13 files changed, 1011 insertions, 0 deletions
diff --git a/sys-libs/Manifest.gz b/sys-libs/Manifest.gz
index af067f49eb35..4de4bb8baac9 100644
--- a/sys-libs/Manifest.gz
+++ b/sys-libs/Manifest.gz
diff --git a/sys-libs/compiler-rt-sanitizers/Manifest b/sys-libs/compiler-rt-sanitizers/Manifest
index ded65c14166c..a8d7b19a226f 100644
--- a/sys-libs/compiler-rt-sanitizers/Manifest
+++ b/sys-libs/compiler-rt-sanitizers/Manifest
@@ -7,12 +7,15 @@ DIST llvm-project-17.0.6.src.tar.xz 127838860 BLAKE2B d6ede1a9fda8756995c3e06541
 DIST llvm-project-17.0.6.src.tar.xz.sig 438 BLAKE2B 186e75b6a0fbfe1e85408589c149e1800fcc47d685b74e4260018e05cd08bc793d1d1197c9c50e177eea941a3d0c65cb0c583ce6dae449099b920adf8a508ef7 SHA512 f78c55053a6450625f3e95f52c305110b4468a9854fec75831b65b8d6ceee3c9206ab9e63c4b5fda8be9bd344f72cfbdaae0520ed240abd505e08ebeaa25d340
 DIST llvm-project-18.1.0rc2.src.tar.xz 131993176 BLAKE2B 8df1e34a54214975efe1b9a649753a2dc20c04e3c763bd8648000f48dd18f27ccfdc597ff6e68e0f408310493dfa92f48c7eee53376501e8ebc3b7c614809c15 SHA512 b595bb5d029723fee4e8f8edeaddd6fdcd48d668f66f4239e3208fd19d3a3622e8e4f90ae3fa4b1216fca1621d6c6b6ebf4d99dec7febff2457d0ceb79e8617a
 DIST llvm-project-18.1.0rc2.src.tar.xz.sig 566 BLAKE2B c765549386a92883bd348d9be25a3c92b1e66a1bac71385ef99978ec2af413a7616a2d9699c57554d927f95b80a3584572557d26e3df16b2ff6678359d5fd6b0 SHA512 83bb4c133f34faec8a0109689ed7aa18222c9a803ba8c95c571a18e854726024f106a1c8e3a820020255c426b7fa8bda26789ff1546972e233fbe3e3ab3a8e91
+DIST llvm-project-18.1.0rc3.src.tar.xz 132011280 BLAKE2B 482a0e1b806292598bd646f225705140a463706ec391e4e42f203606b85673601a65fe55f2432d77f4c2f4c6584b35e53eeaded42e0b67aa6538c37d7cceb4ff SHA512 6c0adcf6e4057de8fb1dcd062845d14d725833d23d8e1362cbccab176931f55600a3971f01690179b795ff3feca0af9141b16dee4d4159755596cc9c904bf099
+DIST llvm-project-18.1.0rc3.src.tar.xz.sig 566 BLAKE2B dac9c174e2eeda5e0af0153d78a2e9c8f145efe03250582a27df1bd6a89ba70afdcfa1ed6aa46adb1f7f21077cadb6e43963758358ff17122c36781ee4018c05 SHA512 91a2778f9b66bc80172172f36d6027fb2455f3ffd03b06ad0dd376471c4d4e2e34c8bee69c76cfe95003ae34f0d28c394c7d135fbbb75686ff89aee56b6c45c3
 DIST llvm-project-3496927edcd0685807351ba88a7e2cfb006e1c0d.tar.gz 206227842 BLAKE2B cd27e9e9bca3622c2241bfa91c78eb8443df7465c1efcec57d5e701e2c61d3b2d3619483199e67b56deed9410f5382fc3164cdc7e864dcd77f4d12f3f9d2b159 SHA512 156d441074aff4d85af956b9abf89f9aefccccbe5b39e315c9c7c249ad01f95b42a303c23e9142292e7746f691c2ee704a7cd4a60916594ea1d468240c9b8152
 DIST llvm-project-8884ba43a8485bebef5c4d41e7ed457e3fa84f07.tar.gz 205853916 BLAKE2B 115809efbf062ced32ffe61b25e65e44a0b3c293f68bf40fc4d9e596cd077fc4781a059ad24c4dc7a139c6ec884a6a183ebac06535f2498116266695e19daf00 SHA512 cb496111ec72163a1872fa9a14f8963108d3185f4464a74cc45d26ccc5071bc36895618b81c29063cde0564a50017a0194da4dc559a046a12550d9ab0d9b8347
 EBUILD compiler-rt-sanitizers-15.0.7.ebuild 6556 BLAKE2B e434e692cef521b574c9c566bb19f990910e25de620f284ae84204da588f4ed42996348ab1a9b58b4c4c4ae3f140fd8bcad42431416b15888f12e085cadcdbd6 SHA512 5f6b4ae9010ff21c7eefcb77cae85d73ef5d64cc961b0f6672e5158eb5242f55c6bf2bdadc3f18eb8a18fbdbd94442156539386d229aee3dbe6b953440cb39a6
 EBUILD compiler-rt-sanitizers-16.0.6.ebuild 6523 BLAKE2B 9e81f29f1928262b3ea0fdec218f4430351da68a569bfaeea007a4d4e7552be1aa0232bfe5e74b164103d9908f7ac3fe1dd790ce06bb2e5b2b05a82879b271c4 SHA512 f04019755779116adadc66e6f4485c2b100d737e793d9f8532081688c195a6dd7f0dd8cf9077febf424d52d21982d0a266f3e4c8f453a34b4f16c05437d2cb28
 EBUILD compiler-rt-sanitizers-17.0.6.ebuild 6357 BLAKE2B fc5e42e7b52d57e2ed4e3c83229569652b21250c9919d25623b349e90b9baf128eef97d98d863f5df2f10b799258e5faab8c9a69c9cc085e381e504b6d0d913c SHA512 ca0a3ddcd8b46bb060aa2e677820fc3fdd29237b3375a4e1fda5b74436ba819767dfa1c10a79c333a3662b9b1e0119c35812830666f4e5a176db23adba13ff1a
 EBUILD compiler-rt-sanitizers-18.1.0_rc2.ebuild 6268 BLAKE2B 98422f1f8be179031ffed4ea9176843521842aff5be2cbdcb21f6ea2020a8d13a1c6fc4810e769c0ec0775f92af45831c4385cc70680765f474885c5ad5b389f SHA512 8677df281de24325290cb99cc4f6087460443c716ac2eea7b3c8175281daad874cd7aab0dda8f4d60213a1b73a8f1a921ae7ad0733d104a7db0e8e5f2ac35127
+EBUILD compiler-rt-sanitizers-18.1.0_rc3.ebuild 6268 BLAKE2B 98422f1f8be179031ffed4ea9176843521842aff5be2cbdcb21f6ea2020a8d13a1c6fc4810e769c0ec0775f92af45831c4385cc70680765f474885c5ad5b389f SHA512 8677df281de24325290cb99cc4f6087460443c716ac2eea7b3c8175281daad874cd7aab0dda8f4d60213a1b73a8f1a921ae7ad0733d104a7db0e8e5f2ac35127
 EBUILD compiler-rt-sanitizers-19.0.0.9999.ebuild 6268 BLAKE2B 98422f1f8be179031ffed4ea9176843521842aff5be2cbdcb21f6ea2020a8d13a1c6fc4810e769c0ec0775f92af45831c4385cc70680765f474885c5ad5b389f SHA512 8677df281de24325290cb99cc4f6087460443c716ac2eea7b3c8175281daad874cd7aab0dda8f4d60213a1b73a8f1a921ae7ad0733d104a7db0e8e5f2ac35127
 EBUILD compiler-rt-sanitizers-19.0.0_pre20240210.ebuild 6268 BLAKE2B 98422f1f8be179031ffed4ea9176843521842aff5be2cbdcb21f6ea2020a8d13a1c6fc4810e769c0ec0775f92af45831c4385cc70680765f474885c5ad5b389f SHA512 8677df281de24325290cb99cc4f6087460443c716ac2eea7b3c8175281daad874cd7aab0dda8f4d60213a1b73a8f1a921ae7ad0733d104a7db0e8e5f2ac35127
 EBUILD compiler-rt-sanitizers-19.0.0_pre20240218.ebuild 6268 BLAKE2B 98422f1f8be179031ffed4ea9176843521842aff5be2cbdcb21f6ea2020a8d13a1c6fc4810e769c0ec0775f92af45831c4385cc70680765f474885c5ad5b389f SHA512 8677df281de24325290cb99cc4f6087460443c716ac2eea7b3c8175281daad874cd7aab0dda8f4d60213a1b73a8f1a921ae7ad0733d104a7db0e8e5f2ac35127
diff --git a/sys-libs/compiler-rt-sanitizers/compiler-rt-sanitizers-18.1.0_rc3.ebuild b/sys-libs/compiler-rt-sanitizers/compiler-rt-sanitizers-18.1.0_rc3.ebuild
new file mode 100644
index 000000000000..57f868d54be6
--- /dev/null
+++ b/sys-libs/compiler-rt-sanitizers/compiler-rt-sanitizers-18.1.0_rc3.ebuild
@@ -0,0 +1,217 @@
+# Copyright 1999-2024 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+PYTHON_COMPAT=( python3_{10..12} )
+inherit check-reqs cmake flag-o-matic llvm.org llvm-utils python-any-r1
+
+DESCRIPTION="Compiler runtime libraries for clang (sanitizers & xray)"
+HOMEPAGE="https://llvm.org/"
+
+LICENSE="Apache-2.0-with-LLVM-exceptions || ( UoI-NCSA MIT )"
+SLOT="${LLVM_MAJOR}"
+IUSE="+abi_x86_32 abi_x86_64 +clang +debug test"
+# base targets
+IUSE+=" +libfuzzer +memprof +orc +profile +xray"
+# sanitizer targets, keep in sync with config-ix.cmake
+# NB: ubsan, scudo deliberately match two entries
+SANITIZER_FLAGS=(
+	asan dfsan lsan msan hwasan tsan ubsan safestack cfi scudo
+	shadowcallstack gwp-asan
+)
+IUSE+=" ${SANITIZER_FLAGS[@]/#/+}"
+REQUIRED_USE="
+	|| ( ${SANITIZER_FLAGS[*]} libfuzzer orc profile xray )
+	test? (
+		cfi? ( ubsan )
+		gwp-asan? ( scudo )
+	)
+"
+RESTRICT="
+	!clang? ( test )
+	!test? ( test )
+"
+
+DEPEND="
+	sys-devel/llvm:${LLVM_MAJOR}
+	virtual/libcrypt[abi_x86_32(-)?,abi_x86_64(-)?]
