1 files changed, 160 insertions, 0 deletions
diff --git a/src/md/ceefilegen/ceegentokenmapper.cpp b/src/md/ceefilegen/ceegentokenmapper.cpp
new file mode 100644
index 0000000000..95ccbcd3f2
--- /dev/null
+++ b/src/md/ceefilegen/ceegentokenmapper.cpp
@@ -0,0 +1,160 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+//*****************************************************************************
+// CeeGenTokenMapper.cpp
+// 
+
+//
+// This helper class tracks mapped tokens from their old value to the new value
+// which can happen when the data is optimized on save.
+//
+//*****************************************************************************
+#include "stdafx.h"
+#include "ceegentokenmapper.h"
+
+
+//*****************************************************************************
+// At this point, only a select set of token values are stored for remap.
+// If others should become required, this needs to get updated.
+//*****************************************************************************
+int CeeGenTokenMapper::IndexForType(mdToken tk)
+{
+#ifdef CEEGEN_TRACKED_TOKEN
+#undef CEEGEN_TRACKED_TOKEN
+#endif
+#define CEEGEN_TRACKED_TOKEN(type) case INDEX_OF_TYPE(mdt ## type): return (tkix ## type);
+    
+    int iType = INDEX_OF_TYPE(TypeFromToken(tk));
+    switch(iType)
+    {
+        CEEGEN_TRACKED_TOKENS()
+    }
+    
+    return (-1);
+}
+
+
+//*****************************************************************************
+// Called by the meta data engine when a token is remapped to a new location.
+// This value is recorded in the m_rgMap array based on type and rid of the
+// from token value.
+//*****************************************************************************
+HRESULT __stdcall CeeGenTokenMapper::Map(
+    mdToken     tkFrom, 
+    mdToken     tkTo)
+{
+    HRESULT hr = S_OK;
+    mdToken *pToken = NULL;
+    ULONG ridFrom = 0;
+    TOKENMAP *pMap = NULL;
+
+    BEGIN_ENTRYPOINT_NOTHROW;
+
+    if ( IndexForType(tkFrom) == -1 )
+    {
+        // It is a type that we are not tracking, such as mdtProperty or mdtEvent,
+        // just return S_OK.
+        goto ErrExit;
+    }
+
+    _ASSERTE(IndexForType(tkFrom) < GetMaxMapSize());
+    _ASSERTE(IndexForType(tkTo) != -1 && IndexForType(tkTo) < GetMaxMapSize());
+
+    // If there is another token mapper that the user wants called, go
+    // ahead and call it now.
+    if (m_pIMapToken)
+        m_pIMapToken->Map(tkFrom, tkTo);
+    
+    ridFrom = RidFromToken(tkFrom);
+    pMap = &m_rgMap[IndexForType(tkFrom)];
+
+    // If there isn't enough entries, fill out array up to the count
+    // and mark the token to nil so we know there is no valid data yet.
+    if ((ULONG) pMap->Count() <= ridFrom)
+    {
+        for (int i=ridFrom - pMap->Count() + 1;  i;  i--) 
+        {
+            pToken = pMap->Append();
+            if (!pToken)
+                break;
+            *pToken = mdTokenNil;
+        }
+        _ASSERTE(!pToken || pMap->Get(ridFrom) == pToken);
+    }
+    else
+        pToken = pMap->Get(ridFrom);
+
+    IfNullGo(pToken);
+    
+    *pToken = tkTo;
+
+ErrExit:
+    END_ENTRYPOINT_NOTHROW;
+    
+    return hr;
+}
+
+
+//*****************************************************************************
+// Check the given token to see if it has moved to a new location.  If so,
+// return true and give back the new token.
+//*****************************************************************************
+int CeeGenTokenMapper::HasTokenMoved(
+    mdToken     tkFrom,
+    mdToken     &tkTo)
+{
+    mdToken     tk;
+
+    int i = IndexForType(tkFrom);
+    if(i == -1) return false;
+
+    _ASSERTE(i < GetMaxMapSize());
+    TOKENMAP *pMap = &m_rgMap[i];
+
+    // Assume nothing moves.
+    tkTo = tkFrom;
+
+    // If the array is smaller than the index, can't have moved.
+    if ((ULONG) pMap->Count() <= RidFromToken(tkFrom))
+        return (false);
+
+    // If the entry is set to 0, then nothing there.
+    tk = *pMap->Get(RidFromToken(tkFrom));
+    if (tk == mdTokenNil)
+        return (false);
+    
+    // Had to move to a new location, return that new location.
+    tkTo = tk;
+    return (true);
+}
+
+
+//*****************************************************************************
+// Hand out a copy of the meta data information.
+//*****************************************************************************
+
+HRESULT CeeGenTokenMapper::GetMetaData(
+    IMetaDataImport **ppIImport)
+{
+    if (m_pIImport)
+        return (m_pIImport->QueryInterface(IID_IMetaDataImport, (PVOID *) ppIImport));
+    *ppIImport = 0;
+    return E_FAIL;
+}
+
+
+HRESULT __stdcall CeeGenTokenMapper::QueryInterface(REFIID iid, PVOID *ppIUnk)
+{
+    if (iid == IID_IUnknown || iid == IID_IMapToken)
+        *ppIUnk = static_cast<IMapToken*>(this);
+    else
+    {
+        *ppIUnk = 0;
+        return (E_NOINTERFACE);
+    }
+    AddRef();
+    return (S_OK);
+}
+
+