# cmake/ProcessOptions.cmake
#
# This file is part of NEST.
#
# Copyright (C) 2004 The NEST Initiative
#
# NEST is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 2 of the License, or
# (at your option) any later version.
#
# NEST is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with NEST.  If not, see <http://www.gnu.org/licenses/>.

# Here all user defined options will be processed.

# add custom warnings and optimizations
function( NEST_PROCESS_WITH_OPTIMIZE )
  if ( with-optimize )
  string(TOUPPER "${with-optimize}" WITHOPTIMIZE)
    if ( WITHOPTIMIZE STREQUAL "ON" )
      set( with-optimize "-O2" )
    endif ()
    set(OPTIMIZATION_FLAGS "")
    string(JOIN " " OPTIMIZATION_FLAGS  ${with-optimize} )
    set( CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${OPTIMIZATION_FLAGS}" PARENT_SCOPE )
    set( CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${OPTIMIZATION_FLAGS}" PARENT_SCOPE )
  endif ()
endfunction()

function( NEST_PROCESS_WITH_DEBUG )
  if ( with-debug )
    if ( with-debug STREQUAL "ON" )
      set( with-debug "-g" )
    endif ()
    foreach ( flag ${with-debug} )
      set( CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${flag}" PARENT_SCOPE )
      set( CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${flag}" PARENT_SCOPE )
    endforeach ()
  endif ()
endfunction()

function( NEST_PROCESS_WITH_STD )
  set( CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=${with-cpp-std}" PARENT_SCOPE )
endfunction()

function( NEST_PROCESS_WITH_INTEL_COMPILER_FLAGS )
  if ( NOT with-intel-compiler-flags )
    set( with-intel-compiler-flags "-fp-model strict" )
  endif ()
  if ("${CMAKE_C_COMPILER_ID}" STREQUAL "Intel")
  foreach ( flag ${with-intel-compiler-flags} )
    set( CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${flag}" PARENT_SCOPE )
  endforeach ()
  endif ()
  if ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "Intel")
    foreach ( flag ${with-intel-compiler-flags} )
      set( CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${flag}" PARENT_SCOPE )
    endforeach ()
  endif ()
endfunction()

function( NEST_PROCESS_WITH_WARNING )
  if ( with-warning )
    if ( with-warning STREQUAL "ON" )
      set( with-warning "-Wall" )
    endif ()
    foreach ( flag ${with-warning} )
      set( CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${flag}" PARENT_SCOPE )
      set( CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${flag}" PARENT_SCOPE )
    endforeach ()
  endif ()
endfunction()

function( NEST_PROCESS_WITH_LIBRARIES )
  if ( with-libraries )
    if ( with-libraries STREQUAL "ON" )
      printError( "-Dwith-libraries requires full library paths." )
    endif ()
    foreach ( lib ${with-libraries} )
      if ( EXISTS "${lib}" )
        link_libraries( "${lib}" )
      else ()
        printError( "Library '${lib}' does not exist!" )
      endif ()
    endforeach ()
  endif ()
endfunction()

function( NEST_PROCESS_WITH_INCLUDES )
  if ( with-includes )
    if ( with-includes STREQUAL "ON" )
      printError( "-Dwith-includes requires full paths." )
    endif ()
    foreach ( inc ${with-includes} )
      if ( IS_DIRECTORY "${inc}" )
        include_directories( "${inc}" )
      else ()
        printError( "Include path '${inc}' does not exist!" )
      endif ()
    endforeach ()
  endif ()
endfunction()

function( NEST_PROCESS_WITH_DEFINES )
  if ( with-defines )
    if ( with-defines STREQUAL "ON" )
      printError( "-Dwith-defines requires compiler defines -DXYZ=... ." )
    endif ()
    foreach ( def ${with-defines} )
      if ( "${def}" MATCHES "^-D.*" )
        add_definitions( "${def}" )
      else ()
        printError( "Define '${def}' does not match '-D.*' !" )
      endif ()
    endforeach ()
  endif ()
endfunction()

function( NEST_GET_COLOR_FLAGS )
    set( NEST_C_COLOR_FLAGS "" PARENT_SCOPE )
    set( NEST_CXX_COLOR_FLAGS "" PARENT_SCOPE )

