--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/clang/test/PCH/cxx1y-default-initializer.cpp	Thu Feb 13 15:10:13 2020 +0900
@@ -0,0 +1,46 @@
+// RUN: %clang_cc1 -pedantic -std=c++1y -include %s -include %s -verify %s
+// RUN: %clang_cc1 -pedantic -std=c++1y -emit-pch -o %t.1 %s
+// RUN: %clang_cc1 -pedantic -std=c++1y -include-pch %t.1 -emit-pch -o %t.2 %s
+// RUN: %clang_cc1 -pedantic -std=c++1y -include-pch %t.2 -verify %s
+
+#ifndef HEADER_1
+#define HEADER_1
+
+struct A {
+  int x;
+  int y = 3;
+  int z = x + y;
+};
+template<typename T> constexpr A make() { return A {}; }
+template<typename T> constexpr A make(T t) { return A { t }; }
+
+struct B {
+  int z1, z2 = z1;
+  constexpr B(int k) : z1(k) {}
+};
+
+template<typename T> struct C {
+  constexpr C() {}
+  T c = T();
+  struct U {};
+};
+// Instantiate C<int> but not the default initializer.
+C<int>::U ciu;
+
+#elif !defined(HEADER_2)
+#define HEADER_2
+
+// Instantiate the default initializer now, should create an update record.
+C<int> ci;
+
+#else
+
+static_assert(A{}.z == 3, "");
+static_assert(A{1}.z == 4, "");
+static_assert(A{.y = 5}.z == 5, ""); // expected-warning {{C++20}}
+static_assert(A{3, .y = 1}.z == 4, ""); // expected-warning {{C99}} expected-note {{here}}
+static_assert(make<int>().z == 3, "");
+static_assert(make<int>(12).z == 15, "");
+static_assert(C<int>().c == 0, "");
+
+#endif