org.sonar.java.se.checks.ConditionAlwaysTrueOrFalseCheck.java Source code

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Here is the source code for org.sonar.java.se.checks.ConditionAlwaysTrueOrFalseCheck.java

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/*
 * SonarQube Java
 * Copyright (C) 2012-2017 SonarSource SA
 * mailto:info AT sonarsource DOT 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  02110-1301, USA.
 */
package org.sonar.java.se.checks;

import com.google.common.collect.HashMultimap;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.Lists;
import com.google.common.collect.Multimap;
import com.google.common.collect.Sets;

import org.sonar.check.Rule;
import org.sonar.java.cfg.CFG;
import org.sonar.java.se.CheckerContext;
import org.sonar.java.se.ExplodedGraph;
import org.sonar.java.se.FlowComputation;
import org.sonar.java.se.constraint.BooleanConstraint;
import org.sonar.java.se.constraint.Constraint;
import org.sonar.java.se.constraint.ObjectConstraint;
import org.sonar.plugins.java.api.JavaFileScannerContext;
import org.sonar.plugins.java.api.tree.MethodTree;
import org.sonar.plugins.java.api.tree.Tree;

import java.util.Collection;
import java.util.Deque;
import java.util.LinkedList;
import java.util.List;
import java.util.Set;
import java.util.stream.Collectors;

@Rule(key = "S2583")
public class ConditionAlwaysTrueOrFalseCheck extends SECheck {

    private Deque<EvaluatedConditions> evaluatedConditions = new LinkedList<>();

    @Override
    public void init(MethodTree methodTree, CFG cfg) {
        evaluatedConditions.push(new EvaluatedConditions());
    }

    @Override
    public void checkEndOfExecution(CheckerContext context) {
        EvaluatedConditions ec = evaluatedConditions.pop();
        for (Tree condition : Sets.difference(ec.evaluatedToFalse.keySet(), ec.evaluatedToTrue.keySet())) {
            context.reportIssue(condition, this,
                    "Change this condition so that it does not always evaluate to \"false\"",
                    collectFlow(ec.evaluatedToFalse.get(condition), false));
        }
        for (Tree condition : Sets.difference(ec.evaluatedToTrue.keySet(), ec.evaluatedToFalse.keySet())) {
            context.reportIssue(condition, this,
                    "Change this condition so that it does not always evaluate to \"true\"",
                    collectFlow(ec.evaluatedToTrue.get(condition), true));
        }
    }

    private static Set<List<JavaFileScannerContext.Location>> collectFlow(Collection<ExplodedGraph.Node> nodes,
            boolean conditionIsAlwaysTrue) {
        return nodes.stream().map(node -> flowFromNode(node, conditionIsAlwaysTrue)).flatMap(Set::stream)
                .collect(Collectors.toSet());
    }

    private static Set<List<JavaFileScannerContext.Location>> flowFromNode(ExplodedGraph.Node node,
            boolean conditionIsAlwaysTrue) {
        List<Class<? extends Constraint>> domains = Lists.newArrayList(ObjectConstraint.class,
                BooleanConstraint.class);
        Set<List<JavaFileScannerContext.Location>> flows = FlowComputation.flow(node.parent(),
                node.programState.peekValue(), domains);
        return flows.stream().map(f -> addIssueLocation(f, node, conditionIsAlwaysTrue))
                .collect(Collectors.toSet());
    }

    private static List<JavaFileScannerContext.Location> addIssueLocation(
            List<JavaFileScannerContext.Location> flow, ExplodedGraph.Node node, boolean conditionIsAlwaysTrue) {
        return ImmutableList.<JavaFileScannerContext.Location>builder()
                .add(new JavaFileScannerContext.Location("Condition is always " + conditionIsAlwaysTrue + ".",
                        node.programPoint.syntaxTree()))
                .addAll(flow).build();
    }

    public void evaluatedToFalse(Tree condition, ExplodedGraph.Node node) {
        evaluatedConditions.peek().evaluatedToFalse(condition, node);
    }

    public void evaluatedToTrue(Tree condition, ExplodedGraph.Node node) {
        evaluatedConditions.peek().evaluatedToTrue(condition, node);
    }

    @Override
    public void interruptedExecution(CheckerContext context) {
        evaluatedConditions.pop();
    }

    private static class EvaluatedConditions {
        private final Multimap<Tree, ExplodedGraph.Node> evaluatedToFalse = HashMultimap.create();
        private final Multimap<Tree, ExplodedGraph.Node> evaluatedToTrue = HashMultimap.create();

        void evaluatedToFalse(Tree condition, ExplodedGraph.Node node) {
            evaluatedToFalse.put(condition, node);
        }

        void evaluatedToTrue(Tree condition, ExplodedGraph.Node node) {
            evaluatedToTrue.put(condition, node);
        }

    }
}