text: // 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: stubhelpers.cpp
  //
  
  //
  
  
  #include "common.h"
  
  #include "mlinfo.h"
  #include "stubhelpers.h"
  #include "jitinterface.h"
  #include "dllimport.h"
  #include "fieldmarshaler.h"
  #include "comdelegate.h"
  #include "eventtrace.h"
  #include "comdatetime.h"
  #include "gcheaputilities.h"
  #include "interoputil.h"
  
  #ifdef FEATURE_COMINTEROP
  #include <oletls.h>
  #include "olecontexthelpers.h"
  #include "runtimecallablewrapper.h"
  #include "comcallablewrapper.h"
  #include "clrtocomcall.h"
  #include "cominterfacemarshaler.h"
  #endif
  
  #ifdef VERIFY_HEAP
  
  CQuickArray<StubHelpers::ByrefValidationEntry> StubHelpers::s_ByrefValidationEntries;
  SIZE_T StubHelpers::s_ByrefValidationIndex = 0;
  CrstStatic StubHelpers::s_ByrefValidationLock;
  
  // static
  void StubHelpers::Init()
  {
      WRAPPER_NO_CONTRACT;
      s_ByrefValidationLock.Init(CrstPinnedByrefValidation);
  }
  
  // static
  void StubHelpers::ValidateObjectInternal(Object *pObjUNSAFE, BOOL fValidateNextObj)
  {
  	CONTRACTL
  	{
  	NOTHROW;
  	GC_NOTRIGGER;
  	MODE_ANY;
  }
  	CONTRACTL_END;
  
  	_ASSERTE(GCHeapUtilities::GetGCHeap()->RuntimeStructuresValid());
  
  	// validate the object - there's no need to validate next object's
  	// header since we validate the next object explicitly below
  	if (pObjUNSAFE)
  	{
  		pObjUNSAFE->Validate(/*bDeep=*/ TRUE, /*bVerifyNextHeader=*/ FALSE, /*bVerifySyncBlock=*/ TRUE);
  	}
  
  	// and the next object as required
  	if (fValidateNextObj)
  	{
  		Object *nextObj = GCHeapUtilities::GetGCHeap()->NextObj(pObjUNSAFE);
  		if (nextObj != NULL)
  		{
  			// Note that the MethodTable of the object (i.e. the pointer at offset 0) can change from
  			// g_pFreeObjectMethodTable to NULL, from NULL to <legal-value>, or possibly also from
  			// g_pFreeObjectMethodTable to <legal-value> concurrently while executing this function.
  			// Once <legal-value> is seen, we believe that the object should pass the Validate check.
  			// We have to be careful and read the pointer only once to avoid "phantom reads".
  			MethodTable *pMT = VolatileLoad(nextObj->GetMethodTablePtr());
  			if (pMT != NULL && pMT != g_pFreeObjectMethodTable)
  			{
  				// do *not* verify the next object's syncblock - the next object is not guaranteed to
  				// be "alive" so the finalizer thread may have already released its syncblock
  				nextObj->Validate(/*bDeep=*/ TRUE, /*bVerifyNextHeader=*/ FALSE, /*bVerifySyncBlock=*/ FALSE);
  			}
  		}
  	}
  }
  
  // static
  MethodDesc *StubHelpers::ResolveInteropMethod(Object *pThisUNSAFE, MethodDesc *pMD)
  {
      WRAPPER_NO_CONTRACT;
  
      if (pMD == NULL && pThisUNSAFE != NULL)
      {
          // if this is a call via delegate, get its Invoke method
          MethodTable *pMT = pThisUNSAFE->GetMethodTable();
  
          _ASSERTE(pMT->IsDelegate());
          return ((DelegateEEClass *)pMT->GetClass())->GetInvokeMethod();
      }
      return pMD;
  }
  
  // static
  void StubHelpers::FormatValidationMessage(MethodDesc *pMD, SString &ssErrorString)
  {
      CONTRACTL
      {
          THROWS;
          GC_NOTRIGGER;
          MODE_ANY;
      }
      CONTRACTL_END;
  
      ssErrorString.Append(W("Detected managed heap corruption, likely culprit is interop call through "));
  
      if (pMD == NULL)
      {
          // the only case where we don't have interop MD is CALLI
          ssErrorString.Append(W("CALLI."));
      }
      else
      {
          ssErrorString.Append(W("method '"));
  
          StackSString ssClassName;
          pMD->GetMethodTable()->_GetFullyQualifiedNameForClass(ssClassName);
  
          ssErrorString.Append(ssClassName);
          ssErrorString.Append(NAMESPACE_SEPARATOR_CHAR);
          ssErrorString.AppendUTF8(pMD->GetName());
  
          ssErrorString.Append(W("'."));
      }
  }
  
  // static
  void StubHelpers::ProcessByrefValidationList()
  {
      CONTRACTL
      {
          NOTHROW;
          GC_NOTRIGGER;
          MODE_ANY;
      }
      CONTRACTL_END;
  
      StackSString errorString;
      ByrefValidationEntry entry = { NULL, NULL };
  
      EX_TRY
      {
          AVInRuntimeImplOkayHolder AVOkay;
  
          // Process all byref validation entries we have saved since the last GC. Note that EE is suspended at
          // this point so we don't have to take locks and we can safely call code:GCHeap.GetContainingObject.
          for (SIZE_T i = 0; i < s_ByrefValidationIndex; i++)
          {
              entry = s_ByrefValidationEntries[i];
  
              Object *pObjUNSAFE = GCHeapUtilities::GetGCHeap()->GetContainingObject(entry.pByref, false);
              ValidateObjectInternal(pObjUNSAFE, TRUE);
          }
      }
      EX_CATCH
      {
          EX_TRY
          {
              FormatValidationMessage(entry.pMD, errorString);
              EEPOLICY_HANDLE_FATAL_ERROR_WITH_MESSAGE(COR_E_EXECUTIONENGINE, errorString.GetUnicode());
          }
          EX_CATCH
          {
              EEPOLICY_HANDLE_FATAL_ERROR(COR_E_EXECUTIONENGINE);
          }
          EX_END_CATCH_UNREACHABLE;
      }
      EX_END_CATCH_UNREACHABLE;
  
      s_ByrefValidationIndex = 0;
  }
  
  #endif // VERIFY_HEAP
  
  #ifdef FEATURE_COMINTEROP
  
  FORCEINLINE static void GetCOMIPFromRCW_ClearFP()
  {
      LIMITED_METHOD_CONTRACT;
  
  #ifdef TARGET_X86
      // As per ASURT 146699 we need to clear FP state before calling to COM
      // the following sequence was previously generated to compiled ML stubs
      // and is faster than _clearfp().
      __asm
      {
          fnstsw ax
          and    eax, 0x3F
          jz     NoNeedToClear
          fnclex
  NoNeedToClear:
      }
  #endif // TARGET_X86
  }
  
  FORCEINLINE static SOleTlsData *GetOrCreateOleTlsData()
  {
      LIMITED_METHOD_CONTRACT;
  
      SOleTlsData *pOleTlsData;
  #ifdef TARGET_X86
      // This saves 1 memory instruction over NtCurretTeb()->ReservedForOle because
      // NtCurrentTeb() reads _TEB.NtTib.Self which is the same as what FS:0 already
      // points to.
      pOleTlsData = (SOleTlsData *)(ULONG_PTR)__readfsdword(offsetof(TEB, ReservedForOle));
  #else // TARGET_X86
      pOleTlsData = (SOleTlsData *)NtCurrentTeb()->ReservedForOle;
  #endif // TARGET_X86
      if (pOleTlsData == NULL)
      {
          pOleTlsData = (SOleTlsData *)SetupOleContext();
      }
      return pOleTlsData;
  }
  
  FORCEINLINE static void *GetCOMIPFromRCW_GetTargetNoInterception(IUnknown *pUnk, ComPlusCallInfo *pComInfo)
  {
      LIMITED_METHOD_CONTRACT;
  
      LPVOID *lpVtbl = *(LPVOID **)pUnk;
      return lpVtbl[pComInfo->m_cachedComSlot];
  }
  
  FORCEINLINE static IUnknown *GetCOMIPFromRCW_GetIUnknownFromRCWCache(RCW *pRCW, MethodTable * pItfMT)
  {
      LIMITED_METHOD_CONTRACT;
  
      // The code in this helper is the "fast path" that used to be generated directly
      // to compiled ML stubs. The idea is to aim for an efficient RCW cache hit.
      SOleTlsData * pOleTlsData = GetOrCreateOleTlsData();
  
      // test for free-threaded after testing for context match to optimize for apartment-bound objects
      if (pOleTlsData->pCurrentCtx == pRCW->GetWrapperCtxCookie() || pRCW->IsFreeThreaded())
      {
          for (int i = 0; i < INTERFACE_ENTRY_CACHE_SIZE; i++)
          {
              if (pRCW->m_aInterfaceEntries[i].m_pMT == pItfMT)
              {
                  return pRCW->m_aInterfaceEntries[i].m_pUnknown;
              }
          }
      }
  
      return NULL;
  }
  
  // Like GetCOMIPFromRCW_GetIUnknownFromRCWCache but also computes the target. This is a couple of instructions
  // faster than GetCOMIPFromRCW_GetIUnknownFromRCWCache + GetCOMIPFromRCW_GetTargetNoInterception.
  FORCEINLINE static IUnknown *GetCOMIPFromRCW_GetIUnknownFromRCWCache_NoInterception(RCW *pRCW, ComPlusCallInfo *pComInfo, void **ppTarget)
  {
      LIMITED_METHOD_CONTRACT;
  
      // The code in this helper is the "fast path" that used to be generated directly
      // to compiled ML stubs. The idea is to aim for an efficient RCW cache hit.
      SOleTlsData *pOleTlsData = GetOrCreateOleTlsData();
      MethodTable *pItfMT = pComInfo->m_pInterfaceMT;
  
      // test for free-threaded after testing for context match to optimize for apartment-bound objects
      if (pOleTlsData->pCurrentCtx == pRCW->GetWrapperCtxCookie() || pRCW->IsFreeThreaded())
      {
          for (int i = 0; i < INTERFACE_ENTRY_CACHE_SIZE; i++)
          {
              if (pRCW->m_aInterfaceEntries[i].m_pMT == pItfMT)
              {
                  IUnknown *pUnk = pRCW->m_aInterfaceEntries[i].m_pUnknown;
                  _ASSERTE(pUnk != NULL);
                  *ppTarget = GetCOMIPFromRCW_GetTargetNoInterception(pUnk, pComInfo);
                  return pUnk;
              }
          }
      }
  
      return NULL;
  }
  
  FORCEINLINE static void *GetCOMIPFromRCW_GetTarget(IUnknown *pUnk, ComPlusCallInfo *pComInfo)
  {
      LIMITED_METHOD_CONTRACT;
  
  
      LPVOID *lpVtbl = *(LPVOID **)pUnk;
      return lpVtbl[pComInfo->m_cachedComSlot];
  }
  
