notNull

java/java-psi-api/src/com/intellij/psi/stubs/PsiClassHolderFileStub.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2000-2015 JetBrains s.r.o.
+ * Copyright 2000-2016 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.
@@ -17,10 +17,12 @@ package com.intellij.psi.stubs;
 
 import com.intellij.psi.PsiClass;
 import com.intellij.psi.PsiFile;
+import org.jetbrains.annotations.NotNull;
 
 /**
  * @author ilyas
  */
 public interface PsiClassHolderFileStub<T extends PsiFile> extends PsiFileStub<T> {
+  @NotNull
   PsiClass[] getClasses();
 }

java/java-psi-impl/src/com/intellij/psi/impl/java/stubs/JavaClassElementType.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2000-2013 JetBrains s.r.o.
+ * Copyright 2000-2016 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.
@@ -208,7 +208,7 @@ public abstract class JavaClassElementType extends JavaStubElementType<PsiClassS
   }
 
   @Override
-  public String getId(final PsiClassStub stub) {
+  public String getId(@NotNull final PsiClassStub stub) {
     final String name = stub.getName();
     return name != null ? name : super.getId(stub);
   }

java/java-psi-impl/src/com/intellij/psi/impl/java/stubs/impl/PsiJavaFileStubImpl.java

@@ -21,6 +21,7 @@ import com.intellij.psi.impl.java.stubs.*;
 import com.intellij.psi.stubs.PsiFileStubImpl;
 import com.intellij.psi.tree.IStubFileElementType;
 import com.intellij.util.io.StringRef;
+import org.jetbrains.annotations.NotNull;
 
 /**
  * @author max
@@ -41,11 +42,13 @@ public class PsiJavaFileStubImpl extends PsiFileStubImpl<PsiJavaFile> implements
     this(null, StringRef.fromString(packageName), compiled);
   }
 
+  @NotNull
   @Override
   public IStubFileElementType getType() {
     return JavaStubElementTypes.JAVA_FILE;
   }
 
+  @NotNull
   @Override
   public PsiClass[] getClasses() {
     return getChildrenByType(JavaStubElementTypes.CLASS, PsiClass.ARRAY_FACTORY);

platform/core-api/src/com/intellij/psi/stubs/BinaryFileStubBuilder.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2000-2009 JetBrains s.r.o.
+ * Copyright 2000-2016 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.
@@ -21,13 +21,14 @@ package com.intellij.psi.stubs;
 
 import com.intellij.openapi.vfs.VirtualFile;
 import com.intellij.util.indexing.FileContent;
+import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
 /**
  * @see com.intellij.psi.stubs.BinaryFileStubBuilders#EXTENSION_POINT_NAME
  */
 public interface BinaryFileStubBuilder {
-  boolean acceptsFile(VirtualFile file);
+  boolean acceptsFile(@NotNull VirtualFile file);
 
   @Nullable
   Stub buildStubTree(FileContent fileContent);

platform/core-api/src/com/intellij/psi/stubs/IStubElementType.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2000-2009 JetBrains s.r.o.
+ * Copyright 2000-2016 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.
@@ -40,7 +40,7 @@ public abstract class IStubElementType<StubT extends StubElement, PsiT extends P
     return true;
   }
 
-  public String getId(StubT stub) {
+  public String getId(@NotNull StubT stub) {
     assert stub.getStubType() == this;
 
     final StubElement parent = stub.getParentStub();

platform/core-api/src/com/intellij/psi/stubs/ObjectStubBase.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2000-2012 JetBrains s.r.o.
+ * Copyright 2000-2016 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.
@@ -30,6 +30,7 @@ public abstract class ObjectStubBase<T extends Stub>  extends UserDataHolderBase
     myParent = parent;
   }
 
+  @Override
   public T getParentStub() {
     return myParent;
   }

platform/core-api/src/com/intellij/psi/stubs/PsiFileStub.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2000-2009 JetBrains s.r.o.
+ * Copyright 2000-2016 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.
@@ -28,6 +28,7 @@ import org.jetbrains.annotations.Nullable;
 public interface PsiFileStub<T extends PsiFile> extends StubElement<T>, UserDataHolder {
   PsiFileStub[] EMPTY_ARRAY = new PsiFileStub[0];
 
