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.resolve.calls;
018    
019    import com.intellij.lang.ASTNode;
020    import org.jetbrains.annotations.NotNull;
021    import org.jetbrains.annotations.Nullable;
022    import org.jetbrains.jet.lang.descriptors.*;
023    import org.jetbrains.jet.lang.psi.*;
024    import org.jetbrains.jet.lang.resolve.BindingContext;
025    import org.jetbrains.jet.lang.resolve.BindingTrace;
026    import org.jetbrains.jet.lang.resolve.TemporaryBindingTrace;
027    import org.jetbrains.jet.lang.resolve.calls.context.*;
028    import org.jetbrains.jet.lang.resolve.calls.model.ResolvedCall;
029    import org.jetbrains.jet.lang.resolve.calls.model.ResolvedCallWithTrace;
030    import org.jetbrains.jet.lang.resolve.calls.results.OverloadResolutionResults;
031    import org.jetbrains.jet.lang.resolve.calls.results.OverloadResolutionResultsImpl;
032    import org.jetbrains.jet.lang.resolve.calls.results.OverloadResolutionResultsUtil;
033    import org.jetbrains.jet.lang.resolve.calls.util.CallMaker;
034    import org.jetbrains.jet.lang.resolve.constants.ConstantUtils;
035    import org.jetbrains.jet.lang.resolve.name.Name;
036    import org.jetbrains.jet.lang.resolve.scopes.ChainedScope;
037    import org.jetbrains.jet.lang.resolve.scopes.JetScope;
038    import org.jetbrains.jet.lang.resolve.scopes.JetScopeImpl;
039    import org.jetbrains.jet.lang.resolve.scopes.receivers.ExpressionReceiver;
040    import org.jetbrains.jet.lang.resolve.scopes.receivers.ReceiverValue;
041    import org.jetbrains.jet.lang.types.*;
042    import org.jetbrains.jet.lang.types.expressions.DataFlowUtils;
043    import org.jetbrains.jet.lang.types.expressions.ExpressionTypingServices;
044    import org.jetbrains.jet.lang.types.lang.KotlinBuiltIns;
045    import org.jetbrains.jet.lexer.JetTokens;
046    
047    import javax.inject.Inject;
048    import java.util.ArrayList;
049    import java.util.Collections;
050    import java.util.List;
051    
052    import static org.jetbrains.jet.lang.diagnostics.Errors.*;
053    import static org.jetbrains.jet.lang.resolve.BindingContext.*;
054    import static org.jetbrains.jet.lang.resolve.DescriptorUtils.getStaticNestedClassesScope;
055    import static org.jetbrains.jet.lang.types.TypeUtils.NO_EXPECTED_TYPE;
056    
057    public class CallExpressionResolver {
058        @NotNull
059        private ExpressionTypingServices expressionTypingServices;
060    
061        @Inject
062        public void setExpressionTypingServices(@NotNull ExpressionTypingServices expressionTypingServices) {
063            this.expressionTypingServices = expressionTypingServices;
064        }
065    
066        @Nullable
067        private JetType lookupNamespaceOrClassObject(@NotNull JetSimpleNameExpression expression, @NotNull ResolutionContext context) {
068            Name referencedName = expression.getReferencedNameAsName();
069            final ClassifierDescriptor classifier = context.scope.getClassifier(referencedName);
070            if (classifier != null) {
071                JetType classObjectType = classifier.getClassObjectType();
072                if (classObjectType != null) {
073                    context.trace.record(REFERENCE_TARGET, expression, classifier);
074                    JetType result = getExtendedClassObjectType(classObjectType, referencedName, classifier, context);
075                    return DataFlowUtils.checkType(result, expression, context);
076                }
077            }
078            JetType[] result = new JetType[1];
079            TemporaryBindingTrace temporaryTrace = TemporaryBindingTrace.create(
080                    context.trace, "trace for namespace/class object lookup of name", referencedName);
081            if (furtherNameLookup(expression, result, context.replaceBindingTrace(temporaryTrace))) {
082                temporaryTrace.commit();
083                return DataFlowUtils.checkType(result[0], expression, context);
084            }
085            // To report NO_CLASS_OBJECT when no namespace found
086            if (classifier != null) {
087                if (classifier instanceof TypeParameterDescriptor) {
088                    if (context.expressionPosition == ExpressionPosition.FREE) {
089                        context.trace.report(TYPE_PARAMETER_IS_NOT_AN_EXPRESSION.on(expression, (TypeParameterDescriptor) classifier));
090                    }
091                    else {
092                        context.trace.report(TYPE_PARAMETER_ON_LHS_OF_DOT.on(expression, (TypeParameterDescriptor) classifier));
093                    }
094                }
095                else if (context.expressionPosition == ExpressionPosition.FREE) {
096                    context.trace.report(NO_CLASS_OBJECT.on(expression, classifier));
