1 files changed, 316 insertions, 220 deletions

diff --git a/Source/WebCore/css/ElementRuleCollector.cpp b/Source/WebCore/css/ElementRuleCollector.cpp
index 88f1eff18..8c2039750 100644
--- a/Source/WebCore/css/ElementRuleCollector.cpp
+++ b/Source/WebCore/css/ElementRuleCollector.cpp
@@ -2,7 +2,7 @@
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 2004-2005 Allan Sandfeld Jensen (kde@carewolf.com)
  * Copyright (C) 2006, 2007 Nicholas Shanks (webkit@nickshanks.com)
- * Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013 Apple Inc. All rights reserved.
+ * Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014 Apple Inc. All rights reserved.
  * Copyright (C) 2007 Alexey Proskuryakov <ap@webkit.org>
  * Copyright (C) 2007, 2008 Eric Seidel <eric@webkit.org>
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
@@ -36,15 +36,17 @@
 #include "CSSSelectorList.h"
 #include "CSSValueKeywords.h"
 #include "HTMLElement.h"
-#include "InspectorInstrumentation.h"
+#include "HTMLSlotElement.h"
+#include "NodeRenderStyle.h"
 #include "RenderRegion.h"
 #include "SVGElement.h"
-#include "SelectorCheckerFastPath.h"
 #include "SelectorCompiler.h"
+#include "SelectorFilter.h"
+#include "ShadowRoot.h"
 #include "StyleProperties.h"
+#include "StyleScope.h"
 #include "StyledElement.h"
-
-#include <wtf/TemporaryChange.h>
+#include <wtf/SetForScope.h>
 
 namespace WebCore {
 
@@ -53,7 +55,7 @@ static const StyleProperties& leftToRightDeclaration()
     static NeverDestroyed<Ref<MutableStyleProperties>> leftToRightDecl(MutableStyleProperties::create());
     if (leftToRightDecl.get()->isEmpty())
         leftToRightDecl.get()->setProperty(CSSPropertyDirection, CSSValueLtr);
-    return leftToRightDecl.get().get();
+    return leftToRightDecl.get();
 }
 
 static const StyleProperties& rightToLeftDeclaration()
@@ -61,51 +63,72 @@ static const StyleProperties& rightToLeftDeclaration()
     static NeverDestroyed<Ref<MutableStyleProperties>> rightToLeftDecl(MutableStyleProperties::create());
     if (rightToLeftDecl.get()->isEmpty())
         rightToLeftDecl.get()->setProperty(CSSPropertyDirection, CSSValueRtl);
-    return rightToLeftDecl.get().get();
+    return rightToLeftDecl.get();
 }
 
 class MatchRequest {
 public:
-    MatchRequest(RuleSet* ruleSet, bool includeEmptyRules = false)
+    MatchRequest(const RuleSet* ruleSet, bool includeEmptyRules = false, Style::ScopeOrdinal styleScopeOrdinal = Style::ScopeOrdinal::Element)
         : ruleSet(ruleSet)
         , includeEmptyRules(includeEmptyRules)
+        , styleScopeOrdinal(styleScopeOrdinal)
     {
     }
     const RuleSet* ruleSet;
     const bool includeEmptyRules;
+    Style::ScopeOrdinal styleScopeOrdinal;
 };
 
+ElementRuleCollector::ElementRuleCollector(const Element& element, const DocumentRuleSets& ruleSets, const SelectorFilter* selectorFilter)
+    : m_element(element)
+    , m_authorStyle(ruleSets.authorStyle())
+    , m_userStyle(ruleSets.userStyle())
+    , m_selectorFilter(selectorFilter)
+{
+    ASSERT(!m_selectorFilter || m_selectorFilter->parentStackIsConsistent(element.parentNode()));
+}
+
+ElementRuleCollector::ElementRuleCollector(const Element& element, const RuleSet& authorStyle, const SelectorFilter* selectorFilter)
+    : m_element(element)
+    , m_authorStyle(authorStyle)
+    , m_selectorFilter(selectorFilter)
+{
+    ASSERT(!m_selectorFilter || m_selectorFilter->parentStackIsConsistent(element.parentNode()));
+}
+
 StyleResolver::MatchResult& ElementRuleCollector::matchedResult()
 {
-    ASSERT(m_mode == SelectorChecker::ResolvingStyle);
+    ASSERT(m_mode == SelectorChecker::Mode::ResolvingStyle);
     return m_result;
 }
 
-const Vector<RefPtr<StyleRuleBase>>& ElementRuleCollector::matchedRuleList() const
+const Vector<RefPtr<StyleRule>>& ElementRuleCollector::matchedRuleList() const
 {
-    ASSERT(m_mode == SelectorChecker::CollectingRules);
+    ASSERT(m_mode == SelectorChecker::Mode::CollectingRules);
     return m_matchedRuleList;
 }
 
