dev-lang/rust: use dynamic linking for arm64/amd64 musl builds

Package-Manager: Portage-3.0.28, Repoman-3.0.3
Signed-off-by: Jory Pratt <anarchy@gentoo.org>

5 files changed, 889 insertions, 0 deletions

diff --git a/dev-lang/rust/Manifest b/dev-lang/rust/Manifest
new file mode 100644
index 00000000..7b40980d
--- /dev/null
+++ b/dev-lang/rust/Manifest
@@ -0,0 +1,34 @@
+DIST rust-1.55.0-aarch64-unknown-linux-gnu.tar.xz 233469360 BLAKE2B ac0529d771dcd22ed55cf52af12a5b55a8ee008d9dec2c09fb1aacb0c7ced78e87a6b7cd8d17a3dd81241d553b750720e48631c3a3702ee59bcac905f3a51420 SHA512 223a024701762675adb5c7c59fc54717d23f2ae4ea5984cd1cc0568d39c5207aa07a104ddad68da057f6434eecf23415ae13be2235797897d8d0f7cb5f2fc4b5
+DIST rust-1.55.0-aarch64-unknown-linux-gnu.tar.xz.asc 801 BLAKE2B 02fec5fd64e97da4c74aa5354f557b3090c3df9c55d827c1811fbc41fe513ba00d8f854f95babafc7c9a4d2dadf50f4cbe6d3bf60cc10f12609c0957971c571b SHA512 1c2f41efb85971009a705ff3f82a45b6e3688d12b2c919c2555cc19dcc3b9575b516223a72caccb5ec3622e353fa0380ae3481a63ed2fa9b89f8e01c2771c95e
+DIST rust-1.55.0-aarch64-unknown-linux-musl.tar.xz 233248308 BLAKE2B 263506150ecb677c73a9a670952796d7df90b572ceada5fa4afd8b1478363670d802f6a26f47d0d6cbb34544edc63279dd4b08a9131e5702f4119a2236a91f6b SHA512 a74050bbeabee752d030b07f830b919467af59755b7b79f64edbbb7acf822bfbbd1d013d25091d37ce255ee9796056966d102bf5b3da475a859788af7ebbdf68
+DIST rust-1.55.0-aarch64-unknown-linux-musl.tar.xz.asc 801 BLAKE2B b1b43bf430d33acc9a9b5f99148f1e0b930d3e271d40834a44ca839bf00369a01bfbcc69f4851e1cc951b26d6f7eedfd6f02b6ff9ada8dac85ccda0c22b1ce36 SHA512 04d31f458c285801b0185308a56700f0bc3bc2ad8c4548a1aa91e73bf94878810dbcf483403ad5815e80e87fb1417d958dbb18e6fdf090d2fd41b90d1c8c040c
+DIST rust-1.55.0-arm-unknown-linux-gnueabi.tar.xz 210542012 BLAKE2B 91e6eb6c42f99e13aaeae97ef85cb266378a0201c64c3588335022a7218bd95c438d290a66390ed004a627a667ed6e4acded9f79fd6a7d47017457fe9955c658 SHA512 3cfd6e6968ed4b7872376da4d33f2eae0bf10d99eaf5fcf59e6d9be432f0239b03baf46b70f0146175894f2eb1ef118854d263d4ba8d18913e4f820fdd1f97e8
+DIST rust-1.55.0-arm-unknown-linux-gnueabi.tar.xz.asc 801 BLAKE2B 0902e4acc3a70750d8c2de86c22cfefad261e2b204c63d948c7e232adece894c4f7e15d799eaa3fadcef9a63953e603f5bf1e17c6f4b601cb4d93b88d8c970bd SHA512 39db8c7421e86c79189f1e0cc5a79dfae6e7633c43749f49cff371af862c0becead4a977cb75295b06da75d64516ceef68de4f42beee6d63e1eb4fb0bf976dd5
+DIST rust-1.55.0-arm-unknown-linux-gnueabihf.tar.xz 210534624 BLAKE2B cf02334a4b0182073b5387f3d1f16b6ae0d0508fc07e81ecc7623eb21031b03c1e6ab10cb2b6fd23071c3cc0c77adcf4cbd7d34d38e81853cd0ef02368c99036 SHA512 83a888c334caeda24f365df43df0fb83f367fda477d1bd7c869c88cff5407ffc134d8bd172a037c27a34d79cb28eb2e9629f26a7cfbc0db9209e581e06ec86bf
+DIST rust-1.55.0-arm-unknown-linux-gnueabihf.tar.xz.asc 801 BLAKE2B 17911a4745c705f7a4a2849301901912161c85300305e77588180d0fa4160a7ccd9188415c97a266613f35fdfd5b0b45879814c0afef6c6c2fea2bac700d0f39 SHA512 95d0731d84b49ecec8388fbcc0cb65f0ce93956a44dc62e1628f7e51e5726de6b611ed426a5e5c586a028d8808e6bca4257a8a1354b524087d833a32c3e0a231
+DIST rust-1.55.0-armv7-unknown-linux-gnueabihf.tar.xz 216342104 BLAKE2B ea2cb2d41c0a994124c5a5893cd3764f078157cb225117d9ca8641ca8896f02724beab7561a828d1163055e4c999ecece669f77920ccce0f495f2ff1b6632368 SHA512 b06b3c36b5ca35391030f3c9d2f64725263ac987002923d9263c4c27877d91453db3191e01d40c78f439a48f83da220926a2841337d815dd333591d453f2fc0e
+DIST rust-1.55.0-armv7-unknown-linux-gnueabihf.tar.xz.asc 801 BLAKE2B f35d5adf2ef48d52d22f6066a2dbf6a61543cf7e478a5d201caf1831f5cda53b7003148477fd043de98530bf3160de51f44f87d4e30be6cb7768344c6754f16e SHA512 e3cc3596e3f96d0aa6ec915690730118cea023e57b7bd9255acf80782acb865a1aa5ed3e404654d7eaa8110947f50f42b575d3df1eaef616afd2c55e8502b535
+DIST rust-1.55.0-i686-unknown-linux-gnu.tar.xz 228160060 BLAKE2B a5c37f6a25b8e09b3ca831f4f69d65d71f97bf0b0e975e7c92e8a4b2ec791f166f477b2fdce0ae6d9f539e598887a54b1e9ed0bc603da0e0c787cd2ba4b59565 SHA512 a0222c68c63ddd67afee552dd9ed636ea02fd3f26000deb7a1dc47806a1ec0b2fafaed903d4dabb0fddeb9e4026bf0da8bb2161c14db24d2883c084932e306b6
+DIST rust-1.55.0-i686-unknown-linux-gnu.tar.xz.asc 801 BLAKE2B 62cc675de6155892cd6c0932d0b354cac4b3a07be58b2d6b021f7e86df058d5ecccef8e4ad9bedfd2432e84cea9720a982cbf9a50bf8a42149d8f197a27f8fb1 SHA512 21efa3b95a0344913666220f2996a8273e7d41077410b9eaafb7467976d0eca0139c780326b3e645d83db0b410e5db3a36342d89af668e65d045309f541c1c1e
+DIST rust-1.55.0-mips-unknown-linux-gnu.tar.xz 152431144 BLAKE2B b5b27cf62f92f551a39ed65c957b73ce30ef9d1d956b5ca342641bb647c4874d7e325ec5f1c22a340668315c8f50c34240d0a2044ac8e5a88608c02fdf4f7e39 SHA512 e7eb3a64ea87c211a77ac73c4cfa001849fde1f73605d4e58cab84b09c886ab1a9a850cf1dcc9e1af19fcea0ea53400529a74adab531bc0a5ae3cee70a7cc99e
+DIST rust-1.55.0-mips-unknown-linux-gnu.tar.xz.asc 801 BLAKE2B 31dde6a6991040bc4772bba2577946837af84922b01c12bfa1ac9003f90f118c24d63bdcaff339b3a256f48cbfc55aac0bd1823727c35ca6424c5cf3b049d4b0 SHA512 685e6d15e79f71de45c9c2532cbbf7ded0c6b8d986c2bbb78887c43c05cc91ad5430c5f04c80d8007a3a86fe2936b29d7c8d92905cebf0ddbd152c526f324077
+DIST rust-1.55.0-mips64-unknown-linux-gnuabi64.tar.xz 159792528 BLAKE2B b762f4965771184fcf3ceaf38c7c8b62d9f4cbafe0fbc0a1e01a30ab9a5c951bff9472796c72ae1945d2a510b0efefd576f3ef0b4041eec7103cb5e5deb75e14 SHA512 74b199449c2237d71d2d8de4d8de05c82f631cda1fbf00b342707b4e99aa6aa7f89957d606c29dfeebb5990b3e6f09de5f360c484c8153cd17076bffbbfac251
+DIST rust-1.55.0-mips64-unknown-linux-gnuabi64.tar.xz.asc 801 BLAKE2B 92a173654e7de569734b9c56f4f9d73d67fdad625b71db20c1f1fbbe20a12cb54a54a69bd215846101fc620b6a995d1f91dccdd59c97a5d6f2efdf59f1c40b3e SHA512 2f166793f3d814f39b11c968921fb9d95627325f588eab9d7b26b76c5824222978286cbfd2cc3b197d7a53711e74dc5da39eb422d0dfead9e2ad2638a2d3692f
+DIST rust-1.55.0-mipsel-unknown-linux-gnu.tar.xz 155530648 BLAKE2B ffdaba2d35b5a6287fa78234df4368cab5e95ee139600d2d0964398eb0eddddf0382fc5e17f721eff3c1b61feaadadfa056727e249266d4a1783dfd441316eb3 SHA512 b4de4aab16039b7119760922fc18e7a5e0d1a1cc61ba5b3b5f778ce9d1d234448c8cfb5d46ced58a5b5705c1ae1a79403b394f0c4894e6387d7a9276768b2014
+DIST rust-1.55.0-mipsel-unknown-linux-gnu.tar.xz.asc 801 BLAKE2B bf9a712e8b3ee8e44a4a1e9bb5e70486d11a65a09134845553c8f2d201eb1f674e64a6dc50a9de7eba3c8c457a747a0c14ec8228710e2725fc4a4630dea9414d SHA512 f9f62b8d12d33446504e193df49b11507cf47f17ea63abe329505af25c29ef928505049e161bd0157f03dab5f54bd59c38382e0e2cd891e79bcb831dc4c1ddef
+DIST rust-1.55.0-powerpc-unknown-linux-gnu.tar.xz 165801508 BLAKE2B 752325711493d0caccd005a2509121992dfd3850eb87cd4100b61be08f42d0680d16098c631b15e4b94f63dc5d11f63f75e2d3d38ff7817fcf254563f80cc6af SHA512 c78fb4a5e7c59fc96f937eaee2e8ddf08be32376f45a6916aebdf046363f5ad792f67dbe1d42b699ee82b5f968671e710233f72d1677e70efaa90c9a54d36688
