dev-lang/rust: bump to 1.49.0

This required a refactor of the gentoo-musl-target-specs.patch, to adopt
the new format of the target() method.

Closes: https://bugs.gentoo.org/768351
Closes: https://github.com/gentoo/gentoo/pull/19060

Signed-off-by: Margarita Manterola <marga@kinvolk.io>
Signed-off-by: Georgy Yakovlev <gyakovlev@gentoo.org>

3 files changed, 794 insertions, 0 deletions

diff --git a/dev-lang/rust/Manifest b/dev-lang/rust/Manifest
index baa93077e9d3..e296ab86edf5 100644
--- a/dev-lang/rust/Manifest
+++ b/dev-lang/rust/Manifest
@@ -40,6 +40,21 @@ DIST rust-1.47.0-powerpc64le-unknown-linux-gnu.tar.xz 141965604 BLAKE2B b4b7ce86
 DIST rust-1.47.0-s390x-unknown-linux-gnu.tar.xz 146987276 BLAKE2B 1810e7bfbd235613563677449376167700c33960eb57b100e65058f6a00692316db518f2f4b79b39e414f3892c62bb1ec09b0866ff2221641c4a3056659a1668 SHA512 dd5877b6ff5c310ca6aa23c1cc621e6b0675d4c46f5a06b2a0b107641b604a1a2101109ba8e286267bab1158768c601d5d9a922a8da72486c91755ef465720c0
 DIST rust-1.47.0-x86_64-unknown-linux-gnu.tar.xz 150891572 BLAKE2B 45ff02465ba82ae96de25dd616fa08abb2396be21236d2f66f831effb349f39b047a380b38cb83254f27e56cecdbea8478f4de8ccc0aa23b11de2f11a28f501b SHA512 f695986ab8e67636b0e92ca7ea223984121e3c22788434a6f1062690e7932f6b30c0c302160fef96831f821acedaf8a909bd3d00a9aa873c7200d2b8fa39013f
 DIST rust-1.47.0-x86_64-unknown-linux-musl.tar.xz 166456672 BLAKE2B d6ccfc574a81ae3e9e6a96805e6863009970b5c480f35ee0d582a204b782fe513b9c6c7094d1adea509de1a3097a8a0524ac00c2186b968f70f390615904eb5a SHA512 f71b162635955ecd8a6ec322818be69c788c18d4e923d84d901916648f2eb58573b1f97b460209294ee64198e76566b78e472f9cbca8665c59444adfc5ae603c
+DIST rust-1.48.0-aarch64-unknown-linux-gnu.tar.xz 133782948 BLAKE2B 95e80db4734a91a1aed6433cb6dcc65358ef713f365216f6c344c4940c2b5e43b7dc5805f53635c4e7585e70c9d5773b6c93034fa2ffd0a28efb2f20a18f1be8 SHA512 6ebbd936b1bc2ccf30b62dbbbc6f3986fb57738d89e33a23d58bab09be57a445c17df7912866add91cc108ef7547d229a08c6206db2d2fb00d72887ff6a0894d
+DIST rust-1.48.0-arm-unknown-linux-gnueabi.tar.xz 133293068 BLAKE2B f98129d16e0de958a164233a1cc6317dc64eeeee76aa88b6982af2cb0a4b9f798a989b6bc153dcd55a7a6dfd3a8a6b36330faae82fedc133ae927b75638629aa SHA512 8958b8548711bb393e188d7516a842dcde5e7f9751804a90621d28a787a28b330057f343f14f930bafdcbdd8fa2cf391d6a4c1953f6d33a34bcbc65fd0e24e9b
+DIST rust-1.48.0-arm-unknown-linux-gnueabihf.tar.xz 132424008 BLAKE2B ed0aad5dba3eff6ca18eac5e7fc1864d2b72e262b5c8d6b510196653edc505bcb2327d529b326b10279ad19d6e2258e40103ed39067094f6ac2bd9dfed170b35 SHA512 d932676a579eed1849e58c133aa3759750b01436aa6f837098953cc558b9025427bdd54f1f2688aa0022934c48177da34874e27cc319c7bf1c96e219615d2bb2
+DIST rust-1.48.0-armv7-unknown-linux-gnueabihf.tar.xz 134716224 BLAKE2B 1918eadca80dbaacb4700dc5af8c791cc0966a29b4d01bba10e8ec31d5506a2748f4a0c9ed6695e9aa9cd88511e0dc347354a1410b419013757d9ae443e9e9af SHA512 9763b0c5bc5dc7b265b86636ed32947aab98bd9b5732c4b298ade93e9a09bab82ad37fc7ca2d7c97dfd87634756b3c55015d47696c0a6ed2cb44be03659bcf55
