org.jetbrains.kotlin.ir.overrides.IrOverrideChecker.kt Maven / Gradle / Ivy
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/*
* Copyright 2010-2023 JetBrains s.r.o. and Kotlin Programming Language contributors.
* 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.ir.overrides
import org.jetbrains.kotlin.ir.declarations.IrOverridableMember
import org.jetbrains.kotlin.ir.declarations.IrProperty
import org.jetbrains.kotlin.ir.declarations.IrSimpleFunction
import org.jetbrains.kotlin.ir.declarations.IrTypeParameter
import org.jetbrains.kotlin.ir.overrides.IrExternalOverridabilityCondition.Contract.CONFLICTS_ONLY
import org.jetbrains.kotlin.ir.overrides.IrExternalOverridabilityCondition.Contract.SUCCESS_ONLY
import org.jetbrains.kotlin.ir.overrides.IrExternalOverridabilityCondition.Result.*
import org.jetbrains.kotlin.ir.types.IrTypeSystemContext
import org.jetbrains.kotlin.ir.types.IrTypeSystemContextWithAdditionalAxioms
import org.jetbrains.kotlin.ir.types.createIrTypeCheckerState
import org.jetbrains.kotlin.ir.util.render
import org.jetbrains.kotlin.resolve.OverridingUtil.OverrideCompatibilityInfo
import org.jetbrains.kotlin.resolve.OverridingUtil.OverrideCompatibilityInfo.*
import org.jetbrains.kotlin.types.AbstractTypeChecker
import org.jetbrains.kotlin.types.TypeCheckerState
import org.jetbrains.kotlin.utils.addToStdlib.unreachableBranch
/**
* @param member declaration that should be checked for overridability.
* @param original the original, unsubstituted version of the declaration if the declaration is a fake override.
*/
class MemberWithOriginal(val member: IrOverridableMember, original: IrOverridableMember? = null) {
internal constructor(fakeOverride: IrFakeOverrideBuilder.FakeOverride) : this(fakeOverride.override, fakeOverride.original)
val original: IrOverridableMember = original ?: member
override fun toString(): String = member.render()
}
class IrOverrideChecker(
private val typeSystem: IrTypeSystemContext,
private val externalOverridabilityConditions: List,
) {
fun getBothWaysOverridability(
overrider: MemberWithOriginal,
candidate: MemberWithOriginal,
): Result {
val result1 = isOverridableBy(candidate, overrider, checkIsInlineFlag = false).result
val result2 = isOverridableBy(overrider, candidate, checkIsInlineFlag = false).result
return if (result1 == result2) result1 else Result.INCOMPATIBLE
}
fun isOverridableBy(
superMember: MemberWithOriginal,
subMember: MemberWithOriginal,
checkIsInlineFlag: Boolean,
): OverrideCompatibilityInfo {
val basicResult = isOverridableByWithoutExternalConditions(superMember.member, subMember.member, checkIsInlineFlag)
return runExternalOverridabilityConditions(superMember, subMember, basicResult)
}
private fun isOverridableByWithoutExternalConditions(
superMember: IrOverridableMember,
subMember: IrOverridableMember,
checkIsInlineFlag: Boolean,
): OverrideCompatibilityInfo {
val (superFunction, subFunction) = when (superMember) {
is IrSimpleFunction -> {
if (subMember !is IrSimpleFunction) return incompatible("Member kind mismatch")
if (superMember.isSuspend != subMember.isSuspend) return incompatible("Incompatible suspendability")
superMember to subMember
}
is IrProperty -> {
if (subMember !is IrProperty) return incompatible("Member kind mismatch")
if (superMember.getter == null || subMember.getter == null) return incompatible("Fields are not overridable")
superMember.getter to subMember.getter
}
else -> error("Unexpected type of declaration: ${superMember::class.java}, $superMember")
}
if (checkIsInlineFlag) {
val isInline = when (superMember) {
is IrSimpleFunction -> superMember.isInline
is IrProperty -> superMember.getter?.isInline == true || superMember.setter?.isInline == true
else -> unreachableBranch(superMember)
}
if (isInline) return incompatible("Inline declaration can't be overridden")
}
if (superMember.name != subMember.name) {
// Check name after member kind checks. This way FO builder will first check types of overridable members and crash
// if member types are not supported (ex: IrConstructor).
