Adds a build_file_content attribute to new_git_repository, new_http_archive, and

new_local_repository which allows the build file to be specified by a string
directly in the rule rather than using a separate file. build_file and
build_file_content are both optional, but one or the other must be
specified.

RELNOTES: build_file_content attribute added to new_git_repository,
new_http_archive, and new_local_repository.

--
MOS_MIGRATED_REVID=114490435

10 files changed, 235 insertions, 83 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/bazel/repository/NewGitRepositoryFunction.java b/src/main/java/com/google/devtools/build/lib/bazel/repository/NewGitRepositoryFunction.java
index b10ed9448a..2b89ce3a5d 100644
--- a/src/main/java/com/google/devtools/build/lib/bazel/repository/NewGitRepositoryFunction.java
+++ b/src/main/java/com/google/devtools/build/lib/bazel/repository/NewGitRepositoryFunction.java
@@ -15,7 +15,8 @@
 package com.google.devtools.build.lib.bazel.repository;
 
 import com.google.devtools.build.lib.packages.Rule;
-import com.google.devtools.build.lib.skyframe.FileValue;
+import com.google.devtools.build.lib.rules.repository.NewRepositoryBuildFileHandler;
+import com.google.devtools.build.lib.rules.repository.RepositoryDirectoryValue;
 import com.google.devtools.build.lib.vfs.Path;
 import com.google.devtools.build.skyframe.SkyFunction.Environment;
 import com.google.devtools.build.skyframe.SkyFunctionException;
@@ -27,15 +28,19 @@ import com.google.devtools.build.skyframe.SkyValue;
 public class NewGitRepositoryFunction extends GitRepositoryFunction {
   @Override
   public SkyValue fetch(Rule rule, Path outputDirectory, Environment env)
-      throws SkyFunctionException {
-    FileValue buildFileValue = getBuildFileValue(rule, env);
-    if (env.valuesMissing()) {
+      throws SkyFunctionException { 
+
+    NewRepositoryBuildFileHandler buildFileHandler =
+        new NewRepositoryBuildFileHandler(getWorkspace());
+    if (!buildFileHandler.prepareBuildFile(rule, env)) {
       return null;
     }
 
     createDirectory(outputDirectory, rule);
     GitCloner.clone(rule, outputDirectory, env.getListener());
     createWorkspaceFile(outputDirectory, rule);
-    return symlinkBuildFile(buildFileValue, outputDirectory);
+    buildFileHandler.finishBuildFile(outputDirectory);
+
+    return RepositoryDirectoryValue.create(outputDirectory);
   }
 }
diff --git a/src/main/java/com/google/devtools/build/lib/bazel/repository/NewHttpArchiveFunction.java b/src/main/java/com/google/devtools/build/lib/bazel/repository/NewHttpArchiveFunction.java
index 8321457ded..9d7af3ebcd 100644
--- a/src/main/java/com/google/devtools/build/lib/bazel/repository/NewHttpArchiveFunction.java
+++ b/src/main/java/com/google/devtools/build/lib/bazel/repository/NewHttpArchiveFunction.java
@@ -16,7 +16,8 @@ package com.google.devtools.build.lib.bazel.repository;
 
 import com.google.devtools.build.lib.packages.AggregatingAttributeMapper;
 import com.google.devtools.build.lib.packages.Rule;
-import com.google.devtools.build.lib.skyframe.FileValue;
+import com.google.devtools.build.lib.rules.repository.NewRepositoryBuildFileHandler;
+import com.google.devtools.build.lib.rules.repository.RepositoryDirectoryValue;
 import com.google.devtools.build.lib.syntax.Type;
 import com.google.devtools.build.lib.vfs.FileSystemUtils;
 import com.google.devtools.build.lib.vfs.Path;
@@ -38,10 +39,13 @@ public class NewHttpArchiveFunction extends HttpArchiveFunction {
   @Override
   public SkyValue fetch(Rule rule, Path outputDirectory, Environment env)
       throws RepositoryFunctionException, InterruptedException {
-    FileValue buildFileValue = getBuildFileValue(rule, env);
-    if (env.valuesMissing()) {
+
+    NewRepositoryBuildFileHandler buildFileHandler =
+        new NewRepositoryBuildFileHandler(getWorkspace());
+    if (!buildFileHandler.prepareBuildFile(rule, env)) {
       return null;
     }
+
     try {
       FileSystemUtils.createDirectoryAndParents(outputDirectory);
     } catch (IOException e) {
@@ -68,8 +72,10 @@ public class NewHttpArchiveFunction extends HttpArchiveFunction {
         .setPrefix(prefix)
         .build());
 
-    // Add WORKSPACE and BUILD files.
+    // Finally, write WORKSPACE and BUILD files.
     createWorkspaceFile(decompressed, rule);
-    return symlinkBuildFile(buildFileValue, outputDirectory);
+    buildFileHandler.finishBuildFile(outputDirectory);
+
+    return RepositoryDirectoryValue.create(outputDirectory);
   }
 }
diff --git a/src/main/java/com/google/devtools/build/lib/bazel/rules/android/AndroidNdkRepositoryFunction.java b/src/main/java/com/google/devtools/build/lib/bazel/rules/android/AndroidNdkRepositoryFunction.java
index 5261bd7a79..04d9c5b8b8 100644
--- a/src/main/java/com/google/devtools/build/lib/bazel/rules/android/AndroidNdkRepositoryFunction.java
+++ b/src/main/java/com/google/devtools/build/lib/bazel/rules/android/AndroidNdkRepositoryFunction.java
@@ -25,6 +25,7 @@ import com.google.devtools.build.lib.bazel.rules.android.ndkcrosstools.StlImpls;
 import com.google.devtools.build.lib.packages.AttributeMap;
 import com.google.devtools.build.lib.packages.NonconfigurableAttributeMapper;
 import com.google.devtools.build.lib.packages.Rule;
+import com.google.devtools.build.lib.rules.repository.RepositoryDirectoryValue;
 import com.google.devtools.build.lib.rules.repository.RepositoryFunction;
 import com.google.devtools.build.lib.skyframe.FileSymlinkException;
 import com.google.devtools.build.lib.skyframe.FileValue;
@@ -124,7 +125,8 @@ public class AndroidNdkRepositoryFunction extends RepositoryFunction {
     }
 
     String buildFile = createBuildFile(ruleName, crosstoolsAndStls.build());
-    return writeBuildFile(outputDirectory, buildFile);
+    writeBuildFile(outputDirectory, buildFile);
+    return RepositoryDirectoryValue.create(outputDirectory);
   }
 
   @Override
diff --git a/src/main/java/com/google/devtools/build/lib/bazel/rules/android/AndroidSdkRepositoryFunction.java b/src/main/java/com/google/devtools/build/lib/bazel/rules/android/AndroidSdkRepositoryFunction.java
index 1e2a4dd360..3e4a767b1d 100644
--- a/src/main/java/com/google/devtools/build/lib/bazel/rules/android/AndroidSdkRepositoryFunction.java
+++ b/src/main/java/com/google/devtools/build/lib/bazel/rules/android/AndroidSdkRepositoryFunction.java
@@ -17,6 +17,7 @@ import com.google.devtools.build.lib.analysis.RuleDefinition;
 import com.google.devtools.build.lib.packages.AttributeMap;
 import com.google.devtools.build.lib.packages.NonconfigurableAttributeMapper;
 import com.google.devtools.build.lib.packages.Rule;
+import com.google.devtools.build.lib.rules.repository.RepositoryDirectoryValue;
 import com.google.devtools.build.lib.rules.repository.RepositoryFunction;
 import com.google.devtools.build.lib.syntax.Type;
 import com.google.devtools.build.lib.util.ResourceFileLoader;
@@ -65,7 +66,8 @@ public class AndroidSdkRepositoryFunction extends RepositoryFunction {
         .replaceAll("%build_tools_version%", buildToolsVersion)
         .replaceAll("%api_level%", apiLevel.toString());
 
