dev-lang/rust: add 1.81.0

Signed-off-by: Arthur Zamarin <arthurzam@gentoo.org>

2 files changed, 817 insertions, 0 deletions

diff --git a/dev-lang/rust/Manifest b/dev-lang/rust/Manifest
index 90b2fb8d0d22..73973e0b0dbb 100644
--- a/dev-lang/rust/Manifest
+++ b/dev-lang/rust/Manifest
@@ -172,6 +172,34 @@ DIST rust-1.79.0-x86_64-unknown-linux-gnu.tar.xz 165014992 BLAKE2B abd9f73c8439f
 DIST rust-1.79.0-x86_64-unknown-linux-gnu.tar.xz.asc 801 BLAKE2B 9cd1a51580d9f70f96c83b603716a5edbd8e1c4d4c2f53c07aa9d37c6c47f3bd252c0a1cf26b77bcd60842fb83ed74cd7b6e4ab3a039c3938423372485f8c1f4 SHA512 b65621f91085f4a5c6f84ed5e530fe56502ca12c5b18486afb1197156c5f6087110578647d428a58a1a6c04765569a28c38ae40a14c72fd41f39948349e8115d
 DIST rust-1.79.0-x86_64-unknown-linux-musl.tar.xz 247326760 BLAKE2B 36bf6787c69971ba7c445d1895001c005af0aeb48aaa3309e971237125a2b6de3ef5f1534572f8a3f4c1bc024962a8fd030e91b63c02f03444b5aec1a3ed2e5a SHA512 02e5c2a67f5470f3320b04e7c4f0a6f5dbd361d5a97aee7e5860d04224683166b21375794c94ae040a2cc6fc119380be9d3465b8c5e1798abd4142d621cf9f99
 DIST rust-1.79.0-x86_64-unknown-linux-musl.tar.xz.asc 801 BLAKE2B 6dde2d3096f7e47d31b1e13e7e5f41cf278e770dcb8a222d76ab5b93b2ca8a6d9e5b45515e097e5285bd2d76130546b3eb302a8391102460c4564e654c88f03c SHA512 4618852fdd81684ddf5bd8758d2551f1c800ef1614fed8ba91a9a1d29b3b51a0b9bf169c499dd8890347f999d002e5aba7b49a98eb819f20bdfe82fa375ed45a
+DIST rust-1.80.1-aarch64-unknown-linux-gnu.tar.xz 226220216 BLAKE2B 41c7a5ba5108da3ae79fc6d6fa229d2a91e6e217c92bbcbe37fe35d48418e0c787a29c43ffb406acabd410efcca0464da325120f925dfd6d1ee0822f0041f517 SHA512 4279028abc347ff1436d055f79523a24f98d94938dd7eb73516bcf39dbbfbd941418d4b1227576870c75a7c0b4c23c74b0528e1c5b8a39d54422af1ee2abb74f
+DIST rust-1.80.1-aarch64-unknown-linux-gnu.tar.xz.asc 801 BLAKE2B 20c46e31535278145d143f619851edf151feb786b6d3112022b63e9dc882aad300665af16ba9dc600554f3d8f95d4ed7715bab5b57fab3e33a2c81fd7cd664a7 SHA512 dc104a9a30945d8f3d3a74cbc31b87ac4cffb81b4dd80a53b3e86432058830d4287542166db273895d9758bbfc36814c384c35a98b360ecf18938c6ebf6beb05
+DIST rust-1.80.1-aarch64-unknown-linux-musl.tar.xz 206752364 BLAKE2B 924f6c1f6b01c048ee9f1fc632e74abf1f5c11936effeb797d45fd500b1ce5a1638cc8061226018dd3e5a910e1d20a7645efbd25dbc5e3b2336cb3d20817fece SHA512 74a9846b328f2a79a75f7cb4c795a78c40ec1c30ac864e20046fa39324800e40ec13737bc580d5949dca92472c1512c747f67d8b67cd5e3e9048b22e2a8b7866
+DIST rust-1.80.1-aarch64-unknown-linux-musl.tar.xz.asc 801 BLAKE2B 49100a62a57a4147c13379bee868f5725b96f4dfa59c83c6d3a1a67eed86b0ed02bb0684b096dd557d07f54d0c3fb32bace38c81aed55cea7a0c001d53049897 SHA512 955d39f554413d51da50d2c66a8e9dd57aa28c850f12410b58a8ae1d8d768b7b5d2687bc6b88218f800f3e4242e282d6fc8d2e76616c30c926af1f9a461b2d9e
+DIST rust-1.80.1-arm-unknown-linux-gnueabi.tar.xz 190441552 BLAKE2B 2907546fe513550e8bb79eb60382503ae55dab8420be41be6d57ef04e9582362324de8639a43671181e439223cf2c677ee4f4819455a264c2eb34ce6e79bfef1 SHA512 1ec38d348e1c888cbbc7b391571e84a3026a5c59fe065d79e5769241c6af9f39c0f689c981695846a9109ab3c9baee9b225316868dd2fed18d15f4f1c81cb5f2
