[IR] Add IrCapturedType into IR type system

- support it in TypeSystemContext

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

@@ -5,12 +5,11 @@
 
 package org.jetbrains.kotlin.ir.types
 
-import org.jetbrains.kotlin.builtins.StandardNames
 import org.jetbrains.kotlin.builtins.PrimitiveType
+import org.jetbrains.kotlin.builtins.StandardNames
 import org.jetbrains.kotlin.descriptors.ClassKind
-import org.jetbrains.kotlin.descriptors.Modality
 import org.jetbrains.kotlin.descriptors.DescriptorVisibilities
-import org.jetbrains.kotlin.descriptors.annotations.AnnotationDescriptor
+import org.jetbrains.kotlin.descriptors.Modality
 import org.jetbrains.kotlin.ir.IrElement
 import org.jetbrains.kotlin.ir.declarations.*
 import org.jetbrains.kotlin.ir.descriptors.IrBuiltIns
@@ -71,7 +70,7 @@ interface IrTypeSystemContext : TypeSystemContext, TypeSystemCommonSuperTypesCon
         }
     }
 
-    override fun SimpleTypeMarker.asCapturedType(): CapturedTypeMarker? = null
+    override fun SimpleTypeMarker.asCapturedType(): CapturedTypeMarker? = this as? IrCapturedType
 
     override fun SimpleTypeMarker.asDefinitelyNotNullType(): DefinitelyNotNullTypeMarker? = null
 
@@ -83,19 +82,24 @@ interface IrTypeSystemContext : TypeSystemContext, TypeSystemCommonSuperTypesCon
         else simpleType.run { IrSimpleTypeImpl(classifier, nullable, arguments, annotations) }
     }
 
-    override fun SimpleTypeMarker.typeConstructor() = (this as IrSimpleType).classifier
+    override fun SimpleTypeMarker.typeConstructor(): TypeConstructorMarker = when (this) {
+        is IrCapturedType -> constructor
+        is IrSimpleType -> classifier
+        else -> error("Unknown type constructor")
+    }
 
     override fun CapturedTypeMarker.typeConstructor(): CapturedTypeConstructorMarker =
-        error("Captured types should be used for IrTypes")
+        (this as IrCapturedType).constructor
 
-    override fun CapturedTypeMarker.isProjectionNotNull(): Boolean =
-        error("Captured types should be used for IrTypes")
+    // Note: `isProjectionNotNull` is used inside inference along with intersection types.
+    // IrTypes are not used in type inference and do not have intersection type so implemenation is default (false)
+    override fun CapturedTypeMarker.isProjectionNotNull(): Boolean = false
 
     override fun CapturedTypeMarker.captureStatus(): CaptureStatus =
-        error("Captured types should be used for IrTypes")
+        (this as IrCapturedType).captureStatus
 
     override fun CapturedTypeConstructorMarker.projection(): TypeArgumentMarker =
-        error("Captured types should be used for IrTypes")
+        (this as IrCapturedType.Constructor).argument
 
     override fun KotlinTypeMarker.argumentsCount(): Int =
         when (this) {
@@ -116,7 +120,7 @@ interface IrTypeSystemContext : TypeSystemContext, TypeSystemCommonSuperTypesCon
 
     override fun KotlinTypeMarker.asTypeArgument() = this as IrTypeArgument
 
-    override fun CapturedTypeMarker.lowerType(): KotlinTypeMarker? = error("Captured Type is not valid for IrTypes")
+    override fun CapturedTypeMarker.lowerType(): KotlinTypeMarker? = (this as IrCapturedType).lowerType
 
     override fun TypeArgumentMarker.isStarProjection() = this is IrStarProjection
 
@@ -139,6 +143,7 @@ interface IrTypeSystemContext : TypeSystemContext, TypeSystemCommonSuperTypesCon
 
     override fun TypeConstructorMarker.supertypes(): Collection<KotlinTypeMarker> {
         return when (this) {
+            is IrCapturedType.Constructor -> superTypes
             is IrClassSymbol -> owner.superTypes
             is IrTypeParameterSymbol -> owner.superTypes
             else -> error("unsupported type constructor")
@@ -159,11 +164,12 @@ interface IrTypeSystemContext : TypeSystemContext, TypeSystemCommonSuperTypesCon
 
     override fun TypeParameterMarker.getTypeConstructor() = this as IrTypeParameterSymbol
 
