001    /*
002     * Copyright 2010-2015 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.kotlin.types.expressions;
018    
019    import com.google.common.base.Function;
020    import com.google.common.collect.Sets;
021    import com.intellij.psi.tree.IElementType;
022    import org.jetbrains.annotations.NotNull;
023    import org.jetbrains.annotations.Nullable;
024    import org.jetbrains.kotlin.builtins.KotlinBuiltIns;
025    import org.jetbrains.kotlin.descriptors.DeclarationDescriptor;
026    import org.jetbrains.kotlin.descriptors.FunctionDescriptor;
027    import org.jetbrains.kotlin.descriptors.VariableDescriptor;
028    import org.jetbrains.kotlin.diagnostics.Errors;
029    import org.jetbrains.kotlin.lexer.JetTokens;
030    import org.jetbrains.kotlin.name.Name;
031    import org.jetbrains.kotlin.psi.*;
032    import org.jetbrains.kotlin.resolve.AnnotationResolver;
033    import org.jetbrains.kotlin.resolve.DescriptorUtils;
034    import org.jetbrains.kotlin.resolve.TemporaryBindingTrace;
035    import org.jetbrains.kotlin.resolve.calls.context.TemporaryTraceAndCache;
036    import org.jetbrains.kotlin.resolve.calls.model.ResolvedCall;
037    import org.jetbrains.kotlin.resolve.calls.results.OverloadResolutionResults;
038    import org.jetbrains.kotlin.resolve.calls.results.OverloadResolutionResultsImpl;
039    import org.jetbrains.kotlin.resolve.calls.results.OverloadResolutionResultsUtil;
040    import org.jetbrains.kotlin.resolve.calls.smartcasts.DataFlowInfo;
041    import org.jetbrains.kotlin.resolve.calls.smartcasts.DataFlowValue;
042    import org.jetbrains.kotlin.resolve.calls.smartcasts.DataFlowValueFactory;
043    import org.jetbrains.kotlin.resolve.scopes.LexicalWritableScope;
044    import org.jetbrains.kotlin.resolve.scopes.receivers.ExpressionReceiver;
045    import org.jetbrains.kotlin.resolve.scopes.utils.UtilsPackage;
046    import org.jetbrains.kotlin.types.JetType;
047    import org.jetbrains.kotlin.types.TypeUtils;
048    import org.jetbrains.kotlin.types.checker.JetTypeChecker;
049    import org.jetbrains.kotlin.types.expressions.typeInfoFactory.TypeInfoFactoryPackage;
050    
051    import java.util.Collection;
052    
053    import static org.jetbrains.kotlin.diagnostics.Errors.*;
054    import static org.jetbrains.kotlin.psi.JetPsiUtil.deparenthesizeWithResolutionStrategy;
055    import static org.jetbrains.kotlin.resolve.BindingContext.AMBIGUOUS_REFERENCE_TARGET;
056    import static org.jetbrains.kotlin.resolve.BindingContext.VARIABLE_REASSIGNMENT;
057    import static org.jetbrains.kotlin.resolve.calls.context.ContextDependency.INDEPENDENT;
058    import static org.jetbrains.kotlin.types.TypeUtils.NO_EXPECTED_TYPE;
059    import static org.jetbrains.kotlin.types.TypeUtils.noExpectedType;
060    
061    @SuppressWarnings("SuspiciousMethodCalls")
062    public class ExpressionTypingVisitorForStatements extends ExpressionTypingVisitor {
063        private final LexicalWritableScope scope;
064        private final BasicExpressionTypingVisitor basic;
065        private final ControlStructureTypingVisitor controlStructures;
066        private final PatternMatchingTypingVisitor patterns;
067        private final FunctionsTypingVisitor functions;
068    
069        public ExpressionTypingVisitorForStatements(
070                @NotNull ExpressionTypingInternals facade,
