--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/clang/test/SemaCXX/invalid-template-base-specifier.cpp	Tue Jun 08 06:07:14 2021 +0900
@@ -0,0 +1,28 @@
+// RUN: %clang_cc1 -frecovery-ast -verify %s
+
+bool Foo(int *); // expected-note 3{{candidate function not viable}}
+
+template <typename T>
+struct Crash : decltype(Foo(T())) { // expected-error {{no matching function for call to 'Foo'}}
+  Crash(){};
+};
+
+void test() { Crash<int>(); } // expected-note {{in instantiation of template class}}
+
+template <typename T>
+using Alias = decltype(Foo(T())); // expected-error {{no matching function for call to 'Foo'}}
+template <typename T>
+struct Crash2 : decltype(Alias<T>()) { // expected-note {{in instantiation of template type alias 'Alias' requested here}}
+  Crash2(){};
+};
+
+void test2() { Crash2<int>(); } // expected-note {{in instantiation of template class 'Crash2<int>' requested here}}
+
+template <typename T>
+class Base {};
+template <typename T>
+struct Crash3 : Base<decltype(Foo(T()))> { // expected-error {{no matching function for call to 'Foo'}}
+  Crash3(){};
+};
+
+void test3() { Crash3<int>(); } // expected-note {{in instantiation of template class}}