code: def generate(env):
      
      fscan = FortranScan("FORTRANPATH")
      SCons.Tool.SourceFileScanner.add_scanner('.i', fscan)
      SCons.Tool.SourceFileScanner.add_scanner('.i90', fscan)
  
      if 'FORTRANFILESUFFIXES' not in env:
          env['FORTRANFILESUFFIXES'] = ['.i']
      else:
          env['FORTRANFILESUFFIXES'].append('.i')
  
      if 'F90FILESUFFIXES' not in env:
          env['F90FILESUFFIXES'] = ['.i90']
      else:
          env['F90FILESUFFIXES'].append('.i90')
  
      add_all_to_env(env)
  
      env['FORTRAN']        = 'ifl'
      env['SHFORTRAN']      = '$FORTRAN'
      env['FORTRANCOM']     = '$FORTRAN $FORTRANFLAGS $_FORTRANINCFLAGS /c $SOURCES /Fo$TARGET'
      env['FORTRANPPCOM']   = '$FORTRAN $FORTRANFLAGS $CPPFLAGS $_CPPDEFFLAGS $_FORTRANINCFLAGS /c $SOURCES /Fo$TARGET'
      env['SHFORTRANCOM']   = '$SHFORTRAN $SHFORTRANFLAGS $_FORTRANINCFLAGS /c $SOURCES /Fo$TARGET'
      env['SHFORTRANPPCOM'] = '$SHFORTRAN $SHFORTRANFLAGS $CPPFLAGS $_CPPDEFFLAGS $_FORTRANINCFLAGS /c $SOURCES /Fo$TARGET'
docs: Add Builders and construction variables for ifl to an Environment.