Implement P0634R3, Down with typename!

	* parser.c (CP_PARSER_FLAGS_TYPENAME_OPTIONAL): New enumerator.
	(cp_parser_type_name): Remove declaration.
	(cp_parser_postfix_expression): Pass CP_PARSER_FLAGS_TYPENAME_OPTIONAL
	to cp_parser_type_id.
	(cp_parser_new_type_id): Pass CP_PARSER_FLAGS_TYPENAME_OPTIONAL to
	cp_parser_type_specifier_seq.
	(cp_parser_lambda_declarator_opt): Pass
	CP_PARSER_FLAGS_TYPENAME_OPTIONAL to
	cp_parser_parameter_declaration_clause.
	(cp_parser_condition): Pass CP_PARSER_FLAGS_NONE to
	cp_parser_declarator.
	(cp_parser_simple_declaration): Pass CP_PARSER_FLAGS_NONE to
	cp_parser_init_declarator.
	(cp_parser_conversion_type_id): Pass CP_PARSER_FLAGS_NONE to
	cp_parser_type_specifier_seq.
	(cp_parser_default_type_template_argument): Pass
	CP_PARSER_FLAGS_TYPENAME_OPTIONAL to cp_parser_type_id.
	(cp_parser_template_parameter): Pass CP_PARSER_FLAGS_TYPENAME_OPTIONAL
	to cp_parser_parameter_declaration.
	(cp_parser_explicit_instantiation): Pass CP_PARSER_FLAGS_NONE to
	cp_parser_declarator.
	(cp_parser_simple_type_specifier): Adjust call to cp_parser_type_name
	to relay if we should treat the typename keyword as optional.  Maybe
	call cp_parser_make_typename_type is parsing a template-id and it's
	not a TYPE_DECL.
	(cp_parser_type_name): Remove unused function.
	(cp_parser_enum_specifier): Pass to CP_PARSER_FLAGS_NONE
	cp_parser_type_specifier_seq.
	(cp_parser_alias_declaration): Pass CP_PARSER_FLAGS_TYPENAME_OPTIONAL
	to cp_parser_type_id.
	(cp_parser_init_declarator): New parameter.  Pass it down to
	cp_parser_declarator.
	(cp_parser_declarator): New parameter.  Pass CP_PARSER_FLAGS_NONE to
	cp_parser_declarator.  Pass the new parameter to
	cp_parser_direct_declarator.
	(cp_parser_direct_declarator): New parameter.  Pass it to
	cp_parser_parameter_declaration_clause and cp_parser_declarator.
	(cp_parser_declarator_id):
	(cp_parser_type_id_1): New parameter.  Pass it to
	cp_parser_type_specifier_seq.  Adjust call to cp_parser_declarator.
	(cp_parser_type_id): New parameter.  Pass it to cp_parser_type_id_1.
	(cp_parser_template_type_arg): Pass CP_PARSER_FLAGS_NONE to
	cp_parser_type_id_1.
	(cp_parser_trailing_type_id): Pass CP_PARSER_FLAGS_TYPENAME_OPTIONAL
	to cp_parser_type_id_1.
	(cp_parser_type_specifier_seq): New parameter.
	(function_being_declared_is_template_p):
	(cp_parser_parameter_declaration_clause): New parameter.  Pass it to
	cp_parser_parameter_declaration_list.
	(cp_parser_parameter_declaration_list): New parameter.  Pass it to
	cp_parser_parameter_declaration.
	(cp_parser_parameter_declaration): New parameter.  Pass it to
	cp_parser_decl_specifier_seq.  Pass CP_PARSER_FLAGS_NONE to
	cp_parser_declarator.
	(cp_parser_member_declaration): Adjust call to
	cp_parser_decl_specifier_seq to also include
	CP_PARSER_FLAGS_TYPENAME_OPTIONAL.  Pass
	CP_PARSER_FLAGS_TYPENAME_OPTIONAL to cp_parser_declarator.
	(cp_parser_exception_declaration): Pass CP_PARSER_FLAGS_NONE to
	cp_parser_type_specifier_seq and cp_parser_declarator.
	(cp_parser_requirement_parameter_list): Pass CP_PARSER_FLAGS_NONE to
	cp_parser_parameter_declaration_clause.
	(cp_parser_constructor_declarator_p): Resolve the TYPENAME_TYPE.
	(cp_parser_single_declaration): Pass CP_PARSER_FLAGS_TYPENAME_OPTIONAL
	to cp_parser_decl_specifier_seq and cp_parser_init_declarator.
	(cp_parser_cache_defarg): Pass CP_PARSER_FLAGS_NONE to
	cp_parser_declarator and cp_parser_parameter_declaration_list.
	(cp_parser_objc_method_tail_params_opt): Pass CP_PARSER_FLAGS_NONE to
	cp_parser_parameter_declaration.
	(cp_parser_objc_class_ivars): Pass CP_PARSER_FLAGS_NONE to
	cp_parser_declarator.
	(cp_parser_objc_try_catch_finally_statement): Pass CP_PARSER_FLAGS_NONE
	to cp_parser_parameter_declaration
	(cp_parser_objc_struct_declaration): Pass CP_PARSER_FLAGS_NONE to
	cp_parser_declarator.
	(cp_parser_omp_for_loop_init): Pass CP_PARSER_FLAGS_NONE to
	cp_parser_declarator and cp_parser_type_specifier_seq.

	* g++.dg/cpp0x/alias-decl-43.C: Adjust dg-error.
	* g++.dg/cpp0x/decltype67.C: Only expect error in c++17_down.
	* g++.dg/cpp1z/typename1.C: New test.
	* g++.dg/cpp2a/typename1.C: New test.
	* g++.dg/cpp2a/typename10.C: New test.
	* g++.dg/cpp2a/typename11.C: New test.
	* g++.dg/cpp2a/typename2.C: New test.
	* g++.dg/cpp2a/typename3.C: New test.
	* g++.dg/cpp2a/typename4.C: New test.
	* g++.dg/cpp2a/typename5.C: New test.
	* g++.dg/cpp2a/typename6.C: New test.
	* g++.dg/cpp2a/typename7.C: New test.
	* g++.dg/cpp2a/typename8.C: New test.
	* g++.dg/cpp2a/typename9.C: New test.
	* g++.dg/diagnostic/missing-typename.C: Only run the test in
	c++17_down.
	* g++.dg/other/crash-9.C: Add template disambiguator.
	* g++.dg/other/nontype-1.C: Only expect error in c++17_down.
	* g++.dg/parse/crash13.C: Likewise.
	* g++.dg/parse/error36.C: Likewise.
	* g++.dg/parse/no-typename1.C: Likewise.
	* g++.dg/parse/typedef2.C: Likewise.
	* g++.dg/parse/typename11.C: Likewise.
	* g++.dg/template/crash48.C: Adjust dg-error.
	* g++.dg/template/dependent-name5.C: Only expect error in c++17_down.
	Add dg-error.
	* g++.dg/template/error29.C: Only expect error in c++17_down.
	* g++.dg/template/nested5.C: Add template disambiguator.
	* g++.dg/template/pr84789.C: Only expect error in c++17_down.
	* g++.dg/template/static30.C: Add dg-error.
	* g++.dg/template/typedef6.C: Adjust dg-error.
	* g++.dg/template/typename3.C: Only expect error in c++17_down.

