[gentoo-commits] repo/gentoo:master commit in: sys-libs/glibc/

["Andreas K. Hüttel" <dilfridge@gentoo.org>]

commit:     9bc453ddfa97fe15588b7b61ee794d0c0d696f44
Author:     Andreas K. Hüttel <dilfridge <AT> gentoo <DOT> org>
AuthorDate: Fri Jan 20 23:58:11 2023 +0000
Commit:     Andreas K. Hüttel <dilfridge <AT> gentoo <DOT> org>
CommitDate: Fri Jan 20 23:58:52 2023 +0000
URL:        https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=9bc453dd

sys-libs/glibc: 2.36 patchset 8 bump

Signed-off-by: Andreas K. Hüttel <dilfridge <AT> gentoo.org>

 sys-libs/glibc/Manifest             |    1 +
 sys-libs/glibc/glibc-2.36-r7.ebuild | 1636 +++++++++++++++++++++++++++++++++++
 2 files changed, 1637 insertions(+)

diff --git a/sys-libs/glibc/Manifest b/sys-libs/glibc/Manifest
index 24e66dbac394..bbabe8853a05 100644
--- a/sys-libs/glibc/Manifest
+++ b/sys-libs/glibc/Manifest
@@ -17,6 +17,7 @@ DIST glibc-2.35-patches-12.tar.xz 266056 BLAKE2B 7979dcfee270107d51c10e5ec74c9c1
 DIST glibc-2.35.tar.xz 18165952 BLAKE2B 623c728884f070cd87ffeb9203f74206197c52405ac9bc44f3dd519a3468b8e8ae2536c883e5d17d94417dbd1e91775de2e674314e4ff7424f9720026d6b7063 SHA512 e7336ce27561be5d7c217832a1136fb327e057bd8d3f92925b35c97e3e9f9e486948b5a1e03e5e4090772ef06437a074d10b82e68f17f1ad8f22077ee39e1b66
 DIST glibc-2.36-patches-5.tar.xz 81348 BLAKE2B 003a59a992302c21132474bcdc994d10b5d50a94368e949ce28cbe389cefd104f66c48cb61a63d24e2f6db94d010e4220bda3fb5291d088cda88069b928c92e0 SHA512 6d6a16114df2223bf04729a79d12a52e41c9b8e756863c1acbb909dc34696958073604ced1b691579271218738511191ddf517e03a700d3948752c455201bcc4
 DIST glibc-2.36-patches-6.tar.xz 100540 BLAKE2B bdd887bd61c5c3f8047e31b1380344da82a5e9c7fe6cf0ebd1177a1dd40462872dd9507594b6669140a1a8c6c08ce3195a3f8d425ce5e2a2ff6e9b42d90c43ed SHA512 3a2620e87eba62d3276c5b09b97337bffe3a51bf23da243fb550f6f9dddb77008a7840ede32b7b1a7ff72e06b89981d9edf27026931a12fae8042002d8328358
+DIST glibc-2.36-patches-8.tar.xz 109968 BLAKE2B b8feaadca2283bd293b1ff13f4714b00dcae0720c3ec8e332275728c1a41fc0d76633423b073d49593d8924690004ec9e56389e7802d3803b1f805e960e5092b SHA512 50eb74ce0b8861c979146a710267e391840c8f5fc7cb90490696865665c816233708c8c07337d16537abf172d6234234f5aac8ea726d846a228924455b219f9e
 DIST glibc-2.36.tar.xz 18610836 BLAKE2B f8375e084043f032609e66fd98c234249df57a595c59672acb1bb8c69aed64d339d526611553449492b097cda900ad1d9bae8873d7f5932b10a9a0d8c9210c55 SHA512 9ea0bbda32f83a85b7da0c34f169607fb8a102f0a11a914e6bf531be47d1bef4f5307128286cffa1e2dc5879f0e6ccaef527dd353486883fa332a0b44bde8b3e
 DIST glibc-systemd-20210729.tar.gz 1480 BLAKE2B 37722c7579df782d890e44dbab99c3de52ab466eb9de80d82405e9bb5620bf39ffc8c5f466a435bdb86ef6d36dd7019c0736573916bda6c67d02a2581e0ec979 SHA512 efd75af58b50522c28cdac7abd1fc56555bc1bb042512c90d8340c1ec09c5791b3872a305bf83723252bbde5855b75d958c041083457765c4cfd170732d09238
 DIST glibc-systemd-20210814.tar.gz 1469 BLAKE2B 10fa7bcb46d4fdce9c0ab353cbd30871e9b09a347a13a9c9a3b5777f931aa3c826c158d2e49532c604d4a834f2fab4089b67495fb88d0398945dc50d45ad9ef1 SHA512 5346a9ea459a1e6ccf665389f2a294de1e16f1e3e05cdf07e3dd99ed0e4f6f8b52cc333d4bff3c75ac90ab6ce70cd4ab2b3e126f920ce7979abd6dda56315efc

diff --git a/sys-libs/glibc/glibc-2.36-r7.ebuild b/sys-libs/glibc/glibc-2.36-r7.ebuild
new file mode 100644
index 000000000000..0027c6f4aaa2
--- /dev/null
+++ b/sys-libs/glibc/glibc-2.36-r7.ebuild
@@ -0,0 +1,1636 @@
+# Copyright 1999-2023 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=7
+
+# Bumping notes: https://wiki.gentoo.org/wiki/Project:Toolchain/sys-libs/glibc
+# Please read & adapt the page as necessary if obsolete.
+
+PYTHON_COMPAT=( python3_{9..11} )
+TMPFILES_OPTIONAL=1
+
+inherit python-any-r1 prefix preserve-libs toolchain-funcs flag-o-matic gnuconfig \
+	multilib systemd multiprocessing tmpfiles
+
+DESCRIPTION="GNU libc C library"
+HOMEPAGE="https://www.gnu.org/software/libc/"
+LICENSE="LGPL-2.1+ BSD HPND ISC inner-net rc PCRE"
+SLOT="2.2"
+
+EMULTILIB_PKG="true"
+
+# Gentoo patchset (ignored for live ebuilds)
+PATCH_VER=8
+PATCH_DEV=dilfridge
+
+if [[ ${PV} == 9999* ]]; then
+	inherit git-r3
+else
+	#KEYWORDS="~alpha ~amd64 ~arm ~arm64 ~hppa ~ia64 ~loong ~m68k ~mips ~ppc ~ppc64 ~riscv ~s390 ~sparc ~x86"
+	SRC_URI="mirror://gnu/glibc/${P}.tar.xz"
+	SRC_URI+=" https://dev.gentoo.org/~${PATCH_DEV}/distfiles/${P}-patches-${PATCH_VER}.tar.xz"
+fi
+
+RELEASE_VER=${PV}
+
+GCC_BOOTSTRAP_VER=20201208
+
+LOCALE_GEN_VER=2.22
+
+GLIBC_SYSTEMD_VER=20210729
+
+SRC_URI+=" https://gitweb.gentoo.org/proj/locale-gen.git/snapshot/locale-gen-${LOCALE_GEN_VER}.tar.gz"
+SRC_URI+=" multilib-bootstrap? ( https://dev.gentoo.org/~dilfridge/distfiles/gcc-multilib-bootstrap-${GCC_BOOTSTRAP_VER}.tar.xz )"
+SRC_URI+=" systemd? ( https://gitweb.gentoo.org/proj/toolchain/glibc-systemd.git/snapshot/glibc-systemd-${GLIBC_SYSTEMD_VER}.tar.gz )"
+
+IUSE="audit caps cet compile-locales +crypt custom-cflags doc gd hash-sysv-compat headers-only +multiarch multilib multilib-bootstrap nscd perl profile selinux +ssp stack-realign +static-libs suid systemd systemtap test vanilla"
+
+# Minimum kernel version that glibc requires
+MIN_KERN_VER="3.2.0"
+# Minimum pax-utils version needed (which contains any new syscall changes for
+# its seccomp filter!). Please double check this!
+MIN_PAX_UTILS_VER="1.3.3"
+
+# Here's how the cross-compile logic breaks down ...
+#  CTARGET - machine that will target the binaries
+#  CHOST   - machine that will host the binaries
+#  CBUILD  - machine that will build the binaries
+# If CTARGET != CHOST, it means you want a libc for cross-compiling.
+# If CHOST != CBUILD, it means you want to cross-compile the libc.
+#  CBUILD = CHOST = CTARGET    - native build/install
+#  CBUILD != (CHOST = CTARGET) - cross-compile a native build
+#  (CBUILD = CHOST) != CTARGET - libc for cross-compiler
+#  CBUILD != CHOST != CTARGET  - cross-compile a libc for a cross-compiler
+# For install paths:
+#  CHOST = CTARGET  - install into /
+#  CHOST != CTARGET - install into /usr/CTARGET/
+#
+export CBUILD=${CBUILD:-${CHOST}}
+export CTARGET=${CTARGET:-${CHOST}}
+if [[ ${CTARGET} == ${CHOST} ]] ; then
+	if [[ ${CATEGORY} == cross-* ]] ; then
+		export CTARGET=${CATEGORY#cross-}
+	fi
+fi
+
+# Note [Disable automatic stripping]
+# Disabling automatic stripping for a few reasons:
+# - portage's attempt to strip breaks non-native binaries at least on
+#   arm: bug #697428
+# - portage's attempt to strip libpthread.so.0 breaks gdb thread
+#   enumeration: bug #697910. This is quite subtle:
+#   * gdb uses glibc's libthread_db-1.0.so to enumerate threads.