-    return writeBuildFile(outputDirectory, buildFile);
+    writeBuildFile(outputDirectory, buildFile);
+    return RepositoryDirectoryValue.create(outputDirectory);
   }
 
   @Override
diff --git a/src/main/java/com/google/devtools/build/lib/bazel/rules/workspace/NewGitRepositoryRule.java b/src/main/java/com/google/devtools/build/lib/bazel/rules/workspace/NewGitRepositoryRule.java
index d75d533946..ae264bc248 100644
--- a/src/main/java/com/google/devtools/build/lib/bazel/rules/workspace/NewGitRepositoryRule.java
+++ b/src/main/java/com/google/devtools/build/lib/bazel/rules/workspace/NewGitRepositoryRule.java
@@ -54,11 +54,19 @@ public class NewGitRepositoryRule implements RuleDefinition {
         /* <!-- #BLAZE_RULE(new_git_repository).ATTRIBUTE(build_file) -->
         The file to use as the BUILD file for this repository.
 
+        <p>Either build_file or build_file_content must be specified.</p>
+
         <p>This path is relative to the build's workspace. The file does not need to be named
         BUILD, but can be something like BUILD.new-repo-name to distinguish it
         from the workspace's actual BUILD files.</p>
         <!-- #END_BLAZE_RULE.ATTRIBUTE --> */
-        .add(attr("build_file", STRING).mandatory())
+        .add(attr("build_file", STRING))
+        /* <!-- #BLAZE_RULE(new_git_repository).ATTRIBUTE(build_file_content) -->
+        The content for the BUILD file for this repository.
+
+        <p>Either build_file or build_file_content must be specified.</p>
+        <!-- #END_BLAZE_RULE.ATTRIBUTE --> */
+        .add(attr("build_file_content", STRING))
         /* <!-- #BLAZE_RULE(new_git_repository).ATTRIBUTE(init_submodules) -->
         Whether to clone submodules in the repository.
 
diff --git a/src/main/java/com/google/devtools/build/lib/bazel/rules/workspace/NewHttpArchiveRule.java b/src/main/java/com/google/devtools/build/lib/bazel/rules/workspace/NewHttpArchiveRule.java
index ab6224eb05..459f80527e 100644
--- a/src/main/java/com/google/devtools/build/lib/bazel/rules/workspace/NewHttpArchiveRule.java
+++ b/src/main/java/com/google/devtools/build/lib/bazel/rules/workspace/NewHttpArchiveRule.java
@@ -51,11 +51,19 @@ public class NewHttpArchiveRule implements RuleDefinition {
         /* <!-- #BLAZE_RULE(new_http_archive).ATTRIBUTE(build_file) -->
          The file to use as the BUILD file for this repository.
 
+         <p>Either build_file or build_file_content must be specified.</p>
+
          <p>This path is relative to the build's workspace. The file does not need to be named
          BUILD, but can be something like BUILD.new-repo-name to distinguish it
          from the workspace's actual BUILD files.</p>
          <!-- #END_BLAZE_RULE.ATTRIBUTE --> */
-        .add(attr("build_file", STRING).mandatory())
+        .add(attr("build_file", STRING))
+        /* <!-- #BLAZE_RULE(new_http_archive).ATTRIBUTE(build_file_content) -->
+        The content for the BUILD file for this repository.
+
+        <p>Either build_file or build_file_content must be specified.</p>
+        <!-- #END_BLAZE_RULE.ATTRIBUTE --> */
+        .add(attr("build_file_content", STRING))
         /* <!-- #BLAZE_RULE(new_http_archive).ATTRIBUTE(type) -->
          The archive type of the downloaded file.
 
diff --git a/src/main/java/com/google/devtools/build/lib/rules/repository/NewLocalRepositoryFunction.java b/src/main/java/com/google/devtools/build/lib/rules/repository/NewLocalRepositoryFunction.java
index 27bdc9a1c4..4fec7696ff 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/repository/NewLocalRepositoryFunction.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/repository/NewLocalRepositoryFunction.java
@@ -16,7 +16,6 @@ package com.google.devtools.build.lib.rules.repository;
 
 import com.google.devtools.build.lib.analysis.RuleDefinition;
 import com.google.devtools.build.lib.packages.Rule;
-import com.google.devtools.build.lib.skyframe.FileValue;
 import com.google.devtools.build.lib.vfs.Path;
 import com.google.devtools.build.lib.vfs.PathFragment;
 import com.google.devtools.build.skyframe.SkyFunction.Environment;
@@ -27,6 +26,7 @@ import com.google.devtools.build.skyframe.SkyValue;
  * Create a repository from a directory on the local filesystem.
  */
 public class NewLocalRepositoryFunction extends RepositoryFunction {
+
   @Override
   public boolean isLocal() {
     return true;
@@ -35,21 +35,25 @@ public class NewLocalRepositoryFunction extends RepositoryFunction {
   @Override
   public SkyValue fetch(Rule rule, Path outputDirectory, Environment env)
       throws SkyFunctionException {
-    FileValue buildFileValue = getBuildFileValue(rule, env);
-    if (env.valuesMissing()) {
+
+    NewRepositoryBuildFileHandler buildFileHandler =
+        new NewRepositoryBuildFileHandler(getWorkspace());
+    if (!buildFileHandler.prepareBuildFile(rule, env)) {
       return null;
     }
+
     prepareLocalRepositorySymlinkTree(rule, outputDirectory);
     PathFragment pathFragment = getTargetPath(rule, getWorkspace());
-    
+
     // Link x/y/z to /some/path/to/y/z.
     if (!symlinkLocalRepositoryContents(
         outputDirectory, getOutputBase().getFileSystem().getPath(pathFragment))) {
       return null;
     }
 
-    // Link x/BUILD to <build_root>/x.BUILD.
-    return symlinkBuildFile(buildFileValue, outputDirectory);
+    buildFileHandler.finishBuildFile(outputDirectory);
+    
+    return RepositoryDirectoryValue.create(outputDirectory);
   }
 
   @Override
diff --git a/src/main/java/com/google/devtools/build/lib/rules/repository/NewLocalRepositoryRule.java b/src/main/java/com/google/devtools/build/lib/rules/repository/NewLocalRepositoryRule.java
index f68b506ed9..baef7788e8 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/repository/NewLocalRepositoryRule.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/repository/NewLocalRepositoryRule.java
@@ -41,11 +41,19 @@ public class NewLocalRepositoryRule implements RuleDefinition {
         /* <!-- #BLAZE_RULE(new_local_repository).ATTRIBUTE(build_file) -->
         A file to use as a BUILD file for this directory.
 
