[OE-core] what means PROV_class-native = ""?

[Robert P. J. Day]

On Fri, 18 Jan 2013, Saul Wold wrote:

> On 01/18/2013 01:45 PM, Martin Jansa wrote:
> > On Fri, Jan 18, 2013 at 04:35:34PM -0500, Robert P. J. Day wrote:
> > >
> > >    perusing oe-core for examples to demonstrate the concept of
> > > "PROVIDES =", and i ran across this in recipes-devtools/dpkg/dpkg.inc:
> > >
> > > PROV = "virtual/update-alternatives"
> > > PROV_class-native = ""
> >
> > PROV is variable with no special meaning
> > class-native is standard override for native recipe (like
> > virtclass-native was before).
> >
> > > PROVIDES += "${PROV}"
> > >
> > >    i'm not sure what to make of that -- what's the purpose of assigning
> > > to PROV, then subsequently assigning to PROVIDES, but with that
> > >
> > > PROV_class-native = ""
> > >
> > > line in between?  i did a grep and saw nothing else like it throughout
> > > oe-core.
> > >

> I believe that idea is since it's PROVIDES += , not a straight
> assignment like = it's not a simple to override with the +=, so for
> the target case PROVIDE the virtual/u-a, but not for the native case
> of that package.
>
> If it was a straight assignment (using =) the ${PROV} would not be
> needed.

  i thought it was something like that, i just wanted to make sure.
as martin pointed out, there's nothing magical about the PROV
variable, so i could just as easily have used, say, RDAY instead of
PROV as it was purely temporary, right?

rday

-- 

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Robert P. J. Day                                 Ottawa, Ontario, CANADA
                        http://crashcourse.ca

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