diff --git a/compiler/backend/src/org/jetbrains/kotlin/codegen/state/BuilderFactoryForDuplicateSignatureDiagnostics.kt b/compiler/backend/src/org/jetbrains/kotlin/codegen/state/BuilderFactoryForDuplicateSignatureDiagnostics.kt
index 1d8d3f2a9f7..b9b546a47a1 100644
--- a/compiler/backend/src/org/jetbrains/kotlin/codegen/state/BuilderFactoryForDuplicateSignatureDiagnostics.kt
+++ b/compiler/backend/src/org/jetbrains/kotlin/codegen/state/BuilderFactoryForDuplicateSignatureDiagnostics.kt
@@ -118,7 +118,12 @@ class BuilderFactoryForDuplicateSignatureDiagnostics(
             if (elementToReportOn == null) return // TODO: it'd be better to report this error without any element at all
 
             val data = ConflictingJvmDeclarationsData(classInternalName, classOrigin, rawSignature, origins)
-            diagnostics.report(ErrorsJvm.ACCIDENTAL_OVERRIDE.on(elementToReportOn, data))
+            if (memberElement != null) {
+                diagnostics.report(ErrorsJvm.ACCIDENTAL_OVERRIDE.on(elementToReportOn, data))
+            }
+            else {
+                diagnostics.report(ErrorsJvm.CONFLICTING_INHERITED_JVM_DECLARATIONS.on(elementToReportOn, data))
+            }
         }
     }
 
diff --git a/compiler/frontend.java/src/org/jetbrains/kotlin/resolve/jvm/diagnostics/DefaultErrorMessagesJvm.java b/compiler/frontend.java/src/org/jetbrains/kotlin/resolve/jvm/diagnostics/DefaultErrorMessagesJvm.java
index 14ce10e0ee2..6c3a5bf4683 100644
--- a/compiler/frontend.java/src/org/jetbrains/kotlin/resolve/jvm/diagnostics/DefaultErrorMessagesJvm.java
+++ b/compiler/frontend.java/src/org/jetbrains/kotlin/resolve/jvm/diagnostics/DefaultErrorMessagesJvm.java
@@ -45,6 +45,7 @@ public class DefaultErrorMessagesJvm implements DefaultErrorMessages.Extension {
     static {
         MAP.put(ErrorsJvm.CONFLICTING_JVM_DECLARATIONS, "Platform declaration clash: {0}", CONFLICTING_JVM_DECLARATIONS_DATA);
         MAP.put(ErrorsJvm.ACCIDENTAL_OVERRIDE, "Accidental override: {0}", CONFLICTING_JVM_DECLARATIONS_DATA);
+        MAP.put(ErrorsJvm.CONFLICTING_INHERITED_JVM_DECLARATIONS, "Inherited platform declarations clash: {0}", CONFLICTING_JVM_DECLARATIONS_DATA);
         MAP.put(ErrorsJvm.JVM_STATIC_NOT_IN_OBJECT, "Only functions in named objects and companion objects of classes can be annotated with 'JvmStatic'");
         MAP.put(ErrorsJvm.OVERRIDE_CANNOT_BE_STATIC, "Override member cannot be 'JvmStatic' in object");
         MAP.put(ErrorsJvm.OVERLOADS_WITHOUT_DEFAULT_ARGUMENTS, "''JvmOverloads'' annotation has no effect for methods without default arguments");
diff --git a/compiler/frontend.java/src/org/jetbrains/kotlin/resolve/jvm/diagnostics/ErrorsJvm.java b/compiler/frontend.java/src/org/jetbrains/kotlin/resolve/jvm/diagnostics/ErrorsJvm.java
index c9b410a86df..bc9ac213ce8 100644
--- a/compiler/frontend.java/src/org/jetbrains/kotlin/resolve/jvm/diagnostics/ErrorsJvm.java
+++ b/compiler/frontend.java/src/org/jetbrains/kotlin/resolve/jvm/diagnostics/ErrorsJvm.java
@@ -39,6 +39,8 @@ public interface ErrorsJvm {
 
     DiagnosticFactory1<PsiElement, ConflictingJvmDeclarationsData> ACCIDENTAL_OVERRIDE =
             DiagnosticFactory1.create(ERROR, DECLARATION_SIGNATURE_OR_DEFAULT);
+    DiagnosticFactory1<PsiElement, ConflictingJvmDeclarationsData> CONFLICTING_INHERITED_JVM_DECLARATIONS =
+            DiagnosticFactory1.create(ERROR, DECLARATION_SIGNATURE_OR_DEFAULT);
 
     DiagnosticFactory0<JetDeclaration> OVERRIDE_CANNOT_BE_STATIC = DiagnosticFactory0.create(ERROR, DECLARATION_SIGNATURE);
     DiagnosticFactory0<JetDeclaration> JVM_STATIC_NOT_IN_OBJECT = DiagnosticFactory0.create(ERROR, DECLARATION_SIGNATURE);
diff --git a/compiler/frontend/src/org/jetbrains/kotlin/diagnostics/Errors.java b/compiler/frontend/src/org/jetbrains/kotlin/diagnostics/Errors.java
index 596254a9e36..c950824329e 100644
--- a/compiler/frontend/src/org/jetbrains/kotlin/diagnostics/Errors.java
+++ b/compiler/frontend/src/org/jetbrains/kotlin/diagnostics/Errors.java
@@ -309,8 +309,13 @@ public interface Errors {
 
     DiagnosticFactory2<JetClassOrObject, JetClassOrObject, CallableMemberDescriptor> ABSTRACT_MEMBER_NOT_IMPLEMENTED =
             DiagnosticFactory2.create(ERROR, DECLARATION_NAME);
+    DiagnosticFactory2<JetClassOrObject, JetClassOrObject, CallableMemberDescriptor> ABSTRACT_CLASS_MEMBER_NOT_IMPLEMENTED =
+            DiagnosticFactory2.create(ERROR, DECLARATION_NAME);
     DiagnosticFactory2<JetClassOrObject, JetClassOrObject, CallableMemberDescriptor> MANY_IMPL_MEMBER_NOT_IMPLEMENTED =
             DiagnosticFactory2.create(ERROR, DECLARATION_NAME);
+    DiagnosticFactory2<JetClassOrObject, JetClassOrObject, CallableMemberDescriptor> MANY_INTERFACES_MEMBER_NOT_IMPLEMENTED =
+            DiagnosticFactory2.create(ERROR, DECLARATION_NAME);
+
 
     DiagnosticFactory1<JetNamedDeclaration, Collection<JetType>> AMBIGUOUS_ANONYMOUS_TYPE_INFERRED =
             DiagnosticFactory1.create(ERROR, DECLARATION_SIGNATURE);
diff --git a/compiler/frontend/src/org/jetbrains/kotlin/diagnostics/rendering/DefaultErrorMessages.java b/compiler/frontend/src/org/jetbrains/kotlin/diagnostics/rendering/DefaultErrorMessages.java
index 24f0b9b00f4..14e5e7b419c 100644
--- a/compiler/frontend/src/org/jetbrains/kotlin/diagnostics/rendering/DefaultErrorMessages.java
+++ b/compiler/frontend/src/org/jetbrains/kotlin/diagnostics/rendering/DefaultErrorMessages.java
@@ -559,9 +559,13 @@ public class DefaultErrorMessages {
 
         MAP.put(ABSTRACT_MEMBER_NOT_IMPLEMENTED, "{0} must be declared abstract or implement abstract member {1}", RENDER_CLASS_OR_OBJECT,
                 FQ_NAMES_IN_TYPES);
+        MAP.put(ABSTRACT_CLASS_MEMBER_NOT_IMPLEMENTED, "{0} must be declared abstract or implement abstract base class member {1}",
+                RENDER_CLASS_OR_OBJECT, FQ_NAMES_IN_TYPES);
 
         MAP.put(MANY_IMPL_MEMBER_NOT_IMPLEMENTED, "{0} must override {1} because it inherits many implementations of it",
                 RENDER_CLASS_OR_OBJECT, FQ_NAMES_IN_TYPES);
+        MAP.put(MANY_INTERFACES_MEMBER_NOT_IMPLEMENTED, "{0} must override {1} because it inherits multiple interface methods of it",
+                RENDER_CLASS_OR_OBJECT, FQ_NAMES_IN_TYPES);
 
