org.jetbrains.kotlin.resolve.calls.results.OverloadingConflictResolver.kt Maven / Gradle / Ivy
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/*
* 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.resolve.calls.results
import gnu.trove.THashSet
import gnu.trove.TObjectHashingStrategy
import org.jetbrains.kotlin.builtins.KotlinBuiltIns
import org.jetbrains.kotlin.descriptors.CallableDescriptor
import org.jetbrains.kotlin.descriptors.ScriptDescriptor
import org.jetbrains.kotlin.descriptors.Visibilities
import org.jetbrains.kotlin.resolve.DescriptorEquivalenceForOverrides
import org.jetbrains.kotlin.resolve.OverridingUtil
import org.jetbrains.kotlin.resolve.calls.context.CheckArgumentTypesMode
import org.jetbrains.kotlin.resolve.descriptorUtil.varargParameterPosition
import org.jetbrains.kotlin.types.KotlinType
import org.jetbrains.kotlin.types.TypeUtils
import java.util.*
class OverloadingConflictResolver(
private val builtIns: KotlinBuiltIns,
private val specificityComparator: TypeSpecificityComparator,
private val getResultingDescriptor: (C) -> CallableDescriptor,
private val createEmptyConstraintSystem: () -> SimpleConstraintSystem,
private val createFlatSignature: (C) -> FlatSignature,
private val getVariableCandidates: (C) -> C?, // vor variable WithInvoke
private val isFromSources: (CallableDescriptor) -> Boolean
) {
private val resolvedCallHashingStrategy = object : TObjectHashingStrategy {
override fun equals(call1: C?, call2: C?): Boolean =
if (call1 != null && call2 != null)
call1.resultingDescriptor == call2.resultingDescriptor
else
call1 == call2
override fun computeHashCode(call: C?): Int =
call?.resultingDescriptor?.hashCode() ?: 0
}
private val C.resultingDescriptor: CallableDescriptor get() = getResultingDescriptor(this)
// if result contains only one element -- it is maximally specific; otherwise we have ambiguity
fun chooseMaximallySpecificCandidates(
candidates: Set,
checkArgumentsMode: CheckArgumentTypesMode,
discriminateGenerics: Boolean,
isDebuggerContext: Boolean
): Set {
if (candidates.size == 1) return candidates
val fixedCandidates = if (getVariableCandidates(candidates.first()) != null) {
findMaximallySpecificVariableAsFunctionCalls(candidates, isDebuggerContext) ?: return candidates
}
else {
candidates
}
val noEquivalentCalls = filterOutEquivalentCalls(fixedCandidates)
val noOverrides = OverridingUtil.filterOverrides(noEquivalentCalls) { it.resultingDescriptor }
if (noOverrides.size == 1) {
return noOverrides
}
val maximallySpecific = findMaximallySpecific(noOverrides, checkArgumentsMode, false, isDebuggerContext)
if (maximallySpecific != null) {
return setOf(maximallySpecific)
}
if (discriminateGenerics) {
val maximallySpecificGenericsDiscriminated = findMaximallySpecific(noOverrides, checkArgumentsMode, true, isDebuggerContext)
if (maximallySpecificGenericsDiscriminated != null) {
return setOf(maximallySpecificGenericsDiscriminated)
}
}
return noOverrides
}
// Sometimes we should compare "copies" from sources and from binary files.
// But we cannot compare return types for such copies, because it may lead us to recursive problem (see KT-11995).
// Because of this we compare them without return type and choose descriptor from source if we found duplicate.
