gecko-dev/parser/html/nsHtml5TreeOpExecutor.cpp

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C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set sw=2 ts=2 et tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "mozilla/DebugOnly.h"
#include "mozilla/Likely.h"
#include "mozilla/dom/BrowsingContext.h"
#include "mozilla/dom/ScriptLoader.h"
#include "mozilla/dom/nsCSPContext.h"
#include "mozilla/dom/nsCSPService.h"
#include "GeckoProfiler.h"
#include "mozAutoDocUpdate.h"
#include "mozilla/IdleTaskRunner.h"
#include "mozilla/Preferences.h"
#include "mozilla/StaticPrefs_content.h"
#include "mozilla/StaticPrefs_security.h"
#include "mozilla/StaticPrefs_view_source.h"
#include "mozilla/css/Loader.h"
#include "nsContentUtils.h"
#include "nsDocShell.h"
#include "nsError.h"
#include "nsHtml5AutoPauseUpdate.h"
#include "nsHtml5Parser.h"
#include "nsHtml5StreamParser.h"
#include "nsHtml5Tokenizer.h"
#include "nsHtml5TreeBuilder.h"
#include "nsHtml5TreeOpExecutor.h"
#include "nsIContentSecurityPolicy.h"
#include "nsIDocShell.h"
#include "nsIDocShellTreeItem.h"
#include "nsINestedURI.h"
#include "nsIScriptContext.h"
#include "nsIScriptError.h"
#include "nsIScriptGlobalObject.h"
#include "nsIViewSourceChannel.h"
#include "nsNetUtil.h"
#include "xpcpublic.h"
using namespace mozilla;
NS_IMPL_ISUPPORTS_CYCLE_COLLECTION_INHERITED(nsHtml5TreeOpExecutor,
nsHtml5DocumentBuilder,
nsIContentSink)
class nsHtml5ExecutorReflusher : public Runnable {
private:
RefPtr<nsHtml5TreeOpExecutor> mExecutor;
public:
explicit nsHtml5ExecutorReflusher(nsHtml5TreeOpExecutor* aExecutor)
: mozilla::Runnable("nsHtml5ExecutorReflusher"), mExecutor(aExecutor) {}
NS_IMETHOD Run() override {
Document* doc = mExecutor->GetDocument();
if (XRE_IsContentProcess() &&
nsContentUtils::
HighPriorityEventPendingForTopLevelDocumentBeforeContentfulPaint(
doc)) {
// Possible early paint pending, reuse the runnable and try to
// call RunFlushLoop later.
nsCOMPtr<nsIRunnable> flusher = this;
if (NS_SUCCEEDED(
doc->Dispatch(TaskCategory::Network, flusher.forget()))) {
PROFILER_MARKER_UNTYPED("HighPrio blocking parser flushing(2)", DOM);
return NS_OK;
}
}
mExecutor->RunFlushLoop();
return NS_OK;
}
};
class MOZ_RAII nsHtml5AutoFlush final {
private:
RefPtr<nsHtml5TreeOpExecutor> mExecutor;
size_t mOpsToRemove;
public:
explicit nsHtml5AutoFlush(nsHtml5TreeOpExecutor* aExecutor)
: mExecutor(aExecutor), mOpsToRemove(aExecutor->OpQueueLength()) {
mExecutor->BeginFlush();
mExecutor->BeginDocUpdate();
}
~nsHtml5AutoFlush() {
if (mExecutor->IsInDocUpdate()) {
mExecutor->EndDocUpdate();
} else {
// We aren't in an update if nsHtml5AutoPauseUpdate
// caused something to terminate the parser.
MOZ_RELEASE_ASSERT(
mExecutor->IsComplete(),
"How do we have mParser but the doc update isn't open?");
}
mExecutor->EndFlush();
mExecutor->RemoveFromStartOfOpQueue(mOpsToRemove);
}
void SetNumberOfOpsToRemove(size_t aOpsToRemove) {
MOZ_ASSERT(aOpsToRemove < mOpsToRemove,
"Requested partial clearing of op queue but the number to clear "
"wasn't less than the length of the queue.");
mOpsToRemove = aOpsToRemove;
}
};
static mozilla::LinkedList<nsHtml5TreeOpExecutor>* gBackgroundFlushList =
nullptr;
StaticRefPtr<IdleTaskRunner> gBackgroundFlushRunner;
nsHtml5TreeOpExecutor::nsHtml5TreeOpExecutor()
: nsHtml5DocumentBuilder(false),
mSuppressEOF(false),
mReadingFromStage(false),
mStreamParser(nullptr),
mPreloadedURLs(23), // Mean # of preloadable resources per page on dmoz
mStarted(false),
mRunFlushLoopOnStack(false),
mCallContinueInterruptedParsingIfEnabled(false),
mAlreadyComplainedAboutCharset(false),
mAlreadyComplainedAboutDeepTree(false) {}
nsHtml5TreeOpExecutor::~nsHtml5TreeOpExecutor() {
if (gBackgroundFlushList && isInList()) {
ClearOpQueue();
removeFrom(*gBackgroundFlushList);
if (gBackgroundFlushList->isEmpty()) {
delete gBackgroundFlushList;
gBackgroundFlushList = nullptr;
if (gBackgroundFlushRunner) {
gBackgroundFlushRunner->Cancel();
gBackgroundFlushRunner = nullptr;
}
}
}
NS_ASSERTION(mOpQueue.IsEmpty(), "Somehow there's stuff in the op queue.");
}
// nsIContentSink
NS_IMETHODIMP
nsHtml5TreeOpExecutor::WillParse() {
MOZ_ASSERT_UNREACHABLE("No one should call this");
return NS_ERROR_NOT_IMPLEMENTED;
}
NS_IMETHODIMP
nsHtml5TreeOpExecutor::WillBuildModel(nsDTDMode aDTDMode) {
mDocument->AddObserver(this);
WillBuildModelImpl();
GetDocument()->BeginLoad();
if (mDocShell && !GetDocument()->GetWindow() && !IsExternalViewSource()) {
// Not loading as data but script global object not ready
return MarkAsBroken(NS_ERROR_DOM_INVALID_STATE_ERR);
}
return NS_OK;
}
// This is called when the tree construction has ended
NS_IMETHODIMP
nsHtml5TreeOpExecutor::DidBuildModel(bool aTerminated) {
if (mRunsToCompletion) {
return NS_OK;
}
MOZ_RELEASE_ASSERT(!IsInDocUpdate(),
"DidBuildModel from inside a doc update.");
// This comes from nsXMLContentSink and nsHTMLContentSink
// If this parser has been marked as broken, treat the end of parse as
// forced termination.
