Matching different/multiple parts of a Makefile target - makefile

Question

Here is a Makefile that I currently use to make targets with different configurations, i.e., I am building different software packages with the same target, either all at once or individually.
.PHONY: build test %.build %.test build-all test-all
%.build %.test: PACKAGE = $*
%.build:
#echo build $(PACKAGE)
%.test:
#echo test $(PACKAGE)
build-all: a.build b.build
test-all: a.test b.test
build: $(PACKAGE).build
test: $(PACKAGE).test
I can now build all packages with make build-all or individual packages with, e.g., make build PACKAGE=a. However I would like to switch the body of the %.build and build, etc. targets as in the following:
.PHONY: build test %.build %.test build-all test-all
build:
#echo build $(PACKAGE)
test:
#echo test $(PACKAGE)
build-all: a.build b.build
test-all: a.test b.test
%.build %.test: PACKAGE = $*
$(PACKAGE).%: $*
This way, the pattern matching logic is fully separated from the "main" targets build and test that should contain the actual build commands; making the important parts of the Makefile more readable. However, the last line does not work as intended, i.e., running make a.build and thus make build-all should trigger the target build with PACKAGE=a. The variable assignment in second-last line works, the target matching in the last line does not.
Question: Is there a way to express a matching target like $(PACKAGE).%: $* or to match separate parts of a target like %.%: $2?

Answer 1

As MadScientist explained, the problem cannot be solved easily in GNU make. For completeness, I would like to add and explain my final and more comprehensive solution:
.PHONY: all build test clean %.build %.test build-all test-all
PACKAGES = a b c e f g
PACKAGE = a
all: clean build-all test-all
%.build %.test: PACKAGE = $*
%.build:
#echo build $(PACKAGE)
%.test:
#echo test $(PACKAGE)
clean:
#echo remove build dir
build-all: $(addsuffix .build, $(PACKAGES))
test-all: $(addsuffix .test, $(PACKAGES))
build: $(PACKAGE).build
test: $(PACKAGE).test
This solution avoids eval and foreach and is based on my initial working solution, where the dynamic %.build and %.test targets contain the actual build commands. I added the PACKAGES variable to facilitate easy addition of new packages, a default PACKAGE to prevent execution of misconfigured build commands, and the common targets all and clean as complements.
From the command line, you just call make all, clean, build PACKAGE=x, build-all, etc., i.e., only the static targets, which will then trigger the build commands in the dynamic targets. The static targets and the two variables are also visible in the Bash/Zsh auto-completion.
I think this is the most flexible and yet readable way to build multiple dynamic targets.

Answer 2

First you probably want:
$(PACKAGE).% : %
not using $*, which is an automatic variable and so it has no value except inside the recipe; you can't use it like that in the prerequisite lists.
Second, you can't do this in GNU make. A pattern rule with no recipe doesn't just a create prerequisite relationship, like an explicit rule would do; instead it deletes the pattern rule. Since you didn't have a pattern rule for $(PACKAGE).% yet, this is basically a no-op. Also, target-specific variables are only available inside the recipe, so trying to use $(PACKAGE) in the target definition and expecting it to take the value from some previously set target-specific variable cannot work.
You could do something like this, but it's not fully dynamic (you still need the list of packages and types):
PACKAGES = a b
TYPES = build test
$(foreach T,$(TYPES),$(eval $(addsuffix .$T,$(PACKAGES)): $T))