--- /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 llvm llvm.org multiprocessing python-any-r1
+
+DESCRIPTION="OCaml bindings for LLVM"
+HOMEPAGE="https://llvm.org/"
+LLVM_COMPONENTS=( llvm )
+llvm.org_set_globals
+
+# Keep in sync with sys-devel/llvm
+ALL_LLVM_EXPERIMENTAL_TARGETS=( ARC AVR )
+ALL_LLVM_TARGETS=( AArch64 AMDGPU ARM BPF Hexagon Lanai Mips MSP430
+ NVPTX PowerPC RISCV Sparc SystemZ WebAssembly X86 XCore
+ "${ALL_LLVM_EXPERIMENTAL_TARGETS[@]}" )
+ALL_LLVM_TARGETS=( "${ALL_LLVM_TARGETS[@]/#/llvm_targets_}" )
+LLVM_TARGET_USEDEPS=${ALL_LLVM_TARGETS[@]/%/?}
+
+LICENSE="Apache-2.0-with-LLVM-exceptions UoI-NCSA"
+SLOT="0/${PV}"
+KEYWORDS=""
+IUSE="debug test ${ALL_LLVM_TARGETS[*]}"
+REQUIRED_USE="|| ( ${ALL_LLVM_TARGETS[*]} )"
+RESTRICT="!test? ( test )"
+
+RDEPEND="
+ >=dev-lang/ocaml-4.00.0:0=
+ dev-ml/ocaml-ctypes:=
+ ~sys-devel/llvm-${PV}:=[${LLVM_TARGET_USEDEPS// /,},debug?]
+ !sys-devel/llvm[ocaml(-)]"
+DEPEND="${RDEPEND}"
+BDEPEND="
+ dev-lang/perl
+ dev-ml/findlib
+ test? ( dev-ml/ounit )
+ ${PYTHON_DEPS}"
+
+# least intrusive of all
+CMAKE_BUILD_TYPE=RelWithDebInfo
+
+pkg_setup() {
+ LLVM_MAX_SLOT=${PV%%.*} llvm_pkg_setup
+ python-any-r1_pkg_setup
+}
+
+src_prepare() {
+ # Python is needed to run tests using lit
+ python_setup
+
+ cmake-utils_src_prepare
+}
+
+src_configure() {
+ local libdir=$(get_libdir)
+ local mycmakeargs=(
+ -DLLVM_LIBDIR_SUFFIX=${libdir#lib}
+
+ -DBUILD_SHARED_LIBS=OFF
+ -DLLVM_BUILD_LLVM_DYLIB=ON
+ -DLLVM_LINK_LLVM_DYLIB=ON
+ -DLLVM_OCAML_OUT_OF_TREE=ON
+
+ # cheap hack: LLVM combines both anyway, and the only difference
+ # is that the former list is explicitly verified at cmake time
+ -DLLVM_TARGETS_TO_BUILD=""
+ -DLLVM_EXPERIMENTAL_TARGETS_TO_BUILD="${LLVM_TARGETS// /;}"
+ -DLLVM_BUILD_TESTS=$(usex test)
+
+ # disable various irrelevant deps and settings
+ -DLLVM_ENABLE_FFI=OFF
+ -DLLVM_ENABLE_TERMINFO=OFF
+ -DHAVE_HISTEDIT_H=NO
+ -DLLVM_ENABLE_ASSERTIONS=$(usex debug)
+ -DLLVM_ENABLE_EH=ON
+ -DLLVM_ENABLE_RTTI=ON
+
+ -DLLVM_HOST_TRIPLE="${CHOST}"
+
+ # disable go bindings
+ -DGO_EXECUTABLE=GO_EXECUTABLE-NOTFOUND
+
+ # TODO: ocamldoc
+ )
+
+ use test && mycmakeargs+=(
+ -DLLVM_LIT_ARGS="-vv;-j;${LIT_JOBS:-$(makeopts_jobs "${MAKEOPTS}" "$(get_nproc)")}"
+ )
+
+ # LLVM_ENABLE_ASSERTIONS=NO does not guarantee this for us, #614844
+ # also: custom rules for OCaml do not work for CPPFLAGS
+ use debug || local -x CFLAGS="${CFLAGS} -DNDEBUG"
+ cmake-utils_src_configure
+
+ local llvm_libdir=$(llvm-config --libdir)
+ # an ugly hack; TODO: figure out a way to pass -L to ocaml...
+ cd "${BUILD_DIR}/${libdir}" || die
+ ln -s "${llvm_libdir}"/*.so . || die
+
+ if use test; then
+ local llvm_bindir=$(llvm-config --bindir)
+ # Force using system-installed tools.
+ sed -i -e "/llvm_tools_dir/s@\".*\"@\"${llvm_bindir}\"@" \
+ "${BUILD_DIR}"/test/lit.site.cfg.py || die
+ fi
+}
+
+src_compile() {
+ cmake-utils_src_compile ocaml_all
+}
+
+src_test() {
+ # respect TMPDIR!
+ local -x LIT_PRESERVES_TMP=1
+ cmake-utils_src_make check-llvm-bindings-ocaml
+}
+
+src_install() {
+ DESTDIR="${D}" \
+ cmake -P "${BUILD_DIR}"/bindings/ocaml/cmake_install.cmake || die
+
+ dodoc bindings/ocaml/README.txt
+}