From-SVN: r266710

gcc/cp/ChangeLog

+2018-12-01  Marek Polacek  <polacek@redhat.com>
+
+	Implement P0634R3, Down with typename!
+	* parser.c (CP_PARSER_FLAGS_TYPENAME_OPTIONAL): New enumerator.
+	(cp_parser_type_name): Remove declaration.
+	(cp_parser_postfix_expression): Pass CP_PARSER_FLAGS_TYPENAME_OPTIONAL
+	to cp_parser_type_id.
+	(cp_parser_new_type_id): Pass CP_PARSER_FLAGS_TYPENAME_OPTIONAL to
+	cp_parser_type_specifier_seq.
+	(cp_parser_lambda_declarator_opt): Pass
+	CP_PARSER_FLAGS_TYPENAME_OPTIONAL to
+	cp_parser_parameter_declaration_clause.
+	(cp_parser_condition): Pass CP_PARSER_FLAGS_NONE to
+	cp_parser_declarator.
+	(cp_parser_simple_declaration): Pass CP_PARSER_FLAGS_NONE to
+	cp_parser_init_declarator.
+	(cp_parser_conversion_type_id): Pass CP_PARSER_FLAGS_NONE to
+	cp_parser_type_specifier_seq.
+	(cp_parser_default_type_template_argument): Pass
+	CP_PARSER_FLAGS_TYPENAME_OPTIONAL to cp_parser_type_id.
+	(cp_parser_template_parameter): Pass CP_PARSER_FLAGS_TYPENAME_OPTIONAL
+	to cp_parser_parameter_declaration.
+	(cp_parser_explicit_instantiation): Pass CP_PARSER_FLAGS_NONE to
+	cp_parser_declarator.
+	(cp_parser_simple_type_specifier): Adjust call to cp_parser_type_name
+	to relay if we should treat the typename keyword as optional.  Maybe
+	call cp_parser_make_typename_type is parsing a template-id and it's
+	not a TYPE_DECL.
+	(cp_parser_type_name): Remove unused function.
+	(cp_parser_enum_specifier): Pass to CP_PARSER_FLAGS_NONE
+	cp_parser_type_specifier_seq.
+	(cp_parser_alias_declaration): Pass CP_PARSER_FLAGS_TYPENAME_OPTIONAL
+	to cp_parser_type_id.
+	(cp_parser_init_declarator): New parameter.  Pass it down to
+	cp_parser_declarator.
+	(cp_parser_declarator): New parameter.  Pass CP_PARSER_FLAGS_NONE to
+	cp_parser_declarator.  Pass the new parameter to
+	cp_parser_direct_declarator.
+	(cp_parser_direct_declarator): New parameter.  Pass it to
+	cp_parser_parameter_declaration_clause and cp_parser_declarator.
+	(cp_parser_declarator_id):
+	(cp_parser_type_id_1): New parameter.  Pass it to
+	cp_parser_type_specifier_seq.  Adjust call to cp_parser_declarator.
+	(cp_parser_type_id): New parameter.  Pass it to cp_parser_type_id_1.
+	(cp_parser_template_type_arg): Pass CP_PARSER_FLAGS_NONE to
+	cp_parser_type_id_1.
+	(cp_parser_trailing_type_id): Pass CP_PARSER_FLAGS_TYPENAME_OPTIONAL
+	to cp_parser_type_id_1.
+	(cp_parser_type_specifier_seq): New parameter.
+	(function_being_declared_is_template_p):
+	(cp_parser_parameter_declaration_clause): New parameter.  Pass it to
+	cp_parser_parameter_declaration_list.
+	(cp_parser_parameter_declaration_list): New parameter.  Pass it to
+	cp_parser_parameter_declaration.
+	(cp_parser_parameter_declaration): New parameter.  Pass it to
+	cp_parser_decl_specifier_seq.  Pass CP_PARSER_FLAGS_NONE to
+	cp_parser_declarator.
+	(cp_parser_member_declaration): Adjust call to
+	cp_parser_decl_specifier_seq to also include
+	CP_PARSER_FLAGS_TYPENAME_OPTIONAL.  Pass
+	CP_PARSER_FLAGS_TYPENAME_OPTIONAL to cp_parser_declarator.
+	(cp_parser_exception_declaration): Pass CP_PARSER_FLAGS_NONE to
+	cp_parser_type_specifier_seq and cp_parser_declarator.
+	(cp_parser_requirement_parameter_list): Pass CP_PARSER_FLAGS_NONE to
+	cp_parser_parameter_declaration_clause.
+	(cp_parser_constructor_declarator_p): Resolve the TYPENAME_TYPE.
+	(cp_parser_single_declaration): Pass CP_PARSER_FLAGS_TYPENAME_OPTIONAL
+	to cp_parser_decl_specifier_seq and cp_parser_init_declarator.
+	(cp_parser_cache_defarg): Pass CP_PARSER_FLAGS_NONE to
+	cp_parser_declarator and cp_parser_parameter_declaration_list.
+	(cp_parser_objc_method_tail_params_opt): Pass CP_PARSER_FLAGS_NONE to
+	cp_parser_parameter_declaration.
+	(cp_parser_objc_class_ivars): Pass CP_PARSER_FLAGS_NONE to
+	cp_parser_declarator.
+	(cp_parser_objc_try_catch_finally_statement): Pass CP_PARSER_FLAGS_NONE
+	to cp_parser_parameter_declaration
+	(cp_parser_objc_struct_declaration): Pass CP_PARSER_FLAGS_NONE to
+	cp_parser_declarator.
+	(cp_parser_omp_for_loop_init): Pass CP_PARSER_FLAGS_NONE to
+	cp_parser_declarator and cp_parser_type_specifier_seq.
+
 2018-11-30  David Malcolm  <dmalcolm@redhat.com>
 
 	* typeck2.c: Include "gcc-rich-location.h".

gcc/testsuite/ChangeLog

+2018-12-01  Marek Polacek  <polacek@redhat.com>
+
+	Implement P0634R3, Down with typename!
+	* g++.dg/cpp0x/alias-decl-43.C: Adjust dg-error.
+	* g++.dg/cpp0x/decltype67.C: Only expect error in c++17_down.
+	* g++.dg/cpp1z/typename1.C: New test.
+	* g++.dg/cpp2a/typename1.C: New test.
+	* g++.dg/cpp2a/typename10.C: New test.
+	* g++.dg/cpp2a/typename11.C: New test.
+	* g++.dg/cpp2a/typename2.C: New test.
+	* g++.dg/cpp2a/typename3.C: New test.
+	* g++.dg/cpp2a/typename4.C: New test.
+	* g++.dg/cpp2a/typename5.C: New test.
+	* g++.dg/cpp2a/typename6.C: New test.
+	* g++.dg/cpp2a/typename7.C: New test.
+	* g++.dg/cpp2a/typename8.C: New test.
+	* g++.dg/cpp2a/typename9.C: New test.
+	* g++.dg/diagnostic/missing-typename.C: Only run the test in
+	c++17_down.
+	* g++.dg/other/crash-9.C: Add template disambiguator.
+	* g++.dg/other/nontype-1.C: Only expect error in c++17_down.
+	* g++.dg/parse/crash13.C: Likewise.
+	* g++.dg/parse/error36.C: Likewise.
+	* g++.dg/parse/no-typename1.C: Likewise.
+	* g++.dg/parse/typedef2.C: Likewise.
+	* g++.dg/parse/typename11.C: Likewise.
+	* g++.dg/template/crash48.C: Adjust dg-error.
+	* g++.dg/template/dependent-name5.C: Only expect error in c++17_down.
+	Add dg-error.
+	* g++.dg/template/error29.C: Only expect error in c++17_down.
+	* g++.dg/template/nested5.C: Add template disambiguator.
+	* g++.dg/template/pr84789.C: Only expect error in c++17_down.
+	* g++.dg/template/static30.C: Add dg-error.
+	* g++.dg/template/typedef6.C: Adjust dg-error.
+	* g++.dg/template/typename3.C: Only expect error in c++17_down.
+
 2018-12-01  Jeff Law  <law@redhat.com>
 
 	* gcc.dg/predict-22.c: Update expected output.

gcc/testsuite/g++.dg/cpp0x/alias-decl-43.C

 // PR c++/59120
 // { dg-do compile { target c++11 } }
 
-template<typename T> using X = int T::T*;  // { dg-error "expected" }
+template<typename T> using X = int T::T*;  // { dg-error "expected|two or more" }

gcc/testsuite/g++.dg/cpp0x/decltype67.C

@@ -3,5 +3,5 @@
 
 template<typename T> struct A
 {
-  void foo(decltype(T())::Y);	// { dg-error {decltype\(T\(\)\)::Y} }
+  void foo(decltype(T())::Y);	// { dg-error "decltype\\(T\\(\\)\\)::Y" "" { target c++17_down } }
 };

gcc/testsuite/g++.dg/cpp1z/typename1.C

+// P0634R3
+// { dg-do compile { target c++17_only } }
+
+// (5.2.1) simple-declaration or a function-definition in namespace scope
+
+template<typename T>
+T::X fn1 (int); // { dg-error "need .typename." }
+
+template<typename T>
+T::X fn1 (int) // { dg-error "need .typename." }
+{
+  return 42;
+}
+
+template<typename T>
+T::X v1; // { dg-error "need .typename." }
+
+namespace N {
+  template<typename T>
+  T::X v2; // { dg-error "need .typename." }
+}
+
+// (5.2.2) member-declaration
+
+template<typename T>
+struct S {
+  [[noreturn]] T::X fn2 (); // { dg-error "need .typename." }
+  T::X fn3 (); // { dg-error "need .typename." }
+  T::X fn4 () { return 5; } // { dg-error "need .typename." }
+  T::X fn5 () final; // { dg-error "need .typename." }
+  T::X fn6 () = 0; // { dg-error "need .typename." }
+  T::X fn8 () override; // { dg-error "need .typename." }
+  T::X v3; // { dg-error "need .typename." }
+  T::X *v4; // { dg-error "need .typename." }
+  T::X v5[5]; // { dg-error "need .typename." }
+  T::X v6 = 0; // { dg-error "need .typename." }
+  T::X v7{0}; // { dg-error "need .typename.|;" }
+  T::X v8 : 16; // { dg-error "need .typename." }
+  static constexpr T::X v9 = 0; // { dg-error "need .typename." }
+  typedef T::X T2; // { dg-error "need .typename." }
+  friend T::X fn7<int> (); // { dg-error "need .typename." }
+  static inline T::X v10; // { dg-error "need .typename." }
+};
+
+// (5.2.3) parameter-declaration in a member-declaration,
+// unless that parameter-declaration appears in a default argument
+
+template<typename T>
+struct S2 {
+  friend int fn1<T::X> (); // { dg-error "" }
+  int fn2 (T::X p); // { dg-error "not a type" }
+  int fn5 (int = T::X);
+};
+
+// (5.2.4) parameter-declaration in a declarator of a function or function
+// template declaration whose declarator-id is qualified,
+// unless that parameter-declaration appears in a default argument
+template<typename T>
+int fn3 (T::X);
+
+template<typename T>
+int fn4 (T::X p) { return p; } // { dg-error "" }
+
+// (5.2.6) parameter-declaration of a (non-type) template-parameter
+
+template<typename T, T::X N> // { dg-error "not a type" }
+struct S3 { };
+
+// default argument of a type-parameter of a template
+template<typename T, typename U = T::X> // { dg-error "need .typename." }
+struct S4 { };
+
+// type-id of a static_cast, const_cast, reinterpret_cast, or dynamic_cast
+template<typename T>
+struct S5 {
+  void fn6 (T::X p) // { dg-error "not a type" }
+  {
+    int i = static_cast<T::Y>(p); // { dg-error "need .typename." }
+    i = dynamic_cast<T::Y>(p); // { dg-error "need .typename." }
+    i = reinterpret_cast<T::Y>(p); // { dg-error "need .typename." }
+    i = const_cast<T::Y>(p); // { dg-error "need .typename." }
+  }
+};
+
+template<typename T>
+void fn7 (T::X p) // { dg-error "" }
+{
+  int i = static_cast<T::Y>(p);
+  i = dynamic_cast<T::Y>(p);
+  i = reinterpret_cast<T::Y>(p);
+  i = const_cast<T::Y>(p);
+}
+
+// new-type-id
+template<typename T>
+void
+fn8 ()
+{
+  new T::X[10]; // { dg-error "need .typename." }
+}
+
+// defining-type-id
+
+template<typename T>
+struct W { typedef int M; };
+
+template<typename T>
+struct S6 {
+  using TT = T::X; // { dg-error "need .typename." }
+  using TT2 = W<T>::M; // { dg-error "need .typename." }
+};
+
+// trailing-return-type
+template<typename T>
+struct S7 {
+  auto fn9() -> W<T>::M; // { dg-error "need .typename." }
+};

