PR c++/60503 - wrong lambda attribute syntax.

This patch fixes two issues with lambda attribute handling: First, it was in
the wrong place in the grammar.  Second, it was treating attributes as
applying to the whole declaration rather than to the function type, as
specified by the standard.

	* parser.c (cp_parser_lambda_declarator_opt): Fix attribute
	handling.

From-SVN: r265787

gcc/cp/ChangeLog

+2018-11-04  Jason Merrill  <jason@redhat.com>
+
+	PR c++/60503 - wrong lambda attribute syntax.
+	* parser.c (cp_parser_lambda_declarator_opt): Fix attribute
+	handling.
+
 2018-11-02  Nathan Sidwell  <nathan@acm.org>
 
 	* decl.c (duplicate_decls): Refactor checks.

gcc/cp/parser.c

@@ -10596,8 +10596,6 @@ cp_parser_lambda_declarator_opt (cp_parser* parser, tree lambda_expr)
 
       parens.require_close (parser);
 
-      attributes = cp_parser_attributes_opt (parser);
-
       /* In the decl-specifier-seq of the lambda-declarator, each
 	 decl-specifier shall either be mutable or constexpr.  */
       int declares_class_or_enum;
@@ -10618,6 +10616,8 @@ cp_parser_lambda_declarator_opt (cp_parser* parser, tree lambda_expr)
       /* Parse optional exception specification.  */
       exception_spec = cp_parser_exception_specification_opt (parser);
 
+      attributes = cp_parser_std_attribute_spec_seq (parser);
+
       /* Parse optional trailing return type.  */
       if (cp_lexer_next_token_is (parser->lexer, CPP_DEREF))
         {
@@ -10668,15 +10668,14 @@ cp_parser_lambda_declarator_opt (cp_parser* parser, tree lambda_expr)
                                        REF_QUAL_NONE,
 				       tx_qual,
 				       exception_spec,
-                                       /*late_return_type=*/NULL_TREE,
+                                       return_type,
                                        /*requires_clause*/NULL_TREE);
     declarator->id_loc = LAMBDA_EXPR_LOCATION (lambda_expr);
-    if (return_type)
-      declarator->u.function.late_return_type = return_type;
+    declarator->std_attributes = attributes;
 
     fco = grokmethod (&return_type_specs,
 		      declarator,
-		      attributes);
+		      NULL_TREE);
     if (fco != error_mark_node)
       {
 	DECL_INITIALIZED_IN_CLASS_P (fco) = 1;

gcc/testsuite/g++.dg/cpp0x/lambda/lambda-attr1.C

+// { dg-do compile { target c++11 } }
+
+auto l = []() [[noreturn]] {};	// { dg-warning "ignored" }

gcc/testsuite/g++.dg/cpp0x/lambda/lambda-attr2.C

+// PR c++/60503
+// { dg-do compile { target c++11 } }
+
+auto l = []() mutable noexcept [[ ]] {};
+auto m = []() [[ ]] mutable noexcept {}; // { dg-error "" }