gcc/ada/a-ztexio.ads

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT RUN-TIME COMPONENTS                         --
   4 --                                                                          --
   5 --                A D A . W I D E _ W I D E _ T E X T _ I O                 --
   6 --                                                                          --
   7 --                                 S p e c                                  --
   8 --                                                                          --
   9 --          Copyright (C) 1992-2009, Free Software Foundation, Inc.         --
  10 --                                                                          --
  11 -- This specification is derived from the Ada Reference Manual for use with --
  12 -- GNAT. The copyright notice above, and the license provisions that follow --
  13 -- apply solely to the  contents of the part following the private keyword. --
  14 --                                                                          --
  15 -- GNAT is free software;  you can  redistribute it  and/or modify it under --
  16 -- terms of the  GNU General Public License as published  by the Free Soft- --
  17 -- ware  Foundation;  either version 3,  or (at your option) any later ver- --
  18 -- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
  19 -- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
  20 -- or FITNESS FOR A PARTICULAR PURPOSE.                                     --
  21 --                                                                          --
  22 -- As a special exception under Section 7 of GPL version 3, you are granted --
  23 -- additional permissions described in the GCC Runtime Library Exception,   --
  24 -- version 3.1, as published by the Free Software Foundation.               --
  25 --                                                                          --
  26 -- You should have received a copy of the GNU General Public License and    --
  27 -- a copy of the GCC Runtime Library Exception along with this program;     --
  28 -- see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see    --
  29 -- <http://www.gnu.org/licenses/>.                                          --
  30 --                                                                          --
  31 -- GNAT was originally developed  by the GNAT team at  New York University. --
  32 -- Extensive contributions were provided by Ada Core Technologies Inc.      --
  33 --                                                                          --
  34 ------------------------------------------------------------------------------
  35
  36 --  Note: the generic subpackages of Wide_Wide_Text_IO (Integer_IO, Float_IO,
  37 --  Fixed_IO, Modular_IO, Decimal_IO and Enumeration_IO) appear as private
  38 --  children in GNAT. These children are with'ed automatically if they are
  39 --  referenced, so this rearrangement is invisible to user programs, but has
  40 --  the advantage that only the needed parts of Wide_Wide_Text_IO are processed
  41 --  and loaded.
  42
  43 with Ada.IO_Exceptions;
  44 with Ada.Streams;
  45 with System;
  46 with System.File_Control_Block;
  47 with System.WCh_Con;
  48
  49 package Ada.Wide_Wide_Text_IO is
  50
  51    type File_Type is limited private;
  52    type File_Mode is (In_File, Out_File, Append_File);
  53
  54    --  The following representation clause allows the use of unchecked
  55    --  conversion for rapid translation between the File_Mode type
  56    --  used in this package and System.File_IO.
  57
  58    for File_Mode use
  59      (In_File     => 0,  -- System.FIle_IO.File_Mode'Pos (In_File)
  60       Out_File    => 2,  -- System.File_IO.File_Mode'Pos (Out_File)
  61       Append_File => 3); -- System.File_IO.File_Mode'Pos (Append_File)
  62
  63    type Count is range 0 .. Natural'Last;
  64    --  The value of Count'Last must be large enough so that the assumption
  65    --  enough so that the assumption that the Line, Column and Page
  66    --  counts can never exceed this value is a valid assumption.
  67
  68    subtype Positive_Count is Count range 1 .. Count'Last;
  69
  70    Unbounded : constant Count := 0;
  71    --  Line and page length
  72
  73    subtype Field is Integer range 0 .. 255;
  74    --  Note: if for any reason, there is a need to increase this value,
  75    --  then it will be necessary to change the corresponding value in
  76    --  System.Img_Real in file s-imgrea.adb.
