src/test/java/com/android/tools/r8/keepanno/KeepStaticBindingTest.java

// Copyright (c) 2023, 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.keepanno;

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

import com.android.tools.r8.TestBase;
import com.android.tools.r8.TestParameters;
import com.android.tools.r8.TestParametersCollection;
import com.android.tools.r8.keepanno.annotations.KeepBinding;
import com.android.tools.r8.keepanno.annotations.KeepEdge;
import com.android.tools.r8.keepanno.annotations.KeepTarget;
import com.android.tools.r8.utils.AndroidApiLevel;
import com.android.tools.r8.utils.StringUtils;
import com.android.tools.r8.utils.codeinspector.CodeInspector;
import com.google.common.collect.ImmutableList;
import java.util.List;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.Parameterized;

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

  static final String EXPECTED = StringUtils.lines("Hello!");

  private final TestParameters parameters;

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

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

  @Test
  public void testReference() throws Exception {
    testForRuntime(parameters)
        .addProgramClasses(getInputClasses())
        .run(parameters.getRuntime(), TestClass.class)
        .assertSuccessWithOutput(EXPECTED);
  }

  @Test
  public void testWithRuleExtraction() throws Exception {
    testForR8(parameters.getBackend())
        .enableExperimentalKeepAnnotations()
        .addProgramClasses(getInputClasses())
        .setMinApi(parameters)
        .compile()
        .run(parameters.getRuntime(), TestClass.class)
        .assertSuccessWithOutput(EXPECTED)
        .inspect(this::checkOutput);
  }

  public List<Class<?>> getInputClasses() {
    return ImmutableList.of(TestClass.class, Unused.class);
  }

  private void checkOutput(CodeInspector inspector) {
    assertThat(inspector.clazz(TestClass.class), isPresent());
    assertThat(inspector.clazz(TestClass.class).mainMethod(), isPresent());
    assertThat(inspector.clazz(Unused.class), isAbsent());
  }

  /**
   * This conditional rule expresses that if any class in the program has a live "bar" method then
   * that same classes "foo" method is to be kept. The binding(s) establishes the relation between
   * the holder of the two methods.
   */
  @KeepEdge(
      bindings = {
        @KeepBinding(
            bindingName = "ClassWithMain",
            methodName = "main",
            methodReturnType = "void",
            methodParameters = {"java.lang.String[]"})
      },
      consequences = {
        @KeepTarget(classFromBinding = "ClassWithMain"),
        @KeepTarget(memberFromBinding = "ClassWithMain")
      })
  static class TestClass {

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

  static class Unused {
    // No matching main method, so should not match the rule.

    public static void main() {
      // Non-matching main.
    }
  }
}