com.google.devtools.build.lib.pkgcache.LoadingPhaseRunner.java Source code

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Here is the source code for com.google.devtools.build.lib.pkgcache.LoadingPhaseRunner.java

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// 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.pkgcache;

import com.google.common.collect.ImmutableMap;
import com.google.common.collect.Iterables;
import com.google.common.eventbus.EventBus;
import com.google.devtools.build.lib.cmdline.PackageIdentifier;
import com.google.devtools.build.lib.cmdline.TargetParsingException;
import com.google.devtools.build.lib.events.Event;
import com.google.devtools.build.lib.events.EventHandler;
import com.google.devtools.build.lib.packages.NonconfigurableAttributeMapper;
import com.google.devtools.build.lib.packages.Package;
import com.google.devtools.build.lib.packages.Rule;
import com.google.devtools.build.lib.packages.Target;
import com.google.devtools.build.lib.syntax.Type;
import com.google.devtools.build.lib.vfs.Path;
import com.google.devtools.build.lib.vfs.PathFragment;
import java.util.Collection;
import java.util.List;
import javax.annotation.Nullable;

/**
 * Implements the loading phase; responsible for:
 * <ul>
 *   <li>target pattern evaluation
 *   <li>test suite expansion
 * </ul>
 *
 * <p>In order to ensure correctness of incremental loading and of full cache hits, this class is
 * very restrictive about access to its internal state and to its collaborators. In particular, none
 * of the collaborators of this class may change in incompatible ways, such as changing the relative
 * working directory for the target pattern parser, without notifying this class.
 *
 * <p>For full caching, this class tracks the exact values of all inputs to the loading phase. To
 * maximize caching, it is vital that these change as rarely as possible.
 */
public abstract class LoadingPhaseRunner {
    /** Performs target pattern evaluation and test suite expansion (if requested). */
    public abstract LoadingResult execute(EventHandler eventHandler, EventBus eventBus, List<String> targetPatterns,
            PathFragment relativeWorkingDirectory, LoadingOptions options, boolean keepGoing,
            boolean determineTests, @Nullable LoadingCallback callback)
            throws TargetParsingException, LoadingFailedException, InterruptedException;

    /**
     * Returns a map of collected package names to root paths.
     */
    public static ImmutableMap<PackageIdentifier, Path> collectPackageRoots(Collection<Package> packages) {
        // Make a map of the package names to their root paths.
        ImmutableMap.Builder<PackageIdentifier, Path> packageRoots = ImmutableMap.builder();
        for (Package pkg : packages) {
            packageRoots.put(pkg.getPackageIdentifier(), pkg.getSourceRoot());
        }
        return packageRoots.build();
    }

    /**
     * Emit a warning when a deprecated target is mentioned on the command line.
     *
     * <p>Note that this does not stop us from emitting "target X depends on deprecated target Y"
     * style warnings for the same target and it is a good thing; <i>depending</i> on a target and
     * <i>wanting</i> to build it are different things.
     */
    // Public for use by skyframe.TargetPatternPhaseFunction until this class goes away.
    public static void maybeReportDeprecation(EventHandler eventHandler, Collection<Target> targets) {
        for (Rule rule : Iterables.filter(targets, Rule.class)) {
            if (rule.isAttributeValueExplicitlySpecified("deprecation")) {
                eventHandler.handle(Event.warn(rule.getLocation(), String.format("target '%s' is deprecated: %s",
                        rule.getLabel(), NonconfigurableAttributeMapper.of(rule).get("deprecation", Type.STRING))));
            }
        }
    }
}