    # add colored output from gcc
    if ( CMAKE_C_COMPILER_ID STREQUAL "GNU" )
      if ( NOT CMAKE_C_COMPILER_VERSION VERSION_LESS "4.9" )
        set( NEST_C_COLOR_FLAGS "-fdiagnostics-color=auto" PARENT_SCOPE )
      endif ()
    endif ()
    if ( CMAKE_CXX_COMPILER_ID STREQUAL "GNU" )
      if ( NOT CMAKE_CXX_COMPILER_VERSION VERSION_LESS "4.9" )
        set( NEST_CXX_COLOR_FLAGS "-fdiagnostics-color=auto" PARENT_SCOPE )
      endif ()
    endif ()
endfunction()

function( NEST_PROCESS_STATIC_LIBRARIES )
  # build static or shared libraries
  if ( static-libraries )

    if ( with-readline )
      printError( "-Dstatic-libraries=ON requires -Dwith-readline=OFF" )
    endif ()

    set( BUILD_SHARED_LIBS OFF PARENT_SCOPE )
    # set RPATH stuff
    set( CMAKE_SKIP_RPATH TRUE PARENT_SCOPE )

    if ( UNIX OR APPLE )
      # On Linux .a is the static library suffix, on Mac OS X .lib can also
      # be used, so we'll add both to the preference list.
      set( CMAKE_FIND_LIBRARY_SUFFIXES ".a;.lib;.dylib;.so" PARENT_SCOPE )
    endif ()

    if ( Fugaku )
    set( CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Bstatic" PARENT_SCOPE )
    else()
    set( CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -static" PARENT_SCOPE )
    endif()

  else ()
    set( BUILD_SHARED_LIBS ON PARENT_SCOPE )

    # set RPATH stuff
    set( CMAKE_SKIP_RPATH FALSE PARENT_SCOPE )
    # use, i.e. don't skip the full RPATH for the build tree
    set( CMAKE_SKIP_BUILD_RPATH FALSE PARENT_SCOPE )
    # on OS X
    set( CMAKE_MACOSX_RPATH ON PARENT_SCOPE )

    # when building, don't use the install RPATH already
    # (but later on when installing)
    set( CMAKE_BUILD_WITH_INSTALL_RPATH FALSE PARENT_SCOPE )

    # set run-time search path (RPATH) so that dynamic libraries in ``lib/nest`` can be located

    # Note: "$ORIGIN" (on Linux) and "@loader_path" (on MacOS) are not CMake variables, but special keywords for the
    # Linux resp. the macOS dynamic loader. They refer to the path in which the object is located, e.g.
    # ``${CMAKE_INSTALL_PREFIX}/bin`` for the nest and sli executables, ``${CMAKE_INSTALL_PREFIX}/lib/nest`` for all
    # dynamic libraries except PyNEST (libnestkernel.so, etc.), and  something like
    # ``${CMAKE_INSTALL_PREFIX}/lib/python3.x/site-packages/nest`` for ``pynestkernel.so``. The RPATH is relative to
    # this origin, so the binary ``bin/nest`` can find the files in the relative location ``../lib/nest``, and
    # similarly for PyNEST and the other libraries. For simplicity, we set all the possibilities on all generated
    # objects.

    # PyNEST can only act as an entry point; it does not need to be included in the other objects' RPATH itself.

    if ( APPLE )
      set( CMAKE_INSTALL_RPATH
          # for binaries
          "@loader_path/../${CMAKE_INSTALL_LIBDIR}/nest"
          # for libraries (except pynestkernel)
          "@loader_path/../../${CMAKE_INSTALL_LIBDIR}/nest"
          # for pynestkernel: origin at <prefix>/lib/python3.x/site-packages/nest
          "@loader_path/../../../nest"
          PARENT_SCOPE )
    else ()
      set( CMAKE_INSTALL_RPATH
          # for binaries
          "\$ORIGIN/../${CMAKE_INSTALL_LIBDIR}/nest"
          # for libraries (except pynestkernel)
          "\$ORIGIN/../../${CMAKE_INSTALL_LIBDIR}/nest"
          # for pynestkernel: origin at <prefix>/lib(64)/python3.x/site-packages/nest
          # while libs are at the root of that at <prefix>/lib(64)/nest
          "\$ORIGIN/../../../nest"
          PARENT_SCOPE )
    endif ()

