Re: [RFC 04/15] linux-module: Do not use shell environment

[Jan Kiszka <jan.kiszka@siemens.com>]

On 26.07.21 15:46, Anton Mikanovich wrote:
> 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>
> ---
>  .../files/debian/{rules => rules.tmpl}        | 10 +++++++-
>  meta/recipes-kernel/linux-module/module.inc   | 23 +++++++------------
>  2 files changed, 17 insertions(+), 16 deletions(-)
>  rename meta/recipes-kernel/linux-module/files/debian/{rules => rules.tmpl} (55%)
> 
> diff --git a/meta/recipes-kernel/linux-module/files/debian/rules b/meta/recipes-kernel/linux-module/files/debian/rules.tmpl
> similarity index 55%
> rename from meta/recipes-kernel/linux-module/files/debian/rules
> rename to meta/recipes-kernel/linux-module/files/debian/rules.tmpl
> index c476bf3..39abc52 100755
> --- a/meta/recipes-kernel/linux-module/files/debian/rules
> +++ b/meta/recipes-kernel/linux-module/files/debian/rules.tmpl
> @@ -24,11 +24,19 @@ 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
> +
>  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
> +	$(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 0515621..5b08623 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 ${S}/
> @@ -31,18 +32,10 @@ do_prepare_build() {
>      for module in "${AUTOLOAD}"; do
>          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}
> +    # remove templates from the source tree
> +    find ${S}/debian -name *.tmpl | xargs rm -f
> +
> +    # restore execute permissions
> +    chmod a+x ${S}/debian/rules
>  }
> 

Exporting build vars via the shell is a fairly common pattern by now,
not only in the many recipes and includes you had to patch in isar.
Can't we do something that people do not have to fork rules files into
rules.tmpl in order to inject variables set in recipes?

Jan

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