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Diffstat (limited to 'eclass/rust.eclass')
| -rw-r--r-- | eclass/rust.eclass | 464 |
1 files changed, 464 insertions, 0 deletions
diff --git a/eclass/rust.eclass b/eclass/rust.eclass new file mode 100644 index 000000000000..12ef4b90a7ac --- /dev/null +++ b/eclass/rust.eclass @@ -0,0 +1,464 @@ +# Copyright 2024 Gentoo Authors +# Distributed under the terms of the GNU General Public License v2 + +# @ECLASS: rust.eclass +# @MAINTAINER: +# Matt Jolly <kangie@gentoo.org> +# @AUTHOR: +# Matt Jolly <kangie@gentoo.org> +# @SUPPORTED_EAPIS: 8 +# @BLURB: Utility functions to build against slotted Rust +# @DESCRIPTION: +# An eclass to reliably depend on a Rust or Rust/LLVM combination for +# a given Rust slot. To use the eclass: +# +# 1. If required, set RUST_{MAX,MIN}_SLOT to the range of supported slots. +# 2. If rust is optional, set RUST_OPTIONAL to a non-empty value then +# appropriately gate ${RUST_DEPEND} +# 3. Use rust_pkg_setup, get_rust_prefix or RUST_SLOT. + +# Example use for a package supporting Rust 1.72.0 to 1.82.0: +# @CODE +# +# RUST_MAX_VER="1.82.0" +# RUST_MIN_VER="1.72.0" +# +# inherit meson rust +# +# # only if you need to define one explicitly +# pkg_setup() { +# rust_pkg_setup +# do-something-else +# } +# @CODE +# +# Example for a package needing Rust w/ a specific target: +# @CODE +# RUST_USEDEP='clippy,${MULTILIB_USEDEP}' +# +# inherit multilib-minimal meson rust +# +# @CODE + +case ${EAPI} in + 8) ;; + *) die "${ECLASS}: EAPI ${EAPI:-0} not supported" ;; +esac + +if [[ -z ${_RUST_ECLASS} ]]; then +_RUST_ECLASS=1 + +if [[ -n ${RUST_NEEDS_LLVM} ]]; then + if [[ -z ${_LLVM_R1_ECLASS} ]]; then + die "Please inherit llvm-r1.eclass before rust.eclass when using RUST_NEEDS_LLVM" + fi +fi + +# == internal control knobs == + +# @ECLASS_VARIABLE: _RUST_LLVM_MAP +# @INTERNAL +# @DESCRIPTION: +# Definitive list of Rust slots and the associated LLVM slot, newest first. +declare -A -g -r _RUST_LLVM_MAP=( + ["1.82.0"]=19 + ["1.81.0"]=18 + ["1.80.1"]=18 + ["1.79.0"]=18 + ["1.77.1"]=17 + ["1.75.0"]=17 + ["1.74.1"]=17 + ["1.71.1"]=16 +) + +# @ECLASS_VARIABLE: _RUST_SLOTS_ORDERED +# @INTERNAL +# @DESCRIPTION: +# Array of Rust slots, newest first. +# While _RUST_LLVM_MAP stores useful info about the relationship between Rust and LLVM slots, +# this array is used to store the Rust slots in a more convenient order for iteration. +declare -a -g -r _RUST_SLOTS_ORDERED=( + "1.82.0" + "1.81.0" + "1.80.1" + "1.79.0" + "1.77.1" + "1.75.0" + "1.74.1" + "1.71.1" +) + +# == control variables == + +# @ECLASS_VARIABLE: RUST_MAX_VER +# @DEFAULT_UNSET +# @DESCRIPTION: +# Highest Rust slot supported by the package. Needs to be set before +# rust_pkg_setup is called. If unset, no upper bound is assumed. + +# @ECLASS_VARIABLE: RUST_MIN_VER +# @DEFAULT_UNSET +# @DESCRIPTION: +# Lowest Rust slot supported by the package. Needs to be set before +# rust_pkg_setup is called. If unset, no lower bound is assumed. + +# @eclass-variable: RUST_NEEDS_LLVM +# @DEFAULT_UNSET +# @DESCRIPTION: +# If set to a non-empty value generate a llvm_slot_${llvm_slot}? gated +# dependency block for rust slots in LLVM_COMPAT. This is useful for +# packages that need a tight coupling between Rust and LLVM but don't +# really care _which_ version of Rust is selected. Combine with +# RUST_MAX_VER and RUST_MIN_VER to limit the range of Rust versions +# that are acceptable. Will `die` if llvm-r1 is not inherited or +# an invalid combination of RUST and LLVM slots is detected; this probably +# means that a LLVM slot in LLVM_COMPAT