/// <summary>
/// Returns the size of the struct using ICppStructOps, otherwise falls back to GetStructureSize().
/// </summary>
/// <returns></returns>
public int GetStructSize()
{
UScriptStruct scriptStruct = this as UScriptStruct;
if (scriptStruct != null)
{
IntPtr cppStructOps = Native_UScriptStruct.GetCppStructOps(scriptStruct.Address);
if (cppStructOps != IntPtr.Zero)
{
return(Native_ICppStructOps.GetSize(cppStructOps));
}
}
return(GetStructureSize());
}
/// <summary>
/// Checks if the given UScriptStruct address is POD and has a zero constructor (initializes to zero).
///
/// NOTE: A struct could be PlainOldData but unsafe to zero initialize due to having a non-zero constructor / EForceInit constructor.
/// </summary>
internal static bool IsPODZeroInit(IntPtr unrealStruct)
{
if (unrealStruct != IntPtr.Zero && Native_UObjectBaseUtility.IsA(unrealStruct, Classes.UScriptStruct))
{
EStructFlags structFlags = Native_UScriptStruct.Get_StructFlags(unrealStruct);
IntPtr cppStructOps = Native_UScriptStruct.GetCppStructOps(unrealStruct);
if (cppStructOps != IntPtr.Zero)
{
bool isPlainOldData = Native_ICppStructOps.IsPlainOldData(cppStructOps);
bool hasZeroConstructor = Native_ICppStructOps.HasZeroConstructor(cppStructOps);
bool hasNoopConstructor = Native_ICppStructOps.HasNoopConstructor(cppStructOps);
if (!hasZeroConstructor && structFlags.HasFlag(EStructFlags.ZeroConstructor))
{
// This struct flag could have been set in the zero constructor check in UScriptStruct::PrepareCppStructOps
hasZeroConstructor = true;
}
if (isPlainOldData && hasZeroConstructor && !hasNoopConstructor)
{
return(true);
}
if (isPlainOldData && !hasZeroConstructor)
{
if (hasNoopConstructor)
{
// The struct has a no-op constructor and takes EForceInit to init
return(false);
}
// This is a copy of a check made in UScriptStruct::PrepareCppStructOps to check if the struct constructs to zero
// if (CppStructOps->IsPlainOldData() && !CppStructOps->HasZeroConstructor()) { ... }
int size = Native_ICppStructOps.GetSize(cppStructOps);
IntPtr buffer = FMemory.Malloc(size);
FMemory.Memzero(buffer, size);
Native_ICppStructOps.Construct(cppStructOps, buffer);
Native_ICppStructOps.Construct(cppStructOps, buffer);// slightly more like to catch "internal counters" if we do this twice
bool isZeroConstruct = true;
unsafe
{
byte *bufferPtr = (byte *)buffer;
for (int i = 0; i < size; i++)
{
if (bufferPtr[i] != 0)
{
isZeroConstruct = false;
break;
}
}
}
FMemory.Free(buffer);
if (isZeroConstruct)
{
// "Native struct %s has DISCOVERED zero construction. Size = %d"
System.Diagnostics.Debugger.Break();
return(true);
}
}
return(false);
}
else
{
// Only treat it as blittable if it is POD and has a zero constructor
return(structFlags.HasFlag(EStructFlags.IsPlainOldData | EStructFlags.ZeroConstructor));
}
}
return(false);
}