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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 com.google.common.annotations.VisibleForTesting;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableSet;
import com.google.common.collect.Lists;
import com.google.common.collect.Multimap;
import com.google.devtools.build.lib.actions.InconsistentFilesystemException;
import com.google.devtools.build.lib.cmdline.Label;
import com.google.devtools.build.lib.cmdline.PackageIdentifier;
import com.google.devtools.build.lib.events.EventHandler;
import com.google.devtools.build.lib.packages.AdvertisedProviderSet;
import com.google.devtools.build.lib.packages.Aspect;
import com.google.devtools.build.lib.packages.AspectDefinition;
import com.google.devtools.build.lib.packages.Attribute;
import com.google.devtools.build.lib.packages.BuildFileNotFoundException;
import com.google.devtools.build.lib.packages.DependencyFilter;
import com.google.devtools.build.lib.packages.LabelVisitationUtils;
import com.google.devtools.build.lib.packages.NoSuchPackageException;
import com.google.devtools.build.lib.packages.NoSuchTargetException;
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.vfs.PathFragment;
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.Collection;
import java.util.List;
import java.util.Map;
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.
*
* <p>The {@code TProcessedTargets} type parameter represents the result of processing a target and
* its transitive dependencies.
*
* <p>{@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.
*/
public abstract class TransitiveBaseTraversalFunction<ProcessedTargetsT> implements SkyFunction {
/**
* Returns a {@link SkyKey} corresponding to the traversal of a target specified by {@code label}
* and its transitive dependencies.
*
* <p>Extenders of this class should implement this function to return a key with their
* specialized {@link SkyFunction}'s name.
*
* <p>{@link TransitiveBaseTraversalFunction} calls this for each dependency of a target, and
* then gets their values from the environment.
*
* <p>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 ProcessedTargetsT processTarget(Label label, TargetAndErrorIfAny targetAndErrorIfAny);
abstract void processDeps(
ProcessedTargetsT processedTargets,
EventHandler eventHandler,
TargetAndErrorIfAny targetAndErrorIfAny,
Iterable<Map.Entry<SkyKey, ValueOrException2<NoSuchPackageException, NoSuchTargetException>>>
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, ProcessedTargetsT processedTargets);
abstract Label argumentFromKey(SkyKey key);
@Override
public SkyValue compute(SkyKey key, Environment env)
throws TransitiveBaseTraversalFunctionException, InterruptedException {
Label label = argumentFromKey(key);
TargetAndErrorIfAny targetAndErrorIfAny;
try {
targetAndErrorIfAny = loadTarget(env, label);
} catch (NoSuchTargetException e) {
throw new TransitiveBaseTraversalFunctionException(e);
} catch (NoSuchPackageException e) {
throw new TransitiveBaseTraversalFunctionException(e);
}
if (targetAndErrorIfAny == null) {
return null;
}
// Process deps from attributes. It is essential that the last getValue(s) call we made to
// skyframe for building this node was for the corresponding PackageValue.
Collection<SkyKey> labelDepKeys = getLabelDepKeys(env, targetAndErrorIfAny);
Map<SkyKey, ValueOrException2<NoSuchPackageException, NoSuchTargetException>> depMap =
env.getValuesOrThrow(labelDepKeys, NoSuchPackageException.class,
NoSuchTargetException.class);
if (env.valuesMissing()) {
return null;
}
// Process deps from attributes. It is essential that the second-to-last getValue(s) call we
// made to skyframe for building this node was for the corresponding PackageValue.
