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.Sets;
020    import com.intellij.psi.tree.IElementType;
021    import org.jetbrains.annotations.NotNull;
022    import org.jetbrains.annotations.Nullable;
023    import org.jetbrains.jet.lang.descriptors.*;
024    import org.jetbrains.jet.lang.descriptors.impl.FunctionDescriptorUtil;
025    import org.jetbrains.jet.lang.diagnostics.Errors;
026    import org.jetbrains.jet.lang.psi.*;
027    import org.jetbrains.jet.lang.resolve.BindingContext;
028    import org.jetbrains.jet.lang.resolve.ModifiersChecker;
029    import org.jetbrains.jet.lang.resolve.TemporaryBindingTrace;
030    import org.jetbrains.jet.lang.resolve.TopDownAnalyzer;
031    import org.jetbrains.jet.lang.resolve.calls.autocasts.DataFlowInfo;
032    import org.jetbrains.jet.lang.resolve.calls.model.ResolvedCall;
033    import org.jetbrains.jet.lang.resolve.calls.results.OverloadResolutionResults;
034    import org.jetbrains.jet.lang.resolve.calls.results.OverloadResolutionResultsUtil;
035    import org.jetbrains.jet.lang.resolve.name.Name;
036    import org.jetbrains.jet.lang.resolve.scopes.JetScope;
037    import org.jetbrains.jet.lang.resolve.scopes.WritableScope;
038    import org.jetbrains.jet.lang.resolve.scopes.receivers.ExpressionReceiver;
039    import org.jetbrains.jet.lang.types.JetType;
040    import org.jetbrains.jet.lang.types.JetTypeInfo;
041    import org.jetbrains.jet.lang.types.TypeUtils;
042    import org.jetbrains.jet.lang.types.lang.KotlinBuiltIns;
043    import org.jetbrains.jet.lexer.JetTokens;
044    
045    import java.util.Collection;
046    
047    import static org.jetbrains.jet.lang.diagnostics.Errors.*;
048    import static org.jetbrains.jet.lang.resolve.BindingContext.AMBIGUOUS_REFERENCE_TARGET;
049    import static org.jetbrains.jet.lang.resolve.BindingContext.VARIABLE_REASSIGNMENT;
050    
051    @SuppressWarnings("SuspiciousMethodCalls")
052    public class ExpressionTypingVisitorForStatements extends ExpressionTypingVisitor {
053        private final WritableScope scope;
054        private final BasicExpressionTypingVisitor basic;
055        private final ControlStructureTypingVisitor controlStructures;
056        private final PatternMatchingTypingVisitor patterns;
057    
058        public ExpressionTypingVisitorForStatements(
059                @NotNull ExpressionTypingInternals facade,
060                @NotNull WritableScope scope,
061                BasicExpressionTypingVisitor basic,
062                @NotNull ControlStructureTypingVisitor controlStructures,
063                @NotNull PatternMatchingTypingVisitor patterns) {
064            super(facade);
065            this.scope = scope;
066            this.basic = basic;
067            this.controlStructures = controlStructures;
068            this.patterns = patterns;
069        }
070    
071        @Nullable
072        private static JetType checkAssignmentType(
073                @Nullable JetType assignmentType,
074                @NotNull JetBinaryExpression expression,
075                @NotNull ExpressionTypingContext context
076        ) {
077            if (assignmentType != null && !KotlinBuiltIns.getInstance().isUnit(assignmentType) && context.expectedType != TypeUtils.NO_EXPECTED_TYPE &&
078                TypeUtils.equalTypes(context.expectedType, assignmentType)) {
079                context.trace.report(Errors.ASSIGNMENT_TYPE_MISMATCH.on(expression, context.expectedType));
080                return null;
081            }
082            return DataFlowUtils.checkStatementType(expression, context);
083        }
084    
085        @Override
086        public JetTypeInfo visitObjectDeclaration(JetObjectDeclaration declaration, ExpressionTypingContext context) {
087            TopDownAnalyzer.processClassOrObject(context.replaceScope(scope), scope.getContainingDeclaration(), declaration);
088            ClassDescriptor classDescriptor = context.trace.getBindingContext().get(BindingContext.CLASS, declaration);
089            if (classDescriptor != null) {
