debug/org.eclipse.ptp.debug.core/src/org/eclipse/ptp/debug/internal/core/model/CVariable.java - ptp/org.eclipse.ptp - Git at Google

 /**********************************************************************
  * Copyright (c) 2004 QNX Software Systems and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Common Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/cpl-v10.html
  *
  * Contributors:
  * QNX Software Systems - Initial API and implementation
  ***********************************************************************/
 package org.eclipse.ptp.debug.internal.core.model;

 import java.text.MessageFormat;

 import org.eclipse.cdt.debug.core.ICDebugConstants;
 import org.eclipse.cdt.debug.core.cdi.CDIException;
 import org.eclipse.cdt.debug.core.cdi.event.ICDIChangedEvent;
 import org.eclipse.cdt.debug.core.cdi.event.ICDIEvent;
 import org.eclipse.cdt.debug.core.cdi.event.ICDIEventListener;
 import org.eclipse.cdt.debug.core.cdi.event.ICDIResumedEvent;
 import org.eclipse.cdt.debug.core.cdi.model.ICDIArgumentDescriptor;
 import org.eclipse.cdt.debug.core.cdi.model.ICDIObject;
 import org.eclipse.cdt.debug.core.cdi.model.ICDIValue;
 import org.eclipse.cdt.debug.core.cdi.model.ICDIVariable;
 import org.eclipse.cdt.debug.core.cdi.model.ICDIVariableDescriptor;
 import org.eclipse.cdt.debug.core.cdi.model.type.ICDIArrayValue;
 import org.eclipse.cdt.debug.core.cdi.model.type.ICDIType;
 import org.eclipse.cdt.debug.core.model.CVariableFormat;
 import org.eclipse.cdt.debug.core.model.ICDebugElementStatus;
 import org.eclipse.cdt.debug.core.model.ICType;
 import org.eclipse.cdt.debug.core.model.ICValue;
 import org.eclipse.core.runtime.CoreException;
 import org.eclipse.debug.core.DebugEvent;
 import org.eclipse.debug.core.DebugException;
 import org.eclipse.debug.core.model.IValue;
 import org.eclipse.ptp.debug.core.IPTPLaunchConfigurationConstants;
 import org.eclipse.ptp.debug.core.PTPDebugCorePlugin;
 import org.eclipse.ptp.debug.core.cdi.model.IPCDITarget;

 /**
  * Represents a variable in the CDI model.
  */
 public class CVariable extends AbstractCVariable implements ICDIEventListener {

 	/**
 	 * Represents a single CDI variable.
 	 */
 	private class InternalVariable {

 		/**
 		 * The enclosing <code>CVariable</code> instance.
 		 */
 		private CVariable fVariable;

 		/**
 		 * The CDI variable object this variable is based on.
 		 */
 		private ICDIVariableDescriptor fCDIVariableObject;

 		/**
 		 * The underlying CDI variable.
 		 */
 		private ICDIVariable fCDIVariable;

 		/**
 		 * The type of this variable.
 		 */
 		private CType fType;

 		/**
 		 * The expression used to eveluate the value of this variable.
 		 */
 		private String fQualifiedName;

 		/**
 		 * The cache of the current value.
 		 */
 		private ICValue fValue;

 		/**
 		 * The change flag.
 		 */
 		private boolean fChanged = false;

 		/**
 		 * Constructor for InternalVariable.
 		 */
 		InternalVariable( CVariable var, ICDIVariableDescriptor varObject ) {
 			setVariable( var );
 			setCDIVariableObject( varObject );
 			setCDIVariable( (varObject instanceof ICDIVariable) ? (ICDIVariable)varObject : null );
 		}

 		InternalVariable createShadow( int start, int length ) throws DebugException {
 			InternalVariable iv = null;
 			try {
 				iv = new InternalVariable( getVariable(), getCDIVariableObject().getVariableDescriptorAsArray( start, length ) );
 			}
 			catch( CDIException e ) {
 				requestFailed( e.getMessage(), null );
 			}
 			return iv;
 		}

 		InternalVariable createShadow( String type ) throws DebugException {
 			InternalVariable iv = null;
 			try {
 				iv = new InternalVariable( getVariable(), getCDIVariableObject().getVariableDescriptorAsType( type ) );
 			}
 			catch( CDIException e ) {
 				requestFailed( e.getMessage(), null );
 			}
 			return iv;
 		}

 		private synchronized ICDIVariable getCDIVariable() throws DebugException {
 			if ( fCDIVariable == null ) {
 				try {
 					fCDIVariable = getCDIVariableObject().createVariable( );
 				}
 				catch( CDIException e ) {
 					requestFailed( e.getMessage(), null );
 				}
 			}
 			return fCDIVariable;
 		}

 		private void setCDIVariable( ICDIVariable variable ) {
 			fCDIVariable = variable;
 		}

 		private ICDIVariableDescriptor getCDIVariableObject() {
 			return fCDIVariableObject;
 		}

 		private void setCDIVariableObject( ICDIVariableDescriptor variableObject ) {
 			fCDIVariableObject = variableObject;
 		}

 		String getQualifiedName() throws DebugException {
 			if ( fQualifiedName == null ) {
 				try {
 					fQualifiedName = (fCDIVariableObject != null) ? fCDIVariableObject.getQualifiedName() : null;
 				}
 				catch( CDIException e ) {
 					requestFailed( e.getMessage(), null );
 				}
 			}
 			return fQualifiedName;
 		}

