code: def read_known(infile, extracolumns=None, relroot=fsutil.USE_CWD):
      extracolumns = EXTRA_COLUMNS + (
          list(extracolumns) if extracolumns else []
      )
      known = {}
      for decl, extra in _parser.iter_decls_tsv(
          infile, extracolumns, relroot
      ):
          known[decl] = extra
      return known
  
file_path: cpython/Tools/c-analyzer/c_analyzer/datafiles.py
imports: import os.path
  from c_common import fsutil
  import c_common.tables
  import c_parser.info
  import c_parser.match
  import c_parser.datafiles
  from .None import analyze
label_desc: Use image node_id 2 for calling a global function with example usage: read_known(infile, extracolumns, relroot) and returns: known