diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 2afb420dc65..ca67d7fc74f 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,12 @@
+2010-09-01  Mikael Pettersson  <mikpe@it.uu.se>
+
+       PR bootstrap/45321
+       * tree.c (stdarg_p): Make fntype parameter const.
+       * tree.h (stdarg_p): Likewise.
+       (function_args_iterator): Remove unused fntype field.
+       (function_args_iter_init): Do not initialize fntype
+       field.  Make fntype parameter const. 
+
 2010-09-01  Richard Guenther  <rguenther@suse.de>
 
 	* tree-vrp.c (adjust_range_with_scev): Use number of iteration
diff --git a/gcc/tree.c b/gcc/tree.c
index a767230d1c8..55275fa0a78 100644
--- a/gcc/tree.c
+++ b/gcc/tree.c
@@ -10508,7 +10508,7 @@ get_name (tree t)
 /* Return true if TYPE has a variable argument list.  */
 
 bool
-stdarg_p (tree fntype)
+stdarg_p (const_tree fntype)
 {
   function_args_iterator args_iter;
   tree n = NULL_TREE, t;
diff --git a/gcc/tree.h b/gcc/tree.h
index 5d431e687b6..17eeba7e81c 100644
--- a/gcc/tree.h
+++ b/gcc/tree.h
@@ -4772,16 +4772,14 @@ extern GTY(()) const char * current_function_func_begin_label;
 
 /* Iterator for going through the function arguments.  */
 typedef struct {
-  tree fntype;			/* function type declaration */
   tree next;			/* TREE_LIST pointing to the next argument */
 } function_args_iterator;
 
 /* Initialize the iterator I with arguments from function FNDECL  */
 
 static inline void
-function_args_iter_init (function_args_iterator *i, tree fntype)
+function_args_iter_init (function_args_iterator *i, const_tree fntype)
 {
-  i->fntype = fntype;
   i->next = TYPE_ARG_TYPES (fntype);
 }
 
@@ -4853,7 +4851,7 @@ extern tree call_expr_arg (tree, int);
 extern tree *call_expr_argp (tree, int);
 extern tree create_artificial_label (location_t);
 extern const char *get_name (tree);
-extern bool stdarg_p (tree);
+extern bool stdarg_p (const_tree);
 extern bool prototype_p (tree);
 extern bool is_typedef_decl (tree x);
 extern bool typedef_variant_p (tree);