 		CType getType() throws DebugException {
 			if ( fType == null ) {
 				ICDIVariableDescriptor varObject = getCDIVariableObject();
 				if ( varObject != null ) {
 					synchronized( this ) {
 						if ( fType == null ) {
 							try {
 								fType = new CType( varObject.getType() );
 							}
 							catch( CDIException e ) {
 								requestFailed( e.getMessage(), null );
 							}
 						}
 					}
 				}
 			}
 			return fType;
 		}

 		synchronized void invalidate( boolean destroy ) {
 			try {
 				if ( destroy && fCDIVariable != null )
 					fCDIVariable.dispose();
 			}
 			catch( CDIException e ) {
 				logError( e.getMessage() );
 			}
 			invalidateValue();
 			setCDIVariable( null );
 			if ( fType != null )
 				fType.dispose();
 			fType = null;
 		}

 		void dispose( boolean destroy ) {
 			invalidate( destroy );
 		}

 		boolean isSameVariable( ICDIVariable cdiVar ) {
 			return ( fCDIVariable != null ) ? fCDIVariable.equals( cdiVar ) : false;
 		}

 		int sizeof() {
 			if ( getCDIVariableObject() != null ) {
 				try {
 					return getCDIVariableObject().sizeof();
 				}
 				catch( CDIException e ) {
 				}
 			}
 			return 0;
 		}

 		boolean isArgument() {
 			return ( getCDIVariableObject() instanceof ICDIArgumentDescriptor );
 		}

 		void setValue( String expression ) throws DebugException {
 			ICDIVariable cdiVariable = null;
 			try {
 				cdiVariable = getCDIVariable();
 				if ( cdiVariable != null )
 					cdiVariable.setValue( expression );
 				else
 					requestFailed( CoreModelMessages.getString( "CModificationVariable.0" ), null ); //$NON-NLS-1$
 			}
 			catch( CDIException e ) {
 				targetRequestFailed( e.getMessage(), null );
 			}
 		}

 		void setValue( ICValue value ) {
 			fValue = value;
 		}

 		synchronized ICValue getValue() throws DebugException {
 			if ( fValue == null ) {
 				ICDIVariable var = getCDIVariable();
 				if ( var != null ) {
 					try {
 						ICDIValue cdiValue = var.getValue();
 						if ( cdiValue != null ) {
 							ICDIType cdiType = cdiValue.getType();
 							if ( cdiValue instanceof ICDIArrayValue && cdiType != null ) {
 								ICType type = new CType( cdiType );
 								if ( type.isArray() ) {
 									int[] dims = type.getArrayDimensions();
 									if ( dims.length > 0 && dims[0] > 0 )
 										fValue = CValueFactory.createIndexedValue( getVariable(), (ICDIArrayValue)cdiValue, 0, dims[0] );
 								}
 							}
 							else {
 								fValue = CValueFactory.createValue( getVariable(), cdiValue );
 							}
 						}
 					}
 					catch( CDIException e ) {
 						requestFailed( e.getMessage(), e );
 					}
 				}
 			}
 			return fValue;
 		}

 		void invalidateValue() {
 			if ( fValue instanceof AbstractCValue ) {
 				((AbstractCValue)fValue).dispose();
 				fValue = null;
 			}
 		}

 		boolean isChanged() {
 			return fChanged;
 		}

 		synchronized void setChanged( boolean changed ) {
 			if ( changed ) {
 				invalidateValue();
 			}
 			if ( fValue instanceof AbstractCValue ) {
 				((AbstractCValue)fValue).setChanged( changed );
 			}
 			fChanged = changed;
 		}

 		synchronized void preserve() {
 			setChanged( false );
 			if ( fValue instanceof AbstractCValue ) {
 				((AbstractCValue)fValue).preserve();
 			}
 		}

 		CVariable getVariable() {
 			return fVariable;
 		}

 		private void setVariable( CVariable variable ) {
 			fVariable = variable;
 		}

 		void resetValue() {
 			if ( fValue instanceof AbstractCValue ) {
 				((AbstractCValue)fValue).reset();
 			}
 		}

 		/**
 		 * Compares the underlying variable objects.
 		 * @see java.lang.Object#equals(java.lang.Object)
 		 */
 		public boolean equals( Object obj ) {
 			if ( obj instanceof InternalVariable ) {
 				return getCDIVariableObject().equals( ((InternalVariable)obj).getCDIVariableObject() );
 			}
 			return false;
 		}

 		boolean sameVariable( ICDIVariableDescriptor vo ) {
 			return getCDIVariableObject().equals( vo );
 		}
 	}

 	/**
 	 * Whether this variable is currently enabled.
 	 */
 	private boolean fIsEnabled = true;

 	/**
 	 * The original internal variable.
 	 */
 	private InternalVariable fOriginal;

 	/**
 	 * The shadow internal variable used for casting.
 	 */
 	private InternalVariable fShadow;

 	/**
 	 * The name of this variable.
 	 */
 	private String fName;

 	/**
 	 * The current format of this variable.
 	 */
 	private CVariableFormat fFormat = CVariableFormat.getFormat( PTPDebugCorePlugin.getDefault().getPluginPreferences().getInt( ICDebugConstants.PREF_DEFAULT_VARIABLE_FORMAT ) );

 	/**
 	 * Constructor for CVariable.
 	 */
 	protected CVariable( PDebugElement parent, ICDIVariableDescriptor cdiVariableObject ) {
 		super( parent );
 		if ( cdiVariableObject != null ) {
 			fName = cdiVariableObject.getName();
 			createOriginal( cdiVariableObject );
 		}
 		fIsEnabled = ( parent instanceof AbstractCValue ) ? ((AbstractCValue)parent).getParentVariable().isEnabled() : !isBookkeepingEnabled();
 		getCDISession().getEventManager().addEventListener( this );
 	}

 	/**
 	 * Constructor for CVariable.
 	 */
 	protected CVariable( PDebugElement parent, ICDIVariableDescriptor cdiVariableObject, String errorMessage ) {
 		super( parent );
 		if ( cdiVariableObject != null ) {
 			fName = cdiVariableObject.getName();
 			createOriginal( cdiVariableObject );
 		}
 		fIsEnabled = !isBookkeepingEnabled();
 		setStatus( ICDebugElementStatus.ERROR, MessageFormat.format( CoreModelMessages.getString( "CVariable.1" ), new String[]{ errorMessage } ) ); //$NON-NLS-1$
 		getCDISession().getEventManager().addEventListener( this );
 	}

 	/*
 	 * (non-Javadoc)
 	 *
 	 * @see org.eclipse.cdt.debug.core.model.ICVariable#getType()
 	 */
 	public ICType getType() throws DebugException {
 		InternalVariable iv = getCurrentInternalVariable();
 		return ( iv != null ) ? iv.getType() : null;
 	}

 	/*
 	 * (non-Javadoc)
 	 *
 	 * @see org.eclipse.cdt.debug.core.model.ICVariable#isEnabled()
 	 */
 	public boolean isEnabled() {
 		return fIsEnabled;
 	}

