[FIR] Calculate property setters visibilities for intersections properly

Basically, just calculate them the same
way it's done for other members.

`chooseIntersectionVisibilityForSymbolsOrNull`
is named like this to prevent a JVM clash.

^KT-66046 Fixed

compiler/fir/java/src/org/jetbrains/kotlin/fir/java/scopes/JavaOverridabilityRules.kt

@@ -12,7 +12,6 @@ import org.jetbrains.kotlin.fir.declarations.FirDeclarationOrigin
 import org.jetbrains.kotlin.fir.declarations.FirProperty
 import org.jetbrains.kotlin.fir.declarations.FirSimpleFunction
 import org.jetbrains.kotlin.fir.java.JavaTypeParameterStack
-import org.jetbrains.kotlin.fir.scopes.MemberWithBaseScope
 import org.jetbrains.kotlin.fir.scopes.PlatformSpecificOverridabilityRules
 import org.jetbrains.kotlin.fir.symbols.impl.FirCallableSymbol
 import org.jetbrains.kotlin.fir.symbols.impl.FirRegularClassSymbol
@@ -51,8 +50,8 @@ class JavaOverridabilityRules(session: FirSession) : PlatformSpecificOverridabil
 
     private fun FirCallableDeclaration.isOriginallyFromJava(): Boolean = unwrapFakeOverrides().origin == FirDeclarationOrigin.Enhancement
 
-    override fun <D : FirCallableSymbol<*>> chooseIntersectionVisibility(
-        extractedOverrides: Collection<MemberWithBaseScope<D>>,
+    override fun chooseIntersectionVisibility(
+        overrides: Collection<FirCallableSymbol<*>>,
         dispatchClassSymbol: FirRegularClassSymbol?,
-    ): Visibility = javaOverrideChecker.chooseIntersectionVisibility(extractedOverrides, dispatchClassSymbol)
+    ): Visibility = javaOverrideChecker.chooseIntersectionVisibility(overrides, dispatchClassSymbol)
 }

compiler/fir/java/src/org/jetbrains/kotlin/fir/java/scopes/JavaOverrideChecker.kt

@@ -25,11 +25,8 @@ import org.jetbrains.kotlin.fir.resolve.substitution.ConeSubstitutor
 import org.jetbrains.kotlin.fir.resolve.substitution.substitutorByMap
 import org.jetbrains.kotlin.fir.resolve.toSymbol
 import org.jetbrains.kotlin.fir.scopes.FirTypeScope
-import org.jetbrains.kotlin.fir.scopes.MemberWithBaseScope
 import org.jetbrains.kotlin.fir.scopes.ProcessorAction
-import org.jetbrains.kotlin.fir.scopes.impl.FirAbstractOverrideChecker
-import org.jetbrains.kotlin.fir.scopes.impl.chooseIntersectionVisibilityOrNull
-import org.jetbrains.kotlin.fir.scopes.impl.isAbstract
+import org.jetbrains.kotlin.fir.scopes.impl.*
 import org.jetbrains.kotlin.fir.scopes.jvm.computeJvmDescriptorRepresentation
 import org.jetbrains.kotlin.fir.scopes.processOverriddenFunctions
 import org.jetbrains.kotlin.fir.symbols.impl.FirCallableSymbol
@@ -370,25 +367,23 @@ class JavaOverrideChecker internal constructor(
         return overridesMutableCollectionRemove
     }
 
