Re: [gentoo-dev] [PATCH 1/5] zig-toolchain.eclass: new eclass

["Ulrich Müller" <ulm@gentoo.org>]

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>>>>> On Thu, 24 Oct 2024, Eric Joldasov wrote:

> --- /dev/null
> +++ b/eclass/zig-toolchain.eclass

I have some general comments about both proposed eclasses.

> @@ -0,0 +1,325 @@
> +# Copyright 2024 Gentoo Authors
> +# Distributed under the terms of the GNU General Public License v2
> +
> +# @ECLASS: zig-toolchain.eclass
> +# @MAINTAINER:
> +# Eric Joldasov <bratishkaerik@landless-city.net>
> +# @AUTHOR:
> +# Eric Joldasov <bratishkaerik@landless-city.net>
> +# @SUPPORTED_EAPIS: 8
> +# @BLURB: Prepare Zig toolchain and set environment variables.
> +# @DESCRIPTION:
> +# Prepare Zig toolchain and set environment variables. Supports Zig 0.13+.
> +# Does not set any default function, ebuilds must call them manually.
> +# Generally, only "zig-toolchain_populate_env_vars" is needed.
> +#
> +# Intended to be used by ebuilds that call "zig build-exe/lib/obj"
> +# or "zig test" directly and by "dev-lang/zig".
> +# For ebuilds with ZBS (Zig Build System), it's usually better
> +# to inherit zig-build instead, as it has default phases-functions.
> +
> +case ${EAPI} in
> +	8) ;;
> +	*) die "${ECLASS}: EAPI ${EAPI:-0} not supported" ;;
> +esac

For new eclasses, the EAPI check should be inside the inherit guard.

> +
> +if [[ ! ${_ZIG_TOOLCHAIN_ECLASS} ]]; then
> +_ZIG_TOOLCHAIN_ECLASS=1
> +
> +inherit edo flag-o-matic
> +
> +# @ECLASS_VARIABLE: ZIG_SLOT
> +# @PRE_INHERIT
> +# @REQUIRED
> +# @DESCRIPTION:
> +# Zig slot that will be used in "ezig" function. Also, if ZIG_OPTIONAL is
> +# empty, adds dev-lang/zig and dev-lang/zig-bin dependency to BDEPEND.
> +# Must be >= "0.13".
> +#
> +# Example:
> +# @CODE
> +# 0.13
> +# @CODE
> +
> +# @ECLASS_VARIABLE: ZIG_OPTIONAL
> +# @PRE_INHERIT
> +# @DEFAULT_UNSET
> +# @DESCRIPTION:
> +# If set to a non-empty value, all logic in zig-toolchain and zig-build
> +# eclasses will be considered optional. No dependencies will be added and
> +# no phase functions will be exported.
> +#
> +# For zig-toolchain.eclass users:
> +# You have to add Zig dependency in your BDEPEND manually and call
> +# at least "zig-toolchain_populate_env_vars" before using "ezig".
> +#
> +# For zig-build.eclass users: see documentation in zig-build.eclass instead.
> +if [[ ! ${ZIG_OPTIONAL} ]]; then
> +	BDEPEND+=" || (
> +		dev-lang/zig:${ZIG_SLOT}
> +		dev-lang/zig-bin:${ZIG_SLOT}
> +	)"

I don't see any previous assignment of BDEPEND, so the += and the
initial space aren't necessary here. (Same issue in zig-build.eclass.)

> +fi
> +
> +# @ECLASS_VARIABLE: ZIG_TARGET
> +# @DESCRIPTION:
> +# Zig target triple to use. Has the following format:
> +# arch-os[.os_version_range]-abi[.abi_version]
> +# Can be passed as:
> +# * "-target " option in "zig test" or "zig build-exe/lib/obj",
> +# * "-Dtarget=" option in "zig build" (if project uses "std.Build.standardTargetOptions").
> +#
> +# Can be overriden by user. If not overriden, then set by "zig-toolchain_populate_env_vars".

