Re: Elaboration of nested generic package.

[mheaney@on2.com (Matthew Heaney)]

"Randy Brukardt" <randy@rrsoftware.com> wrote in message news:<vh8dpifpmicl78@corp.supernews.com>...
> 
> A library unit pragma that applies to a generic unit does not apply to its
> instances, unless a specific rule for the pragma specifies the contrary.
> 
> That means that a categorization pragma does not apply to instances of the
> generic, only to the generic itself. (You need to be able to say that a
> generic is Pure so it can be withed and instantiated in a Pure package; but
> that doesn't necessaryly make it Pure - that depends on the formals).
> 
> The pragma on the instance is not "confirming"; it gives the categorization.
> 
> See AI-00041 for a full discussion.

OK, that clears things up a bit.  But I'm still confused about what
pragma should be used on the instantiation.

For example, in the AI, there's this example:

with Op;

generic 
package GP is
   pragma Preelaborate;
   I : Integer := Op;
   ...
end GP;

The pragma states that the body of GP should be elaborated prior to
the elaboration of any non-preelaborated library units, which means
you can omit elaboration checks during instantiations of GP.

Fine, but then what categorization pragma should one use on the
instantiation of GP:

with GP;
pragma Elaborate_All (GP);
package P is new GP;
pragma What_Goes_Here(P); --???

We can't use Preelaborate on P, because it isn't preelaborateable
(even though GP is).  What would be the difference between using
Elaborate_Body and Elaborate_All on P?