2 files changed, 16 insertions, 9 deletions
diff --git a/Source/cmState.cxx b/Source/cmState.cxx
index 0e738799db..86d238affd 100644
--- a/Source/cmState.cxx
+++ b/Source/cmState.cxx
@@ -35,7 +35,7 @@ struct cmState::SnapshotDataType
   cmState::SnapshotType SnapshotType;
   bool Keep;
   cmLinkedTree<std::string>::iterator ExecutionListFile;
-  cmLinkedTree<cmState::BuildsystemDirectoryStateType>::iterator
+  cmLinkedTree<cmStateDetail::BuildsystemDirectoryStateType>::iterator
     BuildSystemDirectory;
   cmLinkedTree<cmDefinitions>::iterator Vars;
   cmLinkedTree<cmDefinitions>::iterator Root;
@@ -66,7 +66,7 @@ struct cmState::PolicyStackEntry : public cmPolicies::PolicyMap
   bool Weak;
 };
 
-struct cmState::BuildsystemDirectoryStateType
+struct cmStateDetail::BuildsystemDirectoryStateType
 {
   cmState::PositionType DirectoryEnd;
 
@@ -313,7 +313,7 @@ cmState::Snapshot cmState::Reset()
   this->ExecutionListFiles.Truncate();
 
   {
-    cmLinkedTree<BuildsystemDirectoryStateType>::iterator it =
+    cmLinkedTree<cmStateDetail::BuildsystemDirectoryStateType>::iterator it =
       this->BuildsystemDirectory.Truncate();
     it->IncludeDirectories.clear();
     it->IncludeDirectoryBacktraces.clear();
@@ -1119,7 +1119,7 @@ cmPolicies::PolicyStatus cmState::Snapshot::GetPolicy(
     return status;
   }
 
-  cmLinkedTree<BuildsystemDirectoryStateType>::iterator dir =
+  cmLinkedTree<cmStateDetail::BuildsystemDirectoryStateType>::iterator dir =
     this->Position->BuildSystemDirectory;
 
   while (true) {
@@ -1366,7 +1366,7 @@ void cmState::Snapshot::InitializeFromParent_ForSubdirsCommand()
 }
 
 cmState::Directory::Directory(
-  cmLinkedTree<BuildsystemDirectoryStateType>::iterator iter,
+  cmLinkedTree<cmStateDetail::BuildsystemDirectoryStateType>::iterator iter,
   const cmState::Snapshot& snapshot)
   : DirectoryState(iter)
   , Snapshot_(snapshot)
diff --git a/Source/cmState.h b/Source/cmState.h
index feed1c7f41..24db08cfff 100644
--- a/Source/cmState.h
+++ b/Source/cmState.h
@@ -23,13 +23,17 @@ class cmCommand;
 class cmListFileBacktrace;
 class cmPropertyDefinition;
 
+namespace cmStateDetail {
+struct BuildsystemDirectoryStateType;
+}
+
 class cmState
 {
   struct SnapshotDataType;
   struct PolicyStackEntry;
-  struct BuildsystemDirectoryStateType;
   typedef cmLinkedTree<SnapshotDataType>::iterator PositionType;
   friend class Snapshot;
+  friend struct cmStateDetail::BuildsystemDirectoryStateType;
 
 public:
   cmState();
@@ -117,7 +121,8 @@ public:
 
   class Directory
   {
-    Directory(cmLinkedTree<BuildsystemDirectoryStateType>::iterator iter,
+    Directory(cmLinkedTree<
+                cmStateDetail::BuildsystemDirectoryStateType>::iterator iter,
               Snapshot const& snapshot);
 
   public:
@@ -173,7 +178,8 @@ public:
     void ComputeRelativePathTopBinary();
 
   private:
-    cmLinkedTree<BuildsystemDirectoryStateType>::iterator DirectoryState;
+    cmLinkedTree<cmStateDetail::BuildsystemDirectoryStateType>::iterator
+      DirectoryState;
     Snapshot Snapshot_;
     friend class Snapshot;
   };
@@ -329,7 +335,8 @@ private:
   cmPropertyMap GlobalProperties;
   cmCacheManager* CacheManager;
 
-  cmLinkedTree<BuildsystemDirectoryStateType> BuildsystemDirectory;
+  cmLinkedTree<cmStateDetail::BuildsystemDirectoryStateType>
+    BuildsystemDirectory;
 
   cmLinkedTree<std::string> ExecutionListFiles;