org.jetbrains.kotlin.types.AbstractTypeConstructor.kt Maven / Gradle / Ivy
/*
* 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.
*/
package org.jetbrains.kotlin.types
import org.jetbrains.kotlin.descriptors.SupertypeLoopChecker
import org.jetbrains.kotlin.storage.StorageManager
abstract class AbstractTypeConstructor(storageManager: StorageManager) : TypeConstructor {
override fun getSupertypes() = supertypes().supertypesWithoutCycles
// In current version diagnostic about loops in supertypes is reported on each vertex (supertype reference) that lies on the cycle.
// To achieve that we store both versions of supertypes --- before and after loops disconnection.
// The first one is used for computation of neighbours in supertypes graph (see Companion.computeNeighbours)
private class Supertypes(
val allSupertypes: Collection) {
// initializer is only needed as a stub for case when 'getSupertypes' is called while 'supertypes' are being calculated
var supertypesWithoutCycles: List = listOf(ErrorUtils.ERROR_TYPE_FOR_LOOP_IN_SUPERTYPES)
}
private val supertypes = storageManager.createLazyValueWithPostCompute(
{ Supertypes(computeSupertypes()) },
{ Supertypes(listOf(ErrorUtils.ERROR_TYPE_FOR_LOOP_IN_SUPERTYPES)) },
{ supertypes ->
// It's important that loops disconnection begins in post-compute phase, because it guarantees that
// when we start calculation supertypes of supertypes (for computing neighbours), they start their disconnection loop process
// either, and as we want to report diagnostic about loops on all declarations they should see consistent version of 'allSupertypes'
var resultWithoutCycles =
supertypeLoopChecker.findLoopsInSupertypesAndDisconnect(
this, supertypes.allSupertypes,
{ it.computeNeighbours() },
{ reportSupertypeLoopError(it) })
if (resultWithoutCycles.isEmpty()) {
resultWithoutCycles = defaultSupertypeIfEmpty()?.let { listOf(it) }.orEmpty()
}
supertypes.supertypesWithoutCycles = (resultWithoutCycles as? List) ?: resultWithoutCycles.toList()
})
private fun TypeConstructor.computeNeighbours(): Collection =
(this as? AbstractTypeConstructor)?.let {
abstractClassifierDescriptor ->
abstractClassifierDescriptor.supertypes().allSupertypes +
abstractClassifierDescriptor.getAdditionalNeighboursInSupertypeGraph()
} ?: supertypes
protected abstract fun computeSupertypes(): Collection
protected abstract val supertypeLoopChecker: SupertypeLoopChecker
protected open fun reportSupertypeLoopError(type: KotlinType) {}
protected open fun getAdditionalNeighboursInSupertypeGraph(): Collection = emptyList()
protected open fun defaultSupertypeIfEmpty(): KotlinType? = null
}