diff --git a/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/text/c/hover/CDocHover.java b/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/text/c/hover/CDocHover.java
index 3ff06e0a1b1..e9122204de5 100644
--- a/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/text/c/hover/CDocHover.java
+++ b/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/text/c/hover/CDocHover.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2000, 2008 QNX Software Systems and others.
+ * Copyright (c) 2000, 2009 QNX Software Systems and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
@@ -25,6 +25,7 @@ import org.eclipse.cdt.ui.IFunctionSummary;
 import org.eclipse.cdt.ui.IRequiredInclude;
 import org.eclipse.cdt.ui.IFunctionSummary.IFunctionPrototypeSummary;
 import org.eclipse.cdt.ui.text.ICHelpInvocationContext;
+import org.eclipse.cdt.ui.text.IHoverHelpInvocationContext;
 
 import org.eclipse.cdt.internal.ui.CHelpProviderManager;
 import org.eclipse.cdt.internal.ui.editor.CEditorMessages;
@@ -55,10 +56,11 @@ public class CDocHover extends AbstractCEditorTextHover {
 				return null; 
 
 			StringBuilder buffer = new StringBuilder();
+			final IRegion hoverRegion = region;
 
 			// call the Help to get info
 
-			ICHelpInvocationContext context = new ICHelpInvocationContext() {
+			ICHelpInvocationContext context = new IHoverHelpInvocationContext() {
 
 				public IProject getProject() {
 					ITranslationUnit unit = getTranslationUnit();
@@ -71,7 +73,12 @@ public class CDocHover extends AbstractCEditorTextHover {
 				public ITranslationUnit getTranslationUnit() {
 					IEditorInput editorInput= getEditor().getEditorInput();
 					return CUIPlugin.getDefault().getWorkingCopyManager().getWorkingCopy(editorInput);
-				}	
+				}
+
+				public IRegion getHoverRegion() {
+					return hoverRegion; 
+				}
+				
 			};
 
 			IFunctionSummary fs = CHelpProviderManager.getDefault().getFunctionInfo(context, expression);
diff --git a/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/text/contentassist/HelpCompletionProposalComputer.java b/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/text/contentassist/HelpCompletionProposalComputer.java
index a80ef79fe50..babe0ab8df0 100644
--- a/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/text/contentassist/HelpCompletionProposalComputer.java
+++ b/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/text/contentassist/HelpCompletionProposalComputer.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2007, 2008 QNX Software Systems and others.
+ * Copyright (c) 2007, 2009 QNX Software Systems and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
@@ -27,6 +27,7 @@ import org.eclipse.cdt.core.model.ITranslationUnit;
 import org.eclipse.cdt.ui.CUIPlugin;
 import org.eclipse.cdt.ui.IFunctionSummary;
 import org.eclipse.cdt.ui.text.ICHelpInvocationContext;
+import org.eclipse.cdt.ui.text.IContentAssistHelpInvocationContext;
 
 import org.eclipse.cdt.internal.ui.CHelpProviderManager;
 import org.eclipse.cdt.internal.ui.viewsupport.CElementImageProvider;
@@ -63,8 +64,11 @@ public class HelpCompletionProposalComputer extends ParsingBasedProposalComputer
 		}
 		
 		final ITranslationUnit tu = cContext.getTranslationUnit();
+		final IASTCompletionNode cn = completionNode;
+		final int cc = cContext.getInvocationOffset();
+		
 		// Find matching functions
-		ICHelpInvocationContext helpContext = new ICHelpInvocationContext() {
+		ICHelpInvocationContext helpContext = new IContentAssistHelpInvocationContext() {
 
 			public IProject getProject() {
 				return tu.getCProject().getProject();
@@ -73,6 +77,14 @@ public class HelpCompletionProposalComputer extends ParsingBasedProposalComputer
 			public ITranslationUnit getTranslationUnit() {
 				return tu;
 			}
+			
+			public int getInvocationOffset() {
+				return cc;
+			}
+			
+			public IASTCompletionNode getCompletionNode() {
+				return cn;
+			}
 		};
 
 		IFunctionSummary[] summaries = CHelpProviderManager.getDefault()
diff --git a/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/ui/text/ICHelpInvocationContext.java b/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/ui/text/ICHelpInvocationContext.java
index 10029c1edc8..5a27dca844d 100644
--- a/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/ui/text/ICHelpInvocationContext.java
+++ b/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/ui/text/ICHelpInvocationContext.java
@@ -19,6 +19,9 @@ import org.eclipse.core.resources.IProject;
  * 
  * @noextend This interface is not intended to be extended by clients.
  * @noimplement This interface is not intended to be implemented by clients.
+ * 
+ * @see IHoverHelpInvocationContext
+ * @see IContentAssistHelpInvocationContext
  */
 public interface ICHelpInvocationContext {
 	
diff --git a/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/ui/text/IContentAssistHelpInvocationContext.java b/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/ui/text/IContentAssistHelpInvocationContext.java
new file mode 100644
index 00000000000..95c5560752e
--- /dev/null
+++ b/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/ui/text/IContentAssistHelpInvocationContext.java
@@ -0,0 +1,35 @@
+/**********************************************************************
+ * Copyright (c) 2009 Red Hat Inc. and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ * 
+ * Contributors: 
+ *     Red Hat Inc. - Initial API and implementation
+ **********************************************************************/
+
+package org.eclipse.cdt.ui.text;
+
+import org.eclipse.cdt.core.dom.ast.IASTCompletionNode;
+
+/**
+ * Invocation context for content assist.
+ * 
+ * @noextend This interface is not intended to be extended by clients.
+ * @noimplement This interface is not intended to be implemented by clients.
+ * @since 5.1
+ */
+public interface IContentAssistHelpInvocationContext extends ICHelpInvocationContext {
+	
+	/**
+	 * @return the offset of the content assist.
+	 */
+	int getInvocationOffset();
+	
+	/**
+	 * @return the AST completion node or null.
+	 */
+	IASTCompletionNode getCompletionNode();
+	
+}
diff --git a/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/ui/text/IHoverHelpInvocationContext.java b/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/ui/text/IHoverHelpInvocationContext.java
new file mode 100644
index 00000000000..351ec1b0962
--- /dev/null
+++ b/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/ui/text/IHoverHelpInvocationContext.java
@@ -0,0 +1,30 @@
+/**********************************************************************
+ * Copyright (c) 2009 Red Hat Inc. and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ * 
+ * Contributors: 
+ *     Red Hat Inc. - Initial API and implementation
+ **********************************************************************/
+
+package org.eclipse.cdt.ui.text;
+
+import org.eclipse.jface.text.IRegion;
+
+/**
+ * Invocation context for the CHelpProviderManager.
+ * 
+ * @noextend This interface is not intended to be extended by clients.
+ * @noimplement This interface is not intended to be implemented by clients.
+ * @since 5.1
+ */
+public interface IHoverHelpInvocationContext extends ICHelpInvocationContext {
+	
+	/**
+	 * @return the hover region or null
+	 */
+	IRegion getHoverRegion();
+	
+}