Implement TargetProviderForQueryEnvironment.

DirectTargetProvider works with WalkableGraph directly. If it fails to find target, then last try to use delegate TargetProvider which supposed to be PackageManager from SkyframeExecutor.

RELNOTES:none
PiperOrigin-RevId: 190204106

3 files changed, 99 insertions, 2 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/runtime/TargetProviderForQueryEnvironment.java b/src/main/java/com/google/devtools/build/lib/runtime/TargetProviderForQueryEnvironment.java
new file mode 100644
index 0000000000..3df131222e
--- /dev/null
+++ b/src/main/java/com/google/devtools/build/lib/runtime/TargetProviderForQueryEnvironment.java
@@ -0,0 +1,87 @@
+// Copyright 2018 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.runtime;
+
+import com.google.common.base.Preconditions;
+import com.google.common.base.Throwables;
+import com.google.devtools.build.lib.cmdline.Label;
+import com.google.devtools.build.lib.cmdline.PackageIdentifier;
+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.TargetProvider;
+import com.google.devtools.build.lib.skyframe.PackageValue;
+import com.google.devtools.build.skyframe.SkyKey;
+import com.google.devtools.build.skyframe.SkyValue;
+import com.google.devtools.build.skyframe.WalkableGraph;
+import java.util.Optional;
+
+/**
+ * Serves as TargetProvider using WalkableGraph as direct access to graph. Refers to delegate in
+ * case if WalkableGraph has not value for specific key.
+ */
+public class TargetProviderForQueryEnvironment implements TargetProvider {
+
+  private final WalkableGraph walkableGraph;
+
+  /**
+   * If WalkableGraph has not node requested, then delegate used as fall back strategy.
+   */
+  private final TargetProvider delegate;
+
+  public TargetProviderForQueryEnvironment(WalkableGraph walkableGraph, TargetProvider delegate) {
+    this.walkableGraph = Preconditions.checkNotNull(walkableGraph);
+    this.delegate = Preconditions.checkNotNull(delegate);
+  }
+
+  @Override
+  public Target getTarget(ExtendedEventHandler eventHandler, Label label)
+      throws NoSuchPackageException, NoSuchTargetException, InterruptedException {
+
+    Optional<Package> optional = getPackageFromWalkableGraph(label.getPackageIdentifier());
+    if (optional.isPresent()) {
+      return optional.get().getTarget(label.getName());
+    }
+
+    return delegate.getTarget(eventHandler, label);
+  }
+
+  private Optional<Package> getPackageFromWalkableGraph(PackageIdentifier pkgId)
+      throws InterruptedException, NoSuchPackageException {
+
+    SkyKey packageKey = PackageValue.key(pkgId);
+    SkyValue skyValue = walkableGraph.getValue(packageKey);
+
+    if (skyValue != null) {
+      PackageValue packageValue = (PackageValue) skyValue;
+      return Optional.of(packageValue.getPackage());
+    }
+
+    Exception exception = walkableGraph.getException(packageKey);
+    if (exception != null) {
+      // PackageFunction should be catching, swallowing, and rethrowing all transitive
+      // errors as NoSuchPackageExceptions or constructing packages with errors.
+      Throwables.propagateIfPossible(exception, NoSuchPackageException.class);
+      throw new IllegalStateException("Unexpected Exception type from PackageValue for " + pkgId);
+    }
+    if (walkableGraph.isCycle(packageKey)) {
+      throw new BuildFileContainsErrorsException(
+          pkgId, "Cycle encountered while loading package " + pkgId);
+    }
+    return Optional.empty();
+  }
+}
diff --git a/src/main/java/com/google/devtools/build/lib/runtime/commands/QueryCommand.java b/src/main/java/com/google/devtools/build/lib/runtime/commands/QueryCommand.java
index 119712284e..b9e071ce6a 100644
--- a/src/main/java/com/google/devtools/build/lib/runtime/commands/QueryCommand.java
+++ b/src/main/java/com/google/devtools/build/lib/runtime/commands/QueryCommand.java
@@ -42,10 +42,13 @@ import com.google.devtools.build.lib.runtime.Command;
 import com.google.devtools.build.lib.runtime.CommandEnvironment;
 import com.google.devtools.build.lib.runtime.KeepGoingOption;
 import com.google.devtools.build.lib.runtime.LoadingPhaseThreadsOption;
+import com.google.devtools.build.lib.runtime.TargetProviderForQueryEnvironment;
+import com.google.devtools.build.lib.skyframe.SkyframeExecutorWrappingWalkableGraph;
 import com.google.devtools.build.lib.util.AbruptExitException;
 import com.google.devtools.build.lib.util.ExitCode;
 import com.google.devtools.build.lib.vfs.FileSystemUtils;
 import com.google.devtools.build.lib.vfs.Path;
+import com.google.devtools.build.skyframe.WalkableGraph;
 import com.google.devtools.common.options.OptionsParser;
 import com.google.devtools.common.options.OptionsProvider;
 import java.io.BufferedOutputStream;
@@ -283,12 +286,19 @@ public final class QueryCommand implements BlazeCommand {
   public static AbstractBlazeQueryEnvironment<Target> newQueryEnvironment(CommandEnvironment env,
       boolean keepGoing, boolean orderedResults, List<String> universeScope,
       int loadingPhaseThreads, Set<Setting> settings) {
+
+    WalkableGraph walkableGraph =
+        SkyframeExecutorWrappingWalkableGraph.of(env.getSkyframeExecutor());
+
+    TargetProviderForQueryEnvironment targetProviderForQueryEnvironment =
+        new TargetProviderForQueryEnvironment(walkableGraph, env.getPackageManager());
+
     return env.getRuntime()
         .getQueryEnvironmentFactory()
         .create(
             env.getPackageManager().newTransitiveLoader(),
             env.getSkyframeExecutor(),
-            env.getPackageManager(),
+            targetProviderForQueryEnvironment,
             env.getPackageManager(),
             env.newTargetPatternEvaluator(),
             keepGoing,
diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/SkyframeExecutorWrappingWalkableGraph.java b/src/main/java/com/google/devtools/build/lib/skyframe/SkyframeExecutorWrappingWalkableGraph.java
index 42029c15d9..75a8a03d8a 100644
--- a/src/main/java/com/google/devtools/build/lib/skyframe/SkyframeExecutorWrappingWalkableGraph.java
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/SkyframeExecutorWrappingWalkableGraph.java
@@ -26,7 +26,7 @@ import javax.annotation.Nullable;
 /** {@link WalkableGraph} backed by a {@link SkyframeExecutor}. */
 public class SkyframeExecutorWrappingWalkableGraph extends DelegatingWalkableGraph {
 
-  public SkyframeExecutorWrappingWalkableGraph(MemoizingEvaluator evaluator) {
+  private SkyframeExecutorWrappingWalkableGraph(MemoizingEvaluator evaluator) {
     super(
         new QueryableGraph() {
           @Nullable