 	/*
 	 * (non-Javadoc)
 	 *
 	 * @see org.eclipse.cdt.debug.core.model.ICVariable#setEnabled(boolean)
 	 */
 	public void setEnabled( boolean enabled ) throws DebugException {
 		InternalVariable iv = getOriginal();
 		if ( iv != null )
 			iv.dispose( true );
 		iv = getShadow();
 		if ( iv != null )
 			iv.dispose( true );
 		fIsEnabled = enabled;
 		fireChangeEvent( DebugEvent.STATE );
 	}

 	/*
 	 * (non-Javadoc)
 	 *
 	 * @see org.eclipse.cdt.debug.core.model.ICVariable#canEnableDisable()
 	 */
 	public boolean canEnableDisable() {
 		return !( getParent() instanceof IValue );
 	}

 	/*
 	 * (non-Javadoc)
 	 *
 	 * @see org.eclipse.cdt.debug.core.model.ICVariable#isArgument()
 	 */
 	public boolean isArgument() {
 		InternalVariable iv = getOriginal();
 		return ( iv != null ) ? iv.isArgument() : false;
 	}

 	/*
 	 * (non-Javadoc)
 	 *
 	 * @see org.eclipse.debug.core.model.IVariable#getValue()
 	 */
 	public IValue getValue() throws DebugException {
 		if ( isEnabled() ) {
 			InternalVariable iv = getCurrentInternalVariable();
 			if ( iv != null ) {
 				try {
 					return iv.getValue();
 				}
 				catch( DebugException e ) {
 					setStatus( ICDebugElementStatus.ERROR, e.getMessage() );
 				}
 			}
 		}
 		return null;
 	}

 	/*
 	 * (non-Javadoc)
 	 *
 	 * @see org.eclipse.debug.core.model.IVariable#getName()
 	 */
 	public String getName() throws DebugException {
 		return fName;
 	}

 	/*
 	 * (non-Javadoc)
 	 *
 	 * @see org.eclipse.debug.core.model.IVariable#getReferenceTypeName()
 	 */
 	public String getReferenceTypeName() throws DebugException {
 		ICType type = getType();
 		return ( type != null ) ? type.getName() : ""; //$NON-NLS-1$
 	}

 	/*
 	 * (non-Javadoc)
 	 *
 	 * @see org.eclipse.debug.core.model.IVariable#hasValueChanged()
 	 */
 	public boolean hasValueChanged() throws DebugException {
 		InternalVariable iv = getCurrentInternalVariable();
 		return ( iv != null ) ? iv.isChanged() : false;
 	}

 	/*
 	 * (non-Javadoc)
 	 *
 	 * @see org.eclipse.cdt.debug.core.model.IFormatSupport#supportsFormatting()
 	 */
 	public boolean supportsFormatting() {
 		return true;
 	}

 	/*
 	 * (non-Javadoc)
 	 *
 	 * @see org.eclipse.cdt.debug.core.model.IFormatSupport#getFormat()
 	 */
 	public CVariableFormat getFormat() {
 		return fFormat;
 	}

 	/*
 	 * (non-Javadoc)
 	 *
 	 * @see org.eclipse.cdt.debug.core.model.IFormatSupport#changeFormat(org.eclipse.cdt.debug.core.model.CVariableFormat)
 	 */
 	public void changeFormat( CVariableFormat format ) throws DebugException {
 		setFormat( format );
 		resetValue();
 	}

 	/*
 	 * (non-Javadoc)
 	 * Allow this operation only for the pointer types (???).
 	 *
 	 * @see org.eclipse.cdt.debug.core.model.ICastToArray#canCastToArray()
 	 */
 	public boolean canCastToArray() {
 		ICType type;
 		try {
 			type = getType();
 			return ( getOriginal() != null && isEnabled() && type.isPointer() );
 		}
 		catch( DebugException e ) {
 		}
 		return false;
 	}

 	/*
 	 * (non-Javadoc)
 	 *
 	 * @see org.eclipse.cdt.debug.core.model.ICastToArray#castToArray(int, int)
 	 */
 	public void castToArray( int startIndex, int length ) throws DebugException {
 		InternalVariable current = getCurrentInternalVariable();
 		if ( current != null ) {
 			InternalVariable newVar = current.createShadow( startIndex, length );
 			if ( getShadow() != null )
 				getShadow().dispose( true );
 			setShadow( newVar );
 			// If casting of variable to a type or array causes an error, the status
 			// of the variable is set to "error" and it can't be reset by subsequent castings.
 			resetValue();
 		}
 	}

 	/*
 	 * (non-Javadoc)
 	 *
 	 * @see org.eclipse.debug.core.model.IValueModification#setValue(java.lang.String)
 	 */
 	public void setValue( String expression ) throws DebugException {
 		InternalVariable iv = getCurrentInternalVariable();
 		if ( iv != null ) {
 			String newExpression = processExpression( expression );
 			iv.setValue( newExpression );
 		}
 	}

 	/*
 	 * (non-Javadoc)
 	 *
 	 * @see org.eclipse.debug.core.model.IValueModification#setValue(org.eclipse.debug.core.model.IValue)
 	 */
 	public void setValue( IValue value ) throws DebugException {
 		notSupported( CoreModelMessages.getString( "CVariable.3" ) ); //$NON-NLS-1$
 	}

 	/*
 	 * (non-Javadoc)
 	 *
 	 * @see org.eclipse.debug.core.model.IValueModification#supportsValueModification()
 	 */
 	public boolean supportsValueModification() {
 		return true;
 	}

 	/*
 	 * (non-Javadoc)
 	 *
 	 * @see org.eclipse.debug.core.model.IValueModification#verifyValue(java.lang.String)
 	 */
 	public boolean verifyValue( String expression ) throws DebugException {
 		return true;
 	}

 	/*
 	 * (non-Javadoc)
 	 *
 	 * @see org.eclipse.debug.core.model.IValueModification#verifyValue(org.eclipse.debug.core.model.IValue)
 	 */
 	public boolean verifyValue( IValue value ) throws DebugException {
 		return value.getDebugTarget().equals( getDebugTarget() );
 	}

 	/*
 	 * (non-Javadoc)
 	 *
 	 * @see org.eclipse.cdt.debug.core.model.ICastToType#canCast()
 	 */
 	public boolean canCast() {
 		return ( getOriginal() != null && isEnabled() );
 	}

