path: root/eclass/distutils-r1.eclass

# Copyright 1999-2023 Gentoo Authors
# Distributed under the terms of the GNU General Public License v2

# @ECLASS: distutils-r1.eclass
# @MAINTAINER:
# Python team <python@gentoo.org>
# @AUTHOR:
# Author: Michał Górny <mgorny@gentoo.org>
# Based on the work of: Krzysztof Pawlik <nelchael@gentoo.org>
# @SUPPORTED_EAPIS: 7 8
# @PROVIDES: python-r1 python-single-r1
# @BLURB: A simple eclass to build Python packages using distutils.
# @DESCRIPTION:
# A simple eclass providing functions to build Python packages using
# the distutils build system. It exports phase functions for all
# the src_* phases. Each of the phases runs two pseudo-phases:
# python_..._all() (e.g. python_prepare_all()) once in ${S}, then
# python_...() (e.g. python_prepare()) for each implementation
# (see: python_foreach_impl() in python-r1).
#
# In distutils-r1_src_prepare(), the 'all' function is run before
# per-implementation ones (because it creates the implementations),
# per-implementation functions are run in a random order.
#
# In remaining phase functions, the per-implementation functions are run
# before the 'all' one, and they are ordered from the least to the most
# preferred implementation (so that 'better' files overwrite 'worse'
# ones).
#
# If the ebuild doesn't specify a particular pseudo-phase function,
# the default one will be used (distutils-r1_...). Defaults are provided
# for all per-implementation pseudo-phases, python_prepare_all()
# and python_install_all(); whenever writing your own pseudo-phase
# functions, you should consider calling the defaults (and especially
# distutils-r1_python_prepare_all).
#
# Please note that distutils-r1 sets RDEPEND and BDEPEND (or DEPEND
# in earlier EAPIs) unconditionally for you.
#
# Also, please note that distutils-r1 will always inherit python-r1
# as well. Thus, all the variables defined and documented there are
# relevant to the packages using distutils-r1.
#
# For more information, please see the Python Guide:
# https://projects.gentoo.org/python/guide/

case ${EAPI} in
	7|8) ;;
	*) die "${ECLASS}: EAPI ${EAPI:-0} not supported" ;;
esac

# @ECLASS_VARIABLE: DISTUTILS_EXT
# @DEFAULT_UNSET
# @DESCRIPTION:
# Set this variable to a non-null value if the package (possibly
# optionally) builds Python extensions (loadable modules written in C,
# Cython, Rust, etc.).
#
# When enabled, the eclass:
#
# - adds PYTHON_DEPS to DEPEND (for cross-compilation support), unless
#   DISTUTILS_OPTIONAL is used
#
# - adds `debug` flag to IUSE that controls assertions (i.e. -DNDEBUG)
#
# - calls `build_ext` command if setuptools build backend is used
#   and there is potential benefit from parallel builds

# @ECLASS_VARIABLE: DISTUTILS_OPTIONAL
# @DEFAULT_UNSET
# @DESCRIPTION:
# If set to a non-null value, distutils part in the ebuild will
# be considered optional. No dependencies will be added and no phase
# functions will be exported.
#
# If you enable DISTUTILS_OPTIONAL, you have to set proper dependencies
# for your package (using ${PYTHON_DEPS}) and to either call
# distutils-r1 default phase functions or call the build system
# manually.

# @ECLASS_VARIABLE: DISTUTILS_SINGLE_IMPL
# @DEFAULT_UNSET
# @DESCRIPTION:
# If set to a non-null value, the ebuild will support setting a single
# Python implementation only. It will effectively replace the python-r1
# eclass inherit with python-single-r1.
#
# Note that inheriting python-single-r1 will cause pkg_setup()
# to be exported. It must be run in order for the eclass functions
# to function properly.

# @ECLASS_VARIABLE: DISTUTILS_USE_PEP517
# @PRE_INHERIT
# @DEFAULT_UNSET
# @DESCRIPTION:
# Enable the PEP 517 mode for the specified build system.  In this mode,
# the complete build and install is done in python_compile(),
# a venv-style install tree is provided to python_test(),
# and python_install() just merges the temporary install tree
# into the real fs.
#
# This mode is recommended for Python packages.  However, some packages
# using custom hacks on top of distutils/setuptools may not install
# correctly in this mode.  Please verify the list of installed files
# when using it.
#
# The variable specifies the build system used.  Currently,
# the following values are supported:
#
# - flit - flit-core backend
#
# - flit_scm - flit_scm backend
#
# - hatchling - hatchling backend (from hatch)
#
# - jupyter - jupyter_packaging backend
#
# - maturin - maturin backend
#
# - meson-python - meson-python (mesonpy) backend
#
# - no - no PEP517 build system (see below)
#
# - pbr - pbr backend
#
# - pdm - pdm.pep517 backend
#
# - pdm-backend - pdm.backend backend
#
# - poetry - poetry-core backend
#
# - scikit-build-core - scikit-build-core backend
#
# - setuptools - distutils or setuptools (incl. legacy mode)
#
# - sip - sipbuild backend
#
# - standalone - standalone build systems without external deps
#   (used for bootstrapping).
#
# The variable needs to be set before the inherit line.  The eclass
# adds appropriate build-time dependencies and verifies the value.
#
# The special value "no" indicates that the package has no build system.
# This is not equivalent to unset DISTUTILS_USE_PEP517 (legacy mode).
# It causes the eclass not to include any build system dependencies
# and to disable default python_compile() and python_install()
# implementations.  Baseline Python deps and phase functions will still
# be set (depending on the value of DISTUTILS_OPTIONAL).  Most of
# the other eclass functions will work.  Testing venv will be provided
# in ${BUILD_DIR}/install after python_compile(), and if any (other)
# files are found in ${BUILD_DIR}/install after python_install(), they
# will be merged into ${D}.

# @ECLASS_VARIABLE: DISTUTILS_USE_SETUPTOOLS
# @DEFAULT_UNSET
# @PRE_INHERIT
# @DESCRIPTION:
# Controls adding dev-python/setuptools dependency.  The allowed values
# are:
#
# - no -- do not add the dependency (pure distutils package)
#
# - bdepend -- add it to BDEPEND (the default)
#
# - rdepend -- add it to BDEPEND+RDEPEND (e.g. when using pkg_resources)
#
# - manual -- do not add the dependency and suppress the checks
#   (assumes you will take care of doing it correctly)
#
# This variable is effective only if DISTUTILS_OPTIONAL is disabled.
# It is available only in non-PEP517 mode.  It needs to be set before
# the inherit line.

# @ECLASS_VARIABLE: DISTUTILS_DEPS
# @OUTPUT_VARIABLE
# @DESCRIPTION:
# This is an eclass-generated build-time dependency string for the build
# system packages.  This string is automatically appended to BDEPEND
# unless DISTUTILS_OPTIONAL is used.  This variable is available only
# in PEP 517 mode.
#
# Example use:
# @CODE
# DISTUTILS_OPTIONAL=1
# # ...
# RDEPEND="${PYTHON_DEPS}"
# BDEPEND="
#     ${PYTHON_DEPS}
#     ${DISTUTILS_DEPS}"
# @CODE

if [[ -z ${_DISTUTILS_R1_ECLASS} ]]; then
_DISTUTILS_R1_ECLASS=1

inherit flag-o-matic
inherit multibuild multilib multiprocessing ninja-utils toolchain-funcs

if [[ ! ${DISTUTILS_SINGLE_IMPL} ]]; then
	inherit python-r1
else
	inherit python-single-r1
fi

_distutils_set_globals() {
	local rdep bdep
	if [[ ${DISTUTILS_USE_PEP517} ]]; then
		if [[ ${DISTUTILS_USE_SETUPTOOLS} ]]; then
			die "DISTUTILS_USE_SETUPTOOLS is not used in PEP517 mode"
		fi

		bdep='
			>=dev-python/gpep517-13[${PYTHON_USEDEP}]
		'
		case ${DISTUTILS_USE_PEP517} in
			flit)
				bdep+='
					>=dev-python/flit-core-3.9.0[${PYTHON_USEDEP}]
				'
				;;
			flit_scm)
				bdep+='
					>=dev-python/flit_scm-1.7.0[${PYTHON_USEDEP}]
				'
				;;
			hatchling)
				bdep+='
					>=dev-python/hatchling-1.17.0[${PYTHON_USEDEP}]
				'
				;;
			jupyter)
				bdep+='
					>=dev-python/jupyter-packaging-0.12.3[${PYTHON_USEDEP}]
				'
				;;
			maturin)
				bdep+='
					>=dev-util/maturin-1.0.1[${PYTHON_USEDEP}]
				'
				;;
			no)
				# undo the generic deps added above
				bdep=
				;;
			meson-python)
				bdep+='
					>=dev-python/meson-python-0.13.1[${PYTHON_USEDEP}]
				'
				;;
			pbr)
				bdep+='
					>=dev-python/pbr-5.11.1[${PYTHON_USEDEP}]
				'
				;;
			pdm)
				bdep+='
					>=dev-python/pdm-pep517-1.1.4[${PYTHON_USEDEP}]
				'
				;;
			pdm-backend)
				bdep+='
					>=dev-python/pdm-backend-2.1.0[${PYTHON_USEDEP}]
				'
				;;
			poetry)
				bdep+='
					>=dev-python/poetry-core-1.6.1[${PYTHON_USEDEP}]
				'
				;;
			scikit-build-core)
				bdep+='
					>=dev-python/scikit-build-core-0.4.6[${PYTHON_USEDEP}]
				'
				;;
			setuptools)
				bdep+='
					>=dev-python/setuptools-67.8.0-r1[${PYTHON_USEDEP}]
				'
				;;
			sip)
				bdep+='
					>=dev-python/sip-6.7.9[${PYTHON_USEDEP}]
				'
				;;
			standalone)
				;;
			*)
				die "Unknown DISTUTILS_USE_PEP517=${DISTUTILS_USE_PEP517}"
				;;
		esac
	elif [[ ${DISTUTILS_OPTIONAL} ]]; then
		if [[ ${DISTUTILS_USE_SETUPTOOLS} ]]; then
			eqawarn "QA Notice: DISTUTILS_USE_SETUPTOOLS is not used when DISTUTILS_OPTIONAL"
			eqawarn "is enabled."
		fi
	else
		local setuptools_dep='>=dev-python/setuptools-67.8.0-r1[${PYTHON_USEDEP}]'

