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------------------------------------------------------------------------------
-- --
-- GNAT RUN-TIME COMPONENTS --
-- --
-- A D A . D I R E C T _ I O --
-- --
-- B o d y --
-- --
-- Copyright (C) 1992-2006, 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 2, 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. See the GNU General Public License --
-- for more details. You should have received a copy of the GNU General --
-- Public License distributed with GNAT; see file COPYING. If not, write --
-- to the Free Software Foundation, 51 Franklin Street, Fifth Floor, --
-- Boston, MA 02110-1301, USA. --
-- --
-- As a special exception, if other files instantiate generics from this --
-- unit, or you link this unit with other files to produce an executable, --
-- this unit does not by itself cause the resulting executable to be --
-- covered by the GNU General Public License. This exception does not --
-- however invalidate any other reasons why the executable file might be --
-- covered by the GNU Public License. --
-- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc. --
-- --
------------------------------------------------------------------------------
-- This is the generic template for Direct_IO, i.e. the code that gets
-- duplicated. We absolutely minimize this code by either calling routines
-- in System.File_IO (for common file functions), or in System.Direct_IO
-- (for specialized Direct_IO functions)
with Interfaces.C_Streams; use Interfaces.C_Streams;
with System; use System;
with System.CRTL;
with System.File_Control_Block;
with System.File_IO;
with System.Direct_IO;
with System.Storage_Elements;
with Unchecked_Conversion;
use type System.Direct_IO.Count;
package body Ada.Direct_IO is
Zeroes : constant System.Storage_Elements.Storage_Array :=
(1 .. System.Storage_Elements.Storage_Offset (Bytes) => 0);
-- Buffer used to fill out partial records
package FCB renames System.File_Control_Block;
package FIO renames System.File_IO;
package DIO renames System.Direct_IO;
SU : constant := System.Storage_Unit;
subtype AP is FCB.AFCB_Ptr;
subtype FP is DIO.File_Type;
subtype DPCount is DIO.Positive_Count;
function To_FCB is new Unchecked_Conversion (File_Mode, FCB.File_Mode);
function To_DIO is new Unchecked_Conversion (FCB.File_Mode, File_Mode);
use type System.CRTL.size_t;
-----------
-- Close --
-----------
procedure Close (File : in out File_Type) is
begin
FIO.Close (AP (File));
end Close;
------------
-- Create --
------------
procedure Create
(File : in out File_Type;
Mode : File_Mode := Inout_File;
Name : String := "";
Form : String := "")
is
begin
DIO.Create (FP (File), To_FCB (Mode), Name, Form);
File.Bytes := Bytes;
end Create;
------------
-- Delete --
------------
procedure Delete (File : in out File_Type) is
begin
FIO.Delete (AP (File));
end Delete;
-----------------
-- End_Of_File --
-----------------
function End_Of_File (File : File_Type) return Boolean is
begin
return DIO.End_Of_File (FP (File));
end End_Of_File;
----------
-- Form --
----------
function Form (File : File_Type) return String is
begin
return FIO.Form (AP (File));
end Form;
-----------
-- Index --
-----------
function Index (File : File_Type) return Positive_Count is
begin
return Positive_Count (DIO.Index (FP (File)));
end Index;
-------------
-- Is_Open --
-------------
function Is_Open (File : File_Type) return Boolean is
begin
return FIO.Is_Open (AP (File));
end Is_Open;
----------
-- Mode --
----------
function Mode (File : File_Type) return File_Mode is
begin
return To_DIO (FIO.Mode (AP (File)));
end Mode;
----------
-- Name --
----------
function Name (File : File_Type) return String is
begin
return FIO.Name (AP (File));
end Name;
----------
-- Open --
----------
procedure Open
(File : in out File_Type;
Mode : File_Mode;
Name : String;
Form : String := "")
is
begin
DIO.Open (FP (File), To_FCB (Mode), Name, Form);
File.Bytes := Bytes;
end Open;
----------
-- Read --
----------
procedure Read
(File : File_Type;
Item : out Element_Type;
From : Positive_Count)
is
begin
-- For a non-constrained variant record type, we read into an
-- intermediate buffer, since we may have the case of discriminated
-- records where a discriminant check is required, and we may need
-- to assign only part of the record buffer originally written.
-- Note: we have to turn warnings on/off because this use of
-- the Constrained attribute is an obsolescent feature.
pragma Warnings (Off);
if not Element_Type'Constrained then
pragma Warnings (On);
declare
Buf : Element_Type;
begin
DIO.Read (FP (File), Buf'Address, Bytes, DPCount (From));
Item := Buf;
end;
-- In the normal case, we can read straight into the buffer
else
DIO.Read (FP (File), Item'Address, Bytes, DPCount (From));
end if;
end Read;
procedure Read (File : File_Type; Item : out Element_Type) is
begin
-- Same processing for unconstrained case as above
-- Note: we have to turn warnings on/off because this use of
-- the Constrained attribute is an obsolescent feature.
pragma Warnings (Off);
if not Element_Type'Constrained then
pragma Warnings (On);
declare
Buf : Element_Type;
begin
DIO.Read (FP (File), Buf'Address, Bytes);
Item := Buf;
end;
else
DIO.Read (FP (File), Item'Address, Bytes);
end if;
end Read;
-----------
-- Reset --
-----------
procedure Reset (File : in out File_Type; Mode : File_Mode) is
begin
DIO.Reset (FP (File), To_FCB (Mode));
end Reset;
procedure Reset (File : in out File_Type) is
begin
DIO.Reset (FP (File));
end Reset;
---------------
-- Set_Index --
---------------
procedure Set_Index (File : File_Type; To : Positive_Count) is
begin
DIO.Set_Index (FP (File), DPCount (To));
end Set_Index;
----------
-- Size --
----------
function Size (File : File_Type) return Count is
begin
return Count (DIO.Size (FP (File)));
end Size;
-----------
-- Write --
-----------
procedure Write
(File : File_Type;
Item : Element_Type;
To : Positive_Count)
is
begin
DIO.Set_Index (FP (File), DPCount (To));
DIO.Write (FP (File), Item'Address, Item'Size / SU, Zeroes);
end Write;
procedure Write (File : File_Type; Item : Element_Type) is
begin
DIO.Write (FP (File), Item'Address, Item'Size / SU, Zeroes);
end Write;
end Ada.Direct_IO;
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