// Copyright 2014 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.buildtool;

import com.google.devtools.build.lib.packages.Target;
import com.google.devtools.build.lib.pkgcache.LoadingFailedException;

import java.util.Collection;

/**
 * Validator for targets.
 *
 * <p>Used in "blaze run" to make sure that we are building exactly one binary target.
 */
public interface TargetValidator {

  /**
   * Hook for subclasses to validate a build request before building begins.
   * Implementors should print warnings for invalid targets iff keepGoing.
   *
   * @param targets The targets to build.
   * @throws LoadingFailedException if the request is not valid for some reason.
   */
  void validateTargets(Collection<Target> targets, boolean keepGoing)
      throws LoadingFailedException;
}
