dev-lang/spidermonkey: add 128.3.0

 - enable python-3.13 support with a patch from RedHat/Fedora,
 - "machify" configure, compile and tests phases to finally bring SM on par
   with other Mozilla products using mach, allowing us to most likely
   re-introduce an eclass to handle SM, Firefox and Thunderbird at some point.

Closes: https://bugs.gentoo.org/912170
Signed-off-by: Joonas Niilola <juippis@gentoo.org>

3 files changed, 523 insertions, 0 deletions

diff --git a/dev-lang/spidermonkey/Manifest b/dev-lang/spidermonkey/Manifest
index 15055529ddfb..2843f7b0e31c 100644
--- a/dev-lang/spidermonkey/Manifest
+++ b/dev-lang/spidermonkey/Manifest
@@ -5,6 +5,9 @@ DIST firefox-115.15.0esr.source.tar.xz 507920832 BLAKE2B 997a3148b7019fbec95e1e0
 DIST firefox-115.16.0esr.source.tar.xz 515133700 BLAKE2B 9501b617b346d56f6de975f88974be6fdc3d4a901b2a1b952b6bbf6cc46384084260078d23c52bedff83a65bec4ea5ec78c3bcaac86c78d0b44e796317534840 SHA512 b6f93ec3d6acac5df177253c65b833c017e65ed6e78e96ff029098443928d291f6f67164aedb83d80aa28ee9dee305086597798238d3330e35183030e53e3550
 DIST firefox-115esr-patches-10.tar.xz 17256 BLAKE2B 0f6265d6e12f55e9b5128f2f261ba3785b80563e049d2441fde09dedf419c6086c9d994d2b44d1aab35af64cde375bdc254206da9ef148fc20fa90da0417606d SHA512 a1f0012420593a1c1b38dba1785ee9092e0923f56458c38f003cca4ebaac30a73fe3d1f5806a5795c76b2b8d729f8184372e63681daa450c3bb8e5afbe9e2e4f
 DIST firefox-115esr-patches-13.tar.xz 51360 BLAKE2B a048bfadba989ebbd4c6e3df97d303d6853844e66ed92f5f5f322acf18866218b91d52dbbece63827de283eef855c932d67e329c8d93200aa83f11268a5d1b2f SHA512 186ec72323e621362dcef1bc67c476716aff97dfad701faa9220a7302e798d3cb4ed90d5ea59e3e92f016be29875bb5219787635db99a8848b7c76e4e2e09e90
+DIST firefox-128.3.0esr.source.tar.xz 560960556 BLAKE2B 015fefb408dcea5733053151aff05579b007ab757542a47956e007dc127b460f4a35e885a2ee4ef4dbb936820c8ea3907b00383f659b15a84e701590b50a5d72 SHA512 3c6ef272c0fb653d030fe3f7f72aa0e1097b1c6759556166815cde15465330f988b3bc23df4b4eb753daee930edbb1ef72145273cb29d0952bd9d7c547050f9b
+DIST firefox-128esr-patches-03.tar.xz 14156 BLAKE2B 9a618f0ddb8596b740893dc9113f374d193a00e4e8e76dbb2794928ceaafc7b5309cb6f69f6287ae1e423f0be0a060580b0d9d59307c9889362dd17fb7d31d3d SHA512 c6ec7233b368fac623ec0cce6f5c37d358a0fa5bb2154dc67eebb50968376ca9d46f3a734f5d79a4aa4edde9e300a9c65315d0e499aa6a1325b6c76a6c164258
 DIST spidermonkey-102-patches-05j.tar.xz 4596 BLAKE2B 215b770bbdf17973d7b3fd1df6cee9647459d2b02b0be5bdb289d457e5dbdb06ceac7a3082fc2f5836e991a4ac4486d73330b0276a466b5c528dab226a27829c SHA512 d2b8e32dac87d60a00fd93479dc34d8adab4feec24a38591cebeb4cf271aa2fd964f4dc26e67ebfb127a47bc8f684d50b32b2cff18ed5286701a04a289058185
 DIST spidermonkey-115-patches-01.tar.xz 3992 BLAKE2B e97d0cb3edfb885119226f54f22485ed4e8220cd904d3356b87ccc013403f976a042171cf9ca7250bcf3fe3d90996dd80b4104e7d614f95d7bcfcb0e710a8a78 SHA512 cece96f172a09dd0e29f7c2fdbf650cde405b276bc4083956365289f1da4b1d078ccbde760da6553888ddb3c53cf9aded52051db556a2c4ec492fed01dcb03a1
