src/test/java/com/android/tools/r8/ir/optimize/membervaluepropagation/EnumMemberValuePropagationTest.java

// Copyright (c) 2019, 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.membervaluepropagation;

import static com.android.tools.r8.utils.codeinspector.Matchers.isPresent;
import static org.hamcrest.CoreMatchers.not;
import static org.hamcrest.MatcherAssert.assertThat;
import static org.junit.Assert.assertTrue;

import com.android.tools.r8.NeverInline;
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.CodeInspector;
import com.android.tools.r8.utils.codeinspector.InstructionSubject;
import com.android.tools.r8.utils.codeinspector.MethodSubject;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.Parameterized;
import org.junit.runners.Parameterized.Parameters;

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

  private final TestParameters parameters;

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

  public EnumMemberValuePropagationTest(TestParameters parameters) {
    this.parameters = parameters;
  }

  @Test
  public void test() throws Exception {
    testForR8(parameters.getBackend())
        .addInnerClasses(EnumMemberValuePropagationTest.class)
        .addKeepMainRule(TestClass.class)
        .enableInliningAnnotations()
        .setMinApi(parameters.getApiLevel())
        .compile()
        .inspect(this::inspect)
        .run(parameters.getRuntime(), TestClass.class)
        .assertSuccessWithOutputLines("Hello world!");
  }

  private void inspect(CodeInspector inspector) {
    ClassSubject testClassSubject = inspector.clazz(TestClass.class);
    assertThat(testClassSubject, isPresent());
    assertThat(
        testClassSubject.uniqueMethodWithName("deadDueToFieldValuePropagation"), not(isPresent()));
    assertThat(
        testClassSubject.uniqueMethodWithName("deadDueToReturnValuePropagation"), not(isPresent()));

    // Verify that there are no more conditional instructions.
    MethodSubject mainMethodSubject = testClassSubject.mainMethod();
    assertThat(mainMethodSubject, isPresent());
    assertTrue(mainMethodSubject.streamInstructions().noneMatch(InstructionSubject::isIf));
  }

  static class TestClass {

    static MyEnum INSTANCE = MyEnum.A;

    public static void main(String[] args) {
      if (INSTANCE == MyEnum.A) {
        System.out.print("Hello");
      } else {
        deadDueToFieldValuePropagation();
      }
      if (get() == MyEnum.A) {
        System.out.println(" world!");
      } else {
        deadDueToReturnValuePropagation();
      }
    }

    @NeverInline
    static MyEnum get() {
      return MyEnum.A;
    }

    @NeverInline
    static void deadDueToFieldValuePropagation() {
      throw new RuntimeException();
    }

    @NeverInline
    static void deadDueToReturnValuePropagation() {
      throw new RuntimeException();
    }
  }

  enum MyEnum {
    A,
    B
  }
}