fc2e7e7b32830c7cceb1cb7089f47b333346c42fd4153ba1b441799d89fa27207383b7043
+DIST rust-1.44.1-arm-unknown-linux-gnueabihf.tar.xz 105267436 BLAKE2B 6e4c13028dc1751970b04b99db64be6e1ddbbc3b754318e3eabe03e7ae65031c4a5ed87582ec0ffa605a7ac69bee32c5fd48c6dcd84f298d73199a7f7d1c731f SHA512 fffadfc6d8317512ed50df97785a7d0094f59b9465ce5e762c45d6a3a484cdb3c04a72ac49c3d61abad898503378d841ed6abaa16a072aa6adc9069619e26a49
+DIST rust-1.44.1-armv7-unknown-linux-gnueabihf.tar.xz 109724880 BLAKE2B b53eb6441c18c98c12c6e181b499b7e482c9f4eb5e244f6a1fc694371800fe94ec15a9a60ee5e0695e488d3a9d925bc6ef946c23d084e01b43c2bc659874b713 SHA512 6a7bafba9c4d60bb13fac2a7683702352d3a04df24674f993952e9d872b9def47b5f8070925798343f5fd2f83775377ba2ddcf188b8500ec518fe44eb67483eb
+DIST rust-1.44.1-i686-unknown-linux-gnu.tar.xz 124915068 BLAKE2B 5de966d60f8e58e435e29aa63b906e117e7d73897ccdcfa692d0e582cf096c200b8c4f9a6ba76397f6ad29cfafaa4841503cf22764ac9517860bf46172539605 SHA512 fc6259c7b55a1ee457e444885c9604d2bcbe937833bdca9bb70fbfb230032c1e497ea04aa5edd761eefe5b48d34928998c6935563e76c82eccb7a03b1d5aaa45
+DIST rust-1.44.1-mips-unknown-linux-gnu.tar.xz 94537064 BLAKE2B 39a829ad9cea0303599cf8de2654f5fc7291af0a41d03c72cc0f1472162347b7ebf4a2cb7b2ad6e64bbca3b7d39ac7d2843d16a9ad205b8b14be48139b84b34f SHA512 e2284a0cfe38b85e41e5c712ca89b2099617a8836695628c509075772d23314b234730bcbeae060c1fc664bf193286493dcd546f672a6053428304e099acd41d
+DIST rust-1.44.1-mips64-unknown-linux-gnuabi64.tar.xz 102649752 BLAKE2B bc57e6a532c7806b6e302ab31f2dde7b88496bbadfec7185b8c389fa9cfd4a2baf18dccfe4c1b69d0914b7f481813dc4db72ad5944a9d67000493122228505bf SHA512 ef69913b8f448a41b3454bfda2e120ae58233349b215b9419e6f0bf6e41528521cd7904b02c97ed55fef029c7687d8cf9d3ce21fbd09ef771e961e24d3f2547f
+DIST rust-1.44.1-mipsel-unknown-linux-gnu.tar.xz 100002200 BLAKE2B 5befcaab66a965dd9c2dcc5636050099a461270d70102a0a1c489c3a1b721c432d337dec514b685f2710ea4c9e4fe2b9250cd88c55034c82da9b970b8ebdedb6 SHA512 4fef660c68a265da12863b07bcaa1f0fc19d4e377e2404c504047ea1f407e9b47f29f8947f707cfb0fc75216fa44d123c86ed07e261db70d48017cf93b54dfdb
+DIST rust-1.44.1-powerpc-unknown-linux-gnu.tar.xz 97722508 BLAKE2B 98a9ae4dc0c0df087bee8bd5c875e63a54b2ca71465386e19f425a9c35108abe9f04b222ef51f8cbeba3d781ae85f9fb4c612b86f263773ff868ae24866c7df7 SHA512 011dcbdfc8847f6a6004349665207ba89ec84a37d649c082588a1256ff992e374f4bad3d1930270a89d35c2386a16c18be301725b44e46dcc8501f0a98d761f5
