src/main/java/com/google/devtools/build/lib/packages/ExecGroup.java

// Copyright 2020 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.packages;

import com.google.auto.value.AutoValue;
import com.google.common.annotations.VisibleForTesting;
import com.google.common.collect.ImmutableSet;
import com.google.devtools.build.lib.cmdline.Label;
import com.google.devtools.build.lib.starlarkbuildapi.ExecGroupApi;
import java.util.Set;

/** Resolves the appropriate toolchains for the given parameters. */
@AutoValue
public abstract class ExecGroup implements ExecGroupApi {

  // An exec group that inherits requirements from the rule.
  public static final ExecGroup COPY_FROM_RULE_EXEC_GROUP =
      createCopied(ImmutableSet.of(), ImmutableSet.of());

  // This is intentionally a string that would fail {@code Identifier.isValid} so that
  // users can't create a group with the same name.
  @VisibleForTesting public static final String DEFAULT_EXEC_GROUP_NAME = "default-exec-group";

  // Create an exec group that is marked as copying from the rule.
  public static ExecGroup createCopied(
      Set<Label> requiredToolchains, Set<Label> execCompatibleWith) {
    return create(requiredToolchains, execCompatibleWith, /* copyFromRule= */ true);
  }

  // Create an exec group.
  public static ExecGroup create(Set<Label> requiredToolchains, Set<Label> execCompatibleWith) {
    return create(requiredToolchains, execCompatibleWith, /* copyFromRule= */ false);
  }

  private static ExecGroup create(
      Set<Label> requiredToolchains, Set<Label> execCompatibleWith, boolean copyFromRule) {
    return new AutoValue_ExecGroup(
        ImmutableSet.copyOf(requiredToolchains),
        ImmutableSet.copyOf(execCompatibleWith),
        copyFromRule);
  }

  public abstract ImmutableSet<Label> requiredToolchains();

  public abstract ImmutableSet<Label> execCompatibleWith();

  public abstract boolean copyFromRule();
}