         MAP.put(CONFLICTING_OVERLOADS, "''{0}'' is already defined in {1}", COMPACT_WITH_MODIFIERS, STRING);
 
diff --git a/compiler/frontend/src/org/jetbrains/kotlin/resolve/OverrideResolver.java b/compiler/frontend/src/org/jetbrains/kotlin/resolve/OverrideResolver.java
index b3afba995e7..12aa580d0d3 100644
--- a/compiler/frontend/src/org/jetbrains/kotlin/resolve/OverrideResolver.java
+++ b/compiler/frontend/src/org/jetbrains/kotlin/resolve/OverrideResolver.java
@@ -21,6 +21,7 @@ import com.google.common.collect.Maps;
 import com.google.common.collect.Sets;
 import com.intellij.psi.PsiElement;
 import com.intellij.util.Function;
+import com.intellij.util.SmartList;
 import com.intellij.util.containers.ContainerUtil;
 import com.intellij.util.containers.LinkedMultiMap;
 import com.intellij.util.containers.MultiMap;
@@ -34,7 +35,6 @@ import org.jetbrains.kotlin.builtins.KotlinBuiltIns;
 import org.jetbrains.kotlin.descriptors.*;
 import org.jetbrains.kotlin.descriptors.annotations.AnnotationDescriptor;
 import org.jetbrains.kotlin.incremental.components.NoLookupLocation;
-import org.jetbrains.kotlin.lexer.JetToken;
 import org.jetbrains.kotlin.lexer.JetTokens;
 import org.jetbrains.kotlin.name.Name;
 import org.jetbrains.kotlin.psi.*;
@@ -269,32 +269,49 @@ public class OverrideResolver {
         // More than one implementation or no implementations at all
         Set<CallableMemberDescriptor> abstractNoImpl = Sets.newLinkedHashSet();
         Set<CallableMemberDescriptor> manyImpl = Sets.newLinkedHashSet();
-        collectMissingImplementations(classDescriptor, abstractNoImpl, manyImpl);
+        Set<CallableMemberDescriptor> abstractInBaseClassNoImpl = Sets.newLinkedHashSet();
+        Set<CallableMemberDescriptor> conflictingInterfaceOverrides = Sets.newLinkedHashSet();
+        collectMissingImplementations(classDescriptor,
+                                      abstractNoImpl, manyImpl,
+                                      abstractInBaseClassNoImpl, conflictingInterfaceOverrides);
 
-        if (!manyImpl.isEmpty()) {
-            trace.report(MANY_IMPL_MEMBER_NOT_IMPLEMENTED.on(klass, klass, manyImpl.iterator().next()));
+        if (!classCanHaveAbstractMembers(classDescriptor)) {
+            if (!abstractInBaseClassNoImpl.isEmpty()) {
+                trace.report(ABSTRACT_CLASS_MEMBER_NOT_IMPLEMENTED.on(klass, klass, abstractInBaseClassNoImpl.iterator().next()));
+            }
+            else if (!abstractNoImpl.isEmpty()) {
+                trace.report(ABSTRACT_MEMBER_NOT_IMPLEMENTED.on(klass, klass, abstractNoImpl.iterator().next()));
+            }
         }
 
-        if (!classCanHaveAbstractMembers(classDescriptor) && !abstractNoImpl.isEmpty()) {
-            trace.report(ABSTRACT_MEMBER_NOT_IMPLEMENTED.on(klass, klass, abstractNoImpl.iterator().next()));
+        if (!conflictingInterfaceOverrides.isEmpty()) {
+            trace.report(MANY_INTERFACES_MEMBER_NOT_IMPLEMENTED.on(klass, klass, conflictingInterfaceOverrides.iterator().next()));
+        }
+        else if (!manyImpl.isEmpty()) {
+            trace.report(MANY_IMPL_MEMBER_NOT_IMPLEMENTED.on(klass, klass, manyImpl.iterator().next()));
         }
     }
 
     @NotNull
     public static Set<CallableMemberDescriptor> getMissingImplementations(@NotNull ClassDescriptor classDescriptor) {
-        Set<CallableMemberDescriptor> result = new LinkedHashSet<CallableMemberDescriptor>();
-        collectMissingImplementations(classDescriptor, result, result);
-        return result;
+        Set<CallableMemberDescriptor> shouldImplement = new LinkedHashSet<CallableMemberDescriptor>();
+        Set<CallableMemberDescriptor> dontCare = new HashSet<CallableMemberDescriptor>();
+        collectMissingImplementations(classDescriptor, shouldImplement, shouldImplement, dontCare, dontCare);
+        return shouldImplement;
     }
 
     private static void collectMissingImplementations(
             @NotNull ClassDescriptor classDescriptor,
             @NotNull Set<CallableMemberDescriptor> abstractNoImpl,
-            @NotNull Set<CallableMemberDescriptor> manyImpl
+            @NotNull Set<CallableMemberDescriptor> manyImpl,
+            @NotNull Set<CallableMemberDescriptor> abstractInBaseClassNoImpl,
+            @NotNull Set<CallableMemberDescriptor> conflictingInterfaceOverrides
     ) {
         for (DeclarationDescriptor member : classDescriptor.getDefaultType().getMemberScope().getAllDescriptors()) {
             if (member instanceof CallableMemberDescriptor) {
-                collectMissingImplementations((CallableMemberDescriptor) member, abstractNoImpl, manyImpl);
+                collectMissingImplementations((CallableMemberDescriptor) member,
+                                              abstractNoImpl, manyImpl,
+                                              abstractInBaseClassNoImpl, conflictingInterfaceOverrides);
             }
         }
     }
@@ -302,14 +319,16 @@ public class OverrideResolver {
     private static void collectMissingImplementations(
             @NotNull CallableMemberDescriptor descriptor,
             @NotNull Set<CallableMemberDescriptor> abstractNoImpl,
-            @NotNull Set<CallableMemberDescriptor> manyImpl
+            @NotNull Set<CallableMemberDescriptor> manyImpl,
+            @NotNull Set<CallableMemberDescriptor> abstractInBaseClassNoImpl,
+            @NotNull Set<CallableMemberDescriptor> conflictingInterfaceOverrides
     ) {
         if (descriptor.getKind().isReal()) return;
         if (descriptor.getVisibility() == Visibilities.INVISIBLE_FAKE) return;
 
         Collection<? extends CallableMemberDescriptor> directOverridden = descriptor.getOverriddenDescriptors();
         if (directOverridden.size() == 0) {
-            throw new IllegalStateException("A 'fake override' must override something");
+            throw new IllegalStateException("A 'fake override' " + descriptor.getName().asString() + " must override something");
         }
 
         // collects map from the directly overridden descriptor to the set of declarations:
@@ -324,6 +343,8 @@ public class OverrideResolver {
         Set<CallableMemberDescriptor> relevantDirectlyOverridden =
                 getRelevantDirectlyOverridden(overriddenDeclarationsByDirectParent, allFilteredOverriddenDeclarations);
 
+        collectJava8MissingOverrides(relevantDirectlyOverridden, abstractInBaseClassNoImpl, conflictingInterfaceOverrides);
+
         List<CallableMemberDescriptor> implementations = collectImplementations(relevantDirectlyOverridden);
         if (implementations.size() == 1 && isReturnTypeOkForOverride(descriptor, implementations.get(0))) return;
 