DidBuildModelImpl(aTerminated || NS_FAILED(IsBroken()));
bool destroying = true;
if (mDocShell) {
mDocShell->IsBeingDestroyed(&destroying);
}
if (!destroying) {
mDocument->OnParsingCompleted();
if (!mLayoutStarted) {
// We never saw the body, and layout never got started. Force
// layout *now*, to get an initial reflow.
// NOTE: only force the layout if we are NOT destroying the
// docshell. If we are destroying it, then starting layout will
// likely cause us to crash, or at best waste a lot of time as we
// are just going to tear it down anyway.
nsContentSink::StartLayout(false);
}
}
ScrollToRef();
mDocument->RemoveObserver(this);
if (!mParser) {
// DidBuildModelImpl may cause mParser to be nulled out
// Return early to avoid unblocking the onload event too many times.
return NS_OK;
}
// We may not have called BeginLoad() if loading is terminated before
// OnStartRequest call.
if (mStarted) {
mDocument->EndLoad();
}
// Dropping the stream parser changes the parser's apparent
// script-createdness, which is why the stream parser must not be dropped
// before this executor's nsHtml5Parser has been made unreachable from its
// nsHTMLDocument. (mDocument->EndLoad() above drops the parser from the
// document.)
GetParser()->DropStreamParser();
DropParserAndPerfHint();
#ifdef GATHER_DOCWRITE_STATISTICS
printf("UNSAFE SCRIPTS: %d\n", sUnsafeDocWrites);
printf("TOKENIZER-SAFE SCRIPTS: %d\n", sTokenSafeDocWrites);
printf("TREEBUILDER-SAFE SCRIPTS: %d\n", sTreeSafeDocWrites);
#endif
#ifdef DEBUG_NS_HTML5_TREE_OP_EXECUTOR_FLUSH
printf("MAX NOTIFICATION BATCH LEN: %d\n", sAppendBatchMaxSize);
if (sAppendBatchExaminations != 0) {
printf("AVERAGE SLOTS EXAMINED: %d\n",
sAppendBatchSlotsExamined / sAppendBatchExaminations);
}
#endif
return NS_OK;
}
NS_IMETHODIMP
nsHtml5TreeOpExecutor::WillInterrupt() {
MOZ_ASSERT_UNREACHABLE("Don't call. For interface compat only.");
return NS_ERROR_NOT_IMPLEMENTED;
}
NS_IMETHODIMP
nsHtml5TreeOpExecutor::WillResume() {
MOZ_ASSERT_UNREACHABLE("Don't call. For interface compat only.");
return NS_ERROR_NOT_IMPLEMENTED;
}
NS_IMETHODIMP
nsHtml5TreeOpExecutor::SetParser(nsParserBase* aParser) {
mParser = aParser;
return NS_OK;
}
void nsHtml5TreeOpExecutor::InitialTranslationCompleted() {
nsContentSink::StartLayout(false);
}
void nsHtml5TreeOpExecutor::FlushPendingNotifications(FlushType aType) {
if (aType >= FlushType::EnsurePresShellInitAndFrames) {
// Bug 577508 / 253951
nsContentSink::StartLayout(true);
}
}
nsISupports* nsHtml5TreeOpExecutor::GetTarget() {
return ToSupports(mDocument);
}
nsresult nsHtml5TreeOpExecutor::MarkAsBroken(nsresult aReason) {
NS_ASSERTION(NS_IsMainThread(), "Wrong thread!");
mBroken = aReason;
if (mStreamParser) {
mStreamParser->Terminate();
}
// We are under memory pressure, but let's hope the following allocation
// works out so that we get to terminate and clean up the parser from
// a safer point.
if (mParser && mDocument) { // can mParser ever be null here?
