| /* |
| [The "BSD licence"] |
| Copyright (c) 2005-2008 Terence Parr |
| All rights reserved. |
| |
| Redistribution and use in source and binary forms, with or without |
| modification, are permitted provided that the following conditions |
| are met: |
| 1. Redistributions of source code must retain the above copyright |
| notice, this list of conditions and the following disclaimer. |
| 2. Redistributions in binary form must reproduce the above copyright |
| notice, this list of conditions and the following disclaimer in the |
| documentation and/or other materials provided with the distribution. |
| 3. The name of the author may not be used to endorse or promote products |
| derived from this software without specific prior written permission. |
| |
| THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
| IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
| IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
| INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
| THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| package org.eclipse.persistence.internal.libraries.antlr.runtime.debug; |
| |
| import org.eclipse.persistence.internal.libraries.antlr.runtime.RecognitionException; |
| import org.eclipse.persistence.internal.libraries.antlr.runtime.Token; |
| import org.eclipse.persistence.internal.libraries.antlr.runtime.tree.ParseTree; |
| |
| import java.util.Stack; |
| import java.util.ArrayList; |
| import java.util.List; |
| |
| /** This parser listener tracks rule entry/exit and token matches |
| * to build a simple parse tree using ParseTree nodes. |
| */ |
| public class ParseTreeBuilder extends BlankDebugEventListener { |
| public static final String EPSILON_PAYLOAD = "<epsilon>"; |
| |
| Stack callStack = new Stack(); |
| List hiddenTokens = new ArrayList(); |
| int backtracking = 0; |
| |
| public ParseTreeBuilder(String grammarName) { |
| ParseTree root = create("<grammar "+grammarName+">"); |
| callStack.push(root); |
| } |
| |
| public ParseTree getTree() { |
| return (ParseTree)callStack.elementAt(0); |
| } |
| |
| /** What kind of node to create. You might want to override |
| * so I factored out creation here. |
| */ |
| public ParseTree create(Object payload) { |
| return new ParseTree(payload); |
| } |
| |
| public ParseTree epsilonNode() { |
| return create(EPSILON_PAYLOAD); |
| } |
| |
| /** Backtracking or cyclic DFA, don't want to add nodes to tree */ |
| public void enterDecision(int d) { backtracking++; } |
| public void exitDecision(int i) { backtracking--; } |
| |
| public void enterRule(String filename, String ruleName) { |
| if ( backtracking>0 ) return; |
| ParseTree parentRuleNode = (ParseTree)callStack.peek(); |
| ParseTree ruleNode = create(ruleName); |
| parentRuleNode.addChild(ruleNode); |
| callStack.push(ruleNode); |
| } |
| |
| public void exitRule(String filename, String ruleName) { |
| if ( backtracking>0 ) return; |
| ParseTree ruleNode = (ParseTree)callStack.peek(); |
| if ( ruleNode.getChildCount()==0 ) { |
| ruleNode.addChild(epsilonNode()); |
| } |
| callStack.pop(); |
| } |
| |
| public void consumeToken(Token token) { |
| if ( backtracking>0 ) return; |
| ParseTree ruleNode = (ParseTree)callStack.peek(); |
| ParseTree elementNode = create(token); |
| elementNode.hiddenTokens = this.hiddenTokens; |
| this.hiddenTokens = new ArrayList(); |
| ruleNode.addChild(elementNode); |
| } |
| |
| public void consumeHiddenToken(Token token) { |
| if ( backtracking>0 ) return; |
| hiddenTokens.add(token); |
| } |
| |
| public void recognitionException(RecognitionException e) { |
| if ( backtracking>0 ) return; |
| ParseTree ruleNode = (ParseTree)callStack.peek(); |
| ParseTree errorNode = create(e); |
| ruleNode.addChild(errorNode); |
| } |
| } |