Report error on missed specialization in compatibility mode

#KT-39603 Fixed

compiler/backend-common/src/org/jetbrains/kotlin/backend/common/CodegenUtil.kt

@@ -8,7 +8,6 @@ package org.jetbrains.kotlin.backend.common
 import com.intellij.openapi.application.ApplicationManager
 import com.intellij.openapi.project.Project
 import com.intellij.psi.PsiElement
-import org.jetbrains.kotlin.backend.common.bridges.findInterfaceImplementation
 import org.jetbrains.kotlin.descriptors.*
 import org.jetbrains.kotlin.diagnostics.DiagnosticSink
 import org.jetbrains.kotlin.diagnostics.Errors
@@ -24,6 +23,7 @@ import org.jetbrains.kotlin.resolve.calls.callUtil.getResolvedCall
 import org.jetbrains.kotlin.resolve.multiplatform.ExpectedActualResolver
 import org.jetbrains.kotlin.types.KotlinType
 import org.jetbrains.kotlin.util.getExceptionMessage
+import org.jetbrains.kotlin.util.getNonPrivateTraitMembersForDelegation
 import org.jetbrains.kotlin.utils.DFS
 import org.jetbrains.kotlin.utils.KotlinExceptionWithAttachments
 
@@ -55,14 +55,8 @@ object CodegenUtil {
     @JvmOverloads
     fun getNonPrivateTraitMethods(descriptor: ClassDescriptor, copy: Boolean = true): Map<FunctionDescriptor, FunctionDescriptor> {
         val result = linkedMapOf<FunctionDescriptor, FunctionDescriptor>()
-        for (declaration in DescriptorUtils.getAllDescriptors(descriptor.defaultType.memberScope)) {
-            if (declaration !is CallableMemberDescriptor) continue
-
-            val traitMember = findInterfaceImplementation(declaration)
-            if (traitMember == null ||
-                    Visibilities.isPrivate(traitMember.visibility) ||
-                    traitMember.visibility == Visibilities.INVISIBLE_FAKE) continue
 
+        for ((declaration, traitMember) in getNonPrivateTraitMembersForDelegation(descriptor)) {
             assert(traitMember.modality !== Modality.ABSTRACT) { "Cannot delegate to abstract trait method: $declaration" }
 
             // inheritedMember can be abstract here. In order for FunctionCodegen to generate the method body, we're creating a copy here

compiler/backend-common/src/org/jetbrains/kotlin/backend/common/bridges/impl.kt

@@ -24,6 +24,8 @@ import org.jetbrains.kotlin.resolve.OverridingUtil
 import org.jetbrains.kotlin.resolve.calls.callResolverUtil.isOrOverridesSynthesized
 import org.jetbrains.kotlin.resolve.descriptorUtil.isTypeRefinementEnabled
 import org.jetbrains.kotlin.resolve.descriptorUtil.module
+import org.jetbrains.kotlin.util.findImplementationFromInterface
+import org.jetbrains.kotlin.util.findInterfaceImplementation
 
 fun <Signature> generateBridgesForFunctionDescriptor(
     descriptor: FunctionDescriptor,
@@ -81,60 +83,4 @@ open class DescriptorBasedFunctionHandle(val descriptor: FunctionDescriptor) : F
     override fun toString(): String {
         return descriptor.toString()
     }
-}
-
-
-/**
- * Given a fake override in a class, returns an overridden declaration with implementation in trait, such that a method delegating to that
- * trait implementation should be generated into the class containing the fake override; or null if the given function is not a fake
- * override of any trait implementation or such method was already generated into the superclass or is a method from Any.
- */
-fun findInterfaceImplementation(descriptor: CallableMemberDescriptor): CallableMemberDescriptor? {
-    if (descriptor.kind.isReal) return null
-    if (isOrOverridesSynthesized(descriptor)) return null
-
-    val implementation = findImplementationFromInterface(descriptor) ?: return null
-    val immediateConcreteSuper = firstSuperMethodFromKotlin(descriptor, implementation) ?: return null
-
-    if (!DescriptorUtils.isInterface(immediateConcreteSuper.containingDeclaration)) {
-        // If this implementation is already generated into the superclass, we need not generate it again, it'll be inherited
-        return null
-    }
-
-    return immediateConcreteSuper
-}
-
-/**
- * Given a fake override, returns an overridden non-abstract function from an interface which is the actual implementation of this function
- * that should be called when the given fake override is called.
- */
-fun findImplementationFromInterface(descriptor: CallableMemberDescriptor): CallableMemberDescriptor? {
-    val overridden = OverridingUtil.getOverriddenDeclarations(descriptor)
-    val filtered = OverridingUtil.filterOutOverridden(overridden)
-
-    val result = filtered.firstOrNull { it.modality != Modality.ABSTRACT } ?: return null
-
-    if (DescriptorUtils.isClassOrEnumClass(result.containingDeclaration)) return null
-
-    return result
-}
-
-/**
- * Given a fake override and its implementation (non-abstract declaration) somewhere in supertypes,
- * returns the first immediate super function of the given fake override which overrides that implementation.
- * The returned function should be called from TImpl-bridges generated for the given fake override.
- */
-fun firstSuperMethodFromKotlin(
-    descriptor: CallableMemberDescriptor,
-    implementation: CallableMemberDescriptor
-): CallableMemberDescriptor? {
-    return descriptor.overriddenDescriptors.firstOrNull { overridden ->
-        overridden.modality != Modality.ABSTRACT &&
-                (overridden == implementation || OverridingUtil.overrides(
-                    overridden,
-                    implementation,
-                    overridden.module.isTypeRefinementEnabled(),
-                    true
-                ))
-    }
-}
+}