Iterable<SkyKey> labelAspectKeys =
getStrictLabelAspectDepKeys(env, depMap, targetAndErrorIfAny);
Set<Map.Entry<SkyKey, ValueOrException2<NoSuchPackageException, NoSuchTargetException>>>
labelAspectEntries =
env.getValuesOrThrow(
labelAspectKeys, NoSuchPackageException.class, NoSuchTargetException.class)
.entrySet();
if (env.valuesMissing()) {
return null;
}
ProcessedTargetsT processedTargets = processTarget(label, targetAndErrorIfAny);
processDeps(processedTargets, env.getListener(), targetAndErrorIfAny, depMap.entrySet());
processDeps(processedTargets, env.getListener(), targetAndErrorIfAny, labelAspectEntries);
return computeSkyValue(targetAndErrorIfAny, processedTargets);
}
Collection<SkyKey> getLabelDepKeys(
SkyFunction.Environment env, TargetAndErrorIfAny targetAndErrorIfAny)
throws InterruptedException {
ImmutableSet.Builder<SkyKey> depsBuilder = ImmutableSet.builder();
LabelVisitationUtils.visitTarget(
targetAndErrorIfAny.getTarget(),
DependencyFilter.NO_NODEP_ATTRIBUTES_EXCEPT_VISIBILITY,
(fromTarget, attribute, toLabel) -> depsBuilder.add(getKey(toLabel)));
return depsBuilder.build();
}
Iterable<SkyKey> getStrictLabelAspectDepKeys(
SkyFunction.Environment env,
Map<SkyKey, ValueOrException2<NoSuchPackageException, NoSuchTargetException>> depMap,
TargetAndErrorIfAny targetAndErrorIfAny)
throws InterruptedException {
return getStrictLabelAspectKeys(targetAndErrorIfAny.getTarget(), depMap, env);
}
@Override
public String extractTag(SkyKey skyKey) {
return Label.print(argumentFromKey(skyKey));
}
/**
* Return an Iterable of SkyKeys corresponding to the Aspect-related dependencies of target.
*
* <p>This method may return a precise set of aspect keys, but may need to request additional
* dependencies from the env to do so.
*/
private Iterable<SkyKey> getStrictLabelAspectKeys(
Target target,
Map<SkyKey, ValueOrException2<NoSuchPackageException, NoSuchTargetException>> depMap,
Environment env)
throws InterruptedException {
if (!(target instanceof Rule)) {
// Aspects can be declared only for Rules.
return ImmutableList.of();
}
Rule rule = (Rule) target;
List<SkyKey> depKeys = Lists.newArrayList();
Multimap<Attribute, Label> transitions =
rule.getTransitions(DependencyFilter.NO_NODEP_ATTRIBUTES);
for (Attribute attribute : transitions.keySet()) {
for (Aspect aspect : attribute.getAspects(rule)) {
if (hasDepThatSatisfies(aspect, transitions.get(attribute), depMap, env)) {
AspectDefinition.forEachLabelDepFromAllAttributesOfAspect(
rule,
aspect,
DependencyFilter.ALL_DEPS,
(aspectAttribute, aspectLabel) -> depKeys.add(getKey(aspectLabel)));
}
}
}
return depKeys;
}
@Nullable
protected abstract AdvertisedProviderSet getAdvertisedProviderSet(
Label toLabel,
@Nullable ValueOrException2<NoSuchPackageException, NoSuchTargetException> toVal,
Environment env)
throws InterruptedException;
private final boolean hasDepThatSatisfies(
Aspect aspect,
Iterable<Label> depLabels,
Map<SkyKey, ValueOrException2<NoSuchPackageException, NoSuchTargetException>> fullDepMap,
Environment env)
throws InterruptedException {
for (Label depLabel : depLabels) {
AdvertisedProviderSet advertisedProviderSet =
getAdvertisedProviderSet(depLabel, fullDepMap.get(depLabel), env);
if (advertisedProviderSet != null
&& AspectDefinition.satisfies(aspect, advertisedProviderSet)) {
return true;
}
}
return false;
}
interface TargetAndErrorIfAny {
boolean isPackageLoadedSuccessfully();
@Nullable NoSuchTargetException getErrorLoadingTarget();
Target getTarget();
}
@VisibleForTesting
static class TargetAndErrorIfAnyImpl implements TargetAndErrorIfAny {
private final boolean packageLoadedSuccessfully;
@Nullable private final NoSuchTargetException errorLoadingTarget;
private final Target target;
@VisibleForTesting
TargetAndErrorIfAnyImpl(
boolean packageLoadedSuccessfully,
@Nullable NoSuchTargetException errorLoadingTarget,
Target target) {
this.packageLoadedSuccessfully = packageLoadedSuccessfully;
this.errorLoadingTarget = errorLoadingTarget;
this.target = target;
}
@Override
public boolean isPackageLoadedSuccessfully() {
return packageLoadedSuccessfully;
}
@Override
@Nullable
public NoSuchTargetException getErrorLoadingTarget() {
return errorLoadingTarget;
}
@Override
public Target getTarget() {
return target;
}
}
@Nullable // Returns null if values are missing.