+DIST rust-1.48.0-i686-unknown-linux-gnu.tar.xz 161602224 BLAKE2B e4f1d1b51d520f85f7af8ddd12ad716d8c501a25d1bcdf40efd23902da9c35168108ba705c08a7aa3617ac1afb41584180d1d2399732918900f9126158111c25 SHA512 b8b3c5407304a333fc6c10ad70363589a88673640dda7b5fde8971097e679f56a8c733da31b2183044ae2ce30700db923cc3c3cb8c590d785df680b60b199451
+DIST rust-1.48.0-mips-unknown-linux-gnu.tar.xz 96393696 BLAKE2B 6cd06b3b1b8aeb4b251bc14e47dd8b8cd099f9292705402d718657de4efd480f8999bf23694d9be455236e3ebd4d330b2645a0333eeab7f9a189239df5e02698 SHA512 973130e8c0924e4a22e3b803102b96e80d6247328879a92c3bf0d9e80ec185264b980bd481ee79b6f8afe8e47f7fd61b9657a85adb7ae99008357d39e2428a39
+DIST rust-1.48.0-mips64-unknown-linux-gnuabi64.tar.xz 107548156 BLAKE2B 98b481032689f094490689b3af5a0a9162c8bf0ac8a60203b0be2de0f0ac555296e0401d1d534934d2faee852c61b20324aadf0a1696dd57607b71389f03071a SHA512 b3adf893d3e1a36da859bbd3cb39acebb2358522591694e636574ac5a1f81484a60ee53a9de7f348717fbfdaac9f2dd6ec27ea78959cdf94346d251d4a6be877
+DIST rust-1.48.0-mipsel-unknown-linux-gnu.tar.xz 97538116 BLAKE2B c4777428637bf2a08964b0abf048c2ea3b895901130f6b2c4307bfd448c7e09e2d8e862d0a10bab23c73a580aa2e9d868c7716d6a7fd103fa40f0d4207090c71 SHA512 09529c30c2b31317a495b058ee48d8ad7b0c89a59a70e62c9085d59bbd2f22a37223956a13959175cd05b195b7541feac9b8acc49438f575fce3fad26d2bd927
+DIST rust-1.48.0-powerpc-unknown-linux-gnu.tar.xz 106401772 BLAKE2B 2b10bb21198b9104dee49038ca4a7bee9dc93331465166ce9ca451d84c7e759e7bd5635c017223f6a1b96f71430a8240bd65022e9067fb20e5be85d06e79baba SHA512 b77afbca6fe9f1122c863bee14a764adb1dc5f233058292c5aaa72e50f473c1f9cccd1fc08c427485a7edab460fcea595544fd902d5f96d290e208aa03d910a3
+DIST rust-1.48.0-powerpc64-unknown-linux-gnu.tar.xz 120497676 BLAKE2B 6aa1dedcf5953f1292997fa7aac19067a6daa5e676a7e5fb7b7a29707831328b5514a88904edcc00dcf76d32e911646c8a349e40431a531585c373ce755bfb3c SHA512 f79e1f984cc3c4dce08599418be2885666e0b6f73e639b10e97ffff4b900606d880c0596b6c2ab7c5f999cfc364d22b2ca6ab88db6ba38b8b227670b222fe23b
+DIST rust-1.48.0-powerpc64le-unknown-linux-gnu.tar.xz 124335896 BLAKE2B fe95cb27e69258d4b0fe471e856bc98d4ddae3d90c7d5bbd723575cb86da28061c8b0ca8f5fd945f0ce4789997f5e7658edf5f40b57aa215d76ffeb3c3207602 SHA512 7ddd2b0599872012f8613ccab456622cb05a0a43587b7d389e8b7fdf9381f0387763726d892da931233c89e8e3ce45c2b303ed00b1cce1f91c88d8f88d6b148d
+DIST rust-1.48.0-s390x-unknown-linux-gnu.tar.xz 127221600 BLAKE2B 08511be6aadc0feb36caa19df5914a207565eed3b4b3914cad7fc8f7170011a7431c14d50b1334f5d5e00b4c94e7e84ee59afad179286e889480cc9b21e1f402 SHA512 b2b1565f3b1cc0c3bf4aa06aba1da7df775c6e29c892ca7727d0e549f175b632080433be2586e799c5636231de6c678f0228dedee8358fbf167016a1f7d25389
+DIST rust-1.48.0-x86_64-unknown-linux-gnu.tar.xz 155254844 BLAKE2B 37bce978eb297bb1732f9d513bb6fdcee4aefc42a578496a84b5f8abbb9f90f1c524c73f28c85f33c25a365bf5ba566253b1739009bb112c2e1d46a2ed978e10 SHA512 0784e156e70c47386abfa88ecfeb62b1109364459b1fee225de0749c30379c4eb443ff3ff7faa7dc1a6ff373bc6eb43997007f937889cb35daf940a74641753b
