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/*
* Copyright 2010-2018 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.resolve.calls
import com.google.common.collect.Lists
import org.jetbrains.kotlin.builtins.ReflectionTypes
import org.jetbrains.kotlin.builtins.isSuspendFunctionType
import org.jetbrains.kotlin.descriptors.*
import org.jetbrains.kotlin.descriptors.annotations.AnnotationDescriptor
import org.jetbrains.kotlin.descriptors.impl.TypeAliasConstructorDescriptor
import org.jetbrains.kotlin.diagnostics.Errors
import org.jetbrains.kotlin.diagnostics.Errors.EXPANDED_TYPE_CANNOT_BE_CONSTRUCTED
import org.jetbrains.kotlin.diagnostics.Errors.SUPER_CANT_BE_EXTENSION_RECEIVER
import org.jetbrains.kotlin.progress.ProgressIndicatorAndCompilationCanceledStatus
import org.jetbrains.kotlin.psi.*
import org.jetbrains.kotlin.resolve.*
import org.jetbrains.kotlin.resolve.calls.CallTransformer.CallForImplicitInvoke
import org.jetbrains.kotlin.resolve.calls.checkers.AdditionalTypeChecker
import org.jetbrains.kotlin.resolve.calls.context.*
import org.jetbrains.kotlin.resolve.calls.inference.SubstitutionFilteringInternalResolveAnnotations
import org.jetbrains.kotlin.resolve.calls.model.ArgumentMatchStatus
import org.jetbrains.kotlin.resolve.calls.model.MutableResolvedCall
import org.jetbrains.kotlin.resolve.calls.results.ResolutionStatus
import org.jetbrains.kotlin.resolve.calls.results.ResolutionStatus.*
import org.jetbrains.kotlin.resolve.calls.smartcasts.DataFlowValueFactory
import org.jetbrains.kotlin.resolve.calls.smartcasts.SmartCastManager
import org.jetbrains.kotlin.resolve.calls.smartcasts.getReceiverValueWithSmartCast
import org.jetbrains.kotlin.resolve.calls.util.*
import org.jetbrains.kotlin.resolve.calls.util.ResolveArgumentsMode.SHAPE_FUNCTION_ARGUMENTS
import org.jetbrains.kotlin.resolve.scopes.receivers.ExpressionReceiver
import org.jetbrains.kotlin.resolve.scopes.receivers.Receiver
import org.jetbrains.kotlin.resolve.scopes.receivers.ReceiverValue
import org.jetbrains.kotlin.types.*
import org.jetbrains.kotlin.types.TypeUtils.noExpectedType
import org.jetbrains.kotlin.types.checker.ErrorTypesAreEqualToAnything
import org.jetbrains.kotlin.types.checker.KotlinTypeChecker
import org.jetbrains.kotlin.types.error.ErrorUtils
import org.jetbrains.kotlin.types.error.ErrorTypeKind
import org.jetbrains.kotlin.types.expressions.DoubleColonExpressionResolver
import org.jetbrains.kotlin.types.typeUtil.containsTypeProjectionsInTopLevelArguments
import org.jetbrains.kotlin.types.typeUtil.makeNotNullable
import kotlin.math.min
class CandidateResolver(
private val argumentTypeResolver: ArgumentTypeResolver,
private val genericCandidateResolver: GenericCandidateResolver,
private val reflectionTypes: ReflectionTypes,
private val additionalTypeCheckers: Iterable,
private val smartCastManager: SmartCastManager,
private val dataFlowValueFactory: DataFlowValueFactory,
private val upperBoundChecker: UpperBoundChecker
) {
fun performResolutionForCandidateCall(
context: CallCandidateResolutionContext,
checkArguments: CheckArgumentTypesMode
): Unit = with(context) {
ProgressIndicatorAndCompilationCanceledStatus.checkCanceled()
if (ErrorUtils.isError(candidateDescriptor)) {
candidateCall.addStatus(SUCCESS)
return
}
if (!checkOuterClassMemberIsAccessible(this)) {
candidateCall.addStatus(OTHER_ERROR)
return
}
if (!context.isDebuggerContext) {
checkVisibilityWithoutReceiver()
}
when (checkArguments) {
CheckArgumentTypesMode.CHECK_VALUE_ARGUMENTS ->
mapArguments()
CheckArgumentTypesMode.CHECK_CALLABLE_TYPE ->
checkExpectedCallableType()
}
checkReceiverTypeError()
checkExtensionReceiver()
checkDispatchReceiver()
processTypeArguments()
checkValueArguments()
checkAbstractAndSuper()
checkConstructedExpandedType()
}
private fun CallCandidateResolutionContext<*>.checkValueArguments() = checkAndReport {
if (call.typeArguments.isEmpty()
&& !candidateDescriptor.typeParameters.isEmpty()
&& candidateCall.knownTypeParametersSubstitutor == null
) {
genericCandidateResolver.inferTypeArguments(this)
} else {
checkAllValueArguments(this, SHAPE_FUNCTION_ARGUMENTS).status
}
}
private fun CallCandidateResolutionContext<*>.processTypeArguments() = check {
val ktTypeArguments = call.typeArguments
if (candidateCall.knownTypeParametersSubstitutor != null) {
candidateCall.setSubstitutor(candidateCall.knownTypeParametersSubstitutor!!)