+  @NotNull
   StubFileElementType getType();
 
   @NotNull

platform/core-api/src/com/intellij/psi/stubs/Stub.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2000-2012 JetBrains s.r.o.
+ * Copyright 2000-2016 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.
@@ -15,6 +15,8 @@
  */
 package com.intellij.psi.stubs;
 
+import org.jetbrains.annotations.NotNull;
+
 import java.util.List;
 
 /**
@@ -22,8 +24,8 @@ import java.util.List;
  *         Date: 8/2/12
  */
 public interface Stub {
-
   Stub getParentStub();
+  @NotNull
   List<? extends Stub> getChildrenStubs();
   ObjectStubSerializer getStubType();
 

platform/core-api/src/com/intellij/psi/stubs/StubBase.java

@@ -64,7 +64,7 @@ public abstract class StubBase<T extends PsiElement> extends ObjectStubBase<Stub
 
   @Override
   @Nullable
-  public <P extends PsiElement> StubElement<P> findChildStubByType(final IStubElementType<?, P> elementType) {
+  public <P extends PsiElement> StubElement<P> findChildStubByType(@NotNull final IStubElementType<?, P> elementType) {
     final List<StubElement> childrenStubs = getChildrenStubs();
     final int size = childrenStubs.size();
 
@@ -102,6 +102,7 @@ public abstract class StubBase<T extends PsiElement> extends ObjectStubBase<Stub
   }
 
 
+  @NotNull
   @Override
   public <E extends PsiElement> E[] getChildrenByType(@NotNull final IElementType elementType, E[] array) {
     final int count = countChildren(elementType);
@@ -113,6 +114,7 @@ public abstract class StubBase<T extends PsiElement> extends ObjectStubBase<Stub
     return array;
   }
 
+  @NotNull
   @Override
   public <E extends PsiElement> E[] getChildrenByType(@NotNull final TokenSet filter, E[] array) {
     final int count = countChildren(filter);
@@ -124,6 +126,7 @@ public abstract class StubBase<T extends PsiElement> extends ObjectStubBase<Stub
     return array;
   }
 
+  @NotNull
   @Override
   public <E extends PsiElement> E[] getChildrenByType(@NotNull final IElementType elementType, @NotNull final ArrayFactory<E> f) {
     int count = countChildren(elementType);
@@ -182,6 +185,7 @@ public abstract class StubBase<T extends PsiElement> extends ObjectStubBase<Stub
     assert count == result.length;
   }
 
+  @NotNull
   @Override
   public <E extends PsiElement> E[] getChildrenByType(@NotNull final TokenSet filter, @NotNull final ArrayFactory<E> f) {
     final int count = countChildren(filter);

platform/core-api/src/com/intellij/psi/stubs/StubElement.java

@@ -38,14 +38,18 @@ public interface StubElement<T extends PsiElement> extends Stub {
   List<StubElement> getChildrenStubs();
 
   @Nullable
-  <P extends PsiElement> StubElement<P> findChildStubByType(IStubElementType<?, P> elementType);
+  <P extends PsiElement> StubElement<P> findChildStubByType(@NotNull IStubElementType<?, P> elementType);
 
   T getPsi();
 
+  @NotNull
   <E extends PsiElement> E[] getChildrenByType(@NotNull IElementType elementType, final E[] array);
+  @NotNull
   <E extends PsiElement> E[] getChildrenByType(@NotNull TokenSet filter, final E[] array);
 
+  @NotNull
   <E extends PsiElement> E[] getChildrenByType(@NotNull IElementType elementType, @NotNull ArrayFactory<E> f);
+  @NotNull
   <E extends PsiElement> E[] getChildrenByType(@NotNull TokenSet filter, @NotNull ArrayFactory<E> f);
 
