diff --git a/js/js.dart-ast/src/com/google/dart/compiler/backend/js/ast/JsScope.java b/js/js.dart-ast/src/com/google/dart/compiler/backend/js/ast/JsScope.java
index f2d305ddd09..7481c056cc3 100644
--- a/js/js.dart-ast/src/com/google/dart/compiler/backend/js/ast/JsScope.java
+++ b/js/js.dart-ast/src/com/google/dart/compiler/backend/js/ast/JsScope.java
@@ -47,7 +47,7 @@ public abstract class JsScope {
     private final String description;
     private Map<String, JsName> names = Collections.emptyMap();
     private final JsScope parent;
-    protected int tempIndex = 0;
+    private int tempIndex = 0;
     private final String scopeId;
 
     private static final Pattern FRESH_NAME_SUFFIX = Pattern.compile("[\\$_]\\d+$");
@@ -94,7 +94,6 @@ public abstract class JsScope {
     public JsName declareFreshName(@NotNull String suggestedName) {
         assert !suggestedName.isEmpty();
         String ident = getFreshIdent(suggestedName);
-        assert !hasOwnName(ident);
         return doCreateName(ident);
     }
 
@@ -121,7 +120,7 @@ public abstract class JsScope {
      * @return <code>null</code> if the identifier has no associated name
      */
     @Nullable
-    public final JsName findName(String ident) {
+    public final JsName findName(@NotNull String ident) {
         JsName name = findOwnName(ident);
         if (name == null && parent != null) {
             return parent.findName(ident);
@@ -133,6 +132,11 @@ public abstract class JsScope {
         return names.containsKey(name);
     }
 
+    @Nullable
+    public boolean hasName(@NotNull String name) {
+        return hasOwnName(name) || (parent != null && parent.hasName(name));
+    }
+
     /**
      * Returns the parent scope of this scope, or <code>null</code> if this is the
      * root scope.
@@ -209,7 +213,7 @@ public abstract class JsScope {
         }
 
         String freshName = suggestedIdent;
-        while (hasOwnName(freshName)) {
+        while (hasName(freshName)) {
             freshName = baseName + sep + counter++;
         }
 
diff --git a/js/js.dart-ast/src/com/google/dart/compiler/backend/js/ast/jsScopes.kt b/js/js.dart-ast/src/com/google/dart/compiler/backend/js/ast/jsScopes.kt
index 9d49f07ec14..210bc0369cb 100644
--- a/js/js.dart-ast/src/com/google/dart/compiler/backend/js/ast/jsScopes.kt
+++ b/js/js.dart-ast/src/com/google/dart/compiler/backend/js/ast/jsScopes.kt
@@ -32,8 +32,6 @@ open class JsFunctionScope(parent: JsScope, description: String) : JsScope(paren
     private val topLabelScope: LabelScope?
         get() = if (labelScopes.isNotEmpty()) labelScopes.peek() else null
 
-    override fun declareName(identifier: String): JsName = super.declareFreshName(identifier)
-
     override fun hasOwnName(name: String): Boolean = RESERVED_WORDS.contains(name) || super.hasOwnName(name)
 
     open fun declareNameUnsafe(identifier: String): JsName = super.declareName(identifier)
diff --git a/js/js.frontend/src/org/jetbrains/kotlin/js/naming/FQNGenerator.kt b/js/js.frontend/src/org/jetbrains/kotlin/js/naming/FQNGenerator.kt
index ec758073c75..0ff5748399a 100644
--- a/js/js.frontend/src/org/jetbrains/kotlin/js/naming/FQNGenerator.kt
+++ b/js/js.frontend/src/org/jetbrains/kotlin/js/naming/FQNGenerator.kt
@@ -187,7 +187,9 @@ class FQNGenerator {
         return when (containingDeclaration) {
             is PackageFragmentDescriptor -> descriptor.visibility.isPublicAPI
             is ClassDescriptor -> {
-                if (descriptor.modality == Modality.OPEN || descriptor.modality == Modality.ABSTRACT) {
+                if (descriptor.modality == Modality.OPEN || descriptor.modality == Modality.ABSTRACT ||
+                    containingDeclaration.modality == Modality.OPEN || containingDeclaration.modality == Modality.ABSTRACT
+                ) {
                     return descriptor.visibility.isPublicAPI
                 }
 
diff --git a/js/js.frontend/src/org/jetbrains/kotlin/js/resolve/diagnostics/JsNameChecker.kt b/js/js.frontend/src/org/jetbrains/kotlin/js/resolve/diagnostics/JsNameChecker.kt
index e5a32952828..65fe5b455d0 100644
--- a/js/js.frontend/src/org/jetbrains/kotlin/js/resolve/diagnostics/JsNameChecker.kt
+++ b/js/js.frontend/src/org/jetbrains/kotlin/js/resolve/diagnostics/JsNameChecker.kt
@@ -16,7 +16,6 @@
 
 package org.jetbrains.kotlin.js.resolve.diagnostics
 
-import org.jetbrains.kotlin.config.LanguageFeatureSettings
 import org.jetbrains.kotlin.descriptors.*
 import org.jetbrains.kotlin.diagnostics.DiagnosticSink
 import org.jetbrains.kotlin.js.translate.utils.AnnotationsUtils
@@ -26,7 +25,7 @@ import org.jetbrains.kotlin.resolve.SimpleDeclarationChecker
 
 object JsNameChecker : SimpleDeclarationChecker {
     override fun check(declaration: KtDeclaration, descriptor: DeclarationDescriptor, diagnosticHolder: DiagnosticSink,
-                       bindingContext: BindingContext, languageFeatureSettings: LanguageFeatureSettings) {
+                       bindingContext: BindingContext) {
         if (descriptor is PropertyDescriptor) {
             val namedAccessorCount = descriptor.accessors.count { AnnotationsUtils.getJsName(it) != null }
             if (namedAccessorCount > 0 && namedAccessorCount < descriptor.accessors.size) {
diff --git a/js/js.frontend/src/org/jetbrains/kotlin/js/resolve/diagnostics/JsNameClashChecker.kt b/js/js.frontend/src/org/jetbrains/kotlin/js/resolve/diagnostics/JsNameClashChecker.kt
index 47b762fcf4b..3e665a14a1d 100644
--- a/js/js.frontend/src/org/jetbrains/kotlin/js/resolve/diagnostics/JsNameClashChecker.kt
+++ b/js/js.frontend/src/org/jetbrains/kotlin/js/resolve/diagnostics/JsNameClashChecker.kt
@@ -16,7 +16,6 @@
 
