IR: properly compute IrProperty.resolveFakeOverride()

Now that IrProperty has its own overriddenSymbols, we can generalize the
search for fake overrides. Also works for fake override properties
derived from Java fields.

compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/lower/SyntheticAccessorLowering.kt

@@ -776,8 +776,8 @@ internal class SyntheticAccessorLowering(val context: JvmBackendContext) : IrEle
 
         return this.overriddenSymbols
             .map { it.owner }
-            .collectAndFilterRealOverrides(getOverriddenPropertySymbols = IrProperty::overriddenSymbols)
-            .firstOrNull() as? IrProperty
+            .collectAndFilterRealOverrides()
+            .firstOrNull()
             ?: throw AssertionError("No real override for ${this.render()}")
     }
 

compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/declarations/IrDeclaration.kt

@@ -48,7 +48,9 @@ interface IrDeclaration : IrStatement, IrSymbolOwner, IrMutableAnnotationContain
 
 abstract class IrDeclarationBase : IrElementBase(), IrDeclaration
 
-interface IrOverridableDeclaration<S : IrSymbol> : IrDeclaration {
+interface IrOverridableDeclaration<S : IrSymbol> : IrOverridableMember {
+    override val symbol: S
+    val isFakeOverride: Boolean
     var overriddenSymbols: List<S>
 }
 

compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/declarations/IrProperty.kt

@@ -25,7 +25,6 @@ import org.jetbrains.kotlin.ir.visitors.IrElementVisitor
 abstract class IrProperty :
     IrDeclarationBase(),
     IrPossiblyExternalDeclaration,
-    IrOverridableMember,
     IrOverridableDeclaration<IrPropertySymbol>,
     IrMetadataSourceOwner,
     IrAttributeContainer,
@@ -40,7 +39,7 @@ abstract class IrProperty :
     abstract val isLateinit: Boolean
     abstract val isDelegated: Boolean
     abstract val isExpect: Boolean
-    abstract val isFakeOverride: Boolean
+    abstract override val isFakeOverride: Boolean
 
     abstract var backingField: IrField?
     abstract var getter: IrSimpleFunction?

compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/declarations/IrSimpleFunction.kt

@@ -12,14 +12,13 @@ import org.jetbrains.kotlin.ir.visitors.IrElementVisitor
 abstract class IrSimpleFunction :
     IrFunction(),
     IrOverridableDeclaration<IrSimpleFunctionSymbol>,
-    IrOverridableMember,
     IrAttributeContainer {
 
     abstract override val symbol: IrSimpleFunctionSymbol
 
     abstract val isTailrec: Boolean
     abstract val isSuspend: Boolean
-    abstract val isFakeOverride: Boolean
+    abstract override val isFakeOverride: Boolean
     abstract val isOperator: Boolean
     abstract val isInfix: Boolean
 

compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/declarations/lazy/IrLazyProperty.kt

@@ -74,7 +74,7 @@ class IrLazyProperty(
 
     override var overriddenSymbols: List<IrPropertySymbol> by lazyVar(stubGenerator.lock) {
         descriptor.overriddenDescriptors.mapTo(ArrayList()) {
-            stubGenerator.generatePropertyStub(it).symbol
+            stubGenerator.generatePropertyStub(it.original).symbol
         }
     }
 

compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/overrides/IrOverridingUtil.kt

@@ -13,7 +13,6 @@ import org.jetbrains.kotlin.ir.declarations.*
 import org.jetbrains.kotlin.ir.descriptors.IrBuiltIns
 import org.jetbrains.kotlin.ir.symbols.*
 import org.jetbrains.kotlin.ir.types.*
-import org.jetbrains.kotlin.ir.util.collectAndFilterRealOverrides
 import org.jetbrains.kotlin.ir.util.isReal
 import org.jetbrains.kotlin.ir.util.render
 import org.jetbrains.kotlin.resolve.OverridingUtil.OverrideCompatibilityInfo
@@ -36,9 +35,6 @@ abstract class FakeOverrideBuilderStrategy {
 