+#   * libthread_db-1.0.so needs access to libpthread.so.0 local symbols
+#     via 'ps_pglobal_lookup' symbol defined in gdb.
+#   * 'ps_pglobal_lookup' uses '.symtab' section table to resolve all
+#     known symbols in 'libpthread.so.0'. Specifically 'nptl_version'
+#     (unexported) is used to sanity check compatibility before enabling
+#     debugging.
+#     Also see https://sourceware.org/gdb/wiki/FAQ#GDB_does_not_see_any_threads_besides_the_one_in_which_crash_occurred.3B_or_SIGTRAP_kills_my_program_when_I_set_a_breakpoint
+#   * normal 'strip' command trims '.symtab'
+#   Thus our main goal here is to prevent 'libpthread.so.0' from
+#   losing it's '.symtab' entries.
+# As Gentoo's strip does not allow us to pass less aggressive stripping
+# options and does not check the machine target we strip selectively.
+
+# We need a new-enough binutils/gcc to match upstream baseline.
+# Also we need to make sure our binutils/gcc supports TLS,
+# and that gcc already contains the hardened patches.
+# Lastly, let's avoid some openssh nastiness, bug 708224, as
+# convenience to our users.
+
+# gzip, grep, awk are needed by locale-gen, bug 740750
+
+BDEPEND="
+	${PYTHON_DEPS}
+	>=app-misc/pax-utils-${MIN_PAX_UTILS_VER}
+	sys-devel/bison
+	doc? ( sys-apps/texinfo )
+	!compile-locales? (
+		app-arch/gzip
+		sys-apps/grep
+		app-alternatives/awk
+	)
+"
+COMMON_DEPEND="
+	gd? ( media-libs/gd:2= )
+	nscd? ( selinux? (
+		audit? ( sys-process/audit )
+		caps? ( sys-libs/libcap )
+	) )
+	perl? ( dev-lang/perl )
+	suid? ( caps? ( sys-libs/libcap ) )
+	selinux? ( sys-libs/libselinux )
+	systemtap? ( dev-util/systemtap )
+"
+DEPEND="${COMMON_DEPEND}
+	compile-locales? (
+		app-arch/gzip
+		sys-apps/grep
+		app-alternatives/awk
+	)
+	test? ( >=net-dns/libidn2-2.3.0 )
+"
+RDEPEND="${COMMON_DEPEND}
+	app-arch/gzip
+	sys-apps/grep
+	app-alternatives/awk
+	sys-apps/gentoo-functions
+	!<app-misc/pax-utils-${MIN_PAX_UTILS_VER}
+	!<net-misc/openssh-8.1_p1-r2
+"
+
+RESTRICT="!test? ( test )"
+
+if [[ ${CATEGORY} == cross-* ]] ; then
+	BDEPEND+=" !headers-only? (
+		>=${CATEGORY}/binutils-2.27
+		>=${CATEGORY}/gcc-6.2
+	)"
+	[[ ${CATEGORY} == *-linux* ]] && DEPEND+=" ${CATEGORY}/linux-headers"
+else
+	BDEPEND+="
+		>=sys-devel/binutils-2.27
+		>=sys-devel/gcc-6.2
+	"
+	DEPEND+=" virtual/os-headers "
+	RDEPEND+="
+		>=net-dns/libidn2-2.3.0
+		vanilla? ( !sys-libs/timezone-data )
+	"
+	PDEPEND+=" !vanilla? ( sys-libs/timezone-data )"
+fi
+
+# Ignore tests whitelisted below
+GENTOO_GLIBC_XFAIL_TESTS="${GENTOO_GLIBC_XFAIL_TESTS:-yes}"
+
+# The following tests fail due to the Gentoo build system and are thus
+# executed but ignored:
+XFAIL_TEST_LIST=(
+	# buggy test, assumes /dev/ and /dev/null on a single filesystem
+	# 'mount --bind /dev/null /chroot/dev/null' breaks it.
+	# https://sourceware.org/PR25909
+	tst-support_descriptors
+
+	# The following tests fail only inside portage
+	# https://bugs.gentoo.org/831267
+	tst-system
+	tst-strerror
+	tst-strsignal
+)
+
+#
+# Small helper functions
+#
+
+dump_build_environment() {
+	einfo ==== glibc build environment ========================================================
+	local v
+	for v in ABI CBUILD CHOST CTARGET CBUILD_OPT CTARGET_OPT CC CXX CPP LD {AS,C,CPP,CXX,LD}FLAGS MAKEINFO NM AR AS STRIP RANLIB OBJCOPY STRINGS OBJDUMP READELF; do
+		einfo " $(printf '%15s' ${v}:)   ${!v}"
+	done
+	einfo =====================================================================================
+}
+
+is_crosscompile() {
+	[[ ${CHOST} != ${CTARGET} ]]
+}
+
+just_headers() {
+	is_crosscompile && use headers-only
+}
+
+alt_prefix() {
+	is_crosscompile && echo /usr/${CTARGET}
+}
+
+# This prefix is applicable to CHOST when building against this
+# glibc. It is baked into the library at configure time.
+host_eprefix() {
+	is_crosscompile || echo "${EPREFIX}"
+}
+
+# This prefix is applicable to CBUILD when building against this
+# glibc. It determines the destination path at install time.
+build_eprefix() {
+	is_crosscompile && echo "${EPREFIX}"
+}
+
+# We need to be able to set alternative headers for compiling for non-native
+# platform. Will also become useful for testing kernel-headers without screwing
+# up the whole system.
+alt_headers() {
+	echo ${ALT_HEADERS:=$(alt_prefix)/usr/include}
+}
+
+alt_build_headers() {
+	if [[ -z ${ALT_BUILD_HEADERS} ]] ; then
+		ALT_BUILD_HEADERS="$(host_eprefix)$(alt_headers)"
+		if tc-is-cross-compiler ; then
+			ALT_BUILD_HEADERS=${SYSROOT}$(alt_headers)
+			if [[ ! -e ${ALT_BUILD_HEADERS}/linux/version.h ]] ; then
+				local header_path=$(echo '#include <linux/version.h>' | $(tc-getCPP ${CTARGET}) ${CFLAGS} 2>&1 | grep -o '[^"]*linux/version.h')
+				ALT_BUILD_HEADERS=${header_path%/linux/version.h}
+			fi
+		fi
+	fi
+	echo "${ALT_BUILD_HEADERS}"
+}
+
+alt_libdir() {
+	echo $(alt_prefix)/$(get_libdir)
+}
+alt_usrlibdir() {
+	echo $(alt_prefix)/usr/$(get_libdir)
+}
+
+builddir() {
+	echo "${WORKDIR}/build-${ABI}-${CTARGET}-$1"
+}
+
+do_compile_test() {
+	local ret save_cflags=${CFLAGS}
+	CFLAGS+=" $1"
+	shift
+
+	pushd "${T}" >/dev/null
+
+	rm -f glibc-test*
+	printf '%b' "$*" > glibc-test.c
+
+	# We assume CC is already set up.
+	nonfatal emake glibc-test
+	ret=$?
+
+	popd >/dev/null
+
+	CFLAGS=${save_cflags}
+	return ${ret}
+}
+
+do_run_test() {
+	local ret
+
+	if [[ ${MERGE_TYPE} == "binary" ]] ; then
+		# ignore build failures when installing a binary package #324685
+		do_compile_test "" "$@" 2>/dev/null || return 0
+	else
+		if ! do_compile_test "" "$@" ; then
+			ewarn "Simple build failed ... assuming this is desired #324685"
+			return 0
+		fi
+	fi
+
+	pushd "${T}" >/dev/null
+
+	./glibc-test
+	ret=$?
+	rm -f glibc-test*
+
+	popd >/dev/null
+
+	return ${ret}
+}
+
+setup_target_flags() {
+	# This largely mucks with compiler flags.  None of which should matter
+	# when building up just the headers.
+	just_headers && return 0
+
+	case $(tc-arch) in
+		x86)
+			# -march needed for #185404 #199334
+			# TODO: When creating the first glibc cross-compile, this test will
+			# always fail as it does a full link which in turn requires glibc.
+			# Probably also applies when changing multilib profile settings (e.g.
+			# enabling x86 when the profile was amd64-only previously).
+			# We could change main to _start and pass -nostdlib here so that we
+			# only test the gcc code compilation.  Or we could do a compile and
+			# then look for the symbol via scanelf.
+			if ! do_compile_test "" 'void f(int i, void *p) {if (__sync_fetch_and_add(&i, 1)) f(i, p);}\nint main(){return 0;}\n'; then
+				local t=${CTARGET_OPT:-${CTARGET}}
+				t=${t%%-*}
+				filter-flags '-march=*'
+				export CFLAGS="-march=${t} ${CFLAGS}"
+				einfo "Auto adding -march=${t} to CFLAGS #185404"
+			fi
+			# For compatibility with older binaries at slight performance cost.
+			use stack-realign && export CFLAGS+=" -mstackrealign"
+		;;
+		amd64)
+			# -march needed for #185404 #199334
+			# TODO: See cross-compile issues listed above for x86.
