RAPIDS-CMake Basics

Installation

The rapids-cmake module is designed to be acquired via CMake’s Fetch Content into your project.

cmake_minimum_required(...)

file(DOWNLOAD https://raw.githubusercontent.com/rapidsai/rapids-cmake/branch-22.02/RAPIDS.cmake
  ${CMAKE_BINARY_DIR}/RAPIDS.cmake)
include(${CMAKE_BINARY_DIR}/RAPIDS.cmake)
include(rapids-cmake)
include(rapids-cpm)
include(rapids-cuda)
include(rapids-export)
include(rapids-find)

project(...)

Usage

rapids-cmake is designed for projects to use only the subset of features that they need. To enable this rapids-cmake comprises the following primary components:

There are two ways projects can use rapids-cmake functions.

  1. Call include(rapids-<component>), which imports commonly used functions for the component.

  2. Load each function independently via include(${rapids-cmake-dir}/<component>/<function_name>.cmake).

Overriding RAPIDS.cmake

At times projects or developers will need to verify rapids-cmake branches. To do this you need to override the default git repositry and branch that RAPIDS.cmake downloads, which should be done like this:

include(FetchContent)
FetchContent_Declare(
  rapids-cmake
  GIT_REPOSITORY https://github.com/<my_fork>/rapids-cmake.git
  GIT_TAG        <my_feature_branch>
)
file(DOWNLOAD https://raw.githubusercontent.com/rapidsai/rapids-cmake/branch-21.12/RAPIDS.cmake
    ${CMAKE_BINARY_DIR}/RAPIDS.cmake)
include(${CMAKE_BINARY_DIR}/RAPIDS.cmake)

This tells FetchContent to ignore the explicit url and branch in RAPIDS.cmake and use the ones provided.

An incorrect approach that people try is to modify the file(DOWNLOAD) line to point to the custom rapids-cmake branch. That doesn’t work as the downloaded RAPIDS.cmake contains which version of the rapids-cmake repository to clone.