<< Modern CMake >> 2.4 translation project directory structure

<< Modern CMake >> 2.4 translation project directory structure

This section is a bit beside the point. But I think this is a good way. I will tell you how to plan the project directory. This is based on the practice, but it will help you:

• Easy reading other projects in the same mode,
• Lead to conflict avoidance mode,
• Avoid confusion and make the building complicated.

First, if your project is called  project, contains a link library is called  lib, an executable file called  app, then your file directory structure should be similar to the following:

- project
  - .gitignore
  - README.md
  - LICENCE.md
  - CMakeLists.txt
  - cmake
    - FindSomeLib.cmake
  - include
    - project
      - lib.hpp
  - src
    - CMakeLists.txt
    - lib.cpp
  - apps
    - CMakeLists.txt
    - app.cpp
  - tests
    - testlib.cpp
  - docs
    - Doxyfile.in
  - extern
    - googletest
  - scripts
    - helper.py

The name is not absolute; you often see on  test/ vs.  tests/ debate, the Applications folder may be called a different name (for projects only library does not exist). You'll see when there is  python a directory for  python binding, or a folder CMake, assistant to place CMake files, such as  Find<library>.cmake documents. But the main folder above are listed.

Pay attention to some very obvious things;  CMakeLists.txt files are placed in all of the source directory, respectively, but  include the directory does not. This is because you should be able to copy the  include directory to  /usr/include or similar places (except configuration header file, I will describe in another chapter), no additional files or cause any conflict. This is why  include there is a layer of directories  project reasons directory. Use  add_subdirectory to add contains  CMakeLists.txt a subdirectory files.

You often need a  cmake directory to place all constructed assistant module. This is your  Find*.cmake place files in the storage. A common set of helper files can be seen here  github.com/CLIUtils/cmake .

In this way you can add this folder to the CMake path:

set(CMAKE_MODULE_PATH "${PROJECT_SOURCE_DIR}/cmake" ${CMAKE_MODULE_PATH})

Your  extern folder should contain only git submodules. This allows you to explicitly control dependent version of the item, and can be easily upgraded. For an example of adding sub-module, see "Testing" chapter.

In your  .gitignore , you should have something like this  /build*, so that users can create a build directory in the source directory, and build the project in these directories. Some packages prohibited from doing so, but it is likened to a building outside the real source of much better, because then you have to type each build different command-line for the package you build.

If you want to avoid building directly in the source folder, you can add the following lines to your  CMakeLists.txt near the top of the file:

### Require out-of-source builds
file(TO_CMAKE_PATH "${PROJECT_BINARY_DIR}/CMakeLists.txt" LOC_PATH)
if(EXISTS "${LOC_PATH}")
    message(FATAL_ERROR "You cannot build in a source directory (or any directory with a CMakeLists.txt file). Please make a build subdirectory. Feel free to remove CMakeCache.txt and CMakeFiles.") endif()