[Buildroot] [PATCH 5/8] linux: add the generic help rules

[Thomas Petazzoni <thomas.petazzoni@free-electrons.com>]

Hello,

On Thu, 10 Mar 2016 10:21:17 +0100, J?r?me Pouiller wrote:

> >   So now this will be printed on a single line, instead of being split
> > like it was before. Well, J?r?me's patch already did that as well I
> > guess.
> In fact, my patch correctly support this case if you use two separate
> strings:
>   
> EXTRA_HELP += \
>    "linux-update-defconfig : Save the Linux configuration to the path specified" \
>    "                           by BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE"

This is not super great either IMO.

What about doing something more Buildroot-esque and use the concept of
hooks that we already use everywhere ?

For example:

diff --git a/Makefile b/Makefile
index f2822a2..db9aee0 100644
--- a/Makefile
+++ b/Makefile
@@ -969,6 +969,7 @@ endif
        @echo
        @echo '  make V=0|1             - 0 => quiet build (default), 1 => verbose build'
        @echo '  make O=dir             - Locate all output files in "dir", including .config'
+       $(foreach hook,$(HELP_HOOKS),$(call $(hook)$(sep)))
        @echo
        @echo 'For further details, see README, generate the Buildroot manual, or consult'
        @echo 'it on-line at http://buildroot.org/docs.html'
diff --git a/package/busybox/busybox.mk b/package/busybox/busybox.mk
index 7c904c8..1a0b09c 100644
--- a/package/busybox/busybox.mk
+++ b/package/busybox/busybox.mk
@@ -250,4 +250,10 @@ $(error No BusyBox configuration file specified, check your BR2_PACKAGE_BUSYBOX_
 endif
 endif
 
+define BUSYBOX_HELP
+       @echo '  busybox-baz            - do stuff'
+endef
+
+HELP_HOOKS += BUSYBOX_HELP
+
 $(eval $(kconfig-package))

This way, it is just a function call, and the package, or external.mk
can do whatever it wants in terms of formatting the help text.
Including iterating on variables, showing the contents of a file, or
whatever.

Best regards,

Thomas
-- 
Thomas Petazzoni, CTO, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com