GNU make manual 翻译(五十八)
继续翻译
Variable Assignment ------------------- Variable definitions are parsed as follows: IMMEDIATE = DEFERRED IMMEDIATE ?= DEFERRED IMMEDIATE := IMMEDIATE IMMEDIATE += DEFERRED or IMMEDIATE define IMMEDIATE DEFERRED endef define IMMEDIATE = DEFERRED endef define IMMEDIATE ?= DEFERRED endef define IMMEDIATE := IMMEDIATE endef define IMMEDIATE += DEFERRED or IMMEDIATE endef For the append operator, `+=', the right-hand side is considered immediate if the variable was previously set as a simple variable (`:='), and deferred otherwise.
变量定义被如下解析:
IMMEDIATE = DEFERRED
IMMEDIATE ?= DEFERRED
IMMEDIATE := IMMEDIATE
IMMEDIATE += DEFERRED or IMMEDIATE
define IMMEDIATE
DEFERRED
endef
define IMMEDIATE =
DEFERRED
endef
define IMMEDIATE ?=
DEFERRED
endef
define IMMEDIATE :=
IMMEDIATE
endef
define IMMEDIATE +=
DEFERRED or IMMEDIATE
endef
For the append operator, `+=', the right-hand side is considered
immediate if the variable was previously set as a simple variable
(`:='), and deferred otherwise.
对于连接符号 +=, 如果变量已经被定义为一个简单变量(:=),那么右手边就被认为是立即性的,
否则就是推迟性的。
后文待续