+DIST rust-1.44.1-powerpc64-unknown-linux-gnu.tar.xz 107393564 BLAKE2B e3c2d6ae58585e020c4d1129ce26b19441b7f7e5df14d80290855f2931febdf4d2b4c30c4bcdc1747b61b4d1263194777ef7193bdc7c7dc4ce3eab91b137f0a0 SHA512 ff6b96b34b9b7dff362f6f2dcdf3b55fe7f2f349692434de5a11b8ca9956e06dbc6531c2457b4d43d5d19851ecbdbb0108e9f7eb449d9c965ed308ddbd0775a2
+DIST rust-1.44.1-powerpc64le-unknown-linux-gnu.tar.xz 112429740 BLAKE2B 10252623cd291c0e95238ac038544b989d94affd2edf173dce4f10847910aaabec99f8574f3141d4af4115ab6e9ed0536b87c8e8c6c899641e585efc9a3c516d SHA512 cf54b52581d393c2694fbefab90c62aa1f57ece8b200bfd656000950005554fda6fc0145af3aca0c526b8e43b100b8efe632929b6c0c1a4c4f4ce6dde4097283
+DIST rust-1.44.1-s390x-unknown-linux-gnu.tar.xz 119312728 BLAKE2B f5e3209990d3cc0181a200448e4bcbf1f6754847cfc36d7355e191fd49e239d3e0c002310743fd063241c5dec47da3a0776c361241facbcc4a1f1e9254eb805d SHA512 84c6ed736bb7d0c10aaceeb2c2c3c97f6188fd7d7f4466c8ef35ffc591d6bde3b273a0d62d50e60f184ccd81c96a31ed2e610e82fb9ed9efd574e4c5a5f25d26
+DIST rust-1.44.1-x86_64-unknown-linux-gnu.tar.xz 112133992 BLAKE2B c0af6bf1417bbb69be9f552f60805eb0a5f530b667ca2bbd04db9d567f1eb467a9e72912062a3c22d3922c29809258637dd7568c29e461dbeb5d17aa0699dd45 SHA512 540761fd5246f4a48a7606ac0220f0d61963473b57ef703696871dc23fda8154d45351b8e81018d15899c386b44e43b05028cc797d495e9dc46f127fbea7f093
+DIST rust-1.44.1-x86_64-unknown-linux-musl.tar.xz 117456616 BLAKE2B fd2752cf867e1ff701e624caf602fe7a29b47c64e633508e91da1a1b2321f5531441b84cc9f0ad159ef399d38628d60e59f8b7a99e5427df928abceb24f937f2 SHA512 05ca3e07001746511c5fcb5122f487205ffaee771805b0219db018b350d67945f5ab4b0b2cf98b7e7832b53365e3932fef37506a65ecaaf624d0bb8d43cf8427
 DIST rustc-1.41.1-src.tar.xz 93754192 BLAKE2B 235ece650d0c75e1c8700ce73d3811997cd0d827b850a6dd435a269f3f86d85849d54755ea346c5ddcbe0d1224836fd78213f6abeab4a9a8c4c3e2d8a05ff7b4 SHA512 ef33565c9cf4e27ca279072bfed3301e0276c09407d49727640746ba78d289de285278d64b1cce8708461fd6c97c7ab2ea8d56e7a4c4a23b2e66e2d164c35fc9
 DIST rustc-1.42.0-src.tar.xz 94186592 BLAKE2B 82298ef3da44188546bb945bcbfc1af630e6a4466b643667da08a04a33c6417afd68fc86302bdd22ab36c208fdb13cbc479e762d1217c05507bbfeb13bfbef7e SHA512 589bfdc92deedd33b8ea0df7f7c64c2a9a085fbea64936eff92f81e812309c060ed7a7adc96f6010d7adf62a68434a230da0f6c5b3540df4e0a5c6de05a31b16
 DIST rustc-1.43.1-src.tar.xz 94405276 BLAKE2B 8679fe937abc4f758f3e35c2542d57cc1ad0bb72111597881873b30779b6e7b6711baa52493cb5ff954bf9cd31367b36db4e4fc8676635026059197a33659048 SHA512 24bb01237b1f3f5412109290bb4406b9742cf8956162f4090a98ed3a59a6e2e8dda399452bec1c93c8afdcf5effd98e4825e7f218238e0e88735c1ff4a5b385f