 package org.jetbrains.kotlin.js.resolve.diagnostics
 
-import org.jetbrains.kotlin.config.LanguageFeatureSettings
 import org.jetbrains.kotlin.descriptors.*
 import org.jetbrains.kotlin.diagnostics.DiagnosticSink
 import org.jetbrains.kotlin.js.naming.FQNGenerator
@@ -24,7 +23,6 @@ import org.jetbrains.kotlin.js.translate.utils.AnnotationsUtils
 import org.jetbrains.kotlin.psi.KtDeclaration
 import org.jetbrains.kotlin.psi.KtProperty
 import org.jetbrains.kotlin.resolve.BindingContext
-import org.jetbrains.kotlin.resolve.DeclarationChecker
 import org.jetbrains.kotlin.resolve.DescriptorUtils
 import org.jetbrains.kotlin.resolve.SimpleDeclarationChecker
 import org.jetbrains.kotlin.resolve.descriptorUtil.isExtension
@@ -40,8 +38,7 @@ class JsNameClashChecker : SimpleDeclarationChecker {
             declaration: KtDeclaration,
             descriptor: DeclarationDescriptor,
             diagnosticHolder: DiagnosticSink,
-            bindingContext: BindingContext,
-            languageFeatureSettings: LanguageFeatureSettings
+            bindingContext: BindingContext
     ) {
         if (declaration !is KtProperty || !descriptor.isExtension) {
             checkDescriptor(descriptor, declaration, diagnosticHolder)
diff --git a/js/js.frontend/src/org/jetbrains/kotlin/js/resolve/diagnostics/OverriddenJsNameChecker.kt b/js/js.frontend/src/org/jetbrains/kotlin/js/resolve/diagnostics/OverriddenJsNameChecker.kt
deleted file mode 100644
index ea81667011d..00000000000
--- a/js/js.frontend/src/org/jetbrains/kotlin/js/resolve/diagnostics/OverriddenJsNameChecker.kt
+++ /dev/null
@@ -1,77 +0,0 @@
-/*
- * Copyright 2010-2016 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.
- * 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 org.jetbrains.kotlin.js.resolve.diagnostics
-
-import org.jetbrains.kotlin.descriptors.CallableMemberDescriptor
-import org.jetbrains.kotlin.descriptors.ClassDescriptor
-import org.jetbrains.kotlin.descriptors.DeclarationDescriptor
-import org.jetbrains.kotlin.diagnostics.DiagnosticSink
-import org.jetbrains.kotlin.js.naming.FQNGenerator
-import org.jetbrains.kotlin.js.translate.utils.AnnotationsUtils
-import org.jetbrains.kotlin.psi.KtDeclaration
-import org.jetbrains.kotlin.resolve.BindingContext
-import org.jetbrains.kotlin.resolve.DeclarationChecker
-
-class OverriddenJsNameChecker : DeclarationChecker {
-    private val fqnGenerator = FQNGenerator()
-
-    override fun check(declaration: KtDeclaration, descriptor: DeclarationDescriptor, diagnosticHolder: DiagnosticSink,
-                       bindingContext: BindingContext) {
-        doCheck(descriptor) { first, second ->
-            val psi = descriptor.findPsi() ?: declaration
-            diagnosticHolder.report(ErrorsJs.JS_NAME_OVERRIDE_CLASH.on(psi, first, second))
-        }
-
-        if (descriptor is ClassDescriptor) {
-            val fakeOverrides = descriptor.defaultType.memberScope.getContributedDescriptors().asSequence()
-                    .mapNotNull { it as? CallableMemberDescriptor }
-                    .filter { it.kind == CallableMemberDescriptor.Kind.FAKE_OVERRIDE }
-            for (override in fakeOverrides) {
-                val errorFound = doCheck(override) { first, second ->
-                    val psi = descriptor.findPsi() ?: declaration
-                    diagnosticHolder.report(ErrorsJs.JS_NAME_OVERRIDE_CLASH.on(psi, first, second))
-                }
-                if (errorFound) break
-            }
-        }
-    }
-
-    private fun doCheck(descriptor: DeclarationDescriptor, onClash: (CallableMemberDescriptor, CallableMemberDescriptor) -> Unit):
-            Boolean {
-        if (descriptor !is CallableMemberDescriptor) return false
-
-        var knownName: String? = null
-        var knownDescriptor: CallableMemberDescriptor? = null
-        for (overridden in descriptor.overriddenDescriptors) {
-            val fqn = fqnGenerator.generate(overridden)
-            if (!fqn.shared) continue
-
-            val name = fqnGenerator.generate(overridden).names.last()
-            if (knownName == null) {
-                knownName = name
-                knownDescriptor = overridden
-            }
-            else if (knownName != name &&
-                     (AnnotationsUtils.getJsName(knownDescriptor!!) != null || AnnotationsUtils.getJsName(overridden) != null)) {
-                onClash(knownDescriptor, overridden)
-                return true
-            }
-        }
-
-        return false
-    }
-}
diff --git a/js/js.translator/src/org/jetbrains/kotlin/js/translate/context/Namer.java b/js/js.translator/src/org/jetbrains/kotlin/js/translate/context/Namer.java
index 97133e193ab..dda2b1cb181 100644
--- a/js/js.translator/src/org/jetbrains/kotlin/js/translate/context/Namer.java
+++ b/js/js.translator/src/org/jetbrains/kotlin/js/translate/context/Namer.java
@@ -27,6 +27,7 @@ import org.jetbrains.kotlin.descriptors.CallableDescriptor;
 import org.jetbrains.kotlin.descriptors.ClassDescriptor;
 import org.jetbrains.kotlin.descriptors.TypeParameterDescriptor;
 import org.jetbrains.kotlin.idea.KotlinLanguage;
+import org.jetbrains.kotlin.js.naming.FQNGenerator;
 import org.jetbrains.kotlin.js.resolve.JsPlatform;
 import org.jetbrains.kotlin.name.FqName;
 import org.jetbrains.kotlin.name.FqNameUnsafe;
@@ -40,7 +41,6 @@ import static com.google.dart.compiler.backend.js.ast.JsScopesKt.JsObjectScope;
 import static org.jetbrains.kotlin.js.translate.utils.JsAstUtils.pureFqn;
 import static org.jetbrains.kotlin.js.translate.utils.JsDescriptorUtils.getModuleName;
 import static org.jetbrains.kotlin.js.translate.utils.ManglingUtils.getStableMangledNameForDescriptor;
-import static org.jetbrains.kotlin.js.translate.utils.ManglingUtils.getSuggestedName;
 