} else if (ktTypeArguments.isNotEmpty()) {
// Explicit type arguments passed
val typeArguments = ArrayList()
for (projection in ktTypeArguments) {
val type = projection.typeReference?.let { trace.bindingContext.get(BindingContext.TYPE, it) }
?: ErrorUtils.createErrorType(ErrorTypeKind.STAR_PROJECTION_IN_CALL)
typeArguments.add(type)
}
val expectedTypeArgumentCount = candidateDescriptor.typeParameters.size
for (index in ktTypeArguments.size until expectedTypeArgumentCount) {
typeArguments.add(
ErrorUtils.createErrorType(
ErrorTypeKind.MISSED_TYPE_ARGUMENT_FOR_TYPE_PARAMETER,
candidateDescriptor.typeParameters[index].name.toString()
)
)
}
val substitution = FunctionDescriptorUtil.createSubstitution(candidateDescriptor as FunctionDescriptor, typeArguments)
val substitutor = TypeSubstitutor.create(SubstitutionFilteringInternalResolveAnnotations(substitution))
if (expectedTypeArgumentCount != ktTypeArguments.size) {
candidateCall.addStatus(WRONG_NUMBER_OF_TYPE_ARGUMENTS_ERROR)
tracing.wrongNumberOfTypeArguments(trace, expectedTypeArgumentCount, candidateDescriptor)
} else {
checkGenericBoundsInAFunctionCall(ktTypeArguments, typeArguments, candidateDescriptor, substitutor, trace)
}
candidateCall.setSubstitutor(substitutor)
}
}
private fun CallCandidateResolutionContext.mapArguments() = check {
val argumentMappingStatus = ValueArgumentsToParametersMapper.mapValueArgumentsToParameters(
call, tracing, candidateCall, languageVersionSettings
)
if (!argumentMappingStatus.isSuccess) {
candidateCall.addStatus(ARGUMENTS_MAPPING_ERROR)
}
}
private fun CallCandidateResolutionContext.checkExpectedCallableType() = check {
if (!noExpectedType(expectedType)) {
val candidateKCallableType = DoubleColonExpressionResolver.createKCallableTypeForReference(
candidateCall.candidateDescriptor,
(call.callElement.parent as? KtCallableReferenceExpression)?.receiverExpression?.let {
trace.bindingContext.get(BindingContext.DOUBLE_COLON_LHS, it)
},
reflectionTypes, scope.ownerDescriptor
)
if (candidateKCallableType == null ||
!canBeSubtype(candidateKCallableType, expectedType, candidateCall.candidateDescriptor.typeParameters)) {
candidateCall.addStatus(OTHER_ERROR)
}
}
}
private fun canBeSubtype(subType: KotlinType, superType: KotlinType, candidateTypeParameters: List): Boolean {
// Here we need to check that there exists a substitution from type parameters (used in types in candidate signature)
// to arguments such that substituted candidateKCallableType would be a subtype of expectedType.
// It looks like in general this can only be decided by constructing a constraint system and checking
// if it has a contradiction. Currently we use a heuristic that may not work ideally in all cases.
