[Buildroot] [PATCH for-next 2/3] package/swig: enable PCRE regex matching in host-swig

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

Thomas, All,

On 2019-06-01 09:28 +0200, Thomas Petazzoni spake thusly:
> On Wed, 29 May 2019 17:16:54 +0200
> Romain Naour <romain.naour@gmail.com> wrote:
> > The upcoming ogre package needs a host swig binary with PCRE
> > regex support.
> > 
> > Signed-off-by: Romain Naour <romain.naour@gmail.com>
> > ---
> >  package/swig/swig.mk | 4 ++--
> >  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> I never really like the addition of mandatory host package dependencies
> just for the sake of one use case. I was considering adding a hidden
> BR2_PACKAGE_HOST_PCRE option for this, but since pcre takes only 17
> seconds to build, maybe it was not worth the effort. So I've applied to
> next as-is, but I'd be interested to know what Arnout/Peter/Yann thing
> about adding a hidden BR2_PACKAGE_HOST_PCRE hidden option for that kind
> of situation. We had decided to not systematically add such options in
> all host packages, but that we could add some in a case-by-case basis.
> This case-by-case basis however will look "weird": ogre would have
> host-swig in its <pkg>_DEPENDENCIES, but in Config.in would select
> BR2_PACKAGE_HOST_PCRE and not BR2_PACKAGE_HOST_SWIG. This could start
> getting a bit clunky.

As I understand what we said about host packages and their options, what we
would have in this case would be BR2_PACKAGE_HOST_SWIG_NEEDS_PCRE, and ogre
would select that, and BR2_PACKAGE_HOST_SWIG_NEEDS_PCRE would cause swig to
depend on host-pcre, without the need for BR2_PACKAGE_HOST_PCRE.

Consider it from another angle: what you suggested above could also
represent the case that ogre needs host-pcre and host-swig, not that it
needs a host-swig with pcre support.

But I'm OK with adding an unconditional dependency.

Regards,
Yann E. MORIN.

> Best regards,
> 
> Thomas
> -- 
> Thomas Petazzoni, CTO, Bootlin
> Embedded Linux and Kernel engineering
> https://bootlin.com													

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