src/test/java/com/android/tools/r8/ir/optimize/canonicalization/StaticFinalLibraryFieldCanonicalizationTest.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.ir.optimize.canonicalization;

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

import com.android.tools.r8.TestBase;
import com.android.tools.r8.TestParameters;
import com.android.tools.r8.utils.BooleanUtils;
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 com.google.common.collect.ImmutableSet;
import java.util.List;
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 StaticFinalLibraryFieldCanonicalizationTest extends TestBase {

  private final TestParameters parameters;
  private final boolean systemHasClassInitializationSideEffects;

  @Parameters(name = "{0}, System has class initialization side effects: {1}")
  public static List<Object[]> data() {
    return buildParameters(
        getTestParameters().withAllRuntimesAndApiLevels().build(), BooleanUtils.values());
  }

  public StaticFinalLibraryFieldCanonicalizationTest(
      TestParameters parameters, boolean systemHasClassInitializationSideEffects) {
    this.systemHasClassInitializationSideEffects = systemHasClassInitializationSideEffects;
    this.parameters = parameters;
  }

  @Test
  public void test() throws Exception {
    testForR8(parameters.getBackend())
        .addProgramClasses(TestClass.class)
        .addKeepMainRule(TestClass.class)
        .addOptionsModification(
            options -> {
              if (!systemHasClassInitializationSideEffects) {
                options.itemFactory.libraryClassesWithoutStaticInitialization =
                    ImmutableSet.of(options.itemFactory.createType("Ljava/lang/System;"));
              }
            })
        .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());

    MethodSubject mainMethodSubject = testClassSubject.mainMethod();
    assertThat(mainMethodSubject, isPresent());
    assertEquals(
        1, mainMethodSubject.streamInstructions().filter(InstructionSubject::isStaticGet).count());
  }

  static class TestClass {

    public static void main(String[] args) {
      System.out.print("Hello");
      System.out.println(" world!");
    }
  }
}