001    /*
002     * Copyright 2010-2013 JetBrains s.r.o.
003     *
004     * Licensed under the Apache License, Version 2.0 (the "License");
005     * you may not use this file except in compliance with the License.
006     * You may obtain a copy of the License at
007     *
008     * http://www.apache.org/licenses/LICENSE-2.0
009     *
010     * Unless required by applicable law or agreed to in writing, software
011     * distributed under the License is distributed on an "AS IS" BASIS,
012     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013     * See the License for the specific language governing permissions and
014     * limitations under the License.
015     */
016    
017    package org.jetbrains.jet.lang.types.expressions;
018    
019    import com.google.common.collect.Lists;
020    import com.intellij.psi.PsiElement;
021    import com.intellij.psi.tree.IElementType;
022    import com.intellij.psi.tree.TokenSet;
023    import org.jetbrains.annotations.NotNull;
024    import org.jetbrains.annotations.Nullable;
025    import org.jetbrains.jet.lang.descriptors.*;
026    import org.jetbrains.jet.lang.descriptors.annotations.Annotations;
027    import org.jetbrains.jet.lang.descriptors.impl.AnonymousFunctionDescriptor;
028    import org.jetbrains.jet.lang.diagnostics.Diagnostic;
029    import org.jetbrains.jet.lang.diagnostics.Errors;
030    import org.jetbrains.jet.lang.evaluate.ConstantExpressionEvaluator;
031    import org.jetbrains.jet.lang.psi.*;
032    import org.jetbrains.jet.lang.resolve.*;
033    import org.jetbrains.jet.lang.resolve.calls.ArgumentTypeResolver;
034    import org.jetbrains.jet.lang.resolve.calls.CallExpressionResolver;
035    import org.jetbrains.jet.lang.resolve.calls.autocasts.DataFlowInfo;
036    import org.jetbrains.jet.lang.resolve.calls.autocasts.DataFlowValue;
037    import org.jetbrains.jet.lang.resolve.calls.autocasts.DataFlowValueFactory;
038    import org.jetbrains.jet.lang.resolve.calls.autocasts.Nullability;
039    import org.jetbrains.jet.lang.resolve.calls.context.BasicCallResolutionContext;
040    import org.jetbrains.jet.lang.resolve.calls.context.CheckValueArgumentsMode;
041    import org.jetbrains.jet.lang.resolve.calls.context.TemporaryTraceAndCache;
042    import org.jetbrains.jet.lang.resolve.calls.model.*;
043    import org.jetbrains.jet.lang.resolve.calls.results.OverloadResolutionResults;
044    import org.jetbrains.jet.lang.resolve.calls.results.OverloadResolutionResultsImpl;
045    import org.jetbrains.jet.lang.resolve.calls.results.OverloadResolutionResultsUtil;
046    import org.jetbrains.jet.lang.resolve.calls.tasks.ExplicitReceiverKind;
047    import org.jetbrains.jet.lang.resolve.calls.tasks.ResolutionCandidate;
048    import org.jetbrains.jet.lang.resolve.calls.tasks.TracingStrategy;
049    import org.jetbrains.jet.lang.resolve.calls.util.CallMaker;
050    import org.jetbrains.jet.lang.resolve.constants.CompileTimeConstant;
051    import org.jetbrains.jet.lang.resolve.constants.CompileTimeConstantChecker;
052    import org.jetbrains.jet.lang.resolve.constants.IntegerValueTypeConstant;
053    import org.jetbrains.jet.lang.resolve.name.LabelName;
054    import org.jetbrains.jet.lang.resolve.name.Name;
055    import org.jetbrains.jet.lang.resolve.scopes.JetScope;
056    import org.jetbrains.jet.lang.resolve.scopes.WritableScopeImpl;
057    import org.jetbrains.jet.lang.resolve.scopes.receivers.ExpressionReceiver;
058    import org.jetbrains.jet.lang.resolve.scopes.receivers.ReceiverValue;
059    import org.jetbrains.jet.lang.resolve.scopes.receivers.TransientReceiver;
060    import org.jetbrains.jet.lang.types.*;
061    import org.jetbrains.jet.lang.types.checker.JetTypeChecker;
062    import org.jetbrains.jet.lang.types.lang.KotlinBuiltIns;
063    import org.jetbrains.jet.lexer.JetTokens;
064    import org.jetbrains.jet.util.slicedmap.WritableSlice;
065    import org.jetbrains.jet.utils.ThrowingList;
066    
067    import java.util.Collection;
068    import java.util.Collections;
069    import java.util.List;
070    
071    import static org.jetbrains.jet.lang.descriptors.ReceiverParameterDescriptor.NO_RECEIVER_PARAMETER;
072    import static org.jetbrains.jet.lang.diagnostics.Errors.*;
073    import static org.jetbrains.jet.lang.resolve.BindingContext.*;
074    import static org.jetbrains.jet.lang.resolve.DescriptorUtils.getStaticNestedClassesScope;
075    import static org.jetbrains.jet.lang.resolve.calls.context.ContextDependency.INDEPENDENT;
076    import static org.jetbrains.jet.lang.resolve.scopes.receivers.ReceiverValue.NO_RECEIVER;
077    import static org.jetbrains.jet.lang.types.TypeUtils.*;
078    import static org.jetbrains.jet.lang.types.expressions.ControlStructureTypingUtils.createCallForSpecialConstruction;
079    import static org.jetbrains.jet.lang.types.expressions.ExpressionTypingUtils.*;
080    import static org.jetbrains.jet.lang.types.expressions.TypeReconstructionUtil.reconstructBareType;
081    import static org.jetbrains.jet.lexer.JetTokens.AS_KEYWORD;
082    import static org.jetbrains.jet.lexer.JetTokens.AS_SAFE;
083    
084    @SuppressWarnings("SuspiciousMethodCalls")
085    public class BasicExpressionTypingVisitor extends ExpressionTypingVisitor {
086    
087        private static final TokenSet BARE_TYPES_ALLOWED = TokenSet.create(AS_KEYWORD, AS_SAFE);
088    
089        protected BasicExpressionTypingVisitor(@NotNull ExpressionTypingInternals facade) {
090            super(facade);
091        }
092    
093        @Override
094        public JetTypeInfo visitSimpleNameExpression(@NotNull JetSimpleNameExpression expression, ExpressionTypingContext context) {
095            // TODO : other members
096            // TODO : type substitutions???
097            CallExpressionResolver callExpressionResolver = components.expressionTypingServices.getCallExpressionResolver();
098            JetTypeInfo typeInfo = callExpressionResolver.getSimpleNameExpressionTypeInfo(expression, NO_RECEIVER, null, context);
099            JetType type = DataFlowUtils.checkType(typeInfo.getType(), expression, context);
100            ExpressionTypingUtils.checkCapturingInClosure(expression, context.trace, context.scope);
101            return JetTypeInfo.create(type, typeInfo.getDataFlowInfo()); // TODO : Extensions to this
102        }
103    
104        @Override
105        public JetTypeInfo visitParenthesizedExpression(@NotNull JetParenthesizedExpression expression, ExpressionTypingContext context) {
106            return visitParenthesizedExpression(expression, context, false);
107        }
108    
109        public JetTypeInfo visitParenthesizedExpression(JetParenthesizedExpression expression, ExpressionTypingContext context, boolean isStatement) {
110            JetExpression innerExpression = expression.getExpression();
111            if (innerExpression == null) {
112                return JetTypeInfo.create(null, context.dataFlowInfo);
113            }
114            return facade.getTypeInfo(innerExpression, context.replaceScope(context.scope), isStatement);
115        }
116    
117        @Override
118        public JetTypeInfo visitConstantExpression(@NotNull JetConstantExpression expression, ExpressionTypingContext context) {
119            CompileTimeConstant<?> value = ConstantExpressionEvaluator.object$.evaluate(expression, context.trace, context.expectedType);
120    
121            if (!(value instanceof IntegerValueTypeConstant)) {
122                CompileTimeConstantChecker compileTimeConstantChecker = context.getCompileTimeConstantChecker();
123                boolean hasError = compileTimeConstantChecker.checkConstantExpressionType(value, expression, context.expectedType);
124                if (hasError) {
125                    IElementType elementType = expression.getNode().getElementType();
126                    return JetTypeInfo.create(getDefaultType(elementType), context.dataFlowInfo);
127                }
128            }
129    
130            assert value != null : "CompileTimeConstant should be evaluated for constant expression or an error should be recorded " + expression.getText();
131            return createCompileTimeConstantTypeInfo(value, expression, context);
132        }
133    
134        @Override
135        public JetTypeInfo visitBinaryWithTypeRHSExpression(@NotNull JetBinaryExpressionWithTypeRHS expression, ExpressionTypingContext context) {
136            ExpressionTypingContext contextWithNoExpectedType =
137                    context.replaceExpectedType(NO_EXPECTED_TYPE).replaceContextDependency(INDEPENDENT);
138            JetExpression left = expression.getLeft();
139            JetTypeReference right = expression.getRight();
140            if (right == null) {
141                JetTypeInfo leftTypeInfo = facade.getTypeInfo(left, contextWithNoExpectedType);
142                return JetTypeInfo.create(null, leftTypeInfo.getDataFlowInfo());
143            }
144    
145            IElementType operationType = expression.getOperationReference().getReferencedNameElementType();
146    
147            boolean allowBareTypes = BARE_TYPES_ALLOWED.contains(operationType);
148            TypeResolutionContext typeResolutionContext = new TypeResolutionContext(context.scope, context.trace, true, allowBareTypes);
149            PossiblyBareType possiblyBareTarget = components.expressionTypingServices.getTypeResolver().resolvePossiblyBareType(typeResolutionContext, right);
150    
151            if (operationType == JetTokens.COLON) {
152                // We do not allow bare types on static assertions, because static assertions provide an expected type for their argument,
153                // thus causing a circularity in type dependencies
154                assert !possiblyBareTarget.isBare() : "Bare types should not be allowed for static assertions, because argument inference makes no sense there";
155                JetType targetType = possiblyBareTarget.getActualType();
156    
157                JetTypeInfo typeInfo = facade.getTypeInfo(left, contextWithNoExpectedType.replaceExpectedType(targetType));
158                checkBinaryWithTypeRHS(expression, context, targetType, typeInfo.getType());
159                return DataFlowUtils.checkType(targetType, expression, context, typeInfo.getDataFlowInfo());
160            }
161    
162            JetTypeInfo typeInfo = facade.getTypeInfo(left, contextWithNoExpectedType);
163    
164            DataFlowInfo dataFlowInfo = context.dataFlowInfo;
165            JetType subjectType = typeInfo.getType();
166            JetType targetType = reconstructBareType(right, possiblyBareTarget, subjectType, context.trace);
167    
168            if (subjectType != null) {
169                checkBinaryWithTypeRHS(expression, contextWithNoExpectedType, targetType, subjectType);
170                dataFlowInfo = typeInfo.getDataFlowInfo();
171                if (operationType == AS_KEYWORD) {
172                    DataFlowValue value = DataFlowValueFactory.createDataFlowValue(left, subjectType, context.trace.getBindingContext());
173                    dataFlowInfo = dataFlowInfo.establishSubtyping(value, targetType);
174                }
175            }
176    
177            JetType result = operationType == AS_SAFE ? TypeUtils.makeNullable(targetType) : targetType;
178            return DataFlowUtils.checkType(result, expression, context, dataFlowInfo);
179        }
180    
181        private void checkBinaryWithTypeRHS(
182                @NotNull JetBinaryExpressionWithTypeRHS expression,
183                @NotNull ExpressionTypingContext context,
184                @NotNull JetType targetType,
185                @Nullable JetType actualType
186        ) {
187            if (actualType == null) return;
188            JetSimpleNameExpression operationSign = expression.getOperationReference();
189            IElementType operationType = operationSign.getReferencedNameElementType();
190            if (operationType == JetTokens.COLON) {
191                return;
192            }
193            if (operationType != JetTokens.AS_KEYWORD && operationType != JetTokens.AS_SAFE) {
194                context.trace.report(UNSUPPORTED.on(operationSign, "binary operation with type RHS"));
195                return;
196            }
197            checkForCastImpossibility(expression, actualType, targetType, context);
198        }
199    
200        private void checkForCastImpossibility(
201                JetBinaryExpressionWithTypeRHS expression,
202                JetType actualType,
203                JetType targetType,
204                ExpressionTypingContext context
205        ) {
206            if (actualType == null || noExpectedType(targetType)) return;
207    
208            if (!CastDiagnosticsUtil.isCastPossible(actualType, targetType, components.platformToKotlinClassMap)) {
209                context.trace.report(CAST_NEVER_SUCCEEDS.on(expression.getOperationReference()));
210            }
211            else {
212                JetTypeChecker typeChecker = JetTypeChecker.INSTANCE;
213                // Upcast?
214                if (typeChecker.isSubtypeOf(actualType, targetType)) {
215                    if (!typeChecker.isSubtypeOf(targetType, actualType)) {
216                        // proper upcast: String as Any
217                        context.trace.report(USELESS_CAST_STATIC_ASSERT_IS_FINE.on(expression.getOperationReference()));
218                    }
219                    else {
220                        // cast to itself: String as String
221                        context.trace.report(USELESS_CAST.on(expression.getOperationReference()));
222                    }
223                }
224                else if (CastDiagnosticsUtil.isCastErased(actualType, targetType, typeChecker)) {
225                    context.trace.report(Errors.UNCHECKED_CAST.on(expression, actualType, targetType));
226                }
227            }
228        }
229    
230        @Override
231        public JetTypeInfo visitThisExpression(@NotNull JetThisExpression expression, ExpressionTypingContext context) {
232            JetType result = null;
233            LabelResolver.LabeledReceiverResolutionResult resolutionResult = resolveToReceiver(expression, context, false);
234    
235            switch (resolutionResult.getCode()) {
236                case LABEL_RESOLUTION_ERROR:
237                    // Do nothing, the error is already reported
238                    break;
239                case NO_THIS:
240                    context.trace.report(NO_THIS.on(expression));
241                    break;
242                case SUCCESS:
243                    result = resolutionResult.getReceiverParameterDescriptor().getType();
244                    context.trace.record(BindingContext.EXPRESSION_TYPE, expression.getInstanceReference(), result);
245                    break;
246            }
247            return DataFlowUtils.checkType(result, expression, context, context.dataFlowInfo);
248        }
249    
250        @Override
251        public JetTypeInfo visitSuperExpression(@NotNull JetSuperExpression expression, ExpressionTypingContext context) {
252            LabelResolver.LabeledReceiverResolutionResult resolutionResult = resolveToReceiver(expression, context, true);
253    
254            if (!JetPsiUtil.isLHSOfDot(expression)) {
255                context.trace.report(SUPER_IS_NOT_AN_EXPRESSION.on(expression, expression.getText()));
256                return errorInSuper(expression, context);
257            }
258    
259            switch (resolutionResult.getCode()) {
260                case LABEL_RESOLUTION_ERROR:
261                    // The error is already reported
262                    return errorInSuper(expression, context);
263                case NO_THIS:
264                    context.trace.report(SUPER_NOT_AVAILABLE.on(expression));
265                    return errorInSuper(expression, context);
266                case SUCCESS:
267                    JetType result = checkPossiblyQualifiedSuper(expression, context, resolutionResult.getReceiverParameterDescriptor());
268                    if (result != null) {
269                        context.trace.record(BindingContext.EXPRESSION_TYPE, expression.getInstanceReference(), result);
270                    }
271                    return DataFlowUtils.checkType(result, expression, context, context.dataFlowInfo);
272            }
273            throw new IllegalStateException("Unknown code: " + resolutionResult.getCode());
274        }
275    
276        private JetTypeInfo errorInSuper(JetSuperExpression expression, ExpressionTypingContext context) {
277            JetTypeReference superTypeQualifier = expression.getSuperTypeQualifier();
278            if (superTypeQualifier != null) {
279                components.expressionTypingServices.getTypeResolver().resolveType(context.scope, superTypeQualifier, context.trace, true);
280            }
281            return JetTypeInfo.create(null, context.dataFlowInfo);
