configure

#!/bin/sh
CC=`${R_HOME}/bin/R CMD config CC`
CFLAGS=`${R_HOME}/bin/R CMD config CFLAGS`

printf "#include <omp.h>\nint main () { return omp_get_num_threads(); }" | ${CC} ${CFLAGS} -fopenmp -xc ->/dev/null 2>&1 || R_NO_OPENMP=1;
rm a.out >/dev/null 2>&1

if [ "$R_NO_OPENMP" = "1" ]; then
  printf "#include <omp.h>\nint main () { return omp_get_num_threads(); }" | ${CC} ${CFLAGS} -Xpreprocessor -fopenmp -lomp -xc ->/dev/null 2>&1 || R_NO_OPENMP=2;
  rm a.out >/dev/null 2>&1
  if [ "$R_NO_OPENMP" = "2" ]; then
    if [ "`uname`" = "Linux" ] ;then
      echo "*** On Linux and OpenMP not supported!"
      sed -e "s|@openmp_cflags@||g; s|@openmp_libslags@||g; s|@realtime_libslags@|-lrt|g;" src/Makevars.in > src/Makevars
    else
      echo "*** Not on Linux and OpenMP not supported!"
      sed -e "s|@openmp_cflags@||g; s|@openmp_libslags@||g; s|@realtime_libslags@||g;" src/Makevars.in > src/Makevars
    fi
  else
    echo "*** OpenMP supported (-Xpreprocessor)!"
    sed -e "s|@openmp_cflags@|-Xpreprocessor -fopenmp|g; s|@openmp_libslags@|-lomp|g; s|@realtime_libslags@||g;" src/Makevars.in > src/Makevars
  fi
else
  if [ "`uname`" = "Darwin" ] ;then
      if gcc --version | grep -i "gcc" > /dev/null; then
        echo "*** On Darwin and GCC OpenMP supported!"
        sed -e "s|@openmp_cflags@|-Xpreprocessor -fopenmp|g; s|@openmp_libslags@|-lgomp|g; s|@realtime_libslags@||g;" src/Makevars.in > src/Makevars
      elif clang --version | grep -i "clang" > /dev/null; then
        echo "*** On Darwin and CLANG OpenMP supported!"
        sed -e "s|@openmp_cflags@|-Xpreprocessor -fopenmp|g; s|@openmp_libslags@|-lomp|g; s|@realtime_libslags@||g;" src/Makevars.in > src/Makevars
      fi
  else
    echo "*** On Linux and OpenMP supported!"
    sed -e "s|@openmp_cflags@|\$(SHLIB_OPENMP_CFLAGS)|g; s|@openmp_libslags@|\$(SHLIB_OPENMP_CFLAGS)|g; s|@realtime_libslags@|-lrt|g;" src/Makevars.in > src/Makevars
  fi
fi

exit 0