[Buildroot] [PATCH 13/13 v7] core/legal-info: ensure legal-info works in off-line mode

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

Hello,

On Sat,  7 May 2016 18:14:38 +0200, Yann E. MORIN wrote:
> Almost all packages which are saved for legal-info have their source
> archives downloaded as part of 'make source', which makes an off-line
> build completely possible [0].
> 
> However, for the pre-configured external toolchains, the source tarball
> is different, as the main tarball is a binary package. And that source
> tarball is only downloaded during the legal-info phase, which makes it
> inconvenient for full off-line builds.
> 
> We fix that by adding a new rule, $(1)-legal-source which only
> $(1)-all-source depends on, so that we only download it for a top-level
> 'make source', not as part of the standard download mechanism (i.e. only
> what is really needed to build).
> 
> This new rule depends, like the normal download mechanism, on a stamp
> file, so that we do not emit a spurious hash-check message on successive
> runs of 'make source'.
> 
> This way, we can do a complete [0] off-line build and are still able to
> generate legal-info, while at the same time we do not incur any download
> overhead during a simple build.
> 
> Also, we previously downloaded the _ACTUAL_SOURCE_TARBALL when it was
> not empty. However, since _ACTUAL_SOURCE_TARBALL defaults to the value
> of _SOURCE, it can not be empty when _SOURCE is not. Thus, we'd get a
> spurious report of a missing hash for the tarball, since it was not in
> a standard package rule (configure, build, install..) and thus would
> miss the PKG and PKGDIR variables to find the .hash file.
> 
> We fix that in this commit as well, by:
> 
>   - setting PKG and PKGDIR just for the -legal-source rule;
> 
>   - only downloading _ACTUAL_SOURCE_TARBALL if it is not empty *and* not
>     the same as _SOURCE (to avoid a second report about the hash).
> 
> [0] Save for nodejs which invarriably wants to download stuff at build
> time. Sigh... :-( Fixing that is work for another time...
> 
> Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
> Cc: Luca Ceresoli <luca@lucaceresoli.net>
> Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
> Cc: Peter Korsgaard <jacmet@uclibc.org>
> Tested-by: Luca Ceresoli <luca@lucaceresoli.net>
> 
> ---
> Notes: here is a case where one would need to be able to do an off-line
> legal-info:
>   - a build farm (e.g. Jenkins slaves) without access to the internet;
>   - a single machine (not part of the farm) has access to the internet;
>   - that machine runs "make source" to populate a mirror (a "primary
>     mirror" or an NFS-mounted directory or anything else) that is
>     accessible to the build farm;
>   - machines in the build farm need the actual sources to run
>     legal-info, doing so off-line.

Applied to master, thanks.

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