+DIST rust-1.48.0-x86_64-unknown-linux-musl.tar.xz 168361012 BLAKE2B efeb9a9812f2fa2cbf1cfd963b5b714cf18d73ca9b7a3de4efa701acf7e2e8fc3b610cd90f7391b10bddd1c9d44b8b0aa910f58ce739750d4e910b063825dc28 SHA512 7188fb0b1bf6fd6ab320089cd17f334867baefec1a9c57a81e6cb729276456e56850938dbd0eafbc52375266a87392ad3045a4dbd2c41689bba6b0da152e4034
 DIST rustc-1.46.0-src.tar.xz 101868452 BLAKE2B da9798596b124a10d79c236a871228f05e5f571d22c2259328e7026c91e088c85f5de9c0536a16531e0cb10477bfcd16d3ac11467979f5561cb6199442b877ef SHA512 099857f1d295043587a4e2a65ef3e6a90e12c8b6958e98535a1656c113c553f9a9b621aba8a19cf21bd8d2c79d27cbfa4b8e6fabbcb3cbfee23b545be7b450b4
 DIST rustc-1.47.0-src.tar.xz 104143736 BLAKE2B 0454094dde35275488046826da87655e51bf0795481d6d08fd70d644bfc12481bca8641166106ef32f20494906025244715b16ff21a1c023f4bd2818aab42521 SHA512 6ba83c0158f8130ddeae7e070417a2121d8a548c8fe97e28bce116d84048636c75aaee78e0c92cd43a50f5679a1223fc226cc8c5ba9bbd1465e84c5c6034d5c9
 DIST rustc-1.48.0-src.tar.xz 105951736 BLAKE2B 42468fc5ac5e80c4793cfe0913cbb8e43a8def28cc8cf5ed25ab989561e2bf33e155c83e180183362535cbc9008f341eb1273087a2364672b1a4032ac2d6ca45 SHA512 4e12baa6893238a8d336ec9ebe891477d18676f271b32763474fa7a6a8b58fb3187dd4e2aa95bce482989b692cc2e1360221669d6811eec71b326f22a1756c23
+DIST rustc-1.49.0-src.tar.xz 108330280 BLAKE2B 65e36253482ded2df225cbbf15253b6c9a8ae935053b071d9fb9e7b1d47d5d3ac47a138876e4a5cfeda455c655ac06ceff2658c8668cef7d2206116906740653 SHA512 fd8bc67ec0a73d3b6bf9c1fabb7ea981ef817644b4e6ced982fa90b12eae9b55de074634a670bdfb38bfee6588603e818ddcbcc2f2a05f83057c061b4194b4b7
diff --git a/dev-lang/rust/files/1.49.0-gentoo-musl-target-specs.patch b/dev-lang/rust/files/1.49.0-gentoo-musl-target-specs.patch
new file mode 100644
index 000000000000..25f1f27fcce6
--- /dev/null
+++ b/dev-lang/rust/files/1.49.0-gentoo-musl-target-specs.patch
@@ -0,0 +1,164 @@
+From 671ef2d1c228aed031b4232b8bea96f17b825263 Mon Sep 17 00:00:00 2001
+From: Georgy Yakovlev <gyakovlev@gentoo.org>
+Date: Mon, 23 Nov 2020 14:52:04 -0800
+Subject: [PATCH] add gentoo musl target specs
+
+---
+ .../src/spec/aarch64_gentoo_linux_musl.rs             | 11 +++++++++++
+ .../src/spec/armv7_gentoo_linux_musleabihf.rs         | 11 +++++++++++
+ .../rustc_target/src/spec/i686_gentoo_linux_musl.rs   | 11 +++++++++++
+ compiler/rustc_target/src/spec/mod.rs                 |  8 ++++++++
+ .../src/spec/powerpc64_gentoo_linux_musl.rs           | 11 +++++++++++
+ .../src/spec/powerpc64le_gentoo_linux_musl.rs         | 11 +++++++++++
+ .../src/spec/powerpc_gentoo_linux_musl.rs             | 11 +++++++++++
+ .../rustc_target/src/spec/x86_64_gentoo_linux_musl.rs | 11 +++++++++++
+ 8 files changed, 85 insertions(+)
+ create mode 100644 compiler/rustc_target/src/spec/aarch64_gentoo_linux_musl.rs
+ create mode 100644 compiler/rustc_target/src/spec/armv7_gentoo_linux_musleabihf.rs
+ create mode 100644 compiler/rustc_target/src/spec/i686_gentoo_linux_musl.rs
+ create mode 100644 compiler/rustc_target/src/spec/powerpc64_gentoo_linux_musl.rs
+ create mode 100644 compiler/rustc_target/src/spec/powerpc64le_gentoo_linux_musl.rs