// TODO: use constraint system to check if candidateKCallableType can be a subtype of expectedType
val substituteDontCare = makeConstantSubstitutor(candidateTypeParameters, TypeUtils.DONT_CARE)
val subTypeSubstituted = substituteDontCare.substitute(subType, Variance.INVARIANT) ?: return true
return ErrorTypesAreEqualToAnything.isSubtypeOf(subTypeSubstituted, superType)
}
private fun CallCandidateResolutionContext<*>.checkVisibilityWithoutReceiver() = checkAndReport {
checkVisibilityWithDispatchReceiver(DescriptorVisibilities.ALWAYS_SUITABLE_RECEIVER, null)
}
private fun CallCandidateResolutionContext<*>.checkVisibilityWithDispatchReceiver(
receiverArgument: ReceiverValue?,
smartCastType: KotlinType?
): ResolutionStatus {
val invisibleMember = DescriptorVisibilityUtils.findInvisibleMember(
getReceiverValueWithSmartCast(receiverArgument, smartCastType),
candidateDescriptor,
scope.ownerDescriptor,
languageVersionSettings
)
return if (invisibleMember != null) {
tracing.invisibleMember(trace, invisibleMember)
INVISIBLE_MEMBER_ERROR
} else {
SUCCESS
}
}
private fun CallCandidateResolutionContext<*>.isCandidateVisibleOrExtensionReceiver(
receiverArgument: ReceiverValue?,
smartCastType: KotlinType?,
isDispatchReceiver: Boolean
) = !isDispatchReceiver || isCandidateVisible(receiverArgument, smartCastType)
private fun CallCandidateResolutionContext<*>.isCandidateVisible(
receiverArgument: ReceiverValue?,
smartCastType: KotlinType?
) = DescriptorVisibilityUtils.findInvisibleMember(
getReceiverValueWithSmartCast(receiverArgument, smartCastType),
candidateDescriptor, scope.ownerDescriptor,
languageVersionSettings
) == null
private fun CallCandidateResolutionContext<*>.checkExtensionReceiver() = checkAndReport {
val receiverParameter = candidateCall.candidateDescriptor.extensionReceiverParameter
val receiverArgument = candidateCall.extensionReceiver
if (receiverParameter != null && receiverArgument == null) {
tracing.missingReceiver(candidateCall.trace, receiverParameter)
OTHER_ERROR
} else if (receiverParameter == null && receiverArgument != null) {
tracing.noReceiverAllowed(candidateCall.trace)
if (call.calleeExpression is KtSimpleNameExpression) {
RECEIVER_PRESENCE_ERROR
} else {
OTHER_ERROR
}
} else {
SUCCESS
}
}
private fun CallCandidateResolutionContext<*>.checkDispatchReceiver() = checkAndReport {
val candidateDescriptor = candidateDescriptor
val dispatchReceiver = candidateCall.dispatchReceiver
if (dispatchReceiver != null) {
var nestedClass: ClassDescriptor? = null
if (candidateDescriptor is ClassConstructorDescriptor
&& DescriptorUtils.isStaticNestedClass(candidateDescriptor.containingDeclaration)
) {
nestedClass = candidateDescriptor.containingDeclaration
} else if (candidateDescriptor is FakeCallableDescriptorForObject) {
nestedClass = candidateDescriptor.getReferencedObject()
}
if (nestedClass != null) {
tracing.nestedClassAccessViaInstanceReference(trace, nestedClass, candidateCall.explicitReceiverKind)
return@checkAndReport OTHER_ERROR
}
}
assert((dispatchReceiver != null) == (candidateCall.resultingDescriptor.dispatchReceiverParameter != null)) {
"Shouldn't happen because of TaskPrioritizer: $candidateDescriptor"
}
SUCCESS
}
private fun checkOuterClassMemberIsAccessible(context: CallCandidateResolutionContext<*>): Boolean {
fun KtElement.insideScript() = (containingFile as? KtFile)?.isScript() ?: false
// context.scope doesn't contains outer class implicit receiver if we inside nested class
// Outer scope for some class in script file is scopeForInitializerResolution see: DeclarationScopeProviderImpl.getResolutionScopeForDeclaration
if (!context.call.callElement.insideScript()) return true
// In "[email protected]()" the error will be reported on "this@Outer" instead