282        }
283    
284        private JetType checkPossiblyQualifiedSuper(
285                JetSuperExpression expression,
286                ExpressionTypingContext context,
287                ReceiverParameterDescriptor thisReceiver
288        ) {
289            JetType result = null;
290            JetType thisType = thisReceiver.getType();
291            Collection<JetType> supertypes = thisType.getConstructor().getSupertypes();
292            TypeSubstitutor substitutor = TypeSubstitutor.create(thisType);
293    
294            JetTypeReference superTypeQualifier = expression.getSuperTypeQualifier();
295            if (superTypeQualifier != null) {
296                JetTypeElement typeElement = superTypeQualifier.getTypeElement();
297    
298                DeclarationDescriptor classifierCandidate = null;
299                JetType supertype = null;
300                PsiElement redundantTypeArguments = null;
301                if (typeElement instanceof JetUserType) {
302                    JetUserType userType = (JetUserType) typeElement;
303                    // This may be just a superclass name even if the superclass is generic
304                    if (userType.getTypeArguments().isEmpty()) {
305                        classifierCandidate = components.expressionTypingServices.getTypeResolver().resolveClass(context.scope, userType, context.trace);
306                    }
307                    else {
308                        supertype = components.expressionTypingServices.getTypeResolver().resolveType(context.scope, superTypeQualifier, context.trace, true);
309                        redundantTypeArguments = userType.getTypeArgumentList();
310                    }
311                }
312                else {
313                    supertype = components.expressionTypingServices.getTypeResolver().resolveType(context.scope, superTypeQualifier, context.trace, true);
314                }
315    
316                if (supertype != null) {
317                    if (supertypes.contains(supertype)) {
318                        result = supertype;
319                    }
320                }
321                else if (classifierCandidate instanceof ClassDescriptor) {
322                    ClassDescriptor superclass = (ClassDescriptor) classifierCandidate;
323    
324                    for (JetType declaredSupertype : supertypes) {
325                        if (declaredSupertype.getConstructor().equals(superclass.getTypeConstructor())) {
326                            result = substitutor.safeSubstitute(declaredSupertype, Variance.INVARIANT);
327                            break;
328                        }
329                    }
330                }
331    
332                boolean validClassifier = classifierCandidate != null && !ErrorUtils.isError(classifierCandidate);
333                boolean validType = supertype != null && !supertype.isError();
334                if (result == null && (validClassifier || validType)) {
335                    context.trace.report(NOT_A_SUPERTYPE.on(superTypeQualifier));
336                }
337                else if (redundantTypeArguments != null) {
338                    context.trace.report(TYPE_ARGUMENTS_REDUNDANT_IN_SUPER_QUALIFIER.on(redundantTypeArguments));
339                }
340            }
341            else {
342                if (supertypes.size() > 1) {
343                    context.trace.report(AMBIGUOUS_SUPER.on(expression));
344                }
345                else {
346                    // supertypes may be empty when all the supertypes are error types (are not resolved, for example)
347                    JetType type = supertypes.isEmpty()
348                                   ? KotlinBuiltIns.getInstance().getAnyType()
349                                   : supertypes.iterator().next();
350                    result = substitutor.substitute(type, Variance.INVARIANT);
351                }
352            }
353            if (result != null) {
354                if (DescriptorUtils.isTrait(thisType.getConstructor().getDeclarationDescriptor())) {
355                    if (DescriptorUtils.isClass(result.getConstructor().getDeclarationDescriptor())) {
356                        context.trace.report(SUPERCLASS_NOT_ACCESSIBLE_FROM_TRAIT.on(expression));
357                    }
358                }
359                context.trace.record(BindingContext.EXPRESSION_TYPE, expression.getInstanceReference(), result);
360                context.trace.record(BindingContext.REFERENCE_TARGET, expression.getInstanceReference(), result.getConstructor().getDeclarationDescriptor());
361                if (superTypeQualifier != null) {
362                    context.trace.record(BindingContext.TYPE_RESOLUTION_SCOPE, superTypeQualifier, context.scope);
363                }
364            }
365            return result;
366        }
367    
368        @NotNull // No class receivers
369        private static LabelResolver.LabeledReceiverResolutionResult resolveToReceiver(
370                JetLabelQualifiedInstanceExpression expression,
371                ExpressionTypingContext context,
372                boolean onlyClassReceivers
373        ) {
374            String labelName = expression.getLabelName();
375            if (labelName != null) {
376                LabelResolver.LabeledReceiverResolutionResult resolutionResult = context.labelResolver.resolveThisLabel(
377                        expression.getInstanceReference(), expression.getTargetLabel(), context, new LabelName(labelName));
378                if (onlyClassReceivers && resolutionResult.success()) {
379                    if (!isDeclaredInClass(resolutionResult.getReceiverParameterDescriptor())) {
380                        return LabelResolver.LabeledReceiverResolutionResult.labelResolutionSuccess(NO_RECEIVER_PARAMETER);
381                    }
382                }
383                return resolutionResult;
384            }
385            else {
386                ReceiverParameterDescriptor result = NO_RECEIVER_PARAMETER;
387                List<ReceiverParameterDescriptor> receivers = context.scope.getImplicitReceiversHierarchy();
388                if (onlyClassReceivers) {
389                    for (ReceiverParameterDescriptor receiver : receivers) {
390                        if (isDeclaredInClass(receiver)) {
391                            result = receiver;
392                            break;
393                        }
394                    }
395                }
396                else if (!receivers.isEmpty()) {
397                    result = receivers.get(0);
398                }
399                if (result != NO_RECEIVER_PARAMETER) {
400                    context.trace.record(REFERENCE_TARGET, expression.getInstanceReference(), result.getContainingDeclaration());
401                    recordThisOrSuperCallInTraceAndCallExtension(context, result, expression);
402    
403                }
404                return LabelResolver.LabeledReceiverResolutionResult.labelResolutionSuccess(result);
405            }
406        }
407    
408        private static void recordThisOrSuperCallInTraceAndCallExtension(
409                ExpressionTypingContext context,
410                ReceiverParameterDescriptor descriptor,
411                JetExpression expression
412        ) {
413            BindingTrace trace = context.trace;
414            Call call = CallMaker.makeCall(expression, NO_RECEIVER, null, expression, Collections.<ValueArgument>emptyList());
415            ResolutionCandidate<ReceiverParameterDescriptor> resolutionCandidate =
416                    ResolutionCandidate.create(
417                            call, descriptor, NO_RECEIVER, NO_RECEIVER, ExplicitReceiverKind.NO_EXPLICIT_RECEIVER, false);
418    
419            ResolvedCallImpl<ReceiverParameterDescriptor> resolvedCall =
420                    ResolvedCallImpl.create(resolutionCandidate,
421                                            TemporaryBindingTrace.create(trace, "Fake trace for fake 'this' or 'super' resolved call"),
422                                            TracingStrategy.EMPTY,
423                                            new DataFlowInfoForArgumentsImpl(call));
424            resolvedCall.markCallAsCompleted();
425    
426            trace.record(RESOLVED_CALL, expression, resolvedCall);
427            trace.record(CALL, expression, call);
428    
429            context.callResolverExtension.run(resolvedCall,
430                                              BasicCallResolutionContext.create(context, call, CheckValueArgumentsMode.DISABLED));
431        }
432    
433        private static boolean isDeclaredInClass(ReceiverParameterDescriptor receiver) {
434            return receiver.getContainingDeclaration() instanceof ClassDescriptor;
435        }
436    
437        @Override
438        public JetTypeInfo visitBlockExpression(@NotNull JetBlockExpression expression, ExpressionTypingContext context) {
439            return components.expressionTypingServices.getBlockReturnedType(expression, context, false);
440        }
441    
442        @Override
443        public JetTypeInfo visitCallableReferenceExpression(@NotNull JetCallableReferenceExpression expression, ExpressionTypingContext context) {
444            JetTypeReference typeReference = expression.getTypeReference();
445    
446            JetType receiverType =
447                    typeReference == null
448                    ? null
449                    : components.expressionTypingServices.getTypeResolver().resolveType(context.scope, typeReference, context.trace, false);
450    
451            JetSimpleNameExpression callableReference = expression.getCallableReference();
452            if (callableReference.getReferencedName().isEmpty()) {
453                context.trace.report(UNRESOLVED_REFERENCE.on(callableReference, callableReference));
454                JetType errorType = ErrorUtils.createErrorType("Empty callable reference");
455                return DataFlowUtils.checkType(errorType, expression, context, context.dataFlowInfo);
456            }
457    
458            JetType result = getCallableReferenceType(expression, receiverType, context);
459            return DataFlowUtils.checkType(result, expression, context, context.dataFlowInfo);
460        }
461    
462        @Nullable
463        private JetType getCallableReferenceType(
464                @NotNull JetCallableReferenceExpression expression,
465                @Nullable JetType lhsType,
466                @NotNull ExpressionTypingContext context
467        ) {
468            JetSimpleNameExpression reference = expression.getCallableReference();
469    
470            boolean[] result = new boolean[1];
471            FunctionDescriptor descriptor = resolveCallableReferenceTarget(lhsType, context, expression, result);
472    
473            if (!result[0]) {
474                context.trace.report(UNRESOLVED_REFERENCE.on(reference, reference));
475            }
476            if (descriptor == null) return null;
477    
478            ReceiverParameterDescriptor receiverParameter = descriptor.getReceiverParameter();
479            ReceiverParameterDescriptor expectedThisObject = descriptor.getExpectedThisObject();