    # add the automatically determined parts of the RPATH
    # which point to directories outside the build tree to the install RPATH
    set( CMAKE_INSTALL_RPATH_USE_LINK_PATH TRUE PARENT_SCOPE )

    if ( UNIX OR APPLE )
      # reverse the search order for lib extensions
      set( CMAKE_FIND_LIBRARY_SUFFIXES ".so;.dylib;.a;.lib" PARENT_SCOPE )
    endif ()
  endif ()
endfunction()

function( NEST_PROCESS_TICS_PER_MS )
  # Set tics per ms / step
  if ( tics_per_ms )
    set( HAVE_TICS_PER_MS ON PARENT_SCOPE )
  endif ()
endfunction()

function( NEST_PROCESS_TICS_PER_STEP )
  if ( tics_per_step )
    set( HAVE_TICS_PER_STEP ON PARENT_SCOPE )
  endif ()
endfunction()

# Depending on the user options, we search for required libraries and include dirs.

function( NEST_PROCESS_WITH_LIBLTDL )
  # Only find libLTDL if we link dynamically
  set( HAVE_LIBLTDL OFF PARENT_SCOPE )
  if ( with-ltdl AND NOT static-libraries )
    if ( NOT ${with-ltdl} STREQUAL "ON" )
      # a path is set
      set( LTDL_ROOT "${with-ltdl}" )
    endif ()

    find_package( LTDL )
    if ( LTDL_FOUND )
      set( HAVE_LIBLTDL ON PARENT_SCOPE )
      # export found variables to parent scope
      set( LTDL_FOUND ON PARENT_SCOPE )
      set( LTDL_LIBRARIES "${LTDL_LIBRARIES}" PARENT_SCOPE )
      set( LTDL_INCLUDE_DIRS "${LTDL_INCLUDE_DIRS}" PARENT_SCOPE )
      set( LTDL_VERSION "${LTDL_VERSION}" PARENT_SCOPE )

      include_directories( ${LTDL_INCLUDE_DIRS} )
      # is linked in nestkernel/CMakeLists.txt
    endif ()
  endif ()
endfunction()

function( NEST_PROCESS_WITH_READLINE )
  # Find readline
  set( HAVE_READLINE OFF PARENT_SCOPE )
  if ( with-readline )
    if ( NOT ${with-readline} STREQUAL "ON" )
      # a path is set
      set( Readline_ROOT "${with-readline}" )
    endif ()

    find_package( Readline )
    if ( READLINE_FOUND )
      set( HAVE_READLINE ON PARENT_SCOPE )
      # export found variables to parent scope
      set( READLINE_FOUND "${READLINE_FOUND}" PARENT_SCOPE )
      set( READLINE_LIBRARIES "${READLINE_LIBRARIES}" PARENT_SCOPE )
      set( READLINE_INCLUDE_DIRS "${READLINE_INCLUDE_DIRS}" PARENT_SCOPE )
      set( READLINE_VERSION "${READLINE_VERSION}" PARENT_SCOPE )

      include_directories( ${READLINE_INCLUDE_DIRS} )
      # is linked in sli/CMakeLists.txt
    endif ()
  endif ()
endfunction()

function( NEST_PROCESS_WITH_GSL )
  # Find GSL
  set( HAVE_GSL OFF PARENT_SCOPE )
  if ( with-gsl )
    if ( NOT ${with-gsl} STREQUAL "ON" )
      # if set, use this prefix
      set( GSL_ROOT "${with-gsl}" )
    endif ()

    find_package( GSL 1.11 )

    if ( GSL_FOUND )
      set( HAVE_GSL ON PARENT_SCOPE )

