eclass/linux-mod: Sync with gentoo

It's from gentoo commit b984f1b57fba45cebdbf990eb02d25fda34d44a5.

sdk_container/src/third_party/portage-stable/eclass/linux-mod.eclass

@@ -1,4 +1,4 @@
-# Copyright 1999-2018 Gentoo Foundation
+# Copyright 1999-2022 Gentoo Authors
 # Distributed under the terms of the GNU General Public License v2
 
 # @ECLASS: linux-mod.eclass
@@ -7,6 +7,8 @@
 # @AUTHOR:
 # John Mylchreest <johnm@gentoo.org>,
 # Stefan Schweizer <genstef@gentoo.org>
+# @SUPPORTED_EAPIS: 6 7 8
+# @PROVIDES: linux-info
 # @BLURB: It provides the functionality required to install external modules against a kernel source tree.
 # @DESCRIPTION:
 # This eclass is used to interface with linux-info.eclass in such a way
@@ -18,11 +20,15 @@
 # These are as follows:
 
 # @ECLASS-VARIABLE: MODULES_OPTIONAL_USE
+# @PRE_INHERIT
+# @DEFAULT_UNSET
 # @DESCRIPTION:
 # A string containing the USE flag to use for making this eclass optional
 # The recommended non-empty value is 'modules'
 
 # @ECLASS-VARIABLE: MODULES_OPTIONAL_USE_IUSE_DEFAULT
+# @PRE_INHERIT
+# @DEFAULT_UNSET
 # @DESCRIPTION:
 # A boolean to control the IUSE default state for the MODULES_OPTIONAL_USE USE
 # flag. Default value is unset (false). True represented by 1 or 'on', other
@@ -32,21 +38,26 @@
 # @DESCRIPTION:
 # A string containing the directory of the target kernel sources. The default value is
 # "/usr/src/linux"
+: ${KERNEL_DIR:=/usr/src/linux}
 
 # @ECLASS-VARIABLE: ECONF_PARAMS
+# @DEFAULT_UNSET
 # @DESCRIPTION:
 # It's a string containing the parameters to pass to econf.
 # If this is not set, then econf isn't run.
 
 # @ECLASS-VARIABLE: BUILD_PARAMS
+# @DEFAULT_UNSET
 # @DESCRIPTION:
 # It's a string with the parameters to pass to emake.
 
 # @ECLASS-VARIABLE: BUILD_TARGETS
 # @DESCRIPTION:
 # It's a string with the build targets to pass to make. The default value is "clean module"
+: ${BUILD_TARGETS:=clean module}
 
 # @ECLASS-VARIABLE: MODULE_NAMES
+# @DEFAULT_UNSET
 # @DESCRIPTION:
 # It's a string containing the modules to be built automatically using the default
 # src_compile/src_install. It will only make ${BUILD_TARGETS} once in any directory.
@@ -91,12 +102,14 @@
 # This can be explicitly enabled by setting any of the following variables.
 
 # @ECLASS-VARIABLE: MODULESD_<modulename>_ENABLED
+# @DEFAULT_UNSET
 # @DESCRIPTION:
 # This is used to disable the modprobe.d file generation otherwise the file will be
 # always generated (unless no MODULESD_<modulename>_* variable is provided). Set to "no" to disable
 # the generation of the file and the installation of the documentation.
 
 # @ECLASS-VARIABLE: MODULESD_<modulename>_EXAMPLES
+# @DEFAULT_UNSET
 # @DESCRIPTION:
 # This is a bash array containing a list of examples which should
 # be used. If you want us to try and take a guess set this to "guess".
@@ -108,6 +121,7 @@
 # where array_component is "<modulename> options" (see modprobe.conf(5))
 
 # @ECLASS-VARIABLE: MODULESD_<modulename>_ALIASES
+# @DEFAULT_UNSET
 # @DESCRIPTION:
 # This is a bash array containing a list of associated aliases.
 #
@@ -118,22 +132,38 @@
 # where array_component is "wildcard <modulename>" (see modprobe.conf(5))
 
 # @ECLASS-VARIABLE: MODULESD_<modulename>_ADDITIONS
+# @DEFAULT_UNSET
 # @DESCRIPTION:
 # This is a bash array containing a list of additional things to
 # add to the bottom of the file. This can be absolutely anything.
 # Each entry is a new line.
 
 # @ECLASS-VARIABLE: MODULESD_<modulename>_DOCS
+# @DEFAULT_UNSET
 # @DESCRIPTION:
 # This is a string list which contains the full path to any associated
 # documents for <modulename>. These files are installed in the live tree.
 
 # @ECLASS-VARIABLE: KV_OBJ
+# @INTERNAL
 # @DESCRIPTION:
 # It's a read-only variable. It contains the extension of the kernel modules.
 
-inherit eutils linux-info multilib
+case ${EAPI:-0} in
-EXPORT_FUNCTIONS pkg_setup pkg_preinst pkg_postinst src_install src_compile pkg_postrm
+	[67]) 
+		inherit eutils 
+		;;
+	8)
+		;;
+	*) die "${ECLASS}: EAPI ${EAPI:-0} not supported" ;;
+esac
+
+if [[ -z ${_LINUX_MOD_ECLASS} ]] ; then
+_LINUX_MOD_ECLASS=1
+
+# TODO: When adding support for future EAPIs, please audit this list
+# for unused inherits and conditionalise them.
+inherit linux-info multilib toolchain-funcs
 
 case ${MODULES_OPTIONAL_USE_IUSE_DEFAULT:-n} in
   [nNfF]*|[oO][fF]*|0|-) _modules_optional_use_iuse_default='' ;;
@@ -144,9 +174,16 @@ esac
 	0) die "EAPI=${EAPI} is not supported with MODULES_OPTIONAL_USE_IUSE_DEFAULT due to lack of IUSE defaults" ;;
 esac
 
