private static DynamicMetaObject MakeSlotDelete(DeleteBindingInfo/*!*/ info, PythonTypeSlot/*!*/ dts) {
// users can subclass PythonProperty so check the type explicitly
// and only in-line the ones we fully understand.
if (dts.GetType() == typeof(PythonProperty)) {
// properties are mutable so we generate code to get the value rather
// than burning it into the rule.
Expression deleter = Ast.Property(
Ast.Convert(AstUtils.WeakConstant(dts), typeof(PythonProperty)),
"fdel"
);
ParameterExpression tmpDeleter = Ast.Variable(typeof(object), "tmpDel");
info.Body.AddVariable(tmpDeleter);
info.Body.FinishCondition(
Ast.Block(
Ast.Assign(tmpDeleter, deleter),
Ast.Condition(
Ast.NotEqual(
tmpDeleter,
Ast.Constant(null)
),
Ast.Dynamic(
new PythonInvokeBinder(
BinderState.GetBinderState(info.Action),
new CallSignature(1)
),
typeof(void),
Ast.Constant(BinderState.GetBinderState(info.Action).Context),
tmpDeleter,
info.Args[0].Expression
),
Ast.Throw(Ast.Call(typeof(PythonOps).GetMethod("UndeletableProperty")))
)
)
);
return info.Body.GetMetaObject();
}
info.Body.AddCondition(
Ast.Call(
typeof(PythonOps).GetMethod("SlotTryDeleteValue"),
Ast.Constant(BinderState.GetBinderState(info.Action).Context),
AstUtils.Convert(AstUtils.WeakConstant(dts), typeof(PythonTypeSlot)),
AstUtils.Convert(info.Args[0].Expression, typeof(object)),
Ast.Convert(
Ast.Property(
Ast.Convert(
info.Args[0].Expression,
typeof(IPythonObject)),
TypeInfo._IPythonObject.PythonType
),
typeof(PythonType)
)
),
Ast.Constant(null)
);
return null;
}
private static void MakeSlotAccess(GetBindingInfo/*!*/ info, PythonTypeSlot dts) {
ReflectedSlotProperty rsp = dts as ReflectedSlotProperty;
if (rsp != null) {
// we need to fall back to __getattr__ if the value is not defined, so call it and check the result.
info.Body.AddCondition(
Ast.NotEqual(
Ast.Assign(
info.Result,
Ast.ArrayAccess(
Ast.Call(
Ast.Convert(info.Self, typeof(IObjectWithSlots)),
typeof(IObjectWithSlots).GetMethod("GetSlots")
),
Ast.Constant(rsp.Index)
)
),
Ast.Field(null, typeof(Uninitialized).GetField("Instance"))
),
info.Result
);
return;
}
PythonTypeUserDescriptorSlot slot = dts as PythonTypeUserDescriptorSlot;
if (slot != null && !(slot.Value is PythonTypeSlot)) {
PythonType slottype = DynamicHelpers.GetPythonType(slot.Value);
if (slottype.IsSystemType) {
// this is a user slot that's known not to be a descriptor
// so we can just burn the value in. For it to change the
// slot will need to be replaced reving the type version.
info.Body.FinishCondition(
AstUtils.Convert(AstUtils.WeakConstant(slot.Value), typeof(object))
);
return;
}
}
// users can subclass PythonProperty so check the type explicitly
// and only in-line the ones we fully understand.
if (dts.GetType() == typeof(PythonProperty)) {
// properties are mutable so we generate code to get the value rather
// than burning it into the rule.
Expression getter = Ast.Property(
Ast.Convert(AstUtils.WeakConstant(dts), typeof(PythonProperty)),
"fget"
);
ParameterExpression tmpGetter = Ast.Variable(typeof(object), "tmpGet");
info.Body.AddVariable(tmpGetter);
info.Body.FinishCondition(
Ast.Block(
Ast.Assign(tmpGetter, getter),
Ast.Condition(
Ast.NotEqual(
tmpGetter,
Ast.Constant(null)
),
Ast.Dynamic(
new PythonInvokeBinder(
BinderState.GetBinderState(info.Action),
new CallSignature(1)
),
typeof(object),
Ast.Constant(BinderState.GetBinderState(info.Action).Context),
tmpGetter,
info.Self
),
Ast.Throw(Ast.Call(typeof(PythonOps).GetMethod("UnreadableProperty")), typeof(object))
)
)
);
return;
}
Expression tryGet = Ast.Call(
TypeInfo._PythonOps.SlotTryGetBoundValue,
Ast.Constant(BinderState.GetBinderState(info.Action).Context),
Ast.Convert(AstUtils.WeakConstant(dts), typeof(PythonTypeSlot)),
AstUtils.Convert(info.Self, typeof(object)),
Ast.Property(
Ast.Convert(
info.Self,
typeof(IPythonObject)),
TypeInfo._IPythonObject.PythonType
),
info.Result
);
if (dts.GetAlwaysSucceeds) {
info.Body.FinishCondition(
Ast.Block(tryGet, info.Result)
);
} else {
info.Body.AddCondition(
tryGet,
info.Result
);
}
}
