| ------------------------------------------------------------------------------ |
| -- -- |
| -- GNAT COMPILER COMPONENTS -- |
| -- -- |
| -- S Y S T E M . F I N A L I Z A T I O N _ R O O T -- |
| -- -- |
| -- S p e c -- |
| -- -- |
| -- Copyright (C) 1992-2009, Free Software Foundation, Inc. -- |
| -- -- |
| -- GNAT is free software; you can redistribute it and/or modify it under -- |
| -- terms of the GNU General Public License as published by the Free Soft- -- |
| -- ware Foundation; either version 3, or (at your option) any later ver- -- |
| -- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- |
| -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- |
| -- or FITNESS FOR A PARTICULAR PURPOSE. -- |
| -- -- |
| -- As a special exception under Section 7 of GPL version 3, you are granted -- |
| -- additional permissions described in the GCC Runtime Library Exception, -- |
| -- version 3.1, as published by the Free Software Foundation. -- |
| -- -- |
| -- You should have received a copy of the GNU General Public License and -- |
| -- a copy of the GCC Runtime Library Exception along with this program; -- |
| -- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see -- |
| -- <http://www.gnu.org/licenses/>. -- |
| -- -- |
| -- GNAT was originally developed by the GNAT team at New York University. -- |
| -- Extensive contributions were provided by Ada Core Technologies Inc. -- |
| -- -- |
| ------------------------------------------------------------------------------ |
| |
| -- This unit provides the basic support for controlled (finalizable) types |
| |
| with Ada.Streams; |
| with Ada.Unchecked_Conversion; |
| |
| package System.Finalization_Root is |
| pragma Preelaborate; |
| |
| type Root_Controlled is tagged; |
| |
| type Finalizable_Ptr is access all Root_Controlled'Class; |
| |
| function To_Finalizable_Ptr is |
| new Ada.Unchecked_Conversion (Address, Finalizable_Ptr); |
| |
| function To_Addr is |
| new Ada.Unchecked_Conversion (Finalizable_Ptr, Address); |
| |
| type Empty_Root_Controlled is abstract tagged null record; |
| -- Just for the sake of Controlled equality (see Ada.Finalization) |
| |
| type Root_Controlled is new Empty_Root_Controlled with record |
| Prev, Next : Finalizable_Ptr; |
| end record; |
| subtype Finalizable is Root_Controlled'Class; |
| |
| procedure Initialize (Object : in out Root_Controlled); |
| procedure Finalize (Object : in out Root_Controlled); |
| procedure Adjust (Object : in out Root_Controlled); |
| |
| -- Stream-oriented attributes for Root_Controlled. These must be empty so |
| -- as to not copy the finalization chain pointers. They are declared in |
| -- a nested package so that they do not create primitive operations of |
| -- Root_Controlled. Otherwise this would add unwanted primitives to (the |
| -- full view of) Ada.Finalization.Limited_Controlled, which would cause |
| -- trouble in cases where a limited controlled type is used as the |
| -- designated type of a remote access-to-classwide type. |
| |
| package Stream_Attributes is |
| |
| procedure Write |
| (Stream : not null access Ada.Streams.Root_Stream_Type'Class; |
| Item : Root_Controlled) is null; |
| |
| procedure Read |
| (Stream : not null access Ada.Streams.Root_Stream_Type'Class; |
| Item : out Root_Controlled) is null; |
| |
| end Stream_Attributes; |
| |
| for Root_Controlled'Read use Stream_Attributes.Read; |
| for Root_Controlled'Write use Stream_Attributes.Write; |
| |
| end System.Finalization_Root; |