+DIST rust-1.80.1-arm-unknown-linux-gnueabi.tar.xz.asc 801 BLAKE2B 106a856965e94aa260258aa8bb973a513cd13aef7b15f0c5794a699fbfa5445dbdd3628084d7a913849f0dd274075a28bad25a758e031ce851a6afe463dcc882 SHA512 ce34d38c05e8b4a7df9f0a79fe107b7d313bc467b1cf82cac43b8ab9b6ae3e4d3c1f4428f3a627110ce3b66f89086982cc95d0b2b2e85187095f66338aa92d0c
+DIST rust-1.80.1-arm-unknown-linux-gnueabihf.tar.xz 190747600 BLAKE2B 481473bfac35b8a45c4c3a5593b76abf88fe6eb50f0b2a424b1c5ed846e56234c2faa22910623514d0f6804d13f78d28cc3e4cff956ae558ac1dd655a0b62057 SHA512 540f74fe1f43ad8c407620ec47eae1ac4a3c4ddc8497cb79d0784393d17581c41576df7e114efbd6541a8626802c7961c998cd0895618b254814b66efc3bb01d
+DIST rust-1.80.1-arm-unknown-linux-gnueabihf.tar.xz.asc 801 BLAKE2B f1d4aa5cbe123f566d63c3f9165766622048f463c78c0d9635949ac46d6910c1b9c59b0d8c7fce034c1b070416e1ac3f998c4b0c91c796e18669f9294a75bc89 SHA512 f4a75d28a245eaea7deabbbe282cad493175c303f9f0744a248728a7753603ba7e4acf488b3e8e3478a8f7160ed92963d255f0216b1fb598b66a91eb51c30a6f
+DIST rust-1.80.1-armv7-unknown-linux-gnueabihf.tar.xz 195804620 BLAKE2B f279fd6944aaa76a7a35007e0521003140e4a3569cd36e57d7fa4ed7f72b37ffb7d03412588d1b0671677fd95bd6b6626eb9603d55b81971e148ad0137bbbc2d SHA512 487aa0be4230659db1c5cf2436c65062f1c3061fa085f38ec84dce029a6ef3614657ba407d1aa13c1e5ff2cf6e87f7ffc0c1a1947c3dc641a5b6843cdde85615
+DIST rust-1.80.1-armv7-unknown-linux-gnueabihf.tar.xz.asc 801 BLAKE2B 15b450c4743e45c4c2eb9a1ec6afd448a30ad64e9a885bbedd7f8a7f59db45926e7ae4b1b0f350a783adafe93ccecec40f6436b62c8063eac5ad4e91c5418576 SHA512 b5ce5e78cacafd3f0ccfa2797aebecb360bbf56140cf1a1f3dc6c200e7a6ac7d3eceefc0f3cd3fd109ff1b8755b7828c2808ac9bf53f23a3e49c27d6c6050e8c
+DIST rust-1.80.1-i686-unknown-linux-gnu.tar.xz 221151480 BLAKE2B 01c4a29b5cdc47b0070b031984daa5d6f77844cb3ab9a82a40440b5c4a7a1f6bdccd4b8f46e3ab13bc194997c4a1341de484319ad3e8f642c67f7b8d8481c846 SHA512 2c0cc27407265f686d5b3a5e9f00f751924ae47f3d6a5cc044c56278843ee76ba3cedd63575447feb5cda0a2b1d2a26d7a78e0c558e2f47b7cb09f40aa6b8425
+DIST rust-1.80.1-i686-unknown-linux-gnu.tar.xz.asc 801 BLAKE2B 549b27298fbed09727ae6c6086127aab9c0ebf9a6fce70c2e102fd29e983e31b1907f3a2e7c18800ff7b2efcd6f49c36aa11a5021fb9f57e6148e62628cc56a2 SHA512 c20ea2b577aa263e70211198a9fe896b9d560b737d74d640ee107a89dd9d5b31bc843e2fdda75bf21318fd3aaaea58c4ee918d003f7bf7636aa5636fb657133a
+DIST rust-1.80.1-loongarch64-unknown-linux-gnu.tar.xz 172528232 BLAKE2B d308b0aab1ef8dc338025d9a106920f507035efdc04390e9618b6a936ec117b70c791d14d5a73aeb0533f1e8d1952ae36bc3d4e624239d5a64ecfaefa70aa5ab SHA512 1c6d689e43cad549f2f8aa96fd5bf52080276c1de386b771206c7533feb11a47bf515ea72dc7f406852ca7dc5632f1436dde69014d8bf35bd0f25bcc85c3cfa0
+DIST rust-1.80.1-loongarch64-unknown-linux-gnu.tar.xz.asc 801 BLAKE2B 92b347907616b18ae06d85a1380d01bd078c3ea4a03fdf808b79794ffeb1d6661057688050130aec61d29062f07a030ebcf15fe3d866cb411325c44a2c393a33 SHA512 7245d91fc398d787e8bfa2e0bbceda9aa30665699f01bc5490f29f690fc1f8fd5d5ee8d4a941d38f0dc5c4cb7c275bf4b6d4bd3727b1bad65326594101f90cf4
