code: def define_extensions(use_openmp):
      compile_args = []
      if not os.environ.get("LIGHTFM_NO_CFLAGS"):
          compile_args += ["-ffast-math"]
  
          if sys.platform.startswith("darwin"):
              compile_args += []
          else:
              compile_args += ["-march=native"]
  
      if not use_openmp:
          print("Compiling without OpenMP support.")
          return [
              Extension(
                  "lightfm._lightfm_fast_no_openmp",
                  ["lightfm/_lightfm_fast_no_openmp.c"],
                  extra_compile_args=compile_args,
              )
          ]
      else:
          return [
              Extension(
                  "lightfm._lightfm_fast_openmp",
                  ["lightfm/_lightfm_fast_openmp.c"],
                  extra_link_args=["-fopenmp"],
                  extra_compile_args=compile_args + ["-fopenmp"],
              )
          ]
  
file_path: lightfm/setup.py
imports: import os
  import pathlib
  import subprocess
  import sys
  import textwrap
  from setuptools import Command, Extension, setup
label_desc: Use image node_id 1 for calling a global function with example usage: define_extensions(use_openmp) and returns: list, list