gecko/parser/html/nsHtml5TreeOperation.cpp

669 lines
24 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=2 sw=2 et tw=78: */
/* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is Mozilla Communicator client code.
*
* The Initial Developer of the Original Code is
* Netscape Communications Corporation.
* Portions created by the Initial Developer are Copyright (C) 1998
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* Pierre Phaneuf <pp@ludusdesign.com>
* Henri Sivonen <hsivonen@iki.fi>
*
* Alternatively, the contents of this file may be used under the terms of
* either of the GNU General Public License Version 2 or later (the "GPL"),
* or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
#include "nsHtml5TreeOperation.h"
#include "nsContentUtils.h"
#include "nsNodeUtils.h"
#include "nsAttrName.h"
#include "nsHtml5TreeBuilder.h"
#include "nsIDOMMutationEvent.h"
#include "mozAutoDocUpdate.h"
#include "nsBindingManager.h"
#include "nsXBLBinding.h"
#include "nsHtml5DocumentMode.h"
#include "nsHtml5HtmlAttributes.h"
#include "nsContentCreatorFunctions.h"
#include "nsIScriptElement.h"
#include "nsIDTD.h"
#include "nsTraceRefcnt.h"
#include "nsIDOMHTMLFormElement.h"
#include "nsIFormControl.h"
#include "nsIStyleSheetLinkingElement.h"
#include "nsIDOMDocumentType.h"
#include "nsIMutationObserver.h"
#include "nsIFormProcessor.h"
#include "nsIServiceManager.h"
static NS_DEFINE_CID(kFormProcessorCID, NS_FORMPROCESSOR_CID);
/**
* Helper class that opens a notification batch if the current doc
* is different from the executor doc.
*/
class NS_STACK_CLASS nsHtml5OtherDocUpdate {
public:
nsHtml5OtherDocUpdate(nsIDocument* aCurrentDoc, nsIDocument* aExecutorDoc)
{
NS_PRECONDITION(aCurrentDoc, "Node has no doc?");
NS_PRECONDITION(aExecutorDoc, "Executor has no doc?");
if (NS_LIKELY(aCurrentDoc == aExecutorDoc)) {
mDocument = nsnull;
} else {
mDocument = aCurrentDoc;
aCurrentDoc->BeginUpdate(UPDATE_CONTENT_MODEL);
}
}
~nsHtml5OtherDocUpdate()
{
if (NS_UNLIKELY(mDocument)) {
mDocument->EndUpdate(UPDATE_CONTENT_MODEL);
}
}
private:
nsIDocument* mDocument;
};
nsHtml5TreeOperation::nsHtml5TreeOperation()
#ifdef DEBUG
: mOpCode(eTreeOpUninitialized)
#endif
{
MOZ_COUNT_CTOR(nsHtml5TreeOperation);
}
nsHtml5TreeOperation::~nsHtml5TreeOperation()
{
MOZ_COUNT_DTOR(nsHtml5TreeOperation);
NS_ASSERTION(mOpCode != eTreeOpUninitialized, "Uninitialized tree op.");
switch(mOpCode) {
case eTreeOpAddAttributes:
delete mTwo.attributes;
break;
case eTreeOpCreateElementNetwork:
case eTreeOpCreateElementNotNetwork:
delete mThree.attributes;
break;
case eTreeOpAppendDoctypeToDocument:
delete mTwo.stringPair;
break;
case eTreeOpFosterParentText:
case eTreeOpAppendText:
case eTreeOpAppendComment:
case eTreeOpAppendCommentToDocument:
delete[] mTwo.unicharPtr;
break;
case eTreeOpSetDocumentCharset:
case eTreeOpNeedsCharsetSwitchTo:
delete[] mOne.charPtr;
break;
case eTreeOpProcessOfflineManifest:
nsMemory::Free(mOne.unicharPtr);
break;
default: // keep the compiler happy
break;
}
}
nsresult
nsHtml5TreeOperation::AppendTextToTextNode(PRUnichar* aBuffer,
PRInt32 aLength,
nsIContent* aTextNode,
nsHtml5TreeOpExecutor* aBuilder)
{
NS_PRECONDITION(aTextNode, "Got null text node.");
if (aBuilder->HaveNotified(aTextNode)) {
// This text node has already been notified on, so it's necessary to
// notify on the append
nsresult rv = NS_OK;
PRUint32 oldLength = aTextNode->TextLength();
CharacterDataChangeInfo info = {
PR_TRUE,
oldLength,
oldLength,
aLength
};
nsNodeUtils::CharacterDataWillChange(aTextNode, &info);
rv = aTextNode->AppendText(aBuffer, aLength, PR_FALSE);
NS_ENSURE_SUCCESS(rv, rv);
nsNodeUtils::CharacterDataChanged(aTextNode, &info);
return rv;
}
return aTextNode->AppendText(aBuffer, aLength, PR_FALSE);
}
nsresult
nsHtml5TreeOperation::AppendText(PRUnichar* aBuffer,
PRInt32 aLength,
nsIContent* aParent,
nsHtml5TreeOpExecutor* aBuilder)
{
nsresult rv = NS_OK;
nsIContent* lastChild = aParent->GetLastChild();
if (lastChild && lastChild->IsNodeOfType(nsINode::eTEXT)) {
nsHtml5OtherDocUpdate update(aParent->GetOwnerDoc(),
aBuilder->GetDocument());
return AppendTextToTextNode(aBuffer,
aLength,
lastChild,
aBuilder);
}
nsCOMPtr<nsIContent> text;
NS_NewTextNode(getter_AddRefs(text), aBuilder->GetNodeInfoManager());
NS_ASSERTION(text, "Infallible malloc failed?");
rv = text->SetText(aBuffer, aLength, PR_FALSE);
NS_ENSURE_SUCCESS(rv, rv);
return Append(text, aParent, aBuilder);
}
nsresult
nsHtml5TreeOperation::Append(nsIContent* aNode,
nsIContent* aParent,
nsHtml5TreeOpExecutor* aBuilder)
{
nsresult rv = NS_OK;
nsIDocument* executorDoc = aBuilder->GetDocument();
NS_ASSERTION(executorDoc, "Null doc on executor");
nsIDocument* parentDoc = aParent->GetOwnerDoc();
NS_ASSERTION(parentDoc, "Null owner doc on old node.");
if (NS_LIKELY(executorDoc == parentDoc)) {
// the usual case. the parent is in the parser's doc
aBuilder->PostPendingAppendNotification(aParent, aNode);
rv = aParent->AppendChildTo(aNode, PR_FALSE);
return rv;
}
// The parent has been moved to another doc
parentDoc->BeginUpdate(UPDATE_CONTENT_MODEL);
PRUint32 childCount = aParent->GetChildCount();
rv = aParent->AppendChildTo(aNode, PR_FALSE);
nsNodeUtils::ContentAppended(aParent, aNode, childCount);
parentDoc->EndUpdate(UPDATE_CONTENT_MODEL);
return rv;
}
nsresult
nsHtml5TreeOperation::AppendToDocument(nsIContent* aNode,
nsHtml5TreeOpExecutor* aBuilder)
{
nsresult rv = NS_OK;
aBuilder->FlushPendingAppendNotifications();
nsIDocument* doc = aBuilder->GetDocument();
PRUint32 childCount = doc->GetChildCount();
rv = doc->AppendChildTo(aNode, PR_FALSE);
NS_ENSURE_SUCCESS(rv, rv);
nsNodeUtils::ContentInserted(doc, aNode, childCount);
return rv;
}
nsresult
nsHtml5TreeOperation::Perform(nsHtml5TreeOpExecutor* aBuilder,
nsIContent** aScriptElement)
{
nsresult rv = NS_OK;
switch(mOpCode) {