 /**
  * Encapsulates different types of constants and naming conventions.
@@ -128,7 +128,7 @@ public final class Namer {
             qualifier = fqNameParent.asString();
         }
 
-        String mangledName = getSuggestedName(functionDescriptor);
+        String mangledName = new FQNGenerator().generate(functionDescriptor).getNames().get(0);
         return StringUtil.join(Arrays.asList(moduleName, qualifier, mangledName), ".");
     }
 
diff --git a/js/js.translator/src/org/jetbrains/kotlin/js/translate/context/StaticContext.java b/js/js.translator/src/org/jetbrains/kotlin/js/translate/context/StaticContext.java
index 3185e1e64a4..d99227dd83f 100644
--- a/js/js.translator/src/org/jetbrains/kotlin/js/translate/context/StaticContext.java
+++ b/js/js.translator/src/org/jetbrains/kotlin/js/translate/context/StaticContext.java
@@ -110,6 +110,9 @@ public final class StaticContext {
     @NotNull
     private final Map<DeclarationDescriptor, JsName> nameCache = new HashMap<DeclarationDescriptor, JsName>();
 
+    @NotNull
+    private final Map<PropertyDescriptor, JsName> backingFieldNameCache = new HashMap<PropertyDescriptor, JsName>();
+
     private final Map<JsScope, Map<String, JsName>> persistentNames = new HashMap<JsScope, Map<String, JsName>>();
 
     @NotNull
@@ -120,6 +123,9 @@ public final class StaticContext {
 
     private Map<String, JsName> readOnlyImportedModules;
 
+    @NotNull
+    private final JsScope rootPackageScope;
+
     //TODO: too many parameters in constructor
     private StaticContext(
             @NotNull JsProgram program,
@@ -139,6 +145,7 @@ public final class StaticContext {
         this.standardClasses = standardClasses;
         this.config = config;
         currentModule = moduleDescriptor;
+        rootPackageScope = new JsObjectScope(rootScope, "<root package>", "root-package");
     }
 
     @NotNull
@@ -280,6 +287,27 @@ public final class StaticContext {
         return getNameForFQNPart(fqnGenerator.generate(descriptor)).get(0);
     }
 
+    @NotNull
+    public JsName getNameForBackingField(@NotNull PropertyDescriptor property) {
+        JsName name = backingFieldNameCache.get(property);
+
+        if (name == null) {
+            FQNPart fqn = fqnGenerator.generate(property);
+            assert fqn.getNames().size() == 1 : "Private names must always consist of exactly one name";
+
+            JsScope scope = getScopeForDescriptor(fqn.getScope());
+
+            if (DynamicCallsKt.isDynamic(property)) {
+                scope = JsDynamicScope.INSTANCE;
+            }
+            String baseName = fqn.getNames().get(0) + "_0";
+            name = scope.declareFreshName(baseName);
+            backingFieldNameCache.put(property, name);
+        }
+
+        return name;
+    }
+
     @NotNull
     private List<JsName> getNameForFQNPart(@NotNull FQNPart part) {
         JsScope scope = getScopeForDescriptor(part.getScope());
@@ -328,7 +356,7 @@ public final class StaticContext {
             @Override
             public JsName create() {
                 String name = Namer.generatePackageName(packageFqName);
-                return getRootScope().declareName(name);
+                return rootPackageScope.declareName(name);
             }
         });
     }
@@ -427,9 +455,8 @@ public final class StaticContext {
                     if (!(descriptor instanceof CallableDescriptor)) {
                         return null;
                     }
-                    JsScope enclosingScope = getEnclosingScope(descriptor);
 
-                    JsFunction correspondingFunction = JsAstUtils.createFunctionWithEmptyBody(enclosingScope);
+                    JsFunction correspondingFunction = JsAstUtils.createFunctionWithEmptyBody(getRootScope());
                     assert (!scopeToFunction.containsKey(correspondingFunction.getScope())) : "Scope to function value overridden for " + descriptor;
                     scopeToFunction.put(correspondingFunction.getScope(), correspondingFunction);
                     return correspondingFunction.getScope();
diff --git a/js/js.translator/src/org/jetbrains/kotlin/js/translate/context/TranslationContext.java b/js/js.translator/src/org/jetbrains/kotlin/js/translate/context/TranslationContext.java
index 157932b3113..044ebfd42aa 100644
--- a/js/js.translator/src/org/jetbrains/kotlin/js/translate/context/TranslationContext.java
+++ b/js/js.translator/src/org/jetbrains/kotlin/js/translate/context/TranslationContext.java
@@ -229,6 +229,11 @@ public class TranslationContext {
         return staticContext.getQualifiedReference(packageFqName);
     }
 