+DIST rust-1.80.1-powerpc-unknown-linux-gnu.tar.xz 185400364 BLAKE2B 2b37d052d0fc4f612c298e87be9a0afcac3ef8548f3914530737d0435cbdf270e0c3b8422c08f84f96192f89805a9bff9d3fe570eb056afc1fd902202a806025 SHA512 1350aa8c105555778231b4ef7ce1c4c8850cc112ccc2f72621bbb3c011a0733da91df7521bbab0aa3269b4ad61231a631660593d7608d017083cd7af375fde30
+DIST rust-1.80.1-powerpc-unknown-linux-gnu.tar.xz.asc 801 BLAKE2B da5dfb8d287b7a30a32443b0edb80a3994c68f732ce02a6f6d735d589db2c273962e02925fa88311698672eca10441850066c2f1ab2e48ded8ca33109e298509 SHA512 f0d381594d6b164e068cb80e39a508774633db64abd4a9ba68eba48fd627fbda6c0cdf849137f61e196ab44e0f93eba5d08f3dd60fe5820259b8d9fafdd51407
+DIST rust-1.80.1-powerpc64-unknown-linux-gnu.tar.xz 183179096 BLAKE2B 0b7b7af392b8aa1a1df14ea4f53fd231c5c475eddbadd2105a5222393162b187109201f96dbb30c9877ff1c684af48b9868d17dbf26113193cab572d8ea40852 SHA512 67ce98a6f89997c13f576493644634f8ee5055952500e4f6d6ae096fee9570d6e5938c483892e76325905fec35184ff7f7edc21e4ec30199e821017890825289
+DIST rust-1.80.1-powerpc64-unknown-linux-gnu.tar.xz.asc 801 BLAKE2B b5b296291d031d254a4be6f000abade2b5d67cea8cecb332505469af3ec3ed1e21454ba41f96ed4e77dc2324c339f136ad04f034191a639394e6d9390065ac19 SHA512 9ddacb0ccd9da29fb93c66a2d701a03af6a4a2e9911c06a09d9fd5bde2647931e6c61e623d418200038e232227010206561e431331ef866324e9020dfba4597b
+DIST rust-1.80.1-powerpc64le-unknown-linux-gnu.tar.xz 194097292 BLAKE2B 1134beec940443b111594c86f912b2bf26bf3ace83cab3f0176175a6e891d047701e08e8ebc62094fdb4bd7b4d2de115ba0125ecd5ff6b3a20906db30c86c480 SHA512 4275343153b6acec8ba3a25dd4e85abc3ea7872a9cca4cea6f394fc24db6461db7fe7c047d158b61bb0635983a6a033f25da39f5fa1d6d9ee6d3eb956799dafa
+DIST rust-1.80.1-powerpc64le-unknown-linux-gnu.tar.xz.asc 801 BLAKE2B 280558f7b575a5b79c7367715e74f333b7e9bb0d4f6ffd9939ed9daf33899dfc19cf59eca2cfafdd2ad1d6d71ea58486d04931fc3d089c9c491c8374985a1960 SHA512 6c784aa10878531b44e5927b2cab5a81efd4767a5e723747e4a9c506b4c48141b44c98ce364459db47ad8f03f4f066fe96d070806695d76a6abc9e0c7a53a09c
+DIST rust-1.80.1-riscv64gc-unknown-linux-gnu.tar.xz 194141700 BLAKE2B e174c185d35d3974c923233807ff1a27f6736af2a8b97f92153c0518aad4f46653d5e5bab219b51ee1b58cac7216a29e5ad6499a982de8f52f6871903a307b71 SHA512 4d69bfd0fdd2de634a3ab873e8e2929c53baec12e4edcb220b8054c672324dba7a94d06a9c35474b8ba74b2e408d7b42a857ad11a4b7a346509b5fde23e8c779
+DIST rust-1.80.1-riscv64gc-unknown-linux-gnu.tar.xz.asc 801 BLAKE2B 274048978581a816fd8a9c396e7adffa509004121d5e9dc8df53a9f4a850dc7a0bca8652760c1f27c1c0dd57be5a91ff60e2d39ad7681b17efdea91312d0fc40 SHA512 5c34ff90acd4307a57733f8371abf4712c3ca06bf9db88f1d3e3ed9dda1c16a7775d713804ec4f1bc46089428b6b5472ab7e416f10e21d33f10b84b1a33d1957
+DIST rust-1.80.1-s390x-unknown-linux-gnu.tar.xz 209785288 BLAKE2B 01792daab79e7abed8bdeca53295928429b6814672aa4e0426316ec790d22b22abf25d3d5513582206d18f53147e60d252a0557ab9cca3b594c89ad603d94ea7 SHA512 66b20f5d001e978e2db5277da5f01271f0500a59877a849ccadebd5823eaeee35066abdd5d449e024cd5ae8ee41dd60fad77a00648cac1db62137d6722729fd6
