re PR c++/65750 (misinterpret in a virtual member function with a C++11 style function signature)

/cp
2015-06-24  Adam Butcher  <adam@jessamine.co.uk>

	PR c++/65750
	* parser.c (cp_parser_simple_type_specifier): Don't synthesize
	implicit template parm if 'auto' is a placeholder for trailing
	return type.

/testsuite
2015-06-24  Adam Butcher  <adam@jessamine.co.uk>

	PR c++/65750
	* g++.dg/cpp0x/trailing11.C: New.

From-SVN: r224901

gcc/cp/ChangeLog

+2015-06-24  Adam Butcher  <adam@jessamine.co.uk>
+
+	PR c++/65750
+	* parser.c (cp_parser_simple_type_specifier): Don't synthesize
+	implicit template parm if 'auto' is a placeholder for trailing
+	return type.
+
 2015-06-24  Patrick Palka  <ppalka@gcc.gnu.org>
 
 	Revert:

gcc/cp/parser.c

@@ -14939,6 +14939,30 @@ cp_parser_simple_type_specifier (cp_parser* parser,
       maybe_warn_cpp0x (CPP0X_AUTO);
       if (parser->auto_is_implicit_function_template_parm_p)
 	{
+	  /* The 'auto' might be the placeholder return type for a function decl
+	     with trailing return type.  */
+	  bool have_trailing_return_fn_decl = false;
+	  if (cp_lexer_peek_nth_token (parser->lexer, 2)->type
+	      == CPP_OPEN_PAREN)
+	    {
+	      cp_parser_parse_tentatively (parser);
+	      cp_lexer_consume_token (parser->lexer);
+	      cp_lexer_consume_token (parser->lexer);
+	      if (cp_parser_skip_to_closing_parenthesis (parser,
+							 /*recovering*/false,
+							 /*or_comma*/false,
+							 /*consume_paren*/true))
+		have_trailing_return_fn_decl
+		  = cp_lexer_next_token_is (parser->lexer, CPP_DEREF);
+	      cp_parser_abort_tentative_parse (parser);
+	    }
+
+	  if (have_trailing_return_fn_decl)
+	    {
+	      type = make_auto ();
+	      break;
+	    }
+
 	  if (cxx_dialect >= cxx14)
 	    type = synthesize_implicit_template_parm (parser);
 	  else

gcc/testsuite/ChangeLog

+2015-06-24  Adam Butcher  <adam@jessamine.co.uk>
+
+	PR c++/65750
+	* g++.dg/cpp0x/trailing11.C: New.
+
 2015-06-24  Ramana Radhakrishnan  <ramana.radhakrishnan@arm.com>
 
 	* gcc.target/arm/fixed_float_conversion.c: Skip for inappropriate

gcc/testsuite/g++.dg/cpp0x/trailing11.C

+// PR c++/65750
+// { dg-do compile { target c++11 } }
+
+template<typename T> struct F { };
+
+class a
+{
+  virtual auto f( F< void () > ) -> void;
+  virtual auto g( F< auto () -> void > ) -> void;
+};
+
+auto main() -> int { }