src/test/java/com/android/tools/r8/ir/optimize/redundantfieldloadelimination/RedundantFieldLoadEliminationMeetTest.java

package com.android.tools.r8.ir.optimize.redundantfieldloadelimination;

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.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 java.io.PrintStream;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.Parameterized;

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

  private final TestParameters parameters;

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

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

  @Test
  public void test() throws Exception {
    testForR8(parameters.getBackend())
        .addInnerClasses(RedundantFieldLoadEliminationMeetTest.class)
        .addKeepMainRule(TestClass.class)
        .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) {
      boolean unknown = System.currentTimeMillis() > 0;
      PrintStream out = System.out;
      String message = unknown ? "Hello world!" : "Unexpected";
      System.out.println(message);
    }
  }
}