		case ${DISTUTILS_USE_SETUPTOOLS:-bdepend} in
			no|manual)
				;;
			bdepend)
				bdep+=" ${setuptools_dep}"
				;;
			rdepend)
				bdep+=" ${setuptools_dep}"
				rdep+=" ${setuptools_dep}"
				;;
			pyproject.toml)
				die "DISTUTILS_USE_SETUPTOOLS=pyproject.toml is no longer supported, use DISTUTILS_USE_PEP517"
				;;
			*)
				die "Invalid DISTUTILS_USE_SETUPTOOLS=${DISTUTILS_USE_SETUPTOOLS}"
				;;
		esac
	fi

	if [[ ! ${DISTUTILS_SINGLE_IMPL} ]]; then
		bdep=${bdep//\$\{PYTHON_USEDEP\}/${PYTHON_USEDEP}}
		rdep=${rdep//\$\{PYTHON_USEDEP\}/${PYTHON_USEDEP}}
	else
		[[ -n ${bdep} ]] && bdep="$(python_gen_cond_dep "${bdep}")"
		[[ -n ${rdep} ]] && rdep="$(python_gen_cond_dep "${rdep}")"
	fi

	if [[ ${DISTUTILS_USE_PEP517} ]]; then
		if [[ ${DISTUTILS_DEPS+1} ]]; then
			if [[ ${DISTUTILS_DEPS} != "${bdep}" ]]; then
				eerror "DISTUTILS_DEPS have changed between inherits!"
				eerror "Before: ${DISTUTILS_DEPS}"
				eerror "Now   : ${bdep}"
				die "DISTUTILS_DEPS integrity check failed"
			fi
		else
			DISTUTILS_DEPS=${bdep}
			readonly DISTUTILS_DEPS
		fi
	fi

	if [[ ! ${DISTUTILS_OPTIONAL} ]]; then
		RDEPEND="${PYTHON_DEPS} ${rdep}"
		BDEPEND="${PYTHON_DEPS} ${bdep}"
		REQUIRED_USE=${PYTHON_REQUIRED_USE}

		if [[ ${DISTUTILS_EXT} ]]; then
			DEPEND="${PYTHON_DEPS}"
		fi
	fi

	if [[ ${DISTUTILS_EXT} ]]; then
		IUSE="debug"
	fi
}
_distutils_set_globals
unset -f _distutils_set_globals

# @ECLASS_VARIABLE: PATCHES
# @DEFAULT_UNSET
# @DESCRIPTION:
# An array containing patches to be applied to the sources before
# copying them.
#
# If unset, no custom patches will be applied.
#
# Please note, however, that at some point the eclass may apply
# additional distutils patches/quirks independently of this variable.
#
# Example:
# @CODE
# PATCHES=( "${FILESDIR}"/${P}-make-gentoo-happy.patch )
# @CODE

# @ECLASS_VARIABLE: DOCS
# @DEFAULT_UNSET
# @DESCRIPTION:
# An array containing documents installed using dodoc. The files listed
# there must exist in the directory from which
# distutils-r1_python_install_all() is run (${S} by default).
#
# If unset, the function will instead look up files matching default
# filename pattern list (from the Package Manager Specification),
# and install those found.
#
# Example:
# @CODE
# DOCS=( NEWS README )
# @CODE

# @ECLASS_VARIABLE: HTML_DOCS
# @DEFAULT_UNSET
# @DESCRIPTION:
# An array containing documents installed using dohtml. The files
# and directories listed there must exist in the directory from which
# distutils-r1_python_install_all() is run (${S} by default).
#
# If unset, no HTML docs will be installed.
#
# Example:
# @CODE
# HTML_DOCS=( doc/html/. )
# @CODE

# @ECLASS_VARIABLE: DISTUTILS_IN_SOURCE_BUILD
# @DEFAULT_UNSET
# @DESCRIPTION:
# If set to a non-null value, in-source builds will be enabled.
# If unset, the default is to use in-source builds when python_prepare()
# is declared, and out-of-source builds otherwise.
#
# If in-source builds are used, the eclass will create a copy of package
# sources for each Python implementation in python_prepare_all(),
# and work on that copy afterwards.
#
# If out-of-source builds are used, the eclass will instead work
# on the sources directly, prepending setup.py arguments with
# 'build --build-base ${BUILD_DIR}' to enforce keeping & using built
# files in the specific root.

# @ECLASS_VARIABLE: DISTUTILS_ALL_SUBPHASE_IMPLS
# @DEFAULT_UNSET
# @DESCRIPTION:
# An array of patterns specifying which implementations can be used
# for *_all() sub-phase functions. If undefined, defaults to '*'
# (allowing any implementation). If multiple values are specified,
# implementations matching any of the patterns will be accepted.
#
# For the pattern syntax, please see _python_impl_matches
# in python-utils-r1.eclass.
#
# If the restriction needs to apply conditionally to a USE flag,
# the variable should be set conditionally as well (e.g. in an early
# phase function or other convenient location).
#
# Please remember to add a matching || block to REQUIRED_USE,
# to ensure that at least one implementation matching the patterns will
# be enabled.
#
# Example:
# @CODE
# REQUIRED_USE="doc? ( || ( $(python_gen_useflags 'python2*') ) )"
#
# pkg_setup() {
#     use doc && DISTUTILS_ALL_SUBPHASE_IMPLS=( 'python2*' )
# }
# @CODE

# @ECLASS_VARIABLE: DISTUTILS_ARGS
# @DEFAULT_UNSET
# @DESCRIPTION:
# An array containing options to be passed to the build system.
# Supported by a subset of build systems used by the eclass.
#
# For setuptools, the arguments will be passed as first parameters
# to setup.py invocations (via esetup.py), as well as to the PEP517
# backend.  For future compatibility, only global options should be used
# and specifying commands should be avoided.
#
# For sip, the options are passed to the PEP517 backend in a form
# resembling sip-build calls.  Options taking arguments need to
# be specified in the "--key=value" form, while flag options as "--key".
# If an option takes multiple arguments, it can be specified multiple
# times, same as for sip-build.
#
# Example:
# @CODE
# python_configure_all() {
# 	DISTUTILS_ARGS=( --enable-my-hidden-option )
# }
# @CODE

# @FUNCTION: distutils_enable_sphinx
# @USAGE: <subdir> [--no-autodoc | <plugin-pkgs>...]
# @DESCRIPTION:
# Set up IUSE, BDEPEND, python_check_deps() and python_compile_all() for
# building HTML docs via dev-python/sphinx.  python_compile_all() will
# append to HTML_DOCS if docs are enabled.
#
# This helper is meant for the most common case, that is a single Sphinx
# subdirectory with standard layout, building and installing HTML docs
# behind USE=doc.  It assumes it's the only consumer of the three
# aforementioned functions.  If you need to use a custom implementation,
# you can't use it.
#
# If your package uses additional Sphinx plugins, they should be passed
# (without PYTHON_USEDEP) as <plugin-pkgs>.  The function will take care
# of setting appropriate any-of dep and python_check_deps().
#
# If no plugin packages are specified, the eclass will still utilize
# any-r1 API to support autodoc (documenting source code).
# If the package uses neither autodoc nor additional plugins, you should
# pass --no-autodoc to disable this API and simplify the resulting code.
#
# This function must be called in global scope.  Take care not to
# overwrite the variables set by it.  If you need to extend
# python_compile_all(), you can call the original implementation
# as sphinx_compile_all.
distutils_enable_sphinx() {
	debug-print-function ${FUNCNAME} "${@}"
	[[ ${#} -ge 1 ]] || die "${FUNCNAME} takes at least one arg: <subdir>"