090                VariableDescriptor variableDescriptor = context.expressionTypingServices.getDescriptorResolver()
091                        .resolveObjectDeclaration(scope.getContainingDeclaration(), declaration, classDescriptor, context.trace);
092                scope.addVariableDescriptor(variableDescriptor);
093            }
094            return DataFlowUtils.checkStatementType(declaration, context, context.dataFlowInfo);
095        }
096    
097        @Override
098        public JetTypeInfo visitProperty(JetProperty property, ExpressionTypingContext context) {
099            JetTypeReference receiverTypeRef = property.getReceiverTypeRef();
100            if (receiverTypeRef != null) {
101                context.trace.report(LOCAL_EXTENSION_PROPERTY.on(receiverTypeRef));
102            }
103    
104            JetPropertyAccessor getter = property.getGetter();
105            if (getter != null) {
106                context.trace.report(LOCAL_VARIABLE_WITH_GETTER.on(getter));
107            }
108    
109            JetPropertyAccessor setter = property.getSetter();
110            if (setter != null) {
111                context.trace.report(LOCAL_VARIABLE_WITH_SETTER.on(setter));
112            }
113    
114            JetExpression delegateExpression = property.getDelegateExpression();
115            if (delegateExpression != null) {
116                context.expressionTypingServices.getType(scope, delegateExpression, TypeUtils.NO_EXPECTED_TYPE, context.dataFlowInfo, context.trace);
117                context.trace.report(LOCAL_VARIABLE_WITH_DELEGATE.on(property.getDelegate()));
118            }
119    
120            VariableDescriptor propertyDescriptor = context.expressionTypingServices.getDescriptorResolver().
121                    resolveLocalVariableDescriptor(scope, property, context.dataFlowInfo, context.trace);
122            JetExpression initializer = property.getInitializer();
123            DataFlowInfo dataFlowInfo = context.dataFlowInfo;
124            if (initializer != null) {
125                JetType outType = propertyDescriptor.getType();
126                JetTypeInfo typeInfo = facade.getTypeInfo(initializer, context.replaceExpectedType(outType).replaceScope(scope));
127                dataFlowInfo = typeInfo.getDataFlowInfo();
128            }
129            
130            {
131                VariableDescriptor olderVariable = scope.getLocalVariable(propertyDescriptor.getName());
132                ExpressionTypingUtils.checkVariableShadowing(context, propertyDescriptor, olderVariable);
133            }
134    
135            scope.addVariableDescriptor(propertyDescriptor);
136            ModifiersChecker.create(context.trace).checkModifiersForLocalDeclaration(property);
137            return DataFlowUtils.checkStatementType(property, context, dataFlowInfo);
138        }
139    
140        @Override
141        public JetTypeInfo visitMultiDeclaration(JetMultiDeclaration multiDeclaration, ExpressionTypingContext context) {
142            JetExpression initializer = multiDeclaration.getInitializer();
143            if (initializer == null) {
144                context.trace.report(INITIALIZER_REQUIRED_FOR_MULTIDECLARATION.on(multiDeclaration));
145                return JetTypeInfo.create(null, context.dataFlowInfo);
146            }
147            ExpressionReceiver expressionReceiver =
148                    ExpressionTypingUtils.getExpressionReceiver(facade, initializer, context.replaceExpectedType(TypeUtils.NO_EXPECTED_TYPE));
149            DataFlowInfo dataFlowInfo = facade.getTypeInfo(initializer, context).getDataFlowInfo();
150            if (expressionReceiver == null) {
151                return JetTypeInfo.create(null, dataFlowInfo);
152            }
153            ExpressionTypingUtils.defineLocalVariablesFromMultiDeclaration(scope, multiDeclaration, expressionReceiver, initializer, context);
154            return DataFlowUtils.checkStatementType(multiDeclaration, context, dataFlowInfo);
155        }
156    
157        @Override
158        public JetTypeInfo visitNamedFunction(JetNamedFunction function, ExpressionTypingContext context) {