case eTreeOpAppend: {
nsIContent* node = *(mOne.node);
nsIContent* parent = *(mTwo.node);
return Append(node, parent, aBuilder);
}
case eTreeOpDetach: {
nsIContent* node = *(mOne.node);
aBuilder->FlushPendingAppendNotifications();
nsIContent* parent = node->GetParent();
if (parent) {
nsHtml5OtherDocUpdate update(parent->GetOwnerDoc(),
aBuilder->GetDocument());
PRUint32 pos = parent->IndexOf(node);
NS_ASSERTION((pos >= 0), "Element not found as child of its parent");
rv = parent->RemoveChildAt(pos, PR_TRUE, PR_FALSE);
NS_ENSURE_SUCCESS(rv, rv);
}
return rv;
}
case eTreeOpAppendChildrenToNewParent: {
nsIContent* node = *(mOne.node);
nsIContent* parent = *(mTwo.node);
aBuilder->FlushPendingAppendNotifications();
nsHtml5OtherDocUpdate update(parent->GetOwnerDoc(),
aBuilder->GetDocument());
PRUint32 childCount = parent->GetChildCount();
PRBool didAppend = PR_FALSE;
while (node->GetChildCount()) {
nsCOMPtr<nsIContent> child = node->GetChildAt(0);
rv = node->RemoveChildAt(0, PR_TRUE, PR_FALSE);
NS_ENSURE_SUCCESS(rv, rv);
rv = parent->AppendChildTo(child, PR_FALSE);
NS_ENSURE_SUCCESS(rv, rv);
didAppend = PR_TRUE;
}
if (didAppend) {
nsNodeUtils::ContentAppended(parent, parent->GetChildAt(childCount),
childCount);
}
return rv;
}
case eTreeOpFosterParent: {
nsIContent* node = *(mOne.node);
nsIContent* parent = *(mTwo.node);
nsIContent* table = *(mThree.node);
nsIContent* foster = table->GetParent();
if (foster && foster->IsElement()) {
aBuilder->FlushPendingAppendNotifications();
nsHtml5OtherDocUpdate update(foster->GetOwnerDoc(),
aBuilder->GetDocument());
PRUint32 pos = foster->IndexOf(table);
rv = foster->InsertChildAt(node, pos, PR_FALSE);
NS_ENSURE_SUCCESS(rv, rv);
nsNodeUtils::ContentInserted(foster, node, pos);
return rv;
}
return Append(node, parent, aBuilder);
}
case eTreeOpAppendToDocument: {
nsIContent* node = *(mOne.node);
return AppendToDocument(node, aBuilder);
}
case eTreeOpAddAttributes: {
nsIContent* node = *(mOne.node);
nsHtml5HtmlAttributes* attributes = mTwo.attributes;
nsHtml5OtherDocUpdate update(node->GetOwnerDoc(),
aBuilder->GetDocument());
nsIDocument* document = node->GetCurrentDoc();
PRInt32 len = attributes->getLength();
for (PRInt32 i = len; i > 0;) {
--i;
// prefix doesn't need regetting. it is always null or a static atom
// local name is never null
nsCOMPtr<nsIAtom> localName = Reget(attributes->getLocalName(i));
PRInt32 nsuri = attributes->getURI(i);
if (!node->HasAttr(nsuri, localName)) {
// the manual notification code is based on nsGenericElement
PRUint32 stateMask = PRUint32(node->IntrinsicState());
nsNodeUtils::AttributeWillChange(node,
nsuri,
localName,
static_cast<PRUint8>(nsIDOMMutationEvent::ADDITION));
// prefix doesn't need regetting. it is always null or a static atom
// local name is never null
node->SetAttr(nsuri, localName, attributes->getPrefix(i), *(attributes->getValue(i)), PR_FALSE);
// XXX what to do with nsresult?
