public override ComputedInstanceFieldLayout ComputeInstanceLayout(DefType type, InstanceLayoutKind layoutKind)
{
if (!type.IsTemplateUniversal() && (layoutKind == InstanceLayoutKind.TypeOnly))
{
// Non universal generics can just use the template's layout
DefType template = (DefType)type.ComputeTemplate();
return _noMetadataFieldLayoutAlgorithm.ComputeInstanceLayout(template, InstanceLayoutKind.TypeOnly);
}
// Only needed for universal generics, or when looking up an offset for a field for a universal generic
LowLevelList<int> fieldOffsets;
int[] position = ComputeTypeSizeAndAlignment(type, FieldLoadState.Instance, out fieldOffsets);
int numInstanceFields = 0;
foreach (NativeLayoutFieldDesc field in type.NativeLayoutFields)
{
if (!field.IsStatic)
{
numInstanceFields++;
}
}
int byteCountAlignment = position[InstanceAlignmentEntry];
byteCountAlignment = type.Context.Target.GetObjectAlignment(byteCountAlignment);
ComputedInstanceFieldLayout layout = new ComputedInstanceFieldLayout()
{
Offsets = new FieldAndOffset[numInstanceFields],
ByteCountAlignment = byteCountAlignment,
ByteCountUnaligned = position[(int)NativeFormat.FieldStorage.Instance],
PackValue = 0 // TODO, as we add more metadata handling logic, find out if its necessary to use a meaningful value here
};
if (!type.IsValueType)
{
layout.FieldAlignment = type.Context.Target.PointerSize;
layout.FieldSize = type.Context.Target.PointerSize;
}
else
{
layout.FieldAlignment = position[InstanceAlignmentEntry];
layout.FieldSize = MemoryHelpers.AlignUp(position[(int)NativeFormat.FieldStorage.Instance], layout.FieldAlignment);
}
int curInstanceField = 0;
foreach (NativeLayoutFieldDesc field in type.NativeLayoutFields)
{
if (!field.IsStatic)
{
layout.Offsets[curInstanceField] = new FieldAndOffset(field, fieldOffsets[curInstanceField]);
curInstanceField++;
}
}
return layout;
}
public unsafe override bool ComputeContainsGCPointers(DefType type)
{
if (type.IsTemplateCanonical())
{
return type.ComputeTemplate().RuntimeTypeHandle.ToEETypePtr()->HasGCPointers;
}
else
{
if (type.RetrieveRuntimeTypeHandleIfPossible())
{
return type.RuntimeTypeHandle.ToEETypePtr()->HasGCPointers;
}
return type.GetOrCreateTypeBuilderState().InstanceGCLayout != null;
}
}
private static void EnsureFieldLayoutLoadedForNonUniversalType(DefType type)
{
Debug.Assert(type.HasInstantiation);
Debug.Assert(!type.ComputeTemplate().IsCanonicalSubtype(CanonicalFormKind.Universal));
if (type.NativeLayoutFields != null)
return;
// Look up the universal template for this type. Only the universal template has field layout
// information, so we have to use it to parse the field layout.
NativeLayoutInfoLoadContext universalLayoutLoadContext;
NativeParser typeInfoParser = type.GetOrCreateTypeBuilderState().GetParserForUniversalNativeLayoutInfo(out universalLayoutLoadContext);
if (typeInfoParser.IsNull)
throw new TypeBuilder.MissingTemplateException();
// Now parse that layout into the NativeLayoutFields array.
NativeParser fieldLayoutParser = typeInfoParser.GetParserForBagElementKind(BagElementKind.FieldLayout);
type.NativeLayoutFields = ParseFieldLayout(type, universalLayoutLoadContext, fieldLayoutParser);
}
private static void EnsureFieldLayoutLoadedForUniversalType(DefType type, NativeLayoutInfoLoadContext loadContext, NativeParser fieldLayoutParser)
{
Debug.Assert(type.HasInstantiation);
Debug.Assert(type.ComputeTemplate().IsCanonicalSubtype(CanonicalFormKind.Universal));
if (type.NativeLayoutFields != null)
return;
type.NativeLayoutFields = ParseFieldLayout(type, loadContext, fieldLayoutParser);
}