071                @NotNull LexicalWritableScope scope,
072                @NotNull BasicExpressionTypingVisitor basic,
073                @NotNull ControlStructureTypingVisitor controlStructures,
074                @NotNull PatternMatchingTypingVisitor patterns,
075                @NotNull FunctionsTypingVisitor functions
076        ) {
077            super(facade);
078            this.scope = scope;
079            this.basic = basic;
080            this.controlStructures = controlStructures;
081            this.patterns = patterns;
082            this.functions = functions;
083        }
084    
085        @Nullable
086        private JetType checkAssignmentType(
087                @Nullable JetType assignmentType,
088                @NotNull JetBinaryExpression expression,
089                @NotNull ExpressionTypingContext context
090        ) {
091            if (assignmentType != null && !KotlinBuiltIns.isUnit(assignmentType) && !noExpectedType(context.expectedType) &&
092                !context.expectedType.isError() && TypeUtils.equalTypes(context.expectedType, assignmentType)) {
093                context.trace.report(Errors.ASSIGNMENT_TYPE_MISMATCH.on(expression, context.expectedType));
094                return null;
095            }
096            return components.dataFlowAnalyzer.checkStatementType(expression, context);
097        }
098    
099        @Override
100        public JetTypeInfo visitObjectDeclaration(@NotNull JetObjectDeclaration declaration, ExpressionTypingContext context) {
101            components.localClassifierAnalyzer.processClassOrObject(
102                    scope, context.replaceScope(scope).replaceContextDependency(INDEPENDENT),
103                    scope.getOwnerDescriptor(),
104                    declaration);
105            return TypeInfoFactoryPackage.createTypeInfo(components.dataFlowAnalyzer.checkStatementType(declaration, context), context);
106        }
107    
108        @Override
109        public JetTypeInfo visitProperty(@NotNull JetProperty property, ExpressionTypingContext typingContext) {
110            ExpressionTypingContext context = typingContext.replaceContextDependency(INDEPENDENT).replaceScope(scope);
111            JetTypeReference receiverTypeRef = property.getReceiverTypeReference();
112            if (receiverTypeRef != null) {
113                context.trace.report(LOCAL_EXTENSION_PROPERTY.on(receiverTypeRef));
114            }
115    
116            JetPropertyAccessor getter = property.getGetter();
117            if (getter != null) {
118                context.trace.report(LOCAL_VARIABLE_WITH_GETTER.on(getter));
119            }
120    
121            JetPropertyAccessor setter = property.getSetter();
122            if (setter != null) {
123                context.trace.report(LOCAL_VARIABLE_WITH_SETTER.on(setter));
124            }
125    
126            JetExpression delegateExpression = property.getDelegateExpression();
127            if (delegateExpression != null) {
128                components.expressionTypingServices.getTypeInfo(delegateExpression, context);
129                context.trace.report(LOCAL_VARIABLE_WITH_DELEGATE.on(property.getDelegate()));
130            }
131    
132            for (JetTypeParameter typeParameter : property.getTypeParameters()) {