-    override fun <D : FirCallableSymbol<*>> chooseIntersectionVisibility(
-        extractedOverrides: Collection<MemberWithBaseScope<D>>,
+    override fun chooseIntersectionVisibility(
+        overrides: Collection<FirCallableSymbol<*>>,
         dispatchClassSymbol: FirRegularClassSymbol?,
     ): Visibility {
-        val nonSubsumed = extractedOverrides.getNonSubsumedNonPhantomOverriddenSymbols()
-
         // In Java it's OK to inherit multiple implementations of the same function
         // from the supertypes as long as there's an implementation from a class.
         // We shouldn't reject green Java code.
         if (dispatchClassSymbol?.fir is FirJavaClass) {
-            val nonAbstractFromClass = nonSubsumed.find {
-                !it.isAbstract && it.member.dispatchReceiverClassLookupTagOrNull()
+            val nonAbstractFromClass = overrides.find {
+                !it.isAbstractAccordingToRawStatus && it.dispatchReceiverClassLookupTagOrNull()
                     ?.toSymbol(session)?.classKind == ClassKind.CLASS
             }
             if (nonAbstractFromClass != null) {
-                return nonAbstractFromClass.member.rawStatus.visibility
+                return nonAbstractFromClass.rawStatus.visibility
             }
         }
 
-        return chooseIntersectionVisibilityOrNull(nonSubsumed) ?: Visibilities.Unknown
+        return chooseIntersectionVisibilityOrNull(overrides) ?: Visibilities.Unknown
     }
 }

compiler/fir/native/src/org/jetbrains/kotlin/fir/backend/native/FirNativeOverrideChecker.kt

@@ -14,7 +14,6 @@ import org.jetbrains.kotlin.fir.containingClassLookupTag
 import org.jetbrains.kotlin.fir.declarations.*
 import org.jetbrains.kotlin.fir.resolve.toSymbol
 import org.jetbrains.kotlin.fir.scopes.FirOverrideChecker
-import org.jetbrains.kotlin.fir.scopes.MemberWithBaseScope
 import org.jetbrains.kotlin.fir.scopes.impl.*
 import org.jetbrains.kotlin.fir.symbols.impl.FirCallableSymbol
 import org.jetbrains.kotlin.fir.symbols.impl.FirClassSymbol
@@ -38,12 +37,11 @@ class FirNativeOverrideChecker(private val session: FirSession) : FirOverrideChe
         // KT-57640: There's no necessity to implement platform-dependent overridability check for properties
         standardOverrideChecker.isOverriddenProperty(overrideCandidate, baseDeclaration)
 
-    override fun <D : FirCallableSymbol<*>> chooseIntersectionVisibility(
-        extractedOverrides: Collection<MemberWithBaseScope<D>>,
+    override fun chooseIntersectionVisibility(
+        overrides: Collection<FirCallableSymbol<*>>,
         dispatchClassSymbol: FirRegularClassSymbol?,
     ): Visibility {
-        val nonSubsumed = extractedOverrides.getNonSubsumedNonPhantomOverriddenSymbols()
-        return chooseIntersectionVisibilityOrNull(nonSubsumed) { it.isAbstract || it.member.isObjCClassProperty(session) }
+        return chooseIntersectionVisibilityOrNull(overrides) { it.isAbstractAccordingToRawStatus || it.isObjCClassProperty(session) }
             ?: Visibilities.Unknown
     }
 

compiler/fir/providers/src/org/jetbrains/kotlin/fir/scopes/FirIntersectionScopeOverrideChecker.kt

@@ -35,11 +35,11 @@ class FirIntersectionScopeOverrideChecker(session: FirSession) : FirOverrideChec
         return standardOverrideChecker.isOverriddenProperty(overrideCandidate, baseDeclaration)
     }
 
-    override fun <D : FirCallableSymbol<*>> chooseIntersectionVisibility(
-        extractedOverrides: Collection<MemberWithBaseScope<D>>,
+    override fun chooseIntersectionVisibility(
+        overrides: Collection<FirCallableSymbol<*>>,
         dispatchClassSymbol: FirRegularClassSymbol?,
     ): Visibility {
-        platformSpecificOverridabilityRules?.chooseIntersectionVisibility(extractedOverrides, dispatchClassSymbol)?.let { return it }
-        return standardOverrideChecker.chooseIntersectionVisibility(extractedOverrides, dispatchClassSymbol)
+        platformSpecificOverridabilityRules?.chooseIntersectionVisibility(overrides, dispatchClassSymbol)?.let { return it }
+        return standardOverrideChecker.chooseIntersectionVisibility(overrides, dispatchClassSymbol)
     }
 }

compiler/fir/providers/src/org/jetbrains/kotlin/fir/scopes/FirOverrideChecker.kt

@@ -27,8 +27,8 @@ interface FirOverrideChecker : FirSessionComponent {
         baseDeclaration: FirProperty
     ): Boolean
 