+        <p>Either build_file or build_file_content must be specified.</p>
+
         <p>This path is relative to the build's workspace. The file does not need to be named
         BUILD, but can be (something like BUILD.new-repo-name may work well for distinguishing it
         from the repository's actual BUILD files.</p>
         <!-- #END_BLAZE_RULE.ATTRIBUTE --> */
-        .add(attr("build_file", STRING).mandatory())
+        .add(attr("build_file", STRING))
+        /* <!-- #BLAZE_RULE(new_local_repository).ATTRIBUTE(build_file_content) -->
+        The content for the BUILD file for this repository.
+
+        <p>Either build_file or build_file_content must be specified.</p>
+        <!-- #END_BLAZE_RULE.ATTRIBUTE --> */
+        .add(attr("build_file_content", STRING))
         .setWorkspaceOnly()
         .build();
   }
diff --git a/src/main/java/com/google/devtools/build/lib/rules/repository/NewRepositoryBuildFileHandler.java b/src/main/java/com/google/devtools/build/lib/rules/repository/NewRepositoryBuildFileHandler.java
new file mode 100644
index 0000000000..9518248772
--- /dev/null
+++ b/src/main/java/com/google/devtools/build/lib/rules/repository/NewRepositoryBuildFileHandler.java
@@ -0,0 +1,168 @@
+// Copyright 2014 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.rules.repository;
+
+import com.google.devtools.build.lib.packages.AggregatingAttributeMapper;
+import com.google.devtools.build.lib.packages.Rule;
+import com.google.devtools.build.lib.rules.repository.RepositoryFunction.RepositoryFunctionException;
+import com.google.devtools.build.lib.skyframe.FileSymlinkException;
+import com.google.devtools.build.lib.skyframe.FileValue;
+import com.google.devtools.build.lib.skyframe.InconsistentFilesystemException;
+import com.google.devtools.build.lib.syntax.EvalException;
+import com.google.devtools.build.lib.syntax.Type;
+import com.google.devtools.build.lib.vfs.Path;
+import com.google.devtools.build.lib.vfs.PathFragment;
+import com.google.devtools.build.lib.vfs.RootedPath;
+import com.google.devtools.build.skyframe.SkyFunction.Environment;
+import com.google.devtools.build.skyframe.SkyFunctionException.Transience;
+import com.google.devtools.build.skyframe.SkyKey;
+
+import java.io.IOException;
+
+/**
+ * Encapsulates the 2-step behavior of creating build files for the new_*_repository rules.
+ */
+public class NewRepositoryBuildFileHandler {
+
+  private final Path workspacePath;
+  private FileValue buildFileValue;
+  private String buildFileContent;
+
+  public NewRepositoryBuildFileHandler(Path workspacePath) {
+    this.workspacePath = workspacePath;
+  }
+
+  /**
+   * Prepares for writing a build file by validating the build_file and build_file_content
+   * attributes of the rule.
+   *
+   * @return true if the build file was successfully created, false if the environment is missing
+   *     values (the calling fetch() function should return null in this case).
+   * @throws RepositoryFunctionException if the rule does not define the build_file or
+   *     build_file_content attributes, or if it defines both, or if the build file could not be
+   *     retrieved, written, or symlinked.
+   */
+  public boolean prepareBuildFile(Rule rule, Environment env)
+      throws RepositoryFunctionException {
+
+    AggregatingAttributeMapper mapper = AggregatingAttributeMapper.of(rule);
+    boolean hasBuildFile = mapper.isAttributeValueExplicitlySpecified("build_file");
+    boolean hasBuildFileContent = mapper.isAttributeValueExplicitlySpecified("build_file_content");
+
+    if (hasBuildFile && hasBuildFileContent) {
+
+      String error = String.format(
+          "Rule %s cannot have both a 'build_file' and 'build_file_content' attribute", rule);
+      throw new RepositoryFunctionException(
+          new EvalException(rule.getLocation(), error), Transience.PERSISTENT);
+
+    } else if (hasBuildFile) {
+
+      buildFileValue = getBuildFileValue(rule, env);
+      if (env.valuesMissing()) {
+        return false;
+      }
+
+    } else if (hasBuildFileContent) { 
+
+      buildFileContent = mapper.get("build_file_content", Type.STRING);
+
+    } else {
+
+      String error = String.format(
+          "Rule %s requires a 'build_file' or 'build_file_content' attribute", rule);
+      throw new RepositoryFunctionException(
