1 files changed, 150 insertions, 0 deletions
diff --git a/include/lldb/Utility/PriorityPointerPair.h b/include/lldb/Utility/PriorityPointerPair.h
new file mode 100644
index 000000000000..49f0765d0f96
--- /dev/null
+++ b/include/lldb/Utility/PriorityPointerPair.h
@@ -0,0 +1,150 @@
+//===-- PriorityPointerPair.h ----------------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef liblldb_PriorityPointerPair_h_
+#define liblldb_PriorityPointerPair_h_
+
+#include "lldb/lldb-public.h"
+#include "lldb/Utility/SharingPtr.h"
+
+namespace lldb_utility {
+
+//----------------------------------------------------------------------
+// A prioritized pair of SharedPtr<T>. One of the two pointers is high
+// priority, the other is low priority.
+// The Get() method always returns high, if *high != NULL,
+// otherwise, low is returned (even if *low == NULL)
+//----------------------------------------------------------------------
+
+template<typename T>
+class PriorityPointerPair
+{
+public:
+    
+    typedef T& reference_type;
+    typedef T* pointer_type;
+    
+    typedef typename std::shared_ptr<T> T_SP;
+    
+    PriorityPointerPair() : 
+    m_high(),
+    m_low()
+    {}
+    
+    PriorityPointerPair(pointer_type high,
+                        pointer_type low) : 
+    m_high(high),
+    m_low(low)
+    {}
+
+    PriorityPointerPair(pointer_type low) : 
+    m_high(),
+    m_low(low)
+    {}
+
+    PriorityPointerPair(T_SP& high,
+                        T_SP& low) : 
+    m_high(high),
+    m_low(low)
+    {}
+    
+    PriorityPointerPair(T_SP& low) : 
+    m_high(),
+    m_low(low)
+    {}
+    
+    void
+    SwapLow(pointer_type l)
+    {
+        m_low.swap(l);
+    }
+    
+    void
+    SwapHigh(pointer_type h)
+    {
+        m_high.swap(h);
+    }
+    
+    void
+    SwapLow(T_SP l)
+    {
+        m_low.swap(l);
+    }
+
+    void
+    SwapHigh(T_SP h)
+    {
+        m_high.swap(h);
+    }
+    
+    T_SP
+    GetLow()
+    {
+        return m_low;
+    }
+    
+    T_SP
+    GetHigh()
+    {
+        return m_high;
+    }
+    
+    T_SP
+    Get()
+    {
+        if (m_high.get())
+            return m_high;
+        return m_low;
+    }
+    
+    void
+    ResetHigh()
+    {
+        m_high.reset();
+    }
+    
+    void
+    ResetLow()
+    {
+        m_low.reset();
+    }
+    
+    void
+    Reset()
+    {
+        ResetLow();
+        ResetHigh();
+    }
+    
+    reference_type
+    operator*() const
+    {
+        return Get().operator*();
+    }
+    
+    pointer_type
+    operator->() const
+    {
+        return Get().operator->();
+    }
+    
+    ~PriorityPointerPair();
+    
+private:
+
+    T_SP m_high;
+    T_SP m_low;
+    
+    DISALLOW_COPY_AND_ASSIGN (PriorityPointerPair);
+        
+};
+
+} // namespace lldb_utility
+
+#endif // #ifndef liblldb_PriorityPointerPair_h_