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/* valalocalvariable.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 local variable declaration in the source code.
*/
public class Vala.LocalVariable : Variable {
public bool is_result { get; set; }
public bool captured { get; set; }
/* Currently ignored due to GCC 4.8 being strict on possibly uninitialized variables */
public bool no_init { get; set; }
/**
* Creates a new local variable.
*
* @param name name of the variable
* @param init optional initializer expression
* @param source reference to source code
* @return newly created variable declarator
*/
public LocalVariable (DataType? variable_type, string name, Expression? initializer = null, SourceReference? source_reference = null) {
base (variable_type, name, initializer, source_reference);
}
public override void accept (CodeVisitor visitor) {
visitor.visit_local_variable (this);
}
public override void accept_children (CodeVisitor visitor) {
if (initializer != null) {
initializer.accept (visitor);
visitor.visit_end_full_expression (initializer);
}
if (variable_type != null) {
variable_type.accept (visitor);
}
}
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 override bool check (CodeContext context) {
if (checked) {
return !error;
}
checked = true;
if (variable_type != null) {
if (variable_type is VoidType) {
error = true;
Report.error (source_reference, "'void' not supported as variable type");
return false;
}
variable_type.check (context);
}
if (initializer != null) {
initializer.target_type = variable_type;
initializer.check (context);
}
if (variable_type == null) {
/* var type */
if (initializer == null) {
error = true;
Report.error (source_reference, "var declaration not allowed without initializer");
return false;
}
if (initializer.value_type == null) {
error = true;
Report.error (source_reference, "var declaration not allowed with non-typed initializer");
return false;
}
if (initializer.value_type is FieldPrototype) {
error = true;
Report.error (initializer.source_reference, "Access to instance member `%s' denied".printf (initializer.symbol_reference.get_full_name ()));
return false;
}
variable_type = initializer.value_type.copy ();
variable_type.value_owned = true;
variable_type.floating_reference = false;
initializer.target_type = variable_type;
}
if (initializer != null && !initializer.error) {
if (initializer.value_type == null) {
if (!(initializer is MemberAccess) && !(initializer is LambdaExpression)) {
error = true;
Report.error (source_reference, "expression type not allowed as initializer");
return false;
}
if (initializer.symbol_reference is Method &&
variable_type is DelegateType) {
var m = (Method) initializer.symbol_reference;
var dt = (DelegateType) variable_type;
var cb = dt.delegate_symbol;
/* check whether method matches callback type */
if (!cb.matches_method (m, dt)) {
error = true;
Report.error (source_reference, "declaration of method `%s' doesn't match declaration of callback `%s'".printf (m.get_full_name (), cb.get_full_name ()));
return false;
}
initializer.value_type = variable_type;
} else {
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, "Assignment: 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;
}
}
}
context.analyzer.current_symbol.scope.add (name, this);
// current_symbol is a Method if this is the `result'
// variable used for postconditions
var block = context.analyzer.current_symbol as Block;
if (block != null) {
block.add_local_variable (this);
}
active = true;
return !error;
}
}
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