[GNU Make] Generic phony rules

Prev

Newsgroups: comp.unix.programmer
Date: 22 Mar 2007 14:50:48 GMT

I have the following make file:

 all: something else

 .PHONY: MakeAppleJuice MakeOrangeJuice MakeTomatoJuice

 MakeAppleJuice:
         make_juice Apple.in.source  Apple.in.condition

 MakeOrangeJuice:
         make_juice Orange.in.source Orange.in.condition

 MakeTomatoJuice:
         make_juice Tomato.in.source Tomato.in.condition

Is there anyway to combine the 3 rules into one? I hope there is, because the 3 rules only different in what files they use and what juices then make (but I still need the 3 phony targets). I tried the following but it didn't work:

Make%Juice: %.in.source
        make_juice $*.in.source $*.in.condition

Is it possible to have such generic phony rule?

[GNU Make] Generic phony rules

Pattern rules and phonies don't play well. You can't have a rule like this:

.PHONY: %.o

Also, it seems when you define:

.PHONY: AppleJuice

Then make looks for an *explicit* rule to make "AppleJuice". It doesn't do the pattern rule.

Interestingly, I haven't seen this anywhere in the documentation.

> Which shouldn't be, because AppleJuice is a phony target.

Quite the opposite. In light of the above, if you remove the target from the phonies, I mean delete the .PHONY *rule* from your makefile, it works.

If you want to get the effect of .PHONY, there's another trick:

FORCE:
Make%Juice: %.in.source FORCE
        make_juice $*.in.source $*.in.condition

And your original command line works.

info make --index='force'

Jean-Rene David

[GNU Make] Generic phony rules

> Thanks for the reply. I still can't get it working:
>
> $ cat Makefile
> make_juice := echo
>
> all: something else
>
> .PHONY: MakeAppleJuice MakeOrangeJuice MakeTomatoJuice
>
> FORCE:
> Make%Juice: %.in.source FORCE
>         make_juice $*.in.source $*.in.condition
>
> #MakeAppleJuice:
>
> $ make MakeAppleJuice
> make: Nothing to be done for `MakeAppleJuice'.

The "FORCE" trick is meant to *replace* the .PHONY rule. It's not exactly the same thing, but in your case it will allow you to do what you want with a similar overall effect (only performance is affected).

Delete the .PHONY *rule* from your makefile:

% cat Makefile
all: something else

FORCE:
Make%Juice: %.in.source FORCE
        @echo $*.in.source $*.in.condition

% ls *.in.source
Apple.in.source
Orange.in.source
Tomato.in.source

% make MakeAppleJuice
Apple.in.source Apple.in.condition

% touch MakeAppleJuice
% make MakeAppleJuice
Apple.in.source Apple.in.condition

Without "FORCE":

% cat Makefile
all: something else

Make%Juice: %.in.source
        @echo $*.in.source $*.in.condition

% touch MakeAppleJuice
% make MakeAppleJuice
make: `MakeAppleJuice' is up to date.

Jean-Rene David