在make命令行中构建多个目标 [英] build multiple targets in make command line

问题描述

假设我有一个生成文件，并且我有许多目标 MyTarget1，MyTarget2，MyTarget3，...，MyTarget100 .

Suppose I have a make file, and I have many target MyTarget1,MyTarget2,MyTarget3,...,MyTarget100.

如果我想使用12个线程编译所有目标，则可以简单地使用 make -j12 all .

If I want compile all targets using 12 thread, I can simply using make -j12 all.

现在，我想编译所有目标的子集，假设 MyTarget1，MyTarget2，MyTarget3，MyTarget4 .

Now I want compile a subset of all target, suppose MyTarget1, MyTarget2, MyTarget3, MyTarget4.

我知道必须逐个编译每个目标.这样，在 MyTarget1 上有12个线程工作，等待，在 MyTarget2 上工作，等等，...如果 MyTarget 的并行度不高，比如像helloworld这样的小目标，浪费了一些线程的时间.我不喜欢它的低平行度.

I know that compile each target one by one must work. In this way, 12 thread work on MyTarget1, wait, work on MyTarget2, wait, ... If MyTarget do not have a high parallism, for example it is a small target like helloworld, some thread's time is wasted. I do not like it for its low parallism.

我想要一个高度并行的解决方案，例如 make -j12 all ，这12个线程可以在某个时刻在不同的目标上工作.

I want a high parallism solution, like make -j12 all, which 12 thread can work on different target at a certain moment.

我该如何实现?

我想要类似的东西

make -j12 MyTarget1,MyTarget2,MyTarget3,MyTarget4

参考

跟随链接已经给出了 CMake 的解决方案，现在我想知道是否可以使用 make 直接实现.

Reference

follow link already given the CMake's solution, now I am wondering can it be implement directly using make.

• 如何使用cmake --build构建多个目标

感谢您的时间.

推荐答案

这是 CMake 的限制.明确列出了生成的 Makefile ，使其不能并行运行.例如:

This is a limitation of CMake. Generated Makefile is explicitly listed to not run in parallel. For example:

$ cat CMakeLists.txt
project(foo C)

add_custom_target(target1 ALL
  COMMAND python3 -c "import time; time.sleep(5)"
  VERBATIM
  )

add_custom_target(target2 ALL
  COMMAND python3 -c "import time; time.sleep(5)"
  VERBATIM
  )

生成的 Makefile 的相关部分是:

$ cat Makefile
...
# Allow only one "make -f Makefile2" at a time, but pass parallelism.
.NOTPARALLEL:
...
# The main all target
all: cmake_check_build_system
        $(CMAKE_COMMAND) -E cmake_progress_start /home/raspy/so-62013595/CMakeFiles /home/raspy/so-62013595/CMakeFiles/progress.marks
        $(MAKE) -f CMakeFiles/Makefile2 all
        $(CMAKE_COMMAND) -E cmake_progress_start /home/raspy/so-62013595/CMakeFiles 0
.PHONY : all
...
# Build rule for target.
target2: cmake_check_build_system
        $(MAKE) -f CMakeFiles/Makefile2 target2
.PHONY : target2
...
# Build rule for target.
target1: cmake_check_build_system
        $(MAKE) -f CMakeFiles/Makefile2 target1
.PHONY : target1

因此，您可以看到每个目标都传播到一个子makefile，但是由于列出的顶部 Makefile 不是并行的，因此不允许同时构建多个目标./p>

So as you can see every target is propagated to a sub-makefile, but since this top Makefile is listed as not parallel, it will not allow to build multiple targets at the same time.

$ make -j8 target1 target2 | ts
May 26 15:45:06 Built target target1
May 26 15:45:13 Built target target2    # <--- Built after target1 completed

对于任意目标，直接调用sub-makefile可能会成功:

For arbitrary targets, you might be successful with calling sub-makefile directly:

$ make -j8 -f CMakeFiles/Makefile2 target1 target2 | ts
May 26 15:45:42 Built target target2
May 26 15:45:42 Built target target1    # <--- Built simultaneously with target2

YMMV.

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