Obj.toKotlin tiny fix

CHANGELOG.md

@@ -2,6 +2,11 @@
 
 ### Unreleased
 
+- Language: Refined `protected` visibility rules
+  - Ancestor classes can now access `protected` members of their descendants, provided the ancestor also defines or inherits a member with the same name (indicating an override of a member known to the ancestor).
+  - This allows patterns where a base class calls a `protected` method that is implemented in a subclass.
+  - Fixed a regression where self-calls to unmangled members sometimes bypassed visibility checks incorrectly; these are now handled by the refined logic.
+
 - Language: Added `return` statement
   - `return [expression]` exits the innermost enclosing callable (function or lambda).
   - Supports non-local returns using `@label` syntax (e.g., `return@outer 42`).
@@ -96,7 +101,7 @@
     - Header-specified constructor arguments are passed to direct bases.
   - Visibility enforcement under MI:
     - `private` visible only inside the declaring class body.
-    - `protected` visible inside the declaring class and any of its transitive subclasses; unrelated contexts cannot access it (qualification/casts do not bypass).
+    - `protected` visible inside the declaring class and its transitive subclasses. Additionally, ancestor classes can access protected members of their descendants if it's an override of a member known to the ancestor. Unrelated contexts cannot access it (qualification/casts do not bypass).
   - Diagnostics improvements:
     - Missing member/field messages include receiver class and linearization order; hints for `this@Type` or casts when helpful.
     - Invalid `this@Type` reports that the qualifier is not an ancestor and shows the receiver lineage.

LYNG_AI_SPEC.md

@@ -32,7 +32,7 @@ High-density specification for LLMs. Reference this for all Lyng code generation
     val area get = π * r * r
     ```
 - **Mandatory `override`**: Required for all members existing in the ancestor chain.
-- **Visibility**: `public` (default), `protected` (subclasses), `private` (this class instance only). `private set` / `protected set` allowed on properties.
+- **Visibility**: `public` (default), `protected` (subclasses and ancestors for overrides), `private` (this class instance only). `private set` / `protected set` allowed on properties.
 - **Disambiguation**: `this@Base.member()` or `(obj as Base).member()`. `as` returns a qualified view.
 - **Abstract/Interface**: `interface` is a synonym for `abstract class`. Both support state and constructors.
 - **Extensions**: `fun Class.ext()` or `val Class.ext get = ...`. Scope-isolated.

docs/OOP.md

@@ -425,7 +425,7 @@ Key rules and features:
 
 - Visibility
   - `private`: accessible only inside the declaring class body; not visible in subclasses and cannot be accessed via `this@Type` or casts.
-  - `protected`: accessible in the declaring class and in any of its transitive subclasses (including MI), but not from unrelated contexts; qualification/casts do not bypass it.
+  - `protected`: accessible in the declaring class and in any of its transitive subclasses (including MI). Additionally, ancestor classes can access protected members of their descendants if it's an override of a member known to the ancestor. Protected members are not visible from unrelated contexts; qualification/casts do not bypass it.
 
 ## Abstract Classes and Members
 
@@ -859,21 +859,29 @@ Private fields are visible only _inside the class instance_:
 
 ### Protected members
 
-Protected members are available to the declaring class and all of its transitive subclasses (including via MI), but not from unrelated contexts:
+Protected members are available to the declaring class and all of its transitive subclasses (including via MI). Additionally, an ancestor class can access a `protected` member of its descendant if the ancestor also defines or inherits a member with the same name (i.e., it is an override of something the ancestor knows about). 
 
-```
+Protected members are not available from unrelated contexts:
-class A() {
+
-    protected fun ping() { "pong" }
+```lyng
+class Base {
+    abstract protected fun foo()
+    
+    fun bar() {
+        // Ancestor can see foo() because it's an override 
+        // of a member it defines (even as abstract):
+        foo()
     }
-class B() : A() {
-    fun call() { this@A.ping() }
 }
 
-val b = B()
+class Derived : Base {
-assertEquals("pong", b.call())
+    override protected fun foo() { "ok" }
+}
+
+assertEquals("ok", Derived().bar())
 
