[Ada] Ada2012 : incomplete types can be used in more contexts

[Arnaud Charlet <charlet at adacore dot com>]

This patch allows tagged incomplete types to be used in profiles of entries
and entry bodies, without the presence of a regular with_clause on the package
whose limited view provides those types.
The following must compile quietly:

   gcc -c -gnat12 -gnatws tagged_half_1.adb

---
limited with Half_2;
package Half_1 is

   type Unseen_Ref is access all Half_2.Unseen;

   type Seen is record
      Value : Unseen_Ref;
   end record;

   function foo (Val : Seen) return Half_2.Unseen;
   function bar (Val : Half_2.Unseen) return Seen;

   procedure Baz
     (Val_1 : Half_2.Unseen;
      Val_2 : in out Half_2.Unseen;
      Val_3 : out Half_2.Unseen);

   type Tagged_Unseen_Ref is access all Half_2.Tagged_Unseen;

   type Tagged_Seen is tagged record
      Value : Tagged_Unseen_Ref;
   end record;
end Half_1;
---
with Half_1; use Half_1;
package Half_2 is

   type Unseen is record
      Value : Seen;
   end record;

   type Tagged_Unseen is tagged record
      Value : Tagged_Seen;
   end record;
end Half_2;
---
with Half_2;
package body Half_1 is

   function foo (Val : Seen) return Half_2.Unseen is
   begin
      return Val.Value.all;
   end;

   function bar (Val : Half_2.Unseen) return Seen is
   begin
      return Val.Value;
   end;

   procedure Baz
     (Val_1 : Half_2.Unseen;
      Val_2 : in out Half_2.Unseen;
      Val_3 : out Half_2.Unseen) is
   begin
      Val_3 := Val_2;
      Val_2 := Val_1;
   end;
end Half_1;
---
limited with Half_2;
package Tagged_Half_1 is

   type Tagged_Unseen_Ref is access all Half_2.Tagged_Unseen;

   type Tagged_Seen is tagged record
      Value : Tagged_Unseen_Ref;
   end record;

   function bar (Val : Half_2.Tagged_Unseen) return Tagged_Seen;

   procedure Baz
     (Val_1 : Half_2.Tagged_Unseen;
      Val_2 : in out Half_2.Tagged_Unseen;
      Val_3 : out Half_2.Tagged_Unseen);

   function Faux return Boolean;
end Tagged_Half_1;
---
package body Tagged_Half_1 is
   --  Note that there's no "with Half_2;" here; we're still seeing the limited
   --  view.

   function Faux return Boolean is
   begin
      return False;
   end Faux;

   function bar (Val : Half_2.Tagged_Unseen) return Tagged_Seen is
   begin
      return Result : Tagged_Seen;
   end;

   procedure Baz
     (Val_1 : Half_2.Tagged_Unseen;
      Val_2 : in out Half_2.Tagged_Unseen;
      Val_3 : out Half_2.Tagged_Unseen) is
   begin
      if Faux then
         Baz (Val_1, Val_2, Val_3);
      end if;
   end;

   task T is
      entry E
        (Val_1 : Half_2.Tagged_Unseen;
         Val_2 : in out Half_2.Tagged_Unseen;
         Val_3 : out Half_2.Tagged_Unseen);
   end T;

   task body T is
   begin
      select
         accept E
           (Val_1 : Half_2.Tagged_Unseen;
            Val_2 : in out Half_2.Tagged_Unseen;
            Val_3 : out Half_2.Tagged_Unseen);
      or
         terminate;
      end select;
   end T;

   protected Prot is
      entry E
        (Val_1 : Half_2.Tagged_Unseen;
         Val_2 : in out Half_2.Tagged_Unseen;
         Val_3 : out Half_2.Tagged_Unseen);
   end Prot;

   protected body Prot is
      entry E
        (Val_1 : Half_2.Tagged_Unseen;
         Val_2 : in out Half_2.Tagged_Unseen;
         Val_3 : out Half_2.Tagged_Unseen) when True is
      begin
         Baz (Val_1, Val_2, Val_3);
      end E;
   end Prot;
end Tagged_Half_1;

Tested on x86_64-pc-linux-gnu, committed on trunk

2011-08-03  Ed Schonberg  <schonberg@adacore.com>

	* exp_ch9.adb (Build_Renamed_Formal_Declaration): common procedure for
	protected entries and task entries, to build the proper renaming
	declaration for entry formals, used in debugging.
	* exp_ch2.adb (Expand_Entry_Parameter): handle task and entry
	parameters in the same way.

Attachment: difs
Description: Text document