new_contents: # .ycm_extra_conf.py for tea source code.
  import os
  import ycm_core
  
  
  def DirectoryOfThisScript():
      return os.path.dirname(os.path.abspath(__file__))
  
  
  def GetDatabase():
      compilation_database_folder = os.path.join(DirectoryOfThisScript(), 'build')
      if os.path.exists(compilation_database_folder):
          return ycm_core.CompilationDatabase(compilation_database_folder)
      return None
  
  
  def IsHeaderFile(filename):
      extension = os.path.splitext(filename)[1]
      return extension == '.h'
  
  
  def GetCompilationInfoForFile(filename):
      database = GetDatabase()
      if not database:
          return None
      if IsHeaderFile(filename):
          basename = os.path.splitext(filename)[0]
          c_file = basename + '.c'
          # for pure headers (no c file), default to tea.c
          if not os.path.exists(c_file):
              c_file = os.path.join(DirectoryOfThisScript(), 'src', 'tea.c')
          if os.path.exists(c_file):
              compilation_info = database.GetCompilationInfoForFile(c_file)
              if compilation_info.compiler_flags_:
                  return compilation_info
          return None
      return database.GetCompilationInfoForFile(filename)
  
  
  def FlagsForFile(filename):
      compilation_info = GetCompilationInfoForFile(filename)
      if not compilation_info:
          return None
      # Add flags not needed for clang-the-binary,
      # but needed for libclang-the-library (YCM uses this last one).
      flags = (list(compilation_info.compiler_flags_)
               if compilation_info.compiler_flags_
               else [])
      extra_flags = ['-Wno-newline-eof']
      final_flags = flags + extra_flags
      return {
          'flags': final_flags,
          'do_cache': True
      }
  
subject: add .ycm_extra_conf.py to let YouCompleteMe work