1 files changed, 17 insertions, 26 deletions

diff --git a/lib/Sema/SemaLookup.cpp b/lib/Sema/SemaLookup.cpp
index a8a3651c5d..effccc2f3d 100644
--- a/lib/Sema/SemaLookup.cpp
+++ b/lib/Sema/SemaLookup.cpp
@@ -3337,38 +3337,29 @@ void Sema::ArgumentDependentLookup(DeclarationName Name, SourceLocation Loc,
           !isa<FunctionTemplateDecl>(Underlying))
         continue;
 
-      if (!isVisible(D)) {
-        D = findAcceptableDecl(
-            *this, D, (Decl::IDNS_Ordinary | Decl::IDNS_OrdinaryFriend));
-        if (!D)
-          continue;
-        if (auto *USD = dyn_cast<UsingShadowDecl>(D))
-          Underlying = USD->getTargetDecl();
-      }
-
-      // If the only declaration here is an ordinary friend, consider
-      // it only if it was declared in an associated classes.
-      if ((D->getIdentifierNamespace() & Decl::IDNS_Ordinary) == 0) {
-        // If it's neither ordinarily visible nor a friend, we can't find it.
-        if ((D->getIdentifierNamespace() & Decl::IDNS_OrdinaryFriend) == 0)
-          continue;
-
-        bool DeclaredInAssociatedClass = false;
-        for (Decl *DI = D; DI; DI = DI->getPreviousDecl()) {
-          DeclContext *LexDC = DI->getLexicalDeclContext();
-          if (isa<CXXRecordDecl>(LexDC) &&
-              AssociatedClasses.count(cast<CXXRecordDecl>(LexDC)) &&
-              isVisible(cast<NamedDecl>(DI))) {
-            DeclaredInAssociatedClass = true;
+      // The declaration is visible to argument-dependent lookup if either
+      // it's ordinarily visible or declared as a friend in an associated
+      // class.
+      bool Visible = false;
+      for (D = D->getMostRecentDecl(); D;
+           D = cast_or_null<NamedDecl>(D->getPreviousDecl())) {
+        if (D->getIdentifierNamespace() & Decl::IDNS_Ordinary) {
+          if (isVisible(D)) {
+            Visible = true;
+            break;
+          }
+        } else if (D->getFriendObjectKind()) {
+          auto *RD = cast<CXXRecordDecl>(D->getLexicalDeclContext());
+          if (AssociatedClasses.count(RD) && isVisible(D)) {
+            Visible = true;
             break;
           }
         }
-        if (!DeclaredInAssociatedClass)
-          continue;
       }
 
       // FIXME: Preserve D as the FoundDecl.
-      Result.insert(Underlying);
+      if (Visible)
+        Result.insert(Underlying);
     }
   }
 }