// 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.collect.ImmutableMap;
import com.google.common.collect.ImmutableSet;
import com.google.common.collect.Iterables;
import com.google.devtools.build.lib.cmdline.Label;
import com.google.devtools.build.lib.cmdline.PackageIdentifier;
import com.google.devtools.build.lib.cmdline.RepositoryName;
import com.google.devtools.build.lib.collect.nestedset.NestedSetBuilder;
import com.google.devtools.build.lib.events.Event;
import com.google.devtools.build.lib.events.ExtendedEventHandler;
import com.google.devtools.build.lib.packages.BuildFileContainsErrorsException;
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.Target;
import com.google.devtools.build.lib.pkgcache.PathPackageLocator;
import com.google.devtools.build.lib.pkgcache.RecursivePackageProvider;
import com.google.devtools.build.lib.rules.repository.RepositoryDirectoryValue;
import com.google.devtools.build.lib.util.Preconditions;
import com.google.devtools.build.lib.vfs.Path;
import com.google.devtools.build.lib.vfs.PathFragment;
import com.google.devtools.build.lib.vfs.RootedPath;
import com.google.devtools.build.skyframe.SkyFunction.Environment;
import com.google.devtools.build.skyframe.SkyKey;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
/**
* A {@link RecursivePackageProvider} backed by an {@link Environment}. Its methods may throw {@link
* MissingDepException} if the package values this depends on haven't been calculated and added to
* its environment.
*
* <p>This implementation never emits events through the {@link ExtendedEventHandler}s passed to its
* methods. Instead, it emits events through its environment's {@link Environment#getListener()}.
*/
public final class EnvironmentBackedRecursivePackageProvider implements RecursivePackageProvider {
private final Environment env;
public EnvironmentBackedRecursivePackageProvider(Environment env) {
this.env = env;
}
@Override
public Package getPackage(ExtendedEventHandler eventHandler, PackageIdentifier packageName)
throws NoSuchPackageException, MissingDepException, InterruptedException {
SkyKey pkgKey = PackageValue.key(packageName);
PackageValue pkgValue =
(PackageValue) env.getValueOrThrow(pkgKey, NoSuchPackageException.class);
if (pkgValue == null) {
throw new MissingDepException();
}
Package pkg = pkgValue.getPackage();
if (pkg.containsErrors()) {
// If this is a nokeep_going build, we must shut the build down by throwing an exception. To
// do that, we request a node that will throw an exception, and then try to catch it and
// continue. This gives the framework notification to shut down the build if it should.
try {
env.getValueOrThrow(
PackageErrorFunction.key(packageName), BuildFileContainsErrorsException.class);
Preconditions.checkState(env.valuesMissing(), "Should have thrown for %s", packageName);
throw new MissingDepException();
} catch (BuildFileContainsErrorsException e) {
// Expected.
}
}
return pkgValue.getPackage();
}
@Override
public Map<PackageIdentifier, Package> bulkGetPackages(Iterable<PackageIdentifier> pkgIds)
throws NoSuchPackageException, InterruptedException {
ImmutableMap.Builder<PackageIdentifier, Package> builder = ImmutableMap.builder();
for (PackageIdentifier pkgId : pkgIds) {
builder.put(pkgId, getPackage(env.getListener(), pkgId));
}
return builder.build();
}
@Override
public boolean isPackage(ExtendedEventHandler eventHandler, PackageIdentifier packageId)
throws MissingDepException, InterruptedException {
SkyKey packageLookupKey = PackageLookupValue.key(packageId);
try {
PackageLookupValue packageLookupValue =
(PackageLookupValue) env.getValueOrThrow(packageLookupKey, NoSuchPackageException.class,
InconsistentFilesystemException.class);
if (packageLookupValue == null) {
throw new MissingDepException();
}
return packageLookupValue.packageExists();
} catch (NoSuchPackageException | InconsistentFilesystemException e) {
env.getListener().handle(Event.error(e.getMessage()));
return false;
}
}
@Override
public Iterable<PathFragment> getPackagesUnderDirectory(
ExtendedEventHandler eventHandler,
RepositoryName repository,
PathFragment directory,
ImmutableSet<PathFragment> excludedSubdirectories)
throws MissingDepException, InterruptedException {
PathPackageLocator packageLocator = PrecomputedValue.PATH_PACKAGE_LOCATOR.get(env);
if (packageLocator == null) {
throw new MissingDepException();
}
List<Path> roots = new ArrayList<>();
if (repository.isMain()) {
roots.addAll(packageLocator.getPathEntries());
} else {
RepositoryDirectoryValue repositoryValue =
(RepositoryDirectoryValue) env.getValue(RepositoryDirectoryValue.key(repository));
if (repositoryValue == null) {
throw new MissingDepException();
}
if (!repositoryValue.repositoryExists()) {
// This shouldn't be possible; we're given a repository, so we assume that the caller has
// already checked for its existence.
throw new IllegalStateException(String.format("No such repository '%s'", repository));
}
roots.add(repositoryValue.getPath());
}
NestedSetBuilder<String> packageNames = NestedSetBuilder.stableOrder();
for (Path root : roots) {
PathFragment.checkAllPathsAreUnder(excludedSubdirectories, directory);
RecursivePkgValue lookup = (RecursivePkgValue) env.getValue(RecursivePkgValue.key(
repository, RootedPath.toRootedPath(root, directory), excludedSubdirectories));
if (lookup == null) {
// Typically a null value from Environment.getValue(k) means that either the key k is
// missing a dependency or an exception was thrown during evaluation of k. Here, if this
// getValue call returns null in a keep_going build, it can only mean a missing dependency
// because RecursivePkgFunction#compute never throws.
// In a nokeep_going build, a lower-level exception that RecursivePkgFunction ignored may
// bubble up to here, but we ignore it and depend on the top-level caller to be flexible in
// the exception types it can accept.
throw new MissingDepException();
}
packageNames.addTransitive(lookup.getPackages());
}
// TODO(bazel-team): Make RecursivePkgValue return NestedSet<PathFragment> so this transform is
// unnecessary.
return Iterables.transform(packageNames.build(), PathFragment.TO_PATH_FRAGMENT);
}
@Override
public Target getTarget(ExtendedEventHandler eventHandler, Label label)
throws NoSuchPackageException, NoSuchTargetException, MissingDepException,
InterruptedException {
return getPackage(eventHandler, label.getPackageIdentifier()).getTarget(label.getName());
}
/**
* Indicates that a missing dependency is needed before target parsing can proceed. Currently
* used only in skyframe to notify the framework of missing dependencies. Caught by the compute
* method in {@link com.google.devtools.build.lib.skyframe.TargetPatternFunction}, which then
* returns null in accordance with the skyframe missing dependency policy.
*/
static class MissingDepException extends RuntimeException {
}
}