+			if [[ ${ABI} == x86 ]]; then
+				if ! do_compile_test "${CFLAGS_x86}" 'void f(int i, void *p) {if (__sync_fetch_and_add(&i, 1)) f(i, p);}\nint main(){return 0;}\n'; then
+					local t=${CTARGET_OPT:-${CTARGET}}
+					t=${t%%-*}
+					# Normally the target is x86_64-xxx, so turn that into the -march that
+					# gcc actually accepts. #528708
+					[[ ${t} == "x86_64" ]] && t="x86-64"
+					filter-flags '-march=*'
+					# ugly, ugly, ugly.  ugly.
+					CFLAGS_x86=$(CFLAGS=${CFLAGS_x86} filter-flags '-march=*'; echo "${CFLAGS}")
+					export CFLAGS_x86="${CFLAGS_x86} -march=${t}"
+					einfo "Auto adding -march=${t} to CFLAGS_x86 #185404 (ABI=${ABI})"
+				fi
+				# For compatibility with older binaries at slight performance cost.
+				use stack-realign && export CFLAGS_x86+=" -mstackrealign"
+
+				# Workaround for bug #823780.
+				# Need to save/restore CC because earlier on, we stuff it full of CFLAGS, and tc-getCPP doesn't like that.
+				CC_mangled=${CC}
+				CC=${glibc__GLIBC_CC}
+				if tc-is-gcc && (($(gcc-major-version) == 11)) && (($(gcc-minor-version) <= 2)) && (($(gcc-micro-version) == 0)) ; then
+					export CFLAGS_x86="${CFLAGS_x86} -mno-avx512f"
+					einfo "Auto adding -mno-avx512f to CFLAGS_x86 for buggy GCC version (bug #823780) (ABI=${ABI})"
+				fi
+				CC=${CC_mangled}
+			fi
+		;;
+		mips)
+			# The mips abi cannot support the GNU style hashes. #233233
+			filter-ldflags -Wl,--hash-style=gnu -Wl,--hash-style=both
+		;;
+		ppc|ppc64)
+			# Many arch-specific implementations do not work on ppc with
+			# cache-block not equal to 128 bytes. This breaks memset:
+			#   https://sourceware.org/PR26522
+			#   https://bugs.gentoo.org/737996
+			# Use default -mcpu=. For ppc it means non-multiarch setup.
+			filter-flags '-mcpu=*'
+		;;
+		sparc)
+			# Both sparc and sparc64 can use -fcall-used-g6.  -g7 is bad, though.
+			filter-flags "-fcall-used-g7"
+			append-flags "-fcall-used-g6"
+
+			local cpu
+			case ${CTARGET} in
+			sparc64-*)
+				cpu="sparc64"
+				case $(get-flag mcpu) in
+				v9)
+					# We need to force at least v9a because the base build doesn't
+					# work with just v9.
+					# https://sourceware.org/bugzilla/show_bug.cgi?id=19477
+					append-flags "-Wa,-xarch=v9a"
+					;;
+				esac
+				;;
+			sparc-*)
+				case $(get-flag mcpu) in
+				v8|supersparc|hypersparc|leon|leon3)
+					cpu="sparcv8"
+					;;
+				*)
+					cpu="sparcv9"
+					;;
+				esac
+			;;
+			esac
+			[[ -n ${cpu} ]] && CTARGET_OPT="${cpu}-${CTARGET#*-}"
+		;;
+	esac
+}
+
+setup_flags() {
+	# Make sure host make.conf doesn't pollute us
+	if is_crosscompile || tc-is-cross-compiler ; then
+		CHOST=${CTARGET} strip-unsupported-flags
+	fi
+
+	# Store our CFLAGS because it's changed depending on which CTARGET
+	# we are building when pulling glibc on a multilib profile
+	CFLAGS_BASE=${CFLAGS_BASE-${CFLAGS}}
+	CFLAGS=${CFLAGS_BASE}
+	CXXFLAGS_BASE=${CXXFLAGS_BASE-${CXXFLAGS}}
+	CXXFLAGS=${CXXFLAGS_BASE}
+	ASFLAGS_BASE=${ASFLAGS_BASE-${ASFLAGS}}
+	ASFLAGS=${ASFLAGS_BASE}
+
+	# Allow users to explicitly avoid flag sanitization via
+	# USE=custom-cflags.
+	if ! use custom-cflags; then
+		# Over-zealous CFLAGS can often cause problems.  What may work for one
+		# person may not work for another.  To avoid a large influx of bugs
+		# relating to failed builds, we strip most CFLAGS out to ensure as few
+		# problems as possible.
+		strip-flags
+		# Lock glibc at -O2; we want to be conservative here.
+		filter-flags '-O?'
+		append-flags -O2
+	fi
+
+	strip-unsupported-flags
+	filter-flags -m32 -m64 '-mabi=*'
+
+	# glibc aborts if rpath is set by LDFLAGS
+	filter-ldflags '-Wl,-rpath=*'
+
+	# ld can't use -r & --relax at the same time, bug #788901
+	# https://sourceware.org/PR27837
+	filter-ldflags '-Wl,--relax'
+
+	# some weird software relies on sysv hashes in glibc, bug 863863, bug 864100
+	# we have to do that here already so mips can filter it out again :P
+	if use hash-sysv-compat ; then
+		append-ldflags '-Wl,--hash-style=both'
+	fi
+
+	# #492892
+	filter-flags -frecord-gcc-switches
+
+	# #829583
+	filter-lfs-flags
+
+	unset CBUILD_OPT CTARGET_OPT
+	if use multilib ; then
+		CTARGET_OPT=$(get_abi_CTARGET)
+		[[ -z ${CTARGET_OPT} ]] && CTARGET_OPT=$(get_abi_CHOST)
+	fi
+
+	setup_target_flags
+
+	if [[ -n ${CTARGET_OPT} && ${CBUILD} == ${CHOST} ]] && ! is_crosscompile; then
+		CBUILD_OPT=${CTARGET_OPT}
+	fi
+
+	# glibc's headers disallow -O0 and fail at build time:
+	#  include/libc-symbols.h:75:3: #error "glibc cannot be compiled without optimization"
+	replace-flags -O0 -O1
+
+	# glibc handles this internally already where it's appropriate;
+	# can't always have SSP when we're the ones setting it up, etc
+	filter-flags '-fstack-protector*'
+
+	# Similar issues as with SSP. Can't inject yourself that early.
+	filter-flags '-fsanitize=*'
+
+	# See end of bug #830454; we handle this via USE=cet
+	filter-flags '-fcf-protection='
+}
+
+use_multiarch() {
+	# Allow user to disable runtime arch detection in multilib.
+	use multiarch || return 1
+	# Make sure binutils is new enough to support indirect functions,
+	# #336792. This funky sed supports gold and bfd linkers.
+	local bver nver
+	bver=$($(tc-getLD ${CTARGET}) -v | sed -n -r '1{s:[^0-9]*::;s:^([0-9.]*).*:\1:;p}')
+	case $(tc-arch ${CTARGET}) in
+	amd64|x86) nver="2.20" ;;
+	arm)       nver="2.22" ;;
+	hppa)      nver="2.23" ;;
+	ppc|ppc64) nver="2.20" ;;
+	# ifunc support was added in 2.23, but glibc also needs
+	# machinemode which is in 2.24.
+	s390)      nver="2.24" ;;
+	sparc)     nver="2.21" ;;
+	*)         return 1 ;;
+	esac
+	ver_test ${bver} -ge ${nver}
+}
+
+# Setup toolchain variables that had historically been defined in the
+# profiles for these archs.
+setup_env() {
+	# silly users
+	unset LD_RUN_PATH
+	unset LD_ASSUME_KERNEL
+
+	if is_crosscompile || tc-is-cross-compiler ; then
+		multilib_env ${CTARGET_OPT:-${CTARGET}}
+
+		if ! use multilib ; then
+			MULTILIB_ABIS=${DEFAULT_ABI}
+		else
+			MULTILIB_ABIS=${MULTILIB_ABIS:-${DEFAULT_ABI}}
+		fi
+
+		# If the user has CFLAGS_<CTARGET> in their make.conf, use that,
+		# and fall back on CFLAGS.
+		local VAR=CFLAGS_${CTARGET//[-.]/_}
+		CFLAGS=${!VAR-${CFLAGS}}
+		einfo " $(printf '%15s' 'Manual CFLAGS:')   ${CFLAGS}"
+	fi
+
+	setup_flags
+
+	export ABI=${ABI:-${DEFAULT_ABI:-default}}
+
+	if just_headers ; then
+		# Avoid mixing host's CC and target's CFLAGS_${ABI}:
+		# At this bootstrap stage we have only binutils for
+		# target but not compiler yet.
+		einfo "Skip CC ABI injection. We can't use (cross-)compiler yet."
+		return 0
+	fi
+
+	# Glibc does not work with gold (for various reasons) #269274.
+	tc-ld-disable-gold
+
+	if use doc ; then
+		export MAKEINFO=makeinfo
+	else
+		export MAKEINFO=/dev/null
+	fi
+
+	# Reset CC and CXX to the value at start of emerge
+	export CC=${glibc__ORIG_CC:-${CC:-$(tc-getCC ${CTARGET})}}
+	export CXX=${glibc__ORIG_CXX:-${CXX:-$(tc-getCXX ${CTARGET})}}
+
+	# and make sure glibc__ORIG_CC and glibc__ORIG_CXX is defined now.
