FIR2IR: distinguish substitution case when adding external fake overrides

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

@@ -9,6 +9,7 @@ import org.jetbrains.kotlin.KtNodeTypes
 import org.jetbrains.kotlin.builtins.KotlinBuiltIns.*
 import org.jetbrains.kotlin.descriptors.*
 import org.jetbrains.kotlin.descriptors.annotations.Annotations
+import org.jetbrains.kotlin.fir.backend.generators.setOverriddenSymbolsForAccessors
 import org.jetbrains.kotlin.fir.declarations.*
 import org.jetbrains.kotlin.fir.declarations.impl.FirDefaultPropertyGetter
 import org.jetbrains.kotlin.fir.declarations.impl.FirDefaultPropertySetter
@@ -239,31 +240,63 @@ class Fir2IrDeclarationStorage(
                         }
                     }
                     is FirRegularClass -> {
-                        irClass.declarations += classifierStorage.createIrClass(declaration, irClass)
+                        val nestedExternalClass = classifierStorage.createIrClass(declaration, irClass)
+                        addDeclarationsToExternalClass(declaration, nestedExternalClass)
+                        irClass.declarations += nestedExternalClass
                     }
                     else -> continue
                 }
             }
+            // TODO: better to refactor somehow so as to entirely reuse FakeOverrideGenerator's logic.
             val allNames = regularClass.collectCallableNamesFromSupertypes(session)
             for (name in allNames) {
                 if (name in processedNames) continue
                 processedNames += name
                 scope.processFunctionsByName(name) { functionSymbol ->
                     if (functionSymbol is FirNamedFunctionSymbol) {
-                        val fakeOverrideSymbol = FirClassSubstitutionScope.createFakeOverrideFunction(
+                        val originalFunction = functionSymbol.fir
-                            session, functionSymbol.fir, functionSymbol, derivedClassId = regularClass.symbol.classId
+                        if (functionSymbol.isFakeOverride) {
-                        )
+                            // Substitution case
-                        classifierStorage.preCacheTypeParameters(functionSymbol.fir)
+                            val baseSymbol = functionSymbol.deepestOverriddenSymbol() as FirNamedFunctionSymbol
-                        irClass.declarations += createIrFunction(fakeOverrideSymbol.fir, irClass)
+                            val irFunction = createIrFunction(
+                                originalFunction, irParent = irClass,
+                                thisReceiverOwner = findIrParent(baseSymbol.fir) as? IrClass,
+                                origin = IrDeclarationOrigin.FAKE_OVERRIDE
+                            )
+                            val overriddenSymbol = getIrFunctionSymbol(baseSymbol) as IrSimpleFunctionSymbol
+                            irClass.declarations += irFunction.apply {
+                                overriddenSymbols = listOf(overriddenSymbol)
+                            }
+                        } else {
+                            val fakeOverrideSymbol = FirClassSubstitutionScope.createFakeOverrideFunction(
+                                session, originalFunction, functionSymbol, derivedClassId = regularClass.symbol.classId
+                            )
+                            classifierStorage.preCacheTypeParameters(functionSymbol.fir)
+                            irClass.declarations += createIrFunction(fakeOverrideSymbol.fir, irClass)
+                        }
                     }
                 }
                 scope.processPropertiesByName(name) { propertySymbol ->
                     if (propertySymbol is FirPropertySymbol) {
-                        val fakeOverrideSymbol = FirClassSubstitutionScope.createFakeOverrideProperty(
+                        val originalProperty = propertySymbol.fir
-                            session, propertySymbol.fir, propertySymbol, derivedClassId = regularClass.symbol.classId
+                        if (propertySymbol.isFakeOverride) {
-                        )
+                            // Substitution case
-                        classifierStorage.preCacheTypeParameters(propertySymbol.fir)
+                            val baseSymbol = propertySymbol.deepestOverriddenSymbol() as FirPropertySymbol
-                        irClass.declarations += createIrProperty(fakeOverrideSymbol.fir, irClass)
+                            val irProperty = createIrProperty(
+                                originalProperty, irParent = irClass,
+                                thisReceiverOwner = findIrParent(baseSymbol.fir) as? IrClass,
+                                origin = IrDeclarationOrigin.FAKE_OVERRIDE
+                            )
+                            irClass.declarations += irProperty.apply {
+                                setOverriddenSymbolsForAccessors(declarationStorage, originalProperty, baseSymbol)
+                            }
+                        } else {
+                            val fakeOverrideSymbol = FirClassSubstitutionScope.createFakeOverrideProperty(
+                                session, originalProperty, propertySymbol, derivedClassId = regularClass.symbol.classId
+                            )
+                            classifierStorage.preCacheTypeParameters(propertySymbol.fir)
+                            irClass.declarations += createIrProperty(fakeOverrideSymbol.fir, irClass)
+                        }
                     }
                 }
             }

