summaryrefslogtreecommitdiff
path: root/vala/valapointerindirection.vala
blob: 5e14de7f6475805eaa19b6e97e23e99a91e80901 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
/* valapointerindirection.vala
 *
 * Copyright (C) 2007-2010  Jürg Billeter
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.

 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.

 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301  USA
 *
 * Author:
 * 	Jürg Billeter <j@bitron.ch>
 */


/**
 * Represents a pointer indirection.
 *
 * {{{ *foo }}}
 */
public class Vala.PointerIndirection : Expression {
	/**
	 * The pointer to dereference.
	 */
	public Expression inner {
		get {
			return _inner;
		}
		private set {
			_inner = value;
			_inner.parent_node = this;
		}
	}

	private Expression _inner;

	/**
	 * Creates a new pointer indirection.
	 *
	 * @param inner pointer to be dereferenced
	 * @return      newly created pointer indirection
	 */
	public PointerIndirection (Expression inner, SourceReference? source_reference = null) {
		this.source_reference = source_reference;
		this.inner = inner;
	}

	public override void accept (CodeVisitor visitor) {
		visitor.visit_pointer_indirection (this);

		visitor.visit_expression (this);
	}

	public override void accept_children (CodeVisitor visitor) {
		inner.accept (visitor);
	}

	public override void replace_expression (Expression old_node, Expression new_node) {
		if (inner == old_node) {
			inner = new_node;
		}
	}

	public override bool is_pure () {
		return inner.is_pure ();
	}

	public override bool is_accessible (Symbol sym) {
		return inner.is_accessible (sym);
	}

	public override void get_error_types (Collection<DataType> collection, SourceReference? source_reference = null) {
		inner.get_error_types (collection, source_reference);
	}

	public override bool check (CodeContext context) {
		if (checked) {
			return !error;
		}

		checked = true;

		if (!inner.check (context)) {
			return false;
		}
		if (inner.value_type == null) {
			error = true;
			Report.error (source_reference, "internal error: unknown type of inner expression");
			return false;
		}
		if (inner.value_type is PointerType) {
			var pointer_type = (PointerType) inner.value_type;
			if (pointer_type.base_type is ReferenceType || pointer_type.base_type is VoidType) {
				error = true;
				Report.error (source_reference, "Pointer indirection not supported for this expression");
				return false;
			}
			value_type = pointer_type.base_type;
			value_type.value_owned = false;
		} else {
			error = true;
			Report.error (source_reference, "Pointer indirection not supported for this expression");
			return false;
		}

		return !error;
	}

	public override void emit (CodeGenerator codegen) {
		inner.emit (codegen);

		codegen.visit_pointer_indirection (this);

		codegen.visit_expression (this);
	}

	public override void get_defined_variables (Collection<Variable> collection) {
		inner.get_defined_variables (collection);
	}

	public override void get_used_variables (Collection<Variable> collection) {
		inner.get_used_variables (collection);
	}

	public override string to_string () {
		return "(*%s)".printf (inner.to_string ());
	}
}