JS PIR: update the generator

- Use symbols in carriers
- .proto messages for carriers
- carrier serializer/derserializer

compiler/ir/ir.tree.persistent/generator/src/org/jetbrains/kotlin/ir/persistentIrGenerator/AnonymousInitializer.kt

@@ -6,7 +6,7 @@
 package org.jetbrains.kotlin.ir.persistentIrGenerator
 
 internal fun PersistentIrGenerator.generateAnonymousInitializer() {
-    val body = Field("body", IrBlockBody, lateinit = true)
+    val body = Field("body", IrBlockBody, blockBodyProto, lateinit = true)
 
     writeFile("PersistentIrAnonymousInitializer.kt", renderFile("org.jetbrains.kotlin.ir.declarations.persistent") {
         lines(
@@ -33,4 +33,6 @@ internal fun PersistentIrGenerator.generateAnonymousInitializer() {
     writeFile("carriers/AnonymousInitializerCarrier.kt", renderFile("org.jetbrains.kotlin.ir.declarations.persistent.carriers") {
         carriers("AnonymousInitializer", body)()
     })
+
+    addCarrierProtoMessage("AnonymousInitializer", body)
 }

compiler/ir/ir.tree.persistent/generator/src/org/jetbrains/kotlin/ir/persistentIrGenerator/Class.kt

@@ -6,13 +6,17 @@
 package org.jetbrains.kotlin.ir.persistentIrGenerator
 
 internal fun PersistentIrGenerator.generateClass() {
-    val visibilityField = Field("visibility", descriptorType("DescriptorVisibility"))
+    val visibilityField = Field("visibility", DescriptorVisibility, visibilityProto)
-    val thisReceiverField = Field("thisReceiver", irDeclaration("IrValueParameter") + "?")
+    val thisReceiverField = Field(
-    val typeParametersField = Field("typeParameters", +"List<" + irDeclaration("IrTypeParameter") + ">")
+        "thisReceiver",
-    val superTypesField = Field("superTypes", +"List<" + import("IrType", "org.jetbrains.kotlin.ir.types") + ">")
+        IrValueParameter + "?",
-    val metadataField = Field("metadata", irDeclaration("MetadataSource") + "?")
+        valueParameterProto,
-    val modalityField = Field("modality", descriptorType("Modality"))
+        propSymbolType = IrValueParameterSymbol + "?",
-    val attributeOwnerIdField = Field("attributeOwnerId", IrAttributeContainer)
+        symbolToDeclaration = +"?.owner",
+        declarationToSymbol = +"?.symbol"
+    )
+    val superTypesField = Field("superTypes", +"List<" + import("IrType", "org.jetbrains.kotlin.ir.types") + ">", superTypeListProto)
+    val modalityField = Field("modality", descriptorType("Modality"), modalityProto)
 
     writeFile("PersistentIrClass.kt", renderFile("org.jetbrains.kotlin.ir.declarations.persistent") {
         lines(
@@ -66,9 +70,9 @@ internal fun PersistentIrGenerator.generateClass() {
                 ),
                 typeParametersField.toPersistentField(+"emptyList()"),
                 superTypesField.toPersistentField(+"emptyList()"),
-                metadataField.toPersistentField(+"null"),
+                +"override var metadata: " + MetadataSource + "? = null",
                 modalityField.toPersistentField(+"modality"),
-                attributeOwnerIdField.toPersistentField(+"this"),
+                +"override var attributeOwnerId: " + IrAttributeContainer + " = this",
             ),
             id,
         )()
@@ -78,12 +82,19 @@ internal fun PersistentIrGenerator.generateClass() {
         carriers(
             "Class",
             thisReceiverField,
-            metadataField,
             visibilityField,
             modalityField,
-            attributeOwnerIdField,
             typeParametersField,
             superTypesField,
         )()
     })
+
+    addCarrierProtoMessage(
+        "Class",
+        thisReceiverField,
+        visibilityField,
+        modalityField,
+        typeParametersField,
+        superTypesField,
+    )
 }

compiler/ir/ir.tree.persistent/generator/src/org/jetbrains/kotlin/ir/persistentIrGenerator/Constructor.kt

@@ -6,14 +6,9 @@
 package org.jetbrains.kotlin.ir.persistentIrGenerator
 
 internal fun PersistentIrGenerator.generateConstructor() {
-    val returnTypeFieldField = Field("returnTypeField", IrType)
+    val returnTypeFieldField = Field("returnTypeField", IrType, typeProto)
-    val typeParametersField = Field("typeParameters", +"List<" + IrTypeParameter + ">")
+    val bodyField = Field("body", IrBody + "?", bodyProto)
-    val dispatchReceiverParameterField = Field("dispatchReceiverParameter", IrValueParameter + "?")
+    val visibilityField = Field("visibility", DescriptorVisibility, visibilityProto)
-    val extensionReceiverParameterField = Field("extensionReceiverParameter", IrValueParameter + "?")
-    val valueParametersField = Field("valueParameters", +"List<" + IrValueParameter + ">")
-    val bodyField = Field("body", IrBody + "?")
-    val metadataField = Field("metadata", MetadataSource + "?")
-    val visibilityField = Field("visibility", DescriptorVisibility)
 
