1 files changed, 8 insertions, 0 deletions
diff --git a/lib/Sema/SemaLookup.cpp b/lib/Sema/SemaLookup.cpp
index 5507c5770d..44181b141d 100644
--- a/lib/Sema/SemaLookup.cpp
+++ b/lib/Sema/SemaLookup.cpp
@@ -2558,6 +2558,7 @@ void ADLResult::insert(NamedDecl *New) {
 }
 
 void Sema::ArgumentDependentLookup(DeclarationName Name, bool Operator,
+                                   SourceLocation Loc,
                                    Expr **Args, unsigned NumArgs,
                                    ADLResult &Result,
                                    bool StdNamespaceIsAssociated) {
@@ -2578,6 +2579,13 @@ void Sema::ArgumentDependentLookup(DeclarationName Name, bool Operator,
       T2 = Args[1]->getType();
   }
 
+  // Try to complete all associated classes, in case they contain a
+  // declaration of a friend function.
+  for (AssociatedClassSet::iterator C = AssociatedClasses.begin(),
+                                    CEnd = AssociatedClasses.end();
+       C != CEnd; ++C)
+    RequireCompleteType(Loc, Context.getRecordType(*C), 0);
+
   // C++ [basic.lookup.argdep]p3:
   //   Let X be the lookup set produced by unqualified lookup (3.4.1)
   //   and let Y be the lookup set produced by argument dependent