[英]makefile library dependencies - resolve circular dependency
我正在尝试在我的 makefile 中构建一个功能,它允许我指定特定库所依赖的库列表
如果库的依赖项被重建,这将允许库的依赖项自动重建,并且还将依赖项添加到链接行。
我在这里问了一个关于 SO 的相关问题,并通过了一个给定的答案,我想出了以下测试
uniq = $(if $1,$(firstword $1) $(call uniq,$(filter-out $(firstword $1),$1)))
expand-deps = $1 $(foreach _,$1, $(call expand-deps,$($__deps)))
make-dep-list = $(call uniq,$(call expand-deps,$1))
define make-lib
$(warning $1_deps: $2)
# capture the list of libraries this library depends on
$1_deps = $2
endef
define make-bin
# show the fully expanded list of libraries this binary depends on
$(warning $1 dep-list: [$(call make-dep-list,$2)])
endef
#$(eval $(call make-lib, thread, log utils)) circular-dependency log->thread; thread->log
$(eval $(call make-lib, thread, utils))
$(eval $(call make-lib, log, thread))
$(eval $(call make-lib, order, log))
$(eval $(call make-lib, price, log))
$(eval $(call make-bin, test, order price))
运行上面的 makefile 会产生以下结果:
$ make
makefile:15: thread_deps: utils
makefile:16: log_deps: thread
makefile:17: order_deps: log
makefile:18: price_deps: log
makefile:19: test dep-list: [order price log thread utils ]
make: *** No targets. Stop.
库可能具有循环依赖关系。
例如:日志库是多线程的,因此需要线程库。 线程库可以发出日志语句,所以需要日志库。
如果我取消注释掉循环依赖的行
$(eval $(call make-lib, thread, log utils))
$(eval $(call make-lib, log, thread))
makefile 将陷入无限循环。
如何让用户指定循环依赖,跳出无限循环?
所以,你的问题是你递归地扩展lib_deps
(比如说)。 在这样做的同时,您再次开始扩展lib_deps
。 无限循环(呃,堆栈崩溃)。 为了阻止自己,你需要保留一份你已经扩展过的东西的清单。 脱离函数式风格并在全球expansion
保留答案(呃!),例如:
expand-deps = \
$(foreach _,$1, \
$(if $(filter $_,${expansion}),, \
$(eval expansion += $_)$(call expand-deps,${$__deps})))
make-dep-list = $(eval expansion :=)$(call expand-deps,$1)${expansion}
define make-lib
$(warning $1_deps: $2)
# capture the list of libraries this library depends on
$1_deps := $2
endef
define make-bin
# show the fully expanded list of libraries this binary depends on
$(warning $1 dep-list: [$(call make-dep-list,$2)])
endef
$(eval $(call make-lib,thread,log utils))#circular-dependency log->thread; thread->log
#$(eval $(call make-lib,thread,utils))
$(eval $(call make-lib,log,thread))
$(eval $(call make-lib,order,log))
$(eval $(call make-lib,price,log))
$(eval $(call make-bin,test,order price))
(作为练习,您可能想以函数式风格重写它,即,摆脱全局$expansion
将其替换为传递的参数。)
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.