     writeFile("PersistentIrConstructor.kt", renderFile("org.jetbrains.kotlin.ir.declarations.persistent") {
         lines(
@@ -42,7 +37,13 @@ internal fun PersistentIrGenerator.generateConstructor() {
                     +"override var returnType: IrType",
                     lines(
                         +"get() = returnTypeField.let " + block(
-                            +"if (it !== " + import("IrUninitializedType", "org.jetbrains.kotlin.ir.types.impl") + ") it else throw " + import("ReturnTypeIsNotInitializedException", "org.jetbrains.kotlin.ir.types.impl") + "(this)"
+                            +"if (it !== " + import(
+                                "IrUninitializedType",
+                                "org.jetbrains.kotlin.ir.types.impl"
+                            ) + ") it else throw " + import(
+                                "ReturnTypeIsNotInitializedException",
+                                "org.jetbrains.kotlin.ir.types.impl"
+                            ) + "(this)"
                         ),
                         +"set(c) " + block(
                             +"returnTypeField = c"
@@ -54,9 +55,9 @@ internal fun PersistentIrGenerator.generateConstructor() {
                 extensionReceiverParameterField.toPersistentField(+"null"),
                 valueParametersField.toPersistentField(+"emptyList()"),
                 bodyField.toBody(),
-                metadataField.toPersistentField(+"null"),
+                +"override var metadata: " + MetadataSource + "? = null",
                 visibilityField.toPersistentField(+"visibility"),
-                descriptor(ClassConstructorDescriptor)
+                descriptor(ClassConstructorDescriptor),
             ),
             id,
         )()
@@ -69,10 +70,20 @@ internal fun PersistentIrGenerator.generateConstructor() {
             dispatchReceiverParameterField,
             extensionReceiverParameterField,
             bodyField,
-            metadataField,
             visibilityField,
             typeParametersField,
             valueParametersField,
         )()
     })
+
+    addCarrierProtoMessage(
+        "Constructor",
+        returnTypeFieldField,
+        dispatchReceiverParameterField,
+        extensionReceiverParameterField,
+        bodyField,
+        visibilityField,
+        typeParametersField,
+        valueParametersField,
+    )
 }

compiler/ir/ir.tree.persistent/generator/src/org/jetbrains/kotlin/ir/persistentIrGenerator/EnumEntry.kt

@@ -6,8 +6,15 @@
 package org.jetbrains.kotlin.ir.persistentIrGenerator
 
 internal fun PersistentIrGenerator.generateEnumEntry() {
-    val correspondingClassField = Field("correspondingClass", IrClass + "?")
+    val correspondingClassField = Field(
-    val initializerExpressionField = Field("initializerExpression", IrExpressionBody + "?")
+        "correspondingClass",
+        IrClass + "?",
+        classProto,
+        propSymbolType = IrClassSymbol + "?",
+        symbolToDeclaration = +"?.owner",
+        declarationToSymbol = +"?.symbol"
+    )
+    val initializerExpressionField = Field("initializerExpression", IrExpressionBody + "?", expressionBodyProto)
 
     writeFile("PersistentIrEnumEntry.kt", renderFile("org.jetbrains.kotlin.ir.declarations.persistent") {
         lines(
@@ -27,7 +34,7 @@ internal fun PersistentIrGenerator.generateEnumEntry() {
                 descriptor(ClassDescriptor),
 
                 correspondingClassField.toPersistentField(+"null"),
-                initializerExpressionField.toBody()
+                initializerExpressionField.toBody(),
             ),
             id,
         )()
@@ -40,4 +47,6 @@ internal fun PersistentIrGenerator.generateEnumEntry() {
             initializerExpressionField,
         )()
     })
+
+    addCarrierProtoMessage("EnumEntry", correspondingClassField, initializerExpressionField)
 }

compiler/ir/ir.tree.persistent/generator/src/org/jetbrains/kotlin/ir/persistentIrGenerator/ErrorDeclaration.kt

@@ -43,4 +43,6 @@ internal fun PersistentIrGenerator.generateErrorDeclaration() {
             "ErrorDeclaration",
         )()
     })
+
+    addCarrierProtoMessage("ErrorDeclaration")
 }

compiler/ir/ir.tree.persistent/generator/src/org/jetbrains/kotlin/ir/persistentIrGenerator/Field.kt

@@ -6,10 +6,9 @@
 package org.jetbrains.kotlin.ir.persistentIrGenerator
 
 internal fun PersistentIrGenerator.generateField() {
-    val initializerField = Field("initializer", IrExpressionBody + "?")
+    val initializerField = Field("initializer", IrExpressionBody + "?", expressionBodyProto)
-    val correspondingPropertySymbolField = Field("correspondingPropertySymbol", IrPropertySymbol + "?")
+    val correspondingPropertySymbolField = Field("correspondingPropertySymbol", IrPropertySymbol + "?", propertySymbolProto)
-    val metadataField = Field("metadata", MetadataSource + "?")
+    val typeField = Field("type", IrType, typeProto)
-    val typeField = Field("type", IrType)
 
     writeFile("PersistentIrField.kt", renderFile("org.jetbrains.kotlin.ir.declarations.persistent") {
         lines(
@@ -34,7 +33,7 @@ internal fun PersistentIrGenerator.generateField() {
                 descriptor(descriptorType("PropertyDescriptor")),
                 initializerField.toBody(),
                 correspondingPropertySymbolField.toPersistentField(+"null"),
-                metadataField.toPersistentField(+"null"),
+                +"override var metadata: " + MetadataSource + "? = null",
                 typeField.toPersistentField(+"type"),
             ),
             id,
@@ -47,7 +46,8 @@ internal fun PersistentIrGenerator.generateField() {
             typeField,
             initializerField,
             correspondingPropertySymbolField,
-            metadataField,
         )()
     })
+
+    addCarrierProtoMessage("Field", typeField, initializerField, correspondingPropertySymbolField)
 }

compiler/ir/ir.tree.persistent/generator/src/org/jetbrains/kotlin/ir/persistentIrGenerator/Function.kt

