Roland Ver. 4.5 Technical Information PDF herunterladen (Seite 19)

Chapter 2: An Introduction to Makeﬁles 9

2.7 Rules for Cleaning the Directory

Compiling a program is not the only thing you might want to write rules for. Makeﬁles

commonly tell how to do a few other things besides compiling a program: for example, how

to delete all the object ﬁles and executables so that the directory is ‘clean’.

Here is how we could write a make rule for cleaning our example editor:

clean:

rm edit $(objects)

In practice, we might want to write the rule in a somewhat more complicated manner

to handle unanticipated situations. We would do this:

.PHONY : clean

clean :

-rm edit $(objects)

This prevents make from getting confused by an actual ﬁle called clean and causes it to

continue in spite of errors from rm. (See Section 4.5 [Phony Targets], page 29, and Section 5.5

[Errors in Recipes], page 49.)

A rule such as this should not be placed at the beginning of the makeﬁle, because we do

not want it to run by default! Thus, in the example makeﬁle, we want the rule for edit,

which recompiles the editor, to remain the default goal.

Since clean is not a prerequisite of edit, this rule will not run at all if we give the

command ‘make’ with no arguments. In order to make the rule run, we have to type ‘make

clean’. See Chapter 9 [How to Run make], page 99.

1 2 ... 14 15 16 17 18 19 20 21 22 23 24 ... 211 212

Keine Kommentare

Roland Ver. 4.5 Technical Information Seite 19