Introduce BazelPackageLoader.

This is a standalone library for loading packages. It is intended to be used by clients outside of Bazel (for now, Kythe).

Perform BazelPackageLoader#loadPackage in the testing hook used in all of Bazel's unit tests and integration tests. This gives us very good test coverage for BazelPackageLoader.

RELNOTES: None
PiperOrigin-RevId: 155004070

4 files changed, 167 insertions, 54 deletions

diff --git a/src/test/java/com/google/devtools/build/lib/testutil/BazelPackageBuilderHelperForTesting.java b/src/test/java/com/google/devtools/build/lib/testutil/BazelPackageBuilderHelperForTesting.java
new file mode 100644
index 0000000000..21f20cfb16
--- /dev/null
+++ b/src/test/java/com/google/devtools/build/lib/testutil/BazelPackageBuilderHelperForTesting.java
@@ -0,0 +1,108 @@
+// Copyright 2017 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.testutil;
+
+import com.google.common.base.Function;
+import com.google.common.collect.ImmutableSet;
+import com.google.common.collect.Iterables;
+import com.google.common.collect.Sets;
+import com.google.devtools.build.lib.cmdline.Label;
+import com.google.devtools.build.lib.cmdline.PackageIdentifier;
+import com.google.devtools.build.lib.packages.NoSuchPackageException;
+import com.google.devtools.build.lib.packages.Package;
+import com.google.devtools.build.lib.packages.RuleClassProvider;
+import com.google.devtools.build.lib.packages.Target;
+import com.google.devtools.build.lib.skyframe.PackageFunction;
+import com.google.devtools.build.lib.skyframe.packages.BazelPackageLoader;
+import com.google.devtools.build.lib.skyframe.packages.PackageLoader;
+import com.google.devtools.build.lib.vfs.Path;
+import com.google.devtools.build.lib.vfs.PathFragment;
+
+/**
+ * A Package.Builder.Helper for use in tests that a sanity check with {@link BazelPackageLoader} for
+ * each loaded package, for the sake of getting pretty nice test coverage.
+ */
+public class BazelPackageBuilderHelperForTesting implements Package.Builder.Helper {
+  private final RuleClassProvider ruleClassProvider;
+
+  public BazelPackageBuilderHelperForTesting(RuleClassProvider ruleClassProvider) {
+    this.ruleClassProvider = ruleClassProvider;
+  }
+
+  @Override
+  public Package createFreshPackage(PackageIdentifier packageId, String runfilesPrefix) {
+    return Package.Builder.DefaultHelper.INSTANCE.createFreshPackage(packageId, runfilesPrefix);
+  }
+
+  @Override
+  public void onLoadingComplete(Package pkg) {
+    sanityCheckBazelPackageLoader(pkg, ruleClassProvider);
+  }
+
+  private static final Function<Target, Label> TARGET_TO_LABEL =
+      new Function<Target, Label>() {
+        @Override
+        public Label apply(Target input) {
+          return input.getLabel();
+        }
+      };
+
+  // This is synchronized because some Skylark internals aren't thread safe.
+  private synchronized void sanityCheckBazelPackageLoader(
+      Package pkg,
+      RuleClassProvider ruleClassProvider) {
+    PackageIdentifier pkgId = pkg.getPackageIdentifier();
+    if (pkgId.equals(Label.EXTERNAL_PACKAGE_IDENTIFIER)
+        || !pkg.getPackageIdentifier().getRepository().isMain()
+        || PackageFunction.isDefaultsPackage(pkg.getPackageIdentifier())) {
+      // TODO(nharmata): Support these packages.
+      return;
+    }
+    int numNameSegments = pkg.getNameFragment().segmentCount();
+    PathFragment fullFilenameFragment = pkg.getFilename().asFragment();