+    @NotNull
+    public JsName getNameForBackingField(@NotNull PropertyDescriptor property) {
+        return staticContext.getNameForBackingField(property);
+    }
+
     @NotNull
     public TemporaryVariable declareTemporary(@Nullable JsExpression initExpression) {
         return dynamicContext.declareTemporary(initExpression);
diff --git a/js/js.translator/src/org/jetbrains/kotlin/js/translate/context/UsageTracker.kt b/js/js.translator/src/org/jetbrains/kotlin/js/translate/context/UsageTracker.kt
index 55ffb5c7b41..9e7760218dc 100644
--- a/js/js.translator/src/org/jetbrains/kotlin/js/translate/context/UsageTracker.kt
+++ b/js/js.translator/src/org/jetbrains/kotlin/js/translate/context/UsageTracker.kt
@@ -18,8 +18,8 @@ package org.jetbrains.kotlin.js.translate.context
 
 import org.jetbrains.kotlin.descriptors.*
 import com.google.dart.compiler.backend.js.ast.JsName
-import org.jetbrains.kotlin.js.translate.utils.ManglingUtils.getSuggestedName
 import com.google.dart.compiler.backend.js.ast.JsScope
+import org.jetbrains.kotlin.js.naming.FQNGenerator
 import org.jetbrains.kotlin.resolve.DescriptorUtils
 import org.jetbrains.kotlin.resolve.DescriptorUtils.*
 import org.jetbrains.kotlin.resolve.calls.util.FakeCallableDescriptorForObject
@@ -169,7 +169,10 @@ class UsageTracker(
             is TypeParameterDescriptor -> Namer.isInstanceSuggestedName(this)
 
             // Append 'closure$' prefix to avoid name clash between closure and member fields in case of local classes
-            else -> "closure\$${getSuggestedName(this)}"
+            else -> {
+                val mangled = FQNGenerator().generate(this).names.last()
+                "closure\$$mangled"
+            }
         }
 
         return scope.declareFreshName(suggestedName)
diff --git a/js/js.translator/src/org/jetbrains/kotlin/js/translate/declaration/DelegationTranslator.kt b/js/js.translator/src/org/jetbrains/kotlin/js/translate/declaration/DelegationTranslator.kt
index 2b18e368b02..c392f8f05c5 100644
--- a/js/js.translator/src/org/jetbrains/kotlin/js/translate/declaration/DelegationTranslator.kt
+++ b/js/js.translator/src/org/jetbrains/kotlin/js/translate/declaration/DelegationTranslator.kt
@@ -20,13 +20,13 @@ package org.jetbrains.kotlin.js.translate.declaration
 import com.google.dart.compiler.backend.js.ast.*
 import org.jetbrains.kotlin.backend.common.CodegenUtil
 import org.jetbrains.kotlin.descriptors.*
+import org.jetbrains.kotlin.js.naming.FQNGenerator
 import org.jetbrains.kotlin.js.translate.context.Namer
 import org.jetbrains.kotlin.js.translate.context.TranslationContext
 import org.jetbrains.kotlin.js.translate.general.AbstractTranslator
 import org.jetbrains.kotlin.js.translate.general.Translation
 import org.jetbrains.kotlin.js.translate.utils.BindingUtils
 import org.jetbrains.kotlin.js.translate.utils.JsAstUtils
-import org.jetbrains.kotlin.js.translate.utils.ManglingUtils.getMangledMemberNameForExplicitDelegation
 import org.jetbrains.kotlin.js.translate.utils.TranslationUtils.simpleReturnFunction
 import org.jetbrains.kotlin.js.translate.utils.TranslationUtils.translateFunctionAsEcma5PropertyDescriptor
 import org.jetbrains.kotlin.js.translate.utils.generateDelegateCall
@@ -46,7 +46,7 @@ class DelegationTranslator(
     private val delegationBySpecifiers =
             classDeclaration.getSuperTypeListEntries().filterIsInstance<KtDelegatedSuperTypeEntry>()
 
-    private class Field (val name: String, val generateField: Boolean)
+    private class Field (val name: JsName, val generateField: Boolean)
     private val fields = mutableMapOf<KtDelegatedSuperTypeEntry, Field>()
 
     init {
@@ -57,12 +57,15 @@ class DelegationTranslator(
             val propertyDescriptor = CodegenUtil.getDelegatePropertyIfAny(expression, classDescriptor, bindingContext())
 
             if (CodegenUtil.isFinalPropertyWithBackingField(propertyDescriptor, bindingContext())) {
-                fields[specifier] = Field(propertyDescriptor!!.name.asString(), false)
+                val delegateName = context.getNameForDescriptor(propertyDescriptor!!)
+                fields[specifier] = Field(delegateName, false)
             }
             else {
                 val classFqName = DescriptorUtils.getFqName(classDescriptor)
                 val typeFqName = DescriptorUtils.getFqName(descriptor)
-                val delegateName = getMangledMemberNameForExplicitDelegation(Namer.getDelegatePrefix(), classFqName, typeFqName)
+                val suffix = FQNGenerator.mangledId("${classFqName.asString()}:${typeFqName.asString()}")
+                val suggestedName = Namer.getDelegatePrefix() + if (suffix.isNotEmpty()) "_$suffix\$" else ""
+                val delegateName = context.getScopeForDescriptor(classDescriptor).declareFreshName("${suggestedName}_0")
                 fields[specifier] = Field(delegateName, true)
             }
         }
@@ -76,7 +79,8 @@ class DelegationTranslator(
                 val context = context().innerBlock()
                 val delegateInitExpr = Translation.translateAsExpression(expression, context)
                 statements += context.dynamicContext().jsBlock().statements
-                statements += JsAstUtils.defineSimpleProperty(field.name, delegateInitExpr)
+                val lhs = JsAstUtils.pureFqn(field.name, JsLiteral.THIS)
+                statements += JsAstUtils.assignment(lhs, delegateInitExpr).makeStmt()
             }
         }
     }
@@ -105,15 +109,13 @@ class DelegationTranslator(
 
     private fun generateDelegateCallForPropertyMember(
             descriptor: PropertyDescriptor,
-            delegateName: String,
+            delegateName: JsName,
             properties: MutableList<JsPropertyInitializer>
     ) {
         val propertyName: String = descriptor.name.asString()
 
