Description redacted.

--
MOS_MIGRATED_REVID=89134834

1 files changed, 40 insertions, 0 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/packages/RawAttributeMapper.java b/src/main/java/com/google/devtools/build/lib/packages/RawAttributeMapper.java
index a174193226..a2ee1b13cb 100644
--- a/src/main/java/com/google/devtools/build/lib/packages/RawAttributeMapper.java
+++ b/src/main/java/com/google/devtools/build/lib/packages/RawAttributeMapper.java
@@ -13,9 +13,16 @@
 // limitations under the License.
 package com.google.devtools.build.lib.packages;
 
+import com.google.common.base.Preconditions;
 import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableSet;
 import com.google.devtools.build.lib.syntax.Label;
 
+import java.util.Collection;
+import java.util.List;
+
+import javax.annotation.Nullable;
+
 /**
  * {@link AttributeMap} implementation that returns raw attribute information as contained
  * within a {@link Rule}. In particular, configurable attributes of the form
@@ -40,6 +47,39 @@ public class RawAttributeMapper extends AbstractAttributeMapper {
   }
 
   /**
+   * Variation of {@link #get} that merges the values of configurable lists together (with
+   * duplicates removed).
+   *
+   * <p>For example, given:
+   * <pre>
+   *   attr = select({
+   *       ':condition1': [A, B, C],
+   *       ':condition2': [C, D]
+   *       }),
+   * </pre>
+   * this returns the value <code>[A, B, C, D]</code>.
+   *
+   * <p>If the attribute isn't configurable (e.g. <code>attr = [A, B]</code>), returns
+   * its raw value.
+   *
+   * <p>Throws an {@link IllegalStateException} if the attribute isn't a list type.
+   */
+  @Nullable
+  public <T> Collection<T> getMergedValues(String attributeName, Type<List<T>> type) {
+    Preconditions.checkState(type instanceof Type.ListType<?>);
+    if (!isConfigurable(attributeName, type)) {
+      return get(attributeName, type);
+    }
+
+    Type.Selector<List<T>> selector = getSelector(attributeName, type);
+    ImmutableSet.Builder<T> mergedValues = ImmutableSet.builder();
+    for (List<T> configuredList : selector.getEntries().values()) {
+      mergedValues.addAll(configuredList);
+    }
+    return mergedValues.build();
+  }
+
+  /**
    * Returns true if the given attribute is configurable for this rule instance, false
    * otherwise.
    */