[PATCH v2 2/9] linux-module: Do not use shell environment

[Uladzimir Bely <ubely@ilbers.de>]

From: Anton Mikanovich <amikan@ilbers.de>

To make package build process independent of the shell environment we
should remove KDIR and PN passing through export call.
KDIR can be prepared during package build. This also will allow not to
rely on previous builddeps install task.
To pass PN variable we can just migrate to template-based debian/rules
file.

Signed-off-by: Anton Mikanovich <amikan@ilbers.de>
Signed-off-by: Uladzimir Bely <ubely@ilbers.de>
---
 .../linux-module/files/debian/rules           | 37 -------------
 .../linux-module/files/debian/rules.tmpl      | 52 +++++++++++++++++++
 meta/recipes-kernel/linux-module/module.inc   | 19 ++-----
 3 files changed, 55 insertions(+), 53 deletions(-)
 delete mode 100755 meta/recipes-kernel/linux-module/files/debian/rules
 create mode 100755 meta/recipes-kernel/linux-module/files/debian/rules.tmpl

diff --git a/meta/recipes-kernel/linux-module/files/debian/rules b/meta/recipes-kernel/linux-module/files/debian/rules
deleted file mode 100755
index 59720b37..00000000
--- a/meta/recipes-kernel/linux-module/files/debian/rules
+++ /dev/null
@@ -1,37 +0,0 @@
-#!/usr/bin/make -f
-
-# Debian rules for custom kernel module build
-#
-# This software is a part of ISAR.
-# Copyright (c) Siemens AG, 2018
-#
-# SPDX-License-Identifier: MIT
-
-export DEB_BUILD_OPTIONS=parallel=$(shell nproc)
-
-export CROSS_COMPILE=$(DEB_HOST_GNU_TYPE)-
-
-ifeq ($(DEB_HOST_GNU_CPU), arm)
-export ARCH=arm
-endif
-ifeq ($(DEB_HOST_GNU_CPU), aarch64)
-export ARCH=arm64
-endif
-ifeq ($(DEB_HOST_GNU_CPU), riscv64)
-export ARCH=riscv
-endif
-ifneq (,$(findstring 86,$(DEB_HOST_GNU_CPU)))
-export ARCH=x86
-endif
-
-override_dh_auto_clean:
-	$(MAKE) -C $(KDIR) M=$(PWD) clean
-
-override_dh_auto_build:
-	$(MAKE) -C $(KDIR) M=$(PWD) modules
-
-override_dh_auto_install:
-	$(MAKE) -C $(KDIR) M=$(PWD) INSTALL_MOD_PATH=$(PWD)/debian/$(PN) modules_install
-
-%:
-	CFLAGS= LDFLAGS= dh $@ --parallel
diff --git a/meta/recipes-kernel/linux-module/files/debian/rules.tmpl b/meta/recipes-kernel/linux-module/files/debian/rules.tmpl
new file mode 100755
index 00000000..52453e5f
--- /dev/null
+++ b/meta/recipes-kernel/linux-module/files/debian/rules.tmpl
@@ -0,0 +1,52 @@
+#!/usr/bin/make -f
+
+# Debian rules for custom kernel module build
+#
+# This software is a part of ISAR.
+# Copyright (c) Siemens AG, 2018
+#
+# SPDX-License-Identifier: MIT
+
+export DEB_BUILD_OPTIONS=parallel=$(shell nproc)
+
+export CROSS_COMPILE=$(DEB_HOST_GNU_TYPE)-
+
+ifeq ($(DEB_HOST_GNU_CPU), arm)
+export ARCH=arm
+endif
+ifeq ($(DEB_HOST_GNU_CPU), aarch64)
+export ARCH=arm64
+endif
+ifeq ($(DEB_HOST_GNU_CPU), riscv64)
+export ARCH=riscv
+endif
+ifneq (,$(findstring 86,$(DEB_HOST_GNU_CPU)))
+export ARCH=x86
+endif
+
+# Custom kernels contain the build folder directly.
+KDIR := $(shell dpkg -L linux-headers-${KERNEL_NAME} | grep "/lib/modules/.*/build")
+ifeq ($(KDIR),)
+# Debian kernels install that folder indirectly via a dependency.
+KERNEL_DEP := $(shell dpkg-query -W -f '$${Depends}' linux-headers-${KERNEL_NAME} | sed 's/.*\(linux-headers-[[:graph:]]*\).*/\1/')
+KDIR := $(shell dpkg -L $(KERNEL_DEP) | grep "/lib/modules/.*/build")
+endif
+
+# With some build systems like sbuild `dh clean` can be called twice:
+# first, by build system itself before chroot's apt database updated,
+# second, by dpkg-buildpackage during build. So, KDIR may be empty
+# in first case (while no dependencies are yet installed), and a broken
+# 'make ... clean' command is produced. Just skip override in this case.
+ifneq ($(KDIR),)
+override_dh_auto_clean:
+	$(MAKE) -C $(KDIR) M=$(PWD) clean
+endif
+
+override_dh_auto_build:
+	$(MAKE) -C $(KDIR) M=$(PWD) modules
+
+override_dh_auto_install:
+	$(MAKE) -C $(KDIR) M=$(PWD) INSTALL_MOD_PATH=$(PWD)/debian/${PN} modules_install
+
+%:
+	CFLAGS= LDFLAGS= dh $@ --parallel
diff --git a/meta/recipes-kernel/linux-module/module.inc b/meta/recipes-kernel/linux-module/module.inc
index 0515621a..9ae3af9b 100644
--- a/meta/recipes-kernel/linux-module/module.inc
+++ b/meta/recipes-kernel/linux-module/module.inc
@@ -22,8 +22,9 @@ AUTOLOAD ?= ""
 inherit dpkg
 
 TEMPLATE_FILES = "debian/control.tmpl \
-                  debian/changelog.tmpl"
-TEMPLATE_VARS += "KERNEL_NAME"
+                  debian/changelog.tmpl \
+                  debian/rules.tmpl"
+TEMPLATE_VARS += "KERNEL_NAME PN"
 
 do_prepare_build() {
     cp -r ${WORKDIR}/debian ${S}/
@@ -32,17 +33,3 @@ do_prepare_build() {
         echo "echo $module >> /etc/modules" >> ${S}/debian/postinst
     done
 }
-
-dpkg_runbuild_prepend() {
-    # Custom kernels contain the build folder directly.
-    export KDIR=$(dpkg -L --root=${BUILDCHROOT_DIR} linux-headers-${KERNEL_NAME} | \
-                  grep "/lib/modules/.*/build")
-    if [ -z "$KDIR" ]; then
-        # Debian kernels install that folder indirectly via a dependency.
-        KERNEL_DEP=$(dpkg-query -W -f '${Depends}' --admindir=${BUILDCHROOT_DIR}/var/lib/dpkg \
-                     linux-headers-${KERNEL_NAME} | sed 's/.*\(linux-headers-[[:graph:]]*\).*/\1/')
-        export KDIR=$(dpkg -L --root=${BUILDCHROOT_DIR} ${KERNEL_DEP} | \
-                      grep "/lib/modules/.*/build")
-    fi
-    export PN=${PN}
-}
-- 
2.20.1