-    fun <D : FirCallableSymbol<*>> chooseIntersectionVisibility(
-        extractedOverrides: Collection<MemberWithBaseScope<D>>,
+    fun chooseIntersectionVisibility(
+        overrides: Collection<FirCallableSymbol<*>>,
         dispatchClassSymbol: FirRegularClassSymbol?,
     ): Visibility
 }

compiler/fir/providers/src/org/jetbrains/kotlin/fir/scopes/PlatformSpecificOverridabilityRules.kt

@@ -26,8 +26,8 @@ interface PlatformSpecificOverridabilityRules : FirSessionComponent {
         baseDeclaration: FirProperty
     ): Boolean?
 
-    fun <D : FirCallableSymbol<*>> chooseIntersectionVisibility(
-        extractedOverrides: Collection<MemberWithBaseScope<D>>,
+    fun chooseIntersectionVisibility(
+        overrides: Collection<FirCallableSymbol<*>>,
         dispatchClassSymbol: FirRegularClassSymbol?,
     ): Visibility?
 }

compiler/fir/providers/src/org/jetbrains/kotlin/fir/scopes/impl/FirFakeOverrideGenerator.kt

@@ -399,6 +399,7 @@ object FirFakeOverrideGenerator {
         newReturnType: ConeKotlinType? = null,
         newModality: Modality? = null,
         newVisibility: Visibility? = null,
+        newSetterVisibility: Visibility? = null,
         deferredReturnTypeCalculation: DeferredCallableCopyReturnType? = null,
         newSource: KtSourceElement? = derivedClassLookupTag?.toSymbol(session)?.source,
     ): FirProperty = buildProperty {
@@ -436,16 +437,19 @@ object FirFakeOverrideGenerator {
             newSource = newSource ?: baseProperty.getter?.source,
         )
 
-        setter = baseProperty.setter?.buildCopyIfNeeded(
-            moduleData = session.nullableModuleData ?: baseProperty.moduleData,
-            origin = origin,
-            propertyReturnTypeRef = this@buildProperty.returnTypeRef,
-            propertySymbol = newSymbol,
-            dispatchReceiverType = dispatchReceiverType,
-            derivedClassLookupTag = derivedClassLookupTag,
-            baseProperty = baseProperty,
-            newSource = newSource ?: baseProperty.setter?.source,
-        )
+        setter = baseProperty.setter?.let { setter ->
+            setter.buildCopyIfNeeded(
+                moduleData = session.nullableModuleData ?: baseProperty.moduleData,
+                origin = origin,
+                propertyReturnTypeRef = this@buildProperty.returnTypeRef,
+                propertySymbol = newSymbol,
+                dispatchReceiverType = dispatchReceiverType,
+                derivedClassLookupTag = derivedClassLookupTag,
+                baseProperty = baseProperty,
+                newSource = newSource ?: baseProperty.setter?.source,
+                newSetterVisibility ?: setter.visibility,
+            )
+        }
     }.apply {
         containingClassForStaticMemberAttr = derivedClassLookupTag.takeIf { shouldOverrideSetContainingClass(baseProperty) }
     }
@@ -459,8 +463,9 @@ object FirFakeOverrideGenerator {
         derivedClassLookupTag: ConeClassLikeLookupTag?,
         baseProperty: FirProperty,
         newSource: KtSourceElement? = source,
+        newVisibility: Visibility = visibility,
     ) = when {
-        annotations.isNotEmpty() || visibility != baseProperty.visibility -> buildCopy(
+        annotations.isNotEmpty() || newVisibility != baseProperty.visibility -> buildCopy(
             moduleData,
             origin,
             propertyReturnTypeRef,
@@ -469,6 +474,7 @@ object FirFakeOverrideGenerator {
             derivedClassLookupTag,
             baseProperty,
             newSource,
+            newVisibility,
         )
         else -> null
     }
@@ -482,13 +488,14 @@ object FirFakeOverrideGenerator {
         derivedClassLookupTag: ConeClassLikeLookupTag?,
         baseProperty: FirProperty,
         newSource: KtSourceElement? = source,
+        newVisibility: Visibility = visibility,
     ) = when (this) {
         is FirDefaultPropertyGetter -> FirDefaultPropertyGetter(
             source = newSource,
             moduleData = moduleData,
             origin = origin,
             propertyTypeRef = propertyReturnTypeRef,
-            visibility = visibility,
+            visibility = newVisibility,
             propertySymbol = propertySymbol,
             modality = modality ?: Modality.FINAL,
             effectiveVisibility = effectiveVisibility,
@@ -501,7 +508,7 @@ object FirFakeOverrideGenerator {
             moduleData = moduleData,
             origin = origin,
             propertyTypeRef = propertyReturnTypeRef,
-            visibility = visibility,
+            visibility = newVisibility,
             propertySymbol = propertySymbol,
             modality = modality ?: Modality.FINAL,
             effectiveVisibility = effectiveVisibility,
@@ -518,6 +525,7 @@ object FirFakeOverrideGenerator {
             this.dispatchReceiverType = dispatchReceiverType
             this.body = null
             resolvePhase = origin.resolvePhaseForCopy
+            this.status = status.copy(visibility = newVisibility)
         }.also {
             if (it.isSetter) {
                 val originalParameter = it.valueParameters.first()

