107 lines
5.3 KiB
Ada
107 lines
5.3 KiB
Ada
------------------------------------------------------------------------------
|
|
-- --
|
|
-- GNAT COMPILER COMPONENTS --
|
|
-- --
|
|
-- S C N G --
|
|
-- --
|
|
-- S p e c --
|
|
-- --
|
|
-- Copyright (C) 1992-2020, Free Software Foundation, Inc. --
|
|
-- --
|
|
-- GNAT is free software; you can redistribute it and/or modify it under --
|
|
-- terms of the GNU General Public License as published by the Free Soft- --
|
|
-- ware Foundation; either version 3, or (at your option) any later ver- --
|
|
-- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
|
|
-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
|
|
-- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
|
|
-- for more details. You should have received a copy of the GNU General --
|
|
-- Public License distributed with GNAT; see file COPYING3. If not, go to --
|
|
-- http://www.gnu.org/licenses for a complete copy of the license. --
|
|
-- --
|
|
-- GNAT was originally developed by the GNAT team at New York University. --
|
|
-- Extensive contributions were provided by Ada Core Technologies Inc. --
|
|
-- --
|
|
------------------------------------------------------------------------------
|
|
|
|
-- This package contains a generic lexical analyzer. This is used for scanning
|
|
-- Ada source files or text files with an Ada-like syntax, such as project
|
|
-- files. It is instantiated in Scn and Prj.Err.
|
|
|
|
with Casing; use Casing;
|
|
with Styleg;
|
|
with Types; use Types;
|
|
|
|
generic
|
|
with procedure Post_Scan;
|
|
-- Procedure called by Scan for the following tokens: Tok_Char_Literal,
|
|
-- Tok_Identifier, Tok_Real_Literal, Tok_Real_Literal, Tok_Integer_Literal,
|
|
-- Tok_String_Literal, Tok_Operator_Symbol, and Tok_Vertical_Bar. Used to
|
|
-- build Token_Node and also check for obsolescent features.
|
|
|
|
with procedure Error_Msg (Msg : String; Flag_Location : Source_Ptr);
|
|
-- Output a message at specified location
|
|
|
|
with procedure Error_Msg_S (Msg : String);
|
|
-- Output a message at current scan pointer location
|
|
|
|
with procedure Error_Msg_SC (Msg : String);
|
|
-- Output a message at the start of the current token
|
|
|
|
with procedure Error_Msg_SP (Msg : String);
|
|
-- Output a message at the start of the previous token
|
|
|
|
with package Style is new Styleg
|
|
(Error_Msg, Error_Msg_S, Error_Msg_SC, Error_Msg_SP);
|
|
-- Instantiation of Styleg with the same error reporting routines
|
|
|
|
package Scng is
|
|
|
|
procedure Check_End_Of_Line;
|
|
-- Called when end of line encountered. Checks that line is not too long,
|
|
-- and that other style checks for the end of line are met.
|
|
|
|
procedure Initialize_Scanner (Index : Source_File_Index);
|
|
-- Initialize lexical scanner for scanning a new file referenced by Index.
|
|
-- Initialize_Scanner does not call Scan.
|
|
|
|
procedure Scan;
|
|
-- Scan scans out the next token, and advances the scan state accordingly
|
|
-- (see package Scan_State for details). If the scan encounters an illegal
|
|
-- token, then an error message is issued pointing to the bad character,
|
|
-- and Scan returns a reasonable substitute token of some kind.
|
|
-- For tokens Char_Literal, Identifier, Real_Literal, Integer_Literal,
|
|
-- String_Literal and Operator_Symbol, Post_Scan is called after scanning.
|
|
|
|
function Determine_Token_Casing return Casing_Type;
|
|
pragma Inline (Determine_Token_Casing);
|
|
-- Determines the casing style of the current token, which is
|
|
-- either a keyword or an identifier. See also package Casing.
|
|
|
|
procedure Set_Special_Character (C : Character);
|
|
-- Indicate that one of the following character '#', '$', '?', '`',
|
|
-- '\', '^', '_' or '~', when found is a Special token.
|
|
-- AI12-0125-03 : target name (ES) is not in this list because '@' is
|
|
-- handled as a special token as abbreviation of LHS of assignment.
|
|
|
|
procedure Reset_Special_Characters;
|
|
-- Indicate that there is no characters that are Special tokens., which
|
|
-- is the default.
|
|
|
|
procedure Set_End_Of_Line_As_Token (Value : Boolean);
|
|
-- Indicate if End_Of_Line is a token or not.
|
|
-- By default, End_Of_Line is not a token.
|
|
|
|
procedure Set_Comment_As_Token (Value : Boolean);
|
|
-- Indicate if a comment is a token or not.
|
|
-- By default, a comment is not a token.
|
|
|
|
function Set_Start_Column return Column_Number;
|
|
-- This routine is called with Scan_Ptr pointing to the first character
|
|
-- of a line. On exit, Scan_Ptr is advanced to the first non-blank
|
|
-- character of this line (or to the terminating format effector if the
|
|
-- line contains no non-blank characters), and the returned result is the
|
|
-- column number of this non-blank character (zero origin), which is the
|
|
-- value to be stored in the Start_Column scan variable.
|
|
|
|
end Scng;
|