cudd Makefile: recursive calls of make via $(MAKE)

Recursive calls to make should use the special $(MAKE) variable instead
of a direct 'make' call:

https://www.gnu.org/software/make/manual/html_node/MAKE-Variable.html#MAKE-Variable

This allows make to communicate with the sub-makes (e.g., for coordinating parallel
makes).

cudd/Makefile

@@ -223,7 +223,7 @@ build:
 	@for dir in $(DIRS); do \
 		(cd $$dir; \
 		echo Making $$dir ...; \
-		make CC=$(CC) RANLIB=$(RANLIB) MFLAG= MNEMLIB= ICFLAGS="$(ICFLAGS)" XCFLAGS="$(XCFLAGS)" DDDEBUG="$(DDDEBUG)" MTRDEBUG="$(MTRDEBUG)" LDFLAGS="$(LDFLAGS)" PURE="$(PURE)" EXE="$(EXE)" )\
+		$(MAKE) CC=$(CC) RANLIB=$(RANLIB) MFLAG= MNEMLIB= ICFLAGS="$(ICFLAGS)" XCFLAGS="$(XCFLAGS)" DDDEBUG="$(DDDEBUG)" MTRDEBUG="$(MTRDEBUG)" LDFLAGS="$(LDFLAGS)" PURE="$(PURE)" EXE="$(EXE)" )\
 	done
 
 nanotrav: build
@@ -233,7 +233,7 @@ check_leaks:
 	@for dir in $(DIRS); do \
 		(cd $$dir; \
 		echo Making $$dir ...; \
-		make CC=$(CC) RANLIB=$(RANLIB) MFLAG=$(MFLAG) MNEMLIB=$(MNEMLIB) ICFLAGS="$(ICFLAGS)" XCFLAGS="$(XCFLAGS)" DDDEBUG="$(DDDEBUG)" MTRDEBUG="$(MTRDEBUG)" LDFLAGS="$(LDFLAGS)" EXE="$(EXE)" )\
+		$(MAKE) CC=$(CC) RANLIB=$(RANLIB) MFLAG=$(MFLAG) MNEMLIB=$(MNEMLIB) ICFLAGS="$(ICFLAGS)" XCFLAGS="$(XCFLAGS)" DDDEBUG="$(DDDEBUG)" MTRDEBUG="$(MTRDEBUG)" LDFLAGS="$(LDFLAGS)" EXE="$(EXE)" )\
 	done
 
 optimize_dec:
@@ -241,7 +241,7 @@ optimize_dec:
 	@for dir in $(DIRS); do \
 		(cd $$dir; \
 		echo Making $$dir ...; \
-		make CC=$(CC) RANLIB=$(RANLIB) XCFLAGS="$(XCFLAGS)" LDFLAGS="$(LDFLAGS)" optimize_dec )\
+		$(MAKE) CC=$(CC) RANLIB=$(RANLIB) XCFLAGS="$(XCFLAGS)" LDFLAGS="$(LDFLAGS)" optimize_dec )\
 	done
 
 lint:
@@ -249,7 +249,7 @@ lint:
 	@for dir in $(DIRS) obj; do \
 		(cd $$dir; \
 		echo Making lint in $$dir ...; \
-		make CC=$(CC) lint )\
+		$(MAKE) CC=$(CC) lint )\
 	done
 
 tags:
@@ -257,7 +257,7 @@ tags:
 	@for dir in $(DIRS) obj; do \
 		(cd $$dir; \
 		echo Making tags in $$dir ...; \
-		make CC=$(CC) tags )\
+		$(MAKE) CC=$(CC) tags )\
 	done
 