 DIST spidermonkey-115-patches-02.tar.xz 4896 BLAKE2B f78d9804c1427b45d6fda496b4991ec6f672dec9ce031ed57a2920fa1968c942a235f46e40166c8ab8d731a1963f322d34bb2f6984133179175e6f7376d27d13 SHA512 11fd01152d1e7b8ca89bf628076e1f4fb4f1ba6c9dc0f9dd544252495c580c04e4d5ffc238d5587f9e993aa91a47828333564ca55f60e008bd370089cd07d2e6
+DIST spidermonkey-128-patches-01.tar.xz 3612 BLAKE2B 21143ee914743f21c9c68c8ba06b5662019c9526c658514e117da54ae0e82b0c361b859656be9d6cf7db83e64b1164cc19c878dce94f777f200304473fa05041 SHA512 8b21b5b637d00272479333d8d0ef9c04b63e569fa7d123972692e0c3f8b44d2d9fa45e702ed942ae05a0074609e3e41277580768e3228293e9d6256c7ebe7979
diff --git a/dev-lang/spidermonkey/files/spidermonkey-128-known-test-failures.txt b/dev-lang/spidermonkey/files/spidermonkey-128-known-test-failures.txt
new file mode 100644
index 000000000000..5c6f6941b2ad
--- /dev/null
+++ b/dev-lang/spidermonkey/files/spidermonkey-128-known-test-failures.txt
@@ -0,0 +1,44 @@
+non262/Date/15.9.5.7.js
+non262/Date/time-zone-etc_localetime.js
+non262/Intl/Collator/big5han-gb2312han.js
+non262/Intl/Collator/implicithan.js
+non262/Intl/DateTimeFormat/day-period-hour-cycle.js
+non262/Intl/DateTimeFormat/formatRange-timeZone-offset.js
+non262/Intl/DateTimeFormat/formatRange-timeZoneName-matches-format.js
+non262/Intl/DateTimeFormat/formatRange-timeZoneName.js
+non262/Intl/DateTimeFormat/fractional-second-digits-append-item.js
+non262/Intl/DateTimeFormat/related-year.js
+non262/Intl/DisplayNames/calendar.js
+non262/Intl/DisplayNames/currency.js
+non262/Intl/DisplayNames/language-dialect.js
+non262/Intl/ListFormat/conjunction-type.js
+non262/Intl/Locale/likely-subtags-generated.js
+non262/Intl/Locale/likely-subtags.js
+non262/Intl/NumberFormat/currency-narrow-symbol.js
+non262/Intl/available-locales-resolved.js
+non262/Intl/available-locales-supported.js
+test262/built-ins/RegExp/property-escapes/generated/Alphabetic.js
+test262/built-ins/RegExp/property-escapes/generated/Assigned.js
+test262/built-ins/RegExp/property-escapes/generated/General_Category_-_Letter.js
+test262/built-ins/RegExp/property-escapes/generated/General_Category_-_Other.js
+test262/built-ins/RegExp/property-escapes/generated/General_Category_-_Other_Letter.js
+test262/built-ins/RegExp/property-escapes/generated/General_Category_-_Other_Symbol.js
+test262/built-ins/RegExp/property-escapes/generated/General_Category_-_Symbol.js
+test262/built-ins/RegExp/property-escapes/generated/General_Category_-_Unassigned.js
+test262/built-ins/RegExp/property-escapes/generated/Grapheme_Base.js
+test262/built-ins/RegExp/property-escapes/generated/IDS_Binary_Operator.js
+test262/built-ins/RegExp/property-escapes/generated/ID_Continue.js
+test262/built-ins/RegExp/property-escapes/generated/ID_Start.js
+test262/built-ins/RegExp/property-escapes/generated/Ideographic.js
+test262/built-ins/RegExp/property-escapes/generated/Script_-_Common.js
+test262/built-ins/RegExp/property-escapes/generated/Script_-_Han.js
