expr_eval
int expr_eval(struct condexpr *, int (*)(const char *, void *), void *);
(void)expr_eval(fi->fi_optx, checkaux, fi);
sel = expr_eval(fi->fi_optx,
!expr_eval(dm->dm_opts, fixsel, NULL))
return (!expr_eval(expr->cx_not, fn, ctx));
lhs = expr_eval(expr->cx_and.left, fn, ctx);
rhs = expr_eval(expr->cx_and.right, fn, ctx);
lhs = expr_eval(expr->cx_or.left, fn, ctx);
rhs = expr_eval(expr->cx_or.right, fn, ctx);
if (expr_eval(cond, selectopt, NULL))