在递归制作中，防止-j级联 [英] In recursive make, prevent -j from cascading down
问题描述
我有一个顶级makefile，它为并行构建指定了-jn.这个顶层的makefile调用许多不同的组件makefile.不同的组件来自不同的存储库，其中一些支持并行构建，而另一些则不支持.我可以在顶层指定-j1以使所有组件正常工作.但是，有没有一种方法可以在顶层指定-jn，让该标志级联到某些组件，而对其他组件强制使用-j1呢?如果我在选定的较低级别的生成文件中使用NOTPARALLEL phony目标，那么该命令仅对那些组件强制使用-j1吗?
I have a top-level makefile which specifies -jn for parallel build. This top level makefile calls many different component makefiles. Different components come from different repositories, and some of them support parallel build, while others do not. I could specify -j1 at the top level to make all components to work. But is there a way to specify -jn at the top level, let the flag cascade down to some components, but enforce -j1 for other components? If I use NOTPARALLEL phony target in selected lower-level makefiles, will that enforce -j1 only for those components?
推荐答案
如果我在选定的较低级生成文件中使用NOTPARALLEL伪目标，则仅对那些组件强制执行-j1吗?
If I use NOTPARALLEL phony target in selected lower-level makefiles, will that enforce -j1 only for those components?
是的.从GNU制定特殊目标页面:
Yes. From GNU Make Special Targets page:
.NOTPARALLEL
如果提及.NOTPARALLEL作为目标，那么即使给出'-j'选项，make的调用也将连续运行.任何递归调用的make命令仍将并行运行配方(除非其makefile也包含此目标)
If .NOTPARALLEL is mentioned as a target, then this invocation of make will be run serially, even if the ‘-j’ option is given. Any recursively invoked make command will still run recipes in parallel (unless its makefile also contains this target)
值得一提的是，对于那些没有设置.NOTPARALLEL的讨厌的第三方库，有一种方法可以通过递归make命令传递多个文件来实现:
It's worth mentioning that for those pesky 3rd-party libraries that don't set .NOTPARALLEL themselves properly there is a way to do it by passing multiple files the the recursive make command:
- 创建内容为".NOTPARALLEL"的文件，例如notparallel.mk
- 在制作库的食谱中，执行
$(MAKE)-f lib.mk -f notparallel.mk
这将确保在不修改该库本身的情况下，将.NOTPARALLEL称为该make调用的目标.
That'll ensure .NOTPARALLEL is mentioned as a target for that make invocation, without you modifying that library per se.
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