executable_example

executable example

This cmake example demonstrates how to create an executable target "helloworld".

The cpp code(helloworld.cpp) and CMake scripts(CMakeLists.txt) is already prepared. What you need is calling cmake, for the configure and build steps.

1. Preparation

Intall CMake, >= 3.20 recommended. Install a C/C++ compiler.

2. Linux / MacOSX

cd cmake_examples/01_helloworld
cmake -S . -B build
cmake --build build
./build/helloworld

Among which:

• -S . specifies the "source directory", which means the directory that contains CMakeLists.txt file.
• -B build means we specify the configuring and building output files in build directory(if it does not exist, will be created automatically).
• cmake --build build means we choose the build directory's configured result for building.

The cmake -S . -B build is the configure step. It actually won't compile our helloworld.cpp. The cmake --build build is the building step. It compiles (and also links to C++ runtime) our helloworld.cpp.

3. Visual Studio

We use Visual Studio 2022 as the IDE, the we have to specify generator for cmake, thus it use VS2022 instead of other compilers:

cd cmake_examples/01_helloworld
cmake -S . -B build -G "Visual Studio 17 2022" -A x64
cmake --build build

The open build/helloworld.sln with Visual Studio 2022, specify helloworld project as start item, and press Ctrl+F5 keys to run.

4. Other platform/architecture cross-compilation

For example, Android armv8-a for mobile phone, QNX / TDA4 for ADAS. Just pick proper xxx-toolchain.cmake file, and pass it to cmake executable:

cmake -S . -B build -DCMAKE_TOOLCHAIN_FILE="/path/to/xxx-toolchain.cmake"

Different platform/architecture may have different xxx-toolchain.cmake file. You may also just ignore this file, and setting CXX environment variable to your cross-compiler's full path.

Concrete cross-platform cmake usages will be illustreated in further examples.

5. CMake-GUI

Many people choose cmake-gui.exe (on Windows) or ccmake (on Linux / MacOSX) as cmake GUI, to invoking cmake configuration and building.

I prefer command-line style cmake usage, since it can be scripted, especially in CI/CD, and locally you do same operations as CI/CD does. So, just forget cmake-gui.exe and ccmake.