// Copyright 2015 The Bazel Authors. All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//    http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package com.google.devtools.build.lib.skyframe;

import static com.google.common.truth.Truth.assertThat;
import static com.google.devtools.build.skyframe.EvaluationResultSubjectFactory.assertThatEvaluationResult;
import static org.junit.Assert.fail;

import com.google.common.base.Optional;
import com.google.common.base.Predicates;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableMap;
import com.google.common.collect.Maps;
import com.google.common.collect.Sets;
import com.google.devtools.build.lib.actions.FileStateValue;
import com.google.devtools.build.lib.analysis.util.BuildViewTestCase;
import com.google.devtools.build.lib.clock.BlazeClock;
import com.google.devtools.build.lib.cmdline.Label;
import com.google.devtools.build.lib.cmdline.PackageIdentifier;
import com.google.devtools.build.lib.packages.BuildFileNotFoundException;
import com.google.devtools.build.lib.packages.ConstantRuleVisibility;
import com.google.devtools.build.lib.packages.NoSuchPackageException;
import com.google.devtools.build.lib.packages.NoSuchTargetException;
import com.google.devtools.build.lib.packages.SkylarkSemanticsOptions;
import com.google.devtools.build.lib.pkgcache.PackageCacheOptions;
import com.google.devtools.build.lib.pkgcache.PathPackageLocator;
import com.google.devtools.build.lib.rules.repository.RepositoryDelegatorFunction;
import com.google.devtools.build.lib.skyframe.util.SkyframeExecutorTestUtils;
import com.google.devtools.build.lib.testutil.ManualClock;
import com.google.devtools.build.lib.util.io.TimestampGranularityMonitor;
import com.google.devtools.build.lib.vfs.Dirent;
import com.google.devtools.build.lib.vfs.FileStatus;
import com.google.devtools.build.lib.vfs.FileSystem;
import com.google.devtools.build.lib.vfs.FileSystemUtils;
import com.google.devtools.build.lib.vfs.ModifiedFileSet;
import com.google.devtools.build.lib.vfs.Path;
import com.google.devtools.build.lib.vfs.PathFragment;
import com.google.devtools.build.lib.vfs.Root;
import com.google.devtools.build.lib.vfs.RootedPath;
import com.google.devtools.build.lib.vfs.inmemoryfs.InMemoryFileSystem;
import com.google.devtools.build.skyframe.ErrorInfo;
import com.google.devtools.build.skyframe.EvaluationResult;
import com.google.devtools.build.skyframe.RecordingDifferencer;
import com.google.devtools.build.skyframe.SkyKey;
import com.google.devtools.build.skyframe.SkyValue;
import com.google.devtools.common.options.Options;
import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.UUID;
import javax.annotation.Nullable;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.JUnit4;

/**
 * Unit tests of specific functionality of PackageFunction. Note that it's already tested indirectly
 * in several other places.
 */
@RunWith(JUnit4.class)
public class PackageFunctionTest extends BuildViewTestCase {

  private CustomInMemoryFs fs = new CustomInMemoryFs(new ManualClock());

  private void preparePackageLoading(Path... roots) {
    PackageCacheOptions packageCacheOptions = Options.getDefaults(PackageCacheOptions.class);
    packageCacheOptions.defaultVisibility = ConstantRuleVisibility.PUBLIC;
    packageCacheOptions.showLoadingProgress = true;
    packageCacheOptions.globbingThreads = 7;
    getSkyframeExecutor()
        .preparePackageLoading(
            new PathPackageLocator(
                outputBase,
                Arrays.stream(roots).map(Root::fromPath).collect(ImmutableList.toImmutableList()),
                BazelSkyframeExecutorConstants.BUILD_FILES_BY_PRIORITY),
            packageCacheOptions,
            Options.getDefaults(SkylarkSemanticsOptions.class),
            UUID.randomUUID(),
            ImmutableMap.<String, String>of(),
            new TimestampGranularityMonitor(BlazeClock.instance()));
    skyframeExecutor.setActionEnv(ImmutableMap.<String, String>of());
  }

  @Override
  protected FileSystem createFileSystem() {
    return fs;
  }

  private PackageValue validPackage(SkyKey skyKey) throws InterruptedException {
    SkyframeExecutor skyframeExecutor = getSkyframeExecutor();
    skyframeExecutor.injectExtraPrecomputedValues(
        ImmutableList.of(
            PrecomputedValue.injected(
                RepositoryDelegatorFunction.RESOLVED_FILE_INSTEAD_OF_WORKSPACE,
                Optional.<RootedPath>absent())));
    EvaluationResult<PackageValue> result =
        SkyframeExecutorTestUtils.evaluate(
            skyframeExecutor, skyKey, /*keepGoing=*/ false, reporter);
    if (result.hasError()) {
      fail(result.getError(skyKey).getException().getMessage());
    }
    PackageValue value = result.get(skyKey);
    assertThat(value.getPackage().containsErrors()).isFalse();
    return value;
  }

