CMake Best Practices for Modern C++ Projects

CMake has evolved significantly, but many projects still use patterns from the CMake 2.x era. After modernizing build systems for multiple large C++ projects at NVIDIA, here's a comprehensive guide to modern CMake that scales.

Modern CMake Principles

• Target-based approach: Everything revolves around targets, not variables
• Usage requirements: Targets know how to use themselves
• No global state: Avoid CMAKE_CXX_FLAGS and similar globals
• Export/Install properly: Make your library consumable

Project Structure

A scalable structure that works for both small and large projects:

• cmake/ - CMake modules and find scripts
• src/ - Implementation files
• include/project/ - Public headers
• tests/ - Test files
• examples/ - Example applications
• third_party/ - Vendored dependencies

Dependency Management

Modern CMake offers several approaches:

• FetchContent: Download at configure time
• CPM.cmake: Enhanced FetchContent with caching
• Conan/vcpkg: External package managers
• find_package: System-installed libraries

CUDA Integration

Special considerations for CUDA projects:

• Use CMAKE_CUDA_ARCHITECTURES for GPU targets
• Separate device and host code properly
• Handle CUDA toolkit versioning
• Link CUDA libraries as IMPORTED targets

Performance Tips

• Use Ninja generator for faster builds
• Enable ccache or sccache
• Precompiled headers for large projects
• Unity builds for template-heavy code

Complete guide with CMakeLists.txt templates coming soon...