Special macros

make defines two classes of special macros: control macros and runtime macros.

The control macros control make's behavior. If you have several ways of doing the same thing, using the control macros is preferable. A control macro having the same function as a special target or attribute also has the same name.

make defines the runtime macros when making targets, and they are usually useful only within recipes. The exceptions to this are the dynamic prerequisite macros, discussed later in this topic.