1 /*

     2 * Copyright (c) 2004-2008 Nokia Corporation and/or its subsidiary(-ies).

     3 * All rights reserved.

     4 * This component and the accompanying materials are made available

     5 * under the terms of "Eclipse Public License v1.0"

     6 * which accompanies this distribution, and is available

     7 * at the URL "http://www.eclipse.org/legal/epl-v10.html".

     8 *

     9 * Initial Contributors:

    10 * Nokia Corporation - initial contribution.

    11 *

    12 * Contributors:

    13 *

    14 * Description: 

    15 *

    16 */

    17 

    18 using System;

    19 using SymBuildParsingLib.Tree;

    20 using SymBuildParsingLib.Token;

    21 using SymBuildParsingLib.Parser.Framework.Nodes;

    22 using SymBuildParsingLib.Utils;

    23 using SymbianTree;

    24 

    25 namespace SymBuildParsingLib.Parser.Framework.Workers

    26 {

    27 	public class SymParserWorkerCondition : SymParserWorkerConsumer

    28 	{

    29 		#region Constructors & destructor

    30 		public SymParserWorkerCondition( SymParserWorkerContext aContext )

    31 			: this( aContext, new SymNodeCondition( aContext.CurrentToken.Value ) )

    32 		{

    33 		}

    34 

    35 		public SymParserWorkerCondition( SymParserWorkerContext aContext, SymNodeCondition aNodeCondition )

    36 			: base( aContext, SymToken.TClass.EClassNewLine )

    37 		{

    38 			System.Diagnostics.Debug.Assert( aContext.Document.CurrentNode is SymNodeConditionalExpression );

    39 

    40 			// Make a new child node for the conditions. 

    41 			iConditionNode = aNodeCondition;

    42 			aContext.Document.CurrentNode.Add( iConditionNode );

    43 			aContext.Document.CurrentNode = iConditionNode;

    44 

    45 			// Set up the token balancer event handler

    46 			iTokenBalancer.EventLevelFinished += new SymBuildParsingLib.Token.SymTokenBalancer.LevelChangeEventHandler( TokenBalancer_EventLevelFinished );

    47 			iTokenBalancer.EventLevelsImbalanced += new SymBuildParsingLib.Token.SymTokenBalancer.LevelsImbalancedEventHandler( TokenBalancer_EventLevelsImbalanced );

    48 

    49 			// If we're handling an ifdef or ifndef expression, we can tell

    50 			// the token balancer to discard all brackets, irrespective of their level.

    51 			// For normal if statements, we want the brackets.

    52 			bool emitLevelZeroBrackets = !( iConditionNode.Type == SymNodeCondition.TType.ETypeIfdef || iConditionNode.Type == SymNodeCondition.TType.ETypeIfndef );

    53 			iTokenBalancer.RegisterBalancerTokens( emitLevelZeroBrackets );

    54 		}

    55 		#endregion

    56 

    57 		#region From SymParserWorker

    58 		public override SymParserWorker.TTokenConsumptionType OfferToken( SymToken aToken )

    59 		{

    60 			System.Diagnostics.Debug.Assert( WorkerContext.Document.CurrentNode is SymNodeCondition );

    61 			//

    62 			TTokenConsumptionType ret = TTokenConsumptionType.ETokenNotConsumed;

    63 			if	( aToken.Class != SymToken.TClass.EClassNewLine )

    64 			{

    65 				if	( iTokenBalancer.OfferToken( aToken ) )

    66 				{

    67 					ret = TTokenConsumptionType.ETokenConsumed;

    68 				}

    69 			}

    70 

    71 			// Try offering to base class....

    72 			// Base class will dequeue us once we reach the new line

    73 			if	( ret != TTokenConsumptionType.ETokenConsumed )

    74 			{

    75 				ret = base.OfferToken( aToken );

    76 			}

    77 

    78 			return ret;

    79 		}

    80 		#endregion

    81 

    82 		#region From SymParserWorkerConsumer

    83 		protected override void HandleTerminatingConditionMatch( SymToken aToken )

    84 		{

    85 			// Give the condition node ownership of the raw parsed tokens

    86 			iConditionNode.AssignArgumentTokens( iTokenBalancer.DocumentTree );

    87 

    88 			// We only need to evaluate the conditional arguments if we have not yet

    89 			// found a positive branch.

    90 			SymNodeConditionalExpression condExpNode = (SymNodeConditionalExpression) iConditionNode.Parent;

    91 			if	( condExpNode.HasPositiveBranch == false )

    92 			{

    93 				iConditionNode.Evaluate( WorkerContext );

    94 			}

    95 

    96 			// We remain as the current node, even after we die. This allows

    97 			// the body of the condition to be added as our child.

    98 		}

    99 		#endregion

   100 

   101 		#region Properties

   102 		public SymNodeCondition ConditionNode

   103 		{

   104 			get { return iConditionNode; }

   105 		}

   106 		#endregion

   107 

   108 		#region Token balancer event handlers

   109 		private void TokenBalancer_EventLevelFinished( int aLevelCount, SymNode aOldLevel, SymNode aNewLevel )

   110 		{

   111 		}

   112 

   113 		private void TokenBalancer_EventLevelsImbalanced()

   114 		{

   115 			throw new Exception( "Levels not balanced during condition parsing" );

   116 		}

   117 		#endregion

   118 

   119 		#region Data members

   120 		private SymTokenBalancer iTokenBalancer = new SymTokenBalancer();

   121 		private readonly SymNodeCondition iConditionNode;

   122 		#endregion

   123 	}

   124 }