@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);
}
@Override
public JetType visitFunctionLiteralExpression(
JetFunctionLiteralExpression expression, ExpressionTypingContext context) {
JetFunctionLiteral functionLiteral = expression.getFunctionLiteral();
JetBlockExpression bodyExpression = functionLiteral.getBodyExpression();
if (bodyExpression == null) return null;
JetType expectedType = context.expectedType;
boolean functionTypeExpected =
expectedType != TypeUtils.NO_EXPECTED_TYPE
&& JetStandardClasses.isFunctionType(expectedType);
NamedFunctionDescriptorImpl functionDescriptor =
createFunctionDescriptor(expression, context, functionTypeExpected);
List<JetType> parameterTypes = Lists.newArrayList();
List<ValueParameterDescriptor> valueParameters = functionDescriptor.getValueParameters();
for (ValueParameterDescriptor valueParameter : valueParameters) {
parameterTypes.add(valueParameter.getOutType());
}
ReceiverDescriptor receiverParameter = functionDescriptor.getReceiverParameter();
JetType receiver = receiverParameter != NO_RECEIVER ? receiverParameter.getType() : null;
JetType returnType = TypeUtils.NO_EXPECTED_TYPE;
JetScope functionInnerScope =
FunctionDescriptorUtil.getFunctionInnerScope(
context.scope, functionDescriptor, context.trace);
JetTypeReference returnTypeRef = functionLiteral.getReturnTypeRef();
if (returnTypeRef != null) {
returnType = context.getTypeResolver().resolveType(context.scope, returnTypeRef);
context
.getServices()
.checkFunctionReturnType(
expression,
context
.replaceScope(functionInnerScope)
.replaceExpectedType(returnType)
.replaceExpectedReturnType(returnType)
.replaceDataFlowInfo(context.dataFlowInfo));
} else {
if (functionTypeExpected) {
returnType = JetStandardClasses.getReturnTypeFromFunctionType(expectedType);
}
returnType =
context
.getServices()
.getBlockReturnedType(
functionInnerScope,
bodyExpression,
CoercionStrategy.COERCION_TO_UNIT,
context.replaceExpectedType(returnType).replaceExpectedReturnType(returnType));
}
JetType safeReturnType =
returnType == null ? ErrorUtils.createErrorType("<return type>") : returnType;
functionDescriptor.setReturnType(safeReturnType);
boolean hasDeclaredValueParameters = functionLiteral.getValueParameterList() != null;
if (!hasDeclaredValueParameters && functionTypeExpected) {
JetType expectedReturnType = JetStandardClasses.getReturnTypeFromFunctionType(expectedType);
if (JetStandardClasses.isUnit(expectedReturnType)) {
functionDescriptor.setReturnType(JetStandardClasses.getUnitType());
return DataFlowUtils.checkType(
JetStandardClasses.getFunctionType(
Collections.<AnnotationDescriptor>emptyList(),
receiver,
parameterTypes,
JetStandardClasses.getUnitType()),
expression,
context);
}
}
return DataFlowUtils.checkType(
JetStandardClasses.getFunctionType(
Collections.<AnnotationDescriptor>emptyList(),
receiver,
parameterTypes,
safeReturnType),
expression,
context);
}
@NotNull
protected JetTypeInfo visitAssignmentOperation(
JetBinaryExpression expression, ExpressionTypingContext contextWithExpectedType) {
// There is a temporary binding trace for an opportunity to resolve set method for array if
// needed (the initial trace should be used there)
TemporaryBindingTrace temporaryBindingTrace =
TemporaryBindingTrace.create(
contextWithExpectedType.trace,
"trace to resolve array set method for binary expression",
expression);
ExpressionTypingContext context =
contextWithExpectedType
.replaceExpectedType(TypeUtils.NO_EXPECTED_TYPE)
.replaceBindingTrace(temporaryBindingTrace);
JetSimpleNameExpression operationSign = expression.getOperationReference();
IElementType operationType = operationSign.getReferencedNameElementType();
JetTypeInfo leftInfo = facade.getTypeInfo(expression.getLeft(), context);
JetType leftType = leftInfo.getType();
DataFlowInfo dataFlowInfo = leftInfo.getDataFlowInfo();