	_DISTUTILS_SPHINX_SUBDIR=${1}
	shift
	_DISTUTILS_SPHINX_PLUGINS=( "${@}" )

	local deps autodoc=1 d
	deps=">=dev-python/sphinx-5.3.0[\${PYTHON_USEDEP}]"
	for d; do
		if [[ ${d} == --no-autodoc ]]; then
			autodoc=
		else
			deps+="
				${d}[\${PYTHON_USEDEP}]"
			if [[ ! ${autodoc} ]]; then
				die "${FUNCNAME}: do not pass --no-autodoc if external plugins are used"
			fi
		fi
	done

	if [[ ${autodoc} ]]; then
		if [[ ${DISTUTILS_SINGLE_IMPL} ]]; then
			deps="$(python_gen_cond_dep "${deps}")"
		else
			deps="$(python_gen_any_dep "${deps}")"
		fi

		python_check_deps() {
			use doc || return 0

			local p
			for p in ">=dev-python/sphinx-5.3.0" \
				"${_DISTUTILS_SPHINX_PLUGINS[@]}"
			do
				python_has_version "${p}[${PYTHON_USEDEP}]" ||
					return 1
			done
		}
	else
		deps=">=dev-python/sphinx-5.3.0"
	fi

	sphinx_compile_all() {
		use doc || return

		local confpy=${_DISTUTILS_SPHINX_SUBDIR}/conf.py
		[[ -f ${confpy} ]] ||
			die "${confpy} not found, distutils_enable_sphinx call wrong"

		if [[ ${_DISTUTILS_SPHINX_PLUGINS[0]} == --no-autodoc ]]; then
			if grep -F -q 'sphinx.ext.autodoc' "${confpy}"; then
				die "distutils_enable_sphinx: --no-autodoc passed but sphinx.ext.autodoc found in ${confpy}"
			fi
		elif [[ -z ${_DISTUTILS_SPHINX_PLUGINS[@]} ]]; then
			if ! grep -F -q 'sphinx.ext.autodoc' "${confpy}"; then
				die "distutils_enable_sphinx: sphinx.ext.autodoc not found in ${confpy}, pass --no-autodoc"
			fi
		fi

		build_sphinx "${_DISTUTILS_SPHINX_SUBDIR}"
	}
	python_compile_all() { sphinx_compile_all; }

	IUSE+=" doc"
	BDEPEND+=" doc? ( ${deps} )"

	# we need to ensure successful return in case we're called last,
	# otherwise Portage may wrongly assume sourcing failed
	return 0
}

# @FUNCTION: distutils_enable_tests
# @USAGE: [--install] <test-runner>
# @DESCRIPTION:
# Set up IUSE, RESTRICT, BDEPEND and python_test() for running tests
# with the specified test runner.  Also copies the current value
# of RDEPEND to test?-BDEPEND.  The test-runner argument must be one of:
#
# - nose: nosetests (dev-python/nose)
#
# - pytest: dev-python/pytest
#
# - setup.py: setup.py test (no deps included)
#
# - unittest: for built-in Python unittest module
#
# Additionally, if --install is passed as the first parameter,
# 'distutils_install_for_testing --via-root' is called before running
# the test suite.
#
# This function is meant as a helper for common use cases, and it only
# takes care of basic setup.  You still need to list additional test
# dependencies manually.  If you have uncommon use case, you should
# not use it and instead enable tests manually.
#
# This function must be called in global scope, after RDEPEND has been
# declared.  Take care not to overwrite the variables set by it.
distutils_enable_tests() {
	debug-print-function ${FUNCNAME} "${@}"

	_DISTUTILS_TEST_INSTALL=
	case ${1} in
		--install)
			if [[ ${DISTUTILS_USE_PEP517} ]]; then
				die "${FUNCNAME} --install is not implemented in PEP517 mode"
			fi
			_DISTUTILS_TEST_INSTALL=1
			shift
			;;
	esac

	[[ ${#} -eq 1 ]] || die "${FUNCNAME} takes exactly one argument: test-runner"
	local test_pkg
	case ${1} in
		nose)
			test_pkg=">=dev-python/nose-1.3.7_p20221026"
			;;
		pytest)
			test_pkg=">=dev-python/pytest-7.3.1"
			;;
		setup.py)
			;;
		unittest)
			# dep handled below
			;;
		*)
			die "${FUNCNAME}: unsupported argument: ${1}"
	esac

	_DISTUTILS_TEST_RUNNER=${1}
	python_test() { distutils-r1_python_test; }

	local test_deps=${RDEPEND}
	if [[ -n ${test_pkg} ]]; then
		if [[ ! ${DISTUTILS_SINGLE_IMPL} ]]; then
			test_deps+=" ${test_pkg}[${PYTHON_USEDEP}]"
		else
			test_deps+=" $(python_gen_cond_dep "
				${test_pkg}[\${PYTHON_USEDEP}]
			")"
		fi
	elif [[ ${1} == unittest ]]; then
		# unittest-or-fail is needed in py<3.12
		test_deps+="
			$(python_gen_cond_dep '
				dev-python/unittest-or-fail[${PYTHON_USEDEP}]
			' 3.{9..11})
		"
	fi
	if [[ -n ${test_deps} ]]; then
		IUSE+=" test"
		RESTRICT+=" !test? ( test )"
		BDEPEND+=" test? ( ${test_deps} )"
	fi

	# we need to ensure successful return in case we're called last,
	# otherwise Portage may wrongly assume sourcing failed
	return 0
}

# @FUNCTION: esetup.py
# @USAGE: [<args>...]
# @DESCRIPTION:
# Run setup.py using currently selected Python interpreter
# (if ${EPYTHON} is set; fallback 'python' otherwise).
#
# setup.py will be passed the following, in order:
#
# 1. ${DISTUTILS_ARGS[@]}
#
# 2. ${mydistutilsargs[@]} (deprecated)
#
# 3. additional arguments passed to the esetup.py function.
#
# Please note that setup.py will respect defaults (unless overridden
# via command-line options) from setup.cfg that is created
# in distutils-r1_python_compile and in distutils-r1_python_install.
#
# This command dies on failure.
esetup.py() {
	debug-print-function ${FUNCNAME} "${@}"

	_python_check_EPYTHON

	if [[ ${BUILD_DIR} && ! ${DISTUTILS_USE_PEP517} ]]; then
		_distutils-r1_create_setup_cfg
	fi

	local setup_py=( setup.py )
	if [[ ! -f setup.py ]]; then
		# The following call can succeed even if the package does not
		# feature any setuptools configuration.  In non-PEP517 mode this
		# could lead to installing an "empty" package.  In PEP517 mode,
		# we verify the build system when invoking the backend,
		# rendering this check redundant (and broken for projects using
		# pyproject.toml configuration).
		if [[ ! ${DISTUTILS_USE_PEP517} && ! -f setup.cfg ]]; then
			die "${FUNCNAME}: setup.py nor setup.cfg not found"
		fi
		setup_py=( -c "from setuptools import setup; setup()" )
	fi

	if [[ ${EAPI} != 7 && ${mydistutilsargs[@]} ]]; then
		die "mydistutilsargs is banned in EAPI ${EAPI} (use DISTUTILS_ARGS)"
	fi

	set -- "${EPYTHON}" "${setup_py[@]}" "${DISTUTILS_ARGS[@]}" \
		"${mydistutilsargs[@]}" "${@}"

	echo "${@}" >&2
	"${@}" || die -n
	local ret=${?}

	if [[ ${BUILD_DIR} && ! ${DISTUTILS_USE_PEP517} ]]; then
		rm "${HOME}"/.pydistutils.cfg || die -n
	fi

	return ${ret}
}

# @FUNCTION: distutils_install_for_testing
# @USAGE: [--via-root|--via-home|--via-venv] [<args>...]
# @DESCRIPTION:
# Install the package into a temporary location for running tests.
# Update PYTHONPATH appropriately and set TEST_DIR to the test
# installation root. The Python packages will be installed in 'lib'
# subdir, and scripts in 'scripts' subdir (like in BUILD_DIR).
#
# Please note that this function should be only used if package uses
# namespaces (and therefore proper install needs to be done to enforce
# PYTHONPATH) or tests rely on the results of install command.
# For most of the packages, tests built in BUILD_DIR are good enough.
#
# The function supports three install modes.  These are:
#
# --via-root (the default) that uses 'setup.py install --root=...'
# combined with PYTHONPATH and is recommended for the majority
# of packages.
#
# --via-venv that creates a (non-isolated) venv and installs the package
# into it via 'setup.py install'.  This mode does not use PYTHONPATH
# but requires python to be called via PATH.  It may solve a few corner
# cases that --via-root do not support.
#
# --via-home that uses 'setup.py install --home=...'.  This is
# a historical mode that was mostly broken by setuptools 50.3.0+.
# If your package does not work with the other two modes but works with
# this one, please report a bug.
#
# Please note that in order to test the solution properly you need
# to unmerge the package first.
#
# This function is not available in PEP517 mode.  The eclass provides
# a venv-style install unconditionally and therefore it should no longer
# be necessary.
distutils_install_for_testing() {
	debug-print-function ${FUNCNAME} "${@}"

	if [[ ${DISTUTILS_USE_PEP517} ]]; then
		die "${FUNCNAME} is not implemented in PEP517 mode"
	fi

	# A few notes about --via-home mode:
	# 1) 'install --home' is terribly broken on pypy, so we need
	#    to override --install-lib and --install-scripts,
	# 2) non-root 'install' complains about PYTHONPATH and missing dirs,
	#    so we need to set it properly and mkdir them,
	# 3) it runs a bunch of commands which write random files to cwd,
	#    in order to avoid that, we add the necessary path overrides
	#    in _distutils-r1_create_setup_cfg.

	local install_method=root
	case ${1} in
		--via-home)
			[[ ${EAPI} == 7 ]] || die "${*} is banned in EAPI ${EAPI}"
			install_method=home
			shift
			;;
		--via-root)
			install_method=root
			shift
			;;
		--via-venv)
			install_method=venv
			shift
			;;
	esac