-IUSE="kernel_linux ${MODULES_OPTIONAL_USE:+${_modules_optional_use_iuse_default}}${MODULES_OPTIONAL_USE}"
+IUSE="dist-kernel
+	${MODULES_OPTIONAL_USE:+${_modules_optional_use_iuse_default}}${MODULES_OPTIONAL_USE}"
 SLOT="0"
-RDEPEND="${MODULES_OPTIONAL_USE}${MODULES_OPTIONAL_USE:+? (} kernel_linux? ( virtual/modutils ) ${MODULES_OPTIONAL_USE:+)}"
+RDEPEND="
+	${MODULES_OPTIONAL_USE}${MODULES_OPTIONAL_USE:+? (}
+		kernel_linux? (
+			sys-apps/kmod[tools]
+			dist-kernel? ( virtual/dist-kernel:= )
+		)
+	${MODULES_OPTIONAL_USE:+)}"
 DEPEND="${RDEPEND}
     ${MODULES_OPTIONAL_USE}${MODULES_OPTIONAL_USE:+? (}
 	sys-apps/sed
@@ -208,13 +245,13 @@ use_m() {
 
 	# if the kernel version is greater than 2.6.6 then we should use
 	# M= instead of SUBDIRS=
-	[ ${KV_MAJOR} -eq 3 ] && return 0
+	[ ${KV_MAJOR} -ge 3 ] && return 0
 	[ ${KV_MAJOR} -eq 2 -a ${KV_MINOR} -gt 5 -a ${KV_PATCH} -gt 5 ] && \
 		return 0 || return 1
 }
 
 # @FUNCTION: convert_to_m
-# @USAGE: /path/to/the/file
+# @USAGE: </path/to/the/file>
 # @DESCRIPTION:
 # It converts a file (e.g. a makefile) to use M= instead of SUBDIRS=
 convert_to_m() {
@@ -570,11 +607,6 @@ linux-mod_pkg_setup() {
 	local is_bin="${MERGE_TYPE}"
 
 	# If we are installing a binpkg, take a different path.
-	# use MERGE_TYPE if available (eapi>=4); else use non-PMS EMERGE_FROM (eapi<4)
-	if has ${EAPI} 0 1 2 3; then
-		is_bin=${EMERGE_FROM}
-	fi
-
 	if [[ ${is_bin} == binary ]]; then
 		linux-mod_pkg_setup_binary
 		return
@@ -640,6 +672,11 @@ linux-mod_src_compile() {
 
 	[[ -n ${KERNEL_DIR} ]] && addpredict "${KERNEL_DIR}/null.dwo"
 
+	# Set CROSS_COMPILE in the environment.
+	# This allows it to be overridden in local Makefiles.
+	# https://bugs.gentoo.org/550428
+	local -x CROSS_COMPILE=${CROSS_COMPILE-${CHOST}-}
+
 	BUILD_TARGETS=${BUILD_TARGETS:-clean module}
 	strip_modulenames;
 	cd "${S}"
@@ -672,12 +709,11 @@ linux-mod_src_compile() {
 			# inside the variables gets used as targets for Make, which then
 			# fails.
 			eval "emake HOSTCC=\"$(tc-getBUILD_CC)\" \
-						CROSS_COMPILE=${CHOST}- \
 						LDFLAGS=\"$(get_abi_LDFLAGS)\" \
 						${BUILD_FIXES} \
 						${BUILD_PARAMS} \
 						${BUILD_TARGETS} " \
-				|| die "Unable to emake HOSTCC="$(tc-getBUILD_CC)" CROSS_COMPILE=${CHOST}- LDFLAGS="$(get_abi_LDFLAGS)" ${BUILD_FIXES} ${BUILD_PARAMS} ${BUILD_TARGETS}"
+				|| die "Unable to emake HOSTCC="$(tc-getBUILD_CC)" LDFLAGS="$(get_abi_LDFLAGS)" ${BUILD_FIXES} ${BUILD_PARAMS} ${BUILD_TARGETS}"
 			cd "${OLDPWD}"
 			touch "${srcdir}"/.built
 		fi
@@ -689,7 +725,7 @@ linux-mod_src_compile() {
 
 # @FUNCTION: linux-mod_src_install
 # @DESCRIPTION:
-# It install the modules specified in MODULES_NAME. The modules should be inside the ${objdir}
+# It install the modules specified in MODULE_NAMES. The modules should be inside the ${objdir}
 # directory and they are installed inside /lib/modules/${KV_FULL}/${libdir}.
 #
 # The modprobe.d configuration file is automatically generated if the
@@ -720,7 +756,7 @@ linux-mod_src_install() {
 
 		einfo "Installing ${modulename} module"
 		cd "${objdir}" || die "${objdir} does not exist"
-		insinto /lib/modules/${KV_FULL}/${libdir}
+		insinto "${INSTALL_MOD_PATH}"/lib/modules/${KV_FULL}/${libdir}
 		doins ${modulename}.${KV_OBJ} || die "doins ${modulename}.${KV_OBJ} failed"
 		cd "${OLDPWD}"
 
@@ -760,3 +796,8 @@ linux-mod_pkg_postrm() {
 	[ -n "${MODULES_OPTIONAL_USE}" ] && use !${MODULES_OPTIONAL_USE} && return
 	remove_moduledb;
 }
+
+fi
+
+EXPORT_FUNCTIONS pkg_setup src_compile src_install \
+	pkg_preinst pkg_postinst pkg_postrm