+	export glibc__ORIG_CC=${CC}
+	export glibc__ORIG_CXX=${CXX}
+
+	if tc-is-clang && ! use custom-cflags && ! is_crosscompile ; then
+		export glibc__force_gcc=yes
+		# once this is toggled on, it needs to stay on, since with CPP manipulated
+		# tc-is-clang does not work correctly anymore...
+	fi
+
+	if [[ ${glibc__force_gcc} == "yes" ]] ; then
+		# If we are running in an otherwise clang/llvm environment, we need to
+		# recover the proper gcc and binutils settings here, at least until glibc
+		# is finally building with clang. So let's override everything that is
+		# set in the clang profiles.
+		# Want to shoot yourself into the foot? Set USE=custom-cflags, that's always
+		# a good start into that direction.
+		# Also, if you're crosscompiling, let's assume you know what you are doing.
+		# Hopefully.
+		# Last, we need the settings of the *build* environment, not of the
+		# target environment...
+
+		local current_binutils_path=$(env ROOT="${BROOT}" binutils-config -B)
+		local current_gcc_path=$(env ROOT="${BROOT}" gcc-config -B)
+		einfo "Overriding clang configuration, since it won't work here"
+
+		export CC="${current_gcc_path}/gcc"
+		export CPP="${current_gcc_path}/cpp"
+		export CXX="${current_gcc_path}/g++"
+		export LD="${current_binutils_path}/ld.bfd"
+		export AR="${current_binutils_path}/ar"
+		export AS="${current_binutils_path}/as"
+		export NM="${current_binutils_path}/nm"
+		export STRIP="${current_binutils_path}/strip"
+		export RANLIB="${current_binutils_path}/ranlib"
+		export OBJCOPY="${current_binutils_path}/objcopy"
+		export STRINGS="${current_binutils_path}/strings"
+		export OBJDUMP="${current_binutils_path}/objdump"
+		export READELF="${current_binutils_path}/readelf"
+		export ADDR2LINE="${current_binutils_path}/addr2line"
+
+		# do we need to also do flags munging here? yes! at least...
+		filter-flags '-fuse-ld=*'
+		filter-flags '-D_FORTIFY_SOURCE=*'
+
+	else
+
+		# this is the "normal" case
+
+		export CC="$(tc-getCC ${CTARGET})"
+		export CXX="$(tc-getCXX ${CTARGET})"
+
+		# Always use tuple-prefixed toolchain. For non-native ABI glibc's configure
+		# can't detect them automatically due to ${CHOST} mismatch and fallbacks
+		# to unprefixed tools. Similar to multilib.eclass:multilib_toolchain_setup().
+		export NM="$(tc-getNM ${CTARGET})"
+		export READELF="$(tc-getREADELF ${CTARGET})"
+
+	fi
+
+	# We need to export CFLAGS with abi information in them because glibc's
+	# configure script checks CFLAGS for some targets (like mips).  Keep
+	# around the original clean value to avoid appending multiple ABIs on
+	# top of each other. (Why does the comment talk about CFLAGS if the code
+	# acts on CC?)
+	export glibc__GLIBC_CC=${CC}
+	export glibc__GLIBC_CXX=${CXX}
+
+	export glibc__abi_CFLAGS="$(get_abi_CFLAGS)"
+
+	# CFLAGS can contain ABI-specific flags like -mfpu=neon, see bug #657760
+	# To build .S (assembly) files with the same ABI-specific flags
+	# upstream currently recommends adding CFLAGS to CC/CXX:
+	#    https://sourceware.org/PR23273
+	# Note: Passing CFLAGS via CPPFLAGS overrides glibc's arch-specific CFLAGS
+	# and breaks multiarch support. See 659030#c3 for an example.
+	# The glibc configure script doesn't properly use LDFLAGS all the time.
+	export CC="${glibc__GLIBC_CC} ${glibc__abi_CFLAGS} ${CFLAGS} ${LDFLAGS}"
+
+	# Some of the tests are written in C++, so we need to force our multlib abis in, bug 623548
+	export CXX="${glibc__GLIBC_CXX} ${glibc__abi_CFLAGS} ${CFLAGS}"
+
+	if is_crosscompile; then
+		# Assume worst-case bootstrap: glibc is buil first time
+		# when ${CTARGET}-g++ is not available yet. We avoid
+		# building auxiliary programs that require C++: bug #683074
+		# It should not affect final result.
+		export libc_cv_cxx_link_ok=no
+		# The line above has the same effect. We set CXX explicitly
+		# to make build logs less confusing.
+		export CXX=
+	fi
+}
+
+foreach_abi() {
+	setup_env
+
+	local ret=0
+	local abilist=""
+	if use multilib ; then
+		abilist=$(get_install_abis)
+	else
+		abilist=${DEFAULT_ABI}
+	fi
+	local -x ABI
+	for ABI in ${abilist:-default} ; do
+		setup_env
+		einfo "Running $1 for ABI ${ABI}"
+		$1
+		: $(( ret |= $? ))
+	done
+	return ${ret}
+}
+
+glibc_banner() {
+	local b="Gentoo ${PVR}"
+	[[ -n ${PATCH_VER} ]] && ! use vanilla && b+=" p${PATCH_VER}"
+	echo "${b}"
+}
+
+# The following Kernel version handling functions are mostly copied from portage
+# source. It's better not to use linux-info.eclass here since a) it adds too
+# much magic, see bug 326693 for some of the arguments, and b) some of the
+# functions are just not provided.
+
+g_get_running_KV() {
+	uname -r
+	return $?
+}
+
+g_KV_major() {
+	[[ -z $1 ]] && return 1
+	local KV=$@
+	echo "${KV%%.*}"
+}
+
+g_KV_minor() {
+	[[ -z $1 ]] && return 1
+	local KV=$@
+	KV=${KV#*.}
+	echo "${KV%%.*}"
+}
+
+g_KV_micro() {
+	[[ -z $1 ]] && return 1
+	local KV=$@
+	KV=${KV#*.*.}
+	echo "${KV%%[^[:digit:]]*}"
+}
+
+g_KV_to_int() {
+	[[ -z $1 ]] && return 1
+	local KV_MAJOR=$(g_KV_major "$1")
+	local KV_MINOR=$(g_KV_minor "$1")
+	local KV_MICRO=$(g_KV_micro "$1")
+	local KV_int=$(( KV_MAJOR * 65536 + KV_MINOR * 256 + KV_MICRO ))
+
+	# We make version 2.2.0 the minimum version we will handle as
+	# a sanity check ... if its less, we fail ...
+	if [[ ${KV_int} -ge 131584 ]] ; then
+		echo "${KV_int}"
+		return 0
+	fi
+	return 1
+}
+
+g_int_to_KV() {
+	local version=$1 major minor micro
+	major=$((version / 65536))
+	minor=$(((version % 65536) / 256))
+	micro=$((version % 256))
+	echo ${major}.${minor}.${micro}
+}
+
+eend_KV() {
+	[[ $(g_KV_to_int $1) -ge $(g_KV_to_int $2) ]]
+	eend $?
+}
+
+get_kheader_version() {
+	printf '#include <linux/version.h>\nLINUX_VERSION_CODE\n' | \
+	$(tc-getCPP ${CTARGET}) -I "$(build_eprefix)$(alt_build_headers)" - | \
+	tail -n 1
+}
+
+# We collect all sanity checks here. Consistency is not guranteed between
+# pkg_ and src_ phases, so we call this function both in pkg_pretend and in
+# src_unpack.
+sanity_prechecks() {
+	# Prevent native builds from downgrading
+	if [[ ${MERGE_TYPE} != "buildonly" ]] && \
+	   [[ -z ${ROOT} ]] && \
+	   [[ ${CBUILD} == ${CHOST} ]] && \
+	   [[ ${CHOST} == ${CTARGET} ]] ; then
+
+		# The high rev # is to allow people to downgrade between -r#
+		# versions. We want to block 2.20->2.19, but 2.20-r3->2.20-r2
+		# should be fine. Hopefully we never actually use a r# this
+		# high.
+		if has_version ">${CATEGORY}/${P}-r10000" ; then
+			eerror "Sanity check to keep you from breaking your system:"
+			eerror " Downgrading glibc is not supported and a sure way to destruction."
+			[[ ${I_ALLOW_TO_BREAK_MY_SYSTEM} = yes ]] || die "Aborting to save your system."
+		fi
+
+		if ! do_run_test '#include <unistd.h>\n#include <sys/syscall.h>\nint main(){return syscall(1000)!=-1;}\n' ; then
+			eerror "Your old kernel is broken. You need to update it to a newer"
+			eerror "version as syscall(<bignum>) will break. See bug 279260."
+			die "Old and broken kernel."
+		fi
+	fi
+
+	# Users have had a chance to phase themselves, time to give em the boot
+	if [[ -e ${EROOT}/etc/locale.gen ]] && [[ -e ${EROOT}/etc/locales.build ]] ; then
+		eerror "You still haven't deleted ${EROOT}/etc/locales.build."
+		eerror "Do so now after making sure ${EROOT}/etc/locale.gen is kosher."
+		die "Lazy upgrader detected"
+	fi
+
+	if [[ ${CTARGET} == i386-* ]] ; then
+		eerror "i386 CHOSTs are no longer supported."
