Question

There is some CMake magic I don’t understand. How should a CMakeLists.txt file look like for a small C++ project with directories like this:

.
├── bin
└── src
    ├── src
    └── test

bin      — directory for built program
src/src  — directory for source
src/test — directory for tests

The tests will need to include files from src/src.
I’d like to manage all the operations from cmake, however at this moment I even can’t cause cmake to compile file in src/c.cpp.

Any help, links are welcome.

Answer 1

Your CMake files should reside in the main source directory and its sub-directories. The easiest approach is to have one CMakeLists.txt in the src directory, which includes all files from src/src and src/test. A very minimalistic example could look like the following:

# CMakeLists.txt in src
project(myExample)
set(myExample_SOURCES
        src/file1.cpp
        src/main.cpp)
add_executable(myExecutable ${myExample_SOURCES})

set(myExample_test_SOURCES
        src/file1.cpp
        test/test_file2.cpp
        test/test_main.cpp)
add_executable(myTestSuite ${myExample_test_SOURCES})

The output directory is normally not specified, because you can have different active
builds in parallel with
different options, e.g. you can have one build in debug mode -O0 -g, another one in release mode with -O2 -g flags and a third one in release mode with heavy optimization flags -O3. Every build resides in its own directory (e.g. build-debug, build-rel,
build-opt).

You should create the output directory (bin in your case) manually and call the cmake command inside this directory. As an argument you have to supply the path to the main CMakeLists.txt. In other words, just execute

cmake ../src

when you are inside bin. This will take all files from the src directory and put the output to the bin directory.
You can easily create a second output directory, say bin2, where you specify different build flags. The ccmake provides a very minimalistic GUI for that.