  @Test
  public void testValidPackage() throws Exception {
    scratch.file("pkg/BUILD");
    validPackage(PackageValue.key(PackageIdentifier.parse("@//pkg")));
  }

  @Test
  public void testPropagatesFilesystemInconsistencies() throws Exception {
    reporter.removeHandler(failFastHandler);
    RecordingDifferencer differencer = getSkyframeExecutor().getDifferencerForTesting();
    Root pkgRoot = getSkyframeExecutor().getPathEntries().get(0);
    Path fooBuildFile = scratch.file("foo/BUILD");
    Path fooDir = fooBuildFile.getParentDirectory();

    // Our custom filesystem says that fooDir is neither a file nor directory nor symlink
    FileStatus inconsistentFileStatus =
        new FileStatus() {
          @Override
          public boolean isFile() {
            return false;
          }

          @Override
          public boolean isDirectory() {
            return false;
          }

          @Override
          public boolean isSymbolicLink() {
            return false;
          }

          @Override
          public boolean isSpecialFile() {
            return false;
          }

          @Override
          public long getSize() throws IOException {
            return 0;
          }

          @Override
          public long getLastModifiedTime() throws IOException {
            return 0;
          }

          @Override
          public long getLastChangeTime() throws IOException {
            return 0;
          }

          @Override
          public long getNodeId() throws IOException {
            return 0;
          }
        };

    fs.stubStat(fooBuildFile, inconsistentFileStatus);
    RootedPath pkgRootedPath = RootedPath.toRootedPath(pkgRoot, fooDir);
    SkyValue fooDirValue = FileStateValue.create(pkgRootedPath, tsgm);
    differencer.inject(ImmutableMap.of(FileStateValue.key(pkgRootedPath), fooDirValue));
    SkyKey skyKey = PackageValue.key(PackageIdentifier.parse("@//foo"));
    String expectedMessage =
        "according to stat, existing path /workspace/foo/BUILD is neither"
            + " a file nor directory nor symlink.";
    EvaluationResult<PackageValue> result =
        SkyframeExecutorTestUtils.evaluate(
            getSkyframeExecutor(), skyKey, /*keepGoing=*/ false, reporter);
    assertThat(result.hasError()).isTrue();
    ErrorInfo errorInfo = result.getError(skyKey);
    String errorMessage = errorInfo.getException().getMessage();
    assertThat(errorMessage).contains("Inconsistent filesystem operations");
    assertThat(errorMessage).contains(expectedMessage);
  }

  @Test
  public void testPropagatesFilesystemInconsistencies_Globbing() throws Exception {
    reporter.removeHandler(failFastHandler);
    RecordingDifferencer differencer = getSkyframeExecutor().getDifferencerForTesting();
    Root pkgRoot = getSkyframeExecutor().getPathEntries().get(0);
    scratch.file(
        "foo/BUILD",
        "subinclude('//a:a')",
        "sh_library(name = 'foo', srcs = glob(['bar/**/baz.sh']))");
    scratch.file("a/BUILD");
    scratch.file("a/a");
    Path bazFile = scratch.file("foo/bar/baz/baz.sh");
    Path bazDir = bazFile.getParentDirectory();
    Path barDir = bazDir.getParentDirectory();

    // Our custom filesystem says "foo/bar/baz" does not exist but it also says that "foo/bar"
    // has a child directory "baz".
    fs.stubStat(bazDir, null);
    RootedPath barDirRootedPath = RootedPath.toRootedPath(pkgRoot, barDir);
    differencer.inject(
        ImmutableMap.of(
            DirectoryListingStateValue.key(barDirRootedPath),
            DirectoryListingStateValue.create(
                ImmutableList.of(new Dirent("baz", Dirent.Type.DIRECTORY)))));
    SkyKey skyKey = PackageValue.key(PackageIdentifier.parse("@//foo"));
    String expectedMessage = "/workspace/foo/bar/baz is no longer an existing directory";
    EvaluationResult<PackageValue> result =
        SkyframeExecutorTestUtils.evaluate(
            getSkyframeExecutor(), skyKey, /*keepGoing=*/ false, reporter);
    assertThat(result.hasError()).isTrue();
    ErrorInfo errorInfo = result.getError(skyKey);
    String errorMessage = errorInfo.getException().getMessage();
    assertThat(errorMessage).contains("Inconsistent filesystem operations");
    assertThat(errorMessage).contains(expectedMessage);
  }