 // Unrelated access is forbidden, even via cast
-assertThrows { (b as A).ping() }
+assertThrows { (Derived() as Base).foo() }
 ```
 
 It is possible to provide private constructor parameters so they can be

docs/tutorial.md

@@ -1701,7 +1701,7 @@ assertEquals(null, (buzz as? Foo)?.runA())
 
 Notes:
 - Resolution order uses C3 MRO (active): deterministic, monotonic order suitable for diamonds and complex hierarchies. Example: for `class D() : B(), C()` where both `B()` and `C()` derive from `A()`, the C3 order is `D → B → C → A`. The first visible match wins.
-- `private` is visible only inside the declaring class; `protected` is visible from the declaring class and any of its transitive subclasses. Qualialsofication (`this@Type`) or casts do not bypass visibility.
+- `private` is visible only inside the declaring class; `protected` is visible from the declaring class and its subclasses. Additionally, ancestors can access protected members of descendants if they override a member known to the ancestor. Qualification (`this@Type`) or casts do not bypass visibility.
 - Safe‑call `?.` works with `as?` for optional dispatch.
 
 ## Extension members

docs/whats_new.md

@@ -24,6 +24,9 @@ class Person(private var _age: Int) {
 ### Private and Protected Setters
 You can now restrict the visibility of a property's or field's setter using `private set` or `protected set`. This allows members to be publicly readable but only writable from within the declaring class or its subclasses.
 
+### Refined Protected Visibility
+Ancestor classes can now access `protected` members of their descendants if it is an override of a member known to the ancestor. This enables base classes to call protected methods that are implemented or overridden in subclasses.
+
 ```lyng
 class Counter {
     var count = 0

lynglib/build.gradle.kts

@@ -21,7 +21,7 @@ import org.jetbrains.kotlin.gradle.ExperimentalWasmDsl
 import org.jetbrains.kotlin.gradle.dsl.JvmTarget
 
 group = "net.sergeych"
-version = "1.2.0"
+version = "1.2.1-SNAPSHOT"
 
 // Removed legacy buildscript classpath declarations; plugins are applied via the plugins DSL below
 

lynglib/src/commonMain/kotlin/net/sergeych/lyng/ClosureScope.kt

@@ -54,14 +54,14 @@ class ClosureScope(val callScope: Scope, val closureScope: Scope) :
         for (cls in effectiveClass.mro) {
             val rec = cls.members[name] ?: cls.classScope?.objects?.get(name)
             if (rec != null && !rec.isAbstract) {
-                if (canAccessMember(rec.visibility, rec.declaringClass ?: cls, currentClassCtx)) {
+                if (canAccessMember(rec.visibility, rec.declaringClass ?: cls, currentClassCtx, name)) {
                     return rec.copy(receiver = receiver)
                 }
             }
         }
         // Finally, root object fallback
         Obj.rootObjectType.members[name]?.let { rec ->
-            if (canAccessMember(rec.visibility, rec.declaringClass, currentClassCtx)) {
+            if (canAccessMember(rec.visibility, rec.declaringClass, currentClassCtx, name)) {
                 return rec.copy(receiver = receiver)
             }
         }

