File : scn.ads
1 ------------------------------------------------------------------------------
2 -- --
3 -- GNAT COMPILER COMPONENTS --
4 -- --
5 -- S C N --
6 -- --
7 -- S p e c --
8 -- --
9 -- Copyright (C) 1992-2010, 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
43 -- case is when Unit = No_Unit_Number, and Index corresponds to the
44 -- source index for 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
48 -- either a 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;