 	/*
 	 * (non-Javadoc)
 	 *
 	 * @see org.eclipse.cdt.debug.core.model.ICastToType#getCurrentType()
 	 */
 	public String getCurrentType() {
 		String typeName = ""; //$NON-NLS-1$
 		try {
 			typeName = getReferenceTypeName();
 		}
 		catch( DebugException e ) {
 		}
 		return typeName;
 	}

 	/*
 	 * (non-Javadoc)
 	 *
 	 * @see org.eclipse.cdt.debug.core.model.ICastToType#cast(java.lang.String)
 	 */
 	public void cast( String type ) throws DebugException {
 		InternalVariable current = getCurrentInternalVariable();
 		if ( current != null ) {
 			InternalVariable newVar = current.createShadow( type );
 			if ( getShadow() != null )
 				getShadow().dispose( true );
 			setShadow( newVar );
 			// If casting of variable to a type or array causes an error, the status
 			// of the variable is set to "error" and it can't be reset by subsequent castings.
 			resetValue();
 		}
 	}

 	/*
 	 * (non-Javadoc)
 	 *
 	 * @see org.eclipse.cdt.debug.core.model.ICastToType#restoreOriginal()
 	 */
 	public void restoreOriginal() throws DebugException {
 		InternalVariable oldVar = getShadow();
 		setShadow( null );
 		if ( oldVar != null )
 			oldVar.dispose( true );
 		InternalVariable iv = getOriginal();
 		if ( iv != null )
 			iv.invalidateValue();
 		// If casting of variable to a type or array causes an error, the status
 		// of the variable is set to "error" and it can't be reset by subsequent castings.
 		resetValue();
 	}

 	/*
 	 * (non-Javadoc)
 	 *
 	 * @see org.eclipse.cdt.debug.core.model.ICastToType#isCasted()
 	 */
 	public boolean isCasted() {
 		return ( getShadow() != null );
 	}

 	/*
 	 * (non-Javadoc)
 	 *
 	 * @see org.eclipse.cdt.debug.core.cdi.event.ICDIEventListener#handleDebugEvents(org.eclipse.cdt.debug.core.cdi.event.ICDIEvent[])
 	 */
 	public void handleDebugEvents( ICDIEvent[] events ) {
 		InternalVariable iv = getCurrentInternalVariable();
 		if ( iv == null )
 			return;
 		for( int i = 0; i < events.length; i++ ) {
 			ICDIEvent event = events[i];
 			ICDIObject source = event.getSource();
 			if ( source == null )
 				continue;
 			IPCDITarget target = (IPCDITarget) source.getTarget();
 			if ( target.equals( getCDITarget() ) ) {
 				if ( event instanceof ICDIChangedEvent ) {
 					if ( source instanceof ICDIVariable && iv.isSameVariable( (ICDIVariable)source ) ) {
 						handleChangedEvent( (ICDIChangedEvent)event );
 					}
 				}
 				else if ( event instanceof ICDIResumedEvent ) {
 					handleResumedEvent( (ICDIResumedEvent)event );
 				}
 			}
 		}
 	}

 	private void handleResumedEvent( ICDIResumedEvent event ) {
 		boolean changed = false;
 		if ( hasErrors() ) {
 			resetStatus();
 			changed = true;
 			InternalVariable iv = getCurrentInternalVariable();
 			if ( iv != null )
 				iv.invalidateValue();
 		}
 		if ( changed )
 			fireChangeEvent( DebugEvent.STATE );
 	}

 	private void handleChangedEvent( ICDIChangedEvent event ) {
 		InternalVariable iv = getCurrentInternalVariable();
 		if ( iv != null ) {
 			iv.setChanged( true );
 			fireChangeEvent( DebugEvent.STATE );
 		}
 	}

 	private InternalVariable getCurrentInternalVariable() {
 		if ( getShadow() != null )
 			return getShadow();
 		return getOriginal();
 	}

 	private InternalVariable getOriginal() {
 		return fOriginal;
 	}

 	private void setOriginal( InternalVariable original ) {
 		fOriginal = original;
 	}

 	private InternalVariable getShadow() {
 		return fShadow;
 	}

 	private void setShadow( InternalVariable shadow ) {
 		fShadow = shadow;
 	}

 	protected boolean isBookkeepingEnabled() {
 		boolean result = false;
 		try {
 			result = getLaunch().getLaunchConfiguration().getAttribute( IPTPLaunchConfigurationConstants.ATTR_DEBUGGER_ENABLE_VARIABLE_BOOKKEEPING, false );
 		}
 		catch( CoreException e ) {
 		}
 		return result;
 	}

 	private void createOriginal( ICDIVariableDescriptor vo ) {
 		if ( vo != null )
 			fName = vo.getName();
 		setOriginal( new InternalVariable( this, vo ) );
 	}

 	protected boolean hasErrors() {
 		return !isOK();
 	}

 	protected void setChanged( boolean changed ) {
 		InternalVariable iv = getCurrentInternalVariable();
 		if ( iv != null ) {
 			iv.setChanged( changed );
 		}
 	}

 	protected void resetValue() {
 		InternalVariable iv = getCurrentInternalVariable();
 		if ( iv != null ) {
 			resetStatus();
 			iv.resetValue();
 			fireChangeEvent( DebugEvent.STATE );
 		}
 	}

 	private String processExpression( String oldExpression ) throws DebugException {
 		return oldExpression;
 	}

 	/* (non-Javadoc)
 	 * @see org.eclipse.cdt.debug.internal.core.model.AbstractCVariable#dispose()
 	 */
 	public void dispose() {
 		// Hack: do not destroy local variables
 		internalDispose( false );
 	}

 	protected int sizeof() {
 		InternalVariable iv = getCurrentInternalVariable();
 		return ( iv != null ) ? iv.sizeof() : -1;
 	}

 	/**
 	 * Compares the original internal variables.
 	 * @see java.lang.Object#equals(java.lang.Object)
 	 */
 	public boolean equals( Object obj ) {
 		if ( obj instanceof CVariable ) {
 			InternalVariable iv = getOriginal();
 			return ( iv != null ) ? iv.equals( ((CVariable)obj).getOriginal() ) : false;
 		}
 		return false;
 	}

 	protected boolean sameVariable( ICDIVariableDescriptor vo ) {
 		InternalVariable iv = getOriginal();
 		return ( iv != null && iv.sameVariable( vo ) );
 	}

 	protected void setFormat( CVariableFormat format ) {
 		fFormat = format;
 	}

 	/* (non-Javadoc)
 	 * @see org.eclipse.cdt.debug.core.model.ICVariable#getExpressionString()
 	 */
 	public String getExpressionString() throws DebugException {
 		InternalVariable iv = getCurrentInternalVariable();
 		return ( iv != null ) ? iv.getQualifiedName() : null;
 	}

