[IR] Get rid of IrTypeBase

Every IrType subclass also inherited from IrTypeBase, which complicated
the class hierarchy and prevented us from making IrType a sealed class.

Author: broadwaylamb

compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/utils/VariousUtils.kt

@@ -161,7 +161,7 @@ fun IrType.toArrayOrPrimitiveArrayType(builtins: Fir2IrBuiltinSymbolsContainer):
 
 val IrClassSymbol.defaultTypeWithoutArguments: IrSimpleType
     get() = IrSimpleTypeImpl(
-        kotlinType = null,
+        originalKotlinType = null,
         classifier = this,
         nullability = SimpleTypeNullability.DEFINITELY_NOT_NULL,
         arguments = emptyList(),

compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/CheckIrElementVisitor.kt

@@ -1,5 +1,5 @@
 /*
- * Copyright 2010-2020 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Copyright 2010-2024 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.
  */
 
@@ -325,11 +325,9 @@ internal class CheckIrElementVisitor(
     }
 
     private fun checkType(type: IrType, element: IrElement) {
-        when (type) {
-            is IrSimpleType -> {
-                if (!type.classifier.isBound) {
-                    reportError(element, "Type: ${type.render()} has unbound classifier")
-                }
+        if (type is IrSimpleType) {
+            if (!type.classifier.isBound) {
+                reportError(element, "Type: ${type.render()} has unbound classifier")
             }
         }
     }

compiler/ir/backend.wasm/src/org/jetbrains/kotlin/backend/wasm/lower/JsInteropFunctionsLowering.kt

@@ -1,5 +1,5 @@
 /*
- * Copyright 2010-2021 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Copyright 2010-2024 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.
  */
 
@@ -283,7 +283,7 @@ class JsInteropFunctionsLowering(val context: WasmBackendContext) : DeclarationT
             builtIns.doubleType,
             context.wasmSymbols.voidType ->
                 return null
-
+            else -> {}
         }
 
         if (isExternalType(this))
@@ -424,6 +424,7 @@ class JsInteropFunctionsLowering(val context: WasmBackendContext) : DeclarationT
             builtIns.doubleType,
             symbols.voidType ->
                 return null
+            else -> {}
         }
 
         if (isExternalType(this))

compiler/ir/ir.actualization/src/main/kotlin/org/jetbrains/kotlin/backend/common/actualizer/IrExpectActualMatchingContext.kt

@@ -1,5 +1,5 @@
 /*
- * Copyright 2010-2023 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Copyright 2010-2024 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.
  */
 
@@ -16,8 +16,6 @@ import org.jetbrains.kotlin.ir.expressions.IrConstructorCall
 import org.jetbrains.kotlin.ir.symbols.*
 import org.jetbrains.kotlin.ir.types.*
 import org.jetbrains.kotlin.ir.types.impl.IrSimpleTypeImpl
-import org.jetbrains.kotlin.ir.types.impl.IrTypeBase
-import org.jetbrains.kotlin.ir.types.impl.IrTypeProjectionImpl
 import org.jetbrains.kotlin.ir.types.impl.makeTypeProjection
 import org.jetbrains.kotlin.ir.util.*
 import org.jetbrains.kotlin.mpp.*
@@ -450,13 +448,10 @@ internal abstract class IrExpectActualMatchingContext(
         private fun substituteArgumentOrNull(argument: IrTypeArgument): IrTypeArgument? {
             return when (argument) {
                 is IrStarProjection -> null
-                is IrTypeProjection -> when (argument) {
-                    is IrTypeProjectionImpl -> {
-                        val newType = substituteOrNull(argument.type) ?: return null
-                        makeTypeProjection(newType, argument.variance)
-                    }
-                    is IrTypeBase -> substituteOrNull(argument) as IrTypeBase?
-                    else -> shouldNotBeCalled()
+                is IrType -> substituteOrNull(argument)
+                is IrTypeProjection -> {
+                    val newType = substituteOrNull(argument.type) ?: return null
+                    makeTypeProjection(newType, argument.variance)
                 }
             }
         }

compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/descriptors/IrBuiltInsOverDescriptors.kt