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

@@ -41,24 +41,6 @@ internal class FakeOverrideGenerator(
         return conversionScope.withProperty(conversionScope.applyParentFromStackTo(this), f)
     }
 
-    private fun IrProperty.setOverriddenSymbolsForAccessors(
-        property: FirProperty,
-        firOverriddenSymbol: FirPropertySymbol
-    ): IrProperty {
-
-        val irSymbol = declarationStorage.getIrPropertyOrFieldSymbol(firOverriddenSymbol) as? IrPropertySymbol ?: return this
-        val overriddenProperty = irSymbol.owner
-        getter?.apply {
-            overriddenProperty.getter?.symbol?.let { overriddenSymbols = listOf(it) }
-        }
-        if (property.isVar) {
-            setter?.apply {
-                overriddenProperty.setter?.symbol?.let { overriddenSymbols = listOf(it) }
-            }
-        }
-        return this
-    }
-
     private fun FirCallableMemberDeclaration<*>.allowsToHaveFakeOverrideIn(klass: FirClass<*>): Boolean {
         if (!allowsToHaveFakeOverride) return false
         if (this.visibility != JavaVisibilities.PACKAGE_VISIBILITY) return true
@@ -138,7 +120,7 @@ internal class FakeOverrideGenerator(
                             origin = origin
                         )
                         declarations += irProperty.withProperty {
-                            setOverriddenSymbolsForAccessors(originalProperty, firOverriddenSymbol = baseSymbol)
+                            setOverriddenSymbolsForAccessors(declarationStorage, originalProperty, firOverriddenSymbol = baseSymbol)
                         }
                     } else if (fakeOverrideMode != FakeOverrideMode.SUBSTITUTION && originalProperty.allowsToHaveFakeOverrideIn(klass)) {
                         // Trivial fake override case
@@ -167,12 +149,29 @@ internal class FakeOverrideGenerator(
                             return@processPropertiesByName
                         }
                         declarations += irProperty.withProperty {
-                            setOverriddenSymbolsForAccessors(fakeOverrideProperty, firOverriddenSymbol = propertySymbol)
+                            setOverriddenSymbolsForAccessors(declarationStorage, fakeOverrideProperty, firOverriddenSymbol = propertySymbol)
                         }
                     }
                 }
             }
         }
     }
-
+}
+
+internal fun IrProperty.setOverriddenSymbolsForAccessors(
+    declarationStorage: Fir2IrDeclarationStorage,
+    property: FirProperty,
+    firOverriddenSymbol: FirPropertySymbol
+): IrProperty {
+    val irSymbol = declarationStorage.getIrPropertyOrFieldSymbol(firOverriddenSymbol) as? IrPropertySymbol ?: return this
+    val overriddenProperty = irSymbol.owner
+    getter?.apply {
+        overriddenProperty.getter?.symbol?.let { overriddenSymbols = listOf(it) }
+    }
+    if (property.isVar) {
+        setter?.apply {
+            overriddenProperty.setter?.symbol?.let { overriddenSymbols = listOf(it) }
+        }
+    }
+    return this
 }

compiler/testData/codegen/box/reflection/call/bound/companionObjectPropertyAccessors.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 // IGNORE_BACKEND: JS_IR
 // IGNORE_BACKEND: JS_IR_ES6
 // TODO: investigate should it be ran for JS or not

compiler/testData/codegen/box/reflection/call/bound/extensionPropertyAccessors.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 // IGNORE_BACKEND: JS_IR
 // IGNORE_BACKEND: JS_IR_ES6
 // TODO: investigate should it be ran for JS or not

compiler/testData/codegen/box/reflection/call/bound/jvmStaticCompanionObjectPropertyAccessors.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 // TARGET_BACKEND: JVM
 
