eclass/rpm: Add from Gentoo

It's from Gentoo commit 78e5f99cb41eaa50da930e7ab2dc7993fa243e1f.

sdk_container/src/third_party/portage-stable/eclass/rpm.eclass

@@ -0,0 +1,146 @@
+# Copyright 1999-2023 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+# @ECLASS: rpm.eclass
+# @MAINTAINER:
+# base-system@gentoo.org
+# @SUPPORTED_EAPIS: 6 7 8
+# @BLURB: convenience class for extracting RPMs
+
+case ${EAPI} in
+	6) inherit epatch eutils ;; # eutils for eqawarn
+	7|8) ;;
+	*) die "${ECLASS}: EAPI ${EAPI:-0} not supported" ;;
+esac
+
+if [[ -z ${_RPM_ECLASS} ]] ; then
+_RPM_ECLASS=1
+
+inherit estack
+
+case ${EAPI} in
+	6) DEPEND="app-arch/rpm2targz" ;;
+	*) BDEPEND="app-arch/rpm2targz" ;;
+esac
+
+# @FUNCTION: rpm_unpack
+# @USAGE: <rpms>
+# @DESCRIPTION:
+# Unpack the contents of the specified rpms like the unpack() function.
+rpm_unpack() {
+	[[ $# -eq 0 ]] && set -- ${A}
+	local a
+	for a in "$@" ; do
+		echo ">>> Unpacking ${a} to ${PWD}"
+		if [[ ${a} == ./* ]] ; then
+			: # nothing to do -- path is local
+		elif [[ ${a} == "${DISTDIR}"/* ]] ; then
+			eqawarn 'do not use ${DISTDIR} with rpm_unpack -- it is added for you'
+		elif [[ ${a} == /* ]] ; then
+			eqawarn 'do not use full paths with rpm_unpack -- use ./ paths instead'
+		else
+			a="${DISTDIR}/${a}"
+		fi
+		rpm2tar -O "${a}" | tar xf -
+		assert "failure unpacking ${a}"
+	done
+}
+
+# @FUNCTION: srcrpm_unpack
+# @USAGE: <rpms>
+# @DESCRIPTION:
+# Unpack the contents of the specified rpms like the unpack() function as well
+# as any archives that it might contain.  Note that the secondary archive
+# unpack isn't perfect in that it simply unpacks all archives in the working
+# directory (with the assumption that there weren't any to start with).
+srcrpm_unpack() {
+	[[ $# -eq 0 ]] && set -- ${A}
+	rpm_unpack "$@"
+
+	# no .src.rpm files, then nothing to do
+	[[ "$* " != *".src.rpm " ]] && return 0
+
+	eshopts_push -s nullglob
+
+	# unpack everything
+	local a
+	for a in *.tar.{gz,bz2,xz} *.t{gz,bz2,xz} *.zip *.ZIP ; do
+		unpack "./${a}"
+		rm -f "${a}" || die
+	done
+
+	eshopts_pop
+
+	return 0
+}
+
+# @FUNCTION: rpm_src_unpack
+# @DESCRIPTION:
+# Automatically unpack all archives in ${A} including rpms.  If one of the
+# archives in a source rpm, then the sub archives will be unpacked as well.
+rpm_src_unpack() {
+	local a
+	for a in ${A} ; do
+		case ${a} in
+		*.rpm) srcrpm_unpack "${a}" ;;
+		*)     unpack "${a}" ;;
+		esac
+	done
+}
+
+# @FUNCTION: rpm_spec_epatch
+# @USAGE: [spec]
+# @DEPRECATED: none
+# @DESCRIPTION:
+# Read the specified spec (defaults to ${PN}.spec) and attempt to apply
+# all the patches listed in it.  If the spec does funky things like moving
+# files around, well this won't handle that.
+rpm_spec_epatch() {
+	# no epatch in EAPI 7 and later
+	[[ ${EAPI} == 6 ]] || die "${FUNCNAME} is banned in EAPI ${EAPI}"
+
+	local p spec=$1
+	local dir
+
+	if [[ -z ${spec} ]] ; then
+		# search likely places for the spec file
+		for spec in "${PWD}" "${S}" "${WORKDIR}" ; do
+			spec+="/${PN}.spec"
+			[[ -e ${spec} ]] && break
+		done
+	fi
+	[[ ${spec} == */* ]] \
+		&& dir=${spec%/*} \
+		|| dir=
+
+	ebegin "Applying patches from ${spec}"
+
+	grep '^%patch' "${spec}" | \
+	while read line ; do
+		# expand the %patch line
+		set -- ${line}
+		p=$1
+		shift
+
+		# process the %patch arguments
+		local arg
+		EPATCH_OPTS=
+		for arg in "$@" ; do
+			case ${arg} in
+			-b) EPATCH_OPTS+=" --suffix" ;;
+			*)  EPATCH_OPTS+=" ${arg}" ;;
+			esac
+		done
+
+		# extract the patch name from the Patch# line
+		set -- $(grep "^P${p#%p}: " "${spec}")
+		shift
+		epatch "${dir:+${dir}/}$*"
+	done
+
+	eend
+}
+
+fi
+
+EXPORT_FUNCTIONS src_unpack