// allowedFinalSupertypes typically contains a enum type of which supertypeOwner is an entry
private void checkSupertypeList(
@NotNull MutableClassDescriptor supertypeOwner,
@NotNull Map<JetTypeReference, JetType> supertypes,
Set<TypeConstructor> allowedFinalSupertypes) {
Set<TypeConstructor> typeConstructors = Sets.newHashSet();
boolean classAppeared = false;
for (Map.Entry<JetTypeReference, JetType> entry : supertypes.entrySet()) {
JetTypeReference typeReference = entry.getKey();
JetType supertype = entry.getValue();
ClassDescriptor classDescriptor = TypeUtils.getClassDescriptor(supertype);
if (classDescriptor != null) {
if (classDescriptor.getKind() != ClassKind.TRAIT) {
if (classAppeared) {
trace.report(MANY_CLASSES_IN_SUPERTYPE_LIST.on(typeReference));
} else {
classAppeared = true;
}
}
} else {
trace.report(SUPERTYPE_NOT_A_CLASS_OR_TRAIT.on(typeReference));
}
TypeConstructor constructor = supertype.getConstructor();
if (!typeConstructors.add(constructor)) {
trace.report(SUPERTYPE_APPEARS_TWICE.on(typeReference));
}
if (constructor.isSealed() && !allowedFinalSupertypes.contains(constructor)) {
trace.report(FINAL_SUPERTYPE.on(typeReference));
}
}
}
@NotNull
private String renderTypeName(@NotNull TypeConstructor typeConstructor) {
ClassifierDescriptor cd = typeConstructor.getDeclarationDescriptor();
if (cd instanceof TypeParameterDescriptor) {
return renderName(cd.getName());
} else if (cd instanceof ClassDescriptor) {
return renderClassName((ClassDescriptor) cd);
} else {
assert cd == null : "Unexpected classifier: " + cd.getClass();
return typeConstructor.toString();
}
}
@NotNull
public static KotlinType makeUnsubstitutedType(
ClassDescriptor classDescriptor, MemberScope unsubstitutedMemberScope) {
if (ErrorUtils.isError(classDescriptor)) {
return ErrorUtils.createErrorType("Unsubstituted type for " + classDescriptor);
}
TypeConstructor typeConstructor = classDescriptor.getTypeConstructor();
List<TypeProjection> arguments = getDefaultTypeProjections(typeConstructor.getParameters());
return KotlinTypeImpl.create(
Annotations.Companion.getEMPTY(),
typeConstructor,
false,
arguments,
unsubstitutedMemberScope);
}
/**
* Remember that we are trying to cast something of type {@code supertype} to {@code subtype}.
*
* <p>Since at runtime we can only check the class (type constructor), the rest of the subtype
* should be known statically, from supertype. This method reconstructs all static information
* that can be obtained from supertype.
*
* <p>Example 1: supertype = Collection<String> subtype = List<...> result = List<String>, all
* arguments are inferred
*
* <p>Example 2: supertype = Any subtype = List<...> result = List<*>, some arguments were not
* inferred, replaced with '*'
*/
public static TypeReconstructionResult findStaticallyKnownSubtype(
@NotNull KotlinType supertype, @NotNull TypeConstructor subtypeConstructor) {
assert !supertype.isMarkedNullable() : "This method only makes sense for non-nullable types";
// Assume we are casting an expression of type Collection<Foo> to List<Bar>
// First, let's make List<T>, where T is a type variable
ClassifierDescriptor descriptor = subtypeConstructor.getDeclarationDescriptor();
assert descriptor != null : "Can't create default type for " + subtypeConstructor;
KotlinType subtypeWithVariables = descriptor.getDefaultType();
// Now, let's find a supertype of List<T> that is a Collection of something,
// in this case it will be Collection<T>
KotlinType supertypeWithVariables =
TypeCheckingProcedure.findCorrespondingSupertype(subtypeWithVariables, supertype);
final List<TypeParameterDescriptor> variables =
subtypeWithVariables.getConstructor().getParameters();
Map<TypeConstructor, TypeProjection> substitution;
if (supertypeWithVariables != null) {
// Now, let's try to unify Collection<T> and Collection<Foo> solution is a map from T to Foo
TypeUnifier.UnificationResult solution =
TypeUnifier.unify(
new TypeProjectionImpl(supertype),
new TypeProjectionImpl(supertypeWithVariables),
new Predicate<TypeConstructor>() {
@Override
public boolean apply(TypeConstructor typeConstructor) {
ClassifierDescriptor descriptor = typeConstructor.getDeclarationDescriptor();
return descriptor instanceof TypeParameterDescriptor
&& variables.contains(descriptor);
}
});
substitution = Maps.newHashMap(solution.getSubstitution());
} else {
// If there's no corresponding supertype, no variables are determined
// This may be OK, e.g. in case 'Any as List<*>'