if (context.call.explicitReceiver != null || context.call.dispatchReceiver != null) return true
val candidateThis = getDeclaringClass(context.candidateCall.candidateDescriptor)
if (candidateThis == null || candidateThis.kind.isSingleton) return true
return DescriptorResolver.checkHasOuterClassInstance(context.scope, context.trace, context.call.callElement, candidateThis)
}
private fun CallCandidateResolutionContext<*>.checkAbstractAndSuper() = check {
val descriptor = candidateDescriptor
val expression = candidateCall.call.calleeExpression
if (expression is KtSimpleNameExpression) {
// 'B' in 'class A: B()' is KtConstructorCalleeExpression
if (descriptor is ConstructorDescriptor) {
val modality = descriptor.constructedClass.modality
if (modality == Modality.ABSTRACT) {
tracing.instantiationOfAbstractClass(trace)
}
}
}
val superDispatchReceiver = getReceiverSuper(candidateCall.dispatchReceiver)
if (superDispatchReceiver != null) {
if (descriptor is MemberDescriptor && descriptor.modality == Modality.ABSTRACT) {
tracing.abstractSuperCall(trace)
candidateCall.addStatus(OTHER_ERROR)
}
}
// 'super' cannot be passed as an argument, for receiver arguments expression typer does not track this
// See TaskPrioritizer for more
val superExtensionReceiver = getReceiverSuper(candidateCall.extensionReceiver)
if (superExtensionReceiver != null) {
trace.report(SUPER_CANT_BE_EXTENSION_RECEIVER.on(superExtensionReceiver, superExtensionReceiver.text))
candidateCall.addStatus(OTHER_ERROR)
}
}
private fun CallCandidateResolutionContext<*>.checkConstructedExpandedType() = check {
val descriptor = candidateDescriptor
if (descriptor is TypeAliasConstructorDescriptor) {
if (descriptor.returnType.containsTypeProjectionsInTopLevelArguments()) {
trace.report(EXPANDED_TYPE_CANNOT_BE_CONSTRUCTED.on(call.callElement, descriptor.returnType))
candidateCall.addStatus(OTHER_ERROR)
}
}
}
private fun getReceiverSuper(receiver: Receiver?): KtSuperExpression? {
if (receiver is ExpressionReceiver) {
val expression = receiver.expression
if (expression is KtSuperExpression) {
return expression
}
}
return null
}
private fun getDeclaringClass(candidate: CallableDescriptor): ClassDescriptor? {
val expectedThis = candidate.dispatchReceiverParameter ?: return null
val descriptor = expectedThis.containingDeclaration
return if (descriptor is ClassDescriptor) descriptor else null
}
fun checkAllValueArguments(
context: CallCandidateResolutionContext,
resolveFunctionArgumentBodies: ResolveArgumentsMode
): ValueArgumentsCheckingResult {
val checkingResult = checkValueArgumentTypes(context, context.candidateCall, resolveFunctionArgumentBodies)
var resultStatus = checkingResult.status
resultStatus = resultStatus.combine(checkReceivers(context))
return ValueArgumentsCheckingResult(resultStatus, checkingResult.argumentTypes)
}
private fun > checkValueArgumentTypes(
context: CallResolutionContext,
candidateCall: MutableResolvedCall,
resolveFunctionArgumentBodies: ResolveArgumentsMode
): ValueArgumentsCheckingResult {
var resultStatus = SUCCESS
val argumentTypes = Lists.newArrayList()
val infoForArguments = candidateCall.dataFlowInfoForArguments
for ((parameterDescriptor, resolvedArgument) in candidateCall.valueArguments) {
for (argument in resolvedArgument.arguments) {
val expression = argument.getArgumentExpression() ?: continue
val expectedType = getEffectiveExpectedType(parameterDescriptor, argument, context)
val newContext = context.replaceDataFlowInfo(infoForArguments.getInfo(argument)).replaceExpectedType(expectedType)
val typeInfoForCall = argumentTypeResolver.getArgumentTypeInfo(expression, newContext, resolveFunctionArgumentBodies, expectedType.isSuspendFunctionType)
val type = typeInfoForCall.type
infoForArguments.updateInfo(argument, typeInfoForCall.dataFlowInfo)
