// 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 com.google.common.base.Preconditions;
import com.google.common.collect.Iterables;
import com.google.common.collect.Lists;
import com.google.devtools.build.lib.cmdline.Label;
import com.google.devtools.build.lib.events.Event;
import com.google.devtools.build.lib.events.EventHandler;
import com.google.devtools.build.lib.packages.BuildFileContainsErrorsException;
import com.google.devtools.build.lib.packages.InputFile;
import com.google.devtools.build.lib.packages.NoSuchPackageException;
import com.google.devtools.build.lib.packages.NoSuchTargetException;
import com.google.devtools.build.lib.packages.NoSuchThingException;
import com.google.devtools.build.lib.packages.OutputFile;
import com.google.devtools.build.lib.packages.Package;
import com.google.devtools.build.lib.packages.PackageGroup;
import com.google.devtools.build.lib.packages.Rule;
import com.google.devtools.build.lib.packages.Target;
import com.google.devtools.build.lib.packages.TargetUtils;
import com.google.devtools.build.skyframe.SkyFunction;
import com.google.devtools.build.skyframe.SkyFunctionException;
import com.google.devtools.build.skyframe.SkyKey;
import com.google.devtools.build.skyframe.SkyValue;
import com.google.devtools.build.skyframe.ValueOrException2;
import java.util.HashSet;
import java.util.List;
import java.util.Map.Entry;
import java.util.Set;
import javax.annotation.Nullable;
/**
* This class can be extended to define {@link SkyFunction}s that traverse a target and its
* transitive dependencies and return values based on that traversal.
*
*
The {@code TProcessedTargets} type parameter represents the result of processing a target and
* its transitive dependencies.
*
*
{@code TransitiveBaseTraversalFunction} asks for one to be constructed via {@link
* #processTarget}, and then asks for it to be updated based on the current target's
* attributes' dependencies via {@link #processDeps}, and then asks for it to be updated based
* on the current target' aspects' dependencies via {@link #processDeps}. Finally, it calls
* {@link #computeSkyValue} with the {#code ProcessedTargets} to get the {@link SkyValue} to
* return.
*/
abstract class TransitiveBaseTraversalFunction
implements SkyFunction {
/**
* Returns a {@link SkyKey} corresponding to the traversal of a target specified by {@code label}
* and its transitive dependencies.
*
*
Extenders of this class should implement this function to return a key with their
* specialized {@link SkyFunction}'s name.
*
*
{@link TransitiveBaseTraversalFunction} calls this for each dependency of a target, and
* then gets their values from the environment.
*
*
The key's {@link SkyFunction} may throw at most {@link NoSuchPackageException} and
* {@link NoSuchTargetException}. Other exception types are not handled by {@link
* TransitiveBaseTraversalFunction}.
*/
abstract SkyKey getKey(Label label);
abstract TProcessedTargets processTarget(Label label,
TargetAndErrorIfAny targetAndErrorIfAny);
abstract void processDeps(TProcessedTargets processedTargets, EventHandler eventHandler,
TargetAndErrorIfAny targetAndErrorIfAny,
Iterable>>
depEntries);
/**
* Returns a {@link SkyValue} based on the target and any errors it has, and the values
* accumulated across it and a traversal of its transitive dependencies.
*/
abstract SkyValue computeSkyValue(TargetAndErrorIfAny targetAndErrorIfAny,
TProcessedTargets processedTargets);
@Override
public SkyValue compute(SkyKey key, Environment env)
throws TransitiveBaseTraversalFunctionException {
Label label = (Label) key.argument();
LoadTargetResults loadTargetResults;
try {
loadTargetResults = loadTarget(env, label);
} catch (NoSuchTargetException e) {
throw new TransitiveBaseTraversalFunctionException(e);
} catch (NoSuchPackageException e) {
throw new TransitiveBaseTraversalFunctionException(e);
}
LoadTargetResultsType loadTargetResultsType = loadTargetResults.getType();
if (loadTargetResultsType.equals(LoadTargetResultsType.VALUES_MISSING)) {
return null;
}
Preconditions.checkState(
loadTargetResultsType.equals(LoadTargetResultsType.TARGET_AND_ERROR_IF_ANY),
loadTargetResultsType);
TargetAndErrorIfAny targetAndErrorIfAny = (TargetAndErrorIfAny) loadTargetResults;
TProcessedTargets processedTargets = processTarget(label, targetAndErrorIfAny);
// Process deps from attributes and conservative aspects of current target.
Iterable labelDepKeys = getLabelDepKeys(targetAndErrorIfAny.getTarget());
Iterable labelAspectKeys =
getConservativeLabelAspectKeys(targetAndErrorIfAny.getTarget());
Iterable depAndAspectKeys = Iterables.concat(labelDepKeys, labelAspectKeys);
Set>>
depsAndAspectEntries = env.getValuesOrThrow(depAndAspectKeys,
NoSuchPackageException.class, NoSuchTargetException.class).entrySet();
processDeps(processedTargets, env.getListener(), targetAndErrorIfAny, depsAndAspectEntries);
if (env.valuesMissing()) {
return null;
}
// Process deps from strict aspects.
labelAspectKeys = getStrictLabelAspectKeys(targetAndErrorIfAny.getTarget(), env);
Set>>
labelAspectEntries = env.getValuesOrThrow(labelAspectKeys, NoSuchPackageException.class,
NoSuchTargetException.class).entrySet();
processDeps(processedTargets, env.getListener(), targetAndErrorIfAny, labelAspectEntries);
if (env.valuesMissing()) {
return null;
}
return computeSkyValue(targetAndErrorIfAny, processedTargets);
}
@Override
public String extractTag(SkyKey skyKey) {
return Label.print(((Label) skyKey.argument()));
}
/**
* Return an Iterable of SkyKeys corresponding to the Aspect-related dependencies of target.
*
*
This method may return a precise set of aspect keys, but may need to request additional
* dependencies from the env to do so.
*
*
Subclasses should implement only one of #getStrictLabelAspectKeys and
* @getConservativeLabelAspectKeys.
*/
protected abstract Iterable getStrictLabelAspectKeys(Target target, Environment env);
/**
* Return an Iterable of SkyKeys corresponding to the Aspect-related dependencies of target.
*
*
This method may return a conservative over-approximation of the exact set.
*/
protected abstract Iterable getConservativeLabelAspectKeys(Target target);
private Iterable getLabelDepKeys(Target target) {
List depKeys = Lists.newArrayList();
for (Label depLabel : getLabelDeps(target)) {
depKeys.add(getKey(depLabel));
}
return depKeys;
}
// TODO(bazel-team): Unify this logic with that in LabelVisitor, and possibly DependencyResolver.
private static Iterable