  NOINLINE static IUnknown* GetCOMIPFromRCWHelper(LPVOID pFCall, OBJECTREF pSrc, MethodDesc* pMD, void **ppTarget)
  {
      FC_INNER_PROLOG(pFCall);
  
      IUnknown *pIntf = NULL;
  
      // This is only called in IL stubs which are in CER, so we don't need to worry about ThreadAbort
      HELPER_METHOD_FRAME_BEGIN_RET_ATTRIB_1(Frame::FRAME_ATTR_NO_THREAD_ABORT|Frame::FRAME_ATTR_EXACT_DEPTH|Frame::FRAME_ATTR_CAPTURE_DEPTH_2, pSrc);
  
      SafeComHolder<IUnknown> pRetUnk;
  
      ComPlusCallInfo *pComInfo = ComPlusCallInfo::FromMethodDesc(pMD);
      pRetUnk = ComObject::GetComIPFromRCWThrowing(&pSrc, pComInfo->m_pInterfaceMT);
  
      *ppTarget = GetCOMIPFromRCW_GetTarget(pRetUnk, pComInfo);
      _ASSERTE(*ppTarget != NULL);
  
      GetCOMIPFromRCW_ClearFP();
  
      pIntf = pRetUnk.Extract();
  
      // No exception will be thrown here (including thread abort as it is delayed in IL stubs)
      HELPER_METHOD_FRAME_END();
  
      FC_INNER_EPILOG();
      return pIntf;
  }
  
  //==================================================================================================================
  // The GetCOMIPFromRCW helper exists in four specialized versions to optimize CLR->COM perf. Please be careful when
  // changing this code as one of these methods is executed as part of every CLR->COM call so every instruction counts.
  //==================================================================================================================
  
  
  #include <optsmallperfcritical.h>
  
  // This helper can handle any CLR->COM call, it supports hosting,
  // and clears FP state on x86 for compatibility with VB6.
  FCIMPL4(IUnknown*, StubHelpers::GetCOMIPFromRCW, Object* pSrcUNSAFE, MethodDesc* pMD, void **ppTarget, CLR_BOOL* pfNeedsRelease)
  {
      CONTRACTL
      {
          FCALL_CHECK;
          PRECONDITION(pMD->IsComPlusCall() || pMD->IsGenericComPlusCall() || pMD->IsEEImpl());
      }
      CONTRACTL_END;
  
      OBJECTREF pSrc = ObjectToOBJECTREF(pSrcUNSAFE);
      *pfNeedsRelease = false;
  
      ComPlusCallInfo *pComInfo = ComPlusCallInfo::FromMethodDesc(pMD);
      RCW *pRCW = pSrc->PassiveGetSyncBlock()->GetInteropInfoNoCreate()->GetRawRCW();
      if (pRCW != NULL)
      {
  
          IUnknown * pUnk = GetCOMIPFromRCW_GetIUnknownFromRCWCache(pRCW, pComInfo->m_pInterfaceMT);
          if (pUnk != NULL)
          {
              *ppTarget = GetCOMIPFromRCW_GetTarget(pUnk, pComInfo);
              if (*ppTarget != NULL)
              {
                  GetCOMIPFromRCW_ClearFP();
                  return pUnk;
              }
          }
      }
  
      /* if we didn't find the COM interface pointer in the cache we will have to erect an HMF */
      *pfNeedsRelease = true;
      FC_INNER_RETURN(IUnknown*, GetCOMIPFromRCWHelper(StubHelpers::GetCOMIPFromRCW, pSrc, pMD, ppTarget));
  }
  FCIMPLEND
  
  #include <optdefault.h>
  
  FCIMPL2(void, StubHelpers::ObjectMarshaler__ConvertToNative, Object* pSrcUNSAFE, VARIANT* pDest)
  {
      FCALL_CONTRACT;
  
      OBJECTREF pSrc = ObjectToOBJECTREF(pSrcUNSAFE);
  
      HELPER_METHOD_FRAME_BEGIN_1(pSrc);
      if (pDest->vt & VT_BYREF)
      {
          OleVariant::MarshalOleRefVariantForObject(&pSrc, pDest);
      }
      else
      {
          OleVariant::MarshalOleVariantForObject(&pSrc, pDest);
      }
      HELPER_METHOD_FRAME_END();
  }
  FCIMPLEND
  
  FCIMPL1(Object*, StubHelpers::ObjectMarshaler__ConvertToManaged, VARIANT* pSrc)
  {
      FCALL_CONTRACT;
  
      OBJECTREF retVal = NULL;
      HELPER_METHOD_FRAME_BEGIN_RET_1(retVal);
      // The IL stub is going to call ObjectMarshaler__ClearNative() afterwards.
      // If it doesn't it's a bug in ILObjectMarshaler.
      OleVariant::MarshalObjectForOleVariant(pSrc, &retVal);
      HELPER_METHOD_FRAME_END();
  
      return OBJECTREFToObject(retVal);
  }
  FCIMPLEND
  
  FCIMPL1(void, StubHelpers::ObjectMarshaler__ClearNative, VARIANT* pSrc)
  {
      FCALL_CONTRACT;
  
      HELPER_METHOD_FRAME_BEGIN_0();
      SafeVariantClear(pSrc);
      HELPER_METHOD_FRAME_END();
  }
  FCIMPLEND
  
  #include <optsmallperfcritical.h>
  FCIMPL4(IUnknown*, StubHelpers::InterfaceMarshaler__ConvertToNative, Object* pObjUNSAFE, MethodTable* pItfMT, MethodTable* pClsMT, DWORD dwFlags)
  {
      FCALL_CONTRACT;
  
      if (NULL == pObjUNSAFE)
      {
          return NULL;
      }
  
      IUnknown *pIntf = NULL;
      OBJECTREF pObj = ObjectToOBJECTREF(pObjUNSAFE);
  