gcc/testsuite/g++.dg/cpp2a/typename1.C

+// P0634R3
+// { dg-do compile { target c++2a } }
+
+// OK, return type of a function declaration at global scope.
+template<class T> T::R f();
+
+// Ill-formed (no diagnostic required), attempt to declare
+// a void variable template
+template<class T> void f(T::R);
+
+template <class T> struct A;
+template <class T> using B = A<T>::U;
+
+template<typename T>
+struct PtrTraits { typedef int Ptr; };
+
+template<class T> struct S {
+  // OK, in a defining-type-id.
+  using Ptr = PtrTraits<T>::Ptr;
+
+  // OK, trailing-return-type.
+  auto g() -> S<T*>::Ptr;
+
+  // OK, class scope
+  T::R
+  f (T::P p)
+  {
+    // OK, type-id of a static_cast
+    return static_cast<T::R>(p);
+  }
+};
+
+template<typename T>
+void f ()
+{
+  // Variable pf of type void* initialized with T::X
+  void (*pf)(T::X);
+
+  // Error: T::X at block scope does not denote a type
+  // (attempt to declare a void variable)
+  void g(T::X); // { dg-error "declared void" }
+}

gcc/testsuite/g++.dg/cpp2a/typename10.C

+// P0634R3
+// { dg-do compile { target c++2a } }
+
+namespace N {
+ // template<typename T> extern T::type v; // #1a
+  template<typename T> T::type v(typename T::value); // #1b
+}
+template<typename T> T::type N::v(T::value); // #2
+
+namespace N2 {
+  template<typename T> extern T::type v; // #1a
+  //template<typename T> T::type v(typename T::value); // #1b
+}
+template<typename T> T::type N2::v(T::value); // { dg-error "" }
+
+namespace A {
+  inline namespace B { template<typename T> int f(typename T::foo); }
+  inline namespace C { template<typename T> extern int f; }
+}
+template<typename T> int A::f(T::foo); // { dg-error "ambiguous" }

gcc/testsuite/g++.dg/cpp2a/typename11.C

+// P0634R3
+// { dg-do compile { target c++2a } }
+
+template<typename T>
+struct A
+{
+  typedef int I;
+};
+
+template<typename T> struct B
+{
+  A<T>::I i;
+  typename A<T>::I i2;
+
+  A<int>::I i3;
+  typename A<int>::I i4;
+};

gcc/testsuite/g++.dg/cpp2a/typename2.C

+// P0634R3
+// { dg-do compile { target c++2a } }
+
+template<class T> typename T::R f();
+
+template <class T> struct A;
+template <class T> using B = typename A<T>::U;
+
+template<typename T>
+struct PtrTraits { typedef int Ptr; };
+
+template<class T> struct S {
+  using Ptr = typename PtrTraits<T>::Ptr;
+
+  auto g() -> typename S<T*>::Ptr;
+
+  typename T::R
+  f (typename T::P p)
+  {
+    return static_cast<typename T::R>(p);
+  }
+};

gcc/testsuite/g++.dg/cpp2a/typename3.C

+// P0634R3
+// { dg-do compile { target c++2a } }
+
+template<class T>
+void f(int i)
+{
+  T::x * i; // { dg-error "dependent-name" }
+}
+
+struct Foo {
+  typedef int x;
+};
+
+struct Bar {
+  static int const x = 5;
+};
+
+int
+main ()
+{
+  f<Bar>(1);
+  f<Foo>(1);
+}

gcc/testsuite/g++.dg/cpp2a/typename4.C

+// P0634R3
+// { dg-do compile { target c++2a } }
+
+template<class T>
+struct A {
+  typedef int B;
+  B b;
+};

