java: annotation parsing avoided for simple cases

(optimization + Kotlin compatibility)

java/java-psi-impl/src/com/intellij/psi/impl/compiled/ClsAnnotationImpl.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2000-2013 JetBrains s.r.o.
+ * Copyright 2000-2015 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.
@@ -44,23 +44,27 @@ public class ClsAnnotationImpl extends ClsRepositoryPsiElement<PsiAnnotationStub
       @NotNull
       @Override
       protected ClsJavaCodeReferenceElementImpl compute() {
-        String text = PsiTreeUtil.getRequiredChildOfType(getStub().getPsiElement(), PsiJavaCodeReferenceElement.class).getText();
-        return new ClsJavaCodeReferenceElementImpl(ClsAnnotationImpl.this, text);
+        String annotationText = getStub().getText();
+        int index = annotationText.indexOf('(');
+        String refText = index > 0 ? annotationText.substring(1, index) : annotationText.substring(1);
+        return new ClsJavaCodeReferenceElementImpl(ClsAnnotationImpl.this, refText);
       }
     };
     myParameterList = new AtomicNotNullLazyValue<ClsAnnotationParameterListImpl>() {
       @NotNull
       @Override
       protected ClsAnnotationParameterListImpl compute() {
-        PsiAnnotationParameterList paramList = PsiTreeUtil.getRequiredChildOfType(getStub().getPsiElement(), PsiAnnotationParameterList.class);
-        return new ClsAnnotationParameterListImpl(ClsAnnotationImpl.this, paramList.getAttributes());
+        PsiNameValuePair[] attrs = getStub().getText().indexOf('(') > 0
+            ? PsiTreeUtil.getRequiredChildOfType(getStub().getPsiElement(), PsiAnnotationParameterList.class).getAttributes()
+            : PsiNameValuePair.EMPTY_ARRAY;
+        return new ClsAnnotationParameterListImpl(ClsAnnotationImpl.this, attrs);
       }
     };
   }
 
   @Override
   public void appendMirrorText(int indentLevel, @NotNull StringBuilder buffer) {
-    buffer.append("@").append(myReferenceElement.getValue().getCanonicalText());
+    buffer.append('@').append(myReferenceElement.getValue().getCanonicalText());
     appendText(getParameterList(), indentLevel, buffer);
   }
 

java/java-tests/testSrc/com/intellij/psi/ClsPsiTest.java

@@ -0,0 +1,43 @@
+/*
+ * Copyright 2000-2015 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.
+ */
+package com.intellij.psi;
+
+import com.intellij.openapi.application.ex.PathManagerEx;
+import com.intellij.openapi.vfs.LocalFileSystem;
+import com.intellij.openapi.vfs.VirtualFile;
+import com.intellij.psi.impl.compiled.ClsFileImpl;
+import com.intellij.testFramework.LightIdeaTestCase;
+
+public class ClsPsiTest extends LightIdeaTestCase {
+  public void testKeywordAnnotatedClass() {
+    PsiModifierList modList = getFile().getClasses()[0].getModifierList();
+    assertNotNull(modList);
+    assertEquals("@pkg.native", modList.getAnnotations()[0].getText());
+  }
+
+  private PsiJavaFile getFile() {
+    return getFile(getTestName(false));
+  }
+
+  private static PsiJavaFile getFile(String name) {
+    String path = PathManagerEx.getTestDataPath() + "/psi/cls/tree/" + name + ".class";
+    VirtualFile file = LocalFileSystem.getInstance().findFileByPath(path);
+    assertNotNull(path, file);
+    PsiFile clsFile = PsiManager.getInstance(getProject()).findFile(file);
+    assertTrue(String.valueOf(clsFile), clsFile instanceof ClsFileImpl);
+    return (PsiJavaFile)clsFile;
+  }
+}