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 kotlin.Pair;
020 import org.jetbrains.annotations.NotNull;
021 import org.jetbrains.annotations.Nullable;
022 import org.jetbrains.kotlin.builtins.KotlinBuiltIns;
023 import org.jetbrains.kotlin.descriptors.FunctionDescriptor;
024 import org.jetbrains.kotlin.diagnostics.DiagnosticFactory1;
025 import org.jetbrains.kotlin.name.Name;
026 import org.jetbrains.kotlin.psi.Call;
027 import org.jetbrains.kotlin.psi.JetExpression;
028 import org.jetbrains.kotlin.resolve.calls.model.ResolvedCall;
029 import org.jetbrains.kotlin.resolve.calls.results.OverloadResolutionResults;
030 import org.jetbrains.kotlin.resolve.scopes.receivers.ExpressionReceiver;
031 import org.jetbrains.kotlin.resolve.scopes.receivers.TransientReceiver;
032 import org.jetbrains.kotlin.resolve.validation.SymbolUsageValidator;
033 import org.jetbrains.kotlin.types.JetType;
034 import org.jetbrains.kotlin.util.slicedMap.WritableSlice;
035
036 import java.util.Collections;
037
038 import static org.jetbrains.kotlin.diagnostics.Errors.*;
039 import static org.jetbrains.kotlin.resolve.BindingContext.*;
040
041 public class ForLoopConventionsChecker {
042
043 @NotNull private final KotlinBuiltIns builtIns;
044 @NotNull private final SymbolUsageValidator symbolUsageValidator;
045 @NotNull private final FakeCallResolver fakeCallResolver;
046
047 public ForLoopConventionsChecker(
048 @NotNull KotlinBuiltIns builtIns,
049 @NotNull FakeCallResolver fakeCallResolver,
050 @NotNull SymbolUsageValidator symbolUsageValidator
051 ) {
052 this.builtIns = builtIns;
053 this.fakeCallResolver = fakeCallResolver;
054 this.symbolUsageValidator = symbolUsageValidator;
055 }
056
057 @Nullable
058 public JetType checkIterableConvention(@NotNull ExpressionReceiver loopRange, ExpressionTypingContext context) {
059 JetExpression loopRangeExpression = loopRange.getExpression();
060
061 // Make a fake call loopRange.iterator(), and try to resolve it
062 Name iterator = Name.identifier("iterator");
063 Pair<Call, OverloadResolutionResults<FunctionDescriptor>> calls =
064 fakeCallResolver.makeAndResolveFakeCall(loopRange, context, Collections.<JetExpression>emptyList(), iterator,
065 loopRange.getExpression());
066 OverloadResolutionResults<FunctionDescriptor> iteratorResolutionResults = calls.getSecond();
067
068 if (iteratorResolutionResults.isSuccess()) {
069 ResolvedCall<FunctionDescriptor> iteratorResolvedCall = iteratorResolutionResults.getResultingCall();
070 context.trace.record(LOOP_RANGE_ITERATOR_RESOLVED_CALL, loopRangeExpression, iteratorResolvedCall);
071 FunctionDescriptor iteratorFunction = iteratorResolvedCall.getResultingDescriptor();
072
073 symbolUsageValidator.validateCall(iteratorFunction, context.trace, loopRangeExpression);
074
075 JetType iteratorType = iteratorFunction.getReturnType();
076 JetType hasNextType = checkConventionForIterator(context, loopRangeExpression, iteratorType, "hasNext",
077 HAS_NEXT_FUNCTION_AMBIGUITY, HAS_NEXT_MISSING, HAS_NEXT_FUNCTION_NONE_APPLICABLE,
078 LOOP_RANGE_HAS_NEXT_RESOLVED_CALL);
079 if (hasNextType != null && !builtIns.isBooleanOrSubtype(hasNextType)) {
080 context.trace.report(HAS_NEXT_FUNCTION_TYPE_MISMATCH.on(loopRangeExpression, hasNextType));
081 }
082 return checkConventionForIterator(context, loopRangeExpression, iteratorType, "next",
083 NEXT_AMBIGUITY, NEXT_MISSING, NEXT_NONE_APPLICABLE,
084 LOOP_RANGE_NEXT_RESOLVED_CALL);
085 }
086 else {
087 if (iteratorResolutionResults.isAmbiguity()) {
088 context.trace.report(ITERATOR_AMBIGUITY.on(loopRangeExpression, iteratorResolutionResults.getResultingCalls()));
089 }
090 else {
091 context.trace.report(ITERATOR_MISSING.on(loopRangeExpression));
092 }
093 }
094 return null;
095 }
096
097 @Nullable
098 private JetType checkConventionForIterator(
099 @NotNull ExpressionTypingContext context,
100 @NotNull JetExpression loopRangeExpression,
101 @NotNull JetType iteratorType,
102 @NotNull String name,
103 @NotNull DiagnosticFactory1<JetExpression, JetType> ambiguity,
104 @NotNull DiagnosticFactory1<JetExpression, JetType> missing,
105 @NotNull DiagnosticFactory1<JetExpression, JetType> noneApplicable,
106 @NotNull WritableSlice<JetExpression, ResolvedCall<FunctionDescriptor>> resolvedCallKey
107 ) {
108 OverloadResolutionResults<FunctionDescriptor> nextResolutionResults = fakeCallResolver.resolveFakeCall(
109 context, new TransientReceiver(iteratorType), Name.identifier(name), loopRangeExpression);
110 if (nextResolutionResults.isAmbiguity()) {
111 context.trace.report(ambiguity.on(loopRangeExpression, iteratorType));
112 }
113 else if (nextResolutionResults.isNothing()) {
114 context.trace.report(missing.on(loopRangeExpression, iteratorType));
115 }
116 else if (!nextResolutionResults.isSuccess()) {
117 context.trace.report(noneApplicable.on(loopRangeExpression, iteratorType));
118 }
119 else {
120 assert nextResolutionResults.isSuccess();
121 ResolvedCall<FunctionDescriptor> resolvedCall = nextResolutionResults.getResultingCall();
122 context.trace.record(resolvedCallKey, loopRangeExpression, resolvedCall);
123 FunctionDescriptor functionDescriptor = resolvedCall.getResultingDescriptor();
124 symbolUsageValidator.validateCall(functionDescriptor, context.trace, loopRangeExpression);
125 return functionDescriptor.getReturnType();
126 }
127 return null;
128 }
129 }