compiler/fir/providers/src/org/jetbrains/kotlin/fir/scopes/impl/FirOverrideUtils.kt

@@ -14,6 +14,7 @@ import org.jetbrains.kotlin.fir.declarations.utils.visibility
 import org.jetbrains.kotlin.fir.scopes.*
 import org.jetbrains.kotlin.fir.symbols.impl.FirCallableSymbol
 import org.jetbrains.kotlin.fir.symbols.impl.FirNamedFunctionSymbol
+import org.jetbrains.kotlin.fir.symbols.impl.FirPropertyAccessorSymbol
 import org.jetbrains.kotlin.fir.symbols.impl.FirPropertySymbol
 import org.jetbrains.kotlin.name.StandardClassIds
 
@@ -64,40 +65,54 @@ fun <D : FirCallableSymbol<*>> overrides(
 }
 
 inline fun chooseIntersectionVisibilityOrNull(
-    nonSubsumedOverrides: List<MemberWithBaseScope<FirCallableSymbol<*>>>,
-    isAbstract: (MemberWithBaseScope<FirCallableSymbol<*>>) -> Boolean = MemberWithBaseScope<FirCallableSymbol<*>>::isAbstract,
+    nonSubsumedOverrides: Collection<FirCallableSymbol<*>>,
+    isAbstract: (FirCallableSymbol<*>) -> Boolean = FirCallableSymbol<*>::isAbstractAccordingToRawStatus,
+): Visibility? = chooseIntersectionVisibilityOrNull(
+    nonSubsumedOverrides,
+    toSymbol = { it },
+    isAbstract,
+)
+
+inline fun <D> chooseIntersectionVisibilityOrNull(
+    nonSubsumedOverrides: Collection<D>,
+    toSymbol: (D) -> FirCallableSymbol<*>,
+    isAbstract: (D) -> Boolean,
 ): Visibility? {
     val nonAbstract = nonSubsumedOverrides.filter {
         // Kotlin's Cloneable interface contains phantom `protected open fun clone()`.
-        !isAbstract(it) && it.member.callableId != StandardClassIds.Callables.clone
+        !isAbstract(it) && toSymbol(it).callableId != StandardClassIds.Callables.clone
     }
     val allAreAbstract = nonAbstract.isEmpty()
 
     if (allAreAbstract) {
-        return findMaxVisibilityOrNull(nonSubsumedOverrides)
+        return findMaxVisibilityOrNull(nonSubsumedOverrides, toSymbol)
     }
 