	TEST_DIR=${BUILD_DIR}/test
	local add_args=()

	if [[ ${install_method} == venv ]]; then
		# create a quasi-venv
		mkdir -p "${TEST_DIR}"/bin || die
		ln -s "${PYTHON}" "${TEST_DIR}/bin/${EPYTHON}" || die
		ln -s "${EPYTHON}" "${TEST_DIR}/bin/python3" || die
		ln -s "${EPYTHON}" "${TEST_DIR}/bin/python" || die
		cat > "${TEST_DIR}"/pyvenv.cfg <<-EOF || die
			include-system-site-packages = true
		EOF

		# we only do the minimal necessary subset of activate script
		PATH=${TEST_DIR}/bin:${PATH}
		# unset PYTHONPATH in order to prevent BUILD_DIR from overriding
		# venv packages
		unset PYTHONPATH

		# force root-style install (note: venv adds TEST_DIR to prefixes,
		# so we need to pass --root=/)
		add_args=(
			--root=/
		)
	else
		local bindir=${TEST_DIR}/scripts
		local libdir=${TEST_DIR}/lib
		PATH=${bindir}:${PATH}
		PYTHONPATH=${libdir}:${PYTHONPATH}

		case ${install_method} in
			home)
				add_args=(
					--home="${TEST_DIR}"
					--install-lib="${libdir}"
					--install-scripts="${bindir}"
				)
				mkdir -p "${libdir}" || die
				;;
			root)
				add_args=(
					--root="${TEST_DIR}"
					--install-lib=lib
					--install-scripts=scripts
				)
				;;
		esac
	fi

	esetup.py install "${add_args[@]}" "${@}"
}

# @FUNCTION: distutils_write_namespace
# @USAGE: <namespace>...
# @DESCRIPTION:
# Write the __init__.py file for the requested namespace into PEP517
# install tree, in order to fix running tests when legacy namespace
# packages are installed (dev-python/namespace-*).
#
# This function must only be used in python_test().  The created file
# will automatically be removed upon leaving the test phase.
distutils_write_namespace() {
	debug-print-function ${FUNCNAME} "${@}"

	if [[ ! ${DISTUTILS_USE_PEP517:-no} != no ]]; then
		die "${FUNCNAME} is available only in PEP517 mode"
	fi
	if [[ ${EBUILD_PHASE} != test || ! ${BUILD_DIR} ]]; then
		die "${FUNCNAME} should only be used in python_test"
	fi

	local namespace
	for namespace; do
		if [[ ${namespace} == *[./]* ]]; then
			die "${FUNCNAME} does not support nested namespaces at the moment"
		fi

		local path=${BUILD_DIR}/install$(python_get_sitedir)/${namespace}/__init__.py
		if [[ -f ${path} ]]; then
			die "Requested namespace ${path} exists already!"
		fi
		cat > "${path}" <<-EOF || die
			__path__ = __import__('pkgutil').extend_path(__path__, __name__)
		EOF
		_DISTUTILS_POST_PHASE_RM+=( "${path}" )
	done
}

# @FUNCTION: _distutils-r1_disable_ez_setup
# @INTERNAL
# @DESCRIPTION:
# Stub out ez_setup.py and distribute_setup.py to prevent packages
# from trying to download a local copy of setuptools.
_distutils-r1_disable_ez_setup() {
	if [[ ${DISTUTILS_USE_PEP517} ]]; then
		die "${FUNCNAME} is not implemented in PEP517 mode"
	fi

	local stub="def use_setuptools(*args, **kwargs): pass"
	if [[ -f ez_setup.py ]]; then
		echo "${stub}" > ez_setup.py || die
	fi
	if [[ -f distribute_setup.py ]]; then
		echo "${stub}" > distribute_setup.py || die
	fi
}

# @FUNCTION: _distutils-r1_handle_pyproject_toml
# @INTERNAL
# @DESCRIPTION:
# Verify whether DISTUTILS_USE_SETUPTOOLS is set correctly
# for pyproject.toml build systems (in non-PEP517 mode).
_distutils-r1_handle_pyproject_toml() {
	if [[ ${DISTUTILS_USE_PEP517} ]]; then
		die "${FUNCNAME} is not implemented in PEP517 mode"
	fi

	[[ ${DISTUTILS_USE_SETUPTOOLS} == manual ]] && return

	if [[ ! -f setup.py && -f pyproject.toml ]]; then
		eerror "No setup.py found but pyproject.toml is present.  Please migrate"
		eerror "the package to use DISTUTILS_USE_PEP517. See:"
		eerror "  https://projects.gentoo.org/python/guide/distutils.html"
		die "No setup.py found and PEP517 mode not enabled"
	fi
}

# @FUNCTION: _distutils-r1_check_all_phase_mismatch
# @INTERNAL
# @DESCRIPTION:
# Verify whether *_all phase impls is not called from from non-*_all
# subphase.
_distutils-r1_check_all_phase_mismatch() {
	if has "python_${EBUILD_PHASE}" "${FUNCNAME[@]}"; then
		eqawarn "QA Notice: distutils-r1_python_${EBUILD_PHASE}_all called"
		eqawarn "from python_${EBUILD_PHASE}.  Did you mean to use"
		eqawarn "python_${EBUILD_PHASE}_all()?"
		[[ ${EAPI} != 7 ]] &&
			die "distutils-r1_python_${EBUILD_PHASE}_all called from python_${EBUILD_PHASE}."
	fi
}

# @FUNCTION: _distutils-r1_print_package_versions
# @INTERNAL
# @DESCRIPTION:
# Print the version of the relevant build system packages to aid
# debugging.
_distutils-r1_print_package_versions() {
	local packages=()

	if [[ ${DISTUTILS_USE_PEP517} ]]; then
		packages+=(
			dev-python/gpep517
			dev-python/installer
		)
		if [[ ${DISTUTILS_EXT} ]]; then
			packages+=(
				dev-python/cython
			)
		fi
		case ${DISTUTILS_USE_PEP517} in
			flit)
				packages+=(
					dev-python/flit-core
				)
				;;
			flit_scm)
				packages+=(
					dev-python/flit-core
					dev-python/flit_scm
					dev-python/setuptools-scm
				)
				;;
			hatchling)
				packages+=(
					dev-python/hatchling
					dev-python/hatch-fancy-pypi-readme
					dev-python/hatch-vcs
				)
				;;
			jupyter)
				packages+=(
					dev-python/jupyter-packaging
					dev-python/setuptools
					dev-python/setuptools-scm
					dev-python/wheel
				)
				;;
			maturin)
				packages+=(
					dev-util/maturin
				)
				;;
			no)
				return
				;;
			meson-python)
				packages+=(
					dev-python/meson-python
				)
				;;
			pbr)
				packages+=(
					dev-python/pbr
					dev-python/setuptools
					dev-python/wheel
				)
				;;
			pdm)
				packages+=(
					dev-python/pdm-pep517
					dev-python/setuptools
				)
				;;
			pdm-backend)
				packages+=(
					dev-python/pdm-backend
					dev-python/setuptools
				)
				;;
			poetry)
				packages+=(
					dev-python/poetry-core
				)
				;;
			scikit-build-core)
				packages+=(
					dev-python/scikit-build-core
				)
				;;
			setuptools)
				packages+=(
					dev-python/setuptools
					dev-python/setuptools-rust
					dev-python/setuptools-scm
					dev-python/wheel
				)
				;;
			sip)
				packages+=(
					dev-python/sip
				)
				;;
		esac
	else
		case ${DISTUTILS_USE_SETUPTOOLS} in
			manual|no)
				return
				;;
			*)
				packages+=(
					dev-python/setuptools
				)
				;;
		esac
	fi

	local pkg
	einfo "Build system packages:"
	for pkg in "${packages[@]}"; do
		local installed=$(best_version -b "${pkg}")
		einfo "  $(printf '%-30s' "${pkg}"): ${installed#${pkg}-}"
	done
}

# @FUNCTION: distutils-r1_python_prepare_all
# @DESCRIPTION:
# The default python_prepare_all(). It applies the patches from PATCHES
# array, then user patches and finally calls python_copy_sources to
# create copies of resulting sources for each Python implementation.
#
# At some point in the future, it may also apply eclass-specific
# distutils patches and/or quirks.
distutils-r1_python_prepare_all() {
	debug-print-function ${FUNCNAME} "${@}"
	_distutils-r1_check_all_phase_mismatch

	if [[ ! ${DISTUTILS_OPTIONAL} ]]; then
		default
	fi

	# by default, use in-source build if python_prepare() is used
	if [[ ! ${DISTUTILS_IN_SOURCE_BUILD+1} ]]; then
		if declare -f python_prepare >/dev/null; then
			DISTUTILS_IN_SOURCE_BUILD=1
		fi
	fi

	if [[ ! ${DISTUTILS_USE_PEP517} ]]; then
		_distutils-r1_disable_ez_setup
		_distutils-r1_handle_pyproject_toml

		case ${DISTUTILS_USE_SETUPTOOLS} in
			no)
				eqawarn "Non-PEP517 builds are deprecated for ebuilds using plain distutils."
				eqawarn "Please migrate to DISTUTILS_USE_PEP517=setuptools."
				eqawarn "Please see Python Guide for more details:"
				eqawarn "  https://projects.gentoo.org/python/guide/distutils.html"
				;;
		esac
	fi

	if [[ ${DISTUTILS_IN_SOURCE_BUILD} && ! ${DISTUTILS_SINGLE_IMPL} ]]
	then
		# create source copies for each implementation
		python_copy_sources
	fi

	python_export_utf8_locale
	_distutils-r1_print_package_versions

	_DISTUTILS_DEFAULT_CALLED=1
}

# @FUNCTION: _distutils-r1_create_setup_cfg
# @INTERNAL
# @DESCRIPTION:
# Create implementation-specific configuration file for distutils,
# setting proper build-dir (and install-dir) paths.
_distutils-r1_create_setup_cfg() {
	if [[ ${DISTUTILS_USE_PEP517} ]]; then
		die "${FUNCNAME} is not implemented in PEP517 mode"
	fi

	cat > "${HOME}"/.pydistutils.cfg <<-_EOF_ || die
		[build]
		build_base = ${BUILD_DIR}

