FE 1.0: allow OptIn marker on override if base class is marked

#KT-49002 Fixed

compiler/frontend/src/org/jetbrains/kotlin/resolve/checkers/ExperimentalMarkerDeclarationAnnotationChecker.kt

@@ -115,6 +115,13 @@ class ExperimentalMarkerDeclarationAnnotationChecker(private val module: ModuleD
             if (overridden.annotations.any { it.fqName == experimentalFqName }) {
                 return true
             }
+            var containingDeclaration = overridden.containingDeclaration
+            while (containingDeclaration is ClassDescriptor) {
+                if (containingDeclaration.annotations.any { it.fqName == experimentalFqName }) {
+                    return true
+                }
+                containingDeclaration = containingDeclaration.containingDeclaration
+            }
             if (overridden.kind == CallableMemberDescriptor.Kind.FAKE_OVERRIDE &&
                 overridden.hasExperimentalOverriddenDescriptors(experimentalFqName)
             ) {

compiler/testData/diagnostics/testsWithStdLib/experimental/incorrectTargetsForExperimentalAnnotation.fir.kt

@@ -42,7 +42,7 @@ annotation class E4
 annotation class E5
 
 @RequiresOptIn(level = RequiresOptIn.Level.WARNING)
-@Target(PROPERTY, FUNCTION, PROPERTY_SETTER, VALUE_PARAMETER, FIELD, LOCAL_VARIABLE)
+@Target(PROPERTY, FUNCTION, PROPERTY_SETTER, VALUE_PARAMETER, FIELD, LOCAL_VARIABLE, CLASS)
 @Retention(AnnotationRetention.BINARY)
 annotation class E6
 
@@ -84,6 +84,27 @@ class Derived : Base {
     override fun <!OPT_IN_MARKER_ON_WRONG_TARGET!>@receiver:E6<!> String.withReceiver() {}
 }
 
+@E6
+interface BaseMarked {
+    val bar: Int
+}
+
+@E6
+class Outer {
+    interface Nested {
+        val baz: Int
+    }
+}
+
+@OptIn(E6::class)
+class DerivedOptIn : BaseMarked, Outer.Nested {
+    @E6
+    override val bar: Int = 42 // Ok
+
+    @E6
+    override val baz: Int = 24 // Ok
+}
+
 abstract class Another(<!OPT_IN_MARKER_ON_WRONG_TARGET!>@param:E6<!> val x: String) : Base {
     <!OPT_IN_MARKER_ON_WRONG_TARGET!>@delegate:E6<!>
     override val bar: Int by lazy { 42 }

compiler/testData/diagnostics/testsWithStdLib/experimental/incorrectTargetsForExperimentalAnnotation.kt

@@ -42,7 +42,7 @@ annotation class E4
 annotation class E5
 
 @RequiresOptIn(level = RequiresOptIn.Level.WARNING)
-@Target(PROPERTY, FUNCTION, PROPERTY_SETTER, VALUE_PARAMETER, FIELD, LOCAL_VARIABLE)
+@Target(PROPERTY, FUNCTION, PROPERTY_SETTER, VALUE_PARAMETER, FIELD, LOCAL_VARIABLE, CLASS)
 @Retention(AnnotationRetention.BINARY)
 annotation class E6
 
@@ -84,6 +84,27 @@ class Derived : Base {
     override fun <!OPT_IN_MARKER_ON_WRONG_TARGET!>@receiver:E6<!> String.withReceiver() {}
 }
 
+@E6
+interface BaseMarked {
+    val bar: Int
+}
+
+@E6
+class Outer {
+    interface Nested {
+        val baz: Int
+    }
+}
+
+@OptIn(E6::class)
+class DerivedOptIn : BaseMarked, Outer.Nested {
+    @E6
+    override val bar: Int = 42 // Ok
+
+    @E6
+    override val baz: Int = 24 // Ok
+}
+
 abstract class Another(<!OPT_IN_MARKER_ON_WRONG_TARGET!>@param:E6<!> val x: String) : Base {
     <!OPT_IN_MARKER_ON_WRONG_TARGET!>@delegate:E6<!>
     override val bar: Int by lazy { 42 }

compiler/testData/diagnostics/testsWithStdLib/experimental/incorrectTargetsForExperimentalAnnotation.txt

