eclass/cros-rustc.eclass - third_party/overlays/chromiumos-overlay - Git at Google

 # Copyright 2022 The Chromium OS Authors. All rights reserved.
 # Distributed under the terms of the GNU General Public License v2

 # @ECLASS: cros-rustc.eclass
 # @MAINTAINER:
 # The Chromium OS Toolchain Team <chromeos-toolchain@google.com>
 # @BUGREPORTS:
 # Please report bugs via
 # https://issuetracker.google.com/issues/new?component=1038090&template=1576440
 # @VCSURL: https://chromium.googlesource.com/chromiumos/overlays/chromiumos-overlay/+/HEAD/eclass/@ECLASS@
 # @BLURB: Eclass for building CrOS' Rust toolchain.
 # @DESCRIPTION:
 # This eclass is used to build both dev-lang/rust-host and dev-lang/rust.
 #
 # dev-lang/rust-host is an ebuild that provides all artifacts necessary for
 # building Rust for the host. dev-lang/rust supplements this with libraries for
 # cross-compiling. We maintain this split because we need to build Rust
 # binaries for the host prior to cross-* libraries being available.
 #
 # An important concept when building dev-lang/rust-host and dev-lang/rust is
 # continuity: these packages are expected to be built from _identical_ Rust
 # sources. This assumption:
 # - doesn't restrict us in any meaningful way,
 # - keeps us more consistent with upstream flows for building `rustc`, and
 # - allows us to significantly cut down on the build time of dev-lang/rust,
 #   since dev-lang/rust can skip unpacking sources, configuring them, and
 #   rebuilding LLVM + stage0 + stage1.
 #
 # Moreover, if you want to make meaningful changes to Rust, you'll need to
 # always reemerge _both_ dev-lang/rust-host and dev-lang/rust. dev-lang/rust
 # assumes that the sources unpacked by dev-lang/rust-host, if present, are
 # identical to the ones it will build. dev-lang/rust-host always starts with a
 # clean slate.

 if [[ -z ${_ECLASS_CROS_RUSTC} ]]; then
 _ECLASS_CROS_RUSTC="1"

 # Check for EAPI 7+.
 case "${EAPI:-0}" in
 [0123456]) die "unsupported EAPI (${EAPI}) in eclass (${ECLASS})" ;;
 esac

 EXPORT_FUNCTIONS pkg_setup src_unpack src_prepare src_configure src_compile

 PYTHON_COMPAT=( python3_{6..9} )
 inherit python-any-r1 toolchain-funcs

 # @ECLASS-VARIABLE: RUSTC_TARGET_TRIPLES
 # @DEFAULT_UNSET
 # @REQUIRED
 # @DESCRIPTION:
 # This is the list of target triples for rustc as they appear in the cros_sdk.
 # cros-rust_src_configure instructs cros-rust_src_compile to use
 # "${triple}-clang" when building each one of these.

 # @ECLASS-VARIABLE: RUSTC_BARE_TARGET_TRIPLES
 # @DEFAULT_UNSET
 # @DESCRIPTION:
 # These are the triples we use GCC with. `*-cros-*` triples should not be
 # included here.

 # @ECLASS-VARIABLE: CROS_RUSTC_BUILD_RAW_SOURCES
 # @DEFAULT_UNSET
 # @DESCRIPTION:
 # Set to a nonempty value if we want to build a nonstandard set of sources
 # (this is intended mostly to power bisection of rustc itself).
 # This should never be set to anything in production.
 #
 # If you want to set this as a user, each `emerge` of `dev-lang/rust-host` or
 # `dev-lang/rust` assumes the following:
 # 1. A full Rust checkout is available under `_CROS_RUSTC_RAW_SOURCES_ROOT`.
 # 2. You've ensured that all submodules under `_CROS_RUSTC_RAW_SOURCES_ROOT` are
 #    up-to-date with your currently checked out revision.
 # 3. You've ensured that the appropriate bootstrap compiler is cached under
 #    `_CROS_RUSTC_RAW_SOURCES_ROOT/build`.
 # 4. You've run `cargo vendor` under `_CROS_RUSTC_RAW_SOURCES_ROOT`
 # 5. The sources under `_CROS_RUSTC_RAW_SOURCES_ROOT` are the exact sources you
 #    want to apply `${PATCHES}` to.
 # 6. You are OK with this script modifying your rustc sources at
 #    `_CROS_RUSTC_RAW_SOURCES_ROOT` (by applying patches to them).
 #
 # Step 2 can be done with
 # `dev-lang/rust/files/bisect-scripts/clean_and_sync_rust_root.sh`. Steps 3 and
 # 4 can be accomplished with
 # `dev-lang/rust/files/bisect-scripts/prepare_rust_for_offline_build.sh`.
 CROS_RUSTC_BUILD_RAW_SOURCES=

