[gentoo-dev] [PATCH 2/3] kernel-build.eclass: fix determining kernel release with MODULES=n

[Andrew Ammerlaan <andrewammerlaan@gentoo.org>]

For module-less kernels 'make modules_prepare' does nothing, we only get
kernel.release after running src_compile. Luckily the kernel has the
"kernelrelease" target which we can use for this purpose.

Note, in kernel-install.eclass we still read the kernel release directly from
the file since a) kernel.release will always exist and b) calling make there
again would require duplicating (some subset off) ${MAKEARGS[@]}.

The "make help" page specifies that this target should be called with "-s".

The version check is moved up, before 'make modules_prepare' so we quit earlier
if the KV_FULL is wrong. Note it should be run after we have completed the
config in 'make olddefconfig'.

Signed-off-by: Andrew Ammerlaan <andrewammerlaan@gentoo.org>
Closes: https://github.com/gentoo/gentoo/pull/37694
Signed-off-by: Andrew Ammerlaan <andrewammerlaan@gentoo.org>
---
 eclass/kernel-build.eclass | 17 ++++++++---------
 1 file changed, 8 insertions(+), 9 deletions(-)

diff --git a/eclass/kernel-build.eclass b/eclass/kernel-build.eclass
index 29719609b912..f478cf636a27 100644
--- a/eclass/kernel-build.eclass
+++ b/eclass/kernel-build.eclass
@@ -253,25 +253,21 @@ kernel-build_src_configure() {
 	mkdir -p "${WORKDIR}"/modprep || die
 	mv .config "${WORKDIR}"/modprep/ || die
 	emake O="${WORKDIR}"/modprep "${MAKEARGS[@]}" olddefconfig
-	emake O="${WORKDIR}"/modprep "${MAKEARGS[@]}" modules_prepare
-	cp -pR "${WORKDIR}"/modprep "${WORKDIR}"/build || die
 
-	# Now that we have a release file, set KV_FULL
-	local relfile=${WORKDIR}/build/include/config/kernel.release
+	local k_release=$(emake -s O="${WORKDIR}"/modprep "${MAKEARGS[@]}" kernelrelease)
 	if [[ -z ${KV_FULL} ]]; then
-		KV_FULL=$(<"${relfile}") || die
+		KV_FULL=${k_release}
 	fi
 
 	# Make sure we are about to build the correct kernel
 	if [[ ${PV} != *9999 ]]; then
 		local expected_ver=$(dist-kernel_PV_to_KV "${PV}")
-		local expected_rel=$(<"${relfile}")
 
-		if [[ ${KV_FULL} != ${expected_rel} ]]; then
+		if [[ ${KV_FULL} != ${k_release} ]]; then
 			eerror "KV_FULL mismatch!"
 			eerror "KV_FULL:  ${KV_FULL}"
-			eerror "Expected: ${expected_rel}"
-			die "KV_FULL mismatch: got ${KV_FULL}, expected ${expected_rel}"
+			eerror "Expected: ${k_release}"
+			die "KV_FULL mismatch: got ${KV_FULL}, expected ${k_release}"
 		fi
 
 		if [[ ${KV_FULL} != ${expected_ver}* ]]; then
@@ -282,6 +278,9 @@ kernel-build_src_configure() {
 			die "Kernel version mismatch: got ${KV_FULL}, expected ${expected_ver}*"
 		fi
 	fi
+
+	emake O="${WORKDIR}"/modprep "${MAKEARGS[@]}" modules_prepare
+	cp -pR "${WORKDIR}"/modprep "${WORKDIR}"/build || die
 }
 
 # @FUNCTION: kernel-build_src_compile
-- 
2.45.2