Bug 333939: When a statement is replaced or removed using the ASTRewrite class any comment attached to the statement is lost

https://bugs.eclipse.org/bugs/show_bug.cgi?id=333939

core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/core/parser/tests/rewrite/changegenerator/ChangeGeneratorTest.java

@@ -20,6 +20,7 @@ import org.eclipse.cdt.core.parser.tests.rewrite.TestHelper;
 import org.eclipse.cdt.core.tests.BaseTestFramework;
 import org.eclipse.cdt.internal.core.dom.rewrite.ASTModificationStore;
 import org.eclipse.cdt.internal.core.dom.rewrite.changegenerator.ChangeGenerator;
+import org.eclipse.cdt.internal.core.dom.rewrite.commenthandler.ASTCommenter;
 import org.eclipse.core.resources.IFile;
 import org.eclipse.core.resources.IncrementalProjectBuilder;
 import org.eclipse.core.resources.ResourcesPlugin;
@@ -46,24 +47,26 @@ public abstract class ChangeGeneratorTest extends BaseTestFramework {
 	@Override
 	public void runTest() throws Exception{
 		final ASTModificationStore modStore = new ASTModificationStore();
-		final ChangeGenerator changegenartor = new ChangeGenerator(modStore);
+		IFile testFile = importFile("source.h", source); //$NON-NLS-1$			
-		IFile testFile = importFile("source.h", source); //$NON-NLS-1$
+
-		
 		ASTVisitor visitor = createModificator(modStore);
-		
+
 		CCorePlugin.getIndexManager().reindex(cproject);
 
 		ResourcesPlugin.getWorkspace().build(IncrementalProjectBuilder.FULL_BUILD, new NullProgressMonitor());
 
 		boolean joined = CCorePlugin.getIndexManager().joinIndexer(20000, new NullProgressMonitor());
 		assertTrue("The indexing operation of the test CProject has not finished jet. This should not happen...", joined);
-		
+
 		IASTTranslationUnit unit = CoreModelUtil.findTranslationUnit(testFile).getAST();
+		final ChangeGenerator changegenartor = new ChangeGenerator(modStore,
+				ASTCommenter.getCommentedNodeMap(unit));
 		unit.accept(visitor);
-		
+
 		changegenartor.generateChange(unit);
 		Document doc = new Document(source);
-		for (Change curChange : ((CompositeChange)changegenartor.getChange()).getChildren()){
+		for (Change curChange : ((CompositeChange) changegenartor.getChange())
+				.getChildren()) {
 			if (curChange instanceof TextFileChange) {
 				TextFileChange textChange = (TextFileChange) curChange;
 				textChange.getEdit().apply(doc);

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/core/dom/rewrite/ASTRewrite.java

@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2007, 2009 Wind River Systems, Inc. and others.
+ * Copyright (c) 2007, 2011 Wind River Systems, 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
@@ -10,6 +10,8 @@
  *******************************************************************************/ 
 package org.eclipse.cdt.core.dom.rewrite;
 
+import java.util.List;
+
 import org.eclipse.cdt.core.dom.ast.IASTComment;
 import org.eclipse.cdt.core.dom.ast.IASTNode;
 import org.eclipse.cdt.core.dom.ast.IASTPreprocessorStatement;
@@ -17,49 +19,80 @@ import org.eclipse.cdt.core.dom.ast.IASTProblem;
 import org.eclipse.cdt.core.dom.ast.IASTTranslationUnit;
 import org.eclipse.cdt.internal.core.dom.rewrite.ASTLiteralNode;
 import org.eclipse.cdt.internal.core.dom.rewrite.ASTModification;
+import org.eclipse.cdt.internal.core.dom.rewrite.ASTModification.ModificationKind;
 import org.eclipse.cdt.internal.core.dom.rewrite.ASTModificationStore;
 import org.eclipse.cdt.internal.core.dom.rewrite.ASTRewriteAnalyzer;
-import org.eclipse.cdt.internal.core.dom.rewrite.ASTModification.ModificationKind;
+import org.eclipse.cdt.internal.core.dom.rewrite.commenthandler.ASTCommenter;
+import org.eclipse.cdt.internal.core.dom.rewrite.commenthandler.NodeCommentMap;
 import org.eclipse.ltk.core.refactoring.Change;
 import org.eclipse.text.edits.TextEditGroup;
 