fun filterOutEquivalentCalls(candidates: Set): Set {
if (candidates.size <= 1) return candidates
val fromSourcesGoesFirst = candidates.sortedBy { if (isFromSources(it.resultingDescriptor)) 0 else 1 }
val result = LinkedHashSet()
outerLoop@ for (meD in fromSourcesGoesFirst) {
for (otherD in result) {
val me = meD.resultingDescriptor
val other = otherD.resultingDescriptor
val ignoreReturnType = isFromSources(me) != isFromSources(other)
if (DescriptorEquivalenceForOverrides.areCallableDescriptorsEquivalent(me, other, ignoreReturnType)) {
continue@outerLoop
}
}
result.add(meD)
}
return result
}
private fun findMaximallySpecific(
candidates: Set,
checkArgumentsMode: CheckArgumentTypesMode,
discriminateGenerics: Boolean,
isDebuggerContext: Boolean
): C? =
if (candidates.size <= 1)
candidates.firstOrNull()
else when (checkArgumentsMode) {
CheckArgumentTypesMode.CHECK_CALLABLE_TYPE ->
uniquifyCandidatesSet(candidates).filter {
isDefinitelyMostSpecific(it, candidates) {
call1, call2 ->
isNotLessSpecificCallableReference(call1.resultingDescriptor, call2.resultingDescriptor)
}
}.singleOrNull()
CheckArgumentTypesMode.CHECK_VALUE_ARGUMENTS ->
findMaximallySpecificCall(candidates, discriminateGenerics, isDebuggerContext)
?: findMaximallySpecificCall(
candidates.filterNotTo(mutableSetOf()) { createFlatSignature(it).isSyntheticMember },
discriminateGenerics, isDebuggerContext
)
}
// null means ambiguity between variables
private fun findMaximallySpecificVariableAsFunctionCalls(candidates: Set, isDebuggerContext: Boolean): Set? {
val variableCalls = candidates.mapTo(newResolvedCallSet(candidates.size)) {
getVariableCandidates(it) ?: throw AssertionError("Regular call among variable-as-function calls: $it")
}
val maxSpecificVariableCalls = chooseMaximallySpecificCandidates(variableCalls, CheckArgumentTypesMode.CHECK_VALUE_ARGUMENTS,
isDebuggerContext = isDebuggerContext, discriminateGenerics = false)
val maxSpecificVariableCall = maxSpecificVariableCalls.singleOrNull() ?: return null
return candidates.filterTo(newResolvedCallSet(2)) {
getVariableCandidates(it)!!.resultingDescriptor == maxSpecificVariableCall.resultingDescriptor
}
}
private fun findMaximallySpecificCall(
candidates: Set,
discriminateGenerics: Boolean,
isDebuggerContext: Boolean
): C? {
val filteredCandidates = uniquifyCandidatesSet(candidates)
if (filteredCandidates.size <= 1) return filteredCandidates.singleOrNull()
val conflictingCandidates = filteredCandidates.map {
candidateCall ->
createFlatSignature(candidateCall)
}
val bestCandidatesByParameterTypes = conflictingCandidates.filter {
candidate ->
isMostSpecific(candidate, conflictingCandidates) {
call1, call2 ->
isNotLessSpecificCallWithArgumentMapping(call1, call2, discriminateGenerics)
}
}
return bestCandidatesByParameterTypes.exactMaxWith {
call1, call2 ->
isOfNotLessSpecificShape(call1, call2) && isOfNotLessSpecificVisibilityForDebugger(call1, call2, isDebuggerContext)
}?.origin
}
private inline fun Collection.exactMaxWith(isNotWorse: (C, C) -> Boolean): C? {
var result: C? = null
for (candidate in this) {
if (result == null || isNotWorse(candidate, result)) {
result = candidate
}
}
if (result == null) return null
if (any { it != result && isNotWorse(it, result!!) }) {
return null
}
return result
}
private inline fun isMostSpecific(candidate: C, candidates: Collection, isNotLessSpecific: (C, C) -> Boolean): Boolean =
candidates.all {
other ->
candidate === other ||
isNotLessSpecific(candidate, other)
}
private inline fun isDefinitelyMostSpecific(candidate: C, candidates: Collection, isNotLessSpecific: (C, C) -> Boolean): Boolean =
candidates.all {
other ->
candidate === other ||
isNotLessSpecific(candidate, other) && !isNotLessSpecific(other, candidate)
}
/**
* `call1` is not less specific than `call2`
*/
private fun isNotLessSpecificCallWithArgumentMapping(
call1: FlatSignature,
call2: FlatSignature,
discriminateGenerics: Boolean
): Boolean {
return tryCompareDescriptorsFromScripts(call1.candidateDescriptor(), call2.candidateDescriptor()) ?:
compareCallsByUsedArguments(call1, call2, discriminateGenerics)
}
/**
* Returns `true` if [call1] is definitely more or equally specific [call2],
* `false` otherwise.