nsCOMPtr<nsIRunnable> terminator = NewRunnableMethod(
"nsHtml5Parser::Terminate", GetParser(), &nsHtml5Parser::Terminate);
if (NS_FAILED(
mDocument->Dispatch(TaskCategory::Network, terminator.forget()))) {
NS_WARNING("failed to dispatch executor flush event");
}
}
return aReason;
}
static bool BackgroundFlushCallback(TimeStamp /*aDeadline*/) {
RefPtr<nsHtml5TreeOpExecutor> ex = gBackgroundFlushList->popFirst();
if (ex) {
ex->RunFlushLoop();
}
if (gBackgroundFlushList && gBackgroundFlushList->isEmpty()) {
delete gBackgroundFlushList;
gBackgroundFlushList = nullptr;
gBackgroundFlushRunner->Cancel();
gBackgroundFlushRunner = nullptr;
return true;
}
return true;
}
void nsHtml5TreeOpExecutor::ContinueInterruptedParsingAsync() {
if (!mDocument || !mDocument->IsInBackgroundWindow()) {
nsCOMPtr<nsIRunnable> flusher = new nsHtml5ExecutorReflusher(this);
if (NS_FAILED(
mDocument->Dispatch(TaskCategory::Network, flusher.forget()))) {
NS_WARNING("failed to dispatch executor flush event");
}
} else {
if (!gBackgroundFlushList) {
gBackgroundFlushList = new mozilla::LinkedList<nsHtml5TreeOpExecutor>();
}
if (!isInList()) {
gBackgroundFlushList->insertBack(this);
}
if (gBackgroundFlushRunner) {
return;
}
// Now we set up a repetitive idle scheduler for flushing background list.
gBackgroundFlushRunner = IdleTaskRunner::Create(
&BackgroundFlushCallback,
"nsHtml5TreeOpExecutor::BackgroundFlushCallback",
250, // The hard deadline: 250ms.
StaticPrefs::content_sink_interactive_parse_time() /
1000, // Required budget.
true, // repeating
[] { return false; }); // MayStopProcessing
}
}
void nsHtml5TreeOpExecutor::FlushSpeculativeLoads() {
nsTArray<nsHtml5SpeculativeLoad> speculativeLoadQueue;
mStage.MoveSpeculativeLoadsTo(speculativeLoadQueue);
nsHtml5SpeculativeLoad* start = speculativeLoadQueue.Elements();
nsHtml5SpeculativeLoad* end = start + speculativeLoadQueue.Length();
for (nsHtml5SpeculativeLoad* iter = start; iter < end; ++iter) {
if (MOZ_UNLIKELY(!mParser)) {
// An extension terminated the parser from a HTTP observer.
return;
}
iter->Perform(this);
}
}
class nsHtml5FlushLoopGuard {
private:
RefPtr<nsHtml5TreeOpExecutor> mExecutor;
#ifdef DEBUG_NS_HTML5_TREE_OP_EXECUTOR_FLUSH
uint32_t mStartTime;
#endif
public:
explicit nsHtml5FlushLoopGuard(nsHtml5TreeOpExecutor* aExecutor)
: mExecutor(aExecutor)
#ifdef DEBUG_NS_HTML5_TREE_OP_EXECUTOR_FLUSH
,
mStartTime(PR_IntervalToMilliseconds(PR_IntervalNow()))
#endif
{
mExecutor->mRunFlushLoopOnStack = true;
}
~nsHtml5FlushLoopGuard() {
#ifdef DEBUG_NS_HTML5_TREE_OP_EXECUTOR_FLUSH
uint32_t timeOffTheEventLoop =
PR_IntervalToMilliseconds(PR_IntervalNow()) - mStartTime;
if (timeOffTheEventLoop >
nsHtml5TreeOpExecutor::sLongestTimeOffTheEventLoop) {
nsHtml5TreeOpExecutor::sLongestTimeOffTheEventLoop = timeOffTheEventLoop;
}
printf("Longest time off the event loop: %d\n",
nsHtml5TreeOpExecutor::sLongestTimeOffTheEventLoop);
#endif
mExecutor->mRunFlushLoopOnStack = false;
}
};
/**
* The purpose of the loop here is to avoid returning to the main event loop
*/
void nsHtml5TreeOpExecutor::RunFlushLoop() {
AUTO_PROFILER_LABEL("nsHtml5TreeOpExecutor::RunFlushLoop", OTHER);
if (mRunFlushLoopOnStack) {
// There's already a RunFlushLoop() on the call stack.
return;
}
nsHtml5FlushLoopGuard guard(this); // this is also the self-kungfu!
RefPtr<nsParserBase> parserKungFuDeathGrip(mParser);
RefPtr<nsHtml5StreamParser> streamParserGrip;
if (mParser) {
streamParserGrip = GetParser()->GetStreamParser();
}
mozilla::Unused
<< streamParserGrip; // Intentionally not used within function
// Remember the entry time
(void)nsContentSink::WillParseImpl();
for (;;) {
if (!mParser) {
// Parse has terminated.