 	/* (non-Javadoc)
 	 * @see org.eclipse.cdt.debug.internal.core.model.AbstractCVariable#preserve()
 	 */
 	protected void preserve() {
 		resetStatus();
 		InternalVariable iv = getCurrentInternalVariable();
 		if ( iv != null )
 			iv.preserve();
 	}

 	protected void internalDispose( boolean destroy ) {
 		getCDISession().getEventManager().removeEventListener( this );
 		InternalVariable iv = getOriginal();
 		if ( iv != null )
 			iv.dispose( destroy );
 		iv = getShadow();
 		if ( iv != null )
 			iv.dispose( destroy );
 	}
 }
	/**********************************************************************
	* Copyright (c) 2004 QNX Software Systems and others.
	* All rights reserved. This program and the accompanying materials
	* are made available under the terms of the Common Public License v1.0
	* which accompanies this distribution, and is available at
	* http://www.eclipse.org/legal/cpl-v10.html
	*
	* Contributors:
	* QNX Software Systems - Initial API and implementation
	***********************************************************************/
	package org.eclipse.ptp.debug.internal.core.model;

	import java.text.MessageFormat;

	import org.eclipse.cdt.debug.core.ICDebugConstants;
	import org.eclipse.cdt.debug.core.cdi.CDIException;
	import org.eclipse.cdt.debug.core.cdi.event.ICDIChangedEvent;
	import org.eclipse.cdt.debug.core.cdi.event.ICDIEvent;
	import org.eclipse.cdt.debug.core.cdi.event.ICDIEventListener;
	import org.eclipse.cdt.debug.core.cdi.event.ICDIResumedEvent;
	import org.eclipse.cdt.debug.core.cdi.model.ICDIArgumentDescriptor;
	import org.eclipse.cdt.debug.core.cdi.model.ICDIObject;
	import org.eclipse.cdt.debug.core.cdi.model.ICDIValue;
	import org.eclipse.cdt.debug.core.cdi.model.ICDIVariable;
	import org.eclipse.cdt.debug.core.cdi.model.ICDIVariableDescriptor;
	import org.eclipse.cdt.debug.core.cdi.model.type.ICDIArrayValue;
	import org.eclipse.cdt.debug.core.cdi.model.type.ICDIType;
	import org.eclipse.cdt.debug.core.model.CVariableFormat;
	import org.eclipse.cdt.debug.core.model.ICDebugElementStatus;
	import org.eclipse.cdt.debug.core.model.ICType;
	import org.eclipse.cdt.debug.core.model.ICValue;
	import org.eclipse.core.runtime.CoreException;
	import org.eclipse.debug.core.DebugEvent;
	import org.eclipse.debug.core.DebugException;
	import org.eclipse.debug.core.model.IValue;
	import org.eclipse.ptp.debug.core.IPTPLaunchConfigurationConstants;
	import org.eclipse.ptp.debug.core.PTPDebugCorePlugin;
	import org.eclipse.ptp.debug.core.cdi.model.IPCDITarget;

	/**
	* Represents a variable in the CDI model.
	*/
	public class CVariable extends AbstractCVariable implements ICDIEventListener {

	/**
	* Represents a single CDI variable.
	*/
	private class InternalVariable {

	/**
	* The enclosing <code>CVariable</code> instance.
	*/
	private CVariable fVariable;

	/**
	* The CDI variable object this variable is based on.
	*/
	private ICDIVariableDescriptor fCDIVariableObject;

	/**
	* The underlying CDI variable.
	*/
	private ICDIVariable fCDIVariable;

	/**
	* The type of this variable.
	*/
	private CType fType;

	/**
	* The expression used to eveluate the value of this variable.
	*/
	private String fQualifiedName;

	/**
	* The cache of the current value.
	*/
	private ICValue fValue;

	/**
	* The change flag.
	*/
	private boolean fChanged = false;

	/**
	* Constructor for InternalVariable.
	*/
	InternalVariable( CVariable var, ICDIVariableDescriptor varObject ) {
	setVariable( var );
	setCDIVariableObject( varObject );
	setCDIVariable( (varObject instanceof ICDIVariable) ? (ICDIVariable)varObject : null );
	}

	InternalVariable createShadow( int start, int length ) throws DebugException {
	InternalVariable iv = null;
	try {
	iv = new InternalVariable( getVariable(), getCDIVariableObject().getVariableDescriptorAsArray( start, length ) );
	}
	catch( CDIException e ) {
	requestFailed( e.getMessage(), null );
	}
	return iv;
	}

	InternalVariable createShadow( String type ) throws DebugException {
	InternalVariable iv = null;
	try {
	iv = new InternalVariable( getVariable(), getCDIVariableObject().getVariableDescriptorAsType( type ) );
	}
	catch( CDIException e ) {
	requestFailed( e.getMessage(), null );
	}
	return iv;
	}

	private synchronized ICDIVariable getCDIVariable() throws DebugException {
	if ( fCDIVariable == null ) {
	try {
	fCDIVariable = getCDIVariableObject().createVariable( );
	}
	catch( CDIException e ) {
	requestFailed( e.getMessage(), null );
	}
	}
	return fCDIVariable;
	}

	private void setCDIVariable( ICDIVariable variable ) {
	fCDIVariable = variable;
	}

	private ICDIVariableDescriptor getCDIVariableObject() {
	return fCDIVariableObject;
	}

	private void setCDIVariableObject( ICDIVariableDescriptor variableObject ) {
	fCDIVariableObject = variableObject;
	}

	String getQualifiedName() throws DebugException {
	if ( fQualifiedName == null ) {
	try {
	fQualifiedName = (fCDIVariableObject != null) ? fCDIVariableObject.getQualifiedName() : null;
	}
	catch( CDIException e ) {
	requestFailed( e.getMessage(), null );
	}
	}
	return fQualifiedName;
	}

