src/test/java/com/android/tools/r8/ir/optimize/typechecks/DynamicTypeAfterInstanceOfTest.java

// Copyright (c) 2024, 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.ir.optimize.typechecks;

import static com.android.tools.r8.utils.codeinspector.Matchers.isAbsent;
import static com.android.tools.r8.utils.codeinspector.Matchers.isPresent;
import static org.hamcrest.MatcherAssert.assertThat;

import com.android.tools.r8.NoVerticalClassMerging;
import com.android.tools.r8.TestBase;
import com.android.tools.r8.TestParameters;
import com.android.tools.r8.TestParametersCollection;
import com.android.tools.r8.utils.codeinspector.ClassSubject;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.Parameterized;
import org.junit.runners.Parameterized.Parameter;
import org.junit.runners.Parameterized.Parameters;

@RunWith(Parameterized.class)
public class DynamicTypeAfterInstanceOfTest extends TestBase {

  @Parameter(0)
  public TestParameters parameters;

  @Parameters(name = "{0}")
  public static TestParametersCollection data() {
    return getTestParameters().withAllRuntimesAndApiLevels().build();
  }

  @Test
  public void test() throws Exception {
    testForR8(parameters.getBackend())
        .addInnerClasses(getClass())
        .addKeepMainRule(Main.class)
        .enableNoVerticalClassMergingAnnotations()
        .setMinApi(parameters)
        .compile()
        // The call to a.m() should be inlined as a result of the dynamic type information.
        .inspect(
            inspector -> {
              ClassSubject aClassSubject = inspector.clazz(A.class);
              assertThat(aClassSubject, isPresent());
              assertThat(aClassSubject.uniqueMethodWithOriginalName("m"), isAbsent());

              ClassSubject bClassSubject = inspector.clazz(B.class);
              assertThat(bClassSubject, isPresent());
              assertThat(bClassSubject.uniqueMethodWithOriginalName("m"), isAbsent());
            })
        .run(parameters.getRuntime(), Main.class)
        .assertSuccessWithOutputLines("B");
  }

  static class Main {

    public static void main(String[] args) {
      A a = System.currentTimeMillis() > 0 ? new B() : new A();
      if (a instanceof B) {
        a.m();
      }
    }
  }

  @NoVerticalClassMerging
  static class A {

    public void m() {
      System.out.println("A");
    }
  }

  static class B extends A {

    @Override
    public void m() {
      System.out.println("B");
    }
  }
}