 /**
- * Infrastructure for modifying code by describing changes to AST nodes.
+ * Infrastructure for modifying code by describing changes to AST nodes. The AST rewriter collects
- * The AST rewriter collects descriptions of modifications to nodes and
+ * descriptions of modifications to nodes and translates these descriptions into text edits that can then be
- * translates these descriptions into text edits that can then be applied to
+ * applied to the original source. This is all done without actually modifying the original AST. The rewrite
- * the original source. This is all done without actually modifying the 
+ * infrastructure tries to generate minimal text changes, preserve existing comments and indentation, and
- * original AST. The rewrite infrastructure tries to generate minimal
+ * follow code formatter settings. A {@link IASTComment} can be removed from or added to a node.
- * text changes, preserve existing comments and indentation, and follow code
- * formatter settings. 
  * <p>
- * The initial implementation does not support nodes that implement 
+ * The initial implementation does not support nodes that implement {@link IASTPreprocessorStatement} or
- * {@link IASTPreprocessorStatement}, {@link IASTComment} or {@link IASTProblem}.
+ * {@link IASTProblem}.
  * <p>
- * <strong>EXPERIMENTAL</strong>. This class or interface has been added as
+ * <strong>EXPERIMENTAL</strong>. This class or interface has been added as part of a work in progress. There
- * part of a work in progress. There is no guarantee that this API will
+ * is no guarantee that this API will work or that it will remain the same. Please do not use this API without
- * work or that it will remain the same. Please do not use this API without
  * consulting with the CDT team.
  * </p>
+ * 
  * @since 5.0
  * @noinstantiate This class is not intended to be instantiated by clients.
  */
 public final class ASTRewrite {
 	
+	/**
+	 * Defines the positions of the comment.
+	 * 
+	 * @since 5.3
+	 */
+	public enum CommentPosition{
+		
+		/**
+		 * Comments before a statement, declaration, or definition
+		 */
+		leading,
+		/**
+		 * Comments right after the AST node on the same line
+		 */
+		trailing,
+		/**
+		 * Comments before a closing brace such as they occur in namespace-, class- and method-definitions or
+		 * at the end of a file
+		 */
+		freestanding
+	}
+	
 	/**
 	 * Creates a rewriter for a translation unit.
 	 */
 	public static ASTRewrite create(IASTTranslationUnit node) {
-		return new ASTRewrite(node, new ASTModificationStore(), null);
+		NodeCommentMap commentMap = ASTCommenter.getCommentedNodeMap(node);
+		return new ASTRewrite(node, new ASTModificationStore(), null, commentMap);
 	}
 
 	private final IASTNode fRoot;
 	private final ASTModificationStore fModificationStore;
 	private final ASTModification fParentMod;
+	private final NodeCommentMap fCommentMap;
+	
+	private enum Operation{
+		insertBefore,
+		replace,
+		remove
+	}
 
-	private ASTRewrite(IASTNode root, ASTModificationStore modStore, ASTModification parentMod) {
+	private ASTRewrite(IASTNode root, ASTModificationStore modStore, ASTModification parentMod, NodeCommentMap commentMap) {
 		fRoot= root;
 		fModificationStore= modStore;
 		fParentMod= parentMod;
+		fCommentMap = commentMap;
 	}
 
 	/**
@@ -88,7 +121,7 @@ public final class ASTRewrite {
 	 */
 	public final void remove(IASTNode node, TextEditGroup editGroup) {
 		checkBelongsToAST(node);
-		checkSupportedNode(node);
+		checkSupportedNode(node, Operation.remove);
 		ASTModification mod= new ASTModification(ModificationKind.REPLACE, node, null, editGroup);
 		fModificationStore.storeModification(fParentMod, mod);
 	}
@@ -112,11 +145,11 @@ public final class ASTRewrite {
 			throw new IllegalArgumentException();
 		}
 		checkBelongsToAST(node);
-		checkSupportedNode(node);
+		checkSupportedNode(node, Operation.replace);
-		checkSupportedNode(replacement);
+		checkSupportedNode(replacement, Operation.replace);
 		ASTModification mod= new ASTModification(ModificationKind.REPLACE, node, replacement, editGroup);
 		fModificationStore.storeModification(fParentMod, mod);
-		return new ASTRewrite(replacement, fModificationStore, mod);
+		return new ASTRewrite(replacement, fModificationStore, mod, fCommentMap);
 	}
 
 	/**
@@ -140,9 +173,9 @@ public final class ASTRewrite {
 		if (newNode == null) {
 			throw new IllegalArgumentException();
 		}
-		checkSupportedNode(parent);
+		checkSupportedNode(parent, Operation.insertBefore);
-		checkSupportedNode(insertionPoint);
+		checkSupportedNode(insertionPoint, Operation.insertBefore);
-		checkSupportedNode(newNode);
+		checkSupportedNode(newNode, Operation.insertBefore);
 
 		ASTModification mod;
 		if (insertionPoint == null) {
@@ -155,7 +188,7 @@ public final class ASTRewrite {
 			mod= new ASTModification(ModificationKind.INSERT_BEFORE, insertionPoint, newNode, editGroup);
 		}
 		fModificationStore.storeModification(fParentMod, mod);
-		return new ASTRewrite(newNode, fModificationStore, mod);
+		return new ASTRewrite(newNode, fModificationStore, mod, fCommentMap);
 	}
 	