	CType getType() throws DebugException {
	if ( fType == null ) {
	ICDIVariableDescriptor varObject = getCDIVariableObject();
	if ( varObject != null ) {
	synchronized( this ) {
	if ( fType == null ) {
	try {
	fType = new CType( varObject.getType() );
	}
	catch( CDIException e ) {
	requestFailed( e.getMessage(), null );
	}
	}
	}
	}
	}
	return fType;
	}

	synchronized void invalidate( boolean destroy ) {
	try {
	if ( destroy && fCDIVariable != null )
	fCDIVariable.dispose();
	}
	catch( CDIException e ) {
	logError( e.getMessage() );
	}
	invalidateValue();
	setCDIVariable( null );
	if ( fType != null )
	fType.dispose();
	fType = null;
	}

	void dispose( boolean destroy ) {
	invalidate( destroy );
	}

	boolean isSameVariable( ICDIVariable cdiVar ) {
	return ( fCDIVariable != null ) ? fCDIVariable.equals( cdiVar ) : false;
	}

	int sizeof() {
	if ( getCDIVariableObject() != null ) {
	try {
	return getCDIVariableObject().sizeof();
	}
	catch( CDIException e ) {
	}
	}
	return 0;
	}

	boolean isArgument() {
	return ( getCDIVariableObject() instanceof ICDIArgumentDescriptor );
	}

	void setValue( String expression ) throws DebugException {
	ICDIVariable cdiVariable = null;
	try {
	cdiVariable = getCDIVariable();
	if ( cdiVariable != null )
	cdiVariable.setValue( expression );
	else
	requestFailed( CoreModelMessages.getString( "CModificationVariable.0" ), null ); //$NON-NLS-1$
	}
	catch( CDIException e ) {
	targetRequestFailed( e.getMessage(), null );
	}
	}

	void setValue( ICValue value ) {
	fValue = value;
	}

	synchronized ICValue getValue() throws DebugException {
	if ( fValue == null ) {
	ICDIVariable var = getCDIVariable();
	if ( var != null ) {
	try {
	ICDIValue cdiValue = var.getValue();
	if ( cdiValue != null ) {
	ICDIType cdiType = cdiValue.getType();
	if ( cdiValue instanceof ICDIArrayValue && cdiType != null ) {
	ICType type = new CType( cdiType );
	if ( type.isArray() ) {
	int[] dims = type.getArrayDimensions();
	if ( dims.length > 0 && dims[0] > 0 )
	fValue = CValueFactory.createIndexedValue( getVariable(), (ICDIArrayValue)cdiValue, 0, dims[0] );
	}
	}
	else {
	fValue = CValueFactory.createValue( getVariable(), cdiValue );
	}
	}
	}
	catch( CDIException e ) {
	requestFailed( e.getMessage(), e );
	}
	}
	}
	return fValue;
	}

	void invalidateValue() {
	if ( fValue instanceof AbstractCValue ) {
	((AbstractCValue)fValue).dispose();
	fValue = null;
	}
	}

	boolean isChanged() {
	return fChanged;
	}

	synchronized void setChanged( boolean changed ) {
	if ( changed ) {
	invalidateValue();
	}
	if ( fValue instanceof AbstractCValue ) {
	((AbstractCValue)fValue).setChanged( changed );
	}
	fChanged = changed;
	}

	synchronized void preserve() {
	setChanged( false );
	if ( fValue instanceof AbstractCValue ) {
	((AbstractCValue)fValue).preserve();
	}
	}

	CVariable getVariable() {
	return fVariable;
	}

	private void setVariable( CVariable variable ) {
	fVariable = variable;
	}

	void resetValue() {
	if ( fValue instanceof AbstractCValue ) {
	((AbstractCValue)fValue).reset();
	}
	}

	/**
	* Compares the underlying variable objects.
	* @see java.lang.Object#equals(java.lang.Object)
	*/
	public boolean equals( Object obj ) {
	if ( obj instanceof InternalVariable ) {
	return getCDIVariableObject().equals( ((InternalVariable)obj).getCDIVariableObject() );
	}
	return false;
	}

	boolean sameVariable( ICDIVariableDescriptor vo ) {
	return getCDIVariableObject().equals( vo );
	}
	}

	/**
	* Whether this variable is currently enabled.
	*/
	private boolean fIsEnabled = true;

	/**
	* The original internal variable.
	*/
	private InternalVariable fOriginal;

	/**
	* The shadow internal variable used for casting.
	*/
	private InternalVariable fShadow;

	/**
	* The name of this variable.
	*/
	private String fName;

	/**
	* The current format of this variable.
	*/
	private CVariableFormat fFormat = CVariableFormat.getFormat( PTPDebugCorePlugin.getDefault().getPluginPreferences().getInt( ICDebugConstants.PREF_DEFAULT_VARIABLE_FORMAT ) );

	/**
	* Constructor for CVariable.
	*/
	protected CVariable( PDebugElement parent, ICDIVariableDescriptor cdiVariableObject ) {
	super( parent );
	if ( cdiVariableObject != null ) {
	fName = cdiVariableObject.getName();
	createOriginal( cdiVariableObject );
	}
	fIsEnabled = ( parent instanceof AbstractCValue ) ? ((AbstractCValue)parent).getParentVariable().isEnabled() : !isBookkeepingEnabled();
	getCDISession().getEventManager().addEventListener( this );
	}

	/**
	* Constructor for CVariable.
	*/
	protected CVariable( PDebugElement parent, ICDIVariableDescriptor cdiVariableObject, String errorMessage ) {
	super( parent );
	if ( cdiVariableObject != null ) {
	fName = cdiVariableObject.getName();
	createOriginal( cdiVariableObject );
	}
	fIsEnabled = !isBookkeepingEnabled();
	setStatus( ICDebugElementStatus.ERROR, MessageFormat.format( CoreModelMessages.getString( "CVariable.1" ), new String[]{ errorMessage } ) ); //$NON-NLS-1$
	getCDISession().getEventManager().addEventListener( this );
	}

	/*
	* (non-Javadoc)
	*
	* @see org.eclipse.cdt.debug.core.model.ICVariable#getType()
	*/
	public ICType getType() throws DebugException {
	InternalVariable iv = getCurrentInternalVariable();
	return ( iv != null ) ? iv.getType() : null;
	}

	/*
	* (non-Javadoc)
	*
	* @see org.eclipse.cdt.debug.core.model.ICVariable#isEnabled()
	*/
	public boolean isEnabled() {
	return fIsEnabled;
	}