+		eerror "Chances are you don't actually want/need i386."
+		eerror "Please read https://www.gentoo.org/doc/en/change-chost.xml"
+		die "Please fix your CHOST"
+	fi
+
+	if [[ -e /proc/xen ]] && [[ $(tc-arch) == "x86" ]] && ! is-flag -mno-tls-direct-seg-refs ; then
+		ewarn "You are using Xen but don't have -mno-tls-direct-seg-refs in your CFLAGS."
+		ewarn "This will result in a 50% performance penalty when running with a 32bit"
+		ewarn "hypervisor, which is probably not what you want."
+	fi
+
+	# ABI-specific checks follow here. Hey, we have a lot more specific conditions that
+	# we test for...
+	if ! is_crosscompile ; then
+		if use amd64 && use multilib && [[ ${MERGE_TYPE} != "binary" ]] ; then
+			ebegin "Checking that IA32 emulation is enabled in the running kernel"
+			echo 'int main(){return 0;}' > "${T}/check-ia32-emulation.c"
+			local STAT
+			if ${CC-${CHOST}-gcc} ${CFLAGS_x86} "${T}/check-ia32-emulation.c" -o "${T}/check-ia32-emulation.elf32"; then
+				"${T}/check-ia32-emulation.elf32"
+				STAT=$?
+			else
+				# Don't fail here to allow single->multi ABI switch
+				# or recover from breakage like bug #646424
+				ewarn "Failed to compile the ABI test. Broken host glibc?"
+				STAT=0
+			fi
+			rm -f "${T}/check-ia32-emulation.elf32"
+			eend $STAT
+			[[ $STAT -eq 0 ]] || die "CONFIG_IA32_EMULATION must be enabled in the kernel to compile a multilib glibc."
+		fi
+
+	fi
+
+	# When we actually have to compile something...
+	if ! just_headers && [[ ${MERGE_TYPE} != "binary" ]] ; then
+		if [[ -d "${ESYSROOT}"/usr/lib/include ]] ; then
+			# bug #833620, bug #643302
+			eerror "Found ${ESYSROOT}/usr/lib/include directory!"
+			eerror "This is known to break glibc's build."
+			eerror "Please backup its contents then remove the directory."
+			die "Found directory (${ESYSROOT}/usr/lib/include) which will break build (bug #833620)!"
+		fi
+
+		if [[ ${CTARGET} == *-linux* ]] ; then
+			local run_kv build_kv want_kv
+
+			run_kv=$(g_get_running_KV)
+			build_kv=$(g_int_to_KV $(get_kheader_version))
+			want_kv=${MIN_KERN_VER}
+
+			if ! is_crosscompile && ! tc-is-cross-compiler ; then
+				# Building fails on an non-supporting kernel
+				ebegin "Checking running kernel version (${run_kv} >= ${want_kv})"
+				if ! eend_KV ${run_kv} ${want_kv} ; then
+					echo
+					eerror "You need a kernel of at least ${want_kv}!"
+					die "Kernel version too low!"
+				fi
+			fi
+
+			# Do not run this check for pkg_pretend, just pkg_setup and friends (if we ever get used there).
+			# It's plausible (seen it in the wild) that Portage will (correctly) schedule a linux-headers
+			# upgrade before glibc, but because pkg_pretend gets run before any packages are merged at all (not
+			# just glibc), the whole emerge gets aborted without a good reason. We probably don't
+			# need to run this check at all given we have a dependency on the right headers,
+			# but let's leave it as-is for now.
+			if [[ ${EBUILD_PHASE_FUNC} != pkg_pretend ]] ; then
+				ebegin "Checking linux-headers version (${build_kv} >= ${want_kv})"
+				if ! eend_KV ${build_kv} ${want_kv} ; then
+					echo
+					eerror "You need linux-headers of at least ${want_kv}!"
+					die "linux-headers version too low!"
+				fi
+			fi
+		fi
+	fi
+}
+
+upgrade_warning() {
+	if [[ ${MERGE_TYPE} != buildonly && -n ${REPLACING_VERSIONS} && -z ${ROOT} ]]; then
+		local oldv newv=$(ver_cut 1-2 ${PV})
+		for oldv in ${REPLACING_VERSIONS}; do
+			if ver_test ${oldv} -lt ${newv}; then
+				ewarn "After upgrading glibc, please restart all running processes."
+				ewarn "Be sure to include init (telinit u) or systemd (systemctl daemon-reexec)."
+				ewarn "Alternatively, reboot your system."
+				ewarn "(See bug #660556, bug #741116, bug #823756, etc)"
+				break
+			fi
+		done
+	fi
+}
+
+#
+# the phases
+#
+
+# pkg_pretend
+
+pkg_pretend() {
+	upgrade_warning
+}
+
+pkg_setup() {
+	# see bug 682570
+	[[ -z ${BOOTSTRAP_RAP} ]] && python-any-r1_pkg_setup
+}
+
+# src_unpack
+
+src_unpack() {
+	setup_env
+
+	einfo "Checking general environment sanity."
+	sanity_prechecks
+
+	use multilib-bootstrap && unpack gcc-multilib-bootstrap-${GCC_BOOTSTRAP_VER}.tar.xz
+
+	if [[ ${PV} == 9999* ]] ; then
+		EGIT_REPO_URI="https://anongit.gentoo.org/git/proj/toolchain/glibc-patches.git"
+		EGIT_CHECKOUT_DIR=${WORKDIR}/patches-git
+		git-r3_src_unpack
+		mv patches-git/9999 patches || die
+
+		EGIT_REPO_URI="https://sourceware.org/git/glibc.git"
+		EGIT_CHECKOUT_DIR=${S}
+		git-r3_src_unpack
+	else
+		unpack ${P}.tar.xz
+
+		cd "${WORKDIR}" || die
+		unpack glibc-${RELEASE_VER}-patches-${PATCH_VER}.tar.xz
+	fi
+
+	cd "${WORKDIR}" || die
+	unpack locale-gen-${LOCALE_GEN_VER}.tar.gz
+	use systemd && unpack glibc-systemd-${GLIBC_SYSTEMD_VER}.tar.gz
+}
+
+src_prepare() {
+	local patchsetname
+	if ! use vanilla ; then
+		if [[ ${PV} == 9999* ]] ; then
+			patchsetname="from git master"
+		else
+			patchsetname="${RELEASE_VER}-${PATCH_VER}"
+		fi
+		einfo "Applying Gentoo Glibc Patchset ${patchsetname}"
+		eapply "${WORKDIR}"/patches
+		einfo "Done."
+	fi
+
+	default
+
+	gnuconfig_update
+
+	cd "${WORKDIR}"
+	find . -name configure -exec touch {} +
+
+	# move the external locale-gen to its old place
+	mkdir extra || die
+	mv locale-gen-${LOCALE_GEN_VER} extra/locale || die
+
+	eprefixify extra/locale/locale-gen
+
+	# Fix permissions on some of the scripts.
+	chmod u+x "${S}"/scripts/*.sh
+
+	cd "${S}"
+}
+
+glibc_do_configure() {
+	dump_build_environment
+
+	local myconf=()
+
+	# Use '=strong' instead of '=all' to protect only functions
+	# worth protecting from stack smashes.
+	myconf+=( --enable-stack-protector=$(usex ssp strong no) )
+
+	# Keep a whitelist of targets supporing IFUNC. glibc's ./configure
+	# is not robust enough to detect proper support:
+	#    https://bugs.gentoo.org/641216
+	#    https://sourceware.org/PR22634#c0
+	case $(tc-arch ${CTARGET}) in
+		# Keep whitelist of targets where autodetection mostly works.
+		amd64|x86|sparc|ppc|ppc64|arm|arm64|s390) ;;
+		# Blacklist everywhere else
+		*) myconf+=( libc_cv_ld_gnu_indirect_function=no ) ;;
+	esac
+
+	# Enable Intel Control-flow Enforcement Technology on amd64 if requested
+	case ${CTARGET} in
+		x86_64-*) myconf+=( $(use_enable cet) ) ;;
+		*) ;;
+	esac
+
+	[[ $(tc-is-softfloat) == "yes" ]] && myconf+=( --without-fp )
+
+	myconf+=( --enable-kernel=${MIN_KERN_VER} )
+
+	# Since SELinux support is only required for nscd, only enable it if:
+	# 1. USE selinux
+	# 2. only for the primary ABI on multilib systems
+	# 3. Not a crosscompile
+	if ! is_crosscompile && use selinux ; then
+		if use multilib ; then
+			if is_final_abi ; then
+				myconf+=( --with-selinux )
+			else
+				myconf+=( --without-selinux )
+			fi
+		else
+			myconf+=( --with-selinux )
+		fi
+	else
+		myconf+=( --without-selinux )
+	fi
+
+	# Force a few tests where we always know the answer but
+	# configure is incapable of finding it.