  /** Regression test for unexpected exception type from PackageValue. */
  @Test
  public void testDiscrepancyBetweenLegacyAndSkyframePackageLoadingErrors() throws Exception {
    // Normally, legacy globbing and skyframe globbing share a cache for `readdir` filesystem calls.
    // In order to exercise a situation where they observe different results for filesystem calls,
    // we disable the cache. This might happen in a real scenario, e.g. if the cache hits a limit
    // and evicts entries.
    getSkyframeExecutor().turnOffSyscallCacheForTesting();
    reporter.removeHandler(failFastHandler);
    Path fooBuildFile =
        scratch.file("foo/BUILD", "sh_library(name = 'foo', srcs = glob(['bar/*.sh']))");
    Path fooDir = fooBuildFile.getParentDirectory();
    Path barDir = fooDir.getRelative("bar");
    scratch.file("foo/bar/baz.sh");
    fs.scheduleMakeUnreadableAfterReaddir(barDir);

    SkyKey skyKey = PackageValue.key(PackageIdentifier.parse("@//foo"));
    String expectedMessage = "Encountered error 'Directory is not readable'";
    EvaluationResult<PackageValue> result =
        SkyframeExecutorTestUtils.evaluate(
            getSkyframeExecutor(), skyKey, /*keepGoing=*/ false, reporter);
    assertThat(result.hasError()).isTrue();
    ErrorInfo errorInfo = result.getError(skyKey);
    String errorMessage = errorInfo.getException().getMessage();
    assertThat(errorMessage).contains("Inconsistent filesystem operations");
    assertThat(errorMessage).contains(expectedMessage);
  }

  @SuppressWarnings("unchecked") // Cast of srcs attribute to Iterable<Label>.
  @Test
  public void testGlobOrderStable() throws Exception {
    scratch.file("foo/BUILD", "sh_library(name = 'foo', srcs = glob(['**/*.txt']))");
    scratch.file("foo/b.txt");
    scratch.file("foo/c/c.txt");
    preparePackageLoading(rootDirectory);
    SkyKey skyKey = PackageValue.key(PackageIdentifier.parse("@//foo"));
    PackageValue value = validPackage(skyKey);
    assertThat(
            (Iterable<Label>)
                value
                    .getPackage()
                    .getTarget("foo")
                    .getAssociatedRule()
                    .getAttributeContainer()
                    .getAttr("srcs"))
        .containsExactly(
            Label.parseAbsoluteUnchecked("//foo:b.txt"),
            Label.parseAbsoluteUnchecked("//foo:c/c.txt"))
        .inOrder();
    scratch.file("foo/d.txt");
    getSkyframeExecutor()
        .invalidateFilesUnderPathForTesting(
            reporter,
            ModifiedFileSet.builder().modify(PathFragment.create("foo/d.txt")).build(),
            Root.fromPath(rootDirectory));
    value = validPackage(skyKey);
    assertThat(
            (Iterable<Label>)
                value
                    .getPackage()
                    .getTarget("foo")
                    .getAssociatedRule()
                    .getAttributeContainer()
                    .getAttr("srcs"))
        .containsExactly(
            Label.parseAbsoluteUnchecked("//foo:b.txt"),
            Label.parseAbsoluteUnchecked("//foo:c/c.txt"),
            Label.parseAbsoluteUnchecked("//foo:d.txt"))
        .inOrder();
  }

  @Test
  public void testGlobOrderStableWithLegacyAndSkyframeComponents() throws Exception {
    scratch.file("foo/BUILD", "sh_library(name = 'foo', srcs = glob(['*.txt']))");
    scratch.file("foo/b.txt");
    scratch.file("foo/a.config");
    preparePackageLoading(rootDirectory);
    SkyKey skyKey = PackageValue.key(PackageIdentifier.parse("@//foo"));
    assertSrcs(validPackage(skyKey), "foo", "//foo:b.txt");
    scratch.overwriteFile(
        "foo/BUILD", "sh_library(name = 'foo', srcs = glob(['*.txt', '*.config']))");
    getSkyframeExecutor()
        .invalidateFilesUnderPathForTesting(
            reporter,
            ModifiedFileSet.builder().modify(PathFragment.create("foo/BUILD")).build(),
            Root.fromPath(rootDirectory));
    assertSrcs(validPackage(skyKey), "foo", "//foo:a.config", "//foo:b.txt");
    scratch.overwriteFile(
        "foo/BUILD", "sh_library(name = 'foo', srcs = glob(['*.txt', '*.config'])) # comment");
    getSkyframeExecutor()
        .invalidateFilesUnderPathForTesting(
            reporter,
            ModifiedFileSet.builder().modify(PathFragment.create("foo/BUILD")).build(),
            Root.fromPath(rootDirectory));
    assertSrcs(validPackage(skyKey), "foo", "//foo:a.config", "//foo:b.txt");
    getSkyframeExecutor().resetEvaluator();
    PackageCacheOptions packageCacheOptions = Options.getDefaults(PackageCacheOptions.class);
    packageCacheOptions.defaultVisibility = ConstantRuleVisibility.PUBLIC;
    packageCacheOptions.showLoadingProgress = true;
    packageCacheOptions.globbingThreads = 7;
    getSkyframeExecutor()
        .preparePackageLoading(
            new PathPackageLocator(
                outputBase,
                ImmutableList.of(Root.fromPath(rootDirectory)),
                BazelSkyframeExecutorConstants.BUILD_FILES_BY_PRIORITY),
            packageCacheOptions,
            Options.getDefaults(SkylarkSemanticsOptions.class),
            UUID.randomUUID(),
            ImmutableMap.<String, String>of(),
            tsgm);
    getSkyframeExecutor().setActionEnv(ImmutableMap.<String, String>of());
    assertSrcs(validPackage(skyKey), "foo", "//foo:a.config", "//foo:b.txt");
  }

