Dedupe input artifacts when adding them to a filelist to be passed to apple's clang

--
MOS_MIGRATED_REVID=125520039

1 files changed, 2 insertions, 1 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/rules/objc/CompilationSupport.java b/src/main/java/com/google/devtools/build/lib/rules/objc/CompilationSupport.java
index b2c5be01d8..a90787f30f 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/objc/CompilationSupport.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/objc/CompilationSupport.java
@@ -813,10 +813,11 @@ public final class CompilationSupport {
   }
 
   private Action objFilelistAction(Iterable<Artifact> objFiles, Artifact objList) {
+    ImmutableSet<Artifact> dedupedObjFiles = ImmutableSet.copyOf(objFiles);
     return new FileWriteAction(
         ruleContext.getActionOwner(),
         objList,
-        Artifact.joinExecPaths("\n", objFiles),
+        Artifact.joinExecPaths("\n", dedupedObjFiles),
         /*makeExecutable=*/ false);
   }