 DIST rustc-1.44.1-src.tar.xz 94756856 BLAKE2B 60f536c3ba0fa1fec4b6333ee57809ee5226090ad5041c14a136b4356ff3b898062e06c3fe54effe873e27931ac8fcb902cd48a38615a8de7eebc6ecb3bdc2bd SHA512 1c17002edae844a710db9b144c17171416330dc565343c65af8a6e112fb61555e2025bb4cf33cac1229d7df689e6ff8858b91ae00552400ccacafaf1de11849b
+DIST rustc-1.45.0-src.tar.xz 98677856 BLAKE2B 2558ba9444a53268de4f1604f13e701077a27e9480c97732a30706d656682672c17f87d8c015da3b839ed3b38081ef8d132bbab3522911bf9b50f018367e6ec7 SHA512 ff049eb65b36e6c64531d56251ebd446336a782f26504eccf375df1c22fa94b5f18e84660cef423edb815c1b31a1a7c9e57aea4aa0779576f3b0d7e81e19427b
diff --git a/dev-lang/rust/rust-1.45.0.ebuild b/dev-lang/rust/rust-1.45.0.ebuild
new file mode 100644
index 000000000000..12fe630a0da5
--- /dev/null
+++ b/dev-lang/rust/rust-1.45.0.ebuild
@@ -0,0 +1,503 @@
+# Copyright 1999-2020 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=7
+
+PYTHON_COMPAT=( python3_{6,7,8} )
+
+inherit bash-completion-r1 check-reqs estack flag-o-matic llvm multiprocessing multilib-build python-any-r1 rust-toolchain toolchain-funcs
+
+if [[ ${PV} = *beta* ]]; then
+	betaver=${PV//*beta}
+	BETA_SNAPSHOT="${betaver:0:4}-${betaver:4:2}-${betaver:6:2}"
+	MY_P="rustc-beta"
+	SLOT="beta/${PV}"
+	SRC="${BETA_SNAPSHOT}/rustc-beta-src.tar.xz"
+else
+	ABI_VER="$(ver_cut 1-2)"
+	SLOT="stable/${ABI_VER}"
+	MY_P="rustc-${PV}"
+	SRC="${MY_P}-src.tar.xz"
+	KEYWORDS="~amd64 ~arm ~arm64 ~ppc64 ~x86"
+fi
+
+RUST_STAGE0_VERSION="1.$(($(ver_cut 2) - 1)).1"
+
+DESCRIPTION="Systems programming language from Mozilla"
+HOMEPAGE="https://www.rust-lang.org/"
+
+SRC_URI="
+	https://static.rust-lang.org/dist/${SRC} -> rustc-${PV}-src.tar.xz
+	!system-bootstrap? ( $(rust_all_arch_uris rust-${RUST_STAGE0_VERSION}) )
+"
+
+ALL_LLVM_TARGETS=( AArch64 AMDGPU ARM BPF Hexagon Lanai Mips MSP430
+	NVPTX PowerPC RISCV Sparc SystemZ WebAssembly X86 XCore )
+ALL_LLVM_TARGETS=( "${ALL_LLVM_TARGETS[@]/#/llvm_targets_}" )
+LLVM_TARGET_USEDEPS=${ALL_LLVM_TARGETS[@]/%/?}
+
+LICENSE="|| ( MIT Apache-2.0 ) BSD-1 BSD-2 BSD-4 UoI-NCSA"
+
+IUSE="clippy cpu_flags_x86_sse2 debug doc libressl miri nightly parallel-compiler rls rustfmt system-bootstrap system-llvm wasm ${ALL_LLVM_TARGETS[*]}"
+
+# Please keep the LLVM dependency block separate. Since LLVM is slotted,
+# we need to *really* make sure we're not pulling more than one slot
+# simultaneously.
