Skip child ShadowRoots when invalidation does not have boundary crossing rules

Source/core/css/RuleFeature.cpp

 /*
  * 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 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/)
  * Copyright (c) 2011, Code Aurora Forum. All rights reserved.
  * Copyright (C) Research In Motion Limited 2011. All rights reserved.
@@ skipping 189 matching lines @@
     return 0;
 }
 
 RuleFeatureSet::InvalidationSetMode RuleFeatureSet::updateInvalidationSets(const CSSSelector& selector)
 {
     InvalidationSetMode mode = invalidationSetModeForSelector(selector);
     if (mode != AddFeatures)
         return mode;
 
     InvalidationSetFeatures features;
-    const CSSSelector* current = extractInvalidationSetFeatures(selector, features);
-    if (current) {
-        bool wholeSubtree = current->relation() == CSSSelector::DirectAdjacent || current->relation() == CSSSelector::IndirectAdjacent;
-        current = current->tagHistory();
-        if (current)
-            addFeaturesToInvalidationSets(*current, features, wholeSubtree);
-    }
+    if (const CSSSelector* current = extractInvalidationSetFeatures(selector, features))
+        addFeaturesToInvalidationSets(*current, features);
     return AddFeatures;
 }
 
 const CSSSelector* RuleFeatureSet::extractInvalidationSetFeatures(const CSSSelector& selector, InvalidationSetFeatures& features)
 {
     const CSSSelector* lastSelector = &selector;
     for (; lastSelector; lastSelector = lastSelector->tagHistory()) {
         extractInvalidationSetFeature(*lastSelector, features);
         // Initialize the entry in the invalidation set map, if supported.
         invalidationSetForSelector(*lastSelector);
         if (lastSelector->pseudoType() == CSSSelector::PseudoHost || lastSelector->pseudoType() == CSSSelector::PseudoAny) {
             if (const CSSSelectorList* selectorList = lastSelector->selectorList()) {
                 for (const CSSSelector* selector = selectorList->first(); selector; selector = CSSSelectorList::next(*selector))
                     extractInvalidationSetFeatures(*selector, features);
             }
         }
 
+        if (lastSelector->relation() == CSSSelector::ShadowPseudo || lastSelector->relation() == CSSSelector::ShadowDeep)
+            features.treeBoundaryCrossing = true;
+        else if (lastSelector->relation() == CSSSelector::DirectAdjacent || lastSelector->relation() == CSSSelector::IndirectAdjacent)
+            features.wholeSubtree = true;
+
         if (lastSelector->relation() != CSSSelector::SubSelector)
             break;
     }
-    return lastSelector;
+    if (lastSelector)
+        return lastSelector->tagHistory();
+    return 0;
 }
 
-void RuleFeatureSet::addFeaturesToInvalidationSets(const CSSSelector& selector, const InvalidationSetFeatures& features, bool wholeSubtree)
+void RuleFeatureSet::addFeaturesToInvalidationSets(const CSSSelector& selector, InvalidationSetFeatures& features)
 {
     for (const CSSSelector* current = &selector; current; current = current->tagHistory()) {
         if (DescendantInvalidationSet* invalidationSet = invalidationSetForSelector(*current)) {
-            if (wholeSubtree) {
+            if (features.treeBoundaryCrossing)
+                invalidationSet->setTreeBoundaryCrossing();
+            if (features.wholeSubtree) {
                 invalidationSet->setWholeSubtreeInvalid();
             } else {
                 if (!features.id.isEmpty())
                     invalidationSet->addId(features.id);
                 if (!features.tagName.isEmpty())
                     invalidationSet->addTagName(features.tagName);
                 for (Vector<AtomicString>::const_iterator it = features.classes.begin(); it != features.classes.end(); ++it)
                     invalidationSet->addClass(*it);
                 for (Vector<AtomicString>::const_iterator it = features.attributes.begin(); it != features.attributes.end(); ++it)
                     invalidationSet->addAttribute(*it);
                 if (features.customPseudoElement)
                     invalidationSet->setCustomPseudoInvalid();
             }
         } else if (current->pseudoType() == CSSSelector::PseudoHost || current->pseudoType() == CSSSelector::PseudoAny) {
+            if (current->pseudoType() == CSSSelector::PseudoHost)
+                features.treeBoundaryCrossing = true;
             if (const CSSSelectorList* selectorList = current->selectorList()) {
                 for (const CSSSelector* selector = selectorList->first(); selector; selector = CSSSelectorList::next(*selector))
-                    addFeaturesToInvalidationSets(*selector, features, wholeSubtree);
+                    addFeaturesToInvalidationSets(*selector, features);
             }
         }
         switch (current->relation()) {
         case CSSSelector::Descendant:
         case CSSSelector::Child:
+            features.wholeSubtree = false;

[chrishtr, 2014/05/29 20:54:07]

Why this change?

[esprehn, 2014/05/29 21:07:30]

Because I can't handle all 4 types of relations the same way anymore.

[chrishtr, 2014/05/29 21:43:43]

Ah right, fallthrough.

+            break;
         case CSSSelector::ShadowPseudo:
         case CSSSelector::ShadowDeep:
-            wholeSubtree = false;
+            features.treeBoundaryCrossing = true;
+            features.wholeSubtree = false;

[chrishtr, 2014/05/29 20:54:07]

I don't get why it's ok to set wholeSubtree to false here.

[esprehn, 2014/05/29 21:07:30]

We always did that, see the old code. I just split the two cases apart so that
ShadowPseudo/ShadowDeep set both wholeSubtree and treeBoundaryCrossing, and
DirectAdjacent/IndirectAdjacent only set wholeSubtree.

[chrishtr, 2014/05/29 21:43:43]

Oh right.

[chrishtr, 2014/05/29 21:43:43]

Ok.

[rune, 2014/05/30 21:02:45]

FTR, it's because these shadow combinators are like descendant combinators, and
wholeSubtree in this context is about adjacent combinators requiring
wholeSubtree because the features of the rightmost compound selector are not of
a descendant. That is however canceled out as encountering a descendant-like
combinator will make the rightmost compound selector start matching a descendant
again.

.a /deep/ .b + .c // .c not a descendant of .b, but .c a descendant of .a

             break;
         case CSSSelector::DirectAdjacent:
         case CSSSelector::IndirectAdjacent:
-            wholeSubtree = true;
+            features.wholeSubtree = true;
             break;
         case CSSSelector::SubSelector:
             break;
-        default:
-            // All combinators should be handled above.
-            ASSERT_NOT_REACHED();
-            break;
         }
     }
 }
 
 void RuleFeatureSet::addContentAttr(const AtomicString& attributeName)
 {
     DescendantInvalidationSet& invalidationSet = ensureAttributeInvalidationSet(attributeName);
     invalidationSet.setWholeSubtreeInvalid();
 }
 
@@ skipping 217 matching lines @@
     visitor->trace(siblingRules);
     visitor->trace(uncommonAttributeRules);
     visitor->trace(m_classInvalidationSets);
     visitor->trace(m_attributeInvalidationSets);
     visitor->trace(m_idInvalidationSets);
     visitor->trace(m_pseudoInvalidationSets);
     visitor->trace(m_styleInvalidator);
 }
 
 } // namespace WebCore