      # export found variables to parent scope
      set( GSL_VERSION "${GSL_VERSION}" PARENT_SCOPE )
      set( GSL_LIBRARIES "${GSL_LIBRARIES}" PARENT_SCOPE )
      set( GSL_INCLUDE_DIRS "${GSL_INCLUDE_DIRS}" PARENT_SCOPE )

      include_directories( ${GSL_INCLUDE_DIRS} )
      # is linked in libnestutil/CMakeLists.txt
    endif ()
  endif ()
endfunction()

function( NEST_PROCESS_WITH_PYTHON )
  # Find Python
  set( HAVE_PYTHON OFF PARENT_SCOPE )

  if ( ${with-python} STREQUAL "ON" )

    # Localize the Python interpreter and ABI
    find_package( Python 3.8 QUIET COMPONENTS Interpreter Development.Module )
    if ( NOT Python_FOUND )
      find_package( Python 3.8 REQUIRED Interpreter Development )
      string( CONCAT PYABI_WARN "Could not locate Python ABI"
        ", using shared libraries and header file instead."
        " Please clear your CMake cache and build folder and verify that CMake"
        " is up-to-date (3.18+)."
      )
      printWarning("${PYABI_WARN}")
    else()
      find_package( Python 3.8 REQUIRED Interpreter Development.Module )
    endif()

    if ( Python_FOUND )
      if ( CMAKE_INSTALL_PREFIX_INITIALIZED_TO_DEFAULT )
        execute_process( COMMAND "${Python_EXECUTABLE}" "-c"
          "import sys, os; print(int(bool(os.environ.get('CONDA_DEFAULT_ENV', False)) or (sys.prefix != sys.base_prefix)))"
          OUTPUT_VARIABLE Python_InVirtualEnv OUTPUT_STRIP_TRAILING_WHITESPACE )

        if ( NOT Python_InVirtualEnv AND CMAKE_INSTALL_PREFIX_INITIALIZED_TO_DEFAULT )
          printError( "No virtual Python environment found and no installation prefix specified. "
            "Please either build and install NEST in a virtual Python environment or specify CMake option -DCMAKE_INSTALL_PREFIX=<nest_install_dir>.")
        endif()

        # Setting CMAKE_INSTALL_PREFIX effects the inclusion of GNUInstallDirs defining CMAKE_INSTALL_<dir> and CMAKE_INSTALL_FULL_<dir>
        get_filename_component( Python_EnvRoot "${Python_SITELIB}/../../.." ABSOLUTE)
        set ( CMAKE_INSTALL_PREFIX "${Python_EnvRoot}" CACHE PATH "Default install prefix for the active Python interpreter" FORCE )
      endif ( CMAKE_INSTALL_PREFIX_INITIALIZED_TO_DEFAULT )

      # export found variables to parent scope
      set( HAVE_PYTHON ON PARENT_SCOPE )
      set( Python_FOUND "${Python_FOUND}" PARENT_SCOPE )
      set( Python_EXECUTABLE ${Python_EXECUTABLE} PARENT_SCOPE )
      set( PYTHON ${Python_EXECUTABLE} PARENT_SCOPE )
      set( Python_VERSION ${Python_VERSION} PARENT_SCOPE )
      set( Python_VERSION_MAJOR ${Python_VERSION_MAJOR} PARENT_SCOPE )
      set( Python_VERSION_MINOR ${Python_VERSION_MINOR} PARENT_SCOPE )
      set( Python_INCLUDE_DIRS "${Python_INCLUDE_DIRS}" PARENT_SCOPE )
      set( Python_LIBRARIES "${Python_LIBRARIES}" PARENT_SCOPE )

      if ( cythonize-pynest )
        # Need updated Cython because of a change in the C api in Python 3.7
        find_package( Cython 0.28.3 REQUIRED )
        if ( CYTHON_FOUND )
          # export found variables to parent scope
          set( CYTHON_FOUND "${CYTHON_FOUND}" PARENT_SCOPE )
          set( CYTHON_EXECUTABLE "${CYTHON_EXECUTABLE}" PARENT_SCOPE )
          set( CYTHON_VERSION "${CYTHON_VERSION}" PARENT_SCOPE )
        endif ()
      endif ()
    endif ()
  elseif ( ${with-python} STREQUAL "OFF" )
  else ()
    printError( "Invalid value -Dwith-python=${with-python}, please use 'ON' or 'OFF'" )
  endif ()
endfunction()

