blob: bd76caa3c0ca714d0735f63b2983dd286daf797e [file] [log] [blame]
------------------------------------------------------------------------------
-- --
-- GNAT RUN-TIME COMPONENTS --
-- --
-- A D A . T E X T _ I O --
-- --
-- B o d y --
-- --
-- Copyright (C) 1992-2022, 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. --
-- --
------------------------------------------------------------------------------
with Ada.Streams; use Ada.Streams;
with Interfaces.C_Streams; use Interfaces.C_Streams;
with System.File_IO;
with System.CRTL;
with System.WCh_Cnv; use System.WCh_Cnv;
with System.WCh_Con; use System.WCh_Con;
with Ada.Unchecked_Conversion;
with Ada.Unchecked_Deallocation;
pragma Elaborate_All (System.File_IO);
-- Needed because of calls to Chain_File in package body elaboration
package body Ada.Text_IO with
SPARK_Mode => Off,
Refined_State => (File_System => (Standard_In,
Standard_Out,
Standard_Err,
Current_In,
Current_Out,
Current_Err,
In_Name,
Out_Name,
Err_Name,
WC_Encoding))
is
package FIO renames System.File_IO;
subtype AP is FCB.AFCB_Ptr;
function To_FCB is new Ada.Unchecked_Conversion (File_Mode, FCB.File_Mode);
function To_TIO is new Ada.Unchecked_Conversion (FCB.File_Mode, File_Mode);
use type FCB.File_Mode;
use type System.CRTL.size_t;
WC_Encoding : constant Character;
pragma Import (C, WC_Encoding, "__gl_wc_encoding");
-- Default wide character encoding
Err_Name : aliased String := "*stderr" & ASCII.NUL;
In_Name : aliased String := "*stdin" & ASCII.NUL;
Out_Name : aliased String := "*stdout" & ASCII.NUL;
-- Names of standard files
--
-- Use "preallocated" strings to avoid calling "new" during the elaboration
-- of the run time. This is needed in the tasking case to avoid calling
-- Task_Lock too early. A filename is expected to end with a null character
-- in the runtime, here the null characters are added just to have a
-- correct filename length.
--
-- Note: the names for these files are bogus, and probably it would be
-- better for these files to have no names, but the ACVC tests insist.
-- We use names that are bound to fail in open etc.
Null_Str : aliased constant String := "";
-- Used as form string for standard files
-----------------------
-- Local Subprograms --
-----------------------
function Get_Upper_Half_Char
(C : Character;
File : File_Type) return Character;
-- This function is shared by Get and Get_Immediate to extract an encoded
-- upper half character value from the given File. The first byte has
-- already been read and is passed in C. The character value is returned as
-- the result, and the file pointer is bumped past the character.
-- Constraint_Error is raised if the encoded value is outside the bounds of
-- type Character.
function Get_Upper_Half_Char_Immed
(C : Character;
File : File_Type) return Character;
-- This routine is identical to Get_Upper_Half_Char, except that the reads
-- are done in Get_Immediate mode (i.e. without waiting for a line return).
function Getc (File : File_Type) return int;
-- Gets next character from file, which has already been checked for being
-- in read status, and returns the character read if no error occurs. The
-- result is EOF if the end of file was read.
function Getc_Immed (File : File_Type) return int;
-- This routine is identical to Getc, except that the read is done in
-- Get_Immediate mode (i.e. without waiting for a line return).
function Has_Upper_Half_Character (Item : String) return Boolean;
-- Returns True if any of the characters is in the range 16#80#-16#FF#
function Nextc (File : File_Type) return int;
-- Returns next character from file without skipping past it (i.e. it is a
-- combination of Getc followed by an Ungetc).
procedure Put_Encoded (File : File_Type; Char : Character);
-- Called to output a character Char to the given File, when the encoding
-- method for the file is other than brackets, and Char is upper half.
procedure Putc (ch : int; File : File_Type);
-- Outputs the given character to the file, which has already been checked
-- for being in output status. Device_Error is raised if the character
-- cannot be written.
procedure Set_WCEM (File : in out File_Type);
-- Called by Open and Create to set the wide character encoding method for
-- the file, processing a WCEM form parameter if one is present. File is
-- IN OUT because it may be closed in case of an error.
procedure Terminate_Line (File : File_Type);
-- If the file is in Write_File or Append_File mode, and the current line
-- is not terminated, then a line terminator is written using New_Line.
-- Note that there is no Terminate_Page routine, because the page mark at
-- the end of the file is implied if necessary.
procedure Ungetc (ch : int; File : File_Type);
-- Pushes back character into stream, using ungetc. The caller has checked
-- that the file is in read status. Device_Error is raised if the character
-- cannot be pushed back. An attempt to push back and end of file character
-- (EOF) is ignored.
-------------------
-- AFCB_Allocate --
-------------------
function AFCB_Allocate (Control_Block : Text_AFCB) return FCB.AFCB_Ptr is
pragma Unreferenced (Control_Block);
begin
return new Text_AFCB;
end AFCB_Allocate;
----------------
-- AFCB_Close --
----------------
procedure AFCB_Close (File : not null access Text_AFCB) is
begin
-- If the file being closed is one of the current files, then close
-- the corresponding current file. It is not clear that this action
-- is required (RM A.10.3(23)) but it seems reasonable, and besides
-- ACVC test CE3208A expects this behavior.
if File = Current_In then
Current_In := null;
elsif File = Current_Out then
Current_Out := null;
elsif File = Current_Err then
Current_Err := null;
end if;
Terminate_Line (File.all'Access);
end AFCB_Close;
---------------
-- AFCB_Free --
---------------
procedure AFCB_Free (File : not null access Text_AFCB) is
FT : File_Type := File.all'Access;
procedure Free is new Ada.Unchecked_Deallocation (Text_AFCB, File_Type);
begin
Free (FT);
end AFCB_Free;
-----------
-- Close --
-----------
procedure Close (File : in out File_Type) is
begin
FIO.Close (AP (File)'Unrestricted_Access);
end Close;
---------
-- Col --
---------
-- Note: we assume that it is impossible in practice for the column
-- to exceed the value of Count'Last, i.e. no check is required for
-- overflow raising layout error.
