Integrating ROOT into CMake projects

You can integrate ROOT into a CMake based project.
The main interface is the CMake command find_package(…).

Calling find_package(ROOT) makes the following variables available:

Variable Type Description
ROOT_INCLUDE_DIRS PATH Include directories for the ROOT installation.
ROOT_LIBRARIES LIST Libraries to link against. The actual list of libraries is composed using the COMPONENTS listed in the find_package(…) command.
ROOT_DEFINITIONS STRING Compile definitions needed to use ROOT.
ROOT_CXX_FLAGS STRING C++ compiler flags used to build ROOT.
ROOT_CC_FLAGS STRING C compiler flags used to build ROOT.
ROOT_<library>_LIBRARY PATH Full path for each of the ROOT libraries listed in COMPONENTS.
ROOT_<command>_CMD PATH Full path for each ROOT executable (rootcling, root, hadd, etc.).
ROOT_<option>_FOUND BOOL TRUE for each enabled build option (e.g. cocoa, python, xrootd, etc.).
ROOT_FOUND BOOL TRUE if the ROOT package has been found.
ROOT_USE_FILE PATH Path to a CMake module, which makes use of the previous variables and loads modules with useful macros or functions such as ROOT_GENERATE_DICTIONARY.

One CMake target per ROOT library is also available, e.g. ROOT::Core or ROOT::Tree.

Note

To ensure compatibility between ROOT’s C++ interpreter, Cling, and compiled code, your application must be compiled with the same C++ standard with which ROOT was compiled.
The C++ standard used for ROOT appears for example among the flags listed by root-config --cflags.

Adding additional libraries to ROOT_LIBRARIES

You can force additional ROOT libraries in the ROOT_LIBRARIES variable using the COMPONENTS option in the find_package(…) command. For example, to add the RooStats library, you can specify it as an extra component (the name of the component is the name of the library without any library prefix or suffix).

However, prefer passing libraries as CMake targets whenever possible (see the full example below).

Full example (event project)

The following is an example of a project that creates a library and an executable file.