X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=include%2Fllvm%2FADT%2Filist_node.h;h=f0080035cb885157e0a80b9e0300227e21ad3300;hb=75eac5f0ebff4d0ffe10ce6bc8f2867c5f15315b;hp=9c7e6f6a51307248f5656c9c3102c069c63964b6;hpb=76d38384542e2f596e14eb8e80b8e1c6a2652fd1;p=oota-llvm.git

diff --git a/include/llvm/ADT/ilist_node.h b/include/llvm/ADT/ilist_node.h
index 9c7e6f6a513..f0080035cb8 100644
--- a/include/llvm/ADT/ilist_node.h
+++ b/include/llvm/ADT/ilist_node.h
@@ -40,7 +40,7 @@ struct ilist_nextprev_traits;
 /// that use ilist_nextprev_traits or ilist_default_traits.
 ///
 template<typename NodeTy>
-class ilist_node : ilist_half_node<NodeTy> {
+class ilist_node : private ilist_half_node<NodeTy> {
   friend struct ilist_nextprev_traits<NodeTy>;
   friend struct ilist_traits<NodeTy>;
   NodeTy *Next;
@@ -49,17 +49,57 @@ class ilist_node : ilist_half_node<NodeTy> {
   void setNext(NodeTy *N) { Next = N; }
 protected:
   ilist_node() : Next(0) {}
-};
 
-/// When assertions are off, the Next field of sentinels
-/// will not be accessed. So it is not necessary to allocate
-/// space for it. The following macro selects the most
-/// efficient trais class.
-#ifndef NDEBUG
-#   define ILIST_NODE ilist_node
-#else
-#   define ILIST_NODE ilist_half_node
-#endif
+public:
+  /// @name Adjacent Node Accessors
+  /// @{
+
+  /// \brief Get the previous node, or 0 for the list head.
+  NodeTy *getPrevNode() {
+    NodeTy *Prev = this->getPrev();
+
+    // Check for sentinel.
+    if (!Prev->getNext())
+      return 0;
+
+    return Prev;
+  }
+
+  /// \brief Get the previous node, or 0 for the list head.
+  const NodeTy *getPrevNode() const {
+    const NodeTy *Prev = this->getPrev();
+
+    // Check for sentinel.
+    if (!Prev->getNext())
+      return 0;
+
+    return Prev;
+  }
+
+  /// \brief Get the next node, or 0 for the list tail.
+  NodeTy *getNextNode() {
+    NodeTy *Next = getNext();
+
+    // Check for sentinel.
+    if (!Next->getNext())
+      return 0;
+
+    return Next;
+  }
+
+  /// \brief Get the next node, or 0 for the list tail.
+  const NodeTy *getNextNode() const {
+    const NodeTy *Next = getNext();
+
+    // Check for sentinel.
+    if (!Next->getNext())
+      return 0;
+
+    return Next;
+  }
+
+  /// @}
+};
 
 } // End llvm namespace