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Kotlin Full Reflection Library
/*
* Copyright 2010-2017 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 kotlin.reflect.jvm.internal.impl.resolve;
import kotlin.Pair;
import kotlin.Unit;
import kotlin.annotations.jvm.Mutable;
import kotlin.collections.CollectionsKt;
import kotlin.jvm.functions.Function0;
import kotlin.jvm.functions.Function1;
import kotlin.jvm.functions.Function2;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.annotations.Nullable;
import kotlin.reflect.jvm.internal.impl.descriptors.*;
import kotlin.reflect.jvm.internal.impl.descriptors.impl.FunctionDescriptorImpl;
import kotlin.reflect.jvm.internal.impl.descriptors.impl.PropertyAccessorDescriptorImpl;
import kotlin.reflect.jvm.internal.impl.descriptors.impl.PropertyDescriptorImpl;
import kotlin.reflect.jvm.internal.impl.name.Name;
import kotlin.reflect.jvm.internal.impl.resolve.descriptorUtil.DescriptorUtilsKt;
import kotlin.reflect.jvm.internal.impl.types.*;
import kotlin.reflect.jvm.internal.impl.types.checker.KotlinTypeChecker;
import kotlin.reflect.jvm.internal.impl.types.checker.KotlinTypePreparator;
import kotlin.reflect.jvm.internal.impl.types.checker.KotlinTypeRefiner;
import kotlin.reflect.jvm.internal.impl.utils.SmartSet;
import java.util.*;
import static kotlin.reflect.jvm.internal.impl.resolve.OverridingUtil.OverrideCompatibilityInfo.Result.*;
public class OverridingUtil {
private static final List EXTERNAL_CONDITIONS =
CollectionsKt.toList(ServiceLoader.load(
ExternalOverridabilityCondition.class,
ExternalOverridabilityCondition.class.getClassLoader()
));
public static final OverridingUtil DEFAULT;
private static final KotlinTypeChecker.TypeConstructorEquality DEFAULT_TYPE_CONSTRUCTOR_EQUALITY =
new KotlinTypeChecker.TypeConstructorEquality() {
@Override
public boolean equals(@NotNull TypeConstructor a, @NotNull TypeConstructor b) {
return a.equals(b);
}
};
static {
DEFAULT = new OverridingUtil(
DEFAULT_TYPE_CONSTRUCTOR_EQUALITY, KotlinTypeRefiner.Default.INSTANCE, KotlinTypePreparator.Default.INSTANCE,
null
);
}
@NotNull
public static OverridingUtil createWithTypeRefiner(@NotNull KotlinTypeRefiner kotlinTypeRefiner) {
return new OverridingUtil(DEFAULT_TYPE_CONSTRUCTOR_EQUALITY, kotlinTypeRefiner, KotlinTypePreparator.Default.INSTANCE, null);
}
@NotNull
public static OverridingUtil createWithTypePreparatorAndCustomSubtype(
@NotNull KotlinTypePreparator kotlinTypePreparator,
@NotNull Function2 customSubtype
) {
return new OverridingUtil(DEFAULT_TYPE_CONSTRUCTOR_EQUALITY, KotlinTypeRefiner.Default.INSTANCE, kotlinTypePreparator, customSubtype);
}
@NotNull
public static OverridingUtil create(
@NotNull KotlinTypeRefiner kotlinTypeRefiner,
@NotNull KotlinTypeChecker.TypeConstructorEquality equalityAxioms
) {
return new OverridingUtil(equalityAxioms, kotlinTypeRefiner, KotlinTypePreparator.Default.INSTANCE, null);
}
private final KotlinTypeRefiner kotlinTypeRefiner;
private final KotlinTypePreparator kotlinTypePreparator;
private final KotlinTypeChecker.TypeConstructorEquality equalityAxioms;
private final Function2 customSubtype;
private OverridingUtil(
@NotNull KotlinTypeChecker.TypeConstructorEquality axioms,
@NotNull KotlinTypeRefiner kotlinTypeRefiner,
@NotNull KotlinTypePreparator kotlinTypePreparator,
@Nullable Function2 customSubtype
) {
equalityAxioms = axioms;
this.kotlinTypeRefiner = kotlinTypeRefiner;
this.kotlinTypePreparator = kotlinTypePreparator;
this.customSubtype = customSubtype;
}
/**
* Given a set of descriptors, returns a set containing all the given descriptors except those which _are overridden_ by at least
* one other descriptor from the original set.
