macro_expand_if (const struct macro_token *tokens, size_t n_tokens,
int nesting_countdown, const struct macro_set *macros,
const struct macro_expander *me, struct string_map *vars,
macro_expand_if (const struct macro_token *tokens, size_t n_tokens,
int nesting_countdown, const struct macro_set *macros,
const struct macro_expander *me, struct string_map *vars,