diff --git a/java/java-psi-api/src/com/intellij/codeInsight/AnnotationUtil.java b/java/java-psi-api/src/com/intellij/codeInsight/AnnotationUtil.java
index 06489a5793d0..d77d06f10c7b 100644
--- a/java/java-psi-api/src/com/intellij/codeInsight/AnnotationUtil.java
+++ b/java/java-psi-api/src/com/intellij/codeInsight/AnnotationUtil.java
@@ -5,10 +5,7 @@ import com.intellij.openapi.project.Project;
 import com.intellij.openapi.util.Comparing;
 import com.intellij.psi.*;
 import com.intellij.psi.util.*;
-import com.intellij.util.ArrayUtil;
-import com.intellij.util.Consumer;
-import com.intellij.util.Processor;
-import com.intellij.util.Processors;
+import com.intellij.util.*;
 import com.intellij.util.containers.ConcurrentFactoryMap;
 import com.intellij.util.containers.ContainerUtil;
 import gnu.trove.THashMap;
@@ -24,8 +21,6 @@ import java.lang.annotation.Target;
 import java.lang.reflect.Proxy;
 import java.util.*;
 
-import static com.intellij.util.BitUtil.isSet;
-
 /**
  * @author max
  */
@@ -76,7 +71,7 @@ public class AnnotationUtil {
     return skipExternal ? null : findNonCodeAnnotation(listOwner, annotationNames);
   }
 
-  private static PsiAnnotation findOwnAnnotation(final PsiModifierListOwner listOwner, Collection<String> annotationNames) {
+  private static PsiAnnotation findOwnAnnotation(@NotNull final PsiModifierListOwner listOwner, @NotNull Collection<String> annotationNames) {
     final PsiModifierList list = listOwner.getModifierList();
     if (list == null) return null;
     for (PsiAnnotation annotation : list.getAnnotations()) {
@@ -87,7 +82,7 @@ public class AnnotationUtil {
     return null;
   }
 
-  private static PsiAnnotation findNonCodeAnnotation(final PsiModifierListOwner listOwner, Collection<String> annotationNames) {
+  private static PsiAnnotation findNonCodeAnnotation(@NotNull PsiModifierListOwner listOwner, @NotNull Collection<String> annotationNames) {
     if (listOwner instanceof PsiLocalVariable) {
       // Non-code annotations for local variables are not supported: don't bother to search them
       return null;
@@ -137,6 +132,7 @@ public class AnnotationUtil {
     return result == null ? PsiAnnotation.EMPTY_ARRAY : result.toArray(PsiAnnotation.EMPTY_ARRAY);
   }
 
+  @NotNull
   public static <T extends PsiModifierListOwner> List<T> getSuperAnnotationOwners(@NotNull T element) {
     return CachedValuesManager.getCachedValue(element, () -> {
       Set<PsiModifierListOwner> result = ContainerUtil.newLinkedHashSet();
@@ -155,7 +151,8 @@ public class AnnotationUtil {
       List<T> list;
       if(result.isEmpty()) {
         list = Collections.emptyList();
-      } else {
+      }
+      else {
         PsiModifierListOwner[] array = result.toArray(new PsiModifierListOwner[0]);
         //noinspection unchecked
         list = Arrays.asList((T[])array);
@@ -179,7 +176,7 @@ public class AnnotationUtil {
     return null;
   }
 
-  private static void collectSuperParameters(@NotNull final Set<PsiModifierListOwner> result, @NotNull PsiParameter parameter) {
+  private static void collectSuperParameters(@NotNull final Set<? super PsiModifierListOwner> result, @NotNull PsiParameter parameter) {
     PsiElement parent = parameter.getParent();
     if (!(parent instanceof PsiParameterList)) {
       return;
@@ -209,7 +206,7 @@ public class AnnotationUtil {
     }
   }
 
-  private static void collectSuperMethods(@NotNull Set<PsiModifierListOwner> result,
+  private static void collectSuperMethods(@NotNull Set<? super PsiModifierListOwner> result,
                                           @NotNull HierarchicalMethodSignature signature,
                                           @NotNull PsiElement place,
                                           @NotNull PsiResolveHelper resolveHelper) {
@@ -238,7 +235,7 @@ public class AnnotationUtil {
     return isAnnotated(listOwner, annotationFqn, flags, null);
   }
 