  /**
   * Tests that a symlink to a file outside of the package root is handled consistently. If the
   * default behavior of Bazel was changed from {@code
   * ExternalFileAction#DEPEND_ON_EXTERNAL_PKG_FOR_EXTERNAL_REPO_PATHS} to {@code
   * ExternalFileAction#ASSUME_NON_EXISTENT_AND_IMMUTABLE_FOR_EXTERNAL_PATHS} then foo/link.sh
   * should no longer appear in the srcs of //foo:foo. However, either way the srcs should be the
   * same independent of the evaluation being incremental or clean.
   */
  @Test
  public void testGlobWithExternalSymlink() throws Exception {
    scratch.file(
        "foo/BUILD",
        "sh_library(name = 'foo', srcs = glob(['*.sh']))",
        "sh_library(name = 'bar', srcs = glob(['link.sh']))",
        "sh_library(name = 'baz', srcs = glob(['subdir_link/*.txt']))");
    scratch.file("foo/ordinary.sh");
    Path externalTarget = scratch.file("../ops/target.txt");
    FileSystemUtils.ensureSymbolicLink(scratch.resolve("foo/link.sh"), externalTarget);
    FileSystemUtils.ensureSymbolicLink(
        scratch.resolve("foo/subdir_link"), externalTarget.getParentDirectory());
    preparePackageLoading(rootDirectory);
    SkyKey fooKey = PackageValue.key(PackageIdentifier.parse("@//foo"));
    PackageValue fooValue = validPackage(fooKey);
    assertSrcs(fooValue, "foo", "//foo:link.sh", "//foo:ordinary.sh");
    assertSrcs(fooValue, "bar", "//foo:link.sh");
    assertSrcs(fooValue, "baz", "//foo:subdir_link/target.txt");
    scratch.overwriteFile(
        "foo/BUILD",
        "sh_library(name = 'foo', srcs = glob(['*.sh'])) #comment",
        "sh_library(name = 'bar', srcs = glob(['link.sh']))",
        "sh_library(name = 'baz', srcs = glob(['subdir_link/*.txt']))");
    getSkyframeExecutor()
        .invalidateFilesUnderPathForTesting(
            reporter,
            ModifiedFileSet.builder().modify(PathFragment.create("foo/BUILD")).build(),
            Root.fromPath(rootDirectory));
    PackageValue fooValue2 = validPackage(fooKey);
    assertThat(fooValue2).isNotEqualTo(fooValue);
    assertSrcs(fooValue2, "foo", "//foo:link.sh", "//foo:ordinary.sh");
    assertSrcs(fooValue2, "bar", "//foo:link.sh");
    assertSrcs(fooValue2, "baz", "//foo:subdir_link/target.txt");
  }

  private static void assertSrcs(PackageValue value, String targetName, String... expected)
      throws NoSuchTargetException {
    List<Label> expectedLabels = new ArrayList<>();
    for (String item : expected) {
      expectedLabels.add(Label.parseAbsoluteUnchecked(item));
    }
    assertThat(getSrcs(value, targetName)).containsExactlyElementsIn(expectedLabels).inOrder();
  }

  @SuppressWarnings("unchecked")
  private static Iterable<Label> getSrcs(PackageValue packageValue, String targetName)
      throws NoSuchTargetException {
    return (Iterable<Label>)
        packageValue
            .getPackage()
            .getTarget(targetName)
            .getAssociatedRule()
            .getAttributeContainer()
            .getAttr("srcs");
  }

  @Test
  public void testOneNewElementInMultipleGlob() throws Exception {
    scratch.file(
        "foo/BUILD",
        "sh_library(name = 'foo', srcs = glob(['*.sh']))",
        "sh_library(name = 'bar', srcs = glob(['*.sh', '*.txt']))");
    preparePackageLoading(rootDirectory);
    SkyKey skyKey = PackageValue.key(PackageIdentifier.parse("@//foo"));
    PackageValue value = validPackage(skyKey);
    scratch.file("foo/irrelevent");
    getSkyframeExecutor()
        .invalidateFilesUnderPathForTesting(
            reporter,
            ModifiedFileSet.builder().modify(PathFragment.create("foo/irrelevant")).build(),
            Root.fromPath(rootDirectory));
    assertThat(validPackage(skyKey)).isSameAs(value);
  }

