From 8f8e33f25136e92092c4a2c123b812d962097db8 Mon Sep 17 00:00:00 2001
From: Mikhail Zarechenskiy <mikhail.zarechenskiy@jetbrains.com>
Date: Thu, 18 Apr 2019 14:41:24 +0300
Subject: [PATCH] [NI] Strip only `Exact`-annotation preserving others during
 inference

---
 .../AbstractTypeCheckerContextForConstraintSystem.kt      | 4 ++--
 .../org/jetbrains/kotlin/resolve/annotationsForResolve.kt | 2 ++
 .../kotlin/types/checker/ClassicTypeSystemContext.kt      | 8 ++++++++
 .../org/jetbrains/kotlin/types/model/TypeSystemContext.kt | 1 +
 4 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/inference/components/AbstractTypeCheckerContextForConstraintSystem.kt b/compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/inference/components/AbstractTypeCheckerContextForConstraintSystem.kt
index 653d0ae2714..f3726f9eadf 100644
--- a/compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/inference/components/AbstractTypeCheckerContextForConstraintSystem.kt
+++ b/compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/inference/components/AbstractTypeCheckerContextForConstraintSystem.kt
@@ -45,8 +45,8 @@ abstract class AbstractTypeCheckerContextForConstraintSystem : AbstractTypeCheck
         val hasExact = subType.isTypeVariableWithExact() || superType.isTypeVariableWithExact()
 
         // we should strip annotation's because we have incorporation operation and they should be not affected
-        val mySubType = if (hasExact) subType.removeAnnotations() else subType
-        val mySuperType = if (hasExact) superType.removeAnnotations() else superType
+        val mySubType = if (hasExact) subType.removeExactAnnotation() else subType
+        val mySuperType = if (hasExact) superType.removeExactAnnotation() else superType
 
         val result = internalAddSubtypeConstraint(mySubType, mySuperType)
         if (!hasExact) return result
diff --git a/core/descriptors/src/org/jetbrains/kotlin/resolve/annotationsForResolve.kt b/core/descriptors/src/org/jetbrains/kotlin/resolve/annotationsForResolve.kt
index dd4480c070c..53f1bb76106 100644
--- a/core/descriptors/src/org/jetbrains/kotlin/resolve/annotationsForResolve.kt
+++ b/core/descriptors/src/org/jetbrains/kotlin/resolve/annotationsForResolve.kt
@@ -28,6 +28,8 @@ fun KotlinType.hasNoInferAnnotation(): Boolean = annotations.hasAnnotation(NO_IN
 
 fun KotlinType.hasExactAnnotation(): Boolean = annotations.hasAnnotation(EXACT_ANNOTATION_FQ_NAME)
 
+fun AnnotationDescriptor.isExactAnnotation(): Boolean = this.fqName == EXACT_ANNOTATION_FQ_NAME
+
 fun Annotations.hasInternalAnnotationForResolve(): Boolean =
         hasAnnotation(NO_INFER_ANNOTATION_FQ_NAME) || hasAnnotation(EXACT_ANNOTATION_FQ_NAME)
 
diff --git a/core/descriptors/src/org/jetbrains/kotlin/types/checker/ClassicTypeSystemContext.kt b/core/descriptors/src/org/jetbrains/kotlin/types/checker/ClassicTypeSystemContext.kt
index 74be1735287..e955ce1163a 100644
--- a/core/descriptors/src/org/jetbrains/kotlin/types/checker/ClassicTypeSystemContext.kt
+++ b/core/descriptors/src/org/jetbrains/kotlin/types/checker/ClassicTypeSystemContext.kt
@@ -8,11 +8,13 @@ package org.jetbrains.kotlin.types.checker
 import org.jetbrains.kotlin.builtins.KotlinBuiltIns
 import org.jetbrains.kotlin.builtins.KotlinBuiltIns.FQ_NAMES
 import org.jetbrains.kotlin.descriptors.*
+import org.jetbrains.kotlin.descriptors.annotations.AnnotationDescriptor
 import org.jetbrains.kotlin.descriptors.annotations.Annotations
 import org.jetbrains.kotlin.resolve.calls.inference.CapturedType
 import org.jetbrains.kotlin.resolve.descriptorUtil.hasExactAnnotation
 import org.jetbrains.kotlin.resolve.descriptorUtil.hasNoInferAnnotation
 import org.jetbrains.kotlin.resolve.constants.IntegerLiteralTypeConstructor
+import org.jetbrains.kotlin.resolve.descriptorUtil.isExactAnnotation
 import org.jetbrains.kotlin.types.*
 import org.jetbrains.kotlin.types.model.*
 import org.jetbrains.kotlin.types.model.CaptureStatus
@@ -343,6 +345,12 @@ interface ClassicTypeSystemContext : TypeSystemInferenceExtensionContext {
         return this.replaceAnnotations(Annotations.EMPTY)
     }
 
+    override fun KotlinTypeMarker.removeExactAnnotation(): KotlinTypeMarker {
+        require(this is UnwrappedType, this::errorMessage)
+        val annotationsWithoutExact = this.annotations.filterNot(AnnotationDescriptor::isExactAnnotation)
+        return this.replaceAnnotations(Annotations.create(annotationsWithoutExact))
+    }
+
     override fun KotlinTypeMarker.hasExactAnnotation(): Boolean {
         require(this is UnwrappedType, this::errorMessage)
         return hasExactInternal(this)
diff --git a/core/type-system/src/org/jetbrains/kotlin/types/model/TypeSystemContext.kt b/core/type-system/src/org/jetbrains/kotlin/types/model/TypeSystemContext.kt
index e1018cbcd38..fe2b0d2aa82 100644
--- a/core/type-system/src/org/jetbrains/kotlin/types/model/TypeSystemContext.kt
+++ b/core/type-system/src/org/jetbrains/kotlin/types/model/TypeSystemContext.kt
@@ -107,6 +107,7 @@ interface TypeSystemInferenceExtensionContext : TypeSystemContext, TypeSystemBui
 
 
     fun KotlinTypeMarker.removeAnnotations(): KotlinTypeMarker
+    fun KotlinTypeMarker.removeExactAnnotation(): KotlinTypeMarker
 
     fun SimpleTypeMarker.replaceArguments(newArguments: List<TypeArgumentMarker>): SimpleTypeMarker