[Ada] Missing accessibility check

[Arnaud Charlet <charlet at adacore dot com>]

This patch adds a missing case to the accessibility mechanism. The machinery
can now recognize a rewritten interface conversion and properly extract the
level of the operand.

------------
-- Source --
------------

--  types.ads

package Types is
   type Iface is limited interface;
   type Any_Iface_Ptr is access all Iface'Class;

   type Port_Type is tagged record
      Data : Any_Iface_Ptr;
   end record;

   procedure Connect (Port : in out Port_Type; Data : Any_Iface_Ptr);

   type Computer_Type is limited new Iface with record
      Port : Port_Type;
   end record;

   procedure Init_Ports (Comp : in out Computer_Type);
end Types;

--  types.adb

package body Types is
   procedure Connect (Port : in out Port_Type; Data : Any_Iface_Ptr) is
   begin
      Port.Data := Data;
   end Connect;

   procedure Init_Ports (Comp : in out Computer_Type) is
   begin
      Comp.Port.Connect (Iface (Comp)'Access);
   end Init_Ports;
end Types;

----------------------------
-- Compilation and output --
----------------------------

$ gcc -c -gnat05 types.adb
types.adb:9:26: non-local pointer cannot point to local object

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

2013-02-06  Hristian Kirtchev  <kirtchev@adacore.com>

	* sem_util.adb (Is_Interface_Conversion): New routine.
	(Object_Access_Level): Detect an interface conversion
	that has been rewritten into a different construct. Use the
	original form of the conversion to find the access level of
	the operand.

Attachment: difs
Description: Text document