  @Test
  public void testNoNewElementInMultipleGlob() throws Exception {
    scratch.file(
        "foo/BUILD",
        "sh_library(name = 'foo', srcs = glob(['*.sh', '*.txt']))",
        "sh_library(name = 'bar', srcs = glob(['*.sh', '*.txt']))");
    preparePackageLoading(rootDirectory);
    SkyKey skyKey = PackageValue.key(PackageIdentifier.parse("@//foo"));
    PackageValue value = validPackage(skyKey);
    scratch.file("foo/irrelevent");
    getSkyframeExecutor()
        .invalidateFilesUnderPathForTesting(
            reporter,
            ModifiedFileSet.builder().modify(PathFragment.create("foo/irrelevant")).build(),
            Root.fromPath(rootDirectory));
    assertThat(validPackage(skyKey)).isSameAs(value);
  }

  @Test
  public void testTransitiveSkylarkDepsStoredInPackage() throws Exception {
    scratch.file("foo/BUILD", "load('//bar:ext.bzl', 'a')");
    scratch.file("bar/BUILD");
    scratch.file("bar/ext.bzl", "load('//baz:ext.bzl', 'b')", "a = b");
    scratch.file("baz/BUILD");
    scratch.file("baz/ext.bzl", "b = 1");
    scratch.file("qux/BUILD");
    scratch.file("qux/ext.bzl", "c = 1");

    preparePackageLoading(rootDirectory);

    SkyKey skyKey = PackageValue.key(PackageIdentifier.parse("@//foo"));
    PackageValue value = validPackage(skyKey);
    assertThat(value.getPackage().getSkylarkFileDependencies())
        .containsExactly(
            Label.parseAbsolute("//bar:ext.bzl", ImmutableMap.of()),
            Label.parseAbsolute("//baz:ext.bzl", ImmutableMap.of()));

    scratch.overwriteFile("bar/ext.bzl", "load('//qux:ext.bzl', 'c')", "a = c");
    getSkyframeExecutor()
        .invalidateFilesUnderPathForTesting(
            reporter,
            ModifiedFileSet.builder().modify(PathFragment.create("bar/ext.bzl")).build(),
            Root.fromPath(rootDirectory));

    value = validPackage(skyKey);
    assertThat(value.getPackage().getSkylarkFileDependencies())
        .containsExactly(
            Label.parseAbsolute("//bar:ext.bzl", ImmutableMap.of()),
            Label.parseAbsolute("//qux:ext.bzl", ImmutableMap.of()));
  }

  @Test
  public void testNonExistingSkylarkExtension() throws Exception {
    reporter.removeHandler(failFastHandler);
    scratch.file(
        "test/skylark/BUILD",
        "load('//test/skylark:bad_extension.bzl', 'some_symbol')",
        "genrule(name = gr,",
        "    outs = ['out.txt'],",
        "    cmd = 'echo hello >@')");
    invalidatePackages();

    SkyKey skyKey = PackageValue.key(PackageIdentifier.parse("@//test/skylark"));
    EvaluationResult<PackageValue> result =
        SkyframeExecutorTestUtils.evaluate(
            getSkyframeExecutor(), skyKey, /*keepGoing=*/ false, reporter);
    assertThat(result.hasError()).isTrue();
    ErrorInfo errorInfo = result.getError(skyKey);
    String expectedMsg =
        "error loading package 'test/skylark': "
            + "Unable to load file '//test/skylark:bad_extension.bzl': file doesn't exist";
    assertThat(errorInfo.getException()).hasMessage(expectedMsg);
  }

  @Test
  public void testNonExistingSkylarkExtensionFromExtension() throws Exception {
    reporter.removeHandler(failFastHandler);
    scratch.file(
        "test/skylark/extension.bzl",
        "load('//test/skylark:bad_extension.bzl', 'some_symbol')",
        "a = 'a'");
    scratch.file(
        "test/skylark/BUILD",
        "load('//test/skylark:extension.bzl', 'a')",
        "genrule(name = gr,",
        "    outs = ['out.txt'],",
        "    cmd = 'echo hello >@')");
    invalidatePackages();

    SkyKey skyKey = PackageValue.key(PackageIdentifier.parse("@//test/skylark"));
    EvaluationResult<PackageValue> result =
        SkyframeExecutorTestUtils.evaluate(
            getSkyframeExecutor(), skyKey, /*keepGoing=*/ false, reporter);
    assertThat(result.hasError()).isTrue();
    ErrorInfo errorInfo = result.getError(skyKey);
    assertThat(errorInfo.getException())
        .hasMessage(
            "error loading package 'test/skylark': "
                + "in /workspace/test/skylark/extension.bzl: "
                + "Unable to load file '//test/skylark:bad_extension.bzl': file doesn't exist");
  }

