| // Copyright (c) 2020, the R8 project authors. Please see the AUTHORS file |
| // for details. All rights reserved. Use of this source code is governed by a |
| // BSD-style license that can be found in the LICENSE file. |
| |
| package com.android.tools.r8.horizontalclassmerging.policies; |
| |
| import com.android.tools.r8.graph.AppView; |
| import com.android.tools.r8.graph.DexEncodedMethod; |
| import com.android.tools.r8.graph.DexProgramClass; |
| import com.android.tools.r8.horizontalclassmerging.HorizontalClassMerger.Mode; |
| import com.android.tools.r8.horizontalclassmerging.MergeGroup; |
| import com.android.tools.r8.horizontalclassmerging.MultiClassPolicy; |
| import com.android.tools.r8.utils.InternalOptions; |
| import com.android.tools.r8.utils.ListUtils; |
| import com.android.tools.r8.utils.collections.DexMethodSignatureSet; |
| import com.google.common.collect.Lists; |
| import java.util.Collection; |
| import java.util.LinkedHashMap; |
| import java.util.Map; |
| import java.util.Map.Entry; |
| |
| /** |
| * For interfaces, we cannot introduce an instance field `int $r8$classId`. Therefore, we can't |
| * merge two interfaces that declare the same default interface method. |
| * |
| * <p>This policy attempts to split a merge group consisting of interfaces into smaller merge groups |
| * such that each pairs of interfaces in each merge group does not have conflicting default |
| * interface methods. |
| */ |
| public class NoDefaultInterfaceMethodMerging extends MultiClassPolicy { |
| |
| private final Mode mode; |
| private final InternalOptions options; |
| |
| public NoDefaultInterfaceMethodMerging(AppView<?> appView, Mode mode) { |
| this.mode = mode; |
| this.options = appView.options(); |
| } |
| |
| @Override |
| public Collection<MergeGroup> apply(MergeGroup group) { |
| if (!group.isInterfaceGroup()) { |
| return ListUtils.newLinkedList(group); |
| } |
| |
| // Split the group into smaller groups such that no default methods collide. |
| Map<MergeGroup, DexMethodSignatureSet> newGroups = new LinkedHashMap<>(); |
| for (DexProgramClass clazz : group) { |
| addClassToGroup(clazz, newGroups); |
| } |
| |
| return removeTrivialGroups(Lists.newLinkedList(newGroups.keySet())); |
| } |
| |
| private void addClassToGroup( |
| DexProgramClass clazz, Map<MergeGroup, DexMethodSignatureSet> newGroups) { |
| DexMethodSignatureSet classSignatures = DexMethodSignatureSet.create(); |
| classSignatures.addAllMethods(clazz.virtualMethods(DexEncodedMethod::isDefaultMethod)); |
| |
| // Find a group that does not have any collisions with `clazz`. |
| for (Entry<MergeGroup, DexMethodSignatureSet> entry : newGroups.entrySet()) { |
| MergeGroup group = entry.getKey(); |
| DexMethodSignatureSet groupSignatures = entry.getValue(); |
| if (!groupSignatures.containsAnyOf(classSignatures)) { |
| groupSignatures.addAll(classSignatures); |
| group.add(clazz); |
| return; |
| } |
| } |
| |
| // Else create a new group. |
| newGroups.put(new MergeGroup(clazz), classSignatures); |
| } |
| |
| @Override |
| public String getName() { |
| return "NoDefaultInterfaceMethodMerging"; |
| } |
| |
| @Override |
| public boolean shouldSkipPolicy() { |
| return !options.horizontalClassMergerOptions().isInterfaceMergingEnabled(mode); |
| } |
| } |