@@ -342,6 +363,49 @@ public class OverrideResolver {
         }
     }
 
+    private static void collectJava8MissingOverrides(
+            Set<CallableMemberDescriptor> relevantDirectlyOverridden,
+            @NotNull Set<CallableMemberDescriptor> abstractInBaseClassNoImpl,
+            @NotNull Set<CallableMemberDescriptor> conflictingInterfaceOverrides
+    ) {
+        // Java 8:
+        // -- class should implement an abstract member of a super-class,
+        //    even if relevant default implementation is provided in one of the super-interfaces;
+        // -- inheriting multiple override equivalent methods from an interface is a conflict
+        //    regardless of 'default' vs 'abstract'.
+
+        boolean overridesClassMember = false;
+        boolean overridesNonAbstractInterfaceMember = false;
+        CallableMemberDescriptor overridesAbstractInBaseClass = null;
+        List<CallableMemberDescriptor> overriddenInterfaceMembers = new SmartList<CallableMemberDescriptor>();
+        for (CallableMemberDescriptor overridden : relevantDirectlyOverridden) {
+            DeclarationDescriptor containingDeclaration = overridden.getContainingDeclaration();
+            if (containingDeclaration instanceof ClassDescriptor) {
+                ClassDescriptor baseClassOrInterface = (ClassDescriptor) containingDeclaration;
+                if (baseClassOrInterface.getKind() == ClassKind.CLASS) {
+                    overridesClassMember = true;
+                    if (overridden.getModality() == Modality.ABSTRACT) {
+                        overridesAbstractInBaseClass = overridden;
+                    }
+                }
+                else if (baseClassOrInterface.getKind() == ClassKind.INTERFACE) {
+                    overriddenInterfaceMembers.add(overridden);
+                    if (overridden.getModality() != Modality.ABSTRACT) {
+                        overridesNonAbstractInterfaceMember = true;
+                    }
+                }
+            }
+        }
+
+        if (overridesAbstractInBaseClass != null) {
+            abstractInBaseClassNoImpl.add(overridesAbstractInBaseClass);
+        }
+
+        if (!overridesClassMember && overridesNonAbstractInterfaceMember && overriddenInterfaceMembers.size() > 1) {
+            conflictingInterfaceOverrides.addAll(overriddenInterfaceMembers);
+        }
+    }
+
     @NotNull
     private static List<CallableMemberDescriptor> collectImplementations(@NotNull Set<CallableMemberDescriptor> relevantDirectlyOverridden) {
         List<CallableMemberDescriptor> result = new ArrayList<CallableMemberDescriptor>(relevantDirectlyOverridden.size());
diff --git a/compiler/light-classes/src/org/jetbrains/kotlin/asJava/duplicateJvmSignatureUtil.kt b/compiler/light-classes/src/org/jetbrains/kotlin/asJava/duplicateJvmSignatureUtil.kt
index c8c9c087f8c..dde918904c9 100644
--- a/compiler/light-classes/src/org/jetbrains/kotlin/asJava/duplicateJvmSignatureUtil.kt
+++ b/compiler/light-classes/src/org/jetbrains/kotlin/asJava/duplicateJvmSignatureUtil.kt
@@ -27,6 +27,7 @@ import org.jetbrains.kotlin.diagnostics.Errors.*
 import org.jetbrains.kotlin.diagnostics.DiagnosticFactory.*
 import org.jetbrains.kotlin.diagnostics.DiagnosticFactory
 import org.jetbrains.kotlin.psi.*
+import org.jetbrains.kotlin.resolve.jvm.diagnostics.ErrorsJvm
 
 public fun getJvmSignatureDiagnostics(element: PsiElement, otherDiagnostics: Diagnostics, moduleScope: GlobalSearchScope): Diagnostics? {
     fun getDiagnosticsForPackage(file: JetFile): Diagnostics? {
@@ -86,7 +87,7 @@ class FilteredJvmDiagnostics(val jvmDiagnostics: Diagnostics, val otherDiagnosti
     }
 
     override fun forElement(psiElement: PsiElement): Collection<Diagnostic> {
-        val jvmDiagnosticFactories = setOf(CONFLICTING_JVM_DECLARATIONS, ACCIDENTAL_OVERRIDE)
+        val jvmDiagnosticFactories = setOf(CONFLICTING_JVM_DECLARATIONS, ACCIDENTAL_OVERRIDE, CONFLICTING_INHERITED_JVM_DECLARATIONS)
         fun Diagnostic.data() = cast(this, jvmDiagnosticFactories).getA()
         val (conflicting, other) = jvmDiagnostics.forElement(psiElement).partition { it.getFactory() in jvmDiagnosticFactories }
         if (alreadyReported(psiElement)) {
@@ -110,9 +111,10 @@ class FilteredJvmDiagnostics(val jvmDiagnostics: Diagnostics, val otherDiagnosti
                                 other ->
                                 me != other && (
                                         // in case of implementation copied from a super trait there will be both diagnostics on the same signature
-                                        me.getFactory() == ACCIDENTAL_OVERRIDE && other.getFactory() == CONFLICTING_JVM_DECLARATIONS
-                                                // there are paris of corresponding signatures that frequently clash simultaneously: package facade & part, trait and trait-impl
-                                                || other.data() higherThan me.data()
+                                        other.factory == ErrorsJvm.CONFLICTING_JVM_DECLARATIONS && (me.factory == ACCIDENTAL_OVERRIDE ||
+                                                                                                    me.factory == CONFLICTING_INHERITED_JVM_DECLARATIONS)
+                                        // there are paris of corresponding signatures that frequently clash simultaneously: package facade & part, trait and trait-impl
+                                        || other.data() higherThan me.data()
                                         )
                             }
                         }
diff --git a/compiler/testData/codegen/box/bridges/complexTraitImpl.kt b/compiler/testData/codegen/box/bridges/complexTraitImpl.kt
index ff38790023b..6ab6737b8a1 100644
--- a/compiler/testData/codegen/box/bridges/complexTraitImpl.kt
+++ b/compiler/testData/codegen/box/bridges/complexTraitImpl.kt
@@ -9,7 +9,9 @@ interface B {
     fun foo(): ArrayList<String> = ArrayList(Arrays.asList("B"))
 }
 
-open class C : A(), B
+open class C : A(), B {
+    override fun foo(): ArrayList<String> = super<B>.foo()
+}
 
 interface D {
     fun foo(): Collection<String>
diff --git a/compiler/testData/codegen/box/bridges/fakeGenericContravariantOverride1.kt b/compiler/testData/codegen/box/bridges/fakeGenericContravariantOverride1.kt
deleted file mode 100644
index ed98372c3ff..00000000000
--- a/compiler/testData/codegen/box/bridges/fakeGenericContravariantOverride1.kt
+++ /dev/null
@@ -1,30 +0,0 @@
-interface A<T> {
-    fun foo(t: T): String
-}
-
-interface B {
-    fun foo(t: Int) = "B"
-}
-
-class Z1 : A<Int>, B
-
-class Z2 : B, A<Int>
-
-fun box(): String {
-    val z1 = Z1()
-    val z2 = Z2()
-    val z1a: A<Int> = z1
-    val z1b: B = z1
-    val z2a: A<Int> = z2
-    val z2b: B = z2
-
-    return when {
-        z1.foo( 0)  != "B" -> "Fail #1"
-        z1a.foo( 0) != "B" -> "Fail #2"
-        z1b.foo( 0) != "B" -> "Fail #3"
-        z2.foo( 0)  != "B" -> "Fail #4"
-        z2a.foo( 0) != "B" -> "Fail #5"
-        z2b.foo( 0) != "B" -> "Fail #6"
-        else -> "OK"
-    }
-}
\ No newline at end of file
diff --git a/compiler/testData/codegen/box/bridges/fakeGenericContravariantOverride2.kt b/compiler/testData/codegen/box/bridges/fakeGenericContravariantOverride2.kt
deleted file mode 100644
index 69751512658..00000000000
--- a/compiler/testData/codegen/box/bridges/fakeGenericContravariantOverride2.kt
+++ /dev/null
@@ -1,30 +0,0 @@
-interface A<T> {
-    fun foo(t: T): String
-}
-
-interface B<T : Number> {
-    fun foo(a: T) = "B"
-}
-
-class Z1 : A<Int>, B<Int>
-
-class Z2 : B<Int>, A<Int>
-
-fun box(): String {
-    val z1 = Z1()
-    val z2 = Z2()
-    val z1a: A<Int> = z1
-    val z1b: B<Int> = z1
-    val z2a: A<Int> = z2
-    val z2b: B<Int> = z2
-
-    return when {
-        z1.foo( 0)  != "B" -> "Fail #1"
-        z1a.foo( 0) != "B" -> "Fail #2"
-        z1b.foo( 0) != "B" -> "Fail #3"
-        z2.foo( 0)  != "B" -> "Fail #4"
-        z2a.foo( 0) != "B" -> "Fail #5"
-        z2b.foo( 0) != "B" -> "Fail #6"
-        else -> "OK"
-    }
-}
\ No newline at end of file
diff --git a/compiler/testData/codegen/box/bridges/fakeOverrideOfPropertySetterInTraitImpl.kt b/compiler/testData/codegen/box/bridges/fakeOverrideOfPropertySetterInTraitImpl.kt
deleted file mode 100644
index eed49f27531..00000000000
--- a/compiler/testData/codegen/box/bridges/fakeOverrideOfPropertySetterInTraitImpl.kt
+++ /dev/null
@@ -1,25 +0,0 @@
-var result = ""
-
-interface A {
-    var foo: String
-        get() = result
-        set(value) {
-            result += value
-        }
-}
-
-abstract class B {
-    abstract var foo: Any
-}
-
-class C : A, B()
-
-fun box(): String {
-    val c = C()
-    c.foo = "1"
-    val b: B = c
-    val a: A = c
-    b.foo = "2"
-    a.foo = "3"
-    return if (result == "123") "OK" else "Fail: $result"
-}
diff --git a/compiler/testData/codegen/box/bridges/fakeOverrideWithImplementationInTrait.kt b/compiler/testData/codegen/box/bridges/fakeOverrideWithImplementationInTrait.kt
deleted file mode 100644
index 4e1231396fa..00000000000
--- a/compiler/testData/codegen/box/bridges/fakeOverrideWithImplementationInTrait.kt
+++ /dev/null
@@ -1,20 +0,0 @@
-interface A {
-    fun foo(): String = "A"
-}
-
-interface B {
-    fun foo(): Any
-}
-
-class C : A, B
-
-fun box(): String {
-    val c = C()
-    var result = ""
-    val b: B = c
-    val a: A = c
-    result += c.foo()
-    result += b.foo()
-    result += a.foo()
-    return if (result == "AAA") "OK" else "Fail: $result"
-}
diff --git a/compiler/testData/codegen/box/builtinsProperties/bridges.kt b/compiler/testData/codegen/box/builtinsProperties/bridges.kt
index 2dffb290490..6f0a1c8ba5a 100644
--- a/compiler/testData/codegen/box/builtinsProperties/bridges.kt
+++ b/compiler/testData/codegen/box/builtinsProperties/bridges.kt
@@ -9,6 +9,8 @@ class B0 : Collection<String>, A0 {
     override fun contains(o: String) = throw UnsupportedOperationException()
     override fun iterator() = throw UnsupportedOperationException()
     override fun containsAll(c: Collection<String>) = throw UnsupportedOperationException()
+    override val size: Int
+        get() = super.size
 }
 