480            if (receiverParameter != null && expectedThisObject != null) {
481                context.trace.report(EXTENSION_IN_CLASS_REFERENCE_NOT_ALLOWED.on(reference, descriptor));
482                return null;
483            }
484    
485            JetType receiverType = null;
486            if (receiverParameter != null) {
487                receiverType = receiverParameter.getType();
488            }
489            else if (expectedThisObject != null) {
490                receiverType = expectedThisObject.getType();
491            }
492    
493            //noinspection ConstantConditions
494            JetType type = KotlinBuiltIns.getInstance().getKFunctionType(
495                    Annotations.EMPTY,
496                    receiverType,
497                    DescriptorUtils.getValueParametersTypes(descriptor.getValueParameters()),
498                    descriptor.getReturnType(),
499                    receiverParameter != null
500            );
501    
502            AnonymousFunctionDescriptor functionDescriptor = new AnonymousFunctionDescriptor(
503                    context.scope.getContainingDeclaration(),
504                    Annotations.EMPTY,
505                    CallableMemberDescriptor.Kind.DECLARATION);
506    
507            FunctionDescriptorUtil.initializeFromFunctionType(functionDescriptor, type, null, Modality.FINAL, Visibilities.PUBLIC);
508    
509            context.trace.record(FUNCTION, expression, functionDescriptor);
510    
511            return type;
512        }
513    
514        @Nullable
515        private FunctionDescriptor resolveCallableReferenceTarget(
516                @Nullable JetType lhsType,
517                @NotNull ExpressionTypingContext context,
518                @NotNull JetCallableReferenceExpression expression,
519                @NotNull boolean[] result
520        ) {
521            JetSimpleNameExpression reference = expression.getCallableReference();
522    
523            if (lhsType == null) {
524                return resolveCallableNotCheckingArguments(reference, NO_RECEIVER, context, result);
525            }
526    
527            ClassifierDescriptor classifier = lhsType.getConstructor().getDeclarationDescriptor();
528            if (!(classifier instanceof ClassDescriptor)) {
529                context.trace.report(CALLABLE_REFERENCE_LHS_NOT_A_CLASS.on(expression));
530                return null;
531            }
532    
533            ReceiverValue receiver = new TransientReceiver(lhsType);
534            TemporaryTraceAndCache temporaryWithReceiver = TemporaryTraceAndCache.create(
535                    context, "trace to resolve callable reference with receiver", reference);
536            FunctionDescriptor descriptor = resolveCallableNotCheckingArguments(
537                    reference, receiver, context.replaceTraceAndCache(temporaryWithReceiver), result);
538            if (result[0]) {
539                temporaryWithReceiver.commit();
540                return descriptor;
541            }
542    
543            JetScope staticScope = getStaticNestedClassesScope((ClassDescriptor) classifier);
544            TemporaryTraceAndCache temporaryForStatic = TemporaryTraceAndCache.create(
545                    context, "trace to resolve callable reference in static scope", reference);
546            FunctionDescriptor possibleStaticNestedClassConstructor = resolveCallableNotCheckingArguments(reference, NO_RECEIVER,
547                    context.replaceTraceAndCache(temporaryForStatic).replaceScope(staticScope), result);
548            if (result[0]) {
549                temporaryForStatic.commit();
550                return possibleStaticNestedClassConstructor;
551            }
552    
553            return null;
554        }
555    
556        @Nullable
557        private FunctionDescriptor resolveCallableNotCheckingArguments(
558                @NotNull JetSimpleNameExpression reference,
559                @NotNull ReceiverValue receiver,
560                @NotNull ExpressionTypingContext context,
561                @NotNull boolean[] result
562        ) {
563            Call call = CallMaker.makeCall(reference, receiver, null, reference, ThrowingList.<ValueArgument>instance());
564    
565            TemporaryBindingTrace trace = TemporaryBindingTrace.create(context.trace, "trace to resolve as function", reference);
566    
567            ExpressionTypingContext contextForResolve = context.replaceBindingTrace(trace).replaceExpectedType(NO_EXPECTED_TYPE);
568            ResolvedCallWithTrace<FunctionDescriptor> function = components.expressionTypingServices.getCallExpressionResolver()
569                    .getResolvedCallForFunction(call, reference, contextForResolve, CheckValueArgumentsMode.DISABLED, result);
570            if (!result[0]) return null;
571    
572            if (function instanceof VariableAsFunctionResolvedCall) {
573                // TODO: KProperty
574                context.trace.report(UNSUPPORTED.on(reference, "References to variables aren't supported yet"));
575                context.trace.report(UNRESOLVED_REFERENCE.on(reference, reference));
576                return null;
577            }
578    
579            trace.commit();
580            return function != null ? function.getResultingDescriptor() : null;
581        }
582    
583        @Override
584        public JetTypeInfo visitQualifiedExpression(@NotNull JetQualifiedExpression expression, ExpressionTypingContext context) {
585            CallExpressionResolver callExpressionResolver = components.expressionTypingServices.getCallExpressionResolver();
586            return callExpressionResolver.getQualifiedExpressionTypeInfo(expression, context);
587        }
588    
589        @Override
590        public JetTypeInfo visitCallExpression(@NotNull JetCallExpression expression, ExpressionTypingContext context) {
591            CallExpressionResolver callExpressionResolver = components.expressionTypingServices.getCallExpressionResolver();
592            return callExpressionResolver.getCallExpressionTypeInfo(expression, NO_RECEIVER, null, context);
593        }
594    
595        @Override
596        public JetTypeInfo visitUnaryExpression(@NotNull JetUnaryExpression expression, ExpressionTypingContext context) {
597            return visitUnaryExpression(expression, context, false);
598        }
599    
600        public JetTypeInfo visitUnaryExpression(JetUnaryExpression expression, ExpressionTypingContext contextWithExpectedType, boolean isStatement) {
601            ExpressionTypingContext context = isUnaryExpressionDependentOnExpectedType(expression)
602                    ? contextWithExpectedType
603                    : contextWithExpectedType.replaceContextDependency(INDEPENDENT).replaceExpectedType(NO_EXPECTED_TYPE);
604    
605            JetExpression baseExpression = expression.getBaseExpression();
606            if (baseExpression == null) return JetTypeInfo.create(null, context.dataFlowInfo);
607    
608            JetSimpleNameExpression operationSign = expression.getOperationReference();
609    
610            IElementType operationType = operationSign.getReferencedNameElementType();
611            // If it's a labeled expression
612            if (JetTokens.LABELS.contains(operationType)) {
613                return visitLabeledExpression(expression, context, isStatement);
614            }
615    
616            // Special case for expr!!
617            if (operationType == JetTokens.EXCLEXCL) {
618                return visitExclExclExpression(expression, context);
619            }
620    
621            // Type check the base expression
622            JetTypeInfo typeInfo = facade.getTypeInfo(baseExpression, context);
623            JetType type = typeInfo.getType();
624            if (type == null) {
625                return typeInfo;
626            }
627            DataFlowInfo dataFlowInfo = typeInfo.getDataFlowInfo();
628    
629            // Conventions for unary operations
630            Name name = OperatorConventions.UNARY_OPERATION_NAMES.get(operationType);
631            if (name == null) {
632                context.trace.report(UNSUPPORTED.on(operationSign, "visitUnaryExpression"));
633                return JetTypeInfo.create(null, dataFlowInfo);
634            }
635    
636            // a[i]++/-- takes special treatment because it is actually let j = i, arr = a in arr.set(j, a.get(j).inc())
637            if ((operationType == JetTokens.PLUSPLUS || operationType == JetTokens.MINUSMINUS) && baseExpression instanceof JetArrayAccessExpression) {
638                JetExpression stubExpression = ExpressionTypingUtils.createFakeExpressionOfType(baseExpression.getProject(), context.trace, "$e", type);
639                resolveArrayAccessSetMethod((JetArrayAccessExpression) baseExpression,
640                                            stubExpression,
641                                            context.replaceBindingTrace(
642                                                    TemporaryBindingTrace.create(context.trace, "trace to resolve array access set method for unary expression", expression)),
643                                            context.trace);
644            }
645    
646            ExpressionReceiver receiver = new ExpressionReceiver(baseExpression, type);
647    
648            // Resolve the operation reference
649            OverloadResolutionResults<FunctionDescriptor> resolutionResults = components.callResolver.resolveCallWithGivenName(
650                    context,
651                    CallMaker.makeCall(receiver, expression),
652                    expression.getOperationReference(),
653                    name);
654    
655            if (!resolutionResults.isSuccess()) {
656                return JetTypeInfo.create(null, dataFlowInfo);
657            }
658    
659            // Computing the return type
660            JetType returnType = resolutionResults.getResultingDescriptor().getReturnType();
661            JetType result;
662            if (operationType == JetTokens.PLUSPLUS || operationType == JetTokens.MINUSMINUS) {
663                assert returnType != null : "returnType is null for " + resolutionResults.getResultingDescriptor();
664                if (JetTypeChecker.INSTANCE.isSubtypeOf(returnType, KotlinBuiltIns.getInstance().getUnitType())) {
665                    result = ErrorUtils.createErrorType(KotlinBuiltIns.getInstance().getUnit().getName().asString());
666                    context.trace.report(INC_DEC_SHOULD_NOT_RETURN_UNIT.on(operationSign));
667                }
668                else {
669                    JetType receiverType = receiver.getType();
670                    if (!JetTypeChecker.INSTANCE.isSubtypeOf(returnType, receiverType)) {
671                        context.trace.report(RESULT_TYPE_MISMATCH.on(operationSign, name.asString(), receiverType, returnType));
672                    }
673                    else {
674                        context.trace.record(BindingContext.VARIABLE_REASSIGNMENT, expression);
675    
676                        checkLValue(context.trace, baseExpression);
677                    }
678                    // TODO : Maybe returnType?