		# using a single directory for them helps us export
		# ${PYTHONPATH} and ebuilds find the sources independently
		# of whether the package installs extensions or not
		#
		# note: due to some packages (wxpython) relying on separate
		# platlib & purelib dirs, we do not set --build-lib (which
		# can not be overridden with --build-*lib)
		build_platlib = %(build_base)s/lib
		build_purelib = %(build_base)s/lib

		# make the ebuild writer lives easier
		build_scripts = %(build_base)s/scripts

		# this is needed by distutils_install_for_testing since
		# setuptools like to create .egg files for install --home.
		[bdist_egg]
		dist_dir = ${BUILD_DIR}/dist

		# avoid packing up eggs in a zip as it often breaks test suites
		[options]
		zip_safe = False
	_EOF_

	if [[ ${EBUILD_PHASE} == install ]]; then
		# we can't refer to ${D} before src_install()
		cat >> "${HOME}"/.pydistutils.cfg <<-_EOF_ || die

			# installation paths -- allow calling extra install targets
			# without the default 'install'
			[install]
			compile = True
			optimize = 2
			root = ${D%/}
		_EOF_

		if [[ ! ${DISTUTILS_SINGLE_IMPL} ]]; then
			# this gets appended to [install]
			cat >> "${HOME}"/.pydistutils.cfg <<-_EOF_ || die
				install_scripts = $(python_get_scriptdir)
			_EOF_
		fi
	fi
}

# @FUNCTION: _distutils-r1_copy_egg_info
# @INTERNAL
# @DESCRIPTION:
# Copy egg-info files to the ${BUILD_DIR} (that's going to become
# egg-base in esetup.py). This way, we respect whatever's in upstream
# egg-info.
_distutils-r1_copy_egg_info() {
	if [[ ${DISTUTILS_USE_PEP517} ]]; then
		die "${FUNCNAME} is not implemented in PEP517 mode"
	fi

	mkdir -p "${BUILD_DIR}" || die
	# stupid freebsd can't do 'cp -t ${BUILD_DIR} {} +'
	find -name '*.egg-info' -type d -exec cp -R -p {} "${BUILD_DIR}"/ ';' || die
}

# @FUNCTION: _distutils-r1_backend_to_key
# @USAGE: <backend>
# @INTERNAL
# @DESCRIPTION:
# Print the DISTUTILS_USE_PEP517 value corresponding to the backend
# passed as the only argument.
_distutils-r1_backend_to_key() {
	debug-print-function ${FUNCNAME} "${@}"

	local backend=${1}
	case ${backend} in
		flit_core.buildapi|flit.buildapi)
			echo flit
			;;
		flit_scm:buildapi)
			echo flit_scm
			;;
		hatchling.build)
			echo hatchling
			;;
		jupyter_packaging.build_api)
			echo jupyter
			;;
		maturin)
			echo maturin
			;;
		mesonpy)
			echo meson-python
			;;
		pbr.build)
			echo pbr
			;;
		pdm.backend)
			echo pdm-backend
			;;
		pdm.pep517.api)
			echo pdm
			;;
		poetry.core.masonry.api|poetry.masonry.api)
			echo poetry
			;;
		scikit_build_core.build)
			echo scikit-build-core
			;;
		setuptools.build_meta|setuptools.build_meta:__legacy__)
			echo setuptools
			;;
		sipbuild.api)
			echo sip
			;;
		*)
			die "Unknown backend: ${backend}"
			;;
	esac
}

# @FUNCTION: _distutils-r1_get_backend
# @INTERNAL
# @DESCRIPTION:
# Read (or guess, in case of setuptools) the build-backend
# for the package in the current directory.
_distutils-r1_get_backend() {
	debug-print-function ${FUNCNAME} "${@}"

	local build_backend legacy_fallback
	if [[ -f pyproject.toml ]]; then
		# if pyproject.toml exists, try getting the backend from it
		# NB: this could fail if pyproject.toml doesn't list one
		build_backend=$(gpep517 get-backend)
	fi
	if [[ -z ${build_backend} && ${DISTUTILS_USE_PEP517} == setuptools &&
		-f setup.py ]]
	then
		# use the legacy setuptools backend as a fallback
		build_backend=setuptools.build_meta:__legacy__
		legacy_fallback=1
	fi
	if [[ -z ${build_backend} ]]; then
		die "Unable to obtain build-backend from pyproject.toml"
	fi

	if [[ ${DISTUTILS_USE_PEP517} != standalone ]]; then
		# verify whether DISTUTILS_USE_PEP517 was set correctly
		local expected_value=$(_distutils-r1_backend_to_key "${build_backend}")
		if [[ ${DISTUTILS_USE_PEP517} != ${expected_value} ]]; then
			eerror "DISTUTILS_USE_PEP517 does not match pyproject.toml!"
			eerror "    have: DISTUTILS_USE_PEP517=${DISTUTILS_USE_PEP517}"
			eerror "expected: DISTUTILS_USE_PEP517=${expected_value}"
			eerror "(backend: ${build_backend})"
			die "DISTUTILS_USE_PEP517 value incorrect"
		fi

		# fix deprecated backends up
		local new_backend=
		case ${build_backend} in
			flit.buildapi)
				new_backend=flit_core.buildapi
				;;
			poetry.masonry.api)
				new_backend=poetry.core.masonry.api
				;;
			setuptools.build_meta:__legacy__)
				# this backend should only be used as implicit fallback
				[[ ! ${legacy_fallback} ]] &&
					new_backend=setuptools.build_meta
				;;
		esac

		if [[ -n ${new_backend} ]]; then
			if [[ ! -f ${T}/.distutils_deprecated_backend_warned ]]; then
				eqawarn "${build_backend} backend is deprecated.  Please see:"
				eqawarn "https://projects.gentoo.org/python/guide/qawarn.html#deprecated-pep-517-backends"
				eqawarn "The eclass will be using ${new_backend} instead."
				> "${T}"/.distutils_deprecated_backend_warned || die
			fi
			build_backend=${new_backend}
		fi
	fi

	echo "${build_backend}"
}

# @FUNCTION: distutils_wheel_install
# @USAGE: <root> <wheel>
# @DESCRIPTION:
# Install the specified wheel into <root>.
#
# This function is intended for expert use only.
distutils_wheel_install() {
	debug-print-function ${FUNCNAME} "${@}"
	if [[ ${#} -ne 2 ]]; then
		die "${FUNCNAME} takes exactly two arguments: <root> <wheel>"
	fi
	if [[ -z ${PYTHON} ]]; then
		die "PYTHON unset, invalid call context"
	fi

	local root=${1}
	local wheel=${2}

	einfo "  Installing ${wheel##*/} to ${root}"
	local cmd=(
		gpep517 install-wheel
			--destdir="${root}"
			--interpreter="${PYTHON}"
			--prefix="${EPREFIX}/usr"
			--optimize=all
			"${wheel}"
	)
	printf '%s\n' "${cmd[*]}"
	"${cmd[@]}" || die "Wheel install failed"

	# remove installed licenses
	find "${root}$(python_get_sitedir)" -depth \
		\( -path '*.dist-info/COPYING*' \
		-o -path '*.dist-info/LICENSE*' \
		-o -path '*.dist-info/license_files/*' \
		-o -path '*.dist-info/license_files' \
		-o -path '*.dist-info/licenses/*' \
		-o -path '*.dist-info/licenses' \
		\) -delete || die
}

# @FUNCTION: distutils_pep517_install
# @USAGE: <root>
# @DESCRIPTION:
# Build the wheel for the package in the current directory using PEP 517
# backend and install it into <root>.
#
# This function is intended for expert use only.  It does not handle
# wrapping executables.
distutils_pep517_install() {
	debug-print-function ${FUNCNAME} "${@}"
	[[ ${#} -eq 1 ]] || die "${FUNCNAME} takes exactly one argument: root"

	if [[ ! ${DISTUTILS_USE_PEP517:-no} != no ]]; then
		die "${FUNCNAME} is available only in PEP517 mode"
	fi

	local root=${1}
	export BUILD_DIR
	local -x WHEEL_BUILD_DIR=${BUILD_DIR}/wheel
	mkdir -p "${WHEEL_BUILD_DIR}" || die

	if [[ -n ${mydistutilsargs[@]} ]]; then
		die "mydistutilsargs are banned in PEP517 mode (use DISTUTILS_ARGS)"
	fi

	local config_settings=
	case ${DISTUTILS_USE_PEP517} in
		maturin)
			# `maturin pep517 build-wheel --help` for options
			local maturin_args=(
				"${DISTUTILS_ARGS[@]}"
				--jobs="$(makeopts_jobs)"
				--skip-auditwheel # see bug #831171
				$(in_iuse debug && usex debug '--profile=dev' '')
			)

