PR c++/88358 - name wrongly treated as type.

* parser.c (cp_parser_direct_declarator): Don't assume a qualified-id
	in parameter-list is a type if the function's declarator-id is not
	qualified.

	* g++.dg/cpp2a/typename1.C: Add dg-error.
	* g++.dg/cpp2a/typename13.C: New test.
	* g++.dg/cpp2a/typename6.C: Make a function name qualified.
	Add typename.

From-SVN: r268343

gcc/cp/ChangeLog

@@ -1,3 +1,10 @@
+2019-01-28  Marek Polacek  <polacek@redhat.com>
+
+	PR c++/88358 - name wrongly treated as type.
+	* parser.c (cp_parser_direct_declarator): Don't assume a qualified-id
+	in parameter-list is a type if the function's declarator-id is not
+	qualified.
+
 2019-01-27  Marek Polacek  <polacek@redhat.com>
 
 	PR c++/88815 - narrowing conversion lost in decltype.

gcc/cp/parser.c

@@ -21107,23 +21107,28 @@ cp_parser_direct_declarator (cp_parser* parser,
 	    if (cxx_dialect >= cxx2a
 		&& (flags & CP_PARSER_FLAGS_TYPENAME_OPTIONAL)
 		&& declarator->kind == cdk_id
-		/* ...whose declarator-id is qualified.  */
-		&& qualifying_scope != NULL_TREE
 		&& !at_class_scope_p ()
 		&& cp_lexer_next_token_is (parser->lexer, CPP_OPEN_PAREN))
 	      {
-		/* Now we have something like
-		   template <typename T> int C::x(S::p);
-		   which can be a function template declaration or a
-		   variable template definition.  If name lookup for
-		   the declarator-id C::x finds one or more function
-		   templates, assume S::p to name a type.  Otherwise,
-		   don't.  */
-		tree decl
-		  = cp_parser_lookup_name_simple (parser, unqualified_name,
-						  token->location);
-		if (!is_overloaded_fn (decl))
+		/* ...whose declarator-id is qualified.  If it isn't, never
+		   assume the parameters to refer to types.  */
+		if (qualifying_scope == NULL_TREE)
 		  flags &= ~CP_PARSER_FLAGS_TYPENAME_OPTIONAL;
+		else
+		  {
+		    /* Now we have something like
+		       template <typename T> int C::x(S::p);
+		       which can be a function template declaration or a
+		       variable template definition.  If name lookup for
+		       the declarator-id C::x finds one or more function
+		       templates, assume S::p to name a type.  Otherwise,
+		       don't.  */
+		    tree decl
+		      = cp_parser_lookup_name_simple (parser, unqualified_name,
+						      token->location);
+		    if (!is_overloaded_fn (decl))
+		      flags &= ~CP_PARSER_FLAGS_TYPENAME_OPTIONAL;
+		  }
 	      }
 	  }
 

gcc/testsuite/ChangeLog

@@ -1,3 +1,11 @@
+2019-01-28  Marek Polacek  <polacek@redhat.com>
+
+	PR c++/88358 - name wrongly treated as type.
+	* g++.dg/cpp2a/typename1.C: Add dg-error.
+	* g++.dg/cpp2a/typename13.C: New test.
+	* g++.dg/cpp2a/typename6.C: Make a function name qualified.
+	Add typename.
+
 2019-01-28  Marek Polacek  <polacek@redhat.com>
 
 	* g++.dg/cpp0x/enum37.C: Add dg-error.

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

@@ -6,7 +6,7 @@ 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> void f(T::R); // { dg-error "declared void" }
 
 template <class T> struct A;
 template <class T> using B = A<T>::U;

gcc/testsuite/g++.dg/cpp2a/typename13.C

@@ -0,0 +1,13 @@
+// P0634R3, PR c++/88358
+// { dg-do compile { target c++2a } }
+
+template <typename T>
+int pi(T::your_pi);
+
+struct Foo { static constexpr int your_pi = 10; };
+
+int
+main ()
+{
+  return pi<Foo>;
+}

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

@@ -55,11 +55,14 @@ struct S2 {
 // (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);
+
+struct M {
+  template<typename T>
+  int fn (T::X);
+};
 
 template<typename T>
-int fn4 (T::X p) { return p; }
+int M::fn (T::X p) { return p; }
 
 // (5.2.5) parameter-declaration in a lambda-declarator,
 // unless that parameter-declaration appears in a default argument
@@ -92,7 +95,7 @@ struct S5 {
 };
 
 template<typename T>
-void fn7 (T::X p)
+void fn7 (typename T::X p)
 {
   int i = static_cast<T::Y>(p);
   i = dynamic_cast<T::Y>(p);