-extern union type_stack_elt *type_stack;
-extern int type_stack_depth, type_stack_size;
+
+/* The type stack is an instance of this structure. */
+
+struct type_stack
+{
+ /* Elements on the stack. */
+ union type_stack_elt *elements;
+ /* Current stack depth. */
+ int depth;
+ /* Allocated size of stack. */
+ int size;
+};