[Question] multiple targets for implicit rule

[Masahiro Yamada]

Hi.

I have a question about the following behavior.


------------(Makefile begin)---------
.PHONY: all
all: foo.x foo.z

%.x %.z:
        touch $@
-------------(Makefile end)----------



$ rm foo*
$ make
touch foo.x
$ make
touch foo.z
$ make
make: Nothing to be done for 'all'.



When multiple targets appear in one implicit rule,
Make runs the recipe just once instead of twice
even when it is requested to create two targets.

In this case, does Make assume the recipe
will create both %.x and %.z ?


Is this behavior intentional?
Documented somewhere?


--
Best Regards
Masahiro Yamada