+ create mode 100644 compiler/rustc_target/src/spec/powerpc_gentoo_linux_musl.rs
+ create mode 100644 compiler/rustc_target/src/spec/x86_64_gentoo_linux_musl.rs
+
+diff --git a/compiler/rustc_target/src/spec/aarch64_gentoo_linux_musl.rs b/compiler/rustc_target/src/spec/aarch64_gentoo_linux_musl.rs
+new file mode 100644
+index 0000000..420fe7c
+--- /dev/null
++++ b/compiler/rustc_target/src/spec/aarch64_gentoo_linux_musl.rs
+@@ -0,0 +1,11 @@
++use crate::spec::Target;
++
++pub fn target() -> Target {
++    let mut base = super::aarch64_unknown_linux_musl::target();
++
++    base.llvm_target = "aarch64-gentoo-linux-musl".to_string();
++    base.options.vendor = "gentoo".to_string();
++    base.options.crt_static_default = false;
++
++    base
++}
+diff --git a/compiler/rustc_target/src/spec/armv7_gentoo_linux_musleabihf.rs b/compiler/rustc_target/src/spec/armv7_gentoo_linux_musleabihf.rs
+new file mode 100644
+index 0000000..067e2d6
+--- /dev/null
++++ b/compiler/rustc_target/src/spec/armv7_gentoo_linux_musleabihf.rs
+@@ -0,0 +1,11 @@
++use crate::spec::Target;
++
++pub fn target() -> Target {
++    let mut base = super::armv7_unknown_linux_musleabihf::target();
++
++    base.llvm_target = "armv7-gentoo-linux-musleabihf".to_string();
++    base.options.vendor = "gentoo".to_string();
++    base.options.crt_static_default = false;
++
++    base
++}
+diff --git a/compiler/rustc_target/src/spec/i686_gentoo_linux_musl.rs b/compiler/rustc_target/src/spec/i686_gentoo_linux_musl.rs
+new file mode 100644
+index 0000000..1cd39cd
+--- /dev/null
++++ b/compiler/rustc_target/src/spec/i686_gentoo_linux_musl.rs
+@@ -0,0 +1,11 @@
++use crate::spec::Target;
++
++pub fn target() -> Target {
++    let mut base = super::i686_unknown_linux_musl::target();
++
++    base.llvm_target = "i686-gentoo-linux-musl".to_string();
++    base.options.vendor = "gentoo".to_string();
++    base.options.crt_static_default = false;
++
++    base
++}
+diff --git a/compiler/rustc_target/src/spec/mod.rs b/compiler/rustc_target/src/spec/mod.rs
+index f1e8330..d8c0ba0 100644
+--- a/compiler/rustc_target/src/spec/mod.rs
++++ b/compiler/rustc_target/src/spec/mod.rs
+@@ -490,6 +490,14 @@ macro_rules! supported_targets {
+ }
+ 
+ supported_targets! {
++    ("aarch64-gentoo-linux-musl", aarch64_gentoo_linux_musl),
++    ("armv7-gentoo-linux-musleabihf", armv7_gentoo_linux_musleabihf),
++    ("i686-gentoo-linux-musl", i686_gentoo_linux_musl),
++    ("powerpc-gentoo-linux-musl", powerpc_gentoo_linux_musl),
++    ("powerpc64-gentoo-linux-musl", powerpc64_gentoo_linux_musl),
++    ("powerpc64le-gentoo-linux-musl", powerpc64le_gentoo_linux_musl),
++    ("x86_64-gentoo-linux-musl", x86_64_gentoo_linux_musl),
++
+     ("x86_64-unknown-linux-gnu", x86_64_unknown_linux_gnu),
+     ("x86_64-unknown-linux-gnux32", x86_64_unknown_linux_gnux32),
+     ("i686-unknown-linux-gnu", i686_unknown_linux_gnu),
+diff --git a/compiler/rustc_target/src/spec/powerpc64_gentoo_linux_musl.rs b/compiler/rustc_target/src/spec/powerpc64_gentoo_linux_musl.rs
+new file mode 100644