679                    result = receiverType;
680                }
681            }
682            else {
683                result = returnType;
684            }
685    
686            CompileTimeConstant<?> value = ConstantExpressionEvaluator.object$.evaluate(expression, contextWithExpectedType.trace,
687                                                                                        contextWithExpectedType.expectedType);
688            if (value != null) {
689                return createCompileTimeConstantTypeInfo(value, expression, contextWithExpectedType);
690            }
691    
692            return DataFlowUtils.checkType(result, expression, contextWithExpectedType, dataFlowInfo);
693        }
694    
695        @NotNull
696        public static JetTypeInfo createCompileTimeConstantTypeInfo(
697                @NotNull CompileTimeConstant<?> value,
698                @NotNull JetExpression expression,
699                @NotNull ExpressionTypingContext context
700        ) {
701            JetType expressionType = value.getType(KotlinBuiltIns.getInstance());
702            if (value instanceof IntegerValueTypeConstant && context.contextDependency == INDEPENDENT) {
703                expressionType = ((IntegerValueTypeConstant) value).getType(context.expectedType);
704                ArgumentTypeResolver.updateNumberType(expressionType, expression, context.trace);
705            }
706    
707            return DataFlowUtils.checkType(expressionType, expression, context, context.dataFlowInfo);
708        }
709    
710        private JetTypeInfo visitExclExclExpression(@NotNull JetUnaryExpression expression, @NotNull ExpressionTypingContext context) {
711            JetExpression baseExpression = expression.getBaseExpression();
712            assert baseExpression != null;
713            JetSimpleNameExpression operationSign = expression.getOperationReference();
714            assert operationSign.getReferencedNameElementType() == JetTokens.EXCLEXCL;
715    
716            Call call = createCallForSpecialConstruction(expression, Collections.singletonList(baseExpression));
717            components.controlStructureTypingUtils.resolveSpecialConstructionAsCall(
718                    call, "ExclExcl", Collections.singletonList("baseExpr"), Collections.singletonList(true), context, null);
719            JetTypeInfo baseTypeInfo = BindingContextUtils.getRecordedTypeInfo(baseExpression, context.trace.getBindingContext());
720            assert baseTypeInfo != null : "Base expression was not processed: " + expression;
721            JetType baseType = baseTypeInfo.getType();
722            if (baseType == null) {
723                return baseTypeInfo;
724            }
725            DataFlowInfo dataFlowInfo = baseTypeInfo.getDataFlowInfo();
726            if (isKnownToBeNotNull(baseExpression, context) && !baseType.isError()) {
727                context.trace.report(UNNECESSARY_NOT_NULL_ASSERTION.on(operationSign, baseType));
728            }
729            else {
730                DataFlowValue value = DataFlowValueFactory.createDataFlowValue(baseExpression, baseType, context.trace.getBindingContext());
731                dataFlowInfo = dataFlowInfo.disequate(value, DataFlowValue.NULL);
732            }
733            return JetTypeInfo.create(TypeUtils.makeNotNullable(baseType), dataFlowInfo);
734        }
735    
736        private JetTypeInfo visitLabeledExpression(@NotNull JetUnaryExpression expression, @NotNull ExpressionTypingContext context,
737                boolean isStatement) {
738            JetExpression baseExpression = expression.getBaseExpression();
739            assert baseExpression != null;
740            JetSimpleNameExpression operationSign = expression.getOperationReference();
741            assert JetTokens.LABELS.contains(operationSign.getReferencedNameElementType());
742    
743            String referencedName = operationSign.getReferencedName();
744            context.labelResolver.enterLabeledElement(new LabelName(referencedName.substring(1)), baseExpression);
745            // TODO : Some processing for the label?
746            JetTypeInfo typeInfo = facade.getTypeInfo(baseExpression, context, isStatement);
747            context.labelResolver.exitLabeledElement(baseExpression);
748            return typeInfo;
749        }
750    
751        private static boolean isKnownToBeNotNull(JetExpression expression, ExpressionTypingContext context) {
752            JetType type = context.trace.get(EXPRESSION_TYPE, expression);
753            assert type != null : "This method is only supposed to be called when the type is not null";
754            return isKnownToBeNotNull(expression, type, context);
755        }
756    
757        private static boolean isKnownToBeNotNull(JetExpression expression, JetType jetType, ExpressionTypingContext context) {
758            DataFlowValue dataFlowValue = DataFlowValueFactory.createDataFlowValue(expression, jetType, context.trace.getBindingContext());
759            return !context.dataFlowInfo.getNullability(dataFlowValue).canBeNull();
760        }
761    
762        public static void checkLValue(@NotNull BindingTrace trace, @NotNull JetExpression expression) {
763            checkLValue(trace, expression, false);
764        }
765    
766        private static void checkLValue(@NotNull BindingTrace trace, @NotNull JetExpression expressionWithParenthesis, boolean canBeThis) {
767            JetExpression expression = JetPsiUtil.deparenthesize(expressionWithParenthesis);
768            if (expression instanceof JetArrayAccessExpression) {
769                JetExpression arrayExpression = ((JetArrayAccessExpression) expression).getArrayExpression();
770                if (arrayExpression != null) {
771                    checkLValue(trace, arrayExpression, true);
772                }
773                return;
774            }
775            if (canBeThis && expression instanceof JetThisExpression) return;
776            VariableDescriptor variable = BindingContextUtils.extractVariableDescriptorIfAny(trace.getBindingContext(), expression, true);
777    
778            JetExpression reportOn = expression != null ? expression : expressionWithParenthesis;
779            if (variable instanceof PropertyDescriptor) {
780                PropertyDescriptor propertyDescriptor = (PropertyDescriptor) variable;
781                if (propertyDescriptor.isSetterProjectedOut()) {
782                    trace.report(SETTER_PROJECTED_OUT.on(reportOn, propertyDescriptor));
783                }
784            }
785    
786            if (variable == null) {
787                trace.report(VARIABLE_EXPECTED.on(reportOn));
788            }
789        }
790    
791        @Override
792        public JetTypeInfo visitBinaryExpression(@NotNull JetBinaryExpression expression, ExpressionTypingContext contextWithExpectedType) {
793            ExpressionTypingContext context = isBinaryExpressionDependentOnExpectedType(expression)
794                    ? contextWithExpectedType
795                    : contextWithExpectedType.replaceContextDependency(INDEPENDENT).replaceExpectedType(NO_EXPECTED_TYPE);
796    
797            JetSimpleNameExpression operationSign = expression.getOperationReference();
798            JetExpression left = expression.getLeft();
799            JetExpression right = expression.getRight();
800            IElementType operationType = operationSign.getReferencedNameElementType();
801    
802            JetTypeInfo result;
803    
804            //Expressions that can depend on expected type
805            if (operationType == JetTokens.IDENTIFIER) {
806                Name referencedName = operationSign.getReferencedNameAsName();
807                result = getTypeInfoForBinaryCall(referencedName, context, expression);
808            }
809            else if (OperatorConventions.BINARY_OPERATION_NAMES.containsKey(operationType)) {
810                Name referencedName = OperatorConventions.BINARY_OPERATION_NAMES.get(operationType);
811                result = getTypeInfoForBinaryCall(referencedName, context, expression);
812            }
813            else if (operationType == JetTokens.ELVIS) {
814                //base expression of elvis operator is checked for 'type mismatch', so the whole expression shouldn't be checked
815                return visitElvisExpression(expression, context);
816            }
817    
818            //Expressions that don't depend on expected type
819            else if (operationType == JetTokens.EQ) {
820                result = visitAssignment(expression, context);
821            }
822            else if (OperatorConventions.ASSIGNMENT_OPERATIONS.containsKey(operationType)) {
823                result = visitAssignmentOperation(expression, context);
824            }
825            else if (OperatorConventions.COMPARISON_OPERATIONS.contains(operationType)) {
826                result = visitComparison(expression, context, operationSign);
827            }
828            else if (OperatorConventions.EQUALS_OPERATIONS.contains(operationType)) {
829                result = visitEquality(expression, context, operationSign, left, right);
830            }
831            else if (operationType == JetTokens.EQEQEQ || operationType == JetTokens.EXCLEQEQEQ) {
832                ensureNonemptyIntersectionOfOperandTypes(expression, context);
833                // TODO : Check comparison pointlessness
834                result = JetTypeInfo.create(KotlinBuiltIns.getInstance().getBooleanType(), context.dataFlowInfo);
835            }
836            else if (OperatorConventions.IN_OPERATIONS.contains(operationType)) {
837                result = checkInExpression(expression, operationSign, left, right, context);
838            }
839            else if (OperatorConventions.BOOLEAN_OPERATIONS.containsKey(operationType)) {
840                result = visitBooleanOperationExpression(operationType, left, right, context);
841            }
842            else {
843                context.trace.report(UNSUPPORTED.on(operationSign, "Unknown operation"));
844                result = JetTypeInfo.create(null, context.dataFlowInfo);