if (document || node->HasFlag(NODE_FORCE_XBL_BINDINGS)) {
nsIDocument* ownerDoc = node->GetOwnerDoc();
if (ownerDoc) {
nsRefPtr<nsXBLBinding> binding =
ownerDoc->BindingManager()->GetBinding(node);
if (binding) {
binding->AttributeChanged(localName, nsuri, PR_FALSE, PR_FALSE);
}
}
}
stateMask ^= PRUint32(node->IntrinsicState());
if (stateMask && document) {
MOZ_AUTO_DOC_UPDATE(document, UPDATE_CONTENT_STATE, PR_TRUE);
document->ContentStatesChanged(node, nsnull, stateMask);
}
nsNodeUtils::AttributeChanged(node,
nsuri,
localName,
static_cast<PRUint8>(nsIDOMMutationEvent::ADDITION));
}
}
return rv;
}
case eTreeOpCreateElementNetwork:
case eTreeOpCreateElementNotNetwork: {
nsIContent** target = mOne.node;
PRInt32 ns = mInt;
nsCOMPtr<nsIAtom> name = Reget(mTwo.atom);
nsHtml5HtmlAttributes* attributes = mThree.attributes;
PRBool isKeygen = (name == nsHtml5Atoms::keygen && ns == kNameSpaceID_XHTML);
if (NS_UNLIKELY(isKeygen)) {
name = nsHtml5Atoms::select;
}
nsCOMPtr<nsIContent> newContent;
nsCOMPtr<nsINodeInfo> nodeInfo = aBuilder->GetNodeInfoManager()->GetNodeInfo(name, nsnull, ns);
NS_ASSERTION(nodeInfo, "Got null nodeinfo.");
NS_NewElement(getter_AddRefs(newContent),
nodeInfo->NamespaceID(),
nodeInfo,
(mOpCode == eTreeOpCreateElementNetwork ?
NS_FROM_PARSER_NETWORK
: (aBuilder->IsFragmentMode() ?
NS_FROM_PARSER_FRAGMENT :
NS_FROM_PARSER_DOCUMENT_WRITE)));
NS_ASSERTION(newContent, "Element creation created null pointer.");
aBuilder->HoldElement(*target = newContent);
if (NS_UNLIKELY(name == nsHtml5Atoms::style || name == nsHtml5Atoms::link)) {
nsCOMPtr<nsIStyleSheetLinkingElement> ssle(do_QueryInterface(newContent));
if (ssle) {
ssle->InitStyleLinkElement(PR_FALSE);
ssle->SetEnableUpdates(PR_FALSE);
}
} else if (NS_UNLIKELY(isKeygen)) {
// Adapted from CNavDTD
nsCOMPtr<nsIFormProcessor> theFormProcessor =
do_GetService(kFormProcessorCID, &rv);
NS_ENSURE_SUCCESS(rv, rv);
nsTArray<nsString> theContent;
nsAutoString theAttribute;
(void) theFormProcessor->ProvideContent(NS_LITERAL_STRING("select"),
theContent,
theAttribute);
newContent->SetAttr(kNameSpaceID_None,
nsGkAtoms::moztype,
nsnull,
theAttribute,
PR_FALSE);
nsCOMPtr<nsINodeInfo> optionNodeInfo =
aBuilder->GetNodeInfoManager()->GetNodeInfo(nsHtml5Atoms::option,
nsnull,
kNameSpaceID_XHTML);
for (PRUint32 i = 0; i < theContent.Length(); ++i) {
nsCOMPtr<nsIContent> optionElt;
NS_NewElement(getter_AddRefs(optionElt),
optionNodeInfo->NamespaceID(),
optionNodeInfo,
PR_TRUE);
nsCOMPtr<nsIContent> optionText;
NS_NewTextNode(getter_AddRefs(optionText),
aBuilder->GetNodeInfoManager());
(void) optionText->SetText(theContent[i], PR_FALSE);
optionElt->AppendChildTo(optionText, PR_FALSE);
newContent->AppendChildTo(optionElt, PR_FALSE);
newContent->DoneAddingChildren(PR_FALSE);
}
} else if (name == nsHtml5Atoms::frameset && ns == kNameSpaceID_XHTML) {
nsIDocument* doc = aBuilder->GetDocument();
nsCOMPtr<nsIHTMLDocument> htmlDocument = do_QueryInterface(doc);
if (htmlDocument) {
// It seems harmless to call this multiple times, since this
// is a simple field setter
htmlDocument->SetIsFrameset(PR_TRUE);
}
}
if (!attributes) {
return rv;
}
PRInt32 len = attributes->getLength();
for (PRInt32 i = len; i > 0;) {
--i;
// prefix doesn't need regetting. it is always null or a static atom
// local name is never null
nsCOMPtr<nsIAtom> localName = Reget(attributes->getLocalName(i));
newContent->SetAttr(attributes->getURI(i), localName, attributes->getPrefix(i), *(attributes->getValue(i)), PR_FALSE);
// XXX what to do with nsresult?