159            SimpleFunctionDescriptor functionDescriptor = context.expressionTypingServices.getDescriptorResolver().
160                    resolveFunctionDescriptorWithAnnotationArguments(
161                            scope.getContainingDeclaration(), scope, function, context.trace, context.dataFlowInfo);
162    
163            scope.addFunctionDescriptor(functionDescriptor);
164            JetScope functionInnerScope = FunctionDescriptorUtil.getFunctionInnerScope(context.scope, functionDescriptor, context.trace);
165            context.expressionTypingServices.checkFunctionReturnType(functionInnerScope, function, functionDescriptor, context.dataFlowInfo, null, context.trace);
166            ModifiersChecker.create(context.trace).checkModifiersForLocalDeclaration(function);
167            return DataFlowUtils.checkStatementType(function, context, context.dataFlowInfo);
168        }
169    
170        @Override
171        public JetTypeInfo visitClass(JetClass klass, ExpressionTypingContext context) {
172            TopDownAnalyzer.processClassOrObject(context.replaceScope(scope), scope.getContainingDeclaration(), klass);
173            ClassDescriptor classDescriptor = context.trace.getBindingContext().get(BindingContext.CLASS, klass);
174            if (classDescriptor != null) {
175                scope.addClassifierDescriptor(classDescriptor);
176            }
177            return DataFlowUtils.checkStatementType(klass, context, context.dataFlowInfo);
178        }
179    
180        @Override
181        public JetTypeInfo visitTypedef(JetTypedef typedef, ExpressionTypingContext context) {
182            return super.visitTypedef(typedef, context); // TODO
183        }
184    
185        @Override
186        public JetTypeInfo visitDeclaration(JetDeclaration dcl, ExpressionTypingContext context) {
187            return DataFlowUtils.checkStatementType(dcl, context, context.dataFlowInfo);
188        }
189    
190        @Override
191        public JetTypeInfo visitBinaryExpression(JetBinaryExpression expression, ExpressionTypingContext context) {
192            JetSimpleNameExpression operationSign = expression.getOperationReference();
193            IElementType operationType = operationSign.getReferencedNameElementType();
194            JetTypeInfo result;
195            if (operationType == JetTokens.EQ) {
196                result = visitAssignment(expression, context);
197            }
198            else if (OperatorConventions.ASSIGNMENT_OPERATIONS.containsKey(operationType)) {
199                result = visitAssignmentOperation(expression, context);
200            }
201            else {
202                return facade.getTypeInfo(expression, context);
203            }
204            return DataFlowUtils.checkType(result.getType(), expression, context, result.getDataFlowInfo());
205        }
206    
207        @NotNull
208        protected JetTypeInfo visitAssignmentOperation(JetBinaryExpression expression, ExpressionTypingContext contextWithExpectedType) {
209            //There is a temporary binding trace for an opportunity to resolve set method for array if needed (the initial trace should be used there)
210            TemporaryBindingTrace temporaryBindingTrace = TemporaryBindingTrace.create(
211                    contextWithExpectedType.trace, "trace to resolve array set method for binary expression", expression);
212            ExpressionTypingContext context = contextWithExpectedType.replaceExpectedType(TypeUtils.NO_EXPECTED_TYPE).replaceBindingTrace(temporaryBindingTrace);
213    
214            JetSimpleNameExpression operationSign = expression.getOperationReference();
215            IElementType operationType = operationSign.getReferencedNameElementType();
216            JetExpression leftOperand = expression.getLeft();
217            JetTypeInfo leftInfo = ExpressionTypingUtils.getTypeInfoOrNullType(leftOperand, context, facade);
218            JetType leftType = leftInfo.getType();
219            DataFlowInfo dataFlowInfo = leftInfo.getDataFlowInfo();
220    
221            JetExpression right = expression.getRight();
222            JetExpression left = leftOperand == null ? null : JetPsiUtil.deparenthesizeWithNoTypeResolution(leftOperand);
223            if (right == null || left == null) {
224                temporaryBindingTrace.commit();
225                return JetTypeInfo.create(null, dataFlowInfo);
226            }
227    
228            if (leftType == null) {
229                dataFlowInfo = facade.getTypeInfo(right, context.replaceDataFlowInfo(dataFlowInfo)).getDataFlowInfo();
