diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td
index 73df2c16f592..470003754a78 100644
--- a/clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -10593,8 +10593,8 @@ def incomplete_hyperobject : Error<
 def nested_hyperobject : Error<
    "type %0, which contains a hyperobject, may not be a hyperobject">;
 
-def reducer_callbacks_not_allowed: Warning<
-   "reducer callbacks not implemented for structure members">,
+def reducer_registration_not_implemented: Warning<
+   "reducer registration not implemented for structure members">,
     InGroup<CilkIgnored>;
 
 def err_invalid_reducer_callback : Error<
diff --git a/clang/lib/AST/DeclCXX.cpp b/clang/lib/AST/DeclCXX.cpp
index 3cf355714107..1a4e5a790d00 100644
--- a/clang/lib/AST/DeclCXX.cpp
+++ b/clang/lib/AST/DeclCXX.cpp
@@ -1071,6 +1071,12 @@ void CXXRecordDecl::addedMember(Decl *D) {
         data().DefaultedCopyConstructorIsDeleted = true;
     }
 
+    if (T->isHyperobjectType()) {
+      data().HasIrrelevantDestructor = false;
+      data().HasTrivialSpecialMembers &= ~SMF_Destructor;
+      data().HasTrivialSpecialMembersForCall &= ~SMF_Destructor;
+    }
+
     if (!Field->hasInClassInitializer() && !Field->isMutable()) {
       if (CXXRecordDecl *FieldType = T->getAsCXXRecordDecl()) {
         if (FieldType->hasDefinition() && !FieldType->allowConstDefaultInit())
diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index 27366bb87e6d..dffae42a5cea 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -18621,11 +18621,12 @@ void Sema::ActOnFields(Scope *S, SourceLocation RecLoc, Decl *EnclosingDecl,
       continue;
     }
 
-    if (!FDTy->isDependentType()) {
+    // In C++ a constructor and destructor will be synthesized
+    // to register hyperobjects.
+    if (!CXXRecord && !FDTy->isDependentType()) {
       if (const HyperobjectType *HT = FDTy->getAs<HyperobjectType>()) {
-        if (HT->hasCallbacks())
-          Diag(FD->getLocation(), diag::reducer_callbacks_not_allowed)
-            << FD->getDeclName();
+        Diag(FD->getLocation(), diag::reducer_registration_not_implemented)
+          << FD->getDeclName();
       }
     }
 
diff --git a/clang/test/Cilk/222.cpp b/clang/test/Cilk/222.cpp
index 8184b3e11f22..e92e8b975ad7 100644
--- a/clang/test/Cilk/222.cpp
+++ b/clang/test/Cilk/222.cpp
@@ -1,4 +1,5 @@
 // RUN: %clang_cc1 %s -x c++ -fopencilk -emit-llvm -verify -mllvm -use-opencilk-runtime-bc=false -mllvm -debug-abi-calls -o /dev/null
+// expected-no-diagnostics
 #define DEPTH 3
 template<int N> struct R {
   static void identity(void *);
@@ -6,13 +7,7 @@ template<int N> struct R {
   int get(int depth) { return depth <= 0 ? i : field.get(depth - 1); }
 public:
   R<N - 1> field;
-  // expected-note@-1{{in instantiation}}
-  // expected-note@-2{{in instantiation}}
-  // expected-note@-3{{in instantiation}}
   int _Hyperobject(identity, reduce) i;
-  // expected-warning@-1{{reducer callbacks not implemented for structure members}}
-  // expected-warning@-2{{reducer callbacks not implemented for structure members}}
-  // expected-warning@-3{{reducer callbacks not implemented for structure members}}
 };
 
 template<> struct R<0> { int field; int get(int) { return field; } };
@@ -20,7 +15,3 @@ template<> struct R<0> { int field; int get(int) { return field; } };
 extern R<DEPTH> r;
 
 int f() { return r.get(DEPTH / 2); }
-// expected-note@-1{{in instantiation}}
-// expected-note@-2{{in instantiation}}
-// expected-note@-3{{in instantiation}}
-
diff --git a/clang/test/Cilk/hyper-errors.c b/clang/test/Cilk/hyper-errors.c
index 01e269add34e..5458face1382 100644
--- a/clang/test/Cilk/hyper-errors.c
+++ b/clang/test/Cilk/hyper-errors.c
@@ -1,6 +1,6 @@
 // RUN: %clang_cc1 %s -fopencilk -verify -fsyntax-only -Werror=incompatible-function-pointer-types -Werror=int-conversion
-// RUN: %clang_cc1 %s -x c++ -fopencilk -verify -fsyntax-only
 struct C { int _Hyperobject c; };
+// expected-warning@-1{{reducer registration not implemented for structure members}}
 struct C _Hyperobject c; // expected-error{{type 'struct C', which contains a hyperobject, may not be a hyperobject}}
 long _Hyperobject d; // expected-note{{previous definition}}
 void f() {
@@ -17,7 +17,7 @@ extern void reduce(void *, void *), identity(void *);
 
