# Copyright 1999-2023 Gentoo Authors
# Distributed under the terms of the GNU General Public License v2

# @ECLASS: rust-toolchain.eclass
# @MAINTAINER:
# Rust Project <rust@gentoo.org>
# @SUPPORTED_EAPIS: 8
# @BLURB: helps map gentoo arches to rust ABIs
# @DESCRIPTION:
# This eclass contains a src_unpack default phase function, and
# helper functions, to aid in proper rust-ABI handling for various
# gentoo arches.

case ${EAPI} in
	8) ;;
	*) die "${ECLASS}: EAPI ${EAPI:-0} not supported" ;;
esac

inherit multilib-build

# @ECLASS_VARIABLE: RUST_TOOLCHAIN_BASEURL
# @DESCRIPTION:
# This variable specifies the base URL used by the
# rust_arch_uri and rust_all_arch_uris functions when
# generating the URI output list.
: "${RUST_TOOLCHAIN_BASEURL:=https://static.rust-lang.org/dist/}"

# @FUNCTION: rust_abi
# @USAGE: [CHOST-value]
# @DESCRIPTION:
# Outputs the Rust ABI name from a CHOST value, uses CHOST in the
# environment if none is specified.

rust_abi() {
	local CTARGET=${1:-${CHOST}}
	case ${CTARGET%%*-} in
		aarch64*gnu)  echo aarch64-unknown-linux-gnu;;
		aarch64*musl) echo aarch64-unknown-linux-musl;;
		armv6j*h*)    echo arm-unknown-linux-gnueabihf;;
		armv6j*s*)    echo arm-unknown-linux-gnueabi;;
		armv7a*h*)    echo armv7-unknown-linux-gnueabihf;;
		i?86*)        echo i686-unknown-linux-gnu;;
		loongarch64*) echo loongarch64-unknown-linux-gnu;;
		mips64el*)    echo mips64el-unknown-linux-gnuabi64;;
		mips64*)      echo mips64-unknown-linux-gnuabi64;;
		mipsel*)      echo mipsel-unknown-linux-gnu;;
		mips*)        echo mips-unknown-linux-gnu;;
		powerpc64le*) echo powerpc64le-unknown-linux-gnu;;
		powerpc64*)   echo powerpc64-unknown-linux-gnu;;
		powerpc*)     echo powerpc-unknown-linux-gnu;;
		riscv64*)     echo riscv64gc-unknown-linux-gnu;;
		s390x*)       echo s390x-unknown-linux-gnu;;
		x86_64*gnu)   echo x86_64-unknown-linux-gnu;;
		x86_64*musl)  echo x86_64-unknown-linux-musl;;
		*)            echo ${CTARGET};;
  esac
}

# @FUNCTION: rust_all_abis
# @DESCRIPTION:
# Outputs a list of all the enabled Rust ABIs
rust_all_abis() {
	if use multilib; then
		local abi
		local ALL_ABIS=()
		for abi in $(multilib_get_enabled_abis); do
			ALL_ABIS+=( $(rust_abi $(get_abi_CHOST ${abi})) )
		done
		local abi_list
		IFS=, eval 'abi_list=${ALL_ABIS[*]}'
		echo ${abi_list}
	else
		rust_abi
	fi
}

# @FUNCTION: rust_arch_uri
# @USAGE: <rust-ABI> <base-uri> [alt-distfile-basename]
# @DESCRIPTION:
# Output the URI for use in SRC_URI, combining $RUST_TOOLCHAIN_BASEURL
# and the URI suffix provided in ARG2 with the rust ABI in ARG1, and
# optionally renaming to the distfile basename specified in ARG3.
#
# @EXAMPLE:
# SRC_URI="amd64? (
#	 $(rust_arch_uri x86_64-unknown-linux-gnu rustc-${STAGE0_VERSION})
# )"
#
rust_arch_uri() {
	if [ -n "$3" ]; then
		echo "${RUST_TOOLCHAIN_BASEURL}${2}-${1}.tar.xz -> ${3}-${1}.tar.xz"
	else
		echo "${RUST_TOOLCHAIN_BASEURL}${2}-${1}.tar.xz"
		echo "verify-sig? ( ${RUST_TOOLCHAIN_BASEURL}${2}-${1}.tar.xz.asc )"
	fi
}

# @FUNCTION: rust_all_arch_uris
# @USAGE: <base-uri> [alt-distfile-basename]
# @DESCRIPTION:
# Outputs the URIs for SRC_URI to help fetch dependencies, using a base URI
# provided as an argument. Optionally allows for distfile renaming via a specified
# basename.
#
# @EXAMPLE:
# SRC_URI="$(rust_all_arch_uris rustc-${STAGE0_VERSION})"
#
rust_all_arch_uris()
{
	echo "
	abi_x86_32? ( $(rust_arch_uri i686-unknown-linux-gnu "$@") )
	abi_x86_64? (
		elibc_glibc? ( $(rust_arch_uri x86_64-unknown-linux-gnu  "$@") )
		elibc_musl?  ( $(rust_arch_uri x86_64-unknown-linux-musl "$@") )
	)
	arm? (
		$(rust_arch_uri arm-unknown-linux-gnueabi     "$@")
		$(rust_arch_uri arm-unknown-linux-gnueabihf   "$@")
		$(rust_arch_uri armv7-unknown-linux-gnueabihf "$@")
	)
	arm64? (
		elibc_glibc? ( $(rust_arch_uri aarch64-unknown-linux-gnu  "$@") )
		elibc_musl?  ( $(rust_arch_uri aarch64-unknown-linux-musl "$@") )
	)
	ppc? ( $(rust_arch_uri powerpc-unknown-linux-gnu "$@") )
	ppc64? (
		big-endian?  ( $(rust_arch_uri powerpc64-unknown-linux-gnu   "$@") )
		!big-endian? ( $(rust_arch_uri powerpc64le-unknown-linux-gnu "$@") )
	)
	riscv? ( $(rust_arch_uri riscv64gc-unknown-linux-gnu "$@") )
	s390?  ( $(rust_arch_uri s390x-unknown-linux-gnu     "$@") )
	"

	# Upstream did not gain support for loong until v1.71.0.
	# NOTE: Merge this into the block above after every <1.71.0 version is
	# gone from tree.
	local arg_version="${1##*-}"
	arg_version="${arg_version:-$PV}"
	if ver_test "${arg_version}" -ge 1.71.0; then
		echo "loong? ( $(rust_arch_uri loongarch64-unknown-linux-gnu "$@") )"
	fi

	# until https://github.com/rust-lang/rust/pull/113274 is resolved, there
	# will not be upstream-built mips artifacts
	if ver_test "${arg_version}" -lt 1.72.0; then
		echo "mips? (
			abi_mips_o32? (
				big-endian?  ( $(rust_arch_uri mips-unknown-linux-gnu   "$@") )
				!big-endian? ( $(rust_arch_uri mipsel-unknown-linux-gnu "$@") )
			)
			abi_mips_n64? (
				big-endian?  ( $(rust_arch_uri mips64-unknown-linux-gnuabi64   "$@") )
				!big-endian? ( $(rust_arch_uri mips64el-unknown-linux-gnuabi64 "$@") )
			)
		)"
	fi
}