!ASIS Issue #099
!topic  A_Formal_Package_Declaration as an appropriate argument for Corresponding_Declaration
!reference  ASIS 95-15.26, 15.27
!from  Sergey Rybin  98-10-03
!keywords  
!discussion

Consider the following example:

generic
package Genpack is
   function F return Integer;
end Genpack;

package body Genpack is
   function F return Integer is
   begin
      return 0;
   end F;
end Genpack;

with Genpack;
Generic
   with package P is new Genpack; --<<---  (2)
package Genpack2 is
   function F return Integer;
end Genpack2;

package body Genpack2 is
   function F return Integer is
   begin
      return P.F;     -- <<--- (1)
   end F;
end Genpack2;

Consider the function call P.F at point (1). There is no formal reason
for Corresponding_Called_Function to return Nil_Element for it. But
what happens if we apply Enclosing_Element to the result of
Corresponding_Called_Function?  What happens if we apply it several
times? There is nothing in the ASIS which could help to answer this
question.

The most logical solution would probably be to consider the function
declaration which should be returned in this case as belonging to the
expanded geclaration of the generic package Genpack at point (2), but
the problem is, that this expanded generic spec would correspond to a
formal package declaration, but not to a package instantiation. In the
same time, Asis.Declarations.Corresponding declaration can be applied
to a package instantiation (and it will return an expanded spec in
this case), but it cannot be applied to a formal package declaration
(which in fact is also some kind of package instantiation).

It looks like formal packages as appropriate arguments for
Corresponding_Name_Declarations were missed when ASIS 83 was evolved
to ASIS 95.

!resolution  Rejected.

Issue already submitted to ASIS-technical by Alain Le Guennec
as Issue #086.