Method ExpandExpression

Source/cmWindowsRegistry.cxx:721–769

}

cm::optional<std::vector<std::string>> cmWindowsRegistry::ExpandExpression(
  cm::string_view expression, View view, cm::string_view separator)
{
#if defined(_WIN32) && !defined(__CYGWIN__)
  static std::string NOTFOUND{ "/REGISTRY-NOTFOUND" };

  this->LastError.clear();

  // compute list of registry views
  auto views = this->ComputeViews(view);
  std::vector<std::string> result;

  for (auto v : views) {
    ExpressionParser parser(expression);

    while (parser.Find()) {
      try {
        auto handler =
          KeyHandler::OpenKey(parser.GetRootKey(), parser.GetSubKey(), v);
        auto data = handler.ReadValue(parser.GetValueName(),
                                      this->SupportedTypes, separator);
        parser.Replace(data);
      } catch (registry_error const& e) {
        this->LastError = e.what();
        parser.Replace(NOTFOUND);
        continue;
      }
    }
    result.emplace_back(parser.GetExpression());
    if (expression == parser.GetExpression()) {
      // there no substitutions, so can ignore other views
      break;
    }
  }

  return result;
#else
  (void)view;
  (void)separator;

  ExpressionParser parser(expression);
  if (parser.Find()) {
    // expression holds unsupported registry access
    // so the expression cannot be used on this platform
    return cm::nullopt;
  }
  return std::vector<std::string>{ std::string{ expression } };
#endif
}