vue: avoid recursion in getting tag's descriptor

- reuse solution from angular, extract code into common place
- in XmlTagImpl, use RecursionGuard because it is very likely to have such problems with some other tag & descriptor combinations

EA-116625 - SOE: FlexMxmlNSDescriptor.getElementDescriptor

xml/xml-psi-impl/src/com/intellij/psi/impl/source/xml/XmlDescriptorUtil.java

@@ -0,0 +1,45 @@
+// Copyright 2000-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
+package com.intellij.psi.impl.source.xml;
+
+import com.intellij.html.impl.DelegatingRelaxedHtmlElementDescriptor;
+import com.intellij.psi.util.PsiTreeUtil;
+import com.intellij.psi.xml.XmlDocument;
+import com.intellij.psi.xml.XmlTag;
+import com.intellij.util.containers.ContainerUtil;
+import com.intellij.xml.XmlElementDescriptor;
+import com.intellij.xml.XmlNSDescriptor;
+import com.intellij.xml.XmlNSDescriptorEx;
+import org.jetbrains.annotations.NotNull;
+
+import static com.intellij.xml.XmlElementDescriptor.EMPTY_ARRAY;
+
+/**
+ * @author Irina.Chernushina on 3/21/2018.
+ */
+public class XmlDescriptorUtil {
+  public static XmlElementDescriptor[] getElementsDescriptors(XmlTag context) {
+    XmlDocumentImpl xmlDocument = PsiTreeUtil.getParentOfType(context, XmlDocumentImpl.class);
+    if (xmlDocument == null) return EMPTY_ARRAY;
+    return ContainerUtil.map2Array(xmlDocument.getRootTagNSDescriptor().getRootElementsDescriptors(xmlDocument),
+                                   XmlElementDescriptor.class, descriptor -> wrapInDelegating(descriptor));
+  }
+
+  public static XmlElementDescriptor getElementDescriptor(XmlTag childTag, XmlTag contextTag) {
+    final XmlDocument document = PsiTreeUtil.getParentOfType(contextTag, XmlDocument.class);
+    if (document == null) {
+      return null;
+    }
+    final XmlNSDescriptor nsDescriptor = document.getDefaultNSDescriptor(childTag.getNamespace(), true);
+    if (nsDescriptor instanceof XmlNSDescriptorEx) {
+      XmlElementDescriptor descriptor = ((XmlNSDescriptorEx)nsDescriptor).getElementDescriptor(childTag.getLocalName(), childTag.getNamespace());
+      return descriptor != null ? wrapInDelegating(descriptor) : null;
+    }
+    return null;
+  }
+
+  @NotNull
+  public static DelegatingRelaxedHtmlElementDescriptor wrapInDelegating(XmlElementDescriptor descriptor) {
+    return descriptor instanceof DelegatingRelaxedHtmlElementDescriptor ? (DelegatingRelaxedHtmlElementDescriptor)descriptor :
+           new DelegatingRelaxedHtmlElementDescriptor(descriptor);
+  }
+}

xml/xml-psi-impl/src/com/intellij/psi/impl/source/xml/XmlTagImpl.java

@@ -1,18 +1,4 @@
-/*
- * Copyright 2000-2013 JetBrains s.r.o.
- *
- * Licensed under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
+// Copyright 2000-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
 package com.intellij.psi.impl.source.xml;
 
 import com.intellij.javaee.ExternalResourceManager;
@@ -494,9 +480,15 @@ public class XmlTagImpl extends XmlElementImpl implements XmlTag, HintedReferenc
 
   @Override
   public XmlElementDescriptor getDescriptor() {
-    return CachedValuesManager.getCachedValue(this, () ->
-      Result.create(computeElementDescriptor(),
-                                        PsiModificationTracker.MODIFICATION_COUNT, externalResourceModificationTracker()));
+    return CachedValuesManager.getCachedValue(this, () -> {
+      final RecursionGuard.StackStamp stamp = ourGuard.markStack();
+      final XmlElementDescriptor descriptor = ourGuard.doPreventingRecursion(this, true, this::computeElementDescriptor);
+      if (stamp.mayCacheNow()) {
+        return Result.create(descriptor, PsiModificationTracker.MODIFICATION_COUNT, externalResourceModificationTracker());
+      }
+      // = do not cache
+      return Result.create(descriptor, ModificationTracker.EVER_CHANGED);
+    });
   }
 
   private ModificationTracker externalResourceModificationTracker() {