*/
@NotNull
public static Set filterOutOverridden(@NotNull Set candidateSet) {
boolean allowDescriptorCopies = !candidateSet.isEmpty() &&
DescriptorUtilsKt
.isTypeRefinementEnabled(DescriptorUtilsKt.getModule(candidateSet.iterator().next()));
return filterOverrides(candidateSet, allowDescriptorCopies, null, new Function2>() {
@Override
public Pair invoke(D a, D b) {
return new Pair(a, b);
}
});
}
@NotNull
public static Set filterOverrides(
@NotNull Set candidateSet,
boolean allowDescriptorCopies,
@Nullable Function0 cancellationCallback,
@NotNull Function2> transformFirst
) {
if (candidateSet.size() <= 1) return candidateSet;
Set result = new LinkedHashSet();
outerLoop:
for (D meD : candidateSet) {
if (cancellationCallback != null) {
cancellationCallback.invoke();
}
for (Iterator iterator = result.iterator(); iterator.hasNext(); ) {
D otherD = iterator.next();
Pair meAndOther = transformFirst.invoke(meD, otherD);
CallableDescriptor me = meAndOther.component1();
CallableDescriptor other = meAndOther.component2();
if (overrides(me, other, allowDescriptorCopies, true)) {
iterator.remove();
}
else if (overrides(other, me, allowDescriptorCopies, true)) {
continue outerLoop;
}
}
result.add(meD);
}
assert !result.isEmpty() : "All candidates filtered out from " + candidateSet;
return result;
}
/**
* @return whether f overrides g
*/
public static boolean overrides(
@NotNull D f,
@NotNull D g,
boolean allowDeclarationCopies,
boolean distinguishExpectsAndNonExpects
) {
// In a multi-module project different "copies" of the same class may be present in different libraries,
// that's why we use structural equivalence for members (DescriptorEquivalenceForOverrides).
// This first check cover the case of duplicate classes in different modules:
// when B is defined in modules m1 and m2, and C (indirectly) inherits from both versions,
// we'll be getting sets of members that do not override each other, but are structurally equivalent.
// As other code relies on no equal descriptors passed here, we guard against f == g, but this may not be necessary
// Note that this is needed for the usage of this function in the IDE code
if (!f.equals(g)
&& DescriptorEquivalenceForOverrides.INSTANCE.areEquivalent(
f.getOriginal(),
g.getOriginal(),
allowDeclarationCopies,
distinguishExpectsAndNonExpects
)
) {
return true;
}
CallableDescriptor originalG = g.getOriginal();
for (D overriddenFunction : DescriptorUtils.getAllOverriddenDescriptors(f)) {
if (DescriptorEquivalenceForOverrides.INSTANCE.areEquivalent(
originalG,
overriddenFunction,
allowDeclarationCopies,
distinguishExpectsAndNonExpects
)) {
return true;
}
}
return false;
}
/**
* @return overridden real descriptors (not fake overrides). Note that most usages of this method should be followed by calling
* {@link #filterOutOverridden(Set)}, because some of the declarations can override the other.
*/
@NotNull
public static Set getOverriddenDeclarations(@NotNull CallableMemberDescriptor descriptor) {
Set result = new LinkedHashSet();
collectOverriddenDeclarations(descriptor, result);
return result;
}
private static void collectOverriddenDeclarations(
@NotNull CallableMemberDescriptor descriptor,
@NotNull Set result
) {
if (descriptor.getKind().isReal()) {
result.add(descriptor);
}
else {
if (descriptor.getOverriddenDescriptors().isEmpty()) {
throw new IllegalStateException("No overridden descriptors found for (fake override) " + descriptor);
}
for (CallableMemberDescriptor overridden : descriptor.getOverriddenDescriptors()) {
collectOverriddenDeclarations(overridden, result);
}
}
}
@NotNull
public OverrideCompatibilityInfo isOverridableBy(
@NotNull CallableDescriptor superDescriptor,
@NotNull CallableDescriptor subDescriptor,
@Nullable ClassDescriptor subClassDescriptor
) {
return isOverridableBy(superDescriptor, subDescriptor, subClassDescriptor, false);
}
@NotNull
public OverrideCompatibilityInfo isOverridableBy(
@NotNull CallableDescriptor superDescriptor,
@NotNull CallableDescriptor subDescriptor,
@Nullable ClassDescriptor subClassDescriptor,
boolean checkReturnType
) {
OverrideCompatibilityInfo basicResult = isOverridableByWithoutExternalConditions(superDescriptor, subDescriptor, checkReturnType);
boolean wasSuccess = basicResult.getResult() == OVERRIDABLE;
for (ExternalOverridabilityCondition externalCondition : EXTERNAL_CONDITIONS) {
// Do not run CONFLICTS_ONLY while there was no success
if (externalCondition.getContract() == ExternalOverridabilityCondition.Contract.CONFLICTS_ONLY) continue;