+"
+BDEPEND="
+	clang? ( sys-devel/clang )
+	elibc_glibc? ( net-libs/libtirpc )
+	test? (
+		$(python_gen_any_dep ">=dev-python/lit-15[\${PYTHON_USEDEP}]")
+		=sys-devel/clang-${LLVM_VERSION}*:${LLVM_MAJOR}
+		sys-libs/compiler-rt:${LLVM_MAJOR}
+	)
+	!test? (
+		${PYTHON_DEPS}
+	)
+"
+
+LLVM_COMPONENTS=( compiler-rt cmake llvm/cmake )
+LLVM_TEST_COMPONENTS=( llvm/lib/Testing/Support third-party )
+llvm.org_set_globals
+
+python_check_deps() {
+	use test || return 0
+	python_has_version ">=dev-python/lit-15[${PYTHON_USEDEP}]"
+}
+
+check_space() {
+	if use test; then
+		local CHECKREQS_DISK_BUILD=11G
+		check-reqs_pkg_pretend
+	fi
+}
+
+pkg_pretend() {
+	check_space
+}
+
+pkg_setup() {
+	check_space
+	python-any-r1_pkg_setup
+}
+
+src_prepare() {
+	sed -i -e 's:-Werror::' lib/tsan/go/buildgo.sh || die
+
+	local flag
+	for flag in "${SANITIZER_FLAGS[@]}"; do
+		if ! use "${flag}"; then
+			local cmake_flag=${flag/-/_}
+			sed -i -e "/COMPILER_RT_HAS_${cmake_flag^^}/s:TRUE:FALSE:" \
+				cmake/config-ix.cmake || die
+		fi
+	done
+
+	# TODO: fix these tests to be skipped upstream
+	if use asan && ! use profile; then
+		rm test/asan/TestCases/asan_and_llvm_coverage_test.cpp || die
+	fi
+	if use ubsan && ! use cfi; then
+		> test/cfi/CMakeLists.txt || die
+	fi
+	# hangs, sigh
+	rm test/tsan/getline_nohang.cpp || die
+
+	llvm.org_src_prepare
+}
+
+src_configure() {
+	llvm_prepend_path "${LLVM_MAJOR}"
+
+	# LLVM_ENABLE_ASSERTIONS=NO does not guarantee this for us, #614844
+	use debug || local -x CPPFLAGS="${CPPFLAGS} -DNDEBUG"
+
+	# pre-set since we need to pass it to cmake
+	BUILD_DIR=${WORKDIR}/compiler-rt_build
+
+	if use clang; then
+		local -x CC=${CHOST}-clang
+		local -x CXX=${CHOST}-clang++
+		strip-unsupported-flags
+	fi
+
+	local flag want_sanitizer=OFF
+	for flag in "${SANITIZER_FLAGS[@]}"; do
+		if use "${flag}"; then
+			want_sanitizer=ON
+			break
+		fi
+	done
+
+	local mycmakeargs=(
+		-DCOMPILER_RT_INSTALL_PATH="${EPREFIX}/usr/lib/clang/${LLVM_MAJOR}"
+		# use a build dir structure consistent with install
+		# this makes it possible to easily deploy test-friendly clang
+		-DCOMPILER_RT_OUTPUT_DIR="${BUILD_DIR}/lib/clang/${LLVM_MAJOR}"
+
+		-DCOMPILER_RT_INCLUDE_TESTS=$(usex test)
+		# builtins & crt installed by sys-libs/compiler-rt
+		-DCOMPILER_RT_BUILD_BUILTINS=OFF
+		-DCOMPILER_RT_BUILD_CRT=OFF
+		-DCOMPILER_RT_BUILD_LIBFUZZER=$(usex libfuzzer)
+		-DCOMPILER_RT_BUILD_MEMPROF=$(usex memprof)
+		-DCOMPILER_RT_BUILD_ORC=$(usex orc)
+		-DCOMPILER_RT_BUILD_PROFILE=$(usex profile)
+		-DCOMPILER_RT_BUILD_SANITIZERS="${want_sanitizer}"
+		-DCOMPILER_RT_BUILD_XRAY=$(usex xray)
+
+		-DPython3_EXECUTABLE="${PYTHON}"
+	)
+
+	if use amd64; then
+		mycmakeargs+=(
+			-DCAN_TARGET_i386=$(usex abi_x86_32)
+			-DCAN_TARGET_x86_64=$(usex abi_x86_64)
+		)
+	fi
+
+	if use test; then
+		mycmakeargs+=(
+			-DLLVM_EXTERNAL_LIT="${EPREFIX}/usr/bin/lit"
+			-DLLVM_LIT_ARGS="$(get_lit_flags)"
+
+			# they are created during src_test()
+			-DCOMPILER_RT_TEST_COMPILER="${BUILD_DIR}/lib/llvm/${LLVM_MAJOR}/bin/clang"
+			-DCOMPILER_RT_TEST_CXX_COMPILER="${BUILD_DIR}/lib/llvm/${LLVM_MAJOR}/bin/clang++"
+		)
+
+		# same flags are passed for build & tests, so we need to strip
+		# them down to a subset supported by clang
+		CC=${EPREFIX}/usr/lib/llvm/${LLVM_MAJOR}/bin/clang \
+		CXX=${EPREFIX}/usr/lib/llvm/${LLVM_MAJOR}/bin/clang++ \
+		strip-unsupported-flags
+	fi
+
+	if use prefix && [[ "${CHOST}" == *-darwin* ]] ; then
+		mycmakeargs+=(
+			# setting -isysroot is disabled with compiler-rt-prefix-paths.patch
+			# this allows adding arm64 support using SDK in EPREFIX
+			-DDARWIN_macosx_CACHED_SYSROOT="${EPREFIX}/MacOSX.sdk"
+			# Set version based on the SDK in EPREFIX
+			# This disables i386 for SDK >= 10.15
+			# Will error if has_use tsan and SDK < 10.12
+			-DDARWIN_macosx_OVERRIDE_SDK_VERSION="$(realpath ${EPREFIX}/MacOSX.sdk | sed -e 's/.*MacOSX\(.*\)\.sdk/\1/')"
+			# Use our libtool instead of looking it up with xcrun
+			-DCMAKE_LIBTOOL="${EPREFIX}/usr/bin/${CHOST}-libtool"
+		)
+	fi
+
+	cmake_src_configure
+
+	if use test; then
+		local sys_dir=( "${EPREFIX}"/usr/lib/clang/${LLVM_MAJOR}/lib/* )
+		[[ -e ${sys_dir} ]] || die "Unable to find ${sys_dir}"
+		[[ ${#sys_dir[@]} -eq 1 ]] || die "Non-deterministic compiler-rt install: ${sys_dir[*]}"
+
+		# copy clang over since resource_dir is located relatively to binary
+		# therefore, we can put our new libraries in it
+		mkdir -p "${BUILD_DIR}"/lib/{llvm/${LLVM_MAJOR}/{bin,$(get_libdir)},clang/${LLVM_MAJOR}/include} || die
+		cp "${EPREFIX}"/usr/lib/llvm/${LLVM_MAJOR}/bin/clang{,++} \
+			"${BUILD_DIR}"/lib/llvm/${LLVM_MAJOR}/bin/ || die
+		cp "${EPREFIX}"/usr/lib/clang/${LLVM_MAJOR}/include/*.h \
+			"${BUILD_DIR}"/lib/clang/${LLVM_MAJOR}/include/ || die
+		cp "${sys_dir}"/*builtins*.a \
+			"${BUILD_DIR}/lib/clang/${LLVM_MAJOR}/lib/${sys_dir##*/}/" || die
+		# we also need LLVMgold.so for gold-based tests
+		if [[ -f ${EPREFIX}/usr/lib/llvm/${LLVM_MAJOR}/$(get_libdir)/LLVMgold.so ]]; then
+			ln -s "${EPREFIX}"/usr/lib/llvm/${LLVM_MAJOR}/$(get_libdir)/LLVMgold.so \
+				"${BUILD_DIR}"/lib/llvm/${LLVM_MAJOR}/$(get_libdir)/ || die
+		fi
+	fi
+}
+
+src_test() {
+	# respect TMPDIR!
+	local -x LIT_PRESERVES_TMP=1
+	# disable sandbox to have it stop clobbering LD_PRELOAD
+	local -x SANDBOX_ON=0
+	# wipe LD_PRELOAD to make ASAN happy
+	local -x LD_PRELOAD=
+
+	cmake_build check-all
+}
diff --git a/sys-libs/compiler-rt/Manifest b/sys-libs/compiler-rt/Manifest
index e171006be2bd..f275a228d768 100644
--- a/sys-libs/compiler-rt/Manifest
+++ b/sys-libs/compiler-rt/Manifest
@@ -9,6 +9,8 @@ DIST llvm-project-17.0.6.src.tar.xz 127838860 BLAKE2B d6ede1a9fda8756995c3e06541
 DIST llvm-project-17.0.6.src.tar.xz.sig 438 BLAKE2B 186e75b6a0fbfe1e85408589c149e1800fcc47d685b74e4260018e05cd08bc793d1d1197c9c50e177eea941a3d0c65cb0c583ce6dae449099b920adf8a508ef7 SHA512 f78c55053a6450625f3e95f52c305110b4468a9854fec75831b65b8d6ceee3c9206ab9e63c4b5fda8be9bd344f72cfbdaae0520ed240abd505e08ebeaa25d340
 DIST llvm-project-18.1.0rc2.src.tar.xz 131993176 BLAKE2B 8df1e34a54214975efe1b9a649753a2dc20c04e3c763bd8648000f48dd18f27ccfdc597ff6e68e0f408310493dfa92f48c7eee53376501e8ebc3b7c614809c15 SHA512 b595bb5d029723fee4e8f8edeaddd6fdcd48d668f66f4239e3208fd19d3a3622e8e4f90ae3fa4b1216fca1621d6c6b6ebf4d99dec7febff2457d0ceb79e8617a
 DIST llvm-project-18.1.0rc2.src.tar.xz.sig 566 BLAKE2B c765549386a92883bd348d9be25a3c92b1e66a1bac71385ef99978ec2af413a7616a2d9699c57554d927f95b80a3584572557d26e3df16b2ff6678359d5fd6b0 SHA512 83bb4c133f34faec8a0109689ed7aa18222c9a803ba8c95c571a18e854726024f106a1c8e3a820020255c426b7fa8bda26789ff1546972e233fbe3e3ab3a8e91
+DIST llvm-project-18.1.0rc3.src.tar.xz 132011280 BLAKE2B 482a0e1b806292598bd646f225705140a463706ec391e4e42f203606b85673601a65fe55f2432d77f4c2f4c6584b35e53eeaded42e0b67aa6538c37d7cceb4ff SHA512 6c0adcf6e4057de8fb1dcd062845d14d725833d23d8e1362cbccab176931f55600a3971f01690179b795ff3feca0af9141b16dee4d4159755596cc9c904bf099
+DIST llvm-project-18.1.0rc3.src.tar.xz.sig 566 BLAKE2B dac9c174e2eeda5e0af0153d78a2e9c8f145efe03250582a27df1bd6a89ba70afdcfa1ed6aa46adb1f7f21077cadb6e43963758358ff17122c36781ee4018c05 SHA512 91a2778f9b66bc80172172f36d6027fb2455f3ffd03b06ad0dd376471c4d4e2e34c8bee69c76cfe95003ae34f0d28c394c7d135fbbb75686ff89aee56b6c45c3
 DIST llvm-project-3496927edcd0685807351ba88a7e2cfb006e1c0d.tar.gz 206227842 BLAKE2B cd27e9e9bca3622c2241bfa91c78eb8443df7465c1efcec57d5e701e2c61d3b2d3619483199e67b56deed9410f5382fc3164cdc7e864dcd77f4d12f3f9d2b159 SHA512 156d441074aff4d85af956b9abf89f9aefccccbe5b39e315c9c7c249ad01f95b42a303c23e9142292e7746f691c2ee704a7cd4a60916594ea1d468240c9b8152
 DIST llvm-project-8884ba43a8485bebef5c4d41e7ed457e3fa84f07.tar.gz 205853916 BLAKE2B 115809efbf062ced32ffe61b25e65e44a0b3c293f68bf40fc4d9e596cd077fc4781a059ad24c4dc7a139c6ec884a6a183ebac06535f2498116266695e19daf00 SHA512 cb496111ec72163a1872fa9a14f8963108d3185f4464a74cc45d26ccc5071bc36895618b81c29063cde0564a50017a0194da4dc559a046a12550d9ab0d9b8347