gcc/testsuite/g++.dg/cpp2a/typename5.C

+// P0634R3
+// { dg-do compile { target c++2a } }
+
+struct X {
+  template<typename T>
+  struct N { };
+};
+
+template <typename T>
+struct Y {
+  template<typename U>
+  struct N { };
+};
+
+template <typename T>
+struct A
+{
+  template <typename U>
+  struct N { };
+
+  typedef typename A::template N<int> a1;
+  typedef typename A::template N<T> a2;
+  typename A::template N<int> a3;
+  typename A::template N<T> a4;
+  A::template N<int> a9;
+  A::template N<T> a10;
+  typedef A<T>::template N<int> a13;
+  typedef A<T>::template N<T> a14;
+
+  typedef typename X::template N<int> x1;
+  typedef typename X::template N<T> x2;
+  typename X::template N<int> x3;
+  typename X::template N<T> x4;
+  typedef X::N<int> x5;
+  typedef X::N<T> x6;
+  typedef typename X::N<int> x7;
+  typedef typename X::N<T> x8;
+  X::N<int> x9;
+  X::N<T> x10;
+  typename X::N<int> x11;
+  typename X::N<T> x12;
+
+  typedef typename Y<int>::template N<int> y1;
+  typedef typename Y<int>::template N<T> y2;
+  typedef typename Y<T>::template N<int> y3;
+  typedef typename Y<T>::template N<T> y4;
+  typename Y<int>::template N<int> y5;
+  typename Y<int>::template N<T> y6;
+  typename Y<T>::template N<int> y7;
+  typename Y<T>::template N<T> y8;
+  typedef Y<int>::N<int> y9;
+  typedef Y<int>::N<T> y10;
+  typedef Y<T>::template N<int> y11;
+  typedef Y<T>::template N<T> y12;
+  typedef typename Y<int>::N<int> y13;
+  typedef typename Y<int>::N<T> y14;
+  Y<int>::N<int> y17;
+  Y<int>::N<T> y18;
+  typename Y<int>::N<int> y21;
+  typename Y<int>::N<T> y22;
+  typedef Y<int>::N<int> y25;
+  typedef Y<int>::N<T> y26;
+  typedef Y<T>::template N<int> y27;
+  typedef Y<T>::template N<T> y28;
+};

gcc/testsuite/g++.dg/cpp2a/typename6.C

+// P0634R3
+// { dg-do compile { target c++2a } }
+
+// (5.2.1) simple-declaration or a function-definition in namespace scope
+
+template<typename T>
+T::X fn1 (int);
+
+template<typename T>
+T::X fn1 (int)
+{
+  return 42;
+}
+
+template<typename T>
+T::X v1;
+
+namespace N {
+  template<typename T>
+  T::X v2;
+}
+
+// (5.2.2) member-declaration
+
+template<typename T>
+struct S {
+  [[noreturn]] T::X fn2 ();
+  T::X fn3 ();
+  T::X fn4 () { return 5; }
+  T::X fn5 () final;
+  T::X fn6 () = 0;
+  T::X fn8 () override;
+  T::X v3;
+  T::X *v4;
+  T::X v5[5];
+  T::X v6 = 0;
+  T::X v7{0};
+  T::X v8 : 16;
+  static constexpr T::X v9 = 0;
+  typedef T::X T2;
+  friend T::X fn7<int> ();
+  static inline T::X v10;
+};
+
+// (5.2.3) parameter-declaration in a member-declaration,
+// unless that parameter-declaration appears in a default argument
+
+template<typename T>
+struct S2 {
+  friend int fn1<T::X> ();
+  int fn2 (T::X p);
+  int fn5 (int = T::X);
+};
+
+// (5.2.4) parameter-declaration in a declarator of a function or function
+// template declaration whose declarator-id is qualified,
+// unless that parameter-declaration appears in a default argument
+template<typename T>
+int fn3 (T::X);
+
+template<typename T>
+int fn4 (T::X p) { return p; }
+
+// (5.2.5) parameter-declaration in a lambda-declarator,
+// unless that parameter-declaration appears in a default argument
+
+void
+fn5 ()
+{
+  auto j = []<typename T>(T::X t, int i) { return i; };
+}
+
+// (5.2.6) parameter-declaration of a (non-type) template-parameter
+
+template<typename T, T::X N>
+struct S3 { };
+
+// default argument of a type-parameter of a template
+template<typename T, typename U = T::X>
+struct S4 { };
+
+// type-id of a static_cast, const_cast, reinterpret_cast, or dynamic_cast
+template<typename T>
+struct S5 {
+  void fn6 (T::X p)
+  {
+    int i = static_cast<T::Y>(p);
+    i = dynamic_cast<T::Y>(p);
+    i = reinterpret_cast<T::Y>(p);
+    i = const_cast<T::Y>(p);
+  }
+};
+
+template<typename T>
+void fn7 (T::X p)
+{
+  int i = static_cast<T::Y>(p);
+  i = dynamic_cast<T::Y>(p);
+  i = reinterpret_cast<T::Y>(p);
+  i = const_cast<T::Y>(p);
+}
+
+// new-type-id
+template<typename T>
+void
+fn8 ()
+{
+  new T::X[10];
+}
+
+// defining-type-id
+
+template<typename T>
+struct W { typedef int M; };
+
+template<typename T>
+struct S6 {
+  using TT = T::X;
+  using TT2 = W<T>::M;
+};
+
+// trailing-return-type
+template<typename T>
+struct S7 {
+  auto fn9() -> W<T>::M;
+};

gcc/testsuite/g++.dg/cpp2a/typename7.C

+// P0634R3
+// { dg-do compile { target c++2a } }
+
+// Not in namespace scope.
+template<typename T>
+void fn1 ()
+{
+  // init-statement -> simple-declaration
+  if (T::X r = 0; 0) // { dg-error "need .typename.|expected" }
+    ;
+
+  for (T::X g = 0; ;) // { dg-error "need .typename.|expected" }
+    ;
+}
+
+template<typename T>
+void
+fn2 ()
+{
+  T::X fn3 (); // { dg-error "need .typename.|expected" }
+  T::X v1; // { dg-error "need .typename.|expected" }
+  T::X v2 = 0; // { dg-error "need .typename.|expected" }
+  T::X v3{0}; // { dg-error "need .typename.|expected" }
+  static constexpr T::X v4 = 0; // { dg-error "need .typename." }
+  typedef T::X T2; // { dg-error "need .typename." }
+}

gcc/testsuite/g++.dg/cpp2a/typename8.C

+// P0634R3
+// { dg-do compile { target c++2a } }
+
+template<typename T>
+struct S {
+  static int foo ();
+};
+
+template<typename T>
+int
+f ()
+{
+  return S<T>::foo();
+}
+
+void
+test ()
+{
+  f<int>();
+}

gcc/testsuite/g++.dg/cpp2a/typename9.C

+// P0634R3
+// { dg-do compile { target c++2a } }
+// { dg-options "-fconcepts" }
+
+template <typename, typename> class A { class B; };
+
+template <typename T, typename U> class A<T, U>::B {
+  B(A &);
+};
+
+template <typename T, typename U>
+A<T, U>::B::B(A<T, U> &) {}

gcc/testsuite/g++.dg/diagnostic/missing-typename.C

 // fix-it hint for missing "typename" (PR c++/63392)
+// { dg-do compile { target c++17_down } }
 // { dg-options "-fdiagnostics-show-caret" }
 
 template<typename T>

gcc/testsuite/g++.dg/other/crash-9.C

@@ -11,5 +11,5 @@ class A
   };
 };
 template <typename T> template <typename U>
-A<T>::B<U> A<T>::B<U>::foo() {}
+A<T>::template B<U> A<T>::B<U>::foo() {}
 

gcc/testsuite/g++.dg/other/nontype-1.C

 template <class Op>
 bool asfun(Op f,
-           Op::first_argument_type a, // { dg-error "not a type" }
-           Op::second_argument_type b) // { dg-error "not a type" }
+           Op::first_argument_type a, // { dg-error "not a type" "" { target c++17_down } }
+           Op::second_argument_type b) // { dg-error "not a type" "" { target c++17_down } }
 {
    return Op(a, b);
 }

gcc/testsuite/g++.dg/parse/crash13.C

@@ -12,11 +12,11 @@ struct A
 };
 
 template <typename T> 
-void func(A<T>::B* )	// { dg-error "variable|template|expression" }
+void func(A<T>::B* )	// { dg-error "variable|template|expression" "" { target c++17_down } }
 {
 }
 
 int main() 
 {
-  func<void>(0);	// { dg-error "not declared|expression|;" }
+  func<void>(0);	// { dg-error "not declared|expression|;" "" { target c++17_down } }
 }

gcc/testsuite/g++.dg/parse/error36.C

@@ -25,7 +25,7 @@ template <class T> struct B
 
 // PR c++/40738
 template <class T>
-void g(const A<T>::type &t);	// { dg-error "typename" "typename" }
+void g(const A<T>::type &t);	// { dg-error "typename" "" { target c++17_down } }
 
 // PR c++/18451
-template <class T> A<T>::B A<T>::b; // { dg-error "typename" }
+template <class T> A<T>::B A<T>::b; // { dg-error "typename" "" { target c++17_down } }

gcc/testsuite/g++.dg/parse/no-typename1.C

@@ -6,6 +6,6 @@ template <typename T> struct A
 {
     template <typename U> struct B
     {
-        A<T>::template B<U> foo(); // { dg-error "" }
+        A<T>::template B<U> foo(); // { dg-error "" "" { target c++17_down } }
     };
 };

gcc/testsuite/g++.dg/parse/typedef2.C

 template <typename T> struct B { typedef typename T::X X; };
-template <typename T> struct A { typedef B<T>::X::Y Z; }; // { dg-error "before 'B<T>::X::Y' because 'B<T>::X'" }
+template <typename T> struct A { typedef B<T>::X::Y Z; }; // { dg-error "before 'B<T>::X::Y' because 'B<T>::X'" "" { target c++17_down } }

gcc/testsuite/g++.dg/parse/typename11.C

@@ -10,7 +10,7 @@ template <int dim> struct Y : X<dim> {
 
 // note: I is nested type in X, not Y!
 template <int dim>
-Y<dim>::I::I () {}		// { dg-error "dependent typedef" "typedef" }
-// { dg-error "no type|dependent type" "no type" { target *-*-* } .-1 }
+Y<dim>::I::I () {}		// { dg-error "expected|dependent typedef" "typedef" }
+// { dg-error "no type|dependent type" "no type" { target c++17_down } .-1 }
 
 template struct Y<1>;

gcc/testsuite/g++.dg/template/crash48.C

@@ -7,4 +7,4 @@ template<typename T> struct A
   typedef typename T::X X;
 };
 
-template<typename T> A<T>::X::X() {} // { dg-error "no type|invalid use|not a type|dependent" }
+template<typename T> A<T>::X::X() {} // { dg-error "expected|no type|invalid use|not a type|dependent" }

gcc/testsuite/g++.dg/template/dependent-name5.C

@@ -17,13 +17,15 @@ struct A
   typedef Bar          type1;
   typedef A::Bar       type2;
   typedef A<T>::Bar    type3;
-  typedef A<T*>::Bar    type4;  // { dg-error "" }
+  typedef A<T*>::Bar    type4;  // { dg-error "" "" { target c++17_down } }
   typedef typename A<T*>::Bar type5;
 
   typedef N<int>       type6;
   typedef A::N<int>    type7;
+// { dg-error "" "" { target c++2a } .-1 }
   typedef A<T>::N<int> type8;
-  typedef A<T*>::template N<int> type9;  // { dg-error "" }
+// { dg-error "" "" { target c++2a } .-1 }
+  typedef A<T*>::template N<int> type9;  // { dg-error "" "" { target c++17_down } }
   typedef typename A<T*>::template N<int> type10;
 
   typedef D Bar2;
@@ -36,7 +38,7 @@ struct A
 
   typedef A::N2 type12;
   typedef typename type12::K k2;
-  typedef type12::K k1;  // { dg-error "" }
+  typedef type12::K k1;  // { dg-error "" "" { target c++17_down } }
 
   // Check that A::Bar2 is not considered dependent even if we use
   // the typename keyword.

gcc/testsuite/g++.dg/template/error29.C

 // PR c++/33209
 
-template<typename T> void foo(int, T::x); // { dg-error "T::x" }
+template<typename T> void foo(int, T::x); // { dg-error "T::x" "" { target c++17_down } }
 
-template<template<typename> class T> void foo2(int, T<int>::x); // { dg-error "T<int>::x" }
+template<template<typename> class T> void foo2(int, T<int>::x); // { dg-error "T<int>::x" "" { target c++17_down } }

gcc/testsuite/g++.dg/template/nested5.C

@@ -6,7 +6,7 @@ template <typename T> struct A
   {
     template <typename U> struct D {};
   };
-  template <typename S> static C::D<S> bar (S const &);
+  template <typename S> static C::template D<S> bar (S const &);
 };
 
 struct E {};

gcc/testsuite/g++.dg/template/pr84789.C

@@ -9,5 +9,5 @@ template<typename> struct B : A {};
 
 template<typename T> struct C : B<T>
 {
-  B<T>::A::I::I i; // { dg-error "not a class type|does not name a type|typename" }
+  B<T>::A::I::I i; // { dg-error "not a class type|does not name a type|typename" "" { target c++17_down } }
 };

gcc/testsuite/g++.dg/template/static30.C

@@ -6,5 +6,5 @@ template <int> struct A
   static const int i2;
 };
 
-template <int N> const int A<N>::i1(A<N>::i);
+template <int N> const int A<N>::i1(A<N>::i); // { dg-error "no declaration matches" "" { target c++2a } }
 template <int N> const int A<N>::i2(3, A<N>::i); // { dg-error "expression list" }

gcc/testsuite/g++.dg/template/typedef6.C

@@ -5,4 +5,4 @@ template<typename T> struct A
   typedef struct typename T::X X;       // { dg-error "expected identifier|two or more" }
 };
 
-template<typename T> A<T>::X::X() {}    // { dg-error "not a type|forbids declaration|invalid use of" }
+template<typename T> A<T>::X::X() {}    // { dg-error "expected|not a type|forbids declaration|invalid use of" }

gcc/testsuite/g++.dg/template/typename3.C

@@ -3,5 +3,5 @@
 
 template <class A>
 struct B {
- typedef A::C::D E;  // { dg-error "" }
+ typedef A::C::D E;  // { dg-error "" "" { target c++17_down } }
 };