@@ -19,11 +19,7 @@ import org.jetbrains.kotlin.ir.BuiltInOperatorNames
 import org.jetbrains.kotlin.ir.IrBuiltIns
 import org.jetbrains.kotlin.ir.ObsoleteDescriptorBasedAPI
 import org.jetbrains.kotlin.ir.UNDEFINED_OFFSET
-import org.jetbrains.kotlin.ir.declarations.IrClass
-import org.jetbrains.kotlin.ir.declarations.IrConstructor
-import org.jetbrains.kotlin.ir.declarations.IrExternalPackageFragment
-import org.jetbrains.kotlin.ir.declarations.IrFactory
-import org.jetbrains.kotlin.ir.declarations.createEmptyExternalPackageFragment
+import org.jetbrains.kotlin.ir.declarations.*
 import org.jetbrains.kotlin.ir.descriptors.*
 import org.jetbrains.kotlin.ir.expressions.impl.IrConstructorCallImpl
 import org.jetbrains.kotlin.ir.symbols.IrClassSymbol
@@ -34,7 +30,6 @@ import org.jetbrains.kotlin.ir.symbols.impl.IrValueParameterSymbolImpl
 import org.jetbrains.kotlin.ir.types.*
 import org.jetbrains.kotlin.ir.types.impl.IrSimpleTypeBuilder
 import org.jetbrains.kotlin.ir.types.impl.buildSimpleType
-import org.jetbrains.kotlin.ir.types.impl.originalKotlinType
 import org.jetbrains.kotlin.ir.util.*
 import org.jetbrains.kotlin.name.FqName
 import org.jetbrains.kotlin.name.Name

compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/generators/OperatorExpressionGenerator.kt

@@ -1,17 +1,6 @@
 /*
- * Copyright 2010-2016 JetBrains s.r.o.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
+ * Copyright 2010-2024 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.psi2ir.generators
@@ -27,7 +16,6 @@ import org.jetbrains.kotlin.ir.symbols.IrSimpleFunctionSymbol
 import org.jetbrains.kotlin.ir.types.IrType
 import org.jetbrains.kotlin.ir.types.classifierOrFail
 import org.jetbrains.kotlin.ir.types.classifierOrNull
-import org.jetbrains.kotlin.ir.types.impl.originalKotlinType
 import org.jetbrains.kotlin.lexer.KtTokens
 import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.psi.*

compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/intermediate/ArrayAccessAssignmentReceiver.kt

@@ -12,7 +12,6 @@ import org.jetbrains.kotlin.ir.expressions.*
 import org.jetbrains.kotlin.ir.expressions.impl.IrBlockImpl
 import org.jetbrains.kotlin.ir.expressions.impl.IrGetValueImpl
 import org.jetbrains.kotlin.ir.expressions.impl.IrTypeOperatorCallImpl
-import org.jetbrains.kotlin.ir.types.impl.originalKotlinType
 import org.jetbrains.kotlin.ir.util.inlineStatement
 import org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid
 import org.jetbrains.kotlin.ir.visitors.IrElementVisitorVoid

compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/transformations/InsertImplicitCasts.kt

@@ -1,17 +1,6 @@
 /*
- * Copyright 2010-2016 JetBrains s.r.o.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
+ * Copyright 2010-2024 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.psi2ir.transformations
@@ -34,7 +23,6 @@ import org.jetbrains.kotlin.ir.expressions.impl.IrConstImpl
 import org.jetbrains.kotlin.ir.expressions.impl.IrTypeOperatorCallImpl
 import org.jetbrains.kotlin.ir.symbols.IrConstructorSymbol
 import org.jetbrains.kotlin.ir.types.IrType
-import org.jetbrains.kotlin.ir.types.impl.originalKotlinType
 import org.jetbrains.kotlin.ir.types.toKotlinType
 import org.jetbrains.kotlin.ir.util.SymbolTable
 import org.jetbrains.kotlin.ir.util.TypeTranslator

compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/descriptors/IrBasedDescriptors.kt

@@ -1,5 +1,5 @@
 /*
- * Copyright 2010-2019 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Copyright 2010-2024 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.
  */
 
@@ -1151,8 +1151,8 @@ fun IrType.toIrBasedKotlinType(builtins: KotlinBuiltIns? = null): KotlinType = w
                 it
             }
         }
-    is IrDynamicType -> kotlinType ?: builtins?.let(::createDynamicType) ?: error("Couldn't instantiate DynamicType")
-    is IrErrorType -> kotlinType ?: error("Can't find KotlinType in IrErrorType: " + (this as IrType).render())
+    is IrDynamicType -> originalKotlinType ?: builtins?.let(::createDynamicType) ?: error("Couldn't instantiate DynamicType")
+    is IrErrorType -> originalKotlinType ?: error("Can't find KotlinType in IrErrorType: " + (this as IrType).render())
     else ->
         throw AssertionError("Unexpected type: $this = ${this.render()}")
 }

