[yocto] "(-)"??

[Peter Kjellerstedt]

> -----Original Message-----
> From: yocto-bounces at yoctoproject.org [mailto:yocto-
> bounces at yoctoproject.org] On Behalf Of Khem Raj
> Sent: den 21 september 2017 07:15
> To: Takashi Matsuzawa <tmatsuzawa at xevo.com>; yocto at yoctoproject.org
> Subject: Re: [yocto] "(-)"??
> 
> On 9/20/17 8:18 PM, Takashi Matsuzawa wrote:
> > Hello.
> > I am seeing some of the recipes contains lines like below.
> >
> >> COMPATIBLE_MACHINE = "(-)"
> >
> > Sorry being novice, but what is the intended effect of this line?
> > I can see submit comments that this is for blacklisting but I am not
> > sure how it works.  It simply means a '-' letter?
> 
> COMAPTIBLE_MACHINE uses regexp syntax

Which actually makes that a pretty weird COMPATIBLE_MACHINE, 
especially if it is intended for blacklisting. Given that it would 
match any machine with a dash in it, it would match, e.g., qemux86-64
but not qemux86. It would also happen to match about half of our 
machines which happen to have dashes in their names.

A more appropriate way to blacklist machines using COMPATIBLE_MACHINE 
would be something like:

COMPATIBLE_MACHINE = "null"

or:

COMPATIBLE_MACHINE = "nothing"

I found two occurrences of "(-)" being used as COMPATIBLE_MACHINE in 
meta-openembedded for Morty and Pyro, but they have been removed for 
Rocko. If you see them anywhere else, consider changing them.

//Peter