kernel-install.eclass: Refactor /usr/src/linux check to function

Refactor the check whether /usr/src/linux should be updated to
a separate function, to improve readability.

Signed-off-by: Michał Górny <mgorny@gentoo.org>

1 files changed, 43 insertions, 26 deletions

diff --git a/eclass/kernel-install.eclass b/eclass/kernel-install.eclass
index e3357cda0fd6..107a526c328f 100644
--- a/eclass/kernel-install.eclass
+++ b/eclass/kernel-install.eclass
@@ -76,6 +76,45 @@ BDEPEND="
 		x86? ( app-emulation/qemu[qemu_softmmu_targets_i386] )
 	)"
 
+# @FUNCTION: kernel-install_can_update_symlink
+# @USAGE:
+# @DESCRIPTION:
+# Determine whether the symlink at <target> (full path) should be
+# updated.  Returns 0 if it should, 1 to leave as-is.
+kernel-install_can_update_symlink() {
+	debug-print-function ${FUNCNAME} "${@}"
+
+	[[ ${#} -eq 1 ]] || die "${FUNCNAME}: invalid arguments"
+	local target=${1}
+
+	# if the symlink does not exist or is broken, update
+	[[ ! -e ${target} ]] && return 0
+
+	local symlink_target=$(readlink "${target}")
+	# the symlink target should start with the same basename as target
+	# (e.g. "linux-*")
+	[[ ${symlink_target} != ${target##*/}-* ]] && return 1
+
+	# try to establish the kernel version from symlink target
+	local symlink_ver=${symlink_target#${target##*/}-}
+	# strip KV_LOCALVERSION, we want to update the old kernels not using
+	# KV_LOCALVERSION suffix and the new kernels using it
+	symlink_ver=${symlink_ver%${KV_LOCALVERSION}}
+
+	# if ${symlink_ver} contains anything but numbers (e.g. an extra
+	# suffix), it's not our kernel, so leave it alone
+	[[ -n ${symlink_ver//[0-9.]/} ]] && return 1
+
+	local symlink_pkg=${CATEGORY}/${PN}-${symlink_ver}
+	# if the current target is either being replaced, or still
+	# installed (probably depclean candidate), update the symlink
+	has "${symlink_ver}" ${REPLACING_VERSIONS} && return 0
+	has_version -r "~${symlink_pkg}" && return 0
+
+	# otherwise it could be another kernel package, so leave it alone
+	return 1
+}
+
 # @FUNCTION: kernel-install_update_symlink
 # @USAGE: <target> <version>
 # @DESCRIPTION:
@@ -89,35 +128,13 @@ kernel-install_update_symlink() {
 	local target=${1}
 	local version=${2}
 
-	if [[ ! -e ${target} ]]; then
-		ebegin "Creating ${target} symlink"
+	if kernel-install_can_update_symlink "${target}"; then
+		ebegin "Updating ${target} symlink"
 		ln -f -n -s "${target##*/}-${version}" "${target}"
 		eend ${?}
 	else
-		local symlink_target=$(readlink "${target}")
-		local symlink_ver=${symlink_target#${target##*/}-}
-		local updated=
-		symlink_ver=${symlink_ver%${KV_LOCALVERSION}}
-		if [[ ${symlink_target} == ${target##*/}-* && \
-				-z ${symlink_ver//[0-9.]/} ]]
-		then
-			local symlink_pkg=${CATEGORY}/${PN}-${symlink_ver}
-			# if the current target is either being replaced, or still
-			# installed (probably depclean candidate), update the symlink
-			if has "${symlink_ver}" ${REPLACING_VERSIONS} ||
-					has_version -r "~${symlink_pkg}"
-			then
-				ebegin "Updating ${target} symlink"
-				ln -f -n -s "${target##*/}-${version}" "${target}"
-				eend ${?}
-				updated=1
-			fi
-		fi
-
-		if [[ ! ${updated} ]]; then
-			elog "${target} points at another kernel, leaving it as-is."
-			elog "Please use 'eselect kernel' to update it when desired."
-		fi
+		elog "${target} points at another kernel, leaving it as-is."
+		elog "Please use 'eselect kernel' to update it when desired."
 	fi
 }