+          new EvalException(rule.getLocation(), error), Transience.PERSISTENT);
+    }
+
+    return true;
+  }
+
+  /**
+   * Writes the build file, based on the state set by prepareBuildFile().
+   * 
+   * @param outputDirectory the directory to write the build file.
+   * @throws RepositoryFunctionException if the build file could not be written or symlinked
+   * @throws IllegalStateException if prepareBuildFile() was not called before this, or if
+   *     prepareBuildFile() failed and this was called.
+   */
+  public void finishBuildFile(Path outputDirectory) throws RepositoryFunctionException {
+    if (buildFileValue != null) {
+      // Link x/BUILD to <build_root>/x.BUILD.
+      symlinkBuildFile(buildFileValue, outputDirectory);
+    } else if (buildFileContent != null) {
+      RepositoryFunction.writeBuildFile(outputDirectory, buildFileContent);
+    } else {
+      throw new IllegalStateException(
+          "prepareBuildFile() must be called before finishBuildFile()");
+    }
+  }
+
+  private FileValue getBuildFileValue(Rule rule, Environment env)
+      throws RepositoryFunctionException {
+    AggregatingAttributeMapper mapper = AggregatingAttributeMapper.of(rule);
+    PathFragment buildFile = new PathFragment(mapper.get("build_file", Type.STRING));
+    Path buildFileTarget = workspacePath.getRelative(buildFile);
+    if (!buildFileTarget.exists()) {
+      throw new RepositoryFunctionException(
+          new EvalException(rule.getLocation(),
+              String.format("In %s the 'build_file' attribute does not specify an existing file "
+                  + "(%s does not exist)", rule, buildFileTarget)),
+          Transience.PERSISTENT);
+    }
+
+    RootedPath rootedBuild;
+    if (buildFile.isAbsolute()) {
+      rootedBuild = RootedPath.toRootedPath(
+          buildFileTarget.getParentDirectory(), new PathFragment(buildFileTarget.getBaseName()));
+    } else {
+      rootedBuild = RootedPath.toRootedPath(workspacePath, buildFile);
+    }
+    SkyKey buildFileKey = FileValue.key(rootedBuild);
+    FileValue buildFileValue;
+    try {
+      // Note that this dependency is, strictly speaking, not necessary: the symlink could simply
+      // point to this FileValue and the symlink chasing could be done while loading the package
+      // but this results in a nicer error message and it's correct as long as RepositoryFunctions
+      // don't write to things in the file system this FileValue depends on. In theory, the latter
+      // is possible if the file referenced by build_file is a symlink to somewhere under the
+      // external/ directory, but if you do that, you are really asking for trouble.
+      buildFileValue = (FileValue) env.getValueOrThrow(buildFileKey, IOException.class,
+          FileSymlinkException.class, InconsistentFilesystemException.class);
+      if (buildFileValue == null) {
+        return null;
+      }
+    } catch (IOException | FileSymlinkException | InconsistentFilesystemException e) {
+      throw new RepositoryFunctionException(
+          new IOException("Cannot lookup " + buildFile + ": " + e.getMessage()),
+          Transience.TRANSIENT);
+    }
+
+    return buildFileValue;
+  }
+
+  /**
+   * Symlinks a BUILD file from the local filesystem into the external repository's root.
+   * @param buildFileValue {@link FileValue} representing the BUILD file to be linked in
+   * @param outputDirectory the directory of the remote repository
+   * @throws RepositoryFunctionException if the BUILD file specified does not exist or cannot be
+   *         linked.
+   */
+  private void symlinkBuildFile(
+      FileValue buildFileValue, Path outputDirectory) throws RepositoryFunctionException {
+    Path buildFilePath = outputDirectory.getRelative("BUILD");
+    RepositoryFunction.createSymbolicLink(buildFilePath, buildFileValue.realRootedPath().asPath());
+  }
+}
\ No newline at end of file
diff --git a/src/main/java/com/google/devtools/build/lib/rules/repository/RepositoryFunction.java b/src/main/java/com/google/devtools/build/lib/rules/repository/RepositoryFunction.java
index ee93a82227..c2f327d749 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/repository/RepositoryFunction.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/repository/RepositoryFunction.java
@@ -216,7 +216,6 @@ public abstract class RepositoryFunction {
     }
   }
 