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2010-2018 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Copyright 2010-2024 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.
  */
 
@@ -9,13 +9,17 @@ import org.jetbrains.kotlin.ir.declarations.IrAnnotationContainer
 import org.jetbrains.kotlin.ir.symbols.IrClassSymbol
 import org.jetbrains.kotlin.ir.symbols.IrClassifierSymbol
 import org.jetbrains.kotlin.ir.symbols.IrTypeAliasSymbol
-import org.jetbrains.kotlin.ir.types.impl.IrTypeBase
 import org.jetbrains.kotlin.mpp.TypeRefMarker
 import org.jetbrains.kotlin.types.KotlinType
 import org.jetbrains.kotlin.types.Variance
 import org.jetbrains.kotlin.types.model.*
 
-abstract class IrType : KotlinTypeMarker, TypeRefMarker, IrAnnotationContainer {
+sealed class IrType : IrTypeProjection, KotlinTypeMarker, TypeRefMarker, IrAnnotationContainer {
+    final override val type: IrType
+        get() = this
+
+    open val originalKotlinType: KotlinType?
+        get() = null
 
     /**
      * @return true if this type is equal to [other] symbolically. Note that this is NOT EQUIVALENT to the full type checking algorithm
@@ -31,15 +35,14 @@ abstract class IrType : KotlinTypeMarker, TypeRefMarker, IrAnnotationContainer {
 }
 
 abstract class IrErrorType(
-    kotlinType: KotlinType?,
     private val errorClassStubSymbol: IrClassSymbol,
     val isMarkedNullable: Boolean = false
-) : IrTypeBase(kotlinType), SimpleTypeMarker {
+) : IrType(), SimpleTypeMarker {
     val symbol: IrClassSymbol
         get() = errorClassStubSymbol
 }
 
-abstract class IrDynamicType(kotlinType: KotlinType?) : IrTypeBase(kotlinType), DynamicTypeMarker
+abstract class IrDynamicType : IrType(), DynamicTypeMarker
 
 enum class SimpleTypeNullability {
     MARKED_NULLABLE,
@@ -51,7 +54,7 @@ enum class SimpleTypeNullability {
     }
 }
 
-abstract class IrSimpleType(kotlinType: KotlinType?) : IrTypeBase(kotlinType), SimpleTypeMarker, TypeArgumentListMarker {
+abstract class IrSimpleType : IrType(), SimpleTypeMarker, TypeArgumentListMarker {
     abstract val classifier: IrClassifierSymbol
 
     /**

compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/types/impl/IrSimpleTypeImpl.kt

@@ -1,5 +1,5 @@
 /*
- * Copyright 2010-2018 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Copyright 2010-2024 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.
  */
 
@@ -16,7 +16,7 @@ import org.jetbrains.kotlin.types.Variance
 import org.jetbrains.kotlin.types.model.CaptureStatus
 import org.jetbrains.kotlin.utils.compactIfPossible
 
-abstract class IrAbstractSimpleType(kotlinType: KotlinType?) : IrSimpleType(kotlinType) {
+abstract class IrAbstractSimpleType : IrSimpleType() {
     abstract override val classifier: IrClassifierSymbol
     abstract override val nullability: SimpleTypeNullability
     abstract override val arguments: List<IrTypeArgument>
@@ -35,7 +35,7 @@ abstract class IrAbstractSimpleType(kotlinType: KotlinType?) : IrSimpleType(kotl
                 arguments.hashCode()
 }
 
-abstract class IrDelegatedSimpleType(kotlinType: KotlinType? = null) : IrAbstractSimpleType(kotlinType) {
+abstract class IrDelegatedSimpleType : IrAbstractSimpleType() {
 
     protected abstract val delegate: IrSimpleType
 
@@ -52,13 +52,13 @@ abstract class IrDelegatedSimpleType(kotlinType: KotlinType? = null) : IrAbstrac
 }
 
 class IrSimpleTypeImpl(
-    kotlinType: KotlinType?,
+    override val originalKotlinType: KotlinType?,
     override val classifier: IrClassifierSymbol,
     nullability: SimpleTypeNullability,
     override val arguments: List<IrTypeArgument>,
     override val annotations: List<IrConstructorCall>,
     override val abbreviation: IrTypeAbbreviation? = null
-) : IrAbstractSimpleType(kotlinType) {
+) : IrAbstractSimpleType() {
 
