src/keepanno/java/com/android/tools/r8/keepanno/ast/KeepAnnotationPattern.java

// Copyright (c) 2024, 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.keepanno.ast;

import com.android.tools.r8.keepanno.proto.KeepSpecProtos.AnnotationPattern;
import com.android.tools.r8.keepanno.proto.KeepSpecProtos.AnnotationRetention;
import java.lang.annotation.RetentionPolicy;
import java.util.Objects;

public class KeepAnnotationPattern {

  private static final int RUNTIME_RETENTION_MASK = 0x1;
  private static final int CLASS_RETENTION_MASK = 0x2;
  private static final int ANY_RETENTION_MASK = 0x3;

  private static final KeepAnnotationPattern ANY_WITH_ANY_RETENTION =
      new KeepAnnotationPattern(KeepQualifiedClassNamePattern.any(), ANY_RETENTION_MASK);

  private static final KeepAnnotationPattern ANY_WITH_RUNTIME_RETENTION =
      new KeepAnnotationPattern(KeepQualifiedClassNamePattern.any(), RUNTIME_RETENTION_MASK);

  private static final KeepAnnotationPattern ANY_WITH_CLASS_RETENTION =
      new KeepAnnotationPattern(KeepQualifiedClassNamePattern.any(), CLASS_RETENTION_MASK);

  public static KeepAnnotationPattern any() {
    return KeepAnnotationPattern.ANY_WITH_ANY_RETENTION;
  }

  public static KeepAnnotationPattern anyWithRuntimeRetention() {
    return KeepAnnotationPattern.ANY_WITH_RUNTIME_RETENTION;
  }

  public static KeepAnnotationPattern anyWithClassRetention() {
    return KeepAnnotationPattern.ANY_WITH_CLASS_RETENTION;
  }

  public static Builder builder() {
    return new Builder();
  }

  public static KeepAnnotationPattern fromProto(AnnotationPattern proto) {
    return builder().applyProto(proto).build();
  }

  public AnnotationPattern.Builder buildProto() {
    AnnotationPattern.Builder builder = AnnotationPattern.newBuilder();
    namePattern.buildProtoIfNotAny(builder::setName);
    if (retentionPolicies == RUNTIME_RETENTION_MASK) {
      builder.setRetention(AnnotationRetention.RETENTION_RUNTIME);
    } else if (retentionPolicies == CLASS_RETENTION_MASK) {
      builder.setRetention(AnnotationRetention.RETENTION_CLASS);
    }
    return builder;
  }

  public static class Builder {

    private KeepQualifiedClassNamePattern namePattern = KeepQualifiedClassNamePattern.any();
    private int retentionPolicies = 0x0;

    private Builder() {}

    public Builder applyProto(AnnotationPattern proto) {
      assert namePattern.isAny();
      if (proto.hasName()) {
        setNamePattern(KeepQualifiedClassNamePattern.fromProto(proto.getName()));
      }
      // The builder is configured to check that retention is set.
      // Thus, we apply the default case here explicitly.
      assert retentionPolicies != ANY_RETENTION_MASK;
      retentionPolicies = ANY_RETENTION_MASK;
      if (proto.hasRetention()) {
        switch (proto.getRetention().getNumber()) {
          case AnnotationRetention.RETENTION_RUNTIME_VALUE:
            retentionPolicies = RUNTIME_RETENTION_MASK;
            break;
          case AnnotationRetention.RETENTION_CLASS_VALUE:
            retentionPolicies = CLASS_RETENTION_MASK;
            break;
          default:
            // default any applies.
            assert retentionPolicies == ANY_RETENTION_MASK;
        }
      }
      return this;
    }

    public Builder setNamePattern(KeepQualifiedClassNamePattern namePattern) {
      this.namePattern = namePattern;
      return this;
    }

    public Builder addRetentionPolicy(RetentionPolicy policy) {
      switch (policy) {
        case RUNTIME:
          retentionPolicies |= RUNTIME_RETENTION_MASK;
          break;
        case CLASS:
          retentionPolicies |= CLASS_RETENTION_MASK;
          break;
        case SOURCE:
          throw new KeepEdgeException("Retention policy SOURCE cannot be used in patterns");
        default:
          throw new KeepEdgeException("Invalid policy: " + policy);
      }
      return this;
    }

    public KeepAnnotationPattern build() {
      if (retentionPolicies == 0x0) {
        throw new KeepEdgeException("Invalid empty retention policy");
      }
      if (namePattern.isAny()) {
        switch (retentionPolicies) {
          case RUNTIME_RETENTION_MASK:
            return ANY_WITH_RUNTIME_RETENTION;
          case CLASS_RETENTION_MASK:
            return ANY_WITH_CLASS_RETENTION;
          case ANY_RETENTION_MASK:
            return ANY_WITH_ANY_RETENTION;
          default:
            throw new KeepEdgeException("Invalid retention policy value: " + retentionPolicies);
        }
      }
      return new KeepAnnotationPattern(namePattern, retentionPolicies);
    }
  }

  private final KeepQualifiedClassNamePattern namePattern;
  private final int retentionPolicies;

  private KeepAnnotationPattern(KeepQualifiedClassNamePattern namePattern, int retentionPolicies) {
    assert namePattern != null;
    this.namePattern = namePattern;
    this.retentionPolicies = retentionPolicies;
  }

  public boolean isAny() {
    return this == ANY_WITH_ANY_RETENTION;
  }

  public boolean isAnyWithRuntimeRetention() {
    return this == ANY_WITH_RUNTIME_RETENTION;
  }

  public boolean isAnyWithClassRetention() {
    return this == ANY_WITH_CLASS_RETENTION;
  }

  public KeepQualifiedClassNamePattern getNamePattern() {
    return namePattern;
  }

  public boolean includesRuntimeRetention() {
    return (retentionPolicies & RUNTIME_RETENTION_MASK) > 0;
  }

  public boolean includesClassRetention() {
    return (retentionPolicies & CLASS_RETENTION_MASK) > 0;
  }

  @Override
  public boolean equals(Object o) {
    if (this == o) {
      return true;
    }
    if (!(o instanceof KeepAnnotationPattern)) {
      return false;
    }
    KeepAnnotationPattern that = (KeepAnnotationPattern) o;
    return retentionPolicies == that.retentionPolicies && namePattern.equals(that.namePattern);
  }

  @Override
  public int hashCode() {
    return Objects.hash(namePattern, retentionPolicies);
  }
}