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c++cmakeclion

Nested CMakeLists.txt files in CLion

Using CLion, I have a project structure that looks like this:

enter image description here

You'll see that in the root there are an include directory, a src directory, a lib directory, a cmake-build-debug directory, a CMakeLists.txt file (see red arrow), and a tests directory. The project builds a shared object into lib using the root-level CMakeLists.txt file and the various source, header, and external files.

I can successfully run the root-level CMakeList.txt file and build the library. So far, so good.

Here is the issue. In addition to the above, I am now interested -- on an informal, exploratory basis -- in testing some of the code in the project. To that end, as an initial example, I have created a test_nnls directory with its own CMakeLists.txt (see yellow arrow) file and a test_nnls.cpp file. The code in test_nnls.cpp creates some dummy data, calls a function in src/nnls.cpp, and prints the results. The build process here just creates an executable that does this. This approach is not meant to be part of any formal test framework and I do not want the test to run as part of the root-level build. This is just me adding a simple test program in the overall project that I would like to compile and run on an independent basis when I feel the need. I plan to possibly implement a formal test framework later, but at present I don't know how to do this and for now just need to print some simple output to see if the chosen code is working correctly.

The problem is that I cannot seem to execute the CMakeLists.txt file (yellow arrow) to build the test. It does not appear to be possible in CLion to set up a build for the test program using cmake. How do I structure all of this to get what I want? Thanks.

Solution

  • You don't execute a CMakeLists.txt. It is read by cmake (the root CMaksLists.txt file), which is called by CLion. However, CLion only passes the root CMaksLists.txt file to cmake. Even if you call cmake yourself you would only pass this root CMaksLists.txt file.

    If you want to define targets (or anything) in other CMaksLists.txt files located in other folders, then you must add add_subdirectory(folder_name_that_contains_another_CMakeLists_file) to your root CMaksLists.txt file. Only then targets in these other CMaksLists.txt files will appear in CLion.

    Note that a few things should appear in the root CMaksLists.txt file, but not in the other ones. Particularly, the two lines below should only be in the root file

    cmake_minimum_required(VERSION 3.14)  # Choose the minimum cmake version
project(name_of_your_project)