+DIST rust-1.55.0-powerpc-unknown-linux-gnu.tar.xz.asc 801 BLAKE2B bdcea33c2655a29bbb154129e981229cacff826483d950f32b5df5fb9ba7728c68d25d35df796bd75a26cad20ff525e6de4a059d0c908449a68460ae83112767 SHA512 f3ba9d98da9d4eb60c0f07ac509c24281cca419b805e1efe89583c93bb050665992f63069b3a76d8cd810b5a81d28b3f732c54eba081c40e9f8e6e0d39e452ab
+DIST rust-1.55.0-powerpc64-unknown-linux-gnu.tar.xz 179595992 BLAKE2B 3ed33cd7d28f0d8f91fa0ad2e46b7e8e53afe3f0fe8b8557530aa7ddeb3489e054635b636bdedc85bf91f17ea074b286f603b83cdad1c149eec431bd0b440ab5 SHA512 367ddaee0131ae05945b0a81efb73fde479140cb8078d10ec166c0da68afc1fa2aff40a8e6246c2b4861a876b8672a8d8d126bf15d23830c6e170aa27c1d6a7b
+DIST rust-1.55.0-powerpc64-unknown-linux-gnu.tar.xz.asc 801 BLAKE2B 795eda0483df19dc9c3f4439ab01dd3a647cbcd7bdb03a6d236d699214c6d1e2b1d794515bc09b067b0c4ab789893d07ba9905821d4851c84e4b16cdc38e85b7 SHA512 e2c527769342b8c05b60065e74ab7c8b3fa05e39a78f7cdca3044fc3b3167c62911194402d2256cc98ea69a30d5ef8b726dfec76755b7211cb0e9f0131eb556a
+DIST rust-1.55.0-powerpc64le-unknown-linux-gnu.tar.xz 188758520 BLAKE2B 789d6a835f4bf3c5631e55645cb7d8b77674dfa66b49c6f5c089b2a913785aa8962ee5db90a34000958f946b0f00b648a31346aa93d509e898e6476c14d6f551 SHA512 67c98c7cc44482082daa5daa3926dc92782b373b3173181413e68d59ea07f6eee61d46f3832a3fce18bdc44dd563e2e1f85709435e04c599b299981ecd932a9f
+DIST rust-1.55.0-powerpc64le-unknown-linux-gnu.tar.xz.asc 801 BLAKE2B ef25130d02f4570b433ddcd52545c7ceea9b239204a6bf138cc210f8a7fbd48922a0b8ab5a93a9f1c2b2f1d608bf525dd4f5402b03863defc8979fb84ec19760 SHA512 4a707f12d4b1c3113e0b4202fb0a7b66a04572f9c522ad6f0da0b049e1915ccdd9d3978cc03fb9a47a97639430101f3871869e99953374bfc5541d02ee0d7ff8
+DIST rust-1.55.0-riscv64gc-unknown-linux-gnu.tar.xz 182350256 BLAKE2B 1b139ae02b036719c7173d9607329a225455ac430d3911adce74ed0edd7c85e0f63a0beee563b7e26a4efe147083bcecf2dc93b5babad66303dcb7231bd83048 SHA512 c28beb76d9ae3a0727ae368845b4f62f8a087570a5464eac3b966ece6dd30d324696240a404f67c90cf005004bbfac8da31410d51469a7c34a6af3415e958acd
+DIST rust-1.55.0-riscv64gc-unknown-linux-gnu.tar.xz.asc 801 BLAKE2B e04e2c6ae4c2192c558b41201aec4fede2fcb05022f2e841e9048f2891b3baad5737e27297c0479e7363f920b7a63a502fca0fa7481ffdeca5084d1fd8bd2a4d SHA512 96b6412bfe84c6b4d13a13a8bfccb28505e8070c2e5ee94bc572be84dc5a59a7c5208659d20fe0d37cf3c02ca8475e5c9c0d4f0a5b9b86aecce2a35bc91c5a11
+DIST rust-1.55.0-s390x-unknown-linux-gnu.tar.xz 187722100 BLAKE2B 030413321337cab855fdcf6ff4ffdca4cf1105e633fc4b28d049263a5fe40a0097a9e03ff4aeff80b57c761c672d96e65c9f774cd83a9aba0f95180a2eb2dac9 SHA512 7fc83c8723493864a470f32a05db9e16ecba0ff621080d8a3a257e6f42a37bfcc8d364d71aff696991dd85635f6596ffa72efdefee1620c308984536b48d212a
+DIST rust-1.55.0-s390x-unknown-linux-gnu.tar.xz.asc 801 BLAKE2B fa4d8d8bb025a9010a44a9f021ba2fb443146debd9281ba520d764b49db6dd0e8b7b614d7a131f1722b29be4b80eabd3694e14f47a05d87cb3382c799ef96a88 SHA512 9ed8aefb443bc51a33e3cbca80f3ce1e65a565735672a966b73e5f4c8f7363c6d8204ab0f9387739765b70dfa8269372156500d99cc4d74ed94d1c2473c807f2
+DIST rust-1.55.0-x86_64-unknown-linux-gnu.tar.xz 139040728 BLAKE2B 1d7905411b55617178c88a062a1ff3048edb8020126a8c4c047aef762c4fd13b1c8c5de4c06a97477d9cfacadf6dc008c2b7b66862dc0c3fb9a8dc48f12f5ed2 SHA512 4bc304727b1e9459194a9a9ad5c8e1fe63501f01047d479585de6708365b3f59e09aade64c7f4969df204f8bbcf9de9508745d2b96bc25cb74ed093f8053a4d6
+DIST rust-1.55.0-x86_64-unknown-linux-gnu.tar.xz.asc 801 BLAKE2B d454086c93147737c7c144af288394512528e4ce759dc221d7371b62724857fe16e391949b5b4dac436bdcaef8bf817f577e8d951e1f4bae098d687b4a7bdbb5 SHA512 b175e3ddefd036fce29c80c65a86565583167f7859f0941dee6718fd71baa8596f1788a6bed5d992096959e1deda98dc9c10e8cbc896114b7938a05951c29f02
