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diff --git a/Source/cmLinkItemGraphVisitor.h b/Source/cmLinkItemGraphVisitor.h
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+++ b/Source/cmLinkItemGraphVisitor.h
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+/* Distributed under the OSI-approved BSD 3-Clause License.  See accompanying
+   file Copyright.txt or https://cmake.org/licensing for details.  */
+#ifndef cmLinkItemGraphVisitor_h
+#define cmLinkItemGraphVisitor_h
+
+#include <map>
+#include <set>
+#include <string>
+#include <utility>
+
+#include "cmLinkItem.h"
+
+class cmGeneratorTarget;
+
+/** \class cmLinkItemGraphVisitor
+ * \brief Visits a graph of linked items.
+ *
+ * Allows to visit items and dependency links (direct and indirect) between
+ * those items.
+ * This abstract class takes care of the graph traversal, making sure that:
+ *   - it terminates even in the presence of cycles;
+ *   - it visits every object once (and only once);
+ *   - it visits the objects in the same order every time.
+ *
+ * Children classes only have to implement OnItem() etc. to handle whatever
+ * logic they care about.
+ */
+class cmLinkItemGraphVisitor
+{
+public:
+  virtual ~cmLinkItemGraphVisitor() = default;
+
+  virtual void VisitGraph(std::string const& name) = 0;
+
+  void VisitItem(cmLinkItem const& item);
+
+protected:
+  enum class DependencyType
+  {
+    LinkInterface,
+    LinkPublic,
+    LinkPrivate,
+    Object,
+    Utility
+  };
+
+  virtual void OnItem(cmLinkItem const& item) = 0;
+
+  virtual void OnDirectLink(cmLinkItem const& depender,
+                            cmLinkItem const& dependee, DependencyType dt) = 0;
+
+  virtual void OnIndirectLink(cmLinkItem const& depender,
+                              cmLinkItem const& dependee) = 0;
+
+private:
+  std::set<std::string> VisitedItems;
+
+  std::set<std::pair<std::string, std::string>> VisitedLinks;
+
+  void VisitLinks(cmLinkItem const& item, cmLinkItem const& rootItem);
+  void VisitLinks(cmLinkItem const& item, cmLinkItem const& rootItem,
+                  std::string const& config);
+
+  using Dependency = std::pair<DependencyType, cmLinkItem>;
+  using DependencyMap = std::map<std::string, Dependency>;
+
+  bool ItemVisited(cmLinkItem const& item);
+  bool LinkVisited(cmLinkItem const& depender, cmLinkItem const& dependee);
+
+  static void GetDependencies(cmGeneratorTarget const& target,
+                              std::string const& config,
+                              DependencyMap& dependencies);
+};
+
+#endif