Where I grew up (Syr., NY), you really have to listen to know what is being served, when it comes to BBQ.
"Come on over, I’m having a barbecue." meant: come over for food I’m cooking on the BBQ grill – probably hot dogs and hambugers, but could include chicken thighs and chicken legs too, most likely basted in BBQ sauce and possibly marinaded.
"Come on over, I’m making barbecue" meant, low and slow. and most likely was ribs. (9 out of 10 times the person is talking about ribs) But it also included BBQ sauce. Because no one used just a rub if at all. Sometimes, this sentence could be replaced with "come on over, I’m doin’ ribs." In this case, low and slow rib bbq is infered: as is "you bring the beer."
A "chicken barbecue" meant whole chickens rubbed and rotated on a spit.
"Barbecuing chicken" meant grilling chicken legs and chicken thighs on the BBQ, again, using a sauce. Possibly marinaded. But usually in that case, they’d say "we’re grilling some chicken I’ve been marinading for hours." Or, if you were in the southern tier, they’d say, "we’re makin’ speedies" cuz that’s the only real marinading I ever saw down there.
A "pig roast" meant a whole hog on a spit. Growing up, this simply was as close to southern BBQ as you were going to get. No one in the ‘burbs owned a real smoker. So the spit was it.
So, when in the North, you just have to listen closely to know what you’re getting into when a friend mentions "barbecue." don’t just hear the word "barbecue" – you need to hear the context in which the word barbecue has been used.