substitution = Maps.newHashMapWithExpectedSize(variables.size());
}
// If some of the parameters are not determined by unification, it means that these parameters
// are lost,
// let's put stars instead, so that we can only cast to something like List<*>, e.g. (a: Any) as
// List<*>
boolean allArgumentsInferred = true;
for (TypeParameterDescriptor variable : variables) {
TypeProjection value = substitution.get(variable.getTypeConstructor());
if (value == null) {
substitution.put(variable.getTypeConstructor(), TypeUtils.makeStarProjection(variable));
allArgumentsInferred = false;
}
}
// At this point we have values for all type parameters of List
// Let's make a type by substituting them: List<T> -> List<Foo>
KotlinType substituted =
TypeSubstitutor.create(substitution).substitute(subtypeWithVariables, Variance.INVARIANT);
return new TypeReconstructionResult(substituted, allArgumentsInferred);
}
@NotNull
public static ClassDescriptor getClassDescriptorForTypeConstructor(
@NotNull TypeConstructor typeConstructor) {
ClassifierDescriptor descriptor = typeConstructor.getDeclarationDescriptor();
assert descriptor instanceof ClassDescriptor
: "Classifier descriptor of a type should be of type ClassDescriptor: " + typeConstructor;
return (ClassDescriptor) descriptor;
}
@Override
public String toString() {
return constructor.toString();
}
private void checkSupertypeList(
@NotNull ClassDescriptor supertypeOwner,
@NotNull Map<JetTypeReference, JetType> supertypes,
@NotNull JetClassOrObject jetClass) {
Set<TypeConstructor> allowedFinalSupertypes =
getAllowedFinalSupertypes(supertypeOwner, jetClass);
Set<TypeConstructor> typeConstructors = Sets.newHashSet();
boolean classAppeared = false;
for (Map.Entry<JetTypeReference, JetType> entry : supertypes.entrySet()) {
JetTypeReference typeReference = entry.getKey();
JetType supertype = entry.getValue();
boolean addSupertype = true;
ClassDescriptor classDescriptor = TypeUtils.getClassDescriptor(supertype);
if (classDescriptor != null) {
if (ErrorUtils.isError(classDescriptor)) continue;
if (classDescriptor.getKind() != ClassKind.INTERFACE) {
if (supertypeOwner.getKind() == ClassKind.ENUM_CLASS) {
trace.report(CLASS_IN_SUPERTYPE_FOR_ENUM.on(typeReference));
addSupertype = false;
} else if (supertypeOwner.getKind() == ClassKind.INTERFACE
&& !classAppeared
&& !TypesPackage.isDynamic(supertype) /* avoid duplicate diagnostics */) {
trace.report(TRAIT_WITH_SUPERCLASS.on(typeReference));
addSupertype = false;
}
if (classAppeared) {
trace.report(MANY_CLASSES_IN_SUPERTYPE_LIST.on(typeReference));
} else {
classAppeared = true;
}
}
} else {
trace.report(SUPERTYPE_NOT_A_CLASS_OR_TRAIT.on(typeReference));
}
TypeConstructor constructor = supertype.getConstructor();
if (addSupertype && !typeConstructors.add(constructor)) {
trace.report(SUPERTYPE_APPEARS_TWICE.on(typeReference));
}
if (DescriptorUtils.isSingleton(classDescriptor)) {
trace.report(SINGLETON_IN_SUPERTYPE.on(typeReference));
} else if (constructor.isFinal() && !allowedFinalSupertypes.contains(constructor)) {
if (classDescriptor.getModality() == Modality.SEALED) {
DeclarationDescriptor containingDescriptor = supertypeOwner.getContainingDeclaration();
while (containingDescriptor != null && containingDescriptor != classDescriptor) {
containingDescriptor = containingDescriptor.getContainingDeclaration();
}
if (containingDescriptor == null) {
trace.report(SEALED_SUPERTYPE.on(typeReference));
} else {
trace.report(SEALED_SUPERTYPE_IN_LOCAL_CLASS.on(typeReference));
}
} else {
trace.report(FINAL_SUPERTYPE.on(typeReference));
}
}
}
}
@NotNull
@Override
public Annotations getAnnotations() {
return errorTypeConstructor.getAnnotations();
}
@Nullable
@Override
public ClassifierDescriptor getDeclarationDescriptor() {
return errorTypeConstructor.getDeclarationDescriptor();
}
@Override
public boolean isDenotable() {
return errorTypeConstructor.isDenotable();
}
@Override
public boolean isFinal() {
return errorTypeConstructor.isFinal();
}
@NotNull
@Override
public Collection<JetType> getSupertypes() {
return errorTypeConstructor.getSupertypes();
}
@NotNull
@Override
public List<TypeParameterDescriptor> getParameters() {
return errorTypeConstructor.getParameters();
}
private void addConstraint(
@NotNull ConstraintKind constraintKind,
@NotNull JetType subjectType,
@Nullable JetType constrainingType,
@NotNull ConstraintPosition constraintPosition) {
if (constrainingType == TypeUtils.NO_EXPECTED_TYPE
|| constrainingType == DONT_CARE
|| constrainingType == CANT_INFER) {
