src/test/java/com/android/tools/r8/ir/optimize/instanceofremoval/UninstantiatedLibraryTypeTest.java

// Copyright (c) 2018, 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.instanceofremoval;

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.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.google.common.collect.Streams;
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 UninstantiatedLibraryTypeTest extends TestBase {

  static class TestClass {

    public static void main(String[] args) {
      Exception exception = null;
      try {
        method();
      } catch (Exception e) {
        exception = e;
      }

      // Since NullPointerException is a library class, it is not safe to rewrite the instance-of
      // instruction to the constant false, although NullPointerException has never been
      // instantiated directly or indirectly.
      if (exception instanceof NullPointerException) {
        live();
      } else {
        dead();
      }
    }

    @NeverInline
    private static void method() {
      throw null;
    }

    @NeverInline
    private static void live() {
      System.out.print("In TestClass.live()");
    }

    @NeverInline
    private static void dead() {
      System.out.print("In TestClass.dead()");
    }
  }

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

  private final TestParameters parameters;

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

  @Test
  public void test() throws Exception {
    String expected = "In TestClass.live()";

    testForJvm().addTestClasspath().run(TestClass.class).assertSuccessWithOutput(expected);

    CodeInspector inspector =
        testForR8(parameters.getBackend())
            .addInnerClasses(UninstantiatedLibraryTypeTest.class)
            .addKeepMainRule(TestClass.class)
            .enableInliningAnnotations()
            .setMinApi(parameters.getRuntime())
            .run(parameters.getRuntime(), TestClass.class)
            .assertSuccessWithOutput(expected)
            .inspector();

    ClassSubject classSubject = inspector.clazz(TestClass.class);
    assertThat(classSubject, isPresent());
    assertThat(classSubject.method("void", "live"), isPresent());
    assertThat(classSubject.method("void", "dead"), isPresent());

    long numberOfInstanceOfInstructions =
        Streams.stream(
                classSubject.mainMethod().iterateInstructions(InstructionSubject::isInstanceOf))
            .count();
    assertEquals(1, numberOfInstanceOfInstructions);
  }
}