133                AnnotationResolver.reportUnsupportedAnnotationForTypeParameter(typeParameter, context.trace);
134            }
135    
136            VariableDescriptor propertyDescriptor = components.descriptorResolver.
137                    resolveLocalVariableDescriptor(scope, property, context.dataFlowInfo, context.trace);
138            JetExpression initializer = property.getInitializer();
139            JetTypeInfo typeInfo;
140            if (initializer != null) {
141                JetType outType = propertyDescriptor.getType();
142                typeInfo = facade.getTypeInfo(initializer, context.replaceExpectedType(outType));
143                DataFlowInfo dataFlowInfo = typeInfo.getDataFlowInfo();
144                JetType type = typeInfo.getType();
145                // At this moment we do not take initializer value into account if type is given for a property
146                // We can comment first part of this condition to take them into account, like here: var s: String? = "xyz"
147                // In this case s will be not-nullable until it is changed
148                if (property.getTypeReference() == null && type != null) {
149                    DataFlowValue variableDataFlowValue = DataFlowValueFactory.createDataFlowValue(
150                            propertyDescriptor, context.trace.getBindingContext(),
151                            DescriptorUtils.getContainingModuleOrNull(scope.getOwnerDescriptor()));
152                    DataFlowValue initializerDataFlowValue = DataFlowValueFactory.createDataFlowValue(initializer, type, context);
153                    // We cannot say here anything new about initializerDataFlowValue
154                    // except it has the same value as variableDataFlowValue
155                    typeInfo = typeInfo.replaceDataFlowInfo(dataFlowInfo.assign(variableDataFlowValue, initializerDataFlowValue));
156                }
157            }
158            else {
159                typeInfo = TypeInfoFactoryPackage.noTypeInfo(context);
160            }
161    
162            {
163                VariableDescriptor olderVariable = UtilsPackage.getLocalVariable(scope, propertyDescriptor.getName());
164                ExpressionTypingUtils.checkVariableShadowing(context, propertyDescriptor, olderVariable);
165            }
166    
167            scope.addVariableDescriptor(propertyDescriptor);
168            components.modifiersChecker.withTrace(context.trace).checkModifiersForLocalDeclaration(property, propertyDescriptor);
169            return typeInfo.replaceType(components.dataFlowAnalyzer.checkStatementType(property, context));
170        }
171    
172        @Override
173        public JetTypeInfo visitMultiDeclaration(@NotNull JetMultiDeclaration multiDeclaration, ExpressionTypingContext context) {
174            components.annotationResolver.resolveAnnotationsWithArguments(scope, multiDeclaration.getModifierList(), context.trace);
175    
176            JetExpression initializer = multiDeclaration.getInitializer();
177            if (initializer == null) {
178                context.trace.report(INITIALIZER_REQUIRED_FOR_MULTIDECLARATION.on(multiDeclaration));
179                return TypeInfoFactoryPackage.noTypeInfo(context);
180            }
181            ExpressionReceiver expressionReceiver = ExpressionTypingUtils.getExpressionReceiver(
182                    facade, initializer, context.replaceExpectedType(NO_EXPECTED_TYPE).replaceContextDependency(INDEPENDENT));
183            JetTypeInfo typeInfo = facade.getTypeInfo(initializer, context);
184            if (expressionReceiver == null) {
185                return TypeInfoFactoryPackage.noTypeInfo(context);
186            }
187            components.multiDeclarationResolver.defineLocalVariablesFromMultiDeclaration(scope, multiDeclaration, expressionReceiver, initializer, context);
188            components.modifiersChecker.withTrace(context.trace).checkModifiersForMultiDeclaration(multiDeclaration);
189            return typeInfo.replaceType(components.dataFlowAnalyzer.checkStatementType(multiDeclaration, context));
190        }
191    
192        @Override
193        public JetTypeInfo visitNamedFunction(@NotNull JetNamedFunction function, ExpressionTypingContext context) {
194            return functions.visitNamedFunction(function, context, true, scope);
195        }
196    
197        @Override
198        public JetTypeInfo visitClass(@NotNull JetClass klass, ExpressionTypingContext context) {
199            components.localClassifierAnalyzer.processClassOrObject(
200                    scope, context.replaceScope(scope).replaceContextDependency(INDEPENDENT),
201                    scope.getOwnerDescriptor(),
202                    klass);
203            return TypeInfoFactoryPackage.createTypeInfo(components.dataFlowAnalyzer.checkStatementType(klass, context), context);
204        }