  @Test
  public void testSymlinkCycleWithSkylarkExtension() throws Exception {
    reporter.removeHandler(failFastHandler);
    Path extensionFilePath = scratch.resolve("/workspace/test/skylark/extension.bzl");
    FileSystemUtils.ensureSymbolicLink(extensionFilePath, PathFragment.create("extension.bzl"));
    scratch.file(
        "test/skylark/BUILD",
        "load('//test/skylark:extension.bzl', 'a')",
        "genrule(name = gr,",
        "    outs = ['out.txt'],",
        "    cmd = 'echo hello >@')");
    invalidatePackages();

    SkyKey skyKey = PackageValue.key(PackageIdentifier.parse("@//test/skylark"));
    EvaluationResult<PackageValue> result =
        SkyframeExecutorTestUtils.evaluate(
            getSkyframeExecutor(), skyKey, /*keepGoing=*/ false, reporter);
    assertThat(result.hasError()).isTrue();
    ErrorInfo errorInfo = result.getError(skyKey);
    assertThat(errorInfo.getRootCauseOfException()).isEqualTo(skyKey);
    assertThat(errorInfo.getException())
        .hasMessage(
            "error loading package 'test/skylark': Encountered error while reading extension "
                + "file 'test/skylark/extension.bzl': Symlink cycle");
  }

  @Test
  public void testIOErrorLookingForSubpackageForLabelIsHandled() throws Exception {
    reporter.removeHandler(failFastHandler);
    scratch.file("foo/BUILD", "sh_library(name = 'foo', srcs = ['bar/baz.sh'])");
    Path barBuildFile = scratch.file("foo/bar/BUILD");
    fs.stubStatError(barBuildFile, new IOException("nope"));
    SkyKey skyKey = PackageValue.key(PackageIdentifier.parse("@//foo"));
    EvaluationResult<PackageValue> result =
        SkyframeExecutorTestUtils.evaluate(
            getSkyframeExecutor(), skyKey, /*keepGoing=*/ false, reporter);
    assertThat(result.hasError()).isTrue();
    assertContainsEvent("nope");
  }

  @Test
  public void testLoadRelativePath() throws Exception {
    scratch.file("pkg/BUILD", "load(':ext.bzl', 'a')");
    scratch.file("pkg/ext.bzl", "a = 1");
    validPackage(PackageValue.key(PackageIdentifier.parse("@//pkg")));
  }

  @Test
  public void testLoadAbsolutePath() throws Exception {
    scratch.file("pkg1/BUILD");
    scratch.file("pkg2/BUILD", "load('//pkg1:ext.bzl', 'a')");
    scratch.file("pkg1/ext.bzl", "a = 1");
    validPackage(PackageValue.key(PackageIdentifier.parse("@//pkg2")));
  }

  @Test
  public void testBadWorkspaceFile() throws Exception {
    Path workspacePath = scratch.overwriteFile("WORKSPACE", "junk");
    SkyKey skyKey = PackageValue.key(PackageIdentifier.createInMainRepo("external"));
    getSkyframeExecutor()
        .invalidate(
            Predicates.equalTo(
                FileStateValue.key(
                    RootedPath.toRootedPath(
                        Root.fromPath(workspacePath.getParentDirectory()),
                        PathFragment.create(workspacePath.getBaseName())))));

    reporter.removeHandler(failFastHandler);
    EvaluationResult<PackageValue> result =
        SkyframeExecutorTestUtils.evaluate(
            getSkyframeExecutor(), skyKey, /*keepGoing=*/ false, reporter);
    assertThat(result.hasError()).isFalse();
    assertThat(result.get(skyKey).getPackage().containsErrors()).isTrue();
  }

  // Regression test for the two ugly consequences of a bug where GlobFunction incorrectly matched
  // dangling symlinks.
  @Test
  public void testIncrementalSkyframeHybridGlobbingOnDanglingSymlink() throws Exception {
    Path packageDirPath =
        scratch.file("foo/BUILD", "exports_files(glob(['*.txt']))").getParentDirectory();
    scratch.file("foo/existing.txt");
    FileSystemUtils.ensureSymbolicLink(packageDirPath.getChild("dangling.txt"), "nope");

    preparePackageLoading(rootDirectory);

    SkyKey skyKey = PackageValue.key(PackageIdentifier.parse("@//foo"));
    PackageValue value = validPackage(skyKey);
    assertThat(value.getPackage().containsErrors()).isFalse();
    assertThat(value.getPackage().getTarget("existing.txt").getName()).isEqualTo("existing.txt");
    try {
      value.getPackage().getTarget("dangling.txt");
      fail();
    } catch (NoSuchTargetException expected) {
    }

    scratch.overwriteFile(
        "foo/BUILD", "exports_files(glob(['*.txt']))", "#some-irrelevant-comment");

    getSkyframeExecutor()
        .invalidateFilesUnderPathForTesting(
            reporter,
            ModifiedFileSet.builder().modify(PathFragment.create("foo/BUILD")).build(),
            Root.fromPath(rootDirectory));

    value = validPackage(skyKey);
    assertThat(value.getPackage().containsErrors()).isFalse();
    assertThat(value.getPackage().getTarget("existing.txt").getName()).isEqualTo("existing.txt");
    try {
      value.getPackage().getTarget("dangling.txt");
      fail();
    } catch (NoSuchTargetException expected) {
      // One consequence of the bug was that dangling symlinks were matched by globs evaluated by
      // Skyframe globbing, meaning there would incorrectly be corresponding targets in packages
      // that had skyframe cache hits during skyframe hybrid globbing.
    }

    scratch.file("foo/nope");
    getSkyframeExecutor()
        .invalidateFilesUnderPathForTesting(
            reporter,
            ModifiedFileSet.builder().modify(PathFragment.create("foo/nope")).build(),
            Root.fromPath(rootDirectory));

