[FIR] Introduce valueClassRepresentation to FIR

#KT-1179

compiler/fir/fir-deserialization/src/org/jetbrains/kotlin/fir/deserialization/ClassDeserialization.kt

@@ -6,19 +6,13 @@
 package org.jetbrains.kotlin.fir.deserialization
 
 import org.jetbrains.kotlin.builtins.jvm.JvmBuiltInsSignatures
-import org.jetbrains.kotlin.descriptors.ClassKind
-import org.jetbrains.kotlin.descriptors.EffectiveVisibility
-import org.jetbrains.kotlin.descriptors.Modality
-import org.jetbrains.kotlin.descriptors.Visibilities
+import org.jetbrains.kotlin.descriptors.*
 import org.jetbrains.kotlin.fir.*
 import org.jetbrains.kotlin.fir.declarations.*
 import org.jetbrains.kotlin.fir.declarations.builder.*
 import org.jetbrains.kotlin.fir.declarations.comparators.FirMemberDeclarationComparator
 import org.jetbrains.kotlin.fir.declarations.impl.FirResolvedDeclarationStatusImpl
-import org.jetbrains.kotlin.fir.declarations.utils.addDeclarations
-import org.jetbrains.kotlin.fir.declarations.utils.isCompanion
-import org.jetbrains.kotlin.fir.declarations.utils.moduleName
-import org.jetbrains.kotlin.fir.declarations.utils.sourceElement
+import org.jetbrains.kotlin.fir.declarations.utils.*
 import org.jetbrains.kotlin.fir.expressions.FirAnnotation
 import org.jetbrains.kotlin.fir.scopes.FirScopeProvider
 import org.jetbrains.kotlin.fir.symbols.ConeTypeParameterLookupTag
@@ -26,8 +20,7 @@ import org.jetbrains.kotlin.fir.symbols.impl.ConeClassLikeLookupTagImpl
 import org.jetbrains.kotlin.fir.symbols.impl.FirEnumEntrySymbol
 import org.jetbrains.kotlin.fir.symbols.impl.FirNamedFunctionSymbol
 import org.jetbrains.kotlin.fir.symbols.impl.FirRegularClassSymbol
-import org.jetbrains.kotlin.fir.types.ConeAttributes
-import org.jetbrains.kotlin.fir.types.ConeClassLikeType
+import org.jetbrains.kotlin.fir.types.*
 import org.jetbrains.kotlin.fir.types.builder.buildResolvedTypeRef
 import org.jetbrains.kotlin.fir.types.impl.ConeClassLikeTypeImpl
 import org.jetbrains.kotlin.fir.types.impl.ConeTypeParameterTypeImpl
@@ -208,6 +201,9 @@ fun deserializeClassToSymbol(
             }
             it.setSealedClassInheritors(inheritors)
         }
+        
+        it.valueClassRepresentation = computeValueClassRepresentation(it, session)
+        
         (it.annotations as MutableList<FirAnnotation>) +=
             context.annotationDeserializer.loadClassAnnotations(classProto, context.nameResolver)
 

compiler/fir/fir-serialization/src/org/jetbrains/kotlin/fir/serialization/FirElementSerializer.kt

@@ -172,18 +172,18 @@ class FirElementSerializer private constructor(
             builder.companionObjectName = getSimpleNameIndex(companionObject.name)
         }
 
-        val representation = (klass as? FirRegularClass)?.getInlineClassUnderlyingParameter(session)
+        val representation = (klass as? FirRegularClass)?.inlineClassRepresentation
         if (representation != null) {
-            builder.inlineClassUnderlyingPropertyName = getSimpleNameIndex(representation.name)
+            builder.inlineClassUnderlyingPropertyName = getSimpleNameIndex(representation.underlyingPropertyName)
 
             val property = callableMembers.single {
-                it is FirProperty && it.receiverTypeRef == null && it.name == representation.name
+                it is FirProperty && it.receiverTypeRef == null && it.name == representation.underlyingPropertyName
             }
             if (!property.visibility.isPublicAPI) {
                 if (useTypeTable()) {
-                    builder.inlineClassUnderlyingTypeId = typeId(representation.returnTypeRef)
+                    builder.inlineClassUnderlyingTypeId = typeId(representation.underlyingType)
                 } else {
-                    builder.setInlineClassUnderlyingType(typeProto(representation.returnTypeRef))
+                    builder.setInlineClassUnderlyingType(typeProto(representation.underlyingType))
                 }
             }
         }

