gcc/cp/tree.c

710   tree purpose;
725 	  && TREE_PURPOSE (t) == proxy->purpose
734 list_hash_pieces (tree purpose, tree value, tree chain)
745   if (purpose)
746     hashcode += TREE_HASH (purpose);
768 hash_tree_cons (tree purpose, tree value, tree chain)
775   hashcode = list_hash_pieces (purpose, value, chain);
778   proxy.purpose = purpose;
786     *slot = tree_cons (purpose, value, chain);