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.resolve;
018    
019    import com.google.common.collect.Sets;
020    import com.intellij.openapi.util.Pair;
021    import com.intellij.util.containers.MultiMap;
022    import org.jetbrains.annotations.NotNull;
023    import org.jetbrains.kotlin.descriptors.*;
024    import org.jetbrains.kotlin.diagnostics.Errors;
025    import org.jetbrains.kotlin.name.FqNameUnsafe;
026    import org.jetbrains.kotlin.name.Name;
027    import org.jetbrains.kotlin.psi.JetClassOrObject;
028    import org.jetbrains.kotlin.psi.JetDeclaration;
029    import org.jetbrains.kotlin.psi.JetObjectDeclaration;
030    import org.jetbrains.kotlin.psi.JetSecondaryConstructor;
031    
032    import java.util.Collection;
033    import java.util.Map;
034    import java.util.Set;
035    
036    import static org.jetbrains.kotlin.resolve.DescriptorUtils.getFqName;
037    
038    public class OverloadResolver {
039        @NotNull private final BindingTrace trace;
040    
041        public OverloadResolver(@NotNull BindingTrace trace) {
042            this.trace = trace;
043        }
044    
045        public void process(@NotNull BodiesResolveContext c) {
046            checkOverloads(c);
047        }
048    
049        private void checkOverloads(@NotNull BodiesResolveContext c) {
050            MultiMap<ClassDescriptor, ConstructorDescriptor> inClasses = MultiMap.create();
051            MultiMap<FqNameUnsafe, ConstructorDescriptor> inPackages = MultiMap.create();
052            fillGroupedConstructors(c, inClasses, inPackages);
053    
054            for (Map.Entry<JetClassOrObject, ClassDescriptorWithResolutionScopes> entry : c.getDeclaredClasses().entrySet()) {
055                checkOverloadsInAClass(entry.getValue(), entry.getKey(), inClasses.get(entry.getValue()));
056            }
057            checkOverloadsInPackages(c, inPackages);
058        }
059    
060        private static void fillGroupedConstructors(
061                @NotNull BodiesResolveContext c,
062                @NotNull MultiMap<ClassDescriptor, ConstructorDescriptor> inClasses,
063                @NotNull MultiMap<FqNameUnsafe, ConstructorDescriptor> inPackages
064        ) {
065            for (ClassDescriptorWithResolutionScopes klass : c.getDeclaredClasses().values()) {
066                if (klass.getKind().isSingleton() || klass.getName().isSpecial()) {
067                    // Constructors of singletons or anonymous object aren't callable from the code, so they shouldn't participate in overload name checking
068                    continue;
069                }
070                DeclarationDescriptor containingDeclaration = klass.getContainingDeclaration();
071                if (containingDeclaration instanceof ClassDescriptor) {
072                    ClassDescriptor classDescriptor = (ClassDescriptor) containingDeclaration;
073                    inClasses.putValues(classDescriptor, klass.getConstructors());
074                }
075                else if (containingDeclaration instanceof PackageFragmentDescriptor) {
076                    inPackages.putValues(getFqName(klass), klass.getConstructors());
077                }
078                else if (containingDeclaration instanceof ScriptDescriptor) {
079                    // TODO: check overload conflicts of functions with constructors in scripts
080                }
081                else if (!(containingDeclaration instanceof FunctionDescriptor)) {
082                    throw new IllegalStateException("Illegal class container: " + containingDeclaration);
083                }
084            }
085        }
086    
087        private void checkOverloadsInPackages(
088                @NotNull BodiesResolveContext c,
089                @NotNull MultiMap<FqNameUnsafe, ConstructorDescriptor> inPackages
090        ) {
091    
092            MultiMap<FqNameUnsafe, CallableMemberDescriptor> functionsByName = MultiMap.create();
093    
094            for (SimpleFunctionDescriptor function : c.getFunctions().values()) {
095                if (function.getContainingDeclaration() instanceof PackageFragmentDescriptor) {
096                    functionsByName.putValue(getFqName(function), function);
097                }
098            }
099            
100            for (PropertyDescriptor property : c.getProperties().values()) {
101                if (property.getContainingDeclaration() instanceof PackageFragmentDescriptor) {
102                    functionsByName.putValue(getFqName(property), property);
103                }
104            }
105            
106            for (Map.Entry<FqNameUnsafe, Collection<ConstructorDescriptor>> entry : inPackages.entrySet()) {
107                functionsByName.putValues(entry.getKey(), entry.getValue());
108            }
109    
110            for (Map.Entry<FqNameUnsafe, Collection<CallableMemberDescriptor>> e : functionsByName.entrySet()) {
111                // TODO: don't render FQ name here, extract this logic to somewhere
112                FqNameUnsafe fqName = e.getKey().parent();
113                checkOverloadsWithSameName(e.getValue(), fqName.isRoot() ? "root package" : fqName.asString());
114            }
115        }
116    
117        private static String nameForErrorMessage(ClassDescriptor classDescriptor, JetClassOrObject jetClass) {
118            String name = jetClass.getName();
119            if (name != null) {
