public override CodeNode VisitLoadNull(LoadNullNode node)
{
_Writer.WriteStartElement("LoadNull");
_Writer.WriteEndElement();
return(node);
}
CodeNode GenerateAssignment(KeyValuePair <FieldLayoutAttribute, PropertyInfo> pair)
{
var fieldType = pair.Key.FieldType;
StringFieldLayoutAttribute stringLayout = pair.Key as StringFieldLayoutAttribute;
ArrayFieldLayoutAttribute arrayLayout = pair.Key as ArrayFieldLayoutAttribute;
//if it is an array, defer to GenerateArrayAssignment
if (arrayLayout != null)
{
// TODO: Why do we need these fieldType checks at all?
if (fieldType == typeof(string))
{
// TODO: Accept string arrays
throw new InvalidOperationException(Resources.NoStringArrays);
}
if (fieldType == typeof(BitArray))
{
throw new InvalidOperationException(Resources.NoBitArrayArrays);
}
return(GenerateArrayAssignment(pair));
}
var initNodes = new List <CodeNode>();
bool localWasPresent = true;
if (_FieldLocalsTouched.Add(pair.Key.FieldIndex))
{
localWasPresent = false;
//add a create local node
initNodes.Add(new CreateFieldLocalForWritingNode(pair.Key.FieldIndex, pair.Key.FieldType));
_FieldLocalsTouched.Add(pair.Key.FieldIndex);
}
//find out if there is an optional field flag that we need to manage
FieldLayoutAttribute optionalFieldLayout = null;
FlaggedFieldLayoutAttribute currentAsOptionalFieldLayout = pair.Key as FlaggedFieldLayoutAttribute;
if (currentAsOptionalFieldLayout != null)
{
optionalFieldLayout = _Fields[currentAsOptionalFieldLayout.FlagIndex].Key;
if (_FieldLocalsTouched.Add(currentAsOptionalFieldLayout.FlagIndex))
{
initNodes.Add(new CreateFieldLocalForWritingNode(currentAsOptionalFieldLayout.FlagIndex, optionalFieldLayout.FieldType));
}
}
//this will hold a node that will write in the case we have no value to write
CodeNode noValueWriteContingency = null;
//this will hold the source of the write that will happen above
CodeNode noValueWriteContingencySource = null;
//Decide what to do if we don't have a value to write.
//This will happen if we don't store the value in a property, it is "missing" from the property source, or something else
//TODO: should these have a different precedence?
if (pair.Key.MissingValue != null)
{
//if we have a missing value, set that as the write source
noValueWriteContingencySource = new LoadMissingValueNode(pair.Key.MissingValue, fieldType);
}
else if (localWasPresent || optionalFieldLayout != null)
{
//if the local was present when we started, that means it was initialized by another field. We can safely write it
//Similarly, if this is marked as an optional field, we can still write whatever the value of the local is (cheat)
noValueWriteContingencySource = new LoadFieldLocalNode(pair.Key.FieldIndex);
}
else if (fieldType.IsValueType)
{
//if T is a value type, we're up a creek with nothing to write.
//this is obviously not a good place, so throw in the converter
noValueWriteContingency = new ThrowInvalidOperationNode(string.Format(Resources.NonNullableField, pair.Key.FieldIndex, _Type));
}
else
{
//otherwise, we can try to write null (unless it is a fixed-length string, which should have a default instead)
if (stringLayout != null && stringLayout.Length > 0)
{
//TODO: move this check into StdfStringLayout if we can, along with a check that the missing value length matches
throw new NotSupportedException(Resources.FixedLengthStringMustHaveDefault);
}
noValueWriteContingencySource = new LoadNullNode();
}
//create the write node and the no-value contingency if we don't already have one
CodeNode writeNode;
if (stringLayout != null && stringLayout.Length > 0)
{
noValueWriteContingency = noValueWriteContingency ?? new WriteFixedStringNode(stringLayout.Length, noValueWriteContingencySource);
writeNode = new WriteFixedStringNode(stringLayout.Length, new LoadFieldLocalNode(pair.Key.FieldIndex));
}
else
{
noValueWriteContingency = noValueWriteContingency ?? new WriteTypeNode(fieldType, noValueWriteContingencySource);
writeNode = new WriteTypeNode(fieldType, new LoadFieldLocalNode(pair.Key.FieldIndex));
}
//return the crazy node
//TODO: refactor this better, this sucks
return(new WriteFieldNode(pair.Key.FieldIndex, fieldType,
initialization: new BlockNode(initNodes),
sourceProperty: pair.Value,
writeOperation: writeNode,
noValueWriteContingency: noValueWriteContingency,
optionalFieldIndex: optionalFieldLayout == null ? null : (int?)optionalFieldLayout.FieldIndex,
optionalFieldMask: optionalFieldLayout == null ? (byte)0 : currentAsOptionalFieldLayout.FlagMask));
}
public virtual CodeNode VisitLoadNull(LoadNullNode node)
{
return(node);
}
public override CodeNode VisitLoadNull(LoadNullNode node)
{
Log($"Loading null.");
ILGen.Ldnull();
return(node);
}
public override CodeNode VisitLoadNull(LoadNullNode node)
{
ILGen.Ldnull();
return(node);
}