Index: clang/lib/AST/MicrosoftMangle.cpp
===================================================================
--- clang/lib/AST/MicrosoftMangle.cpp
+++ clang/lib/AST/MicrosoftMangle.cpp
@@ -948,11 +948,13 @@
           mangleSourceName(Name);
 
           // If the context of a closure type is an initializer for a class
-          // member (static or nonstatic), it is encoded in a qualified name.
+          // member (static or nonstatic) or is a top level decl, it is encoded
+          // in a qualified name.
           if (LambdaManglingNumber && LambdaContextDecl) {
             if ((isa<VarDecl>(LambdaContextDecl) ||
                  isa<FieldDecl>(LambdaContextDecl)) &&
-                LambdaContextDecl->getDeclContext()->isRecord()) {
+                (LambdaContextDecl->getDeclContext()->isRecord() ||
+                 LambdaContextDecl->getDeclContext()->isTranslationUnit())) {
               mangleUnqualifiedName(cast<NamedDecl>(LambdaContextDecl));
             }
           }