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

[Eric Joldasov <bratishkaerik@landless-city.net>]

Signed-off-by: Eric Joldasov <bratishkaerik@landless-city.net>
---
 eclass/zig-toolchain.eclass | 325 ++++++++++++++++++++++++++++++++++++
 1 file changed, 325 insertions(+)
 create mode 100644 eclass/zig-toolchain.eclass

diff --git a/eclass/zig-toolchain.eclass b/eclass/zig-toolchain.eclass
new file mode 100644
index 000000000000..8504dc0553e1
--- /dev/null
+++ b/eclass/zig-toolchain.eclass
@@ -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
+
+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}
+	)"
+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".
+#
+# 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};;
+	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};;
+	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}" "${@}"
+}
+fi
-- 
2.47.0