------------------------------------------------------------------------------ -- -- -- GNAT RUNTIME COMPONENTS -- -- -- -- A D A . S E Q U E N T I A L _ I O -- -- -- -- B o d y -- -- -- -- Copyright (C) 1992-2003, 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;