diff --git a/debug/org.eclipse.cdt.debug.ui/plugin.xml b/debug/org.eclipse.cdt.debug.ui/plugin.xml
index a1e23e8a182..c2d4a95aa98 100644
--- a/debug/org.eclipse.cdt.debug.ui/plugin.xml
+++ b/debug/org.eclipse.cdt.debug.ui/plugin.xml
@@ -325,5 +325,13 @@
             id="org.eclipse.cdt.debug.internal.ui.editors.DebugTextHover">
       </textHover>
    </extension>
+   <extension
+         point="org.eclipse.debug.core.sourceLocators">
+      <sourceLocator
+            name="Prompting C/C++ Source Locator"
+            class="org.eclipse.cdt.debug.ui.CUISourceLocator"
+            id="org.eclipse.cdt.debug.ui.cSourceLocator">
+      </sourceLocator>
+   </extension>
 
 </plugin>
diff --git a/debug/org.eclipse.cdt.debug.ui/src/org/eclipse/cdt/debug/ui/CUISourceLocator.java b/debug/org.eclipse.cdt.debug.ui/src/org/eclipse/cdt/debug/ui/CUISourceLocator.java
new file mode 100644
index 00000000000..84a120b96a9
--- /dev/null
+++ b/debug/org.eclipse.cdt.debug.ui/src/org/eclipse/cdt/debug/ui/CUISourceLocator.java
@@ -0,0 +1,217 @@
+/*
+ *(c) Copyright QNX Software Systems Ltd. 2002.
+ * All Rights Reserved.
+ * 
+ */
+package org.eclipse.cdt.debug.ui;
+
+import java.text.MessageFormat;
+
+import org.eclipse.cdt.debug.core.IStackFrameInfo;
+import org.eclipse.cdt.debug.core.sourcelookup.CSourceLocator;
+import org.eclipse.core.resources.IProject;
+import org.eclipse.core.runtime.CoreException;
+import org.eclipse.debug.core.DebugException;
+import org.eclipse.debug.core.ILaunchConfiguration;
+import org.eclipse.debug.core.ILaunchConfigurationWorkingCopy;
+import org.eclipse.debug.core.model.IPersistableSourceLocator;
+import org.eclipse.debug.core.model.IStackFrame;
+import org.eclipse.jface.dialogs.Dialog;
+import org.eclipse.swt.SWT;
+import org.eclipse.swt.graphics.FontMetrics;
+import org.eclipse.swt.graphics.GC;
+import org.eclipse.swt.layout.GridData;
+import org.eclipse.swt.layout.GridLayout;
+import org.eclipse.swt.widgets.Button;
+import org.eclipse.swt.widgets.Composite;
+import org.eclipse.swt.widgets.Control;
+import org.eclipse.swt.widgets.Label;
+import org.eclipse.swt.widgets.Shell;
+
+/**
+ * 
+ * A source locator that prompts the user to find source when source cannot
+ * be found on the current source lookup path.
+ * 
+ * @since Sep 24, 2002
+ */
+public class CUISourceLocator implements IPersistableSourceLocator
+{
+	/**
+	 * Identifier for the 'Prompting C/C++ Source Locator' extension
+	 * (value <code>"org.eclipse.cdt.debug.ui.cSourceLocator"</code>).
+	 */
+	public static final String ID_PROMPTING_JAVA_SOURCE_LOCATOR = CDebugUIPlugin.getUniqueIdentifier() + ".cSourceLocator"; //$NON-NLS-1$
+
+	/**
+	 * The project being debugged.
+	 */
+	private IProject fProject; 
+	
+	/**
+	 * Underlying source locator.
+	 */
+	private CSourceLocator fSourceLocator;
+	
+	/**
+	 * Whether the user should be prompted for source.
+	 * Initially true, until the user checks the 'do not
+	 * ask again' box.
+	 */
+	private boolean fAllowedToAsk;
+
+	/**
+	 * Constructor for CUISourceLocator.