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

@@ -643,14 +643,13 @@ fun Fir2IrComponents.createTemporaryVariableForSafeCallConstruction(
 ): Pair<IrVariable, IrValueSymbol> =
     createTemporaryVariable(receiverExpression, conversionScope, "safe_receiver")
 
-// TODO: implement valueClassRepresentation in FirRegularClass instead. zhelenskiy
 fun Fir2IrComponents.computeValueClassRepresentation(klass: FirRegularClass): ValueClassRepresentation<IrSimpleType>? {
-    val parameters = klass.getValueClassUnderlyingParameters(session) ?: return null
-    return createValueClassRepresentation(IrTypeSystemContextImpl(irBuiltIns), parameters.map {
-        val type = it.returnTypeRef.toIrType(typeConverter).safeAs<IrSimpleType>()
-            ?: error("Value class underlying type is not a simple type: ${klass.render()}")
-        it.name to type
-    })
+    require((klass.valueClassRepresentation != null) == klass.isInline)
+    return klass.valueClassRepresentation?.mapUnderlyingType {
+        with(typeConverter) {
+            it.toIrType() as? IrSimpleType?: error("Value class underlying type is not a simple type: ${klass.render()}")
+        }
+    }
 }
 
 fun FirRegularClass.getIrSymbolsForSealedSubclasses(components: Fir2IrComponents): List<IrClassSymbol> {

compiler/fir/providers/src/org/jetbrains/kotlin/fir/declarations/ValueClassesUtils.kt