     override val nullability =
         if (classifier !is IrTypeParameterSymbol && nullability == SimpleTypeNullability.NOT_SPECIFIED)
@@ -169,7 +169,7 @@ class IrTypeProjectionImpl internal constructor(
 fun makeTypeProjection(type: IrType, variance: Variance): IrTypeProjection =
     when {
         type is IrCapturedType -> IrTypeProjectionImpl(type, variance)
-        type is IrTypeProjection && type.variance == variance -> type
+        type.variance == variance -> type
         type is IrSimpleType -> type.toBuilder().buildTypeProjection(variance)
         type is IrDynamicType -> IrDynamicTypeImpl(null, type.annotations, variance)
         type is IrErrorType -> IrErrorTypeImpl(null, type.annotations, variance)

compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/types/impl/IrTypeBase.kt

@@ -16,34 +16,27 @@ import org.jetbrains.kotlin.types.model.CaptureStatus
 import org.jetbrains.kotlin.types.model.CapturedTypeConstructorMarker
 import org.jetbrains.kotlin.types.model.CapturedTypeMarker
 
-abstract class IrTypeBase(val kotlinType: KotlinType?) : IrType(), IrTypeProjection {
-    override val type: IrType get() = this
-}
-
 class IrErrorTypeImpl(
-    kotlinType: KotlinType?,
+    override val originalKotlinType: KotlinType?,
     override val annotations: List<IrConstructorCall>,
     override val variance: Variance,
     isMarkedNullable: Boolean = false
-) : IrErrorType(kotlinType, IrErrorClassImpl.symbol, isMarkedNullable) {
+) : IrErrorType(IrErrorClassImpl.symbol, isMarkedNullable) {
     override fun equals(other: Any?): Boolean = other is IrErrorTypeImpl
 
     override fun hashCode(): Int = IrErrorTypeImpl::class.java.hashCode()
 }
 
 class IrDynamicTypeImpl(
-    kotlinType: KotlinType?,
+    override val originalKotlinType: KotlinType?,
     override val annotations: List<IrConstructorCall>,
     override val variance: Variance,
-) : IrDynamicType(kotlinType) {
+) : IrDynamicType() {
     override fun equals(other: Any?): Boolean = other is IrDynamicTypeImpl
 
     override fun hashCode(): Int = IrDynamicTypeImpl::class.java.hashCode()
 }
 
-val IrType.originalKotlinType: KotlinType?
-    get() = (this as? IrTypeBase)?.kotlinType
-
 data object IrStarProjectionImpl : IrStarProjection
 
 // Please note this type is not denotable which means it could only exist inside type system
@@ -55,7 +48,7 @@ class IrCapturedType(
     override val nullability: SimpleTypeNullability,
     override val annotations: List<IrConstructorCall>,
     override val abbreviation: IrTypeAbbreviation?,
-) : IrSimpleType(null), CapturedTypeMarker {
+) : IrSimpleType(), CapturedTypeMarker {
     class Constructor(val argument: IrTypeArgument, val typeParameter: IrTypeParameter) : CapturedTypeConstructorMarker {
         var superTypes: List<IrType> = emptyList()
             private set

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

@@ -15,7 +15,6 @@ import org.jetbrains.kotlin.ir.expressions.*
 import org.jetbrains.kotlin.ir.symbols.*
 import org.jetbrains.kotlin.ir.types.*
 import org.jetbrains.kotlin.ir.types.impl.IrCapturedType
-import org.jetbrains.kotlin.ir.types.impl.originalKotlinType
 import org.jetbrains.kotlin.ir.visitors.IrElementVisitor
 import org.jetbrains.kotlin.renderer.DescriptorRenderer
 import org.jetbrains.kotlin.types.Variance

compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/linkage/partial/PartiallyLinkedMarkerType.kt

@@ -1,5 +1,5 @@
 /*
- * Copyright 2010-2022 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Copyright 2010-2024 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.
  */
 
@@ -21,7 +21,7 @@ import org.jetbrains.kotlin.ir.types.SimpleTypeNullability
 internal class PartiallyLinkedMarkerType(
     builtIns: IrBuiltIns,
     val unusableClassifier: ExploredClassifier.Unusable,
-) : IrSimpleType(null) {
+) : IrSimpleType() {
     override val annotations: List<IrConstructorCall> get() = emptyList()
     override val classifier: IrClassSymbol = builtIns.anyClass
     override val nullability: SimpleTypeNullability get() = SimpleTypeNullability.MARKED_NULLABLE