}
return rv;
}
case eTreeOpSetFormElement: {
nsIContent* node = *(mOne.node);
nsIContent* parent = *(mTwo.node);
nsCOMPtr<nsIFormControl> formControl(do_QueryInterface(node));
// NS_ASSERTION(formControl, "Form-associated element did not implement nsIFormControl.");
// TODO: uncomment the above line when <output> (bug 346485) and <keygen> (bug 101019) are supported by Gecko
nsCOMPtr<nsIDOMHTMLFormElement> formElement(do_QueryInterface(parent));
NS_ASSERTION(formElement, "The form element doesn't implement nsIDOMHTMLFormElement.");
if (formControl) { // avoid crashing on <output> and <keygen>
formControl->SetForm(formElement);
}
return rv;
}
case eTreeOpAppendText: {
nsIContent* parent = *mOne.node;
PRUnichar* buffer = mTwo.unicharPtr;
PRInt32 length = mInt;
return AppendText(buffer, length, parent, aBuilder);
}
case eTreeOpFosterParentText: {
nsIContent* stackParent = *mOne.node;
PRUnichar* buffer = mTwo.unicharPtr;
PRInt32 length = mInt;
nsIContent* table = *mThree.node;
nsIContent* foster = table->GetParent();
if (foster && foster->IsElement()) {
aBuilder->FlushPendingAppendNotifications();
nsHtml5OtherDocUpdate update(foster->GetOwnerDoc(),
aBuilder->GetDocument());
PRUint32 pos = foster->IndexOf(table);
nsIContent* previousSibling = foster->GetChildAt(pos - 1);
if (previousSibling && previousSibling->IsNodeOfType(nsINode::eTEXT)) {
return AppendTextToTextNode(buffer,
length,
previousSibling,
aBuilder);
}
nsCOMPtr<nsIContent> text;
NS_NewTextNode(getter_AddRefs(text), aBuilder->GetNodeInfoManager());
NS_ASSERTION(text, "Infallible malloc failed?");
rv = text->SetText(buffer, length, PR_FALSE);
NS_ENSURE_SUCCESS(rv, rv);
rv = foster->InsertChildAt(text, pos, PR_FALSE);
NS_ENSURE_SUCCESS(rv, rv);
nsNodeUtils::ContentInserted(foster, text, pos);
return rv;
}
return AppendText(buffer, length, stackParent, aBuilder);
}
case eTreeOpAppendComment: {
nsIContent* parent = *mOne.node;
PRUnichar* buffer = mTwo.unicharPtr;
PRInt32 length = mInt;
nsCOMPtr<nsIContent> comment;
NS_NewCommentNode(getter_AddRefs(comment), aBuilder->GetNodeInfoManager());
NS_ASSERTION(comment, "Infallible malloc failed?");
rv = comment->SetText(buffer, length, PR_FALSE);
NS_ENSURE_SUCCESS(rv, rv);
return Append(comment, parent, aBuilder);
}
case eTreeOpAppendCommentToDocument: {
PRUnichar* buffer = mTwo.unicharPtr;
PRInt32 length = mInt;
nsCOMPtr<nsIContent> comment;
NS_NewCommentNode(getter_AddRefs(comment), aBuilder->GetNodeInfoManager());
NS_ASSERTION(comment, "Infallible malloc failed?");
rv = comment->SetText(buffer, length, PR_FALSE);
NS_ENSURE_SUCCESS(rv, rv);
return AppendToDocument(comment, aBuilder);
}
case eTreeOpAppendDoctypeToDocument: {
nsCOMPtr<nsIAtom> name = Reget(mOne.atom);
nsHtml5TreeOperationStringPair* pair = mTwo.stringPair;
nsString publicId;
nsString systemId;
pair->Get(publicId, systemId);
// Adapted from nsXMLContentSink
// Create a new doctype node
nsCOMPtr<nsIDOMDocumentType> docType;