-inline void ElementRuleCollector::addMatchedRule(const RuleData* rule)
+inline void ElementRuleCollector::addMatchedRule(const RuleData& ruleData, unsigned specificity, Style::ScopeOrdinal styleScopeOrdinal, StyleResolver::RuleRange& ruleRange)
 {
-    if (!m_matchedRules)
-        m_matchedRules = std::make_unique<Vector<const RuleData*, 32>>();
-    m_matchedRules->append(rule);
+    // Update our first/last rule indices in the matched rules array.
+    ++ruleRange.lastRuleIndex;
+    if (ruleRange.firstRuleIndex == -1)
+        ruleRange.firstRuleIndex = ruleRange.lastRuleIndex;
+
+    m_matchedRules.append({ &ruleData, specificity, styleScopeOrdinal });
 }
 
-inline void ElementRuleCollector::clearMatchedRules()
+void ElementRuleCollector::clearMatchedRules()
 {
-    if (!m_matchedRules)
-        return;
-    m_matchedRules->clear();
+    m_matchedRules.clear();
+    m_keepAliveSlottedPseudoElementRules.clear();
 }
 
 inline void ElementRuleCollector::addElementStyleProperties(const StyleProperties* propertySet, bool isCacheable)
 {
     if (!propertySet)
         return;
-    m_result.ranges.lastAuthorRule = m_result.matchedProperties.size();
+    m_result.ranges.lastAuthorRule = m_result.matchedProperties().size();
     if (m_result.ranges.firstAuthorRule == -1)
         m_result.ranges.firstAuthorRule = m_result.ranges.lastAuthorRule;
     m_result.addMatchedProperties(*propertySet);
@@ -113,75 +136,30 @@ inline void ElementRuleCollector::addElementStyleProperties(const StylePropertie
         m_result.isCacheable = false;
 }
 
-class MatchingUARulesScope {
-public:
-    MatchingUARulesScope();
-    ~MatchingUARulesScope();
-
-    static bool isMatchingUARules();
-
-private:
-    static bool m_matchingUARules;
-};
-
-MatchingUARulesScope::MatchingUARulesScope()
-{
-    ASSERT(!m_matchingUARules);
-    m_matchingUARules = true;
-}
-
-MatchingUARulesScope::~MatchingUARulesScope()
-{
-    m_matchingUARules = false;
-}
-
-inline bool MatchingUARulesScope::isMatchingUARules()
-{
-    return m_matchingUARules;
-}
-
-bool MatchingUARulesScope::m_matchingUARules = false;
-
 void ElementRuleCollector::collectMatchingRules(const MatchRequest& matchRequest, StyleResolver::RuleRange& ruleRange)
 {
     ASSERT(matchRequest.ruleSet);
-    ASSERT(m_state.element());
-
-    const StyleResolver::State& state = m_state;
-    Element* element = state.element();
-    const StyledElement* styledElement = state.styledElement();
-    const AtomicString& pseudoId = element->shadowPseudoId();
-    if (!pseudoId.isEmpty()) {
-        ASSERT(styledElement);
-        collectMatchingRulesForList(matchRequest.ruleSet->shadowPseudoElementRules(pseudoId.impl()), matchRequest, ruleRange);
-    }
+    ASSERT_WITH_MESSAGE(!(m_mode == SelectorChecker::Mode::CollectingRulesIgnoringVirtualPseudoElements && m_pseudoStyleRequest.pseudoId != NOPSEUDO), "When in StyleInvalidation or SharingRules, SelectorChecker does not try to match the pseudo ID. While ElementRuleCollector supports matching a particular pseudoId in this case, this would indicate a error at the call site since matching a particular element should be unnecessary.");
 
-#if ENABLE(VIDEO_TRACK)
-    if (element->isWebVTTElement())
-        collectMatchingRulesForList(matchRequest.ruleSet->cuePseudoRules(), matchRequest, ruleRange);
-#endif
-    // Check whether other types of rules are applicable in the current tree scope. Criteria for this:
-    // a) it's a UA rule
-    // b) the tree scope allows author rules
-    // c) the rules comes from a scoped style sheet within the same tree scope
-    if (!MatchingUARulesScope::isMatchingUARules()
-        && !element->treeScope().applyAuthorStyles())
-        return;
+    auto* shadowRoot = m_element.containingShadowRoot();
+    if (shadowRoot && shadowRoot->mode() == ShadowRootMode::UserAgent)
+        collectMatchingShadowPseudoElementRules(matchRequest, ruleRange);
 
     // We need to collect the rules for id, class, tag, and everything else into a buffer and
     // then sort the buffer.
-    if (element->hasID())
-        collectMatchingRulesForList(matchRequest.ruleSet->idRules(element->idForStyleResolution().impl()), matchRequest, ruleRange);
-    if (styledElement && styledElement->hasClass()) {
-        for (size_t i = 0; i < styledElement->classNames().size(); ++i)
-            collectMatchingRulesForList(matchRequest.ruleSet->classRules(styledElement->classNames()[i].impl()), matchRequest, ruleRange);
+    auto& id = m_element.idForStyleResolution();
+    if (!id.isNull())
+        collectMatchingRulesForList(matchRequest.ruleSet->idRules(id), matchRequest, ruleRange);
+    if (m_element.hasClass()) {
+        for (size_t i = 0; i < m_element.classNames().size(); ++i)
+            collectMatchingRulesForList(matchRequest.ruleSet->classRules(m_element.classNames()[i]), matchRequest, ruleRange);
     }
 