function( NEST_POST_PROCESS_WITH_PYTHON )
  if ( Python_FOUND )
    set( PYEXECDIR "${CMAKE_INSTALL_LIBDIR}/python${Python_VERSION_MAJOR}.${Python_VERSION_MINOR}/site-packages" PARENT_SCOPE )
  endif()
endfunction()

function( NEST_PROCESS_WITH_OPENMP )
  # Find OPENMP
  if ( NOT "${with-openmp}" STREQUAL "OFF" )
    if ( NOT "${with-openmp}" STREQUAL "ON" )
      # if set, use this prefix
      set( OpenMP_ROOT "${with-openmp}" )
    endif ()

    find_package( OpenMP REQUIRED )

    if ( OpenMP_FOUND )
      # export found variables to parent scope
      set( OpenMP_FOUND "${OpenMP_FOUND}" PARENT_SCOPE )
      set( OpenMP_C_FLAGS "${OpenMP_C_FLAGS}" PARENT_SCOPE )
      set( OpenMP_CXX_FLAGS "${OpenMP_CXX_FLAGS}" PARENT_SCOPE )
      set( OpenMP_CXX_LIBRARIES "${OpenMP_CXX_LIBRARIES}" PARENT_SCOPE )
      # set flags
      set( CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${OpenMP_C_FLAGS}" PARENT_SCOPE )
      set( CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${OpenMP_CXX_FLAGS}" PARENT_SCOPE )
    else()
      printError( "CMake can not find OpenMP." )
    endif ()
  endif ()  # if NOT OFF

  # Provide a dummy OpenMP::OpenMP_CXX if no OpenMP or if flags explicitly
  # given. Needed to avoid problems where OpenMP::OpenMP_CXX is used.
  if ( NOT TARGET OpenMP::OpenMP_CXX )
    add_library(OpenMP::OpenMP_CXX INTERFACE IMPORTED)
  endif()

endfunction()

function( NEST_PROCESS_WITH_MPI )
  # Find MPI
  set( HAVE_MPI OFF PARENT_SCOPE )
  if ( NOT "${with-mpi}" STREQUAL "OFF" )
    if ( NOT ${with-mpi} STREQUAL "ON" )
      # if set, use this prefix
      set( MPI_ROOT "${with-mpi}" )
    endif ()
    find_package( MPI REQUIRED )
    if ( MPI_CXX_FOUND )
      set( HAVE_MPI ON PARENT_SCOPE )

      set( CMAKE_C_FLAGS "${CMAKE_C_FLAGS}   ${MPI_C_COMPILE_FLAGS}" PARENT_SCOPE )
      set( CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${MPI_CXX_COMPILE_FLAGS}" PARENT_SCOPE )

      set( CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} ${MPI_CXX_LINK_FLAGS}" PARENT_SCOPE )
      include_directories( ${MPI_CXX_INCLUDE_PATH} )
      # is linked in nestkernel/CMakeLists.txt