@@ -0,0 +1,71 @@
+/*
+ * Copyright 2010-2021 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.fir.declarations
+
+import org.jetbrains.kotlin.descriptors.InlineClassRepresentation
+import org.jetbrains.kotlin.descriptors.ValueClassRepresentation
+import org.jetbrains.kotlin.descriptors.createValueClassRepresentation
+import org.jetbrains.kotlin.fir.FirSession
+import org.jetbrains.kotlin.fir.declarations.utils.isInline
+import org.jetbrains.kotlin.fir.resolve.fullyExpandedType
+import org.jetbrains.kotlin.fir.resolve.substitution.createTypeSubstitutorByTypeConstructor
+import org.jetbrains.kotlin.fir.resolve.toSymbol
+import org.jetbrains.kotlin.fir.symbols.ensureResolved
+import org.jetbrains.kotlin.fir.symbols.impl.FirRegularClassSymbol
+import org.jetbrains.kotlin.fir.types.*
+import org.jetbrains.kotlin.name.Name
+import org.jetbrains.kotlin.types.model.typeConstructor
+
+internal fun ConeKotlinType.substitutedUnderlyingTypeForInlineClass(session: FirSession, context: ConeTypeContext): ConeKotlinType? {
+    val unsubstitutedType = unsubstitutedUnderlyingTypeForInlineClass(session) ?: return null
+    val substitutor = createTypeSubstitutorByTypeConstructor(
+        mapOf(this.typeConstructor(context) to this), context, approximateIntegerLiterals = true
+    )
+    return substitutor.substituteOrNull(unsubstitutedType)
+}
+
+internal fun ConeKotlinType.unsubstitutedUnderlyingTypeForInlineClass(session: FirSession): ConeKotlinType? {
+    val symbol = (this.fullyExpandedType(session) as? ConeLookupTagBasedType)
+        ?.lookupTag
+        ?.toSymbol(session) as? FirRegularClassSymbol
+        ?: return null
+    symbol.ensureResolved(FirResolvePhase.STATUS)
+    return symbol.fir.inlineClassRepresentation?.underlyingType
+}
+
+fun computeValueClassRepresentation(klass: FirRegularClass, session: FirSession): ValueClassRepresentation<ConeSimpleKotlinType>? {
+    val parameters = klass.getValueClassUnderlyingParameters(session)?.takeIf { it.isNotEmpty() } ?: return null
+    val fields = parameters.map { it.name to it.returnTypeRef.coneType as ConeSimpleKotlinType }
+    fields.singleOrNull()?.let { (name, type) ->
+        if (isRecursiveSingleFieldValueClass(type, session, mutableSetOf(type))) { // escape stack overflow
+            return InlineClassRepresentation(name, type)
+        }
+    }
+    return createValueClassRepresentation(session.typeContext, fields)
+}
+
+private fun FirRegularClass.getValueClassUnderlyingParameters(session: FirSession): List<FirValueParameter>? =
+    if (isInline) primaryConstructorIfAny(session)?.fir?.valueParameters else null
+
+private fun isRecursiveSingleFieldValueClass(
+    type: ConeSimpleKotlinType,
+    session: FirSession,
+    visited: MutableSet<ConeSimpleKotlinType>
+): Boolean {
+    val nextType = type.valueClassRepresentationTypeMarkersList(session)?.singleOrNull()?.second ?: return false
+    return !visited.add(nextType) || isRecursiveSingleFieldValueClass(nextType, session, visited)
+}
+
+private fun ConeSimpleKotlinType.valueClassRepresentationTypeMarkersList(session: FirSession): List<Pair<Name, ConeSimpleKotlinType>>? {
+    val symbol = this.toSymbol(session) as? FirRegularClassSymbol ?: return null
+    if (!symbol.fir.isInline) return null
+    symbol.fir.valueClassRepresentation?.let { return it.underlyingPropertyNamesToTypes }
+    symbol.ensureResolved(FirResolvePhase.TYPES)
+    val constructorSymbol = symbol.fir.primaryConstructorIfAny(session) ?: return null
+    return constructorSymbol.valueParameterSymbols
+        .onEach { it.ensureResolved(FirResolvePhase.TYPES) }
+        .map { it.name to it.resolvedReturnType as ConeSimpleKotlinType }
+}

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/transformers/FirStatusResolveTransformer.kt

@@ -112,6 +112,9 @@ open class FirStatusResolveTransformer(
          */
         if (computationStatus != StatusComputationSession.StatusComputationStatus.Computed) {
             regularClass.transformStatus(this, statusResolver.resolveStatus(regularClass, containingClass, isLocal = false))
+            if (regularClass.status.isInline) {
+                regularClass.valueClassRepresentation = computeValueClassRepresentation(regularClass, session)
+            }
         }
         return transformClass(regularClass, data).also {
             statusComputationSession.endComputing(regularClass)

compiler/fir/tree/src/org/jetbrains/kotlin/fir/declarations/FirValueClassRepresentation.kt

@@ -0,0 +1,24 @@
+/*
+ * Copyright 2010-2022 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.fir.declarations
+
+import org.jetbrains.kotlin.descriptors.InlineClassRepresentation
+import org.jetbrains.kotlin.descriptors.MultiFieldValueClassRepresentation
+import org.jetbrains.kotlin.descriptors.ValueClassRepresentation
+import org.jetbrains.kotlin.fir.types.ConeSimpleKotlinType
+
+private object FirValueClassRepresentationKey : FirDeclarationDataKey()
+
+var FirRegularClass.valueClassRepresentation: ValueClassRepresentation<ConeSimpleKotlinType>?
+        by FirDeclarationDataRegistry.data(FirValueClassRepresentationKey)
+
+val FirRegularClass.inlineClassRepresentation: InlineClassRepresentation<ConeSimpleKotlinType>?
+    get() = valueClassRepresentation as? InlineClassRepresentation<ConeSimpleKotlinType>
+
+val FirRegularClass.multiFieldValueClassRepresentation: MultiFieldValueClassRepresentation<ConeSimpleKotlinType>?
+    get() = valueClassRepresentation as? MultiFieldValueClassRepresentation<ConeSimpleKotlinType>
+
+

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

@@ -40,12 +40,6 @@ abstract class IrClass :
 
     abstract var valueClassRepresentation: ValueClassRepresentation<IrSimpleType>?
 
