每次我添加新的源子文件夹时，Cmake重新编译所有内容 [英] Cmake recompiles everything each time I add a new source subfolder

问题描述

我有一个项目树组织如下：

  MyProjects /  -  build  -  project1  -  CMakeLists.txt 
 | | project2  -  CMakeLists.txt 
 | 
 | src  -  project1  -  Project1Class1.h 
 | Project1Class1.cpp 
 | Project1Class2.h 
 | Project1Class2.cpp 
 |更多子目录... 
 project2  -  Project2Class1.h 
 | Project2Class1.cpp 
 |更多子目录... 
  

想象project2依赖project1。然后project2直接使用project1文件，不使用静态或动态project1库。
然后，project2 / CMakeLists.txt找到project1和project2源文件，并通过GLOB_RECURSE：

 文件（
 GLOB_RECURSE 
 source_files 
 ../../project1/ 
 ../../project2/ 
）
  
 
 
 
这是在正确构建我的项目的意义上工作。
 
 
 
在新文件夹中添加新的源文件，例如在src / project2 /中输入文件MyNewFolder / myTest.cpp，然后输入
 〜/ MyProjects / build / project2 / $ cmake。 
〜/ MyProjects / build / project2 / $ make 
  
帐户由cmake。 
 
 
 
同样的事情，当我更改一个源文件在project1并尝试编译project2。
 
 
 
请注意，我大大简化了我的CMakeLists.txt的真正的。所以我的问题是：根据我解释，这是CMake期望做什么行为？如果是的，它的背后的理由是什么和我应该做什么 make 只编译新文件？我无法在互联网上找到任何有关它的文档。
 
 
 
注意：随意讨论整个源代码构建文件组织。注意，我想保持我的构建配置与src /文件夹分离。
 
 
 
编辑：我发现这解释了为什么GLOB和GLOB_RECURSE阻止它工作。
 
 
 
编辑2：即使没有GLOB，编译也是从其他情况开始的（参见此问题）
解决方案
 文件（GLOB_RECURSE ...）的效果。我不知道为什么这正是发生，但为了避免这一点，大多数基于CMake的项目明确列出他们的来源：
  set （source_files 
 ../../project1/Project1Class1.cpp 
 ../../project1/Project1Class2.cpp 
 ... 
 ../../project2 /Project2Class1.cpp 
 ../../project2/Project2Class1.cpp 
 ... 
）
  
 
I have a project tree organized as the following:
MyProjects/ - build - project1 - CMakeLists.txt
            |       | project2 - CMakeLists.txt
            |
            | src - project1 - Project1Class1.h
                             | Project1Class1.cpp
                             | Project1Class2.h
                             | Project1Class2.cpp
                             | more subdirectories ...
                    project2 - Project2Class1.h
                             | Project2Class1.cpp
                             | more subdirectories ...
Imagine that project2 depends on project1. Then project2 uses directly project1 files and does not use a static or dynamic project1 library. 
Then project2/CMakeLists.txt finds out the project1 and project2 source files and includes them through a GLOB_RECURSE :
file(
    GLOB_RECURSE
    source_files
    ../../project1/
    ../../project2/
)
This is working in the sense that it correctly builds my projects.

Each time I add a new source file in a new folder, in e.g. file MyNewFolder/myTest.cpp in  src/project2/, and type
~/MyProjects/build/project2/$  cmake .
~/MyProjects/build/project2/$  make
Then the file is correctly taken into account by cmake. However, my problem is that every file is recompiled again.

Same thing when I change a source file in project1 and try to compile project2.

Note that I considerably simplified what really is in my CMakeLists.txt. So my question is: based on what I explained about it, is this behavior what CMake is expected to do? And if yes what is the rationale behind it and what should I do for make to only compile the new file? I was not able to find any documentation about it on the internet.

Note: Feel free to discuss the overall source build files organization. Notice that I wanted to keep my build configuration separated from the src/ folder.

Edit: I found this which explains why GLOB and GLOB_RECURSE prevent it to work.

Edit 2: Even with no GLOB, the compilation is done from the begining is other cases (see this question)
解决方案
You are observing known side effect of file(GLOB_RECURSE ...). I'm not sure why exactly this is happening, but to avoid this most CMake-based projects lists their sources explicitly:
set(source_files
  ../../project1/Project1Class1.cpp
  ../../project1/Project1Class2.cpp
  ...
  ../../project2/Project2Class1.cpp
  ../../project2/Project2Class1.cpp
  ...
)


                        
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