2 files changed, 28 insertions, 21 deletions

diff --git a/clang/lib/Sema/Sema.cpp b/clang/lib/Sema/Sema.cpp
index ec7b61d32a3..e9791a0e644 100644
--- a/clang/lib/Sema/Sema.cpp
+++ b/clang/lib/Sema/Sema.cpp
@@ -284,26 +284,24 @@ static bool ShouldRemoveFromUnused(Sema *SemaRef, const DeclaratorDecl *D) {
 void Sema::ActOnEndOfTranslationUnit() {
   // At PCH writing, implicit instantiations and VTable handling info are
   // stored and performed when the PCH is included.
-  if (CompleteTranslationUnit)
-    while (1) {
-      // C++: Perform implicit template instantiations.
-      //
-      // FIXME: When we perform these implicit instantiations, we do not
-      // carefully keep track of the point of instantiation (C++ [temp.point]).
-      // This means that name lookup that occurs within the template
-      // instantiation will always happen at the end of the translation unit,
-      // so it will find some names that should not be found. Although this is
-      // common behavior for C++ compilers, it is technically wrong. In the
-      // future, we either need to be able to filter the results of name lookup
-      // or we need to perform template instantiations earlier.
-      PerformPendingInstantiations();
-
-      /// If DefinedUsedVTables ends up marking any virtual member
-      /// functions it might lead to more pending template
-      /// instantiations, which is why we need to loop here.
-      if (!DefineUsedVTables())
-        break;
-    }
+  if (CompleteTranslationUnit) {
+    // If DefinedUsedVTables ends up marking any virtual member functions it
+    // might lead to more pending template instantiations, which we then need
+    // to instantiate.
+    DefineUsedVTables();
+
+    // C++: Perform implicit template instantiations.
+    //
+    // FIXME: When we perform these implicit instantiations, we do not
+    // carefully keep track of the point of instantiation (C++ [temp.point]).
+    // This means that name lookup that occurs within the template
+    // instantiation will always happen at the end of the translation unit,
+    // so it will find some names that should not be found. Although this is
+    // common behavior for C++ compilers, it is technically wrong. In the
+    // future, we either need to be able to filter the results of name lookup
+    // or we need to perform template instantiations earlier.
+    PerformPendingInstantiations();
+  }
   
   // Remove file scoped decls that turned out to be used.
   UnusedFileScopedDecls.erase(std::remove_if(UnusedFileScopedDecls.begin(),
diff --git a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
index fc298c10e46..9899a852d01 100644
--- a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
+++ b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
@@ -2108,9 +2108,12 @@ void Sema::InstantiateFunctionDefinition(SourceLocation PointOfInstantiation,
   // If we're performing recursive template instantiation, create our own
   // queue of pending implicit instantiations that we will instantiate later,
   // while we're still within our own instantiation context.
+  llvm::SmallVector<VTableUse, 16> SavedVTableUses;
   std::deque<PendingImplicitInstantiation> SavedPendingInstantiations;
-  if (Recursive)
+  if (Recursive) {
+    VTableUses.swap(SavedVTableUses);
     PendingInstantiations.swap(SavedPendingInstantiations);
+  }
 
   EnterExpressionEvaluationContext EvalContext(*this, 
                                                Sema::PotentiallyEvaluated);
@@ -2173,10 +2176,16 @@ void Sema::InstantiateFunctionDefinition(SourceLocation PointOfInstantiation,
   Scope.Exit();
 
   if (Recursive) {
+    // Define any pending vtables.
+    DefineUsedVTables();
+
     // Instantiate any pending implicit instantiations found during the
     // instantiation of this template.
     PerformPendingInstantiations();
 
+    // Restore the set of pending vtables.
+    VTableUses.swap(SavedVTableUses);
+
     // Restore the set of pending implicit instantiations.
     PendingInstantiations.swap(SavedPendingInstantiations);
   }