Index: cfe/trunk/lib/Sema/SemaDeclCXX.cpp
===================================================================
--- cfe/trunk/lib/Sema/SemaDeclCXX.cpp
+++ cfe/trunk/lib/Sema/SemaDeclCXX.cpp
@@ -167,6 +167,9 @@
   if (ComputedEST == EST_None)
     return;
 
+  if (EST == EST_None && Method->hasAttr<NoThrowAttr>())
+    EST = EST_BasicNoexcept;
+
   switch(EST) {
   // If this function can throw any exceptions, make a note of that.
   case EST_MSAny:
Index: cfe/trunk/test/SemaCXX/nothrow-as-noexcept-ctor.cpp
===================================================================
--- cfe/trunk/test/SemaCXX/nothrow-as-noexcept-ctor.cpp
+++ cfe/trunk/test/SemaCXX/nothrow-as-noexcept-ctor.cpp
@@ -0,0 +1,26 @@
+// RUN: %clang_cc1 %s -fcxx-exceptions -fsyntax-only -Wexceptions -verify -std=c++14
+
+// expected-no-diagnostics
+struct Base {
+  __attribute__((nothrow)) Base() {}
+};
+
+struct Derived : Base {
+  Derived() noexcept = default;
+};
+
+struct Base2 {
+   Base2() noexcept {}
+};
+
+struct Derived2 : Base2 {
+  __attribute__((nothrow)) Derived2() = default;
+};
+
+struct Base3 {
+  __attribute__((nothrow)) Base3() {}
+};
+
+struct Derived3 : Base3 {
+  __attribute__((nothrow)) Derived3() = default;
+};