      # export found variables to parent scope
      set( MPI_C_FOUND "${MPI_C_FOUND}" PARENT_SCOPE )
      set( MPI_C_COMPILER "${MPI_C_COMPILER}" PARENT_SCOPE )
      set( MPI_C_COMPILE_FLAGS "${MPI_C_COMPILE_FLAGS}" PARENT_SCOPE )
      set( MPI_C_INCLUDE_PATH "${MPI_C_INCLUDE_PATH}" PARENT_SCOPE )
      set( MPI_C_LINK_FLAGS "${MPI_C_LINK_FLAGS}" PARENT_SCOPE )
      set( MPI_C_LIBRARIES "${MPI_C_LIBRARIES}" PARENT_SCOPE )
      set( MPI_CXX_FOUND "${MPI_CXX_FOUND}" PARENT_SCOPE )
      set( MPI_CXX_COMPILER "${MPI_CXX_COMPILER}" PARENT_SCOPE )
      set( MPI_CXX_COMPILE_FLAGS "${MPI_CXX_COMPILE_FLAGS}" PARENT_SCOPE )
      set( MPI_CXX_INCLUDE_PATH "${MPI_CXX_INCLUDE_PATH}" PARENT_SCOPE )
      set( MPI_CXX_LINK_FLAGS "${MPI_CXX_LINK_FLAGS}" PARENT_SCOPE )
      set( MPI_CXX_LIBRARIES "${MPI_CXX_LIBRARIES}" PARENT_SCOPE )
      set( MPIEXEC "${MPIEXEC}" PARENT_SCOPE )
      set( MPIEXEC_NUMPROC_FLAG "${MPIEXEC_NUMPROC_FLAG}" PARENT_SCOPE )
      set( MPIEXEC_PREFLAGS "${MPIEXEC_PREFLAGS}" PARENT_SCOPE )
      set( MPIEXEC_POSTFLAGS "${MPIEXEC_POSTFLAGS}" PARENT_SCOPE )
    endif ()
  endif ()
endfunction()

function( NEST_PROCESS_WITH_DETAILED_TIMERS )
  set( TIMER_DETAILED OFF PARENT_SCOPE )
  if ( ${with-detailed-timers} STREQUAL "ON" )
    set( TIMER_DETAILED ON PARENT_SCOPE )
  endif ()
endfunction()

function( NEST_PROCESS_WITH_THREADED_TIMERS )
  set( THREADED_TIMERS OFF PARENT_SCOPE )
  if ( ${with-threaded-timers} STREQUAL "ON" )
    set( THREADED_TIMERS ON PARENT_SCOPE )
  endif ()
endfunction()

function( NEST_PROCESS_WITH_MPI_SYNC_TIMER )
  set( MPI_SYNC_TIMER OFF PARENT_SCOPE )
  if ( ${with-mpi-sync-timer} STREQUAL "ON" )
    set( MPI_SYNC_TIMER ON PARENT_SCOPE )
  endif ()
endfunction()

function( NEST_PROCESS_WITH_LIBNEUROSIM )
  # Find libneurosim
  set( HAVE_LIBNEUROSIM OFF PARENT_SCOPE )
  if ( with-libneurosim )
    if ( NOT ${with-libneurosim} STREQUAL "ON" )
      # a path is set
      set( LibNeurosim_ROOT ${with-libneurosim} )
    endif ()

    find_package( LibNeurosim )
    if ( LIBNEUROSIM_FOUND )
      set( HAVE_LIBNEUROSIM ON PARENT_SCOPE )

      include_directories( ${LIBNEUROSIM_INCLUDE_DIRS} )

      # export found variables to parent scope
      set( LIBNEUROSIM_FOUND "${LIBNEUROSIM_FOUND}" PARENT_SCOPE )
      set( LIBNEUROSIM_LIBRARIES "${LIBNEUROSIM_LIBRARIES}" PARENT_SCOPE )
      set( LIBNEUROSIM_INCLUDE_DIRS "${LIBNEUROSIM_INCLUDE_DIRS}" PARENT_SCOPE )
      set( LIBNEUROSIM_VERSION "${LIBNEUROSIM_VERSION}" PARENT_SCOPE )
    endif ()
  endif ()
endfunction()

function( NEST_PROCESS_WITH_MUSIC )
  # Find music
  set( HAVE_MUSIC OFF PARENT_SCOPE )
  if ( with-music )
    if ( NOT ${with-music} STREQUAL "ON" )
      # a path is set
      set( Music_ROOT "${with-music}" )
    endif ()

    if ( NOT HAVE_MPI )
      printError( "MUSIC requires -Dwith-mpi=ON." )
    endif ()

