SHELL    := $(shell if [ -x "$${BASH}" ]; then echo $${BASH}; \
	else if [ -x /bin/bash ]; then echo /bin/bash; \
	else echo sh; fi; \
	fi)

#  $(call show_cmd,cmd,file)
define show_cmd
  @(CMD="  "$1"        "; echo "$${CMD:0:10}$2";)
endef

# $(call checkdir,dir)
define checkdir
  @(test -d $1 || mkdir -p $1)
endef

# $(call upper,val)
define upper
  $(strip $(shell echo $1 | tr a-z A-Z))
endef

# $(call is_enable,val,true-case,false-case)
define is_enabled
  $(if $(filter y,$($(strip $(1)))),$(2),$(3))
endef