+index 0000000..e840bb2
+--- /dev/null
++++ b/compiler/rustc_target/src/spec/powerpc64_gentoo_linux_musl.rs
+@@ -0,0 +1,11 @@
++use crate::spec::Target;
++
++pub fn target() -> Target {
++    let mut base = super::powerpc64_unknown_linux_musl::target();
++
++    base.llvm_target = "powerpc64-gentoo-linux-musl".to_string();
++    base.options.vendor = "gentoo".to_string();
++    base.options.crt_static_default = false;
++
++    base
++}
+diff --git a/compiler/rustc_target/src/spec/powerpc64le_gentoo_linux_musl.rs b/compiler/rustc_target/src/spec/powerpc64le_gentoo_linux_musl.rs
+new file mode 100644
+index 0000000..1037d82
+--- /dev/null
++++ b/compiler/rustc_target/src/spec/powerpc64le_gentoo_linux_musl.rs
+@@ -0,0 +1,11 @@
++use crate::spec::Target;
++
++pub fn target() -> Target {
++    let mut base = super::powerpc64le_unknown_linux_musl::target();
++
++    base.llvm_target = "powerpc64le-gentoo-linux-musl".to_string();
++    base.options.vendor = "gentoo".to_string();
++    base.options.crt_static_default = false;
++
++    base
++}
+diff --git a/compiler/rustc_target/src/spec/powerpc_gentoo_linux_musl.rs b/compiler/rustc_target/src/spec/powerpc_gentoo_linux_musl.rs
+new file mode 100644
+index 0000000..a623ffe
+--- /dev/null
++++ b/compiler/rustc_target/src/spec/powerpc_gentoo_linux_musl.rs
+@@ -0,0 +1,11 @@
++use crate::spec::Target;
++
++pub fn target() -> Target {
++    let mut base = super::powerpc_unknown_linux_musl::target();
++
++    base.llvm_target = "powerpc-gentoo-linux-musl".to_string();
++    base.options.vendor = "gentoo".to_string();
++    base.options.crt_static_default = false;
++
++    base
++}
+diff --git a/compiler/rustc_target/src/spec/x86_64_gentoo_linux_musl.rs b/compiler/rustc_target/src/spec/x86_64_gentoo_linux_musl.rs
+new file mode 100644
+index 0000000..f330473
+--- /dev/null
++++ b/compiler/rustc_target/src/spec/x86_64_gentoo_linux_musl.rs
+@@ -0,0 +1,11 @@
++use crate::spec::Target;
++
++pub fn target() -> Target {
++    let mut base = super::x86_64_unknown_linux_musl::target();
++
++    base.llvm_target = "x86_64-gentoo-linux-musl".to_string();
++    base.options.vendor = "gentoo".to_string();
++    base.options.crt_static_default = false;
++
++    base
++}
+-- 
+2.29.2
+
diff --git a/dev-lang/rust/rust-1.49.0.ebuild b/dev-lang/rust/rust-1.49.0.ebuild
new file mode 100644
index 000000000000..a1608e5ceeab
--- /dev/null
+++ b/dev-lang/rust/rust-1.49.0.ebuild
@@ -0,0 +1,615 @@
+# Copyright 1999-2020 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=7
+
+PYTHON_COMPAT=( python3_{6..9} )
+
+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="${BETA_SNAPSHOT}/rustc-beta-src.tar.xz -> rustc-${PV}-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)).0"
+
+DESCRIPTION="Systems programming language from Mozilla"
+HOMEPAGE="https://www.rust-lang.org/"
+
+SRC_URI="
+	https://static.rust-lang.org/dist/${SRC}
+	!system-bootstrap? ( $(rust_all_arch_uris rust-${RUST_STAGE0_VERSION}) )
+"
+
+# keep in sync with llvm ebuild of the same version as bundled one.
