dev-lua/luv: migrate to lua-single.eclass

In theory this should be multi-impl but upstream does not directly support
it, in particular their pkgconfig files do not include the Lua ABI
version in their names. For now just keep it simple i.e. stick with the
old behaviour of only supporting one implementation at a time.

Signed-off-by: Marek Szuba <marecki@gentoo.org>

dev-lua/luv/files/luv-1.32.0.0-cmake_lua_version.patch

@@ -0,0 +1,11 @@
+--- a/CMakeLists.txt
++++ b/CMakeLists.txt
+@@ -107,7 +107,7 @@
+       include_directories(${LUAJIT_INCLUDE_DIR})
+       link_directories(${LUAJIT_LIBRARIES})
+     else (USE_LUAJIT)
+-      find_package(Lua REQUIRED)
++      find_package(Lua ${LUA_VERSION} EXACT REQUIRED)
+       include_directories(${LUA_INCLUDE_DIR})
+     endif (USE_LUAJIT)
+ 

dev-lua/luv/luv-1.32.0.0-r100.ebuild

@@ -0,0 +1,79 @@
+# Copyright 2019-2020 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=7
+
+LUA_COMPAT=( lua5-{1..3} luajit )
+
+inherit cmake lua-single unpacker
+
+# e.g. MY_PV = a.b.c-d
+MY_PV="$(ver_rs 3 -)"
+MY_P="${PN}-${MY_PV}"
+
+DESCRIPTION="Bare libuv bindings for lua"
+HOMEPAGE="https://github.com/luvit/luv"
+
+LUA_COMPAT_PV="0.7"
+SRC_URI="
+	https://github.com/luvit/${PN}/archive/${MY_PV}.tar.gz -> ${P}.tar.gz
+	https://github.com/keplerproject/lua-compat-5.3/archive/v${LUA_COMPAT_PV}.tar.gz -> ${PN}-lua-compat-${LUA_COMPAT_PV}.tar.gz
+"
+
+LICENSE="Apache-2.0 MIT"
+SLOT="0"
+KEYWORDS="~amd64 ~arm ~arm64 ~x86"
+IUSE="test"
+RESTRICT="!test? ( test )"
+
+REQUIRED_USE="${LUA_REQUIRED_USE}"
+
+BDEPEND="virtual/pkgconfig"
+DEPEND="${LUA_DEPS}
+	>=dev-libs/libuv-1.32.0:="
+RDEPEND="${DEPEND}"
+
+PATCHES=(
+	"${FILESDIR}"/${PN}-1.32.0.0-cmake_lua_version.patch
+)
+
+S="${WORKDIR}/${MY_P}"
+
+src_prepare() {
+	# Fix libdir
+	# Match '/lib/' and '/lib"' without capturing / or ", replacing with libdir
+	sed -i -r "s/\/lib(\"|\/)/\/$(get_libdir)\1/g" CMakeLists.txt || die "Failed to sed CMakeLists.txt"
+	cmake_src_prepare
+}
+
+# TODO: try to make this multi-impl. Will need at least:
+#  - per-implementation install dirs for headers and the library
+#  - versioned .pc files (which may or may not break revdeps)
+src_configure() {
+	lua_compat_dir="${WORKDIR}/lua-compat-5.3-${LUA_COMPAT_PV}"
+
+	local mycmakeargs=(
+		-DBUILD_MODULE=OFF
+		-DLUA_BUILD_TYPE=System
+		-DLUA_COMPAT53_DIR="${lua_compat_dir}"
+		-DWITH_SHARED_LIBUV=ON
+	)
+	if [[ ${ELUA} == luajit ]]; then
+		mycmakeargs+=(
+			-DWITH_LUA_ENGINE=LuaJIT
+		)
+	else
+		mycmakeargs+=(
+			-DWITH_LUA_ENGINE=Lua
+			-DLUA_VERSION=$(ver_cut 1-2 $(lua_get_version))
+		)
+	fi
+
+	cmake_src_configure
+}
+
+src_test() {
+	# We need to copy the library back so that the tests see it
+	ln -s "${BUILD_DIR}/libluv.so" "./luv.so" || die "Failed to symlink library for tests"
+	${ELUA} "tests/run.lua" || die "Tests failed"
+}