         fun generateDelegateGetterFunction(getterDescriptor: PropertyGetterDescriptor): JsFunction {
-            // TODO review: used wrong scope?
-            val delegateRefName = context().getScopeForDescriptor(getterDescriptor).declareName(delegateName)
-            val delegateRef = JsNameRef(delegateRefName, JsLiteral.THIS)
+            val delegateRef = JsNameRef(delegateName, JsLiteral.THIS)
 
             val returnExpression: JsExpression = if (DescriptorUtils.isExtension(descriptor)) {
                 val getterName = context().getNameForDescriptor(getterDescriptor)
@@ -121,8 +123,7 @@ class DelegationTranslator(
                 JsInvocation(JsNameRef(getterName, delegateRef), JsNameRef(receiver))
             }
             else {
-                @Suppress("USELESS_CAST")
-                (JsNameRef(propertyName, delegateRef) as JsExpression)  // TODO remove explicit type specification after resolving KT-5569
+                JsNameRef(propertyName, delegateRef)
             }
 
             val jsFunction = simpleReturnFunction(context().getScopeForDescriptor(getterDescriptor.containingDeclaration), returnExpression)
@@ -134,15 +135,14 @@ class DelegationTranslator(
         }
 
         fun generateDelegateSetterFunction(setterDescriptor: PropertySetterDescriptor): JsFunction {
-            val jsFunction = JsFunction(context().getScopeForDescriptor(setterDescriptor.containingDeclaration),
+            val jsFunction = JsFunction(context().program().rootScope,
                                         "setter for " + setterDescriptor.name.asString())
 
             assert(setterDescriptor.valueParameters.size == 1) { "Setter must have 1 parameter" }
             val defaultParameter = JsParameter(jsFunction.scope.declareTemporary())
             val defaultParameterRef = defaultParameter.name.makeRef()
 
-            val delegateRefName = context().getScopeForDescriptor(setterDescriptor).declareName(delegateName)
-            val delegateRef = JsNameRef(delegateRefName, JsLiteral.THIS)
+            val delegateRef = JsNameRef(delegateName, JsLiteral.THIS)
 
             // TODO: remove explicit type annotation when Kotlin compiler works this out
             val setExpression: JsExpression = if (DescriptorUtils.isExtension(descriptor)) {
@@ -182,11 +182,10 @@ class DelegationTranslator(
     private fun generateDelegateCallForFunctionMember(
             descriptor: FunctionDescriptor,
             overriddenDescriptor: FunctionDescriptor,
-            delegateName: String,
+            delegateName: JsName,
             properties: MutableList<JsPropertyInitializer>
     ) {
-        val delegateRefName = context().getScopeForDescriptor(descriptor).declareName(delegateName)
-        val delegateRef = JsNameRef(delegateRefName, JsLiteral.THIS)
+        val delegateRef = JsNameRef(delegateName, JsLiteral.THIS)
         properties.add(generateDelegateCall(descriptor, overriddenDescriptor, delegateRef, context()))
     }
 }
diff --git a/js/js.translator/src/org/jetbrains/kotlin/js/translate/declaration/PropertyTranslator.kt b/js/js.translator/src/org/jetbrains/kotlin/js/translate/declaration/PropertyTranslator.kt
index 722a83923d2..d38bb7acaa4 100644
--- a/js/js.translator/src/org/jetbrains/kotlin/js/translate/declaration/PropertyTranslator.kt
+++ b/js/js.translator/src/org/jetbrains/kotlin/js/translate/declaration/PropertyTranslator.kt
@@ -179,8 +179,7 @@ private class PropertyTranslator(
     }
 
     private fun generateDefaultSetterFunction(setterDescriptor: VariableAccessorDescriptor): JsFunction {
-        val containingScope = context().getScopeForDescriptor(setterDescriptor.containingDeclaration)
-        val function = JsFunction(containingScope, JsBlock(), accessorDescription(setterDescriptor))
+        val function = JsFunction(context().program().rootScope, JsBlock(), accessorDescription(setterDescriptor))
 
         assert(setterDescriptor.valueParameters.size == 1) { "Setter must have 1 parameter" }
         val correspondingPropertyName = setterDescriptor.correspondingVariable.name.asString()
diff --git a/js/js.translator/src/org/jetbrains/kotlin/js/translate/utils/ManglingUtils.java b/js/js.translator/src/org/jetbrains/kotlin/js/translate/utils/ManglingUtils.java
index 7806f3f8888..ee695b5bb08 100644
--- a/js/js.translator/src/org/jetbrains/kotlin/js/translate/utils/ManglingUtils.java
+++ b/js/js.translator/src/org/jetbrains/kotlin/js/translate/utils/ManglingUtils.java
@@ -16,321 +16,23 @@
 
 package org.jetbrains.kotlin.js.translate.utils;
 
-import com.intellij.openapi.util.text.StringUtil;
-import com.intellij.util.Function;
-import com.intellij.util.containers.ContainerUtil;
-import kotlin.collections.CollectionsKt;
-import kotlin.jvm.functions.Function1;
 import org.jetbrains.annotations.NotNull;
-import org.jetbrains.kotlin.backend.common.CodegenUtil;
-import org.jetbrains.kotlin.descriptors.*;
-import org.jetbrains.kotlin.descriptors.annotations.Annotations;
-import org.jetbrains.kotlin.descriptors.impl.ClassConstructorDescriptorImpl;
+import org.jetbrains.kotlin.descriptors.ClassDescriptor;
+import org.jetbrains.kotlin.descriptors.SimpleFunctionDescriptor;
 import org.jetbrains.kotlin.incremental.components.NoLookupLocation;
-import org.jetbrains.kotlin.js.descriptorUtils.DescriptorUtilsKt;
-import org.jetbrains.kotlin.name.FqNameUnsafe;
+import org.jetbrains.kotlin.js.naming.FQNGenerator;
 import org.jetbrains.kotlin.name.Name;
-import org.jetbrains.kotlin.resolve.DescriptorUtils;
-import org.jetbrains.kotlin.resolve.scopes.MemberScope;
 