JetExpression right = expression.getRight();
JetExpression left = JetPsiUtil.deparenthesizeWithNoTypeResolution(expression.getLeft());
if (right == null || left == null) {
temporaryBindingTrace.commit();
return JetTypeInfo.create(null, dataFlowInfo);
}
if (leftType == null) {
dataFlowInfo =
facade.getTypeInfo(right, context.replaceDataFlowInfo(dataFlowInfo)).getDataFlowInfo();
context.trace.report(UNRESOLVED_REFERENCE.on(operationSign));
temporaryBindingTrace.commit();
return JetTypeInfo.create(null, dataFlowInfo);
}
ExpressionReceiver receiver = new ExpressionReceiver(left, leftType);
// We check that defined only one of '+=' and '+' operations, and call it (in the case '+' we
// then also assign)
// Check for '+='
Name name = OperatorConventions.ASSIGNMENT_OPERATIONS.get(operationType);
TemporaryBindingTrace assignmentOperationTrace =
TemporaryBindingTrace.create(
context.trace, "trace to check assignment operation like '+=' for", expression);
OverloadResolutionResults<FunctionDescriptor> assignmentOperationDescriptors =
basic.getResolutionResultsForBinaryCall(
scope,
name,
context.replaceBindingTrace(assignmentOperationTrace),
expression,
receiver);
JetType assignmentOperationType =
OverloadResolutionResultsUtil.getResultType(assignmentOperationDescriptors);
// Check for '+'
Name counterpartName =
OperatorConventions.BINARY_OPERATION_NAMES.get(
OperatorConventions.ASSIGNMENT_OPERATION_COUNTERPARTS.get(operationType));
TemporaryBindingTrace binaryOperationTrace =
TemporaryBindingTrace.create(
context.trace, "trace to check binary operation like '+' for", expression);
OverloadResolutionResults<FunctionDescriptor> binaryOperationDescriptors =
basic.getResolutionResultsForBinaryCall(
scope,
counterpartName,
context.replaceBindingTrace(binaryOperationTrace),
expression,
receiver);
JetType binaryOperationType =
OverloadResolutionResultsUtil.getResultType(binaryOperationDescriptors);
JetType type = assignmentOperationType != null ? assignmentOperationType : binaryOperationType;
if (assignmentOperationType != null && binaryOperationType != null) {
OverloadResolutionResults<FunctionDescriptor> ambiguityResolutionResults =
OverloadResolutionResultsUtil.ambiguity(
assignmentOperationDescriptors, binaryOperationDescriptors);
context.trace.report(
ASSIGN_OPERATOR_AMBIGUITY.on(
operationSign, ambiguityResolutionResults.getResultingCalls()));
Collection<DeclarationDescriptor> descriptors = Sets.newHashSet();
for (ResolvedCall<? extends FunctionDescriptor> call :
ambiguityResolutionResults.getResultingCalls()) {
descriptors.add(call.getResultingDescriptor());
}
dataFlowInfo =
facade.getTypeInfo(right, context.replaceDataFlowInfo(dataFlowInfo)).getDataFlowInfo();
context.trace.record(AMBIGUOUS_REFERENCE_TARGET, operationSign, descriptors);
} else if (assignmentOperationType != null) {
assignmentOperationTrace.commit();
if (!KotlinBuiltIns.getInstance().isUnit(assignmentOperationType)) {
context.trace.report(
ASSIGNMENT_OPERATOR_SHOULD_RETURN_UNIT.on(
operationSign,
assignmentOperationDescriptors.getResultingDescriptor(),
operationSign));
}
} else {
binaryOperationTrace.commit();
context.trace.record(VARIABLE_REASSIGNMENT, expression);
if (left instanceof JetArrayAccessExpression) {
ExpressionTypingContext contextForResolve =
context
.replaceScope(scope)
.replaceBindingTrace(
TemporaryBindingTrace.create(
contextWithExpectedType.trace,
"trace to resolve array set method for assignment",
expression));
basic.resolveArrayAccessSetMethod(
(JetArrayAccessExpression) left, right, contextForResolve, context.trace);
}
dataFlowInfo =
facade.getTypeInfo(right, context.replaceDataFlowInfo(dataFlowInfo)).getDataFlowInfo();
}
basic.checkLValue(context.trace, expression.getLeft());
temporaryBindingTrace.commit();
return JetTypeInfo.create(
checkAssignmentType(type, expression, contextWithExpectedType), dataFlowInfo);
}