+
+# How to use it:
+# 1. List all the working slots (with min versions) in ||, newest first.
+# 2. Update the := to specify *max* version, e.g. < 11.
+# 3. Specify LLVM_MAX_SLOT, e.g. 10.
+LLVM_DEPEND="
+	|| (
+		sys-devel/llvm:10[${LLVM_TARGET_USEDEPS// /,}]
+		sys-devel/llvm:9[${LLVM_TARGET_USEDEPS// /,}]
+	)
+	<sys-devel/llvm-11:=
+	wasm? ( sys-devel/lld )
+"
+LLVM_MAX_SLOT=10
+
+BOOTSTRAP_DEPEND="|| ( >=dev-lang/rust-1.$(($(ver_cut 2) - 1)) >=dev-lang/rust-bin-1.$(($(ver_cut 2) - 1)) )"
+
+BDEPEND="${PYTHON_DEPS}
+	app-eselect/eselect-rust
+	|| (
+		>=sys-devel/gcc-4.7
+		>=sys-devel/clang-3.5
+	)
+	system-bootstrap? ( ${BOOTSTRAP_DEPEND} )
+	!system-llvm? (
+		dev-util/cmake
+		dev-util/ninja
+	)
+"
+
+# libgit2 should be at least same as bundled into libgit-sys #707746
+DEPEND="
+	>=dev-libs/libgit2-0.99:=
+	net-libs/libssh2:=
+	net-libs/http-parser:=
+	net-misc/curl:=[ssl]
+	sys-libs/zlib:=
+	!libressl? ( dev-libs/openssl:0= )
+	libressl? ( dev-libs/libressl:0= )
+	elibc_musl? ( sys-libs/libunwind )
+	system-llvm? (
+		${LLVM_DEPEND}
+	)
+"
+
+RDEPEND="${DEPEND}
+	app-eselect/eselect-rust
+"
+
+REQUIRED_USE="|| ( ${ALL_LLVM_TARGETS[*]} )
+	miri? ( nightly )
+	parallel-compiler? ( nightly )
+	wasm? ( llvm_targets_WebAssembly )
+	x86? ( cpu_flags_x86_sse2 )
+"
+
+QA_FLAGS_IGNORED="
+	usr/bin/.*-${PV}
+	usr/lib.*/lib.*.so
+	usr/lib/rustlib/.*/codegen-backends/librustc_codegen_llvm-llvm.so
+	usr/lib/rustlib/.*/lib/lib.*.so
+"
+
+QA_SONAME="
+	usr/lib.*/lib.*.so
+	usr/lib.*/librustc_macros.*.s
+"
+
+# tests need a bit more work, currently they are causing multiple
+# re-compilations and somewhat fragile.