 EBUILD compiler-rt-15.0.7.ebuild 4238 BLAKE2B 22d56dbe24c92400bf58942390b06af70fddba89d8fecc9b85162dd7a41c6ee592eaaf883f5ad483f65f74fabccc28f94528688410ee36e2d5279efcc6066de0 SHA512 ca49d23def580d4dcfc4058768eeb9deb6e59ea44575da272d1c142fffe0bf4e3d3c7c9fa6182ab348a3aab11879af116a549cb1a3a03b27b4bf4151cf892aaa
@@ -16,6 +18,7 @@ EBUILD compiler-rt-16.0.6-r4.ebuild 5226 BLAKE2B 7d2d76d79ce49f3d175de87fa982439
 EBUILD compiler-rt-16.0.6.ebuild 5198 BLAKE2B 2fe2310703d44d330d97b1fa1b407d99898070604037be31ca762fe65043e1d3d1e046298dc74f3d0cbb3493f985661e362b217170cbe1bf74a47dddfe8987ca SHA512 cc9aabc22f689bfc677ceb74793441674aeca2586a28ff96b812af4822d1b8b5a4147484e41f0bf95ae995488d3e8ee77684fd684b9dab8ade4f1fa57e80c709
 EBUILD compiler-rt-17.0.6.ebuild 5220 BLAKE2B 2c45e13981ee1c101cb58f8f271215a3a9b629d6dea83a7e555035783e919001965c696bae3af8b50ffe31e5ac4908c28eb9d686e6affc42cd9cd0d0a8e0fb70 SHA512 daaec1e40b198a4eb764c7c226fa75c6880df89a33ec2bbba66defbee8834f477ffbea8f9762aabb09459b597653ad1849d6eceb89eab7e65a895cf5ee8882cc
 EBUILD compiler-rt-18.1.0_rc2.ebuild 4868 BLAKE2B 479ff19239f03c3bcb25cde41a2cb5c6a9a8569e376fc08a2a5affd62bc766a85d68ea080570a373d6f3258c0b1f96211bbe552e82255186ad105fca88f597a0 SHA512 4e19eaf37ca1d3d140be8a4d2bad0f3d69d62c0884d131aac9b3ee4bc58a5e1dd4ca0540cc1153cc293c9bd9521bea1688f7f2b298ca8a24c4c0aedc20d3d753
+EBUILD compiler-rt-18.1.0_rc3.ebuild 4868 BLAKE2B 479ff19239f03c3bcb25cde41a2cb5c6a9a8569e376fc08a2a5affd62bc766a85d68ea080570a373d6f3258c0b1f96211bbe552e82255186ad105fca88f597a0 SHA512 4e19eaf37ca1d3d140be8a4d2bad0f3d69d62c0884d131aac9b3ee4bc58a5e1dd4ca0540cc1153cc293c9bd9521bea1688f7f2b298ca8a24c4c0aedc20d3d753
 EBUILD compiler-rt-19.0.0.9999.ebuild 4868 BLAKE2B 479ff19239f03c3bcb25cde41a2cb5c6a9a8569e376fc08a2a5affd62bc766a85d68ea080570a373d6f3258c0b1f96211bbe552e82255186ad105fca88f597a0 SHA512 4e19eaf37ca1d3d140be8a4d2bad0f3d69d62c0884d131aac9b3ee4bc58a5e1dd4ca0540cc1153cc293c9bd9521bea1688f7f2b298ca8a24c4c0aedc20d3d753
 EBUILD compiler-rt-19.0.0_pre20240210.ebuild 4868 BLAKE2B 479ff19239f03c3bcb25cde41a2cb5c6a9a8569e376fc08a2a5affd62bc766a85d68ea080570a373d6f3258c0b1f96211bbe552e82255186ad105fca88f597a0 SHA512 4e19eaf37ca1d3d140be8a4d2bad0f3d69d62c0884d131aac9b3ee4bc58a5e1dd4ca0540cc1153cc293c9bd9521bea1688f7f2b298ca8a24c4c0aedc20d3d753
 EBUILD compiler-rt-19.0.0_pre20240218.ebuild 4868 BLAKE2B 479ff19239f03c3bcb25cde41a2cb5c6a9a8569e376fc08a2a5affd62bc766a85d68ea080570a373d6f3258c0b1f96211bbe552e82255186ad105fca88f597a0 SHA512 4e19eaf37ca1d3d140be8a4d2bad0f3d69d62c0884d131aac9b3ee4bc58a5e1dd4ca0540cc1153cc293c9bd9521bea1688f7f2b298ca8a24c4c0aedc20d3d753
diff --git a/sys-libs/compiler-rt/compiler-rt-18.1.0_rc3.ebuild b/sys-libs/compiler-rt/compiler-rt-18.1.0_rc3.ebuild
new file mode 100644
index 000000000000..75ff3c155c03
--- /dev/null
+++ b/sys-libs/compiler-rt/compiler-rt-18.1.0_rc3.ebuild
@@ -0,0 +1,171 @@
+# Copyright 1999-2024 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+PYTHON_COMPAT=( python3_{10..12} )
+inherit cmake crossdev flag-o-matic llvm.org llvm-utils python-any-r1
+inherit toolchain-funcs
+
+DESCRIPTION="Compiler runtime library for clang (built-in part)"
+HOMEPAGE="https://llvm.org/"
+
+LICENSE="Apache-2.0-with-LLVM-exceptions || ( UoI-NCSA MIT )"
+SLOT="${LLVM_MAJOR}"
+IUSE="+abi_x86_32 abi_x86_64 +clang +debug test"
+RESTRICT="!test? ( test ) !clang? ( test )"
+
+DEPEND="
+	sys-devel/llvm:${LLVM_MAJOR}
+"
+BDEPEND="
+	clang? ( sys-devel/clang )
+	test? (
+		$(python_gen_any_dep ">=dev-python/lit-15[\${PYTHON_USEDEP}]")
+		=sys-devel/clang-${LLVM_VERSION}*:${LLVM_MAJOR}
+	)
+	!test? (
+		${PYTHON_DEPS}
+	)
+"
+
+LLVM_COMPONENTS=( compiler-rt cmake llvm/cmake )
+llvm.org_set_globals
+
+python_check_deps() {
+	use test || return 0
+	python_has_version ">=dev-python/lit-15[${PYTHON_USEDEP}]"
+}
+
+pkg_pretend() {
+	if ! use clang && ! tc-is-clang; then
+		ewarn "Building using a compiler other than clang may result in broken atomics"
+		ewarn "library. Enable USE=clang unless you have a very good reason not to."
+	fi
+}
+
+pkg_setup() {
+	if target_is_not_host || tc-is-cross-compiler ; then
+		# strips vars like CFLAGS="-march=x86_64-v3" for non-x86 architectures
+		CHOST=${CTARGET} strip-unsupported-flags
+		# overrides host docs otherwise
+		DOCS=()
+	fi
+	python-any-r1_pkg_setup
+}
+
+test_compiler() {
+	target_is_not_host && return
+	$(tc-getCC) ${CFLAGS} ${LDFLAGS} "${@}" -o /dev/null -x c - \
+		<<<'int main() { return 0; }' &>/dev/null
+}
+
+src_configure() {
+	llvm_prepend_path "${LLVM_MAJOR}"
+
+	# LLVM_ENABLE_ASSERTIONS=NO does not guarantee this for us, #614844
+	use debug || local -x CPPFLAGS="${CPPFLAGS} -DNDEBUG"
+
+	# pre-set since we need to pass it to cmake
+	BUILD_DIR=${WORKDIR}/${P}_build
+
+	if use clang && ! is_crosspkg; then
+		# Only do this conditionally to allow overriding with
+		# e.g. CC=clang-13 in case of breakage
+		if ! tc-is-clang ; then
+			local -x CC=${CHOST}-clang
+			local -x CXX=${CHOST}-clang++
+		fi
+
+		strip-unsupported-flags
+	fi
+
+	if ! is_crosspkg && ! test_compiler ; then
+		local nolib_flags=( -nodefaultlibs -lc )
+
+		if test_compiler "${nolib_flags[@]}"; then
+			local -x LDFLAGS="${LDFLAGS} ${nolib_flags[*]}"
+			ewarn "${CC} seems to lack runtime, trying with ${nolib_flags[*]}"
+		elif test_compiler "${nolib_flags[@]}" -nostartfiles; then
+			# Avoiding -nostartfiles earlier on for bug #862540,
+			# and set available entry symbol for bug #862798.
+			nolib_flags+=( -nostartfiles -emain )
+
+			local -x LDFLAGS="${LDFLAGS} ${nolib_flags[*]}"
+			ewarn "${CC} seems to lack runtime, trying with ${nolib_flags[*]}"
+		fi
+	fi
+
+	local mycmakeargs=(
+		-DCOMPILER_RT_INSTALL_PATH="${EPREFIX}/usr/lib/clang/${LLVM_MAJOR}"
+
+		-DCOMPILER_RT_INCLUDE_TESTS=$(usex test)
+		-DCOMPILER_RT_BUILD_LIBFUZZER=OFF
+		-DCOMPILER_RT_BUILD_MEMPROF=OFF
+		-DCOMPILER_RT_BUILD_ORC=OFF
+		-DCOMPILER_RT_BUILD_PROFILE=OFF
+		-DCOMPILER_RT_BUILD_SANITIZERS=OFF
+		-DCOMPILER_RT_BUILD_XRAY=OFF
+
+		-DPython3_EXECUTABLE="${PYTHON}"
+	)
+
+	if use amd64 && ! target_is_not_host; then
+		mycmakeargs+=(
+			-DCAN_TARGET_i386=$(usex abi_x86_32)
+			-DCAN_TARGET_x86_64=$(usex abi_x86_64)
+		)
+	fi
+
+	if is_crosspkg; then
+		# Needed to target built libc headers
+		export CFLAGS="${CFLAGS} -isystem /usr/${CTARGET}/usr/include"
+		mycmakeargs+=(
+			# Without this, the compiler will compile a test program
+			# and fail due to no builtins.
+			-DCMAKE_C_COMPILER_WORKS=1
+			-DCMAKE_CXX_COMPILER_WORKS=1
+
+			# Without this, compiler-rt install location is not unique
+			# to target triples, only to architecture.
+			# Needed if you want to target multiple libcs for one arch.
+			-DLLVM_ENABLE_PER_TARGET_RUNTIME_DIR=ON
+
+			-DCMAKE_ASM_COMPILER_TARGET="${CTARGET}"
+			-DCMAKE_C_COMPILER_TARGET="${CTARGET}"
+			-DCOMPILER_RT_DEFAULT_TARGET_ONLY=ON
+		)
+	fi
+
+	if use prefix && [[ "${CHOST}" == *-darwin* ]] ; then
+		mycmakeargs+=(
+			# setting -isysroot is disabled with compiler-rt-prefix-paths.patch
+			# this allows adding arm64 support using SDK in EPREFIX
+			-DDARWIN_macosx_CACHED_SYSROOT="${EPREFIX}/MacOSX.sdk"
+			# Set version based on the SDK in EPREFIX.
+			# This disables i386 for SDK >= 10.15
+			-DDARWIN_macosx_OVERRIDE_SDK_VERSION="$(realpath ${EPREFIX}/MacOSX.sdk | sed -e 's/.*MacOSX\(.*\)\.sdk/\1/')"
+			# Use our libtool instead of looking it up with xcrun
+			-DCMAKE_LIBTOOL="${EPREFIX}/usr/bin/${CHOST}-libtool"
+		)
+	fi
+
+	if use test; then
+		mycmakeargs+=(
+			-DLLVM_EXTERNAL_LIT="${EPREFIX}/usr/bin/lit"
+			-DLLVM_LIT_ARGS="$(get_lit_flags)"
+
+			-DCOMPILER_RT_TEST_COMPILER="${EPREFIX}/usr/lib/llvm/${LLVM_MAJOR}/bin/clang"
+			-DCOMPILER_RT_TEST_CXX_COMPILER="${EPREFIX}/usr/lib/llvm/${LLVM_MAJOR}/bin/clang++"
+		)
+	fi
+
+	cmake_src_configure
+}
+
+src_test() {
+	# respect TMPDIR!
