com.google.errorprone.ErrorPronePlugins.java Source code

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Here is the source code for com.google.errorprone.ErrorPronePlugins.java

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/*
 * Copyright 2016 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;

import com.google.common.base.Function;
import com.google.common.collect.Iterables;
import com.google.errorprone.bugpatterns.BugChecker;
import com.google.errorprone.scanner.ScannerSupplier;
import com.sun.tools.javac.util.Context;
import java.util.ServiceLoader;
import javax.tools.JavaFileManager;
import javax.tools.StandardLocation;

/** Loads custom Error Prone checks from the annotation processor classpath. */
public class ErrorPronePlugins {

    private static final Function<BugChecker, Class<? extends BugChecker>> GET_CLASS = new Function<BugChecker, Class<? extends BugChecker>>() {
        @Override
        public Class<? extends BugChecker> apply(BugChecker input) {
            return input.getClass();
        }
    };

    public static ScannerSupplier loadPlugins(ScannerSupplier scannerSupplier, Context context) {

        JavaFileManager fileManager = context.get(JavaFileManager.class);
        // Search ANNOTATION_PROCESSOR_PATH if it's available. Unlike in annotation processor
        // discovery, we never search CLASS_PATH.
        if (!fileManager.hasLocation(StandardLocation.ANNOTATION_PROCESSOR_PATH)) {
            return scannerSupplier;
        }
        ClassLoader loader = fileManager.getClassLoader(StandardLocation.ANNOTATION_PROCESSOR_PATH);
        Iterable<BugChecker> extraBugCheckers = ServiceLoader.load(BugChecker.class, loader);
        if (Iterables.isEmpty(extraBugCheckers)) {
            return scannerSupplier;
        }
        return scannerSupplier
                .plus(ScannerSupplier.fromBugCheckerClasses(Iterables.transform(extraBugCheckers, GET_CLASS)));
    }
}