-  private static boolean isAnnotated(PsiModifierListOwner listOwner, String annotationFQN, int flags, @Nullable Set<PsiMember> processed) {
+  private static boolean isAnnotated(@NotNull PsiModifierListOwner listOwner, @NotNull String annotationFQN, @Flags int flags, @Nullable Set<PsiMember> processed) {
     if (!listOwner.isValid()) return false;
 
     PsiModifierList modifierList = listOwner.getModifierList();
@@ -247,7 +244,7 @@ public class AnnotationUtil {
     PsiAnnotation annotation = modifierList.findAnnotation(annotationFQN);
     if (annotation != null) return true;
 
-    if (isSet(flags, CHECK_TYPE)) {
+    if (BitUtil.isSet(flags, CHECK_TYPE)) {
       PsiType type = null;
       if (listOwner instanceof PsiMethod) {
         type = ((PsiMethod)listOwner).getReturnType();
@@ -260,21 +257,21 @@ public class AnnotationUtil {
       }
     }
 
-    if (isSet(flags, CHECK_EXTERNAL)) {
+    if (BitUtil.isSet(flags, CHECK_EXTERNAL)) {
       Project project = listOwner.getProject();
       if (ExternalAnnotationsManager.getInstance(project).findExternalAnnotation(listOwner, annotationFQN) != null) {
         return true;
       }
     }
 
-    if (isSet(flags, CHECK_INFERRED)) {
+    if (BitUtil.isSet(flags, CHECK_INFERRED)) {
       Project project = listOwner.getProject();
       if (InferredAnnotationsManager.getInstance(project).findInferredAnnotation(listOwner, annotationFQN) != null) {
         return true;
       }
     }
 
-    if (isSet(flags, CHECK_HIERARCHY)) {
+    if (BitUtil.isSet(flags, CHECK_HIERARCHY)) {
       if (listOwner instanceof PsiMethod) {
         PsiMethod method = (PsiMethod)listOwner;
         if (processed == null) processed = new THashSet<>();
@@ -449,7 +446,7 @@ public class AnnotationUtil {
     return annotations;
   }
 
-  public static boolean isInsideAnnotation(PsiElement element) {
+  public static boolean isInsideAnnotation(@NotNull PsiElement element) {
     for (int level = 0; level<4; level++) {
       if (element instanceof PsiNameValuePair) return true;
       element = element.getParent();
@@ -545,7 +542,7 @@ public class AnnotationUtil {
     return true;
   }
 
-  private static boolean fillValueMap(PsiAnnotationParameterList parameterList, Map<String, PsiAnnotationMemberValue> valueMap) {
+  private static boolean fillValueMap(@NotNull PsiAnnotationParameterList parameterList, @NotNull Map<String, PsiAnnotationMemberValue> valueMap) {
     final PsiNameValuePair[] attributes1 = parameterList.getAttributes();
     for (PsiNameValuePair attribute : attributes1) {
       final PsiReference reference = attribute.getReference();
@@ -568,7 +565,7 @@ public class AnnotationUtil {
     return true;
   }
 
-  public static boolean equal(PsiAnnotationMemberValue value1, PsiAnnotationMemberValue value2) {
+  public static boolean equal(@Nullable PsiAnnotationMemberValue value1, @Nullable PsiAnnotationMemberValue value2) {
     if (value1 instanceof PsiArrayInitializerMemberValue && value2 instanceof PsiArrayInitializerMemberValue) {
       final PsiAnnotationMemberValue[] initializers1 = ((PsiArrayInitializerMemberValue)value1).getInitializers();
       final PsiAnnotationMemberValue[] initializers2 = ((PsiArrayInitializerMemberValue)value2).getInitializers();
@@ -595,7 +592,7 @@ public class AnnotationUtil {
   /**
    * Ignores Override and SuppressWarnings annotations.
    */
-  public static boolean equal(PsiAnnotation[] annotations1, PsiAnnotation[] annotations2) {
+  public static boolean equal(@NotNull PsiAnnotation[] annotations1, @NotNull PsiAnnotation[] annotations2) {
     final Map<String, PsiAnnotation> map1 = buildAnnotationMap(annotations1);
     final Map<String, PsiAnnotation> map2 = buildAnnotationMap(annotations2);
     if (map1.size() != map2.size()) {
@@ -609,7 +606,8 @@ public class AnnotationUtil {
     return true;
   }
 