845            }
846            CompileTimeConstant<?> value = ConstantExpressionEvaluator.object$.
847                    evaluate(expression, contextWithExpectedType.trace, contextWithExpectedType.expectedType);
848            if (value != null) {
849                return createCompileTimeConstantTypeInfo(value, expression, contextWithExpectedType);
850            }
851            return DataFlowUtils.checkType(result, expression, contextWithExpectedType);
852        }
853    
854        private JetTypeInfo visitEquality(
855                JetBinaryExpression expression,
856                ExpressionTypingContext context,
857                JetSimpleNameExpression operationSign,
858                final JetExpression left,
859                final JetExpression right
860        ) {
861            DataFlowInfo dataFlowInfo = context.dataFlowInfo;
862            if (right == null || left == null) {
863                ExpressionTypingUtils.getTypeInfoOrNullType(right, context, facade);
864                ExpressionTypingUtils.getTypeInfoOrNullType(left, context, facade);
865                return JetTypeInfo.create(KotlinBuiltIns.getInstance().getBooleanType(), dataFlowInfo);
866            }
867            ExpressionReceiver receiver = ExpressionTypingUtils.safeGetExpressionReceiver(facade, left, context);
868    
869            JetTypeInfo leftTypeInfo = getTypeInfoOrNullType(left, context, facade);
870    
871            dataFlowInfo = leftTypeInfo.getDataFlowInfo();
872            ExpressionTypingContext contextWithDataFlow = context.replaceDataFlowInfo(dataFlowInfo);
873    
874            JetTypeInfo rightTypeInfo = facade.getTypeInfo(right, contextWithDataFlow);
875            dataFlowInfo = rightTypeInfo.getDataFlowInfo();
876    
877            TemporaryBindingTrace traceInterpretingRightAsNullableAny = TemporaryBindingTrace.create(
878                    context.trace, "trace to resolve 'equals(Any?)' interpreting as of type Any? an expression:", right);
879            traceInterpretingRightAsNullableAny.record(EXPRESSION_TYPE, right, KotlinBuiltIns.getInstance().getNullableAnyType());
880    
881            Call call = CallMaker.makeCallWithExpressions(operationSign, receiver, null, operationSign, Collections.singletonList(right));
882            ExpressionTypingContext newContext = context.replaceBindingTrace(traceInterpretingRightAsNullableAny);
883            OverloadResolutionResults<FunctionDescriptor> resolutionResults =
884                    components.callResolver.resolveCallWithGivenName(newContext, call, operationSign, OperatorConventions.EQUALS);
885    
886            traceInterpretingRightAsNullableAny.commit(new TraceEntryFilter() {
887                @Override
888                public boolean accept(@Nullable WritableSlice<?, ?> slice, Object key) {
889                    // the type of the right expression isn't 'Any?' actually
890                    if (key == right && slice == EXPRESSION_TYPE) return false;
891    
892                    // a hack due to KT-678
893                    // without this line an autocast is reported on the receiver (if it was previously checked for not-null)
894                    // with not-null check the resolution result changes from 'fun Any?.equals' to 'equals' member
895                    if (key == left && slice == AUTOCAST) return false;
896    
897                    return true;
898                }
899            }, true);
900    
901            if (resolutionResults.isSuccess()) {
902                FunctionDescriptor equals = resolutionResults.getResultingCall().getResultingDescriptor();
903                if (ensureBooleanResult(operationSign, OperatorConventions.EQUALS, equals.getReturnType(), context)) {
904                    ensureNonemptyIntersectionOfOperandTypes(expression, context);
905                }
906            }
907            else {
908                if (resolutionResults.isAmbiguity()) {
909                    context.trace.report(OVERLOAD_RESOLUTION_AMBIGUITY.on(operationSign, resolutionResults.getResultingCalls()));
910                }
911                else {
912                    context.trace.report(EQUALS_MISSING.on(operationSign));
913                }
914            }
915            return JetTypeInfo.create(KotlinBuiltIns.getInstance().getBooleanType(), dataFlowInfo);
916        }
917    
918        @NotNull
919        private JetTypeInfo visitComparison(
920                @NotNull JetBinaryExpression expression,
921                @NotNull ExpressionTypingContext context,
922                @NotNull JetSimpleNameExpression operationSign
923        ) {
924            JetTypeInfo typeInfo = getTypeInfoForBinaryCall(OperatorConventions.COMPARE_TO, context, expression);
925            DataFlowInfo dataFlowInfo = typeInfo.getDataFlowInfo();
926            JetType compareToReturnType = typeInfo.getType();
927            JetType type = null;
928            if (compareToReturnType != null && !compareToReturnType.isError()) {
929                TypeConstructor constructor = compareToReturnType.getConstructor();
930                KotlinBuiltIns builtIns = KotlinBuiltIns.getInstance();
931                TypeConstructor intTypeConstructor = builtIns.getInt().getTypeConstructor();
932                if (constructor.equals(intTypeConstructor)) {
933                    type = builtIns.getBooleanType();
934                }
935                else {
936                    context.trace.report(COMPARE_TO_TYPE_MISMATCH.on(operationSign, compareToReturnType));
937                }
938            }
939            return JetTypeInfo.create(type, dataFlowInfo);
940        }
941    
942        @NotNull
943        private JetTypeInfo visitBooleanOperationExpression(
944                @Nullable IElementType operationType,
945                @Nullable JetExpression left,
946                @Nullable JetExpression right,
947                @NotNull ExpressionTypingContext context
948        ) {
949            JetType booleanType = KotlinBuiltIns.getInstance().getBooleanType();
950            JetTypeInfo leftTypeInfo = getTypeInfoOrNullType(left, context.replaceExpectedType(booleanType), facade);
951            DataFlowInfo dataFlowInfo = leftTypeInfo.getDataFlowInfo();
952    
953            WritableScopeImpl leftScope = newWritableScopeImpl(context, "Left scope of && or ||");
954            // TODO: This gets computed twice: here and in extractDataFlowInfoFromCondition() for the whole condition
955            boolean isAnd = operationType == JetTokens.ANDAND;
956            DataFlowInfo flowInfoLeft = DataFlowUtils.extractDataFlowInfoFromCondition(left, isAnd, context).and(dataFlowInfo);
957            WritableScopeImpl rightScope = isAnd ? leftScope : newWritableScopeImpl(context, "Right scope of && or ||");
958    
959            ExpressionTypingContext contextForRightExpr =
960                    context.replaceDataFlowInfo(flowInfoLeft).replaceScope(rightScope).replaceExpectedType(booleanType);
961            if (right != null) {
962                facade.getTypeInfo(right, contextForRightExpr);
963            }
964            return JetTypeInfo.create(booleanType, dataFlowInfo);
965        }
966    
967        @NotNull
968        private JetTypeInfo visitElvisExpression(
969                @NotNull JetBinaryExpression expression,
970                @NotNull ExpressionTypingContext contextWithExpectedType
971        ) {
972            ExpressionTypingContext context = contextWithExpectedType.replaceExpectedType(NO_EXPECTED_TYPE);
973            JetExpression left = expression.getLeft();
974            JetExpression right = expression.getRight();
975    
976            if (left == null || right == null) {
977                getTypeInfoOrNullType(left, context, facade);
978                return JetTypeInfo.create(null, context.dataFlowInfo);
979            }
980    
981            Call call = createCallForSpecialConstruction(expression, Lists.newArrayList(left, right));
982            ResolvedCall<FunctionDescriptor> resolvedCall = components.controlStructureTypingUtils.resolveSpecialConstructionAsCall(
983                    call, "Elvis", Lists.newArrayList("left", "right"), Lists.newArrayList(true, false), contextWithExpectedType, null);
984            JetTypeInfo leftTypeInfo = BindingContextUtils.getRecordedTypeInfo(left, context.trace.getBindingContext());
