1_cc-option-supported = $(if $(shell $(CC$(sm)) $(1) -c -x c /dev/null -o /dev/null 2>/dev/null >/dev/null || echo "Not supported"),,1) 2_cc-opt-cached-var-name = $(subst =,~,$(strip cached-cc-option-$(1)-$(subst $(empty) $(empty),,$(CC$(sm))))) 3define _cc-option 4$(eval _var_name := $(call _cc-opt-cached-var-name,$(1))) 5$(eval $(_var_name) := $(if $(filter $(origin $(_var_name)),undefined),$(call _cc-option-supported,$(1)),$($(_var_name)))) 6$(if $($(_var_name)),$(1),$(2)) 7endef 8cc-option = $(strip $(call _cc-option,$(1),$(2))) 9 10