+	if is_crosscompile ; then
+		export \
+			libc_cv_c_cleanup=yes \
+			libc_cv_forced_unwind=yes
+	fi
+
+	myconf+=(
+		--disable-werror
+		--enable-bind-now
+		--build=${CBUILD_OPT:-${CBUILD}}
+		--host=${CTARGET_OPT:-${CTARGET}}
+		$(use_enable profile)
+		$(use_with gd)
+		--with-headers=$(build_eprefix)$(alt_build_headers)
+		--prefix="$(host_eprefix)/usr"
+		--sysconfdir="$(host_eprefix)/etc"
+		--localstatedir="$(host_eprefix)/var"
+		--libdir='$(prefix)'/$(get_libdir)
+		--mandir='$(prefix)'/share/man
+		--infodir='$(prefix)'/share/info
+		--libexecdir='$(libdir)'/misc/glibc
+		--with-bugurl=https://bugs.gentoo.org/
+		--with-pkgversion="$(glibc_banner)"
+		$(use_enable crypt)
+		$(use_multiarch || echo --disable-multi-arch)
+		$(use_enable systemtap)
+		$(use_enable nscd)
+
+		# /usr/bin/mtrace has a Perl shebang. Gentoo Prefix QA checks fail if
+		# Perl hasn't been installed inside the prefix yet and configure picks
+		# up a Perl from outside the prefix instead. configure will fail to
+		# execute Perl during configure if we're cross-compiling a prefix, but
+		# it will just disable mtrace in that case.
+		ac_cv_path_PERL="$(usex perl "${EPREFIX}"/usr/bin/perl no)"
+
+		# locale data is arch-independent
+		# https://bugs.gentoo.org/753740
+		libc_cv_complocaledir='${exec_prefix}/lib/locale'
+
+		# -march= option tricks build system to infer too
+		# high ISA level: https://sourceware.org/PR27318
+		libc_cv_include_x86_isa_level=no
+		# Explicit override of https://sourceware.org/PR27991
+		# exposes a bug in glibc's configure:
+		# https://sourceware.org/PR27991
+		libc_cv_have_x86_lahf_sahf=no
+		libc_cv_have_x86_movbe=no
+
+		${EXTRA_ECONF}
+	)
+
+	# We rely on sys-libs/timezone-data for timezone tools normally.
+	myconf+=( $(use_enable vanilla timezone-tools) )
+
+	# These libs don't have configure flags.
+	ac_cv_lib_audit_audit_log_user_avc_message=$(usex audit || echo no)
+	ac_cv_lib_cap_cap_init=$(usex caps || echo no)
+
+	# There is no configure option for this and we need to export it
+	# since the glibc build will re-run configure on itself
+	export libc_cv_rootsbindir="$(host_eprefix)/sbin"
+	export libc_cv_slibdir="$(host_eprefix)/$(get_libdir)"
+
+	local builddir=$(builddir nptl)
+	mkdir -p "${builddir}"
+	cd "${builddir}"
+	set -- "${S}"/configure "${myconf[@]}"
+	echo "$@"
+	"$@" || die "failed to configure glibc"
+
+	# ia64 static cross-compilers are a pita in so much that they
+	# can't produce static ELFs (as the libgcc.a is broken).  so
+	# disable building of the programs for those targets if it
+	# doesn't work.
+	# XXX: We could turn this into a compiler test, but ia64 is
+	# the only one that matters, so this should be fine for now.
+	if is_crosscompile && [[ ${CTARGET} == ia64* ]] ; then
+		sed -i '1i+link-static = touch $@' config.make
+	fi
+
+	# If we're trying to migrate between ABI sets, we need
+	# to lie and use a local copy of gcc.  Like if the system
+	# is built with MULTILIB_ABIS="amd64 x86" but we want to
+	# add x32 to it, gcc/glibc don't yet support x32.
+	#
+	if [[ -n ${GCC_BOOTSTRAP_VER} ]] && use multilib-bootstrap ; then
+		echo 'main(){}' > "${T}"/test.c
+		if ! $(tc-getCC ${CTARGET}) ${CFLAGS} ${LDFLAGS} "${T}"/test.c -Wl,-emain -lgcc 2>/dev/null ; then
+			sed -i -e '/^CC = /s:$: -B$(objdir)/../'"gcc-multilib-bootstrap-${GCC_BOOTSTRAP_VER}/${ABI}:" config.make || die
+		fi
+	fi
+}
+
+glibc_headers_configure() {
+	export ABI=default
+
+	local builddir=$(builddir "headers")
+	mkdir -p "${builddir}"
+	cd "${builddir}"
+
+	# if we don't have a compiler yet, we can't really test it now ...
+	# hopefully they don't affect header generation, so let's hope for
+	# the best here ...
+	local v vars=(
+		ac_cv_header_cpuid_h=yes
+		libc_cv_{386,390,alpha,arm,hppa,ia64,mips,{powerpc,sparc}{,32,64},sh,x86_64}_tls=yes
+		libc_cv_asm_cfi_directives=yes
+		libc_cv_broken_visibility_attribute=no
+		libc_cv_c_cleanup=yes
+		libc_cv_compiler_powerpc64le_binary128_ok=yes
+		libc_cv_forced_unwind=yes
+		libc_cv_gcc___thread=yes
+		libc_cv_mlong_double_128=yes
+		libc_cv_mlong_double_128ibm=yes
+		libc_cv_ppc_machine=yes
+		libc_cv_ppc_rel16=yes
+		libc_cv_predef_fortify_source=no
+		libc_cv_target_power8_ok=yes
+		libc_cv_visibility_attribute=yes
+		libc_cv_z_combreloc=yes
+		libc_cv_z_execstack=yes
+		libc_cv_z_initfirst=yes
+		libc_cv_z_nodelete=yes
+		libc_cv_z_nodlopen=yes
+		libc_cv_z_relro=yes
+		libc_mips_abi=${ABI}
+		libc_mips_float=$([[ $(tc-is-softfloat) == "yes" ]] && echo soft || echo hard)
+		# These libs don't have configure flags.
+		ac_cv_lib_audit_audit_log_user_avc_message=no
+		ac_cv_lib_cap_cap_init=no
+	)
+
+	einfo "Forcing cached settings:"
+	for v in "${vars[@]}" ; do
+		einfo " ${v}"
+		export ${v}
+	done
+
+	local headers_only_arch_CPPFLAGS=()
+
+	# Blow away some random CC settings that screw things up. #550192
+	if [[ -d ${S}/sysdeps/mips ]]; then
+		pushd "${S}"/sysdeps/mips >/dev/null
+		sed -i -e '/^CC +=/s:=.*:= -D_MIPS_SZPTR=32:' mips32/Makefile mips64/n32/Makefile || die
+		sed -i -e '/^CC +=/s:=.*:= -D_MIPS_SZPTR=64:' mips64/n64/Makefile || die
+
+		# Force the mips ABI to the default.  This is OK because the set of
+		# installed headers in this phase is the same between the 3 ABIs.
+		# If this ever changes, this hack will break, but that's unlikely
+		# as glibc discourages that behavior.
+		# https://crbug.com/647033
+		sed -i -e 's:abiflag=.*:abiflag=_ABIO32:' preconfigure || die
+
+		popd >/dev/null
+	fi
+
+	case ${CTARGET} in
+	riscv*)
+		# RISC-V interrogates the compiler to determine which target to
+		# build.  If building the headers then we don't strictly need a
+		# RISC-V compiler, so the built-in definitions that are provided
+		# along with all RISC-V compiler might not exist.  This causes
+		# glibc's RISC-V preconfigure script to blow up.  Since we're just
+		# building the headers any value will actually work here, so just
+		# pick the standard one (rv64g/lp64d) to make the build scripts
+		# happy for now -- the headers are all the same anyway so it
+		# doesn't matter.
+		headers_only_arch_CPPFLAGS+=(
+			-D__riscv_xlen=64
+			-D__riscv_flen=64
+			-D__riscv_float_abi_double=1
+			-D__riscv_atomic=1
+		) ;;
+	esac
+
+	local myconf=()
+	myconf+=(
+		--disable-sanity-checks
+		--enable-hacker-mode
+		--disable-werror
+		--enable-bind-now
+		--build=${CBUILD_OPT:-${CBUILD}}
+		--host=${CTARGET_OPT:-${CTARGET}}
+		--with-headers=$(build_eprefix)$(alt_build_headers)
+		--prefix="$(host_eprefix)/usr"
+		$(use_enable crypt)
+		${EXTRA_ECONF}
+	)
+
+	# Nothing is compiled here which would affect the headers for the target.
+	# So forcing CC/CFLAGS is sane.
