Remove all current uses of PInvokeArgIterator and the flow of native stack arg sizes through our data structures where possible

src/coreclr/vm/clrtocomcall.cpp

@@ -69,7 +69,9 @@ CLRToCOMCallInfo *CLRToCOMCall::PopulateCLRToCOMCallMethodDesc(MethodDesc* pMD,
             LoaderHeap *pHeap = pMD->GetLoaderAllocator()->GetHighFrequencyHeap();
             CLRToCOMCallInfo *pTemp = (CLRToCOMCallInfo *)(void *)pHeap->AllocMem(S_SIZE_T(sizeof(CLRToCOMCallInfo)));
 
+#ifdef TARGET_X86
             pTemp->InitStackArgumentSize();
+#endif // TARGET_X86
 
             InterlockedCompareExchangeT(&pCMD->m_pCLRToCOMCallInfo, pTemp, NULL);
         }

src/coreclr/vm/comdelegate.cpp

@@ -812,7 +812,9 @@ CLRToCOMCallInfo * COMDelegate::PopulateCLRToCOMCallInfo(MethodTable * pDelMT)
         CLRToCOMCallInfo *pTemp = (CLRToCOMCallInfo *)(void *)pHeap->AllocMem(S_SIZE_T(sizeof(CLRToCOMCallInfo)));
 
         pTemp->m_cachedComSlot = ComMethodTable::GetNumExtraSlots(ifVtable);
+#ifdef TARGET_X86
         pTemp->InitStackArgumentSize();
+#endif // TARGET_X86
 
         InterlockedCompareExchangeT(&pClass->m_pCLRToCOMCallInfo, pTemp, NULL);
     }

src/coreclr/vm/dllimport.cpp

@@ -491,7 +491,7 @@ class ILStubState : public StubState
                 pStubMD->SetStatic();
             }
 
-#ifndef TARGET_X86
+#if !defined(TARGET_X86) && defined(FEATURE_DYNAMIC_METHOD_HAS_NATIVE_STACK_ARG_SIZE)
             // we store the real managed argument stack size in the stub MethodDesc on non-X86
             UINT stackSize = pStubMD->SizeOfNativeArgStack();
 
@@ -3477,6 +3477,7 @@ BOOL PInvoke::MarshalingRequired(
     if (!FitsInU2(dwStackSize))
         return TRUE;
 
+#ifdef TARGET_X86
     // do not set the stack size for varargs - the number is call site specific
     if (pMD != NULL && !pMD->IsVarArg())
     {
@@ -3492,6 +3493,7 @@ BOOL PInvoke::MarshalingRequired(
         }
 #endif // FEATURE_COMINTEROP
     }
+#endif // TARGET_X86
 
     return FALSE;
 }
@@ -3886,11 +3888,13 @@ static void CreatePInvokeStubWorker(StubState*               pss,
         if (!FitsInU2(nativeStackSize))
             COMPlusThrow(kMarshalDirectiveException, IDS_EE_SIGTOOCOMPLEX);
 
+#ifdef FEATURE_DYNAMIC_METHOD_HAS_NATIVE_STACK_ARG_SIZE
         DynamicMethodDesc *pDMD = pMD->AsDynamicMethodDesc();
 
         pDMD->SetNativeStackArgSize(static_cast<WORD>(nativeStackSize));
         if (fStubNeedsCOM)
             pDMD->SetFlags(DynamicMethodDesc::FlagRequiresCOM);
+#endif
     }
 
     // FinishEmit needs to know the native stack arg size so we call it after the number
@@ -3984,11 +3988,13 @@ static void CreateStructStub(ILStubState* pss,
         pss->MarshalField(&mlInfo, managedOffset, externalOffset, pFD);
     }
 
+#if defined(FEATURE_DYNAMIC_METHOD_HAS_NATIVE_STACK_ARG_SIZE)
     if (pMD->IsDynamicMethod())
     {
         DynamicMethodDesc* pDMD = pMD->AsDynamicMethodDesc();
         pDMD->SetNativeStackArgSize(4 * TARGET_POINTER_SIZE); // The native stack arg size is constant since the signature for struct stubs is constant.
     }
+#endif
 
     // FinishEmit needs to know the native stack arg size so we call it after the number
     // has been set in the stub MD (code:DynamicMethodDesc.SetNativeStackArgSize)

src/coreclr/vm/method.cpp

@@ -1728,7 +1728,7 @@ UINT MethodDesc::SizeOfArgStack()
     return argit.SizeOfArgStack();
 }
 
-
+#ifdef FEATURE_DYNAMIC_METHOD_HAS_NATIVE_STACK_ARG_SIZE
 UINT MethodDesc::SizeOfNativeArgStack()
 {
 #ifndef UNIX_AMD64_ABI
@@ -1740,6 +1740,7 @@ UINT MethodDesc::SizeOfNativeArgStack()
     return argit.SizeOfArgStack();
 #endif
 }
+#endif // FEATURE_DYNAMIC_METHOD_HAS_NATIVE_STACK_ARG_SIZE
 
