I have a question for ObjectNative::Equals.

[Takym]

Hello,

I was looking up the behavior of object.Equals and found the code below.

runtime/src/coreclr/classlibnative/bcltype/objectnative.cpp

Lines 139 to 178 in 911640b

	FCIMPL2(FC_BOOL_RET, ObjectNative::Equals, Object *pThisRef, Object *pCompareRef)
	{
	CONTRACTL
	{
	FCALL_CHECK;
	INJECT_FAULT(FCThrow(kOutOfMemoryException););
	}
	CONTRACTL_END;
	if (pThisRef == pCompareRef)
	FC_RETURN_BOOL(TRUE);
	// Since we are in FCALL, we must handle NULL specially.
	if (pThisRef == NULL || pCompareRef == NULL)
	FC_RETURN_BOOL(FALSE);
	MethodTable *pThisMT = pThisRef->GetMethodTable();
	// If it's not a value class, don't compare by value
	if (!pThisMT->IsValueType())
	FC_RETURN_BOOL(FALSE);
	// Make sure they are the same type.
	if (pThisMT != pCompareRef->GetMethodTable())
	FC_RETURN_BOOL(FALSE);
	// Compare the contents (size - vtable - sync block index).
	DWORD dwBaseSize = pThisRef->GetMethodTable()->GetBaseSize();
	if(pThisRef->GetMethodTable() == g_pStringClass)
	dwBaseSize -= sizeof(WCHAR);
	BOOL ret = memcmp(
	(void *) (pThisRef+1),
	(void *) (pCompareRef+1),
	dwBaseSize - sizeof(Object) - sizeof(int)) == 0;
	FC_GC_POLL_RET();
	FC_RETURN_BOOL(ret);
	}
	FCIMPLEND

In the above code, why does not use pThisMT since line 166? Is there a special action in the function pThisRef->GetMethodTable()?

Thanks

[jkotas]

You are right that the code can use pThisMT instead of pThisRef->GetMethodTable(). You are welcomed to submit PR to fix it.

[Takym]

Thank you for replying. I submitted PR #54138.