+ALL_LLVM_TARGETS=( AArch64 AMDGPU ARM AVR 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 test wasm ${ALL_LLVM_TARGETS[*]}"
+
+# Please keep the LLVM dependency block separate. Since LLVM is slotted,
+# we need to *really* make sure we're not pulling more than one slot
+# simultaneously.
+
+# How to use it:
+# 1. List all the working slots (with min versions) in ||, newest first.
+# 2. Update the := to specify *max* version, e.g. < 12.
+# 3. Specify LLVM_MAX_SLOT, e.g. 11.
+LLVM_DEPEND="
+	|| (
+		sys-devel/llvm:11[${LLVM_TARGET_USEDEPS// /,}]
+	)
+	<sys-devel/llvm-12:=
+	wasm? ( sys-devel/lld )
+"
+LLVM_MAX_SLOT=11
+
+# to bootstrap we need at least exactly previous version, or same.
+# most of the time previous versions fail to bootstrap with newer
+# for example 1.47.x, requires at least 1.46.x, 1.47.x is ok,
+# but it fails to bootstrap with 1.48.x
+# https://github.com/rust-lang/rust/blob/${PV}/src/stage0.txt
+BOOTSTRAP_DEPEND="||
+	(
+		=dev-lang/rust-$(ver_cut 1).$(($(ver_cut 2) - 1))*
+		=dev-lang/rust-bin-$(ver_cut 1).$(($(ver_cut 2) - 1))*
+		=dev-lang/rust-$(ver_cut 1).$(ver_cut 2)*
+		=dev-lang/rust-bin-$(ver_cut 1).$(ver_cut 2)*
+	)
+"
+
+BDEPEND="${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
+	)
+"
+
+DEPEND="
+	>=app-arch/xz-utils-5.2
+	net-misc/curl:=[http2,ssl]
+	sys-libs/zlib:=
+	!libressl? ( dev-libs/openssl:0= )
+	libressl? ( dev-libs/libressl:0= )
+	elibc_musl? ( sys-libs/libunwind:= )
+	system-llvm? (
+		${LLVM_DEPEND}
+	)
+"
+
+# we need to block older versions due to layout changes.
+RDEPEND="${DEPEND}
+	app-eselect/eselect-rust
+	!<dev-lang/rust-1.47.0-r1
+	!<dev-lang/rust-bin-1.47.0-r1
+"
+
+REQUIRED_USE="|| ( ${ALL_LLVM_TARGETS[*]} )
+	miri? ( nightly )
+	parallel-compiler? ( nightly )
+	test? ( ${ALL_LLVM_TARGETS[*]} )
+	wasm? ( llvm_targets_WebAssembly )
+	x86? ( cpu_flags_x86_sse2 )
+"
+
+# we don't use cmake.eclass, but can get a warnings
+CMAKE_WARN_UNUSED_CLI=no
+
+QA_FLAGS_IGNORED="
+	usr/lib/${PN}/${PV}/bin/.*
+	usr/lib/${PN}/${PV}/lib/lib.*.so
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/bin/.*
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/lib/lib.*.so
+"
+
+QA_SONAME="
+	usr/lib/${PN}/${PV}/lib/lib.*.so.*
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/lib/lib.*.so
+"
+
+# causes double bootstrap
+RESTRICT="test"
+
+PATCHES=(
+	"${FILESDIR}"/1.47.0-libressl.patch
+	"${FILESDIR}"/1.46.0-don-t-create-prefix-at-time-of-check.patch
+	"${FILESDIR}"/1.47.0-ignore-broken-and-non-applicable-tests.patch
+	"${FILESDIR}"/1.47.0-llvm-tensorflow-fix.patch
+	"${FILESDIR}"/1.49.0-gentoo-musl-target-specs.patch
+)
+
+S="${WORKDIR}/${MY_P}-src"
+
+toml_usex() {
+	usex "${1}" true false
+}
+
+boostrap_rust_version_check() {
+	# never call from pkg_pretend. eselect-rust may be not installed yet.