985            assert leftTypeInfo != null : "Left expression was not processed: " + expression;
986            JetType leftType = leftTypeInfo.getType();
987            if (leftType != null && isKnownToBeNotNull(left, leftType, context)) {
988                context.trace.report(USELESS_ELVIS.on(left, leftType));
989            }
990            JetTypeInfo rightTypeInfo = BindingContextUtils.getRecordedTypeInfo(right, context.trace.getBindingContext());
991            assert rightTypeInfo != null : "Right expression was not processed: " + expression;
992            JetType rightType = rightTypeInfo.getType();
993    
994            DataFlowInfo dataFlowInfo = resolvedCall.getDataFlowInfoForArguments().getResultInfo();
995            JetType type = resolvedCall.getResultingDescriptor().getReturnType();
996            if (type == null || rightType == null) return JetTypeInfo.create(null, dataFlowInfo);
997    
998            return JetTypeInfo.create(TypeUtils.makeNullableAsSpecified(type, rightType.isNullable()), dataFlowInfo);
999        }
1000    
1001        @NotNull
1002        public JetTypeInfo checkInExpression(
1003                @NotNull JetElement callElement,
1004                @NotNull JetSimpleNameExpression operationSign,
1005                @Nullable JetExpression left,
1006                @Nullable JetExpression right,
1007                @NotNull ExpressionTypingContext context
1008        ) {
1009            ExpressionTypingContext contextWithNoExpectedType = context.replaceExpectedType(NO_EXPECTED_TYPE);
1010            if (right == null) {
1011                if (left != null) facade.getTypeInfo(left, contextWithNoExpectedType);
1012                return JetTypeInfo.create(null, context.dataFlowInfo);
1013            }
1014    
1015            DataFlowInfo dataFlowInfo = facade.getTypeInfo(right, contextWithNoExpectedType).getDataFlowInfo();
1016    
1017            ExpressionReceiver receiver = safeGetExpressionReceiver(facade, right, contextWithNoExpectedType);
1018            ExpressionTypingContext contextWithDataFlow = context.replaceDataFlowInfo(dataFlowInfo);
1019    
1020            OverloadResolutionResults<FunctionDescriptor> resolutionResult = components.callResolver.resolveCallWithGivenName(
1021                    contextWithDataFlow,
1022                    CallMaker.makeCallWithExpressions(callElement, receiver, null, operationSign, Collections.singletonList(left)),
1023                    operationSign,
1024                    OperatorConventions.CONTAINS);
1025            JetType containsType = OverloadResolutionResultsUtil.getResultingType(resolutionResult, context.contextDependency);
1026            ensureBooleanResult(operationSign, OperatorConventions.CONTAINS, containsType, context);
1027    
1028            if (left != null) {
1029                dataFlowInfo = facade.getTypeInfo(left, contextWithDataFlow).getDataFlowInfo().and(dataFlowInfo);
1030            }
1031    
1032            return JetTypeInfo.create(resolutionResult.isSuccess() ? KotlinBuiltIns.getInstance().getBooleanType() : null, dataFlowInfo);
1033        }
1034    
1035        private void ensureNonemptyIntersectionOfOperandTypes(JetBinaryExpression expression, ExpressionTypingContext context) {
1036            JetExpression left = expression.getLeft();
1037            if (left == null) return;
1038    
1039            JetExpression right = expression.getRight();
1040    
1041            // TODO : duplicated effort for == and !=
1042            JetType leftType = facade.getTypeInfo(left, context).getType();
1043            if (leftType != null && right != null) {
1044                JetType rightType = facade.getTypeInfo(right, context).getType();
1045    
1046                if (rightType != null) {
1047                    if (TypeUtils.isIntersectionEmpty(leftType, rightType)) {
1048                        context.trace.report(EQUALITY_NOT_APPLICABLE.on(expression, expression.getOperationReference(), leftType, rightType));
1049                    }
1050                    checkSenselessComparisonWithNull(expression, left, right, context);
1051                }
1052            }
1053        }
1054    
1055        private void checkSenselessComparisonWithNull(@NotNull JetBinaryExpression expression, @NotNull JetExpression left, @NotNull JetExpression right, @NotNull ExpressionTypingContext context) {
1056            JetExpression expr;
1057            if (JetPsiUtil.isNullConstant(left)) {
1058                expr = right;
1059            }
1060            else if (JetPsiUtil.isNullConstant(right)) {
1061                expr = left;
1062            }
1063            else return;
1064    
1065            JetSimpleNameExpression operationSign = expression.getOperationReference();
1066            JetType type = facade.getTypeInfo(expr, context).getType();
1067            if (type == null || type.isError()) return;
1068    
1069            DataFlowValue value = DataFlowValueFactory.createDataFlowValue(expr, type, context.trace.getBindingContext());
1070            Nullability nullability = context.dataFlowInfo.getNullability(value);
1071    
1072            boolean expressionIsAlways;
1073            boolean equality = operationSign.getReferencedNameElementType() == JetTokens.EQEQ || operationSign.getReferencedNameElementType() == JetTokens.EQEQEQ;
1074    
1075            if (nullability == Nullability.NULL) {
1076                expressionIsAlways = equality;
1077            }
1078            else if (nullability == Nullability.NOT_NULL) {
1079                expressionIsAlways = !equality;
1080            }
1081            else return;
1082    
1083            context.trace.report(SENSELESS_COMPARISON.on(expression, expression, expressionIsAlways));
1084        }
1085    
1086        @NotNull
1087        private JetTypeInfo visitAssignmentOperation(JetBinaryExpression expression, ExpressionTypingContext context) {
1088            return assignmentIsNotAnExpressionError(expression, context);
1089        }
1090    
1091        @NotNull
1092        private JetTypeInfo visitAssignment(JetBinaryExpression expression, ExpressionTypingContext context) {
1093            return assignmentIsNotAnExpressionError(expression, context);
1094        }
1095    
1096        @NotNull
1097        private JetTypeInfo assignmentIsNotAnExpressionError(JetBinaryExpression expression, ExpressionTypingContext context) {
1098            facade.checkStatementType(expression, context);
1099            context.trace.report(ASSIGNMENT_IN_EXPRESSION_CONTEXT.on(expression));
1100            return JetTypeInfo.create(null, context.dataFlowInfo);
1101        }
1102    
1103        @Override
1104        public JetTypeInfo visitArrayAccessExpression(@NotNull JetArrayAccessExpression expression, ExpressionTypingContext context) {
1105            JetTypeInfo typeInfo = resolveArrayAccessGetMethod(expression, context);
1106            return DataFlowUtils.checkType(typeInfo, expression, context);
1107        }
1108    
1109        @NotNull
1110        public JetTypeInfo getTypeInfoForBinaryCall(
1111                @NotNull Name name,
1112                @NotNull ExpressionTypingContext context,
1113                @NotNull JetBinaryExpression binaryExpression
1114        ) {
1115            JetExpression left = binaryExpression.getLeft();
1116            DataFlowInfo dataFlowInfo = context.dataFlowInfo;
1117            if (left != null) {
1118                //left here is a receiver, so it doesn't depend on expected type
1119                dataFlowInfo = facade.getTypeInfo(
1120                        left, context.replaceContextDependency(INDEPENDENT).replaceExpectedType(NO_EXPECTED_TYPE)).getDataFlowInfo();
1121            }
1122            ExpressionTypingContext contextWithDataFlow = context.replaceDataFlowInfo(dataFlowInfo);
1123    
1124            OverloadResolutionResults<FunctionDescriptor> resolutionResults;
1125            if (left != null) {
1126                ExpressionReceiver receiver = safeGetExpressionReceiver(facade, left, context);
1127                resolutionResults = components.callResolver.resolveBinaryCall(
1128                        contextWithDataFlow.replaceScope(context.scope),
1129                        receiver, binaryExpression, name
1130                );
1131            }
1132            else {
1133                resolutionResults = OverloadResolutionResultsImpl.nameNotFound();
1134            }
1135    
