src/main/java/com/android/tools/r8/PrintSeeds.java

// Copyright (c) 2018, the R8 project authors. Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.
package com.android.tools.r8;

import static com.android.tools.r8.utils.ExceptionUtils.unwrapExecutionException;

import com.android.tools.r8.dex.ApplicationReader;
import com.android.tools.r8.graph.AppInfoWithClassHierarchy;
import com.android.tools.r8.graph.AppServices;
import com.android.tools.r8.graph.AppView;
import com.android.tools.r8.graph.DirectMappedDexApplication;
import com.android.tools.r8.graph.SubtypingInfo;
import com.android.tools.r8.shaking.AppInfoWithLiveness;
import com.android.tools.r8.shaking.Enqueuer;
import com.android.tools.r8.shaking.EnqueuerFactory;
import com.android.tools.r8.shaking.EnqueuerResult;
import com.android.tools.r8.shaking.RootSetUtils.RootSet;
import com.android.tools.r8.shaking.RootSetUtils.RootSetBuilder;
import com.android.tools.r8.utils.ExceptionUtils;
import com.android.tools.r8.utils.InternalOptions;
import com.android.tools.r8.utils.StringUtils;
import com.android.tools.r8.utils.ThreadUtils;
import com.android.tools.r8.utils.Timing;
import java.io.IOException;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.Set;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorService;

/**
 * PrintSeeds prints the classes, interfaces, methods and fields selected by a given ProGuard
 * configuration <pg-conf.txt> when compiling a given program <r8.jar> alongside a given
 * library <rt.jar>.
 *
 * <p>The output format is identical to what is printed when {@code -printseeds} is specified in
 * &lt;pg-conf.txt&gt;, but running PrintSeeds can be faster than running R8 with {@code
 * -printseeds}. See also the {@link PrintUses} program in R8.
 */
public class PrintSeeds {

  private static final String USAGE =
      StringUtils.joinLines(
          "Arguments: <rt.jar> <r8.jar> <pg-conf.txt>",
          "",
          "PrintSeeds prints the classes, interfaces, methods and fields selected by",
          "<pg-conf.txt> when compiling <r8.jar> alongside <rt.jar>.",
          "",
          "The output format is identical to what is printed when -printseeds is specified in",
          "<pg-conf.txt>, but running PrintSeeds can be faster than running R8 with",
          "-printseeds. See also the " + PrintUses.class.getSimpleName() + " program in R8.");

  public static void main(String[] args) throws Exception {
    if (args.length != 3) {
      throw new RuntimeException(StringUtils.joinLines("Invalid invocation.", USAGE));
    }
    Path rtJar = Paths.get(args[0]);
    Path r8Jar = Paths.get(args[1]);
    Path pgConf = Paths.get(args[2]);
    R8Command command =
        R8Command.builder()
            .addLibraryFiles(rtJar)
            .addProgramFiles(r8Jar)
            .addProguardConfigurationFiles(pgConf)
            .setProgramConsumer(ClassFileConsumer.emptyConsumer())
            .build();
    Set<String> descriptors = new ArchiveClassFileProvider(r8Jar).getClassDescriptors();
    InternalOptions options = command.getInternalOptions();
    ExecutorService executorService = ThreadUtils.getExecutorService(options);
    ExceptionUtils.withR8CompilationHandler(
        command.getReporter(),
        () -> {
          try {
            run(command, descriptors, options, executorService);
          } finally {
            executorService.shutdown();
          }
        });
  }

  private static void run(
      R8Command command, Set<String> descriptors, InternalOptions options, ExecutorService executor)
      throws IOException {
    assert !options.forceProguardCompatibility;
    Timing timing = new Timing("PrintSeeds");
    try {
      DirectMappedDexApplication application =
          new ApplicationReader(command.getInputApp(), options, timing).read(executor).toDirect();
      AppView<AppInfoWithClassHierarchy> appView = AppView.createForR8(application);
      appView.setAppServices(AppServices.builder(appView).build());
      SubtypingInfo subtypingInfo = new SubtypingInfo(appView);
      RootSet rootSet =
          RootSet.builder(appView, subtypingInfo, options.getProguardConfiguration().getRules())
              .build(executor);
      Enqueuer enqueuer =
          EnqueuerFactory.createForInitialTreeShaking(appView, executor, subtypingInfo);
      EnqueuerResult enqueuerResult = enqueuer.traceApplication(rootSet, executor, timing);
      AppInfoWithLiveness appInfo = enqueuerResult.getAppInfo();
      RootSetBuilder.writeSeeds(
          appInfo, System.out, type -> descriptors.contains(type.toDescriptorString()));
    } catch (ExecutionException e) {
      throw unwrapExecutionException(e);
    }
  }
}