From ffaca279bcb56e938b6118ec4d9e2dc60e41c40b Mon Sep 17 00:00:00 2001
From: Denis Zharkov <denis.zharkov@jetbrains.com>
Date: Fri, 12 Jul 2019 14:15:56 +0300
Subject: [PATCH] Minor. Turn TypeBasedStarProjectionImpl into
 StarProjectionForAbsentTypeParameter

It's needed to avoid abusing of the class
Star projections should be created based on the relevant type parameter
whenever it's possible
---
 .../kotlin/types/StarProjectionImpl.kt        | 22 +++++++++++--------
 .../deserialization/TypeDeserializer.kt       |  2 +-
 2 files changed, 14 insertions(+), 10 deletions(-)

diff --git a/core/descriptors/src/org/jetbrains/kotlin/types/StarProjectionImpl.kt b/core/descriptors/src/org/jetbrains/kotlin/types/StarProjectionImpl.kt
index fa3a2957542..0353d4019c2 100644
--- a/core/descriptors/src/org/jetbrains/kotlin/types/StarProjectionImpl.kt
+++ b/core/descriptors/src/org/jetbrains/kotlin/types/StarProjectionImpl.kt
@@ -16,6 +16,7 @@
 
 package org.jetbrains.kotlin.types
 
+import org.jetbrains.kotlin.builtins.KotlinBuiltIns
 import org.jetbrains.kotlin.descriptors.ClassifierDescriptorWithTypeParameters
 import org.jetbrains.kotlin.descriptors.TypeParameterDescriptor
 import org.jetbrains.kotlin.resolve.descriptorUtil.builtIns
@@ -44,24 +45,27 @@ fun TypeParameterDescriptor.starProjectionType(): KotlinType {
     val classDescriptor = this.containingDeclaration as ClassifierDescriptorWithTypeParameters
     val typeParameters = classDescriptor.typeConstructor.parameters.map { it.typeConstructor }
     return TypeSubstitutor.create(
-            object : TypeConstructorSubstitution() {
-                override fun get(key: TypeConstructor) =
-                        if (key in typeParameters)
-                            TypeUtils.makeStarProjection(key.declarationDescriptor as TypeParameterDescriptor)
-                        else null
+        object : TypeConstructorSubstitution() {
+            override fun get(key: TypeConstructor) =
+                if (key in typeParameters)
+                    TypeUtils.makeStarProjection(key.declarationDescriptor as TypeParameterDescriptor)
+                else null
 
-            }
+        }
     ).substitute(this.upperBounds.first(), Variance.OUT_VARIANCE) ?: builtIns.defaultBound
 }
 
-class TypeBasedStarProjectionImpl(
-        private val _type: KotlinType
+// It should only be used in rare cases when type parameter for the relevant argument is not available
+class StarProjectionForAbsentTypeParameter(
+    kotlinBuiltIns: KotlinBuiltIns
 ) : TypeProjectionBase() {
+    private val nullableAnyType: KotlinType = kotlinBuiltIns.nullableAnyType
+
     override fun isStarProjection() = true
 
     override fun getProjectionKind() = Variance.OUT_VARIANCE
 
-    override fun getType() = _type
+    override fun getType() = nullableAnyType
 
     @TypeRefinement
     override fun refine(kotlinTypeRefiner: KotlinTypeRefiner): TypeProjection = this
diff --git a/core/deserialization/src/org/jetbrains/kotlin/serialization/deserialization/TypeDeserializer.kt b/core/deserialization/src/org/jetbrains/kotlin/serialization/deserialization/TypeDeserializer.kt
index 9f83e051b07..08725f00569 100644
--- a/core/deserialization/src/org/jetbrains/kotlin/serialization/deserialization/TypeDeserializer.kt
+++ b/core/deserialization/src/org/jetbrains/kotlin/serialization/deserialization/TypeDeserializer.kt
@@ -241,7 +241,7 @@ class TypeDeserializer(
     private fun typeArgument(parameter: TypeParameterDescriptor?, typeArgumentProto: ProtoBuf.Type.Argument): TypeProjection {
         if (typeArgumentProto.projection == ProtoBuf.Type.Argument.Projection.STAR) {
             return if (parameter == null)
-                TypeBasedStarProjectionImpl(c.components.moduleDescriptor.builtIns.nullableAnyType)
+                StarProjectionForAbsentTypeParameter(c.components.moduleDescriptor.builtIns)
             else
                 StarProjectionImpl(parameter)
         }