nsAutoString voidString;
voidString.SetIsVoid(PR_TRUE);
NS_NewDOMDocumentType(getter_AddRefs(docType),
aBuilder->GetNodeInfoManager(),
nsnull,
name,
nsnull,
nsnull,
publicId,
systemId,
voidString);
NS_ASSERTION(docType, "Doctype creation failed.");
nsCOMPtr<nsIContent> asContent = do_QueryInterface(docType);
return AppendToDocument(asContent, aBuilder);
}
case eTreeOpRunScript: {
nsIContent* node = *(mOne.node);
nsAHtml5TreeBuilderState* snapshot = mTwo.state;
if (snapshot) {
aBuilder->InitializeDocWriteParserState(snapshot, mInt);
}
*aScriptElement = node;
return rv;
}
case eTreeOpRunScriptAsyncDefer: {
nsIContent* node = *(mOne.node);
aBuilder->RunScript(node);
return rv;
}
case eTreeOpDoneAddingChildren: {
nsIContent* node = *(mOne.node);
node->DoneAddingChildren(aBuilder->HaveNotified(node));
return rv;
}
case eTreeOpDoneCreatingElement: {
nsIContent* node = *(mOne.node);
node->DoneCreatingElement();
return rv;
}
case eTreeOpFlushPendingAppendNotifications: {
aBuilder->FlushPendingAppendNotifications();
return rv;
}
case eTreeOpSetDocumentCharset: {
char* str = mOne.charPtr;
PRInt32 charsetSource = mInt;
nsDependentCString dependentString(str);
aBuilder->SetDocumentCharsetAndSource(dependentString, charsetSource);
return rv;
}
case eTreeOpNeedsCharsetSwitchTo: {
char* str = mOne.charPtr;
aBuilder->NeedsCharsetSwitchTo(str);
return rv;
}
case eTreeOpUpdateStyleSheet: {
nsIContent* node = *(mOne.node);
aBuilder->FlushPendingAppendNotifications();
aBuilder->UpdateStyleSheet(node);
return rv;
}
case eTreeOpProcessMeta: {
nsIContent* node = *(mOne.node);
rv = aBuilder->ProcessMETATag(node);
return rv;
}
case eTreeOpProcessOfflineManifest: {
PRUnichar* str = mOne.unicharPtr;
nsDependentString dependentString(str);
aBuilder->ProcessOfflineManifest(dependentString);
return rv;
}
case eTreeOpMarkMalformedIfScript: {
nsIContent* node = *(mOne.node);
nsCOMPtr<nsIScriptElement> sele = do_QueryInterface(node);
if (sele) {
// Make sure to serialize this script correctly, for nice round tripping.
sele->SetIsMalformed();
}
return rv;
}
case eTreeOpStreamEnded: {
aBuilder->DidBuildModel(PR_FALSE); // this causes a notifications flush anyway
return rv;
}
case eTreeOpStartLayout: {
aBuilder->StartLayout(); // this causes a notification flush anyway
return rv;
}
case eTreeOpDocumentMode: {
aBuilder->SetDocumentMode(mOne.mode);
return rv;
}
case eTreeOpSetStyleLineNumber: {
nsIContent* node = *(mOne.node);
nsCOMPtr<nsIStyleSheetLinkingElement> ssle = do_QueryInterface(node);
NS_ASSERTION(ssle, "Node didn't QI to style.");
ssle->SetLineNumber(mInt);
return rv;
}
case eTreeOpSetScriptLineNumberAndFreeze: {
nsIContent* node = *(mOne.node);
nsCOMPtr<nsIScriptElement> sele = do_QueryInterface(node);
NS_ASSERTION(sele, "Node didn't QI to script.");
sele->SetScriptLineNumber(mInt);
sele->FreezeUriAsyncDefer();
return rv;
}
default: {
NS_NOTREACHED("Bogus tree op");
}
}
return rv; // keep compiler happy
}