   @Nullable

platform/core-api/src/com/intellij/psi/stubs/StubIndexKey.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2000-2009 JetBrains s.r.o.
+ * Copyright 2000-2016 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.
@@ -22,13 +22,15 @@ package com.intellij.psi.stubs;
 import com.intellij.psi.PsiElement;
 import com.intellij.util.indexing.ID;
 import org.jetbrains.annotations.NonNls;
+import org.jetbrains.annotations.NotNull;
 
 public final class StubIndexKey<K, Psi extends PsiElement> extends ID<K, Psi> {
   private StubIndexKey(@NonNls String name) {
     super(name);
   }
 
-  public static synchronized <K, Psi extends PsiElement> StubIndexKey<K, Psi> createIndexKey(@NonNls String name) {
+  @NotNull
+  public static synchronized <K, Psi extends PsiElement> StubIndexKey<K, Psi> createIndexKey(@NonNls @NotNull String name) {
     return new StubIndexKey<K, Psi>(name);
   }
 

platform/core-api/src/com/intellij/psi/stubs/StubOutputStream.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2000-2012 JetBrains s.r.o.
+ * Copyright 2000-2016 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.
@@ -15,7 +15,10 @@
  */
 package com.intellij.psi.stubs;
 
-import com.intellij.util.io.*;
+import com.intellij.util.io.AbstractStringEnumerator;
+import com.intellij.util.io.DataInputOutputUtil;
+import com.intellij.util.io.DataOutputStream;
+import com.intellij.util.io.IOUtil;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
@@ -29,7 +32,7 @@ public class StubOutputStream extends DataOutputStream {
   private final AbstractStringEnumerator myNameStorage;
   private final byte[] myStringIOBuffer = IOUtil.allocReadWriteUTFBuffer();
 
-  public StubOutputStream(OutputStream out, AbstractStringEnumerator nameStorage) {
+  public StubOutputStream(@NotNull OutputStream out, @NotNull AbstractStringEnumerator nameStorage) {
     super(out);
     myNameStorage = nameStorage;
   }

platform/core-api/src/com/intellij/psi/stubs/StubSerializationUtil.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2000-2012 JetBrains s.r.o.
+ * Copyright 2000-2016 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.
@@ -15,13 +15,15 @@
  */
 package com.intellij.psi.stubs;
 
+import org.jetbrains.annotations.NotNull;
+
 /**
  * Author: dmitrylomov
  */
 public abstract class StubSerializationUtil {
   private StubSerializationUtil() {}
 
-  public static ObjectStubSerializer getSerializer(Stub rootStub) {
+  public static ObjectStubSerializer getSerializer(@NotNull Stub rootStub) {
     if (rootStub instanceof PsiFileStub) {
       final PsiFileStub fileStub = (PsiFileStub)rootStub;
       return fileStub.getType();

platform/core-api/src/com/intellij/util/indexing/ID.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2000-2009 JetBrains s.r.o.
+ * Copyright 2000-2016 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.
@@ -33,7 +33,7 @@ import java.io.*;
 public class ID<K, V> {
   private static final TIntObjectHashMap<ID> ourRegistry = new TIntObjectHashMap<ID>();
   private static final TObjectIntHashMap<String> ourNameToIdRegistry = new TObjectIntHashMap<String>();
-  public static final int MAX_NUMBER_OF_INDICES = Short.MAX_VALUE;
+  static final int MAX_NUMBER_OF_INDICES = Short.MAX_VALUE;
 
   private final String myName;
   private final short myUniqueId;
@@ -119,7 +119,7 @@ public class ID<K, V> {
     }
   }
 
-  public static <K, V> ID<K, V> create(@NonNls String name) {
+  public static <K, V> ID<K, V> create(@NonNls @NotNull String name) {
     final ID<K, V> found = findByName(name);
     return found != null ? found : new ID<K, V>(name);
   }

platform/core-impl/src/com/intellij/extapi/psi/StubBasedPsiElementBase.java

@@ -138,7 +138,7 @@ public class StubBasedPsiElementBase<T extends StubElement> extends ASTDelegateP
     return node;
   }
 
-  private ASTNode failedToBindStubToAst(PsiFileImpl file, FileElement fileElement) {
+  private ASTNode failedToBindStubToAst(@NotNull PsiFileImpl file, @NotNull FileElement fileElement) {
     VirtualFile vFile = file.getVirtualFile();
     StubTree stubTree = file.getStubTree();
     String stubString = stubTree != null ? ((PsiFileStubImpl)stubTree.getRoot()).printTree() : "is null";
@@ -159,7 +159,8 @@ public class StubBasedPsiElementBase<T extends StubElement> extends ASTDelegateP
     throw new IllegalArgumentException(message);
   }
 
-  private String dumpCreationTraces(FileElement fileElement) {
+  @NotNull
+  private String dumpCreationTraces(@NotNull FileElement fileElement) {
     final StringBuilder traces = new StringBuilder("\nNow " + Thread.currentThread() + "\n");
     traces.append("My creation trace:\n").append(getUserData(CREATION_TRACE));
     traces.append("AST creation traces:\n");
@@ -180,7 +181,8 @@ public class StubBasedPsiElementBase<T extends StubElement> extends ASTDelegateP
     return traces.toString();
   }
 
-  private ASTNode notBoundInExistingAst(PsiFileImpl file, FileElement treeElement) {
+  @SuppressWarnings({"NonConstantStringShouldBeStringBuffer", "StringConcatenationInLoop"})
+  private ASTNode notBoundInExistingAst(@NotNull PsiFileImpl file, @NotNull FileElement treeElement) {
     String message = "file=" + file + "; tree=" + treeElement;
     PsiElement each = this;
     while (each != null) {
@@ -188,7 +190,8 @@ public class StubBasedPsiElementBase<T extends StubElement> extends ASTDelegateP
       if (each instanceof StubBasedPsiElementBase) {
         message += "; node=" + ((StubBasedPsiElementBase)each).myNode + "; stub=" + ((StubBasedPsiElementBase)each).myStub;
         each = ((StubBasedPsiElementBase)each).getParentByStub();
-      } else {
+      }
+      else {
         if (each instanceof PsiFile) {
           message += "; same file=" + (each == file) + "; current tree= " + file.getTreeElement() + "; stubTree=" + file.getStubTree() + "; physical=" + file.isPhysical();
         }
@@ -383,7 +386,7 @@ public class StubBasedPsiElementBase<T extends StubElement> extends ASTDelegateP
    * @return a child of specified type, taken from stubs (if this element is currently stub-based) or AST (otherwise).
    */
   @Nullable
-  public <Psi extends PsiElement> Psi getStubOrPsiChild(final IStubElementType<? extends StubElement, Psi> elementType) {
+  public <Psi extends PsiElement> Psi getStubOrPsiChild(@NotNull IStubElementType<? extends StubElement, Psi> elementType) {
     T stub = myStub;
     if (stub != null) {
       //noinspection unchecked
@@ -406,7 +409,7 @@ public class StubBasedPsiElementBase<T extends StubElement> extends ASTDelegateP
    * @return a not-null child of specified type, taken from stubs (if this element is currently stub-based) or AST (otherwise).
    */
   @NotNull
-  public <S extends StubElement, Psi extends PsiElement> Psi getRequiredStubOrPsiChild(final IStubElementType<S, Psi> elementType) {
+  public <S extends StubElement, Psi extends PsiElement> Psi getRequiredStubOrPsiChild(@NotNull IStubElementType<S, Psi> elementType) {
     Psi result = getStubOrPsiChild(elementType);
     assert result != null: "Missing required child of type " + elementType + "; tree: "+DebugUtil.psiToString(this, false);
     return result;
@@ -415,7 +418,8 @@ public class StubBasedPsiElementBase<T extends StubElement> extends ASTDelegateP
   /**
    * @return children of specified type, taken from stubs (if this element is currently stub-based) or AST (otherwise).
    */
-  public <S extends StubElement, Psi extends PsiElement> Psi[] getStubOrPsiChildren(final IStubElementType<S, Psi> elementType, Psi[] array) {
+  @NotNull
+  public <S extends StubElement, Psi extends PsiElement> Psi[] getStubOrPsiChildren(@NotNull IStubElementType<S, Psi> elementType, @NotNull Psi[] array) {
     T stub = myStub;
     if (stub != null) {
       //noinspection unchecked
@@ -436,7 +440,8 @@ public class StubBasedPsiElementBase<T extends StubElement> extends ASTDelegateP
   /**
    * @return children of specified type, taken from stubs (if this element is currently stub-based) or AST (otherwise).
    */
-  public <S extends StubElement, Psi extends PsiElement> Psi[] getStubOrPsiChildren(final IStubElementType<S, Psi> elementType, ArrayFactory<Psi> f) {
+  @NotNull
+  public <S extends StubElement, Psi extends PsiElement> Psi[] getStubOrPsiChildren(@NotNull IStubElementType<S, Psi> elementType, @NotNull ArrayFactory<Psi> f) {
     T stub = myStub;
     if (stub != null) {
       //noinspection unchecked
@@ -456,7 +461,8 @@ public class StubBasedPsiElementBase<T extends StubElement> extends ASTDelegateP
   /**
    * @return children of specified type, taken from stubs (if this element is currently stub-based) or AST (otherwise).
    */
-  public <Psi extends PsiElement> Psi[] getStubOrPsiChildren(TokenSet filter, Psi[] array) {
+  @NotNull
+  public <Psi extends PsiElement> Psi[] getStubOrPsiChildren(@NotNull TokenSet filter, @NotNull Psi[] array) {
     T stub = myStub;
     if (stub != null) {
       //noinspection unchecked
@@ -477,7 +483,8 @@ public class StubBasedPsiElementBase<T extends StubElement> extends ASTDelegateP
   /**
    * @return children of specified type, taken from stubs (if this element is currently stub-based) or AST (otherwise).
    */
-  public <Psi extends PsiElement> Psi[] getStubOrPsiChildren(TokenSet filter, ArrayFactory<Psi> f) {
+  @NotNull
+  public <Psi extends PsiElement> Psi[] getStubOrPsiChildren(@NotNull TokenSet filter, @NotNull ArrayFactory<Psi> f) {
     T stub = myStub;
     if (stub != null) {
       //noinspection unchecked
@@ -498,7 +505,7 @@ public class StubBasedPsiElementBase<T extends StubElement> extends ASTDelegateP
    * @return a first ancestor of specified type, in stub hierarchy (if this element is currently stub-based) or AST hierarchy (otherwise).
    */
   @Nullable
-  protected <E extends PsiElement> E getStubOrPsiParentOfType(final Class<E> parentClass) {
+  protected <E extends PsiElement> E getStubOrPsiParentOfType(@NotNull Class<E> parentClass) {
     T stub = myStub;
     if (stub != null) {
       //noinspection unchecked

platform/core-impl/src/com/intellij/psi/impl/source/tree/SharedImplUtil.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2000-2015 JetBrains s.r.o.
+ * Copyright 2000-2016 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.
@@ -158,7 +158,8 @@ public class SharedImplUtil {
     return node.getTreeParent().getPsi().getManager();
   }
 
-  public static ASTNode[] getChildrenOfType(ASTNode node, IElementType elementType) {
+  @NotNull
+  public static ASTNode[] getChildrenOfType(@NotNull ASTNode node, @NotNull IElementType elementType) {
     int count = countChildrenOfType(node, elementType);
     if (count == 0) {
       return ASTNode.EMPTY_ARRAY;

platform/core-impl/src/com/intellij/psi/stubs/PsiFileStubImpl.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2000-2015 JetBrains s.r.o.
+ * Copyright 2000-2016 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.
@@ -72,6 +72,7 @@ public class PsiFileStubImpl<T extends PsiFile> extends StubBase<T> implements P
     return null;
   }
 
+  @NotNull
   @Override
   public IStubFileElementType getType() {
     return TYPE;

plugins/groovy/groovy-psi/src/org/jetbrains/plugins/groovy/lang/psi/stubs/GrFileStub.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2000-2014 JetBrains s.r.o.
+ * Copyright 2000-2016 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.
@@ -19,6 +19,7 @@ import com.intellij.psi.stubs.PsiFileStubImpl;
 import com.intellij.psi.tree.IStubFileElementType;
 import com.intellij.util.ArrayUtil;
 import com.intellij.util.io.StringRef;
+import org.jetbrains.annotations.NotNull;
 import org.jetbrains.plugins.groovy.lang.parser.GroovyParserDefinition;
 import org.jetbrains.plugins.groovy.lang.psi.GroovyFile;
 import org.jetbrains.plugins.groovy.lang.psi.api.toplevel.packaging.GrPackageDefinition;
@@ -50,6 +51,7 @@ public class GrFileStub extends PsiFileStubImpl<GroovyFile> {
     myAnnotations = annotations;
   }
 
+  @NotNull
   @Override
   public IStubFileElementType getType() {
     return GroovyParserDefinition.GROOVY_FILE;

python/src/com/jetbrains/python/psi/impl/stubs/PyFileStubImpl.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2000-2014 JetBrains s.r.o.
+ * Copyright 2000-2016 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.
@@ -24,6 +24,7 @@ import com.jetbrains.python.psi.FutureFeature;
 import com.jetbrains.python.psi.PyFile;
 import com.jetbrains.python.psi.impl.PyFileImpl;
 import com.jetbrains.python.psi.stubs.PyFileStub;
+import org.jetbrains.annotations.NotNull;
 
 import java.util.BitSet;
 import java.util.List;
@@ -72,6 +73,7 @@ public class PyFileStubImpl extends PsiFileStubImpl<PyFile> implements PyFileStu
     return myDeprecationMessage == null ? null : myDeprecationMessage.getString();
   }
 
+  @NotNull
   @Override
   public IStubFileElementType getType() {
     return (IStubFileElementType) LanguageParserDefinitions.INSTANCE.forLanguage(PythonLanguage.getInstance()).getFileNodeType();

xml/dom-impl/src/com/intellij/util/xml/stubs/AttributeStub.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2000-2012 JetBrains s.r.o.
+ * Copyright 2000-2016 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.
@@ -17,6 +17,7 @@ package com.intellij.util.xml.stubs;
 
 import com.intellij.psi.stubs.ObjectStubSerializer;
 import com.intellij.util.io.StringRef;
+import org.jetbrains.annotations.NotNull;
 
 import java.util.Collections;
 import java.util.List;
@@ -38,6 +39,7 @@ public class AttributeStub extends DomStub {
     return myValue;
   }
 
+  @NotNull
   @Override
   public List<DomStub> getChildrenStubs() {
     return Collections.emptyList();

xml/dom-impl/src/com/intellij/util/xml/stubs/DomStub.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2000-2014 JetBrains s.r.o.
+ * Copyright 2000-2016 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.
@@ -51,6 +51,7 @@ public abstract class DomStub extends ObjectStubBase<DomStub> {
     myLocalName = localName;
   }
 
+  @NotNull
   @Override
   public abstract List<DomStub> getChildrenStubs();
 

xml/dom-impl/src/com/intellij/util/xml/stubs/ElementStub.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2000-2014 JetBrains s.r.o.
+ * Copyright 2000-2016 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.
@@ -56,6 +56,7 @@ public class ElementStub extends DomStub {
     myChildren.add(child);
   }
 
+  @NotNull
   @Override
   public List<DomStub> getChildrenStubs() {
     return myChildren;

xml/dom-impl/src/com/intellij/util/xml/stubs/builder/DomStubBuilder.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2000-2015 JetBrains s.r.o.
+ * Copyright 2000-2016 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.
@@ -36,6 +36,7 @@ import com.intellij.util.xml.impl.DomApplicationComponent;
 import com.intellij.util.xml.impl.DomManagerImpl;
 import com.intellij.util.xml.stubs.FileStub;
 import com.intellij.xml.util.XmlUtil;
+import org.jetbrains.annotations.NotNull;
 
 /**
  * @author Dmitry Avdeev
@@ -45,7 +46,7 @@ public class DomStubBuilder implements BinaryFileStubBuilder {
   private static final Logger LOG = Logger.getInstance(DomStubBuilder.class);
 
   @Override
-  public boolean acceptsFile(VirtualFile file) {
+  public boolean acceptsFile(@NotNull VirtualFile file) {
     FileType fileType = file.getFileType();
     return fileType == XmlFileType.INSTANCE && !FileBasedIndexImpl.isProjectOrWorkspaceFile(file, fileType);
   }