public XamlIlNodeEmitResult Emit(IXamlIlAstNode node, XamlIlEmitContext context, IXamlIlEmitter codeGen)
{
if (!(node is XamlIlPropertyAssignmentNode an))
{
return(null);
}
var setters = ValidateAndGetSetters(an);
for (var c = 0; c < an.Values.Count - 1; c++)
{
context.Emit(an.Values[c], codeGen, an.Values[c].Type.GetClrType());
}
var value = an.Values.Last();
var isValueType = value.Type.GetClrType().IsValueType;
// If there is only one available setter or if value is a value type, always use the first one
if (setters.Count == 1 || isValueType)
{
var setter = an.PossibleSetters.First();
context.Emit(value, codeGen, setter.Parameters.Last());
setter.Emit(codeGen);
}
else
{
var checkedTypes = new List <IXamlIlType>();
IXamlIlLabel exit = codeGen.DefineLabel();
IXamlIlLabel next = null;
var hadJumps = false;
context.Emit(value, codeGen, value.Type.GetClrType());
foreach (var setter in setters)
{
var type = setter.Parameters.Last();
// We have already checked this type or its base type
if (checkedTypes.Any(ch => ch.IsAssignableFrom(type)))
{
continue;
}
if (next != null)
{
codeGen.MarkLabel(next);
next = null;
}
IXamlIlLabel Next() => next ?? (next = codeGen.DefineLabel());
var checkNext = false;
if (setter.BinderParameters.AllowRuntimeNull)
{
checkedTypes.Add(type);
}
else
{
// Check for null; Also don't add this type to the list of checked ones because of the null check
codeGen
.Dup()
.Brfalse(Next());
checkNext = true;
}
// Only do dynamic checks if we know that type is not assignable by downcast
if (!type.IsAssignableFrom(value.Type.GetClrType()))
{
codeGen
.Dup()
.Isinst(type)
.Brfalse(Next());
checkNext = true;
}
if (checkNext)
{
hadJumps = true;
}
TypeSystemHelpers.EmitConvert(context, codeGen, value, value.Type.GetClrType(), type);
setter.Emit(codeGen);
if (hadJumps)
{
codeGen.Br(exit);
}
if (!checkNext)
{
break;
}
}
if (next != null)
{
codeGen.MarkLabel(next);
if (setters.Any(x => !x.BinderParameters.AllowRuntimeNull))
{
next = codeGen.DefineLabel();
codeGen
.Dup()
.Brtrue(next)
.Newobj(context.Configuration.TypeSystem.GetType("System.NullReferenceException")
.FindConstructor())
.Throw();
codeGen.MarkLabel(next);
}
codeGen
.Newobj(context.Configuration.TypeSystem.GetType("System.InvalidCastException")
.FindConstructor())
.Throw();
}
codeGen.MarkLabel(exit);
}
return(XamlIlNodeEmitResult.Void(1));
}