1 files changed, 79 insertions, 0 deletions
diff --git a/src/vm/interoputil.inl b/src/vm/interoputil.inl
new file mode 100644
index 0000000000..80cd8f496d
--- /dev/null
+++ b/src/vm/interoputil.inl
@@ -0,0 +1,79 @@
+// 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.
+
+//
+#include "comcallablewrapper.h"
+
+#ifndef DACCESS_COMPILE
+inline BOOL ComInterfaceSlotIs(IUnknown* pUnk, int slot, LPVOID pvFunction)
+{
+    CONTRACTL
+    {
+        NOTHROW;
+        GC_NOTRIGGER;
+        FORBID_FAULT;
+        MODE_ANY;
+        SO_TOLERANT;
+        PRECONDITION(CheckPointer(pUnk));
+    }
+    CONTRACTL_END;
+    
+    LPVOID pvRetVal = (*((LPVOID**)pUnk))[slot];
+
+    return (pvRetVal == (LPVOID)GetEEFuncEntryPoint(pvFunction));
+}
+
+//Helpers
+// Is the tear-off a CLR created tear-off
+inline BOOL IsInProcCCWTearOff(IUnknown* pUnk)
+{
+    WRAPPER_NO_CONTRACT;
+    return ComInterfaceSlotIs(pUnk, 0, Unknown_QueryInterface) || 
+           ComInterfaceSlotIs(pUnk, 0, Unknown_QueryInterface_IErrorInfo) ||
+           ComInterfaceSlotIs(pUnk, 0, Unknown_QueryInterface_ICCW);
+}
+    
+// is the tear-off represent one of the standard interfaces such as IProvideClassInfo, IErrorInfo etc.
+inline BOOL IsSimpleTearOff(IUnknown* pUnk)
+{
+    WRAPPER_NO_CONTRACT;
+    return ComInterfaceSlotIs(pUnk, TEAR_OFF_SLOT, TEAR_OFF_SIMPLE);
+}
+
+// Is the tear-off represent the inner unknown or the original unknown for the object
+inline BOOL IsInnerUnknown(IUnknown* pUnk)
+{
+    WRAPPER_NO_CONTRACT;
+    return ComInterfaceSlotIs(pUnk, TEAR_OFF_SLOT, TEAR_OFF_SIMPLE_INNER);
+}
+
+// Is this one of our "standard" ComCallWrappers
+inline BOOL IsStandardTearOff(IUnknown* pUnk)
+{
+    WRAPPER_NO_CONTRACT;
+    return ComInterfaceSlotIs(pUnk, TEAR_OFF_SLOT, TEAR_OFF_STANDARD);
+}
+
+// Convert an IUnknown to CCW, does not handle aggregation and ICustomQI.
+FORCEINLINE ComCallWrapper* MapIUnknownToWrapper(IUnknown* pUnk)
+{   
+    CONTRACT (ComCallWrapper*)
+    {
+        NOTHROW;
+        GC_NOTRIGGER;
+        MODE_ANY;
+        SO_TOLERANT;
+        PRECONDITION(CheckPointer(pUnk, NULL_OK));
+    }
+    CONTRACT_END;
+    
+    if (IsStandardTearOff(pUnk))
+        RETURN ComCallWrapper::GetWrapperFromIP(pUnk);
+
+    if (IsSimpleTearOff(pUnk) || IsInnerUnknown(pUnk))
+        RETURN SimpleComCallWrapper::GetWrapperFromIP(pUnk)->GetMainWrapper();
+
+    RETURN NULL;
+}
+#endif // !DACCESS_COMPILE