has had all of its Rust slots filtered. + +# @ECLASS_VARIABLE: RUST_DEPEND +# @OUTPUT_VARIABLE +# @DESCRIPTION: +# This is an eclass-generated Rust dependency string, filtered by +# RUST_MAX_VER and RUST_MIN_VER. If RUST_NEEDS_LLVM is set, this +# is gropeda and gated by an appropriate `llvm_slot_x` USE for all +# implementations listed in LLVM_COMPAT. + +# @ECLASS_VARIABLE: RUST_OPTIONAL +# @DEFAULT_UNSET +# @DESCRIPTION: +# If set to a non-empty value, the Rust dependency will not be added +# to BDEPEND. This is useful for where packages need to gate rust behind +# certain USE themselves. + +# @ECLASS_VARIABLE: RUST_USEDEP +# @DEFAULT_UNSET +# @DESCRIPTION: +# Additional USE-dependencies to be added to the Rust dependency. +# This is useful for packages that need to depend on specific Rust +# features, like clippy or rustfmt. The variable is expanded before +# being used in the Rust dependency. + +# == global metadata == + +_rust_set_globals() { + debug-print-function ${FUNCNAME} "$@" + + # If RUST_MIN_VER is older than our oldest slot we'll just set it to that + # internally so we don't have to worry about it later. + if ! ver_test "${_RUST_SLOTS_ORDERED[-1]}" -gt "${RUST_MIN_VER:-0}"; then + RUST_MIN_VER="${_RUST_SLOTS_ORDERED[-1]}" + fi + + # and if it falls between slots we'll set it to the next highest slot + # We can skip this we match a slot exactly. + if ! [[ "${_RUST_SLOTS_ORDERED[@]}" == *"${RUST_MIN_VER}"* ]]; then + local i + for (( i=${#_RUST_SLOTS_ORDERED[@]}-1 ; i>=0 ; i-- )); do + if ver_test "${_RUST_SLOTS_ORDERED[$i]}" -gt "${RUST_MIN_VER}"; then + RUST_MIN_VER="${_RUST_SLOTS_ORDERED[$i]}" + break + fi + done + fi + + if [[ -n "${RUST_MAX_VER}" && -n "${RUST_MIN_VER}" ]]; then + if ! ver_test "${RUST_MAX_VER}" -ge "${RUST_MIN_VER}"; then + die "RUST_MAX_VER must not be older than RUST_MIN_VER" + fi + fi + + local slot + # Try to keep this in order of newest to oldest + for slot in "${_RUST_SLOTS_ORDERED[@]}"; do + if ver_test "${slot}" -le "${RUST_MAX_VER:-9999}" && \ + ver_test "${slot}" -ge "${RUST_MIN_VER:-0}"; then + _RUST_SLOTS+=( "${slot}" ) + fi + done + + _RUST_SLOTS=( "${_RUST_SLOTS[@]}" ) + + # We may have been passed a variable like ${MULTILIB_USEDEP}; expand it. + if [[ -n "${RUST_USEDEP}" ]]; then + eval $(echo RUST_USEDEP="${RUST_USEDEP}") + [[ -z "${RUST_USEDEP}" ]] && die "When evaluated, RUST_USEDEP is empty" + fi + + readonly _RUST_SLOTS + + local rust_dep=() + local llvm_slot + local rust_slot + local usedep + + # If we're not using LLVM, we can just generate a simple Rust dependency + if [[ -z "${RUST_NEEDS_LLVM}" ]]; then + rust_dep=( "|| (" ) + for slot in "${_RUST_SLOTS[@]}"; do + usedep="${RUST_USEDEP+[${RUST_USEDEP}]}" + rust_dep+=( + "dev-lang/rust:${slot}${usedep}" + "dev-lang/rust-bin:${slot}${usedep}" + ) + done + rust_dep+=( ")" ) + RUST_DEPEND="${rust_dep[*]}" + else + for llvm_slot in "${LLVM_COMPAT[@]}"; do + # Quick sanity check to make sure that the llvm slot is valid for Rust. + if [[ "${_RUST_LLVM_MAP[@]}" == *"${llvm_slot}"* ]]; then + # We're working a bit backwards here; iterate over _RUST_LLVM_MAP, check the + # LLVM slot, and if it matches add this to a new array because it may (and likely will) + # match multiple Rust slots. We already filtered Rust max/min slots. + # We always have a usedep for the LLVM slot, append `,RUST_USEDEP` if it's set + usedep="[llvm_slot_${llvm_slot}${RUST_USEDEP+,${RUST_USEDEP}}]" + local slot_dep_content=() + for rust_slot in "${_RUST_SLOTS[@]}"; do + if [[ "${_RUST_LLVM_MAP[${rust_slot}]}" == "${llvm_slot}" ]]; then + slot_dep_content+=( + "dev-lang/rust:${rust_slot}${usedep}" + "dev-lang/rust-bin:${rust_slot}${usedep}" + ) + fi + done + if [ ${#slot_dep_content[@]} -ne 0 ]; then + rust_dep+=( "llvm_slot_${llvm_slot}? ( || ( ${slot_dep_content[*]} ) )" ) + else + die "${FUNCNAME}: no Rust slots found for LLVM slot ${llvm_slot}" + fi + fi + done + RUST_DEPEND="${rust_dep[*]}" + fi + + readonly RUST_DEPEND + if [[ -z ${RUST_OPTIONAL} ]]; then + BDEPEND="${RUST_DEPEND}" + fi +} +_rust_set_globals +unset -f _rust_set_globals + +# == ebuild helpers == + +# @FUNCTION: get_rust_slot +# @USAGE: [-b|-d] +# @DESCRIPTION: +# Find the newest Rust install that is acceptable for the package, +# and print its version number (i.e. SLOT) and type (source or bin[ary]). +# +# If -b is specified, the checks are performed relative to BROOT, +# and BROOT-path is returned. +# +# If -d is specified, the checks are performed relative to ESYSROOT, +# and ESYSROOT-path is returned. -d is the default. +# +# If RUST_M{AX,IN}_SLOT is non-zero, then only Rust versions that +# are not newer or older than the specified slot(s) will be considered. +# Otherwise, all Rust versions are be considered acceptable. +# +# If the `rust_check_deps()` function is defined within the ebuild, it +# will be called to verify whether a particular slot is accepable. +# Within the function scope, RUST_SLOT and LLVM_SLOT will be defined. +# +# The function should return a true status if the slot is acceptable, +# false otherwise. If rust_check_deps() is not defined, the function +# defaults to checking whether a suitable Rust package is installed. +get_rust_slot() { + debug-print-function ${FUNCNAME} "$@" + + local hv_switch=-d + while [[ ${1} == -* ]]; do + case ${1} in + -b|-d) hv_switch="${1}";; + *) break;; + esac + shift + done + + local max_slot + if [[ -z "${RUST_MAX_VER}" ]]; then + max_slot= + else + max_slot="${RUST_MAX_VER}" + fi + local slot + local llvm_slot + + if [[ -n "${RUST_NEEDS_LLVM}" ]]; then + local unique_slots=() + local llvm_r1_slot + # Associative array keys are unique, so let's use that to our advantage + for llvm_slot in "${_RUST_LLVM_MAP[@]}"; do + unique_slots["${llvm_slot}"]="1" + done + for llvm_slot in "${!unique_slots[@]}"; do + if [[ "${LLVM_COMPAT[@]}" == *"${llvm_slot}"* ]]; then + # We can check for the USE + use "llvm_slot_${llvm_slot}" && llvm_r1_slot="${llvm_slot}" + else + continue + fi + done + if [[ -z "${llvm_r1_slot}" ]]; then + die "${FUNCNAME}: no LLVM slot found" + fi + fi + + # iterate over known slots, newest first + for slot in "${_RUST_SLOTS_ORDERED[@]}"; do + llvm_slot="${_RUST_LLVM_MAP[${slot}]}" + # skip higher slots + if [[ -n "${max_slot}" ]]; then + if ver_test "${slot}" -eq "${max_slot}"; then + max_slot= + elif ver_test "${slot}" -gt "${max_slot}"; then + continue + fi + fi + + # If we're in LLVM mode we can skip any slots that don't match the selected USE + if [[ -n "${RUST_NEEDS_LLVM}" ]]; then + if [[ "${llvm_slot}" != "${llvm_r1_slot}" ]]; then + continue + fi + fi + + if declare -f rust_check_deps >/dev/null; then + local RUST_SLOT="${slot}" + local LLVM_SLOT="${_RUST_LLVM_MAP[${slot}]}" + rust_check_deps && return + else + local rust_usedep="${RUST_USEDEP+[${RUST_USEDEP}]}" + # When checking for installed packages prefer the non `-bin` package + # if effort was put into building it we should use it. + local rust_pkgs=( + "dev-lang/rust:${slot}${rust_usedep}" + "dev-lang/rust-bin:${slot}${rust_usedep}" + ) + local _pkg + for _pkg in "${rust_pkgs[@]}" + do + if has_version "${hv_switch}" "${_pkg}"; then + echo "${slot}" + if [[ "${_pkg}" == "dev-lang/rust:${slot}${rust_usedep}" ]]; then + echo source + else + echo binary + fi + return + fi + done + fi + + # We want to process the slot before escaping the loop if we've hit the minimum slot + if ver_test "${slot}" -eq "${RUST_MIN_VER}"; then + break + fi + + done + + # max_slot should have been unset in the iteration + if [[ -n "${max_slot}" ]]; then + die "${FUNCNAME}: invalid max_slot=${max_slot}" + fi + + die "No Rust slot${1:+ <= ${1}} satisfying the package's dependencies found installed!" +} + +# @FUNCTION: get_rust_path +# @USAGE: prefix slot rust_type +# @DESCRIPTION: +# Given argument of slot and rust_type, return an appropriate path +# for the Rust install. The rust_type should be either "source" +# or "binary". If the rust_type is not one of these, the function +# will die. +get_rust_path() { + debug-print-function ${FUNCNAME} "$@" + + local prefix="${1}" + local slot="${2}" + local rust_type="${3}" + + if [[ ${#} -ne 3 ]]; then + die "${FUNCNAME}: invalid number of arguments" + fi + + if [[ "${rust_type}" != "source" && "${rust_type}" != "binary" ]]; then + die "${FUNCNAME}: invalid rust_type=${rust_type}" + fi + + if [[ "${rust_type}" == "source" ]]; then + echo "${prefix}/usr/lib/rust/${slot}/" + else + echo "${prefix}opt/rust-bin-${slot}/" + fi +} + +# @FUNCTION: get_rust_prefix +# @USAGE: [-b|-d] +# @DESCRIPTION: +# Find the newest Rust install that is acceptable for the package, +# and print an absolute path to it. If both -bin and regular Rust +# are installed, the regular Rust is preferred. +# +# The options and behavior are the same as get_rust_slot. +get_rust_prefix() { + debug-print-function ${FUNCNAME} "$@" + + local prefix=${BROOT} + [[ ${1} == -d ]] && prefix=${ESYSROOT} + + local slot rust_type + { read -r slot; read -r rust_type; } <<< $(get_rust_slot) + echo $(get_rust_path "${prefix}" "${slot}" "${rust_type}") +} + +# @FUNCTION: rust_prepend_path +# @USAGE: <slot> <type> +# @DESCRIPTION: +# Prepend the path to the specified Rust to PATH and re-export it. +rust_prepend_path() { + debug-print-function ${FUNCNAME} "$@" + + [[ ${#} -ne 2 ]] && die "Usage: ${FUNCNAME} <slot> <type>" + local slot="${1}" + local type="${2}" + export PATH="$(get_rust_path "${BROOT}" "${slot}" "${type}")/bin:${PATH}" +} + +# @FUNCTION: rust_pkg_setup +# @DESCRIPTION: +# Prepend the appropriate executable directory for the newest +# acceptable Rust slot to the PATH. If used with LLVM, an appropriate +# `llvm_pkg_setup` call should be made in addition to this function. +# For path determination logic, please see the get_rust_prefix documentation. +# +# The highest acceptable Rust slot can be set in RUST_MAX_VER variable. +# If it is unset or empty, any slot is acceptable. +# +# The lowest acceptable Rust slot can be set in RUST_MIN_VER variable. +# If it is unset or empty, any slot is acceptable. +# +# `CARGO` and `RUSTC` variables are set for the selected slot and exported. +# +# The PATH manipulation is only done for source builds. The function +# is a no-op when installing a binary package. +# +# If any other behavior is desired, the contents of the function +# should be inlined into the ebuild and modified as necessary. +rust_pkg_setup() { + debug-print-function ${FUNCNAME} "$@" + + if [[ ${MERGE_TYPE} != binary ]]; then + { read -r RUST_SLOT; read -r RUST_TYPE; } <<< $(get_rust_slot) + rust_prepend_path "${RUST_SLOT}" "${RUST_TYPE}" + CARGO="$(get_rust_prefix)bin/cargo" + RUSTC="$(get_rust_prefix)bin/rustc" + export CARGO RUSTC + einfo "Using Rust ${RUST_SLOT} (${RUST_TYPE})" + fi +} + +fi + +EXPORT_FUNCTIONS pkg_setup |