2 passes. Crews get a recce road book which helps them to follow the stage with all the junctions, possible chicanes etc.
All the notes will be written to clean sheet of paper unless they have the notes from the previous years when they only do changes if/when needed.
Recce cars have GPS trackers which can be used to measure the distance from corner to corner but usually atleast the drivers I know only use it for longer straights if at all.
GPS tracker is more important when navigating with the road book to get to and on the stages.