+    int numFullFilenameFragmentSegments = fullFilenameFragment.segmentCount();
+    Path workspaceRoot = pkg.getFilename().getFileSystem().getPath(
+        fullFilenameFragment.subFragment(
+            0,
+            numFullFilenameFragmentSegments - (numNameSegments + 1)));
+    PackageLoader packageLoader = BazelPackageLoader.builder(workspaceRoot)
+        .setRuleClassProvider(ruleClassProvider)
+        .build();
+    Package newlyLoadedPkg;
+    try {
+      newlyLoadedPkg = packageLoader.loadPackage(pkg.getPackageIdentifier());
+    } catch (InterruptedException e) {
+      return;
+    } catch (NoSuchPackageException e) {
+      throw new IllegalStateException(e);
+    }
+    ImmutableSet<Label> targetsInPkg =
+        ImmutableSet.copyOf(Iterables.transform(pkg.getTargets(), TARGET_TO_LABEL));
+    ImmutableSet<Label> targetsInNewlyLoadedPkg =
+        ImmutableSet.copyOf(Iterables.transform(newlyLoadedPkg.getTargets(), TARGET_TO_LABEL));
+    if (!targetsInPkg.equals(targetsInNewlyLoadedPkg)) {
+      throw new IllegalStateException(String.format(
+          "The Package for %s had a different set of targets (<targetsInPkg> - "
+          + "<targetsInNewlyLoadedPkg> = %s, <targetsInNewlyLoadedPkg> - <targetsInPkg> = %s) when "
+          + "loaded normally during execution of the current test than it did when loaded via "
+          + "BazelPackageLoader (done automatically by the BazelPackageBuilderHelperForTesting "
+          + "hook). This either means: (i) Skyframe package loading semantics have diverged from "
+          + "BazelPackageLoader semantics (ii) The test in question is doing something that "
+          + "confuses BazelPackageBuilderHelperForTesting.",
+          pkgId,
+          Sets.difference(targetsInPkg, targetsInNewlyLoadedPkg),
+          Sets.difference(targetsInNewlyLoadedPkg, targetsInPkg)));
+    }
+  }
+}
diff --git a/src/test/java/com/google/devtools/build/lib/testutil/PackageFactoryBuilderFactoryForBazelUnitTests.java b/src/test/java/com/google/devtools/build/lib/testutil/PackageFactoryBuilderFactoryForBazelUnitTests.java
new file mode 100644
index 0000000000..04e8e03710
--- /dev/null
+++ b/src/test/java/com/google/devtools/build/lib/testutil/PackageFactoryBuilderFactoryForBazelUnitTests.java
@@ -0,0 +1,56 @@
+// Copyright 2016 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.testutil;
+
+import com.google.devtools.build.lib.packages.Package;
+import com.google.devtools.build.lib.packages.PackageFactory;
+import com.google.devtools.build.lib.packages.RuleClassProvider;
+import com.google.devtools.build.lib.skyframe.packages.PackageFactoryBuilderWithSkyframeForTesting;
+import com.google.devtools.build.lib.vfs.FileSystem;
+
+/**
+ * A {@link PackageFactory.BuilderFactoryForTesting} implementation that injects a
+ * {@link BazelPackageBuilderHelperForTesting}.
+ */
+class PackageFactoryBuilderFactoryForBazelUnitTests
+    extends PackageFactory.BuilderFactoryForTesting {
+  static final PackageFactoryBuilderFactoryForBazelUnitTests INSTANCE =
+      new PackageFactoryBuilderFactoryForBazelUnitTests();
+
+  private PackageFactoryBuilderFactoryForBazelUnitTests() {
+  }
+
+  @Override
+  public PackageFactoryBuilderWithSkyframeForTesting builder() {
+    return new PackageFactoryBuilderForBazelUnitTests();
+  }
+
+  private static class PackageFactoryBuilderForBazelUnitTests
+      extends PackageFactoryBuilderWithSkyframeForTesting {
+    @Override
+    public PackageFactory build(RuleClassProvider ruleClassProvider, FileSystem fs) {
+      Package.Builder.Helper packageBuilderHelperForTesting = doChecksForTesting
+          ? new BazelPackageBuilderHelperForTesting(ruleClassProvider)
+          : Package.Builder.DefaultHelper.INSTANCE;
+      return new PackageFactory(
+          ruleClassProvider,
+          platformSetRegexps,
+          attributeContainerFactory,
+          environmentExtensions,
+          version,
+          packageBuilderHelperForTesting);
+    }
+  }
+}
+
diff --git a/src/test/java/com/google/devtools/build/lib/testutil/PackageFactoryFactoryForBazelUnitTests.java b/src/test/java/com/google/devtools/build/lib/testutil/PackageFactoryFactoryForBazelUnitTests.java
deleted file mode 100644
index 43dea593ab..0000000000
--- a/src/test/java/com/google/devtools/build/lib/testutil/PackageFactoryFactoryForBazelUnitTests.java
+++ /dev/null
@@ -1,51 +0,0 @@
-// Copyright 2016 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.testutil;
-
-import com.google.common.base.Function;
-import com.google.devtools.build.lib.packages.AttributeContainer;
-import com.google.devtools.build.lib.packages.Package;
-import com.google.devtools.build.lib.packages.PackageFactory;
-import com.google.devtools.build.lib.packages.PackageFactory.EnvironmentExtension;
-import com.google.devtools.build.lib.packages.RuleClass;
-import com.google.devtools.build.lib.packages.RuleClassProvider;
-import com.google.devtools.build.lib.vfs.FileSystem;
-
-import java.util.Map;
-
-class PackageFactoryFactoryForBazelUnitTests extends PackageFactory.FactoryForTesting {
-  static final PackageFactoryFactoryForBazelUnitTests INSTANCE =
-      new PackageFactoryFactoryForBazelUnitTests();
-
-  private PackageFactoryFactoryForBazelUnitTests() {
-  }
-
-  @Override
-  protected PackageFactory create(
-      RuleClassProvider ruleClassProvider,
-      Map<String, String> platformSetRegexps,
-      Function<RuleClass, AttributeContainer> attributeContainerFactory,
-      Iterable<EnvironmentExtension> environmentExtensions,
-      String version,
-      FileSystem fs) {
-    return new PackageFactory(
-        ruleClassProvider,
-        platformSetRegexps,
-        attributeContainerFactory,
-        environmentExtensions,
-        version,
-        Package.Builder.DefaultHelper.INSTANCE);
-  }
-}
-
diff --git a/src/test/java/com/google/devtools/build/lib/testutil/TestConstants.java b/src/test/java/com/google/devtools/build/lib/testutil/TestConstants.java
index 52cf1bac99..480a5d3cac 100644
--- a/src/test/java/com/google/devtools/build/lib/testutil/TestConstants.java
+++ b/src/test/java/com/google/devtools/build/lib/testutil/TestConstants.java
@@ -15,7 +15,7 @@
 package com.google.devtools.build.lib.testutil;
 
 import com.google.common.collect.ImmutableList;
-import com.google.devtools.build.lib.packages.PackageFactory;
+import com.google.devtools.build.lib.packages.PackageFactory.BuilderFactoryForTesting;
 import com.google.devtools.build.lib.runtime.proto.InvocationPolicyOuterClass.InvocationPolicy;
 
 /**
@@ -83,6 +83,6 @@ public class TestConstants {
   public static final InvocationPolicy TEST_INVOCATION_POLICY =
       InvocationPolicy.getDefaultInstance();
 
-  public static final PackageFactory.FactoryForTesting PACKAGE_FACTORY_FACTORY_FOR_TESTING =
-      PackageFactoryFactoryForBazelUnitTests.INSTANCE;
+  public static final BuilderFactoryForTesting PACKAGE_FACTORY_BUILDER_FACTORY_FOR_TESTING =
+      PackageFactoryBuilderFactoryForBazelUnitTests.INSTANCE;
 }