      // This is only called in IL stubs which are in CER, so we don't need to worry about ThreadAbort
      HELPER_METHOD_FRAME_BEGIN_RET_ATTRIB_1(Frame::FRAME_ATTR_NO_THREAD_ABORT, pObj);
  
      // We're going to be making some COM calls, better initialize COM.
      EnsureComStarted();
  
      pIntf = MarshalObjectToInterface(&pObj, pItfMT, pClsMT, dwFlags);
  
      // No exception will be thrown here (including thread abort as it is delayed in IL stubs)
      HELPER_METHOD_FRAME_END();
  
      return pIntf;
  }
  FCIMPLEND
  
  FCIMPL4(Object*, StubHelpers::InterfaceMarshaler__ConvertToManaged, IUnknown **ppUnk, MethodTable *pItfMT, MethodTable *pClsMT, DWORD dwFlags)
  {
      FCALL_CONTRACT;
  
      if (NULL == *ppUnk)
      {
          return NULL;
      }
  
      OBJECTREF pObj = NULL;
      HELPER_METHOD_FRAME_BEGIN_RET_1(pObj);
  
      // We're going to be making some COM calls, better initialize COM.
      EnsureComStarted();
  
      UnmarshalObjectFromInterface(&pObj, ppUnk, pItfMT, pClsMT, dwFlags);
  
      HELPER_METHOD_FRAME_END();
  
      return OBJECTREFToObject(pObj);
  }
  FCIMPLEND
  
  void QCALLTYPE StubHelpers::InterfaceMarshaler__ClearNative(IUnknown * pUnk)
  {
      QCALL_CONTRACT;
  
      BEGIN_QCALL;
  
      ULONG cbRef = SafeReleasePreemp(pUnk);
      LogInteropRelease(pUnk, cbRef, "InterfaceMarshalerBase::ClearNative: In/Out release");
  
      END_QCALL;
  }
  #include <optdefault.h>
  
  #endif // FEATURE_COMINTEROP
  
  FCIMPL0(void, StubHelpers::SetLastError)
  {
      // Make sure this is the first thing we do after returning from the target, as almost everything can cause the last error to get trashed
      DWORD lastError = ::GetLastError();
  
      FCALL_CONTRACT;
  
      GetThread()->m_dwLastError = lastError;
  }
  FCIMPLEND
  
  FCIMPL0(void, StubHelpers::ClearLastError)
  {
      FCALL_CONTRACT;
  
      ::SetLastError(0);
  }
  FCIMPLEND
  
  FCIMPL1(FC_BOOL_RET, StubHelpers::IsQCall, NDirectMethodDesc* pNMD)
  {
      FCALL_CONTRACT;
      FC_RETURN_BOOL(pNMD->IsQCall());
  }
  FCIMPLEND
  
  NOINLINE static void InitDeclaringTypeHelper(MethodTable *pMT)
  {
      FC_INNER_PROLOG(StubHelpers::InitDeclaringType);
  
      HELPER_METHOD_FRAME_BEGIN_ATTRIB(Frame::FRAME_ATTR_EXACT_DEPTH|Frame::FRAME_ATTR_CAPTURE_DEPTH_2);
      pMT->CheckRunClassInitThrowing();
      HELPER_METHOD_FRAME_END();
  
      FC_INNER_EPILOG();
  }
  
  // Triggers cctor of pNMD's declarer, similar to code:JIT_InitClass.
  #include <optsmallperfcritical.h>
  FCIMPL1(void, StubHelpers::InitDeclaringType, NDirectMethodDesc* pNMD)
  {
      FCALL_CONTRACT;
  
      MethodTable *pMT = pNMD->GetMethodTable();
      _ASSERTE(!pMT->IsClassPreInited());
  
      if (pMT->GetDomainLocalModule()->IsClassInitialized(pMT))
          return;
  
      FC_INNER_RETURN_VOID(InitDeclaringTypeHelper(pMT));
  }
  FCIMPLEND
  #include <optdefault.h>
  
  FCIMPL1(void*, StubHelpers::GetNDirectTarget, NDirectMethodDesc* pNMD)
  {
      FCALL_CONTRACT;
  
      FCUnique(0xa2);
      return pNMD->GetNDirectTarget();
  }
  FCIMPLEND
  
  FCIMPL2(void*, StubHelpers::GetDelegateTarget, DelegateObject *pThisUNSAFE, UINT_PTR *ppStubArg)
  {
      PCODE pEntryPoint = NULL;
  
  #ifdef _DEBUG
      BEGIN_PRESERVE_LAST_ERROR;
  #endif
  
      CONTRACTL
      {
          FCALL_CHECK;
          PRECONDITION(CheckPointer(pThisUNSAFE));
      }
      CONTRACTL_END;
  
      DELEGATEREF orefThis = (DELEGATEREF)ObjectToOBJECTREF(pThisUNSAFE);
  
  #if defined(TARGET_X86)
      // On x86 we wrap the call with a thunk that handles host notifications.
      SyncBlock *pSyncBlock = orefThis->PassiveGetSyncBlock();
      if (pSyncBlock != NULL)
      {
          InteropSyncBlockInfo *pInteropInfo = pSyncBlock->GetInteropInfoNoCreate();
          if (pInteropInfo != NULL)
          {
              // we return entry point to a stub that wraps the real target
              Stub *pInterceptStub = pInteropInfo->GetInterceptStub();
              if (pInterceptStub != NULL)
              {
                  pEntryPoint = pInterceptStub->GetEntryPoint();
              }
          }
      }
  #endif // TARGET_X86
  