     protected abstract fun linkFunctionFakeOverride(declaration: IrFakeOverrideFunction)
     protected abstract fun linkPropertyFakeOverride(declaration: IrFakeOverrideProperty)
-
-    // TODO: need to make IrProperty carry overriddenSymbols.
-    val propertyOverriddenSymbols: MutableMap<IrOverridableMember, List<IrSymbol>> = mutableMapOf()
 }
 
 fun buildFakeOverrideMember(superType: IrType, member: IrOverridableMember, clazz: IrClass): IrOverridableMember {
@@ -89,35 +85,32 @@ class IrOverridingUtil(
         originalSuperTypes.clear()
     }
 
-    private var IrOverridableMember.overriddenSymbols: List<IrSymbol>
-        get() = when (this) {
-            is IrSimpleFunction -> this.overriddenSymbols
-            is IrProperty -> fakeOverrideBuilder.propertyOverriddenSymbols[this]
-                ?: error("No overridden symbols for ${this.render()}")
+    private val IrOverridableMember.overriddenSymbols: List<IrSymbol>
+        get() = (this as? IrOverridableDeclaration<*>)?.overriddenSymbols
+            ?: error("Unexpected IrOverridableMember: $this")
+
+    private fun IrOverridableMember.setOverriddenSymbols(value: List<IrSymbol>) {
+        when (this) {
+            is IrSimpleFunction -> this.overriddenSymbols =
+                value.map { it as? IrSimpleFunctionSymbol ?: error("Unexpected function overridden symbol: $it") }
+            is IrProperty -> {
+                this.overriddenSymbols =
+                    value.map { it as? IrPropertySymbol ?: error("Unexpected property overridden symbol: $it") }
+                val getter = this.getter ?: error("Property has no getter: ${render()}")
+                getter.overriddenSymbols = value.map { (it.owner as IrProperty).getter!!.symbol }
+                this.setter?.let { setter ->
+                    setter.overriddenSymbols = value.mapNotNull { (it.owner as IrProperty).setter?.symbol }
+                }
+            }
             else -> error("Unexpected declaration for overriddenSymbols: $this")
         }
-        set(value) {
-            when (this) {
-                is IrSimpleFunction -> this.overriddenSymbols =
-                    value.map { it as? IrSimpleFunctionSymbol ?: error("Unexpected function overridden symbol: $it") }
-                is IrProperty -> {
-                    fakeOverrideBuilder.propertyOverriddenSymbols[this] =
-                        value.map { it as? IrPropertySymbol ?: error("Unexpected property overridden symbol: $it") }
-                    val getter = this.getter ?: error("Property has no getter: ${render()}")
-                    getter.overriddenSymbols = value.map { (it.owner as IrProperty).getter!!.symbol }
-                    this.setter?.let { setter ->
-                        setter.overriddenSymbols = value.mapNotNull { (it.owner as IrProperty).setter?.symbol }
-                    }
-                }
-                else -> error("Unexpected declaration for overriddenSymbols: $this")
-            }
-        }
+    }
 
     fun buildFakeOverridesForClass(clazz: IrClass) {
         val superTypes = clazz.superTypes
 
         @Suppress("UNCHECKED_CAST")
-        val fromCurrent = clazz.declarations.filter { it is IrOverridableMember } as List<IrOverridableMember>
+        val fromCurrent = clazz.declarations.filterIsInstance<IrOverridableMember>()
 
         val allFromSuper = superTypes.flatMap { superType ->
             val superClass = superType.getClass() ?: error("Unexpected super type: $superType")
@@ -147,19 +140,8 @@ class IrOverridingUtil(
         clazz: IrClass,
         implementedMembers: List<IrOverridableMember> = emptyList()
     ): List<IrOverridableMember> {
-        fakeOverrideBuilder.propertyOverriddenSymbols.clear()
-
         val overriddenMembers = (clazz.declarations.filterIsInstance<IrOverridableMember>() + implementedMembers)
-            .flatMap {
-                when (it) {
-                    is IrSimpleFunction -> it.overriddenSymbols.map { it.owner }
-                    // TODO: use IrProperty.overriddenSymbols instead: KT-47019
-                    is IrProperty -> (it.getter ?: it.setter)?.overriddenSymbols
-                        ?.map { it.owner.correspondingPropertySymbol!!.owner }
-                        ?: emptyList()
-                    else -> error("Unexpected IrOverridableMember: $it")
-                }
-            }
+            .flatMap { member -> member.overriddenSymbols.map { it.owner } }
             .toSet()
 