@@ -7,17 +7,11 @@ package org.jetbrains.kotlin.ir.persistentIrGenerator
 
 internal fun PersistentIrGenerator.generateFunction() {
 
-    val returnTypeFieldField = Field("returnTypeField", IrType)
+    val returnTypeFieldField = Field("returnTypeField", IrType, typeProto)
-    val typeParametersField = Field("typeParameters", +"List<" + IrTypeParameter + ">")
+    val bodyField = Field("body", IrBody + "?", bodyProto)
-    val dispatchReceiverParameterField = Field("dispatchReceiverParameter", IrValueParameter + "?")
+    val visibilityField = Field("visibility", DescriptorVisibility, visibilityProto)
-    val extensionReceiverParameterField = Field("extensionReceiverParameter", IrValueParameter + "?")
+    val overriddenSymbolsField = Field("overriddenSymbols", +"List<" + IrSimpleFunctionSymbol + ">", simpleFunctionSymbolListProto)
-    val valueParametersField = Field("valueParameters", +"List<" + IrValueParameter + ">")
+    val correspondingPropertySymbolField = Field("correspondingPropertySymbol", IrPropertySymbol + "?", propertySymbolProto)
-    val bodyField = Field("body", IrBody + "?")
-    val metadataField = Field("metadata", MetadataSource + "?")
-    val visibilityField = Field("visibility", DescriptorVisibility)
-    val overriddenSymbolsField = Field("overriddenSymbols", +"List<" + irSymbol("IrSimpleFunctionSymbol") + ">")
-    val attributeOwnerIdField = Field("attributeOwnerId", IrAttributeContainer)
-    val correspondingPropertySymbolField = Field("correspondingPropertySymbol", IrPropertySymbol + "?")
 
     writeFile("PersistentIrFunctionCommon.kt", renderFile("org.jetbrains.kotlin.ir.declarations.persistent") {
         lines(
@@ -65,13 +59,10 @@ internal fun PersistentIrGenerator.generateFunction() {
                 extensionReceiverParameterField.toPersistentField(+"null"),
                 valueParametersField.toPersistentField(+"emptyList()"),
                 bodyField.toBody(),
-                metadataField.toPersistentField(+"null"),
+                +"override var metadata: " + MetadataSource + "? = null",
                 visibilityField.toPersistentField(+"visibility"),
                 overriddenSymbolsField.toPersistentField(+"emptyList()"),
-                lines(
+                +"override var attributeOwnerId: " + IrAttributeContainer + " = this",
-                    +"@Suppress(\"LeakingThis\")",
-                    attributeOwnerIdField.toPersistentField(+"this"),
-                ),
                 correspondingPropertySymbolField.toPersistentField(+"null"),
             ),
             id,
@@ -85,13 +76,24 @@ internal fun PersistentIrGenerator.generateFunction() {
             dispatchReceiverParameterField,
             extensionReceiverParameterField,
             bodyField,
-            metadataField,
             visibilityField,
             typeParametersField,
             valueParametersField,
             correspondingPropertySymbolField,
             overriddenSymbolsField,
-            attributeOwnerIdField,
         )()
     })
+
+    addCarrierProtoMessage(
+        "Function",
+        returnTypeFieldField,
+        dispatchReceiverParameterField,
+        extensionReceiverParameterField,
+        bodyField,
+        visibilityField,
+        typeParametersField,
+        valueParametersField,
+        correspondingPropertySymbolField,
+        overriddenSymbolsField,
+    )
 }

compiler/ir/ir.tree.persistent/generator/src/org/jetbrains/kotlin/ir/persistentIrGenerator/LocalDelegatedProperty.kt

@@ -6,11 +6,25 @@
 package org.jetbrains.kotlin.ir.persistentIrGenerator
 
 internal fun PersistentIrGenerator.generateLocalDelegatedProperty() {
-    val typeField = Field("type", IrType)
+    val typeField = Field("type", IrType, typeProto)
-    val delegateField = Field("delegate", irDeclaration("IrVariable"), lateinit = true)
+    val delegateField = Field("delegate", IrVariable, variableProto, lateinit = true)
-    val getterField = Field("getter", irDeclaration("IrSimpleFunction"), lateinit = true)
+    val getterField = Field(
-    val setterField = Field("setter", irDeclaration("IrSimpleFunction") + "?")
+        "getter",
-    val metadataField = Field("metadata", MetadataSource + "?")
+        IrSimpleFunction,
+        simpleFunctionProto,
+        lateinit = true,
+        propSymbolType = IrSimpleFunctionSymbol,
+        symbolToDeclaration = +".owner",
+        declarationToSymbol = +".symbol"
+    )
+    val setterField = Field(
+        "setter",
+        IrSimpleFunction + "?",
+        simpleFunctionProto,
+        propSymbolType = IrSimpleFunctionSymbol + "?",
+        symbolToDeclaration = +"?.owner",
+        declarationToSymbol = +"?.symbol"
+    )
 
     writeFile("PersistentIrLocalDelegatedProperty.kt", renderFile("org.jetbrains.kotlin.ir.declarations.persistent") {
         lines(
@@ -35,7 +49,7 @@ internal fun PersistentIrGenerator.generateLocalDelegatedProperty() {
                 delegateField.toPersistentField(+"null"),
                 getterField.toPersistentField(+"null"),
                 setterField.toPersistentField(+"null"),
-                metadataField.toPersistentField(+"null"),
+                +"override var metadata: " + MetadataSource + "? = null",
             ),
             id,
         )()
@@ -48,7 +62,14 @@ internal fun PersistentIrGenerator.generateLocalDelegatedProperty() {
             delegateField,
             getterField,
             setterField,
-            metadataField,
         )()
     })
+
+    addCarrierProtoMessage(
+        "LocalDelegatedProperty",
+        typeField,
+        delegateField,
+        getterField,
+        setterField,
+    )
 }

compiler/ir/ir.tree.persistent/generator/src/org/jetbrains/kotlin/ir/persistentIrGenerator/Main.kt

@@ -19,5 +19,9 @@ fun main() {
         generateTypeAlias()
         generateTypeParameter()
         generateValueParameter()
+
+        updateKotlinIrProto()
+        generateCarrierDeserializer()
+        generateCarrierSerializer()
     }
 }

compiler/ir/ir.tree.persistent/generator/src/org/jetbrains/kotlin/ir/persistentIrGenerator/PersistentIrGenerator.kt