var matchStatus = ArgumentMatchStatus.SUCCESS
var resultingType: KotlinType? = type
if (type == null || (type.isError && !type.isFunctionPlaceholder)) {
matchStatus = ArgumentMatchStatus.ARGUMENT_HAS_NO_TYPE
} else if (!noExpectedType(expectedType)) {
if (!argumentTypeResolver.isSubtypeOfForArgumentType(type, expectedType)) {
val smartCast = smartCastValueArgumentTypeIfPossible(expression, newContext.expectedType, type, newContext)
if (smartCast == null) {
resultStatus = tryNotNullableArgument(type, expectedType) ?: OTHER_ERROR
matchStatus = ArgumentMatchStatus.TYPE_MISMATCH
} else {
resultingType = smartCast
}
} else if (ErrorUtils.containsUninferredTypeVariable(expectedType)) {
matchStatus = ArgumentMatchStatus.MATCH_MODULO_UNINFERRED_TYPES
}
val spreadElement = argument.getSpreadElement()
if (spreadElement != null && !type.isFlexible() && type.isMarkedNullable) {
val dataFlowValue = dataFlowValueFactory.createDataFlowValue(expression, type, context)
val smartCastResult = smartCastManager.checkAndRecordPossibleCast(
dataFlowValue, expectedType, expression, context,
call = null, recordExpressionType = false
)
if (smartCastResult == null || !smartCastResult.isCorrect) {
context.trace.report(Errors.SPREAD_OF_NULLABLE.on(spreadElement))
}
}
}
if (resultingType != null) argumentTypes.add(resultingType)
candidateCall.recordArgumentMatchStatus(argument, matchStatus)
}
}
return ValueArgumentsCheckingResult(resultStatus, argumentTypes)
}
private fun smartCastValueArgumentTypeIfPossible(
expression: KtExpression,
expectedType: KotlinType,
actualType: KotlinType,
context: ResolutionContext<*>
): KotlinType? {
val receiverToCast = ExpressionReceiver.create(KtPsiUtil.safeDeparenthesize(expression), actualType, context.trace.bindingContext)
val variants = smartCastManager.getSmartCastVariantsExcludingReceiver(context, receiverToCast)
return variants.firstOrNull { possibleType ->
KotlinTypeChecker.DEFAULT.isSubtypeOf(possibleType, expectedType)
}
}
private fun tryNotNullableArgument(argumentType: KotlinType, parameterType: KotlinType): ResolutionStatus? {
if (!argumentType.isMarkedNullable || parameterType.isMarkedNullable) return null
val notNullableArgumentType = argumentType.makeNotNullable()
val isApplicable = argumentTypeResolver.isSubtypeOfForArgumentType(notNullableArgumentType, parameterType)
return if (isApplicable) NULLABLE_ARGUMENT_TYPE_MISMATCH else null
}
private fun CallCandidateResolutionContext<*>.checkReceiverTypeError(): Unit = check {
val extensionReceiver = candidateDescriptor.extensionReceiverParameter
val dispatchReceiver = candidateDescriptor.dispatchReceiverParameter
// For the expressions like '42.(f)()' where f: String.() -> Unit we'd like to generate a type mismatch error on '1',
// not to throw away the candidate, so the following check is skipped.
if (!isInvokeCallOnExpressionWithBothReceivers(call)) {
checkReceiverTypeError(extensionReceiver, candidateCall.extensionReceiver)
}
checkReceiverTypeError(dispatchReceiver, candidateCall.dispatchReceiver)
}
private fun CallCandidateResolutionContext<*>.checkReceiverTypeError(
receiverParameterDescriptor: ReceiverParameterDescriptor?,
receiverArgument: ReceiverValue?
) = checkAndReport {
if (receiverParameterDescriptor == null || receiverArgument == null) return@checkAndReport SUCCESS
val erasedReceiverType = getErasedReceiverType(receiverParameterDescriptor, candidateDescriptor)
if (smartCastManager.getSmartCastReceiverResult(receiverArgument, erasedReceiverType, this) == null) {
RECEIVER_TYPE_ERROR
} else {
SUCCESS
}
}
private fun checkReceivers(context: CallCandidateResolutionContext): ResolutionStatus {
var resultStatus = SUCCESS
val candidateCall = context.candidateCall
// Comment about a very special case.