	/*
	* (non-Javadoc)
	*
	* @see org.eclipse.cdt.debug.core.model.ICVariable#setEnabled(boolean)
	*/
	public void setEnabled( boolean enabled ) throws DebugException {
	InternalVariable iv = getOriginal();
	if ( iv != null )
	iv.dispose( true );
	iv = getShadow();
	if ( iv != null )
	iv.dispose( true );
	fIsEnabled = enabled;
	fireChangeEvent( DebugEvent.STATE );
	}

	/*
	* (non-Javadoc)
	*
	* @see org.eclipse.cdt.debug.core.model.ICVariable#canEnableDisable()
	*/
	public boolean canEnableDisable() {
	return !( getParent() instanceof IValue );
	}

	/*
	* (non-Javadoc)
	*
	* @see org.eclipse.cdt.debug.core.model.ICVariable#isArgument()
	*/
	public boolean isArgument() {
	InternalVariable iv = getOriginal();
	return ( iv != null ) ? iv.isArgument() : false;
	}

	/*
	* (non-Javadoc)
	*
	* @see org.eclipse.debug.core.model.IVariable#getValue()
	*/
	public IValue getValue() throws DebugException {
	if ( isEnabled() ) {
	InternalVariable iv = getCurrentInternalVariable();
	if ( iv != null ) {
	try {
	return iv.getValue();
	}
	catch( DebugException e ) {
	setStatus( ICDebugElementStatus.ERROR, e.getMessage() );
	}
	}
	}
	return null;
	}

	/*
	* (non-Javadoc)
	*
	* @see org.eclipse.debug.core.model.IVariable#getName()
	*/
	public String getName() throws DebugException {
	return fName;
	}

	/*
	* (non-Javadoc)
	*
	* @see org.eclipse.debug.core.model.IVariable#getReferenceTypeName()
	*/
	public String getReferenceTypeName() throws DebugException {
	ICType type = getType();
	return ( type != null ) ? type.getName() : ""; //$NON-NLS-1$
	}

	/*
	* (non-Javadoc)
	*
	* @see org.eclipse.debug.core.model.IVariable#hasValueChanged()
	*/
	public boolean hasValueChanged() throws DebugException {
	InternalVariable iv = getCurrentInternalVariable();
	return ( iv != null ) ? iv.isChanged() : false;
	}

	/*
	* (non-Javadoc)
	*
	* @see org.eclipse.cdt.debug.core.model.IFormatSupport#supportsFormatting()
	*/
	public boolean supportsFormatting() {
	return true;
	}

	/*
	* (non-Javadoc)
	*
	* @see org.eclipse.cdt.debug.core.model.IFormatSupport#getFormat()
	*/
	public CVariableFormat getFormat() {
	return fFormat;
	}

	/*
	* (non-Javadoc)
	*
	* @see org.eclipse.cdt.debug.core.model.IFormatSupport#changeFormat(org.eclipse.cdt.debug.core.model.CVariableFormat)
	*/
	public void changeFormat( CVariableFormat format ) throws DebugException {
	setFormat( format );
	resetValue();
	}

	/*
	* (non-Javadoc)
	* Allow this operation only for the pointer types (???).
	*
	* @see org.eclipse.cdt.debug.core.model.ICastToArray#canCastToArray()
	*/
	public boolean canCastToArray() {
	ICType type;
	try {
	type = getType();
	return ( getOriginal() != null && isEnabled() && type.isPointer() );
	}
	catch( DebugException e ) {
	}
	return false;
	}

	/*
	* (non-Javadoc)
	*
	* @see org.eclipse.cdt.debug.core.model.ICastToArray#castToArray(int, int)
	*/
	public void castToArray( int startIndex, int length ) throws DebugException {
	InternalVariable current = getCurrentInternalVariable();
	if ( current != null ) {
	InternalVariable newVar = current.createShadow( startIndex, length );
	if ( getShadow() != null )
	getShadow().dispose( true );
	setShadow( newVar );
	// If casting of variable to a type or array causes an error, the status
	// of the variable is set to "error" and it can't be reset by subsequent castings.
	resetValue();
	}
	}

	/*
	* (non-Javadoc)
	*
	* @see org.eclipse.debug.core.model.IValueModification#setValue(java.lang.String)
	*/
	public void setValue( String expression ) throws DebugException {
	InternalVariable iv = getCurrentInternalVariable();
	if ( iv != null ) {
	String newExpression = processExpression( expression );
	iv.setValue( newExpression );
	}
	}

	/*
	* (non-Javadoc)
	*
	* @see org.eclipse.debug.core.model.IValueModification#setValue(org.eclipse.debug.core.model.IValue)
	*/
	public void setValue( IValue value ) throws DebugException {
	notSupported( CoreModelMessages.getString( "CVariable.3" ) ); //$NON-NLS-1$
	}

	/*
	* (non-Javadoc)
	*
	* @see org.eclipse.debug.core.model.IValueModification#supportsValueModification()
	*/
	public boolean supportsValueModification() {
	return true;
	}

	/*
	* (non-Javadoc)
	*
	* @see org.eclipse.debug.core.model.IValueModification#verifyValue(java.lang.String)
	*/
	public boolean verifyValue( String expression ) throws DebugException {
	return true;
	}

	/*
	* (non-Javadoc)
	*
	* @see org.eclipse.debug.core.model.IValueModification#verifyValue(org.eclipse.debug.core.model.IValue)
	*/
	public boolean verifyValue( IValue value ) throws DebugException {
	return value.getDebugTarget().equals( getDebugTarget() );
	}

	/*
	* (non-Javadoc)
	*
	* @see org.eclipse.cdt.debug.core.model.ICastToType#canCast()
	*/
	public boolean canCast() {
	return ( getOriginal() != null && isEnabled() );
	}

	/*
	* (non-Javadoc)
	*
	* @see org.eclipse.cdt.debug.core.model.ICastToType#getCurrentType()
	*/
	public String getCurrentType() {
	String typeName = ""; //$NON-NLS-1$
	try {
	typeName = getReferenceTypeName();
	}
	catch( DebugException e ) {
	}
	return typeName;
	}

	/*
	* (non-Javadoc)
	*
	* @see org.eclipse.cdt.debug.core.model.ICastToType#cast(java.lang.String)
	*/
	public void cast( String type ) throws DebugException {
	InternalVariable current = getCurrentInternalVariable();
	if ( current != null ) {
	InternalVariable newVar = current.createShadow( type );
	if ( getShadow() != null )
	getShadow().dispose( true );
	setShadow( newVar );
	// If casting of variable to a type or array causes an error, the status
	// of the variable is set to "error" and it can't be reset by subsequent castings.
	resetValue();
	}
	}

	/*
	* (non-Javadoc)
	*
	* @see org.eclipse.cdt.debug.core.model.ICastToType#restoreOriginal()
	*/
	public void restoreOriginal() throws DebugException {
	InternalVariable oldVar = getShadow();
	setShadow( null );
	if ( oldVar != null )
	oldVar.dispose( true );
	InternalVariable iv = getOriginal();
	if ( iv != null )
	iv.invalidateValue();
	// If casting of variable to a type or array causes an error, the status
	// of the variable is set to "error" and it can't be reset by subsequent castings.
	resetValue();
	}

	/*
	* (non-Javadoc)
	*
	* @see org.eclipse.cdt.debug.core.model.ICastToType#isCasted()
	*/
	public boolean isCasted() {
	return ( getShadow() != null );
	}

	/*
	* (non-Javadoc)
	*
	* @see org.eclipse.cdt.debug.core.cdi.event.ICDIEventListener#handleDebugEvents(org.eclipse.cdt.debug.core.cdi.event.ICDIEvent[])
	*/
	public void handleDebugEvents( ICDIEvent[] events ) {
	InternalVariable iv = getCurrentInternalVariable();
	if ( iv == null )
	return;
	for( int i = 0; i < events.length; i++ ) {
	ICDIEvent event = events[i];
	ICDIObject source = event.getSource();
	if ( source == null )
	continue;
	IPCDITarget target = (IPCDITarget) source.getTarget();
	if ( target.equals( getCDITarget() ) ) {
	if ( event instanceof ICDIChangedEvent ) {
	if ( source instanceof ICDIVariable && iv.isSameVariable( (ICDIVariable)source ) ) {
	handleChangedEvent( (ICDIChangedEvent)event );
	}
	}
	else if ( event instanceof ICDIResumedEvent ) {
	handleResumedEvent( (ICDIResumedEvent)event );
	}
	}
	}
	}

	private void handleResumedEvent( ICDIResumedEvent event ) {
	boolean changed = false;
	if ( hasErrors() ) {
	resetStatus();
	changed = true;
	InternalVariable iv = getCurrentInternalVariable();
	if ( iv != null )
	iv.invalidateValue();
	}
	if ( changed )
	fireChangeEvent( DebugEvent.STATE );
	}

	private void handleChangedEvent( ICDIChangedEvent event ) {
	InternalVariable iv = getCurrentInternalVariable();
	if ( iv != null ) {
	iv.setChanged( true );
	fireChangeEvent( DebugEvent.STATE );
	}
	}

	private InternalVariable getCurrentInternalVariable() {
	if ( getShadow() != null )
	return getShadow();
	return getOriginal();
	}

	private InternalVariable getOriginal() {
	return fOriginal;
	}

	private void setOriginal( InternalVariable original ) {
	fOriginal = original;
	}

	private InternalVariable getShadow() {
	return fShadow;
	}

	private void setShadow( InternalVariable shadow ) {
	fShadow = shadow;
	}

	protected boolean isBookkeepingEnabled() {
	boolean result = false;
	try {
	result = getLaunch().getLaunchConfiguration().getAttribute( IPTPLaunchConfigurationConstants.ATTR_DEBUGGER_ENABLE_VARIABLE_BOOKKEEPING, false );
	}
	catch( CoreException e ) {
	}
	return result;
	}

	private void createOriginal( ICDIVariableDescriptor vo ) {
	if ( vo != null )
	fName = vo.getName();
	setOriginal( new InternalVariable( this, vo ) );
	}

	protected boolean hasErrors() {
	return !isOK();
	}

	protected void setChanged( boolean changed ) {
	InternalVariable iv = getCurrentInternalVariable();
	if ( iv != null ) {
	iv.setChanged( changed );
	}
	}

	protected void resetValue() {
	InternalVariable iv = getCurrentInternalVariable();
	if ( iv != null ) {
	resetStatus();
	iv.resetValue();
	fireChangeEvent( DebugEvent.STATE );
	}
	}

	private String processExpression( String oldExpression ) throws DebugException {
	return oldExpression;
	}

	/* (non-Javadoc)
	* @see org.eclipse.cdt.debug.internal.core.model.AbstractCVariable#dispose()
	*/
	public void dispose() {
	// Hack: do not destroy local variables
	internalDispose( false );
	}

	protected int sizeof() {
	InternalVariable iv = getCurrentInternalVariable();
	return ( iv != null ) ? iv.sizeof() : -1;
	}

	/**
	* Compares the original internal variables.
	* @see java.lang.Object#equals(java.lang.Object)
	*/
	public boolean equals( Object obj ) {
	if ( obj instanceof CVariable ) {
	InternalVariable iv = getOriginal();
	return ( iv != null ) ? iv.equals( ((CVariable)obj).getOriginal() ) : false;
	}
	return false;
	}

	protected boolean sameVariable( ICDIVariableDescriptor vo ) {
	InternalVariable iv = getOriginal();
	return ( iv != null && iv.sameVariable( vo ) );
	}

	protected void setFormat( CVariableFormat format ) {
	fFormat = format;
	}

	/* (non-Javadoc)
	* @see org.eclipse.cdt.debug.core.model.ICVariable#getExpressionString()
	*/
	public String getExpressionString() throws DebugException {
	InternalVariable iv = getCurrentInternalVariable();
	return ( iv != null ) ? iv.getQualifiedName() : null;
	}

	/* (non-Javadoc)
	* @see org.eclipse.cdt.debug.internal.core.model.AbstractCVariable#preserve()
	*/
	protected void preserve() {
	resetStatus();
	InternalVariable iv = getCurrentInternalVariable();
	if ( iv != null )
	iv.preserve();
	}

	protected void internalDispose( boolean destroy ) {
	getCDISession().getEventManager().removeEventListener( this );
	InternalVariable iv = getOriginal();
	if ( iv != null )
	iv.dispose( destroy );
	iv = getShadow();
	if ( iv != null )
	iv.dispose( destroy );
	}
	}