ClearOpQueue(); // clear in order to be able to assert in destructor
return;
}
if (NS_FAILED(IsBroken())) {
return;
}
if (!parserKungFuDeathGrip->IsParserEnabled()) {
// The parser is blocked.
return;
}
if (mFlushState != eNotFlushing) {
// XXX Can this happen? In case it can, let's avoid crashing.
return;
}
// If there are scripts executing, then the content sink is jumping the gun
// (probably due to a synchronous XMLHttpRequest) and will re-enable us
// later, see bug 460706.
if (IsScriptExecuting()) {
return;
}
if (mReadingFromStage) {
nsTArray<nsHtml5SpeculativeLoad> speculativeLoadQueue;
MOZ_RELEASE_ASSERT(mFlushState == eNotFlushing,
"mOpQueue modified during flush.");
mStage.MoveOpsAndSpeculativeLoadsTo(mOpQueue, speculativeLoadQueue);
// Make sure speculative loads never start after the corresponding
// normal loads for the same URLs.
nsHtml5SpeculativeLoad* start = speculativeLoadQueue.Elements();
nsHtml5SpeculativeLoad* end = start + speculativeLoadQueue.Length();
for (nsHtml5SpeculativeLoad* iter = start; iter < end; ++iter) {
iter->Perform(this);
if (MOZ_UNLIKELY(!mParser)) {
// An extension terminated the parser from a HTTP observer.
ClearOpQueue(); // clear in order to be able to assert in destructor
return;
}
}
} else {
FlushSpeculativeLoads(); // Make sure speculative loads never start after
// the corresponding normal loads for the same
// URLs.
if (MOZ_UNLIKELY(!mParser)) {
// An extension terminated the parser from a HTTP observer.
ClearOpQueue(); // clear in order to be able to assert in destructor
return;
}
// Now parse content left in the document.write() buffer queue if any.
// This may generate tree ops on its own or dequeue a speculation.
nsresult rv = GetParser()->ParseUntilBlocked();
// ParseUntilBlocked flushes operations from the stage to the OpQueue.
// Those operations may have accompanying speculative operations.
// If so, we have to flush those speculative loads so that we maintain
// the invariant that no speculative load starts after the corresponding
// normal load for the same URL. See
// https://bugzilla.mozilla.org/show_bug.cgi?id=1513292#c80
// for a more detailed explanation of why this is necessary.
FlushSpeculativeLoads();
if (NS_FAILED(rv)) {
MarkAsBroken(rv);
return;
}
}
if (mOpQueue.IsEmpty()) {
// Avoid bothering the rest of the engine with a doc update if there's
// nothing to do.
return;
}
nsIContent* scriptElement = nullptr;
bool interrupted = false;
bool streamEnded = false;
{
// autoFlush clears mOpQueue in its destructor unless
// SetNumberOfOpsToRemove is called first, in which case only
// some ops from the start of the queue are cleared.
nsHtml5AutoFlush autoFlush(this);
nsHtml5TreeOperation* first = mOpQueue.Elements();
nsHtml5TreeOperation* last = first + mOpQueue.Length() - 1;
for (nsHtml5TreeOperation* iter = first;; ++iter) {
if (MOZ_UNLIKELY(!mParser)) {
// The previous tree op caused a call to nsIParser::Terminate().
return;
}
MOZ_ASSERT(IsInDocUpdate(),
"Tried to perform tree op outside update batch.");
nsresult rv =
iter->Perform(this, &scriptElement, &interrupted, &streamEnded);
if (NS_FAILED(rv)) {
MarkAsBroken(rv);
break;
}
// Be sure not to check the deadline if the last op was just performed.
if (MOZ_UNLIKELY(iter == last)) {
break;
} else if (MOZ_UNLIKELY(interrupted) ||
MOZ_UNLIKELY(nsContentSink::DidProcessATokenImpl() ==
NS_ERROR_HTMLPARSER_INTERRUPTED)) {
autoFlush.SetNumberOfOpsToRemove((iter - first) + 1);
nsHtml5TreeOpExecutor::ContinueInterruptedParsingAsync();
return;
}
}
if (MOZ_UNLIKELY(!mParser)) {
// The parse ended during an update pause.
return;
}
if (streamEnded) {
GetParser()->PermanentlyUndefineInsertionPoint();
}
} // end autoFlush
if (MOZ_UNLIKELY(!mParser)) {
// Ending the doc update caused a call to nsIParser::Terminate().
return;
}
if (streamEnded) {
DidBuildModel(false);
#ifdef DEBUG
if (scriptElement) {
nsCOMPtr<nsIScriptElement> sele = do_QueryInterface(scriptElement);
if (!sele) {
MOZ_ASSERT(nsNameSpaceManager::GetInstance()->mSVGDisabled,
"Node didn't QI to script, but SVG wasn't disabled.");
}
MOZ_ASSERT(sele->IsMalformed(), "Script wasn't marked as malformed.");
}
#endif
} else if (scriptElement) {
// must be tail call when mFlushState is eNotFlushing
RunScript(scriptElement);
// Always check the clock in nsContentSink right after a script
StopDeflecting();
if (nsContentSink::DidProcessATokenImpl() ==
NS_ERROR_HTMLPARSER_INTERRUPTED) {
#ifdef DEBUG_NS_HTML5_TREE_OP_EXECUTOR_FLUSH
printf("REFLUSH SCHEDULED (after script): %d\n",
++sTimesFlushLoopInterrupted);
#endif
nsHtml5TreeOpExecutor::ContinueInterruptedParsingAsync();
return;
}
}
}
}
nsresult nsHtml5TreeOpExecutor::FlushDocumentWrite() {
nsresult rv = IsBroken();
NS_ENSURE_SUCCESS(rv, rv);
FlushSpeculativeLoads(); // Make sure speculative loads never start after the
// corresponding normal loads for the same URLs.
if (MOZ_UNLIKELY(!mParser)) {
// The parse has ended.
