com.google.devtools.kythe.extractors.java.bazel.JavaExtractor.java Source code

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Here is the source code for com.google.devtools.kythe.extractors.java.bazel.JavaExtractor.java

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/*
 * Copyright 2015 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.devtools.kythe.extractors.java.bazel;

import com.google.common.base.Predicate;
import com.google.common.collect.Iterables;
import com.google.common.collect.Lists;
import com.google.devtools.build.lib.actions.extra.ExtraActionInfo;
import com.google.devtools.build.lib.actions.extra.ExtraActionsBase;
import com.google.devtools.build.lib.actions.extra.JavaCompileInfo;
import com.google.devtools.kythe.extractors.java.JavaCompilationUnitExtractor;
import com.google.devtools.kythe.extractors.shared.CompilationDescription;
import com.google.devtools.kythe.extractors.shared.ExtractionException;
import com.google.devtools.kythe.extractors.shared.FileVNames;
import com.google.devtools.kythe.extractors.shared.IndexInfoUtils;
import com.google.protobuf.CodedInputStream;
import com.google.protobuf.ExtensionRegistry;
import com.sun.tools.javac.main.Option;
import java.io.IOException;
import java.io.InputStream;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.List;

/** Java CompilationUnit extractor using Bazel's extra_action feature. */
public class JavaExtractor {
    public static void main(String[] args) throws IOException, ExtractionException {
        if (args.length != 3) {
            System.err.println("Usage: java_extractor extra-action-file output-file vname-config");
            System.exit(1);
        }

        String extraActionPath = args[0];
        String outputPath = args[1];
        String vNamesConfigPath = args[2];

        ExtensionRegistry registry = ExtensionRegistry.newInstance();
        ExtraActionsBase.registerAllExtensions(registry);

        ExtraActionInfo info;
        try (InputStream stream = Files.newInputStream(Paths.get(extraActionPath))) {
            CodedInputStream coded = CodedInputStream.newInstance(stream);
            info = ExtraActionInfo.parseFrom(coded, registry);
        }

        if (!info.hasExtension(JavaCompileInfo.javaCompileInfo)) {
            throw new IllegalArgumentException("Given ExtraActionInfo without JavaCompileInfo");
        }

        JavaCompileInfo jInfo = info.getExtension(JavaCompileInfo.javaCompileInfo);

        List<String> javacOpts = Lists.newArrayList(Iterables.filter(jInfo.getJavacOptList(), JAVAC_OPT_FILTER));

        // Set up a fresh output directory
        javacOpts.add("-d");
        Path output = Files.createTempDirectory("output");
        javacOpts.add(output.toString());

        // Add the generated sources directory if any processors could be invoked.
        if (!jInfo.getProcessorList().isEmpty()) {
            String gensrcdir = readGeneratedSourceDirParam(jInfo);
            if (gensrcdir != null) {
                javacOpts.add("-s");
                javacOpts.add(gensrcdir);
                // javac expects the directory to already exist.
                Files.createDirectories(Paths.get(gensrcdir));
            }
        }

        CompilationDescription description = new JavaCompilationUnitExtractor(FileVNames.fromFile(vNamesConfigPath),
                System.getProperty("user.dir")).extract(info.getOwner(), jInfo.getSourceFileList(),
                        jInfo.getClasspathList(), jInfo.getSourcepathList(), jInfo.getProcessorpathList(),
                        jInfo.getProcessorList(), javacOpts, jInfo.getOutputjar());

        IndexInfoUtils.writeIndexInfoToFile(description, outputPath);
    }

    /**
     * Reads Bazel's compilation params file and returns the value of the --sourcegendir flag. Returns
     * {@code null} if the value does not exist.
     */
    private static String readGeneratedSourceDirParam(JavaCompileInfo jInfo) throws IOException {
        try (java.io.BufferedReader params = Files.newBufferedReader(Paths.get(jInfo.getOutputjar() + "-2.params"),
                java.nio.charset.StandardCharsets.UTF_8)) {
            String line;
            while ((line = params.readLine()) != null) {
                if ("--sourcegendir".equals(line)) {
                    return params.readLine();
                }
            }
            return null;
        }
    }

    // Predicate that filters out Bazel-specific flags.  Bazel adds its own flags (such as error-prone
    // flags) to the javac_opt list that cannot be handled by the standard javac compiler, or in turn,
    // by this extractor.
    private static final Predicate<String> JAVAC_OPT_FILTER = new Predicate<String>() {
        @Override
        public boolean apply(String opt) {
            return !(opt.startsWith("-Werror:") || opt.startsWith("-extra_checks") || opt.startsWith("-Xep"));
        }
    };
}