-    return nonAbstract.singleOrNull()?.member?.rawStatus?.visibility
+    return nonAbstract.singleOrNull()?.let(toSymbol)?.rawStatus?.visibility
 }
 
-val MemberWithBaseScope<FirCallableSymbol<*>>.isAbstract: Boolean
+val FirCallableSymbol<*>.isAbstractAccordingToRawStatus: Boolean
     get() {
+        val responsibleDeclaration = when (this) {
+            !is FirPropertyAccessorSymbol -> this
+            else -> propertySymbol
+        }
         // This function is expected to be called during FirResolvePhase.STATUS,
         // meaning we can't yet access `resolvedStatus`, because it would require
         // the same phase, but by this time we expect the statuses to have been
         // calculated de-facto.
-        require(member.rawStatus is FirResolvedDeclarationStatus)
-        // Kotlin's Cloneable interface contains phantom `protected open fun clone()`.
-        return member.rawStatus.modality == Modality.ABSTRACT
+        require(responsibleDeclaration.rawStatus is FirResolvedDeclarationStatus)
+        return responsibleDeclaration.rawStatus.modality == Modality.ABSTRACT
     }
 
-fun <D : FirCallableSymbol<*>> findMaxVisibilityOrNull(
-    extractedOverrides: Collection<MemberWithBaseScope<D>>
+inline fun <D> findMaxVisibilityOrNull(
+    extractedOverrides: Collection<D>,
+    toSymbol: (D) -> FirCallableSymbol<*>,
 ): Visibility? {
     var maxVisibility: Visibility = Visibilities.Private
 
-    for ((override) in extractedOverrides) {
-        val visibility = (override.fir as FirMemberDeclaration).visibility
+    for (override in extractedOverrides) {
+        val visibility = (toSymbol(override).fir as FirMemberDeclaration).visibility
         val compare = Visibilities.compare(visibility, maxVisibility) ?: return null
 
         if (compare > 0) {

compiler/fir/providers/src/org/jetbrains/kotlin/fir/scopes/impl/FirStandardOverrideChecker.kt

@@ -13,7 +13,6 @@ import org.jetbrains.kotlin.fir.declarations.utils.isSuspend
 import org.jetbrains.kotlin.fir.declarations.utils.visibility
 import org.jetbrains.kotlin.fir.resolve.substitution.ConeSubstitutor
 import org.jetbrains.kotlin.fir.resolve.transformers.ensureResolvedTypeDeclaration
-import org.jetbrains.kotlin.fir.scopes.MemberWithBaseScope
 import org.jetbrains.kotlin.fir.symbols.impl.FirCallableSymbol
 import org.jetbrains.kotlin.fir.symbols.impl.FirRegularClassSymbol
 import org.jetbrains.kotlin.fir.symbols.lazyResolveToPhase
@@ -162,11 +161,10 @@ class FirStandardOverrideChecker(private val session: FirSession) : FirAbstractO
         }
     }
 
-    override fun <D : FirCallableSymbol<*>> chooseIntersectionVisibility(
-        extractedOverrides: Collection<MemberWithBaseScope<D>>,
+    override fun chooseIntersectionVisibility(
+        overrides: Collection<FirCallableSymbol<*>>,
         dispatchClassSymbol: FirRegularClassSymbol?,
     ): Visibility {
-        val nonSubsumed = extractedOverrides.getNonSubsumedNonPhantomOverriddenSymbols()
-        return chooseIntersectionVisibilityOrNull(nonSubsumed) ?: Visibilities.Unknown
+        return chooseIntersectionVisibilityOrNull(overrides) ?: Visibilities.Unknown
     }
 }

compiler/fir/providers/src/org/jetbrains/kotlin/fir/scopes/impl/FirTypeIntersectionScopeContext.kt