    find_package( Music )
    include_directories( ${MUSIC_INCLUDE_DIRS} )
    # is linked in nestkernel/CMakeLists.txt
    if ( MUSIC_FOUND )
      # export found variables to parent scope
      set( HAVE_MUSIC ON PARENT_SCOPE )
      set( MUSIC_FOUND "${MUSIC_FOUND}" PARENT_SCOPE )
      set( MUSIC_LIBRARIES "${MUSIC_LIBRARIES}" PARENT_SCOPE )
      set( MUSIC_INCLUDE_DIRS "${MUSIC_INCLUDE_DIRS}" PARENT_SCOPE )
      set( MUSIC_EXECUTABLE "${MUSIC_EXECUTABLE}" PARENT_SCOPE )
      set( MUSIC_VERSION "${MUSIC_VERSION}" PARENT_SCOPE )
    endif ()
  endif ()
endfunction()

function( NEST_PROCESS_WITH_SIONLIB )
  set( HAVE_SIONLIB OFF )
  if ( with-sionlib )
    if ( NOT ${with-sionlib} STREQUAL "ON" )
      set( SIONlib_ROOT "${with-sionlib}" CACHE INTERNAL "sionlib" )
    endif()

    if ( NOT HAVE_MPI )
      printError( "SIONlib requires -Dwith-mpi=ON." )
    endif ()

    find_package( SIONlib )
    include_directories( ${SIONLIB_INCLUDE} )

    # is linked in nestkernel/CMakeLists.txt
    if ( SIONLIB_FOUND )
      set( HAVE_SIONLIB ON CACHE INTERNAL "sionlib" )
    endif ()
  endif ()
endfunction()

function( NEST_PROCESS_WITH_BOOST )
  # Find Boost
  set( HAVE_BOOST OFF PARENT_SCOPE )
  if ( with-boost )
    if ( NOT ${with-boost} STREQUAL "ON" )
      # a path is set
      set( Boost_ROOT "${with-boost}" )
    endif ()

    set(Boost_USE_DEBUG_LIBS OFF)  # ignore debug libs
    set(Boost_USE_RELEASE_LIBS ON) # only find release libs
    # Needs Boost version >=1.62.0 to use Boost sorting, JUNIT logging
    # Require Boost version >=1.69.0 due to change in Boost sort
    # Require Boost version >=1.70.0 due to change in package finding
    find_package( Boost 1.70 CONFIG )
    if ( Boost_FOUND )
      # export found variables to parent scope
      set( HAVE_BOOST ON PARENT_SCOPE )
      # Boost uses lower case in variable names
      set( BOOST_FOUND "${Boost_FOUND}" PARENT_SCOPE )
      set( BOOST_LIBRARIES "${Boost_LIBRARIES}" PARENT_SCOPE )
      set( BOOST_INCLUDE_DIR "${Boost_INCLUDE_DIRS}" PARENT_SCOPE )
      set( BOOST_VERSION "${Boost_MAJOR_VERSION}.${Boost_MINOR_VERSION}.${Boost_SUBMINOR_VERSION}" PARENT_SCOPE )

      include_directories( ${Boost_INCLUDE_DIRS} )
    endif ()
  endif ()
endfunction()

function( NEST_PROCESS_WITH_HDF5 )

  set( HAVE_HDF5 OFF PARENT_SCOPE )
  if ( with-hdf5 )
    if ( NOT ${with-hdf5} STREQUAL "ON" )
      # a path is set
      set( HDF5_ROOT "${with-hdf5}" )
    endif ()

    find_package( HDF5 REQUIRED COMPONENTS C CXX )
    if ( HDF5_FOUND )
      # export found variables to parent scope
      set( HAVE_HDF5 ON PARENT_SCOPE )
      set( HDF5_FOUND "${HDF5_FOUND}" PARENT_SCOPE )
      set( HDF5_LIBRARIES "${HDF5_LIBRARIES}" PARENT_SCOPE )
      set( HDF5_INCLUDE_DIR "${HDF5_INCLUDE_DIRS}" PARENT_SCOPE )
      set( HDF5_VERSION "${HDF5_VERSION}" PARENT_SCOPE )
      set( HDF5_HL_LIBRARIES "${HDF5_HL_LIBRARIES}" PARENT_SCOPE )
      set( HDF5_DEFINITIONS "${HDF5_DEFINITIONS}" PARENT_SCOPE )
      include_directories( ${HDF5_INCLUDE_DIRS} )