+DIST rust-1.80.1-s390x-unknown-linux-gnu.tar.xz.asc 801 BLAKE2B 5c0a1a6036d3c3e9af835c281fd347a842cea15bea5f3d5f109f4080a2f93020d5e1c1a7de1894c03e8a2c87c6560f792a0c8024e68eb55d10e50da098f1e621 SHA512 7bbc3e8d3b039b522e62101714f5edb85046cfc06375df4b49c9ece891f8fc57e86027e1fd12a5837be7623c9137840551389e7dec4b2700e1dac0ae69121729
+DIST rust-1.80.1-x86_64-unknown-linux-gnu.tar.xz 167553060 BLAKE2B abc6430cfbbea5dd0ea42a6a3e2796b6f499d5a8343616d310ed22b541bdb15803d882dca9be743a81768bdf55f78c7a803bb594844d7dc3d2bdf09bd3f3d312 SHA512 73e6000af98efe5d90ab484ad88f455f07ccdabe49400d25ac16eeaa51327a5d17eaaae5ef3eb0b04b9aba2015c379eeb2a00076d82ba959e53e3dba470a228b
+DIST rust-1.80.1-x86_64-unknown-linux-gnu.tar.xz.asc 801 BLAKE2B bb52100a14bfa2775ca7cab5cd0f9dbc489ec3b26a8687876c97b666435c44ce58d86fd9f11d4f4832e79c05fa3ddefd7157edc91a3da25ffeba07da61fbddf9 SHA512 08aad912e47341bff29ee1d1b52cd02df8e609747f7061e61ed6a401d798140a8587378aa992b0d52af955a44d2284eefa00f27a6e94b4ed561c06eed60ad6fe
+DIST rust-1.80.1-x86_64-unknown-linux-musl.tar.xz 248220632 BLAKE2B 7f0954379658df0a5cb0bb4bd49fdd1d216bfa5a200789124667d13ad97f0a5278f57e5b6278a969558c834de43a5d7e3f5ad3e331cc5a4c428dc097453a9394 SHA512 079cd3384c0b7f85d5fb2f02f27febe423ff533d71463097fbaa90449a955699fc25d8e4ae16489f7d7920c34c318c0f2e8185eeb9c6fd64c0851e4366c5eca2
+DIST rust-1.80.1-x86_64-unknown-linux-musl.tar.xz.asc 801 BLAKE2B bad9fdebe33c251b8802ecb0150a074e86becac00874137f793b1805bf36373903fbcfd4744b1086851fd1357c6c81262a7eb321685640d856dc2ee3a37917a7 SHA512 405de0a8676755a63a4fc1e61dd358960efc90e4fd2417cfb4311bfaab5a744397e1f751afbe6a9515c1d92626a79fc782272261eed2f72b37b88fd77a84d7c0
 DIST rustc-1.71.1-src.tar.xz 151983068 BLAKE2B 3dfdbc246feb84a79ae94c2de978c5585ee06cf6b683d2245869b62e28f7c79f89cc589f5431537713bf088236a0b824acefc1b68e418e9eb72e1eea98054e3f SHA512 fd0e5a16bdbeb539184513583089e55f681cb772810df357b6b1464853f7022ac02edab3dd155b2262ed0047e2a25dea3808dd078dcdfce9d399384465009db4
 DIST rustc-1.71.1-src.tar.xz.asc 801 BLAKE2B a88c073a70552d73e2d7695eceabdaa478f34501b7271fabf7f4a09f3efa545181f34353e45776b05918e6aeba88adb02f9731454f7085a7abf1602fc6589983 SHA512 9dd0406cf22f1daa7fcfd015fc1c6f8d36586aa99bf14c1491ee464c1f892ab759feb83e8b55b64713170fb777fdbe038fb5fd01a59c911b6599223baaba0677
 DIST rustc-1.74.1-src.tar.xz 155968724 BLAKE2B e05f2379ac94b286f85791a138e1928e5b5b5a7749f0981d82c40c2a12860f55bf96bb2f0e924e35a0f8b2447b13052d38adea909aaa3199105787bb5a4861b3 SHA512 14c7e7ed2f38ab60299d8c7d41d78f042b6b57ef822d577b5138e60bdde31cf141eccd4332a25bc5da3d58eb5313d63c1448b5dfe9e11b8055bb8ea133a9038d
@@ -184,3 +212,5 @@ DIST rustc-1.79.0-src.tar.xz 162359512 BLAKE2B 753c0e9c537644d1a12b4d38024c22952
 DIST rustc-1.79.0-src.tar.xz.asc 801 BLAKE2B 860283021f513f5d4c81ea1f8d9567f0a052cc53a1d51d7fd9a804a39b855e24e06ea4c73db53176c1cf846910147de6bbc26da35755f3d0d4b296503e691e64 SHA512 51eec85d71817fe21073502c1d18e44ce694dc11b1c181e82462b529a24a610c8e215e6f2640e8b6d80f028207a360e43354cafa863f49a12c547b4c5f52d7e7
 DIST rustc-1.80.1-src.tar.xz 199234944 BLAKE2B 39891362f2a4bc249f5d943e3ded48d2add9cd9c0ee3c085d7fbefbfbc784f1e029308d9486cd35a6c03b77243077dc1196c75980faeea0d4319cee057509b6a SHA512 3c746108a86eeb734c1a8c8f63ba1a45e2cb03a8cb553395a167d07dc3ce5d8d9ea365ddd95533b6952d915069b86cad7ad218d27861e0889f8e878136bd32ab