 #ifdef TARGET_X86
 //*******************************************************************************

src/coreclr/vm/method.hpp

@@ -60,6 +60,10 @@ EXTERN_C VOID STDCALL PInvokeImportThunk();
 #define METHOD_TOKEN_RANGE_BIT_COUNT (24 - METHOD_TOKEN_REMAINDER_BIT_COUNT)
 #define METHOD_TOKEN_RANGE_MASK ((1 << METHOD_TOKEN_RANGE_BIT_COUNT) - 1)
 
+#if defined(TARGET_X86) || defined(FEATURE_COMINTEROP)
+#define FEATURE_DYNAMIC_METHOD_HAS_NATIVE_STACK_ARG_SIZE
+#endif
+
 enum class AsyncMethodFlags
 {
     // Method uses CORINFO_CALLCONV_ASYNCCALL call convention.
@@ -858,9 +862,11 @@ class MethodDesc
     // arguments passed in registers.
     UINT SizeOfArgStack();
 
+#ifdef FEATURE_DYNAMIC_METHOD_HAS_NATIVE_STACK_ARG_SIZE
     // Returns the # of bytes of stack used by arguments in a call from native to this function.
     // Does not include arguments passed in registers.
     UINT SizeOfNativeArgStack();
+#endif // FEATURE_DYNAMIC_METHOD_HAS_NATIVE_STACK_ARG_SIZE
 
     // Returns the # of bytes to pop after a call. Not necessary the
     // same as SizeOfArgStack()!
@@ -2887,23 +2893,25 @@ class DynamicMethodDesc : public StoredSigMethodDesc
         return asMetadata;
     }
 
+#if defined(TARGET_X86) || defined(FEATURE_COMINTEROP)
     WORD GetNativeStackArgSize()
     {
         LIMITED_METHOD_DAC_CONTRACT;
         _ASSERTE(IsILStub());
         return (WORD)((m_dwExtendedFlags & StackArgSizeMask) >> 16);
     }
-
+    
     void SetNativeStackArgSize(WORD cbArgSize)
     {
         LIMITED_METHOD_CONTRACT;
         _ASSERTE(IsILStub());
-#if !defined(OSX_ARM64_ABI)
+        #if !defined(OSX_ARM64_ABI)
         _ASSERTE((cbArgSize % TARGET_POINTER_SIZE) == 0);
-#endif
+        #endif
         m_dwExtendedFlags = (m_dwExtendedFlags & ~StackArgSizeMask) | ((DWORD)cbArgSize << 16);
     }
-
+#endif // TARGET_X86 || FEATURE_COMINTEROP
+
     bool IsReversePInvokeStub() const
     {
         LIMITED_METHOD_DAC_CONTRACT;
@@ -3333,11 +3341,11 @@ class PInvokeMethodDesc : public MethodDesc
 #endif
 public:
 
+#if defined(TARGET_X86)
     void SetStackArgumentSize(WORD cbDstBuffer, CorInfoCallConvExtension unmgdCallConv)
     {
         LIMITED_METHOD_CONTRACT;
 
-#if defined(TARGET_X86)
         // thiscall passes the this pointer in ECX
         if (unmgdCallConv == CorInfoCallConvExtension::Thiscall)
         {
@@ -3354,10 +3362,8 @@ class PInvokeMethodDesc : public MethodDesc
         {
             _ASSERTE(m_cbStackArgumentSize == cbDstBuffer);
         }
-#endif // defined(TARGET_X86)
     }
 
-#if defined(TARGET_X86)
     void EnsureStackArgumentSize();
 
     WORD GetStackArgumentSize() const
@@ -3475,16 +3481,6 @@ struct CLRToCOMCallInfo
         _ASSERTE(m_cbStackArgumentSize != 0xFFFF);
         return m_cbStackArgumentSize;
     }
-#else // TARGET_X86
-    void InitStackArgumentSize()
-    {
-        LIMITED_METHOD_CONTRACT;
-    }
-
-    void SetStackArgumentSize(WORD cbDstBuffer)
-    {
-        LIMITED_METHOD_CONTRACT;
-    }
 #endif // TARGET_X86
 };
 
@@ -3554,11 +3550,6 @@ class CLRToCOMCallMethodDesc : public MethodDesc
         LIMITED_METHOD_CONTRACT;
         m_pCLRToCOMCallInfo->m_cbStackPop = (WORD)CbStackPop();
     }
-#else // TARGET_X86
-    void SetStackArgumentSize(WORD cbDstBuffer)
-    {
-        LIMITED_METHOD_CONTRACT;
-    }
 #endif // TARGET_X86
 };
 #endif // FEATURE_COMINTEROP