File : i-cstrea.adb
------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
5 -- I N T E R F A C E S . C _ S T R E A M S --
-- --
-- B o d y --
-- --
-- $Revision: 1.7 $
10 -- --
-- Copyright (C) 1996-2001 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- --
15 -- 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 --
20 -- 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 --
25 -- 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. --
30 -- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- It is now maintained by Ada Core Technologies Inc (http://www.gnat.com). --
-- --
------------------------------------------------------------------------------
35
-- This is the default version which just calls the C versions directly
-- Note: the reason that we provide for specialization here is that on
-- some systems, notably VMS, we may need to worry about buffering.
40 with Unchecked_Conversion;
package body Interfaces.C_Streams is
------------
45 -- fread --
------------
function fread
(buffer : voids;
50 size : size_t;
count : size_t;
stream : FILEs)
return size_t
is
55 function C_fread
(buffer : voids;
size : size_t;
count : size_t;
stream : FILEs)
60 return size_t;
pragma Import (C, C_fread, "fread");
begin
return C_fread (buffer, size, count, stream);
65 end fread;
------------
-- fread --
------------
70
function fread
(buffer : voids;
index : size_t;
size : size_t;
75 count : size_t;
stream : FILEs)
return size_t
is
function C_fread
80 (buffer : voids;
size : size_t;
count : size_t;
stream : FILEs)
return size_t;
85 pragma Import (C, C_fread, "fread");
type Byte_Buffer is array (0 .. size_t'Last / 2 - 1) of Unsigned_8;
-- This should really be 0 .. size_t'last, but there is a problem
-- in gigi in handling such types (introduced in GCC 3 Sep 2001)
90 -- since the size in bytes of this array overflows ???
type Acc_Bytes is access all Byte_Buffer;
function To_Acc_Bytes is new Unchecked_Conversion (voids, Acc_Bytes);
95
begin
return C_fread
(To_Acc_Bytes (buffer) (index * size)'Address, size, count, stream);
end fread;
100
------------
-- fwrite --
------------
105 function fwrite
(buffer : voids;
size : size_t;
count : size_t;
stream : FILEs)
110 return size_t
is
function C_fwrite
(buffer : voids;
size : size_t;
115 count : size_t;
stream : FILEs)
return size_t;
pragma Import (C, C_fwrite, "fwrite");
120 begin
return C_fwrite (buffer, size, count, stream);
end fwrite;
-------------
125 -- setvbuf --
-------------
function setvbuf
(stream : FILEs;
130 buffer : chars;
mode : int;
size : size_t)
return int
is
135 function C_setvbuf
(stream : FILEs;
buffer : chars;
mode : int;
size : size_t)
140 return int;
pragma Import (C, C_setvbuf, "setvbuf");
begin
return C_setvbuf (stream, buffer, mode, size);
145 end setvbuf;
end Interfaces.C_Streams;