 DIST rustc-1.80.1-src.tar.xz.asc 801 BLAKE2B 0fb361678e4b580c89ccc35fd1b29d24ab41af854e5a34d24192671c93140b7d2c91e740a51f1eaa6854d5970bb91a0510aac9cb6cbf2883e77a2b941d65b010 SHA512 9d5731db73b8a982b956cb2c4736c0fc7dedab785d9855508e6a1fc2d2163d561fdcd5b254ea5f7b1f27b3903d10d9d2403366e63f9c690ab722c401109a7c1d
+DIST rustc-1.81.0-src.tar.xz 216743872 BLAKE2B d9f52da9092d0723c862ebbb2dc351cad0670be6872f691b4c9f36faf06803f072720ebd04f06745c355d807991b38312cc830b12d6d3f50b0574bb7325340b7 SHA512 b8a837ced521d2ca2c7f228a0640da591384519e4dbc1ae768524d50616da6abbd2f7bdae3777caebc0447dac91bf76481282ce5a2264d7f30e173caa6321a51
+DIST rustc-1.81.0-src.tar.xz.asc 801 BLAKE2B 01cd9f386d3fd73f4eb43b14d7d479ebababb8640abbff170e697817b94b8a18edd801c6047ecf3c084a0a51764c5e4f3f4bd6b00e8ae000ef0b850e9506572a SHA512 19c0da9d67f2bd9fd79a2078f0f486ee7fad5646a09a609b7e30d9531851955ae8df0ec69f9ddc09e2fd6e74d529648335b0fda833839c88c54c84494ec1988e
diff --git a/dev-lang/rust/rust-1.81.0.ebuild b/dev-lang/rust/rust-1.81.0.ebuild
new file mode 100644
index 000000000000..b6837f265a6f
--- /dev/null
+++ b/dev-lang/rust/rust-1.81.0.ebuild
@@ -0,0 +1,787 @@
+# Copyright 1999-2024 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+PYTHON_COMPAT=( python3_{10..13} )
+
+inherit bash-completion-r1 check-reqs estack flag-o-matic llvm multiprocessing optfeature \
+	multilib 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 ~arm ~arm64 ~loong ~mips ~ppc ~ppc64 ~riscv ~sparc ~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/${SRC}
+	verify-sig? ( https://static.rust-lang.org/dist/${SRC}.asc )
+	!system-bootstrap? ( $(rust_all_arch_uris rust-${RUST_STAGE0_VERSION}) )
+"
+S="${WORKDIR}/${MY_P}-src"
+
+# keep in sync with llvm ebuild of the same version as bundled one.
+ALL_LLVM_TARGETS=( AArch64 AMDGPU ARC ARM AVR BPF CSKY DirectX Hexagon Lanai
+	LoongArch M68k Mips MSP430 NVPTX PowerPC RISCV Sparc SPIRV SystemZ VE
+	WebAssembly X86 XCore Xtensa )
+ALL_LLVM_TARGETS=( "${ALL_LLVM_TARGETS[@]/#/llvm_targets_}" )
+LLVM_TARGET_USEDEPS=${ALL_LLVM_TARGETS[@]/%/(-)?}
+
+LICENSE="|| ( MIT Apache-2.0 ) BSD BSD-1 BSD-2 BSD-4"
+
+IUSE="big-endian clippy cpu_flags_x86_sse2 debug dist doc llvm-libunwind lto miri nightly parallel-compiler profiler rustfmt rust-analyzer rust-src system-bootstrap system-llvm test wasm ${ALL_LLVM_TARGETS[*]}"
+
+# Please keep the LLVM dependency block separate. Since LLVM is slotted,
+# we need to *really* make sure we're not pulling more than one slot
+# simultaneously.
+
+# How to use it:
+# List all the working slots in LLVM_VALID_SLOTS, newest first.
+LLVM_VALID_SLOTS=( 18 )
+LLVM_MAX_SLOT="${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}[${_x}(-)] )
+			wasm? ( sys-devel/lld:${_s} )"
+	done
+	LLVM_DEPEND+=" )"
+done
+unset _s _x
+LLVM_DEPEND+=" )
+	<sys-devel/llvm-$(( LLVM_MAX_SLOT + 1 )):=
+"
+
+# to bootstrap we need at least exactly previous version, or same.
+# most of the time previous versions fail to bootstrap with newer
+# for example 1.47.x, requires at least 1.46.x, 1.47.x is ok,
+# but it fails to bootstrap with 1.48.x
+# https://github.com/rust-lang/rust/blob/${PV}/src/stage0.json
+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-build/cmake-3.13.4
+		app-alternatives/ninja
+	)
+	test? ( dev-debug/gdb )
+	verify-sig? ( sec-keys/openpgp-keys-rust )
+"
+
+DEPEND="
+	>=app-arch/xz-utils-5.2
+	net-misc/curl:=[http2,ssl]
+	sys-libs/zlib:=
+	dev-libs/openssl:0=
+	system-llvm? (
+		${LLVM_DEPEND}
+		llvm-libunwind? ( sys-libs/llvm-libunwind:= )
+	)
+	!system-llvm? (
+		!llvm-libunwind? (
+			elibc_musl? ( sys-libs/libunwind:= )
+		)
+	)
+"
+
+RDEPEND="${DEPEND}
+	app-eselect/eselect-rust
+	sys-apps/lsb-release
+"
+
+REQUIRED_USE="|| ( ${ALL_LLVM_TARGETS[*]} )
+	miri? ( nightly )
+	parallel-compiler? ( nightly )
+	rust-analyzer? ( rust-src )
+	test? ( ${ALL_LLVM_TARGETS[*]} )
+	wasm? ( llvm_targets_WebAssembly )
+	x86? ( cpu_flags_x86_sse2 )
+"
+
+# we don't use cmake.eclass, but can get a warning
+CMAKE_WARN_UNUSED_CLI=no
+
+QA_FLAGS_IGNORED="
+	usr/lib/${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}/${PV}/lib/rustlib/.*/lib/lib.*.so
+"
+
+QA_PRESTRIPPED="
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/bin/rust-llvm-dwp
+	usr/lib/${PN}/${PV}/lib/rustlib/.*/lib/self-contained/crtn.o
+"
+
+# An rmeta file is custom binary format that contains the metadata for the crate.
+# rmeta files do not support linking, since they do not contain compiled object files.
+# so we can safely silence the warning for this QA check.
+QA_EXECSTACK="usr/lib/${PN}/${PV}/lib/rustlib/*/lib*.rlib:lib.rmeta"
+
+# causes double bootstrap
+RESTRICT="test"
+
+VERIFY_SIG_OPENPGP_KEY_PATH=/usr/share/openpgp-keys/rust.asc
+
+PATCHES=(
+	"${FILESDIR}"/1.78.0-musl-dynamic-linking.patch
+	"${FILESDIR}"/1.74.1-cross-compile-libz.patch
+	#"${FILESDIR}"/1.72.0-bump-libc-deps-to-0.2.146.patch  # pending refresh
+	"${FILESDIR}"/1.67.0-doc-wasm.patch
+	"${FILESDIR}"/1.79.0-revert-8c40426.patch
+)
+
+clear_vendor_checksums() {
+	sed -i 's/\("files":{\)[^}]*/\1/' "vendor/${1}/.cargo-checksum.json" || die
+}
+
+toml_usex() {
+	usex "${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=( $(eselect --brief --root="${BROOT}" 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 ${rustc_version} to build"
+	fi
+}
+
+pre_build_checks() {
+	local M=8192
+	# multiply requirements by 1.3 if we are doing x86-multilib
+	if use amd64; then
+		M=$(( $(usex abi_x86_32 13 10) * ${M} / 10 ))
+	fi
+	M=$(( $(usex clippy 128 0) + ${M} ))
+	M=$(( $(usex miri 128 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}[${LLVM_TARGET_USEDEPS// /,}]"
+}
+
+# Is LLVM being linked against libc++?
+is_libcxx_linked() {
+	local code='#include <ciso646>
+#if defined(_LIBCPP_VERSION)
+	HAVE_LIBCXX
+#endif
+'
+	local out=$($(tc-getCXX) ${CXXFLAGS} ${CPPFLAGS} -x c++ -E -P - <<<"${code}") || return 1
+	[[ ${out} == *HAVE_LIBCXX* ]]
+}
+
+pkg_pretend() {
+	pre_build_checks
+}
+
+pkg_setup() {
+	pre_build_checks
+	python-any-r1_pkg_setup
+
+	export LIBGIT2_NO_PKG_CONFIG=1 #749381
+	if tc-is-cross-compiler; then
+		export PKG_CONFIG_ALLOW_CROSS=1
+		export PKG_CONFIG_PATH="${ROOT}/usr/$(get_libdir)/pkgconfig"
+		export OPENSSL_INCLUDE_DIR="${ROOT}/usr/include"
+		export OPENSSL_LIB_DIR="${ROOT}/usr/$(get_libdir)"
+
+		use system-bootstrap || die "USE=system-bootstrap is required when cross-compiling"
+		use system-llvm && die "USE=system-llvm not allowed when cross-compiling"
+		local cross_llvm_target="$(llvm_tuple_to_target "${CBUILD}")"
+		use "llvm_targets_${cross_llvm_target}" || \
+			die "Must enable LLVM_TARGETS=${cross_llvm_target} matching CBUILD=${CBUILD} when cross-compiling"
+	fi
+
+	use system-bootstrap && bootstrap_rust_version_check
+
+	if use system-llvm; then
+		llvm_pkg_setup
+
+		local llvm_config="$(get_llvm_prefix "${LLVM_MAX_SLOT}")/bin/llvm-config"
+		export LLVM_LINK_SHARED=1
+		export RUSTFLAGS="${RUSTFLAGS} -Lnative=$("${llvm_config}" --libdir)"
+	fi
+}
+
+esetup_unwind_hack() {
+	# https://bugs.gentoo.org/870280
+	# this is a hack needed to bootstrap with libgcc_s linked tarball on llvm-libunwind system.
+	# it should trigger for internal bootstrap or system-bootstrap with rust-bin.
