gcc/ada/scn.ads

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT COMPILER COMPONENTS                         --
   4 --                                                                          --
   5 --                                  S C N                                   --
   6 --                                                                          --
   7 --                                 S p e c                                  --
   8 --                                                                          --
   9 --          Copyright (C) 1992-2004 Free Software Foundation, Inc.          --
  10 --                                                                          --
  11 -- GNAT is free software;  you can  redistribute it  and/or modify it under --
  12 -- terms of the  GNU General Public License as published  by the Free Soft- --
  13 -- ware  Foundation;  either version 2,  or (at your option) any later ver- --
  14 -- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
  15 -- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
  16 -- or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License --
  17 -- for  more details.  You should have  received  a copy of the GNU General --
  18 -- Public License  distributed with GNAT;  see file COPYING.  If not, write --
  19 -- to  the  Free Software Foundation,  51  Franklin  Street,  Fifth  Floor, --
  20 -- Boston, MA 02110-1301, USA.                                              --
  21 --                                                                          --
  22 -- GNAT was originally developed  by the GNAT team at  New York University. --
  23 -- Extensive contributions were provided by Ada Core Technologies Inc.      --
  24 --                                                                          --
  25 ------------------------------------------------------------------------------
  26
  27 --  This package contains the lexical analyzer routines. This is used by the
  28 --  compiler for scanning Ada source files.
  29
  30 with Casing; use Casing;
  31 with Errout; use Errout;
  32 with Scng;
  33 with Style;  use Style;
  34 with Types;  use Types;
  35
  36 package Scn is
  37
  38    procedure Initialize_Scanner
  39      (Unit  : Unit_Number_Type;
  40       Index : Source_File_Index);
  41    --  Initialize lexical scanner for scanning a new file. The caller has
  42    --  completed the construction of the Units.Table entry for the specified
  43    --  Unit and Index references the corresponding source file. A special
  44    --  case is when Unit = No_Unit_Number, and Index corresponds to the
  45    --  source index for reading the configuration pragma file.
  46
  47    function Determine_Token_Casing return Casing_Type;
  48    --  Determines the casing style of the current token, which is
  49    --  either a keyword or an identifier. See also package Casing.
  50
  51    procedure Obsolescent_Check (S : Source_Ptr);
  52    --  Called to handle pragma restrictions check for usage of obsolescent
  53    --  character replacements during the scan.
  54
  55    procedure Post_Scan;
  56    pragma Inline (Post_Scan);
  57    --  Create nodes for tokens: Char_Literal, Identifier, Real_Literal,
  58    --  Integer_Literal, String_Literal and Operator_Symbol.
  59
  60    procedure Scan_Reserved_Identifier (Force_Msg : Boolean);
  61    --  This procedure is called to convert the current token, which the caller
  62    --  has checked is for a reserved word, to an equivalent identifier. This is
  63    --  of course only used in error situations where the parser can detect that
  64    --  a reserved word is being used as an identifier. An appropriate error
  65    --  message, pointing to the token, is also issued if either this is the
  66    --  first occurrence of misuse of this identifier, or if Force_Msg is True.
  67
  68    -------------
  69    -- Scanner --
  70    -------------
  71
  72    --  The scanner used by the compiler is an instantiation of the
  73    --  generic package Scng with routines appropriate to the compiler
  74
  75    package Scanner is new Scng
  76      (Post_Scan         => Post_Scan,
  77       Error_Msg         => Error_Msg,
  78       Error_Msg_S       => Error_Msg_S,
  79       Error_Msg_SC      => Error_Msg_SC,
  80       Error_Msg_SP      => Error_Msg_SP,
  81       Obsolescent_Check => Obsolescent_Check,
  82       Style             => Style.Style_Inst);
  83
  84    procedure Scan renames Scanner.Scan;
  85    --  Scan scans out the next token, and advances the scan state accordingly
  86    --  (see package Scans for details). If the scan encounters an illegal
  87    --  token, then an error message is issued pointing to the bad character,
  88    --  and Scan returns a reasonable substitute token of some kind.
  89
  90 end Scn;