 # There's a fair amount of direct commonality between dev-lang/rust and
 # dev-lang/rust-host. Capture that here.
 ABI_VER="$(ver_cut 1-2)"
 SLOT="stable/${ABI_VER}"
 MY_P="rustc-${PV}"
 SRC="${MY_P}-src.tar.gz"

 # The version of rust-bootstrap that we're using to build our current Rust
 # toolchain. This is generally the version released prior to the current one,
 # since Rust uses the beta compiler to build the nightly compiler.
 BOOTSTRAP_VERSION="1.59.0"

 # If `CROS_RUSTC_BUILD_RAW_SOURCES` is nonempty, a full Rust source tree is
 # expected to be available here.
 _CROS_RUSTC_RAW_SOURCES_ROOT="${FILESDIR}/rust"

 HOMEPAGE="https://www.rust-lang.org/"

 if [[ -z "${CROS_RUSTC_BUILD_RAW_SOURCES}" ]]; then
 	SRC_URI="https://static.rust-lang.org/dist/${SRC} -> rustc-${PV}-src.tar.gz"
 else
 	# If a bisection is happening, we use the bootstrap compiler that upstream prefers.
 	# Clear this so we don't accidentally use it below.
 	BOOTSTRAP_VERSION=
 fi

 LICENSE="|| ( MIT Apache-2.0 ) BSD-1 BSD-2 BSD-4 UoI-NCSA"

 RESTRICT="binchecks strip"

 DEPEND="${PYTHON_DEPS}
 	>=dev-libs/libxml2-2.9.6
 	>=dev-lang/perl-5.0
 "

 if [[ -z "${CROS_RUSTC_BUILD_RAW_SOURCES}" ]]; then
 	BDEPEND="dev-lang/rust-bootstrap:${BOOTSTRAP_VERSION}"
 fi

 PATCHES=(
 	"${FILESDIR}/rust-${PV}-add-cros-targets.patch"
 	"${FILESDIR}/rust-${PV}-fix-rpath.patch"
 	"${FILESDIR}/rust-${PV}-Revert-CMake-Unconditionally-add-.h-and-.td-files-to.patch"
 	"${FILESDIR}/rust-${PV}-no-test-on-build.patch"
 	"${FILESDIR}/rust-${PV}-sanitizer-supported.patch"
 	"${FILESDIR}/rust-${PV}-cc.patch"
 	"${FILESDIR}/rust-${PV}-revert-libunwind-build.patch"
 	"${FILESDIR}/rust-${PV}-ld-argv0.patch"
 	"${FILESDIR}/rust-${PV}-Handle-sparse-git-repo-without-erroring.patch"
 	"${FILESDIR}/rust-${PV}-disable-mutable-noalias.patch"
 	"${FILESDIR}/rust-${PV}-add-armv7a-sanitizers.patch"
 	"${FILESDIR}/rust-${PV}-fix-libunwind-backtrace-visibility.patch"
 	"${FILESDIR}/rust-${PV}-passes-only-in-pre-link.patch"
 	"${FILESDIR}/rust-${PV}-Revert-DebugInfo-Re-enable-instruction-referencing-f.patch"
 	"${FILESDIR}/rust-${PV}-Don-t-build-std-for-uefi-targets.patch"
 	"${FILESDIR}/rust-${PV}-Bump-cc-version-in-bootstrap-to-fix-build-of-uefi-ta.patch"
 )

 # Locations where we cache our build/src dirs.
 CROS_RUSTC_DIR="${SYSROOT}/var/cache/portage/${CATEGORY}/rust-artifacts"
 CROS_RUSTC_BUILD_DIR="${CROS_RUSTC_DIR}/build"
 CROS_RUSTC_SRC_DIR="${CROS_RUSTC_DIR}/src"

 S="${CROS_RUSTC_SRC_DIR}/${MY_P}-src"

 _CROS_RUSTC_PREPARED_STAMP="${CROS_RUSTC_SRC_DIR}/cros-rust-prepared"
 _CROS_RUSTC_STAGE1_EXISTS_STAMP="${CROS_RUSTC_BUILD_DIR}/cros-rust-has-stage1-build"

 # @FUNCTION: cros-rustc_has_existing_checkout
 # @DESCRIPTION:
 # Tests whether we have a properly src_prepare'd checkout in ${CROS_RUSTC_DIR}.
 cros-rustc_has_existing_checkout() {
 	[[ -e "${_CROS_RUSTC_PREPARED_STAMP}" ]]
 }