+	local -x LIT_PRESERVES_TMP=1
+
+	cmake_build check-builtins
+}
diff --git a/sys-libs/libcxx/Manifest b/sys-libs/libcxx/Manifest
index 05e73dc742c2..6a87b5d25501 100644
--- a/sys-libs/libcxx/Manifest
+++ b/sys-libs/libcxx/Manifest
@@ -8,12 +8,15 @@ DIST llvm-project-17.0.6.src.tar.xz 127838860 BLAKE2B d6ede1a9fda8756995c3e06541
 DIST llvm-project-17.0.6.src.tar.xz.sig 438 BLAKE2B 186e75b6a0fbfe1e85408589c149e1800fcc47d685b74e4260018e05cd08bc793d1d1197c9c50e177eea941a3d0c65cb0c583ce6dae449099b920adf8a508ef7 SHA512 f78c55053a6450625f3e95f52c305110b4468a9854fec75831b65b8d6ceee3c9206ab9e63c4b5fda8be9bd344f72cfbdaae0520ed240abd505e08ebeaa25d340
 DIST llvm-project-18.1.0rc2.src.tar.xz 131993176 BLAKE2B 8df1e34a54214975efe1b9a649753a2dc20c04e3c763bd8648000f48dd18f27ccfdc597ff6e68e0f408310493dfa92f48c7eee53376501e8ebc3b7c614809c15 SHA512 b595bb5d029723fee4e8f8edeaddd6fdcd48d668f66f4239e3208fd19d3a3622e8e4f90ae3fa4b1216fca1621d6c6b6ebf4d99dec7febff2457d0ceb79e8617a
 DIST llvm-project-18.1.0rc2.src.tar.xz.sig 566 BLAKE2B c765549386a92883bd348d9be25a3c92b1e66a1bac71385ef99978ec2af413a7616a2d9699c57554d927f95b80a3584572557d26e3df16b2ff6678359d5fd6b0 SHA512 83bb4c133f34faec8a0109689ed7aa18222c9a803ba8c95c571a18e854726024f106a1c8e3a820020255c426b7fa8bda26789ff1546972e233fbe3e3ab3a8e91
+DIST llvm-project-18.1.0rc3.src.tar.xz 132011280 BLAKE2B 482a0e1b806292598bd646f225705140a463706ec391e4e42f203606b85673601a65fe55f2432d77f4c2f4c6584b35e53eeaded42e0b67aa6538c37d7cceb4ff SHA512 6c0adcf6e4057de8fb1dcd062845d14d725833d23d8e1362cbccab176931f55600a3971f01690179b795ff3feca0af9141b16dee4d4159755596cc9c904bf099
+DIST llvm-project-18.1.0rc3.src.tar.xz.sig 566 BLAKE2B dac9c174e2eeda5e0af0153d78a2e9c8f145efe03250582a27df1bd6a89ba70afdcfa1ed6aa46adb1f7f21077cadb6e43963758358ff17122c36781ee4018c05 SHA512 91a2778f9b66bc80172172f36d6027fb2455f3ffd03b06ad0dd376471c4d4e2e34c8bee69c76cfe95003ae34f0d28c394c7d135fbbb75686ff89aee56b6c45c3
 DIST llvm-project-3496927edcd0685807351ba88a7e2cfb006e1c0d.tar.gz 206227842 BLAKE2B cd27e9e9bca3622c2241bfa91c78eb8443df7465c1efcec57d5e701e2c61d3b2d3619483199e67b56deed9410f5382fc3164cdc7e864dcd77f4d12f3f9d2b159 SHA512 156d441074aff4d85af956b9abf89f9aefccccbe5b39e315c9c7c249ad01f95b42a303c23e9142292e7746f691c2ee704a7cd4a60916594ea1d468240c9b8152
 DIST llvm-project-8884ba43a8485bebef5c4d41e7ed457e3fa84f07.tar.gz 205853916 BLAKE2B 115809efbf062ced32ffe61b25e65e44a0b3c293f68bf40fc4d9e596cd077fc4781a059ad24c4dc7a139c6ec884a6a183ebac06535f2498116266695e19daf00 SHA512 cb496111ec72163a1872fa9a14f8963108d3185f4464a74cc45d26ccc5071bc36895618b81c29063cde0564a50017a0194da4dc559a046a12550d9ab0d9b8347
 EBUILD libcxx-15.0.7-r1.ebuild 5283 BLAKE2B 4380fc5b851054a5ec226ee4c92a2b79511d73ac9b3f8bccc977211601eca36113fc0ae605854da53898507021f24a8b319197605c556244d84253bede7b84f4 SHA512 0a5859269422e794deb43ed960651a1dea830af28b5e395f32e28de8e67a1f399507340230af1c84248853f554e751709a60a9a78aeb0eb42804cb41907dbfce
 EBUILD libcxx-16.0.6.ebuild 5300 BLAKE2B 4714e22ad2fdcb07c62ead4cfa47fb4734e45dc055700b63a0f24cd6e93dde960c638fa16f55f4c04c6130fc2a7fa5729814c4aee12e9953f603ea5ccb706cc1 SHA512 3eab779107b5c737d971abe29b7bd9f44a73570957bd7d54d6aaa98ec78a6045d7d69272d611f7f09c60e1aa30bbad46b4bd1358b0b2c69e5bc686ab21444857
 EBUILD libcxx-17.0.6.ebuild 5282 BLAKE2B c046d9e3f2b466f5463e10ff253114c014cc35f3f00f372d2df856a768270f3470d94dda9dc0e93f66a13039a5a8001459d8559217c2329df571f14a1625d23a SHA512 8bb2deee9dc94133632e9054412f9796f082632ebfcdd4dd9aa29bf19fd4ded2c98a1e21462b0849abe3cde4c73de97144f9549969710e5826cde742ce236477
 EBUILD libcxx-18.1.0_rc2.ebuild 5367 BLAKE2B f7db8abd6b4c8b6949fb0f5e3a7448ec6ee3209d1459090fed642db04277b396a5418d270bd5d44b08cf13752d8c3f0856e88c93697ef9ab66f7d9b5675465a7 SHA512 06d7ac584a93c185bdb0bac6bae43b7036825b15f31857db865b61b2e9c202826f4c861404d3be012694c4203632342aa4352fc41c6abbbb6eca2b745c33d7e1
+EBUILD libcxx-18.1.0_rc3.ebuild 5367 BLAKE2B f7db8abd6b4c8b6949fb0f5e3a7448ec6ee3209d1459090fed642db04277b396a5418d270bd5d44b08cf13752d8c3f0856e88c93697ef9ab66f7d9b5675465a7 SHA512 06d7ac584a93c185bdb0bac6bae43b7036825b15f31857db865b61b2e9c202826f4c861404d3be012694c4203632342aa4352fc41c6abbbb6eca2b745c33d7e1
 EBUILD libcxx-19.0.0.9999.ebuild 5397 BLAKE2B 800024bbb9b69c7c159d05bf481db08bfb4c89b93a517410a892cd80a0a0bbf07119d0babcc952283bfc4dff51dd4ea4253a63cbc3f301db6e281074e4a2061a SHA512 61a3676d06d6e5f44e5a6f0de8f05c0af5384c3e940b2f504bddbe6b9a806ae5c5ff8311f6986a284338761e554894ddb1bec7f5e1b324a6e211b1d60f0eb635
 EBUILD libcxx-19.0.0_pre20240210.ebuild 5367 BLAKE2B f7db8abd6b4c8b6949fb0f5e3a7448ec6ee3209d1459090fed642db04277b396a5418d270bd5d44b08cf13752d8c3f0856e88c93697ef9ab66f7d9b5675465a7 SHA512 06d7ac584a93c185bdb0bac6bae43b7036825b15f31857db865b61b2e9c202826f4c861404d3be012694c4203632342aa4352fc41c6abbbb6eca2b745c33d7e1
 EBUILD libcxx-19.0.0_pre20240218.ebuild 5397 BLAKE2B 800024bbb9b69c7c159d05bf481db08bfb4c89b93a517410a892cd80a0a0bbf07119d0babcc952283bfc4dff51dd4ea4253a63cbc3f301db6e281074e4a2061a SHA512 61a3676d06d6e5f44e5a6f0de8f05c0af5384c3e940b2f504bddbe6b9a806ae5c5ff8311f6986a284338761e554894ddb1bec7f5e1b324a6e211b1d60f0eb635
diff --git a/sys-libs/libcxx/libcxx-18.1.0_rc3.ebuild b/sys-libs/libcxx/libcxx-18.1.0_rc3.ebuild
new file mode 100644
index 000000000000..c205f3f21b57
--- /dev/null
+++ b/sys-libs/libcxx/libcxx-18.1.0_rc3.ebuild
@@ -0,0 +1,209 @@
+# Copyright 1999-2024 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+PYTHON_COMPAT=( python3_{10..12} )
+inherit cmake-multilib flag-o-matic llvm.org llvm-utils python-any-r1
+inherit toolchain-funcs
+
+DESCRIPTION="New implementation of the C++ standard library, targeting C++11"
+HOMEPAGE="https://libcxx.llvm.org/"
+
+LICENSE="Apache-2.0-with-LLVM-exceptions || ( UoI-NCSA MIT )"
+SLOT="0"
+IUSE="+clang +libcxxabi +static-libs test"
+REQUIRED_USE="test? ( clang )"
+RESTRICT="!test? ( test )"
+
+RDEPEND="
+	libcxxabi? (
+		~sys-libs/libcxxabi-${PV}[static-libs?,${MULTILIB_USEDEP}]
+	)
+	!libcxxabi? ( >=sys-devel/gcc-4.7:=[cxx] )
+"
+DEPEND="
+	${RDEPEND}
+	sys-devel/llvm:${LLVM_MAJOR}
+"
+BDEPEND="
+	clang? (
+		sys-devel/clang:${LLVM_MAJOR}
+	)
+	!test? (
+		${PYTHON_DEPS}
+	)
+	test? (
+		dev-debug/gdb[python]
+		$(python_gen_any_dep 'dev-python/lit[${PYTHON_USEDEP}]')
+	)
+"
+
+LLVM_COMPONENTS=( runtimes libcxx{,abi} llvm/{cmake,utils/llvm-lit} cmake )
+llvm.org_set_globals
+
+python_check_deps() {
+	use test || return 0
+	python_has_version "dev-python/lit[${PYTHON_USEDEP}]"
+}
+
+pkg_setup() {
+	python-any-r1_pkg_setup
+
+	if ! use libcxxabi && ! tc-is-gcc ; then
+		eerror "To build ${PN} against libsupc++, you have to use gcc. Other"
+		eerror "compilers are not supported. Please set CC=gcc and CXX=g++"
+		eerror "and try again."