lynglib/src/commonMain/kotlin/net/sergeych/lyng/Scope.kt

@@ -112,7 +112,7 @@ open class Scope(
             }
         }
         s.objects[name]?.let { rec ->
-            if (rec.declaringClass == null || canAccessMember(rec.visibility, rec.declaringClass, caller)) return rec
+            if (rec.declaringClass == null || canAccessMember(rec.visibility, rec.declaringClass, caller, name)) return rec
         }
         caller?.let { ctx ->
             s.localBindings[ctx.mangledName(name)]?.let { rec ->
@@ -120,11 +120,11 @@ open class Scope(
             }
         }
         s.localBindings[name]?.let { rec ->
-            if (rec.declaringClass == null || canAccessMember(rec.visibility, rec.declaringClass, caller)) return rec
+            if (rec.declaringClass == null || canAccessMember(rec.visibility, rec.declaringClass, caller, name)) return rec
         }
         s.getSlotIndexOf(name)?.let { idx ->
             val rec = s.getSlotRecord(idx)
-            if (rec.declaringClass == null || canAccessMember(rec.visibility, rec.declaringClass, caller)) return rec
+            if (rec.declaringClass == null || canAccessMember(rec.visibility, rec.declaringClass, caller, name)) return rec
         }
         return null
     }
@@ -163,7 +163,7 @@ open class Scope(
             this.extensions[cls]?.get(name)?.let { return it }
         }
         return thisObj.objClass.getInstanceMemberOrNull(name)?.let { rec ->
-            if (canAccessMember(rec.visibility, rec.declaringClass, currentClassCtx)) {
+            if (canAccessMember(rec.visibility, rec.declaringClass, currentClassCtx, name)) {
                 if (rec.type == ObjRecord.Type.Field || rec.type == ObjRecord.Type.Property || rec.isAbstract) null
                 else rec
             } else null
@@ -186,7 +186,7 @@ open class Scope(
                 s.extensions[cls]?.get(name)?.let { return it }
             }
             s.thisObj.objClass.getInstanceMemberOrNull(name)?.let { rec ->
-                if (canAccessMember(rec.visibility, rec.declaringClass, caller)) {
+                if (canAccessMember(rec.visibility, rec.declaringClass, caller, name)) {
                     if (rec.type == ObjRecord.Type.Field || rec.type == ObjRecord.Type.Property || rec.isAbstract) {
                         // ignore fields, properties and abstracts here, they will be handled by the caller via readField
                     } else return rec
@@ -358,14 +358,14 @@ open class Scope(
         for (cls in effectiveClass.mro) {
             val rec = cls.members[name] ?: cls.classScope?.objects?.get(name)
             if (rec != null && !rec.isAbstract) {
-                if (canAccessMember(rec.visibility, rec.declaringClass ?: cls, currentClassCtx)) {
+                if (canAccessMember(rec.visibility, rec.declaringClass ?: cls, currentClassCtx, name)) {
                     return rec.copy(receiver = receiver)
                 }
             }
         }
         // Finally, root object fallback
         Obj.rootObjectType.members[name]?.let { rec ->
-            if (canAccessMember(rec.visibility, rec.declaringClass, currentClassCtx)) {
+            if (canAccessMember(rec.visibility, rec.declaringClass, currentClassCtx, name)) {
                 return rec.copy(receiver = receiver)
             }
         }

lynglib/src/commonMain/kotlin/net/sergeych/lyng/Visibility.kt

@@ -1,5 +1,5 @@
 /*
- * Copyright 2025 Sergey S. Chernov real.sergeych@gmail.com
+ * Copyright 2026 Sergey S. Chernov real.sergeych@gmail.com
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -25,7 +25,12 @@ enum class Visibility {
 }
 
 /** MI-aware visibility check: whether [caller] can access a member declared in [decl] with [visibility]. */
-fun canAccessMember(visibility: Visibility, decl: net.sergeych.lyng.obj.ObjClass?, caller: net.sergeych.lyng.obj.ObjClass?): Boolean {
+fun canAccessMember(
+    visibility: Visibility,
+    decl: net.sergeych.lyng.obj.ObjClass?,
+    caller: net.sergeych.lyng.obj.ObjClass?,
+    name: String? = null
+): Boolean {
     val res = when (visibility) {
         Visibility.Public -> true
         Visibility.Private -> (decl != null && caller === decl)
@@ -33,7 +38,14 @@ fun canAccessMember(visibility: Visibility, decl: net.sergeych.lyng.obj.ObjClass
             decl == null -> false
             caller == null -> false
             caller === decl -> true
-            else -> (caller.allParentsSet.contains(decl))
+            caller.allParentsSet.contains(decl) -> true
+            name != null && decl.allParentsSet.contains(caller) -> {
+                // Ancestor can access protected member of its descendant if it also has this member
+                // (i.e. it's an override of something the ancestor knows about)
+                val existing = caller.getInstanceMemberOrNull(name, includeAbstract = true)
+                existing != null && (existing.visibility == Visibility.Protected || existing.visibility == Visibility.Public)
+            }
+            else -> false
         }
     }
     return res

