Initial commit to populate CoreCLR repo

[tfs-changeset: 1407945]

1 files changed, 131 insertions, 0 deletions

diff --git a/src/vm/extensibleclassfactory.cpp b/src/vm/extensibleclassfactory.cpp
new file mode 100644
index 0000000000..3107f555e7
--- /dev/null
+++ b/src/vm/extensibleclassfactory.cpp
@@ -0,0 +1,131 @@
+//
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+//
+
+/*============================================================
+**
+** Header: ExtensibleClassFactory.cpp
+**
+**
+** Purpose: Native methods on System.Runtime.InteropServices.ExtensibleClassFactory
+**
+
+** 
+===========================================================*/
+
+#include "common.h"
+
+#include "excep.h"
+#include "stackwalk.h"
+#include "extensibleclassfactory.h"
+
+
+// Helper function used to walk stack frames looking for a class initializer.
+static StackWalkAction FrameCallback(CrawlFrame *pCF, void *pData)
+{
+    _ASSERTE(NULL != pCF);
+    MethodDesc *pMD = pCF->GetFunction();
+
+    CONTRACTL
+    {
+        THROWS;
+        GC_TRIGGERS;
+        MODE_ANY;
+        SO_TOLERANT;
+        PRECONDITION(CheckPointer(pMD));
+        PRECONDITION(CheckPointer(pData, NULL_OK));
+        PRECONDITION(pMD->GetMethodTable() != NULL);
+    }
+    CONTRACTL_END;
+    
+
+    // We use the pData context argument to track the class as we move down the
+    // stack and to return the class whose initializer is being called. If
+    // *ppMT is NULL we are looking at the caller's initial frame and just
+    // record the class that the method belongs to. From that point on the class
+    // must remain the same until we hit a class initializer or else we must
+    // fail (to prevent other classes called from a class initializer from
+    // setting the current classes callback). The very first class we will see
+    // belongs to RegisterObjectCreationCallback itself, so skip it (we set
+    // *ppMT to an initial value of -1 to detect this).
+    MethodTable **ppMT = (MethodTable **)pData;
+
+    if (*ppMT == (MethodTable *)-1)
+        *ppMT = NULL;
+    
+    else if (*ppMT == NULL)
+        *ppMT = pMD->GetMethodTable();
+    
+    else if (pMD->GetMethodTable() != *ppMT)
+    {
+        *ppMT = NULL;
+        return SWA_ABORT;
+    }
+
+    if (pMD->IsClassConstructor())
+        return SWA_ABORT;
+
+    return SWA_CONTINUE;
+}
+
+
+// Register a delegate that will be called whenever an instance of a
+// managed type that extends from an unmanaged type needs to allocate
+// the aggregated unmanaged object. This delegate is expected to
+// allocate and aggregate the unmanaged object and is called in place
+// of a CoCreateInstance. This routine must be called in the context
+// of the static initializer for the class for which the callbacks
+// will be made.
+// It is not legal to register this callback from a class that has any
+// parents that have already registered a callback.
+FCIMPL1(void, RegisterObjectCreationCallback, Object* pDelegateUNSAFE)
+{
+    FCALL_CONTRACT;
+
+    OBJECTREF orDelegate = (OBJECTREF) pDelegateUNSAFE;
+    HELPER_METHOD_FRAME_BEGIN_1(orDelegate);
+
+    // Validate the delegate argument.
+    if (orDelegate == 0)
+        COMPlusThrowArgumentNull(W("callback"));
+
+    // We should have been called in the context of a class static initializer.
+    // Walk back up the stack to verify this and to determine just what class
+    // we're registering a callback for.
+    MethodTable *pMT = (MethodTable *)-1;
+    if (GetThread()->StackWalkFrames(FrameCallback, &pMT, FUNCTIONSONLY, NULL) == SWA_FAILED)
+        COMPlusThrow(kInvalidOperationException, IDS_EE_CALLBACK_NOT_CALLED_FROM_CCTOR);
+
+    // If we didn't find a class initializer, we can't continue.
+    if (pMT == NULL)
+    {
+        COMPlusThrow(kInvalidOperationException, IDS_EE_CALLBACK_NOT_CALLED_FROM_CCTOR);
+    }
+    
+    // The object type must derive at some stage from a COM imported object.
+    // Also we must fail the call if some parent class has already registered a
+    // callback.
+    MethodTable *pParent = pMT;
+    do 
+    {
+        pParent = pParent->GetParentMethodTable();
+        if (pParent && !pParent->IsComImport() && (pParent->GetObjCreateDelegate() != NULL))
+        {
+            COMPlusThrow(kInvalidOperationException, IDS_EE_CALLBACK_ALREADY_REGISTERED);
+        }
+    } 
+    while (pParent && !pParent->IsComImport());
+
+    // If the class does not have a COM imported base class then fail the call.
+    if (pParent == NULL || pParent->IsProjectedFromWinRT())
+    {
+        COMPlusThrow(kInvalidOperationException, IDS_EE_CALLBACK_NOT_CALLED_FROM_CCTOR);
+    }
+
+    // Save the delegate in the MethodTable for the class.
+    pMT->SetObjCreateDelegate(orDelegate);
+
+    HELPER_METHOD_FRAME_END();
+}
+FCIMPLEND