+	 */
+	public CUISourceLocator( IProject project )
+	{
+		fProject = project;
+		fSourceLocator = new CSourceLocator( project );
+		fAllowedToAsk = true;
+	}
+
+	/* (non-Javadoc)
+	 * @see org.eclipse.debug.core.model.IPersistableSourceLocator#getMemento()
+	 */
+	public String getMemento() throws CoreException
+	{
+		return null;
+	}
+
+	/* (non-Javadoc)
+	 * @see org.eclipse.debug.core.model.IPersistableSourceLocator#initializeFromMemento(String)
+	 */
+	public void initializeFromMemento( String memento ) throws CoreException
+	{
+	}
+
+	/* (non-Javadoc)
+	 * @see org.eclipse.debug.core.model.IPersistableSourceLocator#initializeDefaults(ILaunchConfiguration)
+	 */
+	public void initializeDefaults( ILaunchConfiguration configuration ) throws CoreException
+	{
+	}
+
+	/* (non-Javadoc)
+	 * @see org.eclipse.debug.core.model.ISourceLocator#getSourceElement(IStackFrame)
+	 */
+	public Object getSourceElement( IStackFrame stackFrame )
+	{
+		Object res = fSourceLocator.getSourceElement( stackFrame );
+		if ( res == null && fAllowedToAsk )
+		{
+			IStackFrameInfo frameInfo = (IStackFrameInfo)stackFrame.getAdapter( IStackFrameInfo.class );
+			if ( frameInfo != null )
+			{
+				showDebugSourcePage( frameInfo.getFile(), stackFrame.getLaunch().getLaunchConfiguration() );
+				res = fSourceLocator.getSourceElement( stackFrame );
+			}
+		}
+		return res;
+	}
+
+	/**
+	 * Prompts to locate the source of the given type. 
+	 * 
+	 * @param frameInfo the frame information for which source
+	 *  could not be located
+	 */
+	private void showDebugSourcePage( final String fileName, final ILaunchConfiguration lc )
+	{
+		Runnable prompter = new Runnable()
+								{
+									public void run()
+									{
+										SourceLookupDialog dialog = new SourceLookupDialog( CDebugUIPlugin.getActiveWorkbenchShell(), fileName, lc, CUISourceLocator.this );
+										dialog.open();
+										fAllowedToAsk = !dialog.isNotAskAgain();
+									}
+								};
+		CDebugUIPlugin.getStandardDisplay().syncExec( prompter );
+	}
+
+	/**
+	 * Dialog that prompts for source lookup path.
+	 */
+	private static class SourceLookupDialog extends Dialog
+	{
+
+		private CUISourceLocator fLocator;
+		private ILaunchConfiguration fConfiguration;
+		private String fFileName;
+		private boolean fNotAskAgain;
+		private Button fAskAgainCheckBox;
+
+		public SourceLookupDialog( Shell shell,
+								   String fileName,
+								   ILaunchConfiguration configuration,
+								   CUISourceLocator locator )
+		{
+			super( shell );
+			fFileName = fileName;
+			fNotAskAgain = false;
+			fAskAgainCheckBox = null;
+			fLocator = locator;
+			fConfiguration = configuration;
+		}
+
+		public boolean isNotAskAgain()
+		{
+			return fNotAskAgain;
+		}
+
+		protected Control createDialogArea(Composite parent)
+		{
+			getShell().setText( "Debugger Source Lookup" );
+
+			Composite composite = (Composite)super.createDialogArea( parent );
+			composite.setLayout( new GridLayout() );
+			Label message = new Label( composite, SWT.LEFT + SWT.WRAP );
+			message.setText( MessageFormat.format( "The source could not be shown as the file ''{0}'' was not found.", new String[] { fFileName }  ) );
+			GridData data = new GridData();
+			data.widthHint = convertWidthInCharsToPixels( message, 70 );
+			message.setLayoutData( data );
+			fAskAgainCheckBox = new Button( composite, SWT.CHECK + SWT.WRAP );
+			data = new GridData();
+			data.widthHint = convertWidthInCharsToPixels( fAskAgainCheckBox, 70 );
+			fAskAgainCheckBox.setLayoutData(data);
+			fAskAgainCheckBox.setText( "Do &not ask again" );
+
+			return composite;
+		}
+
+		/**
+		 * @see Dialog#convertWidthInCharsToPixels(FontMetrics, int)
+		 */
+		protected int convertWidthInCharsToPixels( Control control, int chars )
+		{
+			GC gc = new GC( control );
+			gc.setFont( control.getFont() );
+			FontMetrics fontMetrics = gc.getFontMetrics();
+			gc.dispose();
+			return Dialog.convertWidthInCharsToPixels( fontMetrics, chars );
+		}
+
+		protected void okPressed()
+		{
+			try
+			{
+				if ( fAskAgainCheckBox != null )
+				{
+					fNotAskAgain = fAskAgainCheckBox.getSelection();
+				}
+				ILaunchConfigurationWorkingCopy wc = fConfiguration.getWorkingCopy();
+				if ( !fConfiguration.contentsEqual( wc ) )
+				{
+					fConfiguration = wc.doSave();
+					fLocator.initializeDefaults( fConfiguration );
+				}
+			}
+			catch( CoreException e )
+			{
+				CDebugUIPlugin.log( e );
+			}
+			super.okPressed();
+		}
+	}
+}