-    if (element->isLink())
+    if (m_element.isLink())
         collectMatchingRulesForList(matchRequest.ruleSet->linkPseudoClassRules(), matchRequest, ruleRange);
-    if (SelectorChecker::matchesFocusPseudoClass(element))
+    if (SelectorChecker::matchesFocusPseudoClass(m_element))
         collectMatchingRulesForList(matchRequest.ruleSet->focusPseudoClassRules(), matchRequest, ruleRange);
-    collectMatchingRulesForList(matchRequest.ruleSet->tagRules(element->localName().impl()), matchRequest, ruleRange);
+    collectMatchingRulesForList(matchRequest.ruleSet->tagRules(m_element.localName(), m_element.isHTMLElement() && m_element.document().isHTMLDocument()), matchRequest, ruleRange);
     collectMatchingRulesForList(matchRequest.ruleSet->universalRules(), matchRequest, ruleRange);
 }
 
@@ -203,54 +181,149 @@ void ElementRuleCollector::collectMatchingRulesForRegion(const MatchRequest& mat
 
 void ElementRuleCollector::sortAndTransferMatchedRules()
 {
-    const StyleResolver::State& state = m_state;
-
-    if (!m_matchedRules || m_matchedRules->isEmpty())
+    if (m_matchedRules.isEmpty())
         return;
 
     sortMatchedRules();
 
-    Vector<const RuleData*, 32>& matchedRules = *m_matchedRules;
-    if (m_mode == SelectorChecker::CollectingRules) {
-        for (unsigned i = 0; i < matchedRules.size(); ++i)
-            m_matchedRuleList.append(matchedRules[i]->rule());
+    if (m_mode == SelectorChecker::Mode::CollectingRules) {
+        for (const MatchedRule& matchedRule : m_matchedRules)
+            m_matchedRuleList.append(matchedRule.ruleData->rule());
         return;
     }
 
-    // Now transfer the set of matched rules over to our list of declarations.
-    for (unsigned i = 0; i < matchedRules.size(); i++) {
-        if (state.style() && matchedRules[i]->containsUncommonAttributeSelector())
-            state.style()->setUnique();
-        m_result.addMatchedProperties(matchedRules[i]->rule()->properties(), matchedRules[i]->rule(), matchedRules[i]->linkMatchType(), matchedRules[i]->propertyWhitelistType(MatchingUARulesScope::isMatchingUARules()));
+    for (const MatchedRule& matchedRule : m_matchedRules) {
+        m_result.addMatchedProperties(matchedRule.ruleData->rule()->properties(), matchedRule.ruleData->rule(), matchedRule.ruleData->linkMatchType(), matchedRule.ruleData->propertyWhitelistType(), matchedRule.styleScopeOrdinal);
     }
 }
 
 void ElementRuleCollector::matchAuthorRules(bool includeEmptyRules)
 {
     clearMatchedRules();
-    m_result.ranges.lastAuthorRule = m_result.matchedProperties.size() - 1;
 
-    if (!m_state.element())
+    m_result.ranges.lastAuthorRule = m_result.matchedProperties().size() - 1;
+    StyleResolver::RuleRange ruleRange = m_result.ranges.authorRuleRange();
+
+    {
+        MatchRequest matchRequest(&m_authorStyle, includeEmptyRules);
+        collectMatchingRules(matchRequest, ruleRange);
+        collectMatchingRulesForRegion(matchRequest, ruleRange);
+    }
+
+    auto* parent = m_element.parentElement();
+    if (parent && parent->shadowRoot())
+        matchSlottedPseudoElementRules(includeEmptyRules, ruleRange);
+
+    if (m_element.shadowRoot())
+        matchHostPseudoClassRules(includeEmptyRules, ruleRange);
+
+    if (m_element.isInShadowTree())
+        matchAuthorShadowPseudoElementRules(includeEmptyRules, ruleRange);
+
+    sortAndTransferMatchedRules();
+}
+
+void ElementRuleCollector::matchAuthorShadowPseudoElementRules(bool includeEmptyRules, StyleResolver::RuleRange& ruleRange)
+{
+    ASSERT(m_element.isInShadowTree());
+    auto& shadowRoot = *m_element.containingShadowRoot();
+    if (shadowRoot.mode() != ShadowRootMode::UserAgent)
+        return;
+    // Look up shadow pseudo elements also from the host scope author style as they are web-exposed.
+    auto& hostAuthorRules = Style::Scope::forNode(*shadowRoot.host()).resolver().ruleSets().authorStyle();
+    MatchRequest hostAuthorRequest { &hostAuthorRules, includeEmptyRules, Style::ScopeOrdinal::ContainingHost };
+    collectMatchingShadowPseudoElementRules(hostAuthorRequest, ruleRange);
+}
+
+void ElementRuleCollector::matchHostPseudoClassRules(bool includeEmptyRules, StyleResolver::RuleRange& ruleRange)
+{
+    ASSERT(m_element.shadowRoot());
+
+    auto& shadowAuthorStyle = m_element.shadowRoot()->styleScope().resolver().ruleSets().authorStyle();
+    auto& shadowHostRules = shadowAuthorStyle.hostPseudoClassRules();
+    if (shadowHostRules.isEmpty())
         return;
 