 # @FUNCTION: cros-rustc_has_existing_stage1_build
 # @DESCRIPTION:
 # Tests whether ${CROS_RUSTC_BUILD_DIR} has a valid stage1 toolchain available.
 cros-rustc_has_existing_stage1_build() {
 	[[ -e "${_CROS_RUSTC_STAGE1_EXISTS_STAMP}" ]]
 }

 cros-rustc_pkg_setup() {
 	python-any-r1_pkg_setup

 	if [[ ${MERGE_TYPE} != "binary" ]]; then
 		addwrite "${CROS_RUSTC_DIR}"
 		# Disable warnings about 755 only applying to the deepest directory; that's
 		# fine.
 		# shellcheck disable=SC2174
 		mkdir -p -m 755 "${CROS_RUSTC_DIR}"
 		chown "${PORTAGE_USERNAME}:${PORTAGE_GRPNAME}" "${CROS_RUSTC_DIR}"

 		if [[ -n "${CROS_RUSTC_BUILD_RAW_SOURCES}" ]]; then
 			addwrite "${_CROS_RUSTC_RAW_SOURCES_ROOT}"
 			ewarn "cros-rustc.eclass is using raw sources. This feature is for debugging only."
 		fi
 	fi
 }

 # Sets up a cargo config.toml that instructs our bootstrap rustc to use
 # the correct linker. `rust-bootstrap` can be made to work around this since
 # we have local patches, but bootstrap compilers downloaded from upstream
 # (e.g., during bisection) cannot. This should be called during src_unpack
 # if you opt out of calling `cros-rustc_src_unpack`. Otherwise,
 # `cros-rustc_src_unpack` will take care of this.
 cros-rustc_setup_cargo_home() {
 	export CARGO_HOME="${T}/cargo_home"
 	mkdir -p "${CARGO_HOME}" || die
 	cat >> "${CARGO_HOME}/config.toml" <<EOF || die

 [target.x86_64-unknown-linux-gnu]
 linker = "${CHOST}-clang"

 [target.${CHOST}]
 linker = "${CHOST}-clang"
 EOF
 }

 cros-rustc_src_unpack() {
 	cros-rustc_setup_cargo_home

 	if [[ -n "${CROS_RUSTC_BUILD_RAW_SOURCES}" ]]; then
 		if [[ ! -d "${_CROS_RUSTC_RAW_SOURCES_ROOT}" ]]; then
 			eerror "You must have a full Rust checkout in _CROS_RUSTC_RAW_SOURCES_ROOT."
 			die
 		fi
 		if [[ -e "${S}" && ! -L "${S}" ]]; then
 			rm -rf "${S}" || die
 		fi
 		ln -sf "$(readlink -m "${_CROS_RUSTC_RAW_SOURCES_ROOT}")" "${S}" || die
 		default
 		return
 	fi

 	local dirs=( "${CROS_RUSTC_BUILD_DIR}" "${CROS_RUSTC_SRC_DIR}" )
 	if [[ -e "${CROS_RUSTC_SRC_DIR}" || -e "${CROS_RUSTC_BUILD_DIR}" ]]; then
 		einfo "Removing old source/build directories..."
 		rm -rf "${dirs[@]}"
 	fi

 	# Disable warnings about 755 only applying to the deepest directory; that's
 	# fine.
 	# shellcheck disable=SC2174
 	mkdir -p -m 755 "${dirs[@]}"
 	(cd "${CROS_RUSTC_SRC_DIR}" && default)
 }

 cros-rustc_src_prepare() {
 	if [[ -n "${CROS_RUSTC_BUILD_RAW_SOURCES}" ]]; then
 		einfo "Synchronizing bootstrap compiler caches ..."
 		cp -avu "${_CROS_RUSTC_RAW_SOURCES_ROOT}/build/cache" "${CROS_RUSTC_BUILD_DIR}" || die
 	fi

 	# Copy "unknown" vendor targets to create cros_sdk target triple
 	# variants as referred to in 0001-add-cros-targets.patch and
 	# RUSTC_TARGET_TRIPLES. armv7a is treated specially because the cros
 	# toolchain differs in more than just the vendor part of the target
 	# triple. The arch is armv7a in cros versus armv7.
 	pushd compiler/rustc_target/src/spec || die
 	sed -e 's:"unknown":"pc":g' x86_64_unknown_linux_gnu.rs >x86_64_pc_linux_gnu.rs || die
 	sed -e 's:"unknown":"cros":g' x86_64_unknown_linux_gnu.rs >x86_64_cros_linux_gnu.rs || die
 	sed -e 's:"unknown":"cros":g' armv7_unknown_linux_gnueabihf.rs >armv7a_cros_linux_gnueabihf.rs || die
 	sed -e 's:"unknown":"cros":g' aarch64_unknown_linux_gnu.rs >aarch64_cros_linux_gnu.rs || die
 	popd || die

 	# The miri tool is built because of 'extended = true' in
 	# cros-config.toml, but the build is busted. See the upstream issue:
 	# [https://github.com/rust- lang/rust/issues/56576]. Because miri isn't
 	# installed or needed, this sed script eradicates the command that
 	# builds it during the bootstrap script.
 	pushd src/bootstrap || die
 	sed -i 's@tool::Miri,@@g' builder.rs
 	popd || die

 	# Tsk. Tsk. The rust makefile for LLVM's compiler-rt uses -ffreestanding
 	# but one of the files includes <stdlib.h> causing occasional problems
 	# with MB_LEN_MAX. See crbug.com/730845 for the thrilling details. This
 	# line patches over the problematic include.
 	sed -e 's:#include <stdlib.h>:void abort(void);:g' \
 		-i "${ECONF_SOURCE:-.}"/src/llvm-project/compiler-rt/lib/builtins/int_util.c || die

 	# For the rustc_llvm module, the build will link with -nodefaultlibs and
 	# manually choose the std C++ library. For x86_64 Linux, the build
 	# script always chooses libstdc++ which will not work if LLVM was built
 	# with USE="default-libcxx". This snippet changes that choice to libc++
 	# in the case that clang++ defaults to libc++.
 	if "${CXX}" -### -x c++ - < /dev/null 2>&1 | grep -q -e '-lc++'; then
 		sed -i 's:"stdc++":"c++":g' compiler/rustc_llvm/build.rs || die
 	fi

 	default

 	touch "${_CROS_RUSTC_PREPARED_STAMP}"
 }

 cros-rustc_src_configure() {
 	tc-export CC PKG_CONFIG

 	# If FEATURES=ccache is set, we can cache LLVM builds. We could set this to
 	# true unconditionally, but invoking `ccache` to just have it `exec` the
 	# compiler costs ~10secs of wall time on rust-host builds. No point in
 	# wasting the cycles.
 	local use_ccache=false
 	[[ -z "${CCACHE_DISABLE:-}" ]] && use_ccache=true

 	local targets=""
 	local tt
 	# These variables are defined by users of this eclass; their use here is safe.
 	# shellcheck disable=SC2154
 	for tt in "${RUSTC_TARGET_TRIPLES[@]}" "${RUSTC_BARE_TARGET_TRIPLES[@]}" ; do
 		targets+="\"${tt}\", "
 	done

 	local bootstrap_compiler_info
 	if [[ -z "${CROS_RUSTC_BUILD_RAW_SOURCES}" ]]; then
 		bootstrap_compiler_info="
 cargo = \"/opt/rust-bootstrap-${BOOTSTRAP_VERSION}/bin/cargo\"
 rustc = \"/opt/rust-bootstrap-${BOOTSTRAP_VERSION}/bin/rustc\""
 	fi

 	local config=cros-config.toml
 	cat > "${config}" <<EOF
 [build]
 target = [${targets}]
 docs = false
 submodules = false
 python = "${EPYTHON}"
 vendor = true
 extended = true
 tools = ["cargo", "rustfmt", "clippy", "cargofmt"]
 sanitizers = true
 profiler = true
 build-dir = "${CROS_RUSTC_BUILD_DIR}"
 ${bootstrap_compiler_info}

 [llvm]
 ccache = ${use_ccache}
 ninja = true
 targets = "AArch64;ARM;X86"

 [install]
 prefix = "${ED}usr"
 libdir = "$(get_libdir)"
 mandir = "share/man"

 [rust]
 default-linker = "${CBUILD}-clang"
 description = "${PF}"
 channel = "nightly"
 codegen-units = 0
 llvm-libunwind = 'in-tree'
 codegen-tests = false
 new-symbol-mangling = true

 EOF

 	for tt in "${RUSTC_TARGET_TRIPLES[@]}" ; do
 		cat >> "${config}" <<EOF
 [target."${tt}"]
 cc = "${tt}-clang"
 cxx = "${tt}-clang++"
 linker = "${tt}-clang++"

 EOF
 	done
 }

 cros-rustc_src_compile() {
 	${EPYTHON} x.py build --stage 2 --config cros-config.toml "$@" || die

 	# Remove the src/rust symlink which will be dangling after sources are
 	# removed, and the containing src directory.
 	rm "${CROS_RUSTC_BUILD_DIR}/x86_64-unknown-linux-gnu/stage2/lib/rustlib/src/rust" || die
 	rmdir "${CROS_RUSTC_BUILD_DIR}/x86_64-unknown-linux-gnu/stage2/lib/rustlib/src" || die