+	[[ ${MERGE_TYPE} == binary ]] && return
+	local rustc_wanted="$(ver_cut 1).$(($(ver_cut 2) - 1))"
+	local rustc_toonew="$(ver_cut 1).$(($(ver_cut 2) + 1))"
+	local rustc_version=( $(eselect --brief rust show 2>/dev/null) )
+	rustc_version=${rustc_version[0]#rust-bin-}
+	rustc_version=${rustc_version#rust-}
+
+	[[ -z "${rustc_version}" ]] && die "Failed to determine rust version, check 'eselect rust' output"
+
+	if ver_test "${rustc_version}" -lt "${rustc_wanted}" ; then
+		eerror "Rust >=${rustc_wanted} is required"
+		eerror "please run 'eselect rust' and set correct rust version"
+		die "selected rust version is too old"
+	elif ver_test "${rustc_version}" -ge "${rustc_toonew}" ; then
+		eerror "Rust <${rustc_toonew} is required"
+		eerror "please run 'eselect rust' and set correct rust version"
+		die "selected rust version is too new"
+	else
+		einfo "Using rust ${rustc_version} to build"
+	fi
+}
+
+pre_build_checks() {
+	local M=6144
+	M=$(( $(usex clippy 128 0) + ${M} ))
+	M=$(( $(usex miri 128 0) + ${M} ))
+	M=$(( $(usex rls 512 0) + ${M} ))
+	M=$(( $(usex rustfmt 256 0) + ${M} ))
+	M=$(( $(usex system-llvm 0 2048) + ${M} ))
+	M=$(( $(usex wasm 256 0) + ${M} ))
+	M=$(( $(usex debug 15 10) * ${M} / 10 ))
+	eshopts_push -s extglob
+	if is-flagq '-g?(gdb)?([1-9])'; then
+		M=$(( 15 * ${M} / 10 ))
+	fi
+	eshopts_pop
+	M=$(( $(usex system-bootstrap 0 1024) + ${M} ))
+	M=$(( $(usex doc 256 0) + ${M} ))
+	CHECKREQS_DISK_BUILD=${M}M check-reqs_pkg_${EBUILD_PHASE}
+}
+
+pkg_pretend() {
+	pre_build_checks
+}
+
+pkg_setup() {
+	pre_build_checks
+	python-any-r1_pkg_setup
+
+	export LIBGIT2_NO_PKG_CONFIG=1 #749381
+
+	use system-bootstrap && boostrap_rust_version_check
+
+	if use system-llvm; then
+		llvm_pkg_setup
+
+		local llvm_config="$(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/' compiler/rustc_target/src/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/lib/${PN}/${PV}"
+		sysconfdir = "etc"
+		docdir = "share/doc/rust"
+		bindir = "bin"
+		libdir = "lib"
+		mandir = "share/man"
+		[rust]
+		# https://github.com/rust-lang/rust/issues/54872
+		codegen-units-std = 1
+		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() {
+	# we need \n IFS to have config.env with spaces loaded properly. #734018
+	(
+	IFS=$'\n'
+	env $(cat "${S}"/config.env) RUST_BACKTRACE=1\
+		"${EPYTHON}" ./x.py dist -vv --config="${S}"/config.toml -j$(makeopts_jobs) || die
+	)
+}
+
+src_test() {
+	# https://rustc-dev-guide.rust-lang.org/tests/intro.html
+
+	# those are basic and codegen tests.
+	local tests=(
+		codegen
+		codegen-units
+		compile-fail
+		incremental
+		mir-opt
+		pretty
+		run-make
+	)
+
+	# fails if llvm is not built with ALL targets.
+	# and known to fail with system llvm sometimes.
+	use system-llvm || tests+=( assembly )
+
+	# fragile/expensive/less important tests
+	# or tests that require extra builds
+	# TODO: instead of skipping, just make some nonfatal.