			config_settings=$(
				"${EPYTHON}" - "${maturin_args[@]}" <<-EOF || die
					import json
					import sys
					print(json.dumps({"build-args": sys.argv[1:]}))
				EOF
			)
			;;
		meson-python)
			local -x NINJAOPTS=$(get_NINJAOPTS)
			config_settings=$(
				"${EPYTHON}" - "${DISTUTILS_ARGS[@]}" <<-EOF || die
					import json
					import os
					import shlex
					import sys

					ninjaopts = shlex.split(os.environ["NINJAOPTS"])
					print(json.dumps({
						"builddir": "${BUILD_DIR}",
						"setup-args": sys.argv[1:],
						"compile-args": ["-v"] + ninjaopts,
					}))
				EOF
			)
			;;
		setuptools)
			if [[ -n ${DISTUTILS_ARGS[@]} ]]; then
				config_settings=$(
					"${EPYTHON}" - "${DISTUTILS_ARGS[@]}" <<-EOF || die
						import json
						import sys
						print(json.dumps({"--build-option": sys.argv[1:]}))
					EOF
				)
			fi
			;;
		sip)
			if [[ -n ${DISTUTILS_ARGS[@]} ]]; then
				# NB: for practical reasons, we support only --foo=bar,
				# not --foo bar
				local arg
				for arg in "${DISTUTILS_ARGS[@]}"; do
					[[ ${arg} != -* ]] &&
						die "Bare arguments in DISTUTILS_ARGS unsupported: ${arg}"
				done

				config_settings=$(
					"${EPYTHON}" - "${DISTUTILS_ARGS[@]}" <<-EOF || die
						import collections
						import json
						import sys

						args = collections.defaultdict(list)
						for arg in (x.split("=", 1) for x in sys.argv[1:]): \
							args[arg[0]].extend(
								[arg[1]] if len(arg) > 1 else [])

						print(json.dumps(args))
					EOF
				)
			fi
			;;
		*)
			[[ -n ${DISTUTILS_ARGS[@]} ]] &&
				die "DISTUTILS_ARGS are not supported by ${DISTUTILS_USE_PEP517}"
			;;
	esac

	local build_backend=$(_distutils-r1_get_backend)
	einfo "  Building the wheel for ${PWD#${WORKDIR}/} via ${build_backend}"
	local cmd=(
		gpep517 build-wheel
			--backend "${build_backend}"
			--output-fd 3
			--wheel-dir "${WHEEL_BUILD_DIR}"
	)
	if [[ -n ${config_settings} ]]; then
		cmd+=( --config-json "${config_settings}" )
	fi
	if [[ -n ${SYSROOT} ]]; then
		cmd+=( --sysroot "${SYSROOT}" )
	fi
	printf '%s\n' "${cmd[*]}"
	local wheel=$(
		"${cmd[@]}" 3>&1 >&2 || die "Wheel build failed"
	)
	[[ -n ${wheel} ]] || die "No wheel name returned"

	distutils_wheel_install "${root}" "${WHEEL_BUILD_DIR}/${wheel}"
}

# @FUNCTION: distutils-r1_python_compile
# @USAGE: [additional-args...]
# @DESCRIPTION:
# The default python_compile().
#
# If DISTUTILS_USE_PEP517 is set to "no", a no-op.
#
# If DISTUTILS_USE_PEP517 is set to any other value, builds a wheel
# using the PEP517 backend and installs it into ${BUILD_DIR}/install.
#
# In legacy mode, runs 'esetup.py build'. Any parameters passed to this
# function will be appended to setup.py invocation, i.e. passed
# as options to the 'build' command.
distutils-r1_python_compile() {
	debug-print-function ${FUNCNAME} "${@}"

	_python_check_EPYTHON

	case ${DISTUTILS_USE_PEP517:-setuptools} in
		setuptools)
			# call setup.py build when using setuptools (either via PEP517
			# or in legacy mode)

			# distutils is parallel-capable since py3.5
			local jobs=$(makeopts_jobs "${MAKEOPTS} ${*}")

			if [[ ${DISTUTILS_USE_PEP517} ]]; then
				mkdir -p "${BUILD_DIR}" || die
				local -x DIST_EXTRA_CONFIG="${BUILD_DIR}/extra-setup.cfg"
				cat > "${DIST_EXTRA_CONFIG}" <<-EOF || die
					[build]
					build_base = ${BUILD_DIR}/build

					[build_ext]
					parallel = ${jobs}
				EOF
			else
				_distutils-r1_copy_egg_info
				esetup.py build -j "${jobs}" "${@}"
			fi
			;;
		no)
			return
			;;
	esac

	if [[ ${DISTUTILS_USE_PEP517} ]]; then
		distutils_pep517_install "${BUILD_DIR}/install"
	fi
}

# @FUNCTION: _distutils-r1_wrap_scripts
# @USAGE: <bindir>
# @INTERNAL
# @DESCRIPTION:
# Moves and wraps all installed scripts/executables as necessary.
_distutils-r1_wrap_scripts() {
	debug-print-function ${FUNCNAME} "${@}"

	[[ ${#} -eq 1 ]] || die "usage: ${FUNCNAME} <bindir>"
	local bindir=${1}

	local scriptdir=$(python_get_scriptdir)
	local f python_files=() non_python_files=()

	if [[ -d ${D%/}${scriptdir} ]]; then
		for f in "${D%/}${scriptdir}"/*; do
			[[ -d ${f} ]] && die "Unexpected directory: ${f}"
			debug-print "${FUNCNAME}: found executable at ${f#${D%/}/}"

			local shebang
			read -r shebang < "${f}"
			if [[ ${shebang} == '#!'*${EPYTHON}* ]]; then
				debug-print "${FUNCNAME}: matching shebang: ${shebang}"
				python_files+=( "${f}" )
			else
				debug-print "${FUNCNAME}: non-matching shebang: ${shebang}"
				non_python_files+=( "${f}" )
			fi

			mkdir -p "${D%/}${bindir}" || die
		done

		for f in "${python_files[@]}"; do
			local basename=${f##*/}

			debug-print "${FUNCNAME}: installing wrapper at ${bindir}/${basename}"
			local dosym=dosym
			[[ ${EAPI} == 7 ]] && dosym=dosym8
			"${dosym}" -r /usr/lib/python-exec/python-exec2 \
				"${bindir#${EPREFIX}}/${basename}"
		done

		for f in "${non_python_files[@]}"; do
			local basename=${f##*/}

			debug-print "${FUNCNAME}: moving ${f#${D%/}/} to ${bindir}/${basename}"
			mv "${f}" "${D%/}${bindir}/${basename}" || die
		done
	fi
}

# @FUNCTION: distutils-r1_python_test
# @USAGE: [additional-args...]
# @DESCRIPTION:
# The python_test() implementation used by distutils_enable_tests.
# Runs tests using the specified test runner, possibly installing them
# first.
#
# This function is used only if distutils_enable_tests is called.
distutils-r1_python_test() {
	debug-print-function ${FUNCNAME} "${@}"

	if [[ -z ${_DISTUTILS_TEST_RUNNER} ]]; then
		die "${FUNCNAME} can be only used after calling distutils_enable_tests"
	fi

	_python_check_EPYTHON

	if [[ ${_DISTUTILS_TEST_INSTALL} ]]; then
		distutils_install_for_testing
	fi

	case ${_DISTUTILS_TEST_RUNNER} in
		nose)
			"${EPYTHON}" -m nose -v "${@}"
			;;
		pytest)
			epytest
			;;
		setup.py)
			nonfatal esetup.py test --verbose
			;;
		unittest)
			eunittest
			;;
		*)
			die "Mis-synced test runner between ${FUNCNAME} and distutils_enable_testing"
			;;
	esac

	if [[ ${?} -ne 0 ]]; then
		die -n "Tests failed with ${EPYTHON}"
	fi
}

# @FUNCTION: distutils-r1_python_install
# @USAGE: [additional-args...]
# @DESCRIPTION:
# The default python_install().
#
# In PEP517 mode, merges the files from ${BUILD_DIR}/install
# (if present) to the image directory.
#
# In the legacy mode, calls `esetup.py install` to install the package.
# Any parameters passed to this function will be appended
# to the setup.py invocation (i.e. as options to the 'install' command).
distutils-r1_python_install() {
	debug-print-function ${FUNCNAME} "${@}"

	_python_check_EPYTHON

	local scriptdir=${EPREFIX}/usr/bin
	local merge_root=
	if [[ ${DISTUTILS_USE_PEP517} ]]; then
		local root=${BUILD_DIR}/install
		local reg_scriptdir=${root}/${scriptdir}
		local wrapped_scriptdir=${root}$(python_get_scriptdir)

		# we are assuming that _distutils-r1_post_python_compile
		# has been called and ${root} has not been altered since
		# let's explicitly verify these assumptions

		# remove files that we've created explicitly
		rm "${reg_scriptdir}"/{"${EPYTHON}",python3,python,pyvenv.cfg} || die

		# Automagically do the QA check to avoid issues when bootstrapping
		# prefix.
		if type diff &>/dev/null ; then
			# verify that scriptdir & wrapped_scriptdir both contain
			# the same files
			(
				cd "${reg_scriptdir}" && find . -mindepth 1
			) | sort > "${T}"/.distutils-files-bin
			assert "listing ${reg_scriptdir} failed"
			(
				if [[ -d ${wrapped_scriptdir} ]]; then
					cd "${wrapped_scriptdir}" && find . -mindepth 1
				fi
			) | sort > "${T}"/.distutils-files-wrapped
			assert "listing ${wrapped_scriptdir} failed"
			if ! diff -U 0 "${T}"/.distutils-files-{bin,wrapped}; then
				die "File lists for ${reg_scriptdir} and ${wrapped_scriptdir} differ (see diff above)"
			fi
		fi

