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/* valapostfixexpression.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 postfix increment or decrement expression.
*/
public class Vala.PostfixExpression : Expression {
/**
* The operand, must be a variable or a property.
*/
public Expression inner {
get { return _inner; }
set {
_inner = value;
_inner.parent_node = this;
}
}
/**
* Specifies whether value should be incremented or decremented.
*/
public bool increment { get; set; }
private Expression _inner;
/**
* Creates a new postfix expression.
*
* @param inner operand expression
* @param inc true for increment, false for decrement
* @param source reference to source code
* @return newly created postfix expression
*/
public PostfixExpression (Expression _inner, bool inc, SourceReference source) {
inner = _inner;
increment = inc;
source_reference = source;
}
public override void accept (CodeVisitor visitor) {
visitor.visit_postfix_expression (this);
visitor.visit_expression (this);
}
public override void accept_children (CodeVisitor visitor) {
inner.accept (visitor);
}
public override bool is_pure () {
return false;
}
public override void get_defined_variables (Collection<Variable> collection) {
inner.get_defined_variables (collection);
var local = inner.symbol_reference as LocalVariable;
var 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);
}
public override bool check (CodeContext context) {
if (checked) {
return !error;
}
checked = true;
inner.lvalue = true;
if (!inner.check (context)) {
error = true;
return false;
}
if (!(inner.value_type is IntegerType) && !(inner.value_type is FloatingType) && !(inner.value_type is PointerType)) {
error = true;
Report.error (source_reference, "unsupported lvalue in postfix expression");
return false;
}
if (inner is MemberAccess) {
var ma = (MemberAccess) inner;
if (ma.prototype_access) {
error = true;
Report.error (source_reference, "Access to instance member `%s' denied".printf (ma.symbol_reference.get_full_name ()));
return false;
}
if (ma.error || ma.symbol_reference == null) {
error = true;
/* if no symbol found, skip this check */
return false;
}
} else if (inner is ElementAccess) {
var ea = (ElementAccess) inner;
if (!(ea.container.value_type is ArrayType)) {
error = true;
Report.error (source_reference, "unsupported lvalue in postfix expression");
return false;
}
} else {
error = true;
Report.error (source_reference, "unsupported lvalue in postfix expression");
return false;
}
if (inner is MemberAccess) {
var ma = (MemberAccess) inner;
if (ma.symbol_reference is Property) {
var prop = (Property) ma.symbol_reference;
if (prop.set_accessor == null || !prop.set_accessor.writable) {
ma.error = true;
Report.error (ma.source_reference, "Property `%s' is read-only".printf (prop.get_full_name ()));
return false;
}
}
}
value_type = inner.value_type;
return !error;
}
public override void emit (CodeGenerator codegen) {
inner.emit (codegen);
codegen.visit_postfix_expression (this);
codegen.visit_expression (this);
}
}
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