function Col (File : File_Type) return Positive_Count is
begin
FIO.Check_File_Open (AP (File));
return File.Col;
end Col;
function Col return Positive_Count is
begin
return Col (Current_Out);
end Col;
------------
-- Create --
------------
procedure Create
(File : in out File_Type;
Mode : File_Mode := Out_File;
Name : String := "";
Form : String := "")
is
Dummy_File_Control_Block : Text_AFCB;
pragma Warnings (Off, Dummy_File_Control_Block);
-- Yes, we know this is never assigned a value, only the tag
-- is used for dispatching purposes, so that's expected.
begin
FIO.Open (File_Ptr => AP (File),
Dummy_FCB => Dummy_File_Control_Block,
Mode => To_FCB (Mode),
Name => Name,
Form => Form,
Amethod => 'T',
Creat => True,
Text => True);
File.Self := File;
Set_WCEM (File);
end Create;
-------------------
-- Current_Error --
-------------------
function Current_Error return File_Type is
begin
return Current_Err;
end Current_Error;
function Current_Error return File_Access is
begin
return Current_Err.Self'Access;
end Current_Error;
-------------------
-- Current_Input --
-------------------
function Current_Input return File_Type is
begin
return Current_In;
end Current_Input;
function Current_Input return File_Access is
begin
return Current_In.Self'Access;
end Current_Input;
--------------------
-- Current_Output --
--------------------
function Current_Output return File_Type is
begin
return Current_Out;
end Current_Output;
function Current_Output return File_Access is
begin
return Current_Out.Self'Access;
end Current_Output;
------------
-- Delete --
------------
procedure Delete (File : in out File_Type) is
begin
FIO.Delete (AP (File)'Unrestricted_Access);
end Delete;
-----------------
-- End_Of_File --
-----------------
function End_Of_File (File : File_Type) return Boolean is
ch : int;
begin
FIO.Check_Read_Status (AP (File));
if File.Before_Upper_Half_Character then
return False;
elsif File.Before_LM then
if File.Before_LM_PM then
return Nextc (File) = EOF;
end if;
else
ch := Getc (File);
if ch = EOF then
return True;
elsif ch /= LM then
Ungetc (ch, File);
return False;
else -- ch = LM
File.Before_LM := True;
end if;
end if;
-- Here we are just past the line mark with Before_LM set so that we
-- do not have to try to back up past the LM, thus avoiding the need
-- to back up more than one character.
ch := Getc (File);
if ch = EOF then
return True;
elsif ch = PM and then File.Is_Regular_File then
File.Before_LM_PM := True;
return Nextc (File) = EOF;
-- Here if neither EOF nor PM followed end of line
else
Ungetc (ch, File);
return False;
end if;
end End_Of_File;
function End_Of_File return Boolean is
begin
return End_Of_File (Current_In);
end End_Of_File;
-----------------
-- End_Of_Line --
-----------------
function End_Of_Line (File : File_Type) return Boolean is
ch : int;
begin
FIO.Check_Read_Status (AP (File));
if File.Before_Upper_Half_Character then
return False;
elsif File.Before_LM then
return True;
else
ch := Getc (File);
if ch = EOF then
return True;
else
Ungetc (ch, File);
return (ch = LM);
end if;
end if;
end End_Of_Line;
function End_Of_Line return Boolean is
begin
return End_Of_Line (Current_In);
end End_Of_Line;
-----------------
-- End_Of_Page --
-----------------
function End_Of_Page (File : File_Type) return Boolean is
ch : int;
begin
FIO.Check_Read_Status (AP (File));
if not File.Is_Regular_File then
return False;
elsif File.Before_Upper_Half_Character then
return False;
elsif File.Before_LM then
if File.Before_LM_PM then
return True;
end if;
else
ch := Getc (File);
if ch = EOF then
return True;
elsif ch /= LM then
Ungetc (ch, File);
return False;
else -- ch = LM
File.Before_LM := True;
end if;
end if;
-- Here we are just past the line mark with Before_LM set so that we
-- do not have to try to back up past the LM, thus avoiding the need
-- to back up more than one character.
ch := Nextc (File);
return ch = PM or else ch = EOF;
end End_Of_Page;
function End_Of_Page return Boolean is
begin
return End_Of_Page (Current_In);
end End_Of_Page;
--------------
-- EOF_Char --
--------------
function EOF_Char return Integer is
begin
return EOF;
end EOF_Char;
-----------
-- Flush --
-----------
procedure Flush (File : File_Type) is
begin
FIO.Flush (AP (File));
end Flush;
procedure Flush is
begin
Flush (Current_Out);
end Flush;
----------
-- Form --
----------
function Form (File : File_Type) return String is
begin
return FIO.Form (AP (File));
end Form;
---------
-- Get --
---------
procedure Get
(File : File_Type;
Item : out Character)
is
ch : int;
begin
FIO.Check_Read_Status (AP (File));
if File.Before_Upper_Half_Character then
File.Before_Upper_Half_Character := False;
Item := File.Saved_Upper_Half_Character;
elsif File.Before_LM then
File.Before_LM := False;
File.Col := 1;
if File.Before_LM_PM then
File.Line := 1;
File.Page := File.Page + 1;
File.Before_LM_PM := False;
else
File.Line := File.Line + 1;
end if;
end if;
loop
ch := Getc (File);
if ch = EOF then
raise End_Error;
elsif ch = LM then
File.Line := File.Line + 1;
File.Col := 1;
elsif ch = PM and then File.Is_Regular_File then
File.Page := File.Page + 1;
File.Line := 1;
else
Item := Character'Val (ch);
File.Col := File.Col + 1;
return;
end if;
end loop;
end Get;
procedure Get (Item : out Character) is
begin
Get (Current_In, Item);
end Get;
procedure Get
(File : File_Type;
Item : out String)
is
ch : int;
J : Natural;
begin
FIO.Check_Read_Status (AP (File));
if File.Before_LM then
File.Before_LM := False;