    PackageValue newValue = validPackage(skyKey);
    assertThat(newValue.getPackage().containsErrors()).isFalse();
    assertThat(newValue.getPackage().getTarget("existing.txt").getName()).isEqualTo("existing.txt");
    // Another consequence of the bug is that change pruning would incorrectly cut off changes that
    // caused a dangling symlink potentially matched by a glob to come into existence.
    assertThat(newValue.getPackage().getTarget("dangling.txt").getName()).isEqualTo("dangling.txt");
    assertThat(newValue.getPackage()).isNotSameAs(value.getPackage());
  }

  // Regression test for Skyframe globbing incorrectly matching the package's directory path on
  // 'glob(['**'], exclude_directories = 0)'. We test for this directly by triggering
  // hybrid globbing (gives coverage for both legacy globbing and skyframe globbing).
  @Test
  public void testRecursiveGlobNeverMatchesPackageDirectory() throws Exception {
    scratch.file(
        "foo/BUILD",
        "[sh_library(name = x + '-matched') for x in glob(['**'], exclude_directories = 0)]");
    scratch.file("foo/bar");

    preparePackageLoading(rootDirectory);

    SkyKey skyKey = PackageValue.key(PackageIdentifier.parse("@//foo"));
    PackageValue value = validPackage(skyKey);
    assertThat(value.getPackage().containsErrors()).isFalse();
    assertThat(value.getPackage().getTarget("bar-matched").getName()).isEqualTo("bar-matched");
    try {
      value.getPackage().getTarget("-matched");
      fail();
    } catch (NoSuchTargetException expected) {
    }

    scratch.overwriteFile(
        "foo/BUILD",
        "[sh_library(name = x + '-matched') for x in glob(['**'], exclude_directories = 0)]",
        "#some-irrelevant-comment");
    getSkyframeExecutor()
        .invalidateFilesUnderPathForTesting(
            reporter,
            ModifiedFileSet.builder().modify(PathFragment.create("foo/BUILD")).build(),
            Root.fromPath(rootDirectory));

    value = validPackage(skyKey);
    assertThat(value.getPackage().containsErrors()).isFalse();
    assertThat(value.getPackage().getTarget("bar-matched").getName()).isEqualTo("bar-matched");
    try {
      value.getPackage().getTarget("-matched");
      fail();
    } catch (NoSuchTargetException expected) {
    }
  }

  @Test
  public void testPackageLoadingErrorOnIOExceptionReadingBuildFile() throws Exception {
    Path fooBuildFilePath = scratch.file("foo/BUILD");
    IOException exn = new IOException("nope");
    fs.throwExceptionOnGetInputStream(fooBuildFilePath, exn);

    SkyKey skyKey = PackageValue.key(PackageIdentifier.parse("@//foo"));
    EvaluationResult<PackageValue> result =
        SkyframeExecutorTestUtils.evaluate(
            getSkyframeExecutor(), skyKey, /*keepGoing=*/ false, reporter);
    assertThat(result.hasError()).isTrue();
    ErrorInfo errorInfo = result.getError(skyKey);
    String errorMessage = errorInfo.getException().getMessage();
    assertThat(errorMessage).contains("nope");
    assertThat(errorInfo.getException()).isInstanceOf(NoSuchPackageException.class);
    assertThat(errorInfo.getException()).hasCauseThat().isInstanceOf(IOException.class);
  }

  @Test
  public void testPackageLoadingErrorOnIOExceptionReadingBzlFile() throws Exception {
    scratch.file("foo/BUILD", "load('//foo:bzl.bzl', 'x')");
    Path fooBzlFilePath = scratch.file("foo/bzl.bzl");
    IOException exn = new IOException("nope");
    fs.throwExceptionOnGetInputStream(fooBzlFilePath, exn);

    SkyKey skyKey = PackageValue.key(PackageIdentifier.parse("@//foo"));
    EvaluationResult<PackageValue> result =
        SkyframeExecutorTestUtils.evaluate(
            getSkyframeExecutor(), skyKey, /*keepGoing=*/ false, reporter);
    assertThat(result.hasError()).isTrue();
    ErrorInfo errorInfo = result.getError(skyKey);
    String errorMessage = errorInfo.getException().getMessage();
    assertThat(errorMessage).contains("nope");
    assertThat(errorInfo.getException()).isInstanceOf(NoSuchPackageException.class);
    assertThat(errorInfo.getException()).hasCauseThat().isInstanceOf(IOException.class);
  }