 	# Since we always build for stage2, we're guaranteed that stage1 exists
 	# at this point.
 	touch "${_CROS_RUSTC_STAGE1_EXISTS_STAMP}"
 }
 fi
	# Copyright 2022 The Chromium OS Authors. All rights reserved.
	# Distributed under the terms of the GNU General Public License v2

	# @ECLASS: cros-rustc.eclass
	# @MAINTAINER:
	# The Chromium OS Toolchain Team <chromeos-toolchain@google.com>
	# @BUGREPORTS:
	# Please report bugs via
	# https://issuetracker.google.com/issues/new?component=1038090&template=1576440
	# @VCSURL: https://chromium.googlesource.com/chromiumos/overlays/chromiumos-overlay/+/HEAD/eclass/@ECLASS@
	# @BLURB: Eclass for building CrOS' Rust toolchain.
	# @DESCRIPTION:
	# This eclass is used to build both dev-lang/rust-host and dev-lang/rust.
	#
	# dev-lang/rust-host is an ebuild that provides all artifacts necessary for
	# building Rust for the host. dev-lang/rust supplements this with libraries for
	# cross-compiling. We maintain this split because we need to build Rust
	# binaries for the host prior to cross-* libraries being available.
	#
	# An important concept when building dev-lang/rust-host and dev-lang/rust is
	# continuity: these packages are expected to be built from _identical_ Rust
	# sources. This assumption:
	# - doesn't restrict us in any meaningful way,
	# - keeps us more consistent with upstream flows for building `rustc`, and
	# - allows us to significantly cut down on the build time of dev-lang/rust,
	# since dev-lang/rust can skip unpacking sources, configuring them, and
	# rebuilding LLVM + stage0 + stage1.
	#
	# Moreover, if you want to make meaningful changes to Rust, you'll need to
	# always reemerge _both_ dev-lang/rust-host and dev-lang/rust. dev-lang/rust
	# assumes that the sources unpacked by dev-lang/rust-host, if present, are
	# identical to the ones it will build. dev-lang/rust-host always starts with a
	# clean slate.

	if [[ -z ${_ECLASS_CROS_RUSTC} ]]; then
	_ECLASS_CROS_RUSTC="1"

	# Check for EAPI 7+.
	case "${EAPI:-0}" in
	[0123456]) die "unsupported EAPI (${EAPI}) in eclass (${ECLASS})" ;;
	esac

	EXPORT_FUNCTIONS pkg_setup src_unpack src_prepare src_configure src_compile

	PYTHON_COMPAT=( python3_{6..9} )
	inherit python-any-r1 toolchain-funcs

	# @ECLASS-VARIABLE: RUSTC_TARGET_TRIPLES
	# @DEFAULT_UNSET
	# @REQUIRED
	# @DESCRIPTION:
	# This is the list of target triples for rustc as they appear in the cros_sdk.
	# cros-rust_src_configure instructs cros-rust_src_compile to use
	# "${triple}-clang" when building each one of these.

	# @ECLASS-VARIABLE: RUSTC_BARE_TARGET_TRIPLES
	# @DEFAULT_UNSET
	# @DESCRIPTION:
	# These are the triples we use GCC with. `-cros-` triples should not be
	# included here.

	# @ECLASS-VARIABLE: CROS_RUSTC_BUILD_RAW_SOURCES
	# @DEFAULT_UNSET
	# @DESCRIPTION:
	# Set to a nonempty value if we want to build a nonstandard set of sources
	# (this is intended mostly to power bisection of rustc itself).
	# This should never be set to anything in production.
	#
	# If you want to set this as a user, each `emerge` of `dev-lang/rust-host` or
	# `dev-lang/rust` assumes the following:
	# 1. A full Rust checkout is available under `_CROS_RUSTC_RAW_SOURCES_ROOT`.
	# 2. You've ensured that all submodules under `_CROS_RUSTC_RAW_SOURCES_ROOT` are
	# up-to-date with your currently checked out revision.
	# 3. You've ensured that the appropriate bootstrap compiler is cached under
	# `_CROS_RUSTC_RAW_SOURCES_ROOT/build`.
	# 4. You've run `cargo vendor` under `_CROS_RUSTC_RAW_SOURCES_ROOT`
	# 5. The sources under `_CROS_RUSTC_RAW_SOURCES_ROOT` are the exact sources you
	# want to apply `${PATCHES}` to.
	# 6. You are OK with this script modifying your rustc sources at
	# `_CROS_RUSTC_RAW_SOURCES_ROOT` (by applying patches to them).
	#
	# Step 2 can be done with
	# `dev-lang/rust/files/bisect-scripts/clean_and_sync_rust_root.sh`. Steps 3 and
	# 4 can be accomplished with
	# `dev-lang/rust/files/bisect-scripts/prepare_rust_for_offline_build.sh`.
	CROS_RUSTC_BUILD_RAW_SOURCES=