lynglib/src/commonMain/kotlin/net/sergeych/lyng/obj/Obj.kt

@@ -113,7 +113,7 @@ open class Obj {
             if (rec != null && !rec.isAbstract) {
                 val decl = rec.declaringClass ?: cls
                 val caller = scope.currentClassCtx
-                if (!canAccessMember(rec.visibility, decl, caller))
+                if (!canAccessMember(rec.visibility, decl, caller, name))
                     scope.raiseError(ObjIllegalAccessException(scope, "can't invoke ${name}: not visible (declared in ${decl.className}, caller ${caller?.className ?: "?"})"))
                 
                 if (rec.type == ObjRecord.Type.Property) {
@@ -140,7 +140,7 @@ open class Obj {
                 cls.members[name]?.let { rec ->
                     val decl = rec.declaringClass ?: cls
                     val caller = scope.currentClassCtx
-                    if (!canAccessMember(rec.visibility, decl, caller))
+                    if (!canAccessMember(rec.visibility, decl, caller, name))
                         scope.raiseError(ObjIllegalAccessException(scope, "can't invoke ${name}: not visible (declared in ${decl.className}, caller ${caller?.className ?: "?"})"))
                     
                     if (rec.type == ObjRecord.Type.Property) {
@@ -429,10 +429,10 @@ open class Obj {
     }
 
     /**
-     * Convert Lyng object to its Kotlin counterpart
+     * Convert a Lyng object to its Kotlin counterpart
      */
     open suspend fun toKotlin(scope: Scope): Any? {
-        return toString()
+        return toString(scope).value
     }
 
     fun willMutate(scope: Scope) {
@@ -482,7 +482,7 @@ open class Obj {
                 cls.members[name]?.let { rec ->
                     val decl = rec.declaringClass ?: cls
                     val caller = scope.currentClassCtx
-                    if (!canAccessMember(rec.visibility, decl, caller))
+                    if (!canAccessMember(rec.visibility, decl, caller, name))
                         scope.raiseError(ObjIllegalAccessException(scope, "can't access field ${name}: not visible (declared in ${decl.className}, caller ${caller?.className ?: "?"})"))
                     val resolved = resolveRecord(scope, rec, name, decl)
                     if (resolved.type == ObjRecord.Type.Fun && resolved.value is Statement)
@@ -526,7 +526,7 @@ open class Obj {
         }
         val caller = scope.currentClassCtx
         // Check visibility for non-property members here if they weren't checked before
-        if (!canAccessMember(obj.visibility, decl, caller))
+        if (!canAccessMember(obj.visibility, decl, caller, name))
             scope.raiseError(ObjIllegalAccessException(scope, "can't access field ${name}: not visible (declared in ${decl?.className ?: "?"}, caller ${caller?.className ?: "?"})"))
         return obj
     }
@@ -574,7 +574,7 @@ open class Obj {
 
         val decl = field.declaringClass
         val caller = scope.currentClassCtx
-        if (!canAccessMember(field.effectiveWriteVisibility, decl, caller))
+        if (!canAccessMember(field.effectiveWriteVisibility, decl, caller, name))
             scope.raiseError(ObjIllegalAccessException(scope, "can't assign field ${name}: not visible (declared in ${decl?.className ?: "?"}, caller ${caller?.className ?: "?"})"))
         if (field.type == ObjRecord.Type.Delegated) {
             val del = field.delegate ?: scope.raiseError("Internal error: delegated property $name has no delegate")

lynglib/src/commonMain/kotlin/net/sergeych/lyng/obj/ObjClass.kt

@@ -461,7 +461,7 @@ open class ObjClass(
             if (existing != null && existing.declaringClass != this) {
                 // If the existing member is private in the ancestor, it's not visible for overriding.
                 // It should be treated as a new member in this class.
-                if (!existing.visibility.isPublic && !canAccessMember(existing.visibility, existing.declaringClass, this)) {
+                if (!existing.visibility.isPublic && !canAccessMember(existing.visibility, existing.declaringClass, this, name)) {
                     // It's effectively not there for us, so actualOverride remains false
                 } else {
                     actualOverride = true