 open class A1 {
@@ -45,6 +47,8 @@ class B4 : Collection<String>, I4<Int> {
     override fun contains(o: String) = throw UnsupportedOperationException()
     override fun iterator() = throw UnsupportedOperationException()
     override fun containsAll(c: Collection<String>) = throw UnsupportedOperationException()
+    override val size: Int
+        get() = super.size
 }
 
 interface I5 : Collection<String> {
diff --git a/compiler/testData/codegen/box/classes/kt2477.kt b/compiler/testData/codegen/box/classes/kt2477.kt
index dcac7569a1a..8f45431717c 100644
--- a/compiler/testData/codegen/box/classes/kt2477.kt
+++ b/compiler/testData/codegen/box/classes/kt2477.kt
@@ -10,8 +10,8 @@ interface B {
         get() = "FAIL"
 }
 
-abstract class C {
-    abstract protected val c: String
+open class C {
+    private val c: String = "FAIL"
 }
 
 open class D: C(), A, B {
diff --git a/compiler/testData/codegen/bytecodeText/interfaces/firstInheritedMethodIsAbstract.kt b/compiler/testData/codegen/bytecodeText/interfaces/firstInheritedMethodIsAbstract.kt
index 78f3ebcb85e..971fa09646d 100644
--- a/compiler/testData/codegen/bytecodeText/interfaces/firstInheritedMethodIsAbstract.kt
+++ b/compiler/testData/codegen/bytecodeText/interfaces/firstInheritedMethodIsAbstract.kt
@@ -6,7 +6,9 @@ interface B {
     fun foo(): String = "OK"
 }
 
-interface C : A, B
+interface C : A, B {
+    override fun foo(): String = super<B>.foo()
+}
 
 // There's no 'foo' in A$DefaultImpls, proguard and other tools may fail if we generate calls to it
 // 0 INVOKESTATIC A\$DefaultImpls.foo
diff --git a/compiler/testData/compileKotlinAgainstCustomBinaries/noWarningsOnJavaKotlinInheritance/noWarningsOnJavaKotlinInheritance.kt b/compiler/testData/compileKotlinAgainstCustomBinaries/noWarningsOnJavaKotlinInheritance/noWarningsOnJavaKotlinInheritance.kt
index bc617c7f74c..f92523206a0 100644
--- a/compiler/testData/compileKotlinAgainstCustomBinaries/noWarningsOnJavaKotlinInheritance/noWarningsOnJavaKotlinInheritance.kt
+++ b/compiler/testData/compileKotlinAgainstCustomBinaries/noWarningsOnJavaKotlinInheritance/noWarningsOnJavaKotlinInheritance.kt
@@ -11,4 +11,8 @@ interface KotlinTrait {
     public fun foo(someOtherName: Int) {}
 }
 
-class BothTraitsSubclass : JavaInterface, KotlinTrait
+class BothTraitsSubclass : JavaInterface, KotlinTrait {
+    override fun foo(someOtherName: Int) {
+        super.foo(someOtherName)
+    }
+}
diff --git a/compiler/testData/diagnostics/tests/declarationChecks/kt559.kt b/compiler/testData/diagnostics/tests/declarationChecks/kt559.kt
index a3e440caa9c..ea48a2a953e 100644
--- a/compiler/testData/diagnostics/tests/declarationChecks/kt559.kt
+++ b/compiler/testData/diagnostics/tests/declarationChecks/kt559.kt
@@ -14,17 +14,17 @@ abstract class D(): A() {
     override val i : Int = 34
 }
 
-<!ABSTRACT_MEMBER_NOT_IMPLEMENTED!>class C<!>() : D() {
+<!ABSTRACT_CLASS_MEMBER_NOT_IMPLEMENTED!>class C<!>() : D() {
     fun test() {
         super.i
     }
 }
 
-<!ABSTRACT_MEMBER_NOT_IMPLEMENTED!>class B<!>() : A() {
+<!ABSTRACT_CLASS_MEMBER_NOT_IMPLEMENTED!>class B<!>() : A() {
     override fun foo(): Int {
         super.<!ABSTRACT_SUPER_CALL!>i<!>
 
         super.fff() //everything is ok
         return super.<!ABSTRACT_SUPER_CALL!>foo<!>()  //no error!!
     }
-}
+}
\ No newline at end of file
diff --git a/compiler/testData/diagnostics/tests/delegation/DelegationAndOverriding.kt b/compiler/testData/diagnostics/tests/delegation/DelegationAndOverriding.kt
index 51859a91f2b..1868a537585 100644
--- a/compiler/testData/diagnostics/tests/delegation/DelegationAndOverriding.kt
+++ b/compiler/testData/diagnostics/tests/delegation/DelegationAndOverriding.kt
@@ -9,7 +9,7 @@ open <!ABSTRACT_MEMBER_NOT_IMPLEMENTED!>class Br<!>(<!UNUSED_PARAMETER!>t<!> : T
 
 }
 
-<!ABSTRACT_MEMBER_NOT_IMPLEMENTED!>class Br3<!>(t : T) : Br(t) {
+<!ABSTRACT_CLASS_MEMBER_NOT_IMPLEMENTED!>class Br3<!>(t : T) : Br(t) {
 
 }
 
@@ -35,4 +35,4 @@ open class GC1(g : G<Int>) : G<Int> by g {
 
 open class GC2(g : G<Int>) : GC1(g) {
 
-}
+}
\ No newline at end of file
diff --git a/compiler/testData/diagnostics/tests/delegation/Delegation_MultipleDelegates.kt b/compiler/testData/diagnostics/tests/delegation/Delegation_MultipleDelegates.kt
index 26501f0de2e..5955a9e68af 100644
--- a/compiler/testData/diagnostics/tests/delegation/Delegation_MultipleDelegates.kt
+++ b/compiler/testData/diagnostics/tests/delegation/Delegation_MultipleDelegates.kt
@@ -14,6 +14,6 @@ interface TwoImpl : Two {
   public override fun foo() = 2
 }
 
-<!MANY_IMPL_MEMBER_NOT_IMPLEMENTED!>class Test1<!>() : TwoImpl, OneImpl {}
+<!MANY_INTERFACES_MEMBER_NOT_IMPLEMENTED!>class Test1<!>() : TwoImpl, OneImpl {}
 class Test2(a : One) : One by a, Two {}
 <!MANY_IMPL_MEMBER_NOT_IMPLEMENTED!>class Test3<!>(a : One, b : Two) : Two by b, One by a {}
\ No newline at end of file
diff --git a/compiler/testData/diagnostics/tests/j+k/kt6720_abstractProperty.kt b/compiler/testData/diagnostics/tests/j+k/kt6720_abstractProperty.kt
index f092b608f92..2f58657094a 100644
--- a/compiler/testData/diagnostics/tests/j+k/kt6720_abstractProperty.kt
+++ b/compiler/testData/diagnostics/tests/j+k/kt6720_abstractProperty.kt
@@ -11,8 +11,8 @@ public abstract class B implements A {
 