// Call 'b.foo(1)' where class 'Foo' has an extension member 'fun B.invoke(Int)' should be checked two times for safe call (in 'checkReceiver'), because
// both 'b' (receiver) and 'foo' (this object) might be nullable. In the first case we mark dot, in the second 'foo'.
// Class 'CallForImplicitInvoke' helps up to recognise this case, and parameter 'implicitInvokeCheck' helps us to distinguish whether we check receiver or this object.
resultStatus = resultStatus.combine(
context.checkReceiver(
candidateCall,
candidateCall.resultingDescriptor.extensionReceiverParameter,
candidateCall.extensionReceiver,
candidateCall.explicitReceiverKind.isExtensionReceiver,
implicitInvokeCheck = false, isDispatchReceiver = false
)
)
resultStatus = resultStatus.combine(
context.checkReceiver(
candidateCall,
candidateCall.resultingDescriptor.dispatchReceiverParameter, candidateCall.dispatchReceiver,
candidateCall.explicitReceiverKind.isDispatchReceiver,
// for the invocation 'foo(1)' where foo is a variable of function type we should mark 'foo' if there is unsafe call error
implicitInvokeCheck = context.call is CallForImplicitInvoke,
isDispatchReceiver = true
)
)
if (!context.isDebuggerContext
&& candidateCall.dispatchReceiver != null
// Do not report error if it's already reported when checked without receiver
&& context.isCandidateVisible(receiverArgument = DescriptorVisibilities.ALWAYS_SUITABLE_RECEIVER, smartCastType = null)) {
resultStatus = resultStatus.combine(
context.checkVisibilityWithDispatchReceiver(
candidateCall.dispatchReceiver, candidateCall.smartCastDispatchReceiverType
)
)
}
return resultStatus
}
private fun CallCandidateResolutionContext.checkReceiver(
candidateCall: MutableResolvedCall,
receiverParameter: ReceiverParameterDescriptor?,
receiverArgument: ReceiverValue?,
isExplicitReceiver: Boolean,
implicitInvokeCheck: Boolean,
isDispatchReceiver: Boolean
): ResolutionStatus {
if (receiverParameter == null || receiverArgument == null) return SUCCESS
val candidateDescriptor = candidateCall.candidateDescriptor
if (TypeUtils.dependsOnTypeParameters(receiverParameter.type, candidateDescriptor.typeParameters)) return SUCCESS
// Here we know that receiver is OK ignoring nullability and check that nullability is OK too
// Doing it simply as full subtyping check (receiverValueType <: receiverParameterType)
val call = candidateCall.call
val safeAccess = isExplicitReceiver && !implicitInvokeCheck && call.isSemanticallyEquivalentToSafeCall
val expectedReceiverParameterType = if (safeAccess) TypeUtils.makeNullable(receiverParameter.type) else receiverParameter.type
val smartCastSubtypingResult = smartCastManager.getSmartCastReceiverResult(receiverArgument, expectedReceiverParameterType, this)
if (smartCastSubtypingResult == null) {
tracing.wrongReceiverType(
trace, receiverParameter, receiverArgument,
this.replaceCallPosition(CallPosition.ExtensionReceiverPosition(candidateCall))
)
return OTHER_ERROR
}
val notNullReceiverExpected = smartCastSubtypingResult != SmartCastManager.ReceiverSmartCastResult.OK
val smartCastNeeded =
notNullReceiverExpected || !isCandidateVisibleOrExtensionReceiver(receiverArgument, null, isDispatchReceiver)
var reportUnsafeCall = false
var nullableImplicitInvokeReceiver = false
var receiverArgumentType = receiverArgument.type
if (implicitInvokeCheck && call is CallForImplicitInvoke && call.isSafeCall()) {
val outerCallReceiver = call.outerCall.explicitReceiver
if (outerCallReceiver != call.explicitReceiver && outerCallReceiver is ReceiverValue) {
val outerReceiverDataFlowValue = dataFlowValueFactory.createDataFlowValue(outerCallReceiver, this)