if (wasSuccess && externalCondition.getContract() == ExternalOverridabilityCondition.Contract.SUCCESS_ONLY) continue;
ExternalOverridabilityCondition.Result result =
externalCondition.isOverridable(superDescriptor, subDescriptor, subClassDescriptor);
switch (result) {
case OVERRIDABLE:
wasSuccess = true;
break;
case CONFLICT:
return OverrideCompatibilityInfo.conflict("External condition failed");
case INCOMPATIBLE:
return OverrideCompatibilityInfo.incompatible("External condition");
case UNKNOWN:
// do nothing
// go to the next external condition or default override check
}
}
if (!wasSuccess) {
return basicResult;
}
// Search for conflicts from external conditions
for (ExternalOverridabilityCondition externalCondition : EXTERNAL_CONDITIONS) {
// Run all conditions that was not run before (i.e. CONFLICTS_ONLY)
if (externalCondition.getContract() != ExternalOverridabilityCondition.Contract.CONFLICTS_ONLY) continue;
ExternalOverridabilityCondition.Result result =
externalCondition.isOverridable(superDescriptor, subDescriptor, subClassDescriptor);
switch (result) {
case CONFLICT:
return OverrideCompatibilityInfo.conflict("External condition failed");
case INCOMPATIBLE:
return OverrideCompatibilityInfo.incompatible("External condition");
case OVERRIDABLE:
throw new IllegalStateException(
"Contract violation in " + externalCondition.getClass().getName() + " condition. It's not supposed to end with success");
case UNKNOWN:
// do nothing
// go to the next external condition or default override check
}
}
return OverrideCompatibilityInfo.success();
}
@NotNull
public OverrideCompatibilityInfo isOverridableByWithoutExternalConditions(
@NotNull CallableDescriptor superDescriptor,
@NotNull CallableDescriptor subDescriptor,
boolean checkReturnType
) {
OverrideCompatibilityInfo basicOverridability = getBasicOverridabilityProblem(superDescriptor, subDescriptor);
if (basicOverridability != null) return basicOverridability;
List superValueParameters = compiledValueParameters(superDescriptor);
List subValueParameters = compiledValueParameters(subDescriptor);
List superTypeParameters = superDescriptor.getTypeParameters();
List subTypeParameters = subDescriptor.getTypeParameters();
if (superTypeParameters.size() != subTypeParameters.size()) {
for (int i = 0; i < superValueParameters.size(); ++i) {
// TODO: compare erasure
if (!KotlinTypeChecker.DEFAULT.equalTypes(superValueParameters.get(i), subValueParameters.get(i))) {
return OverrideCompatibilityInfo.incompatible("Type parameter number mismatch");
}
}
return OverrideCompatibilityInfo.conflict("Type parameter number mismatch");
}
TypeCheckerState typeCheckerState = createTypeCheckerState(superTypeParameters, subTypeParameters);
for (int i = 0; i < superTypeParameters.size(); i++) {
if (!areTypeParametersEquivalent(
superTypeParameters.get(i),
subTypeParameters.get(i),
typeCheckerState
)) {
return OverrideCompatibilityInfo.incompatible("Type parameter bounds mismatch");
}
}
for (int i = 0; i < superValueParameters.size(); i++) {
if (!areTypesEquivalent(
superValueParameters.get(i),
subValueParameters.get(i),
typeCheckerState)
) {
return OverrideCompatibilityInfo.incompatible("Value parameter type mismatch");
}
}
if (superDescriptor instanceof FunctionDescriptor && subDescriptor instanceof FunctionDescriptor &&
((FunctionDescriptor) superDescriptor).isSuspend() != ((FunctionDescriptor) subDescriptor).isSuspend()) {
return OverrideCompatibilityInfo.conflict("Incompatible suspendability");
}
if (checkReturnType) {
KotlinType superReturnType = superDescriptor.getReturnType();
KotlinType subReturnType = subDescriptor.getReturnType();
if (superReturnType != null && subReturnType != null) {
boolean bothErrors = KotlinTypeKt.isError(subReturnType) && KotlinTypeKt.isError(superReturnType);
if (!bothErrors &&
!AbstractTypeChecker.INSTANCE.isSubtypeOf(
typeCheckerState,
subReturnType.unwrap(),
superReturnType.unwrap()
)
) {
return OverrideCompatibilityInfo.conflict("Return type mismatch");
}
}
}
return OverrideCompatibilityInfo.success();
}
@Nullable
public static OverrideCompatibilityInfo getBasicOverridabilityProblem(
@NotNull CallableDescriptor superDescriptor,
@NotNull CallableDescriptor subDescriptor
) {
if (superDescriptor instanceof FunctionDescriptor && !(subDescriptor instanceof FunctionDescriptor) ||
superDescriptor instanceof PropertyDescriptor && !(subDescriptor instanceof PropertyDescriptor)) {
return OverrideCompatibilityInfo.incompatible("Member kind mismatch");
}
if (!(superDescriptor instanceof FunctionDescriptor) && !(superDescriptor instanceof PropertyDescriptor)) {