+    SetForScope<bool> change(m_isMatchingHostPseudoClass, true);
+
+    MatchRequest hostMatchRequest { nullptr, includeEmptyRules, Style::ScopeOrdinal::Shadow };
+    collectMatchingRulesForList(&shadowHostRules, hostMatchRequest, ruleRange);
+}
+
+void ElementRuleCollector::matchSlottedPseudoElementRules(bool includeEmptyRules, StyleResolver::RuleRange& ruleRange)
+{
+    auto* slot = m_element.assignedSlot();
+    auto styleScopeOrdinal = Style::ScopeOrdinal::FirstSlot;
+
+    for (; slot; slot = slot->assignedSlot(), ++styleScopeOrdinal) {
+        auto& styleScope = Style::Scope::forNode(*slot);
+        if (!styleScope.resolver().ruleSets().isAuthorStyleDefined())
+            continue;
+        // Find out if there are any ::slotted rules in the shadow tree matching the current slot.
+        // FIXME: This is really part of the slot style and could be cached when resolving it.
+        ElementRuleCollector collector(*slot, styleScope.resolver().ruleSets().authorStyle(), nullptr);
+        auto slottedPseudoElementRules = collector.collectSlottedPseudoElementRulesForSlot(includeEmptyRules);
+        if (!slottedPseudoElementRules)
+            continue;
+        // Match in the current scope.
+        SetForScope<bool> change(m_isMatchingSlottedPseudoElements, true);
+
+        MatchRequest scopeMatchRequest(nullptr, includeEmptyRules, styleScopeOrdinal);
+        collectMatchingRulesForList(slottedPseudoElementRules.get(), scopeMatchRequest, ruleRange);
+
+        m_keepAliveSlottedPseudoElementRules.append(WTFMove(slottedPseudoElementRules));
+    }
+}
+
+void ElementRuleCollector::collectMatchingShadowPseudoElementRules(const MatchRequest& matchRequest, StyleResolver::RuleRange& ruleRange)
+{
+    ASSERT(matchRequest.ruleSet);
+    ASSERT(m_element.containingShadowRoot()->mode() == ShadowRootMode::UserAgent);
+
+    auto& rules = *matchRequest.ruleSet;
+#if ENABLE(VIDEO_TRACK)
+    // FXIME: WebVTT should not be done by styling UA shadow trees like this.
+    if (m_element.isWebVTTElement())
+        collectMatchingRulesForList(rules.cuePseudoRules(), matchRequest, ruleRange);
+#endif
+    auto& pseudoId = m_element.shadowPseudoId();
+    if (!pseudoId.isEmpty())
+        collectMatchingRulesForList(rules.shadowPseudoElementRules(pseudoId), matchRequest, ruleRange);
+}
+
+std::unique_ptr<RuleSet::RuleDataVector> ElementRuleCollector::collectSlottedPseudoElementRulesForSlot(bool includeEmptyRules)
+{
+    ASSERT(is<HTMLSlotElement>(m_element));
+
+    clearMatchedRules();
+
+    m_mode = SelectorChecker::Mode::CollectingRules;
+
     // Match global author rules.
-    MatchRequest matchRequest(m_ruleSets.authorStyle(), includeEmptyRules);
+    MatchRequest matchRequest(&m_authorStyle, includeEmptyRules);
     StyleResolver::RuleRange ruleRange = m_result.ranges.authorRuleRange();
-    collectMatchingRules(matchRequest, ruleRange);
-    collectMatchingRulesForRegion(matchRequest, ruleRange);
+    collectMatchingRulesForList(&m_authorStyle.slottedPseudoElementRules(), matchRequest, ruleRange);
 
-    sortAndTransferMatchedRules();
+    if (m_matchedRules.isEmpty())
+        return { };
+
+    auto ruleDataVector = std::make_unique<RuleSet::RuleDataVector>();
+    ruleDataVector->reserveInitialCapacity(m_matchedRules.size());
+    for (auto& matchedRule : m_matchedRules)
+        ruleDataVector->uncheckedAppend(*matchedRule.ruleData);
+
+    return ruleDataVector;
 }
 
 void ElementRuleCollector::matchUserRules(bool includeEmptyRules)
 {
-    if (!m_ruleSets.userStyle())
+    if (!m_userStyle)
         return;
     
     clearMatchedRules();
 