val outerReceiverNullability = dataFlowInfo.getStableNullability(outerReceiverDataFlowValue)
if (outerReceiverNullability.canBeNull() && !TypeUtils.isNullableType(expectedReceiverParameterType)) {
nullableImplicitInvokeReceiver = true
receiverArgumentType = TypeUtils.makeNullable(receiverArgumentType)
}
}
}
val dataFlowValue = dataFlowValueFactory.createDataFlowValue(receiverArgument, this)
val nullability = dataFlowInfo.getStableNullability(dataFlowValue)
val expression = (receiverArgument as? ExpressionReceiver)?.expression
if (nullability.canBeNull() && !nullability.canBeNonNull()) {
if (!TypeUtils.isNullableType(expectedReceiverParameterType)) {
reportUnsafeCall = true
}
if (dataFlowValue.immanentNullability.canBeNonNull()) {
expression?.let { trace.record(BindingContext.SMARTCAST_NULL, it) }
}
} else if (!nullableImplicitInvokeReceiver && smartCastNeeded) {
// Look if smart cast has some useful nullability info
val smartCastResult = smartCastManager.checkAndRecordPossibleCast(
dataFlowValue, expectedReceiverParameterType,
expression, this, candidateCall.call, recordExpressionType = true
) { possibleSmartCast -> isCandidateVisibleOrExtensionReceiver(receiverArgument, possibleSmartCast, isDispatchReceiver) }
if (smartCastResult == null) {
if (notNullReceiverExpected) {
reportUnsafeCall = true
}
} else {
if (isDispatchReceiver) {
candidateCall.setSmartCastDispatchReceiverType(smartCastResult.resultType)
} else {
candidateCall.updateExtensionReceiverWithSmartCastIfNeeded(smartCastResult.resultType)
}
if (!smartCastResult.isCorrect) {
// Error about unstable smart cast reported within checkAndRecordPossibleCast
return UNSTABLE_SMARTCAST_FOR_RECEIVER_ERROR
}
}
}
if (reportUnsafeCall || nullableImplicitInvokeReceiver) {
tracing.unsafeCall(trace, receiverArgumentType, implicitInvokeCheck)
return UNSAFE_CALL_ERROR
}
additionalTypeCheckers.forEach { it.checkReceiver(receiverParameter, receiverArgument, safeAccess, this) }
return SUCCESS
}
inner class ValueArgumentsCheckingResult(val status: ResolutionStatus, val argumentTypes: List)
private fun CallCandidateResolutionContext<*>.checkGenericBoundsInAFunctionCall(
ktTypeArguments: List,
typeArguments: List,
functionDescriptor: CallableDescriptor,
substitutor: TypeSubstitutor,
trace: BindingTrace
) {
if (functionDescriptor is TypeAliasConstructorDescriptor) {
checkGenericBoundsInTypeAliasConstructorCall(ktTypeArguments, functionDescriptor, substitutor, trace)
return
}
val typeParameters = functionDescriptor.typeParameters
for (i in 0..min(typeParameters.size, ktTypeArguments.size) - 1) {
val typeParameterDescriptor = typeParameters[i]
val typeArgument = typeArguments[i]
val typeReference = ktTypeArguments[i].typeReference
if (typeReference != null) {
upperBoundChecker.checkBounds(typeReference, typeArgument, typeParameterDescriptor, substitutor, trace)
}
}
}
private class TypeAliasSingleStepExpansionReportStrategy(
private val callElement: KtElement,
typeAlias: TypeAliasDescriptor,
ktTypeArguments: List,
private val trace: BindingTrace,
private val upperBoundChecker: UpperBoundChecker
) : TypeAliasExpansionReportStrategy {
init {
assert(!typeAlias.expandedType.isError) { "Incorrect type alias: $typeAlias" }
}
private val argumentsMapping = typeAlias.declaredTypeParameters.zip(ktTypeArguments).toMap()
override fun wrongNumberOfTypeArguments(typeAlias: TypeAliasDescriptor, numberOfParameters: Int) {
// can't happen in single-step expansion
}
override fun conflictingProjection(
typeAlias: TypeAliasDescriptor,
typeParameter: TypeParameterDescriptor?,
substitutedArgument: KotlinType
) {
// can't happen in single-step expansion