 	/**
@@ -175,7 +208,7 @@ public final class ASTRewrite {
 		if (!(fRoot instanceof IASTTranslationUnit)) {
 			throw new IllegalArgumentException("This API can only be used for the root rewrite object."); //$NON-NLS-1$
 		}
-		return ASTRewriteAnalyzer.rewriteAST((IASTTranslationUnit) fRoot, fModificationStore);
+		return ASTRewriteAnalyzer.rewriteAST((IASTTranslationUnit) fRoot, fModificationStore, fCommentMap);
 	}
 
 	private void checkBelongsToAST(IASTNode node) {
@@ -188,15 +221,63 @@ public final class ASTRewrite {
 		throw new IllegalArgumentException();
 	}
 	
-	private void checkSupportedNode(IASTNode node) {
+	private void checkSupportedNode(IASTNode node, Operation op) {
 		if (node instanceof IASTComment) {
-			throw new IllegalArgumentException("Rewriting comments is not yet supported"); //$NON-NLS-1$
+			if(op != Operation.remove) {
+				throw new IllegalArgumentException("Rewriting comments is not yet supported"); //$NON-NLS-1$
+			}
 		}
 		if (node instanceof IASTPreprocessorStatement) {
 			throw new IllegalArgumentException("Rewriting preprocessor statements is not yet supported"); //$NON-NLS-1$
 		}
 		if (node instanceof IASTProblem) {
-			throw new IllegalArgumentException("Rewriting problem nodes is supported"); //$NON-NLS-1$
+			throw new IllegalArgumentException("Rewriting problem nodes is not supported"); //$NON-NLS-1$
 		}		
 	}
+
+
+	/**
+	 * Assigns the comment to the node.
+	 * 
+	 * @param node
+	 * @param comment
+	 * @param pos
+	 * @since 5.3
+	 */
+	public void addComment(IASTNode node, IASTComment comment, CommentPosition pos) {
+		switch (pos) {
+		case leading:
+			fCommentMap.addLeadingCommentToNode(node, comment);
+			break;
+		case trailing:
+			fCommentMap.addTrailingCommentToNode(node, comment);
+			break;
+		case freestanding:
+			fCommentMap.addFreestandingCommentToNode(node, comment);
+			break;
+		}
+	}
+
+
+		/**
+	 * 
+	 * @param node
+	 *            the node
+	 * @param pos
+	 *            the position
+	 * @return All comments assigned to the node at this position
+	 * @since 5.3
+	 */
+	public List<IASTComment> getComments(IASTNode node, CommentPosition pos) {
+		switch (pos) {
+		case leading:
+			return fCommentMap.getLeadingCommentsForNode(node);
+		case trailing:
+			return fCommentMap.getTrailingCommentsForNode(node);
+		case freestanding:
+			return fCommentMap.getFreestandingCommentsForNode(node);
+
+		}
+		return fCommentMap.getLeadingCommentsForNode(node);
+	}
 }

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/rewrite/ASTRewriteAnalyzer.java

@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2008 Wind River Systems, Inc. and others.
+ * Copyright (c) 2008, 2011 Wind River Systems, 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
@@ -12,6 +12,7 @@ package org.eclipse.cdt.internal.core.dom.rewrite;
 
 import org.eclipse.cdt.core.dom.ast.IASTTranslationUnit;
 import org.eclipse.cdt.internal.core.dom.rewrite.changegenerator.ChangeGenerator;
+import org.eclipse.cdt.internal.core.dom.rewrite.commenthandler.NodeCommentMap;
 import org.eclipse.core.resources.IFile;
 import org.eclipse.ltk.core.refactoring.Change;
 import org.eclipse.ltk.core.refactoring.TextFileChange;
@@ -19,8 +20,8 @@ import org.eclipse.ltk.core.refactoring.TextFileChange;
 public class ASTRewriteAnalyzer {
 	private static ICTextFileChangeFactory sFileChangeFactory;
 
-	public static Change rewriteAST(IASTTranslationUnit root, ASTModificationStore modificationStore) {
+	public static Change rewriteAST(IASTTranslationUnit root, ASTModificationStore modificationStore, NodeCommentMap commentMap) {
-		ChangeGenerator rewriter = new ChangeGenerator(modificationStore);
+		ChangeGenerator rewriter = new ChangeGenerator(modificationStore, commentMap);
 		rewriter.generateChange(root);
 		return rewriter.getChange();
 	}

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/rewrite/astwriter/ASTWriter.java

@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2008, 2009 Institute for Software, HSR Hochschule fuer Technik  
+ * Copyright (c) 2008, 2011 Institute for Software, HSR Hochschule fuer Technik  
  * Rapperswil, University of applied sciences and others
  * All rights reserved. This program and the accompanying materials 
  * are made available under the terms of the Eclipse Public License v1.0 
@@ -64,6 +64,10 @@ public class ASTWriter {
 		return write(rootNode, null, new NodeCommentMap());
 	}
 	
+	public String write(IASTNode rootNode, NodeCommentMap commentMap) {
+		return write(rootNode, null, commentMap);
+	}
+	
 	/**
 	 * 
 	 * Generates the source code representing this node including comments.

