Method Evaluate

Source/cmGeneratorExpressionNode.cxx:3375–3450

  int NumExpectedParameters() const override { return OneOrMoreParameters; }

  std::string Evaluate(
    std::vector<std::string> const& parameters, cm::GenEx::Evaluation* eval,
    GeneratorExpressionContent const* content,
    cmGeneratorExpressionDAGChecker* dagChecker) const override
  {
    using ForGenex = cmGeneratorExpressionDAGChecker::ForGenex;

    if (!eval->HeadTarget || !dagChecker ||
        !dagChecker->EvaluatingLinkLibraries(nullptr,
                                             ForGenex::LINK_LIBRARY)) {
      reportError(eval, content->GetOriginalExpression(),
                  "$<LINK_LIBRARY:...> may only be used with binary targets "
                  "to specify link libraries through 'LINK_LIBRARIES', "
                  "'INTERFACE_LINK_LIBRARIES', and "
                  "'INTERFACE_LINK_LIBRARIES_DIRECT' properties.");
      return std::string();
    }

    cmList list{ parameters.begin(), parameters.end() };
    if (list.empty()) {
      reportError(
        eval, content->GetOriginalExpression(),
        "$<LINK_LIBRARY:...> expects a feature name as first argument.");
      return std::string();
    }
    if (list.size() == 1) {
      // no libraries specified, ignore this genex
      return std::string();
    }

    static cmsys::RegularExpression featureNameValidator("^[A-Za-z0-9_]+$");
    auto const& feature = list.front();
    if (!featureNameValidator.find(feature)) {
      reportError(eval, content->GetOriginalExpression(),
                  cmStrCat("The feature name '", feature,
                           "' contains invalid characters."));
      return std::string();
    }

    auto const LL_BEGIN = cmStrCat("<LINK_LIBRARY:", feature, '>');
    auto const LL_END = cmStrCat("</LINK_LIBRARY:", feature, '>');

    // filter out $<LINK_LIBRARY:..> tags with same feature
    // and raise an error for any different feature
    cm::erase_if(list, [&](std::string const& item) -> bool {
      return item == LL_BEGIN || item == LL_END;
    });
    auto it =
      std::find_if(list.cbegin() + 1, list.cend(),
                   [&feature](std::string const& item) -> bool {
                     return cmHasPrefix(item, "<LINK_LIBRARY:"_s) &&
                       item.substr(14, item.find('>', 14) - 14) != feature;
                   });
    if (it != list.cend()) {
      reportError(
        eval, content->GetOriginalExpression(),
        "$<LINK_LIBRARY:...> with different features cannot be nested.");
      return std::string();