}
override fun recursiveTypeAlias(typeAlias: TypeAliasDescriptor) {
// can't happen in single-step expansion
}
override fun repeatedAnnotation(annotation: AnnotationDescriptor) {
// can't happen in single-step expansion
}
override fun boundsViolationInSubstitution(
substitutor: TypeSubstitutor,
unsubstitutedArgument: KotlinType,
argument: KotlinType,
typeParameter: TypeParameterDescriptor
) {
val descriptorForUnsubstitutedArgument = unsubstitutedArgument.constructor.declarationDescriptor
val argumentElement = argumentsMapping[descriptorForUnsubstitutedArgument]
val argumentTypeReferenceElement = argumentElement?.typeReference
upperBoundChecker.checkBounds(argumentTypeReferenceElement, argument, typeParameter, substitutor, trace, callElement)
}
}
private fun CallCandidateResolutionContext<*>.checkGenericBoundsInTypeAliasConstructorCall(
ktTypeArguments: List,
typeAliasConstructorDescriptor: TypeAliasConstructorDescriptor,
typeAliasParametersSubstitutor: TypeSubstitutor,
trace: BindingTrace
) {
val substitutedType = typeAliasParametersSubstitutor.substitute(typeAliasConstructorDescriptor.returnType, Variance.INVARIANT)!!
val boundsSubstitutor = TypeSubstitutor.create(substitutedType)
val typeAliasDescriptor = typeAliasConstructorDescriptor.containingDeclaration
val unsubstitutedType = typeAliasDescriptor.expandedType
if (unsubstitutedType.isError) return
val reportStrategy =
TypeAliasSingleStepExpansionReportStrategy(call.callElement, typeAliasDescriptor, ktTypeArguments, trace, upperBoundChecker)
// TODO refactor TypeResolver
// - perform full type alias expansion
// - provide type alias expansion stack in diagnostics
checkTypeInTypeAliasSubstitutionRec(reportStrategy, unsubstitutedType, typeAliasParametersSubstitutor, boundsSubstitutor)
}
private fun checkTypeInTypeAliasSubstitutionRec(
reportStrategy: TypeAliasExpansionReportStrategy,
unsubstitutedType: KotlinType,
typeAliasParametersSubstitutor: TypeSubstitutor,
boundsSubstitutor: TypeSubstitutor
) {
// TODO refactor TypeResolver
val typeParameters = unsubstitutedType.constructor.parameters
// TODO do not perform substitution for type arguments multiple times
val substitutedTypeArguments = typeAliasParametersSubstitutor.safeSubstitute(unsubstitutedType, Variance.INVARIANT).arguments
for (i in 0..min(typeParameters.size, substitutedTypeArguments.size) - 1) {
val substitutedTypeProjection = substitutedTypeArguments[i]
if (substitutedTypeProjection.isStarProjection) continue
val typeParameter = typeParameters[i]
val substitutedTypeArgument = substitutedTypeProjection.type
val unsubstitutedTypeArgument = unsubstitutedType.arguments[i].type
reportStrategy.boundsViolationInSubstitution(
boundsSubstitutor,
unsubstitutedTypeArgument,
substitutedTypeArgument,
typeParameter
)
checkTypeInTypeAliasSubstitutionRec(
reportStrategy,
unsubstitutedTypeArgument,
typeAliasParametersSubstitutor,
boundsSubstitutor
)
}
}
private fun CallCandidateResolutionContext.shouldContinue() =
candidateResolveMode == CandidateResolveMode.FULLY || candidateCall.status.possibleTransformToSuccess()
private inline fun CallCandidateResolutionContext.check(
crossinline checker: CallCandidateResolutionContext.() -> Unit
) {
if (shouldContinue()) checker() else candidateCall.addRemainingTasks { checker() }
}
private inline fun CallCandidateResolutionContext.checkAndReport(
crossinline checker: CallCandidateResolutionContext.() -> ResolutionStatus
) {
check {
candidateCall.addStatus(checker())
}
}
private val CallCandidateResolutionContext<*>.candidateDescriptor: CallableDescriptor
get() = candidateCall.candidateDescriptor
}