2 files changed, 39 insertions, 1 deletions
diff --git a/lib/Sema/SemaDeclCXX.cpp b/lib/Sema/SemaDeclCXX.cpp
index c898d81a61..12452b2429 100644
--- a/lib/Sema/SemaDeclCXX.cpp
+++ b/lib/Sema/SemaDeclCXX.cpp
@@ -8154,7 +8154,7 @@ hasMoveOrIsTriviallyCopyable(Sema &S, QualType Type, bool IsConstructor) {
   // reference types, are supposed to return false here, but that appears
   // to be a standard defect.
   CXXRecordDecl *ClassDecl = Type->getAsCXXRecordDecl();
-  if (!ClassDecl || !ClassDecl->getDefinition())
+  if (!ClassDecl || !ClassDecl->getDefinition() || ClassDecl->isInvalidDecl())
     return true;
 
   if (Type.isTriviallyCopyableType(S.Context))
diff --git a/test/SemaCXX/cxx11-crashes.cpp b/test/SemaCXX/cxx11-crashes.cpp
new file mode 100644
index 0000000000..d5db10962f
--- /dev/null
+++ b/test/SemaCXX/cxx11-crashes.cpp
@@ -0,0 +1,38 @@
+// RUN: %clang_cc1 -std=c++11 -verify %s
+
+// rdar://12240916 stack overflow.
+namespace rdar12240916 {
+
+struct S2 {
+  S2(const S2&);
+  S2();
+};
+
+struct S { // expected-note {{not complete}}
+  S x; // expected-error {{incomplete type}}
+  S2 y;
+};
+
+S foo() {
+  S s;
+  return s;
+}
+
+struct S3; // expected-note {{forward declaration}}
+
+struct S4 {
+  S3 x; // expected-error {{incomplete type}}
+  S2 y;
+};
+
+struct S3 {
+  S4 x;
+  S2 y;
+};
+
+S4 foo2() {
+  S4 s;
+  return s;
+}
+
+}