-    val inlineClassRepresentation: InlineClassRepresentation<IrSimpleType>?
-        get() = valueClassRepresentation as? InlineClassRepresentation<IrSimpleType>
-
-    val multiFieldValueClassRepresentation: MultiFieldValueClassRepresentation<IrSimpleType>?
-        get() = valueClassRepresentation as? MultiFieldValueClassRepresentation<IrSimpleType>
-
     abstract var sealedSubclasses: List<IrClassSymbol>
 
     override fun <R, D> accept(visitor: IrElementVisitor<R, D>, data: D): R =

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

@@ -10,6 +10,7 @@ import org.jetbrains.kotlin.descriptors.MultiFieldValueClassRepresentation
 import org.jetbrains.kotlin.descriptors.ValueParameterDescriptor
 import org.jetbrains.kotlin.ir.ObsoleteDescriptorBasedAPI
 import org.jetbrains.kotlin.ir.expressions.IrExpressionBody
+import org.jetbrains.kotlin.ir.types.IrSimpleType
 import java.io.File
 
 fun <D : IrAttributeContainer> D.copyAttributes(other: IrAttributeContainer?): D = apply {
@@ -55,3 +56,10 @@ val IrFunction.isStaticMethodOfClass: Boolean
 
 val IrFunction.isPropertyAccessor: Boolean
     get() = this is IrSimpleFunction && correspondingPropertySymbol != null
+
+
+val IrClass.multiFieldValueClassRepresentation: MultiFieldValueClassRepresentation<IrSimpleType>?
+    get() = valueClassRepresentation as? MultiFieldValueClassRepresentation<IrSimpleType>
+
+val IrClass.inlineClassRepresentation: InlineClassRepresentation<IrSimpleType>?
+    get() = valueClassRepresentation as? InlineClassRepresentation<IrSimpleType>

compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/types/IrTypeSystemContext.kt

@@ -465,7 +465,7 @@ interface IrTypeSystemContext : TypeSystemContext, TypeSystemCommonSuperTypesCon
     override fun TypeConstructorMarker.isMultiFieldValueClass(): Boolean =
         (this as? IrClassSymbol)?.owner?.isMultiFieldValueClass == true
 
-    override fun TypeConstructorMarker.valueClassRepresentationTypeMarkersList(): List<Pair<Name, SimpleTypeMarker>>? =
+    override fun TypeConstructorMarker.getValueClassProperties(): List<Pair<Name, SimpleTypeMarker>>? =
         (this as? IrClassSymbol)?.owner?.valueClassRepresentation?.underlyingPropertyNamesToTypes
 
     override fun TypeConstructorMarker.isInnerClass(): Boolean =

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

@@ -8,6 +8,7 @@ package org.jetbrains.kotlin.ir.util
 import org.jetbrains.kotlin.ir.declarations.IrClass
 import org.jetbrains.kotlin.ir.declarations.IrField
 import org.jetbrains.kotlin.ir.declarations.IrProperty
+import org.jetbrains.kotlin.ir.declarations.inlineClassRepresentation
 import org.jetbrains.kotlin.ir.types.IrSimpleType
 
 fun getInlineClassUnderlyingType(irClass: IrClass): IrSimpleType {

core/compiler.common/src/org/jetbrains/kotlin/descriptors/InlineClassRepresentation.kt

@@ -18,5 +18,5 @@ class InlineClassRepresentation<Type : SimpleTypeMarker> constructor(
 
     override fun containsPropertyWithName(name: Name): Boolean = underlyingPropertyName == name
 