throw new IllegalArgumentException("This type of CallableDescriptor cannot be checked for overridability: " + superDescriptor);
}
// TODO: check outside of this method
if (!superDescriptor.getName().equals(subDescriptor.getName())) {
return OverrideCompatibilityInfo.incompatible("Name mismatch");
}
OverrideCompatibilityInfo receiverAndParameterResult = checkReceiverAndParameterCount(superDescriptor, subDescriptor);
if (receiverAndParameterResult != null) {
return receiverAndParameterResult;
}
return null;
}
@NotNull
private TypeCheckerState createTypeCheckerState(
@NotNull List firstParameters,
@NotNull List secondParameters
) {
assert firstParameters.size() == secondParameters.size() :
"Should be the same number of type parameters: " + firstParameters + " vs " + secondParameters;
if (firstParameters.isEmpty()) {
return new OverridingUtilTypeSystemContext(
null, equalityAxioms, kotlinTypeRefiner, kotlinTypePreparator, customSubtype
).newTypeCheckerState(true, true);
}
Map matchingTypeConstructors = new HashMap();
for (int i = 0; i < firstParameters.size(); i++) {
matchingTypeConstructors.put(firstParameters.get(i).getTypeConstructor(), secondParameters.get(i).getTypeConstructor());
}
return new OverridingUtilTypeSystemContext(
matchingTypeConstructors, equalityAxioms, kotlinTypeRefiner, kotlinTypePreparator, customSubtype
).newTypeCheckerState(true, true);
}
@Nullable
private static OverrideCompatibilityInfo checkReceiverAndParameterCount(
CallableDescriptor superDescriptor,
CallableDescriptor subDescriptor
) {
if ((superDescriptor.getExtensionReceiverParameter() == null) != (subDescriptor.getExtensionReceiverParameter() == null)) {
return OverrideCompatibilityInfo.incompatible("Receiver presence mismatch");
}
if (superDescriptor.getValueParameters().size() != subDescriptor.getValueParameters().size()) {
return OverrideCompatibilityInfo.incompatible("Value parameter number mismatch");
}
return null;
}
private static boolean areTypesEquivalent(
@NotNull KotlinType typeInSuper,
@NotNull KotlinType typeInSub,
@NotNull TypeCheckerState typeCheckerState
) {
boolean bothErrors = KotlinTypeKt.isError(typeInSuper) && KotlinTypeKt.isError(typeInSub);
if (bothErrors) return true;
return AbstractTypeChecker.INSTANCE.equalTypes(typeCheckerState, typeInSuper.unwrap(), typeInSub.unwrap());
}
// See JLS 8, 8.4.4 Generic Methods
private static boolean areTypeParametersEquivalent(
@NotNull TypeParameterDescriptor superTypeParameter,
@NotNull TypeParameterDescriptor subTypeParameter,
@NotNull TypeCheckerState typeCheckerState
) {
List superBounds = superTypeParameter.getUpperBounds();
List subBounds = new ArrayList(subTypeParameter.getUpperBounds());
if (superBounds.size() != subBounds.size()) return false;
outer:
for (KotlinType superBound : superBounds) {
ListIterator it = subBounds.listIterator();
while (it.hasNext()) {
KotlinType subBound = it.next();
if (areTypesEquivalent(superBound, subBound, typeCheckerState)) {
it.remove();
continue outer;
}
}
return false;
}
return true;
}
private static List compiledValueParameters(CallableDescriptor callableDescriptor) {
ReceiverParameterDescriptor receiverParameter = callableDescriptor.getExtensionReceiverParameter();
List parameters = new ArrayList();
if (receiverParameter != null) {
parameters.add(receiverParameter.getType());
}
for (ValueParameterDescriptor valueParameterDescriptor : callableDescriptor.getValueParameters()) {
parameters.add(valueParameterDescriptor.getType());
}
return parameters;
}
public void generateOverridesInFunctionGroup(
@SuppressWarnings("UnusedParameters")
@NotNull Name name, //DO NOT DELETE THIS PARAMETER: needed to make sure all descriptors have the same name
@NotNull Collection membersFromSupertypes,
@NotNull Collection membersFromCurrent,
@NotNull ClassDescriptor current,
@NotNull OverridingStrategy strategy
) {
Collection notOverridden = new LinkedHashSet(membersFromSupertypes);
for (CallableMemberDescriptor fromCurrent : membersFromCurrent) {
Collection bound =
extractAndBindOverridesForMember(fromCurrent, membersFromSupertypes, current, strategy);
notOverridden.removeAll(bound);
}
createAndBindFakeOverrides(current, notOverridden, strategy);
}
public static boolean isVisibleForOverride(
@NotNull MemberDescriptor overriding,
@NotNull MemberDescriptor fromSuper,
boolean useSpecialRulesForPrivateSealedConstructors
) {
return !DescriptorVisibilities.isPrivate(fromSuper.getVisibility()) &&