205    
206        @Override
207        public JetTypeInfo visitTypedef(@NotNull JetTypedef typedef, ExpressionTypingContext context) {
208            context.trace.report(UNSUPPORTED.on(typedef, "Typedefs are not supported"));
209            return super.visitTypedef(typedef, context);
210        }
211    
212        @Override
213        public JetTypeInfo visitDeclaration(@NotNull JetDeclaration dcl, ExpressionTypingContext context) {
214            return TypeInfoFactoryPackage.createTypeInfo(components.dataFlowAnalyzer.checkStatementType(dcl, context), context);
215        }
216    
217        @Override
218        public JetTypeInfo visitBinaryExpression(@NotNull JetBinaryExpression expression, ExpressionTypingContext context) {
219            JetSimpleNameExpression operationSign = expression.getOperationReference();
220            IElementType operationType = operationSign.getReferencedNameElementType();
221            JetTypeInfo result;
222            if (operationType == JetTokens.EQ) {
223                result = visitAssignment(expression, context);
224            }
225            else if (OperatorConventions.ASSIGNMENT_OPERATIONS.containsKey(operationType)) {
226                result = visitAssignmentOperation(expression, context);
227            }
228            else {
229                return facade.getTypeInfo(expression, context);
230            }
231            return components.dataFlowAnalyzer.checkType(result, expression, context);
232        }
233    
234        @NotNull
235        protected JetTypeInfo visitAssignmentOperation(JetBinaryExpression expression, ExpressionTypingContext contextWithExpectedType) {
236            //There is a temporary binding trace for an opportunity to resolve set method for array if needed (the initial trace should be used there)
237            TemporaryTraceAndCache temporary = TemporaryTraceAndCache.create(
238                    contextWithExpectedType, "trace to resolve array set method for binary expression", expression);
239            ExpressionTypingContext context = contextWithExpectedType.replaceExpectedType(NO_EXPECTED_TYPE)
240                    .replaceTraceAndCache(temporary).replaceContextDependency(INDEPENDENT);
241    
242            JetSimpleNameExpression operationSign = expression.getOperationReference();
243            IElementType operationType = operationSign.getReferencedNameElementType();
244            JetExpression leftOperand = expression.getLeft();
245            JetTypeInfo leftInfo = ExpressionTypingUtils.getTypeInfoOrNullType(leftOperand, context, facade);
246            JetType leftType = leftInfo.getType();
247    
248            JetExpression right = expression.getRight();
249            JetExpression left = leftOperand == null ? null : JetPsiUtil.deparenthesize(leftOperand);
250            if (right == null || left == null) {
251                temporary.commit();
252                return leftInfo.clearType();
253            }
254    
255            if (leftType == null) {
256                JetTypeInfo rightInfo = facade.getTypeInfo(right, context.replaceDataFlowInfo(leftInfo.getDataFlowInfo()));
257                context.trace.report(UNRESOLVED_REFERENCE.on(operationSign, operationSign));
258                temporary.commit();
259                return rightInfo.clearType();
260            }
261            ExpressionReceiver receiver = new ExpressionReceiver(left, leftType);
262    
263            // We check that defined only one of '+=' and '+' operations, and call it (in the case '+' we then also assign)
264            // Check for '+='
265            Name name = OperatorConventions.ASSIGNMENT_OPERATIONS.get(operationType);
266            TemporaryTraceAndCache temporaryForAssignmentOperation = TemporaryTraceAndCache.create(
267                    context, "trace to check assignment operation like '+=' for", expression);
268            OverloadResolutionResults<FunctionDescriptor> assignmentOperationDescriptors =
269                    components.callResolver.resolveBinaryCall(
270                            context.replaceTraceAndCache(temporaryForAssignmentOperation).replaceScope(scope),
271                            receiver, expression, name
272                    );
273            JetType assignmentOperationType = OverloadResolutionResultsUtil.getResultingType(assignmentOperationDescriptors,
274                                                                                             context.contextDependency);
275    
276            OverloadResolutionResults<FunctionDescriptor> binaryOperationDescriptors;
277            JetType binaryOperationType;
278            TemporaryTraceAndCache temporaryForBinaryOperation = TemporaryTraceAndCache.create(
279                    context, "trace to check binary operation like '+' for", expression);
280            TemporaryBindingTrace ignoreReportsTrace = TemporaryBindingTrace.create(context.trace, "Trace for checking assignability");