ClearOpQueue(); // clear in order to be able to assert in destructor
return rv;
}
if (mFlushState != eNotFlushing) {
// XXX Can this happen? In case it can, let's avoid crashing.
return rv;
}
// avoid crashing near EOF
RefPtr<nsHtml5TreeOpExecutor> kungFuDeathGrip(this);
RefPtr<nsParserBase> parserKungFuDeathGrip(mParser);
mozilla::Unused
<< parserKungFuDeathGrip; // Intentionally not used within function
RefPtr<nsHtml5StreamParser> streamParserGrip;
if (mParser) {
streamParserGrip = GetParser()->GetStreamParser();
}
mozilla::Unused
<< streamParserGrip; // Intentionally not used within function
MOZ_RELEASE_ASSERT(!mReadingFromStage,
"Got doc write flush when reading from stage");
#ifdef DEBUG
mStage.AssertEmpty();
#endif
nsIContent* scriptElement = nullptr;
bool interrupted = false;
bool streamEnded = false;
{
// autoFlush clears mOpQueue in its destructor.
nsHtml5AutoFlush autoFlush(this);
nsHtml5TreeOperation* start = mOpQueue.Elements();
nsHtml5TreeOperation* end = start + mOpQueue.Length();
for (nsHtml5TreeOperation* iter = start; iter < end; ++iter) {
if (MOZ_UNLIKELY(!mParser)) {
// The previous tree op caused a call to nsIParser::Terminate().
return rv;
}
NS_ASSERTION(IsInDocUpdate(),
"Tried to perform tree op outside update batch.");
rv = iter->Perform(this, &scriptElement, &interrupted, &streamEnded);
if (NS_FAILED(rv)) {
MarkAsBroken(rv);
break;
}
}
if (MOZ_UNLIKELY(!mParser)) {
// The parse ended during an update pause.
return rv;
}
if (streamEnded) {
// This should be redundant but let's do it just in case.
GetParser()->PermanentlyUndefineInsertionPoint();
}
} // autoFlush
if (MOZ_UNLIKELY(!mParser)) {
// Ending the doc update caused a call to nsIParser::Terminate().
return rv;
}
if (streamEnded) {
DidBuildModel(false);
#ifdef DEBUG
if (scriptElement) {
nsCOMPtr<nsIScriptElement> sele = do_QueryInterface(scriptElement);
if (!sele) {
MOZ_ASSERT(nsNameSpaceManager::GetInstance()->mSVGDisabled,
"Node didn't QI to script, but SVG wasn't disabled.");
}
MOZ_ASSERT(sele->IsMalformed(), "Script wasn't marked as malformed.");
}
#endif
} else if (scriptElement) {
// must be tail call when mFlushState is eNotFlushing
RunScript(scriptElement);
}
return rv;
}
// copied from HTML content sink
bool nsHtml5TreeOpExecutor::IsScriptEnabled() {
// Note that if we have no document or no docshell or no global or whatnot we
// want to claim script _is_ enabled, so we don't parse the contents of
// <noscript> tags!
if (!mDocument || !mDocShell) {
return true;
}
return mDocument->IsScriptEnabled();
}
void nsHtml5TreeOpExecutor::StartLayout(bool* aInterrupted) {
if (mLayoutStarted || !mDocument) {
return;
}
nsHtml5AutoPauseUpdate autoPause(this);
if (MOZ_UNLIKELY(!mParser)) {
// got terminate
return;
}
nsContentSink::StartLayout(false);
if (mParser) {
*aInterrupted = !GetParser()->IsParserEnabled();
}
}
void nsHtml5TreeOpExecutor::PauseDocUpdate(bool* aInterrupted) {
// Pausing the document update allows JS to run, and potentially block
// further parsing.
nsHtml5AutoPauseUpdate autoPause(this);
if (MOZ_LIKELY(mParser)) {
*aInterrupted = !GetParser()->IsParserEnabled();
}
}
/**
* The reason why this code is here and not in the tree builder even in the
* main-thread case is to allow the control to return from the tokenizer
* before scripts run. This way, the tokenizer is not invoked re-entrantly
* although the parser is.
*
* The reason why this is called as a tail call when mFlushState is set to
* eNotFlushing is to allow re-entry to Flush() but only after the current
* Flush() has cleared the op queue and is otherwise done cleaning up after
* itself.
*/
void nsHtml5TreeOpExecutor::RunScript(nsIContent* aScriptElement) {
if (mRunsToCompletion) {
// We are in createContextualFragment() or in the upcoming document.parse().
// Do nothing. Let's not even mark scripts malformed here, because that
// could cause serialization weirdness later.
return;
}
MOZ_ASSERT(mParser, "Trying to run script with a terminated parser.");
MOZ_ASSERT(aScriptElement, "No script to run");
nsCOMPtr<nsIScriptElement> sele = do_QueryInterface(aScriptElement);
if (!sele) {
MOZ_ASSERT(nsNameSpaceManager::GetInstance()->mSVGDisabled,
"Node didn't QI to script, but SVG wasn't disabled.");
return;
}
if (sele->GetScriptDeferred() || sele->GetScriptAsync()) {
DebugOnly<bool> block = sele->AttemptToExecute();
NS_ASSERTION(!block, "Defer or async script tried to block.");
return;
}
MOZ_RELEASE_ASSERT(mFlushState == eNotFlushing,
"Tried to run script while flushing.");
mReadingFromStage = false;
sele->SetCreatorParser(GetParser());
// Copied from nsXMLContentSink
// Now tell the script that it's ready to go. This may execute the script
// or return true, or neither if the script doesn't need executing.
bool block = sele->AttemptToExecute();
// If the act of insertion evaluated the script, we're fine.
