Use ImmutableList for Option expansion functions

RELNOTES: None
PiperOrigin-RevId: 158279811

1 files changed, 5 insertions, 3 deletions

diff --git a/src/main/java/com/google/devtools/common/options/ExpansionFunction.java b/src/main/java/com/google/devtools/common/options/ExpansionFunction.java
index ffab6e70fc..be4773ec39 100644
--- a/src/main/java/com/google/devtools/common/options/ExpansionFunction.java
+++ b/src/main/java/com/google/devtools/common/options/ExpansionFunction.java
@@ -13,9 +13,11 @@
 // limitations under the License.
 package com.google.devtools.common.options;
 
+import com.google.common.collect.ImmutableList;
+
 /**
- * A function from an option parser's static setup (what flags it knows about) to an expansion
- * String[] to use for one of its options.
+ * A function from an option parser's static setup (what flags it knows about) to a list of
+ * expansion Strings to use for one of its options.
  */
 public interface ExpansionFunction {
 
@@ -27,5 +29,5 @@ public interface ExpansionFunction {
    *     information is computed
    * @return An expansion to use for all occurrences of this option in this parser
    */
-  public String[] getExpansion(IsolatedOptionsData optionsData);
+  ImmutableList<String> getExpansion(IsolatedOptionsData optionsData);
 }