File.Before_LM_PM := False;
File.Col := 1;
if File.Before_LM_PM then
File.Line := 1;
File.Page := File.Page + 1;
File.Before_LM_PM := False;
else
File.Line := File.Line + 1;
end if;
end if;
J := Item'First;
while J <= Item'Last loop
ch := Getc (File);
if ch = EOF then
raise End_Error;
elsif ch = LM then
File.Line := File.Line + 1;
File.Col := 1;
elsif ch = PM and then File.Is_Regular_File then
File.Page := File.Page + 1;
File.Line := 1;
else
Item (J) := Character'Val (ch);
J := J + 1;
File.Col := File.Col + 1;
end if;
end loop;
end Get;
procedure Get (Item : out String) is
begin
Get (Current_In, Item);
end Get;
-------------------
-- Get_Immediate --
-------------------
procedure Get_Immediate
(File : File_Type;
Item : out Character)
is
ch : int;
begin
FIO.Check_Read_Status (AP (File));
if File.Before_Upper_Half_Character then
File.Before_Upper_Half_Character := False;
Item := File.Saved_Upper_Half_Character;
elsif File.Before_LM then
File.Before_LM := False;
File.Before_LM_PM := False;
Item := Character'Val (LM);
else
ch := Getc_Immed (File);
if ch = EOF then
raise End_Error;
else
Item :=
(if not Is_Start_Of_Encoding (Character'Val (ch), File.WC_Method)
then Character'Val (ch)
else Get_Upper_Half_Char_Immed (Character'Val (ch), File));
end if;
end if;
end Get_Immediate;
procedure Get_Immediate
(Item : out Character)
is
begin
Get_Immediate (Current_In, Item);
end Get_Immediate;
procedure Get_Immediate
(File : File_Type;
Item : out Character;
Available : out Boolean)
is
ch : int;
end_of_file : int;
avail : int;
procedure getc_immediate_nowait
(stream : FILEs;
ch : out int;
end_of_file : out int;
avail : out int);
pragma Import (C, getc_immediate_nowait, "getc_immediate_nowait");
begin
FIO.Check_Read_Status (AP (File));
Available := True;
if File.Before_Upper_Half_Character then
File.Before_Upper_Half_Character := False;
Item := File.Saved_Upper_Half_Character;
elsif File.Before_LM then
File.Before_LM := False;
File.Before_LM_PM := False;
Item := Character'Val (LM);
else
getc_immediate_nowait (File.Stream, ch, end_of_file, avail);
if ferror (File.Stream) /= 0 then
raise Device_Error;
elsif end_of_file /= 0 then
raise End_Error;
elsif avail = 0 then
Available := False;
Item := ASCII.NUL;
else
Available := True;
Item :=
(if not Is_Start_Of_Encoding (Character'Val (ch), File.WC_Method)
then Character'Val (ch)
else Get_Upper_Half_Char_Immed (Character'Val (ch), File));
end if;
end if;
end Get_Immediate;
procedure Get_Immediate
(Item : out Character;
Available : out Boolean)
is
begin
Get_Immediate (Current_In, Item, Available);
end Get_Immediate;
--------------
-- Get_Line --
--------------
procedure Get_Line
(File : File_Type;
Item : out String;
Last : out Natural) is separate;
-- The implementation of Ada.Text_IO.Get_Line is split into a subunit so
-- that different implementations can be used on different systems.
procedure Get_Line
(Item : out String;
Last : out Natural)
is
begin
Get_Line (Current_In, Item, Last);
end Get_Line;
function Get_Line (File : File_Type) return String is
function Get_Rest (S : String) return String;
-- This is a recursive function that reads the rest of the line and
-- returns it. S is the part read so far.
--------------
-- Get_Rest --
--------------
function Get_Rest (S : String) return String is
-- The first time we allocate a buffer of size 500. Each following
-- time we allocate a buffer the same size as what we have read so
-- far. This limits us to a logarithmic number of calls to Get_Rest
-- and also ensures only a linear use of stack space.
Buffer : String (1 .. Integer'Max (500, S'Length));
Last : Natural;
begin
Get_Line (File, Buffer, Last);
declare
R : constant String := S & Buffer (1 .. Last);
begin
if Last < Buffer'Last then
return R;
else
pragma Assert (Last = Buffer'Last);
-- If the String has the same length as the buffer, and there
-- is no end of line, check whether we are at the end of file,
-- in which case we have the full String in the buffer.
if End_Of_File (File) then
return R;
else
return Get_Rest (R);
end if;
end if;
end;
end Get_Rest;
-- Start of processing for Get_Line
begin
return Get_Rest ("");
end Get_Line;
function Get_Line return String is
begin
return Get_Line (Current_In);
end Get_Line;
-------------------------
-- Get_Upper_Half_Char --
-------------------------
function Get_Upper_Half_Char
(C : Character;
File : File_Type) return Character
is
Result : Wide_Character;
function In_Char return Character;
-- Function used to obtain additional characters it the wide character
-- sequence is more than one character long.
function WC_In is new Char_Sequence_To_Wide_Char (In_Char);
-------------
-- In_Char --
-------------
function In_Char return Character is
ch : constant Integer := Getc (File);
begin
if ch = EOF then
raise End_Error;
else
return Character'Val (ch);
end if;
end In_Char;
-- Start of processing for Get_Upper_Half_Char
begin
Result := WC_In (C, File.WC_Method);
if Wide_Character'Pos (Result) > 16#FF# then
raise Constraint_Error with
"invalid wide character in Text_'I'O input";
else
return Character'Val (Wide_Character'Pos (Result));
end if;
end Get_Upper_Half_Char;
-------------------------------
-- Get_Upper_Half_Char_Immed --
-------------------------------
function Get_Upper_Half_Char_Immed
(C : Character;
File : File_Type) return Character
is
Result : Wide_Character;
function In_Char return Character;
-- Function used to obtain additional characters it the wide character
-- sequence is more than one character long.