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/rewrite/astwriter/ASTWriterVisitor.java

@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2008, 2009 Institute for Software, HSR Hochschule fuer Technik  
+ * Copyright (c) 2008, 2011 Institute for Software, HSR Hochschule fuer Technik  
  * Rapperswil, University of applied sciences and others
  * All rights reserved. This program and the accompanying materials 
  * are made available under the terms of the Eclipse Public License v1.0 
@@ -12,10 +12,13 @@
  *******************************************************************************/
 package org.eclipse.cdt.internal.core.dom.rewrite.astwriter;
 
+import java.util.ArrayList;
+
 import org.eclipse.cdt.core.dom.ast.ASTVisitor;
 import org.eclipse.cdt.core.dom.ast.IASTArrayModifier;
 import org.eclipse.cdt.core.dom.ast.IASTComment;
 import org.eclipse.cdt.core.dom.ast.IASTCompoundStatement;
+import org.eclipse.cdt.core.dom.ast.IASTCopyLocation;
 import org.eclipse.cdt.core.dom.ast.IASTDeclSpecifier;
 import org.eclipse.cdt.core.dom.ast.IASTDeclaration;
 import org.eclipse.cdt.core.dom.ast.IASTDeclarator;
@@ -23,6 +26,7 @@ import org.eclipse.cdt.core.dom.ast.IASTExpression;
 import org.eclipse.cdt.core.dom.ast.IASTInitializer;
 import org.eclipse.cdt.core.dom.ast.IASTName;
 import org.eclipse.cdt.core.dom.ast.IASTNode;
+import org.eclipse.cdt.core.dom.ast.IASTNodeLocation;
 import org.eclipse.cdt.core.dom.ast.IASTParameterDeclaration;
 import org.eclipse.cdt.core.dom.ast.IASTStatement;
 import org.eclipse.cdt.core.dom.ast.IASTTranslationUnit;
@@ -110,11 +114,23 @@ public class ASTWriterVisitor extends ASTVisitor {
 	}
 
 	private void writeLeadingComments(IASTNode node) {
-		for(IASTComment comment : commentMap.getLeadingCommentsForNode(node)) {
+		for(IASTComment comment : getLeadingComments(node)) {
 			scribe.print(comment.getComment());
 			scribe.newLine();
 		}		
 	}
+
+
+
+	private ArrayList<IASTComment> getLeadingComments(IASTNode node) {
+		ArrayList<IASTComment> leadingComments = commentMap.getLeadingCommentsForNode(node);
+		IASTNodeLocation[] locs = node.getNodeLocations();
+		if (locs != null && locs.length > 0 && locs[0] instanceof IASTCopyLocation) {
+			IASTCopyLocation copyLoc = (IASTCopyLocation) locs[0];
+			leadingComments.addAll(commentMap.getLeadingCommentsForNode(copyLoc.getOriginalNode()));
+		}
+		return leadingComments;
+	}
 	
 	public void visit(ASTLiteralNode lit) {
 		scribe.print(lit.getRawSignature());

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/rewrite/astwriter/NodeWriter.java

@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2008, 2010 Institute for Software, HSR Hochschule fuer Technik  
+ * Copyright (c) 2008, 2011 Institute for Software, HSR Hochschule fuer Technik  
  * Rapperswil, University of applied sciences and others
  * All rights reserved. This program and the accompanying materials 
  * are made available under the terms of the Eclipse Public License v1.0 
@@ -11,9 +11,13 @@
  *******************************************************************************/
 package org.eclipse.cdt.internal.core.dom.rewrite.astwriter;
 
+import java.util.ArrayList;
+
 import org.eclipse.cdt.core.dom.ast.ASTVisitor;
 import org.eclipse.cdt.core.dom.ast.IASTComment;
+import org.eclipse.cdt.core.dom.ast.IASTCopyLocation;
 import org.eclipse.cdt.core.dom.ast.IASTNode;
+import org.eclipse.cdt.core.dom.ast.IASTNodeLocation;
 import org.eclipse.cdt.internal.core.dom.rewrite.commenthandler.NodeCommentMap;
 
