1 files changed, 2 insertions, 1 deletions
diff --git a/include/llvm/CodeGen/MachineRegisterInfo.h b/include/llvm/CodeGen/MachineRegisterInfo.h
index 736a0a2b75..58ca907316 100644
--- a/include/llvm/CodeGen/MachineRegisterInfo.h
+++ b/include/llvm/CodeGen/MachineRegisterInfo.h
@@ -30,8 +30,9 @@ class PSetIterator;
 class MachineRegisterInfo {
 public:
   class Delegate {
+    virtual void anchor();
   public:
-    virtual void MRI_NoteNewVirtualRegister(unsigned Reg) {}
+    virtual void MRI_NoteNewVirtualRegister(unsigned Reg) = 0;
 
     virtual ~Delegate() {}
   };