lynglib/src/commonMain/kotlin/net/sergeych/lyng/obj/ObjInstance.kt

@@ -68,7 +68,7 @@ class ObjInstance(override val objClass: ObjClass) : Obj() {
             if (cls.className == "Obj") break
             val mangled = cls.mangledName(name)
             instanceScope.objects[mangled]?.let { rec ->
-                if ((scope.thisObj === this && caller != null) || canAccessMember(rec.visibility, cls, caller)) {
+                if (canAccessMember(rec.visibility, cls, caller, name)) {
                     return resolveRecord(scope, rec, name, cls)
                 }
             }
@@ -77,8 +77,7 @@ class ObjInstance(override val objClass: ObjClass) : Obj() {
         // 2. Unmangled storage
         instanceScope.objects[name]?.let { rec ->
             val decl = rec.declaringClass
-            // Unmangled access is only allowed if it's public OR we are inside the same instance's method
+            if (canAccessMember(rec.visibility, decl, caller, name)) {
-            if ((scope.thisObj === this && caller != null) || canAccessMember(rec.visibility, decl, caller)) {
                 return resolveRecord(scope, rec, name, decl)
             }
         }
@@ -174,7 +173,7 @@ class ObjInstance(override val objClass: ObjClass) : Obj() {
             if (cls.className == "Obj") break
             val mangled = cls.mangledName(name)
             instanceScope.objects[mangled]?.let { rec ->
-                if ((scope.thisObj === this && caller != null) || canAccessMember(rec.effectiveWriteVisibility, cls, caller)) {
+                if (canAccessMember(rec.effectiveWriteVisibility, cls, caller, name)) {
                     updateRecord(scope, rec, name, newValue, cls)
                     return
                 }
@@ -184,7 +183,7 @@ class ObjInstance(override val objClass: ObjClass) : Obj() {
         // 2. Unmangled storage
         instanceScope.objects[name]?.let { rec ->
             val decl = rec.declaringClass
-            if ((scope.thisObj === this && caller != null) || canAccessMember(rec.effectiveWriteVisibility, decl, caller)) {
+            if (canAccessMember(rec.effectiveWriteVisibility, decl, caller, name)) {
                 updateRecord(scope, rec, name, newValue, decl)
                 return
             }
@@ -282,7 +281,7 @@ class ObjInstance(override val objClass: ObjClass) : Obj() {
                 }
                 val decl = rec.declaringClass ?: cls
                 val effectiveCaller = caller ?: if (scope.thisObj === this) objClass else null
-                if (!canAccessMember(rec.visibility, decl, effectiveCaller))
+                if (!canAccessMember(rec.visibility, decl, effectiveCaller, name))
                     scope.raiseError(
                         ObjIllegalAccessException(
                             scope,
@@ -433,7 +432,7 @@ class ObjQualifiedView(val instance: ObjInstance, private val startClass: ObjCla
             // Visibility: declaring class is the qualified ancestor for mangled storage
             val decl = rec.declaringClass ?: startClass
             val caller = scope.currentClassCtx
-            if (!canAccessMember(rec.visibility, decl, caller))
+            if (!canAccessMember(rec.visibility, decl, caller, name))
                 scope.raiseError(ObjIllegalAccessException(scope, "can't access field $name (declared in ${decl.className})"))
             return instance.resolveRecord(scope, rec, name, decl)
         }
@@ -442,7 +441,7 @@ class ObjQualifiedView(val instance: ObjInstance, private val startClass: ObjCla
             instance.instanceScope[name]?.let { rec ->
                 val decl = rec.declaringClass ?: instance.objClass.findDeclaringClassOf(name)
                 val caller = scope.currentClassCtx
-                if (!canAccessMember(rec.visibility, decl, caller))
+                if (!canAccessMember(rec.visibility, decl, caller, name))
                     scope.raiseError(
                         ObjIllegalAccessException(
                             scope,
@@ -456,7 +455,7 @@ class ObjQualifiedView(val instance: ObjInstance, private val startClass: ObjCla
         val r = memberFromAncestor(name) ?: scope.raiseError("no such field: $name")
         val decl = r.declaringClass ?: startClass
         val caller = scope.currentClassCtx
-        if (!canAccessMember(r.visibility, decl, caller))
+        if (!canAccessMember(r.visibility, decl, caller, name))
             scope.raiseError(ObjIllegalAccessException(scope, "can't access field $name (declared in ${decl.className})"))
         