return incompatible("Name mismatch")
}
val superExtensionReceiver = superFunction?.extensionReceiverParameter
val subExtensionReceiver = subFunction?.extensionReceiverParameter
if ((superExtensionReceiver == null) != (subExtensionReceiver == null)) return incompatible("Receiver presence mismatch")
val superTypeParameters = superFunction?.typeParameters.orEmpty()
val subTypeParameters = subFunction?.typeParameters.orEmpty()
if (superTypeParameters.size != subTypeParameters.size) return incompatible("Type parameter number mismatch")
val superValueParameters = superFunction?.valueParameters.orEmpty()
val subValueParameters = subFunction?.valueParameters.orEmpty()
if (superValueParameters.size != subValueParameters.size) return incompatible("Value parameter number mismatch")
val typeCheckerState = createIrTypeCheckerState(
IrTypeSystemContextWithAdditionalAxioms(typeSystem, superTypeParameters, subTypeParameters)
)
for ((index, superTypeParameter) in superTypeParameters.withIndex()) {
if (!areTypeParametersEquivalent(superTypeParameter, subTypeParameters[index], typeCheckerState)) {
return incompatible("Type parameter bounds mismatch")
}
}
if (superExtensionReceiver != null && subExtensionReceiver != null &&
!AbstractTypeChecker.equalTypes(typeCheckerState, subExtensionReceiver.type, superExtensionReceiver.type)
) {
return incompatible("Extension receiver parameter type mismatch")
}
for ((index, superValueParameter) in superValueParameters.withIndex()) {
if (!AbstractTypeChecker.equalTypes(typeCheckerState, subValueParameters[index].type, superValueParameter.type)) {
return incompatible("Value parameter type mismatch")
}
}
return success()
}
private fun areTypeParametersEquivalent(
superTypeParameter: IrTypeParameter,
subTypeParameter: IrTypeParameter,
typeCheckerState: TypeCheckerState,
): Boolean {
val superBounds = superTypeParameter.superTypes
val subBounds = subTypeParameter.superTypes.toMutableList()
if (superBounds.size != subBounds.size) return false
outer@ for (superBound in superBounds) {
val it = subBounds.listIterator()
while (it.hasNext()) {
val subBound = it.next()
if (AbstractTypeChecker.equalTypes(typeCheckerState, superBound, subBound)) {
it.remove()
continue@outer
}
}
return false
}
return true
}
private fun runExternalOverridabilityConditions(
superMember: MemberWithOriginal,
subMember: MemberWithOriginal,
basicResult: OverrideCompatibilityInfo,
): OverrideCompatibilityInfo {
var wasSuccess = basicResult.result == OverrideCompatibilityInfo.Result.OVERRIDABLE
for (externalCondition in externalOverridabilityConditions) {
// Do not run CONFLICTS_ONLY while there was no success
if (externalCondition.contract == CONFLICTS_ONLY) continue
if (wasSuccess && externalCondition.contract == SUCCESS_ONLY) continue
val result =
externalCondition.isOverridable(superMember, subMember)
when (result) {
OVERRIDABLE -> wasSuccess = true
INCOMPATIBLE -> return incompatible("External condition")
UNKNOWN -> {}
}
}
if (!wasSuccess) return basicResult
// Search for conflicts from external conditions
for (externalCondition in externalOverridabilityConditions) {
// Run all conditions that was not run before (i.e. CONFLICTS_ONLY)
if (externalCondition.contract != CONFLICTS_ONLY) continue
val result =
externalCondition.isOverridable(superMember, subMember)
when (result) {
INCOMPATIBLE -> return incompatible("External condition")
OVERRIDABLE -> error(
"Contract violation in ${externalCondition.javaClass} condition. It's not supposed to end with success"
)
UNKNOWN -> {}
}
}
return success()
}
}