230                context.trace.report(UNRESOLVED_REFERENCE.on(operationSign, operationSign));
231                temporaryBindingTrace.commit();
232                return JetTypeInfo.create(null, dataFlowInfo);
233            }
234            ExpressionReceiver receiver = new ExpressionReceiver(left, leftType);
235    
236            // We check that defined only one of '+=' and '+' operations, and call it (in the case '+' we then also assign)
237            // Check for '+='
238            Name name = OperatorConventions.ASSIGNMENT_OPERATIONS.get(operationType);
239            TemporaryBindingTrace assignmentOperationTrace = TemporaryBindingTrace.create(context.trace, "trace to check assignment operation like '+=' for", expression);
240            OverloadResolutionResults<FunctionDescriptor> assignmentOperationDescriptors = BasicExpressionTypingVisitor.getResolutionResultsForBinaryCall(
241                    scope, name, context.replaceBindingTrace(assignmentOperationTrace), expression, receiver);
242            JetType assignmentOperationType = OverloadResolutionResultsUtil.getResultType(assignmentOperationDescriptors);
243    
244            // Check for '+'
245            Name counterpartName = OperatorConventions.BINARY_OPERATION_NAMES.get(OperatorConventions.ASSIGNMENT_OPERATION_COUNTERPARTS.get(operationType));
246            TemporaryBindingTrace binaryOperationTrace = TemporaryBindingTrace.create(context.trace, "trace to check binary operation like '+' for", expression);
247            OverloadResolutionResults<FunctionDescriptor> binaryOperationDescriptors = BasicExpressionTypingVisitor.getResolutionResultsForBinaryCall(
248                    scope, counterpartName, context.replaceBindingTrace(binaryOperationTrace), expression, receiver);
249            JetType binaryOperationType = OverloadResolutionResultsUtil.getResultType(binaryOperationDescriptors);
250    
251            JetType type = assignmentOperationType != null ? assignmentOperationType : binaryOperationType;
252            if (assignmentOperationType != null && binaryOperationType != null) {
253                // Both 'plus()' and 'plusAssign()' available => ambiguity
254                OverloadResolutionResults<FunctionDescriptor> ambiguityResolutionResults = OverloadResolutionResultsUtil.ambiguity(assignmentOperationDescriptors, binaryOperationDescriptors);
255                context.trace.report(ASSIGN_OPERATOR_AMBIGUITY.on(operationSign, ambiguityResolutionResults.getResultingCalls()));
256                Collection<DeclarationDescriptor> descriptors = Sets.newHashSet();
257                for (ResolvedCall<? extends FunctionDescriptor> call : ambiguityResolutionResults.getResultingCalls()) {
258                    descriptors.add(call.getResultingDescriptor());
259                }
260                dataFlowInfo = facade.getTypeInfo(right, context.replaceDataFlowInfo(dataFlowInfo)).getDataFlowInfo();
261                context.trace.record(AMBIGUOUS_REFERENCE_TARGET, operationSign, descriptors);
262            }
263            else if (assignmentOperationType != null) {
264                // There's 'plusAssign()', so we do a.plusAssign(b)
265                assignmentOperationTrace.commit();
266                if (!KotlinBuiltIns.getInstance().isUnit(assignmentOperationType)) {
267                    context.trace.report(ASSIGNMENT_OPERATOR_SHOULD_RETURN_UNIT.on(operationSign, assignmentOperationDescriptors.getResultingDescriptor(), operationSign));
268                }
269            }
270            else {
271                // There's only 'plus()', so we try 'a = a + b'
272                binaryOperationTrace.commit();
273                context.trace.record(VARIABLE_REASSIGNMENT, expression);
274                if (left instanceof JetArrayAccessExpression) {
275                    ExpressionTypingContext contextForResolve = context.replaceScope(scope).replaceBindingTrace(TemporaryBindingTrace.create(
276                            contextWithExpectedType.trace, "trace to resolve array set method for assignment", expression));
277                    basic.resolveArrayAccessSetMethod((JetArrayAccessExpression) left, right, contextForResolve, context.trace);
278                }
279                dataFlowInfo = facade.getTypeInfo(right, context.replaceDataFlowInfo(dataFlowInfo)).getDataFlowInfo();
280                BasicExpressionTypingVisitor.checkLValue(context.trace, leftOperand);
281            }
282            temporaryBindingTrace.commit();
283            return JetTypeInfo.create(checkAssignmentType(type, expression, contextWithExpectedType), dataFlowInfo);