 /**
@@ -89,14 +93,24 @@ public class NodeWriter {
 	}
 	
 	protected boolean hasTrailingComments(IASTNode node){
-		if(commentMap.getTrailingCommentsForNode(node).size()>0) {
+		if(getTrailingComments(node).size()>0) {
 			return true;
 		}
 		return false;
 	}
+
+	private ArrayList<IASTComment> getTrailingComments(IASTNode node) {
+		ArrayList<IASTComment> trailingComments = commentMap.getTrailingCommentsForNode(node);
+		IASTNodeLocation[] locs = node.getNodeLocations();
+		if (locs != null && locs.length > 0 && locs[0] instanceof IASTCopyLocation) {
+			IASTCopyLocation loc = (IASTCopyLocation) locs[0];
+			trailingComments.addAll(commentMap.getTrailingCommentsForNode(loc.getOriginalNode()));
+		}
+		return trailingComments;
+	}
 	
 	protected void writeTrailingComments(IASTNode node, boolean newLine) {
-		for(IASTComment comment : commentMap.getTrailingCommentsForNode(node)) {
+		for(IASTComment comment : getTrailingComments(node)) {
 			scribe.printSpace();
 			scribe.print(comment.getComment());
 			if(newLine) {
@@ -106,14 +120,24 @@ public class NodeWriter {
 	}
 
 	protected boolean hasFreestandingComments(IASTNode node){
-		if(commentMap.getFreestandingCommentsForNode(node).size()>0) {
+		if(getFreestandingComments(node).size()>0) {
 			return true;
 		}
 		return false;
 	}
 
+	private ArrayList<IASTComment> getFreestandingComments(IASTNode node) {
+		ArrayList<IASTComment> freestandingComments = commentMap.getFreestandingCommentsForNode(node);
+		IASTNodeLocation[] locs = node.getNodeLocations();
+		if (locs != null && locs.length > 0 && locs[0] instanceof IASTCopyLocation) {
+			IASTCopyLocation loc = (IASTCopyLocation) locs[0];
+			freestandingComments.addAll(commentMap.getFreestandingCommentsForNode(loc.getOriginalNode()));
+		}
+		return freestandingComments;
+	}
+
 	protected void writeFreeStandingComments(IASTNode node) {
-		for(IASTComment comment : commentMap.getFreestandingCommentsForNode(node)) {
+		for(IASTComment comment : getFreestandingComments(node)) {
 			scribe.print(comment.getComment());
 			scribe.newLine();
 		}

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/rewrite/changegenerator/ASTModificationHelper.java

@@ -15,14 +15,17 @@ import java.lang.reflect.Array;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
+import java.util.HashMap;
 import java.util.List;
 
+import org.eclipse.cdt.core.dom.ast.IASTComment;
 import org.eclipse.cdt.core.dom.ast.IASTDeclarator;
 import org.eclipse.cdt.core.dom.ast.IASTInitializer;
 import org.eclipse.cdt.core.dom.ast.IASTNode;
 import org.eclipse.cdt.internal.core.dom.rewrite.ASTModification;
 import org.eclipse.cdt.internal.core.dom.rewrite.ASTModification.ModificationKind;
 import org.eclipse.cdt.internal.core.dom.rewrite.astwriter.ContainerNode;
+import org.eclipse.cdt.internal.core.dom.rewrite.commenthandler.NodeCommentMap;
 
 public class ASTModificationHelper {
 
@@ -33,7 +36,7 @@ public class ASTModificationHelper {
 	}
 
 	
-	public <T extends IASTNode> T[] createModifiedChildArray(IASTNode parent, T[] unmodifiedChildren, Class<T> clazz){
+	public <T extends IASTNode> T[] createModifiedChildArray(IASTNode parent, T[] unmodifiedChildren, Class<T> clazz, NodeCommentMap commentMap){
 		ArrayList<T> modifiedChildren = new ArrayList<T>(Arrays.asList(unmodifiedChildren));
 
 		for(ASTModification parentModification : modificationsForNode(parent)){
@@ -78,6 +81,7 @@ public class ASTModificationHelper {
 					switch (childModification.getKind()) {
 					case REPLACE:
 						if (newNode != null) {
+							copyComments(newNode, currentChild, commentMap);
 							modifiedChildren.add(
 									modifiedChildren.indexOf(childModification.getTargetNode()),
 									newNode);
@@ -96,6 +100,33 @@ public class ASTModificationHelper {
 		return modifiedChildren.toArray(newArrayInstance(clazz, modifiedChildren.size()));
 	}
 
