[Buildroot] [PATCH 02/10] core: get rid of our dummy br2-external tree

[Romain Naour <romain.naour@gmail.com>]

Le 25/09/2016 ? 16:52, Yann E. MORIN a ?crit :
> Now that we generate a kconfig snippet, we can conditionally include the
> BR2_EXTERNAL's Config.in only when BR2_EXTERNAL is supplied by the user,
> which means our empty/dummy Config.in is no longer useful to us.
> 
> As for external.mk, we can also include it only when BR2_EXTERNAL is
> supplied by the user, which means our empty/dummy external.mk is no
> longer of any use to us.
> 
> Ditch both of those files, and:
> 
>   - only generate actual content in the Kconfig snippet when we actually
>     do have a BR2_EXTERNAL provided by the user (i.e. BR2_EXTERNAL is not
>     empty);
> 
>   - add a variable that contains the path to the external.mk provided by
>     the user, or empty if none, and include the path set in that variable
>     (make can 'include' nothing without any problem! ;-) )
> 
> Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
> Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
> Cc: Arnout Vandecappelle <arnout@mind.be>
> Cc: Romain Naour <romain.naour@openwide.fr>
> Cc: Julien CORJON <corjon.j@ecagroup.com>

Reviewed-by: Romain Naour <romain.naour@gmail.com>

Best regards,
Romain

> ---
>  Makefile                           | 11 ++++-------
>  support/dummy-external/Config.in   |  0
>  support/dummy-external/external.mk |  0
>  support/scripts/br2-external       | 18 +++++++++++++++---
>  4 files changed, 19 insertions(+), 10 deletions(-)
>  delete mode 100644 support/dummy-external/Config.in
>  delete mode 100644 support/dummy-external/external.mk
> 
> diff --git a/Makefile b/Makefile
> index f44e509..10afcda 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -147,16 +147,11 @@ $(if $(BASE_DIR),, $(error output directory "$(O)" does not exist))
>  # on the command line, therefore the file is re-created every time make is run.
>  #
>  # When BR2_EXTERNAL is set to an empty value (e.g. explicitly in command
> -# line), the .br-external file is removed and we point to
> -# support/dummy-external. This makes sure we can unconditionally include the
> -# Config.in and external.mk from the BR2_EXTERNAL directory. In this case,
> -# override is necessary so the user can clear BR2_EXTERNAL from the command
> -# line, but the dummy path is still used internally.
> +# line), the .br-external file is removed.
>  
>  BR2_EXTERNAL_FILE = $(BASE_DIR)/.br-external
>  -include $(BR2_EXTERNAL_FILE)
>  ifeq ($(BR2_EXTERNAL),)
> -  override BR2_EXTERNAL = support/dummy-external
>    $(shell rm -f $(BR2_EXTERNAL_FILE))
>  else
>    _BR2_EXTERNAL = $(shell cd $(BR2_EXTERNAL) >/dev/null 2>&1 && pwd)
> @@ -165,6 +160,7 @@ else
>    endif
>    override BR2_EXTERNAL := $(_BR2_EXTERNAL)
>    $(shell echo BR2_EXTERNAL ?= $(BR2_EXTERNAL) > $(BR2_EXTERNAL_FILE))
> +  BR2_EXTERNAL_MK = $(BR2_EXTERNAL)/external.mk
>  endif
>  
>  # To make sure that the environment variable overrides the .config option,
> @@ -461,7 +457,8 @@ include boot/common.mk
>  include linux/linux.mk
>  include fs/common.mk
>  
> -include $(BR2_EXTERNAL)/external.mk
> +# Nothing to include if no BR2_EXTERNAL tree in use
> +include $(BR2_EXTERNAL_MK)
>  
>  # Now we are sure we have all the packages scanned and defined. We now
>  # check for each package in the list of enabled packages, that all its
> diff --git a/support/dummy-external/Config.in b/support/dummy-external/Config.in
> deleted file mode 100644
> index e69de29..0000000
> diff --git a/support/dummy-external/external.mk b/support/dummy-external/external.mk
> deleted file mode 100644
> index e69de29..0000000
> diff --git a/support/scripts/br2-external b/support/scripts/br2-external
> index c15c21c..508ddcb 100755
> --- a/support/scripts/br2-external
> +++ b/support/scripts/br2-external
> @@ -19,9 +19,11 @@ main() {
>      # Forget options; keep only positional args
>      shift $((OPTIND-1))
>  
> -    if [ ${#} -ne 1 ]; then
> -        error "need exactly one br2-external tree to be specified\n"
> +    # Accept 0 or 1 br2-external tree.
> +    if [ ${#} -gt 1 ]; then
> +        error "only zero or one br2-external tree allowed.\n"
>      fi
> +
>      br2_ext="${1}"
>  
>      if [ -z "${ofile}" ]; then
> @@ -38,6 +40,11 @@ main() {
>  do_validate() {
>      local br2_ext="${1}"
>  
> +    # No br2-external tree is valid
> +    if [ -z "${br2_ext}" ]; then
> +        return
> +    fi
> +
>      if [ ! -d "${br2_ext}" ]; then
>          error "'%s': no such file or directory\n" "${br2_ext}"
>      fi
> @@ -49,12 +56,17 @@ do_validate() {
>  do_kconfig() {
>      printf '#\n# Automatically generated file; DO NOT EDIT.\n#\n'
>      printf '\n'
> +
> +    if [ -z "${BR2_EXT}" ]; then
> +        printf '# No br2-external tree defined.\n'
> +        return
> +    fi
> +
>      printf 'config BR2_EXTERNAL\n'
>      printf '\tstring\n'
>      printf '\tdefault "%s"\n' "${BR2_EXT}"
>      printf '\n'
>      printf 'menu "User-provided options"\n'
> -    printf '\tdepends on BR2_EXTERNAL != "support/dummy-external"\n'
>      printf '\n'
>      printf 'source "%s/Config.in"\n' "${BR2_EXT}"
>      printf '\n'
>