Build system: General improvements

Makefile

@@ -1,11 +1,27 @@
+QUIET=1
+
 all:first
 
-first:gui.o main.o simdata.o assembly.o
-	gcc -ggdb $^ -fsanitize=address -lncurses -ltinfo -o $@
+OBJECT_FILES=gui.o main.o simdata.o assembly.o
+
+ifeq "${QUIET}" "1"
+       QUIET_CC     = @echo   ' CC    '$@;
+       QUIET_LINK   = @echo   ' LINK  '$@;
+       QUIET_CLEAN  = @echo   ' CLEAN .';
+       Q            = @
+else
+       Q            =
+endif
+
+first: ${OBJECT_FILES}
+	${QUIET_LINK}
+	${Q}gcc -ggdb $^ -fsanitize=address -lncurses -ltinfo -o $@
 
 %.o:%.c
-	gcc -ggdb -c $< -Wall -Wextra -Werror -fsanitize=address
+	${QUIET_CC}
+	${Q} gcc -ggdb -c $< -Wall -Wextra -Werror -fsanitize=address
 
 .PHONY: clean
 clean:
-	rm -f gui.o main.o simdata.o  assembly.o
+	${QUIET_CLEAN}
+	${Q} rm -f ${OBJECT_FILES} first