+	# the whole idea is for stage0 to bootstrap with fake libgcc_s.
+	# final stage will receive -L${T}/lib but not -lgcc_s args, producing clean compiler.
+	local fakelib="${T}/fakelib"
+	mkdir -p "${fakelib}" || die
+	# we need both symlinks, one for cargo runtime, other for linker.
+	ln -s "${ESYSROOT}/usr/lib/libunwind.so" "${fakelib}/libgcc_s.so.1" || die
+	ln -s "${ESYSROOT}/usr/lib/libunwind.so" "${fakelib}/libgcc_s.so" || die
+	export LD_LIBRARY_PATH="${fakelib}"
+	export RUSTFLAGS+=" -L${fakelib}"
+	# this is a literally magic variable that gets through cargo cache, without it some
+	# crates ignore RUSTFLAGS.
+	# this variable can not contain leading space.
+	export MAGIC_EXTRA_RUSTFLAGS+="${MAGIC_EXTRA_RUSTFLAGS:+ }-L${fakelib}"
+}
+
+src_prepare() {
+	# Clear vendor checksums for crates that we patched to bump libc.
+	# NOTE: refresh this on each bump.
+	#for i in addr2line-0.20.0 bstr cranelift-jit crossbeam-channel elasticlunr-rs handlebars icu_locid libffi \
+	#	terminal_size tracing-tree; do
+	#	clear_vendor_checksums "${i}"
+	#done
+
+	if ! use system-bootstrap; then
+		has_version sys-devel/gcc || esetup_unwind_hack
+		local rust_stage0_root="${WORKDIR}"/rust-stage0
+		local rust_stage0="rust-${RUST_STAGE0_VERSION}-$(rust_abi "${CBUILD}")"
+
+		"${WORKDIR}/${rust_stage0}"/install.sh --disable-ldconfig \
+			--without=rust-docs-json-preview,rust-docs --destdir="${rust_stage0_root}" --prefix=/ || die
+	fi
+
+	default
+}
+
+src_configure() {
+	filter-lto # https://bugs.gentoo.org/862109 https://bugs.gentoo.org/866231
+
+	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_abi $(get_abi_CHOST ${v##*.}))\""
+	done
+	if use wasm; then
+		rust_targets+=",\"wasm32-unknown-unknown\""
+		if use system-llvm; then
+			# un-hardcode rust-lld linker for this target
+			# https://bugs.gentoo.org/715348
+			sed -i '/linker:/ s/rust-lld/wasm-ld/' compiler/rustc_target/src/spec/base/wasm.rs || die
+		fi
+	fi
+	rust_targets="${rust_targets#,}"
+
+	# cargo and rustdoc are mandatory and should always be included
+	local tools='"cargo","rustdoc"'
+	use clippy && tools+=',"clippy"'
+	use miri && tools+=',"miri"'
+	use profiler && tools+=',"rust-demangler"'
+	use rustfmt && tools+=',"rustfmt"'
+	use rust-analyzer && tools+=',"rust-analyzer","rust-analyzer-proc-macro-srv"'
+	use rust-src && tools+=',"src"'
+
+	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="$(rust_abi)"
+	rust_build="$(rust_abi "${CBUILD}")"
+	rust_host="$(rust_abi "${CHOST}")"
+
+	local cm_btype="$(usex debug DEBUG RELEASE)"
+	cat <<- _EOF_ > "${S}"/config.toml
+		[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)
+		$(if is_libcxx_linked; then
+			# https://bugs.gentoo.org/732632
+			echo "use-libcxx = true"
+			echo "static-libstdcpp = false"
+		fi)
+		$(case "${rust_target}" in
+			i586-*-linux-*)
+				# https://github.com/rust-lang/rust/issues/93059
+				echo 'cflags = "-fcf-protection=none"'
+				echo 'cxxflags = "-fcf-protection=none"'
+				echo 'ldflags = "-fcf-protection=none"'
+				;;
+			*)
+				;;
+		esac)
+		enable-warnings = false
+		[llvm.build-config]
+		CMAKE_VERBOSE_MAKEFILE = "ON"
+		$(if ! tc-is-cross-compiler; then
+			# When cross-compiling, LLVM is compiled twice, once for host and
+			# once for target.  Unfortunately, this build configuration applies
+			# to both, which means any flags applicable to one target but not
+			# the other will break.  Conditionally disable respecting user
+			# flags when cross-compiling.
