text: /* Distributed under the OSI-approved BSD 3-Clause License.  See accompanying
     file Copyright.txt or https://cmake.org/licensing for details.  */
  #ifndef cmFilePathChecksum_h
  #define cmFilePathChecksum_h
  
  #include "cmConfigure.h" // IWYU pragma: keep
  
  #include <array>
  #include <cstddef>
  #include <string>
  #include <utility>
  
  class cmMakefile;
  
  /** \class cmFilePathChecksum
   * @brief Generates a checksum for the parent directory of a file
   *
   * The checksum is calculated from the relative file path to the
   * closest known project directory. This guarantees reproducibility
   * when source and build directory differ e.g. for different project
   * build directories.
   */
  class cmFilePathChecksum
  {
  public:
    /// Maximum number of characters to use from the path checksum
    static const size_t partLengthDefault = 10;
  
    /// @brief Parent directories are empty
    cmFilePathChecksum();
  
    /// @brief Initializes the parent directories manually
    cmFilePathChecksum(std::string const& currentSrcDir,
                       std::string const& currentBinDir,
                       std::string const& projectSrcDir,
                       std::string const& projectBinDir);
  
    /// @brief Initializes the parent directories from a makefile
    cmFilePathChecksum(cmMakefile* makefile);
  
    /// @brief Allows parent directories setup after construction
    ///
    void setupParentDirs(std::string const& currentSrcDir,
                         std::string const& currentBinDir,
                         std::string const& projectSrcDir,
                         std::string const& projectBinDir);
  
    /* @brief Calculates the path checksum for the parent directory of a file
     *
     */
    std::string get(std::string const& filePath) const;
  
    /* @brief Same as get() but returns only the first length characters
     *
     */
    std::string getPart(std::string const& filePath,
                        size_t length = partLengthDefault) const;
  
  private:
    /// List of (directory name, seed name) pairs
    std::array<std::pair<std::string, std::string>, 4> parentDirs;
  };
  
  #endif
  