1 files changed, 17 insertions, 2 deletions
diff --git a/include/llvm/ADT/ImmutableMap.h b/include/llvm/ADT/ImmutableMap.h
index 4883c5ba0a..f9baec213a 100644
--- a/include/llvm/ADT/ImmutableMap.h
+++ b/include/llvm/ADT/ImmutableMap.h
@@ -288,6 +288,13 @@ public:
       Factory(F) {
     if (Root) { Root->retain(); }
   }
+
+  explicit ImmutableMapRef(const ImmutableMap<KeyT, ValT> &X,
+                           typename ImmutableMap<KeyT, ValT>::Factory &F)
+    : Root(X.getRootWithoutRetain()),
+      Factory(F.getTreeFactory()) {
+    if (Root) { Root->retain(); }
+  }
   
   ImmutableMapRef(const ImmutableMapRef &X)
     : Root(X.Root),
@@ -318,12 +325,20 @@ public:
     return ImmutableMapRef(0, F);
   }
 
-  ImmutableMapRef add(key_type_ref K, data_type_ref D) {
+  void manualRetain() {
+    if (Root) Root->retain();
+  }
+
+  void manualRelease() {
+    if (Root) Root->release();
+  }
+
+  ImmutableMapRef add(key_type_ref K, data_type_ref D) const {
     TreeTy *NewT = Factory->add(Root, std::pair<key_type, data_type>(K, D));
     return ImmutableMapRef(NewT, Factory);
   }
 
-  ImmutableMapRef remove(key_type_ref K) {
+  ImmutableMapRef remove(key_type_ref K) const {
     TreeTy *NewT = Factory->remove(Root, K);
     return ImmutableMapRef(NewT, Factory);
   }