-    m_result.ranges.lastUserRule = m_result.matchedProperties.size() - 1;
-    MatchRequest matchRequest(m_ruleSets.userStyle(), includeEmptyRules);
+    m_result.ranges.lastUserRule = m_result.matchedProperties().size() - 1;
+    MatchRequest matchRequest(m_userStyle, includeEmptyRules);
     StyleResolver::RuleRange ruleRange = m_result.ranges.userRuleRange();
     collectMatchingRules(matchRequest, ruleRange);
     collectMatchingRulesForRegion(matchRequest, ruleRange);
@@ -260,8 +333,6 @@ void ElementRuleCollector::matchUserRules(bool includeEmptyRules)
 
 void ElementRuleCollector::matchUARules()
 {
-    MatchingUARulesScope scope;
-
     // First we match rules from the user agent sheet.
     if (CSSDefaultStyleSheets::simpleDefaultStyleSheet)
         m_result.isCacheable = false;
@@ -270,155 +341,180 @@ void ElementRuleCollector::matchUARules()
     matchUARules(userAgentStyleSheet);
 
     // In quirks mode, we match rules from the quirks user agent sheet.
-    if (document().inQuirksMode())
+    if (m_element.document().inQuirksMode())
         matchUARules(CSSDefaultStyleSheets::defaultQuirksStyle);
-
-    // If document uses view source styles (in view source mode or in xml viewer mode), then we match rules from the view source style sheet.
-    if (document().isViewSource())
-        matchUARules(CSSDefaultStyleSheets::viewSourceStyle());
 }
 
 void ElementRuleCollector::matchUARules(RuleSet* rules)
 {
     clearMatchedRules();
     
-    m_result.ranges.lastUARule = m_result.matchedProperties.size() - 1;
+    m_result.ranges.lastUARule = m_result.matchedProperties().size() - 1;
     StyleResolver::RuleRange ruleRange = m_result.ranges.UARuleRange();
     collectMatchingRules(MatchRequest(rules), ruleRange);
 
     sortAndTransferMatchedRules();
 }
 
-inline bool ElementRuleCollector::ruleMatches(const RuleData& ruleData, PseudoId& dynamicPseudo)
+static const CSSSelector* findSlottedPseudoElementSelector(const CSSSelector* selector)
+{
+    for (; selector; selector = selector->tagHistory()) {
+        if (selector->match() == CSSSelector::PseudoElement && selector->pseudoElementType() == CSSSelector::PseudoElementSlotted) {
+            if (auto* list = selector->selectorList())
+                return list->first();
+            break;
+        }
+    };
+    return nullptr;
+}
+
+inline bool ElementRuleCollector::ruleMatches(const RuleData& ruleData, unsigned& specificity)
 {
-    const StyleResolver::State& state = m_state;
-
-    bool fastCheckableSelector = ruleData.hasFastCheckableSelector();
-    if (fastCheckableSelector) {
-        // We know this selector does not include any pseudo elements.
-        if (m_pseudoStyleRequest.pseudoId != NOPSEUDO)
-            return false;
-        // We know a sufficiently simple single part selector matches simply because we found it from the rule hash.
-        // This is limited to HTML only so we don't need to check the namespace.
-        if (ruleData.hasRightmostSelectorMatchingHTMLBasedOnRuleHash() && state.element()->isHTMLElement()) {
-            if (!ruleData.hasMultipartSelector())
-                return true;
+    // We know a sufficiently simple single part selector matches simply because we found it from the rule hash when filtering the RuleSet.
+    // This is limited to HTML only so we don't need to check the namespace (because of tag name match).
+    MatchBasedOnRuleHash matchBasedOnRuleHash = ruleData.matchBasedOnRuleHash();
+    if (matchBasedOnRuleHash != MatchBasedOnRuleHash::None && m_element.isHTMLElement()) {
+        ASSERT_WITH_MESSAGE(m_pseudoStyleRequest.pseudoId == NOPSEUDO, "If we match based on the rule hash while collecting for a particular pseudo element ID, we would add incorrect rules for that pseudo element ID. We should never end in ruleMatches() with a pseudo element if the ruleData cannot match any pseudo element.");
+
+        switch (matchBasedOnRuleHash) {
+        case MatchBasedOnRuleHash::None:
+            ASSERT_NOT_REACHED();
+            break;
+        case MatchBasedOnRuleHash::Universal:
+            specificity = 0;
+            break;
+        case MatchBasedOnRuleHash::ClassA:
+            specificity = static_cast<unsigned>(SelectorSpecificityIncrement::ClassA);
+            break;
+        case MatchBasedOnRuleHash::ClassB:
+            specificity = static_cast<unsigned>(SelectorSpecificityIncrement::ClassB);
+            break;
+        case MatchBasedOnRuleHash::ClassC:
+            specificity = static_cast<unsigned>(SelectorSpecificityIncrement::ClassC);
+            break;
         }
+        return true;
     }
 