  77
  78    subtype Number_Base is Integer range 2 .. 16;
  79
  80    type Type_Set is (Lower_Case, Upper_Case);
  81
  82    ---------------------
  83    -- File Management --
  84    ---------------------
  85
  86    procedure Create
  87      (File : in out File_Type;
  88       Mode : File_Mode := Out_File;
  89       Name : String := "";
  90       Form : String := "");
  91
  92    procedure Open
  93      (File : in out File_Type;
  94       Mode : File_Mode;
  95       Name : String;
  96       Form : String := "");
  97
  98    procedure Close  (File : in out File_Type);
  99    procedure Delete (File : in out File_Type);
 100    procedure Reset  (File : in out File_Type; Mode : File_Mode);
 101    procedure Reset  (File : in out File_Type);
 102
 103    function Mode (File : File_Type) return File_Mode;
 104    function Name (File : File_Type) return String;
 105    function Form (File : File_Type) return String;
 106
 107    function Is_Open (File : File_Type) return Boolean;
 108
 109    ------------------------------------------------------
 110    -- Control of default input, output and error files --
 111    ------------------------------------------------------
 112
 113    procedure Set_Input  (File : File_Type);
 114    procedure Set_Output (File : File_Type);
 115    procedure Set_Error  (File : File_Type);
 116
 117    function Standard_Input  return File_Type;
 118    function Standard_Output return File_Type;
 119    function Standard_Error  return File_Type;
 120
 121    function Current_Input  return File_Type;
 122    function Current_Output return File_Type;
 123    function Current_Error  return File_Type;
 124
 125    type File_Access is access constant File_Type;
 126
 127    function Standard_Input  return File_Access;
 128    function Standard_Output return File_Access;
 129    function Standard_Error  return File_Access;
 130
 131    function Current_Input  return File_Access;
 132    function Current_Output return File_Access;
 133    function Current_Error  return File_Access;
 134
 135    --------------------
 136    -- Buffer control --
 137    --------------------
 138
 139    --  Note: The parameter file is in out in the RM, but as pointed out
 140    --  in <<95-5166.a Tucker Taft 95-6-23>> this is clearly an oversight.
 141
 142    procedure Flush (File : File_Type);
 143    procedure Flush;
 144
 145    --------------------------------------------
 146    -- Specification of line and page lengths --
 147    --------------------------------------------
 148
 149    procedure Set_Line_Length (File : File_Type; To : Count);
 150    procedure Set_Line_Length (To : Count);
 151
 152    procedure Set_Page_Length (File : File_Type; To : Count);
 153    procedure Set_Page_Length (To : Count);
 154
 155    function Line_Length (File : File_Type) return Count;
 156    function Line_Length return Count;
 157
 158    function Page_Length (File : File_Type) return Count;
 159    function Page_Length return Count;
 160
 161    ------------------------------------
 162    -- Column, Line, and Page Control --
 163    ------------------------------------
 164
 165    procedure New_Line (File : File_Type; Spacing : Positive_Count := 1);
 166    procedure New_Line (Spacing : Positive_Count := 1);
 167
 168    procedure Skip_Line (File : File_Type; Spacing : Positive_Count := 1);
 169    procedure Skip_Line (Spacing : Positive_Count := 1);
 170
 171    function End_Of_Line (File : File_Type) return Boolean;
 172    function End_Of_Line return Boolean;
 173
 174    procedure New_Page (File : File_Type);
 175    procedure New_Page;
 176
 177    procedure Skip_Page (File : File_Type);
 178    procedure Skip_Page;
 179
 180    function End_Of_Page (File : File_Type) return Boolean;
 181    function End_Of_Page return Boolean;
 182
 183    function End_Of_File (File : File_Type) return Boolean;
 184    function End_Of_File return Boolean;
 185
 186    procedure Set_Col (File : File_Type;  To : Positive_Count);
 187    procedure Set_Col (To : Positive_Count);
 188
 189    procedure Set_Line (File : File_Type; To : Positive_Count);
 190    procedure Set_Line (To : Positive_Count);
 191
 192    function Col (File : File_Type) return Positive_Count;
 193    function Col return Positive_Count;
 194
 195    function Line (File : File_Type) return Positive_Count;
 196    function Line return Positive_Count;
 197
 198    function Page (File : File_Type) return Positive_Count;
 199    function Page return Positive_Count;
 200
 201    ----------------------------
 202    -- Character Input-Output --
 203    ----------------------------
 204
 205    procedure Get (File : File_Type; Item : out Wide_Wide_Character);
 206    procedure Get (Item : out Wide_Wide_Character);
