| // 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 static com.android.tools.r8.utils.IteratorUtils.createCircularIterator; |
| |
| import com.android.tools.r8.graph.DexProgramClass; |
| import com.android.tools.r8.horizontalclassmerging.MergeGroup; |
| import com.android.tools.r8.horizontalclassmerging.MultiClassPolicy; |
| import com.google.common.collect.ImmutableList; |
| import java.util.Collection; |
| import java.util.Iterator; |
| import java.util.LinkedList; |
| import java.util.List; |
| |
| public abstract class AtMostOneClassThatMatchesPolicy extends MultiClassPolicy { |
| |
| // TODO(b/270398965): Replace LinkedList. |
| @SuppressWarnings("JdkObsolete") |
| @Override |
| public Collection<MergeGroup> apply(MergeGroup group) { |
| // Create a new merge group for each class that we want at most one of. |
| List<MergeGroup> newGroups = new LinkedList<>(); |
| for (DexProgramClass clazz : group) { |
| if (atMostOneOf(clazz)) { |
| newGroups.add(new MergeGroup(clazz)); |
| } |
| } |
| |
| // If there were at most one class with that we could have at most one of, then just return the |
| // original merge group. |
| if (newGroups.size() <= 1) { |
| return ImmutableList.of(group); |
| } |
| |
| // Otherwise, fill up the new merge groups with the remaining classes. |
| Iterator<MergeGroup> newGroupsIterator = createCircularIterator(newGroups); |
| for (DexProgramClass clazz : group) { |
| if (!atMostOneOf(clazz)) { |
| newGroupsIterator.next().add(clazz); |
| } |
| } |
| return removeTrivialGroups(newGroups); |
| } |
| |
| abstract boolean atMostOneOf(DexProgramClass clazz); |
| } |