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

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

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/*
 * 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.collect.ImmutableSet;
import com.google.common.collect.Sets;
import com.google.errorprone.BugPattern;
import com.google.errorprone.VisitorState;
import com.google.errorprone.annotations.RequiredModifiers;
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 java.util.Set;
import javax.lang.model.element.Modifier;

/** @author sgoldfeder@google.com (Steven Goldfeder) */
@BugPattern(name = "RequiredModifiers", summary = "This annotation is missing required modifiers as specified by its "
        + "@RequiredModifiers annotation", explanation = "This annotation is itself annotated with @RequiredModifiers and "
                + "can only be used when the specified modifiers are present. You are attempting to"
                + "use it on an  element that is missing one or more required modifiers.", linkType = NONE, category = JDK, severity = WARNING)
public class RequiredModifiersChecker extends BugChecker implements AnnotationTreeMatcher {

    private static final String MESSAGE_TEMPLATE = "%s has specified that it must be used together with the following modifiers: %s";

    @Override
    public Description matchAnnotation(AnnotationTree tree, VisitorState state) {
        RequiredModifiers annotation = ASTHelpers.getAnnotation(tree, RequiredModifiers.class);
        if (annotation == null) {
            return Description.NO_MATCH;
        }
        Set<Modifier> requiredModifiers = ImmutableSet.copyOf(annotation.value());
        if (requiredModifiers.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> missing = Sets.difference(requiredModifiers, ((ModifiersTree) parent).getFlags());

        if (missing.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, missing.toString());
        return buildDescription(tree).setMessage(customMessage).build();
    }
}