+		die
+	fi
+}
+
+src_prepare() {
+	# hanging tests
+	# https://github.com/llvm/llvm-project/issues/73791
+	rm ../libcxx/test/std/atomics/atomics.types.generic/atomics.types.float/fetch_* || die
+	rm ../libcxx/test/std/atomics/atomics.types.generic/atomics.types.float/operator.*_equals* || die
+
+	cmake_src_prepare
+}
+
+test_compiler() {
+	$(tc-getCXX) ${CXXFLAGS} ${LDFLAGS} "${@}" -o /dev/null -x c++ - \
+		<<<'int main() { return 0; }' &>/dev/null
+}
+
+src_configure() {
+	llvm_prepend_path "${LLVM_MAJOR}"
+
+	# note: we need to do this before multilib kicks in since it will
+	# alter the CHOST
+	local cxxabi cxxabi_incs
+	if use libcxxabi; then
+		cxxabi=system-libcxxabi
+		cxxabi_incs="${EPREFIX}/usr/include/c++/v1"
+	else
+		local gcc_inc="${EPREFIX}/usr/lib/gcc/${CHOST}/$(gcc-fullversion)/include/g++-v$(gcc-major-version)"
+		cxxabi=libsupc++
+		cxxabi_incs="${gcc_inc};${gcc_inc}/${CHOST}"
+	fi
+
+	multilib-minimal_src_configure
+}
+
+multilib_src_configure() {
+	if use clang; then
+		local -x CC=${CHOST}-clang
+		local -x CXX=${CHOST}-clang++
+		strip-unsupported-flags
+	fi
+
+	# link to compiler-rt
+	local use_compiler_rt=OFF
+	[[ $(tc-get-c-rtlib) == compiler-rt ]] && use_compiler_rt=ON
+
+	# bootstrap: cmake is unhappy if compiler can't link to stdlib
+	local nolib_flags=( -nodefaultlibs -lc )
+	if ! test_compiler; then
+		if test_compiler "${nolib_flags[@]}"; then
+			local -x LDFLAGS="${LDFLAGS} ${nolib_flags[*]}"
+			ewarn "${CXX} seems to lack runtime, trying with ${nolib_flags[*]}"
+		fi
+	fi
+
+	local libdir=$(get_libdir)
+	local mycmakeargs=(
+		-DCMAKE_CXX_COMPILER_TARGET="${CHOST}"
+		-DPython3_EXECUTABLE="${PYTHON}"
+		-DLLVM_ENABLE_RUNTIMES=libcxx
+		-DLLVM_INCLUDE_TESTS=OFF
+		-DLLVM_LIBDIR_SUFFIX=${libdir#lib}
+
+		-DLIBCXX_ENABLE_SHARED=ON
+		-DLIBCXX_ENABLE_STATIC=$(usex static-libs)
+		-DLIBCXX_CXX_ABI=${cxxabi}
+		-DLIBCXX_CXX_ABI_INCLUDE_PATHS=${cxxabi_incs}
+		# we're using our own mechanism for generating linker scripts
+		-DLIBCXX_ENABLE_ABI_LINKER_SCRIPT=OFF
+		-DLIBCXX_HAS_MUSL_LIBC=$(usex elibc_musl)
+		-DLIBCXX_INCLUDE_BENCHMARKS=OFF
+		-DLIBCXX_INCLUDE_TESTS=$(usex test)
+		-DLIBCXX_USE_COMPILER_RT=${use_compiler_rt}
+		# this is broken with standalone builds, and also meaningless
+		-DLIBCXXABI_USE_LLVM_UNWINDER=OFF
+	)
+
+	if use test; then
+		mycmakeargs+=(
+			-DLLVM_EXTERNAL_LIT="${EPREFIX}/usr/bin/lit"
+			-DLLVM_LIT_ARGS="$(get_lit_flags)"
+			-DPython3_EXECUTABLE="${PYTHON}"
+		)
+	fi
+	cmake_src_configure
+}
+
+multilib_src_compile() {
+	cmake_src_compile
+	if [[ ${CHOST} != *-darwin* ]] ; then
+		gen_shared_ldscript
+		use static-libs && gen_static_ldscript
+	fi
+}
+
+multilib_src_test() {
+	local -x LIT_PRESERVES_TMP=1
+	cmake_build check-cxx
+}
+
+multilib_src_install() {
+	cmake_src_install
+	# since we've replaced libc++.{a,so} with ldscripts, now we have to
+	# install the extra symlinks
+	if [[ ${CHOST} != *-darwin* ]] ; then
+		dolib.so lib/libc++_shared.so
+		use static-libs && dolib.a lib/libc++_static.a
+	fi
+}
+
+# Usage: deps
+gen_ldscript() {
+	local output_format
+	output_format=$($(tc-getCC) ${CFLAGS} ${LDFLAGS} -Wl,--verbose 2>&1 | sed -n 's/^OUTPUT_FORMAT("\([^"]*\)",.*/\1/p')
+	[[ -n ${output_format} ]] && output_format="OUTPUT_FORMAT ( ${output_format} )"
+
+	cat <<-END_LDSCRIPT
+/* GNU ld script
+   Include missing dependencies
+*/
+${output_format}
+GROUP ( $@ )
+END_LDSCRIPT
+}
+
+gen_static_ldscript() {
+	# Move it first.
+	mv lib/libc++{,_static}.a || die
+	# Generate libc++.a ldscript for inclusion of its dependencies so that
+	# clang++ -stdlib=libc++ -static works out of the box.
+	local deps=(
+		libc++_static.a
+		$(usex libcxxabi libc++abi.a libsupc++.a)
+	)
+	# On Linux/glibc it does not link without libpthread or libdl. It is
+	# fine on FreeBSD.
+	use elibc_glibc && deps+=( libpthread.a libdl.a )
+
+	gen_ldscript "${deps[*]}" > lib/libc++.a || die
+}
+
+gen_shared_ldscript() {
+	# Move it first.
+	mv lib/libc++{,_shared}.so || die
+	local deps=(
+		libc++_shared.so
+		# libsupc++ doesn't have a shared version
+		$(usex libcxxabi libc++abi.so libsupc++.a)
+	)
+
+	gen_ldscript "${deps[*]}" > lib/libc++.so || die
+}
diff --git a/sys-libs/libcxxabi/Manifest b/sys-libs/libcxxabi/Manifest
index 2f777e81118c..51bd52b13fc4 100644
--- a/sys-libs/libcxxabi/Manifest
+++ b/sys-libs/libcxxabi/Manifest
@@ -6,12 +6,15 @@ DIST llvm-project-17.0.6.src.tar.xz 127838860 BLAKE2B d6ede1a9fda8756995c3e06541
 DIST llvm-project-17.0.6.src.tar.xz.sig 438 BLAKE2B 186e75b6a0fbfe1e85408589c149e1800fcc47d685b74e4260018e05cd08bc793d1d1197c9c50e177eea941a3d0c65cb0c583ce6dae449099b920adf8a508ef7 SHA512 f78c55053a6450625f3e95f52c305110b4468a9854fec75831b65b8d6ceee3c9206ab9e63c4b5fda8be9bd344f72cfbdaae0520ed240abd505e08ebeaa25d340
 DIST llvm-project-18.1.0rc2.src.tar.xz 131993176 BLAKE2B 8df1e34a54214975efe1b9a649753a2dc20c04e3c763bd8648000f48dd18f27ccfdc597ff6e68e0f408310493dfa92f48c7eee53376501e8ebc3b7c614809c15 SHA512 b595bb5d029723fee4e8f8edeaddd6fdcd48d668f66f4239e3208fd19d3a3622e8e4f90ae3fa4b1216fca1621d6c6b6ebf4d99dec7febff2457d0ceb79e8617a
 DIST llvm-project-18.1.0rc2.src.tar.xz.sig 566 BLAKE2B c765549386a92883bd348d9be25a3c92b1e66a1bac71385ef99978ec2af413a7616a2d9699c57554d927f95b80a3584572557d26e3df16b2ff6678359d5fd6b0 SHA512 83bb4c133f34faec8a0109689ed7aa18222c9a803ba8c95c571a18e854726024f106a1c8e3a820020255c426b7fa8bda26789ff1546972e233fbe3e3ab3a8e91
+DIST llvm-project-18.1.0rc3.src.tar.xz 132011280 BLAKE2B 482a0e1b806292598bd646f225705140a463706ec391e4e42f203606b85673601a65fe55f2432d77f4c2f4c6584b35e53eeaded42e0b67aa6538c37d7cceb4ff SHA512 6c0adcf6e4057de8fb1dcd062845d14d725833d23d8e1362cbccab176931f55600a3971f01690179b795ff3feca0af9141b16dee4d4159755596cc9c904bf099
+DIST llvm-project-18.1.0rc3.src.tar.xz.sig 566 BLAKE2B dac9c174e2eeda5e0af0153d78a2e9c8f145efe03250582a27df1bd6a89ba70afdcfa1ed6aa46adb1f7f21077cadb6e43963758358ff17122c36781ee4018c05 SHA512 91a2778f9b66bc80172172f36d6027fb2455f3ffd03b06ad0dd376471c4d4e2e34c8bee69c76cfe95003ae34f0d28c394c7d135fbbb75686ff89aee56b6c45c3
 DIST llvm-project-3496927edcd0685807351ba88a7e2cfb006e1c0d.tar.gz 206227842 BLAKE2B cd27e9e9bca3622c2241bfa91c78eb8443df7465c1efcec57d5e701e2c61d3b2d3619483199e67b56deed9410f5382fc3164cdc7e864dcd77f4d12f3f9d2b159 SHA512 156d441074aff4d85af956b9abf89f9aefccccbe5b39e315c9c7c249ad01f95b42a303c23e9142292e7746f691c2ee704a7cd4a60916594ea1d468240c9b8152
 DIST llvm-project-8884ba43a8485bebef5c4d41e7ed457e3fa84f07.tar.gz 205853916 BLAKE2B 115809efbf062ced32ffe61b25e65e44a0b3c293f68bf40fc4d9e596cd077fc4781a059ad24c4dc7a139c6ec884a6a183ebac06535f2498116266695e19daf00 SHA512 cb496111ec72163a1872fa9a14f8963108d3185f4464a74cc45d26ccc5071bc36895618b81c29063cde0564a50017a0194da4dc559a046a12550d9ab0d9b8347
 EBUILD libcxxabi-15.0.7.ebuild 2911 BLAKE2B 5f2004d2f68fe4eddb0b22be82d28fcca7954d0e3ad9a5510744adc4d0dfd7a1ab9fd928404adcd3eeecc58703f51117d0a80e5895b53e0ae7b71621ad5a435c SHA512 5b8e2c6abdec785649aa41b7f05ab86ecab30ff0631d6078c9b1052b406c320c5847b8f16ffa6d9e62ba4a6bca5959b18770810924d6e6da264fb08d6ff738d0
 EBUILD libcxxabi-16.0.6.ebuild 2932 BLAKE2B 837ab88ee88d5497b8bddb9f001d4b4ddd44ed982ef47114c965174135ed136abd0e3a6f3848a4aba53d0ca3748c54674cb28de8d46fda3bb7a90f326d41c7c6 SHA512 e4ebf7f35d2cad3bf3ba02754c85fee1cd1c4e52887770698ebaa3ef2fe66873f468677d307ea2d6956c2f6d3ac9b61943461193a5315f1e8a2846f2463b0581
