Method GetNextCandidate

Source/cmFindPackageCommand.cxx:229–288

  virtual ~cmDirectoryListGenerator() = default;

  std::string GetNextCandidate(std::string const& parent)
  {
    // Construct a list of matches if not yet
    if (this->Matches.empty()) {
      cmsys::Directory directoryLister;
      // ALERT `Directory::Load()` keeps only names
      // internally and LOST entry type from `dirent`.
      // So, `Directory::FileIsDirectory` gonna use
      // `SystemTools::FileIsDirectory()` and waste a syscall.
      // TODO Need to enhance the `Directory` class.
      directoryLister.Load(parent);

      // ATTENTION Is it guaranteed that first two entries are
      // `.` and `..`?
      // TODO If so, just start with index 2 and drop the
      // `isDirentryToIgnore(i)` condition to check.
      for (auto i = 0ul; i < directoryLister.GetNumberOfFiles(); ++i) {
        char const* const fname = directoryLister.GetFile(i);
        // Skip entries to ignore or that aren't directories.
        if (isDirentryToIgnore(fname)) {
          continue;
        }

        if (!this->Names) {
          if (directoryLister.FileIsDirectory(i)) {
            this->Matches.emplace_back(fname);
          }
        } else {
          for (auto const& n : *this->Names) {
            // NOTE Customization point for
            // `cmMacProjectDirectoryListGenerator`
            auto const name = this->TransformNameBeforeCmp(n);
            // Skip entries that don't match.
            auto const equal =
              ((this->ExactMatch
                  ? cmsysString_strcasecmp(fname, name.c_str())
                  : cmsysString_strncasecmp(fname, name.c_str(),
                                            name.length())) == 0);
            if (equal) {
              if (directoryLister.FileIsDirectory(i)) {
                this->Matches.emplace_back(fname);
              }
              break;
            }
          }
        }
      }
      // NOTE Customization point for `cmProjectDirectoryListGenerator`
      this->OnMatchesLoaded();

      this->Current = this->Matches.cbegin();
    }

    if (this->Current != this->Matches.cend()) {
      auto candidate = cmStrCat(parent, *this->Current++, '/');
      return candidate;
    }