// Else, block the parser till the script has loaded.
if (block) {
if (mParser) {
GetParser()->BlockParser();
}
} else {
// mParser may have been nulled out by now, but the flusher deals
// If this event isn't needed, it doesn't do anything. It is sometimes
// necessary for the parse to continue after complex situations.
nsHtml5TreeOpExecutor::ContinueInterruptedParsingAsync();
}
}
void nsHtml5TreeOpExecutor::Start() {
MOZ_ASSERT(!mStarted, "Tried to start when already started.");
mStarted = true;
}
void nsHtml5TreeOpExecutor::NeedsCharsetSwitchTo(
NotNull<const Encoding*> aEncoding, int32_t aSource, uint32_t aLineNumber) {
nsHtml5AutoPauseUpdate autoPause(this);
if (MOZ_UNLIKELY(!mParser)) {
// got terminate
return;
}
if (!mDocShell) {
return;
}
nsDocShell* docShell = static_cast<nsDocShell*>(mDocShell.get());
if (NS_SUCCEEDED(docShell->CharsetChangeStopDocumentLoad())) {
nsAutoCString charset;
aEncoding->Name(charset);
docShell->CharsetChangeReloadDocument(charset.get(), aSource);
}
// if the charset switch was accepted, mDocShell has called Terminate() on the
// parser by now
if (!mParser) {
// success
if (aSource == kCharsetFromMetaTag) {
MaybeComplainAboutCharset("EncLateMetaReload", false, aLineNumber);
}
return;
}
if (aSource == kCharsetFromMetaTag) {
MaybeComplainAboutCharset("EncLateMetaTooLate", true, aLineNumber);
}
GetParser()->ContinueAfterFailedCharsetSwitch();
}
void nsHtml5TreeOpExecutor::MaybeComplainAboutCharset(const char* aMsgId,
bool aError,
uint32_t aLineNumber) {
if (mAlreadyComplainedAboutCharset) {
return;
}
// The EncNoDeclaration case for advertising iframes is so common that it
// would result is way too many errors. The iframe case doesn't matter
// when the ad is an image or a Flash animation anyway. When the ad is
// textual, a misrendered ad probably isn't a huge loss for users.
// Let's suppress the message in this case.
// This means that errors about other different-origin iframes in mashups
// are lost as well, but generally, the site author isn't in control of
// the embedded different-origin pages anyway and can't fix problems even
// if alerted about them.
if (!strcmp(aMsgId, "EncNoDeclaration") && mDocShell) {
BrowsingContext* const bc = mDocShell->GetBrowsingContext();
if (bc && bc->GetParent()) {
return;
}
}
mAlreadyComplainedAboutCharset = true;
nsContentUtils::ReportToConsole(
aError ? nsIScriptError::errorFlag : nsIScriptError::warningFlag,
"HTML parser"_ns, mDocument, nsContentUtils::eHTMLPARSER_PROPERTIES,
aMsgId, nsTArray<nsString>(), nullptr, u""_ns, aLineNumber);
}
void nsHtml5TreeOpExecutor::ComplainAboutBogusProtocolCharset(Document* aDoc) {
NS_ASSERTION(!mAlreadyComplainedAboutCharset,
"How come we already managed to complain?");
mAlreadyComplainedAboutCharset = true;
nsContentUtils::ReportToConsole(nsIScriptError::errorFlag, "HTML parser"_ns,
aDoc, nsContentUtils::eHTMLPARSER_PROPERTIES,
"EncProtocolUnsupported");
}
void nsHtml5TreeOpExecutor::MaybeComplainAboutDeepTree(uint32_t aLineNumber) {
if (mAlreadyComplainedAboutDeepTree) {
return;
}
mAlreadyComplainedAboutDeepTree = true;
nsContentUtils::ReportToConsole(
nsIScriptError::errorFlag, "HTML parser"_ns, mDocument,
nsContentUtils::eHTMLPARSER_PROPERTIES, "errDeepTree",
nsTArray<nsString>(), nullptr, u""_ns, aLineNumber);
}
nsHtml5Parser* nsHtml5TreeOpExecutor::GetParser() {
MOZ_ASSERT(!mRunsToCompletion);
return static_cast<nsHtml5Parser*>(mParser.get());
}
void nsHtml5TreeOpExecutor::MoveOpsFrom(
nsTArray<nsHtml5TreeOperation>& aOpQueue) {
MOZ_RELEASE_ASSERT(mFlushState == eNotFlushing,
"Ops added to mOpQueue during tree op execution.");
mOpQueue.AppendElements(std::move(aOpQueue));
}
void nsHtml5TreeOpExecutor::ClearOpQueue() {
MOZ_RELEASE_ASSERT(mFlushState == eNotFlushing,
"mOpQueue cleared during tree op execution.");
mOpQueue.Clear();
}
void nsHtml5TreeOpExecutor::RemoveFromStartOfOpQueue(
size_t aNumberOfOpsToRemove) {
MOZ_RELEASE_ASSERT(mFlushState == eNotFlushing,
"Ops removed from mOpQueue during tree op execution.");
mOpQueue.RemoveElementsAt(0, aNumberOfOpsToRemove);
}
void nsHtml5TreeOpExecutor::InitializeDocWriteParserState(
nsAHtml5TreeBuilderState* aState, int32_t aLine) {
GetParser()->InitializeDocWriteParserState(aState, aLine);
}
nsIURI* nsHtml5TreeOpExecutor::GetViewSourceBaseURI() {
if (!mViewSourceBaseURI) {
// We query the channel for the baseURI because in certain situations it
// cannot otherwise be determined. If this process fails, fall back to the
// standard method.