+DIST rust-1.55.0-x86_64-unknown-linux-musl.tar.xz 267291288 BLAKE2B b96e8fa1c8d2e55c07781db37ddd33ec7180cde29c84f5020f2ba0fbf6aa83f9db32723e191c15df765f965d1314a57d12d80e73d20deaab1333afca65bdfac7 SHA512 6fb700d5d17c084fa520b29f3012ac565eaf891705a27c7738a61bb9899bc952f679987ef3790875b5a7adae836c602b394c7e19103f30bbdf5ec82cf3e86567
+DIST rust-1.55.0-x86_64-unknown-linux-musl.tar.xz.asc 801 BLAKE2B 5ccf03518eae6406ff66bff108b26988a6a859e5cf88ca44327f9826d880ea26d6e115fb3e63f6a40d1cb15adc25d6f1c056438466095b7223269fb0d74540fe SHA512 8d84a976d9922d28a5ddac0f47258759a4c7542df02fb9ffede4a3e98ceecc6415229f3eb676a22536ffff842c6e7ee35d50d1507f2d818301493ee3a7db9bb5
+DIST rustc-1.56.1-src.tar.xz 121798264 BLAKE2B 09677b0332022f28a0d80949a6735929dbf64276f7eb57195d8c33e6c80f13c903432ff77d8834093ab551677618fb1d385f2300e2b1b4c064f9c245c696be32 SHA512 193468e211cde9ebc5f6e30b8e3733b79bd8710fe6dd45c7ed8d4392f91010d30466787afd4d0b2041cd7dd994924fee8ad111048824e248bd994959e55bf15f
+DIST rustc-1.56.1-src.tar.xz.asc 801 BLAKE2B 70ed1c26971e864aa6cc9b05eb52c4a140d0d0cccb3ff66d4a13e1b1dbac958c5369f76524c4702311566ed26aff635f5e3d35d9da71d96e070f5f0e978dc2ba SHA512 f997e7962ef8b283c19c97d8b898f3642f1a58c89a9cc5470cf88682263a42e2054d670c12bf93c41e81edf8324a5b51453f402a74bccb7744c7f463cf689aa8
diff --git a/dev-lang/rust/files/1.55.0-ignore-broken-and-non-applicable-tests.patch b/dev-lang/rust/files/1.55.0-ignore-broken-and-non-applicable-tests.patch
new file mode 100644
index 00000000..c3bee9ba
--- /dev/null
+++ b/dev-lang/rust/files/1.55.0-ignore-broken-and-non-applicable-tests.patch
@@ -0,0 +1,76 @@
+From 1879d1d1a284bf51c752e47db284ce22701ed5d0 Mon Sep 17 00:00:00 2001
+From: Samuel Holland <samuel@sholland.org>
+Date: Sun, 16 Sep 2018 16:38:48 +0000
+Subject: [PATCH 12/15] Ignore broken and non-applicable tests
+
+c-link-to-rust-va-list-fn: unstable feature, broken on aarch64, #56475
+env-funky-keys: can't handle LD_PRELOAD (e.g. sandbox)
+long-linker-command-lines: takes >10 minutes to run (but still passes)
+simd-intrinsic-generic-bitmask.rs: broken on BE, #59356
+sparc-struct-abi: no sparc target
+sysroot-crates-are-unstable: can't run rustc without RPATH
+---
+ src/test/codegen/sparc-struct-abi.rs                            | 1 +
+ src/test/run-make-fulldeps/c-link-to-rust-va-list-fn/Makefile   | 2 ++
+ src/test/run-make-fulldeps/long-linker-command-lines/Makefile   | 2 ++
+ src/test/run-make-fulldeps/sysroot-crates-are-unstable/Makefile | 2 ++
+ src/test/ui/env-funky-keys.rs                                   | 1 +
+ 6 files changed, 10 insertions(+)
+
+diff --git a/src/test/codegen/sparc-struct-abi.rs b/src/test/codegen/sparc-struct-abi.rs
+index 78e5b14a212..6f93e93286b 100644
+--- a/src/test/codegen/sparc-struct-abi.rs
++++ b/src/test/codegen/sparc-struct-abi.rs
+@@ -2,6 +2,7 @@
+ 
+ // only-sparc64
+ // compile-flags: -O --target=sparc64-unknown-linux-gnu --crate-type=rlib
+ // needs-llvm-components: sparc
++// ignore-test
+ #![feature(no_core, lang_items)]
+ #![no_core]
+ 
+diff --git a/src/test/run-make-fulldeps/c-link-to-rust-va-list-fn/Makefile b/src/test/run-make-fulldeps/c-link-to-rust-va-list-fn/Makefile
+index f124ca2ab61..363b18f0985 100644
+--- a/src/test/run-make-fulldeps/c-link-to-rust-va-list-fn/Makefile
++++ b/src/test/run-make-fulldeps/c-link-to-rust-va-list-fn/Makefile