 207    procedure Put (File : File_Type; Item : Wide_Wide_Character);
 208    procedure Put (Item : Wide_Wide_Character);
 209
 210    procedure Look_Ahead
 211      (File        : File_Type;
 212       Item        : out Wide_Wide_Character;
 213       End_Of_Line : out Boolean);
 214
 215    procedure Look_Ahead
 216      (Item        : out Wide_Wide_Character;
 217       End_Of_Line : out Boolean);
 218
 219    procedure Get_Immediate
 220      (File : File_Type;
 221       Item : out Wide_Wide_Character);
 222
 223    procedure Get_Immediate
 224      (Item : out Wide_Wide_Character);
 225
 226    procedure Get_Immediate
 227      (File      : File_Type;
 228       Item      : out Wide_Wide_Character;
 229       Available : out Boolean);
 230
 231    procedure Get_Immediate
 232      (Item      : out Wide_Wide_Character;
 233       Available : out Boolean);
 234
 235    -------------------------
 236    -- String Input-Output --
 237    -------------------------
 238
 239    procedure Get (File : File_Type; Item : out Wide_Wide_String);
 240    procedure Get (Item : out Wide_Wide_String);
 241    procedure Put (File : File_Type; Item : Wide_Wide_String);
 242    procedure Put (Item : Wide_Wide_String);
 243
 244    procedure Get_Line
 245      (File : File_Type;
 246       Item : out Wide_Wide_String;
 247       Last : out Natural);
 248
 249    function Get_Line (File : File_Type) return Wide_Wide_String;
 250    pragma Ada_05 (Get_Line);
 251
 252    function Get_Line return Wide_Wide_String;
 253    pragma Ada_05 (Get_Line);
 254
 255    procedure Get_Line
 256      (Item : out Wide_Wide_String;
 257       Last : out Natural);
 258
 259    procedure Put_Line
 260      (File : File_Type;
 261       Item : Wide_Wide_String);
 262
 263    procedure Put_Line
 264      (Item : Wide_Wide_String);
 265
 266    ---------------------------------------
 267    -- Generic packages for Input-Output --
 268    ---------------------------------------
 269
 270    --  The generic packages:
 271
 272    --    Ada.Wide_Wide_Text_IO.Integer_IO
 273    --    Ada.Wide_Wide_Text_IO.Modular_IO
 274    --    Ada.Wide_Wide_Text_IO.Float_IO
 275    --    Ada.Wide_Wide_Text_IO.Fixed_IO
 276    --    Ada.Wide_Wide_Text_IO.Decimal_IO
 277    --    Ada.Wide_Wide_Text_IO.Enumeration_IO
 278
 279    --  are implemented as separate child packages in GNAT, so the
 280    --  spec and body of these packages are to be found in separate
 281    --  child units. This implementation detail is hidden from the
 282    --  Ada programmer by special circuitry in the compiler that
 283    --  treats these child packages as though they were nested in
 284    --  Text_IO. The advantage of this special processing is that
 285    --  the subsidiary routines needed if these generics are used
 286    --  are not loaded when they are not used.
 287
 288    ----------------
 289    -- Exceptions --
 290    ----------------
 291
 292    Status_Error : exception renames IO_Exceptions.Status_Error;
 293    Mode_Error   : exception renames IO_Exceptions.Mode_Error;
 294    Name_Error   : exception renames IO_Exceptions.Name_Error;
 295    Use_Error    : exception renames IO_Exceptions.Use_Error;
 296    Device_Error : exception renames IO_Exceptions.Device_Error;
 297    End_Error    : exception renames IO_Exceptions.End_Error;
 298    Data_Error   : exception renames IO_Exceptions.Data_Error;
 299    Layout_Error : exception renames IO_Exceptions.Layout_Error;
 300
 301 private
 302
 303    --  The following procedures have a File_Type formal of mode IN OUT because
 304    --  they may close the original file. The Close operation may raise an
 305    --  exception, but in that case we want any assignment to the formal to
 306    --  be effective anyway, so it must be passed by reference (or the caller
 307    --  will be left with a dangling pointer).
 308
 309    pragma Export_Procedure
 310      (Internal  => Close,
 311       External  => "",
 312       Mechanism => Reference);
 313    pragma Export_Procedure
 314      (Internal  => Delete,
 315       External  => "",
 316       Mechanism => Reference);
 317    pragma Export_Procedure
 318      (Internal        => Reset,
 319       External        => "",
 320       Parameter_Types => (File_Type),
 321       Mechanism       => Reference);
 322    pragma Export_Procedure
 323      (Internal        => Reset,
 324       External        => "",
 325       Parameter_Types => (File_Type, File_Mode),
 326       Mechanism       => (File => Reference));
 327
 328    package WCh_Con renames System.WCh_Con;
 329
 330    -----------------------------------
 331    -- Handling of Format Characters --
 332    -----------------------------------
 333
 334    --  Line marks are represented by the single character ASCII.LF (16#0A#).
 335    --  In DOS and similar systems, underlying file translation takes care
 336    --  of translating this to and from the standard CR/LF sequences used in
 337    --  these operating systems to mark the end of a line. On output there is
 338    --  always a line mark at the end of the last line, but on input, this
 339    --  line mark can be omitted, and is implied by the end of file.
 340
 341    --  Page marks are represented by the single character ASCII.FF (16#0C#),
 342    --  The page mark at the end of the file may be omitted, and is normally
 343    --  omitted on output unless an explicit New_Page call is made before
 344    --  closing the file. No page mark is added when a file is appended to,
 345    --  so, in accordance with the permission in (RM A.10.2(4)), there may
 346    --  or may not be a page mark separating preexisting text in the file
 347    --  from the new text to be written.
 348
 349    --  A file mark is marked by the physical end of file. In DOS translation
 350    --  mode on input, an EOF character (SUB = 16#1A#) gets translated to the
 351    --  physical end of file, so in effect this character is recognized as
 352    --  marking the end of file in DOS and similar systems.
 353
 354    LM : constant := Character'Pos (ASCII.LF);
 355    --  Used as line mark
 356
 357    PM : constant := Character'Pos (ASCII.FF);
 358    --  Used as page mark, except at end of file where it is implied
 359
 360    -------------------------------------
 361    -- Wide_Wide_Text_IO File Control Block --
 362    -------------------------------------
 363
 364    Default_WCEM : WCh_Con.WC_Encoding_Method := WCh_Con.WCEM_UTF8;
 365    --  This gets modified during initialization (see body) using
 366    --  the default value established in the call to Set_Globals.
 367
 368    package FCB renames System.File_Control_Block;
 369
 370    type Wide_Wide_Text_AFCB is new FCB.AFCB with record
 371       Page        : Count := 1;
 372       Line        : Count := 1;
 373       Col         : Count := 1;
 374       Line_Length : Count := 0;
 375       Page_Length : Count := 0;
 376
 377       Self : aliased File_Type;
 378       --  Set to point to the containing Text_AFCB block. This is used to
 379       --  implement the Current_{Error,Input,Output} functions which return
 380       --  a File_Access, the file access value returned is a pointer to
 381       --  the Self field of the corresponding file.
 382
 383       Before_LM : Boolean := False;
 384       --  This flag is used to deal with the anomalies introduced by the
 385       --  peculiar definition of End_Of_File and End_Of_Page in Ada. These
 386       --  functions require looking ahead more than one character. Since
 387       --  there is no convenient way of backing up more than one character,
 388       --  what we do is to leave ourselves positioned past the LM, but set
 389       --  this flag, so that we know that from an Ada point of view we are
 390       --  in front of the LM, not after it. A bit of a kludge, but it works!
 391
 392       Before_LM_PM : Boolean := False;
 393       --  This flag similarly handles the case of being physically positioned
 394       --  after a LM-PM sequence when logically we are before the LM-PM. This
 395       --  flag can only be set if Before_LM is also set.
 396
 397       WC_Method : WCh_Con.WC_Encoding_Method := Default_WCEM;
 398       --  Encoding method to be used for this file
 399
 400       Before_Wide_Wide_Character : Boolean := False;
 401       --  This flag is set to indicate that a wide character in the input has
 402       --  been read by Wide_Wide_Text_IO.Look_Ahead. If it is set to True,
 403       --  then it means that the stream is logically positioned before the
 404       --  character but is physically positioned after it. The character
 405       --  involved must not be in the range 16#00#-16#7F#, i.e. if the flag is
 406       --  set, then we know the next character has a code greater than 16#7F#,
 407       --  and the value of this character is saved in
 408       --  Saved_Wide_Wide_Character.
 409
 410       Saved_Wide_Wide_Character : Wide_Wide_Character;
 411       --  This field is valid only if Before_Wide_Wide_Character is set. It
 412       --  contains a wide character read by Look_Ahead. If Look_Ahead
 413       --  reads a character in the range 16#0000# to 16#007F#, then it
 414       --  can use ungetc to put it back, but ungetc cannot be called
 415       --  more than once, so for characters above this range, we don't
 416       --  try to back up the file. Instead we save the character in this
 417       --  field and set the flag Before_Wide_Wide_Character to indicate that
 418       --  we are logically positioned before this character even though
 419       --  the stream is physically positioned after it.
