src/main/java/com/android/tools/r8/horizontalclassmerging/policies/NoUnusedArguments.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.horizontalclassmerging.policies;

import com.android.tools.r8.graph.AppView;
import com.android.tools.r8.graph.DexEncodedMethod;
import com.android.tools.r8.graph.DexProgramClass;
import com.android.tools.r8.graph.RewrittenPrototypeDescription;
import com.android.tools.r8.horizontalclassmerging.SingleClassPolicy;
import com.android.tools.r8.shaking.AppInfoWithLiveness;

public class NoUnusedArguments extends SingleClassPolicy {

  private final AppView<AppInfoWithLiveness> appView;

  public NoUnusedArguments(AppView<AppInfoWithLiveness> appView) {
    this.appView = appView;
  }

  @Override
  public boolean canMerge(DexProgramClass program) {
    for (DexEncodedMethod method : program.methods()) {
      RewrittenPrototypeDescription prototypeChanges =
          appView.graphLens().lookupPrototypeChangesForMethodDefinition(method.getReference());
      if (prototypeChanges.getArgumentInfoCollection().numberOfRemovedArguments() > 0) {
        return false;
      }
    }
    return true;
  }
}