097                }
098                context.trace.record(REFERENCE_TARGET, expression, classifier);
099                JetScope scopeForStaticMembersResolution =
100                        classifier instanceof ClassDescriptor
101                        ? getStaticNestedClassesScope((ClassDescriptor) classifier)
102                        : new JetScopeImpl() {
103                                @NotNull
104                                @Override
105                                public DeclarationDescriptor getContainingDeclaration() {
106                                    return classifier;
107                                }
108    
109                                @Override
110                                public String toString() {
111                                    return "Scope for the type parameter on the left hand side of dot";
112                                }
113                            };
114                return new NamespaceType(referencedName, scopeForStaticMembersResolution);
115            }
116            temporaryTrace.commit();
117            return result[0];
118        }
119    
120        @NotNull
121        private JetType getExtendedClassObjectType(
122                @NotNull JetType classObjectType,
123                @NotNull Name referencedName,
124                @NotNull ClassifierDescriptor classifier,
125                @NotNull ResolutionContext context
126        ) {
127            if (context.expressionPosition == ExpressionPosition.LHS_OF_DOT && classifier instanceof ClassDescriptor) {
128                List<JetScope> scopes = new ArrayList<JetScope>(3);
129    
130                scopes.add(classObjectType.getMemberScope());
131                scopes.add(getStaticNestedClassesScope((ClassDescriptor) classifier));
132    
133                NamespaceDescriptor namespace = context.scope.getNamespace(referencedName);
134                if (namespace != null) {
135                    //for enums loaded from java binaries
136                    scopes.add(namespace.getMemberScope());
137                }
138    
139                JetScope scope = new ChainedScope(classifier, scopes.toArray(new JetScope[scopes.size()]));
140                return new NamespaceType(referencedName, scope);
141            }
142            return classObjectType;
143        }
144    
145        private boolean furtherNameLookup(
146                @NotNull JetSimpleNameExpression expression,
147                @NotNull JetType[] result,
148                @NotNull ResolutionContext context
149        ) {
150            NamespaceType namespaceType = lookupNamespaceType(expression, context);
151            if (namespaceType == null) {
152                return false;
153            }
154            if (context.expressionPosition == ExpressionPosition.LHS_OF_DOT) {
155                result[0] = namespaceType;
156                return true;
157            }
158            context.trace.report(EXPRESSION_EXPECTED_NAMESPACE_FOUND.on(expression));
159            result[0] = ErrorUtils.createErrorType("Type for " + expression.getReferencedNameAsName());
160            return false;
161        }
162    
163        @Nullable
164        private NamespaceType lookupNamespaceType(@NotNull JetSimpleNameExpression expression, @NotNull ResolutionContext context) {
165            Name name = expression.getReferencedNameAsName();
166            NamespaceDescriptor namespace = context.scope.getNamespace(name);
167            if (namespace == null) {
168                return null;
169            }
170            context.trace.record(REFERENCE_TARGET, expression, namespace);
171    
172            // Construct a NamespaceType with everything from the namespace and with nested classes of the corresponding class (if any)
173            JetScope scope;
174            ClassifierDescriptor classifier = context.scope.getClassifier(name);
175            if (classifier instanceof ClassDescriptor) {
176                scope = new ChainedScope(namespace, namespace.getMemberScope(), getStaticNestedClassesScope((ClassDescriptor) classifier));
177            }
178            else {
179                scope = namespace.getMemberScope();
180            }
181            return new NamespaceType(name, scope);
182        }
183    
184        @Nullable
185        public ResolvedCallWithTrace<FunctionDescriptor> getResolvedCallForFunction(
186                @NotNull Call call, @NotNull JetExpression callExpression,
187                @NotNull ResolutionContext context, @NotNull CheckValueArgumentsMode checkArguments,
188                @NotNull boolean[] result
189        ) {
190            CallResolver callResolver = expressionTypingServices.getCallResolver();