+	private void copyComments(IASTNode newNode, IASTNode oldNode, NodeCommentMap commentMap) {
+		// Attach all the comments that is attached to oldNode to newNode
+		ArrayList<IASTComment> leadingComments = commentMap.getLeadingCommentsForNode(oldNode);
+		for (IASTComment comment : leadingComments) {
+			commentMap.addLeadingCommentToNode(newNode, comment);
+		}
+		
+		ArrayList<IASTComment> trailingComments = commentMap.getTrailingCommentsForNode(oldNode);
+		for (IASTComment comment : trailingComments) {
+			commentMap.addTrailingCommentToNode(newNode, comment);
+		}
+		
+		ArrayList<IASTComment> freestandingComments = commentMap.getFreestandingCommentsForNode(oldNode);
+		for (IASTComment comment : freestandingComments) {
+			commentMap.addFreestandingCommentToNode(newNode, comment);
+		}
+		
+		// Detach comments from oldNode (to avoid memory leak)
+		HashMap<IASTNode, ArrayList<IASTComment>> leadingMap = commentMap.getLeadingMap();
+		leadingMap.remove(oldNode);
+		
+		HashMap<IASTNode, ArrayList<IASTComment>> trailingMap = commentMap.getTrailingMap();
+		trailingMap.remove(oldNode);
+		
+		HashMap<IASTNode, ArrayList<IASTComment>> freestandingMap = commentMap.getFreestandingMap();
+		freestandingMap.remove(oldNode);
+	}
 
 	private <T> void insertNode(Class<T> clazz, ArrayList<T> modifiedChildren,
 			ASTModification parentModification, IASTNode newNode) {

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/rewrite/changegenerator/ChangeGenerator.java

@@ -37,7 +37,6 @@ import org.eclipse.cdt.internal.core.dom.rewrite.ASTModificationStore;
 import org.eclipse.cdt.internal.core.dom.rewrite.ASTRewriteAnalyzer;
 import org.eclipse.cdt.internal.core.dom.rewrite.astwriter.ASTWriter;
 import org.eclipse.cdt.internal.core.dom.rewrite.astwriter.ProblemRuntimeException;
-import org.eclipse.cdt.internal.core.dom.rewrite.commenthandler.ASTCommenter;
 import org.eclipse.cdt.internal.core.dom.rewrite.commenthandler.NodeCommentMap;
 import org.eclipse.cdt.internal.core.dom.rewrite.util.FileContentHelper;
 import org.eclipse.cdt.internal.core.dom.rewrite.util.FileHelper;
@@ -95,8 +94,9 @@ public class ChangeGenerator extends ASTVisitor {
 
 	}
 
-	public ChangeGenerator(ASTModificationStore modificationStore) {
+	public ChangeGenerator(ASTModificationStore modificationStore, NodeCommentMap commentMap) {
 		this.modificationStore = modificationStore;
+		this.commentMap = commentMap;
 
 	}
 
@@ -108,7 +108,6 @@ public class ChangeGenerator extends ASTVisitor {
 			throws ProblemRuntimeException {
 		change = new CompositeChange(Messages.ChangeGenerator_compositeChange);
 		initParentModList();
-		commentMap = ASTCommenter.getCommentedNodeMap(rootNode.getTranslationUnit());
 		rootNode.accept(pathProvider);
 		for (IFile currentFile : changes.keySet()) {
 

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/rewrite/changegenerator/ChangeGeneratorWriterVisitor.java

@@ -332,7 +332,7 @@ public class ChangeGeneratorWriterVisitor extends ASTWriterVisitor {
 		ASTModificationHelper helper = new ASTModificationHelper(
 				stack);
 
-		IASTDeclaration[] declarations = helper.createModifiedChildArray(tu, tu.getDeclarations(), IASTDeclaration.class);
+		IASTDeclaration[] declarations = helper.createModifiedChildArray(tu, tu.getDeclarations(), IASTDeclaration.class, commentMap);
 		for (IASTDeclaration currentDeclaration : declarations) {
 			currentDeclaration.accept(this);
 		}

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/rewrite/changegenerator/ModifiedASTDeclSpecWriter.java

@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2008 Institute for Software, HSR Hochschule fuer Technik  
+ * Copyright (c) 2008, 2011 Institute for Software, HSR Hochschule fuer Technik  
  * Rapperswil, University of applied sciences and others
  * All rights reserved. This program and the accompanying materials 
  * are made available under the terms of the Eclipse Public License v1.0 
@@ -30,6 +30,6 @@ public class ModifiedASTDeclSpecWriter extends DeclSpecWriter {
 	@Override
 	protected IASTDeclaration[] getMembers(IASTCompositeTypeSpecifier compDeclSpec) {
 		return modificationHelper.createModifiedChildArray(compDeclSpec, compDeclSpec.getMembers(),
-				IASTDeclaration.class);
+				IASTDeclaration.class, commentMap);
 	}
 }

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/rewrite/changegenerator/ModifiedASTDeclarationWriter.java

@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2008 Institute for Software, HSR Hochschule fuer Technik  
+ * Copyright (c) 2008, 2011 Institute for Software, HSR Hochschule fuer Technik  
  * Rapperswil, University of applied sciences and others
  * All rights reserved. This program and the accompanying materials 
  * are made available under the terms of the Eclipse Public License v1.0 
@@ -31,14 +31,14 @@ public class ModifiedASTDeclarationWriter extends DeclarationWriter {
 
