Re: AQ&S Guidance on pragma Elaborate_Body

[mheaney@ni.net (Matthew Heaney)]

In article <dewar.861594771@merv>, dewar@merv.cs.nyu.edu (Robert Dewar) wrote:

><<The only guideline which survived was "Use pragma Elaborate for generics
>named in a context clause." That could imply this paragraph was talking
>only of generics; however, generics cannot be mutually dependent (although
>instantiations can be mutually dependent in an indirect fashion).>>
>
>And this guideline is a poor one. You only need to use pragma Elaborate
>for generics named in the context clause if you instantiate the generic
>in your own elaboration code -- and furthermore, if you *do* such an
>instantiation, use Elaborate_All, not Elaborate -- and of course this
>only applies if the generic has a body!

I don't understand.  What do you mean by elaboration code?  Is it defined
as the package body, or only the begin part of the package body, ie

with GQ;
package body P is

   package Q is new GQ (...);

end P;

or this

with GQ;
package body P is
begin
   declare
      package Q is new GQ (...);
   begin
      null;
   end;
end P;

Do either of these require pragma Elaborate (or Elaborate_All)?  (Assume GQ
does have a body.)

And while I'm on the subject of pragma Elaborate, the Ada 83 RM stated that
that pragma was only guarenteed to work when used on a predefined package
such as Text_IO.  Did this rule go away in Ada 95?  Can I use pragma
Elaborate freely, on user-defined library units, and have a guarentee that
it will do something?

Matt

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