 EBUILD libcxxabi-17.0.6.ebuild 2934 BLAKE2B bdc36d4751d76c5cc18cfd16bf6390a64bcde7c97bd8ee60ffc0be4120474a6aedf8b18936159e605698647a8078f465155f6f12593f6010938201349d916879 SHA512 d0a621dccc711c64fec580af200f6dcef19f8fb3b812fd4971362fc50ef21be0ad1996a32a18b684b9b9a5089dec3414cc39543232d0a7beb37186624ff0bcc6
 EBUILD libcxxabi-18.1.0_rc2.ebuild 2684 BLAKE2B d72cf1584537afd3d13263975a4f903819f6844cac728daab626b269f460865cac59c3199d38ced179ce041294db940b31f07ca74eeabd452f8e2f775e3e206d SHA512 ac7f20fa097c17349959154cce8c75a2083b04d4fb1241d6917c0fd14348a848f9158d050b9791754fc02ec4cd1bc2d82a8ef678a7b025e15524e5af945c9bc1
+EBUILD libcxxabi-18.1.0_rc3.ebuild 2684 BLAKE2B d72cf1584537afd3d13263975a4f903819f6844cac728daab626b269f460865cac59c3199d38ced179ce041294db940b31f07ca74eeabd452f8e2f775e3e206d SHA512 ac7f20fa097c17349959154cce8c75a2083b04d4fb1241d6917c0fd14348a848f9158d050b9791754fc02ec4cd1bc2d82a8ef678a7b025e15524e5af945c9bc1
 EBUILD libcxxabi-19.0.0.9999.ebuild 2684 BLAKE2B d72cf1584537afd3d13263975a4f903819f6844cac728daab626b269f460865cac59c3199d38ced179ce041294db940b31f07ca74eeabd452f8e2f775e3e206d SHA512 ac7f20fa097c17349959154cce8c75a2083b04d4fb1241d6917c0fd14348a848f9158d050b9791754fc02ec4cd1bc2d82a8ef678a7b025e15524e5af945c9bc1
 EBUILD libcxxabi-19.0.0_pre20240210.ebuild 2684 BLAKE2B d72cf1584537afd3d13263975a4f903819f6844cac728daab626b269f460865cac59c3199d38ced179ce041294db940b31f07ca74eeabd452f8e2f775e3e206d SHA512 ac7f20fa097c17349959154cce8c75a2083b04d4fb1241d6917c0fd14348a848f9158d050b9791754fc02ec4cd1bc2d82a8ef678a7b025e15524e5af945c9bc1
 EBUILD libcxxabi-19.0.0_pre20240218.ebuild 2684 BLAKE2B d72cf1584537afd3d13263975a4f903819f6844cac728daab626b269f460865cac59c3199d38ced179ce041294db940b31f07ca74eeabd452f8e2f775e3e206d SHA512 ac7f20fa097c17349959154cce8c75a2083b04d4fb1241d6917c0fd14348a848f9158d050b9791754fc02ec4cd1bc2d82a8ef678a7b025e15524e5af945c9bc1
diff --git a/sys-libs/libcxxabi/libcxxabi-18.1.0_rc3.ebuild b/sys-libs/libcxxabi/libcxxabi-18.1.0_rc3.ebuild
new file mode 100644
index 000000000000..d45de5993114
--- /dev/null
+++ b/sys-libs/libcxxabi/libcxxabi-18.1.0_rc3.ebuild
@@ -0,0 +1,110 @@
+# Copyright 1999-2024 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+PYTHON_COMPAT=( python3_{10..12} )
+inherit cmake-multilib flag-o-matic llvm.org llvm-utils python-any-r1
+inherit toolchain-funcs
+
+DESCRIPTION="Low level support for a standard C++ library"
+HOMEPAGE="https://libcxxabi.llvm.org/"
+
+LICENSE="Apache-2.0-with-LLVM-exceptions || ( UoI-NCSA MIT )"
+SLOT="0"
+IUSE="+clang +static-libs test"
+REQUIRED_USE="test? ( clang )"
+RESTRICT="!test? ( test )"
+
+# in 15.x, cxxabi.h is moving from libcxx to libcxxabi
+RDEPEND+="
+	!<sys-libs/libcxx-15
+"
+DEPEND="
+	${RDEPEND}
+	sys-devel/llvm:${LLVM_MAJOR}
+"
+BDEPEND="
+	clang? (
+		sys-devel/clang:${LLVM_MAJOR}
+	)
+	!test? (
+		${PYTHON_DEPS}
+	)
+	test? (
+		$(python_gen_any_dep 'dev-python/lit[${PYTHON_USEDEP}]')
+	)
+"
+
+LLVM_COMPONENTS=( runtimes libcxx{abi,} llvm/cmake cmake )
+LLVM_TEST_COMPONENTS=( llvm/utils/llvm-lit )
+llvm.org_set_globals
+
+python_check_deps() {
+	use test || return 0
+	python_has_version "dev-python/lit[${PYTHON_USEDEP}]"
+}
+
+multilib_src_configure() {
+	llvm_prepend_path "${LLVM_MAJOR}"
+
+	if use clang; then
+		local -x CC=${CHOST}-clang
+		local -x CXX=${CHOST}-clang++
+		strip-unsupported-flags
+	fi
+
+	# link to compiler-rt
+	local use_compiler_rt=OFF
+	[[ $(tc-get-c-rtlib) == compiler-rt ]] && use_compiler_rt=ON
+
+	local libdir=$(get_libdir)
+	local mycmakeargs=(
+		-DCMAKE_CXX_COMPILER_TARGET="${CHOST}"
+		-DPython3_EXECUTABLE="${PYTHON}"
+		-DLLVM_ENABLE_RUNTIMES="libcxxabi;libcxx"
+		-DLLVM_INCLUDE_TESTS=OFF
+		-DLLVM_LIBDIR_SUFFIX=${libdir#lib}
+		-DLIBCXXABI_ENABLE_SHARED=ON
+		-DLIBCXXABI_ENABLE_STATIC=$(usex static-libs)
+		-DLIBCXXABI_INCLUDE_TESTS=$(usex test)
+		-DLIBCXXABI_USE_COMPILER_RT=${use_compiler_rt}
+
+		# upstream is omitting standard search path for this
+		# probably because gcc & clang are bundling their own unwind.h
+		-DLIBCXXABI_LIBUNWIND_INCLUDES="${EPREFIX}"/usr/include
+		# this is broken with standalone builds, and also meaningless
+		-DLIBCXXABI_USE_LLVM_UNWINDER=OFF
+
+		-DLIBCXX_LIBDIR_SUFFIX=
+		-DLIBCXX_ENABLE_SHARED=ON
+		-DLIBCXX_ENABLE_STATIC=OFF
+		-DLIBCXX_CXX_ABI=libcxxabi
+		-DLIBCXX_ENABLE_ABI_LINKER_SCRIPT=OFF
+		-DLIBCXX_HAS_MUSL_LIBC=$(usex elibc_musl)
+		-DLIBCXX_HAS_GCC_S_LIB=OFF
+		-DLIBCXX_INCLUDE_BENCHMARKS=OFF
+		-DLIBCXX_INCLUDE_TESTS=OFF
+	)
+	if use test; then
+		mycmakeargs+=(
+			-DLLVM_EXTERNAL_LIT="${EPREFIX}/usr/bin/lit"
+			-DLLVM_LIT_ARGS="$(get_lit_flags)"
+			-DPython3_EXECUTABLE="${PYTHON}"
+		)
+	fi
+	cmake_src_configure
+}
+
+multilib_src_compile() {
+	cmake_build cxxabi
+}
+
+multilib_src_test() {
+	local -x LIT_PRESERVES_TMP=1
+	cmake_build check-cxxabi
+}
+
+multilib_src_install() {
+	DESTDIR="${D}" cmake_build install-cxxabi
+}
diff --git a/sys-libs/libomp/Manifest b/sys-libs/libomp/Manifest
index 8cd488fdb970..4844e53307db 100644
--- a/sys-libs/libomp/Manifest
+++ b/sys-libs/libomp/Manifest
@@ -7,12 +7,15 @@ DIST llvm-project-17.0.6.src.tar.xz 127838860 BLAKE2B d6ede1a9fda8756995c3e06541
 DIST llvm-project-17.0.6.src.tar.xz.sig 438 BLAKE2B 186e75b6a0fbfe1e85408589c149e1800fcc47d685b74e4260018e05cd08bc793d1d1197c9c50e177eea941a3d0c65cb0c583ce6dae449099b920adf8a508ef7 SHA512 f78c55053a6450625f3e95f52c305110b4468a9854fec75831b65b8d6ceee3c9206ab9e63c4b5fda8be9bd344f72cfbdaae0520ed240abd505e08ebeaa25d340
 DIST llvm-project-18.1.0rc2.src.tar.xz 131993176 BLAKE2B 8df1e34a54214975efe1b9a649753a2dc20c04e3c763bd8648000f48dd18f27ccfdc597ff6e68e0f408310493dfa92f48c7eee53376501e8ebc3b7c614809c15 SHA512 b595bb5d029723fee4e8f8edeaddd6fdcd48d668f66f4239e3208fd19d3a3622e8e4f90ae3fa4b1216fca1621d6c6b6ebf4d99dec7febff2457d0ceb79e8617a
 DIST llvm-project-18.1.0rc2.src.tar.xz.sig 566 BLAKE2B c765549386a92883bd348d9be25a3c92b1e66a1bac71385ef99978ec2af413a7616a2d9699c57554d927f95b80a3584572557d26e3df16b2ff6678359d5fd6b0 SHA512 83bb4c133f34faec8a0109689ed7aa18222c9a803ba8c95c571a18e854726024f106a1c8e3a820020255c426b7fa8bda26789ff1546972e233fbe3e3ab3a8e91
+DIST llvm-project-18.1.0rc3.src.tar.xz 132011280 BLAKE2B 482a0e1b806292598bd646f225705140a463706ec391e4e42f203606b85673601a65fe55f2432d77f4c2f4c6584b35e53eeaded42e0b67aa6538c37d7cceb4ff SHA512 6c0adcf6e4057de8fb1dcd062845d14d725833d23d8e1362cbccab176931f55600a3971f01690179b795ff3feca0af9141b16dee4d4159755596cc9c904bf099
+DIST llvm-project-18.1.0rc3.src.tar.xz.sig 566 BLAKE2B dac9c174e2eeda5e0af0153d78a2e9c8f145efe03250582a27df1bd6a89ba70afdcfa1ed6aa46adb1f7f21077cadb6e43963758358ff17122c36781ee4018c05 SHA512 91a2778f9b66bc80172172f36d6027fb2455f3ffd03b06ad0dd376471c4d4e2e34c8bee69c76cfe95003ae34f0d28c394c7d135fbbb75686ff89aee56b6c45c3
 DIST llvm-project-3496927edcd0685807351ba88a7e2cfb006e1c0d.tar.gz 206227842 BLAKE2B cd27e9e9bca3622c2241bfa91c78eb8443df7465c1efcec57d5e701e2c61d3b2d3619483199e67b56deed9410f5382fc3164cdc7e864dcd77f4d12f3f9d2b159 SHA512 156d441074aff4d85af956b9abf89f9aefccccbe5b39e315c9c7c249ad01f95b42a303c23e9142292e7746f691c2ee704a7cd4a60916594ea1d468240c9b8152