@@ -6,8 +6,8 @@
 package org.jetbrains.kotlin.ir.persistentIrGenerator
 
 import java.io.File
+import java.lang.IllegalStateException
 import java.lang.StringBuilder
-import java.time.Year
 
 internal interface R {
     fun text(t: String): R
@@ -19,12 +19,42 @@ internal interface R {
 
 internal typealias E = R.() -> R
 
-internal class Field(val name: String, val type: E, val lateinit: Boolean = false, val notEq: String = "!==")
+internal val id: E get() = { this }
+
+internal enum class FieldKind {
+    REQUIRED, OPTIONAL, REPEATED
+}
+
+internal class Proto(
+    val protoPrefix: String?, // null if flag, proto type if not
+    val entityName: String,   // what to deserialize
+    val protoType: E,         // what type ProtoBuf generates
+    val irType: E,            // what Ir class this maps to
+    val fieldKind: FieldKind = FieldKind.OPTIONAL,
+)
+
+internal class Field(
+    val name: String,
+    val propType: E,
+    val proto: Proto? = null,
+    val lateinit: Boolean = false,
+    val notEq: String = "!==",
+    val propSymbolType: E? = null,
+    val symbolToDeclaration: E = id,
+    val declarationToSymbol: E = id,
+    val storeInCarrierImpl: Boolean = false,
+)
 
 internal object PersistentIrGenerator {
 
+    private val protoPackage = "org.jetbrains.kotlin.backend.common.serialization.proto"
+    val carrierPackage = "org.jetbrains.kotlin.ir.declarations.persistent.carriers"
+
     // Imports
 
+    val codedInputStream: E = import("codedInputStream", "org.jetbrains.kotlin.backend.common.serialization")
+    val ExtensionRegistryLite: E = import("ExtensionRegistryLite", "org.jetbrains.kotlin.protobuf")
+
     val ClassDescriptor: E = descriptorType("ClassDescriptor")
     val DeclarationDescriptor: E = descriptorType("DeclarationDescriptor")
     val ClassConstructorDescriptor: E = descriptorType("ClassConstructorDescriptor")
@@ -35,10 +65,14 @@ internal object PersistentIrGenerator {
     val IrDeclarationParent = irDeclaration("IrDeclarationParent")
     val IrAnonymousInitializer = irDeclaration("IrAnonymousInitializer")
     val IrClass = irDeclaration("IrClass")
+    val IrFunction = irDeclaration("IrFunction")
+    val IrSimpleFunction = irDeclaration("IrSimpleFunction")
+    val IrField = irDeclaration("IrField")
     val IrTypeParameter = irDeclaration("IrTypeParameter")
     val IrValueParameter = irDeclaration("IrValueParameter")
     val MetadataSource = irDeclaration("MetadataSource")
     val IrAttributeContainer = irDeclaration("IrAttributeContainer")
+    val IrVariable = irDeclaration("IrVariable")
 
     val IrConstructorCall = irExpression("IrConstructorCall")
     val IrBody = irExpression("IrBody")
@@ -55,7 +89,13 @@ internal object PersistentIrGenerator {
 
     val IrType = import("IrType", "org.jetbrains.kotlin.ir.types")
 
+    val IrSymbol = irSymbol("IrSymbol")
     val IrPropertySymbol = irSymbol("IrPropertySymbol")
+    val IrSimpleFunctionSymbol = irSymbol("IrSimpleFunctionSymbol")
+    val IrFunctionSymbol = irSymbol("IrFunctionSymbol")
+    val IrFieldSymbol = irSymbol("IrFieldSymbol")
+    val IrValueParameterSymbol = irSymbol("IrValueParameterSymbol")
+    val IrTypeParameterSymbol = irSymbol("IrTypeParameterSymbol")
 
     // Constructor parameters
 
@@ -78,7 +118,10 @@ internal object PersistentIrGenerator {
     val source = +"override val source: " + descriptorType("SourceElement") + " = SourceElement.NO_SOURCE"
     val returnType = +"returnType: " + IrType
     val isPrimary = +"override val isPrimary: Boolean"
-    val containerSource = +"override val containerSource: " + import("DeserializedContainerSource", "org.jetbrains.kotlin.serialization.deserialization.descriptors") + "?"
+    val containerSource = +"override val containerSource: " + import(
+        "DeserializedContainerSource",
+        "org.jetbrains.kotlin.serialization.deserialization.descriptors"
+    ) + "?"
 
     val irFactory = +"override val factory: PersistentIrFactory"
 
@@ -86,6 +129,63 @@ internal object PersistentIrGenerator {
         +"symbol.bind(this)"
     )
 
+    // Proto types
+
+    val protoValueParameterType = import("IrValueParameter", protoPackage, "ProtoIrValueParameter")
+    val protoTypeParameterType = import("IrTypeParameter", protoPackage, "ProtoIrTypeParameter")
+    val protoVariable = import("IrVariable", protoPackage, "ProtoIrVariable")
+    val protoIrConstructorCall = import("IrConstructorCall", protoPackage, "ProtoIrConstructorCall")
+
+    val bodyProto = Proto("int32", "body", +"Int", IrBody)
+    val blockBodyProto = Proto("int32", "blockBody", +"Int", IrBlockBody)
+    val expressionBodyProto = Proto("int32", "expressionBody", +"Int", IrExpressionBody)
+    val valueParameterProto = Proto("int64", "valueParameter", +"Long", IrValueParameterSymbol)
+    val valueParameterListProto = Proto("int64", "valueParameter", +"Long", IrValueParameterSymbol, fieldKind = FieldKind.REPEATED)
+    val typeParameterListProto = Proto("int64", "typeParameter", +"Long", IrTypeParameterSymbol, fieldKind = FieldKind.REPEATED)
+    val superTypeListProto = Proto("int32", "superType", +"Int", IrType, fieldKind = FieldKind.REPEATED)
+    val typeProto = Proto("int32", "type", +"Int", IrType, fieldKind = FieldKind.REQUIRED)
+    val optionalTypeProto = Proto("int32", "type", +"Int", IrType, fieldKind = FieldKind.OPTIONAL)
+    val variableProto = Proto("IrVariable", "variable", protoVariable, IrVariable)
+
+    val classProto = Proto("int64", "class", +"Long", IrClassSymbol)
+    val propertySymbolProto = Proto("int64", "propertySymbol", +"Long", IrPropertySymbol)
+    val simpleFunctionProto = Proto("int64", "simpleFunction", +"Long", IrSimpleFunctionSymbol)
+    val simpleFunctionSymbolListProto =
+        Proto("int64", "simpleFunctionSymbol", +"Long", IrSimpleFunctionSymbol, fieldKind = FieldKind.REPEATED)
+    val fieldProto = Proto("int64", "field", +"Long", IrFieldSymbol)
+
+    val visibilityProto = Proto(null, "visibility", +"Long", DescriptorVisibility)
+    val modalityProto = Proto(null, "modality", +"Long", descriptorType("Modality"))
+
+    val isExternalClassProto = Proto(null, "isExternalClass", +"Long", +"Boolean")
+    val isExternalFieldProto = Proto(null, "isExternalField", +"Long", +"Boolean")
+    val isExternalFunctionProto = Proto(null, "isExternalFunction", +"Long", +"Boolean")
+    val isExternalPropertyProto = Proto(null, "isExternalProperty", +"Long", +"Boolean")
+
+    private val allProto = listOf(
+        bodyProto,
+        blockBodyProto,
+        expressionBodyProto,
+        valueParameterProto,
+        valueParameterListProto,
+        typeParameterListProto,
+        superTypeListProto,
+        typeProto,
+        optionalTypeProto,
+        classProto,
+        propertySymbolProto,
+        simpleFunctionProto,
+        simpleFunctionSymbolListProto,
+        fieldProto,
+        variableProto,
+        visibilityProto,
+        modalityProto,
+        isExternalClassProto,
+        isExternalFieldProto,
+        isExternalFunctionProto,
+        isExternalPropertyProto,
+    )
+
     // Fields
     val lastModified = +"override var lastModified: Int = factory.stageController.currentStage"
     val loweredUpTo = +"override var loweredUpTo: Int = factory.stageController.currentStage"
@@ -109,10 +209,214 @@ internal object PersistentIrGenerator {
         annotationsField,
     )
 