  #if defined(HOST_64BIT)
      UINT_PTR target = (UINT_PTR)orefThis->GetMethodPtrAux();
  
      // See code:GenericPInvokeCalliHelper
      // The lowest bit is used to distinguish between MD and target on 64-bit.
      target = (target << 1) | 1;
  
      // On 64-bit we pass the real target to the stub-for-host through this out argument,
      // see IL code gen in NDirectStubLinker::DoNDirect for details.
      *ppStubArg = target;
  
  #elif defined(TARGET_ARM)
      // @ARMTODO: Nothing to do for ARM yet since we don't support the hosted path.
  #endif // HOST_64BIT, TARGET_ARM
  
      if (pEntryPoint == NULL)
      {
          pEntryPoint = orefThis->GetMethodPtrAux();
      }
  
  #ifdef _DEBUG
      END_PRESERVE_LAST_ERROR;
  #endif
  
      return (PVOID)pEntryPoint;
  }
  FCIMPLEND
  
  
  
  FCIMPL2(void, StubHelpers::ThrowInteropParamException, UINT resID, UINT paramIdx)
  {
      FCALL_CONTRACT;
  
      HELPER_METHOD_FRAME_BEGIN_0();
      ::ThrowInteropParamException(resID, paramIdx);
      HELPER_METHOD_FRAME_END();
  }
  FCIMPLEND
  
  #ifdef FEATURE_COMINTEROP
  class COMInterfaceMarshalerCallback : public ICOMInterfaceMarshalerCallback
  {
  public :
      COMInterfaceMarshalerCallback(Thread *pThread, LPVOID pCtxCookie)
      {
          CONTRACTL
          {
              NOTHROW;
              GC_TRIGGERS;
              MODE_ANY;
          }
          CONTRACTL_END;
  
          _ASSERTE(pThread != NULL);
          _ASSERTE(pCtxCookie != NULL);
  
          m_bIsFreeThreaded = false;
          m_pThread = pThread;
          m_pCtxCookie = pCtxCookie;
  
          m_bIsDCOMProxy = false;
      }
  
      virtual void OnRCWCreated(RCW *pRCW)
      {
          LIMITED_METHOD_CONTRACT;
  
          _ASSERTE(pRCW != NULL);
  
          if (pRCW->IsFreeThreaded())
              m_bIsFreeThreaded = true;
  
          if (pRCW->IsDCOMProxy())
              m_bIsDCOMProxy = true;
      }
  
      // Return true if ComInterfaceMarshaler should use this RCW
      // Return false if ComInterfaceMarshaler should just skip this RCW and proceed
      // to create a duplicate one instead
      virtual bool ShouldUseThisRCW(RCW *pRCW)
      {
          LIMITED_METHOD_CONTRACT;
  
          // Is this a free threaded RCW or a context-bound RCW created in the same context
          if (pRCW->IsFreeThreaded() ||
              pRCW->GetWrapperCtxCookie() == m_pCtxCookie)
          {
              return true;
          }
          else
          {
              //
              // Now we get back a WinRT factory RCW created in a different context. This means the
              // factory is a singleton, and the returned IActivationFactory could be either one of
              // the following:
              // 1) A raw pointer, and it acts like a free threaded object
              // 2) A proxy that is used across different contexts. It might maintain a list of contexts
              // that it is marshaled to, and will fail to be called if it is not marshaled to this
              // context yet.
              //
              // In this case, it is unsafe to use this RCW in this context and we should proceed
              // to create a duplicated one instead. It might make sense to have a context-sensitive
              // RCW cache but I don't think this case will be common enough to justify it
              //
              return false;
          }
      }
  
      virtual void OnRCWCacheHit(RCW *pRCW)
      {
          LIMITED_METHOD_CONTRACT;
  
          if (pRCW->IsFreeThreaded())
              m_bIsFreeThreaded = true;
  
          if (pRCW->IsDCOMProxy())
              m_bIsDCOMProxy = true;
      }
  
      bool IsFreeThreaded()
      {
          LIMITED_METHOD_CONTRACT;
  
          return m_bIsFreeThreaded;
      }
  
      bool IsDCOMProxy()
      {
          LIMITED_METHOD_CONTRACT;
  
          return m_bIsDCOMProxy;
      }
  
  private :
      Thread *m_pThread;          // Current thread
      LPVOID m_pCtxCookie;        // Current context cookie
      bool   m_bIsFreeThreaded;   // Whether we got back the RCW from a different context
      bool   m_bIsDCOMProxy;      // Is this a proxy to an object in a different process
  };
  
  #endif
  
  #ifdef PROFILING_SUPPORTED
  FCIMPL3(SIZE_T, StubHelpers::ProfilerBeginTransitionCallback, SIZE_T pSecretParam, Thread* pThread, Object* unsafe_pThis)
  {
      FCALL_CONTRACT;
  
      // We can get here with an ngen image generated with "/prof",
      // even if the profiler doesn't want to track transitions.
      if (!CORProfilerTrackTransitions())
      {
          return NULL;
      }
  
      MethodDesc* pRealMD = NULL;
  
      BEGIN_PRESERVE_LAST_ERROR;
  
      // We must transition to preemptive GC mode before calling out to the profiler,
      // and the transition requires us to set up a HMF.
      DELEGATEREF dref = (DELEGATEREF)ObjectToOBJECTREF(unsafe_pThis);
      HELPER_METHOD_FRAME_BEGIN_RET_1(dref);
  
      bool fReverseInterop = false;
  
      if (NULL == pThread)
      {
          // This is our signal for the reverse interop cases.
          fReverseInterop = true;
          pThread = GET_THREAD();
          // the secret param in this casee is the UMEntryThunk
          pRealMD = ((UMEntryThunk*)pSecretParam)->GetMethod();
      }
      else
      if (pSecretParam == 0)
      {
          // Secret param is null.  This is the calli pinvoke case or the unmanaged delegate case.
          // We have an unmanaged target address but no MD.  For the unmanaged delegate case, we can
          // still retrieve the MD by looking at the "this" object.
  
