code: def preprocess(
      self,
      source,
      output_file=None,
      macros=None,
      include_dirs=None,
      extra_preargs=None,
      extra_postargs=None,
  ):
      fixed_args = self._fix_compile_args(None, macros, include_dirs)
      ignore, macros, include_dirs = fixed_args
      pp_opts = gen_preprocess_options(macros, include_dirs)
      pp_args = self.preprocessor + pp_opts
      if output_file:
          pp_args.extend(["-o", output_file])
      if extra_preargs:
          pp_args[:0] = extra_preargs
      if extra_postargs:
          pp_args.extend(extra_postargs)
      pp_args.append(source)
  
      # reasons to preprocess:
      # - force is indicated
      # - output is directed to stdout
      # - source file is newer than the target
      preprocess = (
          self.force
          or output_file is None
          or newer(source, output_file)
      )
      if not preprocess:
          return
  
      if output_file:
          self.mkpath(os.path.dirname(output_file))
  
      try:
          self.spawn(pp_args)
      except DistutilsExecError as msg:
          raise CompileError(msg)
  
imports: import os
  import sys
  import re
  import shlex
  import itertools
  from .None import sysconfig
  from ._modified import newer
  from .ccompiler import CCompiler, gen_preprocess_options, gen_lib_options
  from .errors import DistutilsExecError, CompileError, LibError, LinkError
  from ._log import log
  from ._macos_compat import compiler_fixup
label_desc: Use image node_id 1 for calling the UnixCCompiler obj's underlying member method code with example usage: obj.preprocess(source, output_file, macros, include_dirs, extra_preargs, extra_postargs) without return types