nsCOMPtr<nsIViewSourceChannel> vsc =
do_QueryInterface(mDocument->GetChannel());
if (vsc) {
nsresult rv = vsc->GetBaseURI(getter_AddRefs(mViewSourceBaseURI));
if (NS_SUCCEEDED(rv) && mViewSourceBaseURI) {
return mViewSourceBaseURI;
}
}
nsCOMPtr<nsIURI> orig = mDocument->GetOriginalURI();
if (orig->SchemeIs("view-source")) {
nsCOMPtr<nsINestedURI> nested = do_QueryInterface(orig);
NS_ASSERTION(nested, "URI with scheme view-source didn't QI to nested!");
nested->GetInnerURI(getter_AddRefs(mViewSourceBaseURI));
} else {
// Fail gracefully if the base URL isn't a view-source: URL.
// Not sure if this can ever happen.
mViewSourceBaseURI = orig;
}
}
return mViewSourceBaseURI;
}
bool nsHtml5TreeOpExecutor::IsExternalViewSource() {
if (!StaticPrefs::view_source_editor_external()) {
return false;
}
if (mDocumentURI) {
return mDocumentURI->SchemeIs("view-source");
}
return false;
}
// Speculative loading
nsIURI* nsHtml5TreeOpExecutor::BaseURIForPreload() {
// The URL of the document without <base>
nsIURI* documentURI = mDocument->GetDocumentURI();
// The URL of the document with non-speculative <base>
nsIURI* documentBaseURI = mDocument->GetDocBaseURI();
// If the two above are different, use documentBaseURI. If they are the same,
// the document object isn't aware of a <base>, so attempt to use the
// mSpeculationBaseURI or, failing, that, documentURI.
return (documentURI == documentBaseURI)
? (mSpeculationBaseURI ? mSpeculationBaseURI.get() : documentURI)
: documentBaseURI;
}
already_AddRefed<nsIURI> nsHtml5TreeOpExecutor::ConvertIfNotPreloadedYet(
const nsAString& aURL) {
if (aURL.IsEmpty()) {
return nullptr;
}
nsIURI* base = BaseURIForPreload();
auto encoding = mDocument->GetDocumentCharacterSet();
nsCOMPtr<nsIURI> uri;
nsresult rv = NS_NewURI(getter_AddRefs(uri), aURL, encoding, base);
if (NS_FAILED(rv)) {
NS_WARNING("Failed to create a URI");
return nullptr;
}
if (ShouldPreloadURI(uri)) {
return uri.forget();
}
return nullptr;
}
bool nsHtml5TreeOpExecutor::ShouldPreloadURI(nsIURI* aURI) {
nsAutoCString spec;
nsresult rv = aURI->GetSpec(spec);
NS_ENSURE_SUCCESS(rv, false);
return mPreloadedURLs.EnsureInserted(spec);
}
dom::ReferrerPolicy nsHtml5TreeOpExecutor::GetPreloadReferrerPolicy(
const nsAString& aReferrerPolicy) {
dom::ReferrerPolicy referrerPolicy =
dom::ReferrerInfo::ReferrerPolicyAttributeFromString(aReferrerPolicy);
return GetPreloadReferrerPolicy(referrerPolicy);
}
dom::ReferrerPolicy nsHtml5TreeOpExecutor::GetPreloadReferrerPolicy(
ReferrerPolicy aReferrerPolicy) {
if (aReferrerPolicy != dom::ReferrerPolicy::_empty) {
return aReferrerPolicy;
}
return mDocument->GetPreloadReferrerInfo()->ReferrerPolicy();
}
void nsHtml5TreeOpExecutor::PreloadScript(
const nsAString& aURL, const nsAString& aCharset, const nsAString& aType,
const nsAString& aCrossOrigin, const nsAString& aIntegrity,
dom::ReferrerPolicy aReferrerPolicy, bool aScriptFromHead, bool aAsync,
bool aDefer, bool aNoModule, bool aLinkPreload) {
nsCOMPtr<nsIURI> uri = ConvertIfNotPreloadedYet(aURL);
if (!uri) {
return;
}
mDocument->ScriptLoader()->PreloadURI(
uri, aCharset, aType, aCrossOrigin, aIntegrity, aScriptFromHead, aAsync,
aDefer, aNoModule, aLinkPreload,
GetPreloadReferrerPolicy(aReferrerPolicy));
}
void nsHtml5TreeOpExecutor::PreloadStyle(const nsAString& aURL,
const nsAString& aCharset,
const nsAString& aCrossOrigin,
const nsAString& aReferrerPolicy,
const nsAString& aIntegrity,
bool aLinkPreload) {
nsCOMPtr<nsIURI> uri = ConvertIfNotPreloadedYet(aURL);
if (!uri) {
return;
}
mDocument->PreloadStyle(uri, Encoding::ForLabel(aCharset), aCrossOrigin,
GetPreloadReferrerPolicy(aReferrerPolicy), aIntegrity,
aLinkPreload);
}
