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/* valareferencetransferexpression.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 reference transfer expression.
*
* {{{ (owned) foo }}}
*/
public class Vala.ReferenceTransferExpression : Expression {
/**
* The variable whose reference is to be transferred.
*/
public Expression inner {
get {
return _inner;
}
private set {
_inner = value;
_inner.parent_node = this;
}
}
private Expression _inner;
/**
* Creates a new reference transfer expression.
*
* @param inner variable whose reference is to be transferred
* @return newly created reference transfer expression
*/
public ReferenceTransferExpression (Expression inner, SourceReference? source_reference = null) {
this.inner = inner;
this.source_reference = source_reference;
}
public override void accept (CodeVisitor visitor) {
visitor.visit_reference_transfer_expression (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 false;
}
public override bool is_accessible (Symbol sym) {
return inner.is_accessible (sym);
}
public override bool check (CodeContext context) {
if (checked) {
return !error;
}
checked = true;
inner.lvalue = true;
inner.check (context);
if (inner.error) {
/* if there was an error in the inner expression, skip type check */
error = true;
return false;
}
if (!(inner is MemberAccess || inner is ElementAccess)) {
error = true;
Report.error (source_reference, "Reference transfer not supported for this expression");
return false;
}
if (inner.value_type is ArrayType && ((ArrayType) inner.value_type).inline_allocated) {
error = true;
Report.error (source_reference, "Ownership of inline-allocated array cannot be transferred");
return false;
}
var is_owned_delegate = inner.value_type is DelegateType && inner.value_type.value_owned;
if (!inner.value_type.is_disposable ()
&& !(inner.value_type is PointerType)
&& !is_owned_delegate) {
error = true;
Report.error (source_reference, "No reference to be transferred");
return false;
}
value_type = inner.value_type.copy ();
value_type.value_owned = true;
value_type.check (context);
return !error;
}
public override void emit (CodeGenerator codegen) {
inner.emit (codegen);
codegen.visit_reference_transfer_expression (this);
codegen.visit_expression (this);
}
public override void get_defined_variables (Collection<Variable> collection) {
inner.get_defined_variables (collection);
unowned LocalVariable? local = inner.symbol_reference as LocalVariable;
unowned Parameter? param = inner.symbol_reference as Parameter;
if (local != null) {
collection.add (local);
} else if (param != null && param.direction == ParameterDirection.OUT) {
collection.add (param);
}
}
public override void get_used_variables (Collection<Variable> collection) {
inner.get_used_variables (collection);
unowned LocalVariable? local = inner.symbol_reference as LocalVariable;
unowned Parameter? param = inner.symbol_reference as Parameter;
if (local != null) {
collection.add (local);
} else if (param != null && param.direction == ParameterDirection.OUT) {
collection.add (param);
}
}
public override string to_string () {
return "(owned) %s".printf (inner.to_string ());
}
}
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