Mac M4 EXP install script

mac-build.sh

# -----------------------------------------------------------------------------
# Run a full compile of exp on a Mac with Apple Silicon (M1, M2, etc.)
# by APW, based on a script by Mike P
# -----------------------------------------------------------------------------

# NOTES:
# - APW used `uv` for Python, but this should also work with Python + virtualenv. This
#   is not tested with `conda` but it might work? I set up and activated my Python
#   environment in the EXPDIR (i.e. the cloned exp repository path) using:
#
#       uv venv --python 3.12
#       source .venv/bin/activate
#
# - You probably need to edit these files to avoid a "-fopenmp -Xclang" error:
#
#       expui/CMakeLists.txt
#       pyEXP/CMakeLists.txt
#
#   to comment out the line (one per file) that looks like:
#
#       target_compile_options(pyEXP PUBLIC ${OpenMP_CXX_FLAGS})
#
# - APW installed all dependencies using Homebrew:
#
#       brew install fftw gsl open-mpi hdf5 libomp libpng eigen cmake ninja
#
# - This installs the exp libaries into `install/lib` (relative to the EXPDIR)

# -----------------------------------------------------------------------------
# Edit this path to point to your local clone of the exp repository:
export EXPDIR=/Users/aprice-whelan/projects/exp

# If your homebrew is installed in a non-standard location, you need to edit this:
export HOMEBREW_PATH=/opt/homebrew
# -----------------------------------------------------------------------------

# Get the path to the python executable that works even within a virtual environment:
export PYTHON_TRUE_BASE=$(python -c "import sys; print(sys.base_prefix)")
export PYTHON_VENV_BASE=$(python -c "import sys; print(sys.prefix)")

# Get Python version info dynamically
export PYTHON_VERSION=$(python -c "import sys; print(f'{sys.version_info.major}.{sys.version_info.minor}')")
export PYTHON_EXEC=$(python -c "import sys, os; print(os.path.realpath(sys.executable))")
export PYTHON_LIBRARY_PATH=$(python -c "import sysconfig; print(sysconfig.get_config_var('LIBDIR'))")
export PYTHON_LIBRARY=${PYTHON_LIBRARY_PATH}/libpython${PYTHON_VERSION}.dylib

echo "Using Python at: ${PYTHON_TRUE_BASE}"

export PATH=${HOMEBREW_PATH}/bin:$PATH
export LD_LIBRARY_PATH=${HOMEBREW_PATH}/lib:$LD_LIBRARY_PATH
export INCLUDE=${HOMEBREW_PATH}/include:$INCLUDE

export OMP_HOME=${HOMEBREW_PATH}/opt/libomp/
export LDFLAGS="-L${OMP_HOME}/lib"
export CPPFLAGS="-I${OMP_HOME}/include"

export CC=mpicc
export CXX=mpicxx

cmake \
    -G Ninja \
    -B build \
    --install-prefix $PWD/install \
    -DCMAKE_INSTALL_PREFIX=$PWD/install \
    -DCMAKE_INSTALL_RPATH=$PWD/install/lib \
    -DENABLE_NBODY=on \
    -DENABLE_USER=on \
    -DENABLE_PYEXP=on \
    -DDISABLE_OPENMP_COMPILE_FLAGS=on \
    -DPYTHON_EXECUTABLE=${PYTHON_EXEC} \
    -DPYTHON_LIBRARY=${PYTHON_LIBRARY} \
    -DOpenMP_CXX_INCLUDE_DIR=${OMP_HOME}/include \
    -DOpenMP_C_INCLUDE_DIR=${OMP_HOME}/include

cmake --build build
cmake --install build

# Add the pyEXP dir as a pyEXP.pth file in Python site-packages:
SITE_PACKAGES=$(python -c "import site; print(site.getsitepackages()[0])")
echo "$PWD/install/lib/python${PYTHON_VERSION}/site-packages" > "${SITE_PACKAGES}/pyEXP.pth"