 	@Override
 	protected void writeDeclarationsInNamespace(ICPPASTNamespaceDefinition namespaceDefinition, IASTDeclaration[] declarations) {
-		IASTDeclaration[] modifiedDeclarations = modificationHelper.createModifiedChildArray(namespaceDefinition, declarations, IASTDeclaration.class);
+		IASTDeclaration[] modifiedDeclarations = modificationHelper.createModifiedChildArray(namespaceDefinition, declarations, IASTDeclaration.class, commentMap);
 		super.writeDeclarationsInNamespace(namespaceDefinition, modifiedDeclarations);
 	}
 	
 	@Override
 	protected void writeCtorChainInitializer(ICPPASTFunctionDefinition funcDec,
 			ICPPASTConstructorChainInitializer[] ctorInitChain) {
-		ICPPASTConstructorChainInitializer[] modifiedChainInitializer = modificationHelper.createModifiedChildArray(funcDec, ctorInitChain, ICPPASTConstructorChainInitializer.class);
+		ICPPASTConstructorChainInitializer[] modifiedChainInitializer = modificationHelper.createModifiedChildArray(funcDec, ctorInitChain, ICPPASTConstructorChainInitializer.class, commentMap);
 		super.writeCtorChainInitializer(funcDec, modifiedChainInitializer);
 	}
 }

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/rewrite/changegenerator/ModifiedASTDeclaratorWriter.java

@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2008 Institute for Software, HSR Hochschule fuer Technik  
+ * Copyright (c) 2008, 2011 Institute for Software, HSR Hochschule fuer Technik  
  * Rapperswil, University of applied sciences and others
  * All rights reserved. This program and the accompanying materials 
  * are made available under the terms of the Eclipse Public License v1.0 
@@ -40,26 +40,29 @@ public class ModifiedASTDeclaratorWriter extends DeclaratorWriter {
 	@Override
 	protected void writeParameterDeclarations(IASTStandardFunctionDeclarator funcDec,
 			IASTParameterDeclaration[] paraDecls) {	
-		IASTParameterDeclaration[] modifiedParameters = modificationHelper.createModifiedChildArray(funcDec, paraDecls, IASTParameterDeclaration.class);			
+		IASTParameterDeclaration[] modifiedParameters = modificationHelper
+				.createModifiedChildArray(funcDec, paraDecls, IASTParameterDeclaration.class,
+						commentMap);
 		super.writeParameterDeclarations(funcDec, modifiedParameters);
 	}
 
 	@Override
 	protected void writePointerOperators(IASTDeclarator declarator,IASTPointerOperator[] unmodifiedPointerOperations) {
-		IASTPointerOperator[] modifiedPointer = modificationHelper.createModifiedChildArray(declarator, unmodifiedPointerOperations, IASTPointerOperator.class);
+		IASTPointerOperator[] modifiedPointer = modificationHelper.createModifiedChildArray(
+				declarator, unmodifiedPointerOperations, IASTPointerOperator.class, commentMap);
 		super.writePointerOperators(declarator, modifiedPointer);
 	}
 	
 	@Override
 	protected void writeArrayModifiers(IASTArrayDeclarator arrDecl,
 			IASTArrayModifier[] arrMods) {
-		IASTArrayModifier[] modifiedModifiers = modificationHelper.createModifiedChildArray(arrDecl, arrMods, IASTArrayModifier.class);
+		IASTArrayModifier[] modifiedModifiers = modificationHelper.createModifiedChildArray(arrDecl, arrMods, IASTArrayModifier.class, commentMap);
 		super.writeArrayModifiers(arrDecl, modifiedModifiers);
 	}
 
 	@Override
 	protected void writeExceptionSpecification(ICPPASTFunctionDeclarator funcDec, IASTTypeId[] exceptions ) {	
-		IASTTypeId[] modifiedExceptions = modificationHelper.createModifiedChildArray(funcDec, exceptions, IASTTypeId.class);
+		IASTTypeId[] modifiedExceptions = modificationHelper.createModifiedChildArray(funcDec, exceptions, IASTTypeId.class, commentMap);
 		// it makes a difference whether the exception array is identical to 
 		// ICPPASTFunctionDeclarator.NO_EXCEPTION_SPECIFICATION
 		if (modifiedExceptions.length == 0 &&
@@ -74,7 +77,7 @@ public class ModifiedASTDeclaratorWriter extends DeclaratorWriter {
 	protected void writeKnRParameterDeclarations(
 			ICASTKnRFunctionDeclarator knrFunct,
 			IASTDeclaration[] knrDeclarations) {
-		IASTDeclaration[] modifiedDeclarations = modificationHelper.createModifiedChildArray(knrFunct, knrDeclarations, IASTDeclaration.class);
+		IASTDeclaration[] modifiedDeclarations = modificationHelper.createModifiedChildArray(knrFunct, knrDeclarations, IASTDeclaration.class, commentMap);
 		
