// Copyright 2016 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.lib.causes;

import com.google.devtools.build.lib.buildeventstream.BuildEventStreamProtos;
import com.google.devtools.build.lib.cmdline.Label;
import com.google.devtools.build.lib.util.DetailedExitCode;
import javax.annotation.Nullable;

/**
 * Interface for classes identifying root causes for a target to fail to build.
 */
public interface Cause {

  /** Return the label associated with the failure. */
  Label getLabel();

  /** Return the event id for the cause in the format of the build event protocol. */
  BuildEventStreamProtos.BuildEventId getIdProto();

  @Nullable // TODO(janakr): override for all callers and make never null.
  default DetailedExitCode getDetailedExitCode() {
    return null;
  }
}