191            OverloadResolutionResultsImpl<FunctionDescriptor> results = callResolver.resolveFunctionCall(
192                    BasicCallResolutionContext.create(context, call, checkArguments));
193            if (!results.isNothing()) {
194                checkSuper(call.getExplicitReceiver(), results, context.trace, callExpression);
195                result[0] = true;
196                return OverloadResolutionResultsUtil.getResultingCall(results, context.contextDependency);
197            }
198            result[0] = false;
199            return null;
200        }
201    
202        @Nullable
203        private JetType getVariableType(@NotNull JetSimpleNameExpression nameExpression, @NotNull ReceiverValue receiver,
204                @Nullable ASTNode callOperationNode, @NotNull ResolutionContext context, @NotNull boolean[] result
205        ) {
206            TemporaryTraceAndCache temporaryForVariable = TemporaryTraceAndCache.create(
207                    context, "trace to resolve as local variable or property", nameExpression);
208            CallResolver callResolver = expressionTypingServices.getCallResolver();
209            Call call = CallMaker.makePropertyCall(receiver, callOperationNode, nameExpression);
210            BasicCallResolutionContext contextForVariable = BasicCallResolutionContext.create(
211                    context.replaceTraceAndCache(temporaryForVariable),
212                    call, CheckValueArgumentsMode.ENABLED);
213            OverloadResolutionResults<VariableDescriptor> resolutionResult = callResolver.resolveSimpleProperty(contextForVariable);
214            if (!resolutionResult.isNothing()) {
215                temporaryForVariable.commit();
216                checkSuper(receiver, resolutionResult, context.trace, nameExpression);
217                result[0] = true;
218                return resolutionResult.isSingleResult() ? resolutionResult.getResultingDescriptor().getReturnType() : null;
219            }
220    
221            ResolutionContext newContext = receiver.exists()
222                                                 ? context.replaceScope(receiver.getType().getMemberScope())
223                                                 : context;
224            TemporaryTraceAndCache temporaryForNamespaceOrClassObject = TemporaryTraceAndCache.create(
225                    context, "trace to resolve as namespace or class object", nameExpression);
226            JetType jetType = lookupNamespaceOrClassObject(nameExpression, newContext.replaceTraceAndCache(temporaryForNamespaceOrClassObject));
227            if (jetType != null) {
228                temporaryForNamespaceOrClassObject.commit();
229    
230                // Uncommitted changes in temp context
231                context.trace.record(RESOLUTION_SCOPE, nameExpression, context.scope);
232                if (context.dataFlowInfo.hasTypeInfoConstraints()) {
233                    context.trace.record(NON_DEFAULT_EXPRESSION_DATA_FLOW, nameExpression, context.dataFlowInfo);
234                }
235                result[0] = true;
236                return jetType;
237            }
238            temporaryForVariable.commit();
239            result[0] = false;
240            return null;
241        }
242    
243        @NotNull
244        public JetTypeInfo getSimpleNameExpressionTypeInfo(@NotNull JetSimpleNameExpression nameExpression, @NotNull ReceiverValue receiver,
245                @Nullable ASTNode callOperationNode, @NotNull ResolutionContext context
246        ) {
247            boolean[] result = new boolean[1];
248    
249            TemporaryTraceAndCache temporaryForVariable = TemporaryTraceAndCache.create(
250                    context, "trace to resolve as variable", nameExpression);
251            JetType type = getVariableType(nameExpression, receiver, callOperationNode, context.replaceTraceAndCache(temporaryForVariable), result);
252            if (result[0]) {
253                temporaryForVariable.commit();
254                if (type instanceof NamespaceType && context.expressionPosition == ExpressionPosition.FREE) {
255                    type = null;
256                }
257                return JetTypeInfo.create(type, context.dataFlowInfo);
258            }
259    
260            Call call = CallMaker.makeCall(nameExpression, receiver, callOperationNode, nameExpression, Collections.<ValueArgument>emptyList());
261            TemporaryTraceAndCache temporaryForFunction = TemporaryTraceAndCache.create(
262                    context, "trace to resolve as function", nameExpression);
263            ResolutionContext newContext = context.replaceTraceAndCache(temporaryForFunction);
264            ResolvedCall<FunctionDescriptor> resolvedCall = getResolvedCallForFunction(