+RESTRICT="test"
+
+PATCHES=(
+	"${FILESDIR}"/0012-Ignore-broken-and-non-applicable-tests.patch
+	"${FILESDIR}"/1.44.0-libressl.patch
+)
+
+S="${WORKDIR}/${MY_P}-src"
+
+toml_usex() {
+	usex "$1" true false
+}
+
+pre_build_checks() {
+	CHECKREQS_DISK_BUILD="9G"
+	eshopts_push -s extglob
+	if is-flagq '-g?(gdb)?([1-9])'; then
+		CHECKREQS_DISK_BUILD="15G"
+	fi
+	eshopts_pop
+	check-reqs_pkg_setup
+}
+
+pkg_pretend() {
+	pre_build_checks
+}
+
+pkg_setup() {
+	pre_build_checks
+	python-any-r1_pkg_setup
+
+	# required to link agains system libs, otherwise
+	# crates use bundled sources and compile own static version
+	export LIBGIT2_SYS_USE_PKG_CONFIG=1
+	export LIBSSH2_SYS_USE_PKG_CONFIG=1
+	export PKG_CONFIG_ALLOW_CROSS=1
+
+	if use system-llvm; then
+		llvm_pkg_setup
+
+		local llvm_config="$(get_llvm_prefix "$LLVM_MAX_SLOT")/bin/llvm-config"
+
+		export LLVM_LINK_SHARED=1
+		export RUSTFLAGS="${RUSTFLAGS} -Lnative=$("${llvm_config}" --libdir)"
+	fi
+}
+
+src_prepare() {
+	if ! use system-bootstrap; then
+		local rust_stage0_root="${WORKDIR}"/rust-stage0
+		local rust_stage0="rust-${RUST_STAGE0_VERSION}-$(rust_abi)"
+
+		"${WORKDIR}/${rust_stage0}"/install.sh --disable-ldconfig \
+			--destdir="${rust_stage0_root}" --prefix=/ || die
+	fi
+
+	default
+}
+
+src_configure() {
+	local rust_target="" rust_targets="" arch_cflags
+
+	# Collect rust target names to compile standard libs for all ABIs.
+	for v in $(multilib_get_enabled_abi_pairs); do
+		rust_targets="${rust_targets},\"$(rust_abi $(get_abi_CHOST ${v##*.}))\""
+	done
+	if use wasm; then
+		rust_targets="${rust_targets},\"wasm32-unknown-unknown\""
+		if use system-llvm; then
+			# un-hardcode rust-lld linker for this target
+			# https://bugs.gentoo.org/715348
+			sed -i '/linker:/ s/rust-lld/wasm-ld/' src/librustc_target/spec/wasm32_base.rs || die
+		fi
+	fi
+	rust_targets="${rust_targets#,}"
+
+	local tools="\"cargo\","
+	if use clippy; then
+		tools="\"clippy\",$tools"
+	fi
+	if use miri; then
+		tools="\"miri\",$tools"
+	fi
+	if use rls; then
+		tools="\"rls\",\"analysis\",\"src\",$tools"
+	fi
+	if use rustfmt; then
+		tools="\"rustfmt\",$tools"
+	fi
+
+	local rust_stage0_root
+	if use system-bootstrap; then
+		rust_stage0_root="$(rustc --print sysroot)"
+	else
+		rust_stage0_root="${WORKDIR}"/rust-stage0
+	fi
+
+	rust_target="$(rust_abi)"
+
+	cat <<- EOF > "${S}"/config.toml
+		[llvm]
+		optimize = $(toml_usex !debug)
+		release-debuginfo = $(toml_usex debug)
+		assertions = $(toml_usex debug)
+		ninja = true
+		targets = "${LLVM_TARGETS// /;}"
+		experimental-targets = ""
+		link-shared = $(toml_usex system-llvm)
+		[build]
+		build = "${rust_target}"
+		host = ["${rust_target}"]
+		target = [${rust_targets}]
+		cargo = "${rust_stage0_root}/bin/cargo"
+		rustc = "${rust_stage0_root}/bin/rustc"
+		docs = $(toml_usex doc)
+		compiler-docs = $(toml_usex doc)
+		submodules = false
+		python = "${EPYTHON}"
+		locked-deps = true
+		vendor = true
+		extended = true