+	if [[ ${ERUST_RUN_EXTRA_TESTS:-no} != no ]]; then
+		tests+=(
+			rustdoc
+			rustdoc-js
+			rustdoc-js-std
+			rustdoc-ui
+			run-make-fulldeps
+			ui
+			ui-fulldeps
+		)
+	fi
+
+	local i failed=()
+	einfo "rust_src_test: enabled tests ${tests[@]/#/src/test/}"
+	for i in "${tests[@]}"; do
+		local t="src/test/${i}"
+		einfo "rust_src_test: running ${t}"
+		if ! (
+				IFS=$'\n'
+				env $(cat "${S}"/config.env) RUST_BACKTRACE=1 \
+				"${EPYTHON}" ./x.py test -vv --config="${S}"/config.toml \
+				-j$(makeopts_jobs) --no-doc --no-fail-fast "${t}"
+			)
+		then
+				failed+=( "${t}" )
+				eerror "rust_src_test: ${t} failed"
+		fi
+	done
+
+	if [[ ${#failed[@]} -ne 0 ]]; then
+		eerror "rust_src_test: failure summary: ${failed[@]}"
+		die "aborting due to test failures"
+	fi
+}
+
+src_install() {
+	# https://github.com/rust-lang/rust/issues/77721
+	# also 1.46.0-don-t-create-prefix-at-time-of-check.patch
+	dodir "/usr/lib/${PN}/${PV}"
+	(
+	IFS=$'\n'
+	env $(cat "${S}"/config.env) DESTDIR="${D}" \
+		"${EPYTHON}" ./x.py install -vv --config="${S}"/config.toml || die
+	)
+
+	# bug #689562, #689160
+	rm -v "${ED}/usr/lib/${PN}/${PV}/etc/bash_completion.d/cargo" || die
+	rmdir -v "${ED}/usr/lib/${PN}/${PV}"/etc{/bash_completion.d,} || die
+	dobashcomp build/tmp/dist/cargo-image/etc/bash_completion.d/cargo
+
+	local symlinks=(
+		cargo
+		rustc
+		rustdoc
+		rust-gdb
+		rust-gdbgui
+		rust-lldb
+	)
+
+	use clippy && symlinks+=( clippy-driver cargo-clippy )
+	use miri && symlinks+=( miri cargo-miri )
+	use rls && symlinks+=( rls )
+	use rustfmt && symlinks+=( rustfmt cargo-fmt )
+
+	einfo "installing eselect-rust symlinks and paths: ${symlinks[@]}"
+	local i
+	for i in "${symlinks[@]}"; do
+		# we need realpath on /usr/bin/* symlink return version-appended binary path.
+		# so /usr/bin/rustc should point to /usr/lib/rust/<ver>/bin/rustc-<ver>
+		# need to fix eselect-rust to remove this hack.
+		local ver_i="${i}-${PV}"
+		if [[ -f "${ED}/usr/lib/${PN}/${PV}/bin/${i}" ]]; then
+			einfo "Installing ${i} symlink"
+			ln -v "${ED}/usr/lib/${PN}/${PV}/bin/${i}" "${ED}/usr/lib/${PN}/${PV}/bin/${ver_i}" || die
+		else
+			ewarn "${i} symlink requested, but source file not found"
+			ewarn "please report this"
+		fi
+		dosym "../lib/${PN}/${PV}/bin/${ver_i}" "/usr/bin/${ver_i}"
+	done
+
+	# symlinks to switch components to active rust in eselect
+	dosym "${PV}/lib" "/usr/lib/${PN}/lib-${PV}"
+	dosym "${PV}/share/man" "/usr/lib/${PN}/man-${PV}"
+	dosym "rust/${PV}/lib/rustlib" "/usr/lib/rustlib-${PV}"
+	dosym "../../lib/${PN}/${PV}/share/doc/rust" "/usr/share/doc/${P}"
+
+	newenvd - "50${P}" <<-_EOF_
+		LDPATH="${EPREFIX}/usr/lib/rust/lib"
+		MANPATH="${EPREFIX}/usr/lib/rust/man"
+		$(usex elibc_musl 'CARGO_TARGET_X86_64_UNKNOWN_LINUX_MUSL_RUSTFLAGS="-C target-feature=-crt-static"' '')
+	_EOF_
+
+	rm -rf "${ED}/usr/lib/${PN}/${PV}"/*.old || die
+	rm -rf "${ED}/usr/lib/${PN}/${PV}/doc"/*.old || die
+
+	# note: eselect-rust adds EROOT to all paths below
+	cat <<-_EOF_ > "${T}/provider-${P}"
+		/usr/bin/cargo
+		/usr/bin/rustdoc
+		/usr/bin/rust-gdb
+		/usr/bin/rust-gdbgui
+		/usr/bin/rust-lldb
+		/usr/lib/rustlib
+		/usr/lib/rust/lib
+		/usr/lib/rust/man
+		/usr/share/doc/rust
+	_EOF_
+
+	if use clippy; then
+		echo /usr/bin/clippy-driver >> "${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-${P}"
+}
+
+pkg_postinst() {
+	eselect rust update
+
+	if has_version sys-devel/gdb || has_version dev-util/lldb; then
+		elog "Rust installs a helper script for calling GDB and LLDB,"
+		elog "for your convenience it is installed under /usr/bin/rust-{gdb,lldb}-${PV}."
+	fi
+
+	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
+}
+
+pkg_postrm() {
+	eselect rust cleanup
+}