-  private static Map<String, PsiAnnotation> buildAnnotationMap(PsiAnnotation[] annotations) {
+  @NotNull
+  private static Map<String, PsiAnnotation> buildAnnotationMap(@NotNull PsiAnnotation[] annotations) {
     final Map<String, PsiAnnotation> map = new HashMap<>();
     for (PsiAnnotation annotation : annotations) {
       map.put(annotation.getQualifiedName(), annotation);
@@ -667,7 +665,8 @@ public class AnnotationUtil {
     return isAnnotated(listOwner, annotationFQN, flags(checkHierarchy, skipExternal, skipExternal));
   }
 
-  private static @Flags int flags(boolean checkHierarchy, boolean skipExternal, boolean skipInferred) {
+  @Flags
+  private static int flags(boolean checkHierarchy, boolean skipExternal, boolean skipInferred) {
     int flags = CHECK_TYPE;
     if (checkHierarchy) flags |= CHECK_HIERARCHY;
     if (!skipExternal) flags |= CHECK_EXTERNAL;
diff --git a/platform/core-api/src/com/intellij/util/indexing/ID.java b/platform/core-api/src/com/intellij/util/indexing/ID.java
index d9fd5ef075f3..8a73b5b13e9a 100644
--- a/platform/core-api/src/com/intellij/util/indexing/ID.java
+++ b/platform/core-api/src/com/intellij/util/indexing/ID.java
@@ -41,14 +41,11 @@ public class ID<K, V> extends IndexId<K,V> {
     try {
       TObjectIntHashMap<String> nameToIdRegistry = new TObjectIntHashMap<>();
       try (BufferedReader reader = new BufferedReader(new FileReader(indices))) {
-        int cnt = 0;
-        do {
-          cnt++;
+        for (int cnt = 1; ; cnt++) {
           final String name = reader.readLine();
           if (name == null) break;
           nameToIdRegistry.put(name, cnt);
         }
-        while (true);
       }
 
       synchronized (ourNameToIdRegistry) {
@@ -67,12 +64,13 @@ public class ID<K, V> extends IndexId<K,V> {
     }
   }
 
+  @NotNull
   private static File getEnumFile() {
     final File indexFolder = PathManager.getIndexRoot();
     return new File(indexFolder, "indices.enum");
   }
 
-  protected ID(String name) {
+  protected ID(@NotNull String name) {
     super(name);
     myUniqueId = stringToId(name);
 
@@ -80,14 +78,14 @@ public class ID<K, V> extends IndexId<K,V> {
     assert old == null : "ID with name '" + name + "' is already registered";
   }
 
-  private static short stringToId(String name) {
+  private static short stringToId(@NotNull String name) {
     synchronized (ourNameToIdRegistry) {
       if (ourNameToIdRegistry.containsKey(name)) {
         return (short)ourNameToIdRegistry.get(name);
       }
 
       int n = ourNameToIdRegistry.size() + 1;
-      assert n <= MAX_NUMBER_OF_INDICES : "Number of indices exceeded";
+      assert n <= MAX_NUMBER_OF_INDICES : "Number of indices exceeded: "+n;
 
       ourNameToIdRegistry.put(name, n);
       writeEnumFile();
@@ -95,7 +93,7 @@ public class ID<K, V> extends IndexId<K,V> {
     }
   }
 
-  public static void reinitializeDiskStorage() {
+  static void reinitializeDiskStorage() {
     synchronized (ourNameToIdRegistry) {
       writeEnumFile();
     }
@@ -126,7 +124,7 @@ public class ID<K, V> extends IndexId<K,V> {
   @NotNull
   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<>(name);
+    return found == null ? new ID<>(name) : found;
   }
 