 DIST llvm-project-8884ba43a8485bebef5c4d41e7ed457e3fa84f07.tar.gz 205853916 BLAKE2B 115809efbf062ced32ffe61b25e65e44a0b3c293f68bf40fc4d9e596cd077fc4781a059ad24c4dc7a139c6ec884a6a183ebac06535f2498116266695e19daf00 SHA512 cb496111ec72163a1872fa9a14f8963108d3185f4464a74cc45d26ccc5071bc36895618b81c29063cde0564a50017a0194da4dc559a046a12550d9ab0d9b8347
 EBUILD libomp-15.0.7-r6.ebuild 3474 BLAKE2B e8ab2666defb3a2d0582f0413ade0efce3d5e5d42ee935dc89915c079dd3d7e2c9dde77edb4e3dadee7b1a60a311615f253feef33f73dee90a0ddc9383bbfaa1 SHA512 e6e672ff57b1419b33b2c0da4e2535005b720e3cd34fa18245fdf319bbe70235bcbaa8baeca36381684041f57032ef4a7f0ece4ad1a84336ebd3087759fe31e9
 EBUILD libomp-16.0.6.ebuild 3988 BLAKE2B 31eee2f5b764917a62cb307fab6dd0744594dc0ebdc04c359a85eb6372421a42431dd9de792671e1f0d326d798df1bbae5949529a22d7f2a99cae02d6734a37b SHA512 4e62220e10ab0aa1b64ae9557055b1ac6ecc145ae81cbe94445a335ad4e0d7e541dd13db4ffcffaaf80a50e2f13136982828d4d0211e5dc925a0b6ef2a2825a7
 EBUILD libomp-17.0.6.ebuild 3991 BLAKE2B 12cfa3e181654b85caee03e7f288631f5cbdb85b1fca67468fda21fc1b9c909a2dbddc9d3c52e46a841149b95a26811217a625cfa1889bf6a0dd93d038291f1e SHA512 e6bc4697f9d8972da5cfa6f6c33328c590ea0c8d394247b6ce5c7ba3a3fb199e3b8f3649341524f7e4217d7ac3ba385c1008b925b8e92d780ae60f24158b766d
 EBUILD libomp-18.1.0_rc2.ebuild 4140 BLAKE2B 61eb192159e506145a15670a15549b69555d29e4da39a2d910fa51ee3dd189ea828556debdd13f97d221a50ce09321b3441ff12eedc58f7c662ff674f9b3a1e4 SHA512 adf985a8fdd31f53d5dc6953dc032a02cd45c8b6e69da9d2e8a0c80cfd010341bd063f30432d9665ee2b97e01ed087987b44deb9e3d6f070b2340f6e35561c0b
+EBUILD libomp-18.1.0_rc3.ebuild 4140 BLAKE2B 61eb192159e506145a15670a15549b69555d29e4da39a2d910fa51ee3dd189ea828556debdd13f97d221a50ce09321b3441ff12eedc58f7c662ff674f9b3a1e4 SHA512 adf985a8fdd31f53d5dc6953dc032a02cd45c8b6e69da9d2e8a0c80cfd010341bd063f30432d9665ee2b97e01ed087987b44deb9e3d6f070b2340f6e35561c0b
 EBUILD libomp-19.0.0.9999.ebuild 4140 BLAKE2B 61eb192159e506145a15670a15549b69555d29e4da39a2d910fa51ee3dd189ea828556debdd13f97d221a50ce09321b3441ff12eedc58f7c662ff674f9b3a1e4 SHA512 adf985a8fdd31f53d5dc6953dc032a02cd45c8b6e69da9d2e8a0c80cfd010341bd063f30432d9665ee2b97e01ed087987b44deb9e3d6f070b2340f6e35561c0b
 EBUILD libomp-19.0.0_pre20240210.ebuild 4140 BLAKE2B 61eb192159e506145a15670a15549b69555d29e4da39a2d910fa51ee3dd189ea828556debdd13f97d221a50ce09321b3441ff12eedc58f7c662ff674f9b3a1e4 SHA512 adf985a8fdd31f53d5dc6953dc032a02cd45c8b6e69da9d2e8a0c80cfd010341bd063f30432d9665ee2b97e01ed087987b44deb9e3d6f070b2340f6e35561c0b
 EBUILD libomp-19.0.0_pre20240218.ebuild 4140 BLAKE2B 61eb192159e506145a15670a15549b69555d29e4da39a2d910fa51ee3dd189ea828556debdd13f97d221a50ce09321b3441ff12eedc58f7c662ff674f9b3a1e4 SHA512 adf985a8fdd31f53d5dc6953dc032a02cd45c8b6e69da9d2e8a0c80cfd010341bd063f30432d9665ee2b97e01ed087987b44deb9e3d6f070b2340f6e35561c0b
diff --git a/sys-libs/libomp/libomp-18.1.0_rc3.ebuild b/sys-libs/libomp/libomp-18.1.0_rc3.ebuild
new file mode 100644
index 000000000000..ce432b31535d
--- /dev/null
+++ b/sys-libs/libomp/libomp-18.1.0_rc3.ebuild
@@ -0,0 +1,158 @@
+# Copyright 1999-2024 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+PYTHON_COMPAT=( python3_{10..12} )
+inherit flag-o-matic cmake-multilib linux-info llvm.org llvm-utils
+inherit python-single-r1 toolchain-funcs
+
+DESCRIPTION="OpenMP runtime library for LLVM/clang compiler"
+HOMEPAGE="https://openmp.llvm.org"
+
+LICENSE="Apache-2.0-with-LLVM-exceptions || ( UoI-NCSA MIT )"
+SLOT="0/${LLVM_SOABI}"
+IUSE="
+	+debug gdb-plugin hwloc offload ompt test
+	llvm_targets_AMDGPU llvm_targets_NVPTX
+"
+REQUIRED_USE="
+	gdb-plugin? ( ${PYTHON_REQUIRED_USE} )
+"
+RESTRICT="!test? ( test )"
+
+RDEPEND="
+	gdb-plugin? ( ${PYTHON_DEPS} )
+	hwloc? ( >=sys-apps/hwloc-2.5:0=[${MULTILIB_USEDEP}] )
+	offload? (
+		dev-libs/libffi:=[${MULTILIB_USEDEP}]
+		~sys-devel/llvm-${PV}[${MULTILIB_USEDEP}]
+		llvm_targets_AMDGPU? ( dev-libs/rocr-runtime:= )
+	)
+"
+# tests:
+# - dev-python/lit provides the test runner
+# - sys-devel/llvm provide test utils (e.g. FileCheck)
+# - sys-devel/clang provides the compiler to run tests
+DEPEND="
+	${RDEPEND}
+"
+BDEPEND="
+	dev-lang/perl
+	offload? (
+		llvm_targets_AMDGPU? ( sys-devel/clang )
+		llvm_targets_NVPTX? ( sys-devel/clang )
+		virtual/pkgconfig
+	)
+	test? (
+		${PYTHON_DEPS}
+		$(python_gen_cond_dep '
+			dev-python/lit[${PYTHON_USEDEP}]
+		')
+		sys-devel/clang
+	)
+"
+
+LLVM_COMPONENTS=( openmp cmake llvm/include )
+llvm.org_set_globals
+
+kernel_pds_check() {
+	if use kernel_linux && kernel_is -lt 4 15 && kernel_is -ge 4 13; then
+		local CONFIG_CHECK="~!SCHED_PDS"
+		local ERROR_SCHED_PDS="\
+PDS scheduler versions >= 0.98c < 0.98i (e.g. used in kernels >= 4.13-pf11
+< 4.14-pf9) do not implement sched_yield() call which may result in horrible
+performance problems with libomp. If you are using one of the specified
+kernel versions, you may want to disable the PDS scheduler."
+
+		check_extra_config
+	fi
+}
+
+pkg_pretend() {
+	kernel_pds_check
+}
+
+pkg_setup() {
+	if use gdb-plugin || use test; then
+		python-single-r1_pkg_setup
+	fi
+}
+
+multilib_src_configure() {
+	use offload && llvm_prepend_path "${LLVM_MAJOR}"
+
+	# LTO causes issues in other packages building, #870127
+	filter-lto
+
+	# LLVM_ENABLE_ASSERTIONS=NO does not guarantee this for us, #614844
+	use debug || local -x CPPFLAGS="${CPPFLAGS} -DNDEBUG"
+
+	local build_omptarget=OFF
+	# upstream disallows building libomptarget when sizeof(void*) != 8
+	if use offload &&
+		"$(tc-getCC)" ${CFLAGS} ${CPPFLAGS} -c -x c - -o /dev/null \
+		<<-EOF &>/dev/null
+			int test[sizeof(void *) == 8 ? 1 : -1];
+		EOF
+	then
+		build_omptarget=ON
+	fi
+
+	local libdir="$(get_libdir)"
+	local mycmakeargs=(
+		-DOPENMP_LIBDIR_SUFFIX="${libdir#lib}"
+
+		-DLIBOMP_USE_HWLOC=$(usex hwloc)
+		-DLIBOMP_OMPD_GDB_SUPPORT=$(multilib_native_usex gdb-plugin)
+		-DLIBOMP_OMPT_SUPPORT=$(usex ompt)
+
+		-DOPENMP_ENABLE_LIBOMPTARGET=${build_omptarget}
+
+		# do not install libgomp.so & libiomp5.so aliases
+		-DLIBOMP_INSTALL_ALIASES=OFF
+		# disable unnecessary hack copying stuff back to srcdir
+		-DLIBOMP_COPY_EXPORTS=OFF
+		# prevent trying to access the GPU
+		-DLIBOMPTARGET_AMDGPU_ARCH=LIBOMPTARGET_AMDGPU_ARCH-NOTFOUND
+	)
+
+	if [[ ${build_omptarget} == ON ]]; then
+		local ffi_cflags=$($(tc-getPKG_CONFIG) --cflags-only-I libffi)
+		local ffi_ldflags=$($(tc-getPKG_CONFIG) --libs-only-L libffi)
+		mycmakeargs+=(
+			-DFFI_INCLUDE_DIR="${ffi_cflags#-I}"
+			-DFFI_LIBRARY_DIR="${ffi_ldflags#-L}"
+		)
+
+		if has "${CHOST%%-*}" aarch64 powerpc64le x86_64; then
+			mycmakeargs+=(
+				-DLIBOMPTARGET_BUILD_AMDGPU_PLUGIN=$(usex llvm_targets_AMDGPU)
+				-DLIBOMPTARGET_BUILD_CUDA_PLUGIN=$(usex llvm_targets_NVPTX)
+			)
+		else
+			mycmakeargs+=(
+				-DLIBOMPTARGET_BUILD_AMDGPU_PLUGIN=OFF
+				-DLIBOMPTARGET_BUILD_CUDA_PLUGIN=OFF
+			)
+		fi
+	fi
+
+	use test && mycmakeargs+=(
+		# this project does not use standard LLVM cmake macros
+		-DOPENMP_LLVM_LIT_EXECUTABLE="${EPREFIX}/usr/bin/lit"
+		-DOPENMP_LIT_ARGS="$(get_lit_flags)"
+
+		-DOPENMP_TEST_C_COMPILER="$(type -P "${CHOST}-clang")"
+		-DOPENMP_TEST_CXX_COMPILER="$(type -P "${CHOST}-clang++")"
+	)
+	addpredict /dev/nvidiactl
+	cmake_src_configure
+}
+
+multilib_src_test() {
+	# respect TMPDIR!