function WC_In is new Char_Sequence_To_Wide_Char (In_Char);
-------------
-- In_Char --
-------------
function In_Char return Character is
ch : constant Integer := Getc_Immed (File);
begin
if ch = EOF then
raise End_Error;
else
return Character'Val (ch);
end if;
end In_Char;
-- Start of processing for Get_Upper_Half_Char_Immed
begin
Result := WC_In (C, File.WC_Method);
if Wide_Character'Pos (Result) > 16#FF# then
raise Constraint_Error with
"invalid wide character in Text_'I'O input";
else
return Character'Val (Wide_Character'Pos (Result));
end if;
end Get_Upper_Half_Char_Immed;
----------
-- Getc --
----------
function Getc (File : File_Type) return int is
ch : int;
begin
ch := fgetc (File.Stream);
if ch = EOF and then ferror (File.Stream) /= 0 then
raise Device_Error;
else
return ch;
end if;
end Getc;
----------------
-- Getc_Immed --
----------------
function Getc_Immed (File : File_Type) return int is
ch : int;
end_of_file : int;
procedure getc_immediate
(stream : FILEs; ch : out int; end_of_file : out int);
pragma Import (C, getc_immediate, "getc_immediate");
begin
FIO.Check_Read_Status (AP (File));
if File.Before_LM then
File.Before_LM := False;
File.Before_LM_PM := False;
ch := LM;
else
getc_immediate (File.Stream, ch, end_of_file);
if ferror (File.Stream) /= 0 then
raise Device_Error;
elsif end_of_file /= 0 then
return EOF;
end if;
end if;
return ch;
end Getc_Immed;
------------------------------
-- Has_Upper_Half_Character --
------------------------------
function Has_Upper_Half_Character (Item : String) return Boolean is
begin
for J in Item'Range loop
if Character'Pos (Item (J)) >= 16#80# then
return True;
end if;
end loop;
return False;
end Has_Upper_Half_Character;
-------------------------------
-- Initialize_Standard_Files --
-------------------------------
procedure Initialize_Standard_Files is
begin
Standard_Err.Stream := stderr;
Standard_Err.Name := Err_Name'Access;
Standard_Err.Form := Null_Str'Unrestricted_Access;
Standard_Err.Mode := FCB.Out_File;
Standard_Err.Is_Regular_File := is_regular_file (fileno (stderr)) /= 0;
Standard_Err.Is_Temporary_File := False;
Standard_Err.Is_System_File := True;
Standard_Err.Text_Encoding := Default_Text;
Standard_Err.Access_Method := 'T';
Standard_Err.Self := Standard_Err;
Standard_Err.WC_Method := Default_WCEM;
Standard_In.Stream := stdin;
Standard_In.Name := In_Name'Access;
Standard_In.Form := Null_Str'Unrestricted_Access;
Standard_In.Mode := FCB.In_File;
Standard_In.Is_Regular_File := is_regular_file (fileno (stdin)) /= 0;
Standard_In.Is_Temporary_File := False;
Standard_In.Is_System_File := True;
Standard_In.Text_Encoding := Default_Text;
Standard_In.Access_Method := 'T';
Standard_In.Self := Standard_In;
Standard_In.WC_Method := Default_WCEM;
Standard_Out.Stream := stdout;
Standard_Out.Name := Out_Name'Access;
Standard_Out.Form := Null_Str'Unrestricted_Access;
Standard_Out.Mode := FCB.Out_File;
Standard_Out.Is_Regular_File := is_regular_file (fileno (stdout)) /= 0;
Standard_Out.Is_Temporary_File := False;
Standard_Out.Is_System_File := True;
Standard_Out.Text_Encoding := Default_Text;
Standard_Out.Access_Method := 'T';
Standard_Out.Self := Standard_Out;
Standard_Out.WC_Method := Default_WCEM;
FIO.Make_Unbuffered (AP (Standard_Out));
FIO.Make_Unbuffered (AP (Standard_Err));
end Initialize_Standard_Files;
-------------
-- Is_Open --
-------------
function Is_Open (File : File_Type) return Boolean is
begin
return FIO.Is_Open (AP (File));
end Is_Open;
----------
-- Line --
----------
-- Note: we assume that it is impossible in practice for the line
-- to exceed the value of Count'Last, i.e. no check is required for
-- overflow raising layout error.
function Line (File : File_Type) return Positive_Count is
begin
FIO.Check_File_Open (AP (File));
return File.Line;
end Line;
function Line return Positive_Count is
begin
return Line (Current_Out);
end Line;
-----------------
-- Line_Length --
-----------------
function Line_Length (File : File_Type) return Count is
begin
FIO.Check_Write_Status (AP (File));
return File.Line_Length;
end Line_Length;
function Line_Length return Count is
begin
return Line_Length (Current_Out);
end Line_Length;
----------------
-- Look_Ahead --
----------------
procedure Look_Ahead
(File : File_Type;
Item : out Character;
End_Of_Line : out Boolean)
is
ch : int;
begin
FIO.Check_Read_Status (AP (File));
-- If we are logically before a line mark, we can return immediately
if File.Before_LM then
End_Of_Line := True;
Item := ASCII.NUL;
-- If we are before an upper half character just return it (this can
-- happen if there are two calls to Look_Ahead in a row).
elsif File.Before_Upper_Half_Character then
End_Of_Line := False;
Item := File.Saved_Upper_Half_Character;
-- Otherwise we must read a character from the input stream
else
ch := Getc (File);
if ch = LM
or else ch = EOF
or else (ch = PM and then File.Is_Regular_File)
then
End_Of_Line := True;
Ungetc (ch, File);
Item := ASCII.NUL;
-- Case where character obtained does not represent the start of an
-- encoded sequence so it stands for itself and we can unget it with
-- no difficulty.
elsif not Is_Start_Of_Encoding
(Character'Val (ch), File.WC_Method)
then
End_Of_Line := False;
Ungetc (ch, File);
Item := Character'Val (ch);
-- For the start of an encoding, we read the character using the
-- Get_Upper_Half_Char routine. It will occupy more than one byte
-- so we can't put it back with ungetc. Instead we save it in the
-- control block, setting a flag that everyone interested in reading
-- characters must test before reading the stream.