-    fun Field.toPersistentField(initializer: E, modifier: String = "override") =
+    val typeParametersField = Field(
-        persistentField(name, type, initializer, lateinit, modifier, notEq = notEq)
+        "typeParameters",
+        +"List<" + IrTypeParameter + ">",
+        typeParameterListProto,
+        propSymbolType = +"List<" + IrTypeParameterSymbol + ">",
+        symbolToDeclaration = +".map { it.owner }",
+        declarationToSymbol = +".map { it.symbol }",
+        storeInCarrierImpl = true,
+    )
 
-    fun Field.toBody() = body(type, lateinit, name)
+    val valueParametersField = Field(
+        "valueParameters",
+        +"List<" + IrValueParameter + ">",
+        valueParameterListProto,
+        propSymbolType = +"List<" + IrValueParameterSymbol + ">",
+        symbolToDeclaration = +".map { it.owner }",
+        declarationToSymbol = +".map { it.symbol }",
+        storeInCarrierImpl = true,
+    )
+
+    val dispatchReceiverParameterField = Field(
+        "dispatchReceiverParameter",
+        IrValueParameter + "?",
+        valueParameterProto,
+        propSymbolType = IrValueParameterSymbol + "?",
+        symbolToDeclaration = +"?.owner",
+        declarationToSymbol = +"?.symbol"
+    )
+
+    val extensionReceiverParameterField = Field(
+        "extensionReceiverParameter",
+        IrValueParameter + "?",
+        valueParameterProto,
+        propSymbolType = IrValueParameterSymbol + "?",
+        symbolToDeclaration = +"?.owner",
+        declarationToSymbol = +"?.symbol"
+    )
+
+    fun Field.toPersistentField(initializer: E, modifier: String = "override") =
+        persistentField(
+            name,
+            propType,
+            initializer,
+            lateinit,
+            modifier,
+            notEq = notEq,
+            symbolType = propSymbolType,
+            declarationToSymbol = declarationToSymbol,
+            symbolToDeclaration = symbolToDeclaration,
+        )
+
+    fun Field.toBody() = body(propType, lateinit, name)
+
+    val protoMessages = mutableListOf<String>()
+
+    fun addCarrierProtoMessage(carrierName: String, vararg fields: Field) {
+        val protoFields = mutableListOf(
+            "required int32 lastModified",
+            "optional int64 parentSymbol",
+            "optional int32 origin",
+            "repeated IrConstructorCall annotation"
+        )
+
+        protoFields += fields.mapNotNull { f ->
+            f.proto?.protoPrefix?.let { p ->
+                val modifier = f.proto.fieldKind.toString().toLowerCase()
+                "$modifier $p ${f.name}"
+            }
+        }
+
+        val sb = StringBuilder("message Pir${carrierName}Carrier {\n")
+        protoFields.forEachIndexed { i, f ->
+            sb.append("    $f = ${i + 1}")
+            sb.append(";\n")
+        }
+
+        if (fields.any { it.proto != null && it.proto.protoPrefix == null }) {
+            sb.append("    optional int64 flags = ${protoFields.size + 1} [default = 0];\n")
+        }
+
+        sb.append("}\n")
+
+        protoMessages += sb.toString()
+
+        addDeserializerMessage(carrierName, *fields)
+        addSerializerMessage(carrierName, *fields)
+    }
+
+    val deserializerMethods = mutableListOf<E>().also { list ->
+
+        list += +"abstract fun deserializeParentSymbol(proto: Long): " + IrSymbol
+        list += +"abstract fun deserializeOrigin(proto: Int): " + IrDeclarationOrigin
+        list += +"abstract fun deserializeAnnotation(proto: " + protoIrConstructorCall + "): " + IrConstructorCall
+
+        val seenEntities = mutableSetOf<String>()
+
+        allProto.forEach { p ->
+            if (p.entityName !in seenEntities) {
+                seenEntities += p.entityName
+                list += +"abstract fun deserialize${p.entityName.capitalize()}(proto: " + p.protoType + "): " + p.irType
+            }
+        }
+    }
+
+    fun addDeserializerMessage(carrierName: String, vararg fields: Field) {
+        val argumentType = import("Pir${carrierName}Carrier", protoPackage)
+        val returnType = import("${carrierName}Carrier", carrierPackage)
+        val carrierImpl = import("${carrierName}CarrierImpl", carrierPackage)
+
+        deserializerMethods += lines(
+            +"fun deserialize${carrierName}Carrier(bytes: ByteArray): " + returnType + " {",
+            lines(
+                +"val proto = " + argumentType + ".parseFrom(bytes." + codedInputStream + ", " + ExtensionRegistryLite + ".newInstance())",
+                +"return " + carrierImpl + "(",
+                arrayOf(
+                    +"proto.lastModified",
+                    +"if (proto.hasParentSymbol()) deserializeParentSymbol(proto.parentSymbol) else null",
+                    +"deserializeOrigin(proto.origin)",
+                    +"proto.annotationList.map { deserializeAnnotation(it) }",
+                    *fields.map { f ->
+                        if (f.proto == null) {
+                            +"null"
+                        } else {
+                            val deserialize = "deserialize${f.proto.entityName.capitalize()}"
+
+                            when {
+                                f.proto.fieldKind == FieldKind.REPEATED ->
+                                    +"proto.${f.name}List.map { $deserialize(it) }"
+                                f.proto.protoPrefix != null && f.proto.fieldKind == FieldKind.OPTIONAL ->