 #if ENABLE(CSS_SELECTOR_JIT)
     void* compiledSelectorChecker = ruleData.compiledSelectorCodeRef().code().executableAddress();
     if (!compiledSelectorChecker && ruleData.compilationStatus() == SelectorCompilationStatus::NotCompiled) {
-        JSC::VM* vm = document().scriptExecutionContext()->vm();
+        JSC::VM& vm = m_element.document().scriptExecutionContext()->vm();
         SelectorCompilationStatus compilationStatus;
         JSC::MacroAssemblerCodeRef compiledSelectorCodeRef;
-        compilationStatus = SelectorCompiler::compileSelector(ruleData.selector(), vm, compiledSelectorCodeRef);
+        compilationStatus = SelectorCompiler::compileSelector(ruleData.selector(), &vm, SelectorCompiler::SelectorContext::RuleCollector, compiledSelectorCodeRef);
 
         ruleData.setCompiledSelector(compilationStatus, compiledSelectorCodeRef);
         compiledSelectorChecker = ruleData.compiledSelectorCodeRef().code().executableAddress();
     }
-    if (compiledSelectorChecker) {
-        if (m_pseudoStyleRequest.pseudoId != NOPSEUDO)
-            return false;
 
-        if (ruleData.compilationStatus() == SelectorCompilationStatus::SimpleSelectorChecker) {
-            SelectorCompiler::SimpleSelectorChecker selectorChecker = SelectorCompiler::simpleSelectorCheckerFunction(compiledSelectorChecker, ruleData.compilationStatus());
-            return selectorChecker(state.element());
-        }
-        ASSERT(ruleData.compilationStatus() == SelectorCompilationStatus::SelectorCheckerWithCheckingContext);
-
-        SelectorCompiler::SelectorCheckerWithCheckingContext selectorChecker = SelectorCompiler::selectorCheckerFunctionWithCheckingContext(compiledSelectorChecker, ruleData.compilationStatus());
-        SelectorCompiler::CheckingContext context;
-        context.elementStyle = state.style();
-        context.resolvingMode = m_mode;
-        return selectorChecker(state.element(), &context);
-    }
-#endif // ENABLE(CSS_SELECTOR_JIT)
+    if (compiledSelectorChecker && ruleData.compilationStatus() == SelectorCompilationStatus::SimpleSelectorChecker) {
+        SelectorCompiler::RuleCollectorSimpleSelectorChecker selectorChecker = SelectorCompiler::ruleCollectorSimpleSelectorCheckerFunction(compiledSelectorChecker, ruleData.compilationStatus());
+#if !ASSERT_MSG_DISABLED
+        unsigned ignoreSpecificity;
+        ASSERT_WITH_MESSAGE(!selectorChecker(&m_element, &ignoreSpecificity) || m_pseudoStyleRequest.pseudoId == NOPSEUDO, "When matching pseudo elements, we should never compile a selector checker without context unless it cannot match anything.");
+#endif
+#if CSS_SELECTOR_JIT_PROFILING
+        ruleData.compiledSelectorUsed();
+#endif
+        bool selectorMatches = selectorChecker(&m_element, &specificity);
 
-    if (fastCheckableSelector) {
-        if (ruleData.selector()->m_match == CSSSelector::Tag && !SelectorChecker::tagMatches(state.element(), ruleData.selector()->tagQName()))
-            return false;
-        SelectorCheckerFastPath selectorCheckerFastPath(ruleData.selector(), state.element());
-        if (!selectorCheckerFastPath.matchesRightmostAttributeSelector())
-            return false;
+        if (selectorMatches && ruleData.containsUncommonAttributeSelector())
+            m_didMatchUncommonAttributeSelector = true;
 
-        return selectorCheckerFastPath.matches();
+        return selectorMatches;
     }
+#endif // ENABLE(CSS_SELECTOR_JIT)
 
-    // Slow path.
-    SelectorChecker selectorChecker(document(), m_mode);
-    SelectorChecker::SelectorCheckingContext context(ruleData.selector(), state.element(), SelectorChecker::VisitedMatchEnabled);
-    context.elementStyle = state.style();
+    SelectorChecker::CheckingContext context(m_mode);
     context.pseudoId = m_pseudoStyleRequest.pseudoId;
     context.scrollbar = m_pseudoStyleRequest.scrollbar;
     context.scrollbarPart = m_pseudoStyleRequest.scrollbarPart;
-    if (!selectorChecker.match(context, dynamicPseudo))
-        return false;
-    if (m_pseudoStyleRequest.pseudoId != NOPSEUDO && m_pseudoStyleRequest.pseudoId != dynamicPseudo)
-        return false;
-    return true;
+    context.isMatchingHostPseudoClass = m_isMatchingHostPseudoClass;
+
+    bool selectorMatches;
+#if ENABLE(CSS_SELECTOR_JIT)
+    if (compiledSelectorChecker) {
+        ASSERT(ruleData.compilationStatus() == SelectorCompilationStatus::SelectorCheckerWithCheckingContext);
+
+        SelectorCompiler::RuleCollectorSelectorCheckerWithCheckingContext selectorChecker = SelectorCompiler::ruleCollectorSelectorCheckerFunctionWithCheckingContext(compiledSelectorChecker, ruleData.compilationStatus());
+
+#if CSS_SELECTOR_JIT_PROFILING
+        ruleData.compiledSelectorUsed();
+#endif
+        selectorMatches = selectorChecker(&m_element, &context, &specificity);
+    } else
+#endif // ENABLE(CSS_SELECTOR_JIT)
+    {
+        auto* selector = ruleData.selector();
+        if (m_isMatchingSlottedPseudoElements) {
+            selector = findSlottedPseudoElementSelector(ruleData.selector());
+            if (!selector)
+                return false;
+        }
+        // Slow path.
+        SelectorChecker selectorChecker(m_element.document());
+        selectorMatches = selectorChecker.match(*selector, m_element, context, specificity);
+    }
+
+    if (ruleData.containsUncommonAttributeSelector()) {
+        if (selectorMatches || context.pseudoIDSet)
+            m_didMatchUncommonAttributeSelector = true;
+    }
+    m_matchedPseudoElementIds.merge(context.pseudoIDSet);
+    m_styleRelations.appendVector(context.styleRelations);
+
+    return selectorMatches;
 }
 
