1 files changed, 11 insertions, 1 deletions
diff --git a/lib/CodeGen/CGVtable.cpp b/lib/CodeGen/CGVtable.cpp
index 9204e4e565..cedefba1e4 100644
--- a/lib/CodeGen/CGVtable.cpp
+++ b/lib/CodeGen/CGVtable.cpp
@@ -3805,7 +3805,17 @@ void CodeGenVTables::EmitVTableRelatedData(GlobalDecl GD) {
     return;
 
   TemplateSpecializationKind kind = RD->getTemplateSpecializationKind();
-  if (kind == TSK_ImplicitInstantiation)
+
+
+  // The reason we have TSK_ExplicitInstantiationDeclaration in here (but not
+  // in  Sema::MaybeMarkVirtualMembersReferenced) is for the case
+  // template<> void stdio_sync_filebuf<wchar_t>::xsgetn() {
+  // }
+  // extern template class stdio_sync_filebuf<wchar_t>;
+  // Since we are called after the extern declaration is seen.
+
+  if (kind == TSK_ImplicitInstantiation ||
+      kind == TSK_ExplicitInstantiationDeclaration)
     CGM.DeferredVtables.push_back(RD);
   else
     GenerateClassData(CGM.getVtableLinkage(RD), RD);