cp-tree.h (enum cp_tree_index): Add CPTI_AUTO_IDENTIFIER & CPTI_DECLTYPE_AUTO_IDENTIFIER.

	* cp-tree.h (enum cp_tree_index): Add CPTI_AUTO_IDENTIFIER &
	CPTI_DECLTYPE_AUTO_IDENTIFIER.
	(auto_identifier, decltype_auto_identifier): New.
	*decl.c (initialize_predefined_identifiers): Add 'auto' and
	'decltype(auto)'.
	(grokdeclarator): Use cached identifier.
	* pt.c (make_decltype_auto, make_auto, make_constrained_auto,
	is_auto): Likewise.

From-SVN: r243342

gcc/cp/ChangeLog

+2016-12-07  Nathan Sidwell  <nathan@acm.org>
+
+	* cp-tree.h (enum cp_tree_index): Add CPTI_AUTO_IDENTIFIER &
+	CPTI_DECLTYPE_AUTO_IDENTIFIER.
+	(auto_identifier, decltype_auto_identifier): New.
+	*decl.c (initialize_predefined_identifiers): Add 'auto' and
+	'decltype(auto)'.
+	(grokdeclarator): Use cached identifier.
+	* pt.c (make_decltype_auto, make_auto, make_constrained_auto,
+	is_auto): Likewise.
+
 2016-12-02  Jakub Jelinek  <jakub@redhat.com>
 
 	PR c++/78649

gcc/cp/cp-tree.h

@@ -1117,6 +1117,8 @@ enum cp_tree_index
     CPTI_PFN_IDENTIFIER,
     CPTI_VPTR_IDENTIFIER,
     CPTI_STD_IDENTIFIER,
+    CPTI_AUTO_IDENTIFIER,
+    CPTI_DECLTYPE_AUTO_IDENTIFIER,
 
     CPTI_LANG_NAME_C,
     CPTI_LANG_NAME_CPLUSPLUS,
@@ -1200,6 +1202,9 @@ extern GTY(()) tree cp_global_trees[CPTI_MAX];
 #define vptr_identifier			cp_global_trees[CPTI_VPTR_IDENTIFIER]
 /* The name of the std namespace.  */
 #define std_identifier			cp_global_trees[CPTI_STD_IDENTIFIER]
+/* auto and declspec(auto) identifiers.  */
+#define auto_identifier			cp_global_trees[CPTI_AUTO_IDENTIFIER]
+#define decltype_auto_identifier	cp_global_trees[CPTI_DECLTYPE_AUTO_IDENTIFIER]
 /* The name of a C++17 deduction guide.  */
 #define lang_name_c			cp_global_trees[CPTI_LANG_NAME_C]
 #define lang_name_cplusplus		cp_global_trees[CPTI_LANG_NAME_CPLUSPLUS]

gcc/cp/decl.c

@@ -4034,6 +4034,8 @@ initialize_predefined_identifiers (void)
     { "__vtt_parm", &vtt_parm_identifier, 0 },
     { "::", &global_scope_name, 0 },
     { "std", &std_identifier, 0 },
+    { "auto", &auto_identifier, 0 },
+    { "decltype(auto)", &decltype_auto_identifier, 0 },
     { NULL, NULL, 0 }
   };
 
@@ -10600,7 +10602,7 @@ grokdeclarator (const cp_declarator *declarator,
 	  gcc_unreachable ();
 	}
       if (TREE_CODE (type) != TEMPLATE_TYPE_PARM
-	  || TYPE_IDENTIFIER (type) != get_identifier ("auto"))
+	  || TYPE_IDENTIFIER (type) != auto_identifier)
 	{
 	  if (type != error_mark_node)
 	    {

gcc/cp/pt.c

@@ -24302,13 +24302,13 @@ make_auto_1 (tree name, bool set_canonical)
 tree
 make_decltype_auto (void)
 {
-  return make_auto_1 (get_identifier ("decltype(auto)"), true);
+  return make_auto_1 (decltype_auto_identifier, true);
 }
 
 tree
 make_auto (void)
 {
-  return make_auto_1 (get_identifier ("auto"), true);
+  return make_auto_1 (auto_identifier, true);
 }
 
 /* Return a C++17 deduction placeholder for class template TMPL.  */
@@ -24330,7 +24330,7 @@ make_template_placeholder (tree tmpl)
 tree
 make_constrained_auto (tree con, tree args)
 {
-  tree type = make_auto_1 (get_identifier ("auto"), false);
+  tree type = make_auto_1 (auto_identifier, false);
 
   /* Build the constraint. */
   tree tmpl = DECL_TI_TEMPLATE (con);
@@ -25016,8 +25016,8 @@ bool
 is_auto (const_tree type)
 {
   if (TREE_CODE (type) == TEMPLATE_TYPE_PARM
-      && (TYPE_IDENTIFIER (type) == get_identifier ("auto")
-	  || TYPE_IDENTIFIER (type) == get_identifier ("decltype(auto)")
+      && (TYPE_IDENTIFIER (type) == auto_identifier
+	  || TYPE_IDENTIFIER (type) == decltype_auto_identifier
 	  || CLASS_PLACEHOLDER_TEMPLATE (type)))
     return true;
   else