Please keep the length of documentation lines below 80 characters;
best is to break them at 70-ish chars for good human readability.
https://devmanual.gentoo.org/ebuild-writing/file-format/index.html#indenting-and-whitespace

Also, full stops at the end of a sentence should be followed by two
spaces, so that groff will recognise the sentence end in the resulting
man page.

> +#
> +# Example:
> +# @CODE
> +# native # autodetected by Zig
> +# x86_64-linux-gnu # Machine running Linux x86_64 system, with glibc
> +# x86_64-linux.6.1.12...6.6.16-gnu.2.38 # Similar to above, but versions are passed explicitly
> +# powerpc64le-linux-musl # Machine running Linux 64-bit little-endian PowerPC system, with musl
> +# @CODE
> +#
> +
> +# @ECLASS_VARIABLE: ZIG_CPU
> +# @DESCRIPTION:
> +# Zig target CPU and features to use. Has the following format:
> +# family_name(\+enable_feature|\-disable_feature)*
> +# Can be passed as:
> +# * "-mcpu " option in "zig test" or "zig build-exe/lib/obj",
> +# * "-Dcpu=" option in "zig build" (if project uses "std.Build.standardTargetOptions").
> +#
> +# Can be overriden by user. If not overriden, then set by "zig-toolchain_populate_env_vars".
> +#
> +# Example:
> +# @CODE
> +# native # autodetected by Zig
> +# znver2 # AMD Zen 2 processor
> +# x86_64+x87-sse2" # x86_64 processor, X87 support enabled, SSE2 support disabled
> +# @CODE
> +
> +# @ECLASS_VARIABLE: ZIG_EXE
> +# @DESCRIPTION:
> +# Absolute path to the used Zig executable.
> +#
> +# Please note that when passing one flag several times with different values:
> +# * to "zig build" in "-Dbar=false -Dbar" form: errors due to conflict of flags,
> +# * to "zig build" in "-Dbar=false -Dbar=true" form: "bar" becomes a list, which is likely not what you (or upstream) want,
> +# * to "zig test" or "zig build-exe/lib/obj" in "-fbar -fno-bar" form: latest value overwrites values before.
> +# Similar situation with other types of options (enums, "std.SemanticVersion", integers, strings, etc.)
> +#
> +# Can be overriden by user. If not overriden, then set by "zig-toolchain_populate_env_vars".
> +
> +# @ECLASS_VARIABLE: ZIG_VER
> +# @OUTPUT_VARIABLE
> +# @DESCRIPTION:
> +# Zig version found during "zig-toolchain_find_installation", as reported by "zig version".
> +#
> +# Example:
> +# @CODE
> +# 0.13.0
> +# @CODE
> +
> +# @FUNCTION: zig-toolchain_get_target
> +# @USAGE: <C-style target triple>
> +# @DESCRIPTION:
> +# Translates C-style target triple (like CHOST or CBUILD)
> +# to Zig-style target triple. Some information (like ARM features)
> +# is handled by "zig-toolchain_get_cpu". Mostly used during cross-compiling
> +# if user does not set ZIG_TARGET variable.
> +#
> +# See ZIG_TARGET description for more information.
> +zig-toolchain_get_target() {
> +	[[ ${#} -eq 1 ]] || die "${FUNCNAME[0]}: exactly one argument must be passed"
> +	local c_target=${1}
> +	local c_target_prefix=${c_target%%-*}
> +	local c_target_suffix=${c_target##*-}
> +
> +	local arch os abi
> +
> +	case ${c_target_prefix} in
> +		i?86)	arch=x86;;
> +		arm64)	arch=aarch64;;
> +		arm*)	arch=arm;;
> +		*)	arch=${c_target_prefix};;

Any reason why the last line isn't aligned with the others?

> +	esac
> +
> +	case ${c_target} in
> +		*linux*)	os=linux;;
> +		*apple*)	os=macos;;
> +	esac
> +
> +	case ${c_target_suffix} in
> +		solaris*)	os=solaris abi=none;;
> +		darwin*)	abi=none;;
> +		*)		abi=${c_target_suffix};;

Ditto.

