code: func (c *Config) ResolvePath(path string) string {
  	if filepath.IsAbs(path) {
  		return path
  	}
  	if c.DataDir == "" {
  		return ""
  	}
  	// Backwards-compatibility: ensure that data directory files created
  	// by geth 1.4 are used if they exist.
  	if warn, isOld := isOldGethResource[path]; isOld {
  		oldpath := ""
  		if c.name() == "geth" {
  			oldpath = filepath.Join(c.DataDir, path)
  		}
  		if oldpath != "" && common.FileExist(oldpath) {
  			if warn {
  				c.warnOnce(&c.oldGethResourceWarning, "Using deprecated resource file %s, please move this file to the 'geth' subdirectory of datadir.", oldpath)
  			}
  			return oldpath
  		}
  	}
  	return filepath.Join(c.instanceDir(), path)
  }
docs: // ResolvePath resolves path in the instance directory.