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) 1992-2017, 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 3,  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 COPYING3.  If not, go to --
  19 -- http://www.gnu.org/licenses for a complete copy of the license.          --
  20 --                                                                          --
  21 -- GNAT was originally developed  by the GNAT team at  New York University. --
  22 -- Extensive contributions were provided by Ada Core Technologies Inc.      --
  23 --                                                                          --
  24 ------------------------------------------------------------------------------
  25
  26 --  This package contains the lexical analyzer routines. This is used by the
  27 --  compiler for scanning Ada source files.
  28
  29 with Casing; use Casing;
  30 with Errout; use Errout;
  31 with Scng;
  32 with Style;  use Style;
  33 with Types;  use Types;
  34
  35 package Scn is
  36
  37    procedure Initialize_Scanner
  38      (Unit  : Unit_Number_Type;
  39       Index : Source_File_Index);
  40    --  Initialize lexical scanner for scanning a new file. The caller has
  41    --  completed the construction of the Units.Table entry for the specified
  42    --  Unit and Index references the corresponding source file. A special case
  43    --  is when Unit = No_Unit, and Index corresponds to the source index for
  44    --  reading the configuration pragma file.
  45
  46    function Determine_Token_Casing return Casing_Type;
  47    --  Determines the casing style of the current token, which is either a
  48    --  keyword or an identifier. See also package Casing.
  49
  50    procedure Post_Scan;
  51    --  Create nodes for tokens: Char_Literal, Identifier, Real_Literal,
  52    --  Integer_Literal, String_Literal and Operator_Symbol.
  53
  54    procedure Scan_Reserved_Identifier (Force_Msg : Boolean);
  55    --  This procedure is called to convert the current token, which the caller
  56    --  has checked is for a reserved word, to an equivalent identifier. This is
  57    --  of course only used in error situations where the parser can detect that
  58    --  a reserved word is being used as an identifier. An appropriate error
  59    --  message, pointing to the token, is also issued if either this is the
  60    --  first occurrence of misuse of this identifier, or if Force_Msg is True.
  61
  62    -------------
  63    -- Scanner --
  64    -------------
  65
  66    --  The scanner used by the compiler is an instantiation of the
  67    --  generic package Scng with routines appropriate to the compiler
  68
  69    package Scanner is new Scng
  70      (Post_Scan    => Post_Scan,
  71       Error_Msg    => Error_Msg,
  72       Error_Msg_S  => Error_Msg_S,
  73       Error_Msg_SC => Error_Msg_SC,
  74       Error_Msg_SP => Error_Msg_SP,
  75       Style        => Style.Style_Inst);
  76
  77    procedure Scan renames Scanner.Scan;
  78    --  Scan scans out the next token, and advances the scan state accordingly
  79    --  (see package Scans for details). If the scan encounters an illegal
  80    --  token, then an error message is issued pointing to the bad character,
  81    --  and Scan returns a reasonable substitute token of some kind.
  82
  83 end Scn;