@Nullable
private static JetType computeUnsafeReturnType(
@NotNull JetFunctionLiteralExpression expression,
@NotNull ExpressionTypingContext context,
@NotNull SimpleFunctionDescriptorImpl functionDescriptor,
@Nullable JetType expectedReturnType) {
JetFunctionLiteral functionLiteral = expression.getFunctionLiteral();
JetBlockExpression bodyExpression = functionLiteral.getBodyExpression();
assert bodyExpression != null;
JetScope functionInnerScope =
FunctionDescriptorUtil.getFunctionInnerScope(
context.scope, functionDescriptor, context.trace);
JetTypeReference returnTypeRef = functionLiteral.getReturnTypeRef();
JetType declaredReturnType = null;
if (returnTypeRef != null) {
declaredReturnType =
context
.expressionTypingServices
.getTypeResolver()
.resolveType(context.scope, returnTypeRef, context.trace, true);
// This is needed for ControlStructureTypingVisitor#visitReturnExpression() to properly
// type-check returned expressions
functionDescriptor.setReturnType(declaredReturnType);
if (expectedReturnType != null) {
if (!JetTypeChecker.INSTANCE.isSubtypeOf(declaredReturnType, expectedReturnType)) {
context.trace.report(EXPECTED_RETURN_TYPE_MISMATCH.on(returnTypeRef, expectedReturnType));
}
}
}
// Type-check the body
ExpressionTypingContext newContext =
context
.replaceScope(functionInnerScope)
.replaceExpectedType(
declaredReturnType != null
? declaredReturnType
: (expectedReturnType != null ? expectedReturnType : NO_EXPECTED_TYPE));
JetType typeOfBodyExpression =
context
.expressionTypingServices
.getBlockReturnedType(bodyExpression, COERCION_TO_UNIT, newContext)
.getType();
List<JetType> returnedExpressionTypes =
Lists.newArrayList(
getTypesOfLocallyReturnedExpressions(
functionLiteral, context.trace, collectReturns(bodyExpression)));
ContainerUtil.addIfNotNull(returnedExpressionTypes, typeOfBodyExpression);
if (declaredReturnType != null) return declaredReturnType;
if (returnedExpressionTypes.isEmpty()) return null;
return CommonSupertypes.commonSupertype(returnedExpressionTypes);
}
@NotNull
private static List<ValueParameterDescriptor> createValueParameterDescriptors(
@NotNull ExpressionTypingContext context,
@NotNull JetFunctionLiteral functionLiteral,
@NotNull FunctionDescriptorImpl functionDescriptor,
boolean functionTypeExpected) {
List<ValueParameterDescriptor> valueParameterDescriptors = Lists.newArrayList();
List<JetParameter> declaredValueParameters = functionLiteral.getValueParameters();
List<ValueParameterDescriptor> expectedValueParameters =
(functionTypeExpected)
? KotlinBuiltIns.getInstance()
.getValueParameters(functionDescriptor, context.expectedType)
: null;
JetParameterList valueParameterList = functionLiteral.getValueParameterList();
boolean hasDeclaredValueParameters = valueParameterList != null;
if (functionTypeExpected
&& !hasDeclaredValueParameters
&& expectedValueParameters.size() == 1) {
ValueParameterDescriptor valueParameterDescriptor = expectedValueParameters.get(0);
ValueParameterDescriptor it =
new ValueParameterDescriptorImpl(
functionDescriptor,
0,
Collections.<AnnotationDescriptor>emptyList(),
Name.identifier("it"),
valueParameterDescriptor.getType(),
valueParameterDescriptor.hasDefaultValue(),
valueParameterDescriptor.getVarargElementType());
valueParameterDescriptors.add(it);
context.trace.record(AUTO_CREATED_IT, it);
} else {
if (expectedValueParameters != null
&& declaredValueParameters.size() != expectedValueParameters.size()) {
List<JetType> expectedParameterTypes =
DescriptorUtils.getValueParametersTypes(expectedValueParameters);
context.trace.report(
EXPECTED_PARAMETERS_NUMBER_MISMATCH.on(
functionLiteral, expectedParameterTypes.size(), expectedParameterTypes));
}
for (int i = 0; i < declaredValueParameters.size(); i++) {
ValueParameterDescriptor valueParameterDescriptor =
createValueParameterDescriptor(
context, functionDescriptor, declaredValueParameters, expectedValueParameters, i);
valueParameterDescriptors.add(valueParameterDescriptor);
}
}
return valueParameterDescriptors;
}
@NotNull
private static AnonymousFunctionDescriptor createFunctionDescriptor(
@NotNull JetFunctionLiteralExpression expression,
@NotNull ExpressionTypingContext context,
boolean functionTypeExpected) {
JetFunctionLiteral functionLiteral = expression.getFunctionLiteral();
JetTypeReference receiverTypeRef = functionLiteral.getReceiverTypeRef();
AnonymousFunctionDescriptor functionDescriptor =
new AnonymousFunctionDescriptor(
context.scope.getContainingDeclaration(),
Collections.<AnnotationDescriptor>emptyList(),
CallableMemberDescriptor.Kind.DECLARATION);
List<ValueParameterDescriptor> valueParameterDescriptors =
createValueParameterDescriptors(
context, functionLiteral,
functionDescriptor, functionTypeExpected);
JetType effectiveReceiverType;
if (receiverTypeRef == null) {
if (functionTypeExpected) {
effectiveReceiverType = KotlinBuiltIns.getInstance().getReceiverType(context.expectedType);
} else {
effectiveReceiverType = null;
}
} else {
effectiveReceiverType =
context
.expressionTypingServices
.getTypeResolver()
.resolveType(context.scope, receiverTypeRef, context.trace, true);
}
functionDescriptor.initialize(
effectiveReceiverType,
ReceiverParameterDescriptor.NO_RECEIVER_PARAMETER,
Collections.<TypeParameterDescriptorImpl>emptyList(),
valueParameterDescriptors,
/*unsubstitutedReturnType = */ null,
Modality.FINAL,
Visibilities.LOCAL);
BindingContextUtils.recordFunctionDeclarationToDescriptor(
context.trace, functionLiteral, functionDescriptor);
return functionDescriptor;
}