-void ElementRuleCollector::collectMatchingRulesForList(const Vector<RuleData>* rules, const MatchRequest& matchRequest, StyleResolver::RuleRange& ruleRange)
+void ElementRuleCollector::collectMatchingRulesForList(const RuleSet::RuleDataVector* rules, const MatchRequest& matchRequest, StyleResolver::RuleRange& ruleRange)
 {
     if (!rules)
         return;
 
-    const StyleResolver::State& state = m_state;
-
     for (unsigned i = 0, size = rules->size(); i < size; ++i) {
         const RuleData& ruleData = rules->data()[i];
-        if (m_canUseFastReject && m_selectorFilter.fastRejectSelector<RuleData::maximumIdentifierCount>(ruleData.descendantSelectorIdentifierHashes()))
+
+        if (!ruleData.canMatchPseudoElement() && m_pseudoStyleRequest.pseudoId != NOPSEUDO)
+            continue;
+
+        if (m_selectorFilter && m_selectorFilter->fastRejectSelector<RuleData::maximumIdentifierCount>(ruleData.descendantSelectorIdentifierHashes()))
             continue;
 
         StyleRule* rule = ruleData.rule();
-        PseudoId dynamicPseudo = NOPSEUDO;
-        if (ruleMatches(ruleData, dynamicPseudo)) {
-            // For SharingRules testing, any match is good enough, we don't care what is matched.
-            if (m_mode == SelectorChecker::SharingRules) {
-                addMatchedRule(&ruleData);
-                break;
-            }
-
-            // If the rule has no properties to apply, then ignore it in the non-debug mode.
-            const StyleProperties& properties = rule->properties();
-            if (properties.isEmpty() && !matchRequest.includeEmptyRules)
-                continue;
-            // FIXME: Exposing the non-standard getMatchedCSSRules API to web is the only reason this is needed.
-            if (m_sameOriginOnly && !ruleData.hasDocumentSecurityOrigin())
-                continue;
-            // If we're matching normal rules, set a pseudo bit if
-            // we really just matched a pseudo-element.
-            if (dynamicPseudo != NOPSEUDO && m_pseudoStyleRequest.pseudoId == NOPSEUDO) {
-                if (m_mode == SelectorChecker::CollectingRules)
-                    continue;
-                if (dynamicPseudo < FIRST_INTERNAL_PSEUDOID)
-                    state.style()->setHasPseudoStyle(dynamicPseudo);
-            } else {
-                // Update our first/last rule indices in the matched rules array.
-                ++ruleRange.lastRuleIndex;
-                if (ruleRange.firstRuleIndex == -1)
-                    ruleRange.firstRuleIndex = ruleRange.lastRuleIndex;
-
-                // Add this rule to our list of matched rules.
-                addMatchedRule(&ruleData);
-                continue;
-            }
-        }
+
+        // If the rule has no properties to apply, then ignore it in the non-debug mode.
+        // Note that if we get null back here, it means we have a rule with deferred properties,
+        // and that means we always have to consider it.
+        const StyleProperties* properties = rule->propertiesWithoutDeferredParsing();
+        if (properties && properties->isEmpty() && !matchRequest.includeEmptyRules)
+            continue;
+
+        // FIXME: Exposing the non-standard getMatchedCSSRules API to web is the only reason this is needed.
+        if (m_sameOriginOnly && !ruleData.hasDocumentSecurityOrigin())
+            continue;
+
+        unsigned specificity;
+        if (ruleMatches(ruleData, specificity))
+            addMatchedRule(ruleData, specificity, matchRequest.styleScopeOrdinal, ruleRange);
     }
 }
 
