src/test/java/com/android/tools/r8/dex/DexCodeDeduppingTest.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.dex;

import static org.junit.Assert.assertEquals;

import com.android.tools.r8.CompilationFailedException;
import com.android.tools.r8.D8TestCompileResult;
import com.android.tools.r8.DexSegments;
import com.android.tools.r8.DexSegments.Command;
import com.android.tools.r8.DexSegments.SegmentInfo;
import com.android.tools.r8.R8TestCompileResult;
import com.android.tools.r8.ResourceException;
import com.android.tools.r8.TestBase;
import com.android.tools.r8.TestParameters;
import com.android.tools.r8.TestParametersCollection;
import com.android.tools.r8.utils.AndroidApiLevel;
import com.google.common.collect.ImmutableList;
import java.io.IOException;
import java.nio.file.Path;
import java.util.List;
import java.util.Map;
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 DexCodeDeduppingTest extends TestBase {
  private final TestParameters parameters;
  private static final List<String> EXPECTED = ImmutableList.of("foo", "bar", "foo", "bar");

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

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

  @Test
  public void testR8SingleClass() throws Exception {
    R8TestCompileResult compile =
        testForR8(parameters.getBackend())
            .addProgramClasses(Foo.class)
            .setMinApi(parameters)
            .addKeepAllClassesRule()
            .compile();
    compile.run(parameters.getRuntime(), Foo.class).assertSuccessWithOutputLines(EXPECTED);
    assertFooSizes(compile.writeToZip());
  }

  @Test
  public void testR8WithLinesSingleClass() throws Exception {
    R8TestCompileResult compile =
        testForR8(parameters.getBackend())
            .addProgramClasses(Foo.class)
            .setMinApi(parameters)
            .addKeepAllClassesRule()
            .addKeepAttributeLineNumberTable()
            .compile();
    compile.run(parameters.getRuntime(), Foo.class).assertSuccessWithOutputLines(EXPECTED);
    assertFooSizes(compile.writeToZip());
  }

  @Test
  public void testD8SingleClassMappingOutput() throws Exception {
    D8TestCompileResult compile =
        testForD8(parameters.getBackend())
            .addProgramClasses(Foo.class)
            .setMinApi(parameters)
            .release()
            .internalEnableMappingOutput()
            .compile();
    compile.run(parameters.getRuntime(), Foo.class).assertSuccessWithOutputLines(EXPECTED);
    assertFooSizes(compile.writeToZip());
  }

  @Test
  public void testD8SingleClassNoMappingOutput() throws Exception {
    D8TestCompileResult compile =
        testForD8(parameters.getBackend())
            .addProgramClasses(Foo.class)
            .setMinApi(parameters)
            .release()
            .compile();
    compile.run(parameters.getRuntime(), Foo.class).assertSuccessWithOutputLines(EXPECTED);
    // When d8 has no map output we can't share debug info and hence can't share code.
    assertSizes(compile.writeToZip(), 4, 4);
  }

  @Test
  public void testR8TwoClasses() throws Exception {
    R8TestCompileResult compile =
        testForR8(parameters.getBackend())
            .addProgramClasses(Foo.class, Bar.class)
            .setMinApi(parameters)
            .addKeepAllClassesRule()
            .compile();
    compile.run(parameters.getRuntime(), Foo.class).assertSuccessWithOutputLines(EXPECTED);
    assertFooAndBarSizes(compile.writeToZip());
  }

  @Test
  public void testR8WithLinesTwoClasses() throws Exception {
    R8TestCompileResult compile =
        testForR8(parameters.getBackend())
            .addProgramClasses(Foo.class, Bar.class)
            .addKeepAttributeLineNumberTable()
            .setMinApi(parameters)
            .addKeepAllClassesRule()
            .compile();
    compile.run(parameters.getRuntime(), Foo.class).assertSuccessWithOutputLines(EXPECTED);
    assertFooAndBarSizes(compile.writeToZip());
  }

  @Test
  public void testD8TwoClassesMappingOutput() throws Exception {
    D8TestCompileResult compile =
        testForD8(parameters.getBackend())
            .addProgramClasses(Foo.class, Bar.class)
            .setMinApi(parameters)
            .release()
            .internalEnableMappingOutput()
            .compile();
    compile.run(parameters.getRuntime(), Foo.class).assertSuccessWithOutputLines(EXPECTED);
    assertFooAndBarSizes(compile.writeToZip());
  }

  @Test
  public void testD8TwoClassesNoMappingOutput() throws Exception {
    D8TestCompileResult compile =
        testForD8(parameters.getBackend())
            .addProgramClasses(Foo.class, Bar.class)
            .setMinApi(parameters)
            .release()
            .compile();
    compile.run(parameters.getRuntime(), Foo.class).assertSuccessWithOutputLines(EXPECTED);
    // When d8 has no map output we can't share debug info and hence can't share code.
    assertSizes(compile.writeToZip(), 6, 6);
  }

  private void assertFooSizes(Path output) throws Exception {
    assertSizes(output, 3, 4);
  }

  private void assertFooAndBarSizes(Path output) throws Exception {
    assertSizes(output, 3, 6);
  }

  private void assertSizes(Path output, int deduppedSize, int originalSize)
      throws CompilationFailedException, ResourceException, IOException {
    if (parameters.isDexRuntime()) {
      SegmentInfo codeSegmentInfo = getCodeSegmentInfo(output);
      if (parameters.getApiLevel().isGreaterThanOrEqualTo(AndroidApiLevel.S)) {
        assertEquals(codeSegmentInfo.getItemCount(), deduppedSize);
      } else {
        assertEquals(codeSegmentInfo.getItemCount(), originalSize);
      }
    }
  }

  public SegmentInfo getCodeSegmentInfo(Path path)
      throws CompilationFailedException, ResourceException, IOException {
    Command.Builder builder = Command.builder().addProgramFiles(path);
    Map<Integer, SegmentInfo> segmentInfoMap = DexSegments.run(builder.build());
    return segmentInfoMap.get(Constants.TYPE_CODE_ITEM);
  }

  public static class Foo {
    public static void main(String[] args) {
      foo();
      bar();
    }

    public static void foo() {
      if (System.currentTimeMillis() == 0) {
        System.out.println("That was early");
      } else {
        System.out.println("foo");
      }
      System.out.println("bar");
    }

    public static void bar() {
      if (System.currentTimeMillis() == 0) {
        System.out.println("That was early");
      } else {
        System.out.println("foo");
      }
      System.out.println("bar");
    }
  }

  public static class Bar {
    public static void foo() {
      if (System.currentTimeMillis() == 0) {
        System.out.println("That was early");
      } else {
        System.out.println("foo");
      }
      System.out.println("bar");
    }
  }
}