         val unoverriddenSuperMembers = clazz.superTypes.flatMap { superType ->
@@ -242,7 +224,7 @@ class IrOverridingUtil(
             }
         }
         //strategy.setOverriddenDescriptors(fromCurrent, overridden)
-        fromCurrent.overriddenSymbols = overridden.map { it.original.symbol }
+        fromCurrent.setOverriddenSymbols(overridden.map { it.original.symbol })
 
         return bound
     }
@@ -400,7 +382,7 @@ class IrOverridingUtil(
             }
         }
 
-        fakeOverride.overriddenSymbols = effectiveOverridden.map { it.original.symbol }
+        fakeOverride.setOverriddenSymbols(effectiveOverridden.map { it.original.symbol })
 
         assert(
             fakeOverride.overriddenSymbols.isNotEmpty()

compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/util/IrFakeOverrideUtils.kt

@@ -7,7 +7,7 @@ package org.jetbrains.kotlin.ir.util
 
 import org.jetbrains.kotlin.descriptors.Modality
 import org.jetbrains.kotlin.ir.declarations.*
-import org.jetbrains.kotlin.ir.symbols.IrPropertySymbol
+import org.jetbrains.kotlin.ir.symbols.IrSymbol
 import org.jetbrains.kotlin.utils.addToStdlib.safeAs
 
 val IrDeclaration.isReal: Boolean get() = !isFakeOverride
@@ -31,65 +31,50 @@ val IrFunction.target: IrFunction get() = when (this) {
     else -> error(this)
 }
 
-fun IrSimpleFunction.collectRealOverrides(
-    toSkip: (IrSimpleFunction) -> Boolean = { false },
-    filter: (IrOverridableMember) -> Boolean = { false }
-): Set<IrSimpleFunction> {
+fun <S : IrSymbol, T : IrOverridableDeclaration<S>> T.collectRealOverrides(
+    toSkip: (T) -> Boolean = { false },
+    filter: (T) -> Boolean = { false }
+): Set<T> {
     if (isReal && !toSkip(this)) return setOf(this)
 
     @Suppress("UNCHECKED_CAST")
     return this.overriddenSymbols
-        .map { it.owner }
-        .collectAndFilterRealOverrides(
-            {
-                require(it is IrSimpleFunction) { "Expected IrSimpleFunction: ${it.render()}" }
-                toSkip(it)
-            },
-            filter
-        ) as Set<IrSimpleFunction>
+        .map { it.owner as T }
+        .collectAndFilterRealOverrides(toSkip, filter)
 }
 
-fun Collection<IrOverridableMember>.collectAndFilterRealOverrides(
-    toSkip: (IrOverridableMember) -> Boolean = { false },
-    filter: (IrOverridableMember) -> Boolean = { false },
-    getOverriddenPropertySymbols: IrProperty.() -> List<IrPropertySymbol> = {
-        // TODO: use IrProperty.overriddenSymbols instead: KT-47019
-        //  (at the moment it breaks K/N in at least :kotlin-native:backend.native:tests:coroutines_functionReference_eqeq_name)
-        (getter ?: setter)?.overriddenSymbols?.mapNotNull { it.owner.correspondingPropertySymbol }.orEmpty()
-    },
-): Set<IrOverridableMember> {
+fun <S : IrSymbol, T : IrOverridableDeclaration<S>> Collection<T>.collectAndFilterRealOverrides(
+    toSkip: (T) -> Boolean = { false },
+    filter: (T) -> Boolean = { false }
+): Set<T> {
 
