Bug 1404897: Implement Element.matches using stylo. r=heycam

MozReview-Commit-ID: 7nxYVcweu0W

--HG--
extra : rebase_source : e660504ba8ec2be7d678049000cb76018dc4ba5e

dom/base/Element.cpp

@@ -3496,21 +3496,31 @@ Element::Closest(const nsAString& aSelector, ErrorResult& aResult)
 bool
 Element::Matches(const nsAString& aSelector, ErrorResult& aError)
 {
-  nsCSSSelectorList* selectorList = ParseSelectorList(aSelector, aError);
-  if (!selectorList) {
-    // Either we failed (and aError already has the exception), or this
-    // is a pseudo-element-only selector that matches nothing.
-    return false;
-  }
-
-  TreeMatchContext matchingContext(false,
-                                   nsRuleWalker::eRelevantLinkUnvisited,
-                                   OwnerDoc(),
-                                   TreeMatchContext::eNeverMatchVisited);
-  matchingContext.SetHasSpecifiedScope();
-  matchingContext.AddScopeElement(this);
-  return nsCSSRuleProcessor::SelectorListMatches(this, matchingContext,
-                                                 selectorList);
+  return WithSelectorList<bool>(
+    aSelector,
+    aError,
+    [&](const RawServoSelectorList* aList) {
+      if (!aList) {
+        return false;
+      }
+      return Servo_SelectorList_Matches(this, aList);
+    },
+    [&](nsCSSSelectorList* aList) {
+      if (!aList) {
+        // Either we failed (and aError already has the exception), or this
+        // is a pseudo-element-only selector that matches nothing.
+        return false;
+      }
+      TreeMatchContext matchingContext(false,
+                                       nsRuleWalker::eRelevantLinkUnvisited,
+                                       OwnerDoc(),
+                                       TreeMatchContext::eNeverMatchVisited);
+      matchingContext.SetHasSpecifiedScope();
+      matchingContext.AddScopeElement(this);
+      return nsCSSRuleProcessor::SelectorListMatches(this, matchingContext,
+                                                     aList);
+    }
+  );
 }
 
 static const nsAttrValue::EnumTable kCORSAttributeTable[] = {

dom/base/nsINode.cpp

@@ -2676,6 +2676,47 @@ nsINode::Length() const
   }
 }
 
+const RawServoSelectorList*
+nsINode::ParseServoSelectorList(
+  const nsAString& aSelectorString,
+  ErrorResult& aRv)
+{
+  nsIDocument* doc = OwnerDoc();
+  MOZ_ASSERT(doc->IsStyledByServo());
+
+  nsIDocument::SelectorCache& cache = doc->GetSelectorCache();
+  nsIDocument::SelectorCache::SelectorList* list =
+    cache.GetList(aSelectorString);
+  if (list) {
+    if (!*list) {
+      // Invalid selector.
+      aRv.ThrowDOMException(NS_ERROR_DOM_SYNTAX_ERR,
+        NS_LITERAL_CSTRING("'") + NS_ConvertUTF16toUTF8(aSelectorString) +
+        NS_LITERAL_CSTRING("' is not a valid selector")
+      );
+    }
+
+    // FIXME(emilio): Make this private and use `WithSelectorList` everywhere,
+    // then assert.
+    if (list->IsServo()) {
+      return list->AsServo();
+    }
+  }
+
+  NS_ConvertUTF16toUTF8 selectorString(aSelectorString);
+
+  auto* selectorList = Servo_SelectorList_Parse(&selectorString);
+  if (!selectorList) {
+    aRv.ThrowDOMException(NS_ERROR_DOM_SYNTAX_ERR,
+      NS_LITERAL_CSTRING("'") + selectorString +
+      NS_LITERAL_CSTRING("' is not a valid selector")
+    );
+  }
+
+  cache.CacheList(aSelectorString, UniquePtr<RawServoSelectorList>(selectorList));
+  return selectorList;
+}
+
 nsCSSSelectorList*
 nsINode::ParseSelectorList(const nsAString& aSelectorString,
                            ErrorResult& aRv)
@@ -2692,8 +2733,12 @@ nsINode::ParseSelectorList(const nsAString& aSelectorString,
         NS_LITERAL_CSTRING("' is not a valid selector")
       );
     }
-    MOZ_ASSERT(list->IsGecko(), "We haven't done anything with Servo yet");
-    return list->AsGecko();
+
+    // FIXME(emilio): Make this private and use `WithSelectorList` everywhere,
+    // then assert.
+    if (list->IsGecko()) {
+      return list->AsGecko();
+    }
   }
 
   nsCSSParser parser(doc->CSSLoader());

dom/base/nsINode.h

@@ -55,6 +55,7 @@ class nsNodeSupportsWeakRefTearoff;
 class nsNodeWeakReference;
 class nsDOMMutationObserver;
 class nsRange;
+struct RawServoSelectorList;
 
 namespace mozilla {
 class EventListenerManager;
@@ -2066,10 +2067,46 @@ protected:
    * contained pseudo-element selectors.
    *
    * A failing aRv means the string was not a valid selector.
+   *
+   * Note that the selector list returned here is owned by the owner doc's
+   * selector cache.
    */
   nsCSSSelectorList* ParseSelectorList(const nsAString& aSelectorString,
                                        mozilla::ErrorResult& aRv);
 
+  /**
+   * Parse the given selector string into a servo SelectorList.
+   *
+   * Never returns null if aRv is not failing.
+   *
+   * Note that the selector list returned here is owned by the owner doc's
+   * selector cache.
+   */
+  const RawServoSelectorList* ParseServoSelectorList(
+    const nsAString& aSelectorString,
+    mozilla::ErrorResult& aRv);
+
+  /**
+   * Parse the given selector string into a SelectorList.
+   *
+   * A null return value with a non-failing aRv means the string only
+   * contained pseudo-element selectors.
+   *
+   * A failing aRv means the string was not a valid selector.
+   */
+  template<typename Ret, typename ServoFunctor, typename GeckoFunctor>
+  Ret WithSelectorList(
+    const nsAString& aSelectorString,
+    mozilla::ErrorResult& aRv,
+    const ServoFunctor& aServoFunctor,
+    const GeckoFunctor& aGeckoFunctor)
+  {
+    if (IsStyledByServo()) {
+      return aServoFunctor(ParseServoSelectorList(aSelectorString, aRv));
+    }
+    return aGeckoFunctor(ParseSelectorList(aSelectorString, aRv));
+  }
+
 public:
   /* Event stuff that documents and elements share.  This needs to be
      NS_IMETHOD because some subclasses implement DOM methods with