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.google.common.base.Function;
020    import com.google.common.collect.Collections2;
021    import com.google.common.collect.Lists;
022    import org.jetbrains.annotations.NotNull;
023    import org.jetbrains.jet.lang.descriptors.CallableDescriptor;
024    import org.jetbrains.jet.lang.descriptors.FunctionDescriptor;
025    import org.jetbrains.jet.lang.descriptors.VariableDescriptor;
026    import org.jetbrains.jet.lang.psi.*;
027    import org.jetbrains.jet.lang.resolve.ChainedTemporaryBindingTrace;
028    import org.jetbrains.jet.lang.resolve.DelegatingBindingTrace;
029    import org.jetbrains.jet.lang.resolve.TemporaryBindingTrace;
030    import org.jetbrains.jet.lang.resolve.calls.context.BasicCallResolutionContext;
031    import org.jetbrains.jet.lang.resolve.calls.context.CallCandidateResolutionContext;
032    import org.jetbrains.jet.lang.resolve.calls.context.ContextDependency;
033    import org.jetbrains.jet.lang.resolve.calls.model.MutableResolvedCall;
034    import org.jetbrains.jet.lang.resolve.calls.model.ResolvedCallImpl;
035    import org.jetbrains.jet.lang.resolve.calls.model.VariableAsFunctionResolvedCallImpl;
036    import org.jetbrains.jet.lang.resolve.calls.results.OverloadResolutionResults;
037    import org.jetbrains.jet.lang.resolve.calls.results.OverloadResolutionResultsImpl;
038    import org.jetbrains.jet.lang.resolve.calls.tasks.ExplicitReceiverKind;
039    import org.jetbrains.jet.lang.resolve.calls.tasks.ResolutionCandidate;
040    import org.jetbrains.jet.lang.resolve.calls.tasks.ResolutionTask;
041    import org.jetbrains.jet.lang.resolve.calls.tasks.TracingStrategyForInvoke;
042    import org.jetbrains.jet.lang.resolve.calls.util.DelegatingCall;
043    import org.jetbrains.jet.lang.resolve.scopes.receivers.ExpressionReceiver;
044    import org.jetbrains.jet.lang.resolve.scopes.receivers.ReceiverValue;
045    import org.jetbrains.jet.lang.types.JetType;
046    
047    import java.util.Collection;
048    import java.util.Collections;
049    import java.util.List;
050    
051    /**
052     * CallTransformer treats specially 'variable as function' call case, other cases keeps unchanged (base realization).
053     *
054     * For the call 'b.foo(1)' where foo is a variable that has method 'invoke' (for example of function type)
055     * CallTransformer creates two contexts, two calls in each, and performs second ('invoke') call resolution:
056     *
057     *   context#1. calls: 'b.foo' 'invoke(1)'
058     *   context#2. calls: 'foo'   'b.invoke(1)'
059     *
060     * If success VariableAsFunctionResolvedCall is created.
061     */
062    public class CallTransformer<D extends CallableDescriptor, F extends D> {
063        private CallTransformer() {}
064    
065        /**
066         * Returns two contexts for 'variable as function' case (in FUNCTION_CALL_TRANSFORMER), one context otherwise
067         */
068        @NotNull
069        public Collection<CallCandidateResolutionContext<D>> createCallContexts(@NotNull ResolutionCandidate<D> candidate,
070                @NotNull ResolutionTask<D, F> task,
071                @NotNull TemporaryBindingTrace candidateTrace
072        ) {
073            ResolvedCallImpl<D> candidateCall = ResolvedCallImpl.create(candidate, candidateTrace, task.tracing, task.dataFlowInfoForArguments);
074            return Collections.singleton(CallCandidateResolutionContext.create(candidateCall, task, candidateTrace, task.tracing));
075        }
076    
077        /**
078         * Returns collection of resolved calls for 'invoke' for 'variable as function' case (in FUNCTION_CALL_TRANSFORMER),
079         * the resolved call from callCandidateResolutionContext otherwise
080         */
081        @NotNull
082        public Collection<MutableResolvedCall<F>> transformCall(@NotNull CallCandidateResolutionContext<D> callCandidateResolutionContext,
083                @NotNull CallResolver callResolver,
084                @NotNull ResolutionTask<D, F> task
085        ) {
086            return Collections.singleton((MutableResolvedCall<F>) callCandidateResolutionContext.candidateCall);
087        }
088    
089    
090        public static CallTransformer<VariableDescriptor, VariableDescriptor> PROPERTY_CALL_TRANSFORMER = new CallTransformer<VariableDescriptor, VariableDescriptor>();
091    
092        public static CallTransformer<CallableDescriptor, FunctionDescriptor> FUNCTION_CALL_TRANSFORMER = new CallTransformer<CallableDescriptor, FunctionDescriptor>() {
093            @NotNull
094            @Override
095            public Collection<CallCandidateResolutionContext<CallableDescriptor>> createCallContexts(@NotNull ResolutionCandidate<CallableDescriptor> candidate,
096                    @NotNull ResolutionTask<CallableDescriptor, FunctionDescriptor> task, @NotNull TemporaryBindingTrace candidateTrace) {