-    val visited = mutableSetOf<IrOverridableMember>()
-    val realOverrides = mutableMapOf<Any, IrOverridableMember>()
+    val visited = mutableSetOf<T>()
+    val realOverrides = mutableMapOf<Any, T>()
 
     /*
         Due to IR copying in performByIrFile, overrides should only be distinguished up to their signatures.
      */
-    fun IrOverridableMember.toKey(): Any = symbol.signature ?: this
+    fun T.toKey(): Any = symbol.signature ?: this
 
-    fun overriddenSymbols(declaration: IrOverridableMember) = when (declaration) {
-        is IrSimpleFunction -> declaration.overriddenSymbols
-        is IrProperty -> declaration.getOverriddenPropertySymbols()
-        else -> error("Unexpected overridable member: ${declaration.render()}")
-    }
-
-    fun collectRealOverrides(member: IrOverridableMember) {
+    fun collectRealOverrides(member: T) {
         if (!visited.add(member) || filter(member)) return
 
         if (member.isReal && !toSkip(member)) {
             realOverrides[member.toKey()] = member
         } else {
-            overriddenSymbols(member).forEach { collectRealOverrides(it.owner as IrOverridableMember) }
+            @Suppress("UNCHECKED_CAST")
+            member.overriddenSymbols.forEach { collectRealOverrides(it.owner as T) }
         }
     }
 
     this.forEach { collectRealOverrides(it) }
 
-    fun excludeRepeated(member: IrOverridableMember) {
+    fun excludeRepeated(member: T) {
         if (!visited.add(member)) return
 
-        overriddenSymbols(member).forEach {
-            val owner = it.owner as IrOverridableMember
+        member.overriddenSymbols.forEach {
+            @Suppress("UNCHECKED_CAST")
+            val owner = it.owner as T
             realOverrides.remove(owner.toKey())
             excludeRepeated(owner)
         }
@@ -101,8 +86,16 @@ fun Collection<IrOverridableMember>.collectAndFilterRealOverrides(
     return realOverrides.values.toSet()
 }
 
+fun Collection<IrOverridableMember>.collectAndFilterRealOverrides(): Set<IrOverridableMember> =
+    @Suppress("UNCHECKED_CAST")
+    (this as Collection<IrOverridableDeclaration<*>>).collectAndFilterRealOverrides()
+
 // TODO: use this implementation instead of any other
-fun IrSimpleFunction.resolveFakeOverride(allowAbstract: Boolean = false, toSkip: (IrSimpleFunction) -> Boolean = { false }): IrSimpleFunction? {
+fun <S : IrSymbol, T : IrOverridableDeclaration<S>> T.resolveFakeOverride(
+    allowAbstract: Boolean = false,
+    toSkip: (T) -> Boolean = { false }
+): T? {
+    if (!isFakeOverride) return this
     return if (allowAbstract) {
         val reals = collectRealOverrides(toSkip)
         if (reals.isEmpty()) error("No real overrides for ${this.render()}")

compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/util/IrUtils.kt

@@ -248,8 +248,6 @@ fun IrSimpleFunction.findInterfaceImplementation(): IrSimpleFunction? {
     return resolveFakeOverride()?.run { if (parentAsClass.isInterface) this else null }
 }
 
-fun IrProperty.resolveFakeOverride(): IrProperty? = getter?.resolveFakeOverride()?.correspondingPropertySymbol?.owner
-
 val IrClass.isAnnotationClass get() = kind == ClassKind.ANNOTATION_CLASS
 val IrClass.isEnumClass get() = kind == ClassKind.ENUM_CLASS
 val IrClass.isEnumEntry get() = kind == ClassKind.ENUM_ENTRY

compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/overrides/FakeOverrides.kt

@@ -159,7 +159,6 @@ class FakeOverrideBuilder(
 
     private fun provideFakeOverrides(klass: IrClass) {
         buildFakeOverrideChainsForClass(klass)
-        propertyOverriddenSymbols.clear()
         irOverridingUtil.clear()
         haveFakeOverrides.add(klass)
     }