1136            if (resolutionResults.isSingleResult()) {
1137                dataFlowInfo = resolutionResults.getResultingCall().getDataFlowInfoForArguments().getResultInfo();
1138            }
1139    
1140            return JetTypeInfo.create(OverloadResolutionResultsUtil.getResultingType(resolutionResults, context.contextDependency), dataFlowInfo);
1141        }
1142    
1143        @Override
1144        public JetTypeInfo visitDeclaration(@NotNull JetDeclaration dcl, ExpressionTypingContext context) {
1145            context.trace.report(DECLARATION_IN_ILLEGAL_CONTEXT.on(dcl));
1146            return JetTypeInfo.create(null, context.dataFlowInfo);
1147        }
1148    
1149        @Override
1150        public JetTypeInfo visitRootPackageExpression(@NotNull JetRootPackageExpression expression, ExpressionTypingContext context) {
1151            if (JetPsiUtil.isLHSOfDot(expression)) {
1152                return DataFlowUtils.checkType(JetModuleUtil.getRootPackageType(expression), expression, context, context.dataFlowInfo);
1153            }
1154            context.trace.report(PACKAGE_IS_NOT_AN_EXPRESSION.on(expression));
1155            return JetTypeInfo.create(null, context.dataFlowInfo);
1156        }
1157    
1158    
1159        @Override
1160        public JetTypeInfo visitStringTemplateExpression(@NotNull JetStringTemplateExpression expression, ExpressionTypingContext contextWithExpectedType) {
1161            final ExpressionTypingContext context = contextWithExpectedType.replaceExpectedType(NO_EXPECTED_TYPE).replaceContextDependency(INDEPENDENT);
1162            final DataFlowInfo[] dataFlowInfo = new DataFlowInfo[] { context.dataFlowInfo };
1163            for (JetStringTemplateEntry entry : expression.getEntries()) {
1164                entry.accept(new JetVisitorVoid() {
1165    
1166                    @Override
1167                    public void visitStringTemplateEntryWithExpression(@NotNull JetStringTemplateEntryWithExpression entry) {
1168                        JetExpression entryExpression = entry.getExpression();
1169                        if (entryExpression != null) {
1170                            JetTypeInfo typeInfo = facade.getTypeInfo(entryExpression, context.replaceDataFlowInfo(dataFlowInfo[0]));
1171                            dataFlowInfo[0] = typeInfo.getDataFlowInfo();
1172                        }
1173                    }
1174    
1175                    @Override
1176                    public void visitEscapeStringTemplateEntry(@NotNull JetEscapeStringTemplateEntry entry) {
1177                        CompileTimeConstantChecker.CharacterWithDiagnostic value = CompileTimeConstantChecker.escapedStringToCharacter(entry.getText(), entry);
1178                        Diagnostic diagnostic = value.getDiagnostic();
1179                        if (diagnostic != null) {
1180                            context.trace.report(diagnostic);
1181                        }
1182                    }
1183                });
1184            }
1185            ConstantExpressionEvaluator.object$.evaluate(expression, context.trace, contextWithExpectedType.expectedType);
1186            return DataFlowUtils.checkType(KotlinBuiltIns.getInstance().getStringType(), expression, contextWithExpectedType, dataFlowInfo[0]);
1187        }
1188    
1189        @Override
1190        public JetTypeInfo visitAnnotatedExpression(@NotNull JetAnnotatedExpression expression, ExpressionTypingContext context) {
1191            return visitAnnotatedExpression(expression, context, false);
1192        }
1193    
1194        public JetTypeInfo visitAnnotatedExpression(JetAnnotatedExpression expression, ExpressionTypingContext context, boolean isStatement) {
1195            components.expressionTypingServices.getAnnotationResolver().resolveAnnotationsWithArguments(
1196                    context.scope, expression.getAnnotationEntries(), context.trace);
1197    
1198            JetExpression baseExpression = expression.getBaseExpression();
1199            if (baseExpression == null) {
1200                return JetTypeInfo.create(null, context.dataFlowInfo);
1201            }
1202            return facade.getTypeInfo(baseExpression, context, isStatement);
1203        }
1204    
1205        @Override
1206        public JetTypeInfo visitJetElement(@NotNull JetElement element, ExpressionTypingContext context) {
1207            context.trace.report(UNSUPPORTED.on(element, getClass().getCanonicalName()));
1208            return JetTypeInfo.create(null, context.dataFlowInfo);
1209        }
1210    
1211        @NotNull
1212            /*package*/ JetTypeInfo resolveArrayAccessSetMethod(@NotNull JetArrayAccessExpression arrayAccessExpression, @NotNull JetExpression rightHandSide, @NotNull ExpressionTypingContext context, @NotNull BindingTrace traceForResolveResult) {
1213            return resolveArrayAccessSpecialMethod(arrayAccessExpression, rightHandSide, context, traceForResolveResult, false);
1214        }
1215    
1216        @NotNull
1217            /*package*/ JetTypeInfo resolveArrayAccessGetMethod(@NotNull JetArrayAccessExpression arrayAccessExpression, @NotNull ExpressionTypingContext context) {
1218            return resolveArrayAccessSpecialMethod(arrayAccessExpression, null, context, context.trace, true);
1219        }
1220    
1221        @NotNull
1222        private JetTypeInfo resolveArrayAccessSpecialMethod(@NotNull JetArrayAccessExpression arrayAccessExpression,
1223                                                        @Nullable JetExpression rightHandSide, //only for 'set' method
1224                                                        @NotNull ExpressionTypingContext oldContext,
1225                                                        @NotNull BindingTrace traceForResolveResult,
1226                                                        boolean isGet) {
1227            JetExpression arrayExpression = arrayAccessExpression.getArrayExpression();
1228            if (arrayExpression == null) return JetTypeInfo.create(null, oldContext.dataFlowInfo);
1229    
1230            JetTypeInfo arrayTypeInfo = facade.getTypeInfo(arrayExpression, oldContext.replaceExpectedType(NO_EXPECTED_TYPE)
1231                    .replaceContextDependency(INDEPENDENT));
1232            JetType arrayType = arrayTypeInfo.getType();
1233            if (arrayType == null) return arrayTypeInfo;
1234    
1235            DataFlowInfo dataFlowInfo = arrayTypeInfo.getDataFlowInfo();
1236            ExpressionTypingContext context = oldContext.replaceDataFlowInfo(dataFlowInfo);
1237            ExpressionReceiver receiver = new ExpressionReceiver(arrayExpression, arrayType);
1238            if (!isGet) assert rightHandSide != null;
1239    
1240            OverloadResolutionResults<FunctionDescriptor> functionResults = components.callResolver.resolveCallWithGivenName(
1241                    context,
1242                    isGet
1243                    ? CallMaker.makeArrayGetCall(receiver, arrayAccessExpression, Call.CallType.ARRAY_GET_METHOD)
1244                    : CallMaker.makeArraySetCall(receiver, arrayAccessExpression, rightHandSide, Call.CallType.ARRAY_SET_METHOD),
1245                    arrayAccessExpression,
1246                    Name.identifier(isGet ? "get" : "set")
1247            );
1248    
1249            List<JetExpression> indices = arrayAccessExpression.getIndexExpressions();
1250            // The accumulated data flow info of all index expressions is saved on the last index
1251            if (!indices.isEmpty()) {
1252                dataFlowInfo = facade.getTypeInfo(indices.get(indices.size() - 1), context).getDataFlowInfo();
1253            }
1254    
1255            if (!isGet) {
1256                dataFlowInfo = facade.getTypeInfo(rightHandSide, context.replaceDataFlowInfo(dataFlowInfo)).getDataFlowInfo();
1257            }
1258    
1259            if (!functionResults.isSingleResult()) {
1260                traceForResolveResult.report(isGet ? NO_GET_METHOD.on(arrayAccessExpression) : NO_SET_METHOD.on(arrayAccessExpression));
1261                return JetTypeInfo.create(null, dataFlowInfo);
1262            }
1263            traceForResolveResult.record(isGet ? INDEXED_LVALUE_GET : INDEXED_LVALUE_SET, arrayAccessExpression, functionResults.getResultingCall());
1264            return JetTypeInfo.create(functionResults.getResultingDescriptor().getReturnType(), dataFlowInfo);
1265        }
1266    }