+                                    +"if (proto.has${f.name.capitalize()}()) $deserialize(proto.${f.name}) else null"
+                                f.proto.protoPrefix == null ->
+                                    +"$deserialize(proto.flags)"
+                                else ->
+                                    +"$deserialize(proto.${f.name})"
+                            }
+                        }
+                    }.toTypedArray()
+                ).join(separator = ",\n").indent(),
+                +")",
+            ).indent(),
+            +"}",
+        )
+    }
+
+    val serializerMethods = mutableListOf<E>().also { list ->
+
+        list += +"abstract fun serializeParentSymbol(value: " + IrSymbol + "): Long"
+        list += +"abstract fun serializeOrigin(value: " + IrDeclarationOrigin + "): Int"
+        list += +"abstract fun serializeAnnotation(value: " + IrConstructorCall + "): " + protoIrConstructorCall
+
+        val seenEntities = mutableSetOf<String>()
+
+        allProto.forEach { p ->
+            if (p.entityName !in seenEntities) {
+                seenEntities += p.entityName
+                list += +"abstract fun serialize${p.entityName.capitalize()}(value: " + p.irType + "): " + p.protoType
+            }
+        }
+    }
+
+
+    fun addSerializerMessage(carrierName: String, vararg fields: Field) {
+        val argumentType = import("${carrierName}Carrier", carrierPackage)
+        val returnType = import("Pir${carrierName}Carrier", protoPackage)
+
+        var flagsHandled = false
+
+        serializerMethods += lines(
+            +"fun serialize${carrierName}Carrier(carrier: " + argumentType + "): ByteArray {",
+            lines(
+                +"val proto = " + returnType + ".newBuilder()",
+                +"proto.setLastModified(carrier.lastModified)",
+                +"carrier.parentSymbolField?.let { proto.setParentSymbol(serializeParentSymbol(it)) }",
+                +"proto.setOrigin(serializeOrigin(carrier.originField))",
+                +"proto.addAllAnnotation(carrier.annotationsField.map { serializeAnnotation(it) })",
+                *(fields.mapNotNull { f ->
+                    f.proto?.let { p ->
+                        if (p.protoPrefix != null) {
+                            val action = "proto." + (if (p.fieldKind == FieldKind.REPEATED) "addAll" else "set") + f.name.capitalize()
+                            val serializationFun = "serialize${f.proto.entityName.capitalize()}"
+                            val argument = "carrier.${f.name}${if (f.propSymbolType != null) "Symbol" else ""}Field"
+
+                            when {
+                                p.fieldKind == FieldKind.OPTIONAL ->
+                                    +"$argument?.let { $action($serializationFun(it)) }"
+                                p.fieldKind == FieldKind.REPEATED ->
+                                    +"$action($argument.map { $serializationFun(it) })"
+                                else ->
+                                    +"$action($serializationFun($argument))"
+                            }
+                        } else {
+                            // It's a flag
+                            if (!flagsHandled) {
+                                flagsHandled = true
+                                val flags = fields.filter { it.proto?.protoPrefix == null }
+
+                                val calls = flags.map { f -> "serialize${f.proto!!.entityName.capitalize()}(carrier.${f.name}Field)" }
+
+                                +"proto.setFlags(${calls.joinToString(separator = " or ")})"
+                            } else null
+                        }
+                    }
+                }).toTypedArray(),
+                +"return proto.build().toByteArray()",
+            ).indent(),
+            +"}",
+        )
+    }
 
     // Helpers
 
@@ -130,11 +434,24 @@ internal object PersistentIrGenerator {
         modifier: String = "override",
         isBody: Boolean = false,
         notEq: String = "!==",
-    ): E = lines(
+        symbolType: E? = null,
-        +"override var ${name}Field: " + type + "${if (lateinit) "?" else ""} = " + initializer,
+        declarationToSymbol: E = id,
-        id,
+        symbolToDeclaration: E = id,
-        +"$modifier var $name: " + type,
+    ): E {
-        lines(
+        val result = mutableListOf(+"override var ${name}Field: " + type + "${if (lateinit) "?" else ""} = " + initializer, id)
+        if (symbolType != null) {
+            result += +"override var ${name}SymbolField: " + symbolType + if (lateinit) "?" else ""
+            result += lines(
+                +"get() = ${name}Field" + (if (lateinit) "?" else "") + declarationToSymbol,
+                +"set(v) " + block(
+                    +"${name}Field = v" + (if (lateinit) "?" else "") + symbolToDeclaration
+                )
+            ).indent()
+            result += id
+        }
+
+        result += +"$modifier var $name: " + type
+        result += lines(
             +"get() = getCarrier().${name}Field${if (lateinit) "!!" else ""}",
             +"set(v) " + block(
                 +"if (${if (lateinit) "getCarrier().${name}Field" else name} $notEq v) " + block(
@@ -148,7 +465,9 @@ internal object PersistentIrGenerator {
                 )
             )
         ).indent()
-    )
+
+        return lines(*result.toTypedArray())
+    }
 
