[Buildroot] [PATCH 1/8] core: add the possibility to provide help for local, custom rules

[Yann E. MORIN <yann.morin.1998@free.fr>]

Arnout, All,

On 2016-03-10 00:35 +0100, Arnout Vandecappelle spake thusly:
> On 03/09/16 23:22, Yann E. MORIN wrote:
> >When using a br2-external tree, it is possible (as stated in our manual)
> >to implement whatever arbitrary extra make rules (such as flashing a
> >board, or extracting the rootfs in an NFS export...). Some of those
> >extra rules might be exposed to the user as new entry points that the
> >user can call by itself.
> >
> >However, there is no way for the br2-external to advertise those new
> >rules in the help text.
> >
> >We add the possibility to do so, by adding a new make rule, called
> >help-local, advertised in our own help info.
> >
> >It is up to the br2-external tree to provide whatever help text is
> >deemed necessary.
> >
> >Note that we need to provide an empty, dummy help-local' rule, since it
> >is always advertised. Since this rule is empty, make gently reports that
> >there is "Nothing to be done for `help-local'", which is pretty well
> >fitting when help-local was not provided (either because there's no
> >br2-external tree, or when the br2-external tree does not provide it.
> >
> >Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
> >Cc: J?r?me Pouiller <jezz@sysmic.org>
> >Cc: Arnout Vandecappelle <arnout@mind.be>
> >Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
> >---
> >  Makefile | 6 ++++++
> >  1 file changed, 6 insertions(+)
> >
> >diff --git a/Makefile b/Makefile
> >index f2822a2..d24793b 100644
> >--- a/Makefile
> >+++ b/Makefile
> >@@ -966,6 +966,7 @@ endif
> >  	@echo '  source-check           - check selected packages for valid download URLs'
> >  	@echo '  external-deps          - list external packages used'
> >  	@echo '  legal-info             - generate info about license compliance'
> >+	@echo '  help-local             - print help about local, custom actions (if any)'
> >  	@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'
> >@@ -974,6 +975,11 @@ endif
> >  	@echo 'it on-line at http://buildroot.org/docs.html'
> >  	@echo
> >
> >+# This rule does nothing, it is expected to be overloaded by
> >+# a br2-external tree or a local.mk . However, it must exist,
> >+# as we reference it in the main help, above.
> >+help-local:
> 
>  It's sufficient and better to do
> 
> .PHONY: help-local

I tried (evenm before I submitted!) and it does not work. It still
prints that there is nothing to do...

Here's my test case:

    $ cat Makefile
    .PHONY: help
    help:

    $ make help
    make: Nothing to be done for `help'.

Regards,
Yann E. MORIN.

> (and then there is no need for a comment either).
> 
>  Regards,
>  Arnout
> 
> >+
> >  list-defconfigs:
> >  	@echo 'Built-in configs:'
> >  	@$(foreach b, $(sort $(notdir $(wildcard $(TOPDIR)/configs/*_defconfig))), \
> >
> 
> 
> -- 
> Arnout Vandecappelle                          arnout at mind be
> Senior Embedded Software Architect            +32-16-286500
> Essensium/Mind                                http://www.mind.be
> G.Geenslaan 9, 3001 Leuven, Belgium           BE 872 984 063 RPR Leuven
> LinkedIn profile: http://www.linkedin.com/in/arnoutvandecappelle
> GPG fingerprint:  7493 020B C7E3 8618 8DEC 222C 82EB F404 F9AC 0DDF

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