modern-cmake/specifics/ROOT.md

ROOT

ROOT is a C++ Toolkit for High Energy Physics. It is huge. There are really a lot of ways to use it in CMake, though many/most of the examples you'll find are probably wrong. Here's my recommendation.

Finding ROOT

ROOT supports config file discovery, so you can just do:

find_package(ROOT CONFIG)

to attempt to find ROOT. If you don't have your paths set up, you can pass -DROOT_DIR=$ROOTSYS/cmake to find ROOT. (But, really, you should source thisroot.sh)

The wrong way

ROOT provides a utility to set up a ROOT project, which you can activate using include(${ROOT_USE_FILE}). This will automatically make ugly global variables for you. Don't use it.

The right way (Targets)

ROOT does not correctly set up it's imported targets. To fix this error, you'll need something like:

In CMake 3.11, you can just do: