diff --git a/java/java-impl/src/com/intellij/psi/impl/source/PsiExpressionCodeFragmentImpl.java b/java/java-impl/src/com/intellij/psi/impl/source/PsiExpressionCodeFragmentImpl.java
index 299abf842186..1db3bac0bcd2 100644
--- a/java/java-impl/src/com/intellij/psi/impl/source/PsiExpressionCodeFragmentImpl.java
+++ b/java/java-impl/src/com/intellij/psi/impl/source/PsiExpressionCodeFragmentImpl.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2000-2009 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.
@@ -25,16 +25,17 @@ import com.intellij.psi.PsiType;
 import com.intellij.psi.impl.source.tree.ElementType;
 import com.intellij.psi.impl.source.tree.JavaElementType;
 import org.jetbrains.annotations.NonNls;
+import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
 public class PsiExpressionCodeFragmentImpl extends PsiCodeFragmentImpl implements PsiExpressionCodeFragment {
   private static final Logger LOG = Logger.getInstance("#com.intellij.psi.impl.source.PsiExpressionCodeFragmentImpl");
   private PsiType myExpectedType;
 
-  public PsiExpressionCodeFragmentImpl(Project project,
+  public PsiExpressionCodeFragmentImpl(@NotNull Project project,
                                        boolean isPhysical,
                                        @NonNls String name,
-                                       CharSequence text,
+                                       @NotNull CharSequence text,
                                        @Nullable final PsiType expectedType,
                                        @Nullable PsiElement context) {
     super(project, JavaElementType.EXPRESSION_TEXT, isPhysical, name, text, context);
diff --git a/java/java-impl/src/com/intellij/psi/impl/source/PsiJavaCodeReferenceCodeFragmentImpl.java b/java/java-impl/src/com/intellij/psi/impl/source/PsiJavaCodeReferenceCodeFragmentImpl.java
index 333894257d04..0748a6f52a80 100644
--- a/java/java-impl/src/com/intellij/psi/impl/source/PsiJavaCodeReferenceCodeFragmentImpl.java
+++ b/java/java-impl/src/com/intellij/psi/impl/source/PsiJavaCodeReferenceCodeFragmentImpl.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2000-2009 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.
@@ -23,6 +23,7 @@ import com.intellij.psi.PsiJavaCodeReferenceElement;
 import com.intellij.psi.impl.source.tree.CompositeElement;
 import com.intellij.psi.impl.source.tree.JavaElementType;
 import org.jetbrains.annotations.NonNls;
+import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
 /**
@@ -32,10 +33,10 @@ public class PsiJavaCodeReferenceCodeFragmentImpl extends PsiCodeFragmentImpl im
   private static final Logger LOG = Logger.getInstance("#com.intellij.psi.impl.source.PsiJavaCodeReferenceCodeFragmentImpl");
   private final boolean myIsClassesAccepted;
 
-  public PsiJavaCodeReferenceCodeFragmentImpl(final Project project,
+  public PsiJavaCodeReferenceCodeFragmentImpl(@NotNull Project project,
                                               final boolean isPhysical,
-                                              @NonNls final String name,
-                                              final CharSequence text,
+                                              @NonNls @NotNull String name,
+                                              @NotNull CharSequence text,
                                               boolean isClassesAccepted,
                                               @Nullable PsiElement context) {
     super(project, JavaElementType.REFERENCE_TEXT, isPhysical, name, text, context);
diff --git a/java/java-psi-impl/src/com/intellij/psi/impl/source/tree/CoreJavaASTFactory.java b/java/java-psi-impl/src/com/intellij/psi/impl/source/tree/CoreJavaASTFactory.java
index 9c888c006b99..4f796dce93e6 100644
--- a/java/java-psi-impl/src/com/intellij/psi/impl/source/tree/CoreJavaASTFactory.java
+++ b/java/java-psi-impl/src/com/intellij/psi/impl/source/tree/CoreJavaASTFactory.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2000-2014 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.
@@ -36,7 +36,7 @@ public class CoreJavaASTFactory extends ASTFactory implements Constants {
   private final DefaultASTFactory myDefaultASTFactory = ServiceManager.getService(DefaultASTFactory.class);
 
   @Override
-  public LeafElement createLeaf(@NotNull final IElementType type, final CharSequence text) {
+  public LeafElement createLeaf(@NotNull final IElementType type, @NotNull final CharSequence text) {
     if (type == C_STYLE_COMMENT || type == END_OF_LINE_COMMENT) {
       return myDefaultASTFactory.createComment(type, text);
     }
diff --git a/java/java-psi-impl/src/com/intellij/psi/impl/source/tree/JavaDocElementType.java b/java/java-psi-impl/src/com/intellij/psi/impl/source/tree/JavaDocElementType.java
index b046de964cdf..793ad40dead4 100644
--- a/java/java-psi-impl/src/com/intellij/psi/impl/source/tree/JavaDocElementType.java
+++ b/java/java-psi-impl/src/com/intellij/psi/impl/source/tree/JavaDocElementType.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2000-2014 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.
@@ -60,7 +60,7 @@ public interface JavaDocElementType {
     }
 
     @Override
-    public ASTNode createNode(final CharSequence text) {
+    public ASTNode createNode(CharSequence text) {
       return new LazyParseablePsiElement(this, text);
     }
   }
diff --git a/java/java-tests/testSrc/com/intellij/lang/java/parser/JavaParsingTestCase.java b/java/java-tests/testSrc/com/intellij/lang/java/parser/JavaParsingTestCase.java
index 861745fba66d..084d34c2194e 100644
--- a/java/java-tests/testSrc/com/intellij/lang/java/parser/JavaParsingTestCase.java
+++ b/java/java-tests/testSrc/com/intellij/lang/java/parser/JavaParsingTestCase.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2000-2014 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.
@@ -105,7 +105,7 @@ public abstract class JavaParsingTestCase extends ParsingTestCase {
     return new PsiJavaFileImpl(viewProvider) {
       @NotNull
       @Override
-      protected FileElement createFileElement(final CharSequence text) {
+      protected FileElement createFileElement(@NotNull final CharSequence text) {
         return new FileElement(TEST_FILE_ELEMENT_TYPE, text);
       }
     };
diff --git a/platform/core-api/src/com/intellij/psi/tree/ILazyParseableElementType.java b/platform/core-api/src/com/intellij/psi/tree/ILazyParseableElementType.java
index 5a6da8aa18ca..8821a1fc27b1 100644
--- a/platform/core-api/src/com/intellij/psi/tree/ILazyParseableElementType.java
+++ b/platform/core-api/src/com/intellij/psi/tree/ILazyParseableElementType.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2000-2011 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.
diff --git a/platform/core-api/src/com/intellij/testFramework/LightVirtualFile.java b/platform/core-api/src/com/intellij/testFramework/LightVirtualFile.java
index fc3404e9c598..719c23b46865 100644
--- a/platform/core-api/src/com/intellij/testFramework/LightVirtualFile.java
+++ b/platform/core-api/src/com/intellij/testFramework/LightVirtualFile.java
@@ -39,30 +39,30 @@ public class LightVirtualFile extends LightVirtualFileBase {
     this("");
   }
 
-  public LightVirtualFile(@NonNls String name) {
+  public LightVirtualFile(@NonNls @NotNull String name) {
     this(name, "");
   }
 
-  public LightVirtualFile(@NonNls String name, CharSequence content) {
+  public LightVirtualFile(@NonNls @NotNull String name, @NotNull CharSequence content) {
     this(name, null, content, LocalTimeCounter.currentTime());
   }
 
-  public LightVirtualFile(final String name, final FileType fileType, final CharSequence text) {
+  public LightVirtualFile(@NotNull String name, final FileType fileType, @NotNull CharSequence text) {
     this(name, fileType, text, LocalTimeCounter.currentTime());
   }
 
-  public LightVirtualFile(VirtualFile original, final CharSequence text, long modificationStamp) {
+  public LightVirtualFile(VirtualFile original, @NotNull CharSequence text, long modificationStamp) {
     this(original.getName(), original.getFileType(), text, modificationStamp);
     setCharset(original.getCharset());
   }
 
-  public LightVirtualFile(final String name, final FileType fileType, final CharSequence text, final long modificationStamp) {
+  public LightVirtualFile(@NotNull String name, final FileType fileType, @NotNull CharSequence text, final long modificationStamp) {
     this(name, fileType, text, CharsetUtil.extractCharsetFromFileContent(null, null, fileType, text), modificationStamp);
   }
 
-  public LightVirtualFile(final String name,
+  public LightVirtualFile(@NotNull String name,
                           final FileType fileType,
-                          final CharSequence text,
+                          @NotNull CharSequence text,
                           Charset charset,
                           final long modificationStamp) {
     super(name, fileType, modificationStamp);
@@ -70,7 +70,7 @@ public class LightVirtualFile extends LightVirtualFileBase {
     setCharset(charset);
   }
 
-  public LightVirtualFile(final String name, final Language language, final CharSequence text) {
+  public LightVirtualFile(@NotNull String name, final Language language, @NotNull CharSequence text) {
     super(name, null, LocalTimeCounter.currentTime());
     setContent(text);
     setLanguage(language);
@@ -121,16 +121,17 @@ public class LightVirtualFile extends LightVirtualFileBase {
     return s.getBytes(charset.name());
   }
 
-  public void setContent(Object requestor, CharSequence content, boolean fireEvent) {
+  public void setContent(Object requestor, @NotNull CharSequence content, boolean fireEvent) {
     setContent(content);
     setModificationStamp(LocalTimeCounter.currentTime());
   }
 
-  private void setContent(CharSequence content) {
+  private void setContent(@NotNull CharSequence content) {
     //StringUtil.assertValidSeparators(content);
     myContent = content;
   }
 
+  @NotNull
   public CharSequence getContent() {
     return myContent;
   }
diff --git a/platform/core-impl/src/com/intellij/core/CoreASTFactory.java b/platform/core-impl/src/com/intellij/core/CoreASTFactory.java
index d4e19d280bb9..16d2c1423d58 100644
--- a/platform/core-impl/src/com/intellij/core/CoreASTFactory.java
+++ b/platform/core-impl/src/com/intellij/core/CoreASTFactory.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2000-2014 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.
@@ -48,7 +48,7 @@ public class CoreASTFactory extends ASTFactory implements DefaultASTFactory {
 
   @Override
   @NotNull
-  public LeafElement createLeaf(@NotNull final IElementType type, final CharSequence text) {
+  public LeafElement createLeaf(@NotNull final IElementType type, @NotNull final CharSequence text) {
     final Language lang = type.getLanguage();
     final ParserDefinition parserDefinition = LanguageParserDefinitions.INSTANCE.forLanguage(lang);
     if (parserDefinition != null) {
@@ -60,8 +60,9 @@ public class CoreASTFactory extends ASTFactory implements DefaultASTFactory {
     return new LeafPsiElement(type, text);
   }
 
+  @NotNull
   @Override
-  public LeafElement createComment(@NotNull IElementType type, CharSequence text) {
+  public LeafElement createComment(@NotNull IElementType type, @NotNull CharSequence text) {
     return new PsiCoreCommentImpl(type, text);
   }
 }
diff --git a/platform/core-impl/src/com/intellij/lang/ASTFactory.java b/platform/core-impl/src/com/intellij/lang/ASTFactory.java
index d923204915b3..e50feb7dcf22 100644
--- a/platform/core-impl/src/com/intellij/lang/ASTFactory.java
+++ b/platform/core-impl/src/com/intellij/lang/ASTFactory.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2000-2014 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.
@@ -21,8 +21,14 @@ import com.intellij.psi.impl.source.CharTableImpl;
 import com.intellij.psi.impl.source.CodeFragmentElement;
 import com.intellij.psi.impl.source.DummyHolderElement;
 import com.intellij.psi.impl.source.codeStyle.CodeEditUtil;
-import com.intellij.psi.impl.source.tree.*;
-import com.intellij.psi.tree.*;
+import com.intellij.psi.impl.source.tree.CompositeElement;
+import com.intellij.psi.impl.source.tree.LazyParseableElement;
+import com.intellij.psi.impl.source.tree.LeafElement;
+import com.intellij.psi.impl.source.tree.PsiWhiteSpaceImpl;
+import com.intellij.psi.tree.ICompositeElementType;
+import com.intellij.psi.tree.IElementType;
+import com.intellij.psi.tree.ILazyParseableElementType;
+import com.intellij.psi.tree.ILeafElementType;
 import com.intellij.util.CharTable;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
@@ -46,14 +52,14 @@ public abstract class ASTFactory {
   }
 
   @Nullable
-  public LeafElement createLeaf(@NotNull IElementType type, final CharSequence text) {
+  public LeafElement createLeaf(@NotNull IElementType type, @NotNull CharSequence text) {
     return null;
   }
 
   // factory methods
 
   @NotNull
-  public static LazyParseableElement lazy(@NotNull final ILazyParseableElementType type, final CharSequence text) {
+  public static LazyParseableElement lazy(@NotNull final ILazyParseableElementType type, CharSequence text) {
     final ASTNode node = type.createNode(text);
     if (node != null) return (LazyParseableElement)node;
 
@@ -79,7 +85,7 @@ public abstract class ASTFactory {
   }
 
   @NotNull
-  public static LeafElement leaf(@NotNull final IElementType type, final CharSequence text) {
+  public static LeafElement leaf(@NotNull final IElementType type, @NotNull CharSequence text) {
     if (type == TokenType.WHITE_SPACE) {
       return new PsiWhiteSpaceImpl(text);
     }
@@ -105,11 +111,7 @@ public abstract class ASTFactory {
   }
   
   public static class DefaultFactoryHolder {
-    public static final ASTFactory DEFAULT = def();
-
-    private static ASTFactory def() {
-      return (ASTFactory)ServiceManager.getService(DefaultASTFactory.class);
-    }
+    public static final ASTFactory DEFAULT = (ASTFactory)ServiceManager.getService(DefaultASTFactory.class);
 
     private DefaultFactoryHolder() {
     }
diff --git a/platform/core-impl/src/com/intellij/lang/DefaultASTFactory.java b/platform/core-impl/src/com/intellij/lang/DefaultASTFactory.java
index 60c12c327854..f97c4119bccf 100644
--- a/platform/core-impl/src/com/intellij/lang/DefaultASTFactory.java
+++ b/platform/core-impl/src/com/intellij/lang/DefaultASTFactory.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2000-2011 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.
@@ -17,6 +17,7 @@ package com.intellij.lang;
 
 import com.intellij.psi.impl.source.tree.LeafElement;
 import com.intellij.psi.tree.IElementType;
+import org.jetbrains.annotations.NotNull;
 
 /**
  * Marker interface for retrieving the service which provides a default implementation of ASTFactory.
@@ -24,5 +25,6 @@ import com.intellij.psi.tree.IElementType;
  * @author yole
  */
 public interface DefaultASTFactory {
-  LeafElement createComment(IElementType type, CharSequence text);
+  @NotNull
+  LeafElement createComment(@NotNull IElementType type, @NotNull CharSequence text);
 }
diff --git a/platform/core-impl/src/com/intellij/lang/ForeignLeafType.java b/platform/core-impl/src/com/intellij/lang/ForeignLeafType.java
index f6e8f3065333..3431f247b82e 100644
--- a/platform/core-impl/src/com/intellij/lang/ForeignLeafType.java
+++ b/platform/core-impl/src/com/intellij/lang/ForeignLeafType.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2000-2009 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.
@@ -25,7 +25,7 @@ import com.intellij.psi.tree.ILeafElementType;
 import org.jetbrains.annotations.NotNull;
 
 public class ForeignLeafType extends TokenWrapper implements ILeafElementType {
-  public ForeignLeafType(IElementType delegate, CharSequence value) {
+  public ForeignLeafType(@NotNull IElementType delegate, @NotNull CharSequence value) {
     super(delegate, value);
   }
 
diff --git a/platform/core-impl/src/com/intellij/lang/TokenWrapper.java b/platform/core-impl/src/com/intellij/lang/TokenWrapper.java
index ade2dc884314..2126a92bd497 100644
--- a/platform/core-impl/src/com/intellij/lang/TokenWrapper.java
+++ b/platform/core-impl/src/com/intellij/lang/TokenWrapper.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2000-2014 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.
@@ -26,7 +26,7 @@ public class TokenWrapper extends IElementType {
   private final IElementType myDelegate;
   private final String myValue;
 
-  public TokenWrapper(@NotNull IElementType delegate, CharSequence value) {
+  public TokenWrapper(@NotNull IElementType delegate, @NotNull CharSequence value) {
     super("Wrapper", delegate.getLanguage(), false);
     myDelegate = delegate;
     myValue = value.toString();
diff --git a/platform/core-impl/src/com/intellij/pom/core/impl/PomModelImpl.java b/platform/core-impl/src/com/intellij/pom/core/impl/PomModelImpl.java
index b9fc9429d5ee..78d52db956b7 100644
--- a/platform/core-impl/src/com/intellij/pom/core/impl/PomModelImpl.java
+++ b/platform/core-impl/src/com/intellij/pom/core/impl/PomModelImpl.java
@@ -21,6 +21,7 @@ import com.intellij.openapi.application.ApplicationManager;
 import com.intellij.openapi.diagnostic.Logger;
 import com.intellij.openapi.editor.Document;
 import com.intellij.openapi.progress.EmptyProgressIndicator;
+import com.intellij.openapi.progress.ProcessCanceledException;
 import com.intellij.openapi.progress.ProgressIndicator;
 import com.intellij.openapi.progress.ProgressIndicatorProvider;
 import com.intellij.openapi.project.Project;
@@ -150,6 +151,9 @@ public class PomModelImpl extends UserDataHolderBase implements PomModel {
           transaction.run();
           event = transaction.getAccumulatedEvent();
         }
+        catch (ProcessCanceledException e) {
+          throw e;
+        }
         catch(Exception e){
           LOG.error(e);
           return;
@@ -186,6 +190,9 @@ public class PomModelImpl extends UserDataHolderBase implements PomModel {
           }
         }
       }
+      catch (ProcessCanceledException e) {
+        throw e;
+      }
       catch (Throwable t) {
         throwables.add(t);
       }
@@ -193,6 +200,9 @@ public class PomModelImpl extends UserDataHolderBase implements PomModel {
         try {
           commitTransaction(transaction);
         }
+        catch (ProcessCanceledException e) {
+          throw e;
+        }
         catch (Throwable t) {
           throwables.add(t);
         }
diff --git a/platform/core-impl/src/com/intellij/psi/impl/PsiFileFactoryImpl.java b/platform/core-impl/src/com/intellij/psi/impl/PsiFileFactoryImpl.java
index 7f4febb38c48..cc62319d3894 100644
--- a/platform/core-impl/src/com/intellij/psi/impl/PsiFileFactoryImpl.java
+++ b/platform/core-impl/src/com/intellij/psi/impl/PsiFileFactoryImpl.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.
@@ -108,7 +108,8 @@ public class PsiFileFactoryImpl extends PsiFileFactory {
   }
 
   @Nullable
-  public PsiFile trySetupPsiForFile(final LightVirtualFile virtualFile, Language language,
+  public PsiFile trySetupPsiForFile(@NotNull LightVirtualFile virtualFile,
+                                    @NotNull Language language,
                                     final boolean physical, final boolean markAsCopy) {
     final FileViewProviderFactory factory = LanguageFileViewProviders.INSTANCE.forLanguage(language);
     FileViewProvider viewProvider = factory != null ? factory.createFileViewProvider(virtualFile, language, myManager, physical) : null;
diff --git a/platform/core-impl/src/com/intellij/psi/impl/source/DummyHolderElement.java b/platform/core-impl/src/com/intellij/psi/impl/source/DummyHolderElement.java
index 4ee148c09841..11dbbbccbbef 100644
--- a/platform/core-impl/src/com/intellij/psi/impl/source/DummyHolderElement.java
+++ b/platform/core-impl/src/com/intellij/psi/impl/source/DummyHolderElement.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2000-2009 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.
@@ -18,9 +18,10 @@ package com.intellij.psi.impl.source;
 
 import com.intellij.psi.TokenType;
 import com.intellij.psi.impl.source.tree.FileElement;
+import org.jetbrains.annotations.NotNull;
 
 public class DummyHolderElement extends FileElement {
-  public DummyHolderElement(CharSequence text) {
+  public DummyHolderElement(@NotNull CharSequence text) {
     super(TokenType.DUMMY_HOLDER, text);
   }
 }
diff --git a/platform/core-impl/src/com/intellij/psi/impl/source/tree/FileElement.java b/platform/core-impl/src/com/intellij/psi/impl/source/tree/FileElement.java
index 8192070f97c6..894d0295870c 100644
--- a/platform/core-impl/src/com/intellij/psi/impl/source/tree/FileElement.java
+++ b/platform/core-impl/src/com/intellij/psi/impl/source/tree/FileElement.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2000-2014 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.
@@ -55,17 +55,13 @@ public class FileElement extends LazyParseableElement implements FileASTNode, Ge
     final IFileElementType contentType = (IFileElementType)getElementType();
     assert contentType instanceof ILightStubFileElementType:contentType;
 
-    LighterAST tree;
     if (!isParsed()) {
       return new FCTSBackedLighterAST(getCharTable(), ((ILightStubFileElementType<?>)contentType).parseContentsLight(this));
     }
-    else {
-      tree = new TreeBackedLighterAST(this);
-    }
-    return tree;
+    return new TreeBackedLighterAST(this);
   }
 
-  public FileElement(IElementType type, CharSequence text) {
+  public FileElement(@NotNull IElementType type, CharSequence text) {
     super(type, text);
   }
 
diff --git a/platform/core-impl/src/com/intellij/psi/impl/source/tree/OwnBufferLeafPsiElement.java b/platform/core-impl/src/com/intellij/psi/impl/source/tree/OwnBufferLeafPsiElement.java
index 7d1abe377f1a..5a9cf378a950 100644
--- a/platform/core-impl/src/com/intellij/psi/impl/source/tree/OwnBufferLeafPsiElement.java
+++ b/platform/core-impl/src/com/intellij/psi/impl/source/tree/OwnBufferLeafPsiElement.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2000-2014 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.
@@ -35,7 +35,7 @@ import org.jetbrains.annotations.NotNull;
 public class OwnBufferLeafPsiElement extends LeafElement implements PsiElement {
   private static final Logger LOG = Logger.getInstance("#com.intellij.psi.impl.source.tree.LeafPsiElement");
 
-  public OwnBufferLeafPsiElement(@NotNull IElementType type, CharSequence text) {
+  public OwnBufferLeafPsiElement(@NotNull IElementType type, @NotNull CharSequence text) {
     super(type, text);
   }
 
diff --git a/platform/core-impl/src/com/intellij/psi/impl/source/tree/PlainTextASTFactory.java b/platform/core-impl/src/com/intellij/psi/impl/source/tree/PlainTextASTFactory.java
index 8674773ac469..5f09bbb81ca7 100644
--- a/platform/core-impl/src/com/intellij/psi/impl/source/tree/PlainTextASTFactory.java
+++ b/platform/core-impl/src/com/intellij/psi/impl/source/tree/PlainTextASTFactory.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2000-2014 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.
@@ -29,7 +29,7 @@ public class PlainTextASTFactory extends ASTFactory {
 
   @Override
   @Nullable
-  public LeafElement createLeaf(@NotNull final IElementType type, CharSequence text) {
+  public LeafElement createLeaf(@NotNull final IElementType type, @NotNull CharSequence text) {
     if (type == PlainTextTokenTypes.PLAIN_TEXT) {
       return new PsiPlainTextImpl(text);
     }
diff --git a/platform/core-impl/src/com/intellij/psi/impl/source/tree/PsiPlainTextImpl.java b/platform/core-impl/src/com/intellij/psi/impl/source/tree/PsiPlainTextImpl.java
index 4bb8c6214cd6..fd0e83240347 100644
--- a/platform/core-impl/src/com/intellij/psi/impl/source/tree/PsiPlainTextImpl.java
+++ b/platform/core-impl/src/com/intellij/psi/impl/source/tree/PsiPlainTextImpl.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2000-2009 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.
@@ -22,7 +22,7 @@ import com.intellij.psi.PsiPlainText;
 import org.jetbrains.annotations.NotNull;
 
 public class PsiPlainTextImpl extends OwnBufferLeafPsiElement implements PsiPlainText {
-  protected PsiPlainTextImpl(CharSequence text) {
+  protected PsiPlainTextImpl(@NotNull CharSequence text) {
     super(PlainTextTokenTypes.PLAIN_TEXT, text);
   }
 
diff --git a/platform/indexing-api/src/com/intellij/psi/stubs/SerializationManager.java b/platform/indexing-api/src/com/intellij/psi/stubs/SerializationManager.java
index 228b14ff6b17..a0534413f902 100644
--- a/platform/indexing-api/src/com/intellij/psi/stubs/SerializationManager.java
+++ b/platform/indexing-api/src/com/intellij/psi/stubs/SerializationManager.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2000-2009 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.
@@ -23,6 +23,7 @@ import com.intellij.openapi.application.ApplicationManager;
 import com.intellij.openapi.extensions.Extensions;
 import com.intellij.psi.tree.IElementType;
 import com.intellij.psi.tree.IStubFileElementType;
+import org.jetbrains.annotations.NotNull;
 
