1------------------------------------------------------------------------------
2--                                                                          --
3--                         GNAT COMPILER COMPONENTS                         --
4--                                                                          --
5--                                  S C N                                   --
6--                                                                          --
7--                                 S p e c                                  --
8--                                                                          --
9--          Copyright (C) 1992-2002 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,  59 Temple Place - Suite 330,  Boston, --
20-- MA 02111-1307, 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
30with Casing; use Casing;
31with Errout; use Errout;
32with Scng;
33with Style;  use Style;
34with Types;  use Types;
35
36package 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 Post_Scan;
52   pragma Inline (Post_Scan);
53   --  Create nodes for tokens: Char_Literal, Identifier, Real_Literal,
54   --  Integer_Literal, String_Literal and Operator_Symbol.
55
56   procedure Scan_Reserved_Identifier (Force_Msg : Boolean);
57   --  This procedure is called to convert the current token, which the caller
58   --  has checked is for a reserved word, to an equivalent identifier. This is
59   --  of course only used in error situations where the parser can detect that
60   --  a reserved word is being used as an identifier. An appropriate error
61   --  message, pointing to the token, is also issued if either this is the
62   --  first occurrence of misuse of this identifier, or if Force_Msg is True.
63
64   -------------
65   -- Scanner --
66   -------------
67
68   --  The scanner used by the compiler is an instantiation of the
69   --  generic package Scng with routines appropriate to the compiler
70
71   package Scanner is new Scng
72     (Post_Scan    => Post_Scan,
73      Error_Msg    => Error_Msg,
74      Error_Msg_S  => Error_Msg_S,
75      Error_Msg_SC => Error_Msg_SC,
76      Error_Msg_SP => Error_Msg_SP,
77      Style        => Style.Style_Inst);
78
79   procedure Scan renames Scanner.Scan;
80   --  Scan scans out the next token, and advances the scan state accordingly
81   --  (see package Scans for details). If the scan encounters an illegal
82   --  token, then an error message is issued pointing to the bad character,
83   --  and Scan returns a reasonable substitute token of some kind.
84
85end Scn;
86