1/*
2 * [The "BSD license"]
3 *  Copyright (c) 2010 Terence Parr
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 the
13 *      documentation and/or other materials provided with the distribution.
14 *  3. The name of the author may not be used to endorse or promote products
15 *      derived from this software without specific prior written permission.
16 *
17 *  THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 *  IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 *  OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 *  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 *  NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 *  DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 *  THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 *  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28package org.antlr.tool;
29
30import org.antlr.analysis.DecisionProbe;
31import org.antlr.analysis.NFAState;
32import org.stringtemplate.v4.ST;
33
34import java.util.List;
35
36/** Reports a potential parsing issue with a decision; the decision is
37 *  nondeterministic in some way.
38 */
39public class GrammarUnreachableAltsMessage extends Message {
40	public DecisionProbe probe;
41    public List alts;
42
43	public GrammarUnreachableAltsMessage(DecisionProbe probe,
44										 List alts)
45	{
46		super(ErrorManager.MSG_UNREACHABLE_ALTS);
47		this.probe = probe;
48		this.alts = alts;
49		// flip msg ID if alts are actually token refs in Tokens rule
50		if ( probe.dfa.isTokensRuleDecision() ) {
51			setMessageID(ErrorManager.MSG_UNREACHABLE_TOKENS);
52		}
53	}
54
55	public String toString() {
56		GrammarAST decisionASTNode = probe.dfa.getDecisionASTNode();
57		line = decisionASTNode.getLine();
58		column = decisionASTNode.getCharPositionInLine();
59		String fileName = probe.dfa.nfa.grammar.getFileName();
60		if ( fileName!=null ) {
61			file = fileName;
62		}
63
64		ST st = getMessageTemplate();
65
66		if ( probe.dfa.isTokensRuleDecision() ) {
67			// alts are token rules, convert to the names instead of numbers
68			for (int i = 0; i < alts.size(); i++) {
69				Integer altI = (Integer) alts.get(i);
70				String tokenName =
71					probe.getTokenNameForTokensRuleAlt(altI.intValue());
72				// reset the line/col to the token definition
73				NFAState ruleStart =
74					probe.dfa.nfa.grammar.getRuleStartState(tokenName);
75				line = ruleStart.associatedASTNode.getLine();
76				column = ruleStart.associatedASTNode.getCharPositionInLine();
77				st.add("tokens", tokenName);
78			}
79		}
80		else {
81			// regular alt numbers, show the alts
82			st.add("alts", alts);
83		}
84
85		return super.toString(st);
86	}
87
88}
89