> +	esac
> +
> +	[[ ${arch} == arm && ${abi} == gnu ]] && die "${FUNCNAME[0]}: Zig does not support old ARM ABI"
> +
> +	echo ${arch}-${os}-${abi}
> +}
> +
> +
> +
> +# @FUNCTION: zig-toolchain_get_cpu
> +# @USAGE: <C-style target triple>
> +# @DESCRIPTION:
> +# Translates C-style target triple (like CHOST or CBUILD)
> +# to Zig-style target CPU and features. Mostly used to get generic target CPU
> +# during cross-compiling if user does not set ZIG_CPU variable.
> +#
> +# See ZIG_CPU description for more information.
> +zig-toolchain_get_cpu() {
> +	[[ ${#} -eq 1 ]] || die "${FUNCNAME[0]}: exactly one argument must be passed"
> +	local c_target=${1}
> +	local c_target_prefix=${c_target%%-*}
> +
> +	local base_cpu features=""
> +
> +	case ${c_target_prefix} in
> +		i?86)					base_cpu=${c_target_prefix};;
> +		loongarch64)			base_cpu=generic_la64;;
> +		powerpc | powerpcle)	base_cpu=ppc;;
> +		powerpc64)				base_cpu=ppc64;;
> +		powerpc64le)			base_cpu=ppc64le;;
> +		riscv32)				base_cpu=generic_rv32;;
> +		riscv64)				base_cpu=generic_rv64;;
> +		*)						base_cpu=generic;;
> +	esac
> +
> +	case ${c_target_prefix} in
> +		armv5tel)	features+="+v5te";;
> +		armv*)		features+="+${c_target_prefix##armv}";;
> +	esac
> +
> +	case ${c_target_prefix} in
> +		arm64)	;;
> +		arm*)
> +			local is_softfloat=$(CTARGET=${c_target} tc-tuple-is-softfloat)
> +			case ${is_softfloat} in
> +				only | yes) features+="+soft_float";;
> +				softfp | no) features+="-soft_float";;
> +				*) die "${FUNCNAME[0]}: tc-tuple-is-softfloat returned unexpected value"
> +			esac
> +		;;
> +	esac
> +
> +	echo ${base_cpu}${features}
> +}
> +
> +# @FUNCTION: zig-toolchain_find_installation
> +# @DESCRIPTION:
> +# Detects suitable Zig installation and sets ZIG_VER and ZIG_EXE variables.
> +#
> +# See ZIG_EXE and ZIG_VER descriptions for more information.
> +zig-toolchain_find_installation() {
> +	# Adapted from https://github.com/gentoo/gentoo/pull/28986
> +	# Many thanks to Florian Schmaus (Flowdalic)!
> +
> +	[[ -n ${ZIG_SLOT} ]] || die "${FUNCNAME[0]}: ZIG_SLOT must be set"
> +	if ver_test "${ZIG_SLOT}" -lt "0.13"; then
> +		die "${ECLASS}: ZIG_SLOT must be >= 0.13, found ${ZIG_SLOT}"
> +	fi
> +
> +	einfo "Searching Zig ${ZIG_SLOT}..."
> +
> +	local selected_path selected_version
> +
> +	# Prefer "dev-lang/zig" over "dev-lang/zig-bin"
> +	local -a candidates candidates1 candidates2
> +	readarray -d '' -t candidates1 < <(find -P "${BROOT}"/usr/bin/ -mindepth 1 -maxdepth 1 -type l -name "zig-bin-*" -print0 2> /dev/null || echo -n "")
> +	readarray -d '' -t candidates2 < <(find -P "${BROOT}"/usr/bin/ -mindepth 1 -maxdepth 1 -type l -name "zig-*" -a '!' -name "zig-bin-*" -print0 2> /dev/null || echo -n "")
> +	candidates=( "${candidates1[@]}" "${candidates2[@]}" )
> +
> +	local candidate_path
> +	for candidate_path in "${candidates[@]}"; do
> +		local candidate_version="${candidate_path##*-}"
> +
> +		# Compare with ZIG_SLOT (like 0.13)
> +		local candidate_slot=$(ver_cut 1-2 ${candidate_version})
> +		if ver_test "${candidate_slot}" -ne ${ZIG_SLOT}; then
> +			# Candidate does not satisfy ZIG_SLOT condition.
> +			continue
> +		fi
> +
> +		# Compare with previous version (like 0.13.0 and 0.13.1, we prefer the second one if possible)
> +		if [[ -n "${selected_path}" ]]; then
> +			local selected_version="${selected_path##*-}"
> +			if ver_test ${candidate_version} -lt ${selected_version}; then
> +				# Previously chosen version is higher, keep it.
> +				continue
> +			fi
> +		fi
> +
> +		selected_path="${candidate_path}"
> +	done
> +
> +	if [[ -z "${selected_path}" ]]; then
> +		die "Could not find (suitable) Zig installation in \"${BROOT}/usr/bin/\""
> +	fi
> +
> +	export ZIG_EXE="${selected_path}"
> +}
> +
> +# @FUNCTION: zig-toolchain_populate_env_vars
> +# @DESCRIPTION:
> +# Populates ZIG_TARGET, ZIG_CPU, ZIG_EXE and ZIG_VER environment
> +# variables with detected values, or, if user set them already,
> +# leaves as-is.
> +zig-toolchain_populate_env_vars() {
> +	# Should be first because it sets ZIG_VER which might be used in the future
> +	# when setting ZIG_TARGET and ZIG_CPU variables for incompatible versions.
> +	if [[ -z "${ZIG_EXE}" ]]; then
> +		zig-toolchain_find_installation
> +	fi
> +	if [[ -z ${ZIG_VER} ]]; then
> +		local selected_ver=$("${ZIG_EXE}" version || die "Failed to get version from \"${ZIG_EXE}\"")
> +		export ZIG_VER=${selected_ver}
> +	fi
> +
> +	if [[ -z ${ZIG_TARGET} ]]; then
> +		if tc-is-cross-compiler; then
> +			export ZIG_TARGET=$(zig-toolchain_get_target ${CHOST})
> +		else
> +			export ZIG_TARGET=native
> +		fi
> +	fi
> +
> +	if [[ -z ${ZIG_CPU} ]]; then
> +		if tc-is-cross-compiler; then
> +			export ZIG_CPU=$(zig-toolchain_get_cpu ${CHOST})
> +		else
> +			export ZIG_CPU=native
> +		fi
> +	fi
> +
> +	einfo "ZIG_EXE:    \"${ZIG_EXE}\""
> +	einfo "ZIG_VER:     ${ZIG_VER}"
> +	einfo "ZIG_TARGET:  ${ZIG_TARGET}"
> +	einfo "ZIG_CPU:     ${ZIG_CPU}"
> +}
> +
> +# @FUNCTION: ezig
> +# @USAGE: [<args>...]
> +# @DESCRIPTION:
> +# Runs ZIG_EXE with supplied arguments. Dies if ZIG_EXE is not set.
> +#
> +# Always disables progress bar (tree in 0.13+).
> +# By default enables ANSI escape codes (colours, etc.), set NO_COLOR
> +# environment variable to disable them.
> +ezig() {
> +	# Sync description above and comments below with "std.io.tty.detectConfig".
> +        debug-print-function "${FUNCNAME[0]}" "${@}"
> +
> +	if [[ -z "${ZIG_EXE}" ]] ; then
> +		die "${FUNCNAME[0]}: ZIG_EXE is not set. Was 'zig-toolchain_populate_env_vars' called before using ezig?"
> +	fi
> +
> +	# Progress bar (tree in newer versions) are helpful indicators in
> +	# TTY, but unfortunately they make Portage logs harder to read in plaintext.
> +	# We pass "TERM=dumb" here to have clean logs, and CLICOLOR_FORCE (or YES_COLOR
> +	# until 0.13) to preserve colors.
> +	# User's NO_COLOR takes precendence over this.
> +	TERM=dumb YES_COLOR=1 CLICOLOR_FORCE=1 "${ZIG_EXE}" "${@}"

No die statement?

> +}
> +fi

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