-import java.util.*;
-
-import static org.jetbrains.kotlin.resolve.DescriptorUtils.getFqName;
+import java.util.Collection;
 
 public class ManglingUtils {
     private ManglingUtils() {}
 
-    private static final Comparator<CallableDescriptor> CALLABLE_COMPARATOR = new CallableComparator();
-
-    @NotNull
-    public static String getMangledName(@NotNull PropertyDescriptor descriptor, @NotNull String suggestedName) {
-        return getStableMangledName(suggestedName, getFqName(descriptor).asString());
-    }
-
-    @NotNull
-    public static String getSuggestedName(@NotNull DeclarationDescriptor descriptor) {
-        String suggestedName = descriptor.getName().isSpecial() ? "f" : descriptor.getName().getIdentifier();
-
-        if (descriptor instanceof FunctionDescriptor ||
-            descriptor instanceof PropertyDescriptor && DescriptorUtils.isExtension((PropertyDescriptor) descriptor)
-        ) {
-            suggestedName = getMangledName((CallableMemberDescriptor) descriptor);
-        }
-
-        ClassifierDescriptorWithTypeParameters localClass = null;
-        if (descriptor instanceof ConstructorDescriptor) {
-            ConstructorDescriptor constructor = (ConstructorDescriptor) descriptor;
-            localClass = constructor.getContainingDeclaration();
-        }
-        else if (descriptor instanceof ClassDescriptor) {
-            localClass = (ClassDescriptor) descriptor;
-        }
-
-        if (DescriptorUtils.isDescriptorWithLocalVisibility(localClass)) {
-            suggestedName = getSuggestedLocalPrefix(localClass) + suggestedName;
-        }
-
-        return suggestedName;
-    }
-
-    @NotNull
-    private static String getSuggestedLocalPrefix(@NotNull DeclarationDescriptor descriptor) {
-        List<String> parts = new ArrayList<String>();
-        while (true) {
-            descriptor = descriptor.getContainingDeclaration();
-            if (descriptor == null || descriptor instanceof ClassOrPackageFragmentDescriptor) {
-                break;
-            }
-            parts.add(descriptor.getName().isSpecial() ? "f" : descriptor.getName().getIdentifier());
-        }
-
-        Collections.reverse(parts);
-        String result = StringUtil.join(parts, "$");
-        return !result.isEmpty() ? result + "$" : "";
-    }
-
-    @NotNull
-    private static String getMangledName(@NotNull CallableMemberDescriptor descriptor) {
-        if (needsStableMangling(descriptor)) {
-            return getStableMangledName(descriptor);
-        }
-
-        return getSimpleMangledName(descriptor);
-    }
-
-    //TODO extend logic for nested/inner declarations
-    private static boolean needsStableMangling(CallableMemberDescriptor descriptor) {
-        // Use stable mangling for overrides because we use stable mangling when any function inside a overridable declaration
-        // for avoid clashing names when inheritance.
-        if (DescriptorUtils.isOverride(descriptor)) {
-            return true;
-        }
-
-        DeclarationDescriptor containingDeclaration = descriptor.getContainingDeclaration();
-
-        if (containingDeclaration instanceof PackageFragmentDescriptor) {
-            return descriptor.getVisibility().isPublicAPI();
-        }
-        else if (containingDeclaration instanceof ClassDescriptor) {
-            ClassDescriptor classDescriptor = (ClassDescriptor) containingDeclaration;
-
-            // Use stable mangling when it's inside an overridable declaration to avoid clashing names on inheritance.
-            if (!ModalityKt.isFinalOrEnum(classDescriptor)) {
-                return true;
-            }
-
-            // valueOf() is created in the library with a mangled name for every enum class
-            if (descriptor instanceof FunctionDescriptor && CodegenUtil.isEnumValueOfMethod((FunctionDescriptor) descriptor)) {
-                return true;
-            }
-
-            // Don't use stable mangling when it inside a non-public API declaration.
-            if (!classDescriptor.getVisibility().isPublicAPI()) {
-                return false;
-            }
-
-            // Ignore the `protected` visibility because it can be use outside a containing declaration
-            // only when the containing declaration is overridable.
-            if (descriptor.getVisibility() == Visibilities.PUBLIC) {
-                return true;
-            }
-
-            return false;
-        }
-
-        assert containingDeclaration instanceof CallableMemberDescriptor :
-                "containingDeclaration for descriptor have unsupported type for mangling, " +
-                "descriptor: " + descriptor + ", containingDeclaration: " + containingDeclaration;
-
-        return false;
-    }
-
-    @NotNull
-    public static String getMangledMemberNameForExplicitDelegation(
-            @NotNull String suggestedName,
-            @NotNull FqNameUnsafe classFqName,
-            @NotNull FqNameUnsafe typeFqName
-    ) {
-        String forCalculateId = classFqName.asString() + ":" + typeFqName.asString();
-        return getStableMangledName(suggestedName, forCalculateId);
-    }
-
-    @NotNull
-    private static String getStableMangledName(@NotNull String suggestedName, String forCalculateId) {
-        int absHashCode = Math.abs(forCalculateId.hashCode());
-        String suffix = absHashCode == 0 ? "" : ("_" + Integer.toString(absHashCode, Character.MAX_RADIX) + "$");
-        return suggestedName + suffix;
-    }
-
-    @NotNull
-    private static String getStableMangledName(@NotNull CallableDescriptor descriptor) {
-        String suggestedName = getSuggestedName(descriptor);
-        return getStableMangledName(suggestedName, getArgumentTypesAsString(descriptor));
-    }
-
-    @NotNull
-    private static String getSuggestedName(@NotNull CallableDescriptor descriptor) {
-        if (descriptor instanceof ConstructorDescriptor && !((ConstructorDescriptor) descriptor).isPrimary()) {
-            return descriptor.getContainingDeclaration().getName().asString() + "_init";
-        }
-        else {
-            return descriptor.getName().asString();
-        }
-    }
-
-    @NotNull
-    private static String getSimpleMangledName(@NotNull CallableMemberDescriptor descriptor) {
-        DeclarationDescriptor containingDeclaration = descriptor.getContainingDeclaration();
-
-        MemberScope jetScope = null;
-
-        String nameToCompare = descriptor.getName().asString();
-
-        if (descriptor instanceof ConstructorDescriptor) {
-            nameToCompare = containingDeclaration.getName().asString();
-            containingDeclaration = containingDeclaration.getContainingDeclaration();
-        }
-
-        if (containingDeclaration instanceof PackageFragmentDescriptor) {
-            jetScope = ((PackageFragmentDescriptor) containingDeclaration).getMemberScope();
-        }
-        else if (containingDeclaration instanceof ClassDescriptor) {
-            jetScope = ((ClassDescriptor) containingDeclaration).getDefaultType().getMemberScope();
-        }
-
-        int counter = 0;
-
-        if (jetScope != null) {
-            final String finalNameToCompare = nameToCompare;
-
-            Collection<DeclarationDescriptor> declarations = DescriptorUtils.getAllDescriptors(jetScope);
-            List<CallableDescriptor> overloadedFunctions =
