# Based on "http://iany.me/wiki/Makefile/" by "Ian Yang" licensed under "CC by 3.0"

BUILD_FOLDER := _build

CUSTOM_TARGETS := cmake

# Do not try to use custom target when invoking external makefile
EXTERNAL_TARGETS := $(filter-out $(CUSTOM_TARGETS), $(MAKECMDGOALS))

# Call all targets using `Makefile` in build directory in one `make` command.
$(or $(lastword $(EXTERNAL_TARGETS)),all):
	$(MAKE) -C $(BUILD_FOLDER) $(EXTERNAL_TARGETS)

# If no targets are specified, use the dummy `all` target
.PHONY: $(EXTERNAL_TARGETS) all

# Do nothing for all targets but last. Also quiet the message "Noting to be done on xxx"
$(filter-out $(lastword $(EXTERNAL_TARGETS)), $(EXTERNAL_TARGETS)):
	@cd .

cmake: $(BUILD_FOLDER)
	cd $(BUILD_FOLDER) && cmake ..

$(BUILD_FOLDER):
	mkdir $(BUILD_FOLDER)

.PHONY: cmake