    endif ()
  endif ()
endfunction()

function( NEST_PROCESS_TARGET_BITS_SPLIT )
  if ( target-bits-split )
    # set to value according to defines in config.h
    if ( ${target-bits-split} STREQUAL "standard" )
      set( TARGET_BITS_SPLIT 0 PARENT_SCOPE )
    elseif ( ${target-bits-split} STREQUAL "hpc" )
      set( TARGET_BITS_SPLIT 1 PARENT_SCOPE )
    else()
      printError( "Invalid target-bits-split selected." )
    endif()
  endif()
endfunction()

function( NEST_PROCESS_MODELS )
  # check mutual exclusivity of -Dwith-models and -Dwith-modelset
  if ( ( NOT with-modelset STREQUAL "full" ) AND  with-models )
    printError( "Only one of -Dwith-modelset or -Dwith-models can be specified." )
  endif ()

  # get the list of models to be built in either from the commandline
  # argument directly or by reading the provided modelset file
  if ( with-models )
    set( BUILTIN_MODELS ${with-models} )
  else()
    if ( NOT EXISTS "${PROJECT_SOURCE_DIR}/modelsets/${with-modelset}" )
      printError( "Cannot find modelset configuration 'modelsets/${with-modelset}'" )
    endif ()
    file(STRINGS "${PROJECT_SOURCE_DIR}/modelsets/${with-modelset}" BUILTIN_MODELS)
  endif()

  # We use python3 here directly, as some of the CI jobs don't seem to have PYTHON
  # or Python_EXECUTABLE set properly.
  execute_process(
    COMMAND "python3" "${PROJECT_SOURCE_DIR}/build_support/generate_modelsmodule.py"
    "${PROJECT_SOURCE_DIR}" "${PROJECT_BINARY_DIR}" "${BUILTIN_MODELS}"
    WORKING_DIRECTORY "${PROJECT_SOURCE_DIR}"
    OUTPUT_VARIABLE MODELS_SOURCES
    ERROR_VARIABLE MODELS_SOURCES_ERROR
    # Uncomment for debugging: ECHO_OUTPUT_VARIABLE ECHO_ERROR_VARIABLE COMMAND_ECHO STDOUT
    COMMAND_ERROR_IS_FATAL ANY
  )

  if ( MODELS_SOURCES_ERROR )
    printError( ${MODELS_SOURCES_ERROR} )
  endif()

  set( BUILTIN_MODELS ${BUILTIN_MODELS} PARENT_SCOPE )
  set( MODELS_SOURCES_GENERATED ${MODELS_SOURCES} PARENT_SCOPE )
endfunction()

function( NEST_PROCESS_WITH_MPI4PY )
  if ( HAVE_MPI AND HAVE_PYTHON )
    include( FindPythonModule )
    find_python_module(mpi4py)

    if ( HAVE_MPI4PY )
      include_directories( "${PY_MPI4PY}/include" )
    endif ()

  endif ()
endfunction ()

function( NEST_PROCESS_USERDOC )
  if ( ${with-userdoc} STREQUAL "ON")
    message( STATUS "Configuring user documentation" )
    find_package( Sphinx REQUIRED)
    find_package( Pandoc REQUIRED)
    set( BUILD_SLI_DOCS ON PARENT_SCOPE )
    set( BUILD_SPHINX_DOCS ON PARENT_SCOPE )
    set( BUILD_DOCS ON PARENT_SCOPE )
  endif ()
endfunction ()

function( NEST_PROCESS_DEVDOC )
  if ( ${with-devdoc} STREQUAL "ON" )
    message( STATUS "Configuring developer documentation" )
    find_package( Doxygen REQUIRED dot )
    set( BUILD_DOXYGEN_DOCS ON PARENT_SCOPE )
    set( BUILD_DOCS ON PARENT_SCOPE )
  endif ()
endfunction ()

function( NEST_PROCESS_FULL_LOGGING )
  if ( ${with-full-logging} STREQUAL "ON" )
    message( STATUS "Configuring full logging" )
    set( ENABLE_FULL_LOGGING ON PARENT_SCOPE )
  endif ()
endfunction ()