1 /*
2 [The "BSD licence"]
3 Copyright (c) 2005-2007 Kunle Odutola
4 All rights reserved.
5 
6 Redistribution and use in source and binary forms, with or without
7 modification, are permitted provided that the following conditions
8 are met:
9 1. Redistributions of source code MUST RETAIN the above copyright
10    notice, this list of conditions and the following disclaimer.
11 2. Redistributions in binary form MUST REPRODUCE the above copyright
12    notice, this list of conditions and the following disclaimer in
13    the documentation and/or other materials provided with the
14    distribution.
15 3. The name of the author may not be used to endorse or promote products
16    derived from this software without specific prior WRITTEN permission.
17 4. Unless explicitly state otherwise, any contribution intentionally
18    submitted for inclusion in this work to the copyright owner or licensor
19    shall be under the terms and conditions of this license, without any
20    additional terms or conditions.
21 
22 THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
23 IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
24 OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
25 IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
26 INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
27 NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28 DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29 THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30 (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
31 THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32 */
33 
34 
35 namespace Antlr.Runtime.Debug
36 {
37 	using System;
38 	using Antlr.Runtime;
39 	using ITreeAdaptor = Antlr.Runtime.Tree.ITreeAdaptor;
40 	using ITreeNodeStream = Antlr.Runtime.Tree.ITreeNodeStream;
41 
42 
43 	/// <summary>
44 	/// The default tracer mimics the traceParser behavior of ANTLR 2.x.
45 	/// This listens for debugging events from the parser and implies
46 	/// that you cannot debug and trace at the same time.
47 	/// </summary>
48 	public class Tracer : BlankDebugEventListener
49 	{
50 		public IIntStream input;
51 		protected int level = 0;
52 
Tracer(IIntStream input)53 		public Tracer(IIntStream input)
54 		{
55 			this.input = input;
56 		}
57 
EnterRule(string grammarFileName, string ruleName)58 		override public void EnterRule(string grammarFileName, string ruleName)
59 		{
60 			for (int i = 1; i <= level; i++)
61 			{
62 				Console.Out.Write(" ");
63 			}
64 			Console.Out.WriteLine("> " + grammarFileName + " " + ruleName + " lookahead(1)=" + GetInputSymbol(1));
65 			level++;
66 		}
67 
ExitRule(string grammarFileName, string ruleName)68 		override public void ExitRule(string grammarFileName, string ruleName)
69 		{
70 			level--;
71 			for (int i = 1; i <= level; i++)
72 			{
73 				Console.Out.Write(" ");
74 			}
75 			Console.Out.WriteLine("< " + grammarFileName + " " + ruleName + " lookahead(1)=" + GetInputSymbol(1));
76 		}
77 
GetInputSymbol(int k)78 		public virtual object GetInputSymbol(int k)
79 		{
80 			if (input is ITokenStream)
81 			{
82 				return ((ITokenStream) input).LT(k);
83 			}
84 			return (char) input.LA(k);
85 		}
86 	}
87 }