+		tools = [${tools}]
+		verbose = 2
+		sanitizers = false
+		profiler = false
+		cargo-native-static = false
+		[install]
+		prefix = "${EPREFIX}/usr"
+		libdir = "lib"
+		docdir = "share/doc/${PF}"
+		mandir = "share/man"
+		[rust]
+		optimize = true
+		debug = $(toml_usex debug)
+		debug-assertions = $(toml_usex debug)
+		debuginfo-level-rustc = 0
+		backtrace = true
+		incremental = false
+		default-linker = "$(tc-getCC)"
+		parallel-compiler = $(toml_usex parallel-compiler)
+		channel = "$(usex nightly nightly stable)"
+		rpath = false
+		verbose-tests = true
+		optimize-tests = $(toml_usex !debug)
+		codegen-tests = true
+		dist-src = false
+		remap-debuginfo = true
+		lld = $(usex system-llvm false $(toml_usex wasm))
+		backtrace-on-ice = true
+		jemalloc = false
+		[dist]
+		src-tarball = false
+	EOF
+
+	for v in $(multilib_get_enabled_abi_pairs); do
+		rust_target=$(rust_abi $(get_abi_CHOST ${v##*.}))
+		arch_cflags="$(get_abi_CFLAGS ${v##*.})"
+
+		cat <<- EOF >> "${S}"/config.env
+			CFLAGS_${rust_target}=${arch_cflags}
+		EOF
+
+		cat <<- EOF >> "${S}"/config.toml
+			[target.${rust_target}]
+			cc = "$(tc-getBUILD_CC)"
+			cxx = "$(tc-getBUILD_CXX)"
+			linker = "$(tc-getCC)"
+			ar = "$(tc-getAR)"
+		EOF
+		# librustc_target/spec/linux_musl_base.rs sets base.crt_static_default = true;
+		if use elibc_musl; then
+			cat <<- EOF >> "${S}"/config.toml
+				crt-static = false
+			EOF
+		fi
+		if use system-llvm; then
+			cat <<- EOF >> "${S}"/config.toml
+				llvm-config = "$(get_llvm_prefix "${LLVM_MAX_SLOT}")/bin/llvm-config"
+			EOF
+		fi
+	done
+	if use wasm; then
+		cat <<- EOF >> "${S}"/config.toml
+			[target.wasm32-unknown-unknown]
+			linker = "$(usex system-llvm lld rust-lld)"
+		EOF
+	fi
+
+	if [[ -n ${I_KNOW_WHAT_I_AM_DOING_CROSS} ]]; then #whitespace intentionally shifted below
+	# experimental cross support
+	# discussion: https://bugs.gentoo.org/679878
+	# TODO: c*flags, clang, system-llvm, cargo.eclass target support
+	# it would be much better if we could split out stdlib
+	# complilation to separate ebuild and abuse CATEGORY to
+	# just install to /usr/lib/rustlib/<target>
+
+	# extra targets defined as a bash array
+	# spec format:  <LLVM target>:<rust-target>:<CTARGET>
+	# best place would be /etc/portage/env/dev-lang/rust
+	# Example:
+	# RUST_CROSS_TARGETS=(
+	#	"AArch64:aarch64-unknown-linux-gnu:aarch64-unknown-linux-gnu"
+	# )
+	# no extra hand holding is done, no target transformations, all
+	# values are passed as-is with just basic checks, so it's up to user to supply correct values
+	# valid rust targets can be obtained with
+	# 	rustc --print target-list
+	# matching cross toolchain has to be installed
+	# matching LLVM_TARGET has to be enabled for both rust and llvm (if using system one)
+	# only gcc toolchains installed with crossdev are checked for now.
+
+	# BUG: we can't pass host flags to cross compiler, so just filter for now
+	# BUG: this should be more fine-grained.