-                    CollectionsKt.flatMap(declarations, new Function1<DeclarationDescriptor, Iterable<? extends CallableDescriptor>>() {
-                @Override
-                public Iterable<? extends CallableDescriptor> invoke(DeclarationDescriptor declarationDescriptor) {
-                    if (declarationDescriptor instanceof ClassDescriptor && finalNameToCompare.equals(declarationDescriptor.getName().asString())) {
-                        ClassDescriptor classDescriptor = (ClassDescriptor) declarationDescriptor;
-                        Collection<ClassConstructorDescriptor> constructors = classDescriptor.getConstructors();
-
-                        if (!DescriptorUtilsKt.hasPrimaryConstructor(classDescriptor)) {
-                            ClassConstructorDescriptorImpl fakePrimaryConstructor =
-                                    ClassConstructorDescriptorImpl
-                                            .create(classDescriptor, Annotations.Companion.getEMPTY(), true, SourceElement.NO_SOURCE);
-                            return CollectionsKt.plus(constructors, fakePrimaryConstructor);
-                        }
-
-                        return constructors;
-                    }
-
-                    if (!(declarationDescriptor instanceof CallableMemberDescriptor)) return Collections.emptyList();
-
-                    CallableMemberDescriptor callableMemberDescriptor = (CallableMemberDescriptor) declarationDescriptor;
-
-                    String name = AnnotationsUtils.getNameForAnnotatedObjectWithOverrides(callableMemberDescriptor);
-
-                    // when name == null it's mean that it's not native.
-                    if (name == null) {
-                        // skip functions without arguments, because we don't use mangling for them
-                        if (needsStableMangling(callableMemberDescriptor) && !callableMemberDescriptor.getValueParameters().isEmpty()) return Collections.emptyList();
-
-                        // TODO add prefix for property: get_$name and set_$name
-                        name = callableMemberDescriptor.getName().asString();
-                    }
-
-                    if (finalNameToCompare.equals(name)) return Collections.singletonList(callableMemberDescriptor);
-
-                    return Collections.emptyList();
-                }
-            });
-
-            if (overloadedFunctions.size() > 1) {
-                Collections.sort(overloadedFunctions, CALLABLE_COMPARATOR);
-                counter = ContainerUtil.indexOfIdentity(overloadedFunctions, descriptor);
-                assert counter >= 0;
-            }
-        }
-
-        String name = getSuggestedName(descriptor);
-        return counter == 0 ? name : name + '_' + counter;
-    }
-
-    private static String getArgumentTypesAsString(CallableDescriptor descriptor) {
-        StringBuilder argTypes = new StringBuilder();
-
-        ReceiverParameterDescriptor receiverParameter = descriptor.getExtensionReceiverParameter();
-        if (receiverParameter != null) {
-            argTypes.append(DescriptorUtilsKt.getJetTypeFqName(receiverParameter.getType(), true)).append(".");
-        }
-
-        argTypes.append(StringUtil.join(descriptor.getValueParameters(), new Function<ValueParameterDescriptor, String>() {
-            @Override
-            public String fun(ValueParameterDescriptor descriptor) {
-                return DescriptorUtilsKt.getJetTypeFqName(descriptor.getType(), true);
-            }
-        }, ","));
-
-        return argTypes.toString();
-    }
-
     @NotNull
     public static String getStableMangledNameForDescriptor(@NotNull ClassDescriptor descriptor, @NotNull String functionName) {
-        Collection<SimpleFunctionDescriptor> functions =
-                descriptor.getDefaultType().getMemberScope().getContributedFunctions(Name.identifier(functionName), NoLookupLocation.FROM_BACKEND);
+        Collection<SimpleFunctionDescriptor> functions = descriptor.getDefaultType().getMemberScope().getContributedFunctions(
+                Name.identifier(functionName), NoLookupLocation.FROM_BACKEND);
         assert functions.size() == 1 : "Can't select a single function: " + functionName + " in " + descriptor;
-        return getSuggestedName((DeclarationDescriptor) functions.iterator().next());
-    }
-
-    private static class CallableComparator implements Comparator<CallableDescriptor> {
-        @Override
-        public int compare(@NotNull CallableDescriptor a, @NotNull CallableDescriptor b) {
-            // primary constructors
-            if (a instanceof ConstructorDescriptor && ((ConstructorDescriptor) a).isPrimary()) {
-                if (!(b instanceof ConstructorDescriptor) || !((ConstructorDescriptor) b).isPrimary()) return -1;
-            }
-            else if (b instanceof ConstructorDescriptor && ((ConstructorDescriptor) b).isPrimary()) {
-                return 1;
-            }
-
-            // native functions
-            if (isNativeOrOverrideNative(a)) {
-                if (!isNativeOrOverrideNative(b)) return -1;
-            }
-            else if (isNativeOrOverrideNative(b)) {
-                return 1;
-            }
-
-            // be visibility
-            // Actually "internal" > "private", but we want to have less number for "internal", so compare b with a instead of a with b.
-            Integer result = Visibilities.compare(b.getVisibility(), a.getVisibility());
-            if (result != null && result != 0) return result;
-
-            // by arity
-            int aArity = arity(a);
-            int bArity = arity(b);
-            if (aArity != bArity) return aArity - bArity;
-
-            // by stringify argument types
-            String aArguments = getArgumentTypesAsString(a);
-            String bArguments = getArgumentTypesAsString(b);
-            assert aArguments != bArguments;
-
-            return aArguments.compareTo(bArguments);
-        }
-
-        private static int arity(CallableDescriptor descriptor) {
-            return descriptor.getValueParameters().size() + (descriptor.getExtensionReceiverParameter() == null ? 0 : 1);
-        }
-
-        private static boolean isNativeOrOverrideNative(CallableDescriptor descriptor) {
-            if (!(descriptor instanceof CallableMemberDescriptor)) return false;
-
-            if (AnnotationsUtils.isNativeObject(descriptor)) return true;
-
-            Set<CallableMemberDescriptor> declarations = DescriptorUtils.getAllOverriddenDeclarations((CallableMemberDescriptor) descriptor);
-            for (CallableMemberDescriptor memberDescriptor : declarations) {
-                if (AnnotationsUtils.isNativeObject(memberDescriptor)) return true;
-            }
-            return false;
-        }
+        return new FQNGenerator().generate(functions.iterator().next()).getNames().get(0);
     }
 }
diff --git a/js/js.translator/src/org/jetbrains/kotlin/js/translate/utils/TranslationUtils.java b/js/js.translator/src/org/jetbrains/kotlin/js/translate/utils/TranslationUtils.java
index d99f2b4af34..1569b243b0c 100644
--- a/js/js.translator/src/org/jetbrains/kotlin/js/translate/utils/TranslationUtils.java
+++ b/js/js.translator/src/org/jetbrains/kotlin/js/translate/utils/TranslationUtils.java
@@ -38,11 +38,9 @@ import java.util.ArrayList;
 import java.util.List;
 
