src/test/java/com/android/tools/r8/classmerging/horizontal/interfaces/IllegalOverrideAfterInterfaceMergingTest.java

// Copyright (c) 2021, 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.classmerging.horizontal.interfaces;

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

import com.android.tools.r8.NeverClassInline;
import com.android.tools.r8.NeverInline;
import com.android.tools.r8.NoHorizontalClassMerging;
import com.android.tools.r8.NoMethodStaticizing;
import com.android.tools.r8.NoUnusedInterfaceRemoval;
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 com.android.tools.r8.utils.codeinspector.HorizontallyMergedClassesInspector;
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 IllegalOverrideAfterInterfaceMergingTest extends TestBase {

  @Parameter(0)
  public TestParameters parameters;

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

  @Test
  public void test() throws Exception {
    testForR8(parameters.getBackend())
        .addInnerClasses(getClass())
        .addKeepMainRule(Main.class)
        .addHorizontallyMergedClassesInspector(
            HorizontallyMergedClassesInspector::assertNoClassesMerged)
        .enableInliningAnnotations()
        .enableNeverClassInliningAnnotations()
        .enableNoHorizontalClassMergingAnnotations()
        .enableNoMethodStaticizingAnnotations()
        .enableNoUnusedInterfaceRemovalAnnotations()
        .enableNoVerticalClassMergingAnnotations()
        .setMinApi(parameters.getApiLevel())
        .compile()
        .inspect(
            inspector -> {
              ClassSubject iClassSubject = inspector.clazz(I.class);
              assertThat(iClassSubject, isPresent());
              assertThat(iClassSubject.uniqueMethodWithName("m"), isAbsent());

              ClassSubject aClassSubject = inspector.clazz(A.class);
              assertThat(aClassSubject, isPresent());
              assertThat(aClassSubject, isImplementing(iClassSubject));
              assertThat(
                  aClassSubject.uniqueMethodWithName("m"), allOf(isPresent(), isPackagePrivate()));
            })
        .run(parameters.getRuntime(), Main.class)
        .assertSuccessWithOutputLines("A.m()", "B.m()");
  }

  static class Main {

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

  @NoUnusedInterfaceRemoval
  @NoVerticalClassMerging
  interface I {}

  // Should not be merged into I, since I has a subclass with a package private method signature
  // `void m()`.
  @NoUnusedInterfaceRemoval
  @NoVerticalClassMerging
  interface J {

    void m();
  }

  @NeverClassInline
  @NoHorizontalClassMerging
  static class A implements I {

    // Intentionally package private. If J is merged into I then this is an illegal override of
    // I.m().
    @NeverInline
    @NoMethodStaticizing
    void m() {
      System.out.println("A.m()");
    }
  }

  @NoHorizontalClassMerging
  static class B implements J {

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

  @NoHorizontalClassMerging
  static class C implements J {

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