-static inline bool compareRules(const RuleData* r1, const RuleData* r2)
+static inline bool compareRules(MatchedRule r1, MatchedRule r2)
 {
-    unsigned specificity1 = r1->specificity();
-    unsigned specificity2 = r2->specificity();
-    return (specificity1 == specificity2) ? r1->position() < r2->position() : specificity1 < specificity2;
+    // For normal properties the earlier scope wins. This may be reversed by !important which is handled when resolving cascade.
+    if (r1.styleScopeOrdinal != r2.styleScopeOrdinal)
+        return r1.styleScopeOrdinal > r2.styleScopeOrdinal;
+
+    if (r1.specificity != r2.specificity)
+        return r1.specificity < r2.specificity;
+
+    return r1.ruleData->position() < r2.ruleData->position();
 }
 
 void ElementRuleCollector::sortMatchedRules()
 {
-    ASSERT(m_matchedRules);
-    std::sort(m_matchedRules->begin(), m_matchedRules->end(), compareRules);
+    std::sort(m_matchedRules.begin(), m_matchedRules.end(), compareRules);
 }
 
 void ElementRuleCollector::matchAllRules(bool matchAuthorAndUserStyles, bool includeSMILProperties)
@@ -430,17 +526,18 @@ void ElementRuleCollector::matchAllRules(bool matchAuthorAndUserStyles, bool inc
         matchUserRules(false);
 
     // Now check author rules, beginning first with presentational attributes mapped from HTML.
-    if (m_state.styledElement()) {
-        addElementStyleProperties(m_state.styledElement()->presentationAttributeStyle());
+    if (is<StyledElement>(m_element)) {
+        auto& styledElement = downcast<StyledElement>(m_element);
+        addElementStyleProperties(styledElement.presentationAttributeStyle());
 
         // Now we check additional mapped declarations.
         // Tables and table cells share an additional mapped rule that must be applied
         // after all attributes, since their mapped style depends on the values of multiple attributes.
-        addElementStyleProperties(m_state.styledElement()->additionalPresentationAttributeStyle());
+        addElementStyleProperties(styledElement.additionalPresentationAttributeStyle());
 
-        if (m_state.styledElement()->isHTMLElement()) {
+        if (is<HTMLElement>(styledElement)) {
             bool isAuto;
-            TextDirection textDirection = toHTMLElement(m_state.styledElement())->directionalityIfhasDirAutoAttribute(isAuto);
+            TextDirection textDirection = downcast<HTMLElement>(styledElement).directionalityIfhasDirAutoAttribute(isAuto);
             if (isAuto)
                 m_result.addMatchedProperties(textDirection == LTR ? leftToRightDeclaration() : rightToLeftDeclaration());
         }
@@ -450,34 +547,33 @@ void ElementRuleCollector::matchAllRules(bool matchAuthorAndUserStyles, bool inc
     if (matchAuthorAndUserStyles)
         matchAuthorRules(false);
 
-    // Now check our inline style attribute.
-    if (matchAuthorAndUserStyles && m_state.styledElement() && m_state.styledElement()->inlineStyle()) {
-        // Inline style is immutable as long as there is no CSSOM wrapper.
-        // FIXME: Media control shadow trees seem to have problems with caching.
-        bool isInlineStyleCacheable = !m_state.styledElement()->inlineStyle()->isMutable() && !m_state.styledElement()->isInShadowTree();
-        // FIXME: Constify.
-        addElementStyleProperties(m_state.styledElement()->inlineStyle(), isInlineStyleCacheable);
-    }
+    if (matchAuthorAndUserStyles && is<StyledElement>(m_element)) {
+        auto& styledElement = downcast<StyledElement>(m_element);
+        // Now check our inline style attribute.
+        if (styledElement.inlineStyle()) {
+            // Inline style is immutable as long as there is no CSSOM wrapper.
+            // FIXME: Media control shadow trees seem to have problems with caching.
+            bool isInlineStyleCacheable = !styledElement.inlineStyle()->isMutable() && !styledElement.isInShadowTree();
+            // FIXME: Constify.
+            addElementStyleProperties(styledElement.inlineStyle(), isInlineStyleCacheable);
+        }
 
-#if ENABLE(SVG)
-    // Now check SMIL animation override style.
-    if (includeSMILProperties && matchAuthorAndUserStyles && m_state.styledElement() && m_state.styledElement()->isSVGElement())
-        addElementStyleProperties(toSVGElement(m_state.styledElement())->animatedSMILStyleProperties(), false /* isCacheable */);
-#else
-    UNUSED_PARAM(includeSMILProperties);
-#endif
+        // Now check SMIL animation override style.
+        if (includeSMILProperties && is<SVGElement>(styledElement))
+            addElementStyleProperties(downcast<SVGElement>(styledElement).animatedSMILStyleProperties(), false /* isCacheable */);
+    }
 }
 
-bool ElementRuleCollector::hasAnyMatchingRules(RuleSet* ruleSet)
+bool ElementRuleCollector::hasAnyMatchingRules(const RuleSet* ruleSet)
 {
     clearMatchedRules();
 
-    m_mode = SelectorChecker::SharingRules;
+    m_mode = SelectorChecker::Mode::CollectingRulesIgnoringVirtualPseudoElements;
     int firstRuleIndex = -1, lastRuleIndex = -1;
     StyleResolver::RuleRange ruleRange(firstRuleIndex, lastRuleIndex);
     collectMatchingRules(MatchRequest(ruleSet), ruleRange);
 
-    return m_matchedRules && !m_matchedRules->isEmpty();
+    return !m_matchedRules.isEmpty();
 }
 
 } // namespace WebCore