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------------------------------------------------------------------------------
-- --
-- GNAT RUN-TIME COMPONENTS --
-- --
-- A D A . S E Q U E N T I A L _ I O --
-- --
-- B o d y --
-- --
-- Copyright (C) 1992-2005 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, 59 Temple Place - Suite 330, Boston, --
-- MA 02111-1307, 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 Sequential_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.Sequential_IO
-- (for specialized Sequential_IO functions)
with Interfaces.C_Streams; use Interfaces.C_Streams;
with System;
with System.CRTL;
with System.File_Control_Block;
with System.File_IO;
with System.Storage_Elements;
with Unchecked_Conversion;
package body Ada.Sequential_IO is
package FIO renames System.File_IO;
package FCB renames System.File_Control_Block;
package SIO renames System.Sequential_IO;
package SSE renames System.Storage_Elements;
SU : constant := System.Storage_Unit;
subtype AP is FCB.AFCB_Ptr;
subtype FP is SIO.File_Type;
function To_FCB is new Unchecked_Conversion (File_Mode, FCB.File_Mode);
function To_SIO 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 : in File_Mode := Out_File;
Name : in String := "";
Form : in String := "")
is
begin
SIO.Create (FP (File), To_FCB (Mode), Name, Form);
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 : in File_Type) return Boolean is
begin
return FIO.End_Of_File (AP (File));
end End_Of_File;
----------
-- Form --
----------
function Form (File : in File_Type) return String is
begin
return FIO.Form (AP (File));
end Form;
-------------
-- Is_Open --
-------------
function Is_Open (File : in File_Type) return Boolean is
begin
return FIO.Is_Open (AP (File));
end Is_Open;
----------
-- Mode --
----------
function Mode (File : in File_Type) return File_Mode is
begin
return To_SIO (FIO.Mode (AP (File)));
end Mode;
----------
-- Name --
----------
function Name (File : in File_Type) return String is
begin
return FIO.Name (AP (File));
end Name;
----------
-- Open --
----------
procedure Open
(File : in out File_Type;
Mode : in File_Mode;
Name : in String;
Form : in String := "")
is
begin
SIO.Open (FP (File), To_FCB (Mode), Name, Form);
end Open;
----------
-- Read --
----------
procedure Read (File : in File_Type; Item : out Element_Type) is
Siz : constant size_t := (Item'Size + SU - 1) / SU;
Rsiz : size_t;
begin
FIO.Check_Read_Status (AP (File));
-- For non-definite type or type with discriminants, read size and
-- raise Program_Error if it is larger than the size of the item.
if not Element_Type'Definite
or else Element_Type'Has_Discriminants
then
FIO.Read_Buf
(AP (File), Rsiz'Address, size_t'Size / System.Storage_Unit);
-- For a type with discriminants, we have to read into a temporary
-- buffer if Item is constrained, to check that the discriminants
-- are correct.
pragma Extensions_Allowed (On);
-- Needed to allow Constrained reference here
if Element_Type'Has_Discriminants
and then Item'Constrained
then
declare
RsizS : constant SSE.Storage_Offset :=
SSE.Storage_Offset (Rsiz - 1);
type SA is new SSE.Storage_Array (0 .. RsizS);
for SA'Alignment use Standard'Maximum_Alignment;
-- We will perform an unchecked conversion of a pointer-to-SA
-- into pointer-to-Element_Type. We need to ensure that the
-- source is always at least as strictly aligned as the target.
type SAP is access all SA;
type ItemP is access all Element_Type;
pragma Warnings (Off);
-- We have to turn warnings off for function To_ItemP,
-- because it gets analyzed for all types, including ones
-- which can't possibly come this way, and for which the
-- size of the access types differs.
function To_ItemP is new Unchecked_Conversion (SAP, ItemP);
pragma Warnings (On);
Buffer : aliased SA;
pragma Unsuppress (Discriminant_Check);
begin
FIO.Read_Buf (AP (File), Buffer'Address, Rsiz);
Item := To_ItemP (Buffer'Access).all;
return;
end;
end if;
-- In the case of a non-definite type, make sure the length is OK.
-- We can't do this in the variant record case, because the size is
-- based on the current discriminant, so may be apparently wrong.
if not Element_Type'Has_Discriminants and then Rsiz > Siz then
raise Program_Error;
end if;
FIO.Read_Buf (AP (File), Item'Address, Rsiz);
-- For definite type without discriminants, use actual size of item
else
FIO.Read_Buf (AP (File), Item'Address, Siz);
end if;
end Read;
-----------
-- Reset --
-----------
procedure Reset (File : in out File_Type; Mode : in File_Mode) is
begin
FIO.Reset (AP (File), To_FCB (Mode));
end Reset;
procedure Reset (File : in out File_Type) is
begin
FIO.Reset (AP (File));
end Reset;
-----------
-- Write --
-----------
procedure Write (File : in File_Type; Item : in Element_Type) is
Siz : constant size_t := (Item'Size + SU - 1) / SU;
begin
FIO.Check_Write_Status (AP (File));
-- For non-definite types or types with discriminants, write the size
if not Element_Type'Definite
or else Element_Type'Has_Discriminants
then
FIO.Write_Buf
(AP (File), Siz'Address, size_t'Size / System.Storage_Unit);
end if;
FIO.Write_Buf (AP (File), Item'Address, Siz);
end Write;
end Ada.Sequential_IO;
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