Welcome	Tutorial	How-to guides	Principles	Reference

Building JANA

First, set your $JANA_HOME environment variable. This is where the executables, libraries, headers, and plugins get installed. (It is also where we will clone the source). CMake will install to $JANA_HOME if it is set (it will install to ${CMAKE_BINARY_DIR}/install if not). Be aware that although CMake usually defaults CMAKE_INSTALL_PREFIX to /usr/local, we have disabled this because we rarely want this in practice, and we don’t want the build system picking up outdated headers and libraries we installed to /usr/local by accident. If you want to set JANA_HOME=/usr/local, you are free to do so, but you must do so deliberately.

Next, set your build directory. This is where CMake’s caches, logs, intermediate build artifacts, etc go. The convention is to name it build and put it in the project’s root directory. If you are using CLion, it will automatically create a cmake-build-debug directory which works just fine.

Finally, you can cd into your build directory and build and install everything the usual CMake way.

export JANA_VERSION=v2.0.5                    # Convenient to set this once for specific release
export JANA_HOME=${PWD}/JANA${JANA_VERSION}   # Set full path to install dir

git clone https://github.com/JeffersonLab/JANA2 --branch ${JANA_VERSION} ${JANA_HOME}  # Get JANA2

mkdir build                                   # Set build dir
cd build
cmake3 ${JANA_HOME}  # Generate makefiles     # Generate makefiles
make -j8 install                              # Build (using 8 threads) and install

source ${JANA_HOME}/bin/jana-this.sh          # Set PATH (and other envars)
jana -Pplugins=JTest                          # Run JTest plugin to verify successful install

Note: If you want to use a compiler other than the default one on your system, it is not enough to modify your $PATH, as CMake ignores this by design. You either need to set the CXX environment variable or the CMAKE_CXX_COMPILER CMake variable.

By default, JANA will look for plugins under $JANA_HOME/plugins. For your plugins to propagate here, you have to install them. If you don’t want to do that, you can also set the environment variable $JANA_PLUGIN_PATH to point to the build directory of your project. JANA will report where exactly it went looking for your plugins and what happened when it tried to load them if you set the JANA config jana:debug_plugin_loading=1.

jana -Pplugins=JTest -Pjana:debug_plugin_loading=1

Using JANA in a CMake project

To use JANA in a CMake project, simply add $JANA_HOME/lib/cmake/JANA to your CMAKE_PREFIX_PATH, or alternatively, set the CMake variable JANA_DIR=$JANA_HOME/lib/cmake/JANA.

Using JANA in a non-CMake project

To use JANA in a non-CMake project:

1. Source $JANA_HOME/bin/jana-this.sh to set the environment variables needed for JANA’s dependencies
2. Use $JANA_HOME/bin/jana-config --cflags to obtain JANA’s compiler flags
3. Use $JANA_HOME/bin/jana_config --libs to obtain JANA’s linker flags