+@@ -1,3 +1,5 @@
++# ignore-aarch64
++
+ -include ../tools.mk
+ 
+ all:
+diff --git a/src/test/run-make-fulldeps/long-linker-command-lines/Makefile b/src/test/run-make-fulldeps/long-linker-command-lines/Makefile
+index 5876fbc94bc..5f167ece1a2 100644
+--- a/src/test/run-make-fulldeps/long-linker-command-lines/Makefile
++++ b/src/test/run-make-fulldeps/long-linker-command-lines/Makefile
+@@ -1,3 +1,5 @@
++# ignore-test
++
+ -include ../tools.mk
+ 
+ all:
+diff --git a/src/test/run-make-fulldeps/sysroot-crates-are-unstable/Makefile b/src/test/run-make-fulldeps/sysroot-crates-are-unstable/Makefile
+index 9e770706857..6d92ec5cec8 100644
+--- a/src/test/run-make-fulldeps/sysroot-crates-are-unstable/Makefile
++++ b/src/test/run-make-fulldeps/sysroot-crates-are-unstable/Makefile
+@@ -1,1 +1,3 @@
++# ignore-test
++
+ all:
+         python2.7 test.py
+diff --git a/src/test/ui/env-funky-keys.rs b/src/test/ui/env-funky-keys.rs
+index c5c824ac58d..f3fe047a79c 100644
+--- a/src/test/ui/env-funky-keys.rs
++++ b/src/test/ui/env-funky-keys.rs
+@@ -1,6 +1,7 @@
+ // run-pass
+ // Ignore this test on Android, because it segfaults there.
+ 
++// ignore-test
+ // ignore-android
+ // ignore-windows
+ // ignore-cloudabi no execve
+-- 
+2.24.1
+
diff --git a/dev-lang/rust/files/1.56.1-musl-dynamic-linking.patch b/dev-lang/rust/files/1.56.1-musl-dynamic-linking.patch
new file mode 100644
index 00000000..b556228c
--- /dev/null
+++ b/dev-lang/rust/files/1.56.1-musl-dynamic-linking.patch
@@ -0,0 +1,69 @@
+From f11729adb9990528a38df7c703bf589d58998c4f Mon Sep 17 00:00:00 2001
+From: Jakub Jirutka <jakub@jirutka.cz>
+Date: Wed, 24 Nov 2021 21:32:50 -0600
+Subject: [PATCH] [PATCH] Fix linux_musl_base for native musl host
+
+See https://github.com/rust-lang/rust/pull/40113
+---
+ compiler/rustc_target/src/spec/crt_objects.rs | 22 -------------------
+ .../rustc_target/src/spec/linux_musl_base.rs  |  6 +----
+ 2 files changed, 1 insertion(+), 27 deletions(-)
+
+diff --git a/compiler/rustc_target/src/spec/crt_objects.rs b/compiler/rustc_target/src/spec/crt_objects.rs
+index 2fc9ab29f..276736159 100644
+--- a/compiler/rustc_target/src/spec/crt_objects.rs
++++ b/compiler/rustc_target/src/spec/crt_objects.rs
+@@ -62,28 +62,6 @@ pub(super) fn all(obj: &str) -> CrtObjects {
+     ])
+ }
+ 
+-pub(super) fn pre_musl_fallback() -> CrtObjects {
+-    new(&[
+-        (LinkOutputKind::DynamicNoPicExe, &["crt1.o", "crti.o", "crtbegin.o"]),
+-        (LinkOutputKind::DynamicPicExe, &["Scrt1.o", "crti.o", "crtbeginS.o"]),
+-        (LinkOutputKind::StaticNoPicExe, &["crt1.o", "crti.o", "crtbegin.o"]),
+-        (LinkOutputKind::StaticPicExe, &["rcrt1.o", "crti.o", "crtbeginS.o"]),
+-        (LinkOutputKind::DynamicDylib, &["crti.o", "crtbeginS.o"]),
+-        (LinkOutputKind::StaticDylib, &["crti.o", "crtbeginS.o"]),
+-    ])
+-}
+-
+-pub(super) fn post_musl_fallback() -> CrtObjects {
+-    new(&[
+-        (LinkOutputKind::DynamicNoPicExe, &["crtend.o", "crtn.o"]),
+-        (LinkOutputKind::DynamicPicExe, &["crtendS.o", "crtn.o"]),
+-        (LinkOutputKind::StaticNoPicExe, &["crtend.o", "crtn.o"]),
+-        (LinkOutputKind::StaticPicExe, &["crtendS.o", "crtn.o"]),
+-        (LinkOutputKind::DynamicDylib, &["crtendS.o", "crtn.o"]),
+-        (LinkOutputKind::StaticDylib, &["crtendS.o", "crtn.o"]),
+-    ])
+-}
+-
+ pub(super) fn pre_mingw_fallback() -> CrtObjects {
+     new(&[
+         (LinkOutputKind::DynamicNoPicExe, &["crt2.o", "rsbegin.o"]),
+diff --git a/compiler/rustc_target/src/spec/linux_musl_base.rs b/compiler/rustc_target/src/spec/linux_musl_base.rs
+index 5038a967d..25d634a1e 100644
+--- a/compiler/rustc_target/src/spec/linux_musl_base.rs
++++ b/compiler/rustc_target/src/spec/linux_musl_base.rs
+@@ -1,16 +1,12 @@
+-use crate::spec::crt_objects::{self, CrtObjectsFallback};
+ use crate::spec::TargetOptions;
+ 
+ pub fn opts() -> TargetOptions {
+     let mut base = super::linux_base::opts();
+ 
+     base.env = "musl".to_string();
+-    base.pre_link_objects_fallback = crt_objects::pre_musl_fallback();
+-    base.post_link_objects_fallback = crt_objects::post_musl_fallback();
+-    base.crt_objects_fallback = Some(CrtObjectsFallback::Musl);
+ 
+     // These targets statically link libc by default
+-    base.crt_static_default = true;
++    base.crt_static_default = false;
+ 
+     base
+ }
+-- 
+2.32.0
+
diff --git a/dev-lang/rust/metadata.xml b/dev-lang/rust/metadata.xml
new file mode 100644
index 00000000..a51257c9
--- /dev/null
+++ b/dev-lang/rust/metadata.xml
@@ -0,0 +1,24 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE pkgmetadata SYSTEM "https://www.gentoo.org/dtd/metadata.dtd">
+<pkgmetadata>
+	<maintainer type="person">
+		<email>gyakovlev@gentoo.org</email>
+		<name>Georgy Yakovlev</name>
+	</maintainer>
+	<maintainer type="project">
+		<email>rust@gentoo.org</email>
+		<name>Rust Project</name>
+	</maintainer>
+	<use>
+		<flag name="clippy">Install clippy, Rust code linter</flag>
+		<flag name="miri">Install miri, an interpreter for Rust's mid-level intermediate representation (requires USE=nightly)</flag>
+		<flag name="nightly">Enable nightly (UNSTABLE) features</flag>
+		<flag name="parallel-compiler">Build a multi-threaded rustc (experimental, not tested by upstream)</flag>
+		<flag name="rls">Install rls, Rust Language Server (used with IDEs supporting RLS protocol)</flag>
+		<flag name="rustfmt">Install rustfmt, Rust code formatter</flag>
+		<flag name="rust-src">Install rust-src, needed by developer tools and for build-std (cross)</flag>
+		<flag name="system-bootstrap">Bootstrap using installed rust compiler</flag>
+		<flag name="system-llvm">Use the system LLVM install</flag>
+		<flag name="wasm">Build support for the wasm32-unknown-unknown target</flag>
+	</use>
+</pkgmetadata>
diff --git a/dev-lang/rust/rust-1.56.1.ebuild b/dev-lang/rust/rust-1.56.1.ebuild
new file mode 100644
index 00000000..df612b6d
--- /dev/null
+++ b/dev-lang/rust/rust-1.56.1.ebuild
@@ -0,0 +1,686 @@
+# Copyright 1999-2021 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=7
+
+PYTHON_COMPAT=( python3_{7..10} )
+
+inherit bash-completion-r1 check-reqs estack flag-o-matic llvm multiprocessing \
+	multilib-build python-any-r1 rust-toolchain toolchain-funcs verify-sig
+
+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 arm64"
+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/${SRC}
+	verify-sig? ( https://static.rust-lang.org/dist/${SRC}.asc )
+	!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 miri nightly parallel-compiler rls rustfmt rust-src system-bootstrap system-llvm test wasm ${ALL_LLVM_TARGETS[*]}"
+
+# Please keep the LLVM dependency block separate. Since LLVM is slotted,
+# we need to *really* make sure we're not pulling more than one slot
+# simultaneously.
+
+# How to use it:
+# List all the working slots in LLVM_VALID_SLOTS, newest first.