281            boolean lhsAssignable = basic.checkLValue(ignoreReportsTrace, context, left, right);
282            if (assignmentOperationType == null || lhsAssignable) {
283                // Check for '+'
284                Name counterpartName = OperatorConventions.BINARY_OPERATION_NAMES.get(OperatorConventions.ASSIGNMENT_OPERATION_COUNTERPARTS.get(operationType));
285                binaryOperationDescriptors = components.callResolver.resolveBinaryCall(
286                        context.replaceTraceAndCache(temporaryForBinaryOperation).replaceScope(scope),
287                        receiver, expression, counterpartName
288                );
289                binaryOperationType = OverloadResolutionResultsUtil.getResultingType(binaryOperationDescriptors, context.contextDependency);
290            }
291            else {
292                binaryOperationDescriptors = OverloadResolutionResultsImpl.nameNotFound();
293                binaryOperationType = null;
294            }
295    
296            JetType type = assignmentOperationType != null ? assignmentOperationType : binaryOperationType;
297            JetTypeInfo rightInfo = leftInfo;
298            if (assignmentOperationDescriptors.isSuccess() && binaryOperationDescriptors.isSuccess()) {
299                // Both 'plus()' and 'plusAssign()' available => ambiguity
300                OverloadResolutionResults<FunctionDescriptor> ambiguityResolutionResults = OverloadResolutionResultsUtil.ambiguity(assignmentOperationDescriptors, binaryOperationDescriptors);
301                context.trace.report(ASSIGN_OPERATOR_AMBIGUITY.on(operationSign, ambiguityResolutionResults.getResultingCalls()));
302                Collection<DeclarationDescriptor> descriptors = Sets.newHashSet();
303                for (ResolvedCall<?> resolvedCall : ambiguityResolutionResults.getResultingCalls()) {
304                    descriptors.add(resolvedCall.getResultingDescriptor());
305                }
306                rightInfo = facade.getTypeInfo(right, context.replaceDataFlowInfo(leftInfo.getDataFlowInfo()));
307                context.trace.record(AMBIGUOUS_REFERENCE_TARGET, operationSign, descriptors);
308            }
309            else if (assignmentOperationType != null && (assignmentOperationDescriptors.isSuccess() || !binaryOperationDescriptors.isSuccess())) {
310                // There's 'plusAssign()', so we do a.plusAssign(b)
311                temporaryForAssignmentOperation.commit();
312                if (!JetTypeChecker.DEFAULT.equalTypes(components.builtIns.getUnitType(), assignmentOperationType)) {
313                    context.trace.report(ASSIGNMENT_OPERATOR_SHOULD_RETURN_UNIT.on(operationSign, assignmentOperationDescriptors.getResultingDescriptor(), operationSign));
314                }
315            }
316            else {
317                // There's only 'plus()', so we try 'a = a + b'
318                temporaryForBinaryOperation.commit();
319                context.trace.record(VARIABLE_REASSIGNMENT, expression);
320                if (left instanceof JetArrayAccessExpression) {
321                    ExpressionTypingContext contextForResolve = context.replaceScope(scope).replaceBindingTrace(TemporaryBindingTrace.create(
322                            context.trace, "trace to resolve array set method for assignment", expression));
323                    basic.resolveArrayAccessSetMethod((JetArrayAccessExpression) left, right, contextForResolve, context.trace);
324                }
325                rightInfo = facade.getTypeInfo(right, context.replaceDataFlowInfo(leftInfo.getDataFlowInfo()));
326                components.dataFlowAnalyzer.checkType(binaryOperationType, expression, context.replaceExpectedType(leftType).replaceDataFlowInfo(rightInfo.getDataFlowInfo()));
327                basic.checkLValue(context.trace, context, leftOperand, right);
328            }
329            temporary.commit();
330            return rightInfo.replaceType(checkAssignmentType(type, expression, contextWithExpectedType));
331        }
332    
333        @NotNull
334        protected JetTypeInfo visitAssignment(JetBinaryExpression expression, ExpressionTypingContext contextWithExpectedType) {
335            final ExpressionTypingContext context =
336                    contextWithExpectedType.replaceExpectedType(NO_EXPECTED_TYPE).replaceScope(scope).replaceContextDependency(INDEPENDENT);
337            JetExpression leftOperand = expression.getLeft();
338            JetExpression left = deparenthesizeWithResolutionStrategy(leftOperand, new Function<JetTypeReference, Void>() {
339                @Override
340                public Void apply(JetTypeReference reference) {
341                    components.typeResolver.resolveType(context.scope, reference, context.trace, true);
342                    return null;