-    override fun areEqualTypeConstructors(c1: TypeConstructorMarker, c2: TypeConstructorMarker) = FqNameEqualityChecker.areEqual(
-        c1 as IrClassifierSymbol, c2 as IrClassifierSymbol
-    )
+    override fun areEqualTypeConstructors(c1: TypeConstructorMarker, c2: TypeConstructorMarker): Boolean =
+        if (c1 is IrClassifierSymbol && c2 is IrClassifierSymbol) {
+            FqNameEqualityChecker.areEqual(c1 , c2)
+        } else c1 === c2
 
-    override fun TypeConstructorMarker.isDenotable() = true
+    override fun TypeConstructorMarker.isDenotable() = this !is IrCapturedType.Constructor
 
     override fun TypeConstructorMarker.isCommonFinalClassConstructor(): Boolean {
         val classSymbol = this as? IrClassSymbol ?: return false
@@ -185,6 +191,8 @@ interface IrTypeSystemContext : TypeSystemContext, TypeSystemCommonSuperTypesCon
         // TODO: is that correct?
         require(type is IrSimpleType)
 
+        if (type is IrCapturedType) return null
+
         val classifier = type.classifier as? IrClassSymbol ?: return null
         val typeArguments = type.arguments
 

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

@@ -95,6 +95,7 @@ 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 is IrSimpleType -> type.toBuilder().apply { this.variance = variance }.buildTypeProjection()
         type is IrDynamicType -> IrDynamicTypeImpl(null, type.annotations, variance)

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

@@ -6,11 +6,15 @@
 package org.jetbrains.kotlin.ir.types.impl
 
 import org.jetbrains.kotlin.ir.declarations.IrFunction
+import org.jetbrains.kotlin.ir.declarations.IrTypeParameter
 import org.jetbrains.kotlin.ir.expressions.IrConstructorCall
+import org.jetbrains.kotlin.ir.symbols.IrClassifierSymbol
 import org.jetbrains.kotlin.ir.types.*
-import org.jetbrains.kotlin.ir.util.fqNameWhenAvailable
 import org.jetbrains.kotlin.types.KotlinType
 import org.jetbrains.kotlin.types.Variance
+import org.jetbrains.kotlin.types.model.CaptureStatus
+import org.jetbrains.kotlin.types.model.CapturedTypeConstructorMarker
+import org.jetbrains.kotlin.types.model.CapturedTypeMarker
 import org.jetbrains.kotlin.utils.addToStdlib.safeAs
 
 abstract class IrTypeBase(val kotlinType: KotlinType?) : IrType, IrTypeProjection {
@@ -69,3 +73,49 @@ object IrUninitializedType : IrType {
 class ReturnTypeIsNotInitializedException(function: IrFunction) : IllegalStateException(
     "Return type is not initialized for function '${function.name}'"
 )
+
+
+// Please note this type is not denotable which means it could only exist inside type system
+class IrCapturedType(
+    val captureStatus: CaptureStatus,
+    val lowerType: IrType?,
+    projection: IrTypeArgument,
+    typeParameter: IrTypeParameter
+) : IrSimpleType, CapturedTypeMarker {
+
+    class Constructor(val argument: IrTypeArgument, val typeParameter: IrTypeParameter) :
+        CapturedTypeConstructorMarker {
+
+        private var _superTypes: List<IrType> = emptyList()
+
+        val superTypes: List<IrType> get() = _superTypes
+
+        fun initSuperTypes(superTypes: List<IrType>) {
+            _superTypes = superTypes
+        }
+    }
+
+    val constructor: Constructor = Constructor(projection, typeParameter)
+
+    override val classifier: IrClassifierSymbol get() = error("Captured Type does not have a classifier")
+    override val arguments: List<IrTypeArgument> get() = emptyList()
+    override val abbreviation: IrTypeAbbreviation? get () = null
+    override val hasQuestionMark: Boolean get() = false
+    override val annotations: List<IrConstructorCall> get() = emptyList()
+
+    override fun equals(other: Any?): Boolean {
+        return other is IrCapturedType
+                && captureStatus == other.captureStatus
+                && lowerType == other.lowerType
+                && constructor.argument == other.constructor.argument
+                && constructor.typeParameter == other.constructor.typeParameter
+                && constructor.superTypes == other.constructor.superTypes
+    }
+
+    override fun hashCode(): Int {
+        return (((captureStatus.hashCode() * 31
+                + (lowerType?.hashCode() ?: 0)) * 31
+                + constructor.argument.hashCode()) * 31
+                + constructor.typeParameter.hashCode()) + constructor.superTypes.hashCode()
+    }
+}