097    
098                if (candidate.getDescriptor() instanceof FunctionDescriptor) {
099                    return super.createCallContexts(candidate, task, candidateTrace);
100                }
101    
102                assert candidate.getDescriptor() instanceof VariableDescriptor;
103    
104                boolean hasReceiver = candidate.getReceiverArgument().exists();
105                Call variableCall = stripCallArguments(task);
106                if (!hasReceiver) {
107                    CallCandidateResolutionContext<CallableDescriptor> context = CallCandidateResolutionContext.create(
108                            ResolvedCallImpl.create(candidate, candidateTrace, task.tracing, task.dataFlowInfoForArguments), task, candidateTrace, task.tracing, variableCall);
109                    return Collections.singleton(context);
110                }
111                CallCandidateResolutionContext<CallableDescriptor> contextWithReceiver = createContextWithChainedTrace(
112                        candidate, variableCall, candidateTrace, task, ReceiverValue.NO_RECEIVER);
113    
114                Call variableCallWithoutReceiver = stripReceiver(variableCall);
115                ResolutionCandidate<CallableDescriptor> candidateWithoutReceiver = ResolutionCandidate.create(
116                        candidate.getCall(), candidate.getDescriptor(), candidate.getThisObject(), ReceiverValue.NO_RECEIVER,
117                        ExplicitReceiverKind.NO_EXPLICIT_RECEIVER, false);
118    
119                CallCandidateResolutionContext<CallableDescriptor> contextWithoutReceiver = createContextWithChainedTrace(
120                        candidateWithoutReceiver, variableCallWithoutReceiver, candidateTrace, task, variableCall.getExplicitReceiver());
121    
122                return Lists.newArrayList(contextWithReceiver, contextWithoutReceiver);
123            }
124    
125            private CallCandidateResolutionContext<CallableDescriptor> createContextWithChainedTrace(
126                    @NotNull ResolutionCandidate<CallableDescriptor> candidate, @NotNull Call call, @NotNull TemporaryBindingTrace temporaryTrace,
127                    @NotNull ResolutionTask<CallableDescriptor, FunctionDescriptor> task, @NotNull ReceiverValue receiverValue
128            ) {
129                ChainedTemporaryBindingTrace chainedTrace = ChainedTemporaryBindingTrace.create(temporaryTrace, "chained trace to resolve candidate", candidate);
130                ResolvedCallImpl<CallableDescriptor> resolvedCall = ResolvedCallImpl.create(candidate, chainedTrace, task.tracing, task.dataFlowInfoForArguments);
131                return CallCandidateResolutionContext.create(resolvedCall, task, chainedTrace, task.tracing, call, receiverValue);
132            }
133    
134            private Call stripCallArguments(@NotNull ResolutionTask<CallableDescriptor, FunctionDescriptor> task) {
135                return new DelegatingCall(task.call) {
136                    @Override
137                    public JetValueArgumentList getValueArgumentList() {
138                        return null;
139                    }
140    
141                    @NotNull
142                    @Override
143                    public List<? extends ValueArgument> getValueArguments() {
144                        return Collections.emptyList();
145                    }
146    
147                    @NotNull
148                    @Override
149                    public List<JetExpression> getFunctionLiteralArguments() {
150                        return Collections.emptyList();
151                    }
152    
153                    @NotNull
154                    @Override
155                    public List<JetTypeProjection> getTypeArguments() {
156                        return Collections.emptyList();
157                    }
158    
159                    @Override
160                    public JetTypeArgumentList getTypeArgumentList() {
161                        return null;
162                    }
163                };
164            }
165    
166            private Call stripReceiver(@NotNull Call variableCall) {
167                return new DelegatingCall(variableCall) {
168                    @NotNull
169                    @Override
170                    public ReceiverValue getExplicitReceiver() {
171                        return ReceiverValue.NO_RECEIVER;
172                    }
173                };
174            }
175    
176            @NotNull
177            @Override
178            public Collection<MutableResolvedCall<FunctionDescriptor>> transformCall(
179                    @NotNull CallCandidateResolutionContext<CallableDescriptor> context,
180                    @NotNull CallResolver callResolver,