DescriptorVisibilities.isVisibleIgnoringReceiver(fromSuper, overriding, useSpecialRulesForPrivateSealedConstructors);
}
private Collection extractAndBindOverridesForMember(
@NotNull CallableMemberDescriptor fromCurrent,
@NotNull Collection descriptorsFromSuper,
@NotNull ClassDescriptor current,
@NotNull OverridingStrategy strategy
) {
Collection bound = new ArrayList(descriptorsFromSuper.size());
Collection overridden = SmartSet.create();
for (CallableMemberDescriptor fromSupertype : descriptorsFromSuper) {
OverrideCompatibilityInfo.Result result = isOverridableBy(fromSupertype, fromCurrent, current).getResult();
boolean isVisibleForOverride = isVisibleForOverride(fromCurrent, fromSupertype, false);
switch (result) {
case OVERRIDABLE:
if (isVisibleForOverride) {
overridden.add(fromSupertype);
}
bound.add(fromSupertype);
break;
case CONFLICT:
if (isVisibleForOverride) {
strategy.overrideConflict(fromSupertype, fromCurrent);
}
bound.add(fromSupertype);
break;
case INCOMPATIBLE:
break;
}
}
strategy.setOverriddenDescriptors(fromCurrent, overridden);
return bound;
}
private static boolean allHasSameContainingDeclaration(@NotNull Collection notOverridden) {
if (notOverridden.size() < 2) return true;
final DeclarationDescriptor containingDeclaration = notOverridden.iterator().next().getContainingDeclaration();
return CollectionsKt.all(notOverridden, new Function1() {
@Override
public Boolean invoke(CallableMemberDescriptor descriptor) {
return descriptor.getContainingDeclaration() == containingDeclaration;
}
});
}
private static void createAndBindFakeOverrides(
@NotNull ClassDescriptor current,
@NotNull Collection notOverridden,
@NotNull OverridingStrategy strategy
) {
// Optimization: If all notOverridden descriptors have the same containing declaration,
// then we can just create fake overrides for them, because they should be matched correctly in their containing declaration
if (allHasSameContainingDeclaration(notOverridden)) {
for (CallableMemberDescriptor descriptor : notOverridden) {
createAndBindFakeOverride(Collections.singleton(descriptor), current, strategy);
}
return;
}
Queue fromSuperQueue = new LinkedList(notOverridden);
while (!fromSuperQueue.isEmpty()) {
CallableMemberDescriptor notOverriddenFromSuper = VisibilityUtilKt.findMemberWithMaxVisibility(fromSuperQueue);
Collection overridables =
extractMembersOverridableInBothWays(notOverriddenFromSuper, fromSuperQueue, strategy);
createAndBindFakeOverride(overridables, current, strategy);
}
}
public static boolean isMoreSpecific(@NotNull CallableDescriptor a, @NotNull CallableDescriptor b) {
KotlinType aReturnType = a.getReturnType();
KotlinType bReturnType = b.getReturnType();
assert aReturnType != null : "Return type of " + a + " is null";
assert bReturnType != null : "Return type of " + b + " is null";
if (!isVisibilityMoreSpecific(a, b)) return false;
TypeCheckerState checkerState =
DEFAULT.createTypeCheckerState(a.getTypeParameters(), b.getTypeParameters());
if (a instanceof FunctionDescriptor) {
assert b instanceof FunctionDescriptor : "b is " + b.getClass();
return isReturnTypeMoreSpecific(a, aReturnType, b, bReturnType, checkerState);
}
if (a instanceof PropertyDescriptor) {
assert b instanceof PropertyDescriptor : "b is " + b.getClass();
PropertyDescriptor pa = (PropertyDescriptor) a;
PropertyDescriptor pb = (PropertyDescriptor) b;
if (!isAccessorMoreSpecific(pa.getSetter(), pb.getSetter())) return false;
if (pa.isVar() && pb.isVar()) {
// TODO(dsavvinov): using DEFAULT here looks suspicious
return AbstractTypeChecker.INSTANCE.equalTypes(checkerState, aReturnType.unwrap(), bReturnType.unwrap());
}
else {
// both vals or var vs val: val can't be more specific then var
return !(!pa.isVar() && pb.isVar()) && isReturnTypeMoreSpecific(a, aReturnType, b, bReturnType, checkerState);
}
}
throw new IllegalArgumentException("Unexpected callable: " + a.getClass());
}
private static boolean isVisibilityMoreSpecific(
@NotNull DeclarationDescriptorWithVisibility a,
@NotNull DeclarationDescriptorWithVisibility b
) {
Integer result = DescriptorVisibilities.compare(a.getVisibility(), b.getVisibility());
return result == null || result >= 0;
}
private static boolean isAccessorMoreSpecific(@Nullable PropertyAccessorDescriptor a, @Nullable PropertyAccessorDescriptor b) {
if (a == null || b == null) return true;
return isVisibilityMoreSpecific(a, b);
}
private static boolean isMoreSpecificThenAllOf(@NotNull CallableDescriptor candidate, @NotNull Collection descriptors) {
// NB subtyping relation in Kotlin is not transitive in presence of flexible types:
// String? <: String! <: String, but not String? <: String
for (CallableDescriptor descriptor : descriptors) {
if (!isMoreSpecific(candidate, descriptor)) {
return false;
}
}
return true;
}
private static boolean isReturnTypeMoreSpecific(
@NotNull CallableDescriptor a,
@NotNull KotlinType aReturnType,
@NotNull CallableDescriptor b,
@NotNull KotlinType bReturnType,
@NotNull TypeCheckerState typeCheckerState
) {
return AbstractTypeChecker.INSTANCE.isSubtypeOf(typeCheckerState, aReturnType.unwrap(), bReturnType.unwrap());
}
@NotNull
public static H selectMostSpecificMember(
@NotNull Collection overridables,
@NotNull Function1 descriptorByHandle
) {
assert !overridables.isEmpty() : "Should have at least one overridable descriptor";
if (overridables.size() == 1) {
return CollectionsKt.first(overridables);
}
Collection candidates = new ArrayList(2);
List callableMemberDescriptors = CollectionsKt.map(overridables, descriptorByHandle);
H transitivelyMostSpecific = CollectionsKt.first(overridables);
CallableDescriptor transitivelyMostSpecificDescriptor = descriptorByHandle.invoke(transitivelyMostSpecific);
for (H overridable : overridables) {
CallableDescriptor descriptor = descriptorByHandle.invoke(overridable);
if (isMoreSpecificThenAllOf(descriptor, callableMemberDescriptors)) {
candidates.add(overridable);
}
if (isMoreSpecific(descriptor, transitivelyMostSpecificDescriptor)
&& !isMoreSpecific(transitivelyMostSpecificDescriptor, descriptor)) {
transitivelyMostSpecific = overridable;
}
}
if (candidates.isEmpty()) {
return transitivelyMostSpecific;
}
else if (candidates.size() == 1) {
return CollectionsKt.first(candidates);
}
H firstNonFlexible = null;
for (H candidate : candidates) {
//noinspection ConstantConditions
if (!FlexibleTypesKt.isFlexible(descriptorByHandle.invoke(candidate).getReturnType())) {
firstNonFlexible = candidate;
break;
}
}
if (firstNonFlexible != null) {
return firstNonFlexible;
}
return CollectionsKt.first(candidates);
}
private static void createAndBindFakeOverride(
@NotNull Collection overridables,
@NotNull ClassDescriptor current,
@NotNull OverridingStrategy strategy
) {
Collection visibleOverridables = filterVisibleFakeOverrides(current, overridables);
boolean allInvisible = visibleOverridables.isEmpty();
Collection effectiveOverridden = allInvisible ? overridables : visibleOverridables;
Modality modality = determineModalityForFakeOverride(effectiveOverridden, current);
DescriptorVisibility visibility = allInvisible ? DescriptorVisibilities.INVISIBLE_FAKE : DescriptorVisibilities.INHERITED;
// FIXME doesn't work as expected for flexible types: should create a refined signature.
// Current algorithm produces bad results in presence of annotated Java signatures such as:
// J: foo(s: String!): String -- @NotNull String foo(String s);
// K: foo(s: String): String?
// --> 'foo(s: String!): String' as an inherited signature with most specific return type.
// This is bad because it can be overridden by 'foo(s: String?): String', which is not override-equivalent with K::foo above.
// Should be 'foo(s: String): String'.
CallableMemberDescriptor mostSpecific =
selectMostSpecificMember(effectiveOverridden,
new Function1() {
@Override
public CallableMemberDescriptor invoke(CallableMemberDescriptor descriptor) {
return descriptor;
}
});
CallableMemberDescriptor fakeOverride =
mostSpecific.copy(current, modality, visibility, CallableMemberDescriptor.Kind.FAKE_OVERRIDE, false);
strategy.setOverriddenDescriptors(fakeOverride, effectiveOverridden);
assert !fakeOverride.getOverriddenDescriptors().isEmpty()
: "Overridden descriptors should be set for " + CallableMemberDescriptor.Kind.FAKE_OVERRIDE;
strategy.addFakeOverride(fakeOverride);
}
@NotNull
private static Modality determineModalityForFakeOverride(
@NotNull Collection descriptors,
@NotNull ClassDescriptor current
) {
// Optimization: avoid creating hash sets in frequent cases when modality can be computed trivially
boolean hasOpen = false;
boolean hasAbstract = false;
for (CallableMemberDescriptor descriptor : descriptors) {
switch (descriptor.getModality()) {
case FINAL:
return Modality.FINAL;
case SEALED:
throw new IllegalStateException("Member cannot have SEALED modality: " + descriptor);
case OPEN:
hasOpen = true;
break;
case ABSTRACT:
hasAbstract = true;
break;
}
}
// Fake overrides of abstract members in non-abstract expected classes should not be abstract, because otherwise it would be
// impossible to inherit a non-expected class from that expected class in common code.