@@ -41,6 +41,13 @@ package api {
         public abstract fun kotlin.String.withReceiver(): kotlin.Unit
     }
 
+    @api.E6 public interface BaseMarked {
+        public abstract val bar: kotlin.Int
+        public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+        public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+        public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+    }
+
     public interface C1 : api.A, api.B {
         public open override /*2*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
         public abstract override /*2*/ /*fake_override*/ fun f(): kotlin.Unit
@@ -66,6 +73,15 @@ package api {
         public open override /*1*/ fun @receiver:api.E6 kotlin.String.withReceiver(): kotlin.Unit
     }
 
+    @kotlin.OptIn(markerClass = {api.E6::class}) public final class DerivedOptIn : api.BaseMarked, api.Outer.Nested {
+        public constructor DerivedOptIn()
+        @api.E6 public open override /*1*/ val bar: kotlin.Int = 42
+        @api.E6 public open override /*1*/ val baz: kotlin.Int = 24
+        public open override /*2*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+        public open override /*2*/ /*fake_override*/ fun hashCode(): kotlin.Int
+        public open override /*2*/ /*fake_override*/ fun toString(): kotlin.String
+    }
+
     @kotlin.RequiresOptIn(level = Level.WARNING) @kotlin.annotation.Target(allowedTargets = {AnnotationTarget.CLASS, AnnotationTarget.ANNOTATION_CLASS, AnnotationTarget.PROPERTY, AnnotationTarget.FIELD, AnnotationTarget.LOCAL_VARIABLE, AnnotationTarget.VALUE_PARAMETER, AnnotationTarget.CONSTRUCTOR, AnnotationTarget.FUNCTION, AnnotationTarget.PROPERTY_SETTER, AnnotationTarget.TYPEALIAS}) @kotlin.annotation.Retention(value = AnnotationRetention.BINARY) public final annotation class E1 : kotlin.Annotation {
         public constructor E1()
         public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
@@ -115,7 +131,7 @@ package api {
         public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
     }
 
-    @kotlin.RequiresOptIn(level = Level.WARNING) @kotlin.annotation.Target(allowedTargets = {AnnotationTarget.PROPERTY, AnnotationTarget.FUNCTION, AnnotationTarget.PROPERTY_SETTER, AnnotationTarget.VALUE_PARAMETER, AnnotationTarget.FIELD, AnnotationTarget.LOCAL_VARIABLE}) @kotlin.annotation.Retention(value = AnnotationRetention.BINARY) public final annotation class E6 : kotlin.Annotation {
+    @kotlin.RequiresOptIn(level = Level.WARNING) @kotlin.annotation.Target(allowedTargets = {AnnotationTarget.PROPERTY, AnnotationTarget.FUNCTION, AnnotationTarget.PROPERTY_SETTER, AnnotationTarget.VALUE_PARAMETER, AnnotationTarget.FIELD, AnnotationTarget.LOCAL_VARIABLE, AnnotationTarget.CLASS}) @kotlin.annotation.Retention(value = AnnotationRetention.BINARY) public final annotation class E6 : kotlin.Annotation {
         public constructor E6()
         public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
         public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
@@ -129,6 +145,20 @@ package api {
         public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
     }
 
+    @api.E6 public final class Outer {
+        public constructor Outer()
+        public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+        public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+        public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+
+        public interface Nested {
+            public abstract val baz: kotlin.Int
+            public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+            public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+            public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+        }
+    }
+
     public final class X1 : api.C1 {
         public constructor X1()
         public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean