Barricade Breaker

Tapping an artifact won't cause its abilities to stop applying unless those abilities say so.

If, during your declare attackers step, Barricade Breaker is tapped or is affected by a spell or ability that says it can't attack, then it doesn't attack. If there's a cost associated with having it attack, you aren't forced to pay that cost, so it doesn't have to attack in that case either.

When calculating a spell's total cost, include any alternative costs, additional costs, or anything else that increases or reduces the cost to cast the spell. Improvise applies after the total cost is calculated.