          if (dref == NULL)
          {
              // calli pinvoke case
              pRealMD = NULL;
          }
          else
          {
              // unmanaged delegate case
              MethodTable* pMT = dref->GetMethodTable();
              _ASSERTE(pMT->IsDelegate());
  
              EEClass * pClass = pMT->GetClass();
              pRealMD = ((DelegateEEClass*)pClass)->GetInvokeMethod();
              _ASSERTE(pRealMD);
          }
      }
      else
      {
          // This is either the COM interop or the pinvoke case.
          pRealMD = (MethodDesc*)pSecretParam;
      }
  
      {
          GCX_PREEMP_THREAD_EXISTS(pThread);
  
          if (fReverseInterop)
          {
              ProfilerUnmanagedToManagedTransitionMD(pRealMD, COR_PRF_TRANSITION_CALL);
          }
          else
          {
              ProfilerManagedToUnmanagedTransitionMD(pRealMD, COR_PRF_TRANSITION_CALL);
          }
      }
  
      HELPER_METHOD_FRAME_END();
  
      END_PRESERVE_LAST_ERROR;
  
      return (SIZE_T)pRealMD;
  }
  FCIMPLEND
  
  FCIMPL2(void, StubHelpers::ProfilerEndTransitionCallback, MethodDesc* pRealMD, Thread* pThread)
  {
      FCALL_CONTRACT;
  
      // We can get here with an ngen image generated with "/prof",
      // even if the profiler doesn't want to track transitions.
      if (!CORProfilerTrackTransitions())
      {
          return;
      }
  
      BEGIN_PRESERVE_LAST_ERROR;
  
      // We must transition to preemptive GC mode before calling out to the profiler,
      // and the transition requires us to set up a HMF.
      HELPER_METHOD_FRAME_BEGIN_0();
      {
          bool fReverseInterop = false;
  
          if (NULL == pThread)
          {
              // if pThread is null, we are doing reverse interop
              pThread = GET_THREAD();
              fReverseInterop = true;
          }
  
          GCX_PREEMP_THREAD_EXISTS(pThread);
  
          if (fReverseInterop)
          {
              ProfilerManagedToUnmanagedTransitionMD(pRealMD, COR_PRF_TRANSITION_RETURN);
          }
          else
          {
              ProfilerUnmanagedToManagedTransitionMD(pRealMD, COR_PRF_TRANSITION_RETURN);
          }
      }
      HELPER_METHOD_FRAME_END();
  
      END_PRESERVE_LAST_ERROR;
  }
  FCIMPLEND
  #endif // PROFILING_SUPPORTED
  
  FCIMPL1(Object*, StubHelpers::GetHRExceptionObject, HRESULT hr)
  {
      FCALL_CONTRACT;
  
      OBJECTREF oThrowable = NULL;
  
      HELPER_METHOD_FRAME_BEGIN_RET_1(oThrowable);
      {
          // GetExceptionForHR uses equivalant logic as COMPlusThrowHR
          GetExceptionForHR(hr, &oThrowable);
      }
      HELPER_METHOD_FRAME_END();
  
      return OBJECTREFToObject(oThrowable);
  }
  FCIMPLEND
  
  #ifdef FEATURE_COMINTEROP
  FCIMPL3(Object*, StubHelpers::GetCOMHRExceptionObject, HRESULT hr, MethodDesc *pMD, Object *unsafe_pThis)
  {
      FCALL_CONTRACT;
  
      OBJECTREF oThrowable = NULL;
  
      // get 'this'
      OBJECTREF oref = ObjectToOBJECTREF(unsafe_pThis);
  
      HELPER_METHOD_FRAME_BEGIN_RET_2(oref, oThrowable);
      {
          IErrorInfo *pErrInfo = NULL;
  
          if (pErrInfo == NULL && pMD != NULL)
          {
              // Retrieve the interface method table.
              MethodTable *pItfMT = ComPlusCallInfo::FromMethodDesc(pMD)->m_pInterfaceMT;
  
              // Get IUnknown pointer for this interface on this object
              IUnknown* pUnk = ComObject::GetComIPFromRCW(&oref, pItfMT);
              if (pUnk != NULL)
              {
                  // Check to see if the component supports error information for this interface.
                  IID ItfIID;
                  pItfMT->GetGuid(&ItfIID, TRUE);
                  pErrInfo = GetSupportedErrorInfo(pUnk, ItfIID);
  
                  DWORD cbRef = SafeRelease(pUnk);
                  LogInteropRelease(pUnk, cbRef, "IUnk to QI for ISupportsErrorInfo");
              }
          }
  
          GetExceptionForHR(hr, pErrInfo, &oThrowable);
      }
      HELPER_METHOD_FRAME_END();
  
      return OBJECTREFToObject(oThrowable);
  }
  FCIMPLEND
  #endif // FEATURE_COMINTEROP
  
  FCIMPL3(void, StubHelpers::FmtClassUpdateNativeInternal, Object* pObjUNSAFE, BYTE* pbNative, OBJECTREF *ppCleanupWorkListOnStack)
  {
      FCALL_CONTRACT;
  
      OBJECTREF pObj = ObjectToOBJECTREF(pObjUNSAFE);
      HELPER_METHOD_FRAME_BEGIN_1(pObj);
  
