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); }