void nsHtml5TreeOpExecutor::PreloadImage(const nsAString& aURL,
const nsAString& aCrossOrigin,
const nsAString& aSrcset,
const nsAString& aSizes,
const nsAString& aImageReferrerPolicy,
bool aLinkPreload) {
nsCOMPtr<nsIURI> baseURI = BaseURIForPreload();
bool isImgSet = false;
nsCOMPtr<nsIURI> uri =
mDocument->ResolvePreloadImage(baseURI, aURL, aSrcset, aSizes, &isImgSet);
if (uri && ShouldPreloadURI(uri)) {
// use document wide referrer policy
mDocument->MaybePreLoadImage(uri, aCrossOrigin,
GetPreloadReferrerPolicy(aImageReferrerPolicy),
isImgSet, aLinkPreload);
}
}
// These calls inform the document of picture state and seen sources, such that
// it can use them to inform ResolvePreLoadImage as necessary
void nsHtml5TreeOpExecutor::PreloadPictureSource(const nsAString& aSrcset,
const nsAString& aSizes,
const nsAString& aType,
const nsAString& aMedia) {
mDocument->PreloadPictureImageSource(aSrcset, aSizes, aType, aMedia);
}
void nsHtml5TreeOpExecutor::PreloadFont(const nsAString& aURL,
const nsAString& aCrossOrigin,
const nsAString& aReferrerPolicy) {
nsCOMPtr<nsIURI> uri = ConvertIfNotPreloadedYet(aURL);
if (!uri) {
return;
}
mDocument->Preloads().PreloadFont(uri, aCrossOrigin, aReferrerPolicy);
}
void nsHtml5TreeOpExecutor::PreloadFetch(const nsAString& aURL,
const nsAString& aCrossOrigin,
const nsAString& aReferrerPolicy) {
nsCOMPtr<nsIURI> uri = ConvertIfNotPreloadedYet(aURL);
if (!uri) {
return;
}
mDocument->Preloads().PreloadFetch(uri, aCrossOrigin, aReferrerPolicy);
}
void nsHtml5TreeOpExecutor::PreloadOpenPicture() {
mDocument->PreloadPictureOpened();
}
void nsHtml5TreeOpExecutor::PreloadEndPicture() {
mDocument->PreloadPictureClosed();
}
void nsHtml5TreeOpExecutor::AddBase(const nsAString& aURL) {
auto encoding = mDocument->GetDocumentCharacterSet();
nsresult rv = NS_NewURI(getter_AddRefs(mViewSourceBaseURI), aURL, encoding,
GetViewSourceBaseURI());
if (NS_FAILED(rv)) {
mViewSourceBaseURI = nullptr;
}
}
void nsHtml5TreeOpExecutor::SetSpeculationBase(const nsAString& aURL) {
if (mSpeculationBaseURI) {
// the first one wins
return;
}
auto encoding = mDocument->GetDocumentCharacterSet();
DebugOnly<nsresult> rv = NS_NewURI(getter_AddRefs(mSpeculationBaseURI), aURL,
encoding, mDocument->GetDocumentURI());
NS_WARNING_ASSERTION(NS_SUCCEEDED(rv), "Failed to create a URI");
mDocument->Preloads().SetSpeculationBase(mSpeculationBaseURI);
}
void nsHtml5TreeOpExecutor::UpdateReferrerInfoFromMeta(
const nsAString& aMetaReferrer) {
mDocument->UpdateReferrerInfoFromMeta(aMetaReferrer, true);
}
void nsHtml5TreeOpExecutor::AddSpeculationCSP(const nsAString& aCSP) {
if (!StaticPrefs::security_csp_enable()) {
return;
}
NS_ASSERTION(NS_IsMainThread(), "Wrong thread!");
nsresult rv = NS_OK;
nsCOMPtr<nsIContentSecurityPolicy> preloadCsp = mDocument->GetPreloadCsp();
if (!preloadCsp) {
preloadCsp = new nsCSPContext();
rv = preloadCsp->SetRequestContextWithDocument(mDocument);
NS_ENSURE_SUCCESS_VOID(rv);
}
// please note that meta CSPs and CSPs delivered through a header need
// to be joined together.
rv = preloadCsp->AppendPolicy(
aCSP,
false, // csp via meta tag can not be report only
true); // delivered through the meta tag
NS_ENSURE_SUCCESS_VOID(rv);
nsPIDOMWindowInner* inner = mDocument->GetInnerWindow();
if (inner) {
inner->SetPreloadCsp(preloadCsp);
}
mDocument->ApplySettingsFromCSP(true);
}
#ifdef DEBUG_NS_HTML5_TREE_OP_EXECUTOR_FLUSH
uint32_t nsHtml5TreeOpExecutor::sAppendBatchMaxSize = 0;
uint32_t nsHtml5TreeOpExecutor::sAppendBatchSlotsExamined = 0;
uint32_t nsHtml5TreeOpExecutor::sAppendBatchExaminations = 0;
uint32_t nsHtml5TreeOpExecutor::sLongestTimeOffTheEventLoop = 0;
uint32_t nsHtml5TreeOpExecutor::sTimesFlushLoopInterrupted = 0;
#endif