   @Nullable
@@ -134,13 +132,15 @@ public class ID<K, V> extends IndexId<K,V> {
     return (ID<K, V>)findById(stringToId(name));
   }
 
+  @Override
   public int hashCode() {
-    return (int)myUniqueId;
+    return myUniqueId;
   }
 
   /**
    * Consider to use {@link ID#getName()} instead of this method
    */
+  @Override
   public String toString() {
     return getName();
   }
diff --git a/platform/core-impl/src/com/intellij/psi/impl/source/tree/SharedImplUtil.java b/platform/core-impl/src/com/intellij/psi/impl/source/tree/SharedImplUtil.java
index fc515f5553db..ae784041cb9e 100644
--- a/platform/core-impl/src/com/intellij/psi/impl/source/tree/SharedImplUtil.java
+++ b/platform/core-impl/src/com/intellij/psi/impl/source/tree/SharedImplUtil.java
@@ -47,24 +47,24 @@ public class SharedImplUtil {
     return SourceTreeToPsiMap.treeElementToPsi(thisElement.getTreeParent());
   }
 
-  public static PsiElement getFirstChild(ASTNode element) {
+  public static PsiElement getFirstChild(@NotNull ASTNode element) {
     return SourceTreeToPsiMap.treeElementToPsi(element.getFirstChildNode());
   }
 
   @Nullable
-  public static PsiElement getLastChild(ASTNode element) {
+  public static PsiElement getLastChild(@NotNull ASTNode element) {
     return SourceTreeToPsiMap.treeElementToPsi(element.getLastChildNode());
   }
 
-  public static PsiElement getNextSibling(ASTNode thisElement) {
+  public static PsiElement getNextSibling(@NotNull ASTNode thisElement) {
     return SourceTreeToPsiMap.treeElementToPsi(thisElement.getTreeNext());
   }
 
-  public static PsiElement getPrevSibling(ASTNode thisElement) {
+  public static PsiElement getPrevSibling(@NotNull ASTNode thisElement) {
     return SourceTreeToPsiMap.treeElementToPsi(thisElement.getTreePrev());
   }
 
-  public static PsiFile getContainingFile(ASTNode thisElement) {
+  public static PsiFile getContainingFile(@NotNull ASTNode thisElement) {
     FileASTNode node = findFileElement(thisElement);
     PsiElement psi = node == null ? null : node.getPsi();
     if (psi == null || psi instanceof PsiFile) return (PsiFile)psi;
@@ -186,7 +186,7 @@ public class SharedImplUtil {
     return count;
   }
 
-  public static void acceptChildren(PsiElementVisitor visitor, ASTNode root) {
+  public static void acceptChildren(@NotNull PsiElementVisitor visitor, @NotNull ASTNode root) {
     ASTNode childNode = root.getFirstChildNode();
 
     while (childNode != null) {
@@ -203,7 +203,7 @@ public class SharedImplUtil {
     }
   }
 
