--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/clang/test/SemaTemplate/constructor-template.cpp	Thu Feb 13 15:10:13 2020 +0900
@@ -0,0 +1,182 @@
+// RUN: %clang_cc1 -fsyntax-only -verify %s
+// RUN: %clang_cc1 -fsyntax-only -verify -std=c++98 %s
+// RUN: %clang_cc1 -fsyntax-only -verify -std=c++11 %s
+
+struct X0 { // expected-note {{candidate constructor (the implicit copy constructor) not viable}}
+#if __cplusplus >= 201103L // C++11 or later
+// expected-note@-2 {{candidate constructor (the implicit move constructor) not viable}}
+#endif
+  X0(int); // expected-note{{candidate}}
+  template<typename T> X0(T); // expected-note {{candidate}}
+  template<typename T, typename U> X0(T*, U*); // expected-note {{candidate}}
+  
+  // PR4761
+  template<typename T> X0() : f0(T::foo) {} // expected-note {{candidate}}
+  int f0;
+};
+
+void accept_X0(X0);
+
+void test_X0(int i, float f) {
+  X0 x0a(i);
+  X0 x0b(f);
+  X0 x0c = i;
+  X0 x0d = f;
+  accept_X0(i);
+  accept_X0(&i);
+  accept_X0(f);
+  accept_X0(&f);
+  X0 x0e(&i, &f);
+  X0 x0f(&f, &i);
+  
+  X0 x0g(f, &i); // expected-error{{no matching constructor}}
+}
+
+template<typename T>
+struct X1 {
+  X1(const X1&);
+  template<typename U> X1(const X1<U>&);
+};
+
+template<typename T>
+struct Outer {
+  typedef X1<T> A;
+  
+  A alloc;
+  
+  explicit Outer(const A& a) : alloc(a) { }
+};
+
+void test_X1(X1<int> xi) {
+  Outer<int> oi(xi);
+  Outer<float> of(xi);
+}
+
+// PR4655
+template<class C> struct A {};
+template <> struct A<int>{A(const A<int>&);};
+struct B { A<int> x; B(B& a) : x(a.x) {} };
+
+struct X2 {
+  X2(); // expected-note{{candidate constructor}}
+  X2(X2&);	// expected-note {{candidate constructor}}
+  template<typename T> X2(T); // expected-note {{candidate template ignored: instantiation would take its own class type by value}}
+};
+
+X2 test(bool Cond, X2 x2) {
+  if (Cond)
+    return x2; // okay, uses copy constructor
+  
+  return X2(); // expected-error{{no matching constructor}}
+}
+
+struct X3 {
+  template<typename T> X3(T);
+};
+
+template<> X3::X3(X3); // expected-error{{must pass its first argument by reference}}
+
+struct X4 {
+  X4();
+  ~X4();
+  X4(X4&);
+  template<typename T> X4(const T&, int = 17);
+};
+
+X4 test_X4(bool Cond, X4 x4) {
+  X4 a(x4, 17); // okay, constructor template
+  X4 b(x4); // okay, copy constructor
+  return X4();
+}
+
+// Instantiation of a non-dependent use of a constructor
+struct DefaultCtorHasDefaultArg {
+  explicit DefaultCtorHasDefaultArg(int i = 17);
+};
+
+template<typename T>
+void default_ctor_inst() {
+  DefaultCtorHasDefaultArg def;
+}
+
+template void default_ctor_inst<int>();
+
+template<typename T>
+struct X5 {
+  X5();
+  X5(const T &);
+};
+
+struct X6 {
+  template<typename T> X6(T);
+};
+
+void test_X5_X6() {
+  X5<X6> tf;
+  X5<X6> tf2(tf);
+}
+
+namespace PR8182 {
+  struct foo {
+    foo();
+    template<class T> foo(T&);
+
+  private:
+    foo(const foo&);
+  };
+
+  void test_foo() {
+    foo f1;
+    foo f2(f1);
+    foo f3 = f1;
+  }
+
+}
+
+// Don't blow out the stack trying to call an illegal constructor
+// instantiation.  We intentionally allow implicit instantiations to
+// exist, so make sure they're unusable.
+//
+// rdar://19199836
+namespace self_by_value {
+  template <class T, class U> struct A {
+    A() {}
+    A(const A<T,U> &o) {}
+    A(A<T,T> o) {}
+  };
+
+  void helper(A<int,float>);
+
+  void test1(A<int,int> a) {
+    helper(a);
+  }
+  void test2() {
+    helper(A<int,int>());
+  }
+}
+
+namespace self_by_value_2 {
+  template <class T, class U> struct A {
+    A() {} // expected-note {{not viable: requires 0 arguments}}
+    A(A<T,U> &o) {} // expected-note {{not viable: expects an l-value}}
+    A(A<T,T> o) {} // expected-note {{ignored: instantiation takes its own class type by value}}
+  };
+
+  void helper_A(A<int,int>); // expected-note {{passing argument to parameter here}}
+  void test_A() {
+    helper_A(A<int,int>()); // expected-error {{no matching constructor}}
+  }
+}
+
+namespace self_by_value_3 {
+  template <class T, class U> struct A {
+    A() {}
+    A(A<T,U> &o) {}
+    A(A<T,T> o) {}
+  };
+
+  void helper_A(A<int,int>);
+  void test_A(A<int,int> b) {
+    helper_A(b);
+  }
+}