+	filter-flags '-mcpu=*' '-march=*' '-mtune=*'
+
+	local cross_target_spec
+	for cross_target_spec in "${RUST_CROSS_TARGETS[@]}";do
+		# extracts first element form <LLVM target>:<rust-target>:<CTARGET>
+		local cross_llvm_target="${cross_target_spec%%:*}"
+		# extracts toolchain triples, <rust-target>:<CTARGET>
+		local cross_triples="${cross_target_spec#*:}"
+		# extracts first element after before : separator
+		local cross_rust_target="${cross_triples%%:*}"
+		# extracts last element after : separator
+		local cross_toolchain="${cross_triples##*:}"
+		use llvm_targets_${cross_llvm_target} || die "need llvm_targets_${cross_llvm_target} target enabled"
+		command -v ${cross_toolchain}-gcc > /dev/null 2>&1 || die "need ${cross_toolchain} cross toolchain"
+
+		cat <<- EOF >> "${S}"/config.toml
+			[target.${cross_rust_target}]
+			cc = "${cross_toolchain}-gcc"
+			cxx = "${cross_toolchain}-g++"
+			linker = "${cross_toolchain}-gcc"
+			ar = "${cross_toolchain}-ar"
+		EOF
+		if use system-llvm; then
+			cat <<- EOF >> "${S}"/config.toml
+				llvm-config = "$(get_llvm_prefix "${LLVM_MAX_SLOT}")/bin/llvm-config"
+			EOF
+		fi
+
+		# append cross target to "normal" target list
+		# example 'target = ["powerpc64le-unknown-linux-gnu"]'
+		# becomes 'target = ["powerpc64le-unknown-linux-gnu","aarch64-unknown-linux-gnu"]'
+
+		rust_targets="${rust_targets},\"${cross_rust_target}\""
+		sed -i "/^target = \[/ s#\[.*\]#\[${rust_targets}\]#" config.toml || die
+
+		ewarn
+		ewarn "Enabled ${cross_rust_target} rust target"
+		ewarn "Using ${cross_toolchain} cross toolchain"
+		ewarn
+		if ! has_version -b 'sys-devel/binutils[multitarget]' ; then
+			ewarn "'sys-devel/binutils[multitarget]' is not installed"
+			ewarn "'strip' will be unable to strip cross libraries"
+			ewarn "cross targets will be installed with full debug information"
+			ewarn "enable 'multitarget' USE flag for binutils to be able to strip object files"
+			ewarn
+			ewarn "Alternatively llvm-strip can be used, it supports stripping any target"
+			ewarn "define STRIP=\"llvm-strip\" to use it (experimental)"
+			ewarn
+		fi
+	done
+	fi # I_KNOW_WHAT_I_AM_DOING_CROSS
+
+	einfo "Rust configured with the following settings:"
+	cat "${S}"/config.toml || die
+}
+
+src_compile() {
+	env $(cat "${S}"/config.env) RUST_BACKTRACE=1\
+		"${EPYTHON}" ./x.py build -vv --config="${S}"/config.toml -j$(makeopts_jobs) || die
+}
+
+src_test() {
+	env $(cat "${S}"/config.env) RUST_BACKTRACE=1\
+		"${EPYTHON}" ./x.py test -vv --config="${S}"/config.toml -j$(makeopts_jobs) --no-doc --no-fail-fast \
+		src/test/codegen \
+		src/test/codegen-units \
+		src/test/compile-fail \
+		src/test/incremental \
+		src/test/mir-opt \
+		src/test/pretty \
+		src/test/run-fail \
+		src/test/run-make \
+		src/test/run-make-fulldeps \
+		src/test/ui \
+		src/test/ui-fulldeps || die
+}
+
+src_install() {
+	env $(cat "${S}"/config.env) DESTDIR="${D}" \
+		"${EPYTHON}" ./x.py install -vv --config="${S}"/config.toml || die
+
+	# bug #689562, #689160
+	rm "${D}/etc/bash_completion.d/cargo" || die
+	rmdir "${D}"/etc{/bash_completion.d,} || die
