public override void Emit(EmitContext ec)
{
Label is_null_label = ec.DefineLabel();
Label end_label = ec.DefineLabel();
unwrap.EmitCheck(ec);
ec.Emit(OpCodes.Brfalse, is_null_label);
if (user_operator != null)
{
user_operator.Emit(ec);
}
else
{
EmitOperator(ec, NullableInfo.GetUnderlyingType(type));
}
ec.Emit(OpCodes.Newobj, NullableInfo.GetConstructor(type));
ec.Emit(OpCodes.Br_S, end_label);
ec.MarkLabel(is_null_label);
LiftedNull.Create(type, loc).Emit(ec);
ec.MarkLabel(end_label);
}
protected override void EmitOperation(EmitContext ec)
{
Label is_null_label = ec.DefineLabel();
Label end_label = ec.DefineLabel();
LocalTemporary lt = new LocalTemporary(type);
// Value is on the stack
lt.Store(ec);
var call = new CallEmitter();
call.InstanceExpression = lt;
call.EmitPredefined(ec, NullableInfo.GetHasValue(expr.Type), null);
ec.Emit(OpCodes.Brfalse, is_null_label);
call = new CallEmitter();
call.InstanceExpression = lt;
call.EmitPredefined(ec, NullableInfo.GetGetValueOrDefault(expr.Type), null);
lt.Release(ec);
base.EmitOperation(ec);
ec.Emit(OpCodes.Newobj, NullableInfo.GetConstructor(type));
ec.Emit(OpCodes.Br_S, end_label);
ec.MarkLabel(is_null_label);
LiftedNull.Create(type, loc).Emit(ec);
ec.MarkLabel(end_label);
}
void EmitBitwiseBoolean(EmitContext ec)
{
Label load_left = ec.DefineLabel();
Label load_right = ec.DefineLabel();
Label end_label = ec.DefineLabel();
// null & value, null | value
if (left_unwrap == null)
{
left_unwrap = right_unwrap;
right_unwrap = null;
right = left;
}
left_unwrap.Emit(ec);
ec.Emit(OpCodes.Brtrue, load_right);
// value & null, value | null
if (right_unwrap != null)
{
right_unwrap.Emit(ec);
ec.Emit(OpCodes.Brtrue_S, load_left);
}
left_unwrap.EmitCheck(ec);
ec.Emit(OpCodes.Brfalse_S, load_right);
// load left
ec.MarkLabel(load_left);
if (Oper == Operator.BitwiseAnd)
{
left_unwrap.Load(ec);
}
else
{
if (right_unwrap == null)
{
right.Emit(ec);
if (right is EmptyConstantCast || right is EmptyCast)
{
ec.Emit(OpCodes.Newobj, NullableInfo.GetConstructor(type));
}
}
else
{
right_unwrap.Load(ec);
right_unwrap = left_unwrap;
}
}
ec.Emit(OpCodes.Br_S, end_label);
// load right
ec.MarkLabel(load_right);
if (right_unwrap == null)
{
if (Oper == Operator.BitwiseAnd)
{
right.Emit(ec);
if (right is EmptyConstantCast || right is EmptyCast)
{
ec.Emit(OpCodes.Newobj, NullableInfo.GetConstructor(type));
}
}
else
{
left_unwrap.Load(ec);
}
}
else
{
right_unwrap.Load(ec);
}
ec.MarkLabel(end_label);
}
public override void Emit(EmitContext ec)
{
child.Emit(ec);
ec.Emit(OpCodes.Newobj, NullableInfo.GetConstructor(type));
}
Expression LiftResult(ResolveContext ec, Expression res_expr)
{
TypeSpec lifted_type;
//
// Avoid double conversion
//
if (left_unwrap == null || IsLeftNullLifted || left_unwrap.Type != left.Type || (left_unwrap != null && IsRightNullLifted))
{
lifted_type = new NullableType(left.Type, loc).ResolveAsType(ec);
if (lifted_type == null)
{
return(null);
}
if (left is UserCast || left is EmptyCast || left is OpcodeCast)
{
left.Type = lifted_type;
}
else
{
left = EmptyCast.Create(left, lifted_type);
}
}
if (left != right && (right_unwrap == null || IsRightNullLifted || right_unwrap.Type != right.Type || (right_unwrap != null && IsLeftNullLifted)))
{
lifted_type = new NullableType(right.Type, loc).ResolveAsType(ec);
if (lifted_type == null)
{
return(null);
}
var r = right;
if (r is ReducedExpression)
{
r = ((ReducedExpression)r).OriginalExpression;
}
if (r is UserCast || r is EmptyCast || r is OpcodeCast)
{
r.Type = lifted_type;
}
else
{
right = EmptyCast.Create(right, lifted_type);
}
}
if ((Oper & Operator.ComparisonMask) == 0)
{
lifted_type = new NullableType(res_expr.Type, loc).ResolveAsType(ec);
if (lifted_type == null)
{
return(null);
}
wrap_ctor = NullableInfo.GetConstructor(lifted_type);
type = res_expr.Type = lifted_type;
}
if (IsLeftNullLifted)
{
left = LiftedNull.Create(right.Type, left.Location);
//
// Special case for bool?, the result depends on both null right side and left side value
//
if ((Oper == Operator.BitwiseAnd || Oper == Operator.BitwiseOr) && NullableInfo.GetUnderlyingType(type).BuiltinType == BuiltinTypeSpec.Type.Bool)
{
return(res_expr);
}
if ((Oper & (Operator.ArithmeticMask | Operator.ShiftMask | Operator.BitwiseMask)) != 0)
{
return(LiftedNull.CreateFromExpression(ec, res_expr));
}
//
// Value types and null comparison
//
if (right_unwrap == null || (Oper & Operator.RelationalMask) != 0)
{
return(CreateNullConstant(ec, right_orig));
}
}
if (IsRightNullLifted)
{
right = LiftedNull.Create(left.Type, right.Location);
//
// Special case for bool?, the result depends on both null right side and left side value
//
if ((Oper == Operator.BitwiseAnd || Oper == Operator.BitwiseOr) && NullableInfo.GetUnderlyingType(type).BuiltinType == BuiltinTypeSpec.Type.Bool)
{
return(res_expr);
}
if ((Oper & (Operator.ArithmeticMask | Operator.ShiftMask | Operator.BitwiseMask)) != 0)
{
return(LiftedNull.CreateFromExpression(ec, res_expr));
}
//
// Value types and null comparison
//
if (left_unwrap == null || (Oper & Operator.RelationalMask) != 0)
{
return(CreateNullConstant(ec, left_orig));
}
}
return(res_expr);
}
