[FIR2IR] Properly compute parent for fake overrides

^KT-61637

compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/Fir2IrDeclarationStorage.kt

@@ -654,7 +654,7 @@ class Fir2IrDeclarationStorage(
             return fieldStaticOverrideCache[staticFakeOverrideKey]!!.symbol
         }
         // In case of type parameters from the parent as the field's return type, find the parent ahead to cache type parameters.
-        val irParent = findIrParent(fir)
+        val irParent = findIrParent(fir, fakeOverrideOwnerLookupTag)
 
         val unwrapped = fir.unwrapFakeOverrides()
         if (unwrapped !== fir) {
@@ -695,7 +695,7 @@ class Fir2IrDeclarationStorage(
                     return localStorage.getDelegatedProperty(fir)?.delegate?.symbol ?: getIrVariableSymbol(fir)
                 }
                 propertyCache[fir]?.let { return it.backingField!!.symbol }
-                val irParent = findIrParent(fir)
+                val irParent = findIrParent(fir, fakeOverrideOwnerLookupTag = null)
                 val parentOrigin = (irParent as? IrDeclaration)?.origin ?: IrDeclarationOrigin.DEFINED
                 createAndCacheIrProperty(fir, irParent, predefinedOrigin = parentOrigin).backingField!!.symbol
             }
@@ -906,7 +906,7 @@ class Fir2IrDeclarationStorage(
         return when (val fir = firFunctionSymbol.fir) {
             is FirAnonymousFunction -> {
                 getCachedIrFunction(fir)?.let { return it.symbol }
-                val irParent = findIrParent(fir)
+                val irParent = findIrParent(fir, fakeOverrideOwnerLookupTag)
                 val parentOrigin = (irParent as? IrDeclaration)?.origin ?: IrDeclarationOrigin.DEFINED
                 val declarationOrigin = computeDeclarationOrigin(firFunctionSymbol, parentOrigin)
                 createAndCacheIrFunction(fir, irParent, predefinedOrigin = declarationOrigin).symbol
@@ -929,7 +929,7 @@ class Fir2IrDeclarationStorage(
                     },
                     createIrLazyDeclaration = { signature, lazyParent, declarationOrigin ->
                         lazyDeclarationsGenerator.createIrLazyFunction(fir, signature, lazyParent, declarationOrigin).also {
-                            cacheIrFunction(fir, it, fakeOverrideOwnerLookupTag = null)
+                            cacheIrFunction(fir, it, fakeOverrideOwnerLookupTag)
                         }
                     },
                 ) as IrFunctionSymbol
@@ -1019,7 +1019,7 @@ class Fir2IrDeclarationStorage(
         createIrLazyDeclaration: (signature: IdSignature, lazyOwner: IrDeclarationParent, origin: IrDeclarationOrigin) -> I,
     ): IrSymbol {
         val fir = firSymbol.fir as F
-        val irParent by lazy { findIrParent(fir) }
+        val irParent by lazy { findIrParent(fir, fakeOverrideOwnerLookupTag) }
         val signature by lazy {
             signatureComposer.composeSignature(
                 fir,
@@ -1185,11 +1185,24 @@ class Fir2IrDeclarationStorage(
         return parentPackage
     }
 
-    private fun findIrParent(callableDeclaration: FirCallableDeclaration): IrDeclarationParent? {
+    private fun findIrParent(
+        callableDeclaration: FirCallableDeclaration,
+        fakeOverrideOwnerLookupTag: ConeClassLikeLookupTag?,
+    ): IrDeclarationParent? {
         val firBasedSymbol = callableDeclaration.symbol
         val callableId = firBasedSymbol.callableId
         val callableOrigin = callableDeclaration.origin
-        return findIrParent(callableId.packageName, callableDeclaration.containingClassLookupTag(), firBasedSymbol, callableOrigin)
+        val parentLookupTag = when {
+            // non-static fields can not be fake overrides
+            firBasedSymbol is FirFieldSymbol && !firBasedSymbol.isStatic -> callableDeclaration.containingClassLookupTag()
+            else -> fakeOverrideOwnerLookupTag ?: callableDeclaration.containingClassLookupTag()
+        }
+        return findIrParent(
+            callableId.packageName,
+            parentLookupTag,
+            firBasedSymbol,
+            callableOrigin
+        )
     }
 
     @OptIn(IrSymbolInternals::class)

compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/generators/Fir2IrLazyDeclarationsGenerator.kt

@@ -5,24 +5,18 @@
 
 package org.jetbrains.kotlin.fir.backend.generators
 
+import org.jetbrains.kotlin.fir.*
 import org.jetbrains.kotlin.fir.backend.Fir2IrComponents
 import org.jetbrains.kotlin.fir.backend.convertWithOffsets
 import org.jetbrains.kotlin.fir.backend.irOrigin
 import org.jetbrains.kotlin.fir.backend.isStubPropertyForPureField
-import org.jetbrains.kotlin.fir.declarations.FirConstructor
-import org.jetbrains.kotlin.fir.declarations.FirProperty
-import org.jetbrains.kotlin.fir.declarations.FirRegularClass
-import org.jetbrains.kotlin.fir.declarations.FirSimpleFunction
-import org.jetbrains.kotlin.fir.dispatchReceiverClassLookupTagOrNull
-import org.jetbrains.kotlin.fir.isSubstitutionOrIntersectionOverride
+import org.jetbrains.kotlin.fir.declarations.*
 import org.jetbrains.kotlin.fir.lazy.Fir2IrLazyClass
 import org.jetbrains.kotlin.fir.lazy.Fir2IrLazyConstructor
 import org.jetbrains.kotlin.fir.lazy.Fir2IrLazyProperty
 import org.jetbrains.kotlin.fir.lazy.Fir2IrLazySimpleFunction
-import org.jetbrains.kotlin.fir.originalForSubstitutionOverride
 import org.jetbrains.kotlin.fir.resolve.providers.firProvider
 import org.jetbrains.kotlin.ir.declarations.*
-import org.jetbrains.kotlin.ir.symbols.IrSymbolInternals
 import org.jetbrains.kotlin.ir.symbols.impl.IrConstructorPublicSymbolImpl
 import org.jetbrains.kotlin.ir.symbols.impl.IrPropertyPublicSymbolImpl
 import org.jetbrains.kotlin.ir.util.IdSignature
@@ -38,10 +32,11 @@ class Fir2IrLazyDeclarationsGenerator(val components: Fir2IrComponents) : Fir2Ir
         val symbol = symbolTable.referenceSimpleFunction(signature)
         val irFunction = fir.convertWithOffsets { startOffset, endOffset ->
             symbolTable.declareSimpleFunction(signature, { symbol }) {
-                val isFakeOverride = fir.isSubstitutionOrIntersectionOverride
+                val firContainingClass = (lazyParent as? Fir2IrLazyClass)?.fir
+                val isFakeOverride = fir.isFakeOverride(firContainingClass)
                 Fir2IrLazySimpleFunction(
                     components, startOffset, endOffset, declarationOrigin,
-                    fir, (lazyParent as? Fir2IrLazyClass)?.fir, symbol, isFakeOverride
+                    fir, firContainingClass, symbol, isFakeOverride
                 ).apply {
                     this.parent = lazyParent
                 }
@@ -52,7 +47,11 @@ class Fir2IrLazyDeclarationsGenerator(val components: Fir2IrComponents) : Fir2Ir
         return irFunction
     }
 
-    @OptIn(IrSymbolInternals::class)
+    private fun FirCallableDeclaration.isFakeOverride(firContainingClass: FirRegularClass?): Boolean {
+        val declaration = unwrapUseSiteSubstitutionOverrides()
+        return declaration.isSubstitutionOrIntersectionOverride || firContainingClass?.symbol?.toLookupTag() != declaration.containingClassLookupTag()
+    }
+
     internal fun createIrLazyProperty(
         fir: FirProperty,
         signature: IdSignature,
@@ -60,16 +59,12 @@ class Fir2IrLazyDeclarationsGenerator(val components: Fir2IrComponents) : Fir2Ir
         declarationOrigin: IrDeclarationOrigin
     ): IrProperty {
         val symbol = IrPropertyPublicSymbolImpl(signature)
-        val firPropertySymbol = fir.symbol
-
-        fun create(startOffset: Int, endOffset: Int): Fir2IrLazyProperty {
-            val isFakeOverride =
-                fir.isSubstitutionOrIntersectionOverride &&
-                        firPropertySymbol.dispatchReceiverClassLookupTagOrNull() !=
-                        firPropertySymbol.originalForSubstitutionOverride?.dispatchReceiverClassLookupTagOrNull()
+        fun create(startOffset: Int, endOffset: Int, isPropertyForField: Boolean): Fir2IrLazyProperty {
+            val firContainingClass = (lazyParent as? Fir2IrLazyClass)?.fir
+            val isFakeOverride = !isPropertyForField && fir.isFakeOverride(firContainingClass)
             return Fir2IrLazyProperty(
                 components, startOffset, endOffset, declarationOrigin,
-                fir, (lazyParent as? Fir2IrLazyClass)?.fir, symbol, isFakeOverride
+                fir, firContainingClass, symbol, isFakeOverride
             ).apply {
                 this.parent = lazyParent
             }
@@ -80,11 +75,10 @@ class Fir2IrLazyDeclarationsGenerator(val components: Fir2IrComponents) : Fir2Ir
                 // Very special case when two similar properties can exist so conflicts in SymbolTable are possible.
                 // See javaCloseFieldAndKotlinProperty.kt in BB tests
                 symbolTable.declarePropertyWithSignature(signature, symbol)
-                create(startOffset, endOffset)
-                symbol.owner
+                create(startOffset, endOffset, isPropertyForField = true)
             } else {
                 symbolTable.declareProperty(signature, { symbol }) {
-                    create(startOffset, endOffset)
+                    create(startOffset, endOffset, isPropertyForField = false)
                 }
             }
         }