--- /dev/null
+# Copyright 1999-2020 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=7
+
+PYTHON_COMPAT=( python3_{6,7,8} )
+inherit cmake-utils flag-o-matic llvm llvm.org multiprocessing \
+ python-any-r1 toolchain-funcs
+
+DESCRIPTION="Compiler runtime library for clang (built-in part)"
+HOMEPAGE="https://llvm.org/"
+LLVM_COMPONENTS=( compiler-rt )
+llvm.org_set_globals
+
+LICENSE="Apache-2.0-with-LLVM-exceptions || ( UoI-NCSA MIT )"
+SLOT="$(ver_cut 1-3)"
+KEYWORDS=""
+IUSE="+clang test"
+RESTRICT="!test? ( test ) !clang? ( test )"
+
+CLANG_SLOT=${SLOT%%.*}
+# llvm-6 for new lit options
+DEPEND="
+ >=sys-devel/llvm-6"
+BDEPEND="
+ clang? ( sys-devel/clang )
+ test? (
+ $(python_gen_any_dep ">=dev-python/lit-9.0.1[\${PYTHON_USEDEP}]")
+ =sys-devel/clang-${PV%_*}*:${CLANG_SLOT} )
+ ${PYTHON_DEPS}"
+
+# least intrusive of all
+CMAKE_BUILD_TYPE=RelWithDebInfo
+
+python_check_deps() {
+ use test || return 0
+ has_version "dev-python/lit[${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() {
+ llvm_pkg_setup
+ python-any-r1_pkg_setup
+}
+
+test_compiler() {
+ $(tc-getCC) ${CFLAGS} ${LDFLAGS} "${@}" -o /dev/null -x c - \
+ <<<'int main() { return 0; }' &>/dev/null
+}
+
+src_configure() {
+ # pre-set since we need to pass it to cmake
+ BUILD_DIR=${WORKDIR}/${P}_build
+
+ local nolib_flags=( -nodefaultlibs -lc )
+ if use clang; then
+ local -x CC=${CHOST}-clang
+ local -x CXX=${CHOST}-clang++
+ strip-unsupported-flags
+ # ensure we can use clang before installing compiler-rt
+ local -x LDFLAGS="${LDFLAGS} ${nolib_flags[*]}"
+ elif ! test_compiler; then
+ if test_compiler "${nolib_flags[@]}"; then
+ 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/${SLOT}"
+
+ -DCOMPILER_RT_INCLUDE_TESTS=$(usex test)
+ -DCOMPILER_RT_BUILD_LIBFUZZER=OFF
+ -DCOMPILER_RT_BUILD_PROFILE=OFF
+ -DCOMPILER_RT_BUILD_SANITIZERS=OFF
+ -DCOMPILER_RT_BUILD_XRAY=OFF
+ )
+
+ if use prefix && [[ "${CHOST}" == *-darwin* ]] ; then
+ mycmakeargs+=(
+ # disable use of SDK for the system itself
+ -DDARWIN_macosx_CACHED_SYSROOT=/
+ )
+ fi
+
+ if use test; then
+ mycmakeargs+=(
+ -DLLVM_EXTERNAL_LIT="${EPREFIX}/usr/bin/lit"
+ -DLLVM_LIT_ARGS="-vv;-j;${LIT_JOBS:-$(makeopts_jobs "${MAKEOPTS}" "$(get_nproc)")}"
+
+ -DCOMPILER_RT_TEST_COMPILER="${EPREFIX}/usr/lib/llvm/${CLANG_SLOT}/bin/clang"
+ -DCOMPILER_RT_TEST_CXX_COMPILER="${EPREFIX}/usr/lib/llvm/${CLANG_SLOT}/bin/clang++"
+ )
+ fi
+
+ cmake-utils_src_configure
+}
+
+src_test() {
+ # respect TMPDIR!
+ local -x LIT_PRESERVES_TMP=1
+
+ cmake-utils_src_make check-builtins
+}