protected override void EmitOperator(EmitContext ec, TypeSpec l)
{
if (user_operator != null)
{
user_operator.Emit(ec);
return;
}
if (left.Type.IsNullableType)
{
l = NullableInfo.GetUnderlyingType(left.Type);
left = EmptyCast.Create(left, l);
}
if (right.Type.IsNullableType)
{
right = EmptyCast.Create(right, NullableInfo.GetUnderlyingType(right.Type));
}
base.EmitOperator(ec, l);
}
protected override Expression ResolveConversions(ResolveContext ec)
{
source = EmptyCast.Create(source, target.Type);
return(this);
}
Expression LiftResult(ResolveContext ec, Expression res_expr)
{
TypeExpr 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);
lifted_type = lifted_type.ResolveAsTypeTerminal(ec, false);
if (lifted_type == null)
{
return(null);
}
if (left is UserCast || left is TypeCast)
{
left.Type = lifted_type.Type;
}
else
{
left = EmptyCast.Create(left, lifted_type.Type);
}
}
if (left != right && (right_unwrap == null || IsRightNullLifted || right_unwrap.Type != right.Type || (right_unwrap != null && IsLeftNullLifted)))
{
lifted_type = new NullableType(right.Type, loc);
lifted_type = lifted_type.ResolveAsTypeTerminal(ec, false);
if (lifted_type == null)
{
return(null);
}
var r = right;
if (r is ReducedExpression)
{
r = ((ReducedExpression)r).OriginalExpression;
}
if (r is UserCast || r is TypeCast)
{
r.Type = lifted_type.Type;
}
else
{
right = EmptyCast.Create(right, lifted_type.Type);
}
}
if ((Oper & Operator.ComparisonMask) == 0)
{
lifted_type = new NullableType(res_expr.Type, loc);
lifted_type = lifted_type.ResolveAsTypeTerminal(ec, false);
if (lifted_type == null)
{
return(null);
}
wrap_ctor = NullableInfo.GetConstructor(lifted_type.Type);
type = res_expr.Type = lifted_type.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);
}
Expression LiftResult(ResolveContext ec, Expression res_expr)
{
TypeExpr lifted_type;
//
// Avoid double conversion
//
if (left_unwrap == null || left_null_lifted || !TypeManager.IsEqual(left_unwrap.Type, left.Type) || (left_unwrap != null && right_null_lifted))
{
lifted_type = new NullableType(left.Type, loc);
lifted_type = lifted_type.ResolveAsTypeTerminal(ec, false);
if (lifted_type == null)
{
return(null);
}
if (left is UserCast || left is TypeCast)
{
left.Type = lifted_type.Type;
}
else
{
left = EmptyCast.Create(left, lifted_type.Type);
}
}
if (right_unwrap == null || right_null_lifted || !TypeManager.IsEqual(right_unwrap.Type, right.Type) || (right_unwrap != null && left_null_lifted))
{
lifted_type = new NullableType(right.Type, loc);
lifted_type = lifted_type.ResolveAsTypeTerminal(ec, false);
if (lifted_type == null)
{
return(null);
}
if (right is UserCast || right is TypeCast)
{
right.Type = lifted_type.Type;
}
else
{
right = EmptyCast.Create(right, lifted_type.Type);
}
}
if ((Oper & Operator.ComparisonMask) == 0)
{
lifted_type = new NullableType(res_expr.Type, loc);
lifted_type = lifted_type.ResolveAsTypeTerminal(ec, false);
if (lifted_type == null)
{
return(null);
}
wrap_ctor = new NullableInfo(lifted_type.Type).Constructor;
type = res_expr.Type = lifted_type.Type;
}
if (left_null_lifted)
{
left = LiftedNull.Create(right.Type, left.Location);
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).Resolve(ec));
}
}
if (right_null_lifted)
{
right = LiftedNull.Create(left.Type, right.Location);
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).Resolve(ec));
}
}
return(res_expr);
}