+	local headers_only_CC=$(tc-getBUILD_CC)
+	local headers_only_CFLAGS="-O1 -pipe"
+	local headers_only_CPPFLAGS="-U_FORTIFY_SOURCE ${headers_only_arch_CPPFLAGS[*]}"
+	local headers_only_LDFLAGS=""
+	set -- "${S}"/configure "${myconf[@]}"
+	echo \
+		"CC=${headers_only_CC}" \
+		"CFLAGS=${headers_only_CFLAGS}" \
+		"CPPFLAGS=${headers_only_CPPFLAGS}" \
+		"LDFLAGS=${headers_only_LDFLAGS}" \
+		"$@"
+	CC=${headers_only_CC} \
+	CFLAGS=${headers_only_CFLAGS} \
+	CPPFLAGS=${headers_only_CPPFLAGS} \
+	LDFLAGS="" \
+	"$@" || die "failed to configure glibc"
+}
+
+do_src_configure() {
+	if just_headers ; then
+		glibc_headers_configure
+	else
+		glibc_do_configure nptl
+	fi
+}
+
+src_configure() {
+	foreach_abi do_src_configure
+}
+
+do_src_compile() {
+	emake -C "$(builddir nptl)"
+}
+
+src_compile() {
+	if just_headers ; then
+		return
+	fi
+
+	foreach_abi do_src_compile
+}
+
+glibc_src_test() {
+	cd "$(builddir nptl)"
+
+	local myxfailparams=""
+	if [[ "${GENTOO_GLIBC_XFAIL_TESTS}" == "yes" ]] ; then
+		for myt in ${XFAIL_TEST_LIST[@]} ; do
+			myxfailparams+="test-xfail-${myt}=yes "
+		done
+	fi
+
+	# sandbox does not understand unshare() and prevents
+	# writes to /proc/, which makes many tests fail
+
+	# we give the tests a bit more time to avoid spurious
+	# bug reports on slow arches
+
+	SANDBOX_ON=0 LD_PRELOAD= TIMEOUTFACTOR=16 emake ${myxfailparams} check
+}
+
+do_src_test() {
+	local ret=0
+
+	glibc_src_test
+	: $(( ret |= $? ))
+
+	return ${ret}
+}
+
+src_test() {
+	if just_headers ; then
+		return
+	fi
+
+	# Give tests more time to complete.
+	export TIMEOUTFACTOR=5
+
+	foreach_abi do_src_test || die "tests failed"
+}
+
+run_locale_gen() {
+	# if the host locales.gen contains no entries, we'll install everything
+	local root="$1"
+	local inplace=""
+
+	if [[ "${root}" == "--inplace-glibc" ]] ; then
+		inplace="--inplace-glibc"
+		root="$2"
+	fi
+
+	local locale_list="${root%/}/etc/locale.gen"
+
+	pushd "${ED}"/$(get_libdir) >/dev/null
+
+	if [[ -z $(locale-gen --list --config "${locale_list}") ]] ; then
+		[[ -z ${inplace} ]] && ewarn "Generating all locales; edit /etc/locale.gen to save time/space"
+		locale_list="${root%/}/usr/share/i18n/SUPPORTED"
+	fi
+
+	set -- locale-gen ${inplace} --jobs $(makeopts_jobs) --config "${locale_list}" \
+		--destdir "${root}"
+	echo "$@"
+	"$@"
+
+	popd >/dev/null
+}
+
+glibc_do_src_install() {
+	local builddir=$(builddir nptl)
+	cd "${builddir}"
+
+	emake install_root="${D}/$(build_eprefix)$(alt_prefix)" install
+
+	# This version (2.26) provides some compatibility libraries for the NIS/NIS+ support
+	# which come without headers etc. Only needed for binary packages since the
+	# external net-libs/libnsl has increased soversion. Keep only versioned libraries.
+	find "${D}" -name "libnsl.a" -delete
+	find "${D}" -name "libnsl.so" -delete
+
+	# Normally upstream_pv is ${PV}. Live ebuilds are exception, there we need
+	# to infer upstream version:
+	# '#define VERSION "2.26.90"' -> '2.26.90'
+	local upstream_pv=$(sed -n -r 's/#define VERSION "(.*)"/\1/p' "${S}"/version.h)
+
+	# Avoid stripping binaries not targeted by ${CHOST}. Or else
+	# ${CHOST}-strip would break binaries build for ${CTARGET}.
+	is_crosscompile && dostrip -x /
+	# gdb thread introspection relies on local libpthreas symbols. stripping breaks it
+	# See Note [Disable automatic stripping]
+	dostrip -x $(alt_libdir)/libpthread-${upstream_pv}.so
+
+	if [[ -e ${ED}/$(alt_usrlibdir)/libm-${upstream_pv}.a ]] ; then
+		# Move versioned .a file out of libdir to evade portage QA checks
+		# instead of using gen_usr_ldscript(). We fix ldscript as:
+		# "GROUP ( /usr/lib64/libm-<pv>.a ..." -> "GROUP ( /usr/lib64/glibc-<pv>/libm-<pv>.a ..."
+		sed -i "s@\(libm-${upstream_pv}.a\)@${P}/\1@" "${ED}"/$(alt_usrlibdir)/libm.a || die
+		dodir $(alt_usrlibdir)/${P}
+		mv "${ED}"/$(alt_usrlibdir)/libm-${upstream_pv}.a "${ED}"/$(alt_usrlibdir)/${P}/libm-${upstream_pv}.a || die
+	fi
+
+	# We'll take care of the cache ourselves
+	rm -f "${ED}"/etc/ld.so.cache
+
+	# Everything past this point just needs to be done once ...
+	is_final_abi || return 0
+
+	# Make sure the non-native interp can be found on multilib systems even
+	# if the main library set isn't installed into the right place.  Maybe
+	# we should query the active gcc for info instead of hardcoding it ?
+	local i ldso_abi ldso_name
+	local ldso_abi_list=(
+		# x86
+		amd64   /lib64/ld-linux-x86-64.so.2
+		x32     /libx32/ld-linux-x32.so.2
+		x86     /lib/ld-linux.so.2
+		# mips
+		o32     /lib/ld.so.1
+		n32     /lib32/ld.so.1
+		n64     /lib64/ld.so.1
+		# powerpc
+		ppc     /lib/ld.so.1
+		# riscv
+		ilp32d  /lib/ld-linux-riscv32-ilp32d.so.1
+		ilp32   /lib/ld-linux-riscv32-ilp32.so.1
+		lp64d   /lib/ld-linux-riscv64-lp64d.so.1
+		lp64    /lib/ld-linux-riscv64-lp64.so.1
+		# s390
+		s390    /lib/ld.so.1
+		s390x   /lib/ld64.so.1
+		# sparc
+		sparc32 /lib/ld-linux.so.2
+		sparc64 /lib64/ld-linux.so.2
+	)
+	case $(tc-endian) in
+	little)
+		ldso_abi_list+=(
+			# arm
+			arm64   /lib/ld-linux-aarch64.so.1
+			# ELFv2 (glibc does not support ELFv1 on LE)
+			ppc64   /lib64/ld64.so.2
+		)
+		;;
+	big)
+		ldso_abi_list+=(
+			# arm
+			arm64   /lib/ld-linux-aarch64_be.so.1
+			# ELFv1 (glibc does not support ELFv2 on BE)
+			ppc64   /lib64/ld64.so.1
+		)
+		;;
+	esac
+	if [[ ${SYMLINK_LIB} == "yes" ]] && [[ ! -e ${ED}/$(alt_prefix)/lib ]] ; then
+		dosym $(get_abi_LIBDIR ${DEFAULT_ABI}) $(alt_prefix)/lib
+	fi
+	for (( i = 0; i < ${#ldso_abi_list[@]}; i += 2 )) ; do
+		ldso_abi=${ldso_abi_list[i]}
+		has ${ldso_abi} $(get_install_abis) || continue
+
+		ldso_name="$(alt_prefix)${ldso_abi_list[i+1]}"
+		if [[ ! -L ${ED}/${ldso_name} && ! -e ${ED}/${ldso_name} ]] ; then
+			dosym ../$(get_abi_LIBDIR ${ldso_abi})/${ldso_name##*/} ${ldso_name}
+		fi
+	done
+
+	# In the LSB 5.0 definition, someone had the excellent idea to "standardize"
+	# the runtime loader name, see also https://xkcd.com/927/
+	# Normally, in Gentoo one should never come across executables that require this.
+	# However, binary commercial packages are known to adhere to weird practices.
+	# https://refspecs.linuxfoundation.org/LSB_5.0.0/LSB-Core-AMD64/LSB-Core-AMD64.html#BASELIB
+	local lsb_ldso_name native_ldso_name lsb_ldso_abi
+	local lsb_ldso_abi_list=(
+		# x86
+		amd64	ld-linux-x86-64.so.2	ld-lsb-x86-64.so.3
+	)
+	for (( i = 0; i < ${#lsb_ldso_abi_list[@]}; i += 3 )) ; do
+		lsb_ldso_abi=${lsb_ldso_abi_list[i]}
+		native_ldso_name=${lsb_ldso_abi_list[i+1]}
+		lsb_ldso_name=${lsb_ldso_abi_list[i+2]}
+		has ${lsb_ldso_abi} $(get_install_abis) || continue
+
+		if [[ ! -L ${ED}/$(get_abi_LIBDIR ${lsb_ldso_abi})/${lsb_ldso_name} && ! -e ${ED}/$(get_abi_LIBDIR ${lsb_ldso_abi})/${lsb_ldso_name} ]] ; then
+			dosym ${native_ldso_name} "$(alt_prefix)/$(get_abi_LIBDIR ${lsb_ldso_abi})/${lsb_ldso_name}"
+		fi
+	done
+
+	# With devpts under Linux mounted properly, we do not need the pt_chown
+	# binary to be setuid.  This is because the default owners/perms will be
+	# exactly what we want.
+	if ! use suid ; then
+		find "${ED}" -name pt_chown -exec chmod -s {} +
+	fi
+
+	#################################################################
+	# EVERYTHING AFTER THIS POINT IS FOR NATIVE GLIBC INSTALLS ONLY #
+	# Make sure we install some symlink hacks so that when we build
+	# a 2nd stage cross-compiler, gcc finds the target system
+	# headers correctly.  See gcc/doc/gccinstall.info
+	if is_crosscompile ; then
+		# We need to make sure that /lib and /usr/lib always exists.
