Line data    Source code

       1              : /* valadostatement.vala
       2              :  *
       3              :  * Copyright (C) 2006-2009  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              :  *      Jürg Billeter <j@bitron.ch>
      21              :  */
      22              : 
      23              : using GLib;
      24              : 
      25              : /**
      26              :  * Represents a do iteration statement in the source code.
      27              :  */
      28           10 : public class Vala.DoStatement : Loop, Statement {
      29              :         /**
      30              :          * Creates a new do statement.
      31              :          *
      32              :          * @param condition         loop condition
      33              :          * @param body              loop body
      34              :          * @param source_reference  reference to source code
      35              :          * @return                  newly created do statement
      36              :          */
      37           27 :         public DoStatement (Expression condition, Block body, SourceReference? source_reference = null) {
      38            9 :                 base (condition, body, source_reference);
      39              :         }
      40              : 
      41            9 :         public override void accept (CodeVisitor visitor) {
      42            9 :                 visitor.visit_do_statement (this);
      43              :         }
      44              : 
      45            9 :         public override void accept_children (CodeVisitor visitor) {
      46            9 :                 body.accept (visitor);
      47              : 
      48            9 :                 condition.accept (visitor);
      49              : 
      50            9 :                 visitor.visit_end_full_expression (condition);
      51              :         }
      52              : 
      53            9 :         public override bool check (CodeContext context) {
      54            9 :                 if (checked) {
      55            0 :                         return !error;
      56              :                 }
      57              : 
      58            9 :                 checked = true;
      59              : 
      60              :                 // convert to simple loop
      61              : 
      62              :                 // do not generate variable and if block if condition is always true
      63            9 :                 if (condition.is_always_true ()) {
      64            3 :                         var loop = new LoopStatement (body, source_reference);
      65              : 
      66            3 :                         unowned Block parent_block = (Block) parent_node;
      67            3 :                         parent_block.replace_statement (this, loop);
      68              : 
      69            3 :                         if (!loop.check (context)) {
      70            0 :                                 error = true;
      71              :                         }
      72              : 
      73            3 :                         return !error;
      74              :                 }
      75              : 
      76            6 :                 var block = new Block (source_reference);
      77              : 
      78            6 :                 var first_local = new LocalVariable (context.analyzer.bool_type.copy (), get_temp_name (), new BooleanLiteral (true, source_reference), source_reference);
      79            6 :                 block.add_statement (new DeclarationStatement (first_local, source_reference));
      80              : 
      81            6 :                 var if_condition = new UnaryExpression (UnaryOperator.LOGICAL_NEGATION, condition, condition.source_reference);
      82            6 :                 var true_block = new Block (condition.source_reference);
      83            6 :                 true_block.add_statement (new BreakStatement (condition.source_reference));
      84            6 :                 var if_stmt = new IfStatement (if_condition, true_block, null, condition.source_reference);
      85              : 
      86            6 :                 var condition_block = new Block (condition.source_reference);
      87            6 :                 condition_block.add_statement (if_stmt);
      88              : 
      89            6 :                 var first_if = new IfStatement (new UnaryExpression (UnaryOperator.LOGICAL_NEGATION, new MemberAccess.simple (first_local.name, source_reference), source_reference), condition_block, null, source_reference);
      90            6 :                 body.insert_statement (0, first_if);
      91            6 :                 body.insert_statement (1, new ExpressionStatement (new Assignment (new MemberAccess.simple (first_local.name, source_reference), new BooleanLiteral (false, source_reference), AssignmentOperator.SIMPLE, source_reference), source_reference));
      92              : 
      93            6 :                 block.add_statement (new LoopStatement (body, source_reference));
      94              : 
      95            6 :                 unowned Block parent_block = (Block) parent_node;
      96            6 :                 parent_block.replace_statement (this, block);
      97              : 
      98            6 :                 if (!block.check (context)) {
      99            0 :                         error = true;
     100              :                 }
     101              : 
     102            6 :                 return !error;
     103              :         }
     104              : }