-
   protected Path prepareLocalRepositorySymlinkTree(Rule rule, Path repositoryDirectory)
       throws RepositoryFunctionException {
     try {
@@ -242,8 +241,8 @@ public abstract class RepositoryFunction {
     }
   }
 
-  protected RepositoryDirectoryValue writeBuildFile(Path repositoryDirectory, String contents)
-      throws RepositoryFunctionException {
+  protected static RepositoryDirectoryValue writeBuildFile(
+      Path repositoryDirectory, String contents) throws RepositoryFunctionException {
     Path buildFilePath = repositoryDirectory.getRelative("BUILD");
     try {
       FileSystemUtils.writeContentAsLatin1(buildFilePath, contents);
@@ -254,64 +253,6 @@ public abstract class RepositoryFunction {
     return RepositoryDirectoryValue.create(repositoryDirectory);
   }
 
-  protected FileValue getBuildFileValue(Rule rule, Environment env)
-      throws RepositoryFunctionException {
-    AggregatingAttributeMapper mapper = AggregatingAttributeMapper.of(rule);
-    PathFragment buildFile = new PathFragment(mapper.get("build_file", Type.STRING));
-    Path buildFileTarget = directories.getWorkspace().getRelative(buildFile);
-    if (!buildFileTarget.exists()) {
-      throw new RepositoryFunctionException(
-          new EvalException(rule.getLocation(),
-              String.format("In %s the 'build_file' attribute does not specify an existing file "
-                  + "(%s does not exist)", rule, buildFileTarget)),
-          Transience.PERSISTENT);
-    }
-
-    RootedPath rootedBuild;
-    if (buildFile.isAbsolute()) {
-      rootedBuild = RootedPath.toRootedPath(
-          buildFileTarget.getParentDirectory(), new PathFragment(buildFileTarget.getBaseName()));
-    } else {
-      rootedBuild = RootedPath.toRootedPath(directories.getWorkspace(), buildFile);
-    }
-    SkyKey buildFileKey = FileValue.key(rootedBuild);
-    FileValue buildFileValue;
-    try {
-      // Note that this dependency is, strictly speaking, not necessary: the symlink could simply
-      // point to this FileValue and the symlink chasing could be done while loading the package
-      // but this results in a nicer error message and it's correct as long as RepositoryFunctions
-      // don't write to things in the file system this FileValue depends on. In theory, the latter
-      // is possible if the file referenced by build_file is a symlink to somewhere under the
-      // external/ directory, but if you do that, you are really asking for trouble.
-      buildFileValue = (FileValue) env.getValueOrThrow(buildFileKey, IOException.class,
-          FileSymlinkException.class, InconsistentFilesystemException.class);
-      if (buildFileValue == null) {
-        return null;
-      }
-    } catch (IOException | FileSymlinkException | InconsistentFilesystemException e) {
-      throw new RepositoryFunctionException(
-          new IOException("Cannot lookup " + buildFile + ": " + e.getMessage()),
-          Transience.TRANSIENT);
-    }
-
-    return buildFileValue;
-  }
-
-  /**
-   * Symlinks a BUILD file from the local filesystem into the external repository's root.
-   * @param buildFileValue {@link FileValue} representing the BUILD file to be linked in
-   * @param outputDirectory the directory of the remote repository
-   * @return the file value of the symlink created.
-   * @throws RepositoryFunctionException if the BUILD file specified does not exist or cannot be
-   *         linked.
-   */
-  protected RepositoryDirectoryValue symlinkBuildFile(
-      FileValue buildFileValue, Path outputDirectory) throws RepositoryFunctionException {
-    Path buildFilePath = outputDirectory.getRelative("BUILD");
-    createSymbolicLink(buildFilePath, buildFileValue.realRootedPath().asPath());
-    return RepositoryDirectoryValue.create(outputDirectory);
-  }
-
   @VisibleForTesting
   protected static PathFragment getTargetPath(Rule rule, Path workspace)
       throws RepositoryFunctionException {
@@ -350,7 +291,7 @@ public abstract class RepositoryFunction {
     return true;
   }
 
-  private static void createSymbolicLink(Path from, Path to)
+  static void createSymbolicLink(Path from, Path to)
       throws RepositoryFunctionException {
     try {
       // Remove not-symlinks that are already there.