Question

Typping make (Gnu Make) with the following Makefile (assuming files foo.x and foo.y are missing)

all: foo.z

foo.z: foo.x foo.y
  cat foo.x foo.y > foo.z

produce the error message:

make: *** No rule to make target `foo.x', needed by `foo.z'.  Stop.

But this Makefile:

all: foo.z

%.z: %.x %.y
  cat %.x %.y > %.z

produce this error message:

make: *** No rule to make target `foo.z', needed by `all'.  Stop.

In the first case, the rule is applied, and a dependency if found to be missing.
In the second case, the rule is found to be not appropriate, and that is a rule that is missing.

I want to use the second Makefile (I have a lot a *.z object to be created), but with an error message like with the first Makefile. My make output is logged, and having the expanded name of the missing files will help debugging.

Is it possible? Maybe a way to force the rule to be used?

Of course I’m not catting file, this is just a example…

Answer 1

I just found:

all: foo.z

OBJ=foo.z

$(OBJ): %.z: %.x %.y
   cat %.x %.y > %.z

One need Static Pattern rule. Amazing make…