 // FILE: C.kt
 
-<!ABSTRACT_MEMBER_NOT_IMPLEMENTED!>class C<!> : B()
+<!ABSTRACT_CLASS_MEMBER_NOT_IMPLEMENTED!>class C<!> : B()
 
 fun main() {
     C().a
-}
+}
\ No newline at end of file
diff --git a/compiler/testData/diagnostics/tests/java8Overrides/abstractBaseClassMemberNotImplemented.kt b/compiler/testData/diagnostics/tests/java8Overrides/abstractBaseClassMemberNotImplemented.kt
new file mode 100644
index 00000000000..0b1c69a3d3b
--- /dev/null
+++ b/compiler/testData/diagnostics/tests/java8Overrides/abstractBaseClassMemberNotImplemented.kt
@@ -0,0 +1,9 @@
+abstract class ALeft {
+    abstract fun foo()
+}
+
+interface IRight {
+    fun foo() {}
+}
+
+<!ABSTRACT_CLASS_MEMBER_NOT_IMPLEMENTED!>class CDerived<!> : ALeft(), IRight
\ No newline at end of file
diff --git a/compiler/testData/diagnostics/tests/java8Overrides/abstractBaseClassMemberNotImplemented.txt b/compiler/testData/diagnostics/tests/java8Overrides/abstractBaseClassMemberNotImplemented.txt
new file mode 100644
index 00000000000..94ece016db7
--- /dev/null
+++ b/compiler/testData/diagnostics/tests/java8Overrides/abstractBaseClassMemberNotImplemented.txt
@@ -0,0 +1,24 @@
+package
+
+public abstract class ALeft {
+    public constructor ALeft()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public abstract fun foo(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public final class CDerived : ALeft, IRight {
+    public constructor CDerived()
+    public open override /*2*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*2*/ /*fake_override*/ fun foo(): kotlin.Unit
+    public open override /*2*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*2*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public interface IRight {
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open fun foo(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
diff --git a/compiler/testData/diagnostics/tests/java8Overrides/abstractVsAbstract.kt b/compiler/testData/diagnostics/tests/java8Overrides/abstractVsAbstract.kt
new file mode 100644
index 00000000000..3e26c7b7b96
--- /dev/null
+++ b/compiler/testData/diagnostics/tests/java8Overrides/abstractVsAbstract.kt
@@ -0,0 +1,13 @@
+interface ILeft {
+    fun foo()
+}
+
+interface IRight {
+    fun foo()
+}
+
+interface IDerived : ILeft, IRight
+
+<!ABSTRACT_MEMBER_NOT_IMPLEMENTED!>class CDerived<!> : ILeft, IRight
+
+abstract class ADerived : ILeft, IRight
\ No newline at end of file
diff --git a/compiler/testData/diagnostics/tests/java8Overrides/abstractVsAbstract.txt b/compiler/testData/diagnostics/tests/java8Overrides/abstractVsAbstract.txt
new file mode 100644
index 00000000000..e14385dbc2b
--- /dev/null
+++ b/compiler/testData/diagnostics/tests/java8Overrides/abstractVsAbstract.txt
@@ -0,0 +1,38 @@
+package
+
+public abstract class ADerived : ILeft, IRight {
+    public constructor ADerived()
+    public open override /*2*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public abstract override /*2*/ /*fake_override*/ fun foo(): kotlin.Unit
+    public open override /*2*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*2*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public final class CDerived : ILeft, IRight {
+    public constructor CDerived()
+    public open override /*2*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public abstract override /*2*/ /*fake_override*/ fun foo(): kotlin.Unit
+    public open override /*2*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*2*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public interface IDerived : ILeft, IRight {
+    public open override /*2*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public abstract override /*2*/ /*fake_override*/ fun foo(): kotlin.Unit
+    public open override /*2*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*2*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public interface ILeft {
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public abstract fun foo(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public interface IRight {
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public abstract fun foo(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
diff --git a/compiler/testData/diagnostics/tests/java8Overrides/defaultVsAbstract.kt b/compiler/testData/diagnostics/tests/java8Overrides/defaultVsAbstract.kt
new file mode 100644
index 00000000000..8c06a401c97
--- /dev/null
+++ b/compiler/testData/diagnostics/tests/java8Overrides/defaultVsAbstract.kt
@@ -0,0 +1,13 @@
+interface ILeft {
+    fun foo() {}
+}
+
+interface IRight {
+    fun foo()
+}
+
+<!MANY_INTERFACES_MEMBER_NOT_IMPLEMENTED!>interface IDerived<!> : ILeft, IRight
+
+<!MANY_INTERFACES_MEMBER_NOT_IMPLEMENTED!>class CDerived<!> : ILeft, IRight
+
+abstract <!MANY_INTERFACES_MEMBER_NOT_IMPLEMENTED!>class ADerived<!> : ILeft, IRight
\ No newline at end of file
diff --git a/compiler/testData/diagnostics/tests/java8Overrides/defaultVsAbstract.txt b/compiler/testData/diagnostics/tests/java8Overrides/defaultVsAbstract.txt
new file mode 100644
index 00000000000..ad7cd6c2c14
--- /dev/null
+++ b/compiler/testData/diagnostics/tests/java8Overrides/defaultVsAbstract.txt
@@ -0,0 +1,38 @@
+package
+
+public abstract class ADerived : ILeft, IRight {
+    public constructor ADerived()
+    public open override /*2*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*2*/ /*fake_override*/ fun foo(): kotlin.Unit
+    public open override /*2*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*2*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public final class CDerived : ILeft, IRight {
+    public constructor CDerived()
+    public open override /*2*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*2*/ /*fake_override*/ fun foo(): kotlin.Unit
+    public open override /*2*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*2*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public interface IDerived : ILeft, IRight {
+    public open override /*2*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*2*/ /*fake_override*/ fun foo(): kotlin.Unit
+    public open override /*2*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*2*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public interface ILeft {
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open fun foo(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public interface IRight {
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public abstract fun foo(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
diff --git a/compiler/testData/diagnostics/tests/java8Overrides/singleRelevantDefault.kt b/compiler/testData/diagnostics/tests/java8Overrides/singleRelevantDefault.kt
new file mode 100644
index 00000000000..9fd93ea94b2
--- /dev/null
+++ b/compiler/testData/diagnostics/tests/java8Overrides/singleRelevantDefault.kt
@@ -0,0 +1,9 @@
+interface ITop {
+    fun foo() {}
+}
+
+interface ILeft : ITop
+
+interface IRight : ITop
+
+interface IDerived : ILeft, IRight
\ No newline at end of file
diff --git a/compiler/testData/diagnostics/tests/java8Overrides/singleRelevantDefault.txt b/compiler/testData/diagnostics/tests/java8Overrides/singleRelevantDefault.txt
new file mode 100644
index 00000000000..b440155463a
--- /dev/null
+++ b/compiler/testData/diagnostics/tests/java8Overrides/singleRelevantDefault.txt
@@ -0,0 +1,29 @@
+package
+
+public interface IDerived : ILeft, IRight {
+    public open override /*2*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*2*/ /*fake_override*/ fun foo(): kotlin.Unit
+    public open override /*2*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*2*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public interface ILeft : ITop {
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun foo(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public interface IRight : ITop {
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun foo(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public interface ITop {
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open fun foo(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
diff --git a/compiler/testData/diagnostics/tests/modifiers/const/applicability.kt b/compiler/testData/diagnostics/tests/modifiers/const/applicability.kt
index a5d271cd593..3eb9dd3bfb3 100644
--- a/compiler/testData/diagnostics/tests/modifiers/const/applicability.kt
+++ b/compiler/testData/diagnostics/tests/modifiers/const/applicability.kt
@@ -22,7 +22,7 @@ abstract class C {
     }
 }
 