      MethodTable* pMT = pObj->GetMethodTable();
  
      if (pMT->IsBlittable())
      {
          memcpyNoGCRefs(pbNative, pObj->GetData(), pMT->GetNativeSize());
      }
      else
      {
          MethodDesc* structMarshalStub;
  
          {
              GCX_PREEMP();
              structMarshalStub = NDirect::CreateStructMarshalILStub(pMT);
          }
  
          MarshalStructViaILStub(structMarshalStub, pObj->GetData(), pbNative, StructMarshalStubs::MarshalOperation::Marshal, (void**)ppCleanupWorkListOnStack);
      }
  
      HELPER_METHOD_FRAME_END();
  }
  FCIMPLEND
  
  FCIMPL2(void, StubHelpers::FmtClassUpdateCLRInternal, Object* pObjUNSAFE, BYTE* pbNative)
  {
      FCALL_CONTRACT;
  
      OBJECTREF pObj = ObjectToOBJECTREF(pObjUNSAFE);
      HELPER_METHOD_FRAME_BEGIN_1(pObj);
  
      MethodTable* pMT = pObj->GetMethodTable();
  
      if (pMT->IsBlittable())
      {
          memcpyNoGCRefs(pObj->GetData(), pbNative, pMT->GetNativeSize());
      }
      else
      {
          MethodDesc* structMarshalStub;
  
          {
              GCX_PREEMP();
              structMarshalStub = NDirect::CreateStructMarshalILStub(pMT);
          }
  
          MarshalStructViaILStub(structMarshalStub, pObj->GetData(), pbNative, StructMarshalStubs::MarshalOperation::Unmarshal);
      }
  
      HELPER_METHOD_FRAME_END();
  }
  FCIMPLEND
  
  FCIMPL2(void, StubHelpers::LayoutDestroyNativeInternal, Object* pObjUNSAFE, BYTE* pbNative)
  {
      FCALL_CONTRACT;
  
      OBJECTREF pObj = ObjectToOBJECTREF(pObjUNSAFE);
      HELPER_METHOD_FRAME_BEGIN_1(pObj);
      MethodTable* pMT = pObj->GetMethodTable();
  
      if (!pMT->IsBlittable())
      {
          MethodDesc* structMarshalStub;
  
          {
              GCX_PREEMP();
              structMarshalStub = NDirect::CreateStructMarshalILStub(pMT);
          }
  
          MarshalStructViaILStub(structMarshalStub, pObj->GetData(), pbNative, StructMarshalStubs::MarshalOperation::Cleanup);
      }
  
      HELPER_METHOD_FRAME_END();
  }
  FCIMPLEND
  
  FCIMPL1(Object*, StubHelpers::AllocateInternal, EnregisteredTypeHandle pRegisteredTypeHnd)
  {
      FCALL_CONTRACT;
  
      TypeHandle typeHnd = TypeHandle::FromPtr(pRegisteredTypeHnd);
      OBJECTREF objRet = NULL;
      HELPER_METHOD_FRAME_BEGIN_RET_1(objRet);
  
      MethodTable* pMT = typeHnd.GetMethodTable();
      objRet = pMT->Allocate();
  
      HELPER_METHOD_FRAME_END();
  
      return OBJECTREFToObject(objRet);
  }
  FCIMPLEND
  
  FCIMPL3(void, StubHelpers::MarshalToUnmanagedVaListInternal, va_list va, DWORD cbVaListSize, const VARARGS* pArgIterator)
  {
      FCALL_CONTRACT;
  
      HELPER_METHOD_FRAME_BEGIN_0();
      VARARGS::MarshalToUnmanagedVaList(va, cbVaListSize, pArgIterator);
      HELPER_METHOD_FRAME_END();
  }
  FCIMPLEND
  
  FCIMPL2(void, StubHelpers::MarshalToManagedVaListInternal, va_list va, VARARGS* pArgIterator)
  {
      FCALL_CONTRACT;
  
      VARARGS::MarshalToManagedVaList(va, pArgIterator);
  }
  FCIMPLEND
  
  FCIMPL3(void, StubHelpers::ValidateObject, Object *pObjUNSAFE, MethodDesc *pMD, Object *pThisUNSAFE)
  {
      FCALL_CONTRACT;
  
  #ifdef VERIFY_HEAP
      HELPER_METHOD_FRAME_BEGIN_0();
  
      StackSString errorString;
      EX_TRY
      {
          AVInRuntimeImplOkayHolder AVOkay;
  		// don't validate the next object if a BGC is in progress.  we can race with background
  	    // sweep which could make the next object a Free object underneath us if it's dead.
          ValidateObjectInternal(pObjUNSAFE, !(GCHeapUtilities::GetGCHeap()->IsConcurrentGCInProgress()));
      }
      EX_CATCH
      {
          FormatValidationMessage(ResolveInteropMethod(pThisUNSAFE, pMD), errorString);
          EEPOLICY_HANDLE_FATAL_ERROR_WITH_MESSAGE(COR_E_EXECUTIONENGINE, errorString.GetUnicode());
      }
      EX_END_CATCH_UNREACHABLE;
  
      HELPER_METHOD_FRAME_END();
  #else // VERIFY_HEAP
      FCUnique(0xa3);
      UNREACHABLE_MSG("No validation support without VERIFY_HEAP");
  #endif // VERIFY_HEAP
  }
  FCIMPLEND
  
  FCIMPL3(void, StubHelpers::ValidateByref, void *pByref, MethodDesc *pMD, Object *pThisUNSAFE)
  {
      FCALL_CONTRACT;
  
  #ifdef VERIFY_HEAP
      // We cannot validate byrefs at this point as code:GCHeap.GetContainingObject could potentially race
      // with allocations on other threads. We'll just remember this byref along with the interop MD and
      // perform the validation on next GC (see code:StubHelpers.ProcessByrefValidationList).
  
