[Buildroot] [PATCH 1/2] help: add a way to document targets declared in local.mk/external.mk

["Jérôme Pouiller" <jezz@sysmic.org>]

It is handy to use local.mk or external.mk to add specific targets
for current project. However, until now, it not possible to add help
message these targets.
This patch add LOCAL_HELP variable. This variable is aimed to be assigned
from any .mk files. Its content is displayed with 'make help'.

For exemple:
  LOCAL_HELP += "flash                  - Flash target"
  LOCAL_HELP += "chroot                 - Chroot into target/"
  LOCAL_HELP += "qemu                   - Run image with qemu"
  LOCAL_HELP += "install-nfs            - Extract rootfs in \$$NFSROOT (=$(NFSROOT))"
  LOCAL_HELP += "`printf '%-22s%s' '$(var)-feature' ' - Call $(var) feature'`"
  LOCAL_HELP += "Please contact support at company.com in case of problem."

Signed-off-by: J?r?me Pouiller <jezz@sysmic.org>
---
 Makefile | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/Makefile b/Makefile
index 80c264f..4322da9 100644
--- a/Makefile
+++ b/Makefile
@@ -901,6 +901,11 @@ ifeq ($(BR2_TARGET_BAREBOX),y)
 	@echo '  barebox-menuconfig     - Run barebox menuconfig'
 	@echo '  barebox-savedefconfig  - Run barebox savedefconfig'
 endif
+ifneq ($(LOCAL_HELP),)
+	@echo
+	@echo 'Local targets:'
+	@for i in $(LOCAL_HELP); do echo "  $$i"; done
+endif
 	@echo
 	@echo 'Documentation:'
 	@echo '  manual                 - build manual in all formats'
-- 
2.1.4