 import java.util.ArrayList;
 import java.util.List;
@@ -49,7 +50,7 @@ public abstract class SerializationManager {
       }
       final IElementType[] stubElementTypes = IElementType.enumerate(new IElementType.Predicate() {
         @Override
-        public boolean matches(final IElementType type) {
+        public boolean matches(@NotNull final IElementType type) {
           return type instanceof StubSerializer;
         }
       });
diff --git a/platform/lang-impl/src/com/intellij/lang/DefaultASTFactoryImpl.java b/platform/lang-impl/src/com/intellij/lang/DefaultASTFactoryImpl.java
index 84b79498e050..1b07b367e78f 100644
--- a/platform/lang-impl/src/com/intellij/lang/DefaultASTFactoryImpl.java
+++ b/platform/lang-impl/src/com/intellij/lang/DefaultASTFactoryImpl.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2000-2014 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.
@@ -22,8 +22,9 @@ import com.intellij.psi.tree.IElementType;
 import org.jetbrains.annotations.NotNull;
 
 public class DefaultASTFactoryImpl extends CoreASTFactory implements DefaultASTFactory {
+  @NotNull
   @Override
-  public LeafElement createComment(@NotNull IElementType type, CharSequence text) {
+  public LeafElement createComment(@NotNull IElementType type, @NotNull CharSequence text) {
     return new PsiCommentImpl(type, text);
   }
 }
diff --git a/plugins/properties/properties-psi-impl/src/com/intellij/lang/properties/psi/impl/PropertiesASTFactory.java b/plugins/properties/properties-psi-impl/src/com/intellij/lang/properties/psi/impl/PropertiesASTFactory.java
index 2f202fe8ba9a..a3d8e5ddb967 100644
--- a/plugins/properties/properties-psi-impl/src/com/intellij/lang/properties/psi/impl/PropertiesASTFactory.java
+++ b/plugins/properties/properties-psi-impl/src/com/intellij/lang/properties/psi/impl/PropertiesASTFactory.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2000-2014 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.
@@ -38,7 +38,7 @@ public class PropertiesASTFactory extends ASTFactory {
 
   @Override
   @Nullable
-  public LeafElement createLeaf(@NotNull final IElementType type, CharSequence text) {
+  public LeafElement createLeaf(@NotNull final IElementType type, @NotNull CharSequence text) {
     if (type == PropertiesTokenTypes.KEY_CHARACTERS) {
       return new PropertyKeyImpl(type, text);
     }
diff --git a/python/src/com/jetbrains/python/formatter/PythonFormattingModelBuilder.java b/python/src/com/jetbrains/python/formatter/PythonFormattingModelBuilder.java
index 04d0c69547da..d399dbec75a1 100644
--- a/python/src/com/jetbrains/python/formatter/PythonFormattingModelBuilder.java
+++ b/python/src/com/jetbrains/python/formatter/PythonFormattingModelBuilder.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2000-2014 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.
@@ -151,7 +151,7 @@ public class PythonFormattingModelBuilder implements FormattingModelBuilderEx, C
     final PythonLanguage pythonLanguage = PythonLanguage.getInstance();
     return TokenSet.create(IElementType.enumerate(new IElementType.Predicate() {
       @Override
-      public boolean matches(IElementType type) {
+      public boolean matches(@NotNull IElementType type) {
         return type != LAMBDA_KEYWORD && type.getLanguage().isKindOf(pythonLanguage);
       }
     }));
diff --git a/xml/xml-psi-impl/src/com/intellij/lang/xml/XmlASTFactory.java b/xml/xml-psi-impl/src/com/intellij/lang/xml/XmlASTFactory.java
index b8dac87836b2..7fdcc6c41502 100644
--- a/xml/xml-psi-impl/src/com/intellij/lang/xml/XmlASTFactory.java
+++ b/xml/xml-psi-impl/src/com/intellij/lang/xml/XmlASTFactory.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2000-2014 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.
@@ -136,7 +136,7 @@ public class XmlASTFactory extends ASTFactory {
   }
 
   @Override
-  public LeafElement createLeaf(@NotNull final IElementType type, CharSequence text) {
+  public LeafElement createLeaf(@NotNull final IElementType type, @NotNull CharSequence text) {
     if (type instanceof IXmlLeafElementType) {
       if (type == XML_REAL_WHITE_SPACE) {
         return new PsiWhiteSpaceImpl(text);