Life has meaning, with or without the additional impact on that meaning by the reality of the prospect of death. To argue that the prospect of death IS the meaning of life, or GIVES life its meaning is pure folly. Certainly the prospect of death does impacts on the meaning of life.
While we argue below that another, more basic meaning to life exists, it remains true that the prospect of death, itself, contributes to the choices before us.... Survive, or don't survive. Choice gives meaning even if no more than the choice.
The notion that life is devoid of meaning is typical of those who spurn popular religious views of the meaning of life. Their aversion to such particular views pushes some of them to the irrationality of rejecting any view of the meaning of life.
Clearly, even for the atheist, life is.
Given that it is, it is something about which choices can be made and individual causes can have an effect. Our lives, for each of us, are opportunities for exploration and creation, at the very least. Failure to avail one's self of such opportunities, is, itself, a choice.
The choice alone, gives meaning to life, amidst whatever other philosophical meaning one may subscribe to.