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 29with Casing; use Casing; 30with Errout; use Errout; 31with Scng; 32with Style; use Style; 33with Types; use Types; 34 35package 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 83end Scn; 84