else
Item := Get_Upper_Half_Char (Character'Val (ch), File);
End_Of_Line := False;
File.Saved_Upper_Half_Character := Item;
File.Before_Upper_Half_Character := True;
end if;
end if;
end Look_Ahead;
procedure Look_Ahead
(Item : out Character;
End_Of_Line : out Boolean)
is
begin
Look_Ahead (Current_In, Item, End_Of_Line);
end Look_Ahead;
----------
-- Mode --
----------
function Mode (File : File_Type) return File_Mode is
begin
return To_TIO (FIO.Mode (AP (File)));
end Mode;
----------
-- Name --
----------
function Name (File : File_Type) return String is
begin
return FIO.Name (AP (File));
end Name;
--------------
-- New_Line --
--------------
procedure New_Line
(File : File_Type;
Spacing : Positive_Count := 1)
is
begin
-- Raise Constraint_Error if out of range value. The reason for this
-- explicit test is that we don't want junk values around, even if
-- checks are off in the caller.
if not Spacing'Valid then
raise Constraint_Error;
end if;
FIO.Check_Write_Status (AP (File));
for K in 1 .. Spacing loop
Putc (LM, File);
File.Line := File.Line + 1;
if File.Page_Length /= 0
and then File.Line > File.Page_Length
then
Putc (PM, File);
File.Line := 1;
File.Page := File.Page + 1;
end if;
end loop;
File.Col := 1;
end New_Line;
procedure New_Line (Spacing : Positive_Count := 1) is
begin
New_Line (Current_Out, Spacing);
end New_Line;
--------------
-- New_Page --
--------------
procedure New_Page (File : File_Type) is
begin
FIO.Check_Write_Status (AP (File));
if File.Col /= 1 or else File.Line = 1 then
Putc (LM, File);
end if;
Putc (PM, File);
File.Page := File.Page + 1;
File.Line := 1;
File.Col := 1;
end New_Page;
procedure New_Page is
begin
New_Page (Current_Out);
end New_Page;
-----------
-- Nextc --
-----------
function Nextc (File : File_Type) return int is
ch : int;
begin
ch := fgetc (File.Stream);
if ch = EOF then
if ferror (File.Stream) /= 0 then
raise Device_Error;
end if;
else
if ungetc (ch, File.Stream) = EOF then
raise Device_Error;
end if;
end if;
return ch;
end Nextc;
----------
-- Open --
----------
procedure Open
(File : in out File_Type;
Mode : File_Mode;
Name : String;
Form : String := "")
is
Dummy_File_Control_Block : Text_AFCB;
pragma Warnings (Off, Dummy_File_Control_Block);
-- Yes, we know this is never assigned a value, only the tag
-- is used for dispatching purposes, so that's expected.
begin
FIO.Open (File_Ptr => AP (File),
Dummy_FCB => Dummy_File_Control_Block,
Mode => To_FCB (Mode),
Name => Name,
Form => Form,
Amethod => 'T',
Creat => False,
Text => True);
File.Self := File;
Set_WCEM (File);
end Open;
----------
-- Page --
----------
-- Note: we assume that it is impossible in practice for the page
-- to exceed the value of Count'Last, i.e. no check is required for
-- overflow raising layout error.
function Page (File : File_Type) return Positive_Count is
begin
FIO.Check_File_Open (AP (File));
return File.Page;
end Page;
function Page return Positive_Count is
begin
return Page (Current_Out);
end Page;
-----------------
-- Page_Length --
-----------------
function Page_Length (File : File_Type) return Count is
begin
FIO.Check_Write_Status (AP (File));
return File.Page_Length;
end Page_Length;
function Page_Length return Count is
begin
return Page_Length (Current_Out);
end Page_Length;
---------
-- Put --
---------
procedure Put
(File : File_Type;
Item : Character)
is
begin
FIO.Check_Write_Status (AP (File));
if File.Line_Length /= 0 and then File.Col > File.Line_Length then
New_Line (File);
end if;
-- If lower half character, or brackets encoding, output directly
if Character'Pos (Item) < 16#80#
or else File.WC_Method = WCEM_Brackets
then
if fputc (Character'Pos (Item), File.Stream) = EOF then
raise Device_Error;
end if;
-- Case of upper half character with non-brackets encoding
else
Put_Encoded (File, Item);
end if;
File.Col := File.Col + 1;
end Put;
procedure Put (Item : Character) is
begin
Put (Current_Out, Item);
end Put;
---------
-- Put --
---------
procedure Put
(File : File_Type;
Item : String)
is
begin
FIO.Check_Write_Status (AP (File));
-- Only have something to do if string is non-null
if Item'Length > 0 then
-- If we have bounded lines, or if the file encoding is other than
-- Brackets and the string has at least one upper half character,
-- then output the string character by character.
if File.Line_Length /= 0
or else (File.WC_Method /= WCEM_Brackets
and then Has_Upper_Half_Character (Item))
then
for J in Item'Range loop
Put (File, Item (J));
end loop;
-- Otherwise we can output the entire string at once. Note that if
-- there are LF or FF characters in the string, we do not bother to
-- count them as line or page terminators.
else
FIO.Write_Buf (AP (File), Item'Address, Item'Length);
File.Col := File.Col + Item'Length;
end if;
end if;
end Put;
procedure Put (Item : String) is
begin
Put (Current_Out, Item);
end Put;
-----------------
-- Put_Encoded --
-----------------
procedure Put_Encoded (File : File_Type; Char : Character) is
procedure Out_Char (C : Character);
-- Procedure to output one character of an upper half encoded sequence
procedure WC_Out is new Wide_Char_To_Char_Sequence (Out_Char);
--------------
-- Out_Char --
--------------
procedure Out_Char (C : Character) is
begin
Putc (Character'Pos (C), File);
end Out_Char;
-- Start of processing for Put_Encoded
begin
WC_Out (Wide_Character'Val (Character'Pos (Char)), File.WC_Method);
end Put_Encoded;
--------------
-- Put_Line --
--------------
procedure Put_Line
(File : File_Type;
Item : String)
is
Ilen : Natural := Item'Length;
Istart : Natural := Item'First;
begin
FIO.Check_Write_Status (AP (File));
-- If we have bounded lines, or if the file encoding is other than
-- Brackets and the string has at least one upper half character, then
-- output the string character by character.
if File.Line_Length /= 0
or else (File.WC_Method /= WCEM_Brackets
and then Has_Upper_Half_Character (Item))
then
for J in Item'Range loop
Put (File, Item (J));
end loop;
New_Line (File);
return;
end if;
-- Normal case where we do not need to output character by character
-- We setup a single string that has the necessary terminators and
-- then write it with a single call. The reason for doing this is
-- that it gives better behavior for the use of Put_Line in multi-
-- tasking programs, since often the OS will treat the entire put
-- operation as an atomic operation.
