src/main/java/com/google/devtools/build/lib/analysis/SkylarkProviderValidationUtil.java

// Copyright 2015 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.analysis;

import com.google.common.base.Joiner;
import com.google.common.collect.ImmutableSet;
import com.google.common.collect.Iterables;
import com.google.devtools.build.lib.actions.Artifact;
import com.google.devtools.build.lib.syntax.EvalException;

/**
 * Utility class to validate results of executing Skylark rules and aspects.
 */
public class SkylarkProviderValidationUtil {
  public static void validateArtifacts(RuleContext ruleContext) throws EvalException {
    ImmutableSet<Artifact> treeArtifactsConflictingWithFiles =
        ruleContext.getAnalysisEnvironment().getTreeArtifactsConflictingWithFiles();
    if (!treeArtifactsConflictingWithFiles.isEmpty()) {
      throw new EvalException(
          null,
          "The following directories were also declared as files:\n"
              + artifactsDescription(treeArtifactsConflictingWithFiles));
    }

    ImmutableSet<Artifact> orphanArtifacts =
        ruleContext.getAnalysisEnvironment().getOrphanArtifacts();
    if (!orphanArtifacts.isEmpty()) {
      throw new EvalException(
          null,
          "The following files have no generating action:\n"
              + artifactsDescription(orphanArtifacts));
    }
  }

  private static String artifactsDescription(ImmutableSet<Artifact> artifacts) {
    return Joiner.on("\n")
        .join(Iterables.transform(artifacts, Artifact::getRootRelativePathString));
  }
}