// We're making their modality that of the containing class, because this is the least confusing behavior for the users.
// However, it may cause problems if we reuse resolution results of common code when compiling platform code (see KT-15220)
boolean transformAbstractToClassModality =
current.isExpect() && (current.getModality() != Modality.ABSTRACT && current.getModality() != Modality.SEALED);
if (hasOpen && !hasAbstract) {
return Modality.OPEN;
}
if (!hasOpen && hasAbstract) {
return transformAbstractToClassModality ? current.getModality() : Modality.ABSTRACT;
}
Set allOverriddenDeclarations = new HashSet();
for (CallableMemberDescriptor descriptor : descriptors) {
allOverriddenDeclarations.addAll(getOverriddenDeclarations(descriptor));
}
return getMinimalModality(filterOutOverridden(allOverriddenDeclarations), transformAbstractToClassModality, current.getModality());
}
@NotNull
private static Modality getMinimalModality(
@NotNull Collection descriptors,
boolean transformAbstractToClassModality,
@NotNull Modality classModality
) {
Modality result = Modality.ABSTRACT;
for (CallableMemberDescriptor descriptor : descriptors) {
Modality effectiveModality =
transformAbstractToClassModality && descriptor.getModality() == Modality.ABSTRACT
? classModality
: descriptor.getModality();
if (effectiveModality.compareTo(result) < 0) {
result = effectiveModality;
}
}
return result;
}
@NotNull
public static Collection filterVisibleFakeOverrides(
@NotNull final ClassDescriptor current,
@NotNull Collection toFilter
) {
return CollectionsKt.filter(toFilter, new Function1() {
@Override
public Boolean invoke(CallableMemberDescriptor descriptor) {
//nested class could capture private member, so check for private visibility added
return !DescriptorVisibilities.isPrivate(descriptor.getVisibility()) &&
DescriptorVisibilities.isVisibleIgnoringReceiver(descriptor, current, false);
}
});
}
/**
* @param is something that handles CallableDescriptor inside
* @return
*/
@NotNull
public static Collection extractMembersOverridableInBothWays(
@NotNull H overrider,
@NotNull @Mutable Collection extractFrom,
@NotNull Function1 descriptorByHandle,
@NotNull Function1 onConflict
) {
Collection overridable = new ArrayList();
overridable.add(overrider);
CallableDescriptor overriderDescriptor = descriptorByHandle.invoke(overrider);
for (Iterator iterator = extractFrom.iterator(); iterator.hasNext(); ) {
H candidate = iterator.next();
CallableDescriptor candidateDescriptor = descriptorByHandle.invoke(candidate);
if (overrider == candidate) {
iterator.remove();
continue;
}
OverrideCompatibilityInfo.Result finalResult = getBothWaysOverridability(overriderDescriptor, candidateDescriptor);
if (finalResult == OVERRIDABLE) {
overridable.add(candidate);
iterator.remove();
}
else if (finalResult == CONFLICT) {
onConflict.invoke(candidate);
iterator.remove();
}
}
return overridable;
}
@Nullable
public static OverrideCompatibilityInfo.Result getBothWaysOverridability(
CallableDescriptor overriderDescriptor,
CallableDescriptor candidateDescriptor
) {
OverrideCompatibilityInfo.Result result1 = DEFAULT.isOverridableBy(candidateDescriptor, overriderDescriptor, null).getResult();
OverrideCompatibilityInfo.Result result2 = DEFAULT.isOverridableBy(overriderDescriptor, candidateDescriptor, null).getResult();
return result1 == OVERRIDABLE && result2 == OVERRIDABLE
? OVERRIDABLE
: ((result1 == CONFLICT || result2 == CONFLICT) ? CONFLICT : INCOMPATIBLE);
}
@NotNull
private static Collection extractMembersOverridableInBothWays(
@NotNull final CallableMemberDescriptor overrider,
@NotNull Queue extractFrom,
@NotNull final OverridingStrategy strategy
) {
return extractMembersOverridableInBothWays(overrider, extractFrom,
// ID
new Function1() {
@Override
public CallableDescriptor invoke(CallableMemberDescriptor descriptor) {
return descriptor;
}
},
new Function1() {
@Override
public Unit invoke(CallableMemberDescriptor descriptor) {
strategy.inheritanceConflict(overrider, descriptor);
return Unit.INSTANCE;
}
});
}
public static void resolveUnknownVisibilityForMember(
@NotNull CallableMemberDescriptor memberDescriptor,
@Nullable Function1 cannotInferVisibility
) {
for (CallableMemberDescriptor descriptor : memberDescriptor.getOverriddenDescriptors()) {
if (descriptor.getVisibility() == DescriptorVisibilities.INHERITED) {
