1 /* valacastexpression.vala
3 * Copyright (C) 2006-2011 Jürg Billeter
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Lesser General Public
7 * License as published by the Free Software Foundation; either
8 * version 2.1 of the License, or (at your option) any later version.
10 * This library is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Lesser General Public License for more details.
15 * You should have received a copy of the GNU Lesser General Public
16 * License along with this library; if not, write to the Free Software
17 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 * Jürg Billeter <j@bitron.ch>
25 * Represents a type cast in the source code.
27 public class Vala
.CastExpression
: Expression
{
29 * The expression to be cast.
31 public Expression inner
{
37 _inner
.parent_node
= this
;
44 public DataType type_reference
{
45 get { return _data_type
; }
48 _data_type
.parent_node
= this
;
53 * Checked casts return NULL instead of raising an error.
55 public bool is_silent_cast
{ get; set; }
57 public bool is_non_null_cast
{ get; set; }
59 private Expression _inner
;
61 private DataType _data_type
;
64 * Creates a new cast expression.
66 * @param inner expression to be cast
67 * @param type_reference target type
68 * @return newly created cast expression
70 public CastExpression (Expression inner
, DataType type_reference
, SourceReference source_reference
, bool is_silent_cast
) {
71 this
.type_reference
= type_reference
;
72 this
.source_reference
= source_reference
;
73 this
.is_silent_cast
= is_silent_cast
;
77 public CastExpression
.non_null (Expression inner
, SourceReference source_reference
) {
79 this
.is_non_null_cast
= true;
80 this
.source_reference
= source_reference
;
83 public override void accept (CodeVisitor visitor
) {
84 visitor
.visit_cast_expression (this
);
86 visitor
.visit_expression (this
);
89 public override void accept_children (CodeVisitor visitor
) {
90 inner
.accept (visitor
);
91 if (!is_non_null_cast
) {
92 type_reference
.accept (visitor
);
96 public override void replace_expression (Expression old_node
, Expression new_node
) {
97 if (inner
== old_node
) {
102 public override bool is_pure () {
103 return inner
.is_pure ();
106 public override bool is_accessible (Symbol sym
) {
107 return inner
.is_accessible (sym
);
110 public override void replace_type (DataType old_type
, DataType new_type
) {
111 if (type_reference
== old_type
) {
112 type_reference
= new_type
;
116 public override bool check (CodeContext context
) {
123 if (!inner
.check (context
)) {
128 if (inner
.value_type
== null) {
129 Report
.error (source_reference
, "Invalid cast expression");
134 if (is_non_null_cast
) {
136 type_reference
= inner
.value_type
.copy ();
137 type_reference
.nullable
= false;
140 type_reference
.check (context
);
142 // FIXME: check whether cast is allowed
144 if (type_reference is DelegateType
&& inner
.value_type is MethodType
) {
145 if (target_type
!= null) {
146 inner
.value_type
.value_owned
= target_type
.value_owned
;
148 inner
.value_type
.value_owned
= true;
152 value_type
= type_reference
;
153 value_type
.value_owned
= inner
.value_type
.value_owned
;
155 if (is_silent_cast
) {
156 value_type
.nullable
= true;
159 if (is_gvariant (context
, inner
.value_type
) && !is_gvariant (context
, value_type
)) {
160 // GVariant unboxing returns owned value
161 value_type
.value_owned
= true;
164 inner
.target_type
= inner
.value_type
.copy ();
169 bool is_gvariant (CodeContext context
, DataType type
) {
170 return type
.data_type
!= null && type
.data_type
.is_subtype_of (context
.analyzer
.gvariant_type
.data_type
);
173 public override void emit (CodeGenerator codegen
) {
174 inner
.emit (codegen
);
176 codegen
.visit_cast_expression (this
);
178 codegen
.visit_expression (this
);
181 public override void get_defined_variables (Collection
<Variable
> collection
) {
182 inner
.get_defined_variables (collection
);
185 public override void get_used_variables (Collection
<Variable
> collection
) {
186 inner
.get_used_variables (collection
);
189 public override bool is_constant () {
190 return inner
.is_constant ();