     fun body(bodyType: E, lateinit: Boolean = false, fieldName: String = "body"): E =
         persistentField(fieldName, bodyType, initializer = +"null", lateinit, isBody = true)
@@ -162,16 +481,24 @@ internal object PersistentIrGenerator {
     fun carriers(name: String, vararg fields: Field): E = lines(
         id,
         +"internal interface ${name}Carrier : DeclarationCarrier" + block(
-            *(fields.map { +"val ${it.name}Field: " + it.type + if (it.lateinit) "?" else "" }.toTypedArray()),
+            *(fields.flatMap {
+                var result = listOf(+"val ${it.name}Field: " + it.propType + if (it.lateinit) "?" else "")
+
+                if (it.propSymbolType != null) {
+                    result += +"val ${it.name}SymbolField: " + it.propSymbolType + if (it.lateinit) "?" else ""
+                }
+
+                result
+            }.toTypedArray()),
             id,
             +"override fun clone(): ${name}Carrier " + block(
                 +"return ${name}CarrierImpl(",
                 arrayOf(
                     +"lastModified",
-                    +"parentField",
+                    +"parentSymbolField",
                     +"originField",
                     +"annotationsField",
-                    *(fields.map { +"${it.name}Field" }.toTypedArray())
+                    *(fields.map { +"${it.name}${if (it.propSymbolType != null) "Symbol" else ""}Field" }.toTypedArray())
                 ).join(separator = ",\n").indent(),
                 +")",
             )
@@ -180,12 +507,33 @@ internal object PersistentIrGenerator {
         +"internal class ${name}CarrierImpl(",
         arrayOf(
             +"override val lastModified: Int",
-            +"override val parentField: " + IrDeclarationParent + "?",
+            +"override val parentSymbolField: " + IrSymbol + "?",
             +"override val originField: " + IrDeclarationOrigin,
             +"override val annotationsField: List<" + IrConstructorCall + ">",
-            *(fields.map { +"override val ${it.name}Field: " + it.type + if (it.lateinit) "?" else "" }.toTypedArray()),
+            *(fields.map {
+                if (it.propSymbolType != null) {
+                    +"override val ${it.name}SymbolField: " + it.propSymbolType + if (it.lateinit) "?" else ""
+                } else {
+                    +"override val ${it.name}Field: " + it.propType + if (it.lateinit) "?" else ""
+                }
+            }.toTypedArray()),
         ).join(separator = ",\n").indent(),
-        +") : ${name}Carrier",
+        +") : ${name}Carrier" + if (fields.all { it.propSymbolType == null }) id else + " " + blockSpaced(
+            *(fields.mapNotNull {
+                it.propSymbolType?.let { _ ->
+                    if (it.storeInCarrierImpl) {
+                        +"override val ${it.name}Field: " + it.propType + " by lazy { ${it.name}SymbolField" + it.symbolToDeclaration + " }"
+                    } else {
+                        lines(
+                            +"override val ${it.name}Field: " + it.propType + if (it.lateinit) "?" else "",
+                            lines(
+                                +"get() = ${it.name}SymbolField" + (if (it.lateinit) "?" else "") + it.symbolToDeclaration,
+                            ).indent()
+                        )
+                    }
+                }
+            }).toTypedArray()
+        ),
         id,
     )
 
@@ -197,7 +545,8 @@ internal object PersistentIrGenerator {
         return block(*(fn.flatMap { listOf(id, it) }.toTypedArray()))
     }
 
-    fun import(name: String, pkg: String): E = { import("$pkg.$name").text(name) }
+    fun import(name: String, pkg: String, alias: String = name): E =
+        { import("$pkg.$name${if (alias != name) " as $alias" else ""}").text(alias) }
 
     fun descriptorType(name: String): E = import(name, "org.jetbrains.kotlin.descriptors")
 
@@ -215,8 +564,6 @@ internal object PersistentIrGenerator {
 
     operator fun String.unaryPlus(): E = { text(this@unaryPlus) }
 
-    val id: E get() = { this }
-
     fun E?.safe(): E = this ?: id
 
     fun Array<out E>.join(prefix: String = "", separator: String = "", suffix: String = ""): E =
@@ -313,4 +660,52 @@ internal object PersistentIrGenerator {
     fun writeFile(path: String, content: String) {
         File(prefix + path).writeText(content)
     }
+
+    fun updateKotlinIrProto() {
+        val file = File("compiler/ir/serialization.common/src/KotlinIr.proto")
+
+        if (!file.exists()) throw IllegalStateException("KotlinIr.proto file not found!")
+
+        val lines = file.readText().lines()
+
+        val start = lines.indexOf("// PIR GENERATOR START")
+        if (start < 0) throw IllegalStateException("Couldn't find the '// PIR GENERATOR START' line. Don't know where to write generated messages.")
+
+        val end = lines.indexOf("// PIR GENERATOR END")
+        if (end < 0) throw IllegalStateException("Couldn't find the '// PIR GENERATOR END' line. Don't know where to write generated messages.")
+
+        val sb = StringBuilder(lines.subList(0, start + 1).joinToString(separator = "\n"))
+
+        for (m in protoMessages) {
+            sb.append("\n").append(m)
+        }
+
+        sb.append("\n").append(lines.subList(end, lines.size).joinToString(separator = "\n"))
+
+        file.writeText(sb.toString())
+    }
+
+    fun generateCarrierDeserializer() {
+        writeFile("../../serialization/IrCarrierDeserializer.kt", renderFile("org.jetbrains.kotlin.ir.serialization") {
+            lines(
+                id,
+                +"internal abstract class IrCarrierDeserializer " + blockSpaced(
+                    *deserializerMethods.toTypedArray()
+                ),
+                id,
+            )()
+        })
+    }
+
+    fun generateCarrierSerializer() {
+        writeFile("../../serialization/IrCarrierSerializer.kt", renderFile("org.jetbrains.kotlin.ir.serialization") {
+            lines(
+                id,
+                +"internal abstract class IrCarrierSerializer " + blockSpaced(
+                    *serializerMethods.toTypedArray()
+                ),
+                id,
+            )()
+        })
+    }
 }

compiler/ir/ir.tree.persistent/generator/src/org/jetbrains/kotlin/ir/persistentIrGenerator/Property.kt