		# remove the altered bindir, executables from the package
		# are already in scriptdir
		rm -r "${reg_scriptdir}" || die
		if [[ ${DISTUTILS_SINGLE_IMPL} ]]; then
			if [[ -d ${wrapped_scriptdir} ]]; then
				mv "${wrapped_scriptdir}" "${reg_scriptdir}" || die
			fi
		fi
		# prune empty directories to see if ${root} contains anything
		# to merge
		find "${BUILD_DIR}"/install -type d -empty -delete || die
		[[ -d ${BUILD_DIR}/install ]] && merge_root=1
	else
		local root=${D%/}/_${EPYTHON}
		[[ ${DISTUTILS_SINGLE_IMPL} ]] && root=${D%/}

		# inline DISTUTILS_ARGS logic from esetup.py in order to make
		# argv overwriting easier
		local args=(
			"${DISTUTILS_ARGS[@]}"
			"${mydistutilsargs[@]}"
			install --skip-build --root="${root}" "${args[@]}"
			"${@}"
		)
		local DISTUTILS_ARGS=()
		local mydistutilsargs=()

		# enable compilation for the install phase.
		local -x PYTHONDONTWRITEBYTECODE=

		# python likes to compile any module it sees, which triggers sandbox
		# failures if some packages haven't compiled their modules yet.
		addpredict "${EPREFIX}/usr/lib/${EPYTHON}"
		addpredict "${EPREFIX}/usr/lib/pypy3.10"
		addpredict "${EPREFIX}/usr/local" # bug 498232

		if [[ ! ${DISTUTILS_SINGLE_IMPL} ]]; then
			merge_root=1

			# user may override --install-scripts
			# note: this is poor but distutils argv parsing is dumb

			# rewrite all the arguments
			set -- "${args[@]}"
			args=()
			while [[ ${@} ]]; do
				local a=${1}
				shift

				case ${a} in
					--install-scripts=*)
						scriptdir=${a#--install-scripts=}
						;;
					--install-scripts)
						scriptdir=${1}
						shift
						;;
					*)
						args+=( "${a}" )
						;;
				esac
			done
		fi

		esetup.py "${args[@]}"
	fi

	if [[ ${merge_root} ]]; then
		multibuild_merge_root "${root}" "${D%/}"
	fi
	if [[ ! ${DISTUTILS_SINGLE_IMPL} ]]; then
		_distutils-r1_wrap_scripts "${scriptdir}"
	fi
}

# @FUNCTION: distutils-r1_python_install_all
# @DESCRIPTION:
# The default python_install_all(). It installs the documentation.
distutils-r1_python_install_all() {
	debug-print-function ${FUNCNAME} "${@}"
	_distutils-r1_check_all_phase_mismatch

	einstalldocs
}

# @FUNCTION: distutils-r1_run_phase
# @USAGE: [<argv>...]
# @INTERNAL
# @DESCRIPTION:
# Run the given command.
#
# If out-of-source builds are used, the phase function is run in source
# directory, with BUILD_DIR pointing at the build directory
# and PYTHONPATH having an entry for the module build directory.
#
# If in-source builds are used, the command is executed in the directory
# holding the per-implementation copy of sources. BUILD_DIR points
# to the 'build' subdirectory.
distutils-r1_run_phase() {
	debug-print-function ${FUNCNAME} "${@}"

	if [[ ${DISTUTILS_IN_SOURCE_BUILD} ]]; then
		[[ ${DISTUTILS_USE_PEP517} ]] &&
			die "DISTUTILS_IN_SOURCE_BUILD is not supported in PEP517 mode"
		# only force BUILD_DIR if implementation is explicitly enabled
		# for building; any-r1 API may select one that is not
		# https://bugs.gentoo.org/701506
		if [[ ! ${DISTUTILS_SINGLE_IMPL} ]] &&
				has "${EPYTHON/./_}" ${PYTHON_TARGETS}; then
			cd "${BUILD_DIR}" || die
		fi
		local BUILD_DIR=${BUILD_DIR}/build
	fi

	if [[ ${DISTUTILS_USE_PEP517} ]]; then
		local -x PATH=${BUILD_DIR}/install${EPREFIX}/usr/bin:${PATH}
	else
		local -x PYTHONPATH="${BUILD_DIR}/lib:${PYTHONPATH}"

		# make PATH local for distutils_install_for_testing calls
		# it makes little sense to let user modify PATH in per-impl phases
		# and _all() already localizes it
		local -x PATH=${PATH}

		if _python_impl_matches "${EPYTHON}" 3.{9..11}; then
			# Undo the default switch in setuptools-60+ for the time being,
			# to avoid replacing .egg-info file with directory in-place.
			local -x SETUPTOOLS_USE_DISTUTILS="${SETUPTOOLS_USE_DISTUTILS:-stdlib}"
		fi

		# Bug 559644
		# using PYTHONPATH when the ${BUILD_DIR}/lib is not created yet might lead to
		# problems in setup.py scripts that try to import modules/packages from that path
		# during the build process (Python at startup evaluates PYTHONPATH, if the dir is
		# not valid then associates a NullImporter object to ${BUILD_DIR}/lib storing it
		# in the sys.path_importer_cache)
		mkdir -p "${BUILD_DIR}/lib" || die
	fi

	# Set up build environment, bug #513664.
	local -x AR=${AR} CC=${CC} CPP=${CPP} CXX=${CXX}
	tc-export AR CC CPP CXX

	if [[ ${DISTUTILS_EXT} ]]; then
		local -x CPPFLAGS="${CPPFLAGS} $(usex debug '-UNDEBUG' '-DNDEBUG')"
		# always generate .c files from .pyx files to ensure we get latest
		# bug fixes from Cython (this works only when setup.py is using
		# cythonize() but it's better than nothing)
		local -x CYTHON_FORCE_REGEN=1
	fi

	# Rust extensions are incompatible with C/C++ LTO compiler
	# see e.g. https://bugs.gentoo.org/910220
	if has cargo ${INHERITED}; then
		filter-lto
	fi

	# How to build Python modules in different worlds...
	local ldopts
	case "${CHOST}" in
		# provided by grobian, 2014-06-22, bug #513664 c7
		*-darwin*) ldopts='-bundle -undefined dynamic_lookup';;
		*) ldopts='-shared';;
	esac

	local -x LDSHARED="${CC} ${ldopts}" LDCXXSHARED="${CXX} ${ldopts}"
	local _DISTUTILS_POST_PHASE_RM=()

	"${@}"
	local ret=${?}

	if [[ -n ${_DISTUTILS_POST_PHASE_RM} ]]; then
		rm "${_DISTUTILS_POST_PHASE_RM[@]}" || die
	fi

	cd "${_DISTUTILS_INITIAL_CWD}" || die
	if [[ ! ${_DISTUTILS_IN_COMMON_IMPL} ]] &&
		declare -f "_distutils-r1_post_python_${EBUILD_PHASE}" >/dev/null
	then
		"_distutils-r1_post_python_${EBUILD_PHASE}"
	fi
	return "${ret}"
}

# @FUNCTION: _distutils-r1_run_common_phase
# @USAGE: [<argv>...]
# @INTERNAL
# @DESCRIPTION:
# Run the given command, restoring the state for a most preferred Python
# implementation matching DISTUTILS_ALL_SUBPHASE_IMPLS.
#
# If in-source build is used, the command will be run in the copy
# of sources made for the selected Python interpreter.
_distutils-r1_run_common_phase() {
	local DISTUTILS_ORIG_BUILD_DIR=${BUILD_DIR}
	local _DISTUTILS_IN_COMMON_IMPL=1

	if [[ ${DISTUTILS_SINGLE_IMPL} ]]; then
		# reuse the dedicated code branch
		_distutils-r1_run_foreach_impl "${@}"
	else
		local -x EPYTHON PYTHON
		local -x PATH=${PATH} PKG_CONFIG_PATH=${PKG_CONFIG_PATH}
		python_setup "${DISTUTILS_ALL_SUBPHASE_IMPLS[@]}"

		local MULTIBUILD_VARIANTS=( "${EPYTHON/./_}" )
		# store for restoring after distutils-r1_run_phase.
		local _DISTUTILS_INITIAL_CWD=${PWD}
		multibuild_foreach_variant \
			distutils-r1_run_phase "${@}"
	fi
}

# @FUNCTION: _distutils-r1_run_foreach_impl
# @INTERNAL
# @DESCRIPTION:
# Run the given phase for each implementation if multiple implementations
# are enabled, once otherwise.
_distutils-r1_run_foreach_impl() {
	debug-print-function ${FUNCNAME} "${@}"

	# store for restoring after distutils-r1_run_phase.
	local _DISTUTILS_INITIAL_CWD=${PWD}
	set -- distutils-r1_run_phase "${@}"

	if [[ ! ${DISTUTILS_SINGLE_IMPL} ]]; then
		local _DISTUTILS_CALLING_FOREACH_IMPL=1
		python_foreach_impl "${@}"
	else
		if [[ ! ${EPYTHON} ]]; then
			die "EPYTHON unset, python-single-r1_pkg_setup not called?!"
		fi
		local BUILD_DIR=${BUILD_DIR:-${S}}
		BUILD_DIR=${BUILD_DIR%%/}_${EPYTHON}