*/
private fun compareCallsByUsedArguments(
call1: FlatSignature,
call2: FlatSignature,
discriminateGenerics: Boolean
): Boolean {
if (discriminateGenerics) {
val isGeneric1 = call1.isGeneric
val isGeneric2 = call2.isGeneric
// generic loses to non-generic
if (isGeneric1 && !isGeneric2) return false
if (!isGeneric1 && isGeneric2) return true
// two generics are non-comparable
if (isGeneric1 && isGeneric2) return false
}
if (!call1.isHeader && call2.isHeader) return true
if (call1.isHeader && !call2.isHeader) return false
return createEmptyConstraintSystem().isSignatureNotLessSpecific(call1, call2, SpecificityComparisonWithNumerics, specificityComparator)
}
private val SpecificityComparisonWithNumerics = object : SpecificityComparisonCallbacks {
override fun isNonSubtypeNotLessSpecific(specific: KotlinType, general: KotlinType): Boolean {
val _double = builtIns.doubleType
val _float = builtIns.floatType
val _long = builtIns.longType
val _int = builtIns.intType
val _byte = builtIns.byteType
val _short = builtIns.shortType
when {
TypeUtils.equalTypes(specific, _double) && TypeUtils.equalTypes(general, _float) -> return true
TypeUtils.equalTypes(specific, _int) -> {
when {
TypeUtils.equalTypes(general, _long) -> return true
TypeUtils.equalTypes(general, _byte) -> return true
TypeUtils.equalTypes(general, _short) -> return true
}
}
TypeUtils.equalTypes(specific, _short) && TypeUtils.equalTypes(general, _byte) -> return true
}
return false
}
}
private fun isOfNotLessSpecificShape(
call1: FlatSignature,
call2: FlatSignature
): Boolean {
val hasVarargs1 = call1.hasVarargs
val hasVarargs2 = call2.hasVarargs
if (hasVarargs1 && !hasVarargs2) return false
if (!hasVarargs1 && hasVarargs2) return true
if (call1.numDefaults > call2.numDefaults) {
return false
}
return true
}
private fun isOfNotLessSpecificVisibilityForDebugger(
call1: FlatSignature,
call2: FlatSignature,
isDebuggerContext: Boolean
): Boolean {
if (isDebuggerContext) {
val isMoreVisible1 = Visibilities.compare(call1.descriptorVisibility(), call2.descriptorVisibility())
if (isMoreVisible1 != null && isMoreVisible1 < 0) return false
}
return true
}
/**
* Returns `true` if `d1` is definitely not less specific than `d2`,
* `false` if `d1` is definitely less specific than `d2`,
* `null` if undecided.
*/
private fun tryCompareDescriptorsFromScripts(d1: CallableDescriptor, d2: CallableDescriptor): Boolean? {
val containingDeclaration1 = d1.containingDeclaration
val containingDeclaration2 = d2.containingDeclaration
if (containingDeclaration1 is ScriptDescriptor && containingDeclaration2 is ScriptDescriptor) {
when {
containingDeclaration1.priority > containingDeclaration2.priority -> return true
containingDeclaration1.priority < containingDeclaration2.priority -> return false
}
}
return null
}
/**
* Returns `true` if `f` is definitely not less specific than `g`,
* `false` if `f` is definitely less specific than `g`,
* `null` if undecided.
*/
private fun isNotLessSpecificCallableReferenceDescriptor(f: CallableDescriptor, g: CallableDescriptor): Boolean {
if (f.valueParameters.size != g.valueParameters.size) return false
if (f.varargParameterPosition() != g.varargParameterPosition()) return false
val fSignature = FlatSignature.createFromCallableDescriptor(f)
val gSignature = FlatSignature.createFromCallableDescriptor(g)
return createEmptyConstraintSystem().isSignatureNotLessSpecific(fSignature, gSignature, SpecificityComparisonWithNumerics, specificityComparator)
}
private fun isNotLessSpecificCallableReference(f: CallableDescriptor, g: CallableDescriptor): Boolean =
// TODO should we "discriminate generic descriptors" for callable references?
tryCompareDescriptorsFromScripts(f, g) ?:
isNotLessSpecificCallableReferenceDescriptor(f, g)
// Different smart casts may lead to the same candidate descriptor wrapped into different ResolvedCallImpl objects
private fun uniquifyCandidatesSet(candidates: Collection): Set =
THashSet(candidates.size, resolvedCallHashingStrategy).apply { addAll(candidates) }
private fun newResolvedCallSet(expectedSize: Int): MutableSet =
THashSet(expectedSize, resolvedCallHashingStrategy)
private fun FlatSignature.candidateDescriptor() =
origin.resultingDescriptor.original
private fun FlatSignature.descriptorVisibility() =
candidateDescriptor().visibility
}