Rule present covering this compiler's back (8)
I believe the answer is:
dominate
'rule' is the definition.
('dominate' can be a synonym of 'rule')
'present covering this compiler's back' is the wordplay.
'present' becomes 'donate' (donating is a kind of presenting**).
'covering' is an insertion indicator.
'this compiler's' becomes 'im' (I've seen this in other clues).
'back' says the letters should be written in reverse.
'im' in reverse letter order is 'mi'.
'donate' enclosing 'mi' is 'DOMINATE'.
(Other definitions for dominate that I've seen before include "corner" , "Tower over" , "Rule" , "Be lord over" , "Command, control" .)