src/main/java/com/android/tools/r8/kotlin/KotlinMetadataEnqueuerExtension.java

// Copyright (c) 2020, 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.kotlin;

import com.android.tools.r8.graph.AppView;
import com.android.tools.r8.graph.DexClass;
import com.android.tools.r8.graph.DexDefinitionSupplier;
import com.android.tools.r8.graph.DexMethod;
import com.android.tools.r8.graph.DexType;
import com.android.tools.r8.graph.analysis.EnqueuerAnalysis;
import com.android.tools.r8.shaking.Enqueuer;
import com.google.common.collect.Sets;
import java.util.Set;

public class KotlinMetadataEnqueuerExtension extends EnqueuerAnalysis {

  private final AppView<?> appView;
  private final DexDefinitionSupplier definitionSupplier;
  private final Set<DexMethod> keepByteCodeFunctions = Sets.newIdentityHashSet();

  public KotlinMetadataEnqueuerExtension(
      AppView<?> appView, DexDefinitionSupplier definitionSupplier) {
    this.appView = appView;
    this.definitionSupplier = definitionSupplier;
  }

  @Override
  public void done(Enqueuer enqueuer) {
    DexType kotlinMetadataType = appView.dexItemFactory().kotlinMetadataType;
    DexClass kotlinMetadataClass =
        appView.appInfo().definitionForWithoutExistenceAssert(kotlinMetadataType);
    // We will process kotlin.Metadata even if the type is not present in the program, as long as
    // the annotation will be in the output
    boolean keepMetadata =
        enqueuer.isPinned(kotlinMetadataType)
            || enqueuer.isMissing(kotlinMetadataType)
            || (kotlinMetadataClass != null && kotlinMetadataClass.isNotProgramClass());
    enqueuer.forAllLiveClasses(
        clazz -> {
          clazz.setKotlinInfo(
              KotlinClassMetadataReader.getKotlinInfo(
                  appView.dexItemFactory().kotlin,
                  clazz,
                  definitionSupplier,
                  appView.options().reporter,
                  !keepMetadata || !enqueuer.isPinned(clazz.type),
                  method -> keepByteCodeFunctions.add(method.method)));
        });
    appView.setCfByteCodePassThrough(keepByteCodeFunctions);
  }
}