CMakeLists.txt File — CMake Build Configuration

CMake files define cross-platform build configurations for C, C++, and other compiled language projects. CMake is a meta-build system — rather than building code directly, it generates native build files for the target platform (Makefiles for Unix, Visual Studio projects for Windows, Ninja build files, Xcode projects for macOS). CMakeLists.txt files use the CMake scripting language with commands like project(), add_executable(), add_library(), target_link_libraries(), find_package(), and install() to define build targets, dependencies, compiler flags, and installation rules. CMake has become the de facto standard build system for C++ projects, used by major projects including LLVM/Clang, Qt, KDE, OpenCV, TensorFlow, and the Linux kernel (experimentally). CMake supports out-of-source builds, conditional compilation, generator expressions, imported targets, and FetchContent for downloading dependencies. The find_package() system discovers installed libraries through Find modules and package configuration files. Modern CMake (3.0+) emphasizes target-based configuration with properties that propagate through dependency chains, replacing the older directory-based variable approach that was error-prone in complex projects.