+	dobashcomp build/tmp/dist/cargo-image/etc/bash_completion.d/cargo
+
+	mv "${ED}/usr/bin/rustc" "${ED}/usr/bin/rustc-${PV}" || die
+	mv "${ED}/usr/bin/rustdoc" "${ED}/usr/bin/rustdoc-${PV}" || die
+	mv "${ED}/usr/bin/rust-gdb" "${ED}/usr/bin/rust-gdb-${PV}" || die
+	mv "${ED}/usr/bin/rust-gdbgui" "${ED}/usr/bin/rust-gdbgui-${PV}" || die
+	mv "${ED}/usr/bin/rust-lldb" "${ED}/usr/bin/rust-lldb-${PV}" || die
+	mv "${ED}/usr/bin/cargo" "${ED}/usr/bin/cargo-${PV}" || die
+	if use clippy; then
+		mv "${ED}/usr/bin/clippy-driver" "${ED}/usr/bin/clippy-driver-${PV}" || die
+		mv "${ED}/usr/bin/cargo-clippy" "${ED}/usr/bin/cargo-clippy-${PV}" || die
+	fi
+	if use miri; then
+		mv "${ED}/usr/bin/miri" "${ED}/usr/bin/miri-${PV}" || die
+		mv "${ED}/usr/bin/cargo-miri" "${ED}/usr/bin/cargo-miri-${PV}" || die
+	fi
+	if use rls; then
+		mv "${ED}/usr/bin/rls" "${ED}/usr/bin/rls-${PV}" || die
+	fi
+	if use rustfmt; then
+		mv "${ED}/usr/bin/rustfmt" "${ED}/usr/bin/rustfmt-${PV}" || die
+		mv "${ED}/usr/bin/cargo-fmt" "${ED}/usr/bin/cargo-fmt-${PV}" || die
+	fi
+
+	# Move public shared libs to abi specific libdir
+	# Private and target specific libs MUST stay in /usr/lib/rustlib/${rust_target}/lib
+	if [[ $(get_libdir) != lib ]]; then
+		dodir /usr/$(get_libdir)
+		mv "${ED}/usr/lib"/*.so "${ED}/usr/$(get_libdir)/" || die
+	fi
+
+	dodoc COPYRIGHT
+	rm "${ED}/usr/share/doc/${P}"/*.old || die
+	rm "${ED}/usr/share/doc/${P}/LICENSE-APACHE" || die
+	rm "${ED}/usr/share/doc/${P}/LICENSE-MIT" || die
+
+	# note: eselect-rust adds EROOT to all paths below
+	cat <<-EOF > "${T}/provider-${P}"
+		/usr/bin/cargo
+		/usr/bin/rustdoc
+		/usr/bin/rust-gdb
+		/usr/bin/rust-gdbgui
+		/usr/bin/rust-lldb
+	EOF
+	if use clippy; then
+		echo /usr/bin/clippy-driver >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-clippy >> "${T}/provider-${P}"
+	fi
+	if use miri; then
+		echo /usr/bin/miri >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-miri >> "${T}/provider-${P}"
+	fi
+	if use rls; then
+		echo /usr/bin/rls >> "${T}/provider-${P}"
+	fi
+	if use rustfmt; then
+		echo /usr/bin/rustfmt >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-fmt >> "${T}/provider-${P}"
+	fi
+
+	insinto /etc/env.d/rust
+	doins "${T}/provider-${P}"
+}
+
+pkg_postinst() {
+	eselect rust update --if-unset
+
+	elog "Rust installs a helper script for calling GDB and LLDB,"
+	elog "for your convenience it is installed under /usr/bin/rust-{gdb,lldb}-${PV}."
+
+	if has_version app-editors/emacs; then
+		elog "install app-emacs/rust-mode to get emacs support for rust."
+	fi
+
+	if has_version app-editors/gvim || has_version app-editors/vim; then
+		elog "install app-vim/rust-vim to get vim support for rust."
+	fi
+
+	if use elibc_musl; then
+		ewarn "${PN} on *-musl targets is configured with crt-static"
+		ewarn ""
+		ewarn "you will need to set RUSTFLAGS=\"-C target-feature=-crt-static\" in make.conf"
+		ewarn "to use it with portage, otherwise you may see failures like"
+		ewarn "error: cannot produce proc-macro for serde_derive v1.0.98 as the target "
+		ewarn "x86_64-unknown-linux-musl does not support these crate types"
+	fi
+}
+
+pkg_postrm() {
+	eselect rust cleanup
+}