com.google.errorprone.bugpatterns.IncompatibleModifiersChecker.java Source code

Introduction

Here is the source code for com.google.errorprone.bugpatterns.IncompatibleModifiersChecker.java

Source

/*
 * Copyright 2013 Google Inc. All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.errorprone.bugpatterns;

import static com.google.errorprone.BugPattern.Category.JDK;
import static com.google.errorprone.BugPattern.LinkType.NONE;
import static com.google.errorprone.BugPattern.SeverityLevel.WARNING;

import com.google.common.base.Function;
import com.google.common.collect.ImmutableSet;
import com.google.common.collect.Iterables;
import com.google.common.collect.Sets;
import com.google.errorprone.BugPattern;
import com.google.errorprone.VisitorState;
import com.google.errorprone.annotations.IncompatibleModifiers;
import com.google.errorprone.bugpatterns.BugChecker.AnnotationTreeMatcher;
import com.google.errorprone.matchers.Description;
import com.google.errorprone.util.ASTHelpers;
import com.sun.source.tree.AnnotationTree;
import com.sun.source.tree.ModifiersTree;
import com.sun.source.tree.Tree;
import com.sun.tools.javac.code.Attribute;
import java.util.List;
import java.util.Set;
import javax.lang.model.element.Modifier;
import javax.lang.model.element.TypeElement;

/** @author sgoldfeder@google.com (Steven Goldfeder) */
@BugPattern(name = "IncompatibleModifiers", summary = "This annotation has incompatible modifiers as specified by its "
        + "@IncompatibleModifiers annotation", explanation = "The @IncompatibleModifiers annotation declares that the target annotation "
                + "is incompatible with a set of provided modifiers. This check ensures that all "
                + "annotations respect their @IncompatibleModifiers specifications.", linkType = NONE, category = JDK, severity = WARNING)
// TODO(cushon): merge the implementation with RequiredModifiersChecker
public class IncompatibleModifiersChecker extends BugChecker implements AnnotationTreeMatcher {

    private static final String MESSAGE_TEMPLATE = "%s has specified that it should not be used"
            + " together with the following modifiers: %s";

    // TODO(cushon): deprecate and remove
    private static final String GUAVA_ANNOTATION = "com.google.common.annotations.IncompatibleModifiers";

    private static final Function<Attribute.Enum, Modifier> TO_MODIFIER = new Function<Attribute.Enum, Modifier>() {
        @Override
        public Modifier apply(Attribute.Enum input) {
            return Modifier.valueOf(input.getValue().name.toString());
        }
    };

    private static Set<Modifier> getIncompatibleModifiers(AnnotationTree tree, VisitorState state) {
        for (Attribute.Compound c : ASTHelpers.getSymbol(tree).getAnnotationMirrors()) {
            if (((TypeElement) c.getAnnotationType().asElement()).getQualifiedName()
                    .contentEquals(GUAVA_ANNOTATION)) {
                @SuppressWarnings("unchecked")
                List<Attribute.Enum> modifiers = (List<Attribute.Enum>) c.member(state.getName("value")).getValue();
                return ImmutableSet.copyOf(Iterables.transform(modifiers, TO_MODIFIER));
            }
        }

        IncompatibleModifiers annotation = ASTHelpers.getAnnotation(tree, IncompatibleModifiers.class);
        if (annotation != null) {
            return ImmutableSet.copyOf(annotation.value());
        }

        return ImmutableSet.of();
    }

    @Override
    public Description matchAnnotation(AnnotationTree tree, VisitorState state) {
        Set<Modifier> incompatibleModifiers = getIncompatibleModifiers(tree, state);
        if (incompatibleModifiers.isEmpty()) {
            return Description.NO_MATCH;
        }

        Tree parent = state.getPath().getParentPath().getLeaf();
        if (!(parent instanceof ModifiersTree)) {
            // e.g. An annotated package name
            return Description.NO_MATCH;
        }

        Set<Modifier> incompatible = Sets.intersection(incompatibleModifiers, ((ModifiersTree) parent).getFlags());

        if (incompatible.isEmpty()) {
            return Description.NO_MATCH;
        }

        String annotationName = ASTHelpers.getAnnotationName(tree);
        String nameString = annotationName != null ? String.format("The annotation '@%s'", annotationName)
                : "This annotation";
        String customMessage = String.format(MESSAGE_TEMPLATE, nameString, incompatible.toString());
        return buildDescription(tree).setMessage(customMessage).build();
    }
}