com.google.devtools.build.lib.rules.platform.ConstraintValue.java Source code

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Here is the source code for com.google.devtools.build.lib.rules.platform.ConstraintValue.java

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// Copyright 2017 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.rules.platform;

import com.google.common.base.Function;
import com.google.common.collect.Iterables;
import com.google.devtools.build.lib.analysis.ConfiguredTarget;
import com.google.devtools.build.lib.analysis.FileProvider;
import com.google.devtools.build.lib.analysis.FilesToRunProvider;
import com.google.devtools.build.lib.analysis.RuleConfiguredTarget.Mode;
import com.google.devtools.build.lib.analysis.RuleConfiguredTargetBuilder;
import com.google.devtools.build.lib.analysis.RuleContext;
import com.google.devtools.build.lib.analysis.RunfilesProvider;
import com.google.devtools.build.lib.analysis.TransitiveInfoCollection;
import com.google.devtools.build.lib.analysis.platform.ConstraintSettingInfo;
import com.google.devtools.build.lib.analysis.platform.ConstraintValueInfo;
import com.google.devtools.build.lib.rules.RuleConfiguredTargetFactory;
import com.google.devtools.build.lib.util.Preconditions;

/** Defines a potential value of a constraint. */
public class ConstraintValue implements RuleConfiguredTargetFactory {

    @Override
    public ConfiguredTarget create(RuleContext ruleContext) throws InterruptedException, RuleErrorException {

        ConstraintSettingInfo constraint = ConstraintSetting.constraintSetting(
                ruleContext.getPrerequisite(ConstraintValueRule.CONSTRAINT_SETTING_ATTR, Mode.DONT_CHECK));

        return new RuleConfiguredTargetBuilder(ruleContext)
                .addProvider(RunfilesProvider.class, RunfilesProvider.EMPTY)
                .addProvider(FileProvider.class, FileProvider.EMPTY)
                .addProvider(FilesToRunProvider.class, FilesToRunProvider.EMPTY)
                .addNativeDeclaredProvider(ConstraintValueInfo.create(constraint, ruleContext.getLabel())).build();
    }

    /** Retrieves and casts the provider from the given target. */
    public static ConstraintValueInfo constraintValue(TransitiveInfoCollection target) {
        Object provider = target.get(ConstraintValueInfo.SKYLARK_IDENTIFIER);
        if (provider == null) {
            return null;
        }
        Preconditions.checkState(provider instanceof ConstraintValueInfo);
        return (ConstraintValueInfo) provider;
    }

    /** Retrieves and casts the providers from the given targets. */
    public static Iterable<ConstraintValueInfo> constraintValues(
            Iterable<? extends TransitiveInfoCollection> targets) {
        return Iterables.transform(targets, new Function<TransitiveInfoCollection, ConstraintValueInfo>() {
            @Override
            public ConstraintValueInfo apply(TransitiveInfoCollection target) {
                return constraintValue(target);
            }
        });
    }
}