+LLVM_VALID_SLOTS=( 13 )
+LLVM_MAX_SLOT="${LLVM_VALID_SLOTS[0]}"
+
+# splitting usedeps needed to avoid CI/pkgcheck's UncheckableDep limitation
+# (-) usedep needed because we may build with older llvm without that target
+LLVM_DEPEND="|| ( "
+for _s in ${LLVM_VALID_SLOTS[@]}; do
+	LLVM_DEPEND+=" ( "
+	for _x in ${ALL_LLVM_TARGETS[@]}; do
+		LLVM_DEPEND+="
+			${_x}? ( sys-devel/llvm:${_s}[${_x}(-)] )"
+	done
+	LLVM_DEPEND+=" )"
+done
+unset _s _x
+LLVM_DEPEND+=" )
+	<sys-devel/llvm-$(( LLVM_MAX_SLOT + 1 )):=
+	wasm? ( sys-devel/lld )
+"
+
+# 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/${PV}/src/stage0.txt
+RUST_DEP_PREV="$(ver_cut 1).$(($(ver_cut 2) - 1))*"
+RUST_DEP_CURR="$(ver_cut 1).$(ver_cut 2)*"
+BOOTSTRAP_DEPEND="||
+	(
+		=dev-lang/rust-"${RUST_DEP_PREV}"
+		=dev-lang/rust-bin-"${RUST_DEP_PREV}"
+		=dev-lang/rust-"${RUST_DEP_CURR}"
+		=dev-lang/rust-bin-"${RUST_DEP_CURR}"
+	)
+"
+
+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-3.13.4
+		dev-util/ninja
+	)
+	test? ( sys-devel/gdb )
+	verify-sig? ( app-crypt/openpgp-keys-rust )
+"
+
+DEPEND="
+	>=app-arch/xz-utils-5.2
+	net-misc/curl:=[http2,ssl]
+	sys-libs/zlib:=
+	dev-libs/openssl: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 )
+	rls? ( rust-src )
+	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}/${PV}/libexec/.*
+	usr/lib/${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}/${PV}/lib/rustlib/.*/lib/lib.*.so
+"
+
+# An rmeta file is custom binary format that contains the metadata for the crate.
+# rmeta files do not support linking, since they do not contain compiled object files.
+# so we can safely silence the warning for this QA check.
+QA_EXECSTACK="usr/lib/${PN}/${PV}/lib/rustlib/*/lib*.rlib:lib.rmeta"
+
+# causes double bootstrap
+RESTRICT="test"
+
+VERIFY_SIG_OPENPGP_KEY_PATH=${BROOT}/usr/share/openpgp-keys/rust.asc
+
+PATCHES=(
+	"${FILESDIR}"/1.55.0-ignore-broken-and-non-applicable-tests.patch
+	"${FILESDIR}"/1.56.1-musl-dynamic-linking.patch
+)
+
+S="${WORKDIR}/${MY_P}-src"
+
+toml_usex() {
+	usex "${1}" true false
+}
+
+bootstrap_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 ${rustc_version} to build"
+	fi
+}
+
+pre_build_checks() {
+	local M=4096
+	# multiply requirements by 1.5 if we are doing x86-multilib
+	if use amd64; then
+		M=$(( $(usex abi_x86_32 15 10) * ${M} / 10 ))
+	fi
+	M=$(( $(usex clippy 128 0) + ${M} ))
+	M=$(( $(usex miri 128 0) + ${M} ))
+	M=$(( $(usex rls 512 0) + ${M} ))
+	M=$(( $(usex rustfmt 256 0) + ${M} ))
+	# add 2G if we compile llvm and 256M per llvm_target
+	if ! use system-llvm; then
+		M=$(( 2048 + ${M} ))
+		local ltarget
+		for ltarget in ${ALL_LLVM_TARGETS[@]}; do
+			M=$(( $(usex ${ltarget} 256 0) + ${M} ))
+		done
+	fi
+	M=$(( $(usex wasm 256 0) + ${M} ))
+	M=$(( $(usex debug 2 1) * ${M} ))
+	eshopts_push -s extglob
+	if is-flagq '-g?(gdb)?([1-9])'; then
+		M=$(( 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_${EBUILD_PHASE}
+}
+
+llvm_check_deps() {
+	has_version -r "sys-devel/llvm:${LLVM_SLOT}[${LLVM_TARGET_USEDEPS// /,}]"
+}
+
+pkg_pretend() {
+	pre_build_checks
+}
+
+pkg_setup() {
+	pre_build_checks
+	python-any-r1_pkg_setup
+
+	export LIBGIT2_NO_PKG_CONFIG=1 #749381
+
+	use system-bootstrap && bootstrap_rust_version_check
+
+	if use system-llvm; then
+		llvm_pkg_setup
+
+		local llvm_config="$(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}/${rust_stage0}"/install.sh --disable-ldconfig \
+			--without=rust-docs --destdir="${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/wasm_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\",$tools"
+	fi
+	if use rls; then
+		tools="\"rls\",\"analysis\",$tools"
+	fi
+	if use rustfmt; then
+		tools="\"rustfmt\",$tools"
+	fi
+	if use rust-src; then
+		tools="\"src\",$tools"
+	fi
+
+	local rust_stage0_root
+	if use system-bootstrap; then
+		local printsysroot
+		printsysroot="$(rustc --print sysroot || die "Can't determine rust's sysroot")"
+		rust_stage0_root="${printsysroot}"
+	else
+		rust_stage0_root="${WORKDIR}"/rust-stage0
+	fi
+	# in case of prefix it will be already prefixed, as --print sysroot returns full path
+	[[ -d ${rust_stage0_root} ]] || die "${rust_stage0_root} is not a directory"
+
+	rust_target="$(rust_abi)"
