private static FieldMemoryInfo[] GetFieldsMemoryInfo(ParsedStruct pdStruct, IDictionary <string, TypeMemoryInfo> typesMemInfo)
{
var fieldsMemInfo = new FieldMemoryInfo[pdStruct.Fields.Length];
for (var i = 0; i < fieldsMemInfo.Length; i++)
{
var pdField = pdStruct.Fields[i];
if (!typesMemInfo.TryGetValue(pdField.Type, out var memInfo))
{
throw new Exception($"Unknown field type `{pdField.Type}` defined in the struct `{pdStruct.Name}`");
}
fieldsMemInfo[i] = new FieldMemoryInfo(i, memInfo);
}
Array.Sort(fieldsMemInfo, (fieldA, fieldB) => {
var(fieldIndexA, memInfoA) = fieldA;
var(fieldIndexB, memInfoB) = fieldB;
if (memInfoA.Alignment != memInfoB.Alignment)
{
return(memInfoB.Alignment.CompareTo(memInfoA.Alignment));
}
return(fieldIndexA.CompareTo(fieldIndexB));
});
return(fieldsMemInfo);
}
private static CodeGenStruct HandleStruct(ParsedStruct pdStruct, IDictionary <string, TypeMemoryInfo> typesMemInfo)
{
if (pdStruct.Fields.Length == 0)
{
throw new Exception($"Struct `{pdStruct.Name}` is zero-sized");
}
var fieldsMemInfo = GetFieldsMemoryInfo(pdStruct, typesMemInfo);
var offset = 0;
var fields = new CodeGenField[pdStruct.Fields.Length];
for (var i = 0; i < fields.Length; i++)
{
var(pdFieldIndex, memInfo) = fieldsMemInfo[i];
var pdField = pdStruct.Fields[pdFieldIndex];
var defaultValue = memInfo.DefaultValueInfo.WithCustomDefaultValueIfPossible(pdField.DefaultValue);
fields[i] = new CodeGenField(pdField.Type, pdField.Name, defaultValue, offset);
offset += memInfo.Size;
}
var unalignedSize = fieldsMemInfo.Sum(fmi => fmi.TypeMemoryInfo.Size);
var alignment = fieldsMemInfo.Max(fmi => fmi.TypeMemoryInfo.Alignment);
var reminder = unalignedSize % alignment;
var padding = reminder == 0 ? 0 : alignment - reminder;
var size = unalignedSize + padding;
var structDefaultValue = DefaultValueInfo.CallWriteDefaultMethod();
typesMemInfo.Add(pdStruct.Name, new TypeMemoryInfo(size, alignment, structDefaultValue));
return(new CodeGenStruct(pdStruct.Name, size, alignment, padding, fields));
}