  @Test
  public void testLabelsCrossesSubpackageBoundaries() throws Exception {
    reporter.removeHandler(failFastHandler);

    scratch.file("pkg/BUILD", "exports_files(['sub/blah'])");
    scratch.file("pkg/sub/BUILD");
    invalidatePackages();

    SkyKey skyKey = PackageValue.key(PackageIdentifier.parse("@//pkg"));
    EvaluationResult<PackageValue> result =
        SkyframeExecutorTestUtils.evaluate(
            getSkyframeExecutor(), skyKey, /*keepGoing=*/ false, reporter);
    assertThatEvaluationResult(result).hasNoError();
    assertThat(result.get(skyKey).getPackage().containsErrors()).isTrue();
    assertContainsEvent("Label '//pkg:sub/blah' crosses boundary of subpackage 'pkg/sub'");
  }

  @Test
  public void testSymlinkCycleEncounteredWhileHandlingLabelCrossingSubpackageBoundaries()
      throws Exception {
    reporter.removeHandler(failFastHandler);

    scratch.file("pkg/BUILD", "exports_files(['sub/blah'])");
    Path subBuildFilePath = scratch.dir("pkg/sub").getChild("BUILD");
    FileSystemUtils.ensureSymbolicLink(subBuildFilePath, subBuildFilePath);
    invalidatePackages();

    SkyKey skyKey = PackageValue.key(PackageIdentifier.parse("@//pkg"));
    EvaluationResult<PackageValue> result =
        SkyframeExecutorTestUtils.evaluate(
            getSkyframeExecutor(), skyKey, /*keepGoing=*/ false, reporter);
    assertThatEvaluationResult(result).hasError();
    assertThatEvaluationResult(result)
        .hasErrorEntryForKeyThat(skyKey)
        .hasExceptionThat()
        .isInstanceOf(BuildFileNotFoundException.class);
    assertThatEvaluationResult(result)
        .hasErrorEntryForKeyThat(skyKey)
        .hasExceptionThat()
        .hasMessageThat()
        .contains(
            "no such package 'pkg/sub': Symlink cycle detected while trying to find BUILD file");
    assertContainsEvent("circular symlinks detected");
  }

  private static class CustomInMemoryFs extends InMemoryFileSystem {
    private abstract static class FileStatusOrException {
      abstract FileStatus get() throws IOException;

      private static class ExceptionImpl extends FileStatusOrException {
        private final IOException exn;

        private ExceptionImpl(IOException exn) {
          this.exn = exn;
        }

        @Override
        FileStatus get() throws IOException {
          throw exn;
        }
      }

      private static class FileStatusImpl extends FileStatusOrException {

        @Nullable private final FileStatus fileStatus;

        private FileStatusImpl(@Nullable FileStatus fileStatus) {
          this.fileStatus = fileStatus;
        }

        @Override
        @Nullable
        FileStatus get() {
          return fileStatus;
        }
      }
    }

    private final Map<Path, FileStatusOrException> stubbedStats = Maps.newHashMap();
    private final Set<Path> makeUnreadableAfterReaddir = Sets.newHashSet();
    private final Map<Path, IOException> pathsToErrorOnGetInputStream = Maps.newHashMap();

    public CustomInMemoryFs(ManualClock manualClock) {
      super(manualClock);
    }

    public void stubStat(Path path, @Nullable FileStatus stubbedResult) {
      stubbedStats.put(path, new FileStatusOrException.FileStatusImpl(stubbedResult));
    }

    public void stubStatError(Path path, IOException stubbedResult) {
      stubbedStats.put(path, new FileStatusOrException.ExceptionImpl(stubbedResult));
    }

    @Override
    public FileStatus statIfFound(Path path, boolean followSymlinks) throws IOException {
      if (stubbedStats.containsKey(path)) {
        return stubbedStats.get(path).get();
      }
      return super.statIfFound(path, followSymlinks);
    }

    public void scheduleMakeUnreadableAfterReaddir(Path path) {
      makeUnreadableAfterReaddir.add(path);
    }

    @Override
    public Collection<Dirent> readdir(Path path, boolean followSymlinks) throws IOException {
      Collection<Dirent> result = super.readdir(path, followSymlinks);
      if (makeUnreadableAfterReaddir.contains(path)) {
        path.setReadable(false);
      }
      return result;
    }

    public void throwExceptionOnGetInputStream(Path path, IOException exn) {
      pathsToErrorOnGetInputStream.put(path, exn);
    }

    @Override
    protected InputStream getInputStream(Path path) throws IOException {
      IOException exnToThrow = pathsToErrorOnGetInputStream.get(path);
      if (exnToThrow != null) {
        throw exnToThrow;
      }
      return super.getInputStream(path);
    }
  }
}