 // WITH_REFLECT

compiler/testData/codegen/box/reflection/call/bound/jvmStaticObjectPropertyAccessors.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 // TARGET_BACKEND: JVM
 
 // WITH_REFLECT

compiler/testData/codegen/box/reflection/call/bound/memberPropertyAccessors.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 // IGNORE_BACKEND: JS_IR
 // IGNORE_BACKEND: JS_IR_ES6
 // TODO: investigate should it be ran for JS or not

compiler/testData/codegen/box/reflection/call/bound/objectPropertyAccessors.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 // IGNORE_BACKEND: JS_IR
 // IGNORE_BACKEND: JS_IR_ES6
 // TODO: investigate should it be ran for JS or not

compiler/testData/codegen/box/reflection/call/disallowNullValueForNotNullField.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 // TARGET_BACKEND: JVM
 
 // WITH_REFLECT

compiler/testData/codegen/box/reflection/call/inlineClasses/fieldAccessors.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 // TARGET_BACKEND: JVM
 // WITH_REFLECT
 

compiler/testData/codegen/box/reflection/call/inlineClasses/jvmStaticFieldInObject.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 // TARGET_BACKEND: JVM
 // JVM_TARGET: 1.8
 // WITH_REFLECT

compiler/testData/codegen/box/reflection/call/inlineClasses/nonOverridingVarOfInlineClass.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 // IGNORE_BACKEND: JS_IR, JS, NATIVE
 // IGNORE_BACKEND: JS_IR_ES6
 // WITH_REFLECT

compiler/testData/codegen/box/reflection/call/inlineClasses/overridingVarOfInlineClass.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 // IGNORE_BACKEND: JS_IR, JS, NATIVE
 // IGNORE_BACKEND: JS_IR_ES6
 // WITH_REFLECT

compiler/testData/codegen/box/reflection/call/inlineClasses/properties.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 // IGNORE_BACKEND: JS_IR, JS, NATIVE
 // IGNORE_BACKEND: JS_IR_ES6
 // WITH_REFLECT

compiler/testData/codegen/box/reflection/call/privateProperty.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 // TARGET_BACKEND: JVM
 
 // WITH_REFLECT

compiler/testData/codegen/box/reflection/call/propertyAccessors.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 // IGNORE_BACKEND: JS_IR
 // IGNORE_BACKEND: JS_IR_ES6
 // TODO: muted automatically, investigate should it be ran for JS or not

compiler/testData/codegen/box/reflection/call/protectedMembers.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 // TARGET_BACKEND: JVM
 // WITH_REFLECT
 

compiler/testData/codegen/box/reflection/callBy/inlineClassMembers.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 // IGNORE_BACKEND: JS_IR, JS, NATIVE
 // IGNORE_BACKEND: JS_IR_ES6
 // WITH_REFLECT

compiler/testData/codegen/box/reflection/multifileClasses/callPropertiesInMultifileClass.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 // TARGET_BACKEND: JVM
 
 // KT-11447 Multifile declaration causes IAE: Method can not access a member of class

compiler/testData/codegen/box/reflection/properties/accessors/extensionPropertyAccessors.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 // IGNORE_BACKEND: JS_IR
 // IGNORE_BACKEND: JS_IR_ES6
 // TODO: muted automatically, investigate should it be ran for JS or not

compiler/testData/codegen/box/reflection/properties/accessors/memberExtensions.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 // IGNORE_BACKEND: JS_IR
 // IGNORE_BACKEND: JS_IR_ES6
 // TODO: muted automatically, investigate should it be ran for JS or not

compiler/testData/codegen/box/reflection/properties/accessors/memberPropertyAccessors.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 // IGNORE_BACKEND: JS_IR
 // IGNORE_BACKEND: JS_IR_ES6
 // TODO: muted automatically, investigate should it be ran for JS or not

compiler/testData/codegen/box/reflection/properties/accessors/topLevelPropertyAccessors.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 // IGNORE_BACKEND: JS_IR
 // IGNORE_BACKEND: JS_IR_ES6
 // TODO: muted automatically, investigate should it be ran for JS or not

compiler/testData/codegen/box/reflection/properties/privatePropertyCallIsAccessibleOnAccessors.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND_FIR: JVM_IR
 // TARGET_BACKEND: JVM
 // WITH_REFLECT