How can I create multi-level projects and multiple installers in one CMake project?

Question

I have the following project form (in Visual Studio terminology):

• MainProject solution
  • MainProjectA Project
  • MainProjectB Project
• Plugin1 solution
  • Plugin1A Project
  • Plugin1B Project
• Plugin2 solution (and the projects...)

Now, if I try to "convert" this terminology to CMake it would be (I think):

• MainProject project (using "project()")
  • MainProjectA target (set by add_library(), add_executable() or add_custom_target())
  • MainProjectB target
• Plugin1 project
  • Plugin1A target
  • Plugin1B target
• Plugin2 project... (and the targets...)

It is important to point out, each "project/solution" has its own installer (i.e. DEB, MSI, PKG) created by CPack.

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Is it possible to create the above multi-level CMake project (i.e. Having another level "above" "CMake project"/"VS solution")?

If it is possible, what is the correct/standard way to define/structure it? Do notice, each "project/solution" has its own installer (created with CPack).

I prefer this kind of structure as the different projects/solutions share configurations, and I don't want to replicate the configurations across the different projects.

I would prefer to avoid "ExternalProject_Add", but having a multi-level "tree" - if it is possible.

Answer 1

If the problem you're trying to solve is that the two buildsystems tend to share buildsystem configuration variables, you can solve the problem by creating a presets file and sharing it between them. The include field can help with this sharing.

I don't know how this would work with CPack since I've never done this myself, but you can also create a CMakeLists.txt in the common parent directory and in that CMakeLists.txt, declare a project() and add_subdirectory() the two sub-projects.