xref: /external/antlr/antlr-3.4/tool/src/main/java/org/antlr/tool/GrammarReport2.java

/*
 * [The "BSD license"]
 *  Copyright (c) 2010 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.antlr.tool;

/** Simplifying report dramatically for LL(*) paper.  Old results were
 *  wrong anyway it seems.  We need:
 *
 * 		percent decisions that potentially backtrack
 *  	histogram of regular lookahead depth (int k or *)
 */
public class GrammarReport2 {
	public static final String newline = System.getProperty("line.separator");

	public Grammar root;

	public GrammarReport2(Grammar rootGrammar) {
		this.root = rootGrammar;
	}

	public String toString() {
		StringBuilder buf = new StringBuilder();
		stats(root, buf);
		CompositeGrammar composite = root.composite;
		for (Grammar g : composite.getDelegates(root)) {
			stats(g, buf);
		}
		return buf.toString();
	}

	void stats(Grammar g, StringBuilder buf) {
		int numDec = g.getNumberOfDecisions();
		for (int decision=1; decision<=numDec; decision++) {
			Grammar.Decision d = g.getDecision(decision);
			if ( d.dfa==null ) { // unusued decisions in auto synpreds
				//System.err.println("no decision "+decision+" dfa for "+d.blockAST.toStringTree());
				continue;
			}
			int k = d.dfa.getMaxLookaheadDepth();
			Rule enclosingRule = d.dfa.decisionNFAStartState.enclosingRule;
			if ( enclosingRule.isSynPred ) continue; // don't count synpred rules
			buf.append(g.name+"."+enclosingRule.name+":" +
					   "");
			GrammarAST decisionAST =
				d.dfa.decisionNFAStartState.associatedASTNode;
			buf.append(decisionAST.getLine());
			buf.append(":");
			buf.append(decisionAST.getCharPositionInLine());
			buf.append(" decision "+decision+":");

			if ( d.dfa.isCyclic() ) buf.append(" cyclic");
			if ( k!=Integer.MAX_VALUE ) buf.append(" k="+k); // fixed, no sempreds
			if ( d.dfa.hasSynPred() ) buf.append(" backtracks"); // isolated synpred not gated
			if ( d.dfa.hasSemPred() ) buf.append(" sempred"); // user-defined sempred
//			else {
//				buf.append("undefined");
//				FASerializer serializer = new FASerializer(g);
//				String result = serializer.serialize(d.dfa.startState);
//				System.err.println(result);
//			}
			nl(buf);
		}
	}

	void nl(StringBuilder buf) {
		buf.append(newline);
	}
}