-<!ABSTRACT_MEMBER_NOT_IMPLEMENTED!>object D<!> : C() {
+<!ABSTRACT_CLASS_MEMBER_NOT_IMPLEMENTED!>object D<!> : C() {
     <!INCOMPATIBLE_MODIFIERS!>override<!> <!INCOMPATIBLE_MODIFIERS!>const<!> val x: Int = 9
 
     const val inObject = 10
diff --git a/compiler/testData/diagnostics/tests/override/AbstractFunNotImplemented.kt b/compiler/testData/diagnostics/tests/override/AbstractFunNotImplemented.kt
index 3e66d7f5c2b..2b74895453e 100644
--- a/compiler/testData/diagnostics/tests/override/AbstractFunNotImplemented.kt
+++ b/compiler/testData/diagnostics/tests/override/AbstractFunNotImplemented.kt
@@ -2,5 +2,5 @@ abstract class A {
     abstract fun foo(): Int
 }
 
-<!ABSTRACT_MEMBER_NOT_IMPLEMENTED!>class B<!>() : A() {
-}
+<!ABSTRACT_CLASS_MEMBER_NOT_IMPLEMENTED!>class B<!>() : A() {
+}
\ No newline at end of file
diff --git a/compiler/testData/diagnostics/tests/override/AbstractValNotImplemented.kt b/compiler/testData/diagnostics/tests/override/AbstractValNotImplemented.kt
index 279bf210af7..657e761ca49 100644
--- a/compiler/testData/diagnostics/tests/override/AbstractValNotImplemented.kt
+++ b/compiler/testData/diagnostics/tests/override/AbstractValNotImplemented.kt
@@ -2,5 +2,5 @@ abstract class A {
     abstract val i: Int
 }
 
-<!ABSTRACT_MEMBER_NOT_IMPLEMENTED!>class B<!>() : A() {
+<!ABSTRACT_CLASS_MEMBER_NOT_IMPLEMENTED!>class B<!>() : A() {
 }
diff --git a/compiler/testData/diagnostics/tests/override/AbstractVarNotImplemented.kt b/compiler/testData/diagnostics/tests/override/AbstractVarNotImplemented.kt
index 11f5bde2801..df976efe482 100644
--- a/compiler/testData/diagnostics/tests/override/AbstractVarNotImplemented.kt
+++ b/compiler/testData/diagnostics/tests/override/AbstractVarNotImplemented.kt
@@ -2,5 +2,5 @@ abstract class A {
     abstract var i: Int
 }
 
-<!ABSTRACT_MEMBER_NOT_IMPLEMENTED!>class B<!>() : A() {
+<!ABSTRACT_CLASS_MEMBER_NOT_IMPLEMENTED!>class B<!>() : A() {
 }
diff --git a/compiler/testData/diagnostics/tests/override/Generics.kt b/compiler/testData/diagnostics/tests/override/Generics.kt
index 6813df144a0..2d042fa9527 100644
--- a/compiler/testData/diagnostics/tests/override/Generics.kt
+++ b/compiler/testData/diagnostics/tests/override/Generics.kt
@@ -40,15 +40,15 @@ abstract class MyAbstractClass1 : MyTrait<Int>, MyAbstractClass<String>() {
     override fun bar(t: String) = t
 }
 
-<!ABSTRACT_MEMBER_NOT_IMPLEMENTED!>class MyIllegalGenericClass1<!><T> : MyTrait<T>, MyAbstractClass<T>() {}
-<!ABSTRACT_MEMBER_NOT_IMPLEMENTED!>class MyIllegalGenericClass2<!><T, R>(r : R) : MyTrait<T>, MyAbstractClass<R>() {
+<!ABSTRACT_CLASS_MEMBER_NOT_IMPLEMENTED!>class MyIllegalGenericClass1<!><T> : MyTrait<T>, MyAbstractClass<T>() {}
+<!ABSTRACT_CLASS_MEMBER_NOT_IMPLEMENTED!>class MyIllegalGenericClass2<!><T, R>(r : R) : MyTrait<T>, MyAbstractClass<R>() {
     <!NOTHING_TO_OVERRIDE!>override<!> fun foo(r: R) = r
     <!CONFLICTING_OVERLOADS!><!NOTHING_TO_OVERRIDE!>override<!> val <T> pr : R<!> = r
 }
-<!ABSTRACT_MEMBER_NOT_IMPLEMENTED!>class MyIllegalClass1<!> : MyTrait<Int>, MyAbstractClass<String>() {}
+<!ABSTRACT_CLASS_MEMBER_NOT_IMPLEMENTED!>class MyIllegalClass1<!> : MyTrait<Int>, MyAbstractClass<String>() {}
 abstract class MyLegalAbstractClass1 : MyTrait<Int>, MyAbstractClass<String>() {}
 
-<!ABSTRACT_MEMBER_NOT_IMPLEMENTED!>class MyIllegalClass2<!><T>(t : T) : MyTrait<Int>, MyAbstractClass<Int>() {
+<!ABSTRACT_CLASS_MEMBER_NOT_IMPLEMENTED!>class MyIllegalClass2<!><T>(t : T) : MyTrait<Int>, MyAbstractClass<Int>() {
     fun foo(t: T) = t
     fun bar(t: T) = t
     <!CONFLICTING_OVERLOADS!>val <R> pr : T<!> = t
diff --git a/compiler/testData/diagnostics/tests/override/NonGenerics.kt b/compiler/testData/diagnostics/tests/override/NonGenerics.kt
index 30a3688a219..aabfb8b26f4 100644
--- a/compiler/testData/diagnostics/tests/override/NonGenerics.kt
+++ b/compiler/testData/diagnostics/tests/override/NonGenerics.kt
@@ -21,9 +21,9 @@ open class MyClass() : MyTrait, MyAbstractClass() {
 
 class MyChildClass() : MyClass() {}
 
-<!ABSTRACT_MEMBER_NOT_IMPLEMENTED!>class MyIllegalClass<!> : MyTrait, MyAbstractClass() {}
+<!ABSTRACT_CLASS_MEMBER_NOT_IMPLEMENTED!>class MyIllegalClass<!> : MyTrait, MyAbstractClass() {}
 
-<!ABSTRACT_MEMBER_NOT_IMPLEMENTED!>class MyIllegalClass2<!>() : MyTrait, MyAbstractClass() {
+<!ABSTRACT_CLASS_MEMBER_NOT_IMPLEMENTED!>class MyIllegalClass2<!>() : MyTrait, MyAbstractClass() {
     override fun foo() {}
     override val pr : Unit = Unit
     override val prr : Unit = Unit
@@ -35,7 +35,7 @@ class MyChildClass() : MyClass() {}
     override val prr : Unit = Unit
 }
 
-<!ABSTRACT_MEMBER_NOT_IMPLEMENTED!>class MyIllegalClass4<!>() : MyTrait, MyAbstractClass() {
+<!ABSTRACT_CLASS_MEMBER_NOT_IMPLEMENTED!>class MyIllegalClass4<!>() : MyTrait, MyAbstractClass() {
     <!VIRTUAL_MEMBER_HIDDEN!>fun foo()<!> {}
     <!VIRTUAL_MEMBER_HIDDEN, MUST_BE_INITIALIZED_OR_BE_ABSTRACT!>val pr : Unit<!>
     <!NOTHING_TO_OVERRIDE!>override<!> fun other() {}
diff --git a/compiler/testData/diagnostics/tests/override/ParentInheritsManyImplementations.kt b/compiler/testData/diagnostics/tests/override/ParentInheritsManyImplementations.kt
index 1d53f7b54bb..75d9920c5c9 100644
--- a/compiler/testData/diagnostics/tests/override/ParentInheritsManyImplementations.kt
+++ b/compiler/testData/diagnostics/tests/override/ParentInheritsManyImplementations.kt
@@ -8,7 +8,7 @@ interface B {
     fun foo() = 2
 }
 
-open <!MANY_IMPL_MEMBER_NOT_IMPLEMENTED!>class C<!> : A, B {}
+open <!MANY_INTERFACES_MEMBER_NOT_IMPLEMENTED!>class C<!> : A, B {}
 
 interface E {
     fun foo(): Int
diff --git a/compiler/testData/diagnostics/tests/override/parameterNames/kotlinInheritsBothJavaAndKotlin.kt b/compiler/testData/diagnostics/tests/override/parameterNames/kotlinInheritsBothJavaAndKotlin.kt
index 4ce9afec0c8..021256a8568 100644
--- a/compiler/testData/diagnostics/tests/override/parameterNames/kotlinInheritsBothJavaAndKotlin.kt
+++ b/compiler/testData/diagnostics/tests/override/parameterNames/kotlinInheritsBothJavaAndKotlin.kt
@@ -10,4 +10,4 @@ interface KotlinTrait {
     public fun foo(someOtherName: Int) {}
 }
 