         return instance.resolveRecord(scope, r, name, decl)
@@ -468,7 +467,7 @@ class ObjQualifiedView(val instance: ObjInstance, private val startClass: ObjCla
         instance.instanceScope.objects[mangled]?.let { f ->
             val decl = f.declaringClass ?: startClass
             val caller = scope.currentClassCtx
-            if (!canAccessMember(f.effectiveWriteVisibility, decl, caller))
+            if (!canAccessMember(f.effectiveWriteVisibility, decl, caller, name))
                 ObjIllegalAccessException(
                     scope,
                     "can't assign to field $name (declared in ${decl.className})"
@@ -482,7 +481,7 @@ class ObjQualifiedView(val instance: ObjInstance, private val startClass: ObjCla
             instance.instanceScope[name]?.let { f ->
                 val decl = f.declaringClass ?: instance.objClass.findDeclaringClassOf(name)
                 val caller = scope.currentClassCtx
-                if (!canAccessMember(f.effectiveWriteVisibility, decl, caller))
+                if (!canAccessMember(f.effectiveWriteVisibility, decl, caller, name))
                     ObjIllegalAccessException(
                         scope,
                         "can't assign to field $name (declared in ${decl?.className ?: "?"})"
@@ -495,7 +494,7 @@ class ObjQualifiedView(val instance: ObjInstance, private val startClass: ObjCla
         val r = memberFromAncestor(name) ?: scope.raiseError("no such field: $name")
         val decl = r.declaringClass ?: startClass
         val caller = scope.currentClassCtx
-        if (!canAccessMember(r.effectiveWriteVisibility, decl, caller))
+        if (!canAccessMember(r.effectiveWriteVisibility, decl, caller, name))
             ObjIllegalAccessException(scope, "can't assign to field $name (declared in ${decl.className})").raise()
         if (!r.isMutable) scope.raiseError("can't assign to read-only field: $name")
         if (r.value.assign(scope, newValue) == null) r.value = newValue
@@ -511,7 +510,7 @@ class ObjQualifiedView(val instance: ObjInstance, private val startClass: ObjCla
         memberFromAncestor(name)?.let { rec ->
             val decl = rec.declaringClass ?: startClass
             val caller = scope.currentClassCtx
-            if (!canAccessMember(rec.visibility, decl, caller))
+            if (!canAccessMember(rec.visibility, decl, caller, name))
                 scope.raiseError(ObjIllegalAccessException(scope, "can't invoke method $name (declared in ${decl.className})"))
             val saved = instance.instanceScope.currentClassCtx
             instance.instanceScope.currentClassCtx = decl
@@ -526,7 +525,7 @@ class ObjQualifiedView(val instance: ObjInstance, private val startClass: ObjCla
             instance.instanceScope[name]?.let { rec ->
                 val decl = rec.declaringClass ?: instance.objClass.findDeclaringClassOf(name)
                 val caller = scope.currentClassCtx
-                if (!canAccessMember(rec.visibility, decl, caller))
+                if (!canAccessMember(rec.visibility, decl, caller, name))
                     scope.raiseError(
                         ObjIllegalAccessException(
                             scope,

