com.liferay.source.formatter.checkstyle.checks.UnusedVariableCheck Maven / Gradle / Ivy

/**
 * Copyright (c) 2000-present Liferay, Inc. All rights reserved.
 *
 * This library is free software; you can redistribute it and/or modify it under
 * the terms of the GNU Lesser General Public License as published by the Free
 * Software Foundation; either version 2.1 of the License, or (at your option)
 * any later version.
 *
 * This library is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
 * details.
 */

package com.liferay.source.formatter.checkstyle.checks;

import com.liferay.source.formatter.checkstyle.util.DetailASTUtil;

import com.puppycrawl.tools.checkstyle.api.DetailAST;
import com.puppycrawl.tools.checkstyle.api.TokenTypes;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

/**
 * @author Hugo Huijser
 */
public class UnusedVariableCheck extends BaseCheck {

	@Override
	public int[] getDefaultTokens() {
		return new int[] {TokenTypes.CTOR_DEF, TokenTypes.METHOD_DEF};
	}

	@Override
	protected void doVisitToken(DetailAST detailAST) {
		List variableDefASTList = DetailASTUtil.getAllChildTokens(
			detailAST, true, TokenTypes.VARIABLE_DEF);

		if (variableDefASTList.isEmpty()) {
			return;
		}

		List tokenNames = _getTokenNames(detailAST);

		for (DetailAST variableDefAST : variableDefASTList) {
			DetailAST modifiersAST = variableDefAST.findFirstToken(
				TokenTypes.MODIFIERS);

			if (modifiersAST.getChildCount() > 0) {
				continue;
			}

			DetailAST nameAST = variableDefAST.findFirstToken(TokenTypes.IDENT);

			String variableName = nameAST.getText();

			if (Collections.frequency(tokenNames, variableName) == 1) {
				log(
					variableDefAST.getLineNo(), _MSG_UNUSED_VARIABLE,
					variableName);
			}
		}
	}

	private List _getTokenNames(DetailAST detailAST) {
		List tokenNames = new ArrayList<>();

		List nameASTList = DetailASTUtil.getAllChildTokens(
			detailAST, true, TokenTypes.IDENT);

		for (DetailAST nameAST : nameASTList) {
			tokenNames.add(nameAST.getText());
		}

		return tokenNames;
	}

	private static final String _MSG_UNUSED_VARIABLE = "variable.unused";

}