src/test/java/com/android/tools/r8/retrace/RetraceLambdaTest.java

// Copyright (c) 2021, 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.retrace;

import static com.android.tools.r8.naming.retrace.StackTrace.isSameExceptForFileNameAndLineNumber;
import static com.android.tools.r8.references.Reference.classFromClass;
import static com.android.tools.r8.utils.codeinspector.Matchers.isCompilerSynthesized;
import static org.hamcrest.CoreMatchers.containsString;
import static org.hamcrest.CoreMatchers.not;
import static org.hamcrest.MatcherAssert.assertThat;
import static org.junit.Assert.assertEquals;
import static org.junit.Assume.assumeTrue;

import com.android.tools.r8.TestBase;
import com.android.tools.r8.TestParameters;
import com.android.tools.r8.TestParametersCollection;
import com.android.tools.r8.naming.retrace.StackTrace;
import com.android.tools.r8.references.ClassReference;
import com.android.tools.r8.synthesis.SyntheticItemsTestUtils;
import com.android.tools.r8.utils.codeinspector.FoundClassSubject;
import com.google.common.collect.ImmutableList;
import java.util.Collection;
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 RetraceLambdaTest extends TestBase {

  private static final String JAVAC_LAMBDA_METHOD = "lambda$main$0";

  // TODO(b/172014416): These should not be needed once fixed.
  private static final String LAMBDA_BRIDGE_METHOD = "$r8$lambda$dX5OYTAgq4ijGUv_zaGoVsFINMs";
  private static final String INTERNAL_LAMBDA_CLASS =
      Main.class.getTypeName()
          + "$$InternalSyntheticLambda$0$11a5d582ed94e937718cf3ed497d4d164b60dfa85d606466457007fade57dce8$0";

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

  private final TestParameters parameters;

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

  @Test
  public void testReference() throws Exception {
    testForRuntime(parameters)
        .addInnerClasses(getClass())
        .run(parameters.getRuntime(), Main.class)
        .assertFailureWithErrorThatMatches(containsString("Hello World!"))
        .inspectStackTrace(
            stackTrace ->
                assertThat(
                    stackTrace,
                    isSameExceptForFileNameAndLineNumber(
                        StackTrace.builder()
                            .addWithoutFileNameAndLineNumber(Main.class, JAVAC_LAMBDA_METHOD)
                            // TODO(b/172014416): Support a D8 mapping and prune the synthetic.
                            .applyIf(
                                parameters.isDexRuntime(),
                                b ->
                                    b.addWithoutFileNameAndLineNumber(
                                        SyntheticItemsTestUtils.syntheticLambdaClass(Main.class, 0),
                                        "run"))
                            .addWithoutFileNameAndLineNumber(Main.class, "runIt")
                            .addWithoutFileNameAndLineNumber(Main.class, "main")
                            .build())));
  }

  @Test
  public void testMappingInformation() throws Exception {
    assumeTrue("R8/CF does not desugar", parameters.isDexRuntime());
    testForR8(parameters.getBackend())
        .addInnerClasses(getClass())
        .addKeepAttributeSourceFile()
        .addKeepAttributeLineNumberTable()
        .noTreeShaking()
        .noMinification()
        .setMinApi(parameters.getApiLevel())
        .run(parameters.getRuntime(), Main.class)
        .assertFailureWithErrorThatMatches(containsString("Hello World!"))
        .inspectFailure(
            inspector -> {
              Collection<ClassReference> inputs =
                  ImmutableList.of(classFromClass(MyRunner.class), classFromClass(Main.class));
              for (FoundClassSubject clazz : inspector.allClasses()) {
                if (inputs.contains(clazz.getFinalReference())) {
                  assertThat(clazz, not(isCompilerSynthesized()));
                } else {
                  assertThat(clazz, isCompilerSynthesized());
                }
              }
              assertEquals(inputs.size() + 1, inspector.allClasses().size());
            });
  }

  @Test
  public void testEverythingInlined() throws Exception {
    testForR8(parameters.getBackend())
        .addInnerClasses(getClass())
        .addKeepMainRule(Main.class)
        .addKeepAttributeSourceFile()
        .addKeepAttributeLineNumberTable()
        .setMinApi(parameters.getApiLevel())
        .run(parameters.getRuntime(), Main.class)
        .assertFailureWithErrorThatMatches(containsString("Hello World!"))
        .inspectStackTrace(
            stackTrace -> {
              int frames = parameters.isCfRuntime() ? 2 : 1;
              checkRawStackTraceFrameCount(stackTrace, frames, "Expected everything to be inlined");
              checkCurrentlyIncorrectStackTrace(stackTrace, JAVAC_LAMBDA_METHOD);
            });
  }

  @Test
  public void testNothingInlined() throws Exception {
    testForR8(parameters.getBackend())
        .addInnerClasses(getClass())
        .addKeepMainRule(Main.class)
        .addKeepPackageNamesRule(getClass().getPackage())
        .noTreeShaking()
        .addKeepAttributeSourceFile()
        .addKeepAttributeLineNumberTable()
        .setMinApi(parameters.getApiLevel())
        .run(parameters.getRuntime(), Main.class)
        .assertFailureWithErrorThatMatches(containsString("Hello World!"))
        .inspectStackTrace(
            stackTrace -> {
              int frames = parameters.isCfRuntime() ? 3 : 5;
              checkRawStackTraceFrameCount(stackTrace, frames, "Expected nothing to be inlined");
              checkCurrentlyIncorrectStackTrace(stackTrace, "lambda$main$0");
            });
  }

  private void checkRawStackTraceFrameCount(
      StackTrace stackTrace, int expectedFrames, String message) {
    int linesFromTest = 0;
    for (String line : stackTrace.getOriginalStderr().split("\n")) {
      if (line.trim().startsWith("at " + getClass().getPackage().getName())) {
        linesFromTest++;
      }
    }
    assertEquals(message + stackTrace.getOriginalStderr(), expectedFrames, linesFromTest);
  }

  private void checkCurrentlyIncorrectStackTrace(StackTrace stackTrace, String javacLambdaMethod) {
    assertThat(
        stackTrace,
        isSameExceptForFileNameAndLineNumber(
            StackTrace.builder()
                .addWithoutFileNameAndLineNumber(Main.class, javacLambdaMethod)
                .applyIf(
                    parameters.isDexRuntime(),
                    b ->
                        b
                            // TODO(b/172014416): Lambda bridges should be marked synthetic
                            //  and removed.
                            .addWithoutFileNameAndLineNumber(Main.class, LAMBDA_BRIDGE_METHOD)
                            // TODO(b/172014416): The frame mapping should have removed this
                            //  entry.
                            // TODO(b/172014416): Synthetics should not map back to internal
                            //  names.
                            .addWithoutFileNameAndLineNumber(INTERNAL_LAMBDA_CLASS, "run"))
                .addWithoutFileNameAndLineNumber(Main.class, "runIt")
                .addWithoutFileNameAndLineNumber(Main.class, "main")
                .build()));
  }

  public interface MyRunner {
    void run();
  }

  public static class Main {

    public static void runIt(MyRunner runner) {
      runner.run();
    }

    public static void main(String[] args) {
      if (args.length == 0) {
        runIt(
            () -> {
              throw new RuntimeException("Hello World!");
            });
      }
    }
  }
}