From 9044dfe394287dc315cf30c7b93e874e53a8704c Mon Sep 17 00:00:00 2001
From: Roman Efremov <roman.efremov@jetbrains.com>
Date: Thu, 6 Apr 2023 10:11:41 +0200
Subject: [PATCH] [FE] Revert prohibition of protected members inside actual
 final classes

^KT-28850 Fixed
---
 .../declaration/FirModifierChecker.kt         |  8 +++----
 .../kotlin/resolve/ModifiersChecker.kt        |  8 +++----
 .../modifiers/protectedInExpectActual.kt      | 24 +++++--------------
 3 files changed, 14 insertions(+), 26 deletions(-)

diff --git a/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirModifierChecker.kt b/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirModifierChecker.kt
index f0bd185cfcc..7aa2af2e2c6 100644
--- a/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirModifierChecker.kt
+++ b/compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirModifierChecker.kt
@@ -250,12 +250,12 @@ object FirModifierChecker : FirBasicDeclarationChecker() {
             return true
         }
 
-        if (modifierToken == KtTokens.PROTECTED_KEYWORD && isFinalExpectOrActualClass(parent)) {
+        if (modifierToken == KtTokens.PROTECTED_KEYWORD && isFinalExpectClass(parent)) {
             reporter.reportOn(
                 modifierSource,
                 FirErrors.WRONG_MODIFIER_CONTAINING_DECLARATION,
                 modifierToken,
-                "final expect or actual class",
+                "final expect class",
                 context,
             )
         }
@@ -277,7 +277,7 @@ object FirModifierChecker : FirBasicDeclarationChecker() {
         return firstOrNull()?.description ?: "this"
     }
 
-    private fun isFinalExpectOrActualClass(d: FirDeclaration?): Boolean {
-        return d is FirClass && d.isFinal && (d.isExpect || d.isActual)
+    private fun isFinalExpectClass(d: FirDeclaration?): Boolean {
+        return d is FirClass && d.isFinal && d.isExpect
     }
 }
diff --git a/compiler/frontend/src/org/jetbrains/kotlin/resolve/ModifiersChecker.kt b/compiler/frontend/src/org/jetbrains/kotlin/resolve/ModifiersChecker.kt
index 965cfe8801d..5a7039c6945 100644
--- a/compiler/frontend/src/org/jetbrains/kotlin/resolve/ModifiersChecker.kt
+++ b/compiler/frontend/src/org/jetbrains/kotlin/resolve/ModifiersChecker.kt
@@ -180,12 +180,12 @@ object ModifierCheckerCore {
             )
             return true
         }
-        if (modifier == PROTECTED_KEYWORD && isFinalExpectOrActualClass(parentDescriptor)) {
+        if (modifier == PROTECTED_KEYWORD && isFinalExpectClass(parentDescriptor)) {
             trace.report(
                 Errors.WRONG_MODIFIER_CONTAINING_DECLARATION.on(
                     node.psi,
                     modifier,
-                    "final expect or actual class"
+                    "final expect class"
                 )
             )
         }
@@ -247,7 +247,7 @@ object ModifierCheckerCore {
         return true
     }
 
-    private fun isFinalExpectOrActualClass(d: DeclarationDescriptor?): Boolean {
-        return d is ClassDescriptor && d.isFinalOrEnum && (d.isExpect || d.isActual)
+    private fun isFinalExpectClass(d: DeclarationDescriptor?): Boolean {
+        return d is ClassDescriptor && d.isFinalOrEnum && d.isExpect
     }
 }
\ No newline at end of file
diff --git a/compiler/testData/diagnostics/tests/modifiers/protectedInExpectActual.kt b/compiler/testData/diagnostics/tests/modifiers/protectedInExpectActual.kt
index f8529688ce4..02c1761d3e4 100644
--- a/compiler/testData/diagnostics/tests/modifiers/protectedInExpectActual.kt
+++ b/compiler/testData/diagnostics/tests/modifiers/protectedInExpectActual.kt
@@ -6,25 +6,21 @@ class SimpleClass {
 }
 
 expect class ExpClass {
-    <!WRONG_MODIFIER_CONTAINING_DECLARATION!>protected<!> fun foo()
+    <!WRONG_MODIFIER_CONTAINING_DECLARATION("protected; final expect class")!>protected<!> fun foo()
 
-    <!WRONG_MODIFIER_CONTAINING_DECLARATION!>protected<!> val bar: Int
+    <!WRONG_MODIFIER_CONTAINING_DECLARATION("protected; final expect class")!>protected<!> val bar: Int
 }
 
 actual class ActClass {
-    actual <!WRONG_MODIFIER_CONTAINING_DECLARATION!>protected<!> fun foo() = Unit
+    actual protected fun foo() = Unit
 
-    actual <!WRONG_MODIFIER_CONTAINING_DECLARATION!>protected<!> val bar: Int = 42
+    actual protected val bar: Int = 42
 }
 
 expect open class ExpOpenClass {
     protected fun foo()
 }
 
-actual open class ActOpenClass {
-    actual protected fun foo() = Unit
-}
-
 enum class SimpleEnum {
     ENTRY;
 
@@ -34,15 +30,7 @@ enum class SimpleEnum {
 expect enum class ExpEnumClass {
     ENTRY;
 
-    <!WRONG_MODIFIER_CONTAINING_DECLARATION!>protected<!> fun foo()
+    <!WRONG_MODIFIER_CONTAINING_DECLARATION("protected; final expect class")!>protected<!> fun foo()
 
-    <!WRONG_MODIFIER_CONTAINING_DECLARATION!>protected<!> val bar: Int
-}
-
-actual enum class ActEnumClass {
-    ENTRY;
-
-    actual <!WRONG_MODIFIER_CONTAINING_DECLARATION!>protected<!> fun foo() = Unit
-
-    <!WRONG_MODIFIER_CONTAINING_DECLARATION!>protected<!> val bar: Int = 42
+    <!WRONG_MODIFIER_CONTAINING_DECLARATION("protected; final expect class")!>protected<!> val bar: Int
 }