com.google.errorprone.bugpatterns.threadsafety.GuardedByUtils.java Source code

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

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/*
 * Copyright 2014 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.threadsafety;

import com.google.auto.value.AutoValue;
import com.google.common.base.Optional;
import com.google.errorprone.VisitorState;
import com.google.errorprone.util.ASTHelpers;
import com.sun.source.tree.Tree;
import com.sun.tools.javac.code.Symbol;
import com.sun.tools.javac.parser.JavacParser;
import com.sun.tools.javac.parser.ParserFactory;
import com.sun.tools.javac.tree.JCTree;
import com.sun.tools.javac.util.Context;

/**
 * @author cushon@google.com (Liam Miller-Cushon)
 */
public class GuardedByUtils {
    static String getGuardValue(Tree tree) {
        {
            net.jcip.annotations.GuardedBy guardedBy = ASTHelpers.getAnnotation(tree,
                    net.jcip.annotations.GuardedBy.class);
            if (guardedBy != null) {
                return guardedBy.value();
            }
        }

        {
            javax.annotation.concurrent.GuardedBy guardedBy = ASTHelpers.getAnnotation(tree,
                    javax.annotation.concurrent.GuardedBy.class);
            if (guardedBy != null) {
                return guardedBy.value();
            }
        }

        return null;
    }

    public static JCTree.JCExpression parseString(String guardedByString, Context context) {
        JavacParser parser = ParserFactory.instance(context).newParser(guardedByString, false, true, false);
        JCTree.JCExpression exp;
        try {
            exp = parser.parseExpression();
        } catch (Throwable e) {
            throw new IllegalGuardedBy(e.getMessage());
        }
        int len = (parser.getEndPos(exp) - exp.getStartPosition());
        if (len != guardedByString.length()) {
            throw new IllegalGuardedBy("Didn't parse entire string.");
        }
        return exp;
    }

    @AutoValue
    abstract static class GuardedByValidationResult {
        abstract String message();

        abstract Boolean isValid();

        static GuardedByValidationResult invalid(String message) {
            return new AutoValue_GuardedByUtils_GuardedByValidationResult(message, false);
        }

        static GuardedByValidationResult ok() {
            return new AutoValue_GuardedByUtils_GuardedByValidationResult("", true);
        }
    }

    public static GuardedByValidationResult isGuardedByValid(Tree tree, VisitorState state) {
        String guard = GuardedByUtils.getGuardValue(tree);
        if (guard == null) {
            return GuardedByValidationResult.ok();
        }

        Optional<GuardedByExpression> boundGuard = GuardedByBinder.bindString(guard,
                GuardedBySymbolResolver.from(tree, state));
        if (!boundGuard.isPresent()) {
            return GuardedByValidationResult.invalid("could not resolve guard");
        }

        Symbol treeSym = ASTHelpers.getSymbol(tree);
        if (treeSym == null) {
            // this shouldn't happen unless the compilation had already failed.
            return GuardedByValidationResult.ok();
        }

        boolean staticGuard = boundGuard.get().kind() == GuardedByExpression.Kind.CLASS_LITERAL
                || (boundGuard.get().sym() != null && boundGuard.get().sym().isStatic());
        if (treeSym.isStatic() && !staticGuard) {
            return GuardedByValidationResult.invalid("static member guarded by instance");
        }

        return GuardedByValidationResult.ok();
    }
}