 struct D {
   int _Hyperobject(identity, reduce) field;
-  // expected-warning@-1{{reducer callbacks not implemented for structure members}}
+  // expected-warning@-1{{reducer registration not implemented for structure members}}
 };
 
 int _Hyperobject(reduce, identity) h;
diff --git a/clang/test/Cilk/hyper-errors.cpp b/clang/test/Cilk/hyper-errors.cpp
new file mode 100644
index 000000000000..664df5983143
--- /dev/null
+++ b/clang/test/Cilk/hyper-errors.cpp
@@ -0,0 +1,38 @@
+// RUN: %clang_cc1 %s -x c++ -fopencilk -verify -fsyntax-only
+struct C { int _Hyperobject c; };
+struct C _Hyperobject c; // expected-error{{type 'struct C', which contains a hyperobject, may not be a hyperobject}}
+long _Hyperobject d; // expected-note{{previous definition}}
+void f() {
+  extern int _Hyperobject d;
+  // expected-error@-1{{redeclaration of 'd' with a different type: 'int _Hyperobject' vs 'long _Hyperobject'}}
+}
+char _Hyperobject e; // expected-note{{previous definition}}
+typedef long _Hyperobject long_h;
+void g() {
+  extern long_h e; // expected-error{{redeclaration of 'e'}}
+}
+
+extern void reduce(void *, void *), identity(void *);
+
+struct D {
+  int _Hyperobject(identity, reduce) field;
+};
+
+int _Hyperobject(reduce, identity) h;
+  // expected-error@-1{{incompatible function pointer types passing 'void (*)(void *, void *)' to parameter of type 'void (*)(void *)'}}
+  // expected-error@-2{{incompatible function pointer types passing 'void (*)(void *)' to parameter of type 'void (*)(void *, void *)'}}
+
+int _Hyperobject(x) i; // expected-error{{use of undeclared identifier 'x'}}
+int _Hyperobject(0) j; // expected-error{{hyperobject must have 0 or 2 callbacks}}
+int _Hyperobject(0,0,0,0) k; // expected-error{{hyperobject must have 0 or 2 callbacks}}
+int _Hyperobject(0, 1) x; // expected-error{{incompatible integer to pointer conversion passing 'int' to parameter of type 'void (*)(void *, void *)'}}
+
+void function() {
+  int _Hyperobject(typo1, reduce) var1 = 0;
+  // expected-error@-1{{use of undeclared identifier 'typo1'}}
+  int _Hyperobject(typo2, typo3) var2 = 0;
+  // expected-error@-1{{use of undeclared identifier 'typo2'}}
+  // expected-error@-2{{use of undeclared identifier 'typo3'}}
+  int _Hyperobject(0, typo4) var3 = 0;
+  // expected-error@-1{{use of undeclared identifier 'typo4'}}
+}
diff --git a/clang/test/Cilk/hyper-struct-assign.c b/clang/test/Cilk/hyper-struct-assign.c
index 23fbc8ae77ed..91c2871fbbc6 100644
--- a/clang/test/Cilk/hyper-struct-assign.c
+++ b/clang/test/Cilk/hyper-struct-assign.c
@@ -1,6 +1,7 @@
 // RUN: %clang_cc1 %s -fopencilk -verify -fsyntax-only
 
 struct S { long _Hyperobject field; };
+// expected-warning@-1{{reducer registration not implemented for structure members}}
 extern struct S x, y;
 
 struct S simple_assign(long val)
diff --git a/clang/test/Cilk/hyper-template2.cpp b/clang/test/Cilk/hyper-template2.cpp
index 01b90a8cda76..883ad62e7961 100644
--- a/clang/test/Cilk/hyper-template2.cpp
+++ b/clang/test/Cilk/hyper-template2.cpp
@@ -1,20 +1,18 @@
-// RUN: %clang_cc1 %s -x c++ -fopencilk -verify -S -emit-llvm -disable-llvm-passes -o - | FileCheck %s
+// RUN: %clang_cc1 %s -x c++ -fopencilk -S -emit-llvm -disable-llvm-passes -o - | FileCheck %s
 template<typename VIEW>
 struct reducer
 {
   static void identity(void *);
   static void reduce(void *, void *);
   char pad;
-  // Registration of structure members is not implemented.
   VIEW _Hyperobject(identity, reduce) value;
-  // expected-warning@-1{{reducer callbacks not implemented}}
   reducer();
   ~reducer();
 };
 
 // CHECK: call {{.+}} @_ZN7reducerIsEC1Ev
 // CHECK: @_ZN7reducerIsED1Ev
-reducer<short> r; // expected-note{{in instantiation}}
+reducer<short> r;
 
 // CHECK-LABEL: _Z1fv
 // CHECK: call ptr @llvm.hyper.lookup