lynglib/src/commonMain/kotlin/net/sergeych/lyng/obj/ObjRef.kt

@@ -1363,7 +1363,7 @@ class MethodCallRef(
                             val decl = hierarchyMember.declaringClass ?: base.objClass
                             mKey1 = key; mVer1 = ver; mInvoker1 = { obj, sc, a ->
                                 val inst = obj as ObjInstance
-                                if (!visibility.isPublic && !canAccessMember(visibility, decl, sc.currentClassCtx))
+                                if (!visibility.isPublic && !canAccessMember(visibility, decl, sc.currentClassCtx, name))
                                     sc.raiseError(ObjIllegalAccessException(sc, "can't invoke non-public method $name"))
                                 callable.invoke(inst.instanceScope, inst, a)
                             }
@@ -1447,7 +1447,7 @@ class LocalVarRef(val name: String, private val atPos: Pos) : ObjRef {
         val slot = if (hit) cachedSlot else resolveSlot(scope)
         if (slot >= 0) {
             val rec = scope.getSlotRecord(slot)
-            if (rec.declaringClass != null && !canAccessMember(rec.visibility, rec.declaringClass, scope.currentClassCtx)) {
+            if (rec.declaringClass != null && !canAccessMember(rec.visibility, rec.declaringClass, scope.currentClassCtx, name)) {
                 // Not visible via slot, fallback to other lookups
             } else {
                 if (PerfFlags.PIC_DEBUG_COUNTERS) {
@@ -1499,7 +1499,7 @@ class LocalVarRef(val name: String, private val atPos: Pos) : ObjRef {
         val slot = if (cachedFrameId == scope.frameId && cachedSlot >= 0 && cachedSlot < scope.slotCount()) cachedSlot else resolveSlot(scope)
         if (slot >= 0) {
             val rec = scope.getSlotRecord(slot)
-            if (rec.declaringClass == null || canAccessMember(rec.visibility, rec.declaringClass, scope.currentClassCtx)) {
+            if (rec.declaringClass == null || canAccessMember(rec.visibility, rec.declaringClass, scope.currentClassCtx, name)) {
                 scope.assign(rec, name, newValue)
                 return
             }
@@ -1608,7 +1608,7 @@ class FastLocalVarRef(
         val actualOwner = cachedOwnerScope
         if (slot >= 0 && actualOwner != null) {
             val rec = actualOwner.getSlotRecord(slot)
-            if (rec.declaringClass == null || canAccessMember(rec.visibility, rec.declaringClass, scope.currentClassCtx)) {
+            if (rec.declaringClass == null || canAccessMember(rec.visibility, rec.declaringClass, scope.currentClassCtx, name)) {
                 if (PerfFlags.PIC_DEBUG_COUNTERS) {
                     if (ownerValid) PerfStats.fastLocalHit++ else PerfStats.fastLocalMiss++
                 }
@@ -1652,7 +1652,7 @@ class FastLocalVarRef(
         val actualOwner = cachedOwnerScope
         if (slot >= 0 && actualOwner != null) {
             val rec = actualOwner.getSlotRecord(slot)
-            if (rec.declaringClass == null || canAccessMember(rec.visibility, rec.declaringClass, scope.currentClassCtx)) {
+            if (rec.declaringClass == null || canAccessMember(rec.visibility, rec.declaringClass, scope.currentClassCtx, name)) {
                 return scope.resolve(rec, name)
             }
         }
@@ -1698,7 +1698,7 @@ class FastLocalVarRef(
         val actualOwner = cachedOwnerScope
         if (slot >= 0 && actualOwner != null) {
             val rec = actualOwner.getSlotRecord(slot)
-            if (rec.declaringClass == null || canAccessMember(rec.visibility, rec.declaringClass, scope.currentClassCtx)) {
+            if (rec.declaringClass == null || canAccessMember(rec.visibility, rec.declaringClass, scope.currentClassCtx, name)) {
                 scope.assign(rec, name, newValue)
                 return
             }

lynglib/src/commonTest/kotlin/OOTest.kt

@@ -776,4 +776,38 @@ class OOTest {
 
         assertEquals("success", result.toString(), "Parameter 'id' should shadow method 'id' in block")
     }
+
+    @Test
+    fun testOverrideVisibilityRules1() = runTest {
+        eval("""
+            interface Base {
+                abstract protected fun foo()
+                
+                fun bar() {
+                    // it must see foo() as it is protected and 
+                    // is declared here (even as abstract):
+                    foo()
+                }
+            }
+            class Derived : Base {
+                protected val suffix = "!"
+                
+                private fun fooPrivateImpl() = "bar"
+            
+                override protected fun foo() { 
+                    // it should access own private and all protected memberes here: 
+                    fooPrivateImpl() + suffix  
+                }
+            }
+            class Derived2: Base {
+                private var value = 42
+                
+                override protected fun foo() {
+                    if( value < 10 ) 10 else value
+                }
+            }
+            assertEquals("bar!", Derived().bar())
+            assertEquals(42, Derived2().bar())
+        """.trimIndent())
+    }
 }