+test262/built-ins/RegExp/property-escapes/generated/Script_Extensions_-_Common.js
+test262/built-ins/RegExp/property-escapes/generated/Script_Extensions_-_Han.js
+test262/built-ins/RegExp/property-escapes/generated/Script_Extensions_-_Malayalam.js
+test262/built-ins/RegExp/property-escapes/generated/Script_Extensions_-_Sharada.js
+test262/built-ins/RegExp/property-escapes/generated/Script_Extensions_-_Sinhala.js
+test262/built-ins/RegExp/property-escapes/generated/Sentence_Terminal.js
+test262/built-ins/RegExp/property-escapes/generated/Unified_Ideograph.js
+test262/built-ins/RegExp/property-escapes/generated/XID_Continue.js
+test262/built-ins/RegExp/property-escapes/generated/XID_Start.js
+test262/intl402/NumberFormat/prototype/format/useGrouping-extended-en-IN.js
diff --git a/dev-lang/spidermonkey/spidermonkey-128.3.0.ebuild b/dev-lang/spidermonkey/spidermonkey-128.3.0.ebuild
new file mode 100644
index 000000000000..a85726775523
--- /dev/null
+++ b/dev-lang/spidermonkey/spidermonkey-128.3.0.ebuild
@@ -0,0 +1,476 @@
+# Copyright 1999-2024 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI="8"
+
+FIREFOX_PATCHSET="firefox-128esr-patches-03.tar.xz"
+SPIDERMONKEY_PATCHSET="spidermonkey-128-patches-01.tar.xz"
+
+LLVM_COMPAT=( 17 18 )
+
+PYTHON_COMPAT=( python3_{10..12} )
+PYTHON_REQ_USE="ncurses,ssl,xml(+)"
+
+WANT_AUTOCONF="2.1"
+
+inherit autotools check-reqs flag-o-matic llvm-r1 multiprocessing python-any-r1 toolchain-funcs
+
+MY_PN="mozjs"
+MY_PV="${PV/_pre*}"
+
+MY_MAJOR=$(ver_cut 1)
+
+MOZ_ESR=yes
+
+MOZ_PV=${PV}
+MOZ_PV_SUFFIX=
+if [[ ${PV} =~ (_(alpha|beta|rc).*)$ ]] ; then
+	MOZ_PV_SUFFIX=${BASH_REMATCH[1]}
+
+	# Convert the ebuild version to the upstream Mozilla version
+	MOZ_PV="${MOZ_PV/_alpha/a}" # Handle alpha for SRC_URI
+	MOZ_PV="${MOZ_PV/_beta/b}"  # Handle beta for SRC_URI
+	MOZ_PV="${MOZ_PV%%_rc*}"    # Handle rc for SRC_URI
+fi
+
+if [[ -n ${MOZ_ESR} ]] ; then
+	# ESR releases have slightly different version numbers
+	MOZ_PV="${MOZ_PV}esr"
+fi
+
+MOZ_PN="firefox"
+MOZ_P="${MOZ_PN}-${MOZ_PV}"
+MOZ_PV_DISTFILES="${MOZ_PV}${MOZ_PV_SUFFIX}"
+MOZ_P_DISTFILES="${MOZ_PN}-${MOZ_PV_DISTFILES}"
+
+MOZ_SRC_BASE_URI="https://archive.mozilla.org/pub/${MOZ_PN}/releases/${MOZ_PV}"
+
+if [[ ${PV} == *_rc* ]] ; then
+	MOZ_SRC_BASE_URI="https://archive.mozilla.org/pub/${MOZ_PN}/candidates/${MOZ_PV}-candidates/build${PV##*_rc}"
+fi
+
+PATCH_URIS=(
+	https://dev.gentoo.org/~juippis/mozilla/patchsets/${FIREFOX_PATCHSET}
+	https://dev.gentoo.org/~juippis/mozilla/patchsets/${SPIDERMONKEY_PATCHSET}
+)
+
+DESCRIPTION="Mozilla's JavaScript engine written in C and C++"
+HOMEPAGE="https://spidermonkey.dev https://firefox-source-docs.mozilla.org/js/index.html"
+SRC_URI="${MOZ_SRC_BASE_URI}/source/${MOZ_P}.source.tar.xz -> ${MOZ_P_DISTFILES}.source.tar.xz
+	${PATCH_URIS[@]}"
+KEYWORDS="~amd64"
+
+LICENSE="MPL-2.0"
+SLOT="$(ver_cut 1)"
+IUSE="clang cpu_flags_arm_neon debug +jit lto test"
+
+#RESTRICT="test"
+RESTRICT="!test? ( test )"
+
+BDEPEND="${PYTHON_DEPS}