+		# gcc likes to use relative paths to get to its multilibs like
+		# /usr/lib/../lib64/.  So while we don't install any files into
+		# /usr/lib/, we do need it to exist.
+		keepdir $(alt_prefix)/lib
+		keepdir $(alt_prefix)/usr/lib
+
+		dosym usr/include $(alt_prefix)/sys-include
+		return 0
+	fi
+
+	# Files for Debian-style locale updating
+	dodir /usr/share/i18n
+	sed \
+		-e "/^#/d" \
+		-e "/SUPPORTED-LOCALES=/d" \
+		-e "s: \\\\::g" -e "s:/: :g" \
+		"${S}"/localedata/SUPPORTED > "${ED}"/usr/share/i18n/SUPPORTED \
+		|| die "generating /usr/share/i18n/SUPPORTED failed"
+	cd "${WORKDIR}"/extra/locale
+	dosbin locale-gen
+	doman *.[0-8]
+	insinto /etc
+	doins locale.gen
+
+	keepdir /usr/lib/locale
+
+	cd "${S}"
+
+	# Install misc network config files
+	insinto /etc
+	doins posix/gai.conf
+
+	if use systemd ; then
+		doins "${WORKDIR}/glibc-systemd-${GLIBC_SYSTEMD_VER}/gentoo-config/nsswitch.conf"
+	else
+		doins nss/nsswitch.conf
+	fi
+
+	# Gentoo-specific
+	newins "${FILESDIR}"/host.conf-1 host.conf
+
+	if use nscd ; then
+		doins nscd/nscd.conf
+
+		newinitd "$(prefixify_ro "${FILESDIR}"/nscd-1)" nscd
+
+		local nscd_args=(
+			-e "s:@PIDFILE@:$(strings "${ED}"/usr/sbin/nscd | grep nscd.pid):"
+		)
+
+		sed -i "${nscd_args[@]}" "${ED}"/etc/init.d/nscd
+
+		use systemd && systemd_dounit nscd/nscd.service
+		newtmpfiles nscd/nscd.tmpfiles nscd.conf
+	fi
+
+	echo 'LDPATH="include ld.so.conf.d/*.conf"' > "${T}"/00glibc
+	doenvd "${T}"/00glibc
+
+	for d in BUGS ChangeLog CONFORMANCE FAQ NEWS NOTES PROJECTS README* ; do
+		[[ -s ${d} ]] && dodoc ${d}
+	done
+	dodoc -r ChangeLog.old
+
+	# Prevent overwriting of the /etc/localtime symlink.  We'll handle the
+	# creation of the "factory" symlink in pkg_postinst().
+	rm -f "${ED}"/etc/localtime
+
+	# Generate all locales if this is a native build as locale generation
+	if use compile-locales && ! is_crosscompile ; then
+		run_locale_gen --inplace-glibc "${ED}/"
+		sed -e 's:COMPILED_LOCALES="":COMPILED_LOCALES="1":' -i "${ED}"/usr/sbin/locale-gen || die
+	fi
+}
+
+glibc_headers_install() {
+	local builddir=$(builddir "headers")
+	cd "${builddir}"
+	emake install_root="${D}/$(build_eprefix)$(alt_prefix)" install-headers
+
+	insinto $(alt_headers)/gnu
+	doins "${S}"/include/gnu/stubs.h
+
+	# Make sure we install the sys-include symlink so that when
+	# we build a 2nd stage cross-compiler, gcc finds the target
+	# system headers correctly.  See gcc/doc/gccinstall.info
+	dosym usr/include $(alt_prefix)/sys-include
+}
+
+src_install() {
+	if just_headers ; then
+		export ABI=default
+		glibc_headers_install
+		return
+	fi
+
+	foreach_abi glibc_do_src_install
+
+	if ! use static-libs ; then
+		einfo "Not installing static glibc libraries"
+		find "${ED}" -name "*.a" -and -not -name "*_nonshared.a" -delete
+	fi
+}
+
+# Simple test to make sure our new glibc isn't completely broken.
+# Make sure we don't test with statically built binaries since
+# they will fail.  Also, skip if this glibc is a cross compiler.
+#
+# If coreutils is built with USE=multicall, some of these files
+# will just be wrapper scripts, not actual ELFs we can test.
+glibc_sanity_check() {
+	cd / #228809
+
+	# We enter ${ED} so to avoid trouble if the path contains
+	# special characters; for instance if the path contains the
+	# colon character (:), then the linker will try to split it
+	# and look for the libraries in an unexpected place. This can
+	# lead to unsafe code execution if the generated prefix is
+	# within a world-writable directory.
+	# (e.g. /var/tmp/portage:${HOSTNAME})
+	pushd "${ED}"/$(get_libdir) >/dev/null
+
+	# first let's find the actual dynamic linker here
+	# symlinks may point to the wrong abi
+	local newldso=$(find . -maxdepth 1 -name 'ld*so.?' -type f -print -quit)
+
+	einfo Last-minute run tests with ${newldso} in /$(get_libdir) ...
+
+	local x striptest
+	for x in cal date env free ls true uname uptime ; do
+		x=$(type -p ${x})
+		[[ -z ${x} || ${x} != ${EPREFIX}/* ]] && continue
+		striptest=$(LC_ALL="C" file -L ${x} 2>/dev/null) || continue
+		case ${striptest} in
+		*"statically linked"*) continue;;
+		*"ASCII text"*) continue;;
+		esac
+		# We need to clear the locale settings as the upgrade might want
+		# incompatible locale data.  This test is not for verifying that.
+		LC_ALL=C \
+		${newldso} --library-path . ${x} > /dev/null \
+			|| die "simple run test (${x}) failed"
+	done
+
+	popd >/dev/null
+}
+
+pkg_preinst() {
+	# nothing to do if just installing headers
+	just_headers && return
+
+	# prepare /etc/ld.so.conf.d/ for files
+	mkdir -p "${EROOT}"/etc/ld.so.conf.d
+
+	# Default /etc/hosts.conf:multi to on for systems with small dbs.
+	if [[ $(wc -l < "${EROOT}"/etc/hosts) -lt 1000 ]] ; then
+		sed -i '/^multi off/s:off:on:' "${ED}"/etc/host.conf
+		einfo "Defaulting /etc/host.conf:multi to on"
+	fi
+
+	[[ -n ${ROOT} ]] && return 0
+	[[ -d ${ED}/$(get_libdir) ]] || return 0
+	[[ -z ${BOOTSTRAP_RAP} ]] && glibc_sanity_check
+
+	if [[ -L ${EROOT}/usr/lib/locale ]]; then
+		# Help portage migrate this to a directory
+		# https://bugs.gentoo.org/753740
+		rm "${EROOT}"/usr/lib/locale || die
+	fi
+
+	# Keep around libcrypt so that Perl doesn't break when merging libxcrypt
+	# (libxcrypt is the new provider for now of libcrypt.so.{1,2}).
+	# bug #802207
+	if ! use crypt && has_version "${CATEGORY}/${PN}[crypt]" && ! has preserve-libs ${FEATURES}; then
+		PRESERVED_OLD_LIBCRYPT=1
+		cp -p "${EROOT}/$(get_libdir)/libcrypt$(get_libname 1)" "${T}/libcrypt$(get_libname 1)" || die
+	else
+		PRESERVED_OLD_LIBCRYPT=0
+	fi
+}
+
+pkg_postinst() {
+	# nothing to do if just installing headers
+	just_headers && return
+
+	if ! tc-is-cross-compiler && [[ -x ${EROOT}/usr/sbin/iconvconfig ]] ; then
+		# Generate fastloading iconv module configuration file.
+		"${EROOT}"/usr/sbin/iconvconfig --prefix="${ROOT}/"
+	fi
+
+	if ! is_crosscompile && [[ -z ${ROOT} ]] ; then
+		use compile-locales || run_locale_gen "${EROOT}/"
+	fi
+
+	upgrade_warning
+
+	# Check for sanity of /etc/nsswitch.conf, take 2
+	if [[ -e ${EROOT}/etc/nsswitch.conf ]] && ! has_version sys-auth/libnss-nis ; then
+		local entry
+		for entry in passwd group shadow; do
+			if grep -E -q "^[ \t]*${entry}:.*nis" "${EROOT}"/etc/nsswitch.conf; then
+				ewarn ""
+				ewarn "Your ${EROOT}/etc/nsswitch.conf uses NIS. Support for that has been"
+				ewarn "removed from glibc and is now provided by the package"
+				ewarn "  sys-auth/libnss-nis"
+				ewarn "Install it now to keep your NIS setup working."
+				ewarn ""
+			fi
+		done
+	fi
+
+	if [[ ${PRESERVED_OLD_LIBCRYPT} -eq 1 ]] ; then
+		cp -p "${T}/libcrypt$(get_libname 1)" "${EROOT}/$(get_libdir)/libcrypt$(get_libname 1)" || die
+		preserve_old_lib_notify /$(get_libdir)/libcrypt$(get_libname 1)
+
+		elog "Please ignore a possible later error message about a file collision involving"
+		elog "${EROOT}/$(get_libdir)/libcrypt$(get_libname 1). We need to preserve this file for the moment to keep"
+		elog "the upgrade working, but it also needs to be overwritten when"
+		elog "sys-libs/libxcrypt is installed. See bug 802210 for more details."
+	fi
+}