@@ -215,7 +215,8 @@ class FirTypeIntersectionScopeContext(
         containsMultipleNonSubsumed: Boolean,
     ): MemberWithBaseScope<FirCallableSymbol<*>> {
         val newModality = chooseIntersectionOverrideModality(extractedOverrides.flatMap { it.flattenIntersectionsRecursively() }.nonSubsumed())
-        val newVisibility = overrideChecker.chooseIntersectionVisibility(extractedOverrides, dispatchClassSymbol)
+        val nonSubsumedNonPhantomOverrides = extractedOverrides.getNonSubsumedNonPhantomOverriddenSymbols().map { it.member }
+        val newVisibility = overrideChecker.chooseIntersectionVisibility(nonSubsumedNonPhantomOverrides, dispatchClassSymbol)
         val mostSpecificSymbols = mostSpecific.map { it.member }
         val extractedOverridesSymbols = extractedOverrides.map { it.member }
         val key = mostSpecific.first()
@@ -227,7 +228,8 @@ class FirTypeIntersectionScopeContext(
 
             is FirPropertySymbol ->
                 createIntersectionOverrideProperty(
-                    mostSpecificSymbols, extractedOverridesSymbols, newModality, newVisibility, containsMultipleNonSubsumed
+                    mostSpecificSymbols, extractedOverridesSymbols, nonSubsumedNonPhantomOverrides, newModality,
+                    newVisibility, containsMultipleNonSubsumed,
                 )
 
             is FirFieldSymbol -> {
@@ -368,6 +370,7 @@ class FirTypeIntersectionScopeContext(
     private fun createIntersectionOverrideProperty(
         mostSpecific: Collection<FirCallableSymbol<*>>,
         overrides: Collection<FirCallableSymbol<*>>,
+        nonSubsumedNonPhantomOverrides: List<FirCallableSymbol<*>>,
         newModality: Modality?,
         newVisibility: Visibility,
         containsMultipleNonSubsumed: Boolean,
@@ -378,6 +381,14 @@ class FirTypeIntersectionScopeContext(
             containsMultipleNonSubsumed,
             ::FirIntersectionOverridePropertySymbol,
         ) { symbol, fir, deferredReturnTypeCalculation, returnType ->
+            // Only setters's visibilities are calculated properly, because
+            // getters' visibilities must be the same as the ones of their
+            // properties and those we've already calculated.
+            val setters = nonSubsumedNonPhantomOverrides.mapNotNull {
+                (it as? FirPropertySymbol)?.unwrapSubstitutionOverrides()?.setterSymbol
+            }
+            val setterVisibility = chooseIntersectionVisibilityOrNull(setters) ?: Visibilities.Unknown
+
             FirFakeOverrideGenerator.createCopyForFirProperty(
                 symbol, fir, derivedClassLookupTag = null, session,
                 FirDeclarationOrigin.IntersectionOverride,
@@ -390,6 +401,7 @@ class FirTypeIntersectionScopeContext(
                 // anyway and their uses should result in an overload resolution error.
                 newReturnType = returnType,
                 newSource = dispatchReceiverType.toSymbol(session)?.source,
+                newSetterVisibility = setterVisibility,
             )
         }
     }

compiler/testData/diagnostics/tests/intersectedVisibilitiesForAbstractPropertyAccessors.fir.kt

@@ -1,22 +0,0 @@
-// ISSUE: KT-66046
-
-abstract class I1 {
-    abstract var a: Int
-        protected set
-}
-
-interface I2 {
-    var a: Int
-}
-
-abstract class <!CANNOT_WEAKEN_ACCESS_PRIVILEGE!>C<!> : I1(), I2
-
-abstract class I3 {
-    protected abstract fun foo(): Int
-}
-
-interface I4 {
-    fun foo(): Int
-}
-
-abstract class B : I3(), I4

compiler/testData/diagnostics/tests/intersectedVisibilitiesForAbstractPropertyAccessors.kt

@@ -1,3 +1,4 @@
+// FIR_IDENTICAL
 // ISSUE: KT-66046
 
 abstract class I1 {