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/* valafield.vala
*
* Copyright (C) 2006-2010 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>
*/
using GLib;
/**
* Represents a type or namespace field.
*/
public class Vala.Field : Variable, Lockable {
/**
* Specifies whether this field may only be accessed with an instance of
* the contained type.
*/
public MemberBinding binding { get; set; default = MemberBinding.INSTANCE; }
/**
* Specifies whether the field is volatile. Volatile fields are
* necessary to allow multi-threaded access.
*/
public bool is_volatile { get; set; }
private bool lock_used = false;
/**
* Creates a new field.
*
* @param name field name
* @param type field type
* @param init initializer expression
* @param source reference to source code
* @return newly created field
*/
public Field (string name, DataType variable_type, Expression? initializer, SourceReference? source_reference = null, Comment? comment = null) {
base (variable_type, name, initializer, source_reference, comment);
}
public override void accept (CodeVisitor visitor) {
visitor.visit_field (this);
}
public override void accept_children (CodeVisitor visitor) {
variable_type.accept (visitor);
if (initializer != null) {
initializer.accept (visitor);
}
}
public bool get_lock_used () {
return lock_used;
}
public void set_lock_used (bool used) {
lock_used = used;
}
public override void replace_expression (Expression old_node, Expression new_node) {
if (initializer == old_node) {
initializer = new_node;
}
}
public override void replace_type (DataType old_type, DataType new_type) {
if (variable_type == old_type) {
variable_type = new_type;
}
}
public string? get_ctype () {
return get_attribute_string ("CCode", "type");
}
public void set_ctype (string ctype) {
set_attribute_string ("CCode", "type", ctype);
}
public override bool check (CodeContext context) {
if (checked) {
return !error;
}
checked = true;
var old_source_file = context.analyzer.current_source_file;
var old_symbol = context.analyzer.current_symbol;
if (source_reference != null) {
context.analyzer.current_source_file = source_reference.file;
}
context.analyzer.current_symbol = this;
if (variable_type is VoidType) {
error = true;
Report.error (source_reference, "'void' not supported as field type");
return false;
}
variable_type.check (context);
// check whether field type is at least as accessible as the field
if (!context.analyzer.is_type_accessible (this, variable_type)) {
error = true;
Report.error (source_reference, "field type `%s` is less accessible than field `%s`".printf (variable_type.to_string (), get_full_name ()));
return false;
}
if (initializer != null) {
initializer.target_type = variable_type;
if (!initializer.check (context)) {
error = true;
return false;
}
if (initializer.value_type == null) {
error = true;
Report.error (source_reference, "expression type not allowed as initializer");
return false;
}
if (!initializer.value_type.compatible (variable_type)) {
error = true;
Report.error (source_reference, "Cannot convert from `%s' to `%s'".printf (initializer.value_type.to_string (), variable_type.to_string ()));
return false;
}
if (initializer.value_type.is_disposable ()) {
/* rhs transfers ownership of the expression */
if (!(variable_type is PointerType) && !variable_type.value_owned) {
/* lhs doesn't own the value */
error = true;
Report.error (source_reference, "Invalid assignment from owned expression to unowned variable");
return false;
}
}
if (parent_symbol is Namespace && !initializer.is_constant ()) {
error = true;
Report.error (source_reference, "Non-constant field initializers not supported in this context");
return false;
}
if (binding == MemberBinding.STATIC && parent_symbol is Class && ((Class)parent_symbol).is_compact && !initializer.is_constant ()) {
error = true;
Report.error (source_reference, "Static fields in compact classes cannot have non-constant initializers");
return false;
}
if (external) {
error = true;
Report.error (source_reference, "External fields cannot use initializers");
}
}
if (binding == MemberBinding.INSTANCE && parent_symbol is Interface) {
error = true;
Report.error (source_reference, "Interfaces may not have instance fields");
return false;
}
bool field_in_header = !is_internal_symbol ();
if (parent_symbol is Class) {
var cl = (Class) parent_symbol;
if (cl.is_compact && !cl.is_internal_symbol ()) {
// compact classes don't have priv structs
field_in_header = true;
}
}
if (!external_package && !hides && get_hidden_member () != null) {
Report.warning (source_reference, "%s hides inherited field `%s'. Use the `new' keyword if hiding was intentional".printf (get_full_name (), get_hidden_member ().get_full_name ()));
}
context.analyzer.current_source_file = old_source_file;
context.analyzer.current_symbol = old_symbol;
return !error;
}
}
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