src/tools/android/java/com/google/devtools/build/android/desugar/nest/ClassMemberRecord.java

// Copyright 2019 The Bazel Authors. All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//    http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package com.google.devtools.build.android.desugar.nest;

import static com.google.common.collect.ImmutableList.toImmutableList;

import com.google.common.collect.ImmutableList;
import com.google.devtools.build.android.desugar.nest.ClassMemberTrackReason.MemberUseKind;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.function.Predicate;

/**
 * A record that tracks the declarations and usages of a class member, including fields,
 * constructors and methods.
 */
public final class ClassMemberRecord {

  /** Tracks a class member with a reason. */
  private final Map<ClassMemberKey, ClassMemberTrackReason> reasons;

  /** The factory method of this class. */
  public static ClassMemberRecord create() {
    return new ClassMemberRecord(new LinkedHashMap<>());
  }

  /** Gets class members with both tracked declarations and tracked usage. */
  boolean filterUsedMemberWithTrackedDeclaration() {
    return reasons
        .values()
        .removeIf(
            reason -> {
              // keep interface members and class members with use references.
              return !(reason.hasInterfaceDeclReason()
                  || (reason.hasDeclReason() && reason.hasMemberUseReason()));
            });
  }

  private ClassMemberRecord(Map<ClassMemberKey, ClassMemberTrackReason> reasons) {
    this.reasons = reasons;
  }

  /** Find all member keys based on the given member key predicate. */
  ImmutableList<ClassMemberKey> findAllMatchedMemberKeys(Predicate<ClassMemberKey> predicate) {
    return reasons.keySet().stream().filter(predicate).collect(toImmutableList());
  }

  boolean hasTrackingReason(ClassMemberKey classMemberKey) {
    return reasons.containsKey(classMemberKey);
  }

  /** Find the original access code for the owner of the class member. */
  int findOwnerAccessCode(ClassMemberKey memberKey) {
    if (reasons.containsKey(memberKey)) {
      return reasons.get(memberKey).getOwnerAccess();
    }
    throw new IllegalStateException(String.format("ClassMemberKey Not Found: %s", memberKey));
  }

  /** Find the original access code for the class member declaration. */
  int findMemberAccessCode(ClassMemberKey memberKey) {
    if (reasons.containsKey(memberKey)) {
      return reasons.get(memberKey).getMemberAccess();
    }
    throw new IllegalStateException(String.format("ClassMemberKey Not Found: %s", memberKey));
  }

  /** Find all invocation codes of a class member. */
  ImmutableList<MemberUseKind> findAllMemberUseKind(ClassMemberKey memberKey) {
    if (reasons.containsKey(memberKey)) {
      return ImmutableList.copyOf(reasons.get(memberKey).getUseAccesses());
    }
    return ImmutableList.of();
  }

  /** Logs the declaration of a class member. */
  ClassMemberTrackReason logMemberDecl(
      ClassMemberKey memberKey, int ownerAccess, int memberDeclAccess) {
    return reasons
        .computeIfAbsent(memberKey, classMemberKey -> new ClassMemberTrackReason())
        .setDeclAccess(ownerAccess, memberDeclAccess);
  }

  /** Logs the use of a class member, including field access and method invocations. */
  ClassMemberTrackReason logMemberUse(ClassMemberKey memberKey, int invokeOpcode) {
    return reasons
        .computeIfAbsent(memberKey, classMemberKey -> new ClassMemberTrackReason())
        .addUseAccess(invokeOpcode);
  }
}