-  public static PsiElement doReplace(PsiElement psiElement, TreeElement treeElement, PsiElement newElement) {
+  public static PsiElement doReplace(@NotNull PsiElement psiElement, @NotNull TreeElement treeElement, @NotNull PsiElement newElement) {
     CompositeElement treeParent = treeElement.getTreeParent();
     LOG.assertTrue(treeParent != null);
     CheckUtil.checkWritable(psiElement);
diff --git a/platform/lang-impl/src/com/intellij/find/impl/FindInProjectUtil.java b/platform/lang-impl/src/com/intellij/find/impl/FindInProjectUtil.java
index 807bbee8e991..be01ff93a2fd 100644
--- a/platform/lang-impl/src/com/intellij/find/impl/FindInProjectUtil.java
+++ b/platform/lang-impl/src/com/intellij/find/impl/FindInProjectUtil.java
@@ -132,10 +132,10 @@ public class FindInProjectUtil {
     VirtualFile virtualFile = LocalFileSystem.getInstance().findFileByPath(path);
     if (virtualFile == null || !virtualFile.isDirectory()) {
       virtualFile = null;
-      @SuppressWarnings("deprecation") VirtualFileSystem[] fileSystems = ApplicationManager.getApplication().getComponents(VirtualFileSystem.class);
+      VirtualFileSystem[] fileSystems = ApplicationManager.getApplication().getComponents(VirtualFileSystem.class);
       for (VirtualFileSystem fs : fileSystems) {
         if (fs instanceof LocalFileProvider) {
-          @SuppressWarnings("deprecation") VirtualFile file = ((LocalFileProvider)fs).findLocalVirtualFileByPath(path);
+          VirtualFile file = ((LocalFileProvider)fs).findLocalVirtualFileByPath(path);
           if (file != null && file.isDirectory()) {
             if (file.getChildren().length > 0) {
               virtualFile = file;
@@ -249,7 +249,7 @@ public class FindInProjectUtil {
                                  @NotNull final PsiFile psiFile,
                                  @NotNull int[] offsetRef,
                                  int maxUsages,
-                                 @NotNull Processor<UsageInfo> consumer) {
+                                 @NotNull Processor<? super UsageInfo> consumer) {
     int count = 0;
     CharSequence text = document.getCharsSequence();
     int textLength = document.getTextLength();
@@ -532,7 +532,7 @@ public class FindInProjectUtil {
 
   private static void addSourceDirectoriesFromLibraries(@NotNull Project project,
                                                         @NotNull VirtualFile directory,
-                                                        @NotNull Collection<VirtualFile> outSourceRoots) {
+                                                        @NotNull Collection<? super VirtualFile> outSourceRoots) {
     ProjectFileIndex index = ProjectFileIndex.SERVICE.getInstance(project);
     // if we already are in the sources, search just in this directory only
     if (!index.isInLibraryClasses(directory)) return;
diff --git a/plugins/properties/properties-psi-impl/src/com/intellij/lang/properties/parsing/PropertyListStubElementType.java b/plugins/properties/properties-psi-impl/src/com/intellij/lang/properties/parsing/PropertyListStubElementType.java
index 438d470f0177..58ed5cf6e235 100644
--- a/plugins/properties/properties-psi-impl/src/com/intellij/lang/properties/parsing/PropertyListStubElementType.java
+++ b/plugins/properties/properties-psi-impl/src/com/intellij/lang/properties/parsing/PropertyListStubElementType.java
@@ -44,6 +44,7 @@ public class PropertyListStubElementType extends ILightStubElementType<Propertie
     return new PropertiesListStubImpl(parentStub);
   }
 
+  @Override
   @NotNull
   public String getExternalId() {
     return "properties.propertieslist";
diff --git a/plugins/properties/properties-psi-impl/src/com/intellij/lang/properties/parsing/PropertyStubElementType.java b/plugins/properties/properties-psi-impl/src/com/intellij/lang/properties/parsing/PropertyStubElementType.java
index 7192288ec742..12e6035e3c51 100644
--- a/plugins/properties/properties-psi-impl/src/com/intellij/lang/properties/parsing/PropertyStubElementType.java
+++ b/plugins/properties/properties-psi-impl/src/com/intellij/lang/properties/parsing/PropertyStubElementType.java
@@ -48,6 +48,7 @@ public class PropertyStubElementType extends ILightStubElementType<PropertyStub,
     return new PropertyStubImpl(parentStub, psi.getKey());
   }
 
+  @Override
   @NotNull
   public String getExternalId() {
     return "properties.prop";
diff --git a/python/psi-api/src/com/jetbrains/python/psi/PyStubElementType.java b/python/psi-api/src/com/jetbrains/python/psi/PyStubElementType.java
index 819ec557388c..39999354a6fa 100644
--- a/python/psi-api/src/com/jetbrains/python/psi/PyStubElementType.java
+++ b/python/psi-api/src/com/jetbrains/python/psi/PyStubElementType.java
@@ -43,6 +43,7 @@ public abstract class PyStubElementType<StubT extends StubElement, PsiT extends
   public void indexStub(@NotNull final StubT stub, @NotNull final IndexSink sink) {
   }
 
+  @Override
   @NotNull
   public String getExternalId() {
     return "py." + super.toString();