org.sonar.cxx.checks.SwitchLastCaseIsDefaultCheck.java Source code

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Here is the source code for org.sonar.cxx.checks.SwitchLastCaseIsDefaultCheck.java

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/*
 * Sonar C++ Plugin (Community)
 * Copyright (C) 2011 Waleri Enns and CONTACT Software GmbH
 * sonarqube@googlegroups.com
 *
 * This program 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 3 of the License, or (at your option) any later version.
 *
 * This program 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.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02
 */
package org.sonar.cxx.checks;

import java.util.List;

import org.sonar.check.Priority;
import org.sonar.check.Rule;
import org.sonar.cxx.parser.CxxGrammarImpl;
import org.sonar.squidbridge.checks.SquidCheck;
import com.google.common.base.Predicate;
import com.google.common.collect.Iterables;
import com.google.common.collect.Lists;
import com.sonar.sslr.api.AstNode;
import com.sonar.sslr.api.AstNodeType;
import com.sonar.sslr.api.Grammar;
import org.sonar.api.server.rule.RulesDefinition;
import org.sonar.squidbridge.annotations.ActivatedByDefault;
import org.sonar.squidbridge.annotations.SqaleConstantRemediation;
import org.sonar.squidbridge.annotations.SqaleSubCharacteristic;

@Rule(key = "SwitchLastCaseIsDefault", name = "Switch statements should end with a default case", priority = Priority.MAJOR)
@ActivatedByDefault
@SqaleSubCharacteristic(RulesDefinition.SubCharacteristics.LOGIC_RELIABILITY)
@SqaleConstantRemediation("5min")
public class SwitchLastCaseIsDefaultCheck extends SquidCheck<Grammar> {

    private static final AstNodeType[] CHECKED_TYPES = new AstNodeType[] { CxxGrammarImpl.switchStatement };

    private static final String MISSING_DEFAULT_CASE_MESSAGE = "Add a default case to this switch.";
    private static final String DEFAULT_CASE_IS_NOT_LAST_MESSAGE = "Move this default to the end of the switch.";
    private static final String DEFAULT_CASE_TOKENVALUE = "default";

    private static final Predicate<AstNode> DEFAULT_CASE_NODE_FILTER = new Predicate<AstNode>() {
        @Override
        public boolean apply(AstNode childNode) {
            return childNode.getTokenValue().equals(DEFAULT_CASE_TOKENVALUE);
        }
    };

    @Override
    public void init() {
        subscribeTo(CHECKED_TYPES);
    }

    @Override
    public void visitNode(AstNode node) {
        List<AstNode> switchCases = getSwitchCases(node);
        int defaultCaseIndex = Iterables.indexOf(switchCases, DEFAULT_CASE_NODE_FILTER);

        if (defaultCaseIndex == -1) {
            getContext().createLineViolation(this, MISSING_DEFAULT_CASE_MESSAGE, node);
        } else {
            AstNode defaultCase = Iterables.get(switchCases, defaultCaseIndex);

            if (!defaultCase.equals(Iterables.getLast(switchCases))) {
                getContext().createLineViolation(this, DEFAULT_CASE_IS_NOT_LAST_MESSAGE, defaultCase);
            }
        }
    }

    private List<AstNode> getSwitchCases(AstNode node) {
        List<AstNode> cases = Lists.newArrayList();

        for (AstNode stmtGroups : node.getChildren(CxxGrammarImpl.switchBlockStatementGroups)) {
            for (AstNode stmtGroup : stmtGroups.getChildren(CxxGrammarImpl.switchBlockStatementGroup)) {
                for (AstNode label : stmtGroup.getChildren(CxxGrammarImpl.switchLabelStatement)) {
                    cases.add(label);
                }
            }
        }

        return cases;
    }

}