In most recipes it will call for the weight of pasta before cooking, or the amount like " 2 cups of uncooked macaroni"
After cooking, you would still refer to it as 2 cups, just like a quarter pounder is still a quarter pounder although the meat actually shrinks while cooking...it is still the same calories.
I hope I answered your question. Now if your trouble is logging in the amount of pasta you ate, are their entries that specify a measure of cooked vs uncooked???? Someone correct me if I'm wrong....I'm going to check this post again soon because I am planning on eating pasta this week so I hope I am logging it correctly.