1 files changed, 64 insertions, 0 deletions
diff --git a/Source/cmFilePathChecksum.h b/Source/cmFilePathChecksum.h
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+++ b/Source/cmFilePathChecksum.h
@@ -0,0 +1,64 @@
+/* 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 <stddef.h>
+#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