 all:
@@ -265,7 +265,7 @@ all:
 	@for dir in $(DIRS); do \
 		(cd $$dir; \
 		echo Making all in $$dir ...; \
-		make CC=$(CC) RANLIB=$(RANLIB) MFLAG= MNEMLIB= ICFLAGS="$(ICFLAGS)" XCFLAGS="$(XCFLAGS)" DDDEBUG="$(DDDEBUG)" MTRDEBUG="$(MTRDEBUG)" LDFLAGS="$(LDFLAGS)" PURE="$(PURE)" EXE="$(EXE)" all )\
+		$(MAKE) CC=$(CC) RANLIB=$(RANLIB) MFLAG= MNEMLIB= ICFLAGS="$(ICFLAGS)" XCFLAGS="$(XCFLAGS)" DDDEBUG="$(DDDEBUG)" MTRDEBUG="$(MTRDEBUG)" LDFLAGS="$(LDFLAGS)" PURE="$(PURE)" EXE="$(EXE)" all )\
 	done
 
 testcudd:
@@ -273,49 +273,49 @@ testcudd:
 	@for dir in util st mtr epd; do \
 		(cd $$dir; \
 		echo Making $$dir ...; \
-		make CC=$(CC) RANLIB=$(RANLIB) MFLAG= MNEMLIB= ICFLAGS="$(ICFLAGS)" XCFLAGS="$(XCFLAGS)" DDDEBUG="$(DDDEBUG)" MTRDEBUG="$(MTRDEBUG)" LDFLAGS="$(LDFLAGS)" PURE="$(PURE)" EXE="$(EXE)" )\
+		$(MAKE) CC=$(CC) RANLIB=$(RANLIB) MFLAG= MNEMLIB= ICFLAGS="$(ICFLAGS)" XCFLAGS="$(XCFLAGS)" DDDEBUG="$(DDDEBUG)" MTRDEBUG="$(MTRDEBUG)" LDFLAGS="$(LDFLAGS)" PURE="$(PURE)" EXE="$(EXE)" )\
 	done
 	@(cd cudd; \
 	echo Making testcudd ...; \
-	make CC=$(CC) RANLIB=$(RANLIB) MFLAG= MNEMLIB= ICFLAGS="$(ICFLAGS)" XCFLAGS="$(XCFLAGS)" DDDEBUG="$(DDDEBUG)" MTRDEBUG="$(MTRDEBUG)" LDFLAGS="$(LDFLAGS)" PURE="$(PURE)" EXE="$(EXE)" testcudd$(EXE) )
+	$(MAKE) CC=$(CC) RANLIB=$(RANLIB) MFLAG= MNEMLIB= ICFLAGS="$(ICFLAGS)" XCFLAGS="$(XCFLAGS)" DDDEBUG="$(DDDEBUG)" MTRDEBUG="$(MTRDEBUG)" LDFLAGS="$(LDFLAGS)" PURE="$(PURE)" EXE="$(EXE)" testcudd$(EXE) )
 
 objlib:
 	sh ./setup.sh
 	@for dir in $(BDIRS); do \
 		(cd $$dir; \
 		echo Making $$dir ...; \
-		make CC=$(CC) RANLIB=$(RANLIB) MFLAG= MNEMLIB= ICFLAGS="$(ICFLAGS)" XCFLAGS="$(XCFLAGS)" DDDEBUG="$(DDDEBUG)" MTRDEBUG="$(MTRDEBUG)" LDFLAGS="$(LDFLAGS)" PURE="$(PURE)" EXE="$(EXE)" )\
+		$(MAKE) CC=$(CC) RANLIB=$(RANLIB) MFLAG= MNEMLIB= ICFLAGS="$(ICFLAGS)" XCFLAGS="$(XCFLAGS)" DDDEBUG="$(DDDEBUG)" MTRDEBUG="$(MTRDEBUG)" LDFLAGS="$(LDFLAGS)" PURE="$(PURE)" EXE="$(EXE)" )\
 	done
 	@(cd obj; \
 	echo Making obj ...; \
-	make CXX=$(CXX) CXXFLAGS=$(CXXFLAGS) RANLIB=$(RANLIB) MFLAG= MNEMLIB= ICFLAGS="$(ICFLAGS)" XCFLAGS="$(XCFLAGS)" DDDEBUG="$(DDDEBUG)" MTRDEBUG="$(MTRDEBUG)" LDFLAGS="$(LDFLAGS)" PURE="$(PURE)" EXE="$(EXE)" )
+	$(MAKE) CXX=$(CXX) CXXFLAGS=$(CXXFLAGS) RANLIB=$(RANLIB) MFLAG= MNEMLIB= ICFLAGS="$(ICFLAGS)" XCFLAGS="$(XCFLAGS)" DDDEBUG="$(DDDEBUG)" MTRDEBUG="$(MTRDEBUG)" LDFLAGS="$(LDFLAGS)" PURE="$(PURE)" EXE="$(EXE)" )
 
