Simplify Makefile and maybe avoid using $(basename $#) is multiple places - makefile

Question

I am new to Makefiles and it works as expected. But I am wondering is there a way to simplify this Makefile I wrote. More specifically I used $(basename $#).scala and $(basename $#) in many places and I think it is an anti-pattern. Or maybe is there a way to generalize it.
I appreciate any feedback or hint.
SPECS=First Follow
EXAMPLES_PATH=../..
ROOT_PATH=../${EXAMPLES_PATH}
SCALAV=2.12
APSLIB=${ROOT_PATH}/lib/aps-library-${SCALAV}.jar
SCALA_FLAGS=.:${APSLIB}
APS2SCALA=${ROOT_PATH}/bin/aps2scala
all: $(addsuffix Spec.compile, $(SPECS)) $(addsuffix Spec.run, $(SPECS))
%.generate:
${APS2SCALA} -DCOT -p ${EXAMPLES_PATH}:${ROOT_PATH}/base $*
%.run:
#scala -cp ${SCALA_FLAGS} $(basename $#)
GrammarUtil.compile: grammar.generate
scalac -cp ${SCALA_FLAGS} grammar.scala $(basename $#).scala
first.compile:
scalac -cp ${SCALA_FLAGS} $(basename $#).scala
follow.compile:
scalac -cp ${SCALA_FLAGS} $(basename $#).scala
Spec.compile:
scalac -cp ${SCALA_FLAGS} $(basename $#).scala
FirstSpec.compile: Spec.compile grammar.generate GrammarUtil.compile first.generate first.compile
scalac -cp ${SCALA_FLAGS} $(basename $#).scala
FollowSpec.compile: Spec.compile grammar.generate GrammarUtil.compile follow.generate follow.compile
scalac -cp ${SCALA_FLAGS} $(basename $#).scala
clean:
rm -f *.class grammar.scala first.scala follow.scala

Answer 1

The Make variable $* does roughly this; it returns whatever matched % in a pattern rule (called the stem).
Several of your recipes have exactly the same code, so there are multiple reasons to refactor to use a pattern rule instead. A complication as that one of the *.compile rules has a second dependency, but we can simply create a rule which leaves this part empty if there is only one dependency.
%.compile: %.scala
scalac -cp ${SCALA_FLAGS} $(filter-out $<,$^) $<
grammar.compile: grammar.generate
This also fixes the bug that it declares the formerly undeclared (but obvious) dependency on the %.scala file; thus, we use $< instead of $*.scala though in this case they are basically equivalent.
$(filter-out $<,$^) removes the first dependency (%.scala) from the list of all depencencies, yielding either nothing or grammar.generate.
However, your Makefile still appears to have several other undeclared dependencies, and inconsistent naming for some targets.
In particular, the above requires you to rename GrammarUtil to grammar; without more information about your inputs and their internal dependencies, I can't tell if that's really feasible.
Probably a less rocky road would be to keep exactly the same stem for all related files, and accept the default output file name (I'm guessing %.o? But I'm not familiar with Scala) instead of made-up and probably nonexistent pseudo-filenames like %.compile. (If you want to keep these, and they indeed do not correspond to actual file names, you should probably declare them as .PHONY; but then you are disabling useful and important make functionality.)