linux - makefile define 问题

bars="chinna"
ifndef twolines
else
        @echo $(bars)
endif
all:
        $(call twolines,$(bars))
.PHONY:clean
clean:
        rm $(bars)

我个人写了个这样的makefile，命令行是tab缩进的，想测试下行不行，make之后出现语法错误：

maketest/mmmm>make
"makefile", line 2: make: 1254-055 Dependency line needs colon or double colon operator.
"makefile", line 3: make: 1254-055 Dependency line needs colon or double colon operator.
"makefile", line 5: make: 1254-055 Dependency line needs colon or double colon operator.
make: 1254-058 Fatal errors encountered -- cannot continue.
我通过谷歌搜索解决问题很久，依然没有。求教～