 420
 421    end record;
 422
 423    type File_Type is access all Wide_Wide_Text_AFCB;
 424
 425    function AFCB_Allocate
 426      (Control_Block : Wide_Wide_Text_AFCB) return FCB.AFCB_Ptr;
 427
 428    procedure AFCB_Close (File : not null access Wide_Wide_Text_AFCB);
 429    procedure AFCB_Free  (File : not null access Wide_Wide_Text_AFCB);
 430
 431    procedure Read
 432      (File : in out Wide_Wide_Text_AFCB;
 433       Item : out Ada.Streams.Stream_Element_Array;
 434       Last : out Ada.Streams.Stream_Element_Offset);
 435    --  Read operation used when Wide_Wide_Text_IO file is treated as a Stream
 436
 437    procedure Write
 438      (File : in out Wide_Wide_Text_AFCB;
 439       Item : Ada.Streams.Stream_Element_Array);
 440    --  Write operation used when Wide_Wide_Text_IO file is treated as a Stream
 441
 442    ------------------------
 443    -- The Standard Files --
 444    ------------------------
 445
 446    Null_Str : aliased constant String := "";
 447    --  Used as name and form of standard files
 448
 449    Standard_Err_AFCB : aliased Wide_Wide_Text_AFCB;
 450    Standard_In_AFCB  : aliased Wide_Wide_Text_AFCB;
 451    Standard_Out_AFCB : aliased Wide_Wide_Text_AFCB;
 452
 453    Standard_Err : aliased File_Type := Standard_Err_AFCB'Access;
 454    Standard_In  : aliased File_Type := Standard_In_AFCB'Access;
 455    Standard_Out : aliased File_Type := Standard_Out_AFCB'Access;
 456    --  Standard files
 457
 458    Current_In   : aliased File_Type := Standard_In;
 459    Current_Out  : aliased File_Type := Standard_Out;
 460    Current_Err  : aliased File_Type := Standard_Err;
 461    --  Current files
 462
 463    -----------------------
 464    -- Local Subprograms --
 465    -----------------------
 466
 467    --  These subprograms are in the private part of the spec so that they can
 468    --  be shared by the routines in the body of Ada.Text_IO.Wide_Wide_Text_IO.
 469
 470    --  Note: we use Integer in these declarations instead of the more accurate
 471    --  Interfaces.C_Streams.int, because we do not want to drag in the spec of
 472    --  this interfaces package with the spec of Ada.Text_IO, and we know that
 473    --  in fact these types are identical
 474
 475    function Getc (File : File_Type) return Integer;
 476    --  Gets next character from file, which has already been checked for
 477    --  being in read status, and returns the character read if no error
 478    --  occurs. The result is EOF if the end of file was read.
 479
 480    procedure Get_Character
 481      (File : File_Type;
 482       Item : out Character);
 483    --  This is essentially a copy of the normal Get routine from Text_IO. It
 484    --  obtains a single character from the input file File, and places it in
 485    --  Item. This character may be the leading character of a
 486    --  Wide_Wide_Character sequence, but that is up to the caller to deal
 487    --  with.
 488
 489    function Get_Wide_Wide_Char
 490      (C    : Character;
 491       File : File_Type) return Wide_Wide_Character;
 492    --  This function is shared by Get and Get_Immediate to extract a wide
 493    --  character value from the given File. The first byte has already been
 494    --  read and is passed in C. The wide character value is returned as the
 495    --  result, and the file pointer is bumped past the character.
 496
 497    function Nextc (File : File_Type) return Integer;
 498    --  Returns next character from file without skipping past it (i.e. it
 499    --  is a combination of Getc followed by an Ungetc).
 500
 501    procedure Putc (ch : Integer; File : File_Type);
 502    --  Outputs the given character to the file, which has already been
 503    --  checked for being in output status. Device_Error is raised if the
 504    --  character cannot be written.
 505
 506    procedure Terminate_Line (File : File_Type);
 507    --  If the file is in Write_File or Append_File mode, and the current
 508    --  line is not terminated, then a line terminator is written using
 509    --  New_Line. Note that there is no Terminate_Page routine, because
 510    --  the page mark at the end of the file is implied if necessary.
 511
 512    procedure Ungetc (ch : Integer; File : File_Type);
 513    --  Pushes back character into stream, using ungetc. The caller has
 514    --  checked that the file is in read status. Device_Error is raised
 515    --  if the character cannot be pushed back. An attempt to push back
 516    --  and end of file character (EOF) is ignored.
 517
 518 end Ada.Wide_Wide_Text_IO;