return;
}
if (constrainingType == null
|| (ErrorUtils.isErrorType(constrainingType)
&& constrainingType != PLACEHOLDER_FUNCTION_TYPE)) {
hasErrorInConstrainingTypes = true;
return;
}
assert subjectType != TypeUtils.NO_EXPECTED_TYPE
: "Subject type shouldn't be NO_EXPECTED_TYPE (in position " + constraintPosition + " )";
if (ErrorUtils.isErrorType(subjectType)) return;
DeclarationDescriptor subjectTypeDescriptor =
subjectType.getConstructor().getDeclarationDescriptor();
KotlinBuiltIns kotlinBuiltIns = KotlinBuiltIns.getInstance();
if (constrainingType == PLACEHOLDER_FUNCTION_TYPE) {
if (!kotlinBuiltIns.isFunctionOrExtensionFunctionType(subjectType)) {
if (subjectTypeDescriptor instanceof TypeParameterDescriptor
&& typeParameterConstraints.get(subjectTypeDescriptor) != null) {
// a constraint binds type parameter and any function type, so there is no new info and no
// error
return;
}
errorConstraintPositions.add(constraintPosition);
}
return;
}
// todo temporary hack
// function literal without declaring receiver type { x -> ... }
// can be considered as extension function if one is expected
// (special type constructor for function/ extension function should be introduced like
// PLACEHOLDER_FUNCTION_TYPE)
if (constraintKind == SUB_TYPE
&& kotlinBuiltIns.isFunctionType(constrainingType)
&& kotlinBuiltIns.isExtensionFunctionType(subjectType)) {
constrainingType = createCorrespondingExtensionFunctionType(constrainingType, DONT_CARE);
}
DeclarationDescriptor constrainingTypeDescriptor =
constrainingType.getConstructor().getDeclarationDescriptor();
if (subjectTypeDescriptor instanceof TypeParameterDescriptor) {
TypeParameterDescriptor typeParameter = (TypeParameterDescriptor) subjectTypeDescriptor;
TypeConstraintsImpl typeConstraints = typeParameterConstraints.get(typeParameter);
if (typeConstraints != null) {
if (TypeUtils.dependsOnTypeParameterConstructors(
constrainingType, Collections.singleton(DONT_CARE.getConstructor()))) {
return;
}
if (subjectType.isNullable() && constrainingType.isNullable()) {
constrainingType = TypeUtils.makeNotNullable(constrainingType);
}
typeConstraints.addBound(constraintKind, constrainingType);
return;
}
}
if (constrainingTypeDescriptor instanceof TypeParameterDescriptor) {
assert typeParameterConstraints.get(constrainingTypeDescriptor) == null
: "Constraining type contains type variable " + constrainingTypeDescriptor.getName();
}
if (constraintKind == SUB_TYPE && kotlinBuiltIns.isNothingOrNullableNothing(constrainingType)) {
// following constraints are always true:
// 'Nothing' is a subtype of any type
if (!constrainingType.isNullable()) return;
// 'Nothing?' is a subtype of nullable type
if (subjectType.isNullable()) return;
}
if (!(constrainingTypeDescriptor instanceof ClassDescriptor)
|| !(subjectTypeDescriptor instanceof ClassDescriptor)) {
errorConstraintPositions.add(constraintPosition);
return;
}
switch (constraintKind) {
case SUB_TYPE:
{
if (kotlinBuiltIns.isNothingOrNullableNothing(constrainingType)) break;
JetType correspondingSupertype =
TypeCheckingProcedure.findCorrespondingSupertype(constrainingType, subjectType);
if (correspondingSupertype != null) {
constrainingType = correspondingSupertype;
}
break;
}
case SUPER_TYPE:
{
if (kotlinBuiltIns.isNothingOrNullableNothing(subjectType)) break;
JetType correspondingSupertype =
TypeCheckingProcedure.findCorrespondingSupertype(subjectType, constrainingType);
if (correspondingSupertype != null) {
subjectType = correspondingSupertype;
}
}
case EQUAL: // nothing
}
if (constrainingType.getConstructor() != subjectType.getConstructor()) {
errorConstraintPositions.add(constraintPosition);
return;
}
TypeConstructor typeConstructor = subjectType.getConstructor();
List<TypeProjection> subjectArguments = subjectType.getArguments();
List<TypeProjection> constrainingArguments = constrainingType.getArguments();
List<TypeParameterDescriptor> parameters = typeConstructor.getParameters();
for (int i = 0; i < subjectArguments.size(); i++) {
Variance typeParameterVariance = parameters.get(i).getVariance();
TypeProjection subjectArgument = subjectArguments.get(i);
TypeProjection constrainingArgument = constrainingArguments.get(i);
ConstraintKind typeParameterConstraintKind =
getTypeParameterConstraintKind(
typeParameterVariance, subjectArgument, constrainingArgument, constraintKind);
addConstraint(
typeParameterConstraintKind,
subjectArgument.getType(),
constrainingArgument.getType(),
constraintPosition);
}
}