		"${@}"
	fi
}

distutils-r1_src_prepare() {
	debug-print-function ${FUNCNAME} "${@}"
	local ret=0
	local _DISTUTILS_DEFAULT_CALLED

	# common preparations
	if declare -f python_prepare_all >/dev/null; then
		python_prepare_all || ret=${?}
	else
		distutils-r1_python_prepare_all || ret=${?}
	fi

	if [[ ! ${_DISTUTILS_DEFAULT_CALLED} ]]; then
		die "QA: python_prepare_all() didn't call distutils-r1_python_prepare_all"
	fi

	if declare -f python_prepare >/dev/null; then
		_distutils-r1_run_foreach_impl python_prepare || ret=${?}
	fi

	return ${ret}
}

distutils-r1_src_configure() {
	debug-print-function ${FUNCNAME} "${@}"
	local ret=0

	if declare -f python_configure >/dev/null; then
		_distutils-r1_run_foreach_impl python_configure || ret=${?}
	fi

	if declare -f python_configure_all >/dev/null; then
		_distutils-r1_run_common_phase python_configure_all || ret=${?}
	fi

	return ${ret}
}

# @FUNCTION: _distutils-r1_post_python_compile
# @INTERNAL
# @DESCRIPTION:
# Post-phase function called after python_compile.  In PEP517 mode,
# it adjusts the install tree for venv-style usage.
_distutils-r1_post_python_compile() {
	debug-print-function ${FUNCNAME} "${@}"

	local root=${BUILD_DIR}/install
	if [[ ${DISTUTILS_USE_PEP517} && -d ${root} ]]; then
		# copy executables to python-exec directory
		# we do it early so that we can alter bindir recklessly
		local bindir=${root}${EPREFIX}/usr/bin
		local rscriptdir=${root}$(python_get_scriptdir)
		[[ -d ${rscriptdir} ]] &&
			die "${rscriptdir} should not exist!"
		if [[ -d ${bindir} ]]; then
			mkdir -p "${rscriptdir}" || die
			cp -a "${bindir}"/. "${rscriptdir}"/ || die
		fi

		# enable venv magic inside the install tree
		mkdir -p "${bindir}" || die
		ln -s "${PYTHON}" "${bindir}/${EPYTHON}" || die
		ln -s "${EPYTHON}" "${bindir}/python3" || die
		ln -s "${EPYTHON}" "${bindir}/python" || die
		cat > "${bindir}"/pyvenv.cfg <<-EOF || die
			include-system-site-packages = true
		EOF

		# we need to change shebangs to point to the venv-python
		find "${bindir}" -type f -exec sed -i \
			-e "1s@^#!\(${EPREFIX}/usr/bin/\(python\|pypy\)\)@#!${root}\1@" \
			{} + || die
	fi
}

distutils-r1_src_compile() {
	debug-print-function ${FUNCNAME} "${@}"
	local ret=0

	if declare -f python_compile >/dev/null; then
		_distutils-r1_run_foreach_impl python_compile || ret=${?}
	else
		_distutils-r1_run_foreach_impl distutils-r1_python_compile || ret=${?}
	fi

	if declare -f python_compile_all >/dev/null; then
		_distutils-r1_run_common_phase python_compile_all || ret=${?}
	fi

	return ${ret}
}

# @FUNCTION: _distutils-r1_clean_egg_info
# @INTERNAL
# @DESCRIPTION:
# Clean up potential stray egg-info files left by setuptools test phase.
# Those files ended up being unversioned, and caused issues:
# https://bugs.gentoo.org/534058
_distutils-r1_clean_egg_info() {
	if [[ ${DISTUTILS_USE_PEP517} ]]; then
		die "${FUNCNAME} is not implemented in PEP517 mode"
	fi

	rm -rf "${BUILD_DIR}"/lib/*.egg-info || die
}

# @FUNCTION: _distutils-r1_post_python_test
# @INTERNAL
# @DESCRIPTION:
# Post-phase function called after python_test.
_distutils-r1_post_python_test() {
	debug-print-function ${FUNCNAME} "${@}"

	if [[ ! ${DISTUTILS_USE_PEP517} ]]; then
		_distutils-r1_clean_egg_info
	fi
}

distutils-r1_src_test() {
	debug-print-function ${FUNCNAME} "${@}"
	local ret=0

	if declare -f python_test >/dev/null; then
		_distutils-r1_run_foreach_impl python_test || ret=${?}
	fi

	if declare -f python_test_all >/dev/null; then
		_distutils-r1_run_common_phase python_test_all || ret=${?}
	fi

	return ${ret}
}

# @FUNCTION: _distutils-r1_strip_namespace_packages
# @USAGE: <sitedir>
# @INTERNAL
# @DESCRIPTION:
# Find and remove setuptools-style namespaces in the specified
# directory.
_distutils-r1_strip_namespace_packages() {
	debug-print-function ${FUNCNAME} "${@}"

	local sitedir=${1}
	local f ns had_any=
	while IFS= read -r -d '' f; do
		while read -r ns; do
			einfo "Stripping pkg_resources-style namespace ${ns}"
			had_any=1
		done < "${f}"

		rm "${f}" || die
	done < <(
		# NB: this deliberately does not include .egg-info, in order
		# to limit this to PEP517 mode.
		find "${sitedir}" -path '*.dist-info/namespace_packages.txt' -print0
	)

	# If we had any namespace packages, remove .pth files as well.
	if [[ ${had_any} ]]; then
		find "${sitedir}" -name '*-nspkg.pth' -delete || die
	fi
}

# @FUNCTION: _distutils-r1_post_python_install
# @INTERNAL
# @DESCRIPTION:
# Post-phase function called after python_install.  Performs QA checks.
# In PEP517 mode, additionally optimizes installed Python modules.
_distutils-r1_post_python_install() {
	debug-print-function ${FUNCNAME} "${@}"

	local sitedir=${D%/}$(python_get_sitedir)
	if [[ -d ${sitedir} ]]; then
		_distutils-r1_strip_namespace_packages "${sitedir}"

		local forbidden_package_names=(
			examples test tests
			.pytest_cache .hypothesis _trial_temp
		)
		local strays=()
		local p
		mapfile -d $'\0' -t strays < <(
			find "${sitedir}" -maxdepth 1 -type f '!' '(' \
					-name '*.egg-info' -o \
					-name '*.pth' -o \
					-name '*.py' -o \
					-name '*.pyi' -o \
					-name "*$(get_modname)" \
				')' -print0
		)
		for p in "${forbidden_package_names[@]}"; do
			[[ -d ${sitedir}/${p} ]] && strays+=( "${sitedir}/${p}" )
		done

		if [[ -n ${strays[@]} ]]; then
			eerror "The following unexpected files/directories were found top-level"
			eerror "in the site-packages directory:"
			eerror
			for p in "${strays[@]}"; do
				eerror "  ${p#${ED}}"
			done
			eerror
			eerror "This is most likely a bug in the build system.  More information"
			eerror "can be found in the Python Guide:"
			eerror "https://projects.gentoo.org/python/guide/qawarn.html#stray-top-level-files-in-site-packages"
			die "Failing install because of stray top-level files in site-packages"
		fi

		if [[ ! ${DISTUTILS_EXT} && ! ${_DISTUTILS_EXT_WARNED} ]]; then
			if [[ $(find "${sitedir}" -name "*$(get_modname)" | head -n 1) ]]
			then
				eqawarn "Python extension modules (*$(get_modname)) found installed. Please set:"
				eqawarn "  DISTUTILS_EXT=1"
				eqawarn "in the ebuild."
				_DISTUTILS_EXT_WARNED=1
			fi
		fi
	fi
}

# @FUNCTION: _distutils-r1_check_namespace_pth
# @INTERNAL
# @DESCRIPTION:
# Check if any *-nspkg.pth files were installed (by setuptools)
# and warn about the policy non-conformance if they were.
_distutils-r1_check_namespace_pth() {
	local f pth=()

	while IFS= read -r -d '' f; do
		pth+=( "${f}" )
	done < <(find "${ED%/}" -name '*-nspkg.pth' -print0)

	if [[ ${pth[@]} ]]; then
		eerror "The following *-nspkg.pth files were found installed:"
		eerror
		for f in "${pth[@]}"; do
			eerror "  ${f#${ED%/}}"
		done
		eerror
		eerror "The presence of those files may break namespaces in Python 3.5+. Please"
		eerror "read our documentation on reliable handling of namespaces and update"
		eerror "the ebuild accordingly:"
		eerror
		eerror "  https://projects.gentoo.org/python/guide/concept.html#namespace-packages"

		die "Installing *-nspkg.pth files is banned"
	fi
}

distutils-r1_src_install() {
	debug-print-function ${FUNCNAME} "${@}"
	local ret=0

	if declare -f python_install >/dev/null; then
		_distutils-r1_run_foreach_impl python_install || ret=${?}
	else
		_distutils-r1_run_foreach_impl distutils-r1_python_install || ret=${?}
	fi

	if declare -f python_install_all >/dev/null; then
		_distutils-r1_run_common_phase python_install_all || ret=${?}
	else
		_distutils-r1_run_common_phase distutils-r1_python_install_all || ret=${?}
	fi

	_distutils-r1_check_namespace_pth

	return ${ret}
}

fi

if [[ ! ${DISTUTILS_OPTIONAL} ]]; then
	EXPORT_FUNCTIONS src_prepare src_configure src_compile src_test src_install
fi