-    override fun propertyTypeByName(name: Name): Type? = underlyingType.takeIf { containsPropertyWithName(name) }
+    override fun getPropertyTypeByName(name: Name): Type? = underlyingType.takeIf { containsPropertyWithName(name) }
 }

core/compiler.common/src/org/jetbrains/kotlin/descriptors/MultiFieldValueClassRepresentation.kt

@@ -17,5 +17,5 @@ class MultiFieldValueClassRepresentation<Type : SimpleTypeMarker>(
     }
 
     override fun containsPropertyWithName(name: Name): Boolean = name in map
-    override fun propertyTypeByName(name: Name): Type? = map[name]
+    override fun getPropertyTypeByName(name: Name): Type? = map[name]
 }

core/compiler.common/src/org/jetbrains/kotlin/types/TypeSystemCommonBackendContext.kt

@@ -32,7 +32,7 @@ interface TypeSystemCommonBackendContext : TypeSystemContext {
 
     fun TypeConstructorMarker.isInlineClass(): Boolean
     fun TypeConstructorMarker.isMultiFieldValueClass(): Boolean
-    fun TypeConstructorMarker.valueClassRepresentationTypeMarkersList(): List<Pair<Name, SimpleTypeMarker>>?
+    fun TypeConstructorMarker.getValueClassProperties(): List<Pair<Name, SimpleTypeMarker>>?
     fun TypeConstructorMarker.isInnerClass(): Boolean
     fun TypeParameterMarker.getRepresentativeUpperBound(): KotlinTypeMarker
     fun KotlinTypeMarker.getUnsubstitutedUnderlyingType(): KotlinTypeMarker?

core/descriptors/src/org/jetbrains/kotlin/types/checker/ClassicTypeSystemContext.kt

@@ -749,7 +749,7 @@ interface ClassicTypeSystemContext : TypeSystemInferenceExtensionContext, TypeSy
         return (declarationDescriptor as? ClassDescriptor)?.valueClassRepresentation is MultiFieldValueClassRepresentation
     }
 
-    override fun TypeConstructorMarker.valueClassRepresentationTypeMarkersList(): List<Pair<Name, SimpleTypeMarker>>? {
+    override fun TypeConstructorMarker.getValueClassProperties(): List<Pair<Name, SimpleTypeMarker>>? {
         require(this is TypeConstructor, this::errorMessage)
         return (declarationDescriptor as? ClassDescriptor)?.valueClassRepresentation?.underlyingPropertyNamesToTypes
     }

kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/InlineClasses.kt

@@ -14,6 +14,7 @@ import org.jetbrains.kotlin.descriptors.ClassDescriptor
 import org.jetbrains.kotlin.descriptors.PackageFragmentDescriptor
 import org.jetbrains.kotlin.ir.declarations.IrClass
 import org.jetbrains.kotlin.ir.declarations.IrProperty
+import org.jetbrains.kotlin.ir.declarations.inlineClassRepresentation
 import org.jetbrains.kotlin.ir.declarations.isSingleFieldValueClass
 import org.jetbrains.kotlin.ir.symbols.IrClassSymbol
 import org.jetbrains.kotlin.ir.symbols.IrTypeParameterSymbol

plugins/parcelize/parcelize-compiler/src/org/jetbrains/kotlin/parcelize/ir/IrParcelSerializerFactory.kt

@@ -9,6 +9,7 @@ import org.jetbrains.kotlin.backend.jvm.ir.erasedUpperBound
 import org.jetbrains.kotlin.backend.jvm.ir.psiElement
 import org.jetbrains.kotlin.descriptors.Modality
 import org.jetbrains.kotlin.ir.IrBuiltIns
+import org.jetbrains.kotlin.ir.declarations.inlineClassRepresentation
 import org.jetbrains.kotlin.ir.types.*
 import org.jetbrains.kotlin.ir.util.*
 import org.jetbrains.kotlin.parcelize.ParcelizeNames.RAW_VALUE_ANNOTATION_FQ_NAMES