CMake is a powerful tool used for automating the build process of software projects. It provides a way to define and manage the build configuration for various platforms and build systems. By using CMake, developers can write platform-independent build scripts or recipes, which are then translated into specific build instructions for the native build systems on different platforms.
The main goal of CMake is to simplify the build process for software projects that need to be compiled and linked on multiple platforms, such as Windows, macOS, Linux, and others. It abstracts the differences between these platforms and provides a unified interface for configuring and generating the build files.
CMake uses a scripting language that allows developers to define the project structure, dependencies, compiler options, and other build-related settings in a platform-agnostic way. These scripts, called CMakeLists.txt files, are written using CMake’s domain-specific language (DSL).
When CMake is invoked with the appropriate CMakeLists.txt file, it generates the build files or “recipes” for the native build system of the target platform. These build files can be Makefiles, Visual Studio solutions, Xcode projects, or other native build system files, depending on the platform and the configuration specified in the CMakeLists.txt file.
By generating platform-specific build files, CMake enables developers to build their projects using familiar build tools and workflows on each platform, while maintaining a single set of configuration files. This significantly simplifies the process of building and maintaining cross-platform software projects, as developers do not have to manually write and maintain separate build configurations for each platform.
cmake Command Examples
1. Generate a build recipe in the current directory with CMakeLists.txt from a project directory:
# cmake /path/to/project_directory
2. Generate a build recipe, with build type set to Release with CMake variable:
# cmake /path/to/project_directory -D CMAKE_BUILD_TYPE=Release
3. Use a generated recipe in a given directory to build artifacts:
# cmake --build /path/to/build_directory
4. Install the build artifacts into /usr/local/ and strip debugging symbols:
# cmake --install /path/to/build_directory --strip
5. Install the build artifacts using the custom prefix for paths:
# cmake --install /path/to/build_directory --strip --prefix /path/to/directory
6. Run a custom build target:
# cmake --build /path/to/build_directory --target target_name
In summary, CMake is a versatile build automation system that provides a higher-level abstraction for configuring and generating build files across multiple platforms. It helps streamline the build process for software projects, making it easier to maintain and distribute cross-platform applications.