284        }
285    
286        @NotNull
287        protected JetTypeInfo visitAssignment(JetBinaryExpression expression, ExpressionTypingContext contextWithExpectedType) {
288            ExpressionTypingContext context = contextWithExpectedType.replaceExpectedType(TypeUtils.NO_EXPECTED_TYPE).replaceScope(scope);
289            JetExpression leftOperand = expression.getLeft();
290            JetExpression left = leftOperand == null ? null : context.expressionTypingServices.deparenthesize(leftOperand, context);
291            JetExpression right = expression.getRight();
292            if (left instanceof JetArrayAccessExpression) {
293                JetArrayAccessExpression arrayAccessExpression = (JetArrayAccessExpression) left;
294                if (right == null) return JetTypeInfo.create(null, context.dataFlowInfo);
295                JetTypeInfo typeInfo = basic.resolveArrayAccessSetMethod(arrayAccessExpression, right, context, context.trace);
296                BasicExpressionTypingVisitor.checkLValue(context.trace, arrayAccessExpression);
297                return JetTypeInfo.create(checkAssignmentType(typeInfo.getType(), expression, contextWithExpectedType),
298                                          typeInfo.getDataFlowInfo());
299            }
300            JetTypeInfo leftInfo = ExpressionTypingUtils.getTypeInfoOrNullType(left, context, facade);
301            JetType leftType = leftInfo.getType();
302            DataFlowInfo dataFlowInfo = leftInfo.getDataFlowInfo();
303            if (right != null) {
304                JetTypeInfo rightInfo = facade.getTypeInfo(right, context.replaceDataFlowInfo(dataFlowInfo).replaceExpectedType(leftType));
305                dataFlowInfo = rightInfo.getDataFlowInfo();
306            }
307            if (leftType != null && leftOperand != null) { //if leftType == null, some other error has been generated
308                BasicExpressionTypingVisitor.checkLValue(context.trace, leftOperand);
309            }
310            return DataFlowUtils.checkStatementType(expression, contextWithExpectedType, dataFlowInfo);
311        }
312    
313    
314        @Override
315        public JetTypeInfo visitExpression(JetExpression expression, ExpressionTypingContext context) {
316            return facade.getTypeInfo(expression, context);
317        }
318    
319        @Override
320        public JetTypeInfo visitJetElement(JetElement element, ExpressionTypingContext context) {
321            context.trace.report(UNSUPPORTED.on(element, "in a block"));
322            return JetTypeInfo.create(null, context.dataFlowInfo);
323        }
324    
325        @Override
326        public JetTypeInfo visitWhileExpression(JetWhileExpression expression, ExpressionTypingContext context) {
327            return controlStructures.visitWhileExpression(expression, context, true);
328        }
329    
330        @Override
331        public JetTypeInfo visitDoWhileExpression(JetDoWhileExpression expression, ExpressionTypingContext context) {
332            return controlStructures.visitDoWhileExpression(expression, context, true);
333        }
334    
335        @Override
336        public JetTypeInfo visitForExpression(JetForExpression expression, ExpressionTypingContext context) {
337            return controlStructures.visitForExpression(expression, context, true);
338        }
339    
340        @Override
341        public JetTypeInfo visitIfExpression(JetIfExpression expression, ExpressionTypingContext context) {
342            return controlStructures.visitIfExpression(expression, context, true);
343        }
344    
345        @Override
346        public JetTypeInfo visitWhenExpression(JetWhenExpression expression, ExpressionTypingContext context) {
347            return patterns.visitWhenExpression(expression, context, true);
348        }
349    
350        @Override
351        public JetTypeInfo visitBlockExpression(JetBlockExpression expression, ExpressionTypingContext context) {
352            return BasicExpressionTypingVisitor.visitBlockExpression(expression, context, true);
353        }
354    
355        @Override
356        public JetTypeInfo visitParenthesizedExpression(JetParenthesizedExpression expression, ExpressionTypingContext context) {
357            return basic.visitParenthesizedExpression(expression, context, true);
358        }
359    
360        @Override
361        public JetTypeInfo visitUnaryExpression(JetUnaryExpression expression, ExpressionTypingContext context) {
362            return basic.visitUnaryExpression(expression, context, true);
363        }
364    }