+			echo "CMAKE_C_FLAGS_${cm_btype} = \"${CFLAGS}\""
+			echo "CMAKE_CXX_FLAGS_${cm_btype} = \"${CXXFLAGS}\""
+			echo "CMAKE_EXE_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_MODULE_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_SHARED_LINKER_FLAGS_${cm_btype} = \"${LDFLAGS}\""
+			echo "CMAKE_STATIC_LINKER_FLAGS_${cm_btype} = \"${ARFLAGS}\""
+		fi)
+		[build]
+		build-stage = 2
+		test-stage = 2
+		build = "${rust_build}"
+		host = ["${rust_host}"]
+		target = [${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 = $(toml_usex profiler)
+		cargo-native-static = false
+		[install]
+		prefix = "${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
+		$(if ! tc-is-cross-compiler; then
+			echo "default-linker = \"$(tc-getCC)\""
+		fi)
+		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 $(usex doc false true) true)
+		backtrace-on-ice = true
+		jemalloc = false
+		# See https://github.com/rust-lang/rust/issues/121124
+		lto = "$(usex lto thin off)"
+		[dist]
+		src-tarball = false
+		compression-formats = ["xz"]
+		compression-profile = "balanced"
+	_EOF_
+
+	for v in $(multilib_get_enabled_abi_pairs); do
+		rust_target=$(rust_abi $(get_abi_CHOST ${v##*.}))
+		arch_cflags="$(get_abi_CFLAGS ${v##*.})"
+
+		export CFLAGS_${rust_target//-/_}="${arch_cflags}"
+
+		cat <<- _EOF_ >> "${S}"/config.toml
+			[target.${rust_target}]
+			ar = "$(tc-getAR)"
+			cc = "$(tc-getCC)"
+			cxx = "$(tc-getCXX)"
+			linker = "$(tc-getCC)"
+			ranlib = "$(tc-getRANLIB)"
+			llvm-libunwind = "$(usex llvm-libunwind $(usex system-llvm system in-tree) no)"
+		_EOF_
+		if use system-llvm; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				llvm-config = "$(get_llvm_prefix "${LLVM_MAX_SLOT}")/bin/llvm-config"
+			_EOF_
+		fi
+		# by default librustc_target/spec/linux_musl_base.rs sets base.crt_static_default = true;
+		# but we patch it and set to false here as well
+		if use elibc_musl; then
+			cat <<- _EOF_ >> "${S}"/config.toml
+				crt-static = false
+				musl-root = "$($(tc-getCC) -print-sysroot)/usr"
+			_EOF_
+		fi
+	done
+	if use wasm; then
+		wasm_target="wasm32-unknown-unknown"
+		export CFLAGS_${wasm_target//-/_}="$(filter-flags '-mcpu*' '-march*' '-mtune*'; echo "$CFLAGS")"
+		cat <<- _EOF_ >> "${S}"/config.toml
+			[target.wasm32-unknown-unknown]
+			linker = "$(usex system-llvm lld rust-lld)"
+			# wasm target does not have profiler_builtins https://bugs.gentoo.org/848483
+			profiler = false
+		_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.${cross_rust_target}]
+			ar = "${cross_toolchain}-ar"
+			cc = "${cross_toolchain}-gcc"
+			cxx = "${cross_toolchain}-g++"
+			linker = "${cross_toolchain}-gcc"
+			ranlib = "${cross_toolchain}-ranlib"
+		_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}\""
+	echo MAGIC_EXTRA_RUSTFLAGS="\"${MAGIC_EXTRA_RUSTFLAGS}\""
+	env | grep "CARGO_TARGET_.*_RUSTFLAGS="
+	env | grep "CFLAGS_.*"
+	echo
+	einfo "config.toml contents:"
+	cat "${S}"/config.toml || die
+	echo
+}
+
+src_compile() {
+	RUST_BACKTRACE=1 "${EPYTHON}" ./x.py build -vvv --config="${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 ${t}"
+		if ! RUST_BACKTRACE=1 "${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: ${failed[@]}"
+		die "aborting due to test failures"
+	fi
+}
+
+src_install() {
+	DESTDIR="${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 profiler && symlinks+=( rust-demangler )
+	use rustfmt && symlinks+=( rustfmt cargo-fmt )
+	use rust-analyzer && symlinks+=( rust-analyzer )
+
+	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="${EPREFIX}/usr/lib/rust/man"
+	_EOF_
+
+	rm -rf "${ED}/usr/lib/${PN}/${PV}"/*.old || die
+	rm -rf "${ED}/usr/lib/${PN}/${PV}/bin"/*.old || die
+	rm -rf "${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 profiler; then
+		echo /usr/bin/rust-demangler >> "${T}/provider-${P}"
+	fi
+	if use rustfmt; then
+		echo /usr/bin/rustfmt >> "${T}/provider-${P}"
+		echo /usr/bin/cargo-fmt >> "${T}/provider-${P}"
+	fi
+	if use rust-analyzer; then
+		echo /usr/bin/rust-analyzer >> "${T}/provider-${P}"
+	fi
+
+	insinto /etc/env.d/rust
+	doins "${T}/provider-${P}"
+
+	if use dist; then
+		"${EPYTHON}" ./x.py dist -vv --config="${S}"/config.toml -j$(makeopts_jobs) || die
+		insinto "/usr/lib/${PN}/${PV}/dist"
+		doins -r "${S}/build/dist/."
+	fi
+}
+
+pkg_postinst() {
+	eselect rust update
+
+	if has_version dev-debug/gdb || has_version dev-debug/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
+		optfeature "emacs support for rust" app-emacs/rust-mode
+	fi
+
+	if has_version app-editors/gvim || has_version app-editors/vim; then
+		optfeature "vim support for rust" app-vim/rust-vim
+	fi
+}
+
+pkg_postrm() {
+	eselect rust cleanup
+}