 		super.writeKnRParameterDeclarations(knrFunct, modifiedDeclarations);
 	}
@@ -82,7 +85,7 @@ public class ModifiedASTDeclaratorWriter extends DeclaratorWriter {
 	@Override
 	protected void writeKnRParameterNames(
 			ICASTKnRFunctionDeclarator knrFunct, IASTName[] parameterNames) {
-		IASTName[] modifiedNames = modificationHelper.createModifiedChildArray(knrFunct, parameterNames, IASTName.class);
+		IASTName[] modifiedNames = modificationHelper.createModifiedChildArray(knrFunct, parameterNames, IASTName.class, commentMap);
 		super.writeKnRParameterNames(knrFunct, modifiedNames);
 	}
 

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/rewrite/changegenerator/ModifiedASTExpressionWriter.java

@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2008, 2010 Institute for Software, HSR Hochschule fuer Technik  
+ * Copyright (c) 2008, 2011 Institute for Software, HSR Hochschule fuer Technik  
  * Rapperswil, University of applied sciences and others
  * All rights reserved. This program and the accompanying materials 
  * are made available under the terms of the Eclipse Public License v1.0 
@@ -37,7 +37,7 @@ public class ModifiedASTExpressionWriter extends ExpressionWriter {
 	@Override
 	protected void writeExpressions(IASTExpressionList expList, IASTExpression[] expressions) {
 		IASTExpression[] modifiedExpressions = modificationHelper.createModifiedChildArray(expList,
-				expressions, IASTExpression.class);
+				expressions, IASTExpression.class, commentMap);
 		super.writeExpressions(expList, modifiedExpressions);
 	}
 

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/rewrite/changegenerator/ModifiedASTStatementWriter.java

@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2008 Institute for Software, HSR Hochschule fuer Technik  
+ * Copyright (c) 2008, 2011 Institute for Software, HSR Hochschule fuer Technik  
  * Rapperswil, University of applied sciences and others
  * All rights reserved. This program and the accompanying materials 
  * are made available under the terms of the Eclipse Public License v1.0 
@@ -41,6 +41,7 @@ public class ModifiedASTStatementWriter extends StatementWriter {
 
 	@Override
 	protected IASTStatement[] getNestedStatements(IASTCompoundStatement compoundStatement) {
-		return modificationHelper.createModifiedChildArray(compoundStatement, compoundStatement.getStatements(), IASTStatement.class);
+		return modificationHelper.createModifiedChildArray(compoundStatement,
+				compoundStatement.getStatements(), IASTStatement.class, commentMap);
 	}
 }

core/org.eclipse.cdt.ui.tests/resources/refactoring/ExtractMethod.rts

@@ -87,7 +87,7 @@ int A::help()
 	return 42;
 }	
 
-//!ExtractFunctionRefactoringTest
+//!ExtractFunctionRefactoringTest with comment
 //#org.eclipse.cdt.ui.tests.refactoring.extractfunction.ExtractFunctionRefactoringTest
 //@A.h
 #ifndef A_H_
@@ -168,6 +168,7 @@ void A::exp(int & i)
 int A::foo()
 {
 	int i = 2;
+	//comment
     exp(i);
 	return i;
 }
@@ -205,6 +206,7 @@ void exp(int & i)
 int main(){
 	
 	int i;
+	// Comment
     exp(i);
 	return i;
 }
@@ -235,7 +237,7 @@ void exp(int & i)
 int main(){
 	
 	int i;
-    exp(i);
+    exp(i); // Comment
 	return i;
 }
 
@@ -2703,7 +2705,8 @@ int Test::exp()
 }
 
 int Test::calculateStuff() {
-    int result = exp();
+	// refactor these lines to a new method:
+	int result = exp();
 	return result;
 }
 
@@ -2860,6 +2863,7 @@ void A::exp(int & i)
 int A::foo()
 {
 	int i = 2;
+	//comment
     exp(i);
 	return i;
 }

core/org.eclipse.cdt.ui.tests/resources/refactoring/ExtractMethodHistory.rts

@@ -178,6 +178,7 @@ void A::exp(int & i)
 int A::foo()
 {
 	int i = 2;
+	//comment
     exp(i);
 	return i;
 }
@@ -217,6 +218,7 @@ void exp(int & i)
 int main(){
 	
 	int i;
+	// Comment
     exp(i);
 	return i;
 }
@@ -249,7 +251,7 @@ void exp(int & i)
 int main(){
 	
 	int i;
-    exp(i);
+    exp(i); // Comment
 	return i;
 }