From d1dc6b528dabd1d4beefd8e81d76f3b05023aa30 Mon Sep 17 00:00:00 2001
From: Ted John <ted@brambles.org>
Date: Thu, 30 Jun 2016 18:53:49 +0100
Subject: [PATCH] Add Memory::Copy overlap check and Memory::Move

---
 src/core/Memory.hpp | 20 ++++++++++++++++----
 src/core/String.cpp |  2 +-
 2 files changed, 17 insertions(+), 5 deletions(-)

diff --git a/src/core/Memory.hpp b/src/core/Memory.hpp
index 4cebdd192a..761bd6b801 100644
--- a/src/core/Memory.hpp
+++ b/src/core/Memory.hpp
@@ -16,10 +16,8 @@
 
 #pragma once
 
-extern "C"
-{
-    #include "../common.h"
-}
+#include "../common.h"
+#include "Guard.hpp"
 
 /**
  * Utility methods for memory management. Typically helpers and wrappers around the C standard library.
@@ -80,9 +78,23 @@ namespace Memory
     T * Copy(T * dst, const T * src, size_t size)
     {
         if (size == 0) return (T*)dst;
+#ifdef DEBUG
+        uintptr_t srcBegin = (uintptr_t)src;
+        uintptr_t srcEnd = srcBegin + size;
+        uintptr_t dstBegin = (uintptr_t)dst;
+        uintptr_t dstEnd = dstBegin + size;
+        Guard::Assert(srcEnd <= dstBegin || srcBegin >= dstEnd, "Source overlaps destination, try using Memory::Move.");
+#endif
         return (T*)memcpy((void*)dst, (const void*)src, size);
     }
 
+    template<typename T>
+    T * Move(T * dst, const T * src, size_t size)
+    {
+        if (size == 0) return (T*)dst;
+        return (T*)memmove((void*)dst, (const void*)src, size);
+    }
+
     template<typename T>
     T * Duplicate(const T * src, size_t size)
     {
diff --git a/src/core/String.cpp b/src/core/String.cpp
index edc22e9b3b..aea62f553a 100644
--- a/src/core/String.cpp
+++ b/src/core/String.cpp
@@ -251,7 +251,7 @@ namespace String
             assert(newStringSize < currentStringSize);
 #endif
 
-            Memory::Copy(str, firstNonWhitespace, newStringSize);
+            Memory::Move(str, firstNonWhitespace, newStringSize);
             str[newStringSize] = '\0';
         }
         else