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.autocasts;
018    
019    import org.jetbrains.annotations.NotNull;
020    import org.jetbrains.jet.lang.resolve.BindingContext;
021    import org.jetbrains.jet.lang.resolve.BindingTrace;
022    import org.jetbrains.jet.lang.resolve.scopes.receivers.ExpressionReceiver;
023    import org.jetbrains.jet.lang.resolve.scopes.receivers.ReceiverValue;
024    import org.jetbrains.jet.lang.resolve.scopes.receivers.ThisReceiver;
025    import org.jetbrains.jet.lang.types.JetType;
026    
027    import java.util.ArrayList;
028    import java.util.Collections;
029    import java.util.List;
030    import java.util.Set;
031    
032    import static org.jetbrains.jet.lang.diagnostics.Errors.AUTOCAST_IMPOSSIBLE;
033    import static org.jetbrains.jet.lang.resolve.BindingContext.AUTOCAST;
034    import static org.jetbrains.jet.lang.resolve.BindingContext.EXPRESSION_TYPE;
035    
036    public class AutoCastUtils {
037    
038        private AutoCastUtils() {}
039    
040        /**
041         * @return variants @param receiverToCast may be cast to according to @param dataFlowInfo, @param receiverToCast itself is NOT included
042         */
043        @NotNull
044        public static List<ReceiverValue> getAutoCastVariants(
045                @NotNull BindingContext bindingContext,
046                @NotNull DataFlowInfo dataFlowInfo,
047                @NotNull ReceiverValue receiverToCast
048        ) {
049            if (receiverToCast instanceof ThisReceiver) {
050                ThisReceiver receiver = (ThisReceiver) receiverToCast;
051                assert receiver.exists();
052                DataFlowValue dataFlowValue = DataFlowValueFactory.createDataFlowValue(receiver);
053                return collectAutoCastReceiverValues(dataFlowInfo, receiver, dataFlowValue);
054            }
055            else if (receiverToCast instanceof ExpressionReceiver) {
056                ExpressionReceiver receiver = (ExpressionReceiver) receiverToCast;
057                DataFlowValue dataFlowValue =
058                        DataFlowValueFactory.createDataFlowValue(receiver.getExpression(), receiver.getType(), bindingContext);
059                return collectAutoCastReceiverValues(dataFlowInfo, receiver, dataFlowValue);
060            }
061            else if (receiverToCast instanceof AutoCastReceiver) {
062                return getAutoCastVariants(bindingContext, dataFlowInfo, ((AutoCastReceiver) receiverToCast).getOriginal());
063            }
064            return Collections.emptyList();
065        }
066    
067        @NotNull
068        private static List<ReceiverValue> collectAutoCastReceiverValues(
069                @NotNull DataFlowInfo dataFlowInfo,
070                @NotNull ReceiverValue receiver,
071                @NotNull DataFlowValue dataFlowValue
072        ) {
073            Set<JetType> possibleTypes = dataFlowInfo.getPossibleTypes(dataFlowValue);
074            List<ReceiverValue> result = new ArrayList<ReceiverValue>(possibleTypes.size());
075            for (JetType possibleType : possibleTypes) {
076                result.add(new AutoCastReceiver(receiver, possibleType, dataFlowValue.isStableIdentifier()));
077            }
078            return result;
079        }
080    
081        public static void recordAutoCastIfNecessary(ReceiverValue receiver, @NotNull BindingTrace trace) {
082            if (receiver instanceof AutoCastReceiver) {
083                AutoCastReceiver autoCastReceiver = (AutoCastReceiver) receiver;
084                ReceiverValue original = autoCastReceiver.getOriginal();
085                if (original instanceof ExpressionReceiver) {
086                    ExpressionReceiver expressionReceiver = (ExpressionReceiver) original;
087                    if (autoCastReceiver.canCast()) {
088                        trace.record(AUTOCAST, expressionReceiver.getExpression(), autoCastReceiver.getType());
089                        trace.record(EXPRESSION_TYPE, expressionReceiver.getExpression(), autoCastReceiver.getType());
090                    }
091                    else {
092                        trace.report(AUTOCAST_IMPOSSIBLE.on(expressionReceiver.getExpression(), autoCastReceiver.getType(), expressionReceiver.getExpression().getText()));
093                    }
094                }
095                else {
096                    assert autoCastReceiver.canCast() : "A non-expression receiver must always be autocastabe: " + original;
097                }
098            }
099        }
100    }