-- We only do this if the message is 512 characters or less in length,
-- since otherwise Put_Line would use an unbounded amount of stack
-- space and could cause undetected stack overflow. If we have a
-- longer string, then output the first part separately to avoid this.
if Ilen > 512 then
FIO.Write_Buf (AP (File), Item'Address, size_t (Ilen - 512));
Istart := Istart + Ilen - 512;
Ilen := 512;
end if;
-- Now prepare the string with its terminator
declare
Buffer : String (1 .. Ilen + 2);
Plen : size_t;
begin
Buffer (1 .. Ilen) := Item (Istart .. Item'Last);
Buffer (Ilen + 1) := Character'Val (LM);
if File.Page_Length /= 0
and then File.Line > File.Page_Length
then
Buffer (Ilen + 2) := Character'Val (PM);
Plen := size_t (Ilen) + 2;
File.Line := 1;
File.Page := File.Page + 1;
else
Plen := size_t (Ilen) + 1;
File.Line := File.Line + 1;
end if;
FIO.Write_Buf (AP (File), Buffer'Address, Plen);
File.Col := 1;
end;
end Put_Line;
procedure Put_Line (Item : String) is
begin
Put_Line (Current_Out, Item);
end Put_Line;
----------
-- Putc --
----------
procedure Putc (ch : int; File : File_Type) is
begin
if fputc (ch, File.Stream) = EOF then
raise Device_Error;
end if;
end Putc;
----------
-- Read --
----------
-- This is the primitive Stream Read routine, used when a Text_IO file
-- is treated directly as a stream using Text_IO.Streams.Stream.
procedure Read
(File : in out Text_AFCB;
Item : out Stream_Element_Array;
Last : out Stream_Element_Offset)
is
Discard_ch : int;
pragma Warnings (Off, Discard_ch);
begin
-- Need to deal with Before_Upper_Half_Character ???
if File.Mode /= FCB.In_File then
raise Mode_Error;
end if;
-- Deal with case where our logical and physical position do not match
-- because of being after an LM or LM-PM sequence when in fact we are
-- logically positioned before it.
if File.Before_LM then
-- If we are before a PM, then it is possible for a stream read
-- to leave us after the LM and before the PM, which is a bit
-- odd. The easiest way to deal with this is to unget the PM,
-- so we are indeed positioned between the characters. This way
-- further stream read operations will work correctly, and the
-- effect on text processing is a little weird, but what can
-- be expected if stream and text input are mixed this way?
if File.Before_LM_PM then
Discard_ch := ungetc (PM, File.Stream);
File.Before_LM_PM := False;
end if;
File.Before_LM := False;
Item (Item'First) := Stream_Element (Character'Pos (ASCII.LF));
if Item'Length = 1 then
Last := Item'Last;
else
Last :=
Item'First +
Stream_Element_Offset
(fread (buffer => Item'Address,
index => size_t (Item'First + 1),
size => 1,
count => Item'Length - 1,
stream => File.Stream));
end if;
return;
end if;
-- Now we do the read. Since this is a text file, it is normally in
-- text mode, but stream data must be read in binary mode, so we
-- temporarily set binary mode for the read, resetting it after.
-- These calls have no effect in a system (like Unix) where there is
-- no distinction between text and binary files.
set_binary_mode (fileno (File.Stream));
Last :=
Item'First +
Stream_Element_Offset
(fread (Item'Address, 1, Item'Length, File.Stream)) - 1;
if Last < Item'Last then
if ferror (File.Stream) /= 0 then
raise Device_Error;
end if;
end if;
set_text_mode (fileno (File.Stream));
end Read;
-----------
-- Reset --
-----------
procedure Reset
(File : in out File_Type;
Mode : File_Mode)
is
begin
-- Don't allow change of mode for current file (RM A.10.2(5))
if (File = Current_In or else
File = Current_Out or else
File = Current_Error)
and then To_FCB (Mode) /= File.Mode
then
raise Mode_Error;
end if;
Terminate_Line (File);
FIO.Reset (AP (File)'Unrestricted_Access, To_FCB (Mode));
File.Page := 1;
File.Line := 1;
File.Col := 1;
File.Line_Length := 0;
File.Page_Length := 0;
File.Before_LM := False;
File.Before_LM_PM := False;
end Reset;
procedure Reset (File : in out File_Type) is
begin
Terminate_Line (File);
FIO.Reset (AP (File)'Unrestricted_Access);
File.Page := 1;
File.Line := 1;
File.Col := 1;
File.Line_Length := 0;
File.Page_Length := 0;
File.Before_LM := False;
File.Before_LM_PM := False;
end Reset;
-------------
-- Set_Col --
-------------
procedure Set_Col
(File : File_Type;
To : Positive_Count)
is
ch : int;
begin
-- Raise Constraint_Error if out of range value. The reason for this
-- explicit test is that we don't want junk values around, even if
-- checks are off in the caller.
if not To'Valid then
raise Constraint_Error;
end if;
FIO.Check_File_Open (AP (File));
-- Output case
if Mode (File) >= Out_File then
-- Error if we attempt to set Col to a value greater than the
-- maximum permissible line length.
if File.Line_Length /= 0 and then To > File.Line_Length then
raise Layout_Error;
end if;
-- If we are behind current position, then go to start of new line
if To < File.Col then
New_Line (File);
end if;
-- Loop to output blanks till we are at the required column
while File.Col < To loop
Put (File, ' ');
end loop;
-- Input case
else
-- If we are logically before a LM, but physically after it, the
-- file position still reflects the position before the LM, so eat
-- it now and adjust the file position appropriately.
if File.Before_LM then
File.Before_LM := False;
File.Before_LM_PM := False;
File.Line := File.Line + 1;
File.Col := 1;
end if;
-- Loop reading characters till we get one at the required Col value
loop
-- Read next character. The reason we have to read ahead is to
-- skip formatting characters, the effect of Set_Col is to set
-- us to a real character with the right Col value, and format
-- characters don't count.