 testobj: objlib
 	@(cd obj; \
 	echo Making testobj ...; \
-	make CXX=$(CXX) CXXFLAGS=$(CXXFLAGS) RANLIB=$(RANLIB) MFLAG= MNEMLIB= ICFLAGS="$(ICFLAGS)" XCFLAGS="$(XCFLAGS)" DDDEBUG="$(DDDEBUG)" MTRDEBUG="$(MTRDEBUG)" LDFLAGS="$(LDFLAGS)" PURE="$(PURE)" EXE="$(EXE)" testobj$(EXE) )
+	$(MAKE) CXX=$(CXX) CXXFLAGS=$(CXXFLAGS) RANLIB=$(RANLIB) MFLAG= MNEMLIB= ICFLAGS="$(ICFLAGS)" XCFLAGS="$(XCFLAGS)" DDDEBUG="$(DDDEBUG)" MTRDEBUG="$(MTRDEBUG)" LDFLAGS="$(LDFLAGS)" PURE="$(PURE)" EXE="$(EXE)" testobj$(EXE) )
 
 testdddmp: build
 	@(cd dddmp; \
 	echo Making testdddmp ...; \
-	make CC=$(CC) RANLIB=$(RANLIB) MFLAG= MNEMLIB= ICFLAGS="$(ICFLAGS)" XCFLAGS="$(XCFLAGS)" DDDEBUG="$(DDDEBUG)" MTRDEBUG="$(MTRDEBUG)" LDFLAGS="$(LDFLAGS)" PURE="$(PURE)" EXE="$(EXE)" testdddmp$(EXE) )
+	$(MAKE) CC=$(CC) RANLIB=$(RANLIB) MFLAG= MNEMLIB= ICFLAGS="$(ICFLAGS)" XCFLAGS="$(XCFLAGS)" DDDEBUG="$(DDDEBUG)" MTRDEBUG="$(MTRDEBUG)" LDFLAGS="$(LDFLAGS)" PURE="$(PURE)" EXE="$(EXE)" testdddmp$(EXE) )
 
 testmtr: build
 	@(cd mtr; \
 	echo Making testmtr ...; \
-	make CC=$(CC) RANLIB=$(RANLIB) MFLAG= MNEMLIB= ICFLAGS="$(ICFLAGS)" XCFLAGS="$(XCFLAGS)" DDDEBUG="$(DDDEBUG)" MTRDEBUG="$(MTRDEBUG)" LDFLAGS="$(LDFLAGS)" PURE="$(PURE)" EXE="$(EXE)" testmtr$(EXE) )
+	$(MAKE) CC=$(CC) RANLIB=$(RANLIB) MFLAG= MNEMLIB= ICFLAGS="$(ICFLAGS)" XCFLAGS="$(XCFLAGS)" DDDEBUG="$(DDDEBUG)" MTRDEBUG="$(MTRDEBUG)" LDFLAGS="$(LDFLAGS)" PURE="$(PURE)" EXE="$(EXE)" testmtr$(EXE) )
 
 clean:
 	@for dir in $(DIRS); do	\
 	    (cd $$dir;	\
 	     echo Cleaning $$dir ...; \
-	     make -s clean	) \
+	     $(MAKE) -s clean	) \
 	done
 
 distclean:
 	@for dir in $(DIRS); do	\
 	    (cd $$dir;	\
 	     echo Cleaning $$dir ...; \
-	     make -s EXE="$(EXE)" distclean	) \
+	     $(MAKE) -s EXE="$(EXE)" distclean	) \
 	done
 	sh ./shutdown.sh