vala/valalockstatement.vala

   1 /* valalockstatement.vala
   2  *
   3  * Copyright (C) 2006-2007  Raffaele Sandrini, Jürg Billeter
   4  *
   5  * This library is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU Lesser General Public
   7  * License as published by the Free Software Foundation; either
   8  * version 2.1 of the License, or (at your option) any later version.
   9
  10  * This library is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * Lesser General Public License for more details.
  14
  15  * You should have received a copy of the GNU Lesser General Public
  16  * License along with this library; if not, write to the Free Software
  17  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301  USA
  18  *
  19  * Author:
  20  *      Raffaele Sandrini <raffaele@sandrini.ch>
  21  */
  22
  23 using GLib;
  24
  25 /**
  26  * Represents a lock statement e.g. "lock (a) { f(a) }".
  27  */
  28 public class Vala.LockStatement : CodeNode, Statement {
  29         /**
  30          * Expression representing the resource to be locked.
  31          */
  32         public Expression resource { get; set; }
  33
  34         /**
  35          * The statement during its execution the resource is locked.
  36          */
  37         public Block body { get; set; }
  38
  39         public LockStatement (Expression resource, Block body, SourceReference? source_reference = null) {
  40                 this.body = body;
  41                 this.source_reference = source_reference;
  42                 this.resource = resource;
  43         }
  44
  45         public override void accept (CodeVisitor visitor) {
  46                 resource.accept (visitor);
  47                 body.accept (visitor);
  48                 visitor.visit_lock_statement (this);
  49         }
  50
  51         public override bool check (SemanticAnalyzer analyzer) {
  52                 if (checked) {
  53                         return !error;
  54                 }
  55
  56                 checked = true;
  57
  58                 resource.check (analyzer);
  59                 body.check (analyzer);
  60
  61                 /* resource must be a member access and denote a Lockable */
  62                 if (!(resource is MemberAccess && resource.symbol_reference is Lockable)) {
  63                         error = true;
  64                         resource.error = true;
  65                         Report.error (resource.source_reference, "Expression is either not a member access or does not denote a lockable member");
  66                         return false;
  67                 }
  68
  69                 /* parent symbol must be the current class */
  70                 if (resource.symbol_reference.parent_symbol != analyzer.current_class) {
  71                         error = true;
  72                         resource.error = true;
  73                         Report.error (resource.source_reference, "Only members of the current class are lockable");
  74                 }
  75
  76                 ((Lockable) resource.symbol_reference).set_lock_used (true);
  77
  78                 return !error;
  79         }
  80 }