resolveUnknownVisibilityForMember(descriptor, cannotInferVisibility);
}
}
if (memberDescriptor.getVisibility() != DescriptorVisibilities.INHERITED) {
return;
}
DescriptorVisibility maxVisibility = computeVisibilityToInherit(memberDescriptor);
DescriptorVisibility visibilityToInherit;
if (maxVisibility == null) {
if (cannotInferVisibility != null) {
cannotInferVisibility.invoke(memberDescriptor);
}
visibilityToInherit = DescriptorVisibilities.PUBLIC;
}
else {
visibilityToInherit = maxVisibility;
}
if (memberDescriptor instanceof PropertyDescriptorImpl) {
((PropertyDescriptorImpl) memberDescriptor).setVisibility(visibilityToInherit);
for (PropertyAccessorDescriptor accessor : ((PropertyDescriptor) memberDescriptor).getAccessors()) {
// If we couldn't infer visibility for property, the diagnostic is already reported, no need to report it again on accessors
resolveUnknownVisibilityForMember(accessor, maxVisibility == null ? null : cannotInferVisibility);
}
}
else if (memberDescriptor instanceof FunctionDescriptorImpl) {
((FunctionDescriptorImpl) memberDescriptor).setVisibility(visibilityToInherit);
}
else {
assert memberDescriptor instanceof PropertyAccessorDescriptorImpl;
PropertyAccessorDescriptorImpl propertyAccessorDescriptor = (PropertyAccessorDescriptorImpl) memberDescriptor;
propertyAccessorDescriptor.setVisibility(visibilityToInherit);
if (visibilityToInherit != propertyAccessorDescriptor.getCorrespondingProperty().getVisibility()) {
propertyAccessorDescriptor.setDefault(false);
}
}
}
@Nullable
private static DescriptorVisibility computeVisibilityToInherit(@NotNull CallableMemberDescriptor memberDescriptor) {
Collection overriddenDescriptors = memberDescriptor.getOverriddenDescriptors();
DescriptorVisibility maxVisibility = findMaxVisibility(overriddenDescriptors);
if (maxVisibility == null) {
return null;
}
if (memberDescriptor.getKind() == CallableMemberDescriptor.Kind.FAKE_OVERRIDE) {
for (CallableMemberDescriptor overridden : overriddenDescriptors) {
// An implementation (a non-abstract overridden member) of a fake override should have the maximum possible visibility
if (overridden.getModality() != Modality.ABSTRACT && !overridden.getVisibility().equals(maxVisibility)) {
return null;
}
}
return maxVisibility;
}
return maxVisibility.normalize();
}
@Nullable
public static DescriptorVisibility findMaxVisibility(@NotNull Collection descriptors) {
if (descriptors.isEmpty()) {
return DescriptorVisibilities.DEFAULT_VISIBILITY;
}
DescriptorVisibility maxVisibility = null;
for (CallableMemberDescriptor descriptor : descriptors) {
DescriptorVisibility visibility = descriptor.getVisibility();
assert visibility != DescriptorVisibilities.INHERITED : "Visibility should have been computed for " + descriptor;
if (maxVisibility == null) {
maxVisibility = visibility;
continue;
}
Integer compareResult = DescriptorVisibilities.compare(visibility, maxVisibility);
if (compareResult == null) {
maxVisibility = null;
}
else if (compareResult > 0) {
maxVisibility = visibility;
}
}
if (maxVisibility == null) {
return null;
}
for (CallableMemberDescriptor descriptor : descriptors) {
Integer compareResult = DescriptorVisibilities.compare(maxVisibility, descriptor.getVisibility());
if (compareResult == null || compareResult < 0) {
return null;
}
}
return maxVisibility;
}
public static class OverrideCompatibilityInfo {
public enum Result {
OVERRIDABLE,
INCOMPATIBLE,
CONFLICT,
}
private static final OverrideCompatibilityInfo SUCCESS = new OverrideCompatibilityInfo(OVERRIDABLE, "SUCCESS");
@NotNull
public static OverrideCompatibilityInfo success() {
return SUCCESS;
}
@NotNull
public static OverrideCompatibilityInfo incompatible(@NotNull String debugMessage) {
return new OverrideCompatibilityInfo(INCOMPATIBLE, debugMessage);
}
@NotNull
public static OverrideCompatibilityInfo conflict(@NotNull String debugMessage) {
return new OverrideCompatibilityInfo(CONFLICT, debugMessage);
}
private final Result overridable;
private final String debugMessage;
public OverrideCompatibilityInfo(@NotNull Result success, @NotNull String debugMessage) {
this.overridable = success;
this.debugMessage = debugMessage;
}
@NotNull
public Result getResult() {
return overridable;
}
@NotNull
public String getDebugMessage() {
return debugMessage;
}
}
}