@VisibleForTesting
TargetAndErrorIfAny loadTarget(Environment env, Label label)
throws NoSuchTargetException, NoSuchPackageException, InterruptedException {
if (label.getName().contains("/")) {
// This target is in a subdirectory, therefore it could potentially be invalidated by
// a new BUILD file appearing in the hierarchy.
PathFragment containingDirectory = getContainingDirectory(label);
PackageIdentifier newPkgId =
PackageIdentifier.create(
label.getPackageIdentifier().getRepository(), containingDirectory);
ContainingPackageLookupValue containingPackageLookupValue;
try {
containingPackageLookupValue =
(ContainingPackageLookupValue)
env.getValueOrThrow(
ContainingPackageLookupValue.key(newPkgId),
BuildFileNotFoundException.class,
InconsistentFilesystemException.class);
} catch (InconsistentFilesystemException e) {
throw new NoSuchTargetException(label, e.getMessage());
}
if (containingPackageLookupValue == null) {
return null;
}
if (!containingPackageLookupValue.hasContainingPackage()) {
// This means the label's package doesn't exist. E.g. there is no package 'a' and we are
// trying to build the target for label 'a:b/foo'.
throw new BuildFileNotFoundException(
label.getPackageIdentifier(),
"BUILD file not found on package path for '"
+ label.getPackageFragment().getPathString()
+ "'");
}
if (!containingPackageLookupValue
.getContainingPackageName()
.equals(label.getPackageIdentifier())) {
throw new NoSuchTargetException(
label,
String.format(
"Label '%s' crosses boundary of subpackage '%s'",
label, containingPackageLookupValue.getContainingPackageName()));
}
}
SkyKey packageKey = PackageValue.key(label.getPackageIdentifier());
PackageValue packageValue =
(PackageValue) env.getValueOrThrow(packageKey, NoSuchPackageException.class);
if (env.valuesMissing() || packageValue == null) {
return null;
}
Package pkg = packageValue.getPackage();
Target target = pkg.getTarget(label.getName());
NoSuchTargetException error = pkg.containsErrors() ? new NoSuchTargetException(target) : null;
return new TargetAndErrorIfAnyImpl(
/* packageLoadedSuccessfully= */ !pkg.containsErrors(), error, target);
}
private static PathFragment getContainingDirectory(Label label) {
PathFragment pkg = label.getPackageFragment();
String name = label.getName();
return name.equals(".") ? pkg : pkg.getRelative(name).getParentDirectory();
}
/**
* Used to declare all the exception types that can be wrapped in the exception thrown by {@link
* TransitiveTraversalFunction#compute}.
*/
public static class TransitiveBaseTraversalFunctionException extends SkyFunctionException {
/**
* Used to propagate an error from a direct target dependency to the target that depended on
* it.
*/
public TransitiveBaseTraversalFunctionException(NoSuchPackageException e) {
super(e, Transience.PERSISTENT);
}
/**
* In nokeep_going mode, used to propagate an error from a direct target dependency to the
* target that depended on it.
*
* <p>In keep_going mode, used the same way, but only for targets that could not be loaded at
* all (we proceed with transitive loading on targets that contain errors).</p>
*/
public TransitiveBaseTraversalFunctionException(NoSuchTargetException e) {
super(e, Transience.PERSISTENT);
}
}
}