Index: cfe/trunk/lib/Sema/SemaExprCXX.cpp
===================================================================
--- cfe/trunk/lib/Sema/SemaExprCXX.cpp
+++ cfe/trunk/lib/Sema/SemaExprCXX.cpp
@@ -6854,8 +6854,9 @@
                                                    QualType DestructedType) {
   // If this is a record type, check if its destructor is callable.
   if (auto *RD = DestructedType->getAsCXXRecordDecl()) {
-    if (CXXDestructorDecl *D = SemaRef.LookupDestructor(RD))
-      return SemaRef.CanUseDecl(D, /*TreatUnavailableAsInvalid=*/false);
+    if (RD->hasDefinition())
+      if (CXXDestructorDecl *D = SemaRef.LookupDestructor(RD))
+        return SemaRef.CanUseDecl(D, /*TreatUnavailableAsInvalid=*/false);
     return false;
   }
 
Index: cfe/trunk/test/SemaCXX/incomplete-call.cpp
===================================================================
--- cfe/trunk/test/SemaCXX/incomplete-call.cpp
+++ cfe/trunk/test/SemaCXX/incomplete-call.cpp
@@ -48,6 +48,10 @@
   c(); // expected-error{{incomplete type in call to object of type}}
 }
 
+void test_incomplete_object_dtor(C *p) {
+  p.~C(); // expected-error{{member reference type 'C *' is a pointer; did you mean to use '->'?}}
+}
+
 namespace pr18542 {
   struct X {
     int count;