343                }
344            });
345            JetExpression right = expression.getRight();
346            if (left instanceof JetArrayAccessExpression) {
347                JetArrayAccessExpression arrayAccessExpression = (JetArrayAccessExpression) left;
348                if (right == null) return TypeInfoFactoryPackage.noTypeInfo(context);
349                JetTypeInfo typeInfo = basic.resolveArrayAccessSetMethod(arrayAccessExpression, right, context, context.trace);
350                basic.checkLValue(context.trace, context, arrayAccessExpression, right);
351                return typeInfo.replaceType(checkAssignmentType(typeInfo.getType(), expression, contextWithExpectedType));
352            }
353            JetTypeInfo leftInfo = ExpressionTypingUtils.getTypeInfoOrNullType(left, context, facade);
354            JetType leftType = leftInfo.getType();
355            DataFlowInfo dataFlowInfo = leftInfo.getDataFlowInfo();
356            JetTypeInfo resultInfo;
357            if (right != null) {
358                resultInfo = facade.getTypeInfo(right, context.replaceDataFlowInfo(dataFlowInfo).replaceExpectedType(leftType));
359                dataFlowInfo = resultInfo.getDataFlowInfo();
360                JetType rightType = resultInfo.getType();
361                if (left != null && leftType != null && rightType != null) {
362                    DataFlowValue leftValue = DataFlowValueFactory.createDataFlowValue(left, leftType, context);
363                    DataFlowValue rightValue = DataFlowValueFactory.createDataFlowValue(right, rightType, context);
364                    // We cannot say here anything new about rightValue except it has the same value as leftValue
365                    resultInfo = resultInfo.replaceDataFlowInfo(dataFlowInfo.assign(leftValue, rightValue));
366                }
367            }
368            else {
369                resultInfo = leftInfo;
370            }
371            if (leftType != null && leftOperand != null) { //if leftType == null, some other error has been generated
372                basic.checkLValue(context.trace, context, leftOperand, right);
373            }
374            return resultInfo.replaceType(components.dataFlowAnalyzer.checkStatementType(expression, contextWithExpectedType));
375        }
376    
377    
378        @Override
379        public JetTypeInfo visitExpression(@NotNull JetExpression expression, ExpressionTypingContext context) {
380            return facade.getTypeInfo(expression, context);
381        }
382    
383        @Override
384        public JetTypeInfo visitJetElement(@NotNull JetElement element, ExpressionTypingContext context) {
385            context.trace.report(UNSUPPORTED.on(element, "in a block"));
386            return TypeInfoFactoryPackage.noTypeInfo(context);
387        }
388    
389        @Override
390        public JetTypeInfo visitWhileExpression(@NotNull JetWhileExpression expression, ExpressionTypingContext context) {
391            return controlStructures.visitWhileExpression(expression, context, true);
392        }
393    
394        @Override
395        public JetTypeInfo visitDoWhileExpression(@NotNull JetDoWhileExpression expression, ExpressionTypingContext context) {
396            return controlStructures.visitDoWhileExpression(expression, context, true);
397        }
398    
399        @Override
400        public JetTypeInfo visitForExpression(@NotNull JetForExpression expression, ExpressionTypingContext context) {
401            return controlStructures.visitForExpression(expression, context, true);
402        }
403    
404        @Override
405        public JetTypeInfo visitAnnotatedExpression(
406                @NotNull JetAnnotatedExpression expression, ExpressionTypingContext data
407        ) {
408            return basic.visitAnnotatedExpression(expression, data, true);
409        }
410    
411        @Override
412        public JetTypeInfo visitIfExpression(@NotNull JetIfExpression expression, ExpressionTypingContext context) {
413            return controlStructures.visitIfExpression(expression, context, true);
414        }
415    
416        @Override
417        public JetTypeInfo visitWhenExpression(@NotNull JetWhenExpression expression, ExpressionTypingContext context) {
418            return patterns.visitWhenExpression(expression, context, true);
419        }
420    
421        @Override
422        public JetTypeInfo visitBlockExpression(@NotNull JetBlockExpression expression, ExpressionTypingContext context) {
423            return components.expressionTypingServices.getBlockReturnedType(expression, context, true);
424        }
425    
426        @Override
427        public JetTypeInfo visitLabeledExpression(@NotNull JetLabeledExpression expression, ExpressionTypingContext context) {
428            return basic.visitLabeledExpression(expression, context, true);
429        }
430    }