181                    @NotNull ResolutionTask<CallableDescriptor, FunctionDescriptor> task
182            ) {
183                CallableDescriptor descriptor = context.candidateCall.getCandidateDescriptor();
184                if (descriptor instanceof FunctionDescriptor) {
185                    return super.transformCall(context, callResolver, task);
186                }
187    
188                assert descriptor instanceof VariableDescriptor;
189                JetType returnType = descriptor.getReturnType();
190                if (returnType == null) {
191                    return Collections.emptyList();
192                }
193    
194                final MutableResolvedCall<VariableDescriptor> variableResolvedCall = (MutableResolvedCall)context.candidateCall;
195    
196                JetExpression calleeExpression = task.call.getCalleeExpression();
197                if (calleeExpression == null) return Collections.emptyList();
198    
199                ExpressionReceiver variableReceiver = new ExpressionReceiver(calleeExpression, variableResolvedCall.getResultingDescriptor().getType());
200                Call functionCall = new CallForImplicitInvoke(context.explicitExtensionReceiverForInvoke, variableReceiver, task.call);
201    
202                DelegatingBindingTrace variableCallTrace = context.candidateCall.getTrace();
203                BasicCallResolutionContext basicCallResolutionContext = BasicCallResolutionContext.create(
204                        context.replaceBindingTrace(variableCallTrace).replaceContextDependency(ContextDependency.DEPENDENT),
205                        functionCall, context.checkArguments, context.dataFlowInfoForArguments);
206    
207                // 'invoke' call resolve
208                TracingStrategyForInvoke tracingForInvoke = new TracingStrategyForInvoke(
209                        calleeExpression, functionCall, variableReceiver.getType());
210                OverloadResolutionResults<FunctionDescriptor> results = callResolver.resolveCallForInvoke(
211                        basicCallResolutionContext, tracingForInvoke);
212                Collection<MutableResolvedCall<FunctionDescriptor>> calls = ((OverloadResolutionResultsImpl<FunctionDescriptor>)results).getResultingCalls();
213    
214                return Collections2.transform(calls, new Function<MutableResolvedCall<FunctionDescriptor>, MutableResolvedCall<FunctionDescriptor>>() {
215                    @Override
216                    public MutableResolvedCall<FunctionDescriptor> apply(MutableResolvedCall<FunctionDescriptor> functionResolvedCall) {
217                        return new VariableAsFunctionResolvedCallImpl(functionResolvedCall, variableResolvedCall);
218                    }
219                });
220            }
221        };
222    
223        public static class CallForImplicitInvoke extends DelegatingCall {
224            final Call outerCall;
225            final ReceiverValue explicitExtensionReceiver;
226            final ExpressionReceiver calleeExpressionAsThisObject;
227            final JetSimpleNameExpression fakeInvokeExpression;
228    
229            public CallForImplicitInvoke(
230                    @NotNull ReceiverValue explicitExtensionReceiver,
231                    @NotNull ExpressionReceiver calleeExpressionAsThisObject,
232                    @NotNull Call call
233            ) {
234                super(call);
235                this.outerCall = call;
236                this.explicitExtensionReceiver = explicitExtensionReceiver;
237                this.calleeExpressionAsThisObject = calleeExpressionAsThisObject;
238                this.fakeInvokeExpression = (JetSimpleNameExpression) JetPsiFactory.createExpression(call.getCallElement().getProject(), "invoke");
239            }
240    
241            @NotNull
242            @Override
243            public ReceiverValue getExplicitReceiver() {
244                return explicitExtensionReceiver;
245            }
246    
247            @NotNull
248            @Override
249            public ReceiverValue getThisObject() {
250                return calleeExpressionAsThisObject;
251            }
252    
253            @Override
254            public JetExpression getCalleeExpression() {
255                return fakeInvokeExpression;
256            }
257    
258            @NotNull
259            @Override
260            public JetElement getCallElement() {
261                return outerCall.getCallElement();
262            }
263    
264            @NotNull
265            @Override
266            public CallType getCallType() {
267                return CallType.INVOKE;
268            }
269    
270            @NotNull
271            public Call getOuterCall() {
272                return outerCall;
273            }
274        }
275    }