-class BothTraitsSubclass : JavaInterface, KotlinTrait
+<!MANY_INTERFACES_MEMBER_NOT_IMPLEMENTED!>class BothTraitsSubclass<!> : JavaInterface, KotlinTrait
\ No newline at end of file
diff --git a/compiler/testData/diagnostics/tests/platformTypes/typeEnhancement/supertypeDifferentParameterNullability.kt b/compiler/testData/diagnostics/tests/platformTypes/typeEnhancement/supertypeDifferentParameterNullability.kt
index f0f8092e51c..c4ac7bba791 100644
--- a/compiler/testData/diagnostics/tests/platformTypes/typeEnhancement/supertypeDifferentParameterNullability.kt
+++ b/compiler/testData/diagnostics/tests/platformTypes/typeEnhancement/supertypeDifferentParameterNullability.kt
@@ -22,7 +22,7 @@ public interface B {
     <!ACCIDENTAL_OVERRIDE!>override fun foo(x: String?)<!> {}
 }
 
-interface <!ACCIDENTAL_OVERRIDE!>I<!> : A, B
+interface <!CONFLICTING_INHERITED_JVM_DECLARATIONS!>I<!> : A, B
 
 <!ABSTRACT_MEMBER_NOT_IMPLEMENTED!>class C3<!> : I {
     <!ACCIDENTAL_OVERRIDE!>override fun foo(x: String)<!> {}
@@ -30,4 +30,4 @@ interface <!ACCIDENTAL_OVERRIDE!>I<!> : A, B
 
 <!ABSTRACT_MEMBER_NOT_IMPLEMENTED!>class C4<!> : I {
     <!ACCIDENTAL_OVERRIDE!>override fun foo(x: String?)<!> {}
-}
+}
\ No newline at end of file
diff --git a/compiler/testData/diagnostics/tests/regressions/kt302.kt b/compiler/testData/diagnostics/tests/regressions/kt302.kt
index 7905dcb3ef8..299fd7fafae 100644
--- a/compiler/testData/diagnostics/tests/regressions/kt302.kt
+++ b/compiler/testData/diagnostics/tests/regressions/kt302.kt
@@ -10,4 +10,4 @@ interface B {
     open fun foo() {}
 }
 
-<!MANY_IMPL_MEMBER_NOT_IMPLEMENTED!>class C<!> : A, B {} //should be error here
+<!MANY_INTERFACES_MEMBER_NOT_IMPLEMENTED!>class C<!> : A, B {} //should be error here
\ No newline at end of file
diff --git a/compiler/tests/org/jetbrains/kotlin/checkers/JetDiagnosticsTestGenerated.java b/compiler/tests/org/jetbrains/kotlin/checkers/JetDiagnosticsTestGenerated.java
index 7563573b39f..2c27deef057 100644
--- a/compiler/tests/org/jetbrains/kotlin/checkers/JetDiagnosticsTestGenerated.java
+++ b/compiler/tests/org/jetbrains/kotlin/checkers/JetDiagnosticsTestGenerated.java
@@ -9184,6 +9184,60 @@ public class JetDiagnosticsTestGenerated extends AbstractJetDiagnosticsTest {
             }
         }
 
+        @TestMetadata("compiler/testData/diagnostics/tests/jdk-annotations")
+        @TestDataPath("$PROJECT_ROOT")
+        @RunWith(JUnit3RunnerWithInners.class)
+        public static class Jdk_annotations extends AbstractJetDiagnosticsTest {
+            public void testAllFilesPresentInJdk_annotations() throws Exception {
+                JetTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("compiler/testData/diagnostics/tests/jdk-annotations"), Pattern.compile("^(.+)\\.kt$"), true);
+            }
+
+            @TestMetadata("ArrayListAndMap.kt")
+            public void testArrayListAndMap() throws Exception {
+                String fileName = JetTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/jdk-annotations/ArrayListAndMap.kt");
+                doTest(fileName);
+            }
+
+            @TestMetadata("ArrayListClone.kt")
+            public void testArrayListClone() throws Exception {
+                String fileName = JetTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/jdk-annotations/ArrayListClone.kt");
+                doTest(fileName);
+            }
+
+            @TestMetadata("ArrayListToArray.kt")
+            public void testArrayListToArray() throws Exception {
+                String fileName = JetTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/jdk-annotations/ArrayListToArray.kt");
+                doTest(fileName);
+            }
+
+            @TestMetadata("compiler/testData/diagnostics/tests/jdk-annotations/sql")
+            @TestDataPath("$PROJECT_ROOT")
+            @RunWith(JUnit3RunnerWithInners.class)
+            public static class Sql extends AbstractJetDiagnosticsTest {
+                public void testAllFilesPresentInSql() throws Exception {
+                    JetTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("compiler/testData/diagnostics/tests/jdk-annotations/sql"), Pattern.compile("^(.+)\\.kt$"), true);
+                }
+
+                @TestMetadata("DriverManager.kt")
+                public void testDriverManager() throws Exception {
+                    String fileName = JetTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/jdk-annotations/sql/DriverManager.kt");
+                    doTest(fileName);
+                }
+
+                @TestMetadata("ResultSet.kt")
+                public void testResultSet() throws Exception {
+                    String fileName = JetTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/jdk-annotations/sql/ResultSet.kt");
+                    doTest(fileName);
+                }
+
+                @TestMetadata("Statement.kt")
+                public void testStatement() throws Exception {
+                    String fileName = JetTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/jdk-annotations/sql/Statement.kt");
+                    doTest(fileName);
+                }
+            }
+        }
+
         @TestMetadata("compiler/testData/diagnostics/tests/labels")
         @TestDataPath("$PROJECT_ROOT")
         @RunWith(JUnit3RunnerWithInners.class)
diff --git a/compiler/tests/org/jetbrains/kotlin/codegen/generated/BlackBoxCodegenTestGenerated.java b/compiler/tests/org/jetbrains/kotlin/codegen/generated/BlackBoxCodegenTestGenerated.java
index 42cdfe14b5c..a6cc25b2190 100644
--- a/compiler/tests/org/jetbrains/kotlin/codegen/generated/BlackBoxCodegenTestGenerated.java
+++ b/compiler/tests/org/jetbrains/kotlin/codegen/generated/BlackBoxCodegenTestGenerated.java
@@ -454,18 +454,6 @@ public class BlackBoxCodegenTestGenerated extends AbstractBlackBoxCodegenTest {
             doTest(fileName);
         }
 
-        @TestMetadata("fakeGenericContravariantOverride1.kt")
-        public void testFakeGenericContravariantOverride1() throws Exception {
-            String fileName = JetTestUtils.navigationMetadata("compiler/testData/codegen/box/bridges/fakeGenericContravariantOverride1.kt");
-            doTest(fileName);
-        }
-
-        @TestMetadata("fakeGenericContravariantOverride2.kt")
-        public void testFakeGenericContravariantOverride2() throws Exception {
-            String fileName = JetTestUtils.navigationMetadata("compiler/testData/codegen/box/bridges/fakeGenericContravariantOverride2.kt");
-            doTest(fileName);
-        }
-
         @TestMetadata("fakeGenericCovariantOverride.kt")
         public void testFakeGenericCovariantOverride() throws Exception {
             String fileName = JetTestUtils.navigationMetadata("compiler/testData/codegen/box/bridges/fakeGenericCovariantOverride.kt");
@@ -478,24 +466,12 @@ public class BlackBoxCodegenTestGenerated extends AbstractBlackBoxCodegenTest {
             doTest(fileName);
         }
 
-        @TestMetadata("fakeOverrideOfPropertySetterInTraitImpl.kt")
-        public void testFakeOverrideOfPropertySetterInTraitImpl() throws Exception {
-            String fileName = JetTestUtils.navigationMetadata("compiler/testData/codegen/box/bridges/fakeOverrideOfPropertySetterInTraitImpl.kt");
-            doTest(fileName);
-        }
-
         @TestMetadata("fakeOverrideOfTraitImpl.kt")
         public void testFakeOverrideOfTraitImpl() throws Exception {
             String fileName = JetTestUtils.navigationMetadata("compiler/testData/codegen/box/bridges/fakeOverrideOfTraitImpl.kt");
             doTest(fileName);
         }
 