+	$(llvm_gen_dep '
+		sys-devel/llvm:${LLVM_SLOT}
+		clang? (
+			sys-devel/clang:${LLVM_SLOT}
+			sys-devel/lld:${LLVM_SLOT}
+			virtual/rust:0/llvm-${LLVM_SLOT}
+		)
+	')
+	!clang? ( virtual/rust )
+	!elibc_glibc? ( dev-lang/rust )
+	>=dev-util/cbindgen-0.26.0
+	virtual/pkgconfig
+	test? (
+		$(python_gen_any_dep 'dev-python/six[${PYTHON_USEDEP}]')
+	)"
+DEPEND=">=dev-libs/icu-73.1:=
+	dev-libs/nspr
+	sys-libs/readline:0=
+	sys-libs/zlib"
+RDEPEND="${DEPEND}"
+
+S="${WORKDIR}/firefox-${PV%_*}"
+
+llvm_check_deps() {
+	if ! has_version -b "sys-devel/llvm:${LLVM_SLOT}" ; then
+		einfo "sys-devel/llvm:${LLVM_SLOT} is missing! Cannot use LLVM slot ${LLVM_SLOT} ..." >&2
+		return 1
+	fi
+
+	if use clang ; then
+		if ! has_version -b "sys-devel/clang:${LLVM_SLOT}" ; then
+			einfo "sys-devel/clang:${LLVM_SLOT} is missing! Cannot use LLVM slot ${LLVM_SLOT} ..." >&2
+			return 1
+		fi
+
+		if ! has_version -b "virtual/rust:0/llvm-${LLVM_SLOT}" ; then
+			einfo "virtual/rust:0/llvm-${LLVM_SLOT} is missing! Cannot use LLVM slot ${LLVM_SLOT} ..." >&2
+			return 1
+		fi
+
+		if ! tc-ld-is-mold ; then
+			if ! has_version -b "sys-devel/lld:${LLVM_SLOT}" ; then
+				einfo "sys-devel/lld:${LLVM_SLOT} is missing! Cannot use LLVM slot ${LLVM_SLOT} ..." >&2
+				return 1
+			fi
+		fi
+	fi
+
+	einfo "Using LLVM slot ${LLVM_SLOT} to build" >&2
+}
+
+mozconfig_add_options_ac() {
+	debug-print-function ${FUNCNAME} "$@"
+
+	if [[ ${#} -lt 2 ]] ; then
+		die "${FUNCNAME} requires at least two arguments"
+	fi
+
+	local reason=${1}
+	shift
+
+	local option
+	for option in ${@} ; do
+		echo "ac_add_options ${option} # ${reason}" >>${MOZCONFIG}
+	done
+}
+
+mozconfig_add_options_mk() {
+	debug-print-function ${FUNCNAME} "$@"
+
+	if [[ ${#} -lt 2 ]] ; then
+		die "${FUNCNAME} requires at least two arguments"
+	fi
+
+	local reason=${1}
+	shift
+
+	local option
+	for option in ${@} ; do
+		echo "mk_add_options ${option} # ${reason}" >>${MOZCONFIG}
+	done
+}
+
+mozconfig_use_enable() {
+	debug-print-function ${FUNCNAME} "$@"
+
+	if [[ ${#} -lt 1 ]] ; then
+		die "${FUNCNAME} requires at least one arguments"
+	fi
+
+	local flag=$(use_enable "${@}")
+	mozconfig_add_options_ac "$(use ${1} && echo +${1} || echo -${1})" "${flag}"
+}
+
+python_check_deps() {
+	if use test ; then
+		python_has_version "dev-python/six[${PYTHON_USEDEP}]"
+	fi
+}
+
+pkg_pretend() {
+	if use test ; then
+		CHECKREQS_DISK_BUILD="4400M"
+	else
+		CHECKREQS_DISK_BUILD="4300M"
+	fi
+
+	check-reqs_pkg_pretend
+}
+
+pkg_setup() {
+	if [[ ${MERGE_TYPE} != binary ]] ; then
+		if use test ; then
+			CHECKREQS_DISK_BUILD="4400M"
+		else
+			CHECKREQS_DISK_BUILD="4300M"
+		fi
+
+		check-reqs_pkg_setup
+
+		llvm-r1_pkg_setup
+
+		if use clang && use lto && tc-ld-is-lld ; then
+			local version_lld=$(ld.lld --version 2>/dev/null | awk '{ print $2 }')
+			[[ -n ${version_lld} ]] && version_lld=$(ver_cut 1 "${version_lld}")
+			[[ -z ${version_lld} ]] && die "Failed to read ld.lld version!"