ch := Getc (File);
-- Error if we hit an end of file
if ch = EOF then
raise End_Error;
-- If line mark, eat it and adjust file position
elsif ch = LM then
File.Line := File.Line + 1;
File.Col := 1;
-- If recognized page mark, eat it, and adjust file position
elsif ch = PM and then File.Is_Regular_File then
File.Page := File.Page + 1;
File.Line := 1;
File.Col := 1;
-- Otherwise this is the character we are looking for, so put it
-- back in the input stream (we have not adjusted the file
-- position yet, so everything is set right after this ungetc).
elsif To = File.Col then
Ungetc (ch, File);
return;
-- Keep skipping characters if we are not there yet, updating the
-- file position past the skipped character.
else
File.Col := File.Col + 1;
end if;
end loop;
end if;
end Set_Col;
procedure Set_Col (To : Positive_Count) is
begin
Set_Col (Current_Out, To);
end Set_Col;
---------------
-- Set_Error --
---------------
procedure Set_Error (File : File_Type) is
begin
FIO.Check_Write_Status (AP (File));
Current_Err := File;
end Set_Error;
---------------
-- Set_Input --
---------------
procedure Set_Input (File : File_Type) is
begin
FIO.Check_Read_Status (AP (File));
Current_In := File;
end Set_Input;
--------------
-- Set_Line --
--------------
procedure Set_Line
(File : File_Type;
To : Positive_Count)
is
begin
-- Raise Constraint_Error if out of range value. The reason for this
-- explicit test is that we don't want junk values around, even if
-- checks are off in the caller.
if not To'Valid then
raise Constraint_Error;
end if;
FIO.Check_File_Open (AP (File));
if To = File.Line then
return;
end if;
if Mode (File) >= Out_File then
if File.Page_Length /= 0 and then To > File.Page_Length then
raise Layout_Error;
end if;
if To < File.Line then
New_Page (File);
end if;
while File.Line < To loop
New_Line (File);
end loop;
else
while To /= File.Line loop
Skip_Line (File);
end loop;
end if;
end Set_Line;
procedure Set_Line (To : Positive_Count) is
begin
Set_Line (Current_Out, To);
end Set_Line;
---------------------
-- Set_Line_Length --
---------------------
procedure Set_Line_Length (File : File_Type; To : Count) is
begin
-- Raise Constraint_Error if out of range value. The reason for this
-- explicit test is that we don't want junk values around, even if
-- checks are off in the caller.
if not To'Valid then
raise Constraint_Error;
end if;
FIO.Check_Write_Status (AP (File));
File.Line_Length := To;
end Set_Line_Length;
procedure Set_Line_Length (To : Count) is
begin
Set_Line_Length (Current_Out, To);
end Set_Line_Length;
----------------
-- Set_Output --
----------------
procedure Set_Output (File : File_Type) is
begin
FIO.Check_Write_Status (AP (File));
Current_Out := File;
end Set_Output;
---------------------
-- Set_Page_Length --
---------------------
procedure Set_Page_Length (File : File_Type; To : Count) is
begin
-- Raise Constraint_Error if out of range value. The reason for this
-- explicit test is that we don't want junk values around, even if
-- checks are off in the caller.
if not To'Valid then
raise Constraint_Error;
end if;
FIO.Check_Write_Status (AP (File));
File.Page_Length := To;
end Set_Page_Length;
procedure Set_Page_Length (To : Count) is
begin
Set_Page_Length (Current_Out, To);
end Set_Page_Length;
--------------
-- Set_WCEM --
--------------
procedure Set_WCEM (File : in out File_Type) is
Start : Natural;
Stop : Natural;
begin
FIO.Form_Parameter (File.Form.all, "wcem", Start, Stop);
if Start = 0 then
File.WC_Method := Default_WCEM;
else
if Stop = Start then
for J in WC_Encoding_Letters'Range loop
if File.Form (Start) = WC_Encoding_Letters (J) then
File.WC_Method := J;
return;
end if;
end loop;
end if;
Close (File);
raise Use_Error with "invalid WCEM form parameter";
end if;
end Set_WCEM;
---------------
-- Skip_Line --
---------------
procedure Skip_Line
(File : File_Type;
Spacing : Positive_Count := 1)
is
ch : int;
begin
-- Raise Constraint_Error if out of range value. The reason for this
-- explicit test is that we don't want junk values around, even if
-- checks are off in the caller.
if not Spacing'Valid then
raise Constraint_Error;
end if;
FIO.Check_Read_Status (AP (File));
for L in 1 .. Spacing loop
if File.Before_LM then
File.Before_LM := False;
-- Note that if File.Before_LM_PM is currently set, we also have
-- to reset it (because it makes sense for Before_LM_PM to be set
-- only when Before_LM is also set). This is done later on in this
-- subprogram, as soon as Before_LM_PM has been taken into account
-- for the purpose of page and line counts.
else
ch := Getc (File);
-- If at end of file now, then immediately raise End_Error. Note
-- that we can never be positioned between a line mark and a page
-- mark, so if we are at the end of file, we cannot logically be
-- before the implicit page mark that is at the end of the file.
-- For the same reason, we do not need an explicit check for a
-- page mark. If there is a FF in the middle of a line, the file
-- is not in canonical format and we do not care about the page
-- numbers for files other than ones in canonical format.
if ch = EOF then
raise End_Error;
end if;
-- If not at end of file, then loop till we get to an LM or EOF.
-- The latter case happens only in non-canonical files where the
-- last line is not terminated by LM, but we don't want to blow
-- up for such files, so we assume an implicit LM in this case.
loop
exit when ch = LM or else ch = EOF;
ch := Getc (File);
end loop;
end if;
-- We have got past a line mark, now, for a regular file only,
-- see if a page mark immediately follows this line mark and
-- if so, skip past the page mark as well. We do not do this
-- for non-regular files, since it would cause an undesirable
-- wait for an additional character.
