# Copyright 1999-2025 Gentoo Authors
# Distributed under the terms of the GNU General Public License v2

EAPI=8

PYTHON_COMPAT=( python3_{11..14} )
inherit cmake crossdev flag-o-matic llvm.org python-any-r1
inherit toolchain-funcs

DESCRIPTION="OpenMP offloading support"
HOMEPAGE="https://openmp.llvm.org"

LICENSE="Apache-2.0-with-LLVM-exceptions || ( UoI-NCSA MIT )"
SLOT="0/${LLVM_SOABI}"
KEYWORDS="~amd64 ~arm64 ~ppc64"
IUSE="+clang debug ompt test llvm_targets_AMDGPU llvm_targets_NVPTX"
REQUIRED_USE="
	llvm_targets_AMDGPU? ( clang )
	llvm_targets_NVPTX? ( clang )
"
RESTRICT="!test? ( test )"

RDEPEND="
	dev-libs/libffi:=
	~llvm-core/llvm-${PV}
	~llvm-runtimes/openmp-${PV}[ompt?]
	llvm_targets_AMDGPU? ( dev-libs/rocr-runtime:= )
"
DEPEND="
	${RDEPEND}
"
# tests:
# - dev-python/lit provides the test runner
# - llvm-core/llvm provide test utils (e.g. FileCheck)
# - llvm-core/clang provides the compiler to run tests
BDEPEND="
	dev-lang/perl
	virtual/pkgconfig
	clang? ( llvm-core/clang )
	llvm_targets_AMDGPU? ( llvm-core/clang[llvm_targets_AMDGPU] )
	llvm_targets_NVPTX? ( llvm-core/clang[llvm_targets_NVPTX] )
	test? (
		$(python_gen_any_dep '
			dev-python/lit[${PYTHON_USEDEP}]
		')
		llvm-core/clang
	)
"

LLVM_COMPONENTS=( offload cmake runtimes/cmake libc )
LLVM_TEST_COMPONENTS=( openmp/cmake )
llvm.org_set_globals

pkg_pretend() {
	if [[ ${LLVM_ALLOW_GPU_TESTING} ]]; then
		ewarn "LLVM_ALLOW_GPU_TESTING set.  This package will run tests against your"
		ewarn "GPU if it is supported.  Note that these tests may be flaky, fail or"
		ewarn "hang, or even cause your GPU to crash (requiring a reboot)."
	fi
}

python_check_deps() {
	python_has_version "dev-python/lit[${PYTHON_USEDEP}]"
}

pkg_setup() {
	if use test; then
		python-any-r1_pkg_setup
	fi
}

src_configure() {
	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

	# LLVM_ENABLE_ASSERTIONS=NO does not guarantee this for us, #614844
	use debug || local -x CPPFLAGS="${CPPFLAGS} -DNDEBUG"

	local libdir="$(get_libdir)"
	local ffi_cflags=$($(tc-getPKG_CONFIG) --cflags-only-I libffi)
	local ffi_ldflags=$($(tc-getPKG_CONFIG) --libs-only-L libffi)
	local plugins="host"
	local build_devicertl=FALSE

	if has "${CHOST%%-*}" aarch64 powerpc64le x86_64; then
		if use llvm_targets_AMDGPU; then
			plugins+=";amdgpu"
			build_devicertl=TRUE
		fi
		if use llvm_targets_NVPTX; then
			plugins+=";cuda"
			build_devicertl=TRUE
		fi
	fi

	local mycmakeargs=(
		-DLLVM_ROOT="${ESYSROOT}/usr/lib/llvm/${LLVM_MAJOR}"

		-DOFFLOAD_LIBDIR_SUFFIX="${libdir#lib}"
		-DOFFLOAD_INCLUDE_TESTS=$(usex test)
		-DLIBOMPTARGET_PLUGINS_TO_BUILD="${plugins}"
		-DLIBOMPTARGET_OMPT_SUPPORT="$(usex ompt)"
		-DLIBOMPTARGET_BUILD_DEVICERTL_BCLIB="${build_devicertl}"

		# this breaks building static target libs
		-DBUILD_SHARED_LIBS=OFF

		-DFFI_INCLUDE_DIR="${ffi_cflags#-I}"
		-DFFI_LIBRARY_DIR="${ffi_ldflags#-L}"
		# force using shared libffi
		-DFFI_STATIC_LIBRARIES=NO
	)

	[[ ! ${LLVM_ALLOW_GPU_TESTING} ]] && mycmakeargs+=(
		# prevent trying to access the GPU
		-DLIBOMPTARGET_AMDGPU_ARCH=LIBOMPTARGET_AMDGPU_ARCH-NOTFOUND
		-DLIBOMPTARGET_NVPTX_ARCH=LIBOMPTARGET_NVPTX_ARCH-NOTFOUND
	)
	use test && mycmakeargs+=(
		# this project does not use standard LLVM cmake macros
		-DOPENMP_LLVM_LIT_EXECUTABLE="${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++")"
		# requires flang
		-DOPENMP_TEST_Fortran_COMPILER=
	)

	cmake_src_configure
}

src_test() {
	# respect TMPDIR!
	local -x LIT_PRESERVES_TMP=1

	cmake_build check-offload
}