 import static com.google.dart.compiler.backend.js.ast.JsBinaryOperator.*;
-import static org.jetbrains.kotlin.js.translate.context.Namer.getKotlinBackingFieldName;
 import static org.jetbrains.kotlin.js.translate.utils.BindingUtils.getCallableDescriptorForOperationExpression;
 import static org.jetbrains.kotlin.js.translate.utils.JsAstUtils.assignment;
 import static org.jetbrains.kotlin.js.translate.utils.JsAstUtils.createDataDescriptor;
-import static org.jetbrains.kotlin.js.translate.utils.ManglingUtils.getMangledName;
 import static org.jetbrains.kotlin.resolve.DescriptorUtils.isAnonymousObject;
 
 public final class TranslationUtils {
@@ -152,13 +150,8 @@ public final class TranslationUtils {
             @NotNull PropertyDescriptor descriptor) {
         JsName backingFieldName = context.getNameForDescriptor(descriptor);
         if(!JsDescriptorUtils.isSimpleFinalProperty(descriptor)) {
-            String backingFieldMangledName;
-            if (!Visibilities.isPrivate(descriptor.getVisibility())) {
-                backingFieldMangledName = getMangledName(descriptor, getKotlinBackingFieldName(backingFieldName.getIdent()));
-            } else {
-                backingFieldMangledName = getKotlinBackingFieldName(backingFieldName.getIdent());
-            }
-            backingFieldName = context.declarePropertyOrPropertyAccessorName(descriptor, backingFieldMangledName, false);
+            JsName backingFieldMangledName = context.getNameForBackingField(descriptor);
+            backingFieldName = context.declarePropertyOrPropertyAccessorName(descriptor, backingFieldMangledName.getIdent(), false);
         }
 
         DeclarationDescriptor containingDescriptor = descriptor.getContainingDeclaration();
diff --git a/js/js.translator/src/org/jetbrains/kotlin/js/translate/utils/utils.kt b/js/js.translator/src/org/jetbrains/kotlin/js/translate/utils/utils.kt
index f1673320cf7..106aa456423 100644
--- a/js/js.translator/src/org/jetbrains/kotlin/js/translate/utils/utils.kt
+++ b/js/js.translator/src/org/jetbrains/kotlin/js/translate/utils/utils.kt
@@ -43,14 +43,14 @@ fun generateDelegateCall(
     val functionScope = context.getScopeForDescriptor(fromDescriptor)
 
     if (DescriptorUtils.isExtension(fromDescriptor)) {
-        val extensionFunctionReceiverName = functionScope.declareName(Namer.getReceiverParameterName())
+        val extensionFunctionReceiverName = functionScope.declareFreshName(Namer.getReceiverParameterName())
         parameters.add(JsParameter(extensionFunctionReceiverName))
         args.add(JsNameRef(extensionFunctionReceiverName))
     }
 
     for (param in fromDescriptor.valueParameters) {
         val paramName = param.name.asString()
-        val jsParamName = functionScope.declareName(paramName)
+        val jsParamName = functionScope.declareFreshName(paramName)
         parameters.add(JsParameter(jsParamName))
         args.add(JsNameRef(jsParamName))
     }
diff --git a/js/js.translator/testData/box/inline/metadataForPublicFunction.kt b/js/js.translator/testData/box/inline/metadataForPublicFunction.kt
index 378fede11f1..0e4d7b68a72 100644
--- a/js/js.translator/testData/box/inline/metadataForPublicFunction.kt
+++ b/js/js.translator/testData/box/inline/metadataForPublicFunction.kt
@@ -6,7 +6,7 @@ package foo
 // CHECK_CONTAINS_NO_CALLS: test4_buocd8$
 // CHECK_CONTAINS_NO_CALLS: test5_0
 // CHECK_HAS_INLINE_METADATA: apply_hiyix$
-// CHECK_HAS_INLINE_METADATA: applyL_0
+// CHECK_HAS_INLINE_METADATA: applyL_hiyix$
 // CHECK_HAS_INLINE_METADATA: applyM_hiyix$
 // CHECK_HAS_NO_INLINE_METADATA: applyN_0
 // CHECK_HAS_NO_INLINE_METADATA: applyO_hiyix$