Does the Haste Spell give +1 BAB or only +1 attack roll?

So, the haste spells would give a character +1 extra attack and…..

+1 bonus on attack roll.

Could that be considered BAB or it is just an attack roll bonus?

Example: A level 5 Barbarian (+5 BAB), after being hasted, would have 6 BAB or +5 BAB and +1 bonus attack roll?