@@ -6,11 +6,30 @@
 package org.jetbrains.kotlin.ir.persistentIrGenerator
 
 internal fun PersistentIrGenerator.generateProperty() {
-    val backingFieldField = Field("backingField", irDeclaration("IrField") + "?")
+    val backingFieldField = Field(
-    val getterField = Field("getter", irDeclaration("IrSimpleFunction") + "?")
+        "backingField",
-    val setterField = Field("setter", irDeclaration("IrSimpleFunction") + "?")
+        IrField + "?",
-    val metadataField = Field("metadata", MetadataSource + "?")
+        fieldProto,
-    val attributeOwnerIdField = Field("attributeOwnerId", IrAttributeContainer)
+        propSymbolType = IrFieldSymbol + "?",
+        symbolToDeclaration = +"?.owner",
+        declarationToSymbol = +"?.symbol"
+    )
+    val getterField = Field(
+        "getter",
+        IrSimpleFunction + "?",
+        simpleFunctionProto,
+        propSymbolType = IrSimpleFunctionSymbol + "?",
+        symbolToDeclaration = +"?.owner",
+        declarationToSymbol = +"?.symbol"
+    )
+    val setterField = Field(
+        "setter",
+        IrSimpleFunction + "?",
+        simpleFunctionProto,
+        propSymbolType = IrSimpleFunctionSymbol + "?",
+        symbolToDeclaration = +"?.owner",
+        declarationToSymbol = +"?.symbol"
+    )
 
     writeFile("PersistentIrPropertyCommon.kt", renderFile("org.jetbrains.kotlin.ir.declarations.persistent") {
         lines(
@@ -36,10 +55,10 @@ internal fun PersistentIrGenerator.generateProperty() {
                 backingFieldField.toPersistentField(+"null"),
                 getterField.toPersistentField(+"null"),
                 setterField.toPersistentField(+"null"),
-                metadataField.toPersistentField(+"null"),
+                +"override var metadata: " + MetadataSource + "? = null",
                 lines(
                     +"@Suppress(\"LeakingThis\")",
-                    attributeOwnerIdField.toPersistentField(+"this"),
+                    +"override var attributeOwnerId: " + IrAttributeContainer + " = this",
                 ),
             ),
             id,
@@ -52,8 +71,13 @@ internal fun PersistentIrGenerator.generateProperty() {
             backingFieldField,
             getterField,
             setterField,
-            metadataField,
-            attributeOwnerIdField,
         )()
     })
+
+    addCarrierProtoMessage(
+        "Property",
+        backingFieldField,
+        getterField,
+        setterField,
+    )
 }

compiler/ir/ir.tree.persistent/generator/src/org/jetbrains/kotlin/ir/persistentIrGenerator/TypeAlias.kt

@@ -6,8 +6,7 @@
 package org.jetbrains.kotlin.ir.persistentIrGenerator
 
 internal fun PersistentIrGenerator.generateTypeAlias() {
-    val typeParametersField = Field("typeParameters", +"List<" + IrTypeParameter + ">")
+    val expandedTypeField = Field("expandedType", IrType, typeProto)
-    val expandedTypeField = Field("expandedType", IrType)
 
     writeFile("PersistentIrTypeAlias.kt", renderFile("org.jetbrains.kotlin.ir.declarations.persistent") {
         lines(
@@ -43,4 +42,6 @@ internal fun PersistentIrGenerator.generateTypeAlias() {
             expandedTypeField,
         )()
     })
+
+    addCarrierProtoMessage("TypeAlias", typeParametersField, expandedTypeField)
 }

compiler/ir/ir.tree.persistent/generator/src/org/jetbrains/kotlin/ir/persistentIrGenerator/TypeParameter.kt

@@ -6,7 +6,7 @@
 package org.jetbrains.kotlin.ir.persistentIrGenerator
 
 internal fun PersistentIrGenerator.generateTypeParameter() {
-    val superTypesField = Field("superTypes", +"List<" + IrType + ">")
+    val superTypesField = Field("superTypes", +"List<" + IrType + ">", superTypeListProto)
 
     writeFile("PersistentIrTypeParameter.kt", renderFile("org.jetbrains.kotlin.ir.declarations.persistent") {
         lines(
@@ -39,4 +39,6 @@ internal fun PersistentIrGenerator.generateTypeParameter() {
             superTypesField,
         )()
     })
+
+    addCarrierProtoMessage("TypeParameter", superTypesField)
 }

compiler/ir/ir.tree.persistent/generator/src/org/jetbrains/kotlin/ir/persistentIrGenerator/ValueParameter.kt

@@ -7,9 +7,9 @@ package org.jetbrains.kotlin.ir.persistentIrGenerator
 
 internal fun PersistentIrGenerator.generateValueParameter() {
 
-    val defaultValueField = Field("defaultValue", IrExpressionBody + "?")
+    val defaultValueField = Field("defaultValue", IrExpressionBody + "?", expressionBodyProto)
-    val typeField = Field("type", IrType)
+    val typeField = Field("type", IrType, typeProto)
-    val varargElementTypeField = Field("varargElementType", IrType + "?")
+    val varargElementTypeField = Field("varargElementType", IrType + "?", optionalTypeProto)
 
     writeFile("PersistentIrValueParameter.kt", renderFile("org.jetbrains.kotlin.ir.declarations.persistent") {
         lines(
@@ -49,4 +49,6 @@ internal fun PersistentIrGenerator.generateValueParameter() {
             varargElementTypeField,
         )()
     })
+
+    addCarrierProtoMessage("ValueParameter", defaultValueField, typeField, varargElementTypeField)
 }