tree_modifier
struct tree_modifier *next;
struct tree_modifier *modifiers;
static struct tree_modifier *gen_tree_modifier(void);
static struct tree_modifier *
struct tree_modifier *new_modifier;
new_modifier = (struct tree_modifier *)safe_calloc
(sizeof (struct tree_modifier));
struct tree_modifier *new_mod_ptr, *curr_mod_ptr;
struct tree_modifier *mod_ptr;