265                    call, nameExpression, newContext, CheckValueArgumentsMode.ENABLED, result);
266            if (result[0]) {
267                FunctionDescriptor functionDescriptor = resolvedCall != null ? resolvedCall.getResultingDescriptor() : null;
268                temporaryForFunction.commit();
269                boolean hasValueParameters = functionDescriptor == null || functionDescriptor.getValueParameters().size() > 0;
270                context.trace.report(FUNCTION_CALL_EXPECTED.on(nameExpression, nameExpression, hasValueParameters));
271                type = functionDescriptor != null ? functionDescriptor.getReturnType() : null;
272                return JetTypeInfo.create(type, context.dataFlowInfo);
273            }
274    
275            temporaryForVariable.commit();
276            return JetTypeInfo.create(null, context.dataFlowInfo);
277        }
278    
279        @NotNull
280        public JetTypeInfo getCallExpressionTypeInfo(
281                @NotNull JetCallExpression callExpression, @NotNull ReceiverValue receiver,
282                @Nullable ASTNode callOperationNode, @NotNull ResolutionContext context
283        ) {
284            JetTypeInfo typeInfo = getCallExpressionTypeInfoWithoutFinalTypeCheck(
285                    callExpression, receiver, callOperationNode, context);
286            if (context.contextDependency == ContextDependency.INDEPENDENT) {
287                DataFlowUtils.checkType(typeInfo, callExpression, context);
288            }
289            return typeInfo;
290        }
291    
292        @NotNull
293        public JetTypeInfo getCallExpressionTypeInfoWithoutFinalTypeCheck(
294                @NotNull JetCallExpression callExpression, @NotNull ReceiverValue receiver,
295                @Nullable ASTNode callOperationNode, @NotNull ResolutionContext context
296        ) {
297            boolean[] result = new boolean[1];
298            Call call = CallMaker.makeCall(receiver, callOperationNode, callExpression);
299    
300            TemporaryTraceAndCache temporaryForFunction = TemporaryTraceAndCache.create(
301                    context, "trace to resolve as function call", callExpression);
302            ResolvedCallWithTrace<FunctionDescriptor> resolvedCall = getResolvedCallForFunction(
303                    call, callExpression, context.replaceTraceAndCache(temporaryForFunction),
304                    CheckValueArgumentsMode.ENABLED, result);
305            if (result[0]) {
306                FunctionDescriptor functionDescriptor = resolvedCall != null ? resolvedCall.getResultingDescriptor() : null;
307                temporaryForFunction.commit();
308                if (callExpression.getValueArgumentList() == null && callExpression.getFunctionLiteralArguments().isEmpty()) {
309                    // there are only type arguments
310                    boolean hasValueParameters = functionDescriptor == null || functionDescriptor.getValueParameters().size() > 0;
311                    context.trace.report(FUNCTION_CALL_EXPECTED.on(callExpression, callExpression, hasValueParameters));
312                }
313                if (functionDescriptor == null) {
314                    return JetTypeInfo.create(null, context.dataFlowInfo);
315                }
316                JetType type = functionDescriptor.getReturnType();
317    
318                return JetTypeInfo.create(type, resolvedCall.getDataFlowInfoForArguments().getResultInfo());
319            }
320    
321            JetExpression calleeExpression = callExpression.getCalleeExpression();
322            if (calleeExpression instanceof JetSimpleNameExpression && callExpression.getTypeArgumentList() == null) {
323                TemporaryTraceAndCache temporaryForVariable = TemporaryTraceAndCache.create(
324                        context, "trace to resolve as variable with 'invoke' call", callExpression);
325                JetType type = getVariableType((JetSimpleNameExpression) calleeExpression, receiver, callOperationNode,
326                                               context.replaceTraceAndCache(temporaryForVariable), result);
327                if (result[0]) {
328                    temporaryForVariable.commit();
329                    context.trace.report(FUNCTION_EXPECTED.on((JetReferenceExpression) calleeExpression, calleeExpression,
330                                                              type != null ? type : ErrorUtils.createErrorType("")));
331                    return JetTypeInfo.create(null, context.dataFlowInfo);
332                }
333            }
334            temporaryForFunction.commit();
335            return JetTypeInfo.create(null, context.dataFlowInfo);
336        }
337    
