[Core API] Introduce KotlinTypeRefiner component

core/descriptors/src/org/jetbrains/kotlin/descriptors/impl/ModuleDescriptorImpl.kt

@@ -26,8 +26,10 @@ import org.jetbrains.kotlin.name.FqName
 import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.platform.TargetPlatform
 import org.jetbrains.kotlin.storage.StorageManager
+import org.jetbrains.kotlin.types.checker.REFINER_CAPABILITY
+import org.jetbrains.kotlin.types.checker.Ref
+import org.jetbrains.kotlin.types.refinement.TypeRefinement
 import org.jetbrains.kotlin.utils.sure
-import java.lang.IllegalArgumentException
 
 class ModuleDescriptorImpl @JvmOverloads constructor(
     moduleName: Name,
@@ -35,13 +37,18 @@ class ModuleDescriptorImpl @JvmOverloads constructor(
     override val builtIns: KotlinBuiltIns,
     // May be null in compiler context, should be not-null in IDE context
     override val platform: TargetPlatform? = null,
-    private val capabilities: Map<ModuleDescriptor.Capability<*>, Any?> = emptyMap(),
+    capabilities: Map<ModuleDescriptor.Capability<*>, Any?> = emptyMap(),
     override val stableName: Name? = null
 ) : DeclarationDescriptorImpl(Annotations.EMPTY, moduleName), ModuleDescriptor {
+    private val capabilities: Map<ModuleDescriptor.Capability<*>, Any?>
+
     init {
         if (!moduleName.isSpecial) {
             throw IllegalArgumentException("Module name must be special: $moduleName")
         }
+        this.capabilities = capabilities.toMutableMap()
+        @UseExperimental(TypeRefinement::class)
+        this.capabilities[REFINER_CAPABILITY] = Ref(null)
     }
 
     private var dependencies: ModuleDependencies? = null

core/descriptors/src/org/jetbrains/kotlin/resolve/DescriptorUtils.kt

@@ -17,9 +17,9 @@ import org.jetbrains.kotlin.name.ClassId
 import org.jetbrains.kotlin.name.FqName
 import org.jetbrains.kotlin.name.FqNameUnsafe
 import org.jetbrains.kotlin.name.Name
+import org.jetbrains.kotlin.platform.TargetPlatform
 import org.jetbrains.kotlin.resolve.DescriptorUtils
 import org.jetbrains.kotlin.resolve.DescriptorUtils.getContainingClass
-import org.jetbrains.kotlin.platform.TargetPlatform
 import org.jetbrains.kotlin.resolve.constants.ConstantValue
 import org.jetbrains.kotlin.resolve.constants.EnumValue
 import org.jetbrains.kotlin.resolve.scopes.DescriptorKindFilter
@@ -29,6 +29,9 @@ import org.jetbrains.kotlin.types.TypeProjection
 import org.jetbrains.kotlin.types.TypeSubstitutor
 import org.jetbrains.kotlin.types.Variance
 import org.jetbrains.kotlin.types.checker.KotlinTypeChecker
+import org.jetbrains.kotlin.types.checker.KotlinTypeRefiner
+import org.jetbrains.kotlin.types.checker.REFINER_CAPABILITY
+import org.jetbrains.kotlin.types.refinement.TypeRefinement
 import org.jetbrains.kotlin.types.typeUtil.isAnyOrNullableAny
 import org.jetbrains.kotlin.types.typeUtil.makeNullable
 import org.jetbrains.kotlin.utils.DFS
@@ -441,3 +444,6 @@ fun DeclarationDescriptor.isAnnotationConstructor(): Boolean =
 
 fun DeclarationDescriptor.isPrimaryConstructorOfInlineClass(): Boolean =
     this is ConstructorDescriptor && this.isPrimary && this.constructedClass.isInline
+
+@TypeRefinement
+fun ModuleDescriptor.getKotlinTypeRefiner(): KotlinTypeRefiner = getCapability(REFINER_CAPABILITY)?.value ?: KotlinTypeRefiner.Default

core/descriptors/src/org/jetbrains/kotlin/types/checker/KotlinTypeRefiner.kt

@@ -0,0 +1,82 @@
+/*
+ * Copyright 2010-2019 JetBrains s.r.o. 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.types.checker
+
+import org.jetbrains.kotlin.container.DefaultImplementation
+import org.jetbrains.kotlin.descriptors.*
+import org.jetbrains.kotlin.name.ClassId
+import org.jetbrains.kotlin.resolve.scopes.MemberScope
+import org.jetbrains.kotlin.types.KotlinType
+import org.jetbrains.kotlin.types.TypeConstructor
+import org.jetbrains.kotlin.types.UnwrappedType
+import org.jetbrains.kotlin.types.refinement.TypeRefinement
+
+@DefaultImplementation(impl = KotlinTypeRefiner.Default::class)
+abstract class KotlinTypeRefiner {
+    @TypeRefinement
+    abstract fun refineType(type: KotlinType): KotlinType
+
+    @TypeRefinement
+    abstract fun refineSupertypes(classDescriptor: ClassDescriptor): Collection<KotlinType>
+
+    @TypeRefinement
+    abstract fun refineDescriptor(descriptor: DeclarationDescriptor): ClassifierDescriptor?
+
+    @TypeRefinement
+    abstract fun findClassAcrossModuleDependencies(classId: ClassId): ClassDescriptor?
+
+    @TypeRefinement
+    abstract fun isRefinementNeededForModule(moduleDescriptor: ModuleDescriptor): Boolean
+
+    @TypeRefinement
+    abstract fun isRefinementNeededForTypeConstructor(typeConstructor: TypeConstructor): Boolean
+
+    @TypeRefinement
+    abstract fun <S : MemberScope> getOrPutScopeForClass(classDescriptor: ClassDescriptor, compute: () -> S): S
+
+    object Default : KotlinTypeRefiner() {
+        @TypeRefinement
+        override fun refineType(type: KotlinType): KotlinType = type
+
+        @TypeRefinement
+        override fun refineSupertypes(classDescriptor: ClassDescriptor): Collection<KotlinType> {
+            return classDescriptor.typeConstructor.supertypes
+        }
+
+        @TypeRefinement
+        override fun refineDescriptor(descriptor: DeclarationDescriptor): ClassDescriptor? {
+            return null
+        }
+
+        @TypeRefinement
+        override fun findClassAcrossModuleDependencies(classId: ClassId): ClassDescriptor? {
+            return null
+        }
+
+        @TypeRefinement
+        override fun isRefinementNeededForModule(moduleDescriptor: ModuleDescriptor): Boolean {
+            return false
+        }
+
+        @TypeRefinement
+        override fun isRefinementNeededForTypeConstructor(typeConstructor: TypeConstructor): Boolean {
+            return false
+        }
+
+        @TypeRefinement
+        override fun <S : MemberScope> getOrPutScopeForClass(classDescriptor: ClassDescriptor, compute: () -> S): S {
+            return compute()
+        }
+    }
+}
+
+@TypeRefinement
+fun KotlinTypeRefiner.refineTypes(types: Iterable<KotlinType>): List<KotlinType> = types.map { refineType(it) }
+
+class Ref<T : Any>(var value: T?)
+
+@TypeRefinement
+val REFINER_CAPABILITY = ModuleDescriptor.Capability<Ref<KotlinTypeRefiner>>("KotlinTypeRefiner")