	# There's a fair amount of direct commonality between dev-lang/rust and
	# dev-lang/rust-host. Capture that here.
	ABI_VER="$(ver_cut 1-2)"
	SLOT="stable/${ABI_VER}"
	MY_P="rustc-${PV}"
	SRC="${MY_P}-src.tar.gz"

	# The version of rust-bootstrap that we're using to build our current Rust
	# toolchain. This is generally the version released prior to the current one,
	# since Rust uses the beta compiler to build the nightly compiler.
	BOOTSTRAP_VERSION="1.59.0"

	# If `CROS_RUSTC_BUILD_RAW_SOURCES` is nonempty, a full Rust source tree is
	# expected to be available here.
	_CROS_RUSTC_RAW_SOURCES_ROOT="${FILESDIR}/rust"

	HOMEPAGE="https://www.rust-lang.org/"

	if [[ -z "${CROS_RUSTC_BUILD_RAW_SOURCES}" ]]; then
	SRC_URI="https://static.rust-lang.org/dist/${SRC} -> rustc-${PV}-src.tar.gz"
	else
	# If a bisection is happening, we use the bootstrap compiler that upstream prefers.
	# Clear this so we don't accidentally use it below.
	BOOTSTRAP_VERSION=
	fi

	LICENSE="\|\| ( MIT Apache-2.0 ) BSD-1 BSD-2 BSD-4 UoI-NCSA"

	RESTRICT="binchecks strip"

	DEPEND="${PYTHON_DEPS}
	>=dev-libs/libxml2-2.9.6
	>=dev-lang/perl-5.0
	"

	if [[ -z "${CROS_RUSTC_BUILD_RAW_SOURCES}" ]]; then
	BDEPEND="dev-lang/rust-bootstrap:${BOOTSTRAP_VERSION}"
	fi

	PATCHES=(
	"${FILESDIR}/rust-${PV}-add-cros-targets.patch"
	"${FILESDIR}/rust-${PV}-fix-rpath.patch"
	"${FILESDIR}/rust-${PV}-Revert-CMake-Unconditionally-add-.h-and-.td-files-to.patch"
	"${FILESDIR}/rust-${PV}-no-test-on-build.patch"
	"${FILESDIR}/rust-${PV}-sanitizer-supported.patch"
	"${FILESDIR}/rust-${PV}-cc.patch"
	"${FILESDIR}/rust-${PV}-revert-libunwind-build.patch"
	"${FILESDIR}/rust-${PV}-ld-argv0.patch"
	"${FILESDIR}/rust-${PV}-Handle-sparse-git-repo-without-erroring.patch"
	"${FILESDIR}/rust-${PV}-disable-mutable-noalias.patch"
	"${FILESDIR}/rust-${PV}-add-armv7a-sanitizers.patch"
	"${FILESDIR}/rust-${PV}-fix-libunwind-backtrace-visibility.patch"
	"${FILESDIR}/rust-${PV}-passes-only-in-pre-link.patch"
	"${FILESDIR}/rust-${PV}-Revert-DebugInfo-Re-enable-instruction-referencing-f.patch"
	"${FILESDIR}/rust-${PV}-Don-t-build-std-for-uefi-targets.patch"
	"${FILESDIR}/rust-${PV}-Bump-cc-version-in-bootstrap-to-fix-build-of-uefi-ta.patch"
	)

	# Locations where we cache our build/src dirs.
	CROS_RUSTC_DIR="${SYSROOT}/var/cache/portage/${CATEGORY}/rust-artifacts"
	CROS_RUSTC_BUILD_DIR="${CROS_RUSTC_DIR}/build"
	CROS_RUSTC_SRC_DIR="${CROS_RUSTC_DIR}/src"

	S="${CROS_RUSTC_SRC_DIR}/${MY_P}-src"

	_CROS_RUSTC_PREPARED_STAMP="${CROS_RUSTC_SRC_DIR}/cros-rust-prepared"
	_CROS_RUSTC_STAGE1_EXISTS_STAMP="${CROS_RUSTC_BUILD_DIR}/cros-rust-has-stage1-build"

	# @FUNCTION: cros-rustc_has_existing_checkout
	# @DESCRIPTION:
	# Tests whether we have a properly src_prepare'd checkout in ${CROS_RUSTC_DIR}.
	cros-rustc_has_existing_checkout() {
	[[ -e "${_CROS_RUSTC_PREPARED_STAMP}" ]]
	}