      // Skip byref if is not pointing inside managed heap
      if (!GCHeapUtilities::GetGCHeap()->IsHeapPointer(pByref))
      {
          return;
      }
      ByrefValidationEntry entry;
      entry.pByref = pByref;
      entry.pMD = ResolveInteropMethod(pThisUNSAFE, pMD);
  
      HELPER_METHOD_FRAME_BEGIN_0();
  
      SIZE_T NumOfEntries = 0;
      {
          CrstHolder ch(&s_ByrefValidationLock);
  
          if (s_ByrefValidationIndex >= s_ByrefValidationEntries.Size())
          {
              // The validation list grows as necessary, for simplicity we never shrink it.
              SIZE_T newSize;
              if (!ClrSafeInt<SIZE_T>::multiply(s_ByrefValidationIndex, 2, newSize) ||
                  !ClrSafeInt<SIZE_T>::addition(newSize, 1, newSize))
              {
                  ThrowHR(COR_E_OVERFLOW);
              }
  
              s_ByrefValidationEntries.ReSizeThrows(newSize);
              _ASSERTE(s_ByrefValidationIndex < s_ByrefValidationEntries.Size());
          }
  
          s_ByrefValidationEntries[s_ByrefValidationIndex] = entry;
          NumOfEntries = ++s_ByrefValidationIndex;
      }
  
      if (NumOfEntries > BYREF_VALIDATION_LIST_MAX_SIZE)
      {
          // if the list is too big, trigger GC now
          GCHeapUtilities::GetGCHeap()->GarbageCollect(0);
      }
  
      HELPER_METHOD_FRAME_END();
  #else // VERIFY_HEAP
      FCUnique(0xa4);
      UNREACHABLE_MSG("No validation support without VERIFY_HEAP");
  #endif // VERIFY_HEAP
  }
  FCIMPLEND
  
  FCIMPL0(void*, StubHelpers::GetStubContext)
  {
      FCALL_CONTRACT;
  
      FCUnique(0xa0);
      UNREACHABLE_MSG_RET("This is a JIT intrinsic!");
  }
  FCIMPLEND
  
  FCIMPL2(void, StubHelpers::LogPinnedArgument, MethodDesc *target, Object *pinnedArg)
  {
      FCALL_CONTRACT;
  
      SIZE_T managedSize = 0;
  
      if (pinnedArg != NULL)
      {
          // Can pass null objects to interop, only check the size if the object is valid.
          managedSize = pinnedArg->GetSize();
      }
  
      if (target != NULL)
      {
          STRESS_LOG3(LF_STUBS, LL_INFO100, "Managed object %#X with size '%#X' pinned for interop to Method [%pM]\n", pinnedArg, managedSize, target);
      }
      else
      {
          STRESS_LOG2(LF_STUBS, LL_INFO100, "Managed object %#X pinned for interop with size '%#X'", pinnedArg, managedSize);
      }
  }
  FCIMPLEND
  
  #ifdef TARGET_64BIT
  FCIMPL0(void*, StubHelpers::GetStubContextAddr)
  {
      FCALL_CONTRACT;
  
      FCUnique(0xa1);
      UNREACHABLE_MSG("This is a JIT intrinsic!");
  }
  FCIMPLEND
  #endif // TARGET_64BIT
  
  FCIMPL1(DWORD, StubHelpers::CalcVaListSize, VARARGS *varargs)
  {
      FCALL_CONTRACT;
  
      return VARARGS::CalcVaListSize(varargs);
  }
  FCIMPLEND
  
  #ifdef FEATURE_ARRAYSTUB_AS_IL
  NOINLINE static void ArrayTypeCheckSlow(Object* element, PtrArray* arr)
  {
      FC_INNER_PROLOG(StubHelpers::ArrayTypeCheck);
      HELPER_METHOD_FRAME_BEGIN_ATTRIB(Frame::FRAME_ATTR_EXACT_DEPTH|Frame::FRAME_ATTR_CAPTURE_DEPTH_2);
  
      if (!ObjIsInstanceOf(element, arr->GetArrayElementTypeHandle()))
          COMPlusThrow(kArrayTypeMismatchException);
  
      HELPER_METHOD_FRAME_END();
  
      FC_INNER_EPILOG();
  }
  
  FCIMPL2(void, StubHelpers::ArrayTypeCheck, Object* element, PtrArray* arr)
  {
      FCALL_CONTRACT;
  
      if (ObjIsInstanceOfCached(element, arr->GetArrayElementTypeHandle()) == TypeHandle::CanCast)
          return;
  
      FC_INNER_RETURN_VOID(ArrayTypeCheckSlow(element, arr));
  }
  FCIMPLEND
  #endif // FEATURE_ARRAYSTUB_AS_IL
  
  #ifdef FEATURE_MULTICASTSTUB_AS_IL
  FCIMPL2(void, StubHelpers::MulticastDebuggerTraceHelper, Object* element, INT32 count)
  {
      FCALL_CONTRACT;
      FCUnique(0xa5);
  }
  FCIMPLEND
  #endif // FEATURE_MULTICASTSTUB_AS_IL
  
  FCIMPL0(void*, StubHelpers::NextCallReturnAddress)
  {
      FCALL_CONTRACT;
      UNREACHABLE_MSG("This is a JIT intrinsic!");
  }
  FCIMPLEND
  