+	local -x LIT_PRESERVES_TMP=1
+
+	cmake_build check-libomp
+}
diff --git a/sys-libs/llvm-libunwind/Manifest b/sys-libs/llvm-libunwind/Manifest
index db7ad30419bd..89c0a9c09001 100644
--- a/sys-libs/llvm-libunwind/Manifest
+++ b/sys-libs/llvm-libunwind/Manifest
@@ -6,12 +6,15 @@ DIST llvm-project-17.0.6.src.tar.xz 127838860 BLAKE2B d6ede1a9fda8756995c3e06541
 DIST llvm-project-17.0.6.src.tar.xz.sig 438 BLAKE2B 186e75b6a0fbfe1e85408589c149e1800fcc47d685b74e4260018e05cd08bc793d1d1197c9c50e177eea941a3d0c65cb0c583ce6dae449099b920adf8a508ef7 SHA512 f78c55053a6450625f3e95f52c305110b4468a9854fec75831b65b8d6ceee3c9206ab9e63c4b5fda8be9bd344f72cfbdaae0520ed240abd505e08ebeaa25d340
 DIST llvm-project-18.1.0rc2.src.tar.xz 131993176 BLAKE2B 8df1e34a54214975efe1b9a649753a2dc20c04e3c763bd8648000f48dd18f27ccfdc597ff6e68e0f408310493dfa92f48c7eee53376501e8ebc3b7c614809c15 SHA512 b595bb5d029723fee4e8f8edeaddd6fdcd48d668f66f4239e3208fd19d3a3622e8e4f90ae3fa4b1216fca1621d6c6b6ebf4d99dec7febff2457d0ceb79e8617a
 DIST llvm-project-18.1.0rc2.src.tar.xz.sig 566 BLAKE2B c765549386a92883bd348d9be25a3c92b1e66a1bac71385ef99978ec2af413a7616a2d9699c57554d927f95b80a3584572557d26e3df16b2ff6678359d5fd6b0 SHA512 83bb4c133f34faec8a0109689ed7aa18222c9a803ba8c95c571a18e854726024f106a1c8e3a820020255c426b7fa8bda26789ff1546972e233fbe3e3ab3a8e91
+DIST llvm-project-18.1.0rc3.src.tar.xz 132011280 BLAKE2B 482a0e1b806292598bd646f225705140a463706ec391e4e42f203606b85673601a65fe55f2432d77f4c2f4c6584b35e53eeaded42e0b67aa6538c37d7cceb4ff SHA512 6c0adcf6e4057de8fb1dcd062845d14d725833d23d8e1362cbccab176931f55600a3971f01690179b795ff3feca0af9141b16dee4d4159755596cc9c904bf099
+DIST llvm-project-18.1.0rc3.src.tar.xz.sig 566 BLAKE2B dac9c174e2eeda5e0af0153d78a2e9c8f145efe03250582a27df1bd6a89ba70afdcfa1ed6aa46adb1f7f21077cadb6e43963758358ff17122c36781ee4018c05 SHA512 91a2778f9b66bc80172172f36d6027fb2455f3ffd03b06ad0dd376471c4d4e2e34c8bee69c76cfe95003ae34f0d28c394c7d135fbbb75686ff89aee56b6c45c3
 DIST llvm-project-3496927edcd0685807351ba88a7e2cfb006e1c0d.tar.gz 206227842 BLAKE2B cd27e9e9bca3622c2241bfa91c78eb8443df7465c1efcec57d5e701e2c61d3b2d3619483199e67b56deed9410f5382fc3164cdc7e864dcd77f4d12f3f9d2b159 SHA512 156d441074aff4d85af956b9abf89f9aefccccbe5b39e315c9c7c249ad01f95b42a303c23e9142292e7746f691c2ee704a7cd4a60916594ea1d468240c9b8152
 DIST llvm-project-8884ba43a8485bebef5c4d41e7ed457e3fa84f07.tar.gz 205853916 BLAKE2B 115809efbf062ced32ffe61b25e65e44a0b3c293f68bf40fc4d9e596cd077fc4781a059ad24c4dc7a139c6ec884a6a183ebac06535f2498116266695e19daf00 SHA512 cb496111ec72163a1872fa9a14f8963108d3185f4464a74cc45d26ccc5071bc36895618b81c29063cde0564a50017a0194da4dc559a046a12550d9ab0d9b8347
 EBUILD llvm-libunwind-15.0.7.ebuild 3032 BLAKE2B 9b47e894db1a764f3eca3135f4caba68261953f4433af017b7bb53181e345ad26c570733f997022c53c9ef49a0a3b823188d92cfcc16a2113825d767b1ffab2a SHA512 0b68480fb2a8e5a351574e81fbcff824cd324754ed40378f06fec12fedbba94a921043d72db6ecc37f8b0680b7f518bbbd8d63f69ce8d84f86ca522653d293fb
 EBUILD llvm-libunwind-16.0.6-r1.ebuild 3440 BLAKE2B eafe21a3de172043ca0039ba27c80c64d32b02cc86bdb5a6d108ded35770e0352216337cbf24ee4fde43b699a68a85c8145be2d17510d525452bfd5a02674998 SHA512 164fdc1c62405e02c035af7997b8522b51f5b9337d2bb66d7fc9b1f45df74ec70d31b26dc5324c59792d32c543fe18abf74ed3b07a64c131e3c1bb4f9f733c5d
 EBUILD llvm-libunwind-17.0.6.ebuild 3443 BLAKE2B aa12631c752811bb9f4102c1ee36bdefaf43a90bbef93314878afefa8e7ddccb6142cb256c88b99bf8f926df7d7b23f7ce0711b7c56453d0a4474cf8c5bb3e31 SHA512 3b7908e764835a26c9b101bb6b9a7f57294b18af68b39c2d4ab1ae52ab678b8a5b7ca4950e9dea1d521d9ea1f54655ccef77b96a5aa23db8b7990ca26739a326
 EBUILD llvm-libunwind-18.1.0_rc2.ebuild 3316 BLAKE2B 013ff60e8fa1fa480e1e56c6c8c1d5a657d946264a279a8fad53e3047fcde1f439e10b25e151af0d9c3f7f6fe014c2cf3372d311f3963c78e633e986b28a33e5 SHA512 4aaa97553c0e3e5421fe5864b81fdcd0e8a1167e37bec37e8706d3b9b939b5220a171576f800bdc6ae25f2bbfd60b063c84934d1daa0bdfd6989a80d08044301
+EBUILD llvm-libunwind-18.1.0_rc3.ebuild 3316 BLAKE2B 013ff60e8fa1fa480e1e56c6c8c1d5a657d946264a279a8fad53e3047fcde1f439e10b25e151af0d9c3f7f6fe014c2cf3372d311f3963c78e633e986b28a33e5 SHA512 4aaa97553c0e3e5421fe5864b81fdcd0e8a1167e37bec37e8706d3b9b939b5220a171576f800bdc6ae25f2bbfd60b063c84934d1daa0bdfd6989a80d08044301
 EBUILD llvm-libunwind-19.0.0.9999.ebuild 3316 BLAKE2B 013ff60e8fa1fa480e1e56c6c8c1d5a657d946264a279a8fad53e3047fcde1f439e10b25e151af0d9c3f7f6fe014c2cf3372d311f3963c78e633e986b28a33e5 SHA512 4aaa97553c0e3e5421fe5864b81fdcd0e8a1167e37bec37e8706d3b9b939b5220a171576f800bdc6ae25f2bbfd60b063c84934d1daa0bdfd6989a80d08044301
 EBUILD llvm-libunwind-19.0.0_pre20240210.ebuild 3316 BLAKE2B 013ff60e8fa1fa480e1e56c6c8c1d5a657d946264a279a8fad53e3047fcde1f439e10b25e151af0d9c3f7f6fe014c2cf3372d311f3963c78e633e986b28a33e5 SHA512 4aaa97553c0e3e5421fe5864b81fdcd0e8a1167e37bec37e8706d3b9b939b5220a171576f800bdc6ae25f2bbfd60b063c84934d1daa0bdfd6989a80d08044301
 EBUILD llvm-libunwind-19.0.0_pre20240218.ebuild 3316 BLAKE2B 013ff60e8fa1fa480e1e56c6c8c1d5a657d946264a279a8fad53e3047fcde1f439e10b25e151af0d9c3f7f6fe014c2cf3372d311f3963c78e633e986b28a33e5 SHA512 4aaa97553c0e3e5421fe5864b81fdcd0e8a1167e37bec37e8706d3b9b939b5220a171576f800bdc6ae25f2bbfd60b063c84934d1daa0bdfd6989a80d08044301
diff --git a/sys-libs/llvm-libunwind/llvm-libunwind-18.1.0_rc3.ebuild b/sys-libs/llvm-libunwind/llvm-libunwind-18.1.0_rc3.ebuild
new file mode 100644
index 000000000000..df7d3e6095bc
--- /dev/null
+++ b/sys-libs/llvm-libunwind/llvm-libunwind-18.1.0_rc3.ebuild
@@ -0,0 +1,128 @@
+# Copyright 1999-2024 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+PYTHON_COMPAT=( python3_{10..12} )
+inherit cmake-multilib flag-o-matic llvm.org llvm-utils python-any-r1
+inherit toolchain-funcs
+
+DESCRIPTION="C++ runtime stack unwinder from LLVM"
+HOMEPAGE="https://llvm.org/docs/ExceptionHandling.html"
+
+LICENSE="Apache-2.0-with-LLVM-exceptions || ( UoI-NCSA MIT )"
+SLOT="0"
+IUSE="+clang +debug static-libs test"
+REQUIRED_USE="test? ( clang )"
+RESTRICT="!test? ( test )"
+
+RDEPEND="
+	!sys-libs/libunwind
+"
+DEPEND="
+	sys-devel/llvm:${LLVM_MAJOR}
+"
+BDEPEND="
+	clang? (
+		sys-devel/clang:${LLVM_MAJOR}
+	)
+	!test? (
+		${PYTHON_DEPS}
+	)
+	test? (
+		$(python_gen_any_dep 'dev-python/lit[${PYTHON_USEDEP}]')
+	)
+"
+
+LLVM_COMPONENTS=( runtimes libunwind libcxx llvm/cmake cmake )
+LLVM_TEST_COMPONENTS=( libcxxabi llvm/utils/llvm-lit )
+llvm.org_set_globals
+
+python_check_deps() {
+	use test || return 0
+	python_has_version "dev-python/lit[${PYTHON_USEDEP}]"
+}
+
+multilib_src_configure() {
+	llvm_prepend_path "${LLVM_MAJOR}"
+
+	local libdir=$(get_libdir)
+
+	# https://github.com/llvm/llvm-project/issues/56825
+	# also separately bug #863917
+	filter-lto
+
+	if use clang; then
+		local -x CC=${CHOST}-clang
+		local -x CXX=${CHOST}-clang++
+		strip-unsupported-flags
+	fi
+
+	# link to compiler-rt
+	# https://github.com/gentoo/gentoo/pull/21516
+	local use_compiler_rt=OFF
+	[[ $(tc-get-c-rtlib) == compiler-rt ]] && use_compiler_rt=ON
+
+	# Respect upstream build type assumptions (bug #910436) where they do:
+	# -DLIBUNWIND_ENABLE_ASSERTIONS=ON =>
+	#       -DCMAKE_BUILD_TYPE=DEBUG  => -UNDEBUG
+	#       -DCMAKE_BUILD_TYPE!=debug => -DNDEBUG
+	# -DLIBUNWIND_ENABLE_ASSERTIONS=OFF =>
+	#       -UNDEBUG
+	# See also https://github.com/llvm/llvm-project/issues/86#issuecomment-1649668826.
+	use debug || append-cppflags -DNDEBUG
+
+	local mycmakeargs=(
+		-DCMAKE_CXX_COMPILER_TARGET="${CHOST}"
+		-DPython3_EXECUTABLE="${PYTHON}"
+		-DLLVM_ENABLE_RUNTIMES="libunwind"
+		-DLLVM_LIBDIR_SUFFIX=${libdir#lib}
+		-DLLVM_INCLUDE_TESTS=OFF
+		-DLIBUNWIND_ENABLE_ASSERTIONS=$(usex debug)
+		-DLIBUNWIND_ENABLE_STATIC=$(usex static-libs)
+		-DLIBUNWIND_INCLUDE_TESTS=$(usex test)
+		-DLIBUNWIND_INSTALL_HEADERS=ON
+
+		# support non-native unwinding; given it's small enough,
+		# enable it unconditionally
+		-DLIBUNWIND_ENABLE_CROSS_UNWINDING=ON
+
+		# avoid dependency on libgcc_s if compiler-rt is used
+		-DLIBUNWIND_USE_COMPILER_RT=${use_compiler_rt}
+	)
+	if use test; then
+		mycmakeargs+=(
+			-DLLVM_ENABLE_RUNTIMES="libunwind;libcxxabi;libcxx"
+			-DLLVM_EXTERNAL_LIT="${EPREFIX}/usr/bin/lit"
+			-DLLVM_LIT_ARGS="$(get_lit_flags)"
+			-DLIBUNWIND_LIBCXX_PATH="${WORKDIR}/libcxx"
+
+			-DLIBCXXABI_LIBDIR_SUFFIX=
+			-DLIBCXXABI_ENABLE_SHARED=OFF
+			-DLIBCXXABI_ENABLE_STATIC=ON
+			-DLIBCXXABI_USE_LLVM_UNWINDER=ON
+			-DLIBCXXABI_INCLUDE_TESTS=OFF
+
+			-DLIBCXX_LIBDIR_SUFFIX=
+			-DLIBCXX_ENABLE_SHARED=OFF
+			-DLIBCXX_ENABLE_STATIC=ON
+			-DLIBCXX_CXX_ABI=libcxxabi
+			-DLIBCXX_ENABLE_ABI_LINKER_SCRIPT=OFF
+			-DLIBCXX_HAS_MUSL_LIBC=$(usex elibc_musl)
+			-DLIBCXX_HAS_GCC_S_LIB=OFF
+			-DLIBCXX_INCLUDE_TESTS=OFF
+			-DLIBCXX_INCLUDE_BENCHMARKS=OFF
+		)
+	fi
+
+	cmake_src_configure
+}
+
+multilib_src_test() {
+	local -x LIT_PRESERVES_TMP=1
+	cmake_build check-unwind
+}
+
+multilib_src_install() {
+	DESTDIR=${D} cmake_build install-unwind
+}