Update from Google.

--
MOE_MIGRATED_REVID=85702957
diff --git a/src/main/java/com/google/devtools/build/lib/packages/ProtoUtils.java b/src/main/java/com/google/devtools/build/lib/packages/ProtoUtils.java
new file mode 100644
index 0000000..7b6eaf1
--- /dev/null
+++ b/src/main/java/com/google/devtools/build/lib/packages/ProtoUtils.java
@@ -0,0 +1,83 @@
+// Copyright 2014 Google Inc. 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.packages;
+
+import static com.google.devtools.build.lib.packages.Type.BOOLEAN;
+import static com.google.devtools.build.lib.packages.Type.DISTRIBUTIONS;
+import static com.google.devtools.build.lib.packages.Type.FILESET_ENTRY_LIST;
+import static com.google.devtools.build.lib.packages.Type.INTEGER;
+import static com.google.devtools.build.lib.packages.Type.INTEGER_LIST;
+import static com.google.devtools.build.lib.packages.Type.LABEL;
+import static com.google.devtools.build.lib.packages.Type.LABEL_LIST;
+import static com.google.devtools.build.lib.packages.Type.LABEL_LIST_DICT;
+import static com.google.devtools.build.lib.packages.Type.LICENSE;
+import static com.google.devtools.build.lib.packages.Type.NODEP_LABEL;
+import static com.google.devtools.build.lib.packages.Type.NODEP_LABEL_LIST;
+import static com.google.devtools.build.lib.packages.Type.OUTPUT;
+import static com.google.devtools.build.lib.packages.Type.OUTPUT_LIST;
+import static com.google.devtools.build.lib.packages.Type.STRING;
+import static com.google.devtools.build.lib.packages.Type.STRING_DICT;
+import static com.google.devtools.build.lib.packages.Type.STRING_DICT_UNARY;
+import static com.google.devtools.build.lib.packages.Type.STRING_LIST;
+import static com.google.devtools.build.lib.packages.Type.STRING_LIST_DICT;
+import static com.google.devtools.build.lib.packages.Type.TRISTATE;
+
+import com.google.common.base.Preconditions;
+import com.google.common.collect.ImmutableMap;
+import com.google.devtools.build.lib.query2.proto.proto2api.Build.Attribute.Discriminator;
+
+import java.util.Map;
+
+/**
+ * Shared code used in proto buffer output for rules and rule classes.
+ */
+public class ProtoUtils {
+  /**
+   * This map contains all attribute types that are recognized by the protocol
+   * output formatter.
+   */
+  private static final Map<Type<?>, Discriminator> TYPE_MAP
+      = new ImmutableMap.Builder<Type<?>, Discriminator>()
+          .put(INTEGER, Discriminator.INTEGER)
+          .put(DISTRIBUTIONS, Discriminator.DISTRIBUTION_SET)
+          .put(LABEL, Discriminator.LABEL)
+          // NODEP_LABEL attributes are not really strings. This is implemented
+          // this way for the sake of backward compatibility.
+          .put(NODEP_LABEL, Discriminator.STRING)
+          .put(LABEL_LIST, Discriminator.LABEL_LIST)
+          .put(NODEP_LABEL_LIST, Discriminator.STRING_LIST)
+          .put(STRING, Discriminator.STRING)
+          .put(STRING_LIST, Discriminator.STRING_LIST)
+          .put(OUTPUT, Discriminator.OUTPUT)
+          .put(OUTPUT_LIST, Discriminator.OUTPUT_LIST)
+          .put(LICENSE, Discriminator.LICENSE)
+          .put(STRING_DICT, Discriminator.STRING_DICT)
+          .put(FILESET_ENTRY_LIST, Discriminator.FILESET_ENTRY_LIST)
+          .put(LABEL_LIST_DICT, Discriminator.LABEL_LIST_DICT)
+          .put(STRING_LIST_DICT, Discriminator.STRING_LIST_DICT)
+          .put(BOOLEAN, Discriminator.BOOLEAN)
+          .put(TRISTATE, Discriminator.TRISTATE)
+          .put(INTEGER_LIST, Discriminator.INTEGER_LIST)
+          .put(STRING_DICT_UNARY, Discriminator.STRING_DICT_UNARY)
+          .build();
+
+  /**
+   * Returns the appropriate Attribute.Discriminator value from an internal attribute type.
+   */
+  public static Discriminator getDiscriminatorFromType(Type<?> type) {
+    Preconditions.checkArgument(TYPE_MAP.containsKey(type));
+    return TYPE_MAP.get(type);
+  }
+}