-        @TestMetadata("fakeOverrideWithImplementationInTrait.kt")
-        public void testFakeOverrideWithImplementationInTrait() throws Exception {
-            String fileName = JetTestUtils.navigationMetadata("compiler/testData/codegen/box/bridges/fakeOverrideWithImplementationInTrait.kt");
-            doTest(fileName);
-        }
-
         @TestMetadata("fakeOverrideWithSeveralSuperDeclarations.kt")
         public void testFakeOverrideWithSeveralSuperDeclarations() throws Exception {
             String fileName = JetTestUtils.navigationMetadata("compiler/testData/codegen/box/bridges/fakeOverrideWithSeveralSuperDeclarations.kt");
diff --git a/idea/testData/diagnosticMessage/wrongReturnTypeInImplementation.kt b/idea/testData/diagnosticMessage/abstractBaseClassMemberNotImplemented.kt
similarity index 84%
rename from idea/testData/diagnosticMessage/wrongReturnTypeInImplementation.kt
rename to idea/testData/diagnosticMessage/abstractBaseClassMemberNotImplemented.kt
index 40dd0987d70..609071129d9 100644
--- a/idea/testData/diagnosticMessage/wrongReturnTypeInImplementation.kt
+++ b/idea/testData/diagnosticMessage/abstractBaseClassMemberNotImplemented.kt
@@ -1,5 +1,5 @@
 // !DIAGNOSTICS_NUMBER: 1
-// !DIAGNOSTICS: ABSTRACT_MEMBER_NOT_IMPLEMENTED
+// !DIAGNOSTICS: ABSTRACT_CLASS_MEMBER_NOT_IMPLEMENTED
 // !MESSAGE_TYPE: TEXT
 
 interface T1
diff --git a/idea/testData/diagnosticMessage/abstractBaseClassMemberNotImplemented1.txt b/idea/testData/diagnosticMessage/abstractBaseClassMemberNotImplemented1.txt
new file mode 100644
index 00000000000..dc73fbf39d0
--- /dev/null
+++ b/idea/testData/diagnosticMessage/abstractBaseClassMemberNotImplemented1.txt
@@ -0,0 +1,2 @@
+<!-- abstractBaseClassMemberNotImplemented1 -->
+Class 'E' must be declared abstract or implement abstract base class member public abstract fun f(): T4 defined in D
\ No newline at end of file
diff --git a/idea/testData/diagnosticMessage/wrongReturnTypeInImplementation1.txt b/idea/testData/diagnosticMessage/wrongReturnTypeInImplementation1.txt
deleted file mode 100644
index be95618029b..00000000000
--- a/idea/testData/diagnosticMessage/wrongReturnTypeInImplementation1.txt
+++ /dev/null
@@ -1,2 +0,0 @@
-<!-- wrongReturnTypeInImplementation1 -->
-Class 'E' must be declared abstract or implement abstract member public abstract fun f(): T3 defined in C
\ No newline at end of file
diff --git a/idea/testData/quickfix/changeSignature/notEditable.kt b/idea/testData/quickfix/changeSignature/notEditable.kt
index e6ed21079d5..460fab40ce1 100644
--- a/idea/testData/quickfix/changeSignature/notEditable.kt
+++ b/idea/testData/quickfix/changeSignature/notEditable.kt
@@ -1,11 +1,11 @@
 // "class org.jetbrains.kotlin.idea.quickfix.RemoveFunctionParametersFix" "false"
 //ERROR: No value passed for parameter other
 
-interface StringComparable {
+abstract class StringComparable {
     public fun compareTo(other: String): Int = 0
 }
 
-class X: Comparable<String>, StringComparable
+class X: Comparable<String>, StringComparable()
 
 fun main(args: Array<String>) {
     X().compareTo(<caret>)
diff --git a/idea/tests/org/jetbrains/kotlin/idea/highlighter/DiagnosticMessageTestGenerated.java b/idea/tests/org/jetbrains/kotlin/idea/highlighter/DiagnosticMessageTestGenerated.java
index fe280f402fc..731c114df4e 100644
--- a/idea/tests/org/jetbrains/kotlin/idea/highlighter/DiagnosticMessageTestGenerated.java
+++ b/idea/tests/org/jetbrains/kotlin/idea/highlighter/DiagnosticMessageTestGenerated.java
@@ -31,6 +31,12 @@ import java.util.regex.Pattern;
 @TestDataPath("$PROJECT_ROOT")
 @RunWith(JUnit3RunnerWithInners.class)
 public class DiagnosticMessageTestGenerated extends AbstractDiagnosticMessageTest {
+    @TestMetadata("abstractBaseClassMemberNotImplemented.kt")
+    public void testAbstractBaseClassMemberNotImplemented() throws Exception {
+        String fileName = JetTestUtils.navigationMetadata("idea/testData/diagnosticMessage/abstractBaseClassMemberNotImplemented.kt");
+        doTest(fileName);
+    }
+
     public void testAllFilesPresentInDiagnosticMessage() throws Exception {
         JetTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("idea/testData/diagnosticMessage"), Pattern.compile("^(.+)\\.kt$"), false);
     }
@@ -202,10 +208,4 @@ public class DiagnosticMessageTestGenerated extends AbstractDiagnosticMessageTes
         String fileName = JetTestUtils.navigationMetadata("idea/testData/diagnosticMessage/upperBoundViolated.kt");
         doTest(fileName);
     }
-
-    @TestMetadata("wrongReturnTypeInImplementation.kt")
-    public void testWrongReturnTypeInImplementation() throws Exception {
-        String fileName = JetTestUtils.navigationMetadata("idea/testData/diagnosticMessage/wrongReturnTypeInImplementation.kt");
-        doTest(fileName);
-    }
 }
diff --git a/js/js.tests/test/org/jetbrains/kotlin/js/test/semantics/BridgeTestGenerated.java b/js/js.tests/test/org/jetbrains/kotlin/js/test/semantics/BridgeTestGenerated.java
index 37adce31a2f..9f0172dd596 100644
--- a/js/js.tests/test/org/jetbrains/kotlin/js/test/semantics/BridgeTestGenerated.java
+++ b/js/js.tests/test/org/jetbrains/kotlin/js/test/semantics/BridgeTestGenerated.java
@@ -77,18 +77,6 @@ public class BridgeTestGenerated extends AbstractBridgeTest {
         doTest(fileName);
     }
 
-    @TestMetadata("fakeGenericContravariantOverride1.kt")
-    public void testFakeGenericContravariantOverride1() throws Exception {
-        String fileName = JetTestUtils.navigationMetadata("compiler/testData/codegen/box/bridges/fakeGenericContravariantOverride1.kt");
-        doTest(fileName);
-    }
-
-    @TestMetadata("fakeGenericContravariantOverride2.kt")
-    public void testFakeGenericContravariantOverride2() throws Exception {
-        String fileName = JetTestUtils.navigationMetadata("compiler/testData/codegen/box/bridges/fakeGenericContravariantOverride2.kt");
-        doTest(fileName);
-    }
-
     @TestMetadata("fakeGenericCovariantOverride.kt")
     public void testFakeGenericCovariantOverride() throws Exception {
         String fileName = JetTestUtils.navigationMetadata("compiler/testData/codegen/box/bridges/fakeGenericCovariantOverride.kt");
@@ -101,24 +89,12 @@ public class BridgeTestGenerated extends AbstractBridgeTest {
         doTest(fileName);
     }
 
-    @TestMetadata("fakeOverrideOfPropertySetterInTraitImpl.kt")
-    public void testFakeOverrideOfPropertySetterInTraitImpl() throws Exception {
-        String fileName = JetTestUtils.navigationMetadata("compiler/testData/codegen/box/bridges/fakeOverrideOfPropertySetterInTraitImpl.kt");
-        doTest(fileName);
-    }
-
     @TestMetadata("fakeOverrideOfTraitImpl.kt")
     public void testFakeOverrideOfTraitImpl() throws Exception {
         String fileName = JetTestUtils.navigationMetadata("compiler/testData/codegen/box/bridges/fakeOverrideOfTraitImpl.kt");
         doTest(fileName);
     }
 
-    @TestMetadata("fakeOverrideWithImplementationInTrait.kt")
-    public void testFakeOverrideWithImplementationInTrait() throws Exception {
-        String fileName = JetTestUtils.navigationMetadata("compiler/testData/codegen/box/bridges/fakeOverrideWithImplementationInTrait.kt");
-        doTest(fileName);
-    }
-
     @TestMetadata("fakeOverrideWithSeveralSuperDeclarations.kt")
     public void testFakeOverrideWithSeveralSuperDeclarations() throws Exception {
         String fileName = JetTestUtils.navigationMetadata("compiler/testData/codegen/box/bridges/fakeOverrideWithSeveralSuperDeclarations.kt");