If the left operand of an equality operator is null, the visibility of the
operator must be determined from the interpretation of the right operand. This
processing was done for universal numeric types but not for Any_Access, the
internal representation of the type of the literal null.
Compiling my_procedure.adb must yield the error message:
my_procedure.adb:7:12: operator for type "My_Access" defined at
myproc_types.ads:3 is not directly visible
my_procedure.adb:7:12: use clause would make operation legal
--
with Ada.Text_IO;
with MyProc_Types;
procedure My_Procedure is
Local : MyProc_Types.My_Access;
begin
if null /= Local then -- ERROR: use clause needed
Ada.Text_IO.Put_Line ("Branch A");
else
Ada.Text_IO.Put_Line ("Branch B");
end if;
end My_Procedure;
---
package MyProc_Types is
type My_Record is limited private;
type My_Access is access all My_Record;
private
type My_Record is null record;
end MyProc_Types;
Tested on x86_64-pc-linux-gnu, committed on trunk
2012-12-05 Ed Schonberg <schonb...@adacore.com>
* sem_ch4.adb (Find_Non_Universal_Interpretation): Use the
types of the right operand if the left operand is null.
Index: sem_ch4.adb
===================================================================
--- sem_ch4.adb (revision 194188)
+++ sem_ch4.adb (working copy)
@@ -192,7 +192,9 @@
-- of the operand types. If one of the operands has a universal interpre-
-- tation, the legality check uses some compatible non-universal
-- interpretation of the other operand. N can be an operator node, or
- -- a function call whose name is an operator designator.
+ -- a function call whose name is an operator designator. Any_Access, which
+ -- is the initial type of the literal NULL, is a universal type for the
+ -- purpose of this routine.
function Find_Primitive_Operation (N : Node_Id) return Boolean;
-- Find candidate interpretations for the name Obj.Proc when it appears
@@ -5504,6 +5506,7 @@
begin
if T1 = Universal_Integer
or else T1 = Universal_Real
+ or else T1 = Any_Access
then
if not Is_Overloaded (R) then
Add_One_Interp
