Firstly, Target is assumed to be a file, which, if doesn't exist or its timestamp is later than any of its dependencies, is remade. If you change the target name from the actual filename to something random, your target will always be remade, because that arbitrary file you are fooling make with doesn't exist and it is not created when make runs the commands you specified.

Edit: your compiler has no idea make invokes it, it executes exactly the instructions you gave it (as every computer program does and should do). If you say '-o hello', it will...