120                return name;
121            }
122            if (jetClass instanceof JetObjectDeclaration) {
123                // must be companion object
124                name = classDescriptor.getContainingDeclaration().getName().asString();
125                return "companion object " + name;
126            }
127            // safe
128            return "<unknown>";
129        }
130    
131        private void checkOverloadsInAClass(
132                ClassDescriptorWithResolutionScopes classDescriptor, JetClassOrObject klass,
133                Collection<ConstructorDescriptor> nestedClassConstructors
134        ) {
135            MultiMap<Name, CallableMemberDescriptor> functionsByName = MultiMap.create();
136            
137            for (CallableMemberDescriptor function : classDescriptor.getDeclaredCallableMembers()) {
138                functionsByName.putValue(function.getName(), function);
139            }
140            
141            for (ConstructorDescriptor nestedClassConstructor : nestedClassConstructors) {
142                functionsByName.putValue(nestedClassConstructor.getContainingDeclaration().getName(), nestedClassConstructor);
143            }
144            
145            for (Map.Entry<Name, Collection<CallableMemberDescriptor>> e : functionsByName.entrySet()) {
146                checkOverloadsWithSameName(e.getValue(), nameForErrorMessage(classDescriptor, klass));
147            }
148        }
149        
150        private void checkOverloadsWithSameName(
151                Collection<CallableMemberDescriptor> functions,
152                @NotNull String functionContainer
153        ) {
154            if (functions.size() == 1) {
155                // micro-optimization
156                return;
157            }
158            reportRedeclarations(functionContainer, findRedeclarations(functions));
159        }
160    
161        @NotNull
162        private Set<Pair<JetDeclaration, CallableMemberDescriptor>> findRedeclarations(@NotNull Collection<CallableMemberDescriptor> functions) {
163            Set<Pair<JetDeclaration, CallableMemberDescriptor>> redeclarations = Sets.newLinkedHashSet();
164            for (CallableMemberDescriptor member : functions) {
165                for (CallableMemberDescriptor member2 : functions) {
166                    if (member == member2 || isConstructorsOfDifferentRedeclaredClasses(member, member2)) {
167                        continue;
168                    }
169    
170                    OverloadUtil.OverloadCompatibilityInfo overloadable = OverloadUtil.isOverloadable(member, member2);
171                    if (!overloadable.isSuccess() && member.getKind() != CallableMemberDescriptor.Kind.SYNTHESIZED) {
172                        JetDeclaration jetDeclaration = (JetDeclaration) DescriptorToSourceUtils.descriptorToDeclaration(member);
173                        if (jetDeclaration != null) {
174                            redeclarations.add(Pair.create(jetDeclaration, member));
175                        }
176                    }
177                }
178            }
179            return redeclarations;
180        }
181    
182        private static boolean isConstructorsOfDifferentRedeclaredClasses(
183                @NotNull CallableMemberDescriptor member, @NotNull CallableMemberDescriptor member2
184        ) {
185            if (!(member instanceof ConstructorDescriptor) || !(member2 instanceof ConstructorDescriptor)) return false;
186            // ignore conflicting overloads for constructors of different classes because their redeclarations will be reported
187            // but don't ignore if there's possibility that classes redeclarations will not be reported
188            // (e.g. they're declared in different packages)
189            assert member.getContainingDeclaration().getContainingDeclaration() != null : "Grandparent of constructor should not be null";
190            return member.getContainingDeclaration() != member2.getContainingDeclaration() &&
191                   member.getContainingDeclaration().getContainingDeclaration().equals(member2.getContainingDeclaration().getContainingDeclaration());
192        }
193    
194        private void reportRedeclarations(@NotNull String functionContainer,
195                @NotNull Set<Pair<JetDeclaration, CallableMemberDescriptor>> redeclarations) {
196            for (Pair<JetDeclaration, CallableMemberDescriptor> redeclaration : redeclarations) {
197                CallableMemberDescriptor memberDescriptor = redeclaration.getSecond();
198                JetDeclaration jetDeclaration = redeclaration.getFirst();
199                if (memberDescriptor instanceof PropertyDescriptor) {
200                    trace.report(Errors.REDECLARATION.on(jetDeclaration, memberDescriptor.getName().asString()));
201                }
202                else {
203                    String containingClassName = jetDeclaration instanceof JetSecondaryConstructor ?
204                                                   ((JetSecondaryConstructor) jetDeclaration).getContainingClassOrObject().getName() : null;
205    
206                    trace.report(Errors.CONFLICTING_OVERLOADS.on(
207                            jetDeclaration, memberDescriptor,
208                            containingClassName != null ? containingClassName : functionContainer));
209                }
210            }
211        }
212    }