+
+	cat <<- _EOF_ > "${S}"/config.toml
+		changelog-seen = 2
+		[llvm]
+		download-ci-llvm = false
+		optimize = $(toml_usex !debug)
+		release-debuginfo = $(toml_usex debug)
+		assertions = $(toml_usex debug)
+		ninja = true
+		targets = "${LLVM_TARGETS// /;}"
+		experimental-targets = ""
+		link-shared = $(toml_usex system-llvm)
+		[build]
+		build-stage = 2
+		test-stage = 2
+		doc-stage = 2
+		build = "${rust_target}"
+		host = ["${rust_target}"]
+		target = [${rust_targets}]
+		cargo = "${rust_stage0_root}/bin/cargo"
+		rustc = "${rust_stage0_root}/bin/rustc"
+		rustfmt = "${rust_stage0_root}/bin/rustfmt"
+		docs = $(toml_usex doc)
+		compiler-docs = false
+		submodules = false
+		python = "${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)
+		debug-assertions-std = $(toml_usex debug)
+		debuginfo-level = $(usex debug 2 0)
+		debuginfo-level-rustc = $(usex debug 2 0)
+		debuginfo-level-std = $(usex debug 2 0)
+		debuginfo-level-tools = $(usex debug 2 0)
+		debuginfo-level-tests = 0
+		backtrace = true
+		incremental = false
+		default-linker = "$(tc-getCC)"
+		parallel-compiler = $(toml_usex parallel-compiler)
+		channel = "$(usex nightly nightly stable)"
+		description = "gentoo"
+		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))
+		# only deny warnings if doc+wasm are NOT requested, documenting stage0 wasm std fails without it
+		# https://github.com/rust-lang/rust/issues/74976
+		# https://github.com/rust-lang/rust/issues/76526
+		deny-warnings = $(usex wasm $(usex doc false true) true)
+		backtrace-on-ice = true
+		jemalloc = false
+		[dist]
+		src-tarball = false
+		compression-formats = ["gz"]
+	_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
+		if [[ "${cross_toolchain}" == *-musl* ]]; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				musl-root = "$(${cross_toolchain}-gcc -print-sysroot)/usr"
+			_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 ${cross_toolchain} cross toolchain"
+		ewarn
+		if ! has_version -b 'sys-devel/binutils[multitarget]' ; then
+			ewarn "'sys-devel/binutils[multitarget]' is not installed"
+			ewarn "'strip' will be unable to strip cross libraries"
+			ewarn "cross targets will be installed with full debug information"
+			ewarn "enable 'multitarget' USE flag for binutils to be able to strip object files"
+			ewarn
+			ewarn "Alternatively llvm-strip can be used, it supports stripping any target"
+			ewarn "define STRIP=\"llvm-strip\" to use it (experimental)"
+			ewarn
+		fi
+	done
+	fi # I_KNOW_WHAT_I_AM_DOING_CROSS
+
+	einfo "Rust configured with the following flags:"
+	echo
+	echo RUSTFLAGS="${RUSTFLAGS:-}"
+	echo RUSTFLAGS_BOOTSTRAP="${RUSTFLAGS_BOOTSTRAP:-}"
+	echo RUSTFLAGS_NOT_BOOTSTRAP="${RUSTFLAGS_NOT_BOOTSTRAP:-}"
+	env | grep "CARGO_TARGET_.*_RUSTFLAGS="
+	cat "${S}"/config.env || die
+	echo
+	einfo "config.toml contents:"
+	cat "${S}"/config.toml || die
+	echo
+}
+
+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\
+		"${EPYTHON}" ./x.py build -vv --config="${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: ${failed[@]}"
+		die "aborting due to test failures"
+	fi
+}
+
+src_install() {
+	(
+	IFS=$'\n'
+	env $(cat "${S}"/config.env) DESTDIR="${D}" \
+		"${EPYTHON}" ./x.py install	-vv --config="${S}"/config.toml -j$(makeopts_jobs) || 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
+	newbashcomp src/tools/cargo/src/etc/cargo.bashcomp.sh 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}/libexec" "/usr/lib/${PN}/libexec-${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"
+		$(use amd64 && usex elibc_musl 'CARGO_TARGET_X86_64_UNKNOWN_LINUX_MUSL_RUSTFLAGS="-C target-feature=-crt-static"' '')
+		$(use arm64 && usex elibc_musl 'CARGO_TARGET_AARCH64_UNKNOWN_LINUX_MUSL_RUSTFLAGS="-C target-feature=-crt-static"' '')
+	_EOF_
+
+	rm -rf "${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-${P}"
+		/usr/bin/cargo
+		/usr/bin/rustdoc
+		/usr/bin/rust-gdb
+		/usr/bin/rust-gdbgui
+		/usr/bin/rust-lldb
+		/usr/lib/rustlib
+		/usr/lib/rust/lib
+		/usr/lib/rust/libexec
+		/usr/lib/rust/man
+		/usr/share/doc/rust
+	_EOF_
+
+	if use clippy; then
+		echo /usr/bin/clippy-driver >> "${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
+}