	# @FUNCTION: cros-rustc_has_existing_stage1_build
	# @DESCRIPTION:
	# Tests whether ${CROS_RUSTC_BUILD_DIR} has a valid stage1 toolchain available.
	cros-rustc_has_existing_stage1_build() {
	[[ -e "${_CROS_RUSTC_STAGE1_EXISTS_STAMP}" ]]
	}

	cros-rustc_pkg_setup() {
	python-any-r1_pkg_setup

	if [[ ${MERGE_TYPE} != "binary" ]]; then
	addwrite "${CROS_RUSTC_DIR}"
	# Disable warnings about 755 only applying to the deepest directory; that's
	# fine.
	# shellcheck disable=SC2174
	mkdir -p -m 755 "${CROS_RUSTC_DIR}"
	chown "${PORTAGE_USERNAME}:${PORTAGE_GRPNAME}" "${CROS_RUSTC_DIR}"

	if [[ -n "${CROS_RUSTC_BUILD_RAW_SOURCES}" ]]; then
	addwrite "${_CROS_RUSTC_RAW_SOURCES_ROOT}"
	ewarn "cros-rustc.eclass is using raw sources. This feature is for debugging only."
	fi
	fi
	}

	# Sets up a cargo config.toml that instructs our bootstrap rustc to use
	# the correct linker. `rust-bootstrap` can be made to work around this since
	# we have local patches, but bootstrap compilers downloaded from upstream
	# (e.g., during bisection) cannot. This should be called during src_unpack
	# if you opt out of calling `cros-rustc_src_unpack`. Otherwise,
	# `cros-rustc_src_unpack` will take care of this.
	cros-rustc_setup_cargo_home() {
	export CARGO_HOME="${T}/cargo_home"
	mkdir -p "${CARGO_HOME}" \|\| die
	cat >> "${CARGO_HOME}/config.toml" <<EOF \|\| die

	[target.x86_64-unknown-linux-gnu]
	linker = "${CHOST}-clang"

	[target.${CHOST}]
	linker = "${CHOST}-clang"
	EOF
	}

	cros-rustc_src_unpack() {
	cros-rustc_setup_cargo_home

	if [[ -n "${CROS_RUSTC_BUILD_RAW_SOURCES}" ]]; then
	if [[ ! -d "${_CROS_RUSTC_RAW_SOURCES_ROOT}" ]]; then
	eerror "You must have a full Rust checkout in _CROS_RUSTC_RAW_SOURCES_ROOT."
	die
	fi
	if [[ -e "${S}" && ! -L "${S}" ]]; then
	rm -rf "${S}" \|\| die
	fi
	ln -sf "$(readlink -m "${_CROS_RUSTC_RAW_SOURCES_ROOT}")" "${S}" \|\| die
	default
	return
	fi

	local dirs=( "${CROS_RUSTC_BUILD_DIR}" "${CROS_RUSTC_SRC_DIR}" )
	if [[ -e "${CROS_RUSTC_SRC_DIR}" \|\| -e "${CROS_RUSTC_BUILD_DIR}" ]]; then
	einfo "Removing old source/build directories..."
	rm -rf "${dirs[@]}"
	fi

	# Disable warnings about 755 only applying to the deepest directory; that's
	# fine.
	# shellcheck disable=SC2174
	mkdir -p -m 755 "${dirs[@]}"
	(cd "${CROS_RUSTC_SRC_DIR}" && default)
	}

	cros-rustc_src_prepare() {
	if [[ -n "${CROS_RUSTC_BUILD_RAW_SOURCES}" ]]; then
	einfo "Synchronizing bootstrap compiler caches ..."
	cp -avu "${_CROS_RUSTC_RAW_SOURCES_ROOT}/build/cache" "${CROS_RUSTC_BUILD_DIR}" \|\| die
	fi

	# Copy "unknown" vendor targets to create cros_sdk target triple
	# variants as referred to in 0001-add-cros-targets.patch and
	# RUSTC_TARGET_TRIPLES. armv7a is treated specially because the cros
	# toolchain differs in more than just the vendor part of the target
	# triple. The arch is armv7a in cros versus armv7.
	pushd compiler/rustc_target/src/spec \|\| die
	sed -e 's:"unknown":"pc":g' x86_64_unknown_linux_gnu.rs >x86_64_pc_linux_gnu.rs \|\| die
	sed -e 's:"unknown":"cros":g' x86_64_unknown_linux_gnu.rs >x86_64_cros_linux_gnu.rs \|\| die
	sed -e 's:"unknown":"cros":g' armv7_unknown_linux_gnueabihf.rs >armv7a_cros_linux_gnueabihf.rs \|\| die
	sed -e 's:"unknown":"cros":g' aarch64_unknown_linux_gnu.rs >aarch64_cros_linux_gnu.rs \|\| die
	popd \|\| die

	# The miri tool is built because of 'extended = true' in
	# cros-config.toml, but the build is busted. See the upstream issue:
	# [https://github.com/rust- lang/rust/issues/56576]. Because miri isn't
	# installed or needed, this sed script eradicates the command that
	# builds it during the bootstrap script.
	pushd src/bootstrap \|\| die
	sed -i 's@tool::Miri,@@g' builder.rs
	popd \|\| die

	# Tsk. Tsk. The rust makefile for LLVM's compiler-rt uses -ffreestanding
	# but one of the files includes <stdlib.h> causing occasional problems
	# with MB_LEN_MAX. See crbug.com/730845 for the thrilling details. This
	# line patches over the problematic include.
	sed -e 's:#include <stdlib.h>:void abort(void);:g' \
	-i "${ECONF_SOURCE:-.}"/src/llvm-project/compiler-rt/lib/builtins/int_util.c \|\| die

	# For the rustc_llvm module, the build will link with -nodefaultlibs and
	# manually choose the std C++ library. For x86_64 Linux, the build
	# script always chooses libstdc++ which will not work if LLVM was built
	# with USE="default-libcxx". This snippet changes that choice to libc++
	# in the case that clang++ defaults to libc++.
	if "${CXX}" -### -x c++ - < /dev/null 2>&1 \| grep -q -e '-lc++'; then
	sed -i 's:"stdc++":"c++":g' compiler/rustc_llvm/build.rs \|\| die
	fi

	default

	touch "${_CROS_RUSTC_PREPARED_STAMP}"
	}

	cros-rustc_src_configure() {
	tc-export CC PKG_CONFIG

	# If FEATURES=ccache is set, we can cache LLVM builds. We could set this to
	# true unconditionally, but invoking `ccache` to just have it `exec` the
	# compiler costs ~10secs of wall time on rust-host builds. No point in
	# wasting the cycles.
	local use_ccache=false
	[[ -z "${CCACHE_DISABLE:-}" ]] && use_ccache=true

	local targets=""
	local tt
	# These variables are defined by users of this eclass; their use here is safe.
	# shellcheck disable=SC2154
	for tt in "${RUSTC_TARGET_TRIPLES[@]}" "${RUSTC_BARE_TARGET_TRIPLES[@]}" ; do
	targets+="\"${tt}\", "
	done

	local bootstrap_compiler_info
	if [[ -z "${CROS_RUSTC_BUILD_RAW_SOURCES}" ]]; then
	bootstrap_compiler_info="
	cargo = \"/opt/rust-bootstrap-${BOOTSTRAP_VERSION}/bin/cargo\"
	rustc = \"/opt/rust-bootstrap-${BOOTSTRAP_VERSION}/bin/rustc\""
	fi

	local config=cros-config.toml
	cat > "${config}" <<EOF
	[build]
	target = [${targets}]
	docs = false
	submodules = false
	python = "${EPYTHON}"
	vendor = true
	extended = true
	tools = ["cargo", "rustfmt", "clippy", "cargofmt"]
	sanitizers = true
	profiler = true
	build-dir = "${CROS_RUSTC_BUILD_DIR}"
	${bootstrap_compiler_info}

	[llvm]
	ccache = ${use_ccache}
	ninja = true
	targets = "AArch64;ARM;X86"

	[install]
	prefix = "${ED}usr"
	libdir = "$(get_libdir)"
	mandir = "share/man"

	[rust]
	default-linker = "${CBUILD}-clang"
	description = "${PF}"
	channel = "nightly"
	codegen-units = 0
	llvm-libunwind = 'in-tree'
	codegen-tests = false
	new-symbol-mangling = true

	EOF

	for tt in "${RUSTC_TARGET_TRIPLES[@]}" ; do
	cat >> "${config}" <<EOF
	[target."${tt}"]
	cc = "${tt}-clang"
	cxx = "${tt}-clang++"
	linker = "${tt}-clang++"

	EOF
	done
	}

	cros-rustc_src_compile() {
	${EPYTHON} x.py build --stage 2 --config cros-config.toml "$@" \|\| die

	# Remove the src/rust symlink which will be dangling after sources are
	# removed, and the containing src directory.
	rm "${CROS_RUSTC_BUILD_DIR}/x86_64-unknown-linux-gnu/stage2/lib/rustlib/src/rust" \|\| die
	rmdir "${CROS_RUSTC_BUILD_DIR}/x86_64-unknown-linux-gnu/stage2/lib/rustlib/src" \|\| die

	# Since we always build for stage2, we're guaranteed that stage1 exists
	# at this point.
	touch "${_CROS_RUSTC_STAGE1_EXISTS_STAMP}"
	}
	fi