+
+			local version_llvm_rust=$(rustc -Vv 2>/dev/null | grep -F -- 'LLVM version:' | awk '{ print $3 }')
+			[[ -n ${version_llvm_rust} ]] && version_llvm_rust=$(ver_cut 1 "${version_llvm_rust}")
+			[[ -z ${version_llvm_rust} ]] && die "Failed to read used LLVM version from rustc!"
+
+			if ver_test "${version_lld}" -ne "${version_llvm_rust}" ; then
+				eerror "Rust is using LLVM version ${version_llvm_rust} but ld.lld version belongs to LLVM version ${version_lld}."
+				eerror "You will be unable to link ${CATEGORY}/${PN}. To proceed you have the following options:"
+				eerror "  - Manually switch rust version using 'eselect rust' to match used LLVM version"
+				eerror "  - Switch to dev-lang/rust[system-llvm] which will guarantee matching version"
+				eerror "  - Build ${CATEGORY}/${PN} without USE=lto"
+				eerror "  - Rebuild lld with llvm that was used to build rust (may need to rebuild the whole "
+				eerror "    llvm/clang/lld/rust chain depending on your @world updates)"
+				die "LLVM version used by Rust (${version_llvm_rust}) does not match with ld.lld version (${version_lld})!"
+			fi
+		fi
+
+		python-any-r1_pkg_setup
+
+		# Build system is using /proc/self/oom_score_adj, bug #604394
+		addpredict /proc/self/oom_score_adj
+
+		if ! mountpoint -q /dev/shm ; then
+			# If /dev/shm is not available, configure is known to fail with
+			# a traceback report referencing /usr/lib/pythonN.N/multiprocessing/synchronize.py
+			ewarn "/dev/shm is not mounted -- expect build failures!"
+		fi
+
+		# Ensure we use C locale when building, bug #746215
+		export LC_ALL=C
+	fi
+}
+
+src_prepare() {
+	if use lto ; then
+		rm -v "${WORKDIR}"/firefox-patches/*-LTO-Only-enable-LTO-*.patch || die
+	fi
+
+	# Workaround for bgo #915651,915651,929013 on musl
+	if use elibc_glibc ; then
+		rm -v "${WORKDIR}"/firefox-patches/*bgo-748849-RUST_TARGET_override.patch || die
+	fi
+
+	eapply "${WORKDIR}"/firefox-patches
+	eapply "${WORKDIR}"/spidermonkey-patches
+
+	default
+
+	# Make cargo respect MAKEOPTS
+	export CARGO_BUILD_JOBS="$(makeopts_jobs)"
+
+	# Workaround for bgo #915651,915651,929013 on musl
+	if ! use elibc_glibc ; then
+		if use amd64 ; then
+			export RUST_TARGET="x86_64-unknown-linux-musl"
+		elif use x86 ; then
+			export RUST_TARGET="i686-unknown-linux-musl"
+		elif use arm64 ; then
+			export RUST_TARGET="aarch64-unknown-linux-musl"
+		elif use ppc64 ; then
+			export RUST_TARGET="powerpc64le-unknown-linux-musl"
+		else
+			die "Unknown musl chost, please post your rustc -vV along with emerge --info on Gentoo's bug #915651"
+		fi
+	fi
+
+	# sed-in toolchain prefix
+	sed -i \
+		-e "s/objdump/${CHOST}-objdump/" \
+		python/mozbuild/mozbuild/configure/check_debug_ranges.py \
+		|| die "sed failed to set toolchain prefix"
+
+	einfo "Removing pre-built binaries ..."
+	find third_party -type f \( -name '*.so' -o -name '*.o' \) -print -delete || die
+
+	# Create build dir
+	BUILD_DIR="${WORKDIR}/${PN}_build"
+	mkdir -p "${BUILD_DIR}" || die
+}
+
+src_configure() {
+	# Show flags set at the beginning
+	einfo "Current BINDGEN_CFLAGS:\t${BINDGEN_CFLAGS:-no value set}"
+	einfo "Current CFLAGS:    ${CFLAGS}"
+	einfo "Current CXXFLAGS:  ${CXXFLAGS}"
+	einfo "Current LDFLAGS:   ${LDFLAGS}"
+	einfo "Current RUSTFLAGS: ${RUSTFLAGS}"
+
+	local have_switched_compiler=
+	if use clang; then
+		# Force clang
+		einfo "Enforcing the use of clang due to USE=clang ..."
+
+		local version_clang=$(clang --version 2>/dev/null | grep -F -- 'clang version' | awk '{ print $3 }')
+		[[ -n ${version_clang} ]] && version_clang=$(ver_cut 1 "${version_clang}")
+		[[ -z ${version_clang} ]] && die "Failed to read clang version!"
+
+		if tc-is-gcc; then
+			have_switched_compiler=yes
+		fi
+		AR=llvm-ar
+		CC=${CHOST}-clang-${version_clang}
+		CXX=${CHOST}-clang++-${version_clang}
+		NM=llvm-nm
+		RANLIB=llvm-ranlib
+
+	elif ! use clang && ! tc-is-gcc ; then
+		# Force gcc
+		have_switched_compiler=yes
+		einfo "Enforcing the use of gcc due to USE=-clang ..."
+		AR=gcc-ar
+		CC=${CHOST}-gcc
+		CXX=${CHOST}-g++
+		NM=gcc-nm
+		RANLIB=gcc-ranlib
+	fi
+
+	if [[ -n "${have_switched_compiler}" ]] ; then
+		# Because we switched active compiler we have to ensure
+		# that no unsupported flags are set
+		strip-unsupported-flags
+	fi
+
+	# Ensure we use correct toolchain,
+	# AS is used in a non-standard way by upstream, #bmo1654031
+	export HOST_CC="$(tc-getBUILD_CC)"
+	export HOST_CXX="$(tc-getBUILD_CXX)"
+	export AS="$(tc-getCC) -c"
+
+	tc-export CC CXX LD AR AS NM OBJDUMP RANLIB PKG_CONFIG
+
+	# Pass the correct toolchain paths through cbindgen
+	if tc-is-cross-compiler ; then
+		export BINDGEN_CFLAGS="${SYSROOT:+--sysroot=${ESYSROOT}} --target=${CHOST} ${BINDGEN_CFLAGS-}"
+	fi
+
+	# ../python/mach/mach/mixin/process.py fails to detect SHELL
+	export SHELL="${EPREFIX}/bin/bash"
+
+	# Set state path
+	export MOZBUILD_STATE_PATH="${BUILD_DIR}"
+
+	# Set MOZCONFIG
+	export MOZCONFIG="${S}/.mozconfig"
+
+	# Initialize MOZCONFIG
+	mozconfig_add_options_ac '' --enable-project=js
+
+	mozconfig_add_options_ac 'Gentoo default' \
+		--host="${CBUILD:-${CHOST}}" \
+		--target="${CHOST}" \
+		--disable-ctype \
+		--disable-jemalloc \
+		--disable-smoosh \
+		--disable-strip \
+		--enable-readline \
+		--enable-release \
+		--enable-shared-js \
+		--libdir="${EPREFIX}/usr/$(get_libdir)" \
+		--prefix="${EPREFIX}/usr" \
+		--with-intl-api \
+		--with-system-icu \
+		--with-system-nspr \
+		--with-system-zlib \
+		--with-toolchain-prefix="${CHOST}-" \
+		--x-includes="${ESYSROOT}/usr/include" \
+		--x-libraries="${ESYSROOT}/usr/$(get_libdir)"
+
+	mozconfig_use_enable debug
+	mozconfig_use_enable jit
+	mozconfig_use_enable test tests
+
+	if use debug ; then
+		mozconfig_add_options_ac '+debug' --disable-optimize
+		mozconfig_add_options_ac '+debug' --enable-debug-symbols
+		mozconfig_add_options_ac '+debug' --enable-real-time-tracing
+	else
+		mozconfig_add_options_ac '-debug' --enable-optimize
+		mozconfig_add_options_ac '-debug' --disable-debug-symbols