338        private void checkSuper(@NotNull ReceiverValue receiverValue, @NotNull OverloadResolutionResults<? extends CallableDescriptor> results,
339                @NotNull BindingTrace trace, @NotNull JetExpression expression) {
340            if (!results.isSingleResult()) return;
341            if (!(receiverValue instanceof ExpressionReceiver)) return;
342            JetExpression receiver = ((ExpressionReceiver) receiverValue).getExpression();
343            CallableDescriptor descriptor = results.getResultingDescriptor();
344            if (receiver instanceof JetSuperExpression && descriptor instanceof MemberDescriptor) {
345                if (((MemberDescriptor) descriptor).getModality() == Modality.ABSTRACT) {
346                    trace.report(ABSTRACT_SUPER_CALL.on(expression));
347                }
348            }
349        }
350    
351        @NotNull
352        private JetTypeInfo getSelectorReturnTypeInfo(
353                @NotNull ReceiverValue receiver,
354                @Nullable ASTNode callOperationNode,
355                @NotNull JetExpression selectorExpression,
356                @NotNull ResolutionContext context
357        ) {
358            if (selectorExpression instanceof JetCallExpression) {
359                return getCallExpressionTypeInfoWithoutFinalTypeCheck((JetCallExpression) selectorExpression, receiver,
360                                                                      callOperationNode, context);
361            }
362            else if (selectorExpression instanceof JetSimpleNameExpression) {
363                return getSimpleNameExpressionTypeInfo((JetSimpleNameExpression) selectorExpression, receiver, callOperationNode, context);
364            }
365            else {
366                context.trace.report(ILLEGAL_SELECTOR.on(selectorExpression, selectorExpression.getText()));
367            }
368            return JetTypeInfo.create(null, context.dataFlowInfo);
369        }
370    
371        @NotNull
372        public JetTypeInfo getQualifiedExpressionTypeInfo(
373                @NotNull JetQualifiedExpression expression, @NotNull ResolutionContext context
374        ) {
375            // TODO : functions as values
376            JetExpression selectorExpression = expression.getSelectorExpression();
377            JetExpression receiverExpression = expression.getReceiverExpression();
378            ResolutionContext contextForReceiver = context
379                    .replaceExpectedType(NO_EXPECTED_TYPE).replaceExpressionPosition(ExpressionPosition.LHS_OF_DOT)
380                    .replaceContextDependency(ContextDependency.INDEPENDENT);
381            JetTypeInfo receiverTypeInfo = expressionTypingServices.getTypeInfo(receiverExpression, contextForReceiver);
382            JetType receiverType = receiverTypeInfo.getType();
383            if (selectorExpression == null) return JetTypeInfo.create(null, context.dataFlowInfo);
384            if (receiverType == null) receiverType = ErrorUtils.createErrorType("Type for " + expression.getText());
385    
386            context = context.replaceDataFlowInfo(receiverTypeInfo.getDataFlowInfo());
387    
388            if (selectorExpression instanceof JetSimpleNameExpression) {
389                ConstantUtils.propagateConstantValues(expression, context.trace, (JetSimpleNameExpression) selectorExpression);
390            }
391    
392            JetTypeInfo selectorReturnTypeInfo = getSelectorReturnTypeInfo(
393                    new ExpressionReceiver(receiverExpression, receiverType),
394                    expression.getOperationTokenNode(), selectorExpression, context);
395            JetType selectorReturnType = selectorReturnTypeInfo.getType();
396    
397            //TODO move further
398            if (!(receiverType instanceof NamespaceType) && expression.getOperationSign() == JetTokens.SAFE_ACCESS) {
399                if (selectorReturnType != null && !selectorReturnType.isNullable() && !KotlinBuiltIns.getInstance().isUnit(selectorReturnType)) {
400                    if (receiverType.isNullable()) {
401                        selectorReturnType = TypeUtils.makeNullable(selectorReturnType);
402                    }
403                }
404            }
405    
406            // TODO : this is suspicious: remove this code?
407            if (selectorReturnType != null) {
408                context.trace.record(BindingContext.EXPRESSION_TYPE, selectorExpression, selectorReturnType);
409            }
410            JetTypeInfo typeInfo = JetTypeInfo.create(selectorReturnType, selectorReturnTypeInfo.getDataFlowInfo());
411            if (context.contextDependency == ContextDependency.INDEPENDENT) {
412                DataFlowUtils.checkType(typeInfo, expression, context);
413            }
414            return typeInfo;
415        }
416    }