Improve Makefile.

Makefile

@@ -1,29 +1,39 @@
 SRC_DIR := src/
-ALL_FOLDERS := $(shell find $(SRC_DIR) -mindepth 1 -maxdepth 1 -type d -print0 | xargs -0)
+ALL_FOLDERS := $(sort $(shell find $(SRC_DIR) -mindepth 1 -maxdepth 1 -type d -print0 | xargs -0))
 ALL_MODULES := $(sort $(subst $(SRC_DIR),,$(ALL_FOLDERS)))
-ALL_TARGETS := ${shell bin/findtargets.py build/ $(ALL_FOLDERS)}
+ALL_TARGETS := $(shell bin/findtargets.py build/ $(ALL_FOLDERS))
 
 all: $(ALL_TARGETS)
 
 # cleanup
 
-.PHONY: clean show_targets
+.PHONY: clean
 clean:
 	-rm ./build/*.mkp
 
 # debug
 
+.PHONY: show_targets
 show_targets:
 	@echo $(ALL_FOLDERS)
 	@echo $(ALL_TARGETS)
 	@echo $(ALL_MODULES)
 
+# https://stackoverflow.com/questions/4219255/how-do-you-get-the-list-of-targets-in-a-makefile
+.PHONY: list
+list:
+	@$(MAKE) -pRrq -f $(lastword $(MAKEFILE_LIST)) : 2>/dev/null | awk -v RS= -F: '/^# File/,/^# Finished Make data base/ {if ($$1 !~ "^[#.]") {print $$1}}' | sort | egrep -v -e '^[^[:alnum:]]' -e '^$@$$' | xargs
+
 # setup
 
-define make-goal
-${shell bin/findtargets.py build/ $(SRC_DIR)$1}: $(SRC_DIR)$1
+define make-targets
+$(eval OUTPUT_FILE := $(shell bin/findtargets.py build/ $(SRC_DIR)$(1)))
+
+$(OUTPUT_FILE): $(SRC_DIR)$(1)
 	@echo "Building $$@"
-	bin/makemkp.py $$< ./build/
+	@bin/makemkp.py $$< ./build/
+
+$(1): $(OUTPUT_FILE)
 endef
 
-$(foreach mod,$(ALL_MODULES),$(eval $(call make-goal,$(mod))))
+$(foreach mod,$(ALL_MODULES),$(eval $(call make-targets,$(mod))))