File.Col := 1;
File.Line := File.Line + 1;
if File.Before_LM_PM then
File.Page := File.Page + 1;
File.Line := 1;
File.Before_LM_PM := False;
elsif File.Is_Regular_File then
ch := Getc (File);
-- Page mark can be explicit, or implied at the end of the file
if (ch = PM or else ch = EOF)
and then File.Is_Regular_File
then
File.Page := File.Page + 1;
File.Line := 1;
else
Ungetc (ch, File);
end if;
end if;
end loop;
File.Before_Upper_Half_Character := False;
end Skip_Line;
procedure Skip_Line (Spacing : Positive_Count := 1) is
begin
Skip_Line (Current_In, Spacing);
end Skip_Line;
---------------
-- Skip_Page --
---------------
procedure Skip_Page (File : File_Type) is
ch : int;
begin
FIO.Check_Read_Status (AP (File));
-- If at page mark already, just skip it
if File.Before_LM_PM then
File.Before_LM := False;
File.Before_LM_PM := False;
File.Page := File.Page + 1;
File.Line := 1;
File.Col := 1;
return;
end if;
-- This is a bit tricky, if we are logically before an LM then
-- it is not an error if we are at an end of file now, since we
-- are not really at it.
if File.Before_LM then
File.Before_LM := False;
File.Before_LM_PM := False;
ch := Getc (File);
-- Otherwise we do raise End_Error if we are at the end of file now
else
ch := Getc (File);
if ch = EOF then
raise End_Error;
end if;
end if;
-- Now we can just rumble along to the next page mark, or to the
-- end of file, if that comes first. The latter case happens when
-- the page mark is implied at the end of file.
loop
exit when ch = EOF
or else (ch = PM and then File.Is_Regular_File);
ch := Getc (File);
end loop;
File.Page := File.Page + 1;
File.Line := 1;
File.Col := 1;
File.Before_Upper_Half_Character := False;
end Skip_Page;
procedure Skip_Page is
begin
Skip_Page (Current_In);
end Skip_Page;
--------------------
-- Standard_Error --
--------------------
function Standard_Error return File_Type is
begin
return Standard_Err;
end Standard_Error;
function Standard_Error return File_Access is
begin
return Standard_Err'Access;
end Standard_Error;
--------------------
-- Standard_Input --
--------------------
function Standard_Input return File_Type is
begin
return Standard_In;
end Standard_Input;
function Standard_Input return File_Access is
begin
return Standard_In'Access;
end Standard_Input;
---------------------
-- Standard_Output --
---------------------
function Standard_Output return File_Type is
begin
return Standard_Out;
end Standard_Output;
function Standard_Output return File_Access is
begin
return Standard_Out'Access;
end Standard_Output;
--------------------
-- Terminate_Line --
--------------------
procedure Terminate_Line (File : File_Type) is
begin
FIO.Check_File_Open (AP (File));
-- For file other than In_File, test for needing to terminate last line
if Mode (File) /= In_File then
-- If not at start of line definition need new line
if File.Col /= 1 then
New_Line (File);
-- For files other than standard error and standard output, we
-- make sure that an empty file has a single line feed, so that
-- it is properly formatted. We avoid this for the standard files
-- because it is too much of a nuisance to have these odd line
-- feeds when nothing has been written to the file.
-- We also avoid this for files opened in append mode, in
-- accordance with (RM A.8.2(10))
elsif (File /= Standard_Err and then File /= Standard_Out)
and then (File.Line = 1 and then File.Page = 1)
and then Mode (File) = Out_File
then
New_Line (File);
end if;
end if;
end Terminate_Line;
------------
-- Ungetc --
------------
procedure Ungetc (ch : int; File : File_Type) is
begin
if ch /= EOF then
if ungetc (ch, File.Stream) = EOF then
raise Device_Error;
end if;
end if;
end Ungetc;
-----------
-- Write --
-----------
-- This is the primitive Stream Write routine, used when a Text_IO file
-- is treated directly as a stream using Text_IO.Streams.Stream.
procedure Write
(File : in out Text_AFCB;
Item : Stream_Element_Array)
is
pragma Warnings (Off, File);
-- Because in this implementation we don't need IN OUT, we only read
function Has_Translated_Characters return Boolean;
-- return True if Item array contains a character which will be
-- translated under the text file mode. There is only one such
-- character under DOS based systems which is character 10.
text_translation_required : Boolean;
for text_translation_required'Size use Character'Size;
pragma Import (C, text_translation_required,
"__gnat_text_translation_required");
Siz : constant size_t := Item'Length;
-------------------------------
-- Has_Translated_Characters --
-------------------------------
function Has_Translated_Characters return Boolean is
begin
for K in Item'Range loop
if Item (K) = 10 then
return True;
end if;
end loop;
return False;
end Has_Translated_Characters;
Needs_Binary_Write : constant Boolean :=
text_translation_required and then Has_Translated_Characters;
-- Start of processing for Write
begin
if File.Mode = FCB.In_File then
raise Mode_Error;
end if;
-- Now we do the write. Since this is a text file, it is normally in
-- text mode, but stream data must be written in binary mode, so we
-- temporarily set binary mode for the write, resetting it after. This
-- is done only if needed (i.e. there is some characters in Item which
-- needs to be written using the binary mode).
-- These calls have no effect in a system (like Unix) where there is
-- no distinction between text and binary files.
-- Since the character translation is done at the time the buffer is
-- written (this is true under Windows) we first flush current buffer
-- with text mode if needed.
if Needs_Binary_Write then
if fflush (File.Stream) = -1 then
raise Device_Error;
end if;
set_binary_mode (fileno (File.Stream));
end if;
if fwrite (Item'Address, 1, Siz, File.Stream) /= Siz then
raise Device_Error;
end if;
-- At this point we need to flush the buffer using the binary mode then
-- we reset to text mode.
if Needs_Binary_Write then
if fflush (File.Stream) = -1 then
raise Device_Error;
end if;
set_text_mode (fileno (File.Stream));
end if;
end Write;
begin
-- Initialize Standard Files
for J in WC_Encoding_Method loop
if WC_Encoding = WC_Encoding_Letters (J) then
Default_WCEM := J;
end if;
end loop;
Initialize_Standard_Files;
FIO.Chain_File (AP (Standard_In));
FIO.Chain_File (AP (Standard_Out));
FIO.Chain_File (AP (Standard_Err));
end Ada.Text_IO;