+		mozconfig_add_options_ac '-debug' --disable-real-time-tracing
+	fi
+
+	# We always end up disabling this at some point due to newer rust versions. bgo#933372
+	mozconfig_add_options_ac '--disable-rust-simd' --disable-rust-simd
+
+	# Modifications to better support ARM, bug 717344
+	if use cpu_flags_arm_neon ; then
+		mozconfig_add_options_ac '+cpu_flags_arm_neon' --with-fpu=neon
+
+		if ! tc-is-clang ; then
+			# thumb options aren't supported when using clang, bug 666966
+			mozconfig_add_options_ac '+cpu_flags_arm_neon' --with-thumb=yes
+			mozconfig_add_options_ac '+cpu_flags_arm_neon' --with-thumb-interwork=no
+		fi
+	fi
+
+	# Tell build system that we want to use LTO
+	if use lto ; then
+		if use clang ; then
+			if tc-ld-is-mold ; then
+				mozconfig_add_options_ac '+lto' --enable-linker=mold
+			else
+				mozconfig_add_options_ac '+lto' --enable-linker=lld
+			fi
+			mozconfig_add_options_ac '+lto' --enable-lto=cross
+
+		else
+			mozconfig_add_options_ac '+lto' --enable-linker=bfd
+			mozconfig_add_options_ac '+lto' --enable-lto=full
+		fi
+	fi
+
+	# LTO flag was handled via configure
+	filter-lto
+
+	# Pass MAKEOPTS to build system
+	export MOZ_MAKE_FLAGS="${MAKEOPTS}"
+
+	# Use system's Python environment
+	export MACH_BUILD_PYTHON_NATIVE_PACKAGE_SOURCE="none"
+	export PIP_NETWORK_INSTALL_RESTRICTED_VIRTUALENVS=mach
+
+	# Disable notification when build system has finished
+	export MOZ_NOSPAM=1
+
+	# Portage sets XARGS environment variable to "xargs -r" by default which
+	# breaks build system's check_prog() function which doesn't support arguments
+	mozconfig_add_options_ac 'Gentoo default' "XARGS=${EPREFIX}/usr/bin/xargs"
+
+	# Set build dir
+	mozconfig_add_options_mk 'Gentoo default' "MOZ_OBJDIR=${BUILD_DIR}"
+
+	# Show flags we will use
+	einfo "Build BINDGEN_CFLAGS:\t${BINDGEN_CFLAGS:-no value set}"
+	einfo "Build CFLAGS:    ${CFLAGS}"
+	einfo "Build CXXFLAGS:  ${CXXFLAGS}"
+	einfo "Build LDFLAGS:   ${LDFLAGS}"
+	einfo "Build RUSTFLAGS: ${RUSTFLAGS}"
+
+	./mach configure || die
+}
+
+src_compile() {
+	./mach build --verbose || die
+}
+
+src_test() {
+	if "${BUILD_DIR}/js/src/js" -e 'print("Hello world!")'; then
+		einfo "Smoke-test successful, continuing with full test suite"
+	else
+		die "Smoke-test failed: did interpreter initialization fail?"
+	fi
+
+	cp "${FILESDIR}"/spidermonkey-${SLOT}-known-test-failures.txt "${T}"/known_test_failures.list || die
+
+	./mach jstests --exclude-file="${T}"/known_test_failures.list || die
+}
+
+src_install() {
+	cd "${BUILD_DIR}" || die
+	default
+	# DESTDIR="${D}" ./mach install || die
+
+	# fix soname links
+	pushd "${ED}"/usr/$(get_libdir) &>/dev/null || die
+	mv lib${MY_PN}-${MY_MAJOR}.so lib${MY_PN}-${MY_MAJOR}.so.0.0.0 || die
+	ln -s lib${MY_PN}-${MY_MAJOR}.so.0.0.0 lib${MY_PN}-${MY_MAJOR}.so.0 || die
+	ln -s lib${MY_PN}-${MY_MAJOR}.so.0 lib${MY_PN}-${MY_MAJOR}.so || die
+	popd &>/dev/null || die
+
+	# remove unneeded files
+	rm \
+		"${ED}"/usr/bin/js${MY_MAJOR}-config \
+		"${ED}"/usr/$(get_libdir)/libjs_static.ajs || die
+
+	# fix permissions
+	chmod -x \
+		"${ED}"/usr/$(get_libdir)/pkgconfig/*.pc \
+		"${ED}"/usr/include/mozjs-${MY_MAJOR}/js-config.h || die
+}