1 files changed, 125 insertions, 0 deletions
diff --git a/src/inc/mscorpesxswrapper.h b/src/inc/mscorpesxswrapper.h
new file mode 100644
index 0000000000..52656f6711
--- /dev/null
+++ b/src/inc/mscorpesxswrapper.h
@@ -0,0 +1,125 @@
+// 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.
+// 
+// File: MscorpeSxSWrapper.h
+// 
+
+// 
+// This file defines a wrapper for SxS version of mscorpe.dll (dynamically loaded via shim).
+// 
+
+#pragma once
+
+#include "utilcode.h"
+
+#include "iceefilegen.h"
+
+// 
+// Wrapper for calls into mscorpehost.dll (SxS version of mscorpe.dll).
+// Template parameter will load the DLL as it is required in the context.
+// 
+// Note that _LoadMscorpeDll method can be called more than once and in parallel from more threads if race 
+// happens.
+// 
+template <HRESULT (* _LoadMscorpeDll)(HMODULE * phModule)>
+class MscorpeSxSWrapper
+{
+private:
+    // mscorpehost.dll module, if not NULL, entry points are already initialized
+    static Volatile<HMODULE>                s_hModule;
+    // mscorpehost.dll entry points
+    static Volatile<PFN_CreateICeeFileGen>  s_pfnCreateICeeFileGen;
+    static Volatile<PFN_DestroyICeeFileGen> s_pfnDestroyICeeFileGen;
+    
+    // Loads the DLL and sets all statics
+    static HRESULT Init();
+    
+public:
+    
+    // Wrapper of file:ICeeFileGen.cpp#CreateICeeFileGen from mscorpehost.dll
+    static HRESULT CreateICeeFileGen(ICeeFileGen ** ppCeeFileGen)
+    {
+        HRESULT hr = S_OK;
+        IfFailGo(Init());
+        hr = s_pfnCreateICeeFileGen(ppCeeFileGen);
+    ErrExit:
+        return hr;
+    }
+    
+    // Wrapper of file:ICeeFileGen.cpp#DestroyICeeFileGen from mscorpehost.dll
+    static HRESULT DestroyICeeFileGen(ICeeFileGen ** ppCeeFileGen)
+    {
+        HRESULT hr = S_OK;
+        IfFailGo(Init());
+        hr = s_pfnDestroyICeeFileGen(ppCeeFileGen);
+    ErrExit:
+        return hr;
+    }
+    
+#ifdef _DEBUG
+    // Returns TRUE if the DLL has been already loaded
+    static BOOL Debug_IsLoaded()
+    {
+        return (s_hModule != (HMODULE)NULL);
+    }
+#endif //_DEBUG
+};  // class MscorpeSxS
+
+template <HRESULT (* _LoadMscorpeDll)(HMODULE * phModule)>
+// code:MscorpeSxS statics initialization
+Volatile<HMODULE> MscorpeSxSWrapper<_LoadMscorpeDll>::s_hModule = NULL;
+
+template <HRESULT (* _LoadMscorpeDll)(HMODULE * phModule)>
+Volatile<PFN_CreateICeeFileGen> MscorpeSxSWrapper<_LoadMscorpeDll>::s_pfnCreateICeeFileGen = NULL;
+
+template <HRESULT (* _LoadMscorpeDll)(HMODULE * phModule)>
+Volatile<PFN_DestroyICeeFileGen> MscorpeSxSWrapper<_LoadMscorpeDll>::s_pfnDestroyICeeFileGen = NULL;
+
+// Loads the DLL and sets all statics
+//static 
+template <HRESULT (* _LoadMscorpeDll)(HMODULE * phModule)>
+HRESULT 
+MscorpeSxSWrapper<_LoadMscorpeDll>::Init()
+{
+    HRESULT hr = S_OK;
+    
+    if (s_hModule != (HMODULE)NULL)
+    {
+        return S_OK;
+    }
+    
+    // Local mscorpehost.dll module
+    HMODULE hModule = NULL;
+    // Local mscorpehost.dll entry points
+    PFN_CreateICeeFileGen  pfnCreateICeeFileGen = NULL;
+    PFN_DestroyICeeFileGen pfnDestroyICeeFileGen = NULL;
+    
+    // Load mscorpehost.dll and initialize it
+    IfFailGo(_LoadMscorpeDll(&hModule));
+    _ASSERTE(hModule != NULL);
+    
+    pfnCreateICeeFileGen = (PFN_CreateICeeFileGen)GetProcAddress(hModule, "CreateICeeFileGen");
+    if (pfnCreateICeeFileGen == NULL)
+    {
+        IfFailGo(COR_E_EXECUTIONENGINE);
+    }
+    
+    pfnDestroyICeeFileGen = (PFN_DestroyICeeFileGen)GetProcAddress(hModule, "DestroyICeeFileGen");
+    if (pfnDestroyICeeFileGen == NULL)
+    {
+        IfFailGo(COR_E_EXECUTIONENGINE);
+    }
+    
+ErrExit:
+    if (SUCCEEDED(hr))
+    {
+        // First publish mscorpehost.dll entry points
+        s_pfnCreateICeeFileGen = pfnCreateICeeFileGen;
+        s_pfnDestroyICeeFileGen = pfnDestroyICeeFileGen;
+        // Then we can publish/initialize the mscorpehost.dll module
+        s_hModule = hModule;
+    }
+    
+    return hr;
+} // MscorpeSxSWrapper::Init