com.google.devtools.build.lib.skyframe.ConfiguredTargetCycleReporter.java Source code

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Here is the source code for com.google.devtools.build.lib.skyframe.ConfiguredTargetCycleReporter.java

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// 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.skyframe;

import static com.google.devtools.build.lib.skyframe.SkyFunctions.TRANSITIVE_TARGET;

import com.google.common.base.Function;
import com.google.common.base.Predicate;
import com.google.common.base.Predicates;
import com.google.common.collect.Iterables;
import com.google.devtools.build.lib.cmdline.Label;
import com.google.devtools.build.lib.events.EventHandler;
import com.google.devtools.build.lib.pkgcache.PackageProvider;
import com.google.devtools.build.lib.skyframe.AspectValue.AspectKey;
import com.google.devtools.build.skyframe.CycleInfo;
import com.google.devtools.build.skyframe.SkyKey;

/**
 * Reports cycles between {@link ConfiguredTargetValue}s. Similar to
 * {@link TransitiveTargetCycleReporter}, these indicate cycles between targets, but during the
 * analysis phase. In the current target-parsing, loading, analysis, and execution phase
 * distinction, such cycles can only occur due to the presence of a specific configuration (if
 * such a cycle occurs regardless of the configuration, then it would have been caught during the
 * target parsing or loading phase).
 */
class ConfiguredTargetCycleReporter extends AbstractLabelCycleReporter {

    private static final Predicate<SkyKey> IS_CONFIGURED_TARGET_SKY_KEY = Predicates.or(
            SkyFunctions.isSkyFunction(SkyFunctions.CONFIGURED_TARGET),
            SkyFunctions.isSkyFunction(SkyFunctions.ASPECT));

    private static final Predicate<SkyKey> IS_TRANSITIVE_TARGET_SKY_KEY = SkyFunctions
            .isSkyFunction(TRANSITIVE_TARGET);

    private final TransitiveTargetCycleReporter targetReporter;

    ConfiguredTargetCycleReporter(PackageProvider packageProvider) {
        super(packageProvider);
        targetReporter = new TransitiveTargetCycleReporter(packageProvider);
    }

    @Override
    protected boolean canReportCycle(SkyKey topLevelKey, CycleInfo cycleInfo) {
        if (!IS_CONFIGURED_TARGET_SKY_KEY.apply(topLevelKey)) {
            return false;
        }
        Iterable<SkyKey> cycleKeys = Iterables.concat(cycleInfo.getPathToCycle(), cycleInfo.getCycle());
        // Static configurations expect all keys to be ConfiguredTargetValue keys. Dynamic
        // configurations expect the top-level key to be a ConfiguredTargetValue key, but cycles and
        // paths to them can travel through TransitiveTargetValue keys because ConfiguredTargetFunction
        // visits TransitiveTargetFunction as a part of dynamic configuration computation.
        //
        // Unfortunately this class can't easily figure out if we're in static or dynamic configuration
        // mode, so we loosely permit both cases.
        //
        // TODO: remove the static-style checking once dynamic configurations fully replace them
        return Iterables.all(cycleKeys,
                Predicates.<SkyKey>or(IS_CONFIGURED_TARGET_SKY_KEY, IS_TRANSITIVE_TARGET_SKY_KEY));
    }

    @Override
    protected String getAdditionalMessageAboutCycle(EventHandler eventHandler, SkyKey topLevelKey,
            CycleInfo cycleInfo) {
        if (Iterables.all(cycleInfo.getCycle(), IS_TRANSITIVE_TARGET_SKY_KEY)) {
            // The problem happened strictly in loading, so delegate the explanation to
            // TransitiveTargetCycleReporter.
            Iterable<SkyKey> pathAsTargetKeys = Iterables.transform(cycleInfo.getPathToCycle(),
                    new Function<SkyKey, SkyKey>() {
                        @Override
                        public SkyKey apply(SkyKey key) {
                            return asTransitiveTargetKey(key);
                        }
                    });
            return targetReporter.getAdditionalMessageAboutCycle(eventHandler, asTransitiveTargetKey(topLevelKey),
                    new CycleInfo(pathAsTargetKeys, cycleInfo.getCycle()));
        } else {
            return "\nThis cycle occurred because of a configuration option";
        }
    }

    private SkyKey asTransitiveTargetKey(SkyKey key) {
        return IS_TRANSITIVE_TARGET_SKY_KEY.apply(key) ? key
                : SkyKey.create(TRANSITIVE_TARGET, ((ConfiguredTargetKey) key.argument()).getLabel());
    }

    @Override
    public String prettyPrint(SkyKey key) {
        if (SkyFunctions.isSkyFunction(SkyFunctions.CONFIGURED_TARGET).apply(key)) {
            return ((ConfiguredTargetKey) key.argument()).prettyPrint();
        } else if (SkyFunctions.isSkyFunction(SkyFunctions.ASPECT).apply(key)) {
            return ((AspectKey) key.argument()).prettyPrint();
        } else {
            return getLabel(key).toString();
        }
    }

    @Override
    public Label getLabel(SkyKey key) {
        if (SkyFunctions.isSkyFunction(SkyFunctions.CONFIGURED_TARGET).apply(key)) {
            return ((ConfiguredTargetKey) key.argument()).getLabel();
        } else if (SkyFunctions.isSkyFunction(SkyFunctions.ASPECT).apply(key)) {
            return ((AspectKey) key.argument()).getLabel();
        } else if (SkyFunctions.isSkyFunction(TRANSITIVE_TARGET).apply(key)) {
            return (Label) key.argument();
        } else {
            throw new UnsupportedOperationException();
        }
    }
}