vendor/llvm/llvm-trunk-r303571

1 files changed, 6 insertions, 0 deletions

diff --git a/include/llvm/IR/OperandTraits.h b/include/llvm/IR/OperandTraits.h
index e97a8009ccc0..7b94283856b6 100644
--- a/include/llvm/IR/OperandTraits.h
+++ b/include/llvm/IR/OperandTraits.h
@@ -30,6 +30,9 @@ namespace llvm {
 template <typename SubClass, unsigned ARITY>
 struct FixedNumOperandTraits {
   static Use *op_begin(SubClass* U) {
+    static_assert(
+        !std::is_polymorphic<SubClass>::value,
+        "adding virtual methods to subclasses of User breaks use lists");
     return reinterpret_cast<Use*>(U) - ARITY;
   }
   static Use *op_end(SubClass* U) {
@@ -65,6 +68,9 @@ struct OptionalOperandTraits : public FixedNumOperandTraits<SubClass, ARITY> {
 template <typename SubClass, unsigned MINARITY = 0>
 struct VariadicOperandTraits {
   static Use *op_begin(SubClass* U) {
+    static_assert(
+        !std::is_polymorphic<SubClass>::value,
+        "adding virtual methods to subclasses of User breaks use lists");
     return reinterpret_cast<Use*>(U) - static_cast<User*>(U)->getNumOperands();
   }
   static Use *op_end(SubClass* U) {