# Copyright 2019-2023 Gentoo Authors
# Distributed under the terms of the GNU General Public License v2

EAPI=8

LLVM_MAX_SLOT=15
inherit edo cmake llvm check-reqs toolchain-funcs

DESCRIPTION="A robust, optimal, and maintainable programming language"
HOMEPAGE="https://ziglang.org/"
if [[ ${PV} == 9999 ]]; then
	EGIT_REPO_URI="https://github.com/ziglang/zig.git"
	inherit git-r3
else
	SRC_URI="https://ziglang.org/download/${PV}/${P}.tar.xz"
	KEYWORDS="~amd64 ~arm ~arm64"
fi

LICENSE="MIT"
SLOT="$(ver_cut 1-2)"
IUSE="doc"

BUILD_DIR="${S}/build"

# Zig requires zstd and zlib compression support in LLVM, if using LLVM backend.
# (non-LLVM backends don't require these)
# They are not required "on their own", so please don't add them here.
# You can check https://github.com/ziglang/zig-bootstrap in future, to see
# options that are passed to LLVM CMake building (excluding "static" ofc).
DEPEND="
	sys-devel/clang:${LLVM_MAX_SLOT}=
	sys-devel/lld:${LLVM_MAX_SLOT}=
	sys-devel/llvm:${LLVM_MAX_SLOT}=[zstd]
"

RDEPEND="
	${DEPEND}
"

IDEPEND="app-eselect/eselect-zig"

# see https://github.com/ziglang/zig/issues/3382
# For now, Zig Build System doesn't support enviromental CFLAGS/LDFLAGS/etc.
QA_FLAGS_IGNORED="usr/bin/zig"

# Since commit https://github.com/ziglang/zig/commit/e7d28344fa3ee81d6ad7ca5ce1f83d50d8502118
# Zig uses self-hosted compiler only
CHECKREQS_MEMORY="4G"

llvm_check_deps() {
	has_version "sys-devel/clang:${LLVM_SLOT}"
}

ctarget_to_zigtarget() {
	# Zig's Target Format: arch-os-abi
	local CTARGET="${CTARGET:-${CHOST}}"

	local ZIG_ARCH
	case "${CTARGET%%-*}" in
		i?86)		ZIG_ARCH=x86;;
		sparcv9)	ZIG_ARCH=sparc64;;
		*)		ZIG_ARCH="${CTARGET%%-*}";; # Same as in CHOST
	esac

	local ZIG_OS
	case "${CTARGET}" in
		*linux*)	ZIG_OS=linux;;
		*apple*)	ZIG_OS=macos;;
	esac

	local ZIG_ABI
	case "${CTARGET##*-}" in
		gnu)		ZIG_ABI=gnu;;
		solaris*)	ZIG_OS=solaris ZIG_ABI=none;;
		darwin*)	ZIG_ABI=none;;
		*)		ZIG_ABI="${CTARGET##*-}";; # Same as in CHOST
	esac

	echo "${ZIG_ARCH}-${ZIG_OS}-${ZIG_ABI}"
}

get_zig_mcpu() {
	local ZIG_DEFAULT_MCPU=native
	tc-is-cross-compiler && ZIG_DEFAULT_MCPU=baseline
	echo "${ZIG_MCPU:-${ZIG_DEFAULT_MCPU}}"
}

get_zig_target() {
	local ZIG_DEFAULT_TARGET=native
	tc-is-cross-compiler && ZIG_DEFAULT_TARGET="$(ctarget_to_zigtarget)"
	echo "${ZIG_TARGET:-${ZIG_DEFAULT_TARGET}}"
}

pkg_setup() {
	llvm_pkg_setup
	check-reqs_pkg_setup
}

src_configure() {
	local mycmakeargs=(
		-DZIG_USE_CCACHE=OFF
		-DZIG_SHARED_LLVM=ON
		-DZIG_TARGET_TRIPLE="$(get_zig_target)"
		-DZIG_TARGET_MCPU="$(get_zig_mcpu)"
		-DZIG_USE_LLVM_CONFIG=ON
		-DCMAKE_PREFIX_PATH="$(get_llvm_prefix ${LLVM_MAX_SLOT})"
		-DCMAKE_INSTALL_PREFIX="${EPREFIX}/usr/$(get_libdir)/zig/${PV}"
	)

	cmake_src_configure
}

src_compile() {
	cmake_src_compile

	if use doc; then
		cd "${BUILD_DIR}" || die
		edo ./zig2 run ../doc/docgen.zig -- --zig ./zig2 ../doc/langref.html.in "${S}/langref.html"
		edo ./zig2 test ../lib/std/std.zig --zig-lib-dir ../lib -fno-emit-bin -femit-docs="${S}/std"
	fi
}

src_test() {
	cd "${BUILD_DIR}" || die
	local ZIG_TEST_ARGS="-Dstatic-llvm=false -Denable-llvm -Dskip-non-native \
		-Drelease -Dtarget=$(get_zig_target) -Dcpu=$(get_zig_mcpu)"
	# TBF zig2 -> stage3/bin/zig when (if) https://github.com/ziglang/zig/pull/14255 will be merged
	edo ./zig2 build test ${ZIG_TEST_ARGS}
}

src_install() {
	use doc && local HTML_DOCS=( "langref.html" "std" )
	cmake_src_install

	cd "${ED}/usr/$(get_libdir)/zig/${PV}/" || die
	mv lib/zig/ lib2/ || die
	rm -rf